Testing and quality

1/2011 

Proven quality 

Innovation 

through testing 

Advanced measuring 

Development of 

plastic products 

Prevention of outage 

Monitoring of motors 

and generators 

Testing and quality

EDITORIAL 

Test procedures for the development 

of high-quality products 

Dear Technology Professionals, Customers, and Partners, 

Continuous innovation and product improvements are often supported by 

sophisticated, state-of-the-art test and measurement methods. The articles of the 

current issue of the Sulzer Technical Review (STR) will present test equipment, 

measuring methods, and specific competencies of the Sulzer divisions that are crucial 

for research and development, for quality assessments, and for the improvement 

of our products. 

Sulzer Pumps operates test facilities around the globe. Learn more about the 

world's largest string testing facility in Leeds (UK), as well as our expertise and test 

facilities in Suzhou (CN), Kotka (FIN), and Winterthur (CH). 

Modern development and production facilities and globally coordinated teams 

allow Sulzer Metco to produce new application-tailored coating materials. Learn more 

about our new pilot plant in Troy (MI, USA), which can efficiently produce test 

powders in amounts of 5 to 100 kilograms. 

In the article from Sulzer Chemtech, you will learn more about the importance of 

modern analysis during the production and processing of plastics. Sulzer Turbo 

Services uses a variety of monitoring methods to assess the status of motors and 

generators during operation. This measurement technique protects the customers 

from long downtimes and production losses. Sulzer Innotec’s engineering, testing 

and interpretation skills have allowed for new ways of analysis and evaluation of 

pump impeller measurements. 

In the other contributions, you will learn more about our solutions for energy 

recovery, our research capabilities, and our services for repairing motors and 

generators. 

I hope you enjoy this issue. 

Sincerely yours, 

Ton Büchner 

CEO Sulzer 

2 | Sulzer Technical Review 1/2011 

Sulzer today 

The Sulzer brothers laid the foundations of 

today's company in 1834 in Winterthur, 

Switzerland. Sulzer is active in the fields of 

machinery, equipment manufacturing, and 

surface technology in more than 160 locations 

around the world. Its divisions are global 

leaders in their respec tive markets, including 

the oil and gas sector, the hydrocarbon 

processing industry, power generation, pulp 

and paper, aviation, and the automotive 

industry. Sulzer employs more than 13 000 

professionals who develop innovative new 

technical solutions. These prod ucts and services 

enable Sulzer's customers to achieve sustained 

improvements in their competitive positions. 

www.sulzer.com 

Sulzer Pumps 

Sulzer Pumps offers a variety of centrifugal 

pumps, ranging from custom-built models to 

standardized series. The division's marketleading 

position reflects its research and 

development activities relating to processoriented 

materials as well as its reliable service. 

It serves customers in the oil and gas, hydro - 

carbon processing, pulp and paper, power 

generation, water distribution and treatment 

sectors, as well as other specialized areas. 

www.sulzerpumps.com 

Sulzer Metco 

Sulzer Metco specializes in thermal-spray and 

thin-film processes for surface technology 

applications. The division coats and enhances 

surfaces, produces materials and equipment, 

and develops machining processes for special 

components. Its customers are active in the 

aviation and automotive industries, the power 

generation segment, and other specialized 

markets. 

www.sulzermetco.com 

Sulzer Chemtech 

Sulzer Chemtech is the market leader in the 

fields of process tech nol ogy, separation 

columns, static mixing, and cartridge tech - 

nologies. The division has sales, engineering, 

production, and customer service facilities 

throughout the world that enable it to meet the 

needs of its customers in the oil and gas, 

chemical, petro chemical and plastics industries. 

www.sulzerchemtech.com 

Sulzer Turbo Services 

Sulzer Turbo Services is a leading independent 

provider of repair and maintenance services for 

turbomachinery, generators, and motors with 

expertise in rotating equipment. The division 

also manufactures and sells replacement parts 

for gas and steam turbines, compressors, 

generators, and motors. Sulzer Turbo Services’ 

customers are located in the oil and gas, hydrocarbon 

processing, power generation, transport, 

mining, and other industrial markets. 

www.sulzerts.com 

Sulzer Innotec 

The research and development unit supports 

the development projects of Sulzer's own 

divisions as well as projects of industrial 

companies around the world by providing 

contract research and special technical services. 

Sulzer Innotec has considerable expertise in 

materials engineering, surface engineering, 

fluid technology, as well as in the field of 

mechanics. Its core competencies in the area of 

contract research also focus on these traditional 

disciplines. 

www.sulzerinnotec.com

Testing and quality 

Panorama 

4 News 

Exhibitions, Events 

6 Proven quality 

Innovation through testing—test facilities that support product development 

10 The key to application-tailored coating materials 

Driving development through an expanded “global-local” organization 

14 Filter and fit 

Revealing and interpreting hidden features using dedicated signal analysis 

17 Sulzer analogy 

Testing poisons 

18 A crucial factor in product development 

State-of-the-art measurement technology 

22 Prevention of outage major downtime 

Condition-based monitoring of motors and generators 

25 Sulzer innovation 

The ideal solution for corrosive media 

26 Reducing pressure—increasing efficiency 

When pressure has to be reduced in a process, 

using pumps as turbines increases 

the overall efficiency significantly 

30 Characterization of arbitrary distributions 

A new method 

33 Sulzer world 

Welcome to Sulzer Pumps in Suzhou 

34 Interview 

John Allen, Sulzer Dowding & Mills 

35 Imprint 

On the cover: 

The vibration responses of an impeller of a centrifugal compressor is measured without contact with a laser vibrometer. 

The post-processing of the measurement results uses a method developed by Sulzer Innotec that enables the determination 

of the natural frequencies and the mode shapes of the wheel—for quality control and for safe operation. 

CONTENTS 

Sulzer Technical Review 1/2011 | 

3


April 7–9, 2011, Shanghai, China 

China International Engineering Expo & Symposium 2011 

www.seexpo.net 

Information for Sulzer Metco: Simon Xiao 

Phone +86 21 5226 4713 

simon.xiao@sulzer.com 

April 10–13, 2011, Rotorua, New Zealand 

APPITA 2011 

www.appita.com 

Information for Sulzer Pumps: Claudia Pröger 

Phone +41 52 262 39 04 

claudia.proeger@sulzer.com 

April 10–14, 2011, Palm Beach, FL, USA 

Spring CTOTF 

www.ctotf.org 

Information for Sulzer Turbo Services: Stephanie King 

Phone +1 713 567 2748 

stephanie.king@sulzer.com 

April 11–16, 2011, Beijing, China 

The 12th China International Machine Tool Show 

www.cimtshow.com 

Information for Sulzer Metco: Simon Xiao 

Phone +86 21 5226 4713 

simon.xiao@sulzer.com 

April 12–14, 2011, Rotterdam, The Netherlands 

Ahoy Rotterdam 

www.maintenannext.nl 

Information for Sulzer Turbo Services: 

Elisabeth van den Houten 

Phone +31 181 282 088 

elisabeth.vandenHouten@sulzer.com 

May 2–6, 2011, San Diego, CA, USA 

ICMCTF 2011 

www2.avs.org 

Information for Sulzer Metco: Corinna Heinz 

Phone +49 2204 299 215 

corinna.heinz@sulzer.com 

May 2–5, 2011, Houston, TX, USA 

OTC 2011 

www.otcnet.org 


Phone +41 52 262 39 04 


May 9–11, 2011, Adelaide, Australia 

Ozwater 2011 

www.ozwater11.com.au 


Phone +41 52 262 39 04 


May 9–13, 2011, Houston, TX, USA 

GE 7FA Users Group Conference 

http://ge7fa.users-groups.com 


Phone +1 713 567 2748 


Geographical expansion, innovation, 

and selective acquisitions 

In 2010, Sulzer proved its ability to adapt 

quickly to changed market conditions. 

The company achieved a strong doubledigit 

profitability with a return on sales 

of 12.8% and an improved return on capital 

employed of 28.1%. Sales (CHF 3.2 

billion, –5.0%) were still impacted by the 

notable decrease in order intake in 2009. 

Net income increased by 11% to 

CHF 300.4 million, corresponding to 

earnings per share (EPS) of CHF 8.92. 

Sulzer’s global presence was further 

strengthened as major investments in the 

emerging markets went into operation. 

The service business was substantially 

enhanced through acquisitions. Based 

on a healthy balance sheet, Sulzer continues 

to assess additional acquisitions. 

For 2011, Sulzer expects a moderate 

growth in order intake and increased 

sales on an adjusted basis. The divisional 

operating income is anticipated to be 

moderately higher. 

Sulzer to strengthen tower field 

service activities in Canada 

On February 11, 2011, Sulzer Chemtech acquired the company Black Magic Crew 

Ltd. in Canada. Black Magic Crew’s annual sales is approximately CAD 1.5 million. 

All staff, including the former owner, will be retained after the acquisition. With 

this acquisition, Sulzer Chemtech will enhance its competitiveness of the tower field 

service activities in Canada by adding the competencies of a local contractor with 

a skilled crew. 

Black Magic Crew Ltd. is a recognized specialist in the installation of tower 

internals and general maintenance of gas and ethanol plants as well as refineries; 

it is mainly active in the Alberta region. The 

company is listed as an aboriginal-owned corporation 

with registered and records offices 

in Turner Valley, Alberta. Sulzer Chemtech, a 

global market leader for components and 

services for separation, mixing, and cartridge 

technology, is present in all significant markets 

in the areas of sales, engineering, production, 

and customer support. As a main supplier of 

mass transfer components and provider of 

tower field services, it is Sulzer Chemtech’s 

strategy to strengthen its ability to supply 

installation and maintenance services to its 

customers in all geographic regions. 

4 | Sulzer Technical Review 1/2011 4327

Shell Global Solutions and Sulzer 

Chemtech extend strategic alliance 

Shell Global Solutions International B.V. 

and Sulzer Chemtech Ltd have renewed 

and extended their strategic alliance 

agreement, originally concluded in 2000. 

The new agreement further strengthens 

the long-standing relationship between 

Shell Global Solutions and Sulzer 

Chemtech, a leading globally active 

supplier of separation and mixing technology. 

Under the previous agreement, Sulzer 

Chemtech became the world-wide 

licensee for Shell Global Solutions’ highcapacity 

tray and phase separation technology. 

The agreement proved mutually 

beneficial and, due to its success, both 

parties have agreed not only to continue 

but also extend their collaboration to 

include provisions to support and formalize 

the joint development of new 

mass transfer and separation equipment. 

Both Shell Global Solutions and Sulzer 

Chemtech are of the firm belief that the 

extended alliance can result in improved 

utilization of resources and can yield 

truly exciting products, combining all 

aspects from process requirement and 

utilization to manufacturing and marketing. 

“By joining forces in common development, 

Shell Global Solutions and 

Sulzer Chemtech will be in a unique 

position to develop products that are 

well-adapted to the challenges of the 

future”, said Dr Dave Clark, General 

Manager, Process Licensing, Shell Global 

Solutions International B.V. 

“We are satisfied that we can continue 

our successful cooperation with Shell 

Global Solutions and excited about the 

opportunity of joint product development 

with an operating process licensor,” said 

Philipp Süess, Senior Vice President, 

Mass Transfer Technology, Sulzer 

Chemtech Ltd. 


