HEAT PROCESSING Seco/Warwick Group (Vorschau)

International Magazine for Industrial Furnaces
Heat Treatment & Equipment
01 I 2013
ISSN 1611-616X
Vulkan-Verlag
www.heatprocessing-online.com
9 th - 10 th July 2013
Congress Center
Düsseldorf, Germany
www.itps-online.com
Organized by

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EDITORIAL
Looking ahead to new
opportunities
2012 saw thermal processing equipment manufacturers gaining
confidence while coping with the increasing complexities of
global markets. Companies have learned the lessons the recent
crisis has taught. In particular, the downward trends in steel and
automotive production called for continued efforts in 2012.
Even though orders kept dropping for a while, eventually the
struggle paid off. Wether tireless research and development, elaborate
market analyses, or tailored products and services for new
markets – manufacturers pulled out all the stops. Being a provider
of a key technology for a wide range of applications and markets, of
course, also had its part in overcoming the difficulties. The German
manufacturers of thermo processing equipment were able to increase
their exports by around 10 per cent in 2012 (January through
October) and they are expected to reach out to the two billion
Euro threshold which they last exceeded in 2008. Latest economic
indicators like the Purchasing Managers’ indexes of China, the United
States or the Eurozone point to a gain in stability and have incited
economic experts to raise their predictions for 2013.
Throughout the world, efforts are being stepped up to conserve
resources and reduce pollutant emissions. Energy consumption is
becoming a decisive factor in competition within manufacturing
industry. In this respect, thermal process technologies not just play
a key role in the production and processing of a wide range of
products or for the recovery of raw materials but notably in making
production and processes more efficient, sustainable and environmentally
friendly – for all application areas. Thanks to their expert
knowledge of many customers’ industrial sectors, manufacturers
act as competent advisors on process engineering decisions and
process selection and optimization. In order to support customers
in their efficiency and sustainability efforts manufacturers and the
VDMA Thermo Processing Association have developed ‘The Energy
Efficiency Manual for Thermo Processing Plants’, by now available
in four languages. On the European level the ‘Ecodesign for Energy
Related Products Directive’ (ErP) is well under way to be implemented
for industrial and laboratory furnaces and ovens. Right from the
start, CECOF – The European Committee of Industrial Furnace and
Heating Equipment Associations, has participated in the process as
one of the stakeholders. With its contribution CECOF aims at raising
the practicability of the new measures that the EU Commission
will issue for implementation, being convinced that any guideline
needs to take into account that most of the industrial furnaces are
built tailor-made for specific applications and individual customers.
While starting optimistically in a new year of opportunities heat
processing equipment providers are well aware that in the globalized
economic environment risks will change but not vanish.
Regardless of company size, confidence
has grown that the industry is well
prepared to tackle the challenges
lying ahead in 2013
and what is more, to open
up new horizons.
Dr. Timo Würz
Managing Director of Thermo Process Technology
within VDMA and General Secretary of CECOF
heat processing 1-2013

NEWS
xxxx
INTERNATIONAL
THERM
PROCESS
SUMMIT
“ITPS is a great platform to
share experience about our
global challenges for the heat
treatment industry”
www.itps-online.com
Paweł Wyrzykowski
President of Management Board
SECO/WARWICK Group
2 heat processing 4-2012

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NEWS
Organized by
4-2012 heat processing
3

TABLE OF CONTENTS 1-2013
8
HOT SHOTS
Suspector in action
41
REPORTS
New heating hood generation
Reports
Heat Treatment
by Mario Hoffelner, Franz Winter, Michael Springer, Frank Hügel, Andreas Buhr, Rainer Kockegey-Lorenz
33 Reduction of heat losses on the skid pipe system of a pusher type furnace
by Peter Wendt, Frank Maschler, Georg Velten, Jörg Wortmann, Andreas Heßler, Jörg Zumbrink
41 New heating hood generation for energy saving and NO x reduction
by Gregory Matula, Jelena Bogović, Srećko Stopić, Bernd Friedrich
46 Scale up of ultrasonic spray pyrolysis process for nanopowder production - Part I
Burner & Combustion
by Joachim G. Wünning
51 The role of flameless oxidation in the ”Energiewende”
by Sabine von Gersum, Martin Wicker
57 New low NO x solution for high-speed burners
Induction Technology
by Ralf Winkelmann, Arne Röttger, Christian Krause
61 Inductive supported coating
by Edmund Zok, Dirk M. Schibisch
67 Energy-efficient power supply for induction hardening and heating processes
4
heat processing 1-2013

1-2013 TABLE OF CONTENTS
52 92
REPORTS
Flameless oxidation
STATEMENT
Energy resources – from the point of view of the
furnace industry
Research & Development
by Steven MacLean, Jörg Leicher, Anne Giese, Josef Irlenbusch
75 Low NO x oxy-fuel combustion in non-ferrous metallurgy
News
10 Trade & Industry
20 Diary
21 Events
26 Personal
28 Media
Visit our websites:
www.heatprocessing-online.com
www.heatprocessing-directory.com
98 Products & Services
CECOF Corner
32 ISO/TC 244 – Fourth plenary meeting
Profile +
82 Edition 2: LEP - Laboratory for Electroheat of Padua University
1-2013 heat processing
5

TABLE OF CONTENTS 1-2013
59
REPORTS
85
Low NO x solution for high-speed burners
PROFILE+
Laboratory for Electroheat of Padua University
Focus On
89 Edition 5: Dr. Hermann Stumpp
”Global presence is a must for the company”
Statement
92 Energy and global natural resources – from the point of view of the furnace industry
Technology in Practice
95 Pot furnace transfer line for the aeronautics and automotive industry
Companies Profile
124 Schmetz GmbH
heatprocessing
Stay informed and follow us on Twitter
heat processing
@heatprocessing
heat processing is the international magazine for industrial furnaces,
heat treatment & equipment
Essen · http://www.heatprocessing-online.com
6
heat processing 1-2013

1-2013 TABLE OF CONTENTS
90
FOCUS ON
Edition 5: Dr. Hermann Stumpp
Business Directory
102 I. Furnaces and plants for industrial
heat treatment processes
112 II. Components, equipment,
production and auxiliary materials
120 III. Consulting, design, service and engineering
121 IV. Trade associations, institutes,
universities, organisations
122 V. Exhibition organizers, training and education
We are
playing
SIL/PL
Components in accordance to SIL/PL
For the consistent implementation of the safety
functions in industrial thermoprocessing
equipment. Pursuant to EN 746:2010
COLUMN
1 Editorial
8 Hot Shots
100 Index of Advertisers
125 Imprint
1-2013 heat processing
Elster GmbH
Postfach 2809
49018 Osnabrück
T +49 541 1214-0
F +49 541 1214-370
info@kromschroeder.com
www.kromschroeder.com
7
Anz_PW2013_1_89x255_de_en.indd 3 04.02.13 13:22

HOT SHOTS

Trade & Industry
NEWS
Suspector in action
By using a MF power supply of up to 150 kW output power level
a typical working temperature at the susceptor of 1,200 °C is
achieved. This process is used for the production of LEDs.
Source: HÜTTINGER Elektronik GmbH + Co. KG
1-2013 heat processing
9

NEWS
Trade & Industry
Formosa Heavy Industries orders four continuous
casting lines from Siemens
Siemens Metals Technologies received
an order from the Taiwanese
steelmaking company Formosa
Heavy Industries Co. to supply four continuous
casting lines as part of the new construction
of a steelmaking plant in Vung
Ang, Vietnam. The order is specifically for
two slab casters, one billet caster and one
bloom caster with a total installed capacity
of roughly 8.4 million t/a. The end customer
is the Formosa Ha Tinh Steel Corporation,
located in Vietnam. The value of the
order lies in the upper double-digit million
Euro range. The casters are scheduled to
go into operation in mid 2015.
Formosa Heavy Industries is currently
constructing a new integrated steel plant
in the central Vietnamese
province of Ha Tinh. It is currently
the largest greenfield
project in the steelmaking
industry worldwide. Beginning
in mid 2015, approximately
five million t of steel
per year will be produced in
the first construction stage.
Production capacity will then
be expanded to 10 million t,
and finally to 22 million t in
the final stage.
Siemens is supplying two
double-strand continuous
slab casters, an eight-strand
billet caster and a six-strand
bloom caster for the new
steelmaking plant. The slab
casters are designed for an annual capacity
of 2.7 million t each. The product range
contains low-, medium- and high-carbon
steels as well as peritectic steel grades.
Slabs can be cast in thicknesses of 210 to
270 mm and in widths ranging between
900 and 1880 mm. The bow-type casters
with straight mold and segmented strand
containment have a radius of ten meters.
They are equipped with SmartMold and
Dynaflex mold oscillation device. In optimizing
the casting process and ensuring
high internal and external slab quality,
Siemens has installed a series of technology
packages, including the LevCon
mold-level control system, the MoldExpert
breakout detection system, DynaWidth for
adjustment of the slab width and Smart
Segments for rapid changes in slab thicknesses.
A combination of the Dynacs 3D
cooling model, the DynaJet spray cooling
system and internally cooled I-Star rolls
provide maximum flexibility in secondary
cooling, which is an essential prerequisite
to the high slab surface quality. The use of
DynaGap Soft Reduction makes it possible
to precisely determine the point of final
strand solidification. This permits precise
regulation of the roll gap and results in
high internal slab quality. The project also
includes the entire basic and process automation
systems of both slab casters.
Gunung Steel Group to rely on Paul Wurth
blast furnace technology
The Indonesian steelmaker PT
Gunung Raja Paksi (Gunung Steel
Group) is currently expanding its
production capacity to become one of
the most comprehensive integrated steel
mills in the region. In this context, Paul
Wurth was awarded on 20 April 2012 an
order for the basic engineering and supply
of key equipment of Gunung’s new blast
furnace at the site of Cibitung in Cikarang
Barat, West Java Province, Indonesia. The
new blast furnace N°1 will have a working
volume of 2,251 m 3 and is designed for
an annual hot metal capacity of up to 2
million Mt. The scope of Paul Wurth includes
the complete basic engineering and
partial detail engineering, as well as the
supply of key components for the BF top
charging, BF proper, hot blast stoves, wet
gas cleaning plant and INBA slag granulation
system. Furthermore, the furnace
will be equipped with the state-of-theart
BFXpert level 2 blast furnace control
system. Featuring proven solutions as well
as state-of-the-art Paul Wurth technology,
the start-up of the new hot metal production
unit is scheduled for April 2015.
10 heat processing 1-2013

Trade & Industry
NEWS
EFD Induction opens new subsidiary in Brazil
EFD Induction’s worldwide network
expanded recently with the launch
of its Brazilian subsidiary. The new
company – with the formal name of EFD
Induction Ltda. – is based in the city of Sorocaba,
about 60 km from the metropolis of
São Paulo.
“This is a milestone in our growth,”
says EFD Induction CEO Eivin Jørgensen.
“We have previously sold many systems
throughout Latin America. But having a
subsidiary in Brazil’s economic heartland
means we can offer better and faster
support to customers in the region.” The
new subsidiary is headed by Mr. Evandro
Nishimuni, a mechanical engineering graduate
who has previously worked in France
and in the Brazilian automotive industry.
“EFD Induction and Brazil have so much
to offer each other,” says Nishimuni. “There
is growing awareness throughout Brazil
and the continent that sustained economic
growth can only be maintained by
investing in modern, efficient and proven
technologies such as induction heating.”
Although the subsidiary is new, Brazil and
Latin America is no stranger to EFD Induction
products and services. For instance,
several of mobile Minac induction heating
systems are being used to braze hydroelectric
turbine stators at the Santo Antônio
and Jirau dams, key structures in a new
hydroelectric complex being constructed in
Amazonia. And Basso, the world-renowned
valve makers in Argentina, recently installed
an EFD Induction hardening system.
Mr. Evandro Nishmuni is however keen
to stress that most of the new company’s
business will most likely occur much closer
to home. “True, if Brazil is the engine of
South American economic growth, then
the state of São Paulo where we are located
is its dynamo. In fact this state alone is
responsible for a third of all Brazilian GDP.
That gives you some idea of just how economically
vibrant the region is.”
EFD Induction Brazil currently has three
employees: Nishimuni as manager and salesman,
Aline Gonçalves as administrator, and
Carlos Feliciano Ferreira as engineer and
after-sales support technician.
Safe and durable.
LOI HPH ® Bell-Type
Annealing Technology.
LOI Italimpianti HPH ® Bell-Type Annealing Plants are
outstanding not only due to their uniquely high safety
levels but also due to the practically unlimited service life
of the LOI Italimpianti bases.
*HPH: High Performance Hydrogen
The design of the base plate of the annealing base, with
individual supports and loose encapsulation, provides an
effective seal between the annealing atmosphere and the
surrounding air, ensuring a very long service life with no
need for frequent maintenance.
More than 2.500 HPH ® Bell-Type Annealing Bases have
been installed throughout the world.
1-2013 heat processing
LOI Thermprocess GmbH - Tenova Iron & Steel Division
Am Lichtbogen 29 - 45141 Essen / Germany
Phone +49 (0)201 1891.1 - Fax +49 (0)201 1891.321
info@loi-italimpianti.de - www.loi-italimpianti.com
11

NEWS
Trade & Industry
Baosteel passed performance test of hot-metal
production
One year following startup of the
second Corex module at the Chinese
steelmaker Baosteel in Shanghai,
a successful performance test has proven
the economy efficiency of this alternative
technology for the production of hot metal.
After the successful performance test, also
the Final Acceptance Certificate has been
signed by Baosteel.
“As opposed to the conventional blastfurnace
route, the Corex production costs
are substantially lower,” Dieter Siuka said
about the performance test. Mr. Siuka is
responsible worldwide for iron production
at Siemens Metals Technologies. Less
expensive and locally available raw materials
yield the same quality of hot metal as
higher-quality imports. Siuka expects that
the Corex route will now be further rolled
out as an alternative to conventional blast
furnace production, especially in markets
with increasing hot-metal production.
Following startup of the Corex plant in
2011, Baosteel and Siemens have been working
together over the past few months to
optimize operation of the plant, which is
designed for the production of 1.5 million t
of hot metal per year. “All performance parameters
stipulated in the contract were achieved
or exceeded,” Siuka reported. The performance
test was completed in a total of
170 h. The guaranteed production rate of
175 t of hot metal per hour was achieved in
addition to a reduction in the specific fuel
rate from 950 kg to 870 kg/t of hot metal
based on local raw materials. Uniformly high
quality of the hot metal was achieved in
spite of the heavy fluctuation in the quality
of the raw materials. “The quality of the hot
metal produced in the Corex plant is comparable
to that found in the product of conventional
blast furnaces,” Siuka emphasized.
In light of the continuing depletion and
the high cost of high-quality raw materials,
and because of the environmental restrictions
placed on blast furnace operation
in numerous countries, the Corex-C-3000
route offers an environmentally compatible
and economically efficient alternative that
conserves resources. The successful performance
test is a “further milestone in commercialization
of the Corex production technology,”
Siuka emphasized, who expects
demand “particularly in markets with increasing
hot-metal production levels and where
raw materials are readily available.” Current
plans at Baosteel call for continued operation
of the Corex plant at high capacity.
The conventional blast furnace route
consists of the sintering plant, coke oven
plant and the blast furnace and produces
hot metal from agglomerated iron ore (sinter)
with the help of coke. In addition to high
investment costs, the disadvantages of this
route include the comparatively high emissions,
for example, of sulfur oxides (SO x ), nitrous
oxides (NO x ), dust and phenols. Liquid
hot metal produced in the Corex route is
melted directly from pellets and lump ore,
and non-coking coal is the primary source of
energy. In comparison with the conventional
route, the production costs and emissions
of the Corex route are lower because the
coking and sintering plants (systems with
the highest emissions) are not required. The
Corex gas can also be used as an energy
source to generate electricity or as a reducing
gas in a direct-reduction plant.
Electro-Total secures contract for two forging
furnaces at ZIROM in Romania
During the year 2013, Electro-Total
will deliver two forging furnaces of
15m 2 /15 t for heating of titanium
and titanium and zirconium alloys forging
billets. The furnaces will work at 1300 °C with
a temperature uniformity of +/-10 °C. The furnaces
will be fitted with flat-flame burners
produced by Elster-Kromschroeder and recuperators
manufactured by Helmut Peiler Montanwärme
in order to achieve high levels of
combustion efficiency. A sophisticated automation
system will be used for the control of
each furnace. One of the main functions of
these systems will be to provide an oxidizing
atmosphere inside the furnace, controlled by
a combustion flue gas analyzer. This project
will be a premiere in Romania for both the customer
ZIROM and the supplier Electro-Total.
12 heat processing 1-2013

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13

NEWS
Trade & Industry
CAN-ENG ships bright tube annealing furnace
for JMC Steel Group
CAN-ENG Furnaces International
Limited announces the shipment
of a Bright Tube Annealing Furnace
for the JMC Steel Group. The 25,000 lbs/
hr line will be installed in Wheatland, PA as
part of JMC Steel’s Wheatland Tube Division
expansion. The unit is configured to
operate under dry EXO gas for the bright
annealing of heavy walled precision cold
drawn mechanical tubing. With an overall
line layout stretching out more than 300
feet by 14 feet wide, the furnace will form
the basis for one of the largest bright tube
annealing facilities in the North America.
This is the fourth major contract that CAN-
ENG has undertaken for JMC in recent years,
including subsidiaries Atlas Tube, Sharon
Tube, and Wheatland Tube company. JMC
Steel Group is one of North America’s largest
producers of tubing utilized in the OCTG,
Hollow Structural, Electrical Conduit, Sprinkler
Pipe, and Mechanical Tubing industries.
Linde to build LNG terminal near Gothenburg
The Linde Group has been commissioned
by Norwegian-based Skangass
AS to build a mid-scale liquefied natural
gas (LNG) import terminal at the west
coast of Sweden, in Lysekil, 100 km north
of Gothenburg. The corresponding engineering,
procurement, construction and
installation (EPCI) contract is worth around
€ 44 m. The works include the integration of
the cryogenic tank structures to be erected
by a third party. The new LNG terminal is
planned to start operations in spring 2014
and will supply natural gas to the nearby
Preem refinery as well as LNG for industrial
and transportation applications.
The new terminal will have a storage
capacity of 30,000 m 3 of LNG, compared to
20,000 m 3 at Nynäshamn, and will include
a truck filling station. Linde Engineering has
performed the basic engineering and will
support with the procurement of rotating
equipment, commissioning and start-up.
LNG for both terminals – Nynäshamn and
Lysekil – comes from the mid-scale LNG
plant at Risavika near Stavanger, Norway.
This plant – also built for Skangass by Linde
– started operations in 2010.
ArcelorMittal steel helps Chernobyl’s new reactor
‘sarcophagus’ take shape
The first part of the new sarcophagus
which will encase the now-defunct
Chernobyl reactor in Ukraine was
raised into place on November 2012 – a key
landmark in the project that ArcelorMittal is
contributing to. The company has supplied
around 164000 m² of steel for a state-of-theart
containment structure for the Chernobyl
nuclear power plant in Ukraine. Demonstrating
an integrated multi-team approach, the
international construction project team has
supplied more than 91,000 m² of steel profiles
for use in the external supporting deck
and ArcelorMittal Construction Poland and
FCE sites are providing 73,000 m² of profiles
for the internal supporting deck of the New
Safe Confinement (NSC) structure designed
to encase the defunct reactor number four.
Another 106,000 m of Omega Purlins, supporting
profiles, have now also been delivered
for the seam roof.
14 heat processing 1-2013

Trade & Industry
NEWS
ThyssenKrupp sells Tailored Blanks to WISCO
ThyssenKrupp AG has signed an agreement
with Wuhan Iron and Steel Corporation
(WISCO) for the sale of for its
subsidiary ThyssenKrupp Tailored Blanks,
which produces tailored steel blanks for the
automotive industry. The parties have agreed
not to disclose the purchase price. The sale is
subject to approval by the supervisory bodies
and the responsible regulatory authorities. It is
a further step in the optimisation of the portfolio,
which the Group announced on May
13, 2011 in connection with its strategic development
programme. As part of the portfolio
optimization, the Group is divesting businesses
for which there are stronger alternative
strategic options. ThyssenKrupp is proceeding
fully according to plan, and sale agreements
have already been signed or closed for around
95 % of the business activities up for disposal.
ThyssenKrupp Tailored Blanks is an important
supplier of body systems to the
auto industry. Tailored products are made
of individual sheets of different steel grade,
thickness or finish, joined together by laser
welding. The blanks are designed from the
outset to meet the stresses in the parts in
which they will be used. This results in significant
weight and cost savings, for example
in the production of body parts.
Headquartered in Duisburg, Germany,
the global ThyssenKrupp Tailored Blanks
group has been producing tailored blanks
since 1985 and is the leading supplier in
this segment with a roughly 40 % global
market share. The company has 13 plants
in Germany, Sweden, Italy, Turkey, the USA,
Mexico and China. It employs around 950
people and last year produced some 58
million parts for automotive OEMs. Sales
in the 2010/2011 fiscal year were approximately
€700 million.
Wuhan Iron and Steel Corporation
(WISCO) started production in 1958, making
it one of China’s longest-standing steel
producers. The internationally successful
and fast-growing group headquartered in
Wuhan has more than 80,000 employees
and a capacity of around 40 million t. In
2011, WISCO achieved a turnover of around
€26 billion, produced nearly 34 million t and
was China’s fourth biggest steel producer. It
has subsidiaries and sales offices in over ten
countries, and is ranked 321 in the Fortune
500 ranking in 2012.
Setting The Standards For Highest
Efficiency In Thermal Processing
EcoMelter©, 105t per day, cont. 35t
PulsReg® Medusa Regenerator
JASPER
Gesellschaft für Energiewirtschaft und Kybernetik mbH / Bönninghauser Str. 10 / D-59590 Geseke
Telefon: +49 2942 9747 0 / Fax: +49 2942 9747 47 / www.jasper-gmbh.com / info@jasper-gmbh.de
1-2013 heat processing
15

NEWS
Trade & Industry
Five Stein to supply two
vertical digital annealing
furnaces in China
Valin ArcelorMittal Automotive Co,
Ltd. (VAMA), founded in September
2010, is a joint-venture between
ArcelorMittal and the Chinese steelmaker
Valin Group. VAMA is focused on establishing
itself as a premier quality supplier of
high-strength steels and value-added products
for China’s fast growing automotive
market. The new greenfield cold-rolling
mill complex will be installed in Loudi,
Hunan province, for an annual production
capacity of 1.5 million t of steel strip
and will include a Continuous Automotive
hot dip Galvanizing Line and a Continuous
mixte Annealing and Aluminizing
Line. Both of these lines will be equipped
with Fives Stein’s vertical Digital annealing
furnaces and are scheduled to start-up by
mid-2014.
Fives Stein is engineering and supplying
the complete furnace and related automation
systems, including imported key process
technologies from Europe and all local manufacturing
and supplies in China through its
local organization Fives Stein Shanghai which
has an experienced team of more than 100
employees. Fives Stein’s vertical Digital furnace
technologies were selected thanks to superior
performances in high efficiency Digital
heating sections and outstanding cooling
performances of the patented Flash Cooling®
system. A wide range of steel qualities can
be processed in the two lines, including mild,
high-strength, low-alloyed, IF, Dual-Phase, TRIP
and bake-hardening (BH) grades.
In particular, the latest Advanced High-
Strength Steels (AHSS) can be processed
in the line to respond to the needs of the
automotive industry to produce lighter
vehicles. Additional operation flexibility
is also provided for the mixte Continuous
Annealing and Aluminizing Line through
specific furnace features and automation
system giving VAMA the possibility to
produce uncoated as well as coated annealed
strips in the same line. The new high
added-value coatings will be the first introduced
by VAMA in the Chinese market.
LOESCHE
signs landmark
retrofit contract
in India
The LOESCHE Group signed the first
dynamic classifier retrofit contract within
the Indian subcontinent. The project is
being designed and engineered at LOESCHE’s
office in Horsham, UK, with client interface
maintained through local representation by
LOESCHE’s office in New Delhi, India. Thanks
to the support from Loesche Energy Systems
Ltd. in Horsham, UK, Loesche India (Pvt.) Ltd.
now realize their first order in power sector.
The contract with the Doosan Power Services
India Ltd is for Bandel Power station, located
in West Bengal. This power station is owned &
operated by West Bengal Power Development
Corporation. The project is for 6 units of LOE-
SCHE LSKS 33 ZD high-efficiency dynamic coal
classifiers for upgrading its Bandel power plant.
The project will improve the performance of
the aged Bandel Thermal Power Plant, which
has been in operation for thirty years since its
completion in 1982.
Quarter 3 stainless steel production
surprisingly strong
Preliminary figures released by the International
Stainless Steel Forum (ISSF)
show that worldwide stainless steel
crude steel production has increased after the
first nine months of 2012 by 2.9 % compared to
the same period of 2011. Total production for
the first three quarters was 26.1 million metric
t (Mt). This is 0.7 Mt more than in the same
period of 2011. Total production for the quarter
was 8.3 Mt – a new all-time high for a third
quarter. However, there were big differences
in the performance of the individual regions.
In Asia (excluding China) stainless steel production
decreased slightly by 0.2 % to 6.6 Mt.
However, the growth rates of the individual
stainless producing countries in Asia showed
variations ranging from plus 5 % (India) to
minus 4 % (Taiwan, China).
China increased its stainless steel production
in the first nine months of 2012 by 7.9 % to
11.4 Mt. The country now accounts for about
44 % of the world’s stainless steel production.
At the same point in 2011, China’s market share
was at about 42 %. After the first nine months
of 2012, Asia (including China) accounts for
almost 70 % of the world’s stainless steel production
and this share is tending to increase.
Looking at the third quarter of 2012 individually,
the level of stainless steel production
is the highest for any third quarter. However,
worldwide production was lower in the third
quarter than in the previous three months.
This is a normal seasonal variation. In Q3 2012,
all major stainless producing areas have seen
this contraction which is partially driven by
lower demand from end users.
16 heat processing 1-2013

Trade & Industry
NEWS
1-2013 heat processing
17

NEWS
Trade & Industry
Impressive steel arches from Ruukki
Aurora Bridge, for light traffic and
pedestrians, opened in Helsinki in
November 2012. The bridge links
the Eläintarha district with Central Park and
significantly improves traffic flow and safety,
especially during large events such as athletics
championships and concerts. Ruukki
was responsible for manufacturing, installing
and surface finishing the steel structures
for the bridge. Aurora Bridge is over 160 m
long and about five m wide. The design of
the bridge is dominated by two steel arches
spanning Nordenskiöldenkatu street. These
arches converge into pylons – bridge pillars
– on the north side of the street. The steel
arches, which stretch to a height of 20 m,
and tie bars attached to them support the
concrete deck of the bridge.
The bridge received the RIL (The Finnish
Association of Civil Engineers’ Award) for
2012. The RIL Award is an annual recognition
made by the Finnish Association of Civil
Engineers for building projects demonstrating
excellent competence in design and
implementation. Besides technology, choice
of winners also takes into account economic,
social and environmental aspects. The
award has been given since 1972.
A bridge design contest held by the
City of Helsinki in 2009 was won by WSP
Finland. Aurora Bridge was ordered by the
City of Helsinki Public Works Department
and the lead contractor was Lemminkäinen
Infra Oy. The steel structures for the
bridge were manufactured at Ruukki’s
plant in Ylivieska, Finland.
International furnace manufacturer
Seco/Warwick restructures
SECO/WARWICK now consists of a
holding located Świebodzin, Poland,
which is listed on the Warsaw stock
exchange and which keeps the shares and
control of the manufacturing sites SECO/
WARWICK Europe (Poland), SECO/WARWICK
Corporation and Retech (both USA), SECO/
WARWICK Retech (China), SECO/WARWICK
Allied (India) and the service sites SECO/
WARWICK Service (Germany) and SECO/
WARWICK Russia (Russia).
The Holding itself has a lean structure, in
which five vice presidents control the five
business segments vacuum technology,
atmosphere technology, aluminum processes,
controlled atmosphere brazing and
vacuum metallurgy equipment. The holding
is globally responsible for functions such as
procurement, HR and finances. A contractual
frame takes care of the legal, logistical and
technological cooperation between the
global sites of the group.
SECO/WARWICK’s new structure achieves
a better penetration of the markets
and a better service of local and international
operating customers. At the end of
2012 a further step for the exploitation of
the west European market was carried out
by the acquisition of a service company in
Germany (renamed to SECO/WARWICK Service
GmbH). Globally further steps for the
extension of the activities on the markets
will follow in 2013.
Tenova Strip Processing receives final acceptance
certificate for the new electrolytic tinning line
Tenova Strip Processing has received
the FAC (Final Acceptance Certificate)
for the high-speed electrolytic
tinning line in Jiangsu Dajiang Metal
Material plant (China), one of the fastest
in the world (550 m/min) that produces
250, 000 mt/year of tin plate. This order
confirms the importance of Tenova ongoing
investment in research and innovation.
From the environmental point
of view, the line confirms the better expectations.
The main advantages of the
new technology compared to the traditional
soluble anodes electrolytic process
are the reduction of waste sludge and
the very good uniformity reached on
the material’s deposit thickness.
Other advantages are related to the protection
of the working environment: the
tank containing the electrolyte is sealed,
so as to eliminate the acid vapour loss in
the environment, while the process is fully
automated and requires no manual intervention
by operators.
18 heat processing 1-2013

Trade & Industry
NEWS
Miura Private Equity to invest in
GH Induction Group
Miura Private Equity has acquired
GH Induction Group, together
with its management team,
through a management buyout (MBO).
The company belonged to Corporación IBV.
The terms of the transaction remain confidential.
GH Induction Group, is one of the
leading companies in the world dedicated
to the design and manufacturing of “turnkey”
solutions within the induction heating
technology for the automotive, cable, tube,
renewable energies, aeronautics and medical
sector. The company has more than 50
years of history and approximately 3,000
clients worldwide. With headquarters in
Valencia, GH production plants are located
in Germany, India, Brazil, the USA and
China, and employ 370 people. The company
sales exceeded € 40 million in 2011,
globally distributed within Europe, Asia, the
USA and Latin America. The Spanish market
represents 10 % of total sales.
With Miura’s entry in the shareholding,
GH will boost its international growth
with new production plants and extension
of existing ones. The most significant
investments will be a new plant in India,
which will triple the size of the current
one; the increase of the production capacity
in China; and the development of the
American subsidiary business, acquired in
2010, which is specialized in machinery
for the aerospace and medical sector. GH
management team, lead by Jose Vicente
Gonzalez and Vicente Juan, have increased
their shareholding position and will continue
leading the company. BBVA Corporate
Finance and Impulsa Capital have been the
advisors on the deal.
For a Clean Future. BLOOM ENGINEERING.
Regenerative Burners
100 - 10.000 kW
Energy Saving
Emission Reduction
Quality Results
Cost Reduction
1150 ULTRA 3 LOW NOx
REGENERATIVE BURNER
ULTRA 3 LOW NOx
SMALL CAPACITY
REGENERATIVE BURNER
BLOOM ENGINEERING
(EUROPA) GMBH
Phone: +49(0)211 500 91-0
info@bloomeng.de
www.bloomeng.de
1-2013 heat processing
19