May 10–12, 2011, Rosemont, IL, USA 

Electric Power 

www.electricpowerexpo.com 


Phone +1 713 567 2748 


May 11, 2011, Amsterdam, The Netherlands 

ERTC Energy Efficiency Conference 

www.ev551.eventive.incisivecms.co.uk 

Information for Sulzer Chemtech: Claudia von Scala 

Phone +41 52 262 61 41 

claudia.vonscala@sulzer.com 

May 17–19, 2011, Stockholm, Sweden 

SPCI 2011 

www.spcievent.com 


Phone +41 52 262 39 04 


May 18–19, 2011, Bari, Italy 

3rd Carbon Capture and Storage 

www.wplgroup.com/aci/conferences/eu-ecc3.asp 

Information for Sulzer Chemtech: Loris Tonon 

Phone +41 52 262 61 89 

loris.tonon@sulzer.com 

May 18–20, 2011, Yokohama, Japan 

Automotive Engineering Exposition 2011 

www.taiseisha.co.jp 

Information for Sulzer Metco: Aiko Usami 

Phone +81 3 5920 3800 

aiko.usami@sulzer.com 

May 23–28, 2011, São Paulo, Brazil 

FEIMAFE 2011 

www.feimafe.co.br 

Information for Sulzer Metco: Andre O’Czerny 

Phone +1 305 477 25 25 

andre.oczerny@sulzer.com 

May 24–27, 2011, Denver, CO, USA 

NPRA Reliability and Maintenance Conference 

www.npra.org 

Information for Sulzer Chemtech: Rodney Alario 

Phone +1 281 441 5807 

rodney.alario@sulzer.com 

May 26–28, 2011, Shanghai, China 

The 6th China International Starch & Starch 

Derivatives Exhibition 

www.cisie.cn 


Phone +41 52 262 39 04 


May 30–June 2, 2011, Abu Dhabi, UAE 

Global Refinery Expansion and Upgrading 

www.praxis-global.com 

Information for Sulzer Chemtech: 

Claudia von Scala 

Phone +41 52 262 61 41 

claudia.vonscala@sulzer.com 

For more exhibitions and events: 

www.sulzer.com/technicalevents 


5

TESTING AND QUALITY 

Innovation through testing—test facilities that support product development 

Proven quality 

Continuous innovation requires state-of-the-art tools and equipment. Though numerical flow 

simulation (computational fluid dynamics, CFD) has evolved tremendously over recent years, 

it is the correct correlation of CFD prediction and real fluid testing that enables the develop - 

ment of pumps that fulfill the most stringent needs of clients and industry. Sulzer Pumps 

therefore operates test beds for both product development and final design validation. 

6 

1 Kotka (Finland) 

research center. 

| Sulzer Technical Review 1/2011 

Sulzer Pumps delivers pumps 

for demanding applications and, 

at the same time, continuously 

improves the technology in order to 

be able to meet tomorrow’s customer 

challenges. According to the testing 

requirements of these two tasks, Sulzer 

runs test beds all over the world—each 

dedicated to the needs of specific 

products and markets. Among these 

are the world’s largest installations 

for full pump string testing at Leeds 

(UK)—with an installed drive power 

of 30 MW— and the recently opened 

largest Sulzer Pumps factory in 

Suzhou (China) with a test bed featuring 

eight stations and a total power 

supply of 15 MW. Key to the success of 

Sulzer is its capability to fully test every 

pump prior to shipping to ensure 

performance and problem-free commissioning. 

Adapted test installation 

In Sulzer’s competence center for process 

pumps in Kotka (Finland), the test loop 

is set up to allow the rapid testing of 

end suction pumps of all sizes for the 

pulp and paper, food, metal, and 

fertilizer industries, as well as desalination 

processes. The relatively high production 

volume of the process pump 

range requires adapted installations. In 

order to deliver thousands of pumps per 

4328

year, the test setup needs to be standardized 

with a high turnover. The required 

rapid setup and breakdown is achieved 

with modular pump interface piping 

that can be quickly rotated into position 

using custom-built rotating assemblies 

holding the required range of suction 

and discharge pipe sizes. 

At the factories there are test beds for 

each pump type with multiple test beds 

for different sizes. Apart from a general 

test station for vertical pumps, process 

pumps, and multistage pumps with 

power up to 500 kW, the newest and 

largest operation test bed of Sulzer 

Process Pumps is the test station for large 

process pumps. In this test bed, mea - 

surements can be carried out with high 

flow together with low pressure on the 

suction side. Such tests with pressures 

close to the vapor pressure in the suction 

pipe in combination with high flow rates 

are very important in the design phase 

of high specific speed pumps. One use 

of this low-pressure test rig is the simulation 

of pumping conditions in large 

evaporators. 

Energy efficiency 

Very similar test beds are available 

in the product development test bed 

in the Kotka research center 1. The 

medium-consistency pulp pump loop— 

with power up to 600 kW, flow rates up 

to 1200 l/s, and pressures up to 25 bar— 

conforms to the requirements of the pulp 

2 Energy recovery system. 

and paper industry. In this loop, the 

usual test materials are multiphase suspensions 

with gas, most commonly a 

mixture of water, pulp fibers, and air. 

To optimize the energy efficiency of 

the tests, equipment for energy recovery 

will be installed in the multistage pump 

loop in Finland 2. A Pelton turbine connected 

to the same shaft train as motor 

and pump will recover the high pressure 

created by the pump. This setup will 

allow testing of multistage pumps at 

2.7 MW power while taking only 1.4 MW 

from the grid. At optimum conditions, 

only one quarter of the pump energy is 

taken from the grid. At the same time, 

the turbine reduces pressure with high 

efficiency and with much lower noise 

emission than when dissipating—and 

thus losing—the energy in the valves. 

The hydraulics group in Finland has 

optimized both the energy efficiency of 

the new multistage pump for reverse 

osmosis and of the associated test bed. 

This test bed will be used to validate the 

hydraulic and mechanical improvements 

to the existing multistage pump range 

and to develop new pump sizes. Needle 

valves with electric actuators control the 

turbine of the energy recovery system, 

which means the test loop operator 

using a Pelton turbine will see no difference 

in the loop operating philosophy. 

A test series for a pump with a drive 

power requirement of 1.4 MW will be 

carried out with just 400 kW of loss. 

Comparisons with a traditional test 

setup shows that the test rig will save 

8000 kWh of electric power in a single 

day. As a usual test series for one pump 

hydraulic takes about 20 days, with the 

new energy saving test rig, the environmental 

benefits and cost savings are 

significant. 

Testing before delivery 

In addition to aiding the development 

of new products, testing also ensures the 

quality of the output. All pumps leaving 

the production plant of Sulzer in Leeds 

are fully tested to both international standards 

and customer-specific requirements. 

On this test bed, highly engineered 

pumps and packages (including the 

contract driver) for the upstream oil and 

gas industry are tested before delivery 

to site. 

This enormous facility is equipped 

with the required systems to test pumps 

driven by gas turbines of up to 30 MW, 

large diesel engines, and high-voltage 

electric motors. Recent modifications 

to the power grid gave Sulzer in the 

UK access to 45 MW of electrical power 

and two in-house variable-speed drives 

(VSD). The test bed provides sufficient 

space to install multiple skids, including 

pump and driver, and, if required, the 

contract VSD plus all of the support 

equipment, such as mechanical seal and 

lubrication systems. 


3 With seven singular test loops, the test bed in Oberwinterthur 

is highly flexible. 


7


4 Rapid prototyping 

using NC machining 

speeds up the 

manufacturing of the 

test components. 

This ability to rapidly test large 

amounts of equipment shows the 

facility’s testing flexibility and highlights 

the knowledge base available at Sulzer 

Pumps. These tests ensure that all 

systems are working in synergy before 

their arrival on site, thus removing 

potential delays to the site’s commissioning 

program. 

Testing validates CFD design 

In Oberwinterthur (Switzerland), Sulzer 

Pumps operates a dedicated test bed, 

which supports product development, 

large contract-related development 

projects, and fundamental research 3. 

5 String test of a gas-turbine-driven pump at Sulzer facility in Leeds, UK. 


This development test bed is part of the 

development process for new products 

or pump ranges as well as of special 

large engineered pumps. The hydraulics 

group in Switzerland has significantly 

contributed to the design of new pump 

ranges with a greenfield approach. For 

example, the model testing in Winterthur 

verified the CFD analysis and hydraulic 

design of pumps developed for a new 

pipeline in Eastern Asia. 

The main goal of the development test 

bed is the validation of all characteristics 

of a newly developed hydraulic before 

it is used in a new pump design. For 

this purpose, the validation tests are 

executed on scaled model pumps 

produced in aluminum using rapid prototyping 

(mainly NC machining) 4. The 

test bed features seven small-to-medium 

size loops that are designed to allow 

high flexibility in terms of the type of 

pumps that can be tested—with one 

loop devoted to two-phase testing for 

the development of the Sulzer multiphase 

pumps. 

During these development tests, all 

standard pump characteristics, such as 

flow, head, power, efficiency, and net 

positive suction head (NPSH) are 

recorded. NPSH is an important value 

relating to cavitation behavior of the 

pumps; it describes the difference 

between the actual pressure of a liquid 

and its vapor pressure at a given temperature. 

Additionally, all relevant information 

is measured that may be needed 

for the final design of a pump or in order 

to ensure its proper behavior under site 

conditions. These additional tests include: 

• internal pressure measurements in 

order to identify the losses in the different 

hydraulic components 

• radial- and axial-static and -dynamic 

load measurements 

• pressure pulsation measurement at 

suction and discharge 

• visualization of cavitation bubbles on 

the suction side and occasionally on 

the pressure side of the vanes 

• measurement of pressures, vibrations, 

or stresses in the rotating parts of the 

pump, i.e., within the impellers in 

very special cases 

Research on the impact of surface 

roughness 

For the development of high-performance 

pumps, both advanced CFD and 

high-accuracy measurement are needed; 

these involve specialized tools and 

highly trained personnel. Sulzer Pumps 

has invested heavily into both to ensure 

continuing success and has used the 

test results to validate CFD data for 

many years. Due to these efforts, the 

Sulzer experts know the application 

limits of CFD for the design of pump 

hydraulics. Within these limits, design 

correlations linking CFD results and 

geometric design parameters give essential 

support during the design of new 

hydraulic contours. 

Modern research requires the interaction 

of measurements and CFD calculations 

in order to improve the accuracy 

of the design process. Currently, Sulzer 

specialists are particularly engaged in 

examining the use of CFD calculations 

in predicting the influence of surface 

roughness on pump performance. In 

order to calibrate the various models 

for surface roughness in the CFD codes, 

the developers need surface quality 

measurements of the pump parts, mea - 

surements of their hydraulic per - 

formance, and CFD calculations, including 

manufacturing-quality models. 

In the Finnish R&D location, an extensive 

test program for new multistage 

pump hydraulics and mechanics will 

start in 2011. For this pump, every 

wetted surface has been calculated by 

CFD. Consequently, expected hydraulic 

performance, leakage losses, and force 

balancing are based on CFD calculations. 

During these tests, the Sulzer engineers 

expect to gain more in-depth knowledge 

about the validity of the applied CFD 

surface roughness model. 

Visualization of cavitation 

For projects with demanding suction 

performance or where high-suction 

energy leads to a high risk of erosion 

due to cavitation, Sulzer performs 

bubble tests on the test rig in Oberwinterthur. 

These bubble tests are used to 

assess the extent of cavitation develop-

ment as a function of suction pressure 

or NPSH. For this purpose, model 

pumps are equipped with large windows 

allowing visual access to the entire eye 

of the suction impeller over 360°. Sulzer 

Pumps uses the high competencies of 

Sulzer Innotec in complex NC machining 

for the production of these model 

pumps. These skills are needed to successfully 

machine the complex 3D 

contours of casings and impellers out 

of solid blocks of aluminum. 

The window at the suction side allows 

the experimental confirmation of the 

suction pressure at which the first 

bubbles are visible on the vane surface 

at all positions of the impeller within 

the pump inlet casing. It also allows the 

identification of the cavitation length for 

a given suction pressure and, consequently, 

the estimation of the according 

risk of erosion. 

Because the pressure side of the vane 

is not visible in the impeller eye if fully 

metallic vanes are used, in order to also 

confirm the cavitation development on 

the pressure side of the vanes, one or 

two vanes of the development impellers 

are machined from acrylic glass. The estimation 

of cavitation is especially important 

for large injection pumps for the 

petroleum industry or for large boiler 

feed pumps for thermal power plants 

for which the suction energy and the 

risk of cavitation erosion may be very 

high. 

6 Subsea test bed at Sulzer facility in Leeds, UK. 

Focus on prototype performance 

When a model pump is used in the development 

of new suction impellers for 

these applications, it is designed at prototype 

scale. This procedure allows the 

job impellers to be tested in order to 

confirm cavitation-free operation on site. 

Because of the presence of a window 

that limits the suction pressure, as a compromise, 

tests are performed at a 

reduced speed compared with site conditions, 

and the full-speed performance 

is calculated using standard affinity 

laws. 

The development test bed is also used 

to check the mechanical performance of 

key elements of pumps, such as bearings 

or seals. For example, dedicated testing 

equipment has been developed in order 

to test different material combinations 

for the product-lubricated line shaft 

bearings under real site conditions using 

water charged with sand. 

Prepared for future demands 

Sulzer Pumps continuously develops 

and improves the testing methods for 

new products and for machines. For 

example, the demand for subsea 

pumping is growing, along with the 

requirements that pumps operating 

under water have to fulfill. To be able 

to test subsea processing equipment 

under realistic conditions, Sulzer is 

investing in a dedicated multiphase 

subsea test bed in the UK. This state-ofthe-art 

addition to the already impressive 

string testing facilities in Leeds 5 will 

position Sulzer as the market leader with 

respect to pump-testing facilities. In this 

installation, it will be possible to 

examine subsea pump/motor packages 

with weights approaching 100 tons in 

water depths of up to 10 m 6. 

When deployed in the open ocean, 

these pumps will operate in many kilometers 

of water depth and are designed 

to take high external and internal pressures 

whilst delivering the high pressure 

rises that customers require. The first 

pump that will be tested once the test 

bed is commissioned will be a 3 MW, 

6000 rpm multiphase pump able to 

deliver over 100 bar pressure rise—well 

suited for many of the current subsea 

applications. 

Current specifications and market 

ideas set the standards for capabilities 

and capacity of any new test bed. Sulzer, 

however, follows the motto “designing 

for the future” and requires that new 

test installations must consider future 

possibilities for expansion. Sulzer thereby 

plans to keep these investments operational 

and useful for many years, as both 

products and markets mature and adapt. 

This philosophy makes it possible for 

Sulzer Pumps to deliver pumps adapted 

to market and client requirements now 

and in future years. 


Matt Bourne 

Sulzer Pumps (UK) Ltd. 

Manor Mill Lane 

Leeds, LS11 8BR 

UK 

Phone +44 113 272 5704 

matt.bourne@sulzer.com 

Matti Koivikko 

Sulzer Pumps Finland Oy 

P.O.Box 66 

48601 Kotka 

Finland 

Phone +358 50 555 0268 

matti.koivikko@sulzer.com 

Philippe Dupont 

Sulzer Pumps Ltd. 

Zürcherstrasse 12 

8401 Winterthur 

Switzerland 

Phone +41 52 262 40 30 

philippe.dupont@sulzer.com 


9


Driving development through an expanded “global-local” organization 

The key to application-tailored 

coating materials 

Sulzer Metco produces coating materials with clear customer benefits thanks to stateof-the-art 

facilities, globally coordinated teams, and superior manufacturing capabilities. 

Customers profit from many application-tailored new materials and solutions. 

10 


New and emerging markets are 

increasing the need for cuttingedge, 

engineered coating solutions. 

At the same time, the challenge in 

existing markets is to lower coating 

application costs, innovatively reuse and 

recycle materials, address and find 

suitable alternatives for critical raw 

materials, and, in particular, to have 

more predictable and robust coatings. 

“Designed to cost and purpose” (application 

and service conditions) coating 

solutions should start with the choice of 

the most suitable coating material. This 

The pilot atomizer allows Sulzer to efficiently provide experimental powders in quantities of 5 to 100kg. 

method requires an in-depth approach 

that examines: how material characteristics 

and coating properties are influenced 

by the choice of materials manufacturing 

processes and parameters; the 

subtleties of choosing one raw material 

instead of another; and material charac- 

4329

teristics such as apparent density, surface 

area, particle morphology and structure, 

and other key physical properties. Such 

factors must be considered to a far 

greater degree than in the past, where 

coating engineers would traditionally 

just focus on selecting a material 

based on chemistry and particle size 

distribution and modify coating characteristics 

by varying the spray equipment 

and parameters 1. 

Expanded material research and 

development capabilities 

Sulzer Metco’s Materials Business Unit 

provides powder, wire, and specialty rod 

materials for coating applications such 

as thermal spray, laser cladding, and 

plasma-transferred arc (PTA), as well as 

for processes such as high-temperature 

brazing, pack diffusion, specialty welding, 

and electronic filler applications. The 

products offered range from many types 

of oxide ceramics, carbides, cermets, 

metals, and metal alloys—including 

superalloys, MCrAlYs, self-fluxing 

materials, and various blends or clad 

combinations of these materials. 

Sulzer Metco’s mission is not only to 

continue to lead this particular market 

1 Influence of manufacturing process for 

alumina-13 titania powders on deposition 

efficiency sprayed with a Sulzer Metco 

TriplexPro-200™ gun (similar microstructures). 

Deposition efficiency (%) 

100 

80 

60 

40 

20 

0 

100 µm 

Metco 6221 

A&S 

Metco 130 

Mechanical Clad 

Amdry 6228 

F&C/Blend 

with lean, high-volume material manufacturing 

using in-place, state-of-the-art 

quality systems, but also to address the 

need for faster, more efficient, and 

higher-impact innovation based on 

cutting-edge product development. This 

includes fast availability of test powders 

for sampling purposes, assurance of efficient 

prototype-to-production transfer 

and scale-up capability, and responsiveness 

to the customers’ needs based on 

expert knowledge of how to tailor 

coating materials to achieve specific 

coating performance and application 

demands. 

A specialized infrastructure is needed 

that allows the rapid manufacture of 

small batches of materials with full flexibility 

to widely vary material processing 

parameters, manufacturing technologies, 

and chosen raw materials. It also 

requires the ability to test the resulting 

material and coating characteristics, 

properties, and performance quickly. 

Consequently, Sulzer Metco has 

strengthened and expanded its materials 

research and development (R&D) capabilities 

over the last several years. 

Powder development and pilot labs 

R&D powder development laboratories 

were established at each of the four 

material manufacturing sites, and they 

were equipped with the latest processing 

equipment and cutting-edge characterization 

technologies 2. Each powder 

development laboratory has specialized 

core competencies that, at minimum, 

mirror the manufacturing methods available 

at that particular plant. 

• Westbury, NY, USA: The powder 

development laboratory at Westbury, 

the largest of the powder labs, has 

undergone a major expansion and 

refurbishment over the last 2.5 years. 

Pilot equipment for high-energy ball 

milling, attrition milling, jet milling, 

sintering, mechanical cladding, screen- 

ing, and air classification were added. 

This laboratory is now able to deliver 

HOSP™ ceramics, agglomerated and 

sintered ceramics, mechanically clad 

metal and ceramic test powders, and 

blends of various material families. It 

can produce these test lots in quantities 

up to several hundred kilograms— 

completely independently of the production 

facilities 3. 

• Troy, MI, USA: The powder laboratory 

at the Troy plant specializes in 

gas atomization, including a newly 

installed pilot atomizer. Screening, air 

classification, and blending capabilities 

are currently in the works. Based on 

these, the lab will be able to efficiently 

provide experimental powders in 

quantities of 5 to 100 kilograms. The 

Troy lab is focused on evaluating the 

influence of atomization parameters 

on powder characteristics and yields, 

testing various atomization devices, 

and developing new chemistries 4. 

• Barchfeld, Germany (WOKA): The 

WOKA powder laboratory, which 

started up in 2009, has a small spray 

dryer, a tablet press, several furnaces, 

crushing equipment with hard metal 

tools, and an air classifier combined 

with a jet mill. The lab can produce 

agglomerated and sintered ceramics 

and carbides as well as sintered and 

crushed carbides as test powders. 

• Fort Saskatchewan AB, Canada 

(SMCA): At the SMCA development 


2 Cutting-edge characterization technologies: 

New scanning electron microscope with energy-dispersive X-ray 

spectroscopy (Materials R&D in Westbury, NY, USA). 


11


3 High-energy ball mill (R&D lab in Westbury, NY, USA). 


laboratory, a large variety of powders 

are chemically clad using hydrometallurgy 

technology. The volumes 

produced are suitable for thermalspray 

testing and developmental lots 

using a laboratory-sized pilot autoclave 

5. This facility also has the capability 

to resize, dry, and furnace-heat-treat 

powders in different atmospheres, 

thereby fully reproducing the capabilities 

of the actual production facilities. 

In this manner, new materials can be 

developed in fully scalable conditions. 

The materials R&D lab also features 

scale-up development and commercial 

production of high-quality, goldcoated 

nickel-based composite 

powders using a proprietary process. 

These materials are primarily used for 

electronic and military applications. 

Coating research labs 

Beside the powder development labs, 

the coating research laboratories are an 

important part of Sulzer Metco’s materials 

R&D capabilities. The focus of these 

labs is to enable initial, fast, in-house 

testing of coatings produced using 

the experimental powders—an essential 

step in screening promising material candidates. 

In this way, correlations can be 

drawn quickly between material characteristics 

and coating properties. 

The engineers can then optimize the 

materials manufacturing processes and 

the manufacturing parameters to tailor 

materials to specific application and 

service conditions. The available equipment 

includes salt spray, climate 

chambers, and electrochemical equipment 

for corrosion testing, various wear 

testers, and thermal-cycle furnaces. A 

burner rig and a cavitation wear tester 

were recently added 6. 

4 “A new MCrAlY in the making”: pilot atomizer (Materials R&D in Troy, MI, USA). 

For final validation and testing of 

coating properties beyond the in-house 

capabilities, Sulzer Metco calls on an 

extensive partner network of respected 

research and testing facilities that extend 

its coating testing capabilities even 

further. As an example, Sulzer Metco 

Materials, through its cooperation with 

Sulzer Innotec in Winterthur, Switzerland, 

has a cutting-edge abradable test rig at 

its disposal. The rig is a vital tool for 

Sulzer Metco and its OEM aerospace and 

industrial gas turbine partners for joint 

abradable development programs. 