NEWS
Trade & Industry
DIARY
8-12 April Hannover Messe 2013
in Hanover, Germany
www.hannovermesse.com
23-25 April Aluminium Middle East 2013
in Dubai, United Arab Emirates
www.aluminium-middleeast.com
25-26 April European Conference on Heat Treatment 2013
in Lucerne, Switzerland
www.awt-online.org/en/awt_events/
european_conference_lucerne.html
18-21 June Beijing Essen Welding & Cutting
in Shanghai, China
www.beijing-essen-welding-cutting.com
25-28 June Metallurgy-Litmash
in Moscow, Russia
www.metallurgy-tube-russia.com
2-4 July ALUMINIUM China 2013
in Shanghai, China
www.aluminiumchina.com
9-10 July ITPS - International Thermo Process Summit
in Düsseldorf, Germany
www.itps-online.com
10-12 Sept. Heat Treatment
in Moscow, Russia
www.htexporus.com
12-17 Sept. Aluminium India 2013
in Mumbai, India
www.aluminium-india.com
15-18 Sept. EuroPM 2013
in Gothenborg, Sweden
www.epma.com/pm 2013
17-19 Sept. Tube Southeast Asia
in Bangkok, Thailand
www.tube-southeastasia.com
17-19 Sept. wire Southeast Asia
in Bangkok, Thailand
www.wire-southeastasia.com
17-19 Sept. Hybrid Expo 2013
in Stuttgart, Germany
www.hybrid-expo.com
25-26 Sept. International Colloquium on Refractories
in Aachen, Germany
www.feuerfest-kolloquium.de
15-17 Oct. Pipe & Tube 2013
in St. Petersburg, Russia
www.itatube.org
Crude steel
production
for the 62
countries
reporting to
worldsteel
World crude steel production for the
62 countries reporting to the World
Steel Association (worldsteel) was
122 million tonnes (Mt) in November 2012, an
increase of 5.1 % compared to November 2011.
China’s crude steel production for November
2012 was 57.5 Mt, up by 13.7 % compared to
November 2011. Elsewhere in Asia, Japan produced
8.5 Mt of crude steel in November 2012,
a decrease of -2.3 % compared to the same
month last year. South Korea’s crude steel production
was 5.6 Mt in November 2012, -2.7 %
lower than November 2011.
In the EU, Germany produced 3.4 Mt of
crude steel in November 2012, a slight decrease
of -0.2 % on November 2011. Italy’s crude steel
production was 2.2 Mt, down by -12.9 % compared
to November 2011. France’s crude steel
production was 1.3 Mt, a decrease of -5.4 % on
November 2011. Spain produced 1.0 Mt of crude
steel, -14.2 % lower than November 2011.
Turkey’s crude steel production for November
2012 was 3.0 Mt, an increase of 4.6 % compared
to November 2011. In November 2012, Russia produced
5.5 Mt of crude steel, a decrease of -0.7 %
compared to the same month last year. Ukraine’s
crude steel production for November 2012 was
2.7 Mt, -7.9 % less than November 2011. The US
produced 6.7 Mt of crude steel in November
2012, down by -4.8 % on November 2011.
Brazil’s crude steel production for November
2012 was 2.8 Mt, an increase of 2.4 %
compared to November 2011. The crude steel
capacity utilisation ratio for the 62 countries in
November 2012 declined to 76.1 % from 76.5 %
in October 2012. Compared to November 2011,
it is 1.6 percentage points higher.
20 heat processing 1-2013

Events
NEWS
Aluminium China 2013
In 2013, ALUMINIUM CHINA, the leading
aluminium sourcing platform in Asia for
industry professionals and buyers from
the aluminium industry and a wide array
of application industries will expand its
buyer delegation programs on further key
Asian industry clusters in China, South East
Asia and India. Over 200 exhibitors already
booked exhibition space occupying 80 % of
the overall exhibition space.
The organizer of ALUMINIUM CHINA 2013
will leverage this strong demand and invite
an even bigger number of 550 targeted
top buyers from China as well as procurement
delegations from selected application
industry sectors in Asia, for pre-arranged
match-making sessions with international
exhibitors. This combination of the supply
and demand side of the aluminium industry
will present a number of attractive business
opportunities to both parties.
Reed Exhibition’s international
delegation program for ALU-
MINIUM CHINA 2013 includes
new partnerships with
tour operators and buying
associations from countries
with increasing demand for
equipment and aluminium
products: India, South East
Asia and Russia.
For ALUMINIUM CHINA
2013 the blend of material
exhibitions, high profile conferences and
the complementary trade exhibitions COP-
PER CHINA 2013 and MAGNESIUM CHINA
2013 will again enhance the show’s success.
Additionally, the China Aluminium Fabrication
Forum, organized by the China Metal
Information Network, and a new edition
of the Lightweight Automotive Forum, will
give participants a synergetic opportunity to
source and display diversified exhibits while
learning more about the key issues affecting
today’s aluminium industry.
www.aluminiumchina.com/en/
Hannover Messe 2013
Roughly one
month before
the start
of HANNOVER
MESSE 2013 (8 to 12
April), its organizer,
Deutsche Messe, is
expecting a strong trade fair performance
coupled with a winning Partner Country
showcase. The volume of exhibitor registrations
received to date suggests that the
Hannover Exhibition Center will be full to
capacity at this year’s show. The organizers
are expecting more than 6,000 exhibitors
from 60 countries. The lead theme of “Integrated
Industry” signals the strong focus on
the current trend towards integration across
all areas of industry. For instance, in the near
future, intelligent materials will be able to tell
machines how they should be processed,
and components will be able to issue their
own maintenance and repair requests. In
addition to these various forms of technical
and electronic networking, “Integrated
Industry” encompasses the challenge facing
all areas of industry as they seek to cooperate
across corporate and sector boundaries.
HANNOVER MESSE 2013 will place a
strong emphasis on industrial automation
and IT, energy and environmental technologies,
power transmission and control, industrial
subcontracting, manufacturing technologies,
services and R&D. These keynote themes
will be covered in no fewer than eleven
tradeshows: Industrial Automation – Motion,
Drive & Automation (MDA) – Energy – Wind
– MobiliTec – Digital Factory – ComVac –
Industrial Supply – Surface Technology –
IndustrialGreenTec – Research & Technology.
As well as offering eleven full-fledged tradeshows
where market leaders can present
their innovations, the trade fair features a
rich lineup of supporting forums, conferences
and special events. These include the
premium international trade platform Global
Business & Markets, the Job & Career Market
recruitment platform, the TectoYou careers
initiative, and the WoMenPower congress.
Each year, HANNOVER MESSE’s strategy
for achieving lasting international resonance
includes a strong showcase by a
featured Partner Country. The economic
power selected as this year’s Partner
Country is Russia. The keynote themes of
Russia’s Partner Country showcase include
energy transmission and distribution,
international energy business, industrial
processing and production, technology
partnerships, innovations in R&D, and Russia
as a destination for strategic partnerships
and foreign investment.
www.hannovermesse.de
1-2013 heat processing
21

NEWS
Trade & Industry
ENGINEER
SUCCESS
New technologies
New solutions
New networks
A date to remember:
8–12 April 2013
Which subcontracting solutions optimize
production efficiency?
Industrial Supply provides you with a complete market overview of innovations
in materials, components, systems and processes across the whole production
chain.
Meet global players in industrial supply at this international
meeting-place and benefit from the latest know-how in sectors such as lightweight
engineering and innovative materials technology.
Don’t miss the world’s most important technology event.
You can find out more at hannovermesse.com
8–12 April 2013 · Hannover · Germany
22 heat processing 1-2013
For more information please contact: Tel. +49 511 89-0, hannovermesse@messe.de

Events
NEWS
First Loesche Technical Seminar 2012
On 26 September 2012 the LOE-
SCHE Training Center invited to
the very first Technical Seminar
in Dusseldorf. More than 30 people from
all over the world followed this invitation
and seminar in Duesseldorf-Kaiserswerth.
Theodora Bruns and the LOESCHE Training
Center team organised the seminar and Dr.
Daniel Strohmeyer (Process Technology
department, LOG) moderated the session.
Six lecturers presented an up-to-date
overview on grinding technologies. Two
presentations were held by specialists
from the VDZ (the German Cement Works
Association): Philipp Fleiger gave an overview
on advanced grinding technologies
and compared different grinding systems.
Dr Klaus Eichas talked about
the optimisation of existing
grinding plants. Dr Winfried
Ruhkamp, Process Technology
department at LOG, started the
afternoon session which concentrated
on LOESCHE technology.
He explained the function
of a LOESCHE vertical roller mill
and its dimensioning. In the following,
Christian Ruthenberg,
technical trainer at LOG and coorganiser
of this seminar, spoke about the
processing and operating of a LOESCHE
mill. A presentation on the hydropneumatic
spring system in a LOESCHE mill was
held by Dirk Grube, Design department
at LOG. The event was rounded off with a
lecture given by Stefan Frankemölle (Procurement
department at LOG) on gear
boxes and its performance categories and
designs respectively its monitoring.
HITHERM
PRAGUE
2013 – Call
for Papers
The Czech Silicate Society is preparing
an international conference on hightemperature
processes, which will take
place on June 25-26, 2013 in the traditional
Congress Hall on Novotného lávka 5, Prague
and will focus the following topics:
■■
■■
■■
energy efficiency and heat recovery in
high temperature technologies
materials for high temperature technologies
high temperature processes, heating and
burner
Submission of abstracts: deadline is February
26, 2013. Proceedings: manuscripts of
papers (only in English) must be submitted
till May 1, 2013.
HTIFE China 2013
2013 is the 10 th year of the International
Heat Treatment & Industrial
Furnace Expo (HTIFE). In order to
promote the development and deepen
interaction within the industry, HTIFE
2013 will be held at the China International
Exhibition Center on 16 to 18
October, with a new image, the show
will present to new and frequent customers
from home and abroad. HTIFE went
through a decade of trials, this year, is the
year to seek development and innovation.
Based on the previous exhibitions,
HTIFE will integrate industry resources
and regional advantages, improve service
system, strengthen the organization
and operational capability. This edition
of exhibition area is expected to increase
by 20 % compared with the last one,
there will be hundreds of exhibitors from
Asia, Europe and Americas join the event,
enterprises and top-class representatives
would be invited to gather in Beijing to
further explore the future of the thermal
processing industry.
Founded in 2004, HTIFE always
adhere to the principle of resource
sharing, win-win benefit, the show
displays various products and devices
while focuses on combination of up
and down stream industrial chain
to create a cooperative pattern for
project development, product sales,
technical service so as to deepen international
cooperation and exchange.
The traditional thermal processing
industry usher in a broad development
prospects as the rapid progress
of new manufacturing industry like
steel, automobile, equipment manufacturing,
shipbuilding, aerospace
in recent years. Numerous enterprises
take advantage of this favorable
opportunity to research and develop
new technologies according to industry
needs, to improve technologies and
product quality, accelerate the pace of
industrial upgrading.
www.htifexpo.com
www.silikaweb.cz
1-2013 heat processing
23

NEWS
Events
ITPS - International Thermprocess Summit
for the first time in Duesseldorf
The No. 1 key event and B2B-forum for
executives and the top management
is to be held in the Düsseldorf Congress
Centre (Germany) from July 9 to 10
2013. The 2-day event is organized by Messe
Düsseldorf, VDMA, CECOF and the magazine
heat processing.
The four technology trade fairs GIFA,
METEC, THERMPROCESS and NEWCAST
caused a stir in the industry in June 2011.
With 79,000 visitors from 83 countries and
1,958 exhibitors, the four events provided
impressive confirmation of their position
as the leading trade fairs in their industry.
As far as the corporate exhibitors were
concerned, the good business done
both during and after the trade fairs was
a particularly convincing demonstration of
the excellent position held by the ”Bright
World of Metals”, as the international technology
forum is often known as well.
It was primarily the experts from overseas,
especially those from India, who
opened new sales markets up for the
THERMPROCESS exhibitors. However,
since the innovation cycles in the industry
are becoming increasingly short, Messe
Düsseldorf, VDMA (with the German thermoprocess
technology trade association,
Frankfurt), CECOF (European Committee
of Industrial Furnace and Heating Equipment
Associations, Frankfurt) and the trade
magazine “heat processing” published by
Vulkan-Verlag are initiating an International
Thermprocess Summit known as ITPS, a
first-rate congress for which the experts
from the industry are being invited to come
to Düsseldorf.
The target group for the event will be
the CEOs and senior executives from the
relevant markets – such key industries as
metal production and processing, automotive
manufacturing, glass, ceramics,
cement, chemicals and petrochemicals.
Messe Düsseldorf Director Friedrich-Georg
Kehrer: “We have a very specific aim here,
which is to bring the users together with
the plant manufacturers and to offer them
a highly professional lecture programme
as well as time for technical discussions.”
Kehrer also points out that both sides
will enjoy tremendous additional benefits
from attending the ITPS as a result of
the ideal combination of networking and
opportunities to talk about technical issues
with other experts from the industry.
The ITPS programme reflects the pressing
issues of our time, with the focus on sustain-
ability, minimisation of resource consumption
and energy efficiency. These are particularly
tough challenges that the representatives
of the key industries have to tackle today
and in future. The topics include the future
of energy-intensive industries in Europe, the
current economic situation on the market,
technical development trends in thermoprocess
technology and the requirements
made by customers on the manufacturers
(the motto here: “Technological innovation
driven by the customer”).
Alongside the lecture programme, customers
who are interested can act as ITPS sponsors
and present their companies in the foyer
of the Congress Centre CCD South at Messe
Düsseldorf during the Summit. The sponsoring
arrangements are not limited exclusively
to the two days of the event; they also include
a website presence at www.itps-online.com.
The website also incorporates all the Internet
tools that exhibitors and visitors are familiar
with from THERMPROCESS. Admission to the
ITPS costs € 1,500, with a discount for bookings
that are made early: the sooner the ticket is
bought, the lower the price. For further information
please visit:
www.itps-online.com
24
heat processing 1-2013

Events
NEWS
Second EPMA Sintering Short Course for 2013
The European Powder Metallurgy Association
(EPMA) has organized a second Short
Course on PM Sintering – Advanced Processes
and Materials, following on from last
year’s successful PM Sintering Course in Helsingborg.
This year’s course will be held in
Vienna, Austria, 24 th – 26 th March.
PM Sintering – Advanced Processes and
Materials will provide an excellent learning
opportunity for engineers and scientists
with an interest in the Sintering process.
Thanks to the unique combination of high
level industrial specialists and academics
from across Europe this course will provide
unrivalled insights into the practical capabilities
and applications of sintering technology
as applied to the powder metallurgy (PM)
process.
The two-day course will include individual
aspects of the process starting from
sintering concepts through to practical considerations,
mainly for batch scale materials
and applications. The course will also feature
lectures on the sintering atmospheres,
process variation and new developments
in furnace technology. At the end of the
Short Course an Open Forum will discuss
case studies and problem solving with a
panel of international PM experts. Further
information and programme details can be
found at:
www.epma.com/shortcourse
Heat Treatment Plants for Aluminium Alloys
Schwartz GmbH
Edisonstrasse 5
52152 Simmerath
Germany
Phone: + 4 9 ( 0 ) 24 73/94 88-0
FAX: + 4 9 ( 0 ) 24 73/94 88-11
1-2013 E-Mail: heat info@schwartz-wba.de
processing
Internet: www.schwartz-wba.de
Schwartz Heat Treatment Sys tems
Asia (Kunshan) Co. Ltd.
278 JuJin Road Zhangpu Town Kunshan City
Jiangsu Province, 215321
P. R. China
Phone: +86-512-50159005
FAX: +86-512-50159007
E-Mail: U.Mierswa@schwartz-hts.com
Schwartz, INC.
2015 J. Route 34
Oswego IL 60543
USA
Phone: +1-630-875-3000
25

NEWS
Personal
P.C. Abraham nominated
Managing Director of Loesche
India Pvt. Ltd.
In his new position as Managing Director,
Mr P.C. Abraham is responsible for
the management of Loesche India Pvt.
Ltd. Mr P.C. Abraham joined Loesche India
Pvt. Ltd. on 1 st March 1995 and has been
working as Executive Director of the Technical
Department. Under his leadership
Loesche India established a successful
and competent Technical Field Service
Department. Further he has been responsible
for significant growth in the
After Sales Business of the company
owing to his outstanding knowledge
of the Indian cement industry backed
by profound management and organisational
skills.
Alberto Iperti new CEO of Tenova
Alberto Iperti has been appointed
chief executive officier of Tenova.
48 years old, electrical engineer graduated
at Politecnico di Milano, he started
his career working for the most important
consulting firms. In 2000 he entered in the
Techint Group, first as Planning Director of
TenarisDalmine in Italy and then as Managing
Director of Exiros in Argentina, the procurement
company of the Techint Group’s
Steel Area. From 2005 on he held the office
of Tenaris Global Planning Director in Argentina
as well. In order to join Tenova he has
left the role of Managing Director Tenaris
Canada’s, the leading supplier of tubes
and related services for the world’s energy
industry of the Techint Group which today
includes 1.500 employees, a position he
has held since 2006. During the last years
Iperti has wisely led the company, creating
growth and expanding the business.
During his stay in Canada Iperti was also
elected Vice Chairman of the Canadian Steel
Producers Association, and he was an executive
member of the board of Canadian
Manufacturers & Exporters and a member
of the Canadian Council of Chief Executives.
Alberto Iperti succeds Gianluigi Nova
who will continue his collaboration in the
Tenova Board.
New group sales and marketing
director at EFD Induction
EFD Induction has announced the appointment
of Terje Moldestad as new Group
Sales and Marketing Director. Moldestad
takes over from Truls Larsen, who is moving into
the company’s business development department.
He formally took over his new role on
January 1, and is based at EFD Induction corporate
headquarters in Skien, Norway.
26
heat processing 1-2013

Handbook of
thermoprocessing
technologies
Volume 1: fundamentals | Processes | Calculations
This Handbook provides a detailed overview of the entire thermoprocessing
sector, structured on practical criteria, and will be of particular assistance
to manufacturers and users of thermoprocessing equipment.
In europe thermoprocessing is the third largest energy consumption
sector with a very diversified and complex structure. therefore it is split
into a large number of subdivisions, each having a high importance
for the industrial economy. Accordingly we find the application knowhow
for the design and the execution of respective equipment represented
by a multitude of small but very specialized companies and their experts.
So this second edition is based on the contribution of many highly
experienced engineers working in this fi eld. the book’s main intention is
the presentation of practical thermal processing for the improvement of
materials and parts in industrial application. Additionally it offers a summary
of respective thermal and material science fundamentals. further it
covers the basic fuel-related and electrical engineering knowledge and
design aspects, components and safety requirements for the necessary
heating installations.
editors: f. Beneke, B. Nacke, H. Pfeifer
2nd edition 2012, 680 pages with additional media files and
e-book on DVD, hardcover
www.vulkan-verlag.de
Trade & Industry NEWS
Jetzt bestellen!
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen
knowledge for tHe
future
order now by fax: +49 201 / 82002-34 or send in a letter
Deutscher Industrieverlag GmbH | Arnulfstr. 124 | 80636 München
Yes, I place a firm order for the technical book. Please send
— copies of Handbook of Thermoprocessing Technologies 2nd edition 2012
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(ISBN: 978-3-8027-2966-9) at the special price of € 180,- (plus postage and packing)
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27

NEWS
Media
INFO
by Daniel H. Herring
£ 123.99
$ 87.99
www.store.bnpmedia.
com
Vacuum Heat Treatment
Vacuum Heat Treatment is a new book
focused on principles, practices and
applications providing the heat-treating
industry with its first truly comprehensive
resource on the subject of vacuum technology,
which is the fastest growing segment
of the heat treat industry today. This book
provides the reader with practical advice,
a diverse set of application examples and
a wide range of technical and engineering
information necessary to make informed
decisions about how to heat treat and
what equipment features are necessary
to do the job.
What makes this book unique is that
it is written in such a way that engineers,
metallurgists, heat treater operators, supervisors,
managers, quality, industrial and
manufacturing engineers and just about
anyone interested in thermal processing or
manufacturing can become skilled in the
art and science of vacuum heat treatment.
INFO
by Franz Beneke,
Bernard Nacke, Herbert
Pfeifer
Volume 1: Fundamentals
| Processes | Calculations,
2 nd Edition 2012
700 pages, hardcover
with DVD (eBook)
€ 200.00
ISBN: 978-3-8027-2966-9
www.vulkan-verlag.de
Handbook of Thermoprocessing
Technologies
The Handbook of Thermoprocessing
Technologies provides a detailed overview
of the entire thermoprocessing sector,
structured on practical criteria, and will be
of particular assistance to students of all
relevant disciplines and to engineers in this
field. The first volume examines the basic
principles, procedures and processes involved
in thermoprocessing technology.
Content of the book: introduction, fundamentals
of materials engineering, heat
transfer, fuels and combustion, electrothermal
processes, energy balances and energy
efficiency for industrial furnaces, thermoprocesses
with gas recirculation, furnace
atmospheres, materials for industrial furnace
construction, appendix.
INFO
by William S. Levine
2 nd Edition 2010
CRC Press (London)
942 pages
hardcover
available as eBook
£ 57.99
ISBN: 978-1-4200-7360-7
www.crcpress.com
The Control Handbook
William Levine had once again compiled
the most comprehensive and authoritative
resource on control engineering. He
had fully reorganized the text to reflect the
technical advances achieved since the last
edition and had expanded its contents to
include the multidisciplinary perspective
that is making control engineering a critical
component in so many fields.
Now expanded from one to three volumes,
The Control Handbook, second edition
organizes cutting-edge contributions from
more than 200 leading experts. The second
volume, Control System Applications, includes
35 entirely new applications organized
by subject area. Covering the design and
use of control systems, this volume includes
applications for: automobiles, including
PEM fuel cells; aerospace; industrial control
of machines and processes; biomedical
uses, including robotic surgery and drug
discovery and development; electronics and
communication networks.
Other applications are included in a section
that reflects the multidisciplinary nature
of control system work. These include applications
for the construction of financial portfolios,
earthquake response control for civil
structures, quantum estimation and control,
and the modeling and control of air conditioning
and refrigeration systems. As with the
first edition, the new edition not only stands
as a record of accomplishment in control
engineering but provides researchers with
the means to make further advances. Progressively
organized, the other two volumes in
the set include: Control System Fundamentals
and Control System Advanced Methods.
28
heat processing 1-2013

Media
NEWS
Next generation consequence modeling
launched by DNV Software
DNV Software is launching a new
version of the world’s leading consequence
analysis software tool for
the process industries, Phast 7. Following the
tradition of over thirty years of continuous
development and innovation, this latest version
introduces an array of new features for
managing risk.
The management of risks from major
accident hazard facilities has historically
focused on safe operation rather than
areas such as improved financial performance
or increased productivity. But
with major advances in information and
communication technology and the maturing
of technology in other domains, the
emphasis has moved beyond straightforward
compliance with safety legislation.
A typical process plant will include
equipment for processing, transporting
and storing a wide range of hazardous
materials. Therefore, design, operation and
maintenance strategies must be equipment
oriented. Phast 7 has adopted a new
“equipment based” study structure whereby
analysis is organised to match the way
the user work – thinking in terms of equipment
and its function. Each equipment
item can have a range of failure scenarios
associated with it. The user can then introduce
variations to any of the failure scenarios
to account for differences e.g. small,
medium and large leaks. In combination
with the tabular display of data this offers
a powerful new approach to complex yet
intuitive analyses.
Phast 7 supports the latest user interface
technology and best practice approaches.
A tabular display of input data has
been introduced for efficient editing and
review of information. This allows the user
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failure cases, making it possible to edit any
aspect without the need to repeatedly
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29

NEWS
Trade & Industry
INTERNATIONAL
THERM
PROCESS
SUMMIT
„Both experts and executives of the
global thermo processing community
will be there: ITPS, summer 2013,
Düsseldorf – the place to be!“
Dr.-Ing. Andreas Seitzer
Managing Director
SMS Elotherm GmbH
www.itps-online.com
30 heat processing 1-2013

Powered by
Trade & Industry
NEWS
Organized by
1-2013 heat processing
31

CECOF CORNER
News from the European Committee of Industrial Furnace
and Heating Equipment Associations
ISO/TC 244 – Fourth plenary meeting
The annual ISO/TC 244 plenary meeting took place on
November 16, 2012 in Kyoto (Japan). Chairman Masaru
Okado welcomed 16 participants from nine member countries,
among them for the first time two Chinese representatives.
Dr. Sven Linow (Heraeus, Hanau/Germany) participated for the
first time in his function as new Chairman of IEC/TC 27.
Besides the status reports of the working groups and the liasion
partners the dissociation from the different standards of ISO/
TC 244 and IEC/TC 27 was discussed. Focus of the differentiation
discussion were the safety requirements for control devices (ISO
13577-4 – protective systems). For example two keywords for
safety relevant functions: SIL respectively PH-level.
The working groups met from November 12 to 15, 2011:
WG 2 - Safety – Combustion and fuel handling system,
WG 5 - Safety – Protective system and
WG 6 - Safety – Generation and use of protective gases.
As a first result of the standardisation work of ISO/TC 244 an
ISO standard (ISO 13577-1) was published end of November. All
general safety requirements for all types of thermo process plants
are determined in this standard, independent from design, heating
system and processes.
The series of standards ISO 13579-1 to -4 determining measuring
methods for energy consumption will be published shortly.
It is assumed that the ISO member countries will implement these
measures on national basis.
Concluded standardisation projects
ISO 13577-1: General safety requirements
ISO 13579-1: Energy balance and efficiency - General methodology
ISO 13579-2: Energy balance and efficiency - Reheating furnace
for steel
ISO 13579-3: Energy balance and efficiency - Batch type aluminium
melting furnace
ISO 13579-4: Energy balance and efficiency - Controlled atmosphere
furnace
Standardisation projects at first enquiry stage
ISO/WD 13574: Terminology
ISO/WD 13577-2: Safety requirements for combustion and fuel
handlings systems
ISO/WD 13577-4: Safety - protective system
Standardisation projects within the working group
ISO/WD 13577-3 Safety requirements for atmospheric gases
The next working group meetings are planned for February 2013
(USA) and the next plenary meeting is planned for September 2013
(Berlin, Germany).
The ISO/TC 244 documents are available to the working group
members via the national standardisation bodies. The standards
already published respectively the draft standards can be obtained
via the national bodies (in Germany via Beuth Verlag).
AUTHOR:
Dr. Franz Beneke
VDMA Thermo Process Technology
www.cecof.org
32 heat processing 1-2013

Heat Treatment
REPORTS
Reduction of heat losses on the
skid pipe system of a pusher
type furnace
by Mario Hoffelner, Franz Winter, Michael Springer, Frank Hügel, Andreas Buhr,
Rainer Kockegey-Lorenz
In the iron and steel making process, hot rolling only accounts for approximately 10 % of the energy consumption. Yet
1.5 to 2 GJ/t steel are consumed for hot rolling, and 80 % of this energy is utilised for reheating of the slab. The rolling
itself requires only 0.3 to 0.4 GJ/t [1]. Increasing energy costs and targets for the reduction of CO 2 emissions provide a
constant challenge for all high temperature process users to optimise their processes. In addition to raw material and
labour costs, the costs for energy and environmental requirements play an increasingly important role. New technical
solutions are required to improve the energy efficiency and reduce the energy consumption, and consequently the
CO 2 emissions. The target of voestalpine Grobblech GmbH and FBB Engineering GmbH is to optimise the hot rolling
process from an energy point of view, reduce CO 2 emissions, and reduce the operational cost of the reheating furnaces.
Another important aspect is the increase in productivity by reducing the shutdown time of the furnace. Cooperation
in partnership between the operator of the kiln and the supplier of refractory materials is an essential requirement for
achieving these goals.
This paper discusses how energy consumption and
energy loss can be reduced in reheating furnaces of
hot rolling mills by new lightweight refractory materials
and a new lining concept for the skid pipe insulation.
The annual tonnage of voestalpine Grobblech GmbH is
800,000 t produced by a workforce of about 640. The main
markets and applications for heavy plates are:
■■
■■
■■
■■
■■
Furnace length: 30,500 mm
Furnace width: 6,600 mm
Burners: Low NO x generation
Number of burners: 42 in side wall, 16 in roof
Installed power: 63 MW
■■
■■
■■
■■
■■
■■
Energy industry (offshore industry)
Sour gas resistant tube sheets
Steel and bridge construction
Shipbuilding and automotive industry
Mining industry
Others.
Fig. 1 shows an overview of the rolling mill facilities.
The reheating of slabs is carried out in two water cooled
pusher type furnaces, where the slabs are heated over a
three hour period to temperatures from 1,100 to 1,200 °C.
■■
■■
Furnace output: nominal 110 t/h
Nominal capacity: 700,000 t/y
Fig. 1: Production facilities at voestalpine Grobblech
GmbH Linz, Austria
1-2013 heat processing
33

REPORTS
Heat Treatment
Fig. 2: Complete cooling system of pusher type furnace, one cooling circuit for each skid, three cooling circuits for posts
and crossover pipes
■■
■■
■■
■■
■■
Specific energy consumption: 320 kWh/t
Energy consumption: 224,000 MWh/y
Fuel: coke oven gas
Furnace temperatures (app.):
Charging zone: 900 °C
Pre-heating zone: 1,200 °C
Heating zone: max. 1,280 °C
Soaking zone: 1,200 °C
Furnace operation: process computer-assisted control
This paper summarises the experiences with the new
lining concept for the water cooled skid pipe system in
voestalpine Grobblech GmbH furnaces as shown in Fig. 2.
There is a separate cooling section for each skid (no. 1 to 6)
and three additional cooling circuits for posts and crossover
pipes: cooling circuit 1 for charging zone (CZ), circuit 2 for
heating zone (HZ) and circuit 3 for soaking zone (SZ).
The furnace loses heat to the cooling water of the skid
pipe system. This is typically 10 to 15 % of the total energy
provided for heating the furnace. These losses can be
reduced by better insulating characteristics and properties
of the refractory lining for the skid pipe system.
Before presenting the development at voestalpine Grobblech
GmbH the new refractory lining concept and the
materials used will be discussed.
Fig. 3: Modular installation concept of skid pipe system in a 110 t/h
pusher type furnace
LINING CONCEPT WITH PRE-FABRICATED
INSULATING SHELLS
The skid pipe system is lined with pre-fabricated shells,
where the design of the shells is adapted to the conditions
in the reheating furnace. The lay out and configuration of
the shells is created using a modular concept in order to
minimise the number of different parts and to allow easy
installation (Fig. 3).
The big advantage of this innovative modular installation
concept using pre-fabricated parts, over an on-site
castable installation, is a significant reduction of installation
34 heat processing 1-2013

Heat Treatment
REPORTS
time. This is typically around 75 %. This reduces the shutdown
time of the furnace and increases the productivity.
Time consuming jobs such as installation of shuttering
on the skids and pipes, mixing and transportation of the
castable on site and the curing time before removing the
shuttering can be eliminated.
The insulating shells have got a thermotechnical optimised
sandwich design. Inside there is a heat resistant
metal sheet responsible for high mechanical stability. The
second layer is a blanket of high temperature insulation
wool (AES‐wool, low bio persistence) which is completely
embedded in dense or lightweight refractory castable as
the third layer on the hot face (Fig. 4).
The most recent and key innovation step in the development
of the shells was the application of an insulating
lightweight castable instead of the dense castable, as
the outer layer. Table 1 shows a comparison of typical
product parameters between the dense castable and
the lightweight castable FLB‐11/150‐I1. The big difference
in bulk density, 2.5 compared to 1.1g/cm³, leads
to a significant reduction in thermal conductivity. This
is in the range of 75 to 80 %. Therefore the heat losses
through the shell into the cooling water can be significantly
reduced.
The key component of the lightweight castable is
SLA-92, an innovative raw material for high temperature
insulation up to 1,500 °C. Data for this raw material are
given in Table 2. SLA-92 was initially developed as an
alternative to high temperature insulating wool (HTIW)
or fibre materials [2,3], and is currently being used successfully
in a variety of applications including reheating
furnaces in the steel industry [3-7]. The microporous
structure is responsible for low thermal conductivity,
because it hampers heat transfer by radiation at temperatures
exceeding 1,000 °C. It also results in a high
thermal shock resistance of insulating refractories based
on SLA-92, because crack propagation is hampered.
PRE-TESTS AND CALCULATIONS
Before the new lightweight shells were introduced in rolling
mills, pre-tests were made in a test furnace at FBB Engineering
GmbH at temperatures up to 1,300 °C. The tests were carried
out using an all side insulated pipe comparable to a post in a
pusher type furnace. These tests were conducted under ideal
conditions e.g. in an inert furnace atmosphere and no scale.
When replacing the dense with the lightweight shell
system, a considerable reduction in heat loss per square
metre pipe surface (more than 50 %) was achieved (Fig. 5).
Thermotechnical calculations by computational fluid
dynamics (CFD) show that installations with lightweight
castable FLB‐11/150‐I1 (BD=1.1 kg/dm³) can reduce heat
loss by 50 % or more when compared to dense castable
(BD=2.5 kg/dm³) [7]. Results are shown in Fig. 6.
Fig. 4: Thermotechnical optimised sandwich design of pre-fabricated
insulating shells for post (left) and skid pipe (right)
INDUSTRIAL APPLICATION IN 110 T/H
PUSHER TYPE FURNACE
The temperature increase of the cooling water in the skid
pipe system between entering and leaving the kiln and the
water flow rate are the indicators of the efficiency of the
insulation. The calculation of power loss, energy loss and
Table 1
Chemical Composition [wt.%]
Dense
castable
Lightweight
castable
FB-25/160-P1 FLB-11/150-I1
Al 2O 3 57 89
SiO 2 38 0.1
CaO 2.3 10
Fe 2O 3 1.1 0.1
Physical Properties
Appl. Temp. [°C] 1,600 1,500
Bulk Density [g/cm³] 2.5 1.1
Cold Crushing Strength
[MPa]
110 °C 95 5
1,200 °C 85 5
1,400 °C 90 6
Thermal Conductivity [W/mK]
200 °C 1.60 0.30
800 °C 1.66 0.28
1,000 °C 1.70 0.30
1,200 °C 1.80 0.36
Perm. Linear Change [%]
1,000 °C -0.1 -0.1
1,200 °C 0.1 -0.2
1,450 °C 0.5 -0.3
Table 1: Typical data of refractory castables for shells
1-2013 heat processing
35

REPORTS
Heat Treatment
Fig. 5: Heat loss per m²pipe for different refractory materials for skid
pipe insulation shells (results from FBB test furnace) [7]
Fig. 6: Density of heat flow [W/m²pipe] for a post between 800 °C and
1.400 °C furnace temperature for different refractory materials
of the insulation shells (CFD calculation)
costs is based on following basic conditions:
■■
Production: approx. 330 days/year
■■
Price for natural gas: approx. 0.03 Euro/kWh
■■
CO 2 : 0.2 kg/kWh natural gas
At the beginning of 2010 the first skid (no. 1) was completely
lined with the new lightweight shells. A first evaluation
of this skid no.1 in comparison with skids nos 2-5 lined with
the dense shells proved the potential for energy saving with
the new lightweight system (Table 3). Consequently the
Table 2 remaining skids nos 2-5 were also lined with the new system
at the end of 2010. During the following summer shut down in
2011 the remaining
posts and crossover
pipes were
Mineralogical composition
Main phase CA6 (~ 90 %)
also equipped with
Minor phase
Corundum
Chemical analysis [mass-%]
the lightweight prefabricated
Al 2O 3
CaO
Fe 2O 3
91
8.5
0.04
shells.
The complete
skid pipe system
SiO 2 0.07
of furnace PTF 1
Na 2O 0.4
was equipped with
Physical properties
lightweight insulating
shells made of
Bulk density [g/cm³] 0.8
Lose bulk density [kg/l] 0.5
Apparent porosity [vol.-%]
Available sizes
3 - 6 mm
1 - 3 mm
70 - 75
FLB-11/150-I1. Only
at the T-joints was
the dense castable
not replaced with
0 - 1 mm
the lightweight
Table 2: SLA-92 product data
one. It was also
not possible to replace the old dense lining with the new
lightweight material at several positions of some crossover
pipes due to the nature of the furnace construction.
Fig. 7 shows an example of the layout of the lining with
pre-fabricated shells for posts and crossover pipes and skid
pipes in the soaking zone of PTF 1. Each shell is labelled
for easy and fast installation according the drawing. The
installation is completed with in-situ casting at the T-joint.
The first shell at the bottom of the posts (labelled 14S
in Fig. 7) is made of dense castable instead of lightweight
material. During operation of the kiln, scale drops on the kiln
floor and is removed with heavy machinery during furnace
maintenance. Therefore a high strength material at this
position is mandatory. In this case that means that only 70
% of the post length can be lined with lightweight material.
In the charging zone (CZ) most of the posts have a
height below 0.5 m. Therefore less than 50 % of the post´s
surface can be lined with lightweight shells, and some posts
stay completely lined with dense shells. In addition the
T-joints are lined with dense material, so that the reduction
of energy loss in this cooling circuit is very limited.
The data of the water cooling system of PTF 1 before
and after the installation of the new lightweight concept
are given in Table 4 and 5 as annualised figures. In addition
to the energy loss through the cooling water, the annual
CO 2 emission is also given. The water flow rate through the
skid pipes (nos 1-6) could be reduced with the lightweight
concept by 12 % and, in addition, the water temperature
difference could be reduced by 13 %. The temperature
increase of the cooling water was reduced in all cases bet-
36 heat processing 1-2013

Heat Treatment
REPORTS
Table 3
ween 16 % in the charging and heating zone and 33 % in
the soaking zone. The average temperature increase of
the entire cooling system, normalised to the amount of
cooling water was reduced by 2.5 °C.
The energy savings differ between the areas of the skid
pipe cooling system. For the skid pipes 1-6 a reduction
of energy loss of about 22 % was achieved. The furnace
is equipped with conventional riders in the charging
and the heating zone and with a hot rider system in the
soaking zone. Rider geometry and system design have
a big influence on the density of heat flow through the
skid pipe. The skid surface which can be insulated is lower
in the area of the hot rider system when compared to the
area with the conventional rider system. This limits to some
extent the potential for energy saving here.
In the cooling circuit SZ (soaking zone) the energy loss
was reduced by approximately 33 %. In total about 70 to
75 % of the surface in the soaking zone was lined with
lightweight castable shells, the remaining surface was still
lined with dense castable shells as described above.
In the cooling circuits of the charging and heating zones
the reduction of energy loss is lower at 10 % and 17 %
respectively when compared to the soaking zone because
the skid design and some installations in the furnace, limits
the possibilities to install more lightweight insulating shells.
In Table 6 the overall energy loss of the two different
lining concepts and the saving achieved with the new
lightweight concept are given. For the complete pusher
type furnace PTF 1 a reduction of energy loss of 21 % is
achieved. Based on the price of fuel of app. 0,03 Euro/
kWh, that equates to a cost reduction of 200.000 Euro
per year. In addition the CO 2 emissions can be reduced
by up to 1,300 t per year, which also accounts for a saving
of several thousand Euros.
Skid
Water
flow
rate
Water
temp.
difference
Out - In
Power loss /
skid
Energy loss /
skid
[m³/h] [°C] [kW] [MWh/y]
1 25.0 12.3 359 2.843
2 - 5 25.1 15.0 437 3.461
Diff. -2.7 -78 -618
Rel. diff. 18 %
Table 3: Comparison of skid no.1 insulated with
lightweight castable and skids nos 2-5 (average
value) insulated with dense castable shells
Fig. 8 shows the energy balance of PTF 1 with skid pipe
system completely lined with pre-fabricated shells made
of lightweight castable FLB‐11/150‐I1. The heat loss of the
skid pipe cooling system amounts in this case to 9.6 %
when compared to 12.5 to 13 % with the dense material
shells previously used.
The investment costs of the new insulating material
lining concept for the complete skid pipe system of the
furnace were app. 170,000 Euro. The cost reduction achieved
by reduced energy losses is 200,000 Euro per year.
That means that the payback period for this installation,
including costs for removal of the old insulation, is only
one year. Meanwhile, these values are also confirmed by
other steel manufacturers having experience with the
new material concept.
Based on this extremely good result achieved in pusher
type furnace 1 the new built pusher type furnace 2 which
was commissioned at the beginning of 2012 was also
equipped with the lightweight insulating shells. In this new
furnace all the T-joint were also lined with a lightweight
version so heat losses can be reduced even more.
Fig. 7: Layout of insulation with pre-fabricated shells for posts,
crossover pipes in the soaking zone of PTF 1
Fig. 8: Energy balance of PTF 1 after complete installation of skid
pipe system with pre-fabricated insulating shells made of
lightweight castable
1-2013 heat processing
37

REPORTS
Heat Treatment
Table 4
Cool.
Circuit
Water
Flow
rate
Water
temp.
diff.
Out - In
Power
loss
Energy
loss
Costs CO 2
[m³/h] [°C] [kW] [MWh/y] [€/y] [t/y]
S 1-6 169.6 14.3 2,802 22,192 665,746 4,438
CZ 37.4 8.3 363 2,874 86,225 575
HZ 39.7 10.2 472 3,740 112,195 748
SZ 39.6 6.4 297 2,352 70,567 470
Σ 286.3 11.8* 3,934 31,158 934,733 6,232
- S 1-6 Skid pipe 1-6
- CZ cooling circuit (1) charging zone
- HZ cooling circuit (2) heating zone
- SZ cooling circuit (3) soaking zone
* weighted average by water flow rate
Table 4: Data from water cooling circuits of the skid pipe
Table 5 system lined with dense castable shells (BD 2.5 g/cm³)
Cool.
Circuit
Water
Flow
rate
Water
temp.
diff.
Out - In
Power
loss
Energy
loss
Costs CO 2
[m³/h] [°C] [kW] [MWh/y] [€/y] [t/y]
S 1-6 150,3 12,4 2.175 17.224 516,732 3,445
CZ 40,2 7,0 327 2.591 77,743 518
HZ 39,7 8,5 391 3.094 92,830 619
SZ 39,7 4,3 200 1.580 47,401 316
Σ 269,9 9,9* 3.092 24.490 734,707 4,898
* weighted average by water flow rate
Table 5: Data from water cooling circuits of the skid pipe
Table 6 system lined with lightweight castable shells (BD 1.1
g/cm³)
Dense castable
(RD = 2.5 kg/cm³)
Lightweight castable
(RD = 1.1 kg/cm³)
Saving
Power
loss
Energy
loss
Costs CO 2
[kW] [MWh/y] [€/y] [t/y]
3.934 31.158 934,733 6,232
3.092 24.490 734,707 4,898
842 6.668 200,026 1,334
21 %
Table 6: Energy savings and cost reduction for complete pusher
type furnace using lightweight castable instead of
dense castable for insulating the skid pipe system
CONCLUSION
The modular lining concept using prefabricated shells for
the skid pipe system in reheating furnaces provides shorter
installation times and reduces the downtime of the furnaces
during maintenance, thus increasing the productivity.
The new lightweight shells based on the microporous
castable FLB-11/150-I1 and a thermotechnical optimised
sandwich construction, can significantly reduce the heat
losses to the cooling system of the skid pipe system in
reheating furnaces, both pusher type and walking beam
furnaces. Trials in a test furnace and CFD calculations show
a potential of more than 50% reduction of heat losses when
compared with dense castable shells.
The industrial application of the new lightweight shell
system in the 110 t/h pusher type furnace 1 of voestalpine
Grobblech GmbH resulted in an overall energy saving of
21 % when compared to the dense castable shells. It has
to be taken into account, that not all areas could be lined
with the new lightweight concept because of the specific
skid design and some installations within the furnace. This
limited the saving to some extent.
The annualised energy saving gives a cost reduction
which is higher than the installation cost for the new lining,
resulting in a payback period of only one year. Consequently,
the newly constructed pusher type furnace 2 at voestalpine
Grobblech GmbH was also lined according to the
lightweight shell concept. Here, the T-joint were also lined
with lightweight castable.
The close and open co-operation between end-user,
refractory supplier, and raw material supplier enabled the
introduction of a new and innovative refractory lining concept
which reduces the energy consumption of rolling mill
furnaces and contributes to the reduction of CO 2 emissions.
In this context voestalpine Grobblech GmbH was a pioneer
in the realisation of innovative solutions in practice.
LITERATURE
[1] Karl Hoen, K. u.a. Energy and resource efficiency for hotrolling
mills, EECR Steel, Düsseldorf, 27 June – 1 July 2011
[2] Van Garsel, D.; Gnauck, V.; Kriechbaum, G.W.; Stinneßen, I.;
Swansinger, T.G.; Routschka, G., “New Insulating Raw Material
for High Temperature Applications” Proc. 41. International
Colloquium on Refractories Aachen, 122–128
[3] Van Garsel, D.; Buhr, A.; Gnauck, V, “Long Term High Temperature
Stability of Microporous Calcium Hexaluminate
Based Insulating Materials”, Proc. UNITECR´99, Berlin, 18-33
[4] Wuthnow, H.; Pötschke, J.; Buhr, A.; Boßelmann, D.; Gerharz,
N.; Golder, P.; Grass, J.: Experiences with Microporous Calcium
Hexaluminate Insulating Materials in Steel Reheating
Furnaces at Hoesch Hohenlimburg and Thyssen Krupp
Stahl AG Bochum. 47 th Colloquium on Refractories, Aachen,
Oct. 2004, p. 198-204
38 heat processing 1-2013

Heat Treatment
REPORTS
[5] Kikuchi, T.; Sakamoto, Y.; Fujita, K.: Non-Fibrous Insulating Castable
which utilize Micro Porous Aggregate. Fourth International
Symposium on Advances in Refractories for the Metallurgical
Industries, Hamilton/Canada, Aug. 2004, paper 49.2
[6] Kockegey-Lorenz, R.; Buhr, A.; Racher, R.: Industrial Application
Experiences with Microporous Calcium Hexaluminate
Insulating Material SLA-92, 48 th Colloquium on Refractories,
Aachen, Sept. 2005, p. 66-70
[7] Springer, M.: Reduction of Heat Losses on the Skid Pipe
system of Reheating Furnaces (Walking Beam Furnace,
Pusher Type Furnace) in the Steel Industry. 53 rd Colloquium
on Refractories, Aachen, Sept. 2010, p. 226-228
AUTHORS
Dipl.-Ing. Mario Hoffelner
voestalpine Grobblech GmbH
Linz, Austria
Tel.: +43 (0)732/ 6585-77068
mario.hoffelner@voestalpine.com
Dipl.-Ing. Michael Springer
FBB Engineering GmbH
Mönchengladbach, Germany
Tel.: +49 (0)2166/ 9700-400
m.springer@fbb-engineering.at
Dipl.-Ing. Frank Hügel
FBB Engineering GmbH
Mönchengladbach, Germany
Tel.: +49 (0)2166/ 9700-666
f.huegel@fbb-engineering.de
Dr.-Ing. Andreas Buhr
Almatis GmbH
Frankfurt, Germany
Tel.: +49 (0)69/ 957341-19
andus.buhr@almatis.com
Dipl.-Ing. Franz Winter
voestalpine Grobblech GmbH
Linz, Austria
Tel.: +43 (0)732/ 6585-6723
franz.winter@voestalpine.com
Dipl.-Ing. Rainer Kockegey-Lorenz
Almatis GmbH
Ludwigshafen, Germany
Tel.: +49 (0)621/ 5707-260
rainer.kockegey-lorenz@almatis.com
1-2013 heat processing
39

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Heat Treatment
REPORTS
New heating hood generation
for energy saving and NO x
reduction
by Peter Wendt, Frank Maschler, Georg Velten, Jörg Wortmann, Andreas Heßler,
Jörg Zumbrink
As a contribution to the reduction of energy use in industrial furnaces, LOI Thermprocess GmbH (a member of the Tenova
LOI Italimpianti Group) has developed a new generation of heating hoods. The new technology has proved itself during
one year of operation with Hoesch Hohenlimburg GmbH; it was possible to obtain 12 % energy saving using significantly
increased air preheating temperatures at the same time as achieving very low NO x emissions of 70 mg/m³. This is the
first time that flameless oxidation has been used in bell-type annealing plants.
Normally, flue gas temperatures downstream from
the recuperator during the recrystallizing of coldrolled
steel strip are of the order of 450 °C, resulting
in flue gas losses of 25 % and more referred to the total
energy input [1]. In the past, there were few incentives
to improve the situation in view of the low price of fuels.
More recently however, changes are becoming apparent
in the bell-type annealing plants on the market, especially
with respect to customers’ expectations.
There is a segment in which customers expect minimal
capital expenditure and are generally not prepared to make
additional investments in measures to reduce operating
expenses. As a result of the large number of new competitors
entering the market, this segment is characterized by
severe pressure on prices, which is likely to become even
worse in the future. At the same time, a segment has developed
in which customers add the long-term operating
expenses to the capital expenditure and consider overall
cost over the entire service life of the plant. These customers
actively require energy-saving solutions and do not expect
the cheapest plant technology in terms of initial expenditure
but the least expensive with respect to capital expenditure
and operating expenses. This article is mainly intended for
this customer segment and describes the successful introduction
of a new, energy-saving heating hood design for
Hoesch Hohenlimburg GmbH in Hagen-Hohenlimburg,
where an HPH® bell-type annealing plant with 8 annealing
bases has already been in operation for several years (Fig. 1).
SOLUTION
Flue gas losses are reduced conventionally by increasing
the recuperator exchange area. The objective was to provide
air preheating temperatures of at least 550 °C with
flue gas temperatures of 700 °C at the recuperator inlet,
thus reducing energy consumption by at least 10 %. This
objective called for an increase in the heat exchange area
normally used by a factor of about three, the use of suitable
materials for hot air lines and burners and, especially,
measures to reduce thermal NO x emissions.
Fig. 1: HPH® Bell-type annealing plant with 8 bases
(Hoesch Hohenlimburg GmbH)
1-2013 heat processing
41

REPORTS
Heat Treatment
NOx @5%O 2 [mg/m³]
A number of articles on NO x reduction measures in gas
firing systems have already been published [2, 3]. In this
context, the avoidance of temperature peaks in combustion
is the most promising approach under the conditions
found in bell-type annealing plants.
Various bell-type annealing plant burners were tested
on a test rig and, among other aspects, the dependence of
NO x emissions on the preheating temperature produced
was investigated (Fig. 2). To date, the most commonly
adopted approach to NO x reduction has been staged air
supply. For the three burners used in the tests, a two-stage
air supply was selected and the ratio between the two
stages was varied. The higher the fuel excess in the primary
stage, the longer and softer the flame and the lower the
NO x emissions. This approach can be continued to the
point where CO formation starts.
As only a relatively small annular space between the
heating hood and the inner cover is available for the firing
system, staged air supply must take into account the length
and shape of the flame. In a heating hood, the flame should
therefore be relatively short. For this reason, the settings will
probably not be ideal in terms of NO x emissions (burners A
and B). Burner C has the lowest NO x emissions but produces
a flame with an unfavourable shape.
Flue gas recirculation was also investigated for NO x reduction,
in the first instance with the addition of cold flue gas to
the combustion air. In practical tests, NO x reductions of 20
to 25 % were reached with recirculation rates of about 10 %.
However, the results missed the target of 100 mg/m³ by a
clear margin. In addition energy consumption was increased
because the cold flue gas recirculation to the combustion air
represented a thermal ballast.
In contrast, the principle of flameless oxidation represents
an opportunity of solving the conflict between the
objectives of ensuring high combustion air preheating
Fig. 2: NOx-Emissions and Limits
600
500
400
300
200
100
BAF Burners with staged Air : NOx-Emissions in Lab Furnace
500 mg/m³ : Limit according to TA Luft for furnaces in rolling mills
250 .. 300 mg/m³ : common range for approvals in Germany
100 mg/m³ : international lowest limits
0
200 250 300 350 400 450 500 550 600
Fig. 2: NO x emissions and limits
Air Preheating [°C]
Natural Gas fired
Furnace temperature 1000 °C
Air / Gas-Ratio 1,15
Burner A
Burner B
Burner C
temperatures on the one hand and avoiding thermal NO x
formation on the other hand.
In the first step, a well-established high-speed burner
with flameless technology was tested on a heating hood
in 2008. Under design conditions, this burner had a very
high flame speed of about 160 m/s. Initially, NO x reduction
in the flame mode was the main objective as it was
assumed that temperatures in the heating hood would
be too low for flameless operation for lengthy periods.
NO x values between 130 and 150 mg/m³ (referred to 5 %
oxygen) were achieved, representing an improvement
of 40 % or more over the initial conditions. During the
tests, it was found that temperatures in the area of flue
gas intake into the burner jet were significantly above
830 °C for a significant period, which had not been
expected. This meant that the flameless combustion
mode could be used for a significant part of a typical annealing
cycle, leading to NO x emissions below 20 mg/m³ for
a certain time.
Unfortunately, the fibre lining of the heating hood was
already largely destroyed after only a few annealing cycles.
Temperatures and gas speeds at the surface of the lining
were therefore measured. In flame operation, speeds were
at least 50 m/s and at least 35 m/s in the flameless mode,
with maximum temperatures between 1,350 and 1,400 °C.
In order to continue operation of the test heating hood
at all, the burner section was lined with lightweight bricks
which have the disadvantages of higher weight, higher
thermal inertia and a higher price. This was not acceptable
as a standard solution.
Finally, the tests with the high-speed burners were discontinued
and a search was made for alternatives with a
view to realizing flameless combustion in a way which is
adapted to the conditions under the heating hood of an
HPH® bell-type annealing furnace:
■ reliable full combustion free from CO, especially from
the safety ignition temperature of 750 °C
■ reduction in the flame speed from 160 m/s to less than
60 m/s.
Two basically equivalent solutions were found. These are
both based on conventional medium-speed burners which
operate in the flame mode below a safety temperature
of 760 to 830 °C and then switch to flameless oxidation
above these temperatures. As patents are still pending,
further details of these burners will be published later. As
a result of this innovation, the previous dimensions of the
annular combustion space under the heating hood and
the standard fibre lining can remain unchanged for the
operation of the HPH® Flameless heating hood.
The intensity of the combustion reaction can be assessed
on the basis of images taken in the radiation range of the
42 heat processing 1-2013

Heat Treatment
REPORTS
OH radicals (Fig. 3): in flame operation, there is an intensive
reaction directly at the base of the flame. In contrast, with
flameless operation, there is only a very weak maximum about
400 to 500 mm downstream from the burner tip. Combustion
occurs diffusely over a far larger area. This reduces temperature
peaks and results in a drastic lowering of NO x emissions.
For the construction of the pilot plant a partner prepared
to support and test this new development was found
in Hoesch Hohenlimburg GmbH. Key objectives were laid
down in a cooperation agreement:
Fig. 3: Lab results with 600 °C air temperature
OH pictures
Flame mode 150 kW NO X > 300 mg / m³
Flameless mode 240 kW NO X < 40 mg / m³
photo
■ an energy saving of 12 % with reference to existing Fig. 3: Lab results with 600 °C air temperature
heating hoods
Fig. 4: HPH ® -flameless heating hood
■ an average NO x emission for the charge of

REPORTS
Heat Treatment
Temperature [°C],
Emission NOx@5 % O2 [mg/m³],
CA Fan Speed [0,1 Hz],
Fuel Gas Flow [m³/h]
Fig. 5: Reference annealing cycle
1000
900
800
700
600
500
400
300
200
100
Annealing Cycle with HPH ® -Flameless Heating Hood
0
0
0 5 10 15 20 25 30
Fig. 5: Reference annealing cycle
Temperature [°C]
Flameless Mode
Fig. 6: Inner cover temperatures
1000
950
900
850
800
750
700
650
Fig. 6: Inner cover temperatures
Time [h]
Flame Mode
Inner Cover Temperatures
600
0 2 4 6 8 10 12 14 16 18 20 22
Time [h]
Flameless mode :
maximum temperature 50 K lower
20
18
16
14
12
10
8
6
4
2
O2 in Flue Gas [%]
Control TC
TC Flame/Flameless
Charge Edge TC
Charge Core TC
Fuel Gas Flow
CA Fan Speed
NOx
@5 % O2 [mg/m³]
Air Preheating
Flue Gas after Recu
O2 in Flue Gas
Burner 1 Flameless
Burner 1 conv.
Burner 2 Flameless
Burner 4 conv.
Burner 3 Flameless
Burner 6 conv.
Burner 4 Flameless
Burner 8 conv.
Burner 5 Flameless
Burner 10 conv.
Burner 6 Flameless
Burner 12 conv.
Energy consumption
A reference charge with a mass of
71.9 t was used. This was subjected
to re-crystallization annealing at a
soaking temperature of 710 °C in an
annealing cycle with the duration
of about 39 h.
The comparison was made using
heating hood 5, which formed part
of the latest expansion stage of
the plant. The heating hood was
adjusted in accordance with the
specifications for the tests. With the
conventional heating hood, energy
consumption was 221.4 kWh/t.
Under identical conditions, the
HPH® Flameless heating hood
reached an energy consumption
of 194.5 kWh/t, corresponding to a
reduction of more than 12 %. Apart
from the higher air pre-heating
temperature, oxygen control is a
key factor in this energy reduction.
Within a range of 100 % to less than
20 % of the heating hood setting, it
was possible to maintain the oxygen
concentration in the flue gas
between 1.3 and 2.5 %.
For a typical recrystallization
annealing cycle for steel strip with
a core temperature of 680 °C and a
duration of 17.5 h, the energy consumption
of the HPH® heating hood
was 173 kWh/t. At an energy price of
0.033 Euro/kWh, this would represent
an annual saving of about 33,000
Euro per heating hood with the usual
duration of recrystallization.
tional heating hood and the newly developed HPH® Flameless
heating hood. The conventional heating hood
with 12 burners has six hot spots in identical positions to
the HPH® Flameless heating hood. Thermocouples were
attached to the heating hood at these six hot spots and one
annealing cycle was completed with the HPH® Flameless
heating hood (thick lines) and one with a conventional
heating hood (thin lines).
Although energy is now supplied by six burners
instead of 12, the maximum temperatures on the inner
cover are about 50 K lower than with the conventional
heating hood. This should prolong the service life of
the inner cover in operation with an HPH® Flameless
heating hood.
CONCLUSION
Flameless oxidation has been shown to be a suitable process
for bell-type annealing plants at soaking temperatures
of about 700 °C. The benefits are:
■ extremely low NO x emissions of approx. 70 mg/m³ on
average over the annealing cycle, referred to 5 % oxygen
in the flue gas
■ a reduction of about 12 % in natural gas consumption as
a result of significantly higher air preheating temperatures
of approx. 550 °C (flue gas temperature downstream
from recuperator: < 300 °C)
■ a reduction of about 50 K in hot spot temperatures on the
inner cover compared with conventional heating hoods
(flame operation).
44 heat processing 1-2013

Heat Treatment
REPORTS
The NO x limits in Germany are defined by the approval
notification issued by the competent environmental authority.
Although TA Luft, the German air pollution regulation,
allows limits of up to 500 mg/m³ for rolling mill furnaces,
the authorities are called upon to take the state of the art
into consideration for approvals. The solution described
here redefines the state of the art for bell-type annealing
furnace firing systems.
Currently, emissions of about 250 mg/m³ are accepted
for natural gas-fired bell-type annealing furnaces. Internationally,
there are significantly more stringent limits in
some cases. For example, limit of 100 mg/m³ applies in
the Netherlands and parts of the USA.
As long as the NO x limits in Germany remain at their
present level, flameless oxidation can only be economical
as a result of reduced fuel gas consumption. Flameless
oxidation only lays the foundations for a reduction in flue
gas losses. The additional investment in increased recuperator
area and modifications to hot air lines and burners
must be recouped. At current natural gas prices and with
a reduction of 12 % in consumption, the payback period
is significantly shorter than three years. In any analysis of
this type, the expected increases in natural gas prices in the
future also need to be taken into consideration.
Trading with CO 2 certificates may also provide additional
motivation. It is not yet possible to put a figure on additional
factors which have a positive impact on plant economics
such as the longer service life of the inner covers.
The effects are highly beneficial. Using flameless oxidation
in combination with higher air preheating temperatures,
it is possible to develop a solution which is already economical
and ensures security for the future with extremely
low NO x emissions.
LITERATURE
[1] Wendt, P.; Kühn, F.: Modernization and efficiency of thermal
processing plants, Heat Processing (Volume 9), issue 1/2011,
pp 21-28
[2] Wünning, J.A.; Wünning, J.G.: Brenner für die flammenlose
Oxidation auch bei höchster Luftvorwärmung, Gaswärme
International 41 (1992) issue 10, pp. 438-444
[3] von Gersum, S.; Wicker, M.: Neue low-NO x -Lösung für Hochgeschwindigkeitsbrenner,
Gaswärme International 61 (2012)
issue 5, pp. 85-89
AUTHORS
Dr.-Ing. Peter Wendt
LOI Thermprocess GmbH
Essen, Germany
Tel.: +49 (0)201/ 1891-236
peter.wendt@loi-italimpianti.de
Dipl.-Ing. Frank Maschler
LOI Thermprocess GmbH
Essen, Germany
Tel.: +49 (0)201/ 1891-308
frank.maschler@loi-italimpianti.de
Georg Velten
LOI Thermprocess GmbH
Essen, Germany
Tel.: +49 (0)201/ 1891-338
georg.velten@loi-italimpianti.de
Dipl.-Ing. Jörg Wortmann
Hoesch Hohenlimburg GMBH
Hagen, Germany
Tel.: +49 (0)2334/ 9122-00
joerg.wortmann@thyssenkrupp.com
Dipl.-Phys. Andreas Heßler
Hoesch Hohenlimburg GMBH
Hagen, Germany
Tel.: +49 (0)2334/ 9125-59
andreas.hessler@thyssenkrupp.com
Dipl.-Ing. Jörg Zumbrink
Hoesch Hohenlimburg GMBH
Hagen, Germany
Tel.: +49 (0)2334/ 9127-90
joerg.zumbrink@thyssenkrupp.com
Hotline Meet the team
Managing Editor: Dipl.-Ing. Stephan Schalm +49(0)201/82002-12 s.schalm@vulkan-verlag.de
Editorial Office: Annamaria Frömgen +49(0)201/82002-91 a.froemgen@vulkan-verlag.de
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Advertising Sales: Bettina Schwarzer-Hahn +49(0)201/82002-24 b.schwarzer-hahn@vulkan-verlag.de
Subscription: Martina Grimm +49(0)931/41704-13 mgrimm@datam-services.de
Hotline_184,5x35.indd 2 15.12.11 15:13
1-2013 heat processing
45