The facility is the largest and most 

sophisticated of its kind—with the 

ability to test shroud temperatures 

up to 1200 °C using a variety of blade, 

knife-edge seal, or labyrinth seal strip 

configurations at a wide range of tip 

speeds and incursion rates. A recently 

installed high-speed infrared pyrometer 

provides additional vital risk-mitigation 

information on friction heating arising 

at shroud-blade interfaces during incursion. 

The advantages of a “global-local” 

approach 

Since each powder development laboratory 

is located at its relevant manufacturing 

site, R&D, production, and 

quality control can exchange know-how 

efficiently; they can optimize the use of 

the analytical instrumentation; and they 

can piggyback on the logistics infrastructure 

of the plant. Time to market is minimized 

through the effective and timely 

introduction of successfully validated 

development products into large-scale 

manufacturing. 

For example, the installation and 

operation at Sulzer Metco WOKA of a 

new sintered- and crushed-carbide production 

line, based on process development 

by the local R&D group has 

resulted in a wide range of new and 

more economical products within a very 

short time—demonstrating the success 

of this concept.

Nevertheless, a global approach is 

needed, as well. Good examples are 

agglomerated and sintered lanthanum 

strontium manganite (LSM) and spherical 

titanium oxide (TiOx) ceramic products, 

which took advantage of the development 

expertise of the Westbury materials 

R&D team, but are manufactured at 

Sulzer Metco WOKA in a newly established 

facility. 

A global approach not only allows 

optimal resource usage, knowledge 

exchange, and utilization of expertise, it 

also guarantees that the best coating— 

and, therefore, the best product solution— 

is offered to the customer. This is particularly 

important as powders with the 

same chemistry can be manufactured at 

the various sites using different manufacturing 

processes resulting in quite different 

coating properties. It is therefore 

important to select the manufacturing 

process independently of the plant or 

the location of the R&D lab and instead 

base it solely on the application and 

service requirements. 

Globally operating materials R&D 

project managers and competence leaders 

who drive and coordinate all research 

6 Furnace testing (thermal cycle). 

activities and who use the various local 

powder and coating research labs for 

their experimental work maintain the 

balance between the local and global 

approaches. The projects are managed 

based on Sulzer’s systematic multistage 

innovation process and are carried out 

with the support of cross-functional and 

multiregional project teams. 

Customer benefits 

A globally coordinated team that has 

state-of-the-art facilities at its disposal, 

combined with local mirroring of manufacturing 

capabilities, and internal and 

external networking allows Sulzer Metco 

to produce coating materials with clear 

5 An experimental autoclave enables quick changes in process parameters 

and efficient material development. 

Temperature (°C) 

1250 

1000 

750 

500 

250 

customer benefits. In the past year alone, 

a record number of test powders were 

produced for customers, and many 

application-tailored new materials were 

developed and released to the market. 

Notably, several of these developments 

did not involve the need for new coating 

chemistries. Some of those examples 

include: 

• New spherical titania powders (TiOx) 

with various x-factors that permit the 

customer to produce coatings with 

higher-than-usual deposition efficiencies 

at very high feed rates, which are 

essential criteria for sputter target 

applications 

• Spherical ceramics such as alumina 

and alumina-titania designed to 

produce coatings faster and with less 

material waste while fulfilling specific 

porosity requirements 

• Cost-effective carbide materials for 

aerospace applications with excellent 

coating deposit efficiencies that do not 

sacrifice wear resistance. 

Sulzer Metco is committed to leading 

the market with application-tailored and 

economical coating solutions that meet 

the needs of our customers. 

Montia C. Nestler 

Sulzer Metco (US) Inc. 

1101 Prospect Ave. 

Westbury, NY 11590-0201 

USA 

Phone +1 516 338 2305 

montia.nestler@sulzer.com 


0 

500 1000 1500 

Time (min) 


13


Revealing and interpreting hidden features using dedicated signal analysis 

Filter and fit 

Based on the signals of only a few sensors, Sulzer Innotec was successful in identifying 

the most important natural frequencies and vibration mode shapes of a pump impeller. 

The results are, essentially, in good agreement with the FEM calculations performed by 

Sulzer Pumps. The measurement results indicate that the mechanical resonances are quite 

well damped, so that they will not jeopardize the integrity of the impeller in any way. 

1 Positions of strain 

gauges and 

accelerometers on the 

impeller (axial view) 

(Source: PhD. thesis 

by Stefan Berten) 

14 


In 2009, Sulzer Innotec received an 

order from the Sulzer Pumps division 

to analyze and assess vibration 

signals measured in a pump test stand. 

The test pump that was examined is the 

reproduction of the last stage of a highpressure 

centrifugal pump operated by 

a variable-speed drive. This impeller 

stage has a rated power of 1.4MW. 

The impeller has seven blades and a 

diameter of 0.35m. In centrifugal pumps, 

rotor-stator interactions and flow separation 

phenomena are known to excite 

vibrations of stationary or rotating components, 

which might result in fatigue 

failure. Based on performance monitoring 

of a particular pump stage in part-load 

SG6 

SG7 

SG5 

SG4 

SG8 

Acc3 

Acc = Accelerometer 

SG = Strain gauge 

SG1 

SG3 

Acc1 

Acc2 

SG2 

conditions, Sulzer Pumps assigned an 

extensive experimental investigation of 

the mechanical and hydraulic oscillations 

to the EPFL (École Polytechnique Fédérale 

de Lausanne). 

Many sensors for pressure, strain, 

acceleration, and displacement were 

installed in order to record the corresponding 

oscillations. All measurements 

were performed by the Laboratoire de 

Machines Hydrauliques (LMH) of the 

EPFL and analyzed, for the most part, 

in the context of a PhD. thesis. 

Customized analysis of the impeller 

mode shapes 

The task of Sulzer Innotec consisted of 

identifying the operational vibration 

mode shapes of the rotating impeller 

based on the measurement signals of the 

strain gauges and accelerometers 

installed on the impeller and assessing 

the results and comparing them with the 

results from FEM calculations. 

For certain operating conditions, a frequency 

excited by the stationary components 

might coincide with a weakly 

damped natural frequency of the impeller 

and might result in substantial resonance 

amplitudes. Conversely, a lack of strong 

resonant vibrations despite excitation at 

the resonance frequency indicates that 

the corresponding resonance is highly 

damped. 

The task of Sulzer Innotec was to 

analyze the vibration signals of two 

speed ramps—one run-up and one coastdown. 

Figure 1 indicates the positions 

of the eight strain gauges and three 

accelerometers installed on the impeller. 

Conditioning of strain gauge signals 

The recorded strain gauge signals were 

considerably affected by noise; substantial 

noise sources were sensor noise, bit noise 

of the analog digital converter ADC, and 

cross talk of external signals. The comparison 

of all strain gauge signals showed 

that these signals are mostly in phase and 

have similar amplitudes. The conclusion 

was that the signals were seriously 

affected by strong cross talk of an external 

signal. Therefore, as a first step of signal 

conditioning, the average value of all 

strain gauge signals was subtracted from 

each individual signal; thereby, the noise 

level could be substantially reduced. The 

resulting spectrograms now revealed the 

typical series of order lines, which result 

from the excitation at integer multiples 

of the pump rotation frequency. In particular, 

the orders 12, 24, and 36 are clearly 

prominent, as expected for a pump 

equipped with 12 diffuser guide vanes. 

4330

Acceleration (g) 

40 

30 

20 

10 

0 

–10 

–20 

–30 

–40 

–50 

–60 

0 10 20 30 40 

Time (s) 

50 60 70 

2 Time traces of accelerometers showing implausible excursions in negative direction 

and clipping at –50 g. 

Signals of the accelerometer 

The accelerometer signals were not 

optimal either (see 2); they showed 

numerous implausible excursions in the 

negative direction and substantial 

clipping at approximately –50g. Nevertheless, 

in the frequency domain, the 

results obtained with the accelerometers 

were quite well defined compared with 

the results from strain gauges and were 

therefore used for further investigations. 

Resonance detection using 

spectrograms 

Spectrograms are a common method for 

displaying characteristics of transient 

vibration signals. Figure 3 shows an 

2500 

2000 

1500 

Frequency (Hz) 3000 

1000 

500 

Example 1: f = 1150 Hz 

(2-diameter mode, 

excitation by 23rd order) 

Example 2: f = 900 Hz 

(0-diameter mode, 

excitation by 21st order) 

example. The vibration levels are color 

coded and displayed as a function of 

time (= x-axis) and frequency (= y-axis). 

In the spectrogram of an accelerometer 

signal depicted in 3, the impeller natural 

frequencies are evident as horizontal, 

slightly fanned-out yellow-red shades 

(marked with red arrows in 3). The frequency 

bandwidth of the yellow-red 

shades is more than 100 Hz wide, indicating 

that the corresponding resonances 

feature considerable damping. A resonance 

with low damping would be 

evident by a rather narrow resonance 

bandwidth; no such feature crops up in 

the spectrogram of 3. Wherever the fanlike 

excitation frequencies of the rotor- 

0 10 20 30 40 

Time (s) 

50 60 70 

5-D 

3 Spectrogram of the accelerometer signal Acc1 (Ramp with decreasing speed; frequency 

bands indicating resonances (yellow-red shades) marked by red arrows, resonances coinciding 

with a speed order line (circled in blue). 

4-D 

3-D 

2-D 

0-D 

1-D 

Deflection (–) 

1.0 

0.8 

0.6 

0.4 

0.2 

0 

–0.2 

–0.4 

–0.6 

–0.8 

–1.0 

stator interaction coincide with a natural 

frequency of the impeller (see bluecircled 

lines), the corresponding resonance 

is excited. However, thanks to substantial 

damping, the amplification of 

the amplitude is not significant, and no 

fatigue damage is expected due to these 

resonances. 

Deflection shape identification 

It is well known that any given excitation 

order of the stationary components can 

excite only certain mode shapes of the 

impeller (Tanaka, 1990). Once the resonance 

frequencies of the impeller have 

been identified from the spectrogram, 

measured data and theoretically 

computed rotor vibrations can be 

matched in order to determine the corresponding 

mode shapes of the impeller. 

Following are two examples: 

• Example 1: Two-diameter mode at 

f=1150 Hz excited by the 23rd order: 

The frequency response function 

between two accelerometer signals is 

computed and averaged for the time 

segment in which a certain resonance 

mode is excited by the suitable excitation 

order. Then, the ratio of 

vibration amplitudes and the phase 

difference can be determined at the 

resonance frequency (f = 1150 Hz); at 

this frequency, the coherence should 

be reasonably good. The amplitude 

ratios and the relative phase at the 

measurement points are then animated 

synchronously with the theoretical 

vibration mode shape, the amplitude 

and phase of which are manually 

adapted to match the measured data. 

Using this methodology, it was 


0 50 100 150 200 250 300 350 

Wheel circumference (º) 

4 Instantaneous deflection of mode shape with two nodal diameters. 

Red: measured vibration signals; blue: theoretical mode shape. 


15


0.00 100.00 (mm) 

50.00 

5 Results of the FEM calculation for the two-diameter and three-diameter natural modes. 

verified that the mode shape with two 

nodal diameters is actually excited 

during operation. Figure 4 depicts an 

instantaneous deflection state of the 

particular vibration mode. 

• Example 2 : Zero-diameter mode at 

f=900 Hz excited by the 21st order: 

From the frequency response function 

for the resonant vibration at f = 900 Hz, 

it is evident that all three acceleration 

signals are in phase and have the 

same amplitude. This is clearly an axisymmetric 

mode with zero nodal 

diameters; in this case, verification 

by a synchronous animation of the 

measured signals and the computed 

mode shape is unnecessary. 