REPORTS
Heat Treatment
Scale up of ultrasonic spray
pyrolysis process for nanopowder
production - Part I
by Gregory Matula, Jelena Bogović, Srećko Stopić, Bernd Friedrich
Nanostructured materials and their application have been one of main research topics in the last decades. Various nanomaterials
and endless application of them is known today. On the other hand, industrial application of nanomaterials is
still challenged with limited offer of methods suitable for big scale nanomaterials production, especially when it comes
to nanomaterials with target morphology and complex composition. In this paper is presented a report on scale up
of Ultrasonic Spray Pyrolysis (USP) process. The USP as the nanoparticle production method is relatively inexpensive
and quite versatile technique based on an aerosol process to produce fine metallic, oxidic, composite nanoparticles of
precisely controlled morphology and defined chemical compositions from water solution using different metal salts
and their mixtures [1-4].
This article is the first of two parts devoted to the result of
research in ultrasonic spray pyrolysis process. This part
contains description of the construction of prototype
device to be launched in the production phase in first quarter
of 2013. Trial phase began in December 2012 and preliminary
results show the correctness of this design as well as success of
scientific and engineering work of the IME Process Metallurgy
and Metal Recycling, RWTH Aachen University team with Elino
GmbH engineers. The second part will be devoted to control
system, the technological process itself and the results of final
tests of the equipment presented in this paper.
INTRODUCTION
In the last ten years an ultrasonic spray pyrolysis synthesis was
subject of research at the IME Process Metallurgy and Metal
Recycling, RWTH Aachen University. Different organic and
inorganic salts were used as precursor material for preparation
of metallic, oxidic and composite nanopowders by ultrasonic
spray pyrolysis, using the equipment shown in Fig. 1a.
Synthetized powders can be divided in three groups:
1. Metals (Au, Ag, Co, Cu, Zn, Ni, Fe) [1-2]
2. Oxide (TiO 2 , ZnO, Al 2 O 3 , RuO 2 ) [3-4]
3. Composite materials with partially core-shell structure
(CuNi, FeCo, NiCo, RuO 2 /TiO 2 , La0.6Sr0.4CoO 3 , C/LiFePO 4 ,
Au/TiO 2 , Ag/TiO 2 ) [4].
Next to variety in chemical composition it is possible also to
produce nanopowders with various morphologies (spherical,
cylindrical, triangular, dense, porous, hollow, core/
shell nanoparticle).
Some of the nanopowders produced by USP are presented
in Fig. 1b and 1c.
DESIGN OF THE DEMO SCALE USP EQUIP-
MENT
One decade of the experience in nanoparticle synthesis by
USP was the basis to develop device on an industrial scale
for Nanotechnology: Demonstration Scale Ultrasonic Spray
Pyrolysis Equipment. The main parts of the equipment
are: A. Aerosol ultrasonic generator, B. High-temperature
furnace with 5 wall heated reactors, C. Electrostatic filter,
D. Vacuum system. The concept draft and device photo
are shown in Fig. 2.
In cooperation with Elino GmbH engineers from Düren,
Germany and basing on previously built prototype in micro
scale by IME Institute (Fig. 1), after nearly six months of
intensive work of two teams: scientific from IME Institute
and engineering from Elino GmbH, the first design of demo
scale version of the device with working title “MIRANDA”
was developed.
The main engineering challenge was to transfer scientific
achievements and maintain process specifics in macro
scale. It involved many complex calculations of gas flow,
temperature uniformity and its impact on the process.
46 heat processing 1-2013

Heat Treatment
REPORTS
The “heart” – furnace consists of
four separately regulated heating zones
(Fig. 3). Additional unique aspect of the
device is its full tightness (remark: thermal
decomposition in inert atmosphere
(Ar, N 2 ), reduction (H 2 ) or oxidation (O 2 )
gases), with occurring negative influence
of high temperature and thermal
expansion of reaction pipes to flange
connections. Engineers from Elino GmbH
worked out a solution to eliminate the
above mentioned problems.
Each heating zone in the furnace is
controlled separately (heating), as well
as has separate temperature monitoring.
Temperature uniformity is min. +/- 10 °C,
max. +/- 15 °C (data collected after first
trials). Proper construction of heating
elements and their heating power
used in each of four zones enables to
set much higher temperatures which
additionally make this device very flexible
in full temperature range necessary
for the unique nanotechnology.
Additional advantage of this construction
(after first trials) is very good
thermal insulation. By working temperature
in heating zone 2 and 3 – 1,000 °C, the temperature
of the shell does not exceed 30 °C, which ensures safe
usage of delicate ultrasonic aerosol generators which
electrical units are very sensitive to high temperatures.
Further important components are ultrasonic aerosol
generators and gas system. In order to
understand the essence of gas system,
one should understand the basis of the
process. Feeding gas flows to the control
valve where it is adjusted depending
on type of gas or mixture of gases.
Successively the gas is sucked by vacuum
pump to aerosol generators and then to
reaction pipes. This gas flow has two
main functions: reaction gas and carrier
gas. Vacuum pump provides the pressure
below atmospheric pressure in the whole
system which has positive influence on
the process itself. The gas and aerosol
generation system are shown in Fig. 4.
One more prototype part of the
equipment is presented at Fig. 4. These
are five aerosol ultrasonic generators
“Priznano”. Their design is the effect of
joint work of IME researchers, engineers
from Elino GmbH and engineers from
a)
Fig. 1: a) USP equipment at IME Process Metallurgy and Metal Recycling,
b) NanoAg (ref. 2], c) TiO 2 [ref. 4]
PRIZMA Company, Kragujevac, Serbia. Big advantage
of this system comparing to other systems for aerosol
production are: small droplet size, industrial design,
continual process, high corrosion resistivity and ability
to operate with H 2 .
Fig. 2: The concept of demo scale USP and photo of the equipment
b)
c)
1-2013 heat processing
47

REPORTS
Heat Treatment
Fig. 3: Furnace with 4 heating zones and wall heated reactors
Nanopowder collection occurs in specially designed
Electrostatic Precipitators (Electro Filter). Based on the mini
version and results of previous research, IME and Elino
GmbH team developed paper version (idea) that was
mathematical extension to lab design previously developed
by the IME and “Schnick Industrieberatung”. It should be
mentioned that there are no exact rules on how to design
or build such devices as electrostatic precipitators with
regard to this particular technology. Professional involvement
of members of “MIRANDA” project showed that there
Fig. 4: The gas and aerosol generation system
is no easy transfer from micro to macro
version. Additional factors, like type of
gasses, acids, gas flow, influence of
temperature to certain materials and
their nonlinear behavior forced the
engineers to reject the original version
and develop entirely new design
shown in Fig. 5.
Additional factor that had influence
on the electrostatic precipitators
design was making it in a version that
could operate with harmful gasses
(tight design version) and acids while
maintaining proper temperature inside
the EGR and simultaneously obtaining
final effect of Nano product in required
industrial quantity. It must be first
clarified that this unit uses electrostatic
precipitators connected to the reaction
pipes coming from the furnace in such
a way that redundant operation and
flexible adjustment of throughput is
possible. Electrostatic precipitators will always be the part
of the device that requires the most of maintenance service
and this is made possible due to the specific design.
As it was mentioned before, gas+nanoproduct is sucked
by vacuum pump from reaction pipes placed in furnace.
The temperature of this stream is measured on inlet to electrostatic
precipitators. It is maintained in auto control. This
is necessary for protection of sealing resistant to corrosion
and acids during technological process.
Inner design of electrostatic precipitator consists of a
few of emitting/collecting electrodes
made from adequately selected
stainless and temperature-proof
steels.
Emitting electrode is connected
to high voltage generator that
create powerful electrostatic field.
Thanks to this, nanoproduct is kept
in collection pipes and the “carrier
atmosphere” is discharged to vacuum
system. It should be mentioned
that pressure, flow and temperature
of gas or else called “carrier atmosphere”
have very big impact on the
process. However, additionally when
the “carrier atmosphere” enters the
electrostatic precipitators, there are
two more factors decisive of obtaining
nanoproduct – the voltage that
creates electrostatic field and geometry
of reaction pipes. In order to
48 heat processing 1-2013

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collect nanoproduct during the production,
each electrostatic precipitators is
equipped with special hammer system
which enables to “pour” nanoproduct
into containers under each EGR.
The last element of the equipment
is vacuum system. This system
is shown in Fig. 6.
The vacuum system in addition to
the pump and vacuum valves consist of
two filters with a design that provides a
completely safe operation of vacuum
pump without the need for frequent oil
replacement or the pump itself damaged
by the remnants of nanoproduct
in “carrier atmosphere”.
The filters, basing on water as a natural
filter, operate in automatic water filling
system and automatic pollutants
removal system thanks to installed
sensors and electromagnetic valves
coupled into automatic control system.
CONCLUSION
Initial tests conducted in the last quarter
of 2012 have proven the correctness of
design for safety, control systems operation
and such parameters as heating
rate, maximum temperature, vacuum
level in the system and gas flow. Previous
conclusions clearly show full readiness
for technological trials which
will also be described along with the
theoretical background in the second
part of the article to which we already
pointed out.
Fig. 5: Design of electrostatic precipitator
ACKNOWLEDGEMENTS
This work was finances by the DFG
Deutsche Forschungsgemeinschaft and
Land NRW in frame of the program “Forschungsgeräte”
(INST 222/874-1 FUGG),
Equipment for Nanopowder production.
We gratefully acknowledge the support
of Dipl.-Ing. Dieter Schäufler general
manager from Elino GmbH.
LITERATURE
Fig. 6: Vacuum system
[1] Rudolf, R.; Friedrich, B.; Stopic, S.; Anzel, I.;
Tomic, S.; Colic, M. (2012): “Cytotoxicity of
Gold Nanoparticles Prepared by Ultrasonic
Spray Pyrolysis”, Journal of Biomaterials
Applications, 26, 1, 595-612
1-2013 heat processing
49

REPORTS
Heat Treatment
www.heatprocessing-online.com
The international magazine
for industrial furnaces,
heat treatment plants
and equipment
The technical journal for the entire field of industrial furnace
and heat treatment engineering, thermal plants,
systems and processes. The publication delivers comprehensive
information, in full technical detail, on developments
and solutions in thermal process engineering for
industrial applications.
Make up your mind on how to subscribe!
· The printed volume suits the classic way of reading.
· The e-paper issue offers the modern way of receiving
informationon a computer, tablet pc or smart phone.
· The printed volume + e-paper issue combine the best
of both worlds.
[2] Stopić, S.; Friedrich, B.; Dvorak, P. (2006): Synthesis of nanosized
spherical silver powder by ultrasonic spray pyrolysis,
Metall, 60, 6, 377-382
[3] Bogovic, J.; Stopic, S.; Friedrich, B. (2011): Nanosized metallic
oxide produced by ultrasonic spray pyrolysis method, Proceeding
of EMC 2011, Duesseldorf, June 26-June 29, 2011, Volume
3: Resources efficiency in the non-ferrous metals industryoptimization
and improvement, 1053-1064
[4] Gürmen, S.; Ebin B.; Stopic, S.; Friedrich, B. (2009): Nanocrystalline
spherical iron–nickel (Fe–Ni) alloy particles prepared by
ultrasonic spray pyrolysis and hydrogen reduction (USP-HR),
Journal of Alloys and Compounds, 480, 529-533
AUTHORS
Dipl.-Ing. Gregory Matula
Elino Industrie-Ofenbau GmbH
Düren, Germnay
Tel.: +49 (0)241/ 6902-253
matula@elino.de
heat processing is published by Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen, Germany
Dipl.-Ing. Jelena Bogović
RWTH Aachen
Institute for Process Metallurgy and Metal
Recycling
Aachen, Germany
Tel.: +49 (0)241/ 8095-202
jbogovic@ime-aachen.de
Dr.-Ing. Sreċko Stopiċ
RWTH Aachen
Institute for Process Metallurgy and Metal
Recycling
Aachen, Germany
Tel.: +49 (0)241/ 8095-860
sstopic@ime-aachen.de
Prof. Dr.-Ing. Dr. h. c. Bernd Friedrich
RWTH Aachen
Institute for Process Metallurgy and Metal
Recycling
Aachen, Germany
Tel.: +49 (0)241/ 8095-850
bfriedrich@ime-aachen.de
knowledge for The
fuTure
50 heat processing 1-2013

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The role of flameless oxidation
in the ”Energiewende”
by Joachim G. Wünning
Combustion is the vital technology for the conversion of fuel energy into heat. The goal of low-emission and efficient
combustion can be achieved in many processes by the use of flameless oxidation. High temperature heating processes,
low temperature processes, space heating as well as power generation will be considered.
The German expression “Energiewende” (energy turn)
describes the process of largely reducing the use of
fossil fuels and simultaneously pulling out of nuclear
power. The correspondent resolution passed the German
parliament on 30th June 2011 with a vast majority [1]. Since
the fossil fuels are burnt it seems useful to take a closer look
to combustion processes and flameless oxidation.
To reduce the utilization of fossil fuels, primarily coal,
oil and natural gas, there are two main approaches which
both have to be addressed with great efforts.
On one hand, the consumption of energy has to be
reduced, mainly by increasing efficiency but also by
many other measures. On the other hand, a growing
percentage of the energy has to come from non fossil
sources. At this time, that is primarily wind
power, photovoltaic, biomass and water power.
A comparison of different heating concepts is shown in
Table 1. Exhaust gas losses, losses at the power plant and
standardized primary energy consumption and CO 2 emissions
are calculated for a heat input into a furnace at 1,000 °C. For
the case of natural gas heating without heat recovery, exhaust
gas losses (1,000 °C exhaust) represent about 50 % of the fuel
energy input. Accordingly, the standardized primary energy
consumption and CO 2 emissions are 2, twice as much as
in a lossless system. The next case shows figures when using
state of the art heat recovery systems. Typical combustion
air preheating temperatures are in a range of 500 °C and that
corresponds to cooling the exhaust gases from 1,000 to 600 °C.
That reduces the exhaust gas losses to about 30 % and the
standardized primary energy consumptions and CO 2 emissi-
EFFICIENT AND CLEAN HEATING
OF HIGH TEMPERATURE PROCES-
SES
Flameless oxidation was initially developed to
suppress thermal NO-formation when using
preheated combustion air. Flameless oxidation
is a stable combustion without the formation
of flames [2]. This is possible by a special recirculation
of hot combustion products. Intense
research and development made it possible,
to meet stringent emission limits even when
using highly preheated combustion air. Therefore,
minimizing exhaust gas losses is only
limited by economic constraints, namely the
cost for heat exchangers used for preheating
combustion air.
Table 1: Comparison of heating systems for industrial furnaces
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Fig. 1: Heat exchanger characteristics
ons to 1.4. When using optimized heat exchangers, exhaust
gas losses can be cut again in half to about 15 % leading to air
preheat temperatures of 850 °C and exhaust temperatures of
about 300 °C for these process temperatures. These numbers
can be realized using regenerative or special recuperative heat
exchangers. Standardized primary energy consumption and
CO 2 emissions are 1.2 and thereby close to loss-free systems.
Its often proposed to use oxygen or oxygen enriched air
instead of air for reducing exhaust gas losses. Actually, the
exhaust gas losses can be reduced by that measure, but
energy, required to produce the oxygen has to be considered.
With state of the art oxygen generators, more than
0.5 kW el of electricity are required for each cubic meter of
oxygen. Considering this, explain why using oxygen instead
of air is not really improving
the overall primary energy
consumption. Standardized
CO 2 emissions with
today’s power generation
methods is even unfavorable
compared to state of
the art natural gas heating.
In the future, when the
majority of electricity is
generated from renewable
resources or if new oxygen
generating technologies
are available, the situation
has to be reevaluated.
The highest numbers
regarding primary energy
efficiency and CO 2 emissions
are incurring for electric
heating even if loss-free
heating is assumed. In the coming decades, a considerable
part of electricity will be still generated from burning fossil
fuels. Electricity prices will remain high even when electricity
generating costs from wind and solar power will
decrease since costs for distribution networks and storage
will rise. Gas heating will remain the most efficient and
economical way to heat industrial furnaces. Electricity is
just too valuable for heating purposes.
COMBUSTION AIR PREHEAT
Combustion air preheat using central heat exchangers or
self recuperative burners can be considered state of the art.
To improve air preheat noteworthy and thereby lowering
the exhaust gas losses requires considerably improved
Fig. 2: Regenerative burner
Fig. 3: Gap flow burner
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heat exchangers. The heat exchanger performance can be
expressed using the characteristic number of transfer units
NTU [2]. Increasing the convective heat transfer is limited
due to pressure loss constrains. The main requirement is
to increase the heat exchanger surface area. As shown in
Fig. 1, the surface area must be increased multiple times
to get a substantial improvement in heat exchanger performance.
For higher burner capacities, this can be achieved
by using regenerators which are used in combination
with alternating operated burner pairs. For smaller burner
capacities up to 200 kW, the integration of the regenerators
and the burners, analogical to self recuperative burners is
favorable. The self regenerative burner, shown in Fig. 2
has even the switching valves, required for alternating flow
directions, integrated into the burner housing. For smaller
burner capacities, it is difficult to achieve an economic
advantage using the regenerative principle. An alternative
solution is a new type of burner, called gap flow burner
which is shown in Fig. 3. The commonly finned cast tube
or structured ceramic heat exchanger is replaced by a large
number of small diameter recuperators. This results in a
large heat exchanger surface area and high heat transfer
combined with low pressure drop. The flow configuration
in small channels is called gap flow. Compatible burner and
flange dimensions, compared to existing burner models
allows to use these burners for new furnaces and for retrofit
projects. The improved heat exchangers typically cut
exhaust gas losses in half, compared to state of the art heat
recovery and can reduce NO x emissions considerably by
using FLOX®-technology.
LOW TEMPERATURE PROCESSES AND
SPACE HEATING
The utilization of waste heat from thermal processes or
from power plants is often not economical because supply
and demand do not fit either by location and or time. This
problem could be overcome by local CHP (combined heat
and power) units. Bigger units could be operated in industry,
for example for drying processes or other continuously
operated processes.
Rising electricity cost will make it profitable to generate
its own electric power. Today, internal combustion
engines are used for medium sized CHP-units. A problem
for these units could be to meet stringent emission limits.
In the future, there will be also alternatives like micro gas
turbines, stirling engines and fuel cell systems. Using external
combustion allows the use of flameless oxidation as
a low emission combustion process. Depending on size
FLOX® inventors, recipients of the German Environmental Award for 2011.
2011. The innovation potential of WS recieves highest accolade. The development of this pivotal
low emissions combustion technology, entirely without flame, is honored with Europe’s
most prestigious prize for achievements contributing to the protection and conservation
of the environment, by the Deutsche Bundestiftung Umwelt (German Environment Foundation).
rekumat® s with gap flow heat exchanger.
innovative burner generation
WS Wärmeprozesstechnik GmbH · Dornierstrasse 14 · d-71272 Renningen / Germany
Phone: +49 (71 59) 16 32-0 · Fax: +49 (71 59) 27 38 · E-mail: ws@flox.com
WS Inc. 8301 West Erie Avenue · Lorain, OH 44053 / USA
1-2013 heat processing Phone +1 (440) 365 8029 · Fax +1 (440) 960 5454 · E-mail: wsinc@flox.com
53

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Burner & Combustion
Table 2: Costs for mobility and CO 2 emissions
and temperature level of the process a large number of
CHP-concepts will be available.
For domestic applications, smaller units with a power
of 1 to 5 kW el will be used. Falling prices for feeding
power into the electrical grid will make it useful to
generate power for own usage. The percentage of own
generated electricity can be increased by installation of
a battery storage unit. An additional benefit of such a
solution is the availability of emergency power in case of
a power outage. Such a system can be combined with a
photovoltaic system to compensate lower CHP-power
during summer month.
In this small power
range, fuel cell systems
are suitable which convert
one third of the
supplied fuel energy
to electric power and
two thirds to space heat
or warm water. At this
time, these units are
expensive but a considerable
cost decrease
is possible when producing
large numbers.
Flameless oxidation is
the ideal combustion
concept for the steam
reformer which is an
integral part of a fuel
cell unit.
LOCAL MOBILITY
An example should illustrate
how a combination of CHP and local mobility using
light electric vehicles can increase efficiency considerably
even when using fossil fuels as an energy source.
In Table 2 fuel costs in Euro per 100 km and CO 2 emissions
in grams per km are shown. Three types of vehicles
are compared. A compact car with a gasoline consumption
of 6 liter/100 km, a similar compact electric car and a light
electric car, the two lat ter ones designed for local traffic
and a range of about 100 km. Fueling is conventional at
a gas station, electricity from the grid or self generated
CHP-power. It can be seen that a switch to electrical mobi-
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Burner & Combustion
REPORTS
lity alone is not beneficial for the environment since CO 2
emissions remain almost unchanged. The corresponding
cost advantage comes only from different taxes for gasoline
and electric power. A clear difference in cost and CO 2 emissions
is possible when changing to light electric vehicles or
when combining electric mobility with CHP-units. Dramatic
reductions are possible when fueling light electric vehicles
with self generated CHP-power. New mobility concepts,
combining car-sharing and public transportation for long
range and light electric vehicles for local traffic are imaginable,
even improving quality of living and not harming the
individual freedom of mobility.
RENEWABLE ENERGY AND MODERN
POWER PLANTS
Flameless oxidation enables extremely low NO x -emissions.
An additional feature is the possibility of combustion of difficult
fuels [3]. That results in a direct and indirect reference
of flameless oxidation to renewable energy.
The direct relevance relates to combustion of biogas,
other non-conventional fuels and residual gases from
biomethan production. The indirect connection to renewables
comes from the discussion to use the natural
gas grid as a storage unit for excess electric power by
converting electricity to hydrogen. The change in the
fuel composition by adding a certain percentage of hydrogen
will be uncritical for most applications. Gas turbine
combustors which are operated with lean premixed
combustion to stay within NO x emission limits are very
sensitive regarding changes in the fuel gas composition.
Tests with flameless oxidation have demonstrated to
achieve extremely low NO x emissions and to be nonsensitive
to gas composition variations. The generation
of artificial methane using excess electric power and
CO 2 could be an alternative but at much higher cost, at
least from todays view.
There are also efforts to reduce emissions, increase
efficiency and allow a more flexible operation regarding
fuels and part loads in coal fired power plants. A european
funded research project FLOXCoal II (http://www.
floxcoal2.eu-projects.de) should deliver the basics for a
successful application of flameless oxidation in coal fired
power plants. Another field is the option to sequestrate
CO 2 from coal firing and to deposit it underground. One
of these technologies, known as CCS (carbon capture and
stroage), was examined in a large national research project
(www.oxycoal.de). In Germany, storage of CO 2 underground
is not very popular and therefore, research on this topic is
not too active.
CONCLUSION
So far, for most people the term “Energiewende” is a
synonym for generating renewable electric energy. Using
this costly generated electric energy for space and process
heating will put a large burden on our national
economy, whoever will pay for it. An intelligent usage
of chemical bound fossil and non-fossil fuels will allow
to reach the energy and climate goals and a benefit for
our national economy.
For high temperature processes, flameless oxidation
in combination with high performance heat exchangers
enables an substantial increase in efficiency and minimal
emissions.
Heating low temperature processes and generation of
space heat can be combined with electric power generation.
Flameless oxidation is a prefered combustion process
for fuel cell reformer, micro gas turbines, stirling engines
and other CHP-units.
Flameless oxidation is also part of the process for
biogas generation and utilization. If the natural gas grid
will be used for storing excess energy, the fuel flexible
flameless oxidation will ensure the safe operation of
combustion processes.
LITERATURE
[1] protocol in german: 117. Sitzung des Deutschen Bundestages
on Thursday, June 30, 2011
[2] Wünning J., Milani A., Handbook of Burner Technology for
Industrial Furnaces, Vulkan Verlag, 2008
[3] Schuster, A.; Berger, R.; Scheffknecht, G.: New Burner Technology
for Low Grade Biofuels to Supply Clean Energy for Processes
in Biorefineries, A. Schuster, R. Berger, G. Scheffknecht,
J.G. Wünning, M. Hiltunen, T. Eriksson, M. Schmid, C. Gaegauf,
Conference Biogas05, Paris, France
AUTHOR
Dr.-Ing. Joachim G. Wünning
WS Wärmeprozesstechnik GmbH
Renningen, Germany
Tel.: +49 (0)7159/ 1632-30
j.g.wuenning@flox.com
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Burner & Combustion
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New low NO x solution for
high-speed burners
by Sabine von Gersum, Martin Wicker
On the basis of the time-tested BIC series, Elster Kromschröder has developed the new low NO x solution, menox®. This
combines the low-cost, simply structured burner BIC..M with simple control technology allowing to switch between two
operating modes: a) traditional flame mode at low furnace temperatures and b) menox® low NO x mode with flameless
combustion at higher furnace temperatures. The new patented solution achieves NO x values below 150 mg/m³ (reference
value of 5 % O 2 ) at a furnace temperature of 1,200 °C without expensive additional piping.
High-speed burners combined with impulse control
create a perfect heating solution for many
industrial heat treatment processes. With On/Off
control, the burner discharge impulse always maintains
full momentum which results in heavy circulation of the
furnace. This in turn ensures a high level of temperature
uniformity on the material being heated. The NO x emissions
from a heating system with high-speed burners are
lower compared to other burner types since the high
discharge impulse also results in a reduction in NOx due
to the flue gas being drawn into the flame. However, the
fact that emissions regulations are growing ever more
stringent has led to the required NOx limit values not
being satisfied by conventional systems in every case
and this is particularly true for systems with combustion
air preheating systems.
The basic requirement for all industrial burners is that they
function perfectly in a wide range of temperatures, beginning
with a cold start, i.e. operation with cold air in a cold furnace,
to operation with preheated combustion air at high operating
temperatures. Low temperatures encourage the formation of
CO and the presence of non-combusted fuel components
in the flue gas. High furnace chamber temperatures and air
preheating to high temperatures result in increased NO x
formation as a result of the high flame temperatures involved.
Despite these contradictory effects, the requirement is
nevertheless for minimum emissions of both CO and NO x .
One solution implemented over the last few years is to use
the burner in two fundamentally different operating modes
[1-4]. One operating mode has been improved to ensure low
CO combustion during the heating process while the other
ensures low NO x combustion at high temperatures. This is
achieved by using burners with two separate flow routes for
gas or air. The furnace operating temperature determines which
route is to be used. The appropriate operating mode is chosen
by selecting or disabling the relevant gas or air supply upstream
of the burner. For changing the gas supply, for example, one
gas valve is closed and another is opened. The solutions which
feature a switching of flow routes involve relatively high costs
because burner construction is generally complex and dual
pipelines as well as control elements are required.
NEW LOW NO X SOLUTION
The new low NO x solution menox® combines a lowcost,
simply structured burner BIC..M with simple control
technology allowing to switch between two operating
modes: traditional flame mode at low furnace temperatures
and menox® low NOx mode with flameless combustion at
higher furnace temperatures.
A patent has been awarded in Europe for the process
which allows low NO x emissions to be produced considerably
below the current limit values [5].
The structural design of the menox® burner BIC..M is similar
to the established high-speed burners in the BIC series (Fig. 1).
Although two operating modes are possible depending on
the combustion chamber temperatures, there is only one
connection for combustion gas and one for combustion air.
Within the burner, too, there is just one flow route for gas and
one for air. The ceramic combustion chamber with a reduced
outlet diameter features the typical (bottle) form used in highspeed
burners. It is installed in the furnace such that the outlet
plane is flush with the furnace wall.
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Fig. 1: High-speed burner BIC
FLAME MODE FOR HEATING
In order to heat up the furnace, the burner operates in
traditional flame mode as long as the furnace temperature
is low. The ignitable gas/air mixture is ignited using an
electrical ignition spark and combusts inside and outside
of the ceramic combustion chamber (Fig. 2). An ionization
electrode monitors the presence of the flame as required by
European Standard EN 746-2 for low temperature equipment
[6]. The hot flue gas leaves the combustion chamber at a
speed of over 120 m/s. The typical blue flame is longitudinal
and quite sharply concentrated with a spatially clearly
defined contour of the reaction zone (Fig. 3). The high
intensity of the combustion reaction at the centre of the
flame, identifiable by the red colour in the photograph taken
using a UV-sensitive camera, ensures that the combustion
produces low levels of CO. At a furnace temperature of just
Fig. 2: menox® burner BIC..M in flame mode
450 °C, CO values of as low as around 500 ppm for burner
operation with cold combustion air have been measured.
As the furnace temperature rises, these values fall rapidly to
50 ppm at 600 °C and they thus lie within the same range
as standard high-speed burners of type BIC..HB.
LOW NO X MODE
With preheated combustion air, switchover to the menox®
low NO x mode takes place when the combustion chamber
temperature exceeds 800 °C. The burner is switched off
and restarted in the new operating mode. In menox®
mode, the gas valve and air control valve are opened
without triggering the electrical ignition spark. Although
gas and air are supplied via the same connections as
in flame mode, the mixture is no longer ignited inside
the combustion chamber, but the chemical combustion
reaction takes place in the furnace as shown in schematic
form in Fig. 4.
In menox® mode, the oxidation reactions take place
without a visible flame, which means that only the
background radiation of the hot furnace wall can be
seen. The picture of the OH radiation in Fig. 5 shows
that the reaction zone is considerably larger compared
to traditional flame mode. The reaction density is
considerably lower and the peak temperatures responsible
for high NO x values are prevented, ensuring that NO x
emissions are drastically reduced.
A comparison of the NO x values for a BIC burner in
traditional flame mode and for menox® burners BIC..M is
shown in Fig. 6. The blue area shows the considerably
reduced NO x values achieved by menox® while the upper
line is based on measurement values from burner model
BIC 140MB at 360 kW and the bottom line shows the NO x
measurement values from a BIC 65MB for 35 kW. When the
furnace temperature is 1,000 °C, an NO x value of less than
50 mg/m³ (reference value of 5 % O 2 ) can be achieved. At
a higher furnace temperature of 1,200 °C, an NO x value of
150 mg can be achieved. The NO x emissions from smaller
burner sizes are even lower, with the NO x measurement
values for a BIC 65MB being recorded at less than 65 mg/
m³ (reference value of 5 % O 2 ) at a furnace temperature
of 1,250 °C.
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BURNERS BIC..M
The main novelty about menox®
is the fact that the combustion air
and gas are supplied via the same
connections in both operating
modes. In menox® mode, however,
the inflammable mixture of
gas and air must be prevented
from igniting prematurely in the
ceramic combustion chamber
each time the burner is switched
on. The combustion reaction can only be transferred to
the furnace if the ignition conditions (temperature and
concentration limits) are not satisfied inside the ceramic
combustion chamber. If the local gas concentration is
inside the ignition limits, the temperature must be below
the ignition temperature and if the ignition temperature is
locally exceeded, there must not be an ignitable mixture in
the combustion chamber.
As with all nozzle-mixing burners, the defined local mixing
of gas and air in the menox® burner BIC..M takes place in the
“burner head” mixing unit. The process of mixing the gas and
air in the burner head is shown in Fig. 7 for a conventional
BIC burner [7]. A new mixing unit (patent pending [8]) has
been developed for the menox® burner BIC..M. The special
geometry of the menox® design ensures both reliable ignition
and a stable flame while also making sure that the combustion
process is transferred to the furnace chamber.
a) Photograph b) OH radiation
Fig. 3: Flame pattern of the high-speed burner BIC
In addition, the flow velocity at the burner nozzle must be
adequately high to prevent flashback into the combustion
chamber when operating in menox® mode. The burners
BIC..M are therefore combined with the tapered ceramic
tubes TSC..B tailored to the specific rating for menox®.
SYSTEM STRUCTURE
The system structure for menox® is shown in Fig. 8. The
burners is switched on and off in cycles, whereby only an air
valve and a gas valve with damping unit are required for this
intermittent burner operating mode. The second gas valve
is specified for every burner in European Standard EN 746-2.
The control system required for safe burner operation takes
the form of a specially designed burner control unit BCU. This
coordinates the signals for starting the burner and the fail-safe
monitoring of the burner in flame mode. In menox® mode, the
ignition device and flame control system are disabled using a
Fig. 4: menox® burner BIC..M in low NO x mode
Fig. 5: OH photograph in menox® low NO x mode
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NO x (mg/m 3 ref. 5% O2)
350
300
250
200
150
100
Natural gas, air preheating to 450°C
Flame mode
BIC 140HB
50
BIC 65MB
0
850 900 950 1000 1050 1100 1150 1200 1250
Furnace temperature (°C)
BIC 140MB
digital signal. The fail-safe evaluation of the furnace temperature
by means of a safety temperature monitor is required for this
purpose. Alternatively, an Elster Kromschröder control cabinet
can provide all the required control and monitoring functions
for more complex requirements.
The burners BIC..M and ceramic tubes TSC for menox®
are available for six ratings of 35 kW, 75 kW, 110 kW, 180 kW,
260 kW and 360 kW for flame mode using natural gas. In
menox® mode, the burner capacity increases by up to 15 %.
menox® mode is possible with cold air and with combustion
air preheated to a temperature of up to 450 °C. In the event
that the combustion air is heated, the customer must provide
an air pressure booster for hot air compensation and an air/
gas ratio monitoring system.
Fig. 6: NO x emissions for menox®
LITERATURE
[1] Wünning, J.A.; Wünning, J.G.: Brenner für die flammlose
Oxidation auch bei höchster Luftvorwärmung. Gas Wärme
International 41 (1992), Volume 10, pp. 438 – 444
Air
[2] Wünning, J.G.; Milani, A.: Handbuch der Brennertechnik für
Industrieöfen, Vulkan-Verlag, Essen, 2007
[3] TriOx Triple Air Staged Ultra Low NO x Burner, product
brochure, Hauck Manufacturing Company, Lebanon, PA
17042, USA
[4] E-Jet Ultra Low Hot/Cold Air Burner, product information,
Hotwork Combustion Technology Ltd, United Kingdom
Gas
Fig. 7: Flow lines of the "burner head" mixing unit in
a conventional BIC burner
[5] Patent document EP 1893915B1
[6] EN 746-2:2010, Industrial thermoprocessing equipment – Part
2: Safety requirements for combustion and fuel handling
systems
[7] Giese, A.: Untersuchung der Auswirkungen von Gasbeschaffenheitsänderungen
auf industrielle und gewerbliche
Anwendungen, DVGW reference G/1/06/10, Intermediate
report, Freiberg, 19.06.2012
[8] Patent document EP 2442026A1
BCU
AKT
BZA
VAS
M
VAS..L
EKO
BIC..M
AUTHORS
Dr.-Ing. Sabine von Gersum
Elster GmbH
Lotte (Büren), Germany
Tel.: +49 (0)541/ 1214-374
sabine.gersum@elster.com
IC 40 +BVH
Fig. 8: System structure for menox®
EKO
Dipl.-Ing. Martin Wicker
Elster GmbH
Lotte (Büren), Germany
Tel.: +49 (0)541/ 1214-624
martin.wicker@elster.com
60 heat processing 1-2013

Induction Technology
REPORTS
Inductive supported coating
by Ralf Winkelmann, Arne Röttger, Christian Krause
The aim of this work was to develop an innovative and economic protective surface layer as wear-resistant coating of
low-alloy mild steel. In order to reduce the manufacturing costs, a new coating process (InduClad = Induction Cladding)
was developed. In order to additionally reduce the material costs, we successfully used inexpensive Fe-based hard alloys.
These new alloys exceed the hardness of conventional Ni-based and Co-based hard alloys applied in deposition welding.
This work aims at armouring low-alloy structural steel
substrates with wear protection layers in an economic
way. In order to reduce the production costs, an innovative
coating process (InduClad = Induction Cladding) was
developed. Economic Fe-based hard alloys were applied to
reduce the production costs also regarding the materials
used. In addition to the cost advantage, Fe-based hard alloys
have a martensitic structure with finely dispersed enclosed
hard phases in case of a suitable chemical composition and
therefore exceed the hardness of conventional Ni-based
and Co-based hard alloys used for deposition welding. If
abrasive wear represents the dominant wear mechanism,
hard composite materials (MMC = metal matrix composite)
have been established as armouring layers. These materials
consist of a metallic binder matrix with enclosed hard
materials. Conventionally, the more expensive hard material
fused tungsten carbide is used. In the second step the aim
was to substitute the fused tungsten carbide by the more
economical alternative Al 2 O 3 -ZrO 2 (AlZrO). In order to be able
to embed this ionic bonded material into the steel matrix in
a firmly bonded way during the compression process, the
surface of the hard material had to be treated metallurgically.
This was achieved by depositing a reactive interlayer onto the
hard material particles via PVD. We were able to demonstrate
that this deposited interlayer embeds the ionic bonded hard
material AlZrO into the metal matrix in a firmly bonded way.
The firm inclusion of the hard materials into the metal matrix
prevents that the hard materials break out prematurely so that
only in this way the full wear protection potential of the hard
material is tapped. By means of practical tests it was possible
to confirm the wear properties of the MMC armouring layers
produced via InduClad, which were positively determined
under laboratory conditions.
STATE OF THE ART
Corrosion and wear annually burden highly developed
industrial countries with approximately 5 % of the gross
domestic product [1]. In Germany, only friction and wear
with their consequences regarding necessary maintenance
measures and loss of production occasion costs of approximately
35 billion Euros per year [2].
In general, friction is referred to as the cause of wear.
According to definition [3], wear of solid bodies is the permanent
change in material or shape of the near-surface
areas of solid bodies produced by friction. If it is not possible
to reduce friction as the cause of wear, wear protection
measures like deposition welding can help to make
processes economic. Flux-cored welding or plasma powder
deposition welding are established technologies to
produce wear-resistant layers. A basic problem of fusion
welding techniques is the limited possibility to control the
energy input. The energy input is significant concerning
the following aspects:
1. dilution with the basis material (5...40 %),
2. thickness of the basis material (d > 4 (2) mm)) as well as
component deformation and
3. destruction of thermosensitive hard materials as well as
of properties of the basis material.
In addition to the technological restrictions of conventional
methods, there are also alloy-dependent constraints.
Basically we can distinguish three types of coating.
1. coatings which form hard phases from the molten mass,
2. coatings into which the hard materials are embedded,
as well as
3. coatings with embedded hard materials and evolving
hard phases.
Hard phases are monocarbides like VC, NbC, borides or
silicides, but also mixed carbides, with M 7 C 3 occupying a
special position. These alloys are usually very inexpensive.
Mainly Fe-Cr-C-xxx alloys are welded.
In wear protection technology by means of deposition
welding, tungsten carbides (WC/W 2 C) are primarily used.
In order to put these hard materials with a limited resistance
to heat into the coating without fusing, there are
two technological possibilities:
1. use of low-melting matrix materials and
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61

Induction Technology
REPORTS
a heat flow before the inductor
stringently required for the process
was not adjustable. The
inductor itself (Fig. 1) has one
loop. The energy concentration
in the middle of the junction
is not required for the process.
The generator provides alternating
current. It flows through
the inductor and generates a
magnetic field. According to
the 1 st Maxwell equation, this
results in a current flow in the
material to be coated (electrical
conductivity provided). Within
the component a magnetic field
is generated too, and the time
displacement of that field leads
to eddy currents. Pursuant to the
2 nd Maxwell equation, they surround
the magnetic field lines in
a ring-shaped manner. The eddy
currents and the primary current
interfere.
Covering the heated area by
Ar or N 2 makes sense in order to
avoid reactions with the atmosphere.
The application of the protective
gas shielding illustrated in
figure 1 proved to be sufficient.
The system used for this investigation
is shown in Fig. 2. It consists of a 60-kW HF generator
and a single-loop inductor which is fixed to an x-y-z
drive unit. The inductor is moved across the component
to be coated.
The generator used for this investigation is coupled to a
PLC. Power control is provided by measuring the temperature
using a calibrated pyrometer. Fig. 3 depicts a measurement
as T-P-t curve as well as the calculated energy. On
this basis, coatings can be manufactured in a reproducible
way. The coating speed is variable.
Fig. 2: Experimental set-up
The coating parameters are suitable if:
1. there is a diffusion zone between coating and basis
material,
2. the coating material has completely been molten, and
3. there is a bonding between hard materials and matrix.
INDUCLAD MATERIALS
The matrix X200CrNiBMo10-4-3 (Table 1) has proven to
be advantageous. The high boron content results in a
low solidus temperature. This allows for applying a lower
energy or heat input, respectively, which diminishes the
Fig. 3: left: T; P = f(t); right: E calculated for 750 s
heat input into the substrate and reduces thermal stress.
The increased boron content stabilizes the carboborides
of the type M 23 (C,B)6 and M 3 (C,B), which primarily
solidify from the molten mass. At the same time, the
increased Cr content facilitates the precipitation of carbides
and borides rich in chromium of the type M 7 C 3 ,
M 2 B, and M 2 B 3 . In addition to these hard phases, the
carboboride rich in iron of the type M 3 (C,B) could be
determined radiographically, with M 3 (C,B) primarily or
eutectic solidifying from the remaining molten mass. The
element Mo has essential influence on the volumetric
content of the hard materials. On the one hand, Mo is
able to substitute metallic elements like Cr and Fe in the
hard phases, like M 7 C 3 , on the other hand, Mo and Fe
form hard phases of the type M 3 B 2 with B. Si increases the
carbon activity and thus facilitates the primary solidification
of the carbide rich in chromium of the type M 7 C 3 .
Table 2 lists the hard materials used. In order to achieve
a safe embedding of ionically or highly covalently
joined hard materials, like AlZrO, into the metallic matrix,
it is beneficial to work with interlayers. These are thin
layers which react both with the ceramics and the matrix.
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Induction Technology
Table 1: Chemical composition
Material C B Cr Mo Ni V Fe Vol.-% HP TSOL
X200CrNiBMo10-4-3 2.1 3.5 10.0 3.5 4.0 --- bal. ~ 75 1,080 °C
Table 2: Physical and mechanical properties of the hard materials used ([6], [7], [8])
Hard material
Crystal
structure
Hardness
[HV0,05]
ρ [kg/dm³]
αth
[10-6 K-1]
E module
[GPa]
KiC
[MPam-1/2]
Costs ) [EUR/
kg]
AlZrO
Al 2 O 3 /ZrO 2
Cubic/
hexagonal
1,400-2,000 5.5 9 220-360 >7 7.5
FTC
(WC/W 2 C)
hexagonal 2260 16 --- 430 6-7 41
RESULTS - EXAMPLES OF APPLICATION
Fig. 4 illustrates the flawless bonding between the wear
protection layer and the mild steel substrate S235JR.
An approximately 100 to 150 µm wide perlite zone is
noticeable in the basis material. Due to the strong diffusion
reaction at the boundary, the wear protection
layer simultaneously became depleted in C, producing a
change in the hard phase morphology near the boundary.
Micro hardness curves along the boundary of the
bonding sample confirm the structural change observed
by means of light microscopy and scanning electron
microscopy. It was possible to determine a micro hardness
of 160 HV0.05 in the unaffected substrate (approx.
200 µm away from the boundary), rising to a hardness
value of 350 HV0.05 due to the perlite formation near
the boundary.
In order to increase the abrasive wear resistance, MMC
wear protection layers were produced using InduClad.
Fig. 4: Boundary between substrate and wear
protection layer applied by means of InduClad
Fig. 5 illustrates the Fe-based MMC wear protection layers
produced by adding the coated hard material AlZrO. It is a
bonding supported by diffusion between the hard material
and the interlayer as well as between the interlayer and
the metal matrix.
The layers produced were examined tribologically in
the laboratory. Especially under the conditions of abrasive
sliding wear, embedded hard materials result in clearly
lower wear rates compared to those registered during
the examination of samples of pure matrix.
On the basis of these laboratory results, several practical
tests were conducted. Amongst other things, grinds
and ploughshares were coated with a 10 wt.% AlZrOreinforced
matrix made of X200CrNiBMo10-4-3 and compared
to other armoured and unarmoured ones. A clearly
reduced erosion of the grinds and ploughshares could
be registered. Fig. 6 underlines the results.
CONCLUSION
A new process to produce coatings
has been developed. The following
advantages are proven:
The fusing performance is similar to
that achieved by flux-cored welding.
The dilution between layer and
basis material is below 2 % and
thus clearly below the values previously
achieved using welding
techniques.
The energy can be adjusted in a
defined way. Therefore thin components
(10 mm).
The generator is controlled using pyrometers. It is possible
to manufacture reproducible layers.
64 heat processing 1-2013

Induction Technology
REPORTS
Fig. 5: MMC, by means of InduClad
Fig. 6: Ploughshares
Hard materials with a low density can be processed. They
cannot be processed using conventional welding techniques
as they float. This results in a new generation of coatings.
The combination of InduClad and interlayers applied to
ionic or highly covalently bonded hard materials serves
to realize an excellent embedding into metallic matrices.
The structure of the MMC layers very rich in hard materials
features low porosity, low crack density in the matrix and in
the hard materials, good hard material bonding to the steel
matrix, as well as a homogenous hard material distribution.
The laboratory results could be confirmed in the practical test.
It is possible to produce completely new material combinations
using InduClad.
[6] Kieffer, R.; Benesovsky, F.: Hartstoffe. Springer-Verlag, Berlin,
1963
[7] Friedrich, C.; Berg, G.; Broszeit, E.; Berger, C.: Datensammlung
zu Hartstoffeigenschaften, Materialwissemschaft und Werkstofftechnik
28, 1997, p. 59-76
[8] Holleck, H.: Binäre und ternäre Carbid- und Nitridsysteme der
Übergangsmetalle, Borntraeger Verlag,Stuttgart, 1984
AUTHORS
LITERATURE
[1] Jost, H. P.: Lubrication (Tribology) – A Report of the Present
Position and Industry’s Nedds, Departmant of Education and
Science. HM Stationary Office, London, 1966
[2] www.gft-ev.de (Stand 21.10.2012)
[3] Fleischer, G.; Wamser, H.: Terminologie Reibung und Verschleiß.
Schmierungstechnik 3, 1972, p. 7-12
[4] Theisen, W. u. a.: Auftragschweißen von Wolframkarbid in Fe-
Basis-Legierungen, 7. Fachtagung „Verschleißschutz von Bauteilen
durch Auftragschweißen“, Halle, 2008
[5] Benkowsky, G.: Induktionserwärmung. Verlag Technik, Berlin,
1990
Prof. Dr.-Ing. Ralf Winkelmann
Hochschule Lausitz (FH)
Fertigungstechnik/Tribologie
Lausitz, Germany
Tel.: +49 (0)3573/ 85-426
ralf.winkelmann@hs-lausitz.de
Dr.-Ing. Arne Röttger
Ruhr-Universität Bochum
Lehrstuhl Werkstofftechnik
Lausitz, Germany
Tel.: +49 (0)234/ 32-22366
roettger@wtech.rub.de
Dr.-Ing. Christian Krause
eldec Schwenk Induction GmbH
Dornstetten, Germany
Tel.: +49 (0)7443/ 9649-73
christian.krause@eldec.de
1-2013 heat processing
65

Handbook of
Aluminium recycling
www.vulkan-verlag.de
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fundamentals | Mechanical Preparation
Metallurgical Processing | Plant design
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PAHBAr2013

Induction Technology
REPORTS
Energy-efficient power supply
for induction hardening and
heating processes
by Edmund Zok, Dirk M. Schibisch
Induction heating is an established, highly energy-efficient industrial process. The traditional areas of application include,
among other things, induction hardening, forge heating, tube welding and annealing as well as the heating and
quenching followed by tempering of steel bars or tubes. More and more new applications are being added, as the
shortage of fossil fuels means that heating processes are being increasingly switched from oil or gas to electroheat. This
does not always mean that conventional furnaces should not be used, rather both combustion furnaces and induction
technology can be used intelligently side by side.
With induction heating the energy is transferred
from the inductor into the product to be
heated (workpiece). The inductor’s most basic
design is that of a cylindrical coil, however it can have
a variety of forms, depending on the application. If the
inductor is connected to an AC supply, an electromagnetic
alternating field is created around it. This field
generates an alternating voltage within the electrically
conductive material, resulting in so-called eddy-currents
in the near-surface area of the workpiece. Heat is generated
in the workpiece due to the electrical resistance of
the material. Heat conduction causes the temperature
of the workpiece to homogenize from the outside in
over a period of time.
The power supply for induction heating has to meet various
requirements. If one looks at the typical applications from
the point of view of the power and frequencies required only,
it becomes apparent that both the power range and frequency
range cover three to four logarithmic orders of magnitude.
Fig. 1 shows several widely used applications of induction
electroheat in the frequency-power diagram. The bordered
area shows the key areas of application. There are numerous
other applications shown outside the area marked.
It is clear that different power supplies are required for
the variety of applications. The difference is not just in
the electrical data of the equipment itself, but primarily
in the circuit topology.
Nevertheless, there are common features with almost
all types of power supplies used, and these can be attributed
to the physical properties of the inductor-workpiece
arrangement.
PHYSICAL PROPERTIES OF THE INDUC-
TOR-WORKPIECE ARRANGEMENT
The inductor-workpiece arrangement roughly corresponds
to a transformer with shorted secondary winding. In the
simplified equivalent circuit diagram it can be roughly
seen as the parallel or series connection of an equivalent
resistance and inductance. For a more detailed analysis
the parallel connection of the components is chosen, as
shown in Fig. 2.
It is theoretically possible to connect the inductor with the
workpiece directly to an AC power supply. This can be done
provided the frequency of the voltage source can be adjusted
to the requirements of the process. For most practical requirements
it can be seen that the inductor’s reactive current I L ,
which lags the feeding voltage by 90°, will be several times
greater (by a factor of 3 to 10) than the active current I R , which
is in phase with the voltage. This is shown in the right-hand
section of Fig. 2 as a vector diagram.
Only the active current I R causes the workpiece to heat
up. It is true that the inductor’s reactive current I L is absolutely
essential for building the magnetic alternating field,
however it does not contribute to the energy expended in
the workpiece. Since the power source and the transmission
paths are subject to extreme loads due to its intensity,
it may be potentially unfavourable for the energy balance
to connect the inductor directly to the power source. The
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67

​
REPORTS
Induction Technology
Converter for induction heating
Fig. 2: Equivalent circuit diagram and vector diagram
of the inductor-workpiece arrangement
Fig. 1: Power and frequency range of the power supply for induction electroheat
Fig. 3: Parallel resonant circuit and its vector diagram
power source and the transmission paths would have to
be multiply over dimensioned to cover the reactive current
requirements.
ADVANTAGES OF A RESONANT LOAD
The reactive power of the inductor does not necessarily
have to be supplied by the power source, it can also be
generated within the load. A simple load configuration,
which has been tried and tested for years now and allows
this approach, is the so-called oscillating circuit. An oscillating
circuit is created when a capacitor is connected in
parallel or in series to the inductor. For the sake of simplicity,
this study deals only with a parallel resonant circuit (Fig. 3) a
series resonant circuit behaves similar to the parallel resonant
circuit.
The capacitor current I C leads the alternating voltage U
at the capacitor by 90°. It is also a reactive current, however
its phase is displaced by 180° with respect to the phase of
the inductor reactive current I L . The amounts of both reactive
currents depend on the frequency. However, while the
capacitor reactive current rises as the frequency increases,
the inductor reactive current is reduced with an increase in
the frequency. For the arrangement shown in Figure 3 there
is exactly one frequency at which the absolute values of
both reactive currents are identical, as shown in the vector
diagram in Fig. 3 on the right-hand side. This frequency is
called resonant frequency.
Since the phases of both reactive currents are in opposition,
in the case of resonance the inductor reactive current
is fully compensated by the capacitor reactive current.
The external power source only has to supply the active
current I = I R , it is not loaded with any reactive power.
The advantageous behaviour of the oscillating resonant
circuit described has resulted in it becoming the established
method in almost all induction heating applications.
Several characteristic variables for the parallel resonant
circuit are shown below [1].
​ω​ 0
​ = ​ ______ 1
​√ ​ Natural angular frequency (1)
L · C δ = ​_____
R
Damping (2)
2L · ​​ ​ω​0
​ω​ e
​ = ​ω​0 ​· ​ √ _____
1 − ​δ​ 2 ​ ​ Resonant angular frequency (3)
With induction heating the resonant frequency changes
during the heating process. The eddy-current intensity
induced in the workpiece decreases from the surface of
the material to the interior. The penetration depth [2] is the
distance δ from the surface, at which the current density
has dropped to a 1/e-fold amount of the surface current
density. It depends on the frequency as well as on the
specific electrical conductivity and magnetic permeability
of the workpiece material.
_____
δ = ​ √
______ 1
ω · κ · μ ​ ​ (4)
δ = Penetration depth
κ = Specific electrical conductivity of the material
μ = Magnetic permeability of the material
ω = Induced angular frequency
Since the material parameters change with the
temperature and field intensity, the inductance of the
inductor-workpiece arrangement and therefore both,
68 heat processing 1-2013

Induction Technology
REPORTS
the resonant frequency and oscillating circuit damping
also change. This change in the resonant frequency
needs to be picked up and evaluated by the power
source, in order that the operating frequency of the
power source must continuously track the resonant
frequency of the resonant load.
Fig. 4 shows the frequency characteristic [1] of a parallel
resonant circuit. The top section shows the magnitude
of the impedance, and the bottom section shows the
phase response of the complex impedance as a function
of the frequency. The maximum magnitude of impedance,
as well as a 0° phase shift between the voltage
and current at the resonant frequency are characteristic
of the parallel resonant circuit.
RESONANT CONVERTERS
For induction heating various types of frequency converters
were developed over time which convert the mains
current into alternating current with the parameters suitable
for the respective process. Most are resonant converters.
Resonant converters (Fig. 5) belong to a class of frequency
converters used for supplying power to a resonant
load. Most resonant converters are indirect (dc link) converters,
whereby the front-end rectifier and the back-end
inverter are connected by either an inductive or capacitive
energy buffer (dc link). With all resonant converters the
reactive power requirements of the inductor can be supplied
locally from the capacitors of the oscillating circuit.
The most universal converters in this class are the parallel
and series resonant converters. However, more complex
systems are also used, such as the L-LC topology for
example. PWM converters may also be used in conjunction
with a resonant circuit. A direct converter can also be used
for feeding an oscillating circuit.
In general, the more complex converters
cannot be used as universally as the simple
parallel or series resonant converters. Their limitations
are mostly attributable to a restricted
frequency range at a given converter configuration.
Broadband applications are not possible
with these types of converters or are difficult
to implement.
Fig. 4: Frequency characteristics of a parallel resonant circuit
Reverse-blocking switches are required in the inverter
of a parallel resonant converter. For this reason, fast diodes
with soft recovery characteristics are connected in series
with the IGBTs or MOSFETs. A thyristor is naturally reverseblocking.
Hence, a parallel resonant converter with thyristor
inverter was therefore easy to design.
Due to the inductive dc link, a parallel resonant converter
has the characteristics of a power source. Its output
current almost has a rectangular wave form, the voltage
generated at the resonant load is sinusoidal. Fig. 7 shows
the typical wave form of the output current and voltage
of a parallel resonant converter.
The switching frequency of a parallel resonant inverter
is derived from the resonant frequency of the load and
must be quickly re-adjusted in the event of changes
in the load. Power control is usually performed by the
fully-controlled rectifier. The line-side power factor of
the converter depends on its output voltage and incre-
PARALLEL RESONANT CONVER-
TERS
The parallel resonant converter is an indirect
converter, assembled from a fully controlled,
line-commutated rectifier, a current dc link
and a load-controlled, self or load-commutated
inverter. A parallel-compensated inductor is
connected to the output of the inverter. Fig. 6
shows a parallel resonant converter with an
IGBT inverter.
Fig. 5: Resonant converters for induction heating
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REPORTS
Induction Technology
Fig. 6: Parallel resonant converter with IGBT inverter
Fig. 7: Voltage and current of a parallel resonant converter
Fig. 8: Parallel resonant converter 800kW, 450V, 200kHz, MOSFET inverter
(source: SMS Elotherm)
asingly diminishes within the partial load range.
For a long time the parallel resonant converter
was the preferred system for induction heating
of material. When using thyristors a sophisticated
extinction-angle control system enabled the maximum
power level to be attained. Power components
with switch-off capabilities, such as MOSFET transistors
or IGBTs for example (Fig. 8) enable operation
both at the resonance frequency and with a slightly
capacitive or inductive phase shift at the inverter
output [2].
Parallel resonant converters can be used within
a very wide frequency range, achieving a high level
of operating efficiency with dynamically optimized
commutation control [3]. The circuit is robust and
short-circuits on the inductor can be easily managed.
As a rule, no output transformer is required. It is only
in the case of very short inductors, for example those
often used for induction hardening, that a transformer
is needed directly in front of the inductor to match
its impedance to the converter output impedance. A
poor power factor within the partial load range is one
disadvantage of the parallel resonant converter.
SERIES RESONANT CONVERTERS
The inductor coil L L can also be connected with
the capacitor C L to a series resonant circuit, which
may be used as a series resonant converter load
(Fig. 9).
The series resonant converter is a voltage fed
converter. Its inverter is load controlled and it may be
operated either self-commutated or load-commutated.
The power may be controlled by the frequency
of the inverter, modulation of the inverter control
pulses or a change in the dc link voltage.
Series resonant converters are also available for
a wide frequency and power range (Fig. 10). Since
high voltages can be attained relatively simply
with the aid of series resonant circuits, they are
ideally suited for high-power melting furnaces
and generally wherever a high inductor voltage is
required. In the case of both smaller inductor voltages
and short inductors, an output transformer
must also be used.
Series resonant converters boast a high degree
of operating efficiency, as only a few components
are needed to set up a transistorized inverter, and
the switching losses in the load-commutated
inverter can be effectively reduced through optimized
commutation [5]. If power control is done
by the inverter’s control system, an uncontrolled
rectifier may be used. In this way good power factor
can be achieved under all operating conditions.
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Induction Technology
REPORTS
CONVERTERS WITH L-LC LOADS
The development of power electronics is largely driven by
converter technology for electrical drive systems. These converters
generally have an uncontrolled rectifier, a voltage link
and an IGBT inverter. The uncontrolled rectifier has a better
power factor than the controlled rectifier, whose power factor
changes with its control angle. Therefore, topologies with an
uncontrolled rectifier are the preferred system also in terms
of resonant converters.
An uncontrolled rectifier and a voltage link are part of the
basic circuit of a series resonant converter. Since, however,
a parallel resonant circuit is preferred over a series resonant
circuit, solutions had to be found which made it possible to
feed the parallel resonant circuit from the voltage fed converter.
This cannot be done directly. The task could be solved,
however, by adding a coupling inductor L S at the output of
the inverter (Fig. 11). This topology is often referred to in
technical literature as an L-LC circuit. The disadvantages of this
converter type is that the system is far more complex and,
more importantly, the useful frequency range is considerably
limited. This is because the L S value has to be designed tightly
for the operating frequency of the converter.
The L-LC circuit features two points of resonance (Fig. 12):
one with parallel and one with series resonance. Depending
on the desired circuit properties and application, both may
be used. To control the inverter, special algorithms have to be
used to find the desired point of resonance (parallel or serial)
and clearly establish the working point. Despite the L-LC circuit
has the advantage that both the frequency and power can
be controlled via the inverter. This technology has become
very widely used in recent years, although an L-LC converter
can only be used within a limited frequency range. There
are many applications for which a small operating frequency
range is sufficient.
CONVERTER WITH PWM INVERTER
In a voltage fed converter as shown in Fig. 11, the inverter
can be controlled according to various algorithms. The
Fig. 9: Series resonant converter with IGBT inverter
Fig. 11: Converter with L-LC load
IGBTs do not necessarily have to be switched once every
load voltage period, as with the L-LC converter. Therefore,
in the case of very low operating frequencies, for example
below 200 Hz, it may be beneficial to control the inverter
with a sine-weighted pulse pattern (Fig. 13), whereby
the modulation frequency is the same as the resonant
frequency of the parallel resonant circuit.
Fig. 10: Series resonant converter 2,400 kW, 800 V, 150 kHz, IGBT inverter (source: SMS Elotherm)
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Fig. 12: Frequency characteristics of an L-LC oscillating circuit
Fig. 13: Converter with PWM inverter; top: output voltage and current; bottom: load voltage
Under this condition the output current of the inverter
is in phase with the fundamental component of the
output voltage and hardly subjects the inverter to reactive
power. The load voltage is sinusoidal, just like the
inductor current. The control method described means
that applications with operating frequencies up to 200 Hz
can be used.
CONVERTER WITHOUT RESONANT CIR-
CUIT (DIRECT CONVERTER)
A voltage dc link converter with a PWM inverter can also
feed the inductor directly (Fig. 14). Since no resonant circuit
and no resonant load exist, the output frequency of
the converter can be freely modified during operation.
This may be advantageous for certain applications [6]. The
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Fig. 14: Direct converter without resonant circuit
Fig. 15: PWM voltage control of a converter without resonant circuit
output power of the direct converter can be controlled by
changing the width of the inverter pulses (Fig. 15).
This circuit, however, has one serious disadvantage; the
entire inductor current, including the full proportion of reactive
current, flows through the inverter and the connecting
cables between the inductor and the inverter. See also the
explanations given in Chapter 2 et seq. in this article.
With this type of topology the inverter has to be
heavily over dimensioned. Since the losses in the connecting
cables show a square-law increase with the
current, the efficiency of the system decreases overall,
compared to resonant converters with the same level
of power. Only the need to continuously change the
operating frequency during the heating process may
justify the use of this circuit.
CONCLUSION
Looking to the future, resonant converters will continue to
maintain their position as highly efficient standard power
supply systems for induction heating applications. Parallel
and series resonant converters will still be used as universal
systems. Modern power semiconductors as well as optimized
control algorithms will result in a further reduction
in frequency-dependent switching losses in the inverter.
This means the maximum operating frequencies of such
converters can be further increased.
New converter topologies, such as the voltage link converter
with an L-LC resonant load, have gained considerably
in importance, in spite of some limitations compared to
parallel and series resonant converters. For system-related
reasons, they can only be used within a very narrow frequency
range without changing their components. Additional
components, such as the coupling choke, contribute to an
increase in the losses.
The direct converter without resonant circuit will continue
to be used only for applications where continuous
adjustment of the operating frequency is required during
operation. It is otherwise so inferior compared to resonant
converters in terms of its efficiency that it is really no alternative
when it comes to energy efficiency.
More and more importance is being attached to a reduction
in the system perturbation of frequency converters. It
is not only the cos φ power factor of the fundamental that
plays an important role here. The loading of the system with
harmonic currents may result in a variety of problems and
needs to be kept in check. Higher pulse rectifiers, power
factor correction circuits or active filter technologies may be
useful here. The improvement in the cos φ and the reduction
in harmonic current both result in the enhancement of the
energy efficiency of the power supply.
Frequency thyristors, the further development of which
was virtually stopped, are now only being used by a handful
of converter manufacturers in high-power inverters and at low
operating frequencies. More and more frequency thyristors
are being discontinued by the manufacturers, with the result
that their use may continue to dwindle.
Due to their advantageous properties IGBTs are ideal for
use in voltage dc link converters. This topology forms the
basis of many of the types of converters described. The most
well-known of these are the series resonant converter and
the converter with L-LC load. Converters with sine-weighted
PWM modulation of the inverter can also be used to feed a
parallel resonant circuit via a coupling choke.
IGBTs and MOSFETs are semiconductor technologies
which, to some extent, compete with each other. For high
frequencies MOSFETs still offer more benefits than IGBTs,
even though the range of IGBT-applications is continuously
growing.
It will still be some time before power semiconductors
from silicon carbide (SiC) are used in medium and highpower
frequency converters. Silicon-based IGBTs and MOS-
FETs will remain the components of choice for a long time
to come. Future areas of application for SiC components
may first be found in high-frequency converters.
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LITERATURE
[1] Fricke, H. ; Vaske, P.: Grundlagen der Elektrotechnik Teil 1. Elektrische
Netzwerke, B. G. Teubner Verlag Stuttgart 1982
[2] Dede, E.: Static Inverters for Induction Heating: From the Fundamentals
to the Analysis and Design. PCIM International
Conference 1998 Seminar Notes
[3] Patent DE 101 15 326 B4 2009.10.15 Verfahren zur Ansteuerung
eines Schwingkreis-Wechselrichters. Schwingkreis-
Wechselrichter und Regler.
[4] Mohan; Undeland; Robbins: Power Electronics. Converters,
Applications and Design. John Wiley & Sons, Inc. 1995
[5] Zok, E.; Matthes, H.G.: Kritische Halbleiterbelastungen im
Schwingkreisumrichter, VDE Konferenz Leistungselektronik
und ihre Bauelemente in Bad Nauheim 2002
[6] Nuding, M.: MF-Umrichtertechnologie zur Vereinfachung
induktiver Erwärmprozesse, Elektrowärme International,
issue 1/2009
AUTHORS
Dipl.-Ing. Edmund Zok
SMS Elotherm GmbH
Remscheid, Germany
Tel.: +49 (0) 2191/ 891-639
e.zok@sms-elotherm.com
Dipl.-Wirtsch.-Ing. Dirk M. Schibisch
SMS Elotherm GmbH
Remscheid, Germany
Tel.: +49 (0)2191/ 891-300
d.schibisch@sms-elotherm.com
56 th INTERNATIONAL COLLOQUIUM ON REFRACTORIES 2013
September 25 th and 26 th , 2013 . EUROGRESS, Aachen, Germany
For further information please contact:
Conference Topic
Refractories for Industrials
• Glass • Chemistry • Quality management
• Cement/lime • Refractory raw materials • Wear and Corrossion
/plaster • Shaped and unshaped • Recycling
• Ceramics refractories • Environmental
• Incineration • Processing and refractory Protection
lining service
The deadline for submission of abstracts is 8 th March 2013.
ECREF European Centre for Refractories gGmbH
– Feuerfest-Kolloquium –
Rheinstrasse 58, 56203 Höhr-Grenzhausen, GERMANY
Tel.: +49 2624 9433130, Fax: +49 2624 9433135
74 E-Mail: events@ecref.eu Internet: www.ecref.eu
heat processing 1-2013
www.feuerfest-kolloquium.de