Comparison with results of the FEM 

calculation 

Finally, the measurement results were 

compared with the FEM calculations 

carried out by Sulzer Pumps 5. A rotor 

surrounded by water was used as 

boundary condition. The impeller was 

modeled as non-rotating, since stiffening 

due to centrifugal forces has only a negligible 

influence on the natural frequencies. 

Figure 6 shows a comparison of 

the measured and the computed natural 

frequencies. 

6 Comparison of the measured and computed natural frequencies. 


The frequencies are in good agreement, 

except for the «umbrella»-mode with a 

measured natural frequency of approx. 

900 Hz, vs. the FEM calculation resulting 

in a frequency of 701 Hz. This deviation 

could be due to a truncated shaft stub, 

which is included in the finite element 

model. 

Note that the forces induced by the 

12 diffuser guide vanes and acting on 

the impeller have lowest relevant excitation 

orders of 12 and 24; the corresponding 

excitation frequencies lie just below 

the matching natural modes of the 

impeller: 

• 12th order of the maximum pump 

speed: 1135 Hz ↔ natural frequency 

of two-diameter mode: 1150Hz 

• 24th order of the maximum pump 

speed: 2250 Hz ↔ nat. frequency of 

four-diameter mode: 2500Hz. 

Spatial aliasing 

With seven sensors that are equally 

spaced around the circumference, theoretically, 

only the vibration modes with 

zero to three nodal diameters can be 

detected positively. For vibration modes 

with four or more nodal diameters, 

spatial undersampling occurs due to the 

sensor arrangement, which has an insuf- 

Number of f [Hz] f [Hz] Remarks Excitation order 

nodal diameters 

approx. reading computed by FEM from spectrogram 

0 900 701 «umbrella»-mode 21 

1 750 757 «rocker»-mode 22 

2 1150 1199 23 

3 1900 1846 24 

4 2500 not computed by FEM 38 

Max. 

5 2800 not computed by FEM 

Min. 

50.00 

0.00 100.00 (mm) 

25.00 75.00 

ficient sensor density. For instance, mode 

shapes with 1 or 6 nodal diameters 

cannot be differentiated, since both 

modes would result in identical vibrations 

at the sensor positions. 

With the additional knowledge of the 

FEM results, the vibration mode shapes 

can usually be unambiguously identified, 

even with only three sensors. Without 

the combination with FEM results, a considerably 

denser sensor arrangement 

would be necessary in order to avoid 

spatial aliasing. 

Interpretation 

The vibrations measured during operation 

indicate that the natural frequencies 

of the impeller are near the predictions 

by the FEM. However, the resonances 

have sufficient damping so that the corresponding 

vibration levels remain well 

within acceptable limits and the integrity 

of the impeller is not at risk. 

Literature 

• Berten, S., Thesis EPFL No. 4642, 

http://library.epfl.ch/en/theses/?nr=4642 

• Tanaka, H., “Vibration behaviour and dynamic stress 

of runners of very high head reversible pump-turbines,” 

IAHR Symposium 1990, special session, Belgrade 

Ulrich Moser 

Sulzer Markets and Technology AG 


Sulzer-Allee 25 



Phone +41 52 262 82 61 

ulrich.moser@sulzer.com 

Hans Rudolf Graf 

Sulzer Markets and Technology AG 





Phone +41 52 262 82 40 

hansrudolf.graf@sulzer.com

SULZER ANALOGY 

Testing poisons 

In the plant world, there are numerous poisons, which, 

when consumed, can lead to serious problems or even 

death for human beings. People always have to try 

something out first in order to determine whether it is 

poisonous or not. So how do animals know which plants 

to beware of and which are beneficial? 

Structural formula of 

the alkaloid morphine, 

which Friedrich Wilhelm 

Sertürner extracted 

from the opium poppy 

in pure form in 1806. 

The struggle for survival in the natural 

world takes place not only between 

hunting lions and fleeing gazelles. Even 

the apparently peaceful coexistence 

between plants and animals is an incessant 

battle with the aim of surviving 

long enough to pass on one’s own genes 

to the next generation. As plants are 

unable to flee their predators, they have 

to defend themselves from the hungry 

mouths of animals in other ways. Spines, 

thorns, and bristly hairs offer mechanical 

protection. Unpleasant odors may also 

discourage consumption. The most effective 

defenses, however, are plant toxins 

that punish the “attacker” with physical 

problems or even death. 

It’s purely the dosage that makes 

the poison 

The plant world has developed an 

incredible wealth of chemical defenses. 

Tannins are very astringent. They cause 

the tongue to contract, dry out the 

mouth and throat, and disturb digestion. 

The greatest poison arsenal, however, 

are the alkaloids, which can be found 

© Smellme | Dreamstime.com 

in 20 percent of all flowering plants. 

Anyone who does not regard the 

bitter taste as a warning will have to 

experience on this own body how these 

nerve agents work. 

Humans also know about these 

poisons—from the atropine in the 

deadly nightshade and the quinine in 

cinchona bark to the nicotine in tobacco 

and the caffeine in coffee. Like almost 

any poison, alkaloids are digestible in 

small dosages, and they can have a 

stimulating or intoxicating effect. Both 

humans and animals have learned that 

low quantities of alkaloids only damage 

microbes and insects, and thereby 

provide the body with some protection 

against certain infections and pests. 

How do animals know what is poisonous? 

In order to avoid risks, the 

panda bear restricts itself to harmless 

bamboo plants—with the disadvantage 

that it has to consume enormous quantities 

of this plant, which is low in nutrition. 

The rat has a very different strategy. 

It is an omnivore and has conquered the 

entire world thanks to its flexibility. As 

poisons lurk everywhere, the rat is very 

mistrustful of new things. If it finds an 

unfamiliar food source, it only eats a 

mini-portion at first. Only if it does 

not suffer any adverse reaction does it 

consume the new discovery in larger 

quantities. Moreover, if it sees that other 

rats are eating a new food without any 

Black howler monkey: Consumes unknown plant material only in small 

quantities in order to avoid a possible poisoning. 

problem, the rat knows that it can also 

eat the new food. 

Poison training course for rat 

embryos 

The poison training course for rats starts 

in the womb, where the embryo 

develops aversions to noxious smells 

and a preference for safe tastes. In 

mammals, young animals learn with 

their mother’s milk how good food 

smells and tastes. Moreover, when the 

baby animal takes its food from its 

mother’s mouth, this is not simply convenience, 

but vital training of the highest 

quality. 

Anyone who is mainly surrounded by 

poisonous leaves, such as the howler 

monkeys in the coastal forest of Costa 

Rica, has to come up with a particularly 

subtle feeding strategy. The more 

abundant a type of tree, the more is it 

avoided by the apes—because the only 

plants that can thrive are those that are 

inedible for herbivores. If a tree is judged 

acceptable, the animals seek out the 

youngest and smallest leaves—and if 

the plant nevertheless produces toxins, 

these would initially only be present in 

small amounts in fresh plant material. 

Furthermore, the howler monkeys only 

eat the stem of the leaf, thereby keeping 

to the part of the plant with the lowest 

toxic content. 

Herbert Cerutti 

4331 Sulzer Technical Review 1/2011 | 17


State-of-the-art measurement technology 

A crucial factor in product 

development 

The product development process at Sulzer Mixpac—a business unit within the 

Sulzer Chemtech Division—has similarities with the way a top athlete prepares 

for competition. There is a defined process to verify properties of new products 

made from plastics using the latest analytical tools. 

1 The production of 

tools for injection 

molding production 

requires high precision. 

18 


The athlete first defines a training 

plan (process)—where to train, 

by when to train, but also how to 

train. If the basic parameters appear to 

be achievable, the top athlete starts with 

the training plan. A promising training 

plan begins with small training units and 

increases in stages. If the goal is a 

marathon run, the top athlete measures 

his time and his pulse rate while training. 

He starts with small distances and 

increases these gradually. In this way, 

the athlete thereby moves from the target 

on the training plan to the actual performance 

in the reality of the training. 

4332

A product development process at 

Sulzer Mixpac also has to pass through 

a number of stages—from the product 

idea through the first prototypes to the 

manufacturing of the tools 1 and the 

subsequent production by injection 

molding and other manufacturing 

processes 2. The last milestone in the 

product development before the first 

“marathon“ is the so-called series 

approval. This example should illustrate 

that the process planning (the training 

plan), the determination of the process 

steps (the training), and also the mea - 

surement (target/actual) are decisive for 

the success of the product development 

3. Processes and their desired results 

have to be defined before they can be 

measured. At Sulzer Mixpac, it is taken 

for granted that “if something needs to 

be improved, one first has to measure it.” 

Sulzer Mixpac is a “top athlete” in the 

plastics industry. The company does not 

deal with all types of plastics, however. 

The focus lies on the world of semi-crystalline 

thermoplastics. Due to their properties, 

semi-crystalline thermoplastics 

are being increasingly used. At the same 

time, however, the specifications and 

legal regulations for the industries are 

becoming stricter. Both the legal requirements 

and the daily pursuit of optimal 

processes require solid measurement 

and analysis technology based on stateof-the-art 

science and technology. These 

technologies are used in research and 

development, quality testing, and process 

and product optimizations, as well as 

for failure analysis. 

A wide bandwidth of physical and 

analytical methods is necessary in order 

to portray the complete product development 

process in a measurable manner. 

In its own laboratories, Sulzer Mixpac 

has the required instrumentation, the 

many years of experience, and the knowhow 

that are necessary for the polymer 

analysis. 

Thermal analysis 

Many of the properties of the starting 

materials that are important for plastic 

injection molding, and also for the end 

products, can be determined with the 

help of thermal analysis. 

• DSC (differential scanning calori - 

metry): DSC analysis measures the 

necessary amounts of heat that are 

used or arise in the physical transformation 

of the plastic. The reaction heat, 

the decomposition temperatures, and 

also the glass transition and melting 

ranges can be cited as examples. 

• TGA (thermo-gravimetric analysis): 

The composition and filling materials 

of the returns can be analyzed through 

the “controlled evaporation” of plastics. 

In order to do this, the materials 

are heated up to 1100 °C. 

Rheology 

Rheology describes the flow characteristics 

of substances. In the plastics 

industry, this property is a very 

important measurement parameter for 

the processing of various plastics, as 

well as for the individual batches of 

the same plastics. 

• MFR/MVR (melt flow rate/melt 

volume rate): The end result provided 

by the melt flow rate (MFR) is the 

flow behavior of the plastic under 

certain temperature and pressure conditions. 

The viscosity of the plastic 

melt is determined by this measurement 

procedure. 

2 Injection molding production in Haag, Switzerland. 

• Rotation viscometer: Lying on a 

heated plate, a plate or a cone is 

pressed on to the specimen by means 

of a pressure-driven motor. During the 

rotation process, the frictional force 

(torque) that is necessary to overcome 

the flow resistance is measured. The 

result measured is, for example, the 

shear viscosity of the specimen. This 

measurement is taken to determine 

the characteristics of plastics or mixed 

adhesives with regard to workability 

and/or mixing quality. 

Spectroscopy 

It is possible to determine the structure 

and/or the identity of the plastic 

through spectroscopy. With color analysis, 

it is, thereby, possible to break down subjective 

color perceptions into reproducible 

measurements. 

• FTIR (Fourier transformation infrared 

spectrometer): With this measuring 

instrument, it is possible to carry out 

very fast identifications (characterizations) 

on organic materials. The 

specimen is clamped in the ATR unit 

and is, thereby, placed in the path of 

a laser-controlled infrared beam. The 

penetration of the radiation excites the 

atomic groupings of the melt (vibrations), 

from which the absorption 

spectrum can be measured. The position 

and intensity of these peaks 

are characteristic for certain atomic 

groupings. By comparison with the 

“standard spectra” available in the 

database, the material characterization 

and contamination of plastics, as 

examples, can be carried out quickly 

and easily. 



19


3 Sulzer engineers in computer-aided product development. 


• Spectral photometer: The spectral photometer 

is used to precisely determine 

a color. The complete color spectrum 

from ultraviolet to infrared is hereby 

registered and then taken apart. The 

result is the value for the brightness 

(L*) in connection with the color (a*b*). 

It is also possible to carry out mea - 

surements of reflection and transmission 

colors. 

Physical and chemical analyses 

Using physical and chemical analyses, it 

is possible, for example, to look inside 

the molecular structure of plastics. The 

processing properties or even the processing 

and construction errors can be 

measured here. 

• Karl Fischer titration (water content 

determination): With certain plastics, 

the final quality of the product is 

dependent on the water content in the 

plastic granulate before the injection 

molding process. The use of the Karl 

Fischer method makes it possible to 

determine the water content quantitatively 

through titration procedures. 

The surface water and the water that 

is bound up between the molecule 

chains can be quantified. 

• Thin-section microscopy: Thin-section 

microscopy is the “pathology” of 

plastics. A component is embedded, 

cut and ground to approx. 30 µm thickness 

(by comparison: a human hair 

has a diameter of about 50 µm). Stress 

cracks become visible under the microscope 

(by means of polarized light). 

Structural defects or glass-fiber distributions 

and orientations are also visualized 

here. 

• GC (gas chromatography): Undesired 

components (e.g., monomers, plasticizers, 

phthalates) can remain in the 

granulate during the manufacture of 

polymers (plastic granulate). These 

could be harmful under certain 

circumstances and must, therefore, 

be detected and excluded. By means 

of gas chromatography, it is possible 

to obtain a “fingerprint” of these 

unwanted substances and to quantify 

them. 

Mechanical analysis 

Many of the desired component properties 

can be simply tested by means of 

destructive, mechanical part testing. 

• Tension and pressure test: The products 

will be subjected to pressure on 

tension on these measuring devices. 

The force needed to cause the component 

to fail is measured and analyzed. 

Statements with regard to expansion, 

type of breakage, and burst values are 

important information for development 

(e.g., for the selection of new 

materials), but also for the periodic inprocess 

tests carried out in series production. 

• Torsion measurements: Torsional forces 

are often subjective perceptions. 

Whether it is difficult or rather easy to 

place a stopper on a cartridge should 

not depend on the condition of the individual 

user on a particular day. It is 

important to ensure reproducible 

forces for the assembly by the user. In 

addition, both the product development 

and the series production are 

continually monitored via torsion 

measurement instruments. 

Metrology and tribology 

Before the final approval step for series 

production, the dimensional agreement 

of the plastic products or tools must be 

checked against the drawing specifications. 

It is, thereby, important to be able 

to measure and analyze the geometry at 

as many points as possible. The requirements 

for dimensional accuracy have 

also increased significantly in this area 

over the last few years. The basis for 

this increase is the use of the measuring 

instruments in a fully air-conditioned 

measurement room. 

CNC 3D coordinate measuring instruments: 

In order to achieve the most 

accurate measurement results by means 

of "tactile” measurement, we make use 

of high-precision, high-speed scanning 

procedures. It is, thereby, possible to 

register even the most complex product 

or tool geometries with multi-point 

measurement. The measurement 

accuracy is below 1 µm in these cases. 

CNC 3D optical measuring device 

(with fiber probe technology): In CNC 

3D coordinate measurement technology, 

the diameters to be measured are limited 

to 0.3 mm due to the contact forces. 

Everything that is smaller than 0.3 mm 

is measured on the Sulzer Mixpac CNC 

3D optical measuring device. Here, too, 

the measurement accuracy is in the µmrange. 

Roughness, waviness, and profile 

measurement: Tool surfaces are decisive 

for the surface quality of the plastic 

products manufactured with them. 

Through highly precise roughness mea - 

surement, it is possible for Sulzer Mixpac 

to measure these surfaces and to initiate 

corrective measures in good time where 

necessary. 

CT (computer tomography) evaluations: 

In order to obtain a full picture of 

the complete workpiece geometry, for 

example, in damage analyses, it is necessary 

to make use of computer tomography. 

Here, an external partner of 

Sulzer Mixpac carries out the measurements 

using CT, and Sulzer Mixpac laboratory 

carries out the evaluation of the 

registered data. 

In order to make the procedures

simpler from the viewpoint of the 

„internal customer”, all the methods of 

analysis were brought together into a 

single laboratory at the start of 2011. 

Rapid order processing is thereby 

ensured. 

Application engineering 

The understanding of the processes of 

our customers and of the end users is 

the prerequisite for the continuous 

further development of our existing 

products and for the development of 

new product ideas. We have set ourselves 

the target of being a competent partner 

for our customers, and of speaking the 

same language when it comes to the use 

of our products in very different application 

areas. 

In the technology department, we 

therefore deal with the processes of our 

direct customers, such as labeling, filling, 

storage, transport, or recycling, but also 

with the typical application fields of end 

customers, which also include benchmarking 

and comparison tests. 

The functional performance of our 

systems is thereby always in the foreground, 

together with the medium 

used in a specific application. 

The following two examples shall 

explain this approach. A basic function 

4 Simultaneous filling of the two cylinders of a cartridge via the outlet. 

of all our cartridges is the storage and 

delivery of reactive, two-component 

materials. During the filling, the two 

components must first be optimally 

filled into the cartridge cylinder 4. The 

economic efficiency of a simple and 

rapid filling and the insertion of the 

piston, on the one hand, and the reproducible, 

constant, and air-free filling, on 

the other, are both decisive for the 

success of the two-component system 

during the application. We must, therefore, 

know all about the filling process 

with all its sophistications in order to be 

able to develop the right products at all, 

and to also be able to competently advise 

our customers on the question of filling. 

We can, therefore, carry out our own 

filling trials in house using customer 

materials. In addition to the close cooperation 

with professional filling companies, 

this setup allows us to develop the 

necessary know-how in a direct and 

independent way. 

Another typical task is the buildup of 

know-how for protective coating applications, 

in which the spray method is 

often used. This market segment with 

its special technology represents a completely 

new application area for Sulzer 

Mixpac 5, and the fact that our products 

meet the requirements and peculiarities 

5 Coating application from a cartridge with a Sulzer Mixpac mixer spray. 

of this market is, once again, decisive 

for successful entry into the market. We 

therefore carry out in-house spraying 

trials in order to test our products with 

different materials and to enable us to 

develop the overall system optimally. 

The QESH and technology departments 

within our laboratories cooperate 

in order to develop the application 

know-how and the test methods and 

systems required; they thereby contribute 

to the sustained success of Sulzer 

Mixpac. 

A successful product thanks to 

state-of-the-art analysis 

Sulzer Mixpac combines manufacturing 

expertise, analytics, and measurement 

with the associated engineering knowhow. 

Our customers benefit from our 

excellent knowledge in test technology 

and our R&D expertise with materials. 

Sulzer Mixpac develops and analyses 

demanding plastic products for the 

benefit of our customers. 

Stephan Schatz 

Sulzer Mixpac AG 

Ruetistrasse 7 

9469 Haag 


Phone +41 81 772 20 20 

stephan.schatz@sulzer.com 

Paul Jutzi 

Sulzer Mixpac AG 

Ruetistrassee 7 

9469 Haag 


Phone +41 81 772 21 50 

paul.jutzi@sulzer.com 



21


Condition-based monitoring of motors and generators 

Prevention of outage major 

downtime 

Sulzer Dowding & Mills uses a range of condition-monitoring methods to assess the status 

of motors and generators to prevent the customer from major downtime and lost production. 

1 Low-frequency 

high-resolution 

spectrum showing 

four rotation speed 

harmonics. 

2 Expanded view of 

the 1X rotation data. 


One of the most common root 

causes of failure of rotating electrical 

machines is bearing failure; 

but the failure mode that has the greatest 

impact, with regards to downtime and 

lost production, is failure of the stator 

winding insulation, particularly in highvoltage 

machines. Premature failure 

of stator insulation can cause a costly, 

forced outage. Therefore, prevention of 

such outages is a major objective. To this 

end, there has been a lot of effort put 

toward developing reliable insulation 

quality assessment techniques. 

Sulzer Dowding & Mills uses a range 

of condition monitoring methods, partial 

discharge analysis (PD), phase current 

analysis, insulation resistance (IR), polarization 

index (PI), tan delta analysis, and, 

RMS Acceleration (G-s) 

RMS Acceleration (G-s) 

0.20 

0.15 

0.10 

0.05 

0.05 

0.04 

0.03 

0.02 

0.01 

0 

20 40 60 80 100 120 

Frequency (Hz) 

0 

20 40 60 80 100 120 


3 Photo of the damaged rotor “called” from the vibration data in figures 1 and 2. 

most importantly, close visual inspection 

to assess the status of the winding insulation 

and bearing system. Vibration 

analysis is used to assess the condition 

of the bearings and rotating parts of the 

machine, whilst thermographic cameras 

are used to identify variations in heat 

that result from bearing problems, bad 

electrical connections, unbalance in 

phase loadings, etc. 

Parameters routinely monitored— 

either periodically or online—include 

vibration, temperature, partial discharge, 

and, occasionally, shaft voltage. This 

data together with operating data such 

as load, running hours, ambient and 

environmental conditions, system disturbances, 

etc., are used for condition 

assessment of the entire machine. 

Analysis of mechanical vibrations 

Analysis of the measured mechanical 

vibration is an excellent method to 

indicate the current condition of a 

machine—even where the vibration 

levels are not necessarily at high levels. 

They provide an indication of the 

machine condition because they reflect 

the dynamic forces acting on the rotating 

assembly in service, and with good 

analysis can be used for the early detection 

of abnormalities and trouble. 

High vibration, in addition to causing 

bearing overheating and, ultimately, 

bearing failure, can also cause damage 

to winding insulation systems in rotor 

and stator. All of these conditions 

require extensive out-of-service repairs. 

A modern vibration monitor system 

4333

provides a database, which, by reviewing 

vibration trends, is helpful in predicting 

mechanical problems in rotating 

machines and estimating future maintenance 

needs, extending the duration 

between inspections, and minimizing 

downtime for maintenance. 

Vibration or displacement sensors are 

mounted on or as close as possible to 

the bearings at the drive and non-drive 

ends of the machine. Vibration measurements 

will be recorded radially—at two 

points 90° apart at each end—and 

axially—generally at the drive end. The 

sensors signals can be reviewed as a 

waveform or processed using fast 

Fourier transformations and displayed 

as a frequency spectrum for detailed 

analysis. Trend analysis is used to 

identify change in condition and to 

predict failure. 

Case study Gillette 

Vibration analysis was carried out on 

a four-pole induction motor driving a 

48-inch conveyor belt in a surface 

coalmine preparation plant. Figures 1 

and 2 illustrate the correlation of the 

vibration data to the actual damage on 

the rotor of a 1000HP (750 kW) induction 

motor. The amplitude of the harmonics 

and amount of side banding at rotor slip 

frequency are indicators of severity of 

the problem. 