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Low NO x oxy-fuel combustion
in non-ferrous metallurgy
by Steven MacLean, Jörg Leicher, Anne Giese, Josef Irlenbusch
Oxy-fuel combustion, i.e. the combustion of fuel with oxygen instead of air, may cause strong nitrous oxides formation if
there is any molecular nitrogen in the furnace. N 2 sources in the furnace might be nitrogen traces in natural gas or impurities
in the oxygen flow. Nevertheless, sophisticated burner design, based on reaction kinetics simulations and detailed
experimental investigations, allow for acceptable NO x emissions even when strongly N 2 -contaminated oxygen is used.
Oxy-fuel combustion, i. e. the combustion of fuel
(usually natural gas) with almost pure oxygen
instead of ambient air as an oxidizer, has established
itself as a „state of the art“ approach to provide very
high furnace temperatures in both the metals [1], [2] and
the glass industry [3], [4].
The definition of „oxy-fuel combustion“ is somewhat
ambiguous: in power plant engineering, oxy-fuel combustion
is defined as the combustion of fuel (often coal)
with oxygen diluted by large amounts of recirculated dry
exhaust gas (basically pure CO 2 ), usually as a precursor to
a carbon sequestration unit [5], [6]. In this context, flame
temperatures do not differ much from those of conventional
fuel-air combustion, the use of an O 2 /CO 2 mixture is
seen simply as a means to facilitate CO 2 capturing.
In process engineering, however, this terms refers to the
combustion of fuel with pure oxygen in order to produce
high furnace temperatures and heat fluxes without strong
air pre-heating. For the purpose of this paper, this second
definition is the relevant one.
For purely thermodynamic reasons, the combustion efficiency
of an oxy-fuel process is higher than that of a conventional
fuel-air combustion since the nitrogen content of the
combustion is not heated as well, resulting in much higher
flame temperatures [7]. While the adiabatic flame temperature
of a stoichiometric, non-preheated methane-air flame
is about 2,000 °C, the adiabatic flame temperature of a CH 4 /
O 2 flame at identical boundary conditions achieves almost
2,800 °C. As there are no chemically inert components in
an oxy-fuel combustion system, the heat release from the
combustion process itself is transformed almost completely
to a temperature increase of the flue gas. Additional
advantages of this form of combustion are that air pre-heating
systems such as recuperators or regenerators are no longer
required. In fuel-air firing systems, such pre-heaters, producing
air pre-heat temperatures of up to 1,400 °C, depending on
the application, are necessary to achieve high combustion
temperatures. Regenerators can easily be as large as the
actual furnace itself. Thus, being able to dispense with air
preheating equipment can be a significant benefit. On
the other hand, there is increased operational cost due
to required oxygen supply. Nevertheless, it can be shown
that for many industrial applications, it is economically
sensible to use oxy-fuel combustion, as an higher heating
rates and hence increased productivity can compensate
for the additional cost of oxygen production [1]. Other
advantages are easier and faster process control as well as
smaller furnaces and peripheral equipment because the
amount of flue gas is drastically reduced.
In the metallurgical industry, the main reason to go for
oxy-fuel combustion is of an economic nature. In the glass
industry, on the other hand, pollutant emissions legislation,
especially with regards to nitrous oxides (NO x ), leads to ever
increasing numbers of oxy-fuel furnaces. Glass melting requires
very high furnace temperatures up to 1,600 °C and higher,
depending on glass quality. The maximum temperatures in
the furnace are even higher. These very high temperatures
can only be achieved either with very strong air pre-heating
(pre-heat temperatures of 1,400 °C are common in regenerative
glass melting furnaces [4]) or oxy-fuel combustion.
If air is used as oxidizer, the high furnace temperature will
lead to a strong formation of thermal NO x , which is highly
dependent on local temperature levels as well as oxygen
and nitrogen concentrations and residence times. Oxy-fuel
combustion, on the other hand, has the potential to drastically
reduce NO x formation as the main nitrogen source, the
combustion air, is eliminated. From the point of view of the
glass industry, oxy-fuel combustion is therefore attractive
since it can achieve very high temperatures without high
NO x emissions, thus avoiding the need for expensive flue
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gas treatment such as SCR or SNCR plants.
However, oxy-fuel combustion will not necessarily lead
to a reduction of NO x emissions. Due to the extremely high
flame temperatures, available molecular nitrogen will be
oxidized to NO x much faster than in a conventional combustion
process with pre-heated air. In this context, the
source of molecular nitrogen is not important: it could be
air leakage from the surroundings, it could be nitrogen
within the fuel (natural gas can contain several volume
percent of N 2 ) or trace of nitrogen in the oxidizer Thus, the
operating pressure in oxy-fuel should be somewhat higher
than the ambient pressure to prevent air leaks. In any case,
the nitrogen content of both fuel and oxidizer needs to be
closely monitored to minimize NO x emissions.
In the project presented here, the challenge was to
develop an oxy-fuel burner lance for a precious metals
converter furnace which achieved acceptable NO x emissions
despite a N 2 content of 5 vol.-% in the oxygen supply.
INVESTIGATION OF THE IMPACT OF VARI-
OUS PARAMETERS ON NO x FORMATION
As long as there are no compounds containing nitrogen (such
as NH 3 ) present in the chemical system, the most important
production process of nitrous oxides during the combustion
of gaseous fuels is the so-called thermal NO x . This formation
pathway was discovered by Zeldovich in 1946 and describes
the conversion of molecular nitrogen, extant either in the
fuel or the oxidizer flow, to NO. Since thermal NO x primarily
consists of NO (the other species being NO 2 and N 2 O), the
formation of NO from N 2 and O 2 is especially relevant.
This relatively simple process can be described by three
elementary reactions:
O + N 2 ↔ NO + N
N + O 2 ↔ NO + O
N + OH ↔ NO + H
As the name implies, this formation mechanism is highly
dependent on local temperature, as dissolution of the triple
bond of molecular nitrogen requires a lot of energy and
Fig. 1: Principle of the perfectly stirred reactor
hence only occurs at high temperature levels. Thus, the
net production rate of NO, based on the three elementary
reactions, is an exponential function of temperature. Additional
important parameters are the local concentrations of
O 2 and N 2 as well as the residence time in a sufficiently hot
region [8]. While the basic formation pathway of thermal
NO is the same for both conventional fuel-air combustion
and oxy-fuel combustion, the reactions will occur faster in
oxy-fuel combustion due to the much higher temperatures,
leading to drastically increased NO emissions if there is a
sufficient amount of molecular nitrogen in the chemical
system.
Thus, the first step of the burner design was to determine
by means of a series of chemical kinetics simulations
which parameters have the most profound impact on
NO formation. The objective was to find guidelines on
how to minimize NO emissions if the complete removal of
nitrogen from the oxygen supply is not an option. As CFD
simulations of oxy-fuel combustion systems in an industrial
context are either numerically expensive or prone to
significant uncertainties due to the combustion models [9],
[10], it was decided to use a two-step cascade of perfectly
stirred reactors (PSR) to model the combustion process
in the converter furnace. This approach allows for a quick
evaluation of the qualitative impact of various parameters
on the overall NO formation. Fig. 1 shows a sketch of the
basic principle of a PSR.
This stationary ideal chemical model reactor can be
considered as a zero-dimensional system, i. e. the temperature
within the reactor is equal to the flue gas temperature,
as all processes are assumed to take place within a single
point. Such a reactor is characterized by its volume or mean
residence time and a heat loss Q. Both fuel and oxidizer
mass flows undergo instantaneous and perfect mixing
which is why the effects of convection and turbulence on
the combustion are neglected for this model.
The main advantage of this modeling approach is that,
due to the extreme spatial simplification, comprehensive
reaction mechanisms can be used to describe the chemical
processes in detail. For the work presented here, a
medium-sized reaction mechanism, GRI 3.0 [12], was used.
This mechanism is a standard mechanism for the combustion
of natural gas and consists of 53 chemical species and
325 elementary reaction equations.
In order to realistically describe the combustion process
in a precious metals converter furnace, a sequence of two
PSR is used (Fig. 2). The first reactor describes the main
combustion processes, which is assumed to be adiabatic
in this case. This assumption seems reasonable as only a
qualitative prediction of the impact of various operating
parameters on NO production is intended. Quantitative
predictions are not sensible with this kind of modeling
approach anyway. In the subsequent reactor, the flue gas is
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cooled down to the intended temperature of 1,250 °C. The
heat loss applied here is equal to the heat flux required for
the melting process in the converter furnace and the heat
losses through the walls for the furnace. This amount of
energy is no longer available for the combustion processes
and hence can be considered as a net heat loss from the
chemical system.
Using this very simple model, the qualitative influence of
changes of various operating parameters on the overall NO
formation of the system is examined. The relevant parameters
are the residence times in the two reactors (t PSR1 and
t PSR2 respectively), the chemical composition of the oxidizer
(in the form of its N 2 content) and the oxidizer ratio λ. The
flue gas temperature was kept constant at 1,250 °C. This was
changed in another set of simulation runs where the flue
gas temperature was varied. In order to keep the system
simple, all simulations used pure methane (CH 4 ) as a fuel
while the oxidizer consisted of 95 vol.-% O 2 and 5 vol.-%
N 2 , except for those simulations where the composition
of the oxidizer itself was varied in order to investigate the
impact of oxygen purity on NO emissions. For both fuel and
oxidizer flows, an inlet temperature of 20 °C was chosen.
In general, it can be stated that oxy-fuel combustion
takes place at a much faster pace than the conventional
combustion of fuel and air. This was to be expected
because in a conventional methane-air system, the nitrogen
mass fraction is much higher than that of any other
species involved. As nitrogen is practically inert chemically,
it only serves as a heat sink, reducing the flame temperature
in a fuel-air flame. In oxy-fuel combustion however,
this heat sink is not present, leading
to much higher local temperatures. The
consequence is that NO concentrations in
an oxy-fuel system will be much closer to
their chemical equilibrium, compared to
conventional firing systems, where actual
NO x emissions are usually well below their
equilibrium values [8].
As a consequence, there is very little room
to improve NO x emissions by means of burner
design if there is a significant amount of
molecular nitrogen in either fuel or oxidizer
flow. This can be shown by varying the flue
gas temperature. Even a decrease of the
flue gas temperature by 2,000 K only causes
a reduction of NO emissions by 7 %. The
local temperatures in the reaction zone are
so high that even the kinetically slow NO
formation reactions are almost at their chemical
equilibrium. Thus, the primary factor
for NO fomation in an oxy-fuel system is the
amount of available molecular nitrogen, as
can be seen in Fig. 3 and Fig. 4.
Fig. 2: Schematic of the combustion process in the converter as used
for the chemical kinetics simulations
Fig. 3 shows the influence of oxygen purity on the
relative NO formation, as described by the chemical kinetics
simulation. All NO concentrations are referenced to
the intended point of operation, i. e. with an O 2 content of
95 vol.-% in the oxidizer. It is obvious that the N 2 content
of the oxidizer is the dominant factor for NO formation
as flue gas temperatures for the different cases vary only
slightly. In the case of a perfectly pure oxygen supply, no
NO is produced as there is no nitrogen in the combustion
Fig. 3: Influence of oxygen purity on the relative NO formation
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Fig. 4: Influence of the oxidizer ratio on the relative NO formation
system at all. In the real life application, this would not be
feasible since the presence of trace amounts of nitrogen
cannot be avoided, for example due to N 2 traces in the fuel
gas or air leakages of the furnace.
The impact of the oxidizer ratio λ on the relative NO
production is described in Fig. 4. It can be seen as well
that only the amount of available N 2 is the decisive factor
for NO production. Contrary to what one would expect
from conventional combustion systems, in this case higher
oxidizer ratios lead to higher NO emissions. An increase in
Fig. 5: Measuring plan of GWI’s semi-industrial test rig
oxidizer flow will bring more N 2 into the combustion
system, while the temperature is so high that
the slightly decreased local temperature due to
higher λ is insignificant.
Both figures show that the predicted NO emissions
are primarily dependent on the supply of
molecular nitrogen which can either result from
impurities in the oxidizer or higher oxidizer ratios.
All other parameters are of secondary importance.
The only way to significantly reduce NO
formation without changing the N 2 supply is a
drastic reduction of the residence time in the first
reactor. A reduction of this time scale by a factor
of 100 will cause a reduction of NO emissions by
about 93 %, compared to the reference case.
This fact allows for two conclusions. First,
the chosen residence time in the reaction zone
was too high which also corresponds with the
experimental findings. The NO emissions in the
experimental campaign were much lower than
those predicted by the numerical model. However, it also
points out the only design measure that can be taken to
improve NO emissions. If it is possible to significantly reduce
the residence time of the reacting flow in the very hot
reaction zone, NO formation can be inhibited even despite
the large N 2 supply. This can be achieved by injecting both
fuel and oxidizer with very high velocities, resulting in a
high momentum burner. Nevertheless, the most promising
way to reduce NO emissions would still be to improve the
purity of the oxygen supply.
In this manner, chemical kinetics simulations
were able to provide valuable information for
the design of the oxy-fuel burner at negligible
numerical cost.
EXPERIMENTAL INVESTIGATIONS
Based on the simulations carried out prior to
the burner design it was obvious that NO formation
within the oxy-fuel combustion process
is primarily controlled by the amount of molecular
N 2 available and the residence time (and
hence momentum). Since an improvement of
the purity of the oxygen supply was not possible
for the actual application in this case, the
design process in this project focused on the
development of a high-momentum burner. Ten
different burner configurations with different
geometries and varying operating parameters
were tested and compared, using GWI’s semiindustrial
burner test rig. The principle of the
the test furnace can be seen in Fig. 5. The entire
furnace space can be accessed by both suction
probes and optical measurement techniques,
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using various access ports and observation windows.
In the course of the measurement campaign, temperatures
and flue gas compositions at the exit of the combustion
chamber were measured. Also, the shapes of the
flames of the different burner variants were visualized using
the OH chemoluminiscence technique. All measurements
were taken under atmospheric conditions in a regime close
to stoichiometry (λ = 1.0 to 1.1), i. e. close to the conditions
found in a precious metals converter. The test furnace itself
was operated at slightly elevated pressure levels to prevent
ambient air from leaking into the furnace. For the most part,
burner loads were at 800 kW although some measurements
were carried out at partial loads. In all cases, locally available
natural gas was used as a fuel.
In the following, the main results of the measurement
campaign will be described using three different burner
variants, pointing out NO x reduction potentials.
Based on previous investigations, the geometry described
here was found to be the most promising. Other geometries,
for example, pipe-in-pipe burners where natural
gas and oxygen flow in parallel were proven to be unsatisfactory,
both because of extremely high NO x emissions
and extensive scaling at the tip due to the significant local
heat flux.
All tested burner variants share the same basic geometry.
Natural gas is injected into the combustion chamber
by means of a central nozzle while several oxygen nozzles
are positioned around the central fuel nozzle. The different
burner variants vary due to different diameters of both fuel
and oxygen nozzles. Also, the angle at which the oxygen
jets enter the combustion chamber was varied.
Variant 1, the reference case, is characterized by rather
large oxygen nozzles while the diameter of the fuel gas nozzle
is about 8 % smaller than in the other presented cases.
In Variants 2 and 3, on the other hand, the cross section
of the oxygen nozzles was reduced, resulting in diameters
that are 24 % smaller than in Variant 1. This means that the
oxygen jets enter the combustion chamber with a velocity
that is 42 % higher than in Variant 1, resulting in a much
higher momentum. The difference between Variants 2
and 3 can be found in the orientation of the O 2 nozzles. In
Variant 2, all oxygen nozzles have the same angle while in
case 3, two different angles are used.
The impact of the higher momentum of the oxygen jets
on the flame can easily be seen in Fig. 6 and Fig 7. These
figures show OH chemoluminiscence images of Variants
1 and 2 respectively at identical boundary conditions. OH
is especially interesting for the purpose of combustion
measurements because it is relatively easy to detect but
also provides valuable information on the shape and size
of the reaction zone. OH is only formed in regions of high
local temperatures, thus either in the primary reaction
zone itself or in regions were local dissociation processes
take place due to high local temperatures. As local OH
concentrations are directly proportional to temperatures,
local temperature peaks, so called „hot spots“, can easily
be detected.
The comparison of the two images illustrates the
effect of higher oxygen jet momenta on the combustion
process. Variant 2 shows significantly lower local OH
concentrations indicating lower local temperatures. The
OH distributions appear to be much more diffuse than
in Variant 1 where a core region of higher local OH concentrations
(and higher local temperatures, accordingly)
can be found.
Higher jet momenta lead to an increased entrainment
of hot, but chemically inert flue gas by the oxygen jets,
thus diluting the reaction zone. In this manner, the local
concentrations of both fuel gas and oxidizer as well as
intermediate species are reduced compared to what can
be found in Variant 1. The recirculated flue gas also serves
as an additional local heat sink in the reaction zone, reducing
the temperature level (and hence the energy density)
there while also decelerating the progress of the chemical
processes. One consequence is that the lower temperature
in the reaction zone will reduce the formation of thermal
nitrous oxides which is highly dependent on local temperatures.
This effect is well-known in conventional fuel-air
burners (for example in the so-called "flameless oxidation"
[13]), but works similarly in oxy-fuel systems (cf. [14], [15]).
The details of the burner design, however, play an
important role. For example, comparing Variants 2 and
3 shows that Variant 3 yields much higher NO x emissions
than Variant 2, even though the oxygen jets have the same
momenta. The different configuration of the jets in Variant 3
seems to inhibit the recirculative transport of hot flue gas
into the reaction zone, resulting in stronger NO x formation.
The comparison underlines the positive impact of intensive
mixing of fuel, oxidizer and flue gas. If a very thorough
mixing can be achieved, NO x formation can be significantly
reduced, even at high local temperature levels typical for
near-stoichiometric oxy-fuel combustion. In this manner, NO x
emissions could be reduced from 816 ppm (normalized to
an O 2 content of 3 % in the flue gas) to 537 ppm at identical
operating conditions (P = 800 kW, λ = 1,04, 5 vol.-% nitrogen
in the oxidizer), a decrease by 34 %. Variant 3, on the other
hand, yielded much higher NO x emissions (1558 ppm) for
the same operating parameters, indicitating inferior mixing
despite having the same ratio of momenta as Variant 2. In all
cases, however, NO x emissions remain relatively high, due
to the high N 2 content of the oxidizer in combination with
high furnace temperatures. Any N 2 present, regardless of
the source, will be oxidized up to the chemical equilibrium.
The nitrogen content of the natural gas used during the
measurement campaign was at about 0.8 %.
This shows that the most effective way to reduce NO x
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Table 1: NO x emissions (@ 3 vol.-% O 2 in the flue gas) for the different burner variants at identical operating conditions
N 2 /O 2 -Content in the Oxidizer λ NO x (Variant 1) NO x (Variant 2) NO x (Variant 3)
[Vol.-%] [–] [ppm] [ppm] [ppm]
5/95 1.04 816 537 1558
0/100 1.04 134 70 240
emissions remains the reduction of the amount of nitrogen
in the system. For example, when pure oxygen was used,
the NO x emissions for Variant 2 fell to 70 ppm, a decrease
by 87 %. Flow field optimization is a much more ineffecient
way to reduce NO x formation. All relevant data from these
experiments can be found in Table 1. All data is normalized
to an excess O 2 content of 3 % in the flue gas.
The measurements prove that oxy-fuel combustion will
not necessarily lead to reduced NO x emissions. Though
there is less molecular nitrogen present in the chemical
system in total, the extremely high local temperatures and
the resulting high reactivity of the chemical system mean
that any N 2 in the reaction zone will be oxidized almost up
to the NO chemical equilibrium. For oxy-fuel combustion
systems in thermal processing applications, it is vital to
monitor possible sources of nitrogen. The oxygen supply
should provide as pure oxygen as possible, and also the
N 2 content of the fuel has to be taken into account. Air
leakages have to be avoided at all costs.
The comparison between the chemical kinetics analysis
and experimental investigations shows that even using a
simplified numerical model, the impact of the various operating
parameters on pollutant formation can be estimated
in a qualitative manner. NO x predictions were generally too
Fig. 6: OH chemoluminiscence image of the flame for burner variant 1
Fig. 7: OH chemoluminiscence image of the flame for burner variant 2
high but this is due to the fact that the flow field (and hence
residence time distribution in the combustion chamber)
were impossible to predict without resorting to numerically
expensive CFD studies which bring additional uncertainties
when it comes to oxy-fuel combustion. The measurements
confirm the trends predicted by the modeling approach.
A clever burner design, based on extensive theoretical
and experimental investigations, can help to mitigate NO x
formation even despite unfavorable boundary conditions
such as a highly impure oxygen supply. A precious metals
converter furnace using the burner design developed in the
course of this project will be commissioned by a customer
of Breidenbach Maschinen GmbH in the near future.
CONCLUSION
In the work presented here, NO x emissions of an oxy-fuel
burner for use in a precious metal converter furnace were
investigated, using both chemical kinetics simulations and
measurements in a semi-industrial test rig. The challenge
was that for the intended application of the burner system,
an oxygen supply had to be used which could only provide
oxygen with a nitrogen content of 5 vol.-%, resulting in
potentially very high nitrous oxides emissions. Nevertheless,
low NO x emissions were to be achieved.
Using chemical kinetics modeling,
the driving factors for the production
of NO x were evaluated. It was found
that, for a given N 2 concentration of 5
vol.-% in the oxidizer, only an extreme
reduction of the residence time oft
he fluid in the reaction zone led to a
significant mitigation of NO formation.
This indicated that a high-momentum
burner had to be designed.
This finding was confirmed by a
measurement campaign carried out
at GWI’s semi-industrial burner test rig.
However, a high-momentum injection
of both fuel and oxidizer by itself is not
sufficient to reduce NO x formation, as
the importance of mixing of fuel, oxidizer
and exhaust gas in an oxy-fuel
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Research & Development
REPORTS
application cannot be overstated. Insufficient mixing may
result in even higher NO x emissions than a low-momentum
burner.
Despite all measures to improve the NO x emissions,
they are still relatively high. If at all possible, the use of
purer oxygen is the most effective method to reduce NO x
formation, a fact that is confirmed by both simulation and
experiment.
In oxy-fuel combustion system, any molecular nitrogen
available will be converted to NO up to the chemical equilibrium.
This means that all possible sources of nitrogen have
to be monitored, from the N 2 content of oxidizer and fuel
flows to air leakages.
If the use of pure oxygen is not technically or economically
possible for whatever reason, flow field optimization
can be a viable way to reduce NO x emissions. However,
this requires detailed knowledge of the physical and chemical
processes in the furnace near the burner, based on
comprehensive measurements.
LITERATURE
[9] Cuoci, A., Frassoldati, A., Faravelli, T., Ranzi, E., Candusso, C.,
Tolazzi, D., “CFD simulation of a turbulent oxy-fuel flame,” Processes
and Technologies for a Sustainable Energy, Ischia, Italien,
2010
[10] Leicher, J., Giese, A., “Untersuchungen zur Oxy-Fuel-Feuerung
von Glasschmelzwannen,” Gaswärme International, vol.
60, no. 7/8, pp. 617-623, 2011
[11] Glarborg, P., Kee, R. J., Gcar, J. F. Miller, J. A., “PSR: A FORTRAN
Program for Modeling Well-Stirred Reactors,” SANDIA National
Laboratories, SAND 86-8209, 1986
[12] Smith, G. P., Golden, D. M., Frenklach, M., Moriarty, N. W., Eiteneer,
B., Goldenberg, M., Bowman, C. T., Hanson, R. K., Song,
S., Gardiner Jr., W. C., Lissianski, V. V., Quin, Z., 2000. [Online].
Available: www.me.berkeley.edu/gri_mech
[13] Wünning, J. G., “Flammlose Oxidation von Brennstoff,” RWTH
Aachen, 1996
[14] von Schéele, J., Gartz, M., Paul, R., Lantz, M. T., Riegert, J. P.,
Söderlund, S., “Flameless oxyfuel combustion for increased
production and reduced CO 2 and NO x emissions,” stahl und
eisen, vol. 128, no. 7, pp. 35–40, 2008
[15] Untersuchung zur Verbesserung der Energieeffizienz und der
Wärmeübertragung einer Oxy-Fuel-Glasschmelzwanne -
‘O 2 -Glaswanne, Abschlussbericht zum AiF-Forschungsprojekt
Nr. 15987 N, Essen, 2012
[1] Pfeifer, H.; Högner, W.; Fredriksson, P.; von Scheele, J.; Paul, R.:
Energieeffizienz und Minderung des CO 2 -Ausstoßes durch
Sauerstoffverbrennung, stahl und eisen, vol. 129, no. 8, pp.
51-62, 2009
[2] Roth, J.L.: The status of oxycombustion in the metallurgical
industries, TOTeM17: The Use of Oxygen for Industrial Combustion,
Cernay la Ville, Frankreich, 2000
[3] Yamazaki, H.: The Status of Oxy-Fuel Technology in the Glass
Industry, TOTeM17: The Use of Oxygen for Industrial Combustion,
Cernay la Ville, Frankreich, 2000
[4] Kobayashi, H.: Emissions and heat transfer characteristics of
low NO x oxy-fuel burners, Thermadag Lonox vorbrandingstechnologie
Lownox-Glasdag, Utrecht, Niederlande, 1994
[5] Kluger, F.; Mönckert, P.; Wild, T.; Marquard, A.; Levasseur, A. A.:
Entwicklungsstand der Oxy-Fuel-Verbrennungstechnologie,
in Kraftwerkstechnik - Sichere und nachhaltige Energieversorgung,
Vol. 2, Neuruppin: TK-Verlag Karl Thomé-Kozmiensky,
2010
[6] Kuckshinrichs, W., Markewitz, P., Linssen, J., Zapp, P., Peters, M.,
Köhler, B., Müller, T. E., Leitner, W., “Weltweite Innovationen bei
der Entwicklung von CCS-Technologien und Möglichkeiten
der Nutzung und des Recyclings von CO 2 ,” Studie im Auftrag
des Bundesministeriums für Wirtschaft und Technologie
(BMWi) Projektnummer 25/08 AZ I D4-020815, 2010
[7] Wünning, J. G., Milani, A., Handbuch der Brennertechnik für
Industrieöfen - Grundlagen, Brennertechniken, Anwendungen,
2 nd ed. Essen, Vulkan-Verlag, 2011
[8] Warnatz, J., Maas, U., Dibble, R. W., Verbrennung: Physikalisch-
Chemische Grundlagen, Modellierung und Simulation, Experimente,
Schadstoffentstehung, 3 rd ed. Springer-Verlag, 2001
AUTHORS
B.Eng. Steven McLean
Gas- und Wärme-Institut e. V.
Essen, Germany
Tel.: +49 (0)201/ 3618-244
maclean@gwi-essen.de
Dr.-Ing. Jörg Leicher
Gas- und Wärme-Institut e. V.
Essen, Germany
Tel.: +49 (0)201/ 3618-278
leicher@gwi-essen.de
Dr.-Ing. Anne Giese
Gas- und Wärme-Institut e. V.
Essen, Germany
Tel.: +49 (0)201/ 3618-257
a.giese@gwi-essen.de
Josef Irlenbusch
Breidenbach Maschinen GmbH
Kürten, Germany
Tel.: +49 (0)2268/90287
irlenbusch@breidenbach-maschinen.com
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This is where we focus at regular intervals on the main institutions and organisations active in the field of
thermoprocessing technology. This issue spotlights the Laboratory for Electroheat of Padua University.
LEP - Laboratory for Electroheat of Padua University
The Laboratory for Electroheat of Padua
University, LEP, is the only Italian academic
group that researches about electroheating.
LEP was founded about 40
years ago by prof. Di Pieri, it was leaded
for many years by prof. Lupi and now it is
directed by prof. Dughiero. Actually, about
10 people are working in the group. It is
also the organizer of the conference ‘HES’,
Heating by Electromagnetic Sources,
whose 6th triannual edition will take place
this year in May.
In the paper, the latest research activities
of LEP are presented, mostly with reference
to the fields where LEP concentrates its
research activity: innovative technologies for
the through heating of non ferrous billets,
contour induction hardening, silicon melting
and crystallization, microwave heating and
biomedical application of electromagnetic
fields.
HISTORICAL BACKGROUND
The first years after the second World War
have seen in Italy an increasing interest for
all induction heating applications, mostly
due to the fast development of the automotive
industry. The main center of this
interest was Padua, where a wide research
activity was initiated and developed at
the University by the emeritus Prof. Ciro
Di Pieri.
In 1931 he graduated at the University
of Padua and started his activity at the
Institute of Electrotechnics. From 1943 he
oriented his research on frequency converters,
medium and high-frequency heat
treatments and, in general, all induction
heating applications.
He dedicated his scientific interest not
only to the theoretical research but also to
industrial realizations as technical director of
the company SIATEM - Società Italiana Apparechiature
Termo Elettromeccaniche, establishing
a very close and fruitful link between
university and industry and a new school on
induction heating at the University.
An important step forwards for the
research activity was made by prof. Di
Pieri in 1969 with the foundation of the
“Laboratory of the Institute of Electrotechnics
and Electronics of the University of
Padua for researches and tests in the field
of induction heating and hardening”; the
laboratory was equipped with a 100 kW
motor-generator at 9800 Hz and a 90 kW
HF generator at 450 kHz.
From 1983 till his retirement in 2010 the
activity of the laboratory has been directed
by the emeritus prof. Sergio Lupi. The main
research activities till 2010 are extensively
described in [1,2,3].
Nowadays, all the facilities available in
the Laboratory have been replaced with
modern solid state generators: a MF generator,
200 kW – 2 to 30 kHz and a HF one,
200 kW to 200 kHz.
MAIN RESEARCH ACTIVITIES
PMH – Permanent Magnet Heating
The mass heating of billets before hot
metal forming plays a major role among
industrial induction heating applications
as regards the number of installations, unit
rated power of the heaters and energy
consumption. The efficiency of induction
process, i.e. the ratio between the power
transferred to the work piece and the
power supplied to the inductor, is around
50 % for aluminum or copper billets. For
these materials, a DC induction heating
concept has been proposed to improve
the process efficiency. In this approach the
billet is forced to rotate inside a transverse
DC magnetic field by means of an electric
motor. Due to the change of magnetic
flux an induced current distribution reacts
to the driving torque during the rotation
and generates thermal power within the
billet. The distribution of the average heating
power and its dependence on the
applied field and angular velocity have
been demonstrated to be identical to
those of conventional longitudinal flux
AC induction heating, even if induced
current paths are geometrically different
(azimuthally directed in traditional longitudinal
flux heaters while currents are mostly
longitudinal in rotating heater). Recently,
LEP has proposed a rotating system of
permanent magnets as sketched in Fig. 1.
This solution looks very promising
because it allows to reach high efficiency,
that depends mostly upon the efficiency of
the motor drive, without using an expensive
superconductive system [a_3]. An industrial
scale prototype (Fig. 2) has been recently
realized and several tests have been carried
out. The prototype has been designed
to heat 200 mm diameter, 500 mm length
aluminium billet of an approximate weight
of 42 kg. The motor drive has a rated power
of 55 kW at a rated speed of 2,500 rpm, while
the magnetic field is produced by SmCo,
rare earth permanent magnets.
The preliminary tests showed the robustness
of the design of permanent magnet
heater (Fig. 3). Several tests have been
carried out up to around 400 °C, at various
rotational speed: the global process efficiency
(i.e. the ratio between the amount of
heat supplied to billet and the total electric
energy consumption) is around 70 %.
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(a)
(b)
Fig. 1: Concept of rotating permanent magnets heater; (a) Schematic of the rotating permanent magnet induction heater, (b) Induced
current distribution in the billet and equiflux lines as result of a FEM calculation
Electroheat and photovoltaic
The reduction of the environmental impact
of electrical energy generation is nowadays a
key issue for the electrical energy community.
Photovoltaic (PV) is one of the most important
source for clean electricity and costs
related to this technology are continuously
going down, but the photovoltaic community
needs further technological improvements
to achieve a cleaner production of cells, cost
competitive and less energy intensive.
The possibilities to develop electrothermal
processes for industrial PV applications
are numerous and LEP currently works on two
projects related to PV: an induction DSS furnace
for crystalline silicon casting and a thermal
process for recycling end of life modules.
iDSS
The production of silicon ingots and wafers
from raw polysilicon is one of the most cost
and energy intensive process in the whole
crystalline silicon solar panels production
chain. Multi-crystalline silicon ingots and
solar wafers are usually made using directional
solidification system (DSS) furnaces
with resistive heating (Fig. 4). While this
technology is well established and mature, it
has some drawbacks that can be hurdles for
the competitiveness of the multi-crystalline
silicon PV technology in the fast changing
solar energy market.
The knowledge acquired by the Laboratory
of Electroheat at Padua University on
induction heating processes and the need
for the photovoltaic industry to develop
innovative solutions for keeping this industry
competitive has pushed the start of the
iDSS project: a DSS furnace based on an
induction heating system.
The advantages of adopting induction
heating systems, in substitution of resistors,
range from the possibility to induce directly
the heat to the hot zone of the system (e.g.
the graphite susceptors inside the thermal
insulation layers), thus reducing drastically
the thermal losses of the system, to a better
control of the temperature distribution
during the melting and solidification process,
allowing an active control of the process
and producing silicon ingots and wafers
with better physical characteristics.
Fig. 2: Industrial scale laboratory prototype
installed at LEP
Fig. 3: Arrangement of the permanent
magnets inside the steel rotor
Fig. 4: Industrial scale laboratory prototype:
350 kg Multicrystalline silicon ingot
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Fig. 5: 120 kg iDSS furnace at LEP
Fig. 6: Experimental apparatus for PV
panels RF de-lamination
Fig. 7: Simulated geometry
A full-scale induction DSS furnace has
been built by an Italian company in collaboration
with LEP and a smaller 120 kg labscale
furnace (Fig. 5) has been designed
and built at Padova University in the framework
of the project “Polo del Fotovoltaico
della Regione Veneto”. This will allow to
make experimental tests on silicon crystal
growth and to develop and promote the
use of induction heating systems in silicon
casting applications.
PV Recycling
Most of the materials used in photovoltaic
solar modules, (i.e. silicon, glass, metals and
aluminum) can be easily recycled and reused
in the solar panels production chain.
The separation of these materials from end
of life crystalline silicon solar panels, though,
is a real technological challenge; in fact the
polymeric materials used as encapsulant between
solar cells, glass and backsheet layer
act as a strong adhesive and don’t allow
them to be mechanically separated (Fig. 6).
The recovery of silicon and glass from
end of life c-Si solar panels is usually done
manually after the incineration of the
polymeric materials of the panels at high
temperature in incinerating ovens with big
environmental impact due to the emission
of hazardous fumes.
At LEP a low temperature thermal process
has been developed for the separation
of glass from the solar panels. This delamination
process is based on dielectric
heating using radio-frequency and allow to
heat directly the polymeric material used as
encapsulant (EVA); heating EVA at temperature
lower than 80 °C leads to the reduction
of its adhesive strength and the possibility
of mechanical separation of clean glass from
the panel with no harmful emissions after
the thermal treatment. This possibility has
been demonstrated experimentally; further
tests and multi-physics simulations are currently
carried out for developing a full scale
de-lamination system for the separation of
glass and silicon from end of life c-Si photovoltaic
panels.
Induction hardening of gears
Induction heating has been widely used by
the heat treatment industry, i.e. in the windpower
and automotive sectors, in particular
for hardening purposes, in a broad range
of applications; main benefits of switching
to induction hardening of gears are related
to a significant reduction in process steps
and fabrication costs, ease achievement
of compressive residual stress, and lower
distortions, in order to eliminate the grinding
process. Though, traditional furnacebased
case hardening still represents the
choice of reference when performance
requirements are particularly demanding,
either for the critical operating conditions
or safety-related issues.
An accurate optimization of the induction
treatment by numerical means can
speed-up the process development and
help meeting design specifications and
mechanical requirements (Fig. 7).
During induction hardening an high
intensity magnetic field is generated by a
contour single-turn coil, and high intensity
currents are induced, heating the treated
workpiece by Joule effect.
The induced power density distribution
is mainly function of the material’s properties
and frequency/ies of the exciting
magnetic field.
The hardening process is generally carried
out in two phases: a medium frequency
(i.e. 5 to 20 kHz) pre-heating stage, in which
the root of the gear is brought to a temperature
close to 500 °C, and a high frequency
(i.e. 100 to 400 kHz) heating stage that give
the characteristic contour profile to the gear,
reaching a superficial temperature of 1,000
to 1,100 °C in few tenths of second (Fig. 8).
In this way, it is possible to localize the treatment
only in a superficial layer, generally
thinner than a millimeter.
An electromagnetic and thermal coupled
numerical simulation (FEM) can be developed
in order to predict the temperature
distribution during the heating process.
LEP is working about induction hardening
with several industrial partners. LEP
also participates to the EU project ‘ESPOSA’,
together with other 39 companies and
research institutions from 15 European and
non-European countries.
Magneto Fluid Hyperthermia
Magneto Fluid Hyperthermia (MFH) is one
technique among clinical applications of
hyperthermia for the tumor treating. MFH uses
magnetic NanoParticles (NPs) dispersed in a
fluid in order to heat locally a tumor mass. This
technique provides a temperature rise that can
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damage tumor cells because heating a tumor
up to 42 °C can induce the cell apoptosis.
In this technique magnetic NPs are
injected in the human tissues and heated
by means of an external AC magnetic
field. The target of MFH treatment is to heat
uniformly and locally the tumor region. In
order to improve the effectiveness of this
kind of therapy, our laboratory has evaluated
new designs of the heating systems by
means of numerical simulation and optimization
algorithms (Fig. 9). These numerical
simulations are mostly intended to optimize
the thermal source depending upon the
NPs dimension and concentration.
The proposed solution is based on
Loney’s solenoid scheme, that gives the
possibility of adapting the induction coil
shape to the various physical conformations
of different patients and to the different region
to treat (e.g. thorax or leg).
The final goal of the research is the design
of the full therapy treatment planning.
Fig. 8: Temperature distribution at the end of high frequency stage; isotherm
at 950°
Electrochemotherapy
Electrochemotherapy (ECT) is a cancer therapy
that uses pulses of electric field in order
to open some “pores” on cell membrane
that improve the delivery of chemotherapeutic
drugs into cancer cells (Fig. 10a). It is
well known that, if the electric field strength
overcomes a suitable threshold, it induces
the reversible cell membrane permeabilization.
In standard clinic therapy, the electric
field is applied to tumor tissues by means
of needle electrodes suitably positioned in
the target volume.
Therapy optimization is searched in order
to improve effectiveness. A multiobjective
optimization method based on NSGA
algorithm has been used to search optimal
positioning of needles in the tumor mass to
maximize the sub-volume where the electric
field overcomes the electroporation
threshold and preserve healthy or critical
area. Fig. 10b shows an optimized electrode
configuration and the electric field intensity
on tumor (T) and healthy (H) tissue.
Fig. 9: Color shade of temperature for optimized MFH treatment planning and optimized position of the inductors (Loney’s solenoid)
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T
H
(a)
(b)
Fig. 10: (a) Principle of the electrochemotherapy, (b) electric field generated by an optimized 8-electrodes configuration
Microwave Heating
LEP has recently started to research about
applications of microwave heating (Fig. 11).
Nowadays microwave ovens for household
use and industrial installations at 2.45 GHz
frequency band use magnetrons as a high
power sources of microwave energy. Those
bulky and old-fashioned devices characterize
with limited efficiency of energy conversion
from power supply to microwaves.
They are also difficult to control, which
leads to mismatch losses due to significant
changes in reflection characteristics of the
resonant cavity caused by large variations
of load parameters (permittivity, loss tangent)
as a function of its temperature.
New semiconductor technologies allow
us for building innovative high power microwave
sources. They exhibit great advantages
over magnetrons like a precise frequency,
phase and output power level control ability.
It is clear that the absorption of microwave
energy in foods is dependent on
both the electromagnetic fields and the
microwave penetration pattern in the
food material. The field distribution is in
turn strongly influenced both by the type
of cavity, the waveguide system, as well as
by the type, shape and distribution of the
food inside the oven.
Although traditionally extensive experimentation
was the major technique
exploited in the development of microwave
(MW) applicators, it has been
recently realized that advanced computer
simulation could make the design of
the MW heating systems more intelligent
and thoughtful, shorten the development
time, and reduce the project’s cost.
LEP is also involved in a EU FP7 project,
‘High efficiency electronic cooking systems
HEECS’, which main goal is the design of an
Fig. 11: Experimental set-up for microwave heating measurements, on the right: the simulation of microwave heating of a agar sample
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Fig. 12: Participants to HES_07 are attending to the banquet of the Symposium
innovative microwave oven in cooperation
with industrial and academic partners.
OTHER ACTIVITIES
High performance computation for
numerical modeling
In most industrial cases, induction heating
processes involves many different fields of
physics, i.e. electromagnetic fields, thermal
exchange, mechanical stresses, metallurgical
phase transitions, fluid dynamics and other
aspects. Thus, it is necessary to analyze multiphysics
phenomena, not only by taking into
account all the physics but also the correct
interaction among them. This kind of virtual
prototyping yields to very complex numerical
simulations, characterized by a rapidly growing
computational cost, in terms of very long
computing time and large need of numerical
memory.
With the purpose of reducing the computing
time, and to facilitate the design and
optimization of new processes, the most
recent parallel hardware architectures and
the most advanced numerical methods
and parallelization techniques have been
exploited to reduce the solution time of a
commercial Finite Element software.
Thanks to fruitful cooperation with
software houses (a special mention has
to be done to Cedrat s.a., the French software
house that develops Flux2-3D and
INCA software) and international research
teams, the computing time and memory
needs have been considerably reduced
and now results of complex multi-physics
simulation of induction heating processes
can be obtained in a reasonable time.
International Collaborations
LEP intensively collaborates with several
Academic Intuitions worldwide. In particular,
we acknowledge the active and
fruitful scientific and didactic collaborations
with Leibniz University of Hannover
(Germany), University of Silesia in Katowice
(Poland), Ècole de Technologie Supérieure
in Montreal (Canada), Saint Petersburg
Electrotechnical University “LETI”, Samara
Technical University, Novosibirsk Technical
University (Russia).
LEP collaborates also with University of
Pavia, prof. DiBarba, in the field of inverse
problems and optimization techniques.
HES-13
Since 1998, LEP and the Department of Industrial
Engineering organize in Padua the triannual
International Symposium HES - Heating
by Electromagnetic Sources (Fig. 12).
The HES conferences have became a traditional
appointment for all the researchers
in the field of electroheating technologies,
encouraging the meeting of Industries and
Academic Institutions.
The next conference, HES-13, will be
organized in Padova on 21-24 May 2013.
For further information, please look to the
Symposium website: www.hes-13.com.
During the conference, authors coming
from about 20 different countries will present
the latest results of research and industrial
development activities in the field of: Induction,
Conduction, Dielectric, Microwaves Heating
and EMP (Electromagnetic Processing).
LEP invites you to attend the conference!
LITERATURE
[1] Lupi, S.: “Research in the field of induction heating
at the university of Padua”, Lecture given
at the Dept. of Electrical Engineering, Dec. 13,
2010, ed. SGE, Padua (Italy), 33 pp., http://www.
die.unipd.it/~lupi/
[2] Lupi, S.; Dughiero F.; Forzan, M.: “LEP-Laboratory
for Electroheat of Padua University”, HES-
04 - Heating by Electromagnetic Sources Conf.
Proc. (Padua, June 22-25, 2004), (2004), XXI-
XXXII; printed in Elektrowaerme international,
n.1, March 2004, 30-36
[3] Dughiero, F.; Forzan S.; Lupi S.: “Research in the
Field of Electroheat at LEP – Laboratory for
Electroheat of the University of Padova”,
AMPERE 2011, 13 th International Conference on
Microwave and High Frequency Heating, 5-8
September 2011, Toulouse - FRANCE
[4] Lupi S.: “Survey on Induction Heating Development
in Italy”, Conf. HISTELCON 2012, Pavia
(Italy), Sept. 2012
[5] Dughiero, F.; Forzan, M.; Lupi, S.: “Induction
heating of aluminum billets rotating in a DC
magnetic field”. Proc. of VIII Int. Conf. on Prob-
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lems of Control and Modeling Complex Systems,
Samara - Russia, June 24-29, 2006, pp.
171-176
[6] Araneo, R.; Dughiero, F.; Fabbri, M.; Forzan, M.;
Geri, A.; Lupi, S.; Morandi, A.; Ribani, P.; Veca, G.:
“Electromagnetic and thermal analysis of the
induction heating of aluminum billets rotating
in DC magnetic field”, HES-07 – Heating by
Electromagnetic Sources, June 19-22, 2007, vol.
1, pp. 487-496. ISBN 88-89884-07-x, Padua:
Sgeditoriali (Italy); printed in COMPEL, vol.27,
No.2, 2008, 467-479, ISSN 0332-1649
[7] Forzan, M.; Lupi, S.; Morandi, A.; Spagnolo, A.:
“Edge effects in aluminum billets heated by
rotation in DC magnetic field”. HES-07 – Heating
by Electromagnetic Sources, June 19-22,
2007, 317-324, ISBN 88-89884-07-x., Padova:
Sgeditoriali (Italy)
[8] Lupi, S.; Forzan, M.: “A promising high efficiency
technology for the induction heating of
aluminium billets”, XI Int. Congress on Electricity
Applications UIE’08, Krakòw (Poland), May
19-21, 2008; printed in ELECTRICAL REVIEW
(Poland), n.11, 2008, 105-110
[9] Fabbri, M.; Forzan, M.; Lupi, S.; Morandi, A.;
Ribani, P.L.: “Experimental and Numerical Analysis
of DC Induction Heating of Aluminium
Billets”. IEEE Trans. on MAGNETICS. Vol.45, n.1,
January 2009, 192-200
[10] Dughiero, F.; Forzan, M.; Lupi, S.; Nicoletti,
F.:”Aluminium billets heated by rotating magnets:
comparison of analytical and numerical
results”, XII Int. Conf. on Complex Systems: Control
and Modelling Problems, June 21-23,2010,
Samara (Russia), 67-73, ISBN 978-5-93424-476-8
[11] Dughiero, F.; Forzan, M.; Lupi, S.; Nicoletti, F.;
Zerbetto, M.: “A new high efficiency technology
for the induction heating of non magnetic
billets”, HES-10 Conf. Proc., Padua, May 18-21,
2010, 531-538; printed in COMPEL, Volume 30,
Number 5, 1528-1538, 2011
[12] Bullo, M.; Dughiero, F.; Forzan, M.; Zerbetto, M.:
“Experimental Analysis of an Innovative High
Efficiency Aluminium Billet Heater”, Proceedings
of EPM 2012, 24-26 October 2012, Beijing,
China
[13] Dughiero, F.; Forzan, M.; Ciscato, D.: “A new DSS
furnace for energy saving in the production of
multicrystalline silicon”, 35 th IEEE Photovoltaic
Specialists Conference, Honolulu, 20-25 June
2010
[14] Dughiero, F.; Forzan, M.; Ciscato, D.; Giusto, F.:
“Multi-crystalline silicon ingots growth with an
innovative induction heating directional solidification
furnace”, 37 th IEEE Photovoltaic Specialists
Conference, Seattle, 19-24 June 2011
[15] Dughiero, F.; Forzan, M.; Ciscato, D.; Giusto, F.;
Spagnolo, A.; Doni, A.: “Retroactive insulation
system for highly effective thermal control in
an induction heating DSS furnace for Si-ingot
casting”, 5 th International Workshop on Crystal
Growth Technology, Berlin, 26-30 June 2011
[16] Dughiero, F.; Forzan, M.; Giusto, F.; Doni, A.: “A
new induction DSS furnace for the production
of multi crystalline silicon ingots”, 5 th Int. Workshop
on Crystalline Silicon Solar Cells, Boston,
1-3 November 2011
[17] Dughiero, F.; Forzan, M.; Doni, A.; Giusto, F.;
Tolomio, A.: “A lab scale induction DSS furnace
for crystalline silicon growth”, 4 th European
Conference on Crystal Growth, Glasgow, 17-20
June 2012
[18] Doni, A.; Dughiero, F.: “Electrothermal Heating
Process Applied to c-Si PV Recycling”, 38 th IEEE
Photovoltaic Specialists Conference, Austin,
3-8 June 2012
[19] Lupi, S.; Dughiero, F.; Forzan, M.: “Modelling
Single- and Double-Frequency Induction Hardening
of Gear-Wheels”, EPM 2006 – The 5 th
International Symposium on Electromagnetic
Processing of Materials, Sendai (Japan), October
23-27, 2006, 473-478, ISBN 4-930980 C3057
[20] Candeo, A.; Ducassy, C.; Bocher, P.; Dughiero,
F..: “Multiphysics Modeling of Induction Hardening
of Ring Gears for the Aerospace Industry”,
IEEE Transactions on Magnetics, Vol. 47, No. 5
(2011), 918-921
[21] Candeo, A.; Bocher, P.; Dughiero, F.: “Multiphysics
Modeling of Induction Hardening of Ring
Gears for the Aerospace Industry”, CEFC 2010,
14 th Biennial IEEE on Electromagnetic Field
Computation Conf. Proc., no. 5481552
[22] http://www.esposa-project.eu
[23] Gneveckow, U.; Jordan, A.; Scholz, Volker; Brüß,
R.; Waldöfner, N.; Ricke, J.; Feussner, A.; Hildebrandt,
B.; Rau, B.; Wust, P.: “Description and
characterization of the novel hyperthermia
and thermoablation-system MFH®300F for clinical
magnetic fluid hyperthermia”, Med. Phys.,
2004, 1444-1451
[24] Di Barba, P.; Dughiero, F.; Sieni, E.: “Magnetic
field synthesis in the design of inductors for
magnetic fluid hyperthermia”, IEEE Trans. on
Magnetics, 46, 2010, 2931-2934
[25] Di Barba, P.; Dughiero, F.; Sieni, E.; Candeo, A.:
“Coupled field synthesis in magnetic fluid
hyperthermia”, IEEE Trans. on Magnetics, 47,
2011, 914-917
[26] Di Barba, P.; Dughiero, F.; Sieni, E.: “Synthesizing
a nanoparticle distribution in magnetic fluid
hyperthermia”, COMPEL - Int. J. for Computation
and Mathematics in Electrical and Electronic
Engineering, vol. 30, n. 5, 2011, 1507-1516
[27] Di Barba, P.; Dughiero, F.; Sieni, E.: “Synthesizing
Distributions of Magnetic Nanoparticles for Clinical
Hyperthermia”, IEEE Trans. on Magnetics,
vol.48 (2), 2012, 263-266
[28] Candeo, A.; Dughiero, F.: “Numerical FEM
models for the planning of magnetic induction
hyperthermia treatments with nanoparticles,”
IEEE Trans. on Magnetics, vol.45, 2009, 1654-
1657
[29] Campana, L.; Mocellin, S.; Basso, M.; Puccetti,
O.; De Salvo, G.; Chiarion-Sileni, V.; Vecchiato,
A.; Corti, L.; Rossi, C.; Nitti D.: “Bleomycin-Based
Electrochemotherapy: Clinical Outcome from a
Single Institution’s Experience with 52 Patients”
Annals of Surgical Oncology, 16 (1), 2009,
191-199
[30] Di Barba, P.; Campana, L.G.; Dughiero, F.; Rossi,
C.R.; Sieni, E.: “Optimal Needle Positioning for
Electro chemotherapy: a Constrained Multiobjective
Strategy” , in press to IEEE Trans. on
Magnetics, 2013
[31] Bressan, F.; Bullo, M.; Dughiero, F.: “Experimental
validation of numerical analysis and optimization
of household microwave ovens”, Proceedings
IMPI’s 46 th Annual Microwave Power
Symposium 2012
[32] http://www.eniac.eu/web/downloads/projectprofiles/call3_heecs.pdf
Authors:
F. Dughiero
M. Forzan
M. Bullo
F. Bressan
A. Doni
C. Pozza
E. Sieni
M. Spezzapria
A. Tolomio
Contact:
University of Padova
Dept. of Industrial Engineering
via Gradenigo 6/a
35131 Padova, Italy
www.dii.unipd.it
88 heat processing 1-2013