Note: These side bands, with differential 

frequency of 0.67 Hz from the fundamental, 

can be used to calculate the 

rotor slip of this four-pole motor at the 

rotation speed indicated in the data plot. 

The height of the side bands, together 

with an increase of the slip frequency, 

gives an indication of the severity of 

damage to the cage rotor winding. 

Figure 3 clearly confirms the fault 

condition identified in the vibration 

analysis as a failure of the rotor cage 

winding with several broken rotor bars. 

Vibration analysis has also been successful 

at determining bearing defects associated 

with variable frequency drives 

(VFDs). VFDs are notorious for causing 

fluting damage (EDM, electrical discharge 

machining) in antifriction bearings if the 

rotor shaft is not grounded properly. 

These defects have been detected by 

the reliability groups at several of our 

customers’ plants. 

The following example is of a 350HP 

(4160 volt) four-pole induction motor 

driving a conveyor in a surface coal mine 

prep plant. 

The vibration data in the trend display 

and high frequency spectrums indicated 

a defect that had become so significant 

that corrective action was recommended 

to the customer 4. 

The bearings, which had been removed 

from the motor, clearly showed evidence 

of electrical discharge machining 5. 

They were replaced and a commercially 

available shaft current diverter ring was 

installed in the motor to discharge the 

eddy currents developed on the rotor. 

These changes should prevent recurrence 

of this motor failure. 

PD analysis and further tests 

When high partial discharge (PD) 

activity is detected during online testing, 

equipment users usually want to verify 

the problem by performing a visual 

inspection and/or doing some off-line 

testing before taking the machine out of 

service. The traditional off-line tests are 

the direct current (DC) insulation resistance 

(IR), polarization index (PI), and 

alternating current (AC) tan delta tests 

(called Tip Up Test in North America), 

off-line PD test and close visual inspection. 

All these tests are well understood 

and have been employed for many 

years. 

The main limitation of off-line insulation 

tests is the requirement for a 

machine outage, which, in some cases, 

may take several days. In addition, 

during off-line tests, winding insulation 

is not subjected to operating stresses 

experienced in service, and, therefore, it 

does not truly reflect the condition of 

the insulation system in service. Online 

testing provides more accurate and more 

reliable diagnostic information regarding 

the insulation condition whilst in service. 

Online PD monitors can detect PD 

activity, a significant increase of which 

is an indication of potential insulation 

degradation; this increase can, over time, 

lead to insulation failure for large 

machines above 5000V. 

PK (in/s) 

RMS Acc. (G-s) 

Acc. (G-s) 

1.6 

1.2 

0.8 

0.4 

0 

1.6 

1.2 

0.8 

0.4 

0 

10 

5 

0 

–5 

–10 

–15 

Measurement principle 

Partial discharge (PD) activity, in rotating 

electrical machines, is the physical breakdown 

of a gas, usually air, within a void, 

in a gap, or adjacent to solid insulation 

within an insulation system in the 

presence of high electrical stress. This 

discharge can cause chemical and 

thermal degradation in the materials 

adjacent to the discharge. As Pd activity 

continues, highly conductive materials 

are formed from the epoxy resin binders 

or other materials. As the carbon atoms 

contained in the insulating materials 

become free molecules, they join together 

and form carbon tracks. If this Pd 

activity continues, it will cause permanent 

damage to the insulation system and 

eventually will cause a complete breakdown 

or failure of the insulation system. 

This breakdown of the gas results in 

an electrical spark, which generates a 

high-frequency signal that can be moni - 

tored by a variety of methods: though 

a directly connected capacitor, indirectly 

using a Rogowski coil, through a radio 

frequency receiver, by employing an 


0 400 800 1200 1600 

Days 

0 1000 2000 3000 4000 5000 


0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 

4 Conveyor drive motor trend display, frequency spectrum, 

and waveform. 

Revolution number 

5 Photo of the bearing 

damage detected by 

the vibration data in 

figure 4. 

Sulzer Technical Review 1/2011 | 23


1 

2 

3 

4 

5 

6 

7 

8 

1 2 

Rogowski coils 

Local termination box 

StatorMONITOR signal 

conditioning unit 

Signal cable (up to 30m max.) 

Laptop with data acquisition cards 

StatorMONITOR analysis software 

Signal cable 

RS232 (serial) filter control cable 

6 Typical test setup for partial discharge 

using the StatorMONITOR system. 

RTD lead, etc. The StatorMONITOR ® 

online PD measurement system was 

developed by Sulzer Dowding & Mills 

to monitor, diagnose, and evaluate the 

condition of insulating systems used in 

the stator windings of HV motors and 

generators. The system is designed to 

detect insulation problems in their early 

stages, when remedial action would 

prove to be most beneficial in terms of 

the avoidance of unplanned downtime 

and consequential financial implications. 

The StatorMONITOR system developed 

by Sulzer Dowding & Mills uses 

Rogowski coils as PD detectors. Data is 

collected online from the three phases 

simultaneously, which permits the distinction 

between discharges activity in 

the main insulation wall (for each phase), 

between phases, and in the endwindings. 

The system quantizes and 

records the basic discharge parameters 

associated with each individual PD 

pulse. These include the discharge pulse 

magnitude, its polarity, and its phase 

position relative to the power frequency. 

Pattern recognition algorithms are 

then applied to these basic quantities to 

identify the type and severity of 

problems. They also help in the detection 

of and removals elimination of regular 

commonly known interference—such as 

that due to converter equipment or generator 

excitation systems—which could 

reduce the accuracy of analysis. The 

trending facilities of the system allow 

the identification of potential problems 

or degradation processes developing 

within the insulation. The fundamental 

requirement of the system is to detect 

discharge activity that may be harmful 

to the insulation system and its location. 


4 

5 

3 

6 7 8 

Case study—partial discharge in 

highvoltage rotating machines 

Three identical two-pole machines with 

the following specifications were tested 

for partial discharge using the Stator- 

MONITOR system: 

• Motor Size: 4 MW 

• Voltage: 11 kV 

• Duty: Induction motor 

• Location: Offshore oil platform 

A typical test setup is shown in 6. 

Two of the three machines tested on 

site showed normal low-level discharge 

activity. However, the discharge levels 

on one machine were measured at 90 000 

picocoulomb (pC) and suggested phaseto-phase 

discharge sites between the 

RED and YELLOW phases as shown 

below in figure 7. There was also 

evidence of slot discharge modulation 

normally associated with coil movement 

in the slot, identified as a distinct modulation 

of the discharge pattern. This 

effect was pronounced in the blue phase. 

Coil movement is most commonly associated 

with the presence of loose wedges. 

It was recommended that this motor 

be removed from service and overhauled. 

The spare motor was scheduled to be 

installed during a planned shutdown 

three months later. This exchange was 

delayed a few months and later the 

motor suffered a winding failure just 

prior to the shutdown. An investigation 

of the winding after removal showed 

that the bracing had become loose, 

allowing a phase cable to rub and eventually 

discharge until a failure occurred 

in between this phase and another in the 

end-winding. 

8 White deposits in the end-windings as a result of discharge activity. 

7 The discharge levels on one of the machines 

suggested phase-to-phase discharge 

(RED and YELLOW phases). There was also 

evidence of slot discharge modulation—most 

pronounced in the blue phase. 

Figure 8 shows the photograph of the 

white powdery deposits in the endwinding 

as a result of discharge activity. 

Further investigation showed that there 

were approximately 10% of the wedges 

loose—also possibly due to the bracing 

problem. 

Conclusions 

Online condition monitoring using vibration 

analysis and partial discharge can 

detect failure mechanisms within a 

machine before catastrophic failures or 

unplanned outages occur. Engineers are 

able to take remedial action to keep the 

machine in serviceable condition and 

thus extend the life of the machine. 

John Allen 

Sulzer Dowding & Mills Ltd. 

Camp Hill, Bordesley 

Birmingham, B12 0JJ 

United Kingdom 

Phone +44 121 766 6161 

john.allen@sulzer.com 

1 

2 

1 Phase-to-phase discharge 

2 

Slot discharge modulation 

(Coil movement in slot)

SULZER INNOVATION 

The ideal solution for corrosive media 

The new Sulzer KnitMesh XCOAT™ mist eliminator 

combines the chemical resistance of fluoropolymers 

with the strength and form stability of alloys. Thus, 

the Sulzer KnitMesh XCOAT mist eliminator sets a 

new dimension in contact with strong acids, especially 

in applications involving sulfuric and acetic acid. 

In many applications, droplets need to 

be efficiently separated from a gas 

stream in order to avoid problems or 

damages in downstream processes. For 

applications with severe process conditions 

involving corrosive liquids, special 

resistant materials are required. Suitable 

materials are characterized by a high 

corrosion resistance in a wide range of 

operating conditions and a long lifetime 

of service. 

Sulfuric acid production process 

Sulfuric acid is a chemical compound 

of sulfur with the formula H2SO4. It 

is a colorless, oily, very viscous, and 

hygroscopic liquid. It is one of the 

strongest acids and is highly corrosive. 

Sulfuric acid is one of the most 

important chemicals in general and 

one of the most-produced commodity 

chemicals. 

The new Sulzer KnitMesh XCOAT mist eliminator. 

Sulfuric acid is produced from sulfur 

dioxide (SO2), which is oxidized to sulfur 

trioxide (SO3). This is reacted with water 

in concentrated sulfuric acid to sulfuric 

acid. 

Drying column in the sulfuric acid 

production 

The gas stream to and from the reactor 

is, in direct contact with concentrated 

sulfuric acid, dehydrated in order to 

prevent corrosion caused by wet SO2 or 

SO3 gas as well as to avoid condensation 

of acid during plant shutdowns, which 

would damage the catalyst in the reactor. 

Therefore, to avoid corrosion, the 

columns are either made of special high 

alloy steels or lined with acid- and heatresistant 

bricks. 

Droplet in the drying column 

At the top of the drying column, a mist 

eliminator is installed so that no droplets 

are entrained to the downstream process. 

Sulzer Chemtech markets wire mesh 

mist eliminators with the trademark 

KnitMesh. A KnitMesh mist eliminator 

is knitted from wires or fibers. 

The strengths of the KnitMesh 

XCOAT mist eliminator 

Mist eliminators in sulfuric acid drying 

columns require high-grade materials. 

Particularly concerned are the knitted 

mesh pads with their thin wires which 

are most sensitive for corrosion. Therefore, 

alloys that are optimized to prevent cor- 

Close-up image of XCOAT: 

Thin metal wire coated with 100% 

pure PTFE (polytetrafluoroethylene). 

rosion caused by sulfuric acid are 

applied. Alternatively, synthetic fibers, 

in some cases in combination with metal 

wires, are used. 

However, the above alloys do not 

completely prevent corrosion, which is 

why the lifetime is limited. Mist eliminators 

using fluoropolymer fibers show, 

indeed, an excellent chemical resistance, 

but at higher temperatures they tend 

to shrink, which leads to bypasses in 

the mesh pad. 

In the Sulzer KnitMesh XCOAT mist 

eliminator, the strength and form 

stability of a metal wire are ideally 

combined for the first time with the 

chemical resistance of fluoropolymers. A 

thin metal wire coated with 100% pure 

PTFE, the best known chemical- and 

temperature-resistant plastic, shows a 

longer service time in hot corrosive 

media than wires from special alloys or 

fibers from fluoropolymers. Thus, the 

Sulzer KnitMesh XCOAT mist eliminator 

sets a new dimension in contact with 

strong acids. 

The Sulzer KnitMesh XCOAT mist 

eliminator is now exclusively available 

to our customers from Sulzer Chemtech. 

Daniel Egger 

For more information or to express your interest, 

please contact: 

Rohit N. Joshi 

Sulzer Chemtech India, Pune 

Phone +91 2137 304740 

rohitn.joshi@sulzer.com 

4334 Sulzer Technical Review 1/2011 | 25

PANORAMA 

Reducing pressure— 

increasing efficiency 

In several industrial processes, a fluid under high pressure must be throttled to suit subsequent 

process steps. Typically, conventional pressure-reducing valves are used to dissipate, and 

consequently waste, this hydraulic energy. Hydraulic power recovery turbines (HPRT’s) can 

convert the excess pressure into mechanical shaft energy and increase the overall process 

efficiency. Sulzer Pumps has years of experience in using reverse running pumps as turbines 

as an economical solution to recover energy. 

26 


Generally, pumps are a means of 

fluid transport that convert mechanical 

energy into hydraulic energy; i.e., pumps 

increase fluid pressure. When process 

conditions call for pressure to be dissipated, 

a pump running backwards may 

be used to capture that otherwise wasted 

energy. The reverse running mode 

converts hydraulic energy into mechanical 

energy and can be used to drive a 

generator or to assist the driver of other 

rotating machines. By using an HPRT, 

as much as 85% of the energy otherwise 

wasted in a throttling valve can be 

captured. When modified standard 

pumps are used as HPRTs, investment 

costs are low as compared with those 

for conventional turbines. Energy 

recovery may merit consideration even 

if the pressure reduction is relatively 

small. 

Almost any centrifugal pump can 

operate as a turbine. The direction of 

fluid flow is reversed compared with 

that in a pump. The pump discharge 

flange becomes the inlet of the HPRT, 

and the pump suction flange becomes 

the outlet, or exhaust. For larger HPRTs, 

the interior of the pump casing is 

modified to provide uniform flow to the 

runner. 

Energy recovery 

Conventional hydraulic turbines can be 

of axial, mixed, or radial flow type, and 

single or multistage. Differential head, 

flow, and speed govern which type is 

applied for a particular application. These 

three parameters determine the specific 

speed of a hydraulic machine. Specific 

speed is a characteristic number for each 

pump or turbine, and it increases with 

higher flow and lower head. High specific 

speed (axial flow) runners are used for 

lower head and higher flow, as in runof-river 

hydropower plants 1. 

Single-stage or multistage radial-flow 

or mixed-flow turbines are used for 

higher heads. For very low flow with 

high head, an impulse, or Pelton turbine 

may be an appropriate choice. The power 

output of a hydraulic power recovery 

device is a function of flow and head. 

Reaction type turbines are used for power 

ratings between 500 kW and about 

700 MW in hydropower plants. 

In some industrial installations, such 

as reverse osmosis plants, petroleum 

refineries, fertilizer plants, and gas 

treating facilities, some processes may 

need to operate at high pressure. For 

example, amine contactors are widely 

used to scrub CO2 and H2S from natural 

gas. The contactor operates at pipeline 

pressure. Then pressure is reduced to 

flash out various components of the 

process stream. Usually throttling devices 

(valves, orifices etc.) are used to reduce 

the pressure. Single-stage HPRTs can be 

used to recover that energy. In refining 

hydro treaters, multistage HPRTs may be 

needed due to the large pressure drop 

required. 

Know-how for correct layout 

When planning the use of a pump as 

turbine, it is essential to know the differences 

in machine performance when 

reversing flow direction and sense of 

rotation. For equal rotational speed and 

runner diameter, the following general 

differences are noted 2: 

• The efficiency at the best operating 

point of the turbine corresponds 

4335

approximately to that of the pump, or 

it can be slightly higher depending on 

the size of the machine. 

• The efficiency curve under overload 

conditions drops more slowly in the 

turbine than in the pump mode since 

the losses are associated with a high 

power. 

• The best efficiency point of the turbine 

is located at higher flow rate and higher 

head. That means the capacity is higher 

in the turbine mode than when 

pumping. 

• In most instances, the shaft power at 

the best operating point of the turbine 

is somewhat higher than that at the 

corresponding point of the pump. 

• Susceptibility to cavitation is lower in 

the turbine than in the pumping mode, 

since the low pressure zone is at the 

runner outlet in turbine mode. 

Sulzer has provided hundreds of HPRTs 

3 in various configurations and has 

established methods to calculate HPRT 

performance from pump performance. 

However, if exact data are necessary, it 

is essential to test the HPRT. Turbine 

testing requires a lot of equipment and 

thus costs measurably more than pump 

testing 4 . 

A booster pump with sufficient power 

must be used to provide the inlet flow 

and high inlet pressure. The output power 

of the HPRT must be measured with a 

calibrated generator, torque meter, or 

dynamometer. Measurements of power, 

flow, and pressure are used to calculate 

turbine efficiency. To avoid cavitation at 

the HPRT outlet, backpressure at the 

outlet must be controlled. 

Considering the complete system 

Determination of the runaway speed is 

essential for the operation of the reverse 

running pump. Runaway is the operation 

at maximum speed and no load. 

This is an exceptional case that occurs 

when the generator loses its grid connection 

due to a power outage or lightning 

strike. Runaway could occur in fractions 

of a second and has to be considered 

in the layout of a hydraulic system. 

Runaway speed of a radial machine 

0 1 2 

2 

0 2 

QPop: QTop: 

2 Characteristics of a pump impeller in pump 

and turbine mode (n = constant, D = constant). 

The best efficiency point (BEP) of the turbine 

is shifted to higher head and flow rate. 

1 Large water turbines can have a power rating of 700 MW or more. At much smaller ratings, conventional pumps running as turbines 

are an economical solution for pressure reduction in industrial processes. 

© Andrey Shchekalev | Dreamstime.com 

HT / HP 

1 

0 

PT / PP 

1 

0 

-0.5 

HT 

HP 

ηT 

ηP 

PT 

PP 

1 

ηT / ηP 

0 

QT/QP 

PANORAMA 

Pump 

Turbine 

Anticipation Range 


27

PANORAMA 

3 In many cases, a single-stage HPRT is used to capture the process stream energy and drive a multistage pump. 

4 Typical HPRT test setup in a closed loop. 

Electric 

Power 

Supply 

Electric 

Power 

Grid 

Electrical 

Power 

Measurement 

Pump discharge 

pressure 

Pl 

Throttle valve 

Turbine inlet pressure 

can be between 140% and 200% of 

the nominal speed, depending on the 

specific speed and the rated conditions. 

This condition should be taken into 

account for generator operation and in 

the selection of the trip device that 

operates at transient conditions. If the 

HPRT is used to drive a generator, it 

may be prudent to use a gear reducer 

and drive the generator at four- or sixpole 

(1500 RPM or 1000 RPM at 50 Hz 

power frequency, 1800 RPM or 1200 RPM 

at 60Hz power frequency) speeds but 

mechanically design the generator rotor 

for two-pole speed (3000 RPM at 50 Hz, 

3600 RPM at 60Hz). 

Motor 

Pl Pl 

Electrical 

Power 

Measurement 

Booster 

Pump 

Turbine 

Generator 

P 

Pump suction 

pressure 

Suction 

valve 

Turbine outlet pressure 


Vacuum 

Pump 

Flow meter 

(Venturi or magnetic) 

Suppression 

Tank 

Flow 

Fluid temperature 

Air pressure 

supply 

Vent 

Fill 

Drain 

Back pressure 

valve 

Hydropower turbines have flow 

control devices, such as wicket gates, 

which help to avoid high pressure surge 

during transient conditions. In process 

HPRT applications, the turbine bypass 

is always slightly open and is quickly 

adjusted to maintain inlet vessel level 

control when the turbine inlet valve trips. 

Operating with two-phase flow 

Care must be taken when starting up an 

HPRT. When an HPRT is driving a generator, 

it is normally spun-up to near 

operating speed, and then as the speed 

nears synchronous speed, the generator 

is switched to the power grid, which 

provides a load. Without load, the HPRT 

may quickly overspeed. 

Process control is important when 

applying HPRTs. If the pressure in the 

exhaust vessel is lowered by 20%, head 

across the turbine increases, and it will 

generate 20% more power than at the 

rated flow and head. For that reason, it 

is often prudent to oversize the HPRTs, 

shaft torque capacity to take into account 

various system upsets in pressure control. 

Processes have to be started before the 

HPRT can be brought on stream. Often, 

there will be a full-size pump with motor 

driver to get the process started and a 

parallel HPRT clutch motor pump that 

is used during normal operation 5 6. 

For processes with entrained gas or 

vapor (natural gas treating, fertilizer 

plants, hydrotreaters, etc.), a small volume 

percent of gas at the high-pressure side 

will turn into a measurable volume at 

the low-pressure side. This gas volume 

at the outlet may influence the size of 

the HPRT. The high gas volume in the 

exhaust may not be an issue if the shaft 

is robust, the runner is made of cavitation-resistant 

materials, and the wear 

parts are hardened to reduce contact 

damage. However, gas bubbles in the 

seal chamber will surely do damage to 

the mechanical seals. Dual seals within 

Plan 53 or 54 are therefore recommended 

for process HPRTs to assure that the 

mechanical seals operate in a controlled, 

liquid state. 

Application in hydrocarbon 

processing 

A large Brazilian oil company is using 

pumps as turbines instead of throttle 

valves and is thus recovering energy. 

In one case, liquid charged with gas 

must be expanded in a scrubbing tower. 

Sulzer worked with oil company engineers 

to understand the multiphase flow. 

That knowledge was then used to design 

the HPRT’s runner and rotor. The experience 

of Sulzer Pumps in designing such 

HPRTs helped to find a solution for these 

challenging conditions. 

Between the inlet and outlet of a 

turbine, the pressure drops in very short 

time. Gas dissolved in the fluid at high 

pressure diffuses out of the liquid causing 

gas bubbles to form, resulting in twophase 

flow. The required pressure reduction 

is from 74.8 bar (1080 psi) to 14.8bar 

(210psi). A five-stage HPRT with one 

dummy stage was chosen, so that a 

further stage may be fitted for smaller 

flow rates in the future 7. The continuous 

power of 258 kW recovered from the 

expansion assists the 870-kW motor 

driving the pressure increasing pump. A 

pump running as a turbine is difficult 

5 HPRT equipment layout: Driving the 

generator at reduced speed can save it on 

overspeed caused by a sudden power loss. 

Pump 

HPRT 

Gear 

reducer 

Motor 

Clutch 

Generator 

HPRT

6 Some HPRT trains are so long that the baseplate is split at one coupling to facilitate 

shipping, lifting, and installation. Setup: HT-MSD – clutch – motor (missing) – MSD pump. 

to regulate. Depending upon the pressure 

drop and application, an HPRT flow 

rate may be established amounting to 

80%–90% of the effective throughput. 

The remaining 10%–20% of the flow is 

expanded via a bypass valve and is used 

to control the vessel level supplying the 

HPRT. 

During plant startup, the turbine 

cannot perform work and may actually 

8 Gas plant: MSD pump – motor – clutch – HST turbine. 

consume energy. If the motor must be 

used for startup, an overrunning clutch 

prevents the motor from having to put 

additional energy