Edition 5
FOCUS ON
”Global presence is a must for
the company”
Dr. Hermann Stumpp is Chief Technology Officer of TENOVA Iron & Steel Group. In this
interview with heat processing he talks about the future of the energy industry and technological
challenges, revealing his own personal energy-saving achievement.
How do you assess the future ranking of fossil fuels
such as oil, coal and gas?
Stumpp: Coal, oil and gas term should be considered as
valuable ‘chemical’ resources. On the longer term their
usage as fuel should be reduced essentially whereby a
main reason is also the minimization of CO 2 emissions into
the atmosphere.
Irrespective of the form of energy and the technology
used, many consider the term “energy-efficiency” to
be the key to the energy questions of the future. How
do you view this subject? What do you consider to be
the most important development in this field in the
heat-processing technology industry?
Stumpp: As discussed above a high consumption of
energy – to which a low ‘energy efficiency’ might contribute
– is especially undesirable if fossil fuels are the
energy source as high emissions will occur. In this case
good ‘energy efficiency’ is very desirable. In case of no
emissions as with usage of renewable energies ‘energy
efficiency’ is more a question of costs.
In your opinion, how will energy consumption in industry,
commerce and domestic households change?
Stumpp: According to newest publications of the German
government the consumption of energy in 2011 was: industry
30 %, transportation 29 %, households 25 % and others 16 %.
This means we should not forget the sector transportation.
Especially airplanes are more or less just gigantic combustion
machines and are using fossil fuels and thus causing
the undesirable emissions. I guess that a German 3-person
family consumes for a holiday flight to Far East at least
10 times more fuel than if they would go by car to the
Mediterranean area. And air traffic is forecasting further
massive growth. Technologies for usage of other energies
in airplanes are actually not in sight. Political resistance on
the global level makes it difficult to influence the fuel prices
in an appropriate way as in case of ground transportation.
In the various parts and regions of the world the
households are exposed to quite different conditions
from social environment, income to climate etc.. E.g. air
condition with a power of 2 kW with electrical energy
generated in a solar panel has environmentally other
implications than 2 kW heating with fossil fuel. A real
full comparison is difficult. This allows flexibility to develop
the energy policy in the field of households more
independently from other regions and thus rather fast.
It is my impression that in the private sector within the
German society the consciousness for ecological aspects
anyway is developed already quite well.
In contrary to the households the major part of the industry
however has to act under global competition. Without
losing totally the competitiveness major changes in the
energy policy need co-ordination on the global level. The
experience of the last years shows that this is quite complicated.
Currently just the German industry is sincerely
confronted with this problem.
In summary I see therefore the fasted changes in the field
of the households.
What role does your company currently play on the
energy market?
Stumpp: LOI and the other branches of TENOVA Iron &
Steel are suppliers of equipment for processes which require
large quantities of energy. With our technologies we
are setting and corresponding to the highest standards
concerning ecology in this field.
How do the expansion of the EU and globalization affect
your company and its business?
Stumpp: We have seen the necessity for global presence
already 20 years ago and have correspondingly established
it; therefore we are prepared for the global developments.
Without question in certain foreign markets local companies
are becoming stronger which 10 years ago might have
been still weak.
1-2013 heat processing
89

FOCUS ON Edition 5
Within the EU we are facing additional regulations and
efforts for standardisation of technologies and even for definition
of ‘Best Available Technologies’. This might however
not only to be seen negative as it will contribute to transparency
such that our high technical standards are valued.
How important is a trade name or a brand for the success
of products in the industrial sector?
Stumpp: Our customers are investing in huge projects and
will have to work with the equipment delivered by us for
many years. The reliability of our work is for them of key
importance. The long term satisfaction of many customers
but also the technology level of a company are forming
the value of a brand. The brand and thus image is in our
business of greatest importance. It takes not less than 20
years to build up a top brand.
Does a management team need greater media capabilities
in order to convince investors?
Stumpp: Amongst the capabilities a management must
have are to develop visions for the company, to convey
these to customers, employees and as well as from time
to time to the shareholders. Media are one way of communication
for this.
How important is expansion abroad for your company?
Stumpp: Global presence is a must for the company, mainly
for two reasons: you have to be able to reach the moving
markets at any time; there are customers with a global set
up which are requesting that you are available for them
on site wherever they are active.
How receptive is your company to new technologies?
Stumpp: During the past 10 years we have become globally
well known for accepting the technically as well as
size wise most challenging projects in our business. This
has given us the leading edge in several fields and we will
continue this policy.
What do you think the people around you particularly
appreciate about you?
Stumpp: You better ask these persons.
How do you manage to be sure of some time for yourself,
and not always to be dealing with internal and
external challenges?
Stumpp: From my view to enjoy time for yourself is only
really possible after you have done what you feel is necessary
to comply properly with the challenges of the business.
Do you, or did you, have any people whom you regard
as examples to you?
Stumpp: Not in general.
What is your motto for life?
Stumpp: Make sure that you can look back to your life with
saying ‘I have done what was in the range of my capabilities
and what was necessary’.
What personal characteristics are most important to you?
Stumpp: Passion, loyalty and reliability.
When do you not think about your work?
Stumpp: Time wise when enjoying music and sports.
What is your own personal tip for the upcoming generations?
Stumpp: They will and have to find their own ways.
Thank you for this interview.
“Energy efficiency
is more a question
of costs.”
90 heat processing 1-2013

Edition 5
Powered by
FOCUS ON
RESUME
Dr. Hermann Stumpp
Date of birth: 19 of December 1948
Place of birth: Hirrlingen/Tübingen, Germany
Married and three children
INTERNATIONAL
THERM
PROCESS
SUMMIT
Current job:
Chief Technology Officer of TENOVA Iron & Steel Group
Organized by
Studies:
Secondary education at the Eugen-Bolz Grammar School In Rottenburg
am Neckar, Germany
Studied Physics at the Eberhard-Karls University in Tübingen, Germany
Received the Dr. Friedrich-Förster Prize for his degree and doctorate
thesis in the field of electron optics and electron-beam technology
Completed a six-term university course in business administration
Career:
1984: Leybold-Heraeus GmbH in Hanau, Germany: Project
Engineer, Product-sector manager and Head of the
Vacuum Metallurgy division
1991: moved to LOI Thermprocess GmbH in Essen, Germany
1994: LOI Thermprocess GmbH in Essen, Germany: Chairman
of the management board of LOI Thermprocess
GmbH
Since 2011 Chief Technology Officer of TENOVA Iron + Steel Group
The Key Event
for Thermo Process
Technology
Congress Center
Düsseldorf, Germany
09-10 July 2013
1-2013 heat processing
www.itps-online.com
91

FOCUS ON
Statement
Energy and global natural resources –
from the point of view of the Furnace
Industry
The furnace industry and its product range as represented by the association Thermoprozesstechnik
within German VDMA and the European association CECOF
by Dr. Hermann Stumpp
Two of the current main challenges for man kind
are the careful usage of all natural resources on
earth and the limitation - or better - reduction of
the emission of greenhouse gases into the atmosphere.
In short: we have to behave ecologically beneficial. The
exploitation of natural resources and the emission of CO 2
as the most important greenhouse gas are to a very high
degree determined by the generation of a high share of
the energy consumed today from the fossil fuels oil, gas
and coal. Only a small share is used in a valuable way
directly for ‘chemical’ applications. Since this dependency
can only be reduced slowly all possible efforts have
to be done to reduce the consumption of energy and
at the same time to increase the ‘energy efficiency’ of all
systems. As nuclear power for known reasons is as well
not a desirable source of energy globally great efforts
are ongoing to develop the so called ‘renewable energies’.
The two most important related technologies are
currently photovoltaic power generation and usage of
wind energy. Both are providing directly electrical energy
and thus are avoiding the exhaustive usage of natural
resources as well as the emission of greenhouse gases.
From the warming up of the earth observed during the
past years has to be deducted that the development
actually has to be as fast as possible.
On the other hand the problem of balancing the contributions
of the various countries on earth to this goal is
complicated. Especially in Germany the political pressure
92 heat processing 1-2013

Statement
FOCUS ON
for the so called ‘energy turnaround’ is high such that the
question arises whether the German industry will survive
these efforts without significant damage of its dynamism and
competitiveness. Besides the burden caused by the financial
crisis of the past years it has to be kept in mind that a balance
should remain between the realization of the energy goals
and the performance of the industry and society.
The manufacturers of Industrial Furnaces are aware that
the equipment supplied by them is utilizing a not insignificant
share of energy resources, whereby fossil fuels play
the most important role. Concerning share of the business
and especially concerning utilization of energy and thus
emissions the steel industry represents the largest customer
group for the furnace industry. In Germany the steel
industry consumes approx. 30 % of the overall industrial
energy consumption. Within the process route from the
iron ore to the semi finished steel products hereof the share
of energy consumed in industrial furnaces can reach 15 %
(this means approx. 4.5 % of the consumption of the whole
industry) whereby coke oven plants, blast furnaces, electric
arc furnaces, ladle furnaces are not sub summarized under
Industrial Furnaces but under Metallurgical Equipment.
As furnaces are also applied in other industrial sectors the
overall share of the furnaces will be above 5 %.
The main field of application of Industrial Furnaces
lays in the production of metals which are besides steel
non-ferrous and light metals. Besides just heating up of
the material for subsequent forming processes the even
more important field is ‘heat treatment’ of these metals
but also of ceramic materials and glas. Typical temperatures
in industrial furnaces are in the range of 600 to
1,500 °C. The purpose of ‘heat treatment’ is to modify
the physical properties of the materials by undergoing
temperature profiles in combination with process gas
atmospheres but also cooling processes. Especially in
case of heat treatment the material has to dissipate the
heat energy again within the furnace line. This means
that heat recovery will be a focus for the future.
For the large scale heating to high temperature the
combustion of fossil fuel is nearly unavoidable. The efficiency
of the heat input into the furnace can even exceed
80 %. Electrical heating can be advantageous in specific
applications even if the efficiency of the heating itself will
be less than 40 % if the generation of the electrical energy
from fossil fuel is considered.
The manufacturers of Industrial Furnaces but also the
government authorities are since long already focusing
efforts on the energy efficiency whereby mainly the
heating systems have been optimized. Drivers for this
development were on the one hand the goal of reducing
the energy consumption but also continuously
sharpening legal regulations concerning limitation of
emissions. Besides the technical progess in the combustion
systems sophisticated process automation systems
and off- and online process simulations were introduced.
These efforts will have to continue however I see not
unlimited potential.
We have to investigate complete heat processing lines
and even whole process lines of which the furnaces are a
limited portion.
A peculiarity of industrial furnaces can be recognized
from the following comparison: The price of the
energy (fossil fuel) consumed by a car within a life time
of ten years reaches typically not more than 5 % of its
purchasing price, whereby the portion of tax on gasoline
is neglected. Depending on the application of furnaces
and based on the current price of natural gas in Europe
the costs for energy consumed in a furnace in one year
can reach 100 % of its investment costs. Considering
the first ten years of operation the buyer determines
with the selection of the equipment energy costs which
are ten times of the initial investment. It is obvious that
the furnace makers will have to propose options for
reduced energy consumptions whereby increased
investment costs will have to be balanced versus the
energy consumption and thus emissions and costs. In
the past energy costs and emissions played a minor
role for investment decisions. This will change and new
balances will have to be found.
As discussed above a high consumption of energy – to
which a low ‘energy efficiency’ might contribute – is especially
undesirable if fossil fuels are the energy source as high
emissions will occur. In this case good ‘energy efficiency’
is very desirable. In case of usage of renewable energies
where emissions do not occur ‘energy efficiency’ is more
a question of costs.
1-2013 heat processing
93

Handbook of
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TECHNOLOGY IN PRACTICE
Pot furnace transfer line for the aeronautics
and automotive industry
SOLO Swiss, manufacturer of controlled
atmosphere furnaces since 1945, just
launched a Profitherm 1000 heat treatment
transfer line for the Asian aeronautics and
automotive industry (Fig. 1).
This SOLO Swiss line, designed to treat
parts up to 3 m long, such as 45CrNiMoVA
transmission shafts, includes a load transfer
bell, a vertical austenitizing, carburizing and
carbonitriding pot furnace up to 950 °C, a
120 °C oil tank, a nitrogen-controlled tempering
furnace, a tempering furnace under
N 2 atmosphere, a washing machine with
oil separator, a loading, unloading and storage
area, and an AXRON Swiss Technology
control and oversight system (www.axron.
com). Treatment is carried out in a controlled
atmosphere to avoid any superficial weathering
on small-diameter parts.
CUSTOMER SPECIFICATIONS
■■
■■
■■
■■
Homogeneous quenching over the entire
length of the part
Decarburizing less than 0.05 mm
No carburizing and a homogeneous
structure according to Chinese National
Aviation Standard HB5354
No tolerance for exceeding the carbon
potential setting
Fig. 2: Loads of up to 850 mm in diameter
and 3,000 mm in height for a
weight of 1,000 kg
■■
■■
■■
■■
■■
■■
■■
Microstructure after quenching: carbide
class ≤ image type 3, martensite class ≤
image type 3, residual austenite class ≤
image type 3
Carbon potential strictly controlled in a
stable manner between 0.4 and 0.6 %
Control of hydrogen enrichment
Heating of a 1,000 kg load in less than
two and a half hours
Furnace temperature uniformity within
± 8 °C
Precision in temperature control within
± 1 °C
Precision in carbon potential control
within ±0.05 %
■■
Gases required: N 2 , C 3 H 8 , CH 3 OH+N 2
■■
Floor space required: length 20 m, width
4 m, depth 5 m, height 5.10 m
■■
■■
Simply designed and easy to use
Easy repair and maintenance.
This installation can handle loads of
up to 850 mm in diameter and 3,000 mm
in height for a weight of 1,000 kg in the
aeronautics, aerospace, automotive and
weapons industries (Fig. 2).
As soon as the treatment recipe is launched,
the load is retrieved at transfer station
No. 1, which transports it on the first programmed
station in the cycle, in this case,
the quenching furnace in station 3.
Once the load is placed in the furnace,
the treatment cycle can then begin.
The transfer of the load from the furnace
into the oil tank (station 4) takes place
via the transfer station (belt). The load can
thus travel shielded by gas. After positioning
the belt on the oil tank, the transfer belt‘s
elevator takes the load to immerse it in the
tank. The descent of the furnace into the
tank takes place in less than ten seconds.
Once quenching has occurred, the parts
then pass into the washing machine (station
5), from which they are transferred in
the tempering furnace according to the
planned recipe (Fig. 3).
GASES
In this case, the parts are treated with a carbon
potential controlled by an oxygen sensor
and a CO/CO 2 analyzer. The atmosphere
is obtained in the bell furnace by direct
cracking of methanol. The gas distribution
system is composed of:
■■
■■
■■
Fig. 1: Heat treatment transfer line
two streams of methanol sprayed with
nitrogen, equipped with flow-control:
a small stream for the treatment and a
large flow to transfer loads
a mass flowmeter for propane, air and
ammonia
three separately adjustable nitrogen
flows (safety, venting and cycle).
It is thus possible to quickly switch from a
methanol atmosphere to a methanol/nitrogen
atmosphere, which allows to work just
as well with 32 % CO (to enable high transfer
coefficients to work) as with lower CO % (to
limit intergranular oxidation and also reduce
the % H 2 of the carburizing atmosphere).
1-2013 heat processing
95

TECHNOLOGY IN PRACTICE
Propane decomposes into carbon,
The recipe can include as many steps
C 3 H 8 3C + 4H 2 separately in order to maximally limit weathe-
as necessary. In each step all the parameters
cited above are definable: temperature,
which immediately reacts with dioxide in
this reaction:
speed of temperature increase,
holding period, turbine speed, choice of C + CO 2 2CO
carrier gas, choice of additional gas (NH 3 ),
CO value, regulation of carbon potential,
choice for means to measure carbon
potential (sensor or analyzer), regulation
of carbon potential without air or without
propane, etc. The treatment recipe becomes
a true metallurgical recipe in which
each parameter is an ingredient that can
The role of the liquid fuel is to maintain
the carbon potential at a constant value. In
carbonitriding, ammonia is added to the
basic atmosphere. Part of the nitrogen from
the dissociation of ammonia penetrates into
the crystal lattice of the steel by causing an
increase in the hardenability.
be adjusted as needed to best optimize
this range. Each step is equivalent, for 2NH 3 N 2 + 3H 2
example, to an area of an pusher furnace,
but the difference here is that the steps
are unlimited.
THE DIFFERENT MODULES
The furnace (station 2)
The furnace is equipped with six independent
ATMOSPHERE
The introduction of methanol gives the carrier
gas, formed essentially of carbon monoxide
and hydrogen, a gas for which the
transfer coefficient of carbon is excellent.
heating areas with a cascade control to
respect the homogeneity of ± 8 °C requested
by the customer over the entire height
of the furnace.
It is outfitted with several gas injectors
and a turbine of the latest generation equipped
with a frequency converter.
CH 3 OH CO + 2H 2
A muffle (bell) of heat-resistant steal constitutes
the core of the furnace to obtain a good
CO + H 2 0 CO 2 + H 2
CO + 3H 2 CH 4 + H 2 0
homogenization of the gases and a perfect
2H 2 O 2H 2 + O 2
exchange between the gases and the parts.
To regulate the potential, a liquid fuel
rich in carbon with no oxygen content (for
example, propane), is needed.
The tank (station 4)
With a 12,000 l oil capacity, the tank is equipped
with two beaters that can be activated
ring on long parts. A cooler keeps the temperature
homogeneous, even during quenching.
It is also equipped with a nitrogen injector.
The transfer bell (station 1)
This allows for moving loads in hot or cold. It
is composed of several gas injection systems
in order to permit a furnace/tank transfer in
a shielded atmosphere to avoid any decarburizing
or oxidation. It also has a door to
better shield the load.
Its movement from one station to another
takes place at variable speeds. The
converter for the movement system of the
transfer bell guarantees precise positioning.
The washing machine (station 5)
It is composed of two tanks laid out in cascade,
with a sprinkling system made of booms
with rotating nozzles and bath-heating that
can go up to 100 °C.
An oil catcher, hooked up to the washing
machine, separates the oil from the water
and recycles the washing water.
The tempering furnace (station 6)
The tempering furnace, which can reach
temperatures of 650 °C, is equipped with
shielding gas and a blade turbine positioned
to obtain a better homogenization of temperatures
around 180 °C.
Preparation station (station 2)
Once the load has been assembled by the
operator, it is placed in this transit station
Fig. 3: Pathway of loads
on the line
Fig. 4: Transfer
bell
96
heat processing 1-2013

TECHNOLOGY IN PRACTICE
before being transported into the treatment
furnace by means of transfer bell
No. 1 (Fig. 4).
AXRON control and oversight system
With its intuitive graphic interface, the
AXRON system is simple to use: clear functions,
with texts and alarms in the customer‘s
language, facilitate control. This a system is
based on the latest industry standards with
100 % Siemens upgradeable equipment.
The software is scalable and modular, precise
and safe: security process compliant
with the ATEX standard.
OPERATIONS
■■
■■
■■
■■
■■
■■
■■
Temperature regulation (cascade)
Regulation of % C (oxygen weld and
CO-CO 2 analyzer)
Offline simulation and online calculation
of the diffusion of carbon in the part,
effective depth, surface carbon and
weight increase
Screens defining the calibration parameters
of the instruments and measurement
sensors (SAT) and the heating
chamber (TUS); traceability of all the
parameter modifications (date, time and
name of the operator)
Management of families, with notion of
recipe, cycle, subcycle and steps, structure
of treatments and very granular operational
elements. Start-stop by weekly
schedule, delayed start of treatments
Management of parts: entry of miscellaneous
information on the part (name,
operation, weight, customer, comments
and load information); part-family link
Management of guided records for loads,
with numerous research criteria (date,
■■
family, part, order no., manufacturing
order, item 1, item 2, configurable for the
customer), generation of paper reports
Automization of loading, unloading and
of the quenching sequence with secured
manual control functions and complete
automization of installation.
Thanks to solid foundations, the customer
has a guarantee of the durability of its
technical choice, which assures an excellent
duration of its system; a continuously
improved ergonomic system; a very flexible
malfunction response capacity and
a simplified integration of its production
management.
Experience shows that with such a
system, the start times are cut in half at
the beginning, an interface which is much
appreciated by the operators.
PERFORMANCE OF THE SOLO
SWISS LINE
■■
■■
■■
■■
■■
■■
Safety: no contact with hot parts
Quality: no oxidation during transfer
Reliability: automatic transfer of the furnace
into the tank
Minimized output of effluent: quenching
takes place in an enclosed space
Economical: Thanks to the design of the
muffle around the load, the consumption
of treatment gases is much smaller
and thus less costly than those of other
batch-type furnaces
Homogeneity of quenching: the design
of the quenching tank that is separate
from the heating chamber guarantees
a perfect quenching homogeneity over
all the treated parts thanks to the quality
■■
■■
■■
■■
■■
■■
■■
of thermal exchange in quenching that
is unequaled in a batch furnace
Precision: direct furnace/tank transfer
ensures better temperature control
during the quenching phase
Maintenance facilitated by easy accessibility
of all mechanical parts
No weathering of heavily-used parts: no
mechanical movement is subjected to a
high temperature, which also increases
their lifetime
Independent tank/furnace modules:
maximal optimization of their use and
thus higher level of occupancy
Cylindrical muffle for better efficiency:
reproducibility and perfect homogeneity
(± 5 °C)
Treatment gases uniquely in contact with
heat-resistant elements: rapid change
time and perfect thermo-chemical
homogeneity and thus significant energy
savings for a batch-type furnace
Heat-resistant steel muffle allows the
rapid conditioning of the atmospheres
of the different desired treatments.
According to the results obtained, this
line of pot furnaces equipped with a gasshielded
transfer compartment offers a
solution that will interest customers concerned
about treating long parts while guaranteeing
a quality of treatments similar to
removable-cover furnaces.
Contact:
SOLO Swiss Group
Biel, Switzerland
Tel.: +41 (0)32/4659-600
press@soloswiss.com
www.soloswiss.com
Hotline Meet the team
Managing Editor: Dipl.-Ing. Stephan Schalm +49(0)201/82002-12 s.schalm@vulkan-verlag.de
Editorial Office: Annamaria Frömgen +49(0)201/82002-91 a.froemgen@vulkan-verlag.de
Editor: Silvija Subasic +49(0)201/82002-15 s.subasic@vulkan-verlag.de
Advertising Sales: Bettina Schwarzer-Hahn +49(0)201/82002-24 b.schwarzer-hahn@vulkan-verlag.de
Subscription: Martina Grimm +49(0)931/41704-13 mgrimm@datam-services.de
Hotline_184,5x35.indd 2 15.12.11 15:13
1-2013 heat processing
97

PRODUCTS & SERVICES
Carbon fiber production line for processing
of precursor fibers under protective gas
Linn High Therm presents Carbon
fiber pilot line consisting of oxidation
furnace (stabilization), carbonization
furnace and graphitization
furnace. The pilot line includes the 4-zone
oxidation furnace (325 °C) for stabilization
of precursor fibers with connecting 2-step
system for carbonization and graphitization
at temperatures (low temperatures 4-zones
up to 1050 °C, high temperature 4-zones up
to 1600 °C, option 1800 - 2100 °C) and dwell
times with gas supply in between.
Linn High Therm GmbH
www.linn.de
Communication and configuration
with new modem
In addition to the HART-compatible sensors
for virtually every industrial application
such as temperature, pressure, force,
flow and humidity measurement Müller
Industrie-Elektronik offers also a range
of components and accessories for
the industrial measurement and
control technology. This includes
the HART modem DEV-
HM, which can be used in
conjunction with a PC and
the supplied software for
the setup, configuration,
signal analysis, to the point
of data backup and documentation
of a HART field
device. As PC interface
via the supplied
driver, a virtual
COM port will
be created. In
the active operation
mode of
the modem, there
is no additional sensor
supply unit and no further power
supply necessary because of the
built-in loop power, which
have a stand-alone mode to
configure individual devices
and provides galvanic isolation with an insulation
voltage up to 1.5 kVAC between HART
modem and PC. In the passive operation
mode field devices which are already installed
in plants can be configured as usual.
The HART Modem DEV HM can be used to
configure HART-capable field devices directly
connected via USB port to the PC. The
delivery package contains the modem with
a PC software, which includes graphical and
menu-driven control program as well as a
HART cable and a USB cable.
Müller Industrie-Elektronik GmbH
www.mueller-ie.com
98 heat processing 1-2013

PRODUCTS & SERVICES
Applications for leather drying technology
Oerlikon Leybold Vacuum offers optimized
solutions also for applications
for Leather Vacuum Drying Technology.
One of the important operations in
the leather-making process is the removal
of excess water from leather-drying. Leather
acquires its final texture, consistency and flexibility
in the drying operations. Leather Vacuum
Drying is key to augmenting the surface
properties of leather. It enables modification
of the quality of leather, correction of textural
faults and inconsistencies, and increases its
lifecycle significantly. Vacuum Drying involves
leather being placed on a hot plate within
an insulated chamber and its water content
being removed by creating a vacuum inside
the chamber. Vacuum technology is simply
because moisture evaporates more quickly
under vacuum and reduces waste water. The
Indian leather industry, which is dependent
on exports to a very large extent, is sensitive
to this. Moreover, the older technology involving
Liquid Ring Pumps requires post water
treatment, which adds to the cost as well as
reduces efficiency. The DRYVAC pumps are
a new family of dry compressing vacuum
pumps. Depending on the application the
pumps are available with various equipment
components. The DRYVAC series has been
specifically developed for process industry
applications. All versions of the DRYVAC family
are water cooled, compact and can be mounted
to various vacuum systems.
Oerlikon Leybold Vacuum GmbH
www.oerlikon.com/leyboldvacuum
Spetrometer with new applications
for precious metals
Spectro has
equipped the
SPECTRO xSORT
handheld XRF spectrometer
with a new application
package for precious
metal analysis. The portable instrument is able
to identify the gold and silver content in many
jewelry alloys within seconds. In addition, the
XRF instrument’s non-destructive measuring
makes it suitable for applications in archaeometallurgy.
Operation of the instrument is
simple; measurements are conducted at the
press of a button. For precious metal recycling,
the handheld spectrometer offers security for
both buyer as well as seller. The device also has
an optional integrated video camera so the
measuring point can be exactly determined.
Spectro Analytical Instruments GmbH
www.spectro.com
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INDEX OF ADVERTISERS
INDEX OF ADVERTISERS
Company
Page
4th International Cupola Conference 2012, Dresden, 63
Germany Company
Page
AICHELIN Holding GmbH, Mödling, Austria Back Cover
56 th International Colloquium on Refractories 2013,
ALUMINIUM
Aachen, Germany
2012, Düsseldorf, Germany 32
74
ALUMINIUM CHINA 2012, Shanghai, People’s 21
Republic AFC-HOLCROFT, of China Wixom, Michigan, USA
ANDRITZ Maerz GmbH, Düsseldorf, Germany 13
29
ALUMINIUM CHINA 2013,
ANKIROS 2012 / ANNOFER 2012 / TURKCAST 2012,
Istanbul,
Shanghai,
Turkey
People’s Republic of China
22
17
Bloom Engineering (Europa) GmbH, Düsseldorf, 11
ALUMINIUM INDIA 2013, Mumbai, India
Germany
56
Elster ALUMINIUM GmbH, MIDDLE Osnabrück, EAST Germany 2013, Dubai, UAE 07 40
BLOOM ENGINEERING (EUROPA) GMBH, Düsseldorf, Germany 19
Elster GmbH, Osnabrück, Germany 7
Hannover Messe 2013, Hannover, Germany 22
Company
Page
Euro PM2012, ‚Basel, Switzerland 88
FIB BELGIUM s.a., Tubize (Saintes), Belgium 15
HEAT TREATMENT 2012, 2013, Moscow, Russia 27 39
JASPER Gesellschaft für Energiewirtschaft Front Cover
und ITPS Kybernetik 2013, Düsseldorf, mbH, Geseke, Germany Germany Back Cover, 54, 91, 99
LOI Thermprocess GmbH, Essen, Germany 61
JASPER Gesellschaft für Energiewirtschaft
SECO / Warwick THERMAL S.A., Swiebodzin, Poland 35
und Kybernetik mbH, Geseke, Germany 15
Siemens AG, Rastatt, Germany 93
SMS LOI Thermprocess Elotherm GmbH, GmbH, Remscheid, Essen, Germany Inside Front Cover 11
Germany
Schwartz GmbH, Simmerath, Germany
Uni-Geräte GmbH, Weeze, Germany 25
25
SECO / Warwick Europe S.A., Swiebodzin, Poland Front Cover
SMS Elotherm GmbH, Remscheid, Germany inside Front Cover
WS Wärmeprozesstechnik GmbH, Renningen, Germany 53
Business Directory 101-122
International Magazine for Industrial Furnaces,
Heat Treatment & Equipment
www.heatprocessing-online.com
YOUR CONTACT TO THE
HEAT PROCESSING TEAM
Managing Editor:
Dipl.-Ing. Stephan Schalm
Phone: +49 201 82002 12
Fax: +49 201 82002 40
E-Mail: s.schalm@vulkan-verlag.de
Editorial Office:
Annamaria Frömgen
Phone: +49 201 82002 91
Fax: +49 201 82002 40
E-Mail: a.froemgen@vulkan-verlag.de
Advertising Sales:
Bettina Schwarzer-Hahn
Phone: +49 201 82002 24
Fax: +49 201 82002 40
E-Mail: b.schwarzer-hahn@vulkan-verlag.de
Advertising Administration:
Martina Mittermayer
Phone: +49 89 2035366 16
Fax: +49 89 2035366 66
E-Mail: mittermayer@di-verlag.de
Editorial Department:
Silvija Subasic
Phone: +49 201 82002 15
Fax: +49 201 82002 40
E-Mail: s.subasic@vulkan-verlag.de
www.heatprocessing-online.com
100 heat processing 4-2012

International Magazine for Industrial Furnaces
Heat Treatment & Equipment
www.heatprocessing-online.com
2013
Business Directory
I. Furnaces and plants for industrial
heat treatment processes ............................................................................................................................102
II.
III.
IV.
Components, equipment, production
and auxiliary materials .......................................................................................................................................112
Consulting, design, service
and engineering ......................................................................................................................................................120
Trade associations, institutes,
universities, organisations .............................................................................................................................121
V. Exhibition organizers,
training and education ...................................................................................................................................122
Contact:
Mrs Bettina Schwarzer-Hahn
Tel.: +49 (0)201 / 82002-24
Fax: +49 (0)201 / 82002-40
E-mail: b.schwarzer-hahn@vulkan-verlag.de
www.heatprocessing-directory.com

Business Directory 1-2013
I. Furnaces and plants for industrial heat treatment processes
thermal production
Melting, Pouring, casting
102 heat processing 1-2013

1-2013 Business Directory
I. Furnaces and plants for industrial heat treatment processes
Powder metallurgy
Heating
More information available:
www.heatprocessing-directory.com
1-2013 heat processing
103

Business Directory 1-2013
I. Furnaces and plants for industrial heat treatment processes
Heating
104 heat processing 1-2013

1-2013 Business Directory
I. Furnaces and plants for industrial heat treatment processes
Heat treatment
More information available:
www.heatprocessing-directory.com
1-2013 heat processing
105

Business Directory 1-2013
I. Furnaces and plants for industrial heat treatment processes
Heat treatment
106 heat processing 1-2013

1-2013 Business Directory
I. Furnaces and plants for industrial heat treatment processes
More information available:
www.heatprocessing-directory.com
1-2013 heat processing
107

Business Directory 1-2013
I. Furnaces and plants for industrial heat treatment processes
Heat treatment
cooling and Quenching
108 heat processing 1-2013

1-2013 Business Directory
I. Furnaces and plants for industrial heat treatment processes
cleaning and drying
surface treatment
Joining
More information available:
www.heatprocessing-directory.com
1-2013 heat processing
109

Business Directory 1-2013
I. Furnaces and plants for industrial heat treatment processes
Joining
recycling
energy efficiency
110 heat processing 1-2013

1-2013 Business Directory
I. Furnaces and plants for industrial heat treatment processes
retrofit
KNOWLEDGE for the FUTURE
Handbook of Refractory Materials Design | Properties | Testing
This new edition has been completely revised, expanded and appears in a
compact format.
Readers obtain an extensive and detailed overview focusing on design, properties,
calculations, terminology and testing of refractory materials. With the great
amount of information this compact book is a necessity for professional working in
the refractory material or thermal process sectors.
Editors: G. Routschka / H. Wuthnow
4th edition 2012, 380 pages with additional information and
e-book on DVD, hardcover
Handbook
with additional
information
and entire e-book
on DVD
Vulkan-Verlag
www.vulkan-verlag.de
Order now by fax: +49 (0)201 / 82002-34 or send in a letter
Yes, I place a fi rm order for the technical book. Please send me
___ copies of the Handbook of Refractory Materials plus DVD ROM.
4th edition 2012 – ISBN: 978-3-8027-3162-4
at the price of € 80.00 (postage and packing extra)
Company/institution
First name and surname of recipient
Street/P.O. Box, No.
REPLY / ANTWORT
Vulkan Verlag GmbH
Versandbuchhandlung
Postfach 10 39 62
45039 Essen
Germany
Country, postcode, town
Phone
E-mail
Fax
Please note: According to German law this request may be withdrawn within 14 days after order date in writing to Vulkan Verlag GmbH, Versandbuchhandlung,
Postfach 10 39 62, 45039 Essen, Germany. In order to accomplish your request and for communication purposes your personal data are being
1-2013 heat processing
recorded and stored. It is approved that this data may also be used in commercial ways □ by mail, □ by phone, □ by fax, □ by e-mail,
□ none. This approval may be withdrawn at any time.
Line of business
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Date, signature
111
PAHRM42012

Business Directory 1-2013
II. Components, equipment, production and auxiliary materials
Quenching equipment
Fittings
Burners
transport equipment
112 heat processing 1-2013

1-2013 Business Directory
II. Components, equipment, production and auxiliary materials
More information available:
www.heatprocessing-directory.com
1-2013 heat processing
113

Business Directory 1-2013
II. Components, equipment, production and auxiliary materials
Burners
Burner equipment
Burner applications
Your contact to
HEAT PROCESSING
Bettina Schwarzer-Hahn
Tel. +49(0)201-82002-24
Fax +49(0)201-82002-40
b.schwarzer-hahn@vulkan-verlag.de
114 heat processing 1-2013

1-2013 Business Directory
II. Components, equipment, production and auxiliary materials
More information available:
www.heatprocessing-directory.com
1-2013 heat processing
115

Business Directory 1-2013
II. Components, equipment, production and auxiliary materials
Hardening accessories
casting and melting
accessories
resistance heating
elements
inductors
116 heat processing 1-2013

1-2013 Business Directory
II. Components, equipment, production and auxiliary materials
Measuring and automation
Gases
1-2013 heat processing
117

Business Directory 1-2013
II. Components, equipment, production and auxiliary materials
Measuring and automation
Power supply
118 heat processing 1-2013

1-2013 Business Directory
II. Components, equipment, production and auxiliary materials
cleaning and drying
equipment
refractories
More information available:
www.heatprocessing-directory.com
1-2013 heat processing
119

Business Directory 1-2013
III. Consulting, design, service and engineering
120 heat processing 1-2013

III. Consulting, design, service and engineering
1-2013 Business Directory
IV. Trade associations, institutes, universities, organisations
1-2013 heat processing
121

Business Directory 1-2013
V. Exhibition organizers, training and education
Hotline Meet the team
Managing Editor: Dipl.-Ing. Stephan Schalm +49(0)201/82002-12 s.schalm@vulkan-verlag.de
Editorial Office: Annamaria Frömgen +49(0)201/82002-91 a.froemgen@vulkan-verlag.de
Editor: Silvija Subasic +49(0)201/82002-15 s.subasic@vulkan-verlag.de
Advertising Sales: Bettina Schwarzer-Hahn +49(0)201/82002-24 b.schwarzer-hahn@vulkan-verlag.de
Subscription: Martina Grimm +49(0)931/41704-13 mgrimm@datam-services.de
Hotline_184,5x35.indd 2 15.12.11 15:13
122 heat processing 1-2013

Handbook of
thermoprocessing
technologies
Volume 1: fundamentals | Processes | Calculations
This Handbook provides a detailed overview of the entire thermoprocessing
sector, structured on practical criteria, and will be of particular assistance
to manufacturers and users of thermoprocessing equipment.
In europe thermoprocessing is the third largest energy consumption
sector with a very diversified and complex structure. therefore it is split
into a large number of subdivisions, each having a high importance
for the industrial economy. Accordingly we find the application knowhow
for the design and the execution of respective equipment represented
by a multitude of small but very specialized companies and their experts.
So this second edition is based on the contribution of many highly
experienced engineers working in this fi eld. the book’s main intention is
the presentation of practical thermal processing for the improvement of
materials and parts in industrial application. Additionally it offers a summary
of respective thermal and material science fundamentals. further it
covers the basic fuel-related and electrical engineering knowledge and
design aspects, components and safety requirements for the necessary
heating installations.
editors: f. Beneke, B. Nacke, H. Pfeifer
2nd edition 2012, 680 pages with additional media files and
e-book on DVD, hardcover
www.vulkan-verlag.de
Jetzt bestellen!
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen
knowledge for tHe
future
order now by fax: +49 201 / 82002-34 or send in a letter
Deutscher Industrieverlag GmbH | Arnulfstr. 124 | 80636 München
Yes, I place a firm order for the technical book. Please send
— copies of Handbook of Thermoprocessing Technologies 2nd edition 2012
(ISBN: 978-3-8027-2966-9) at the price of € 200,- (plus postage and packing)
— copies of Handbook of Thermoprocessing Technologies 2nd edition 2012
(ISBN: 978-3-8027-2966-9) at the special price of € 180,- (plus postage and packing)
for subscribers of heat processing
Company/institution
first name and surname of recipient
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It is approved that this data may also be used in commercial ways by mail, by phone, by fax, by email, none.
this approval may be withdrawn at any time.
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COMPANIES PROFILE
SCHMETZ GMBH
SCHMETZ GMBH
Contact:
Mr. Hubert Schulte
hubert.schulte@
schmetz.de
COMPANY:
SCHMETZ GmbH
Vacuum Furnaces
58708 Menden
Germany
BOARD OF MANAGEMENT:
Dipl.-Ing. Stefan Blum
HISTORY:
Schmetz GmbH was founded in 1945; 1955 a first vacuum furnace
was developed and built. 1999 Schmetz became member of Metall
Technologie Holding GmbH Group.
GROUP:
Schmetz belongs to MTH GmbH Group with totally approx. 300
employees and locations in Germany, France, Poland and China.
NUMBER OF STAFF:
SCHMETZ GmbH: 70
PRODUCT RANGE:
Specialized on vacuum heat treatment furnaces for hardening,
tempering, annealing, high temperature brazing as well as the possibility
to integrate sub-zero processes to be realized automatically
or energy saving systems.
PRODUCTION:
Vacuum furnaces with over pressure gas quench in horizontal and
vertical types, repairs, maintenance, training, spare parts and service
support.
COMPETITIVE ADVANTAGES:
Innovative leading technologies specialized upon the range of
vacuum industrial furnaces with modular systems for high technical
applications in key industries. Schmetz provides high quality
systems with highest reliability and sustainability.
Schmetz has an intensively working and structure adapted organization
team with short direct ways internally and towards end-users..
SERVICE POTENTIALS:
By intensively trained own employees we are offering optimum
support for our customers for installation, training, maintenance,
directly in our offices or at site with additionally available external
spare parts storage in various countries.
EXPORT QUOTA:
70 %
CERTIFICATIONS:
Quality management system DIN EN ISO 9001 2008
Environment management system DIN EN ISO 14001 2004
INTERNET ADDRESS:
www.schmetz.de
124 heat processing 1-2013

1-2013 IMPRINT
www.heatprocessing-online.com
Volume 11 · Issue 1 · February 2013
Official Publication
Editors
Advisory Board
Publishing House
Managing Editor
Editorial Office
Editorial Department
Advertising Sales
CECOF – European Committee of Industrial Furnace and Heating Equipment Associations
H. Berger, AICHELIN Ges.m.b.H., Mödling, Prof. Dr.-Ing. A. von Starck, Appointed Professor for Electric Heating at RWTH
Aachen, Dr. H. Stumpp, Chairman of the Association for Thermal Process Technology within VDMA, CTO Tenova Iron &
Steel Group
Dr. H. Altena, Aichelin Ges.m.b.H., Prof. Dr.-Ing. E. Baake, Institute for Electrothermal Processes, Leibniz University of
Hanover, Dr.-Ing. F. Beneke, VDMA, Prof. Y. Blinov, St. Petersburg State Electrotechnical University “Leti“, Russia, René
Branders, President of CECOF, Mike Debier, CECOF, Dr.-Ing. F. Kühn, LOI Thermprocess GmbH, Dipl.-Ing. W. Liere-Netheler,
Elster GmbH, H. Lochner, EBNER Industrieofenbau GmbH, Prof. S. Lupi, University of Padova, Dept. of Electrical Eng., Italy,
Prof. Dr.-Ing. H. Pfeifer, RWTH Aachen, Dipl.-Phys. M. Rink, Ipsen International GmbH, Dipl.-Ing. St. Schalm, Vulkan-Verlag
GmbH, M.Sc. S. Segerberg, Heattec Värmebehandling AB, Sweden, Dr.-Ing. A. Seitzer, SMS Elotherm GmbH, Dr.-Ing. P. Wendt,
LOI Thermprocess GmbH, Dr.-Ing. J. G. Wünning, WS Wärmeprozesstechnik GmbH, Dr.-Ing. T. Würz, CECOF
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen, Germany
P.O. Box 103962, 45039 Essen
Managing Directors: Carsten Augsburger, Jürgen Franke
Dipl.-Ing. Stephan Schalm, Vulkan-Verlag GmbH
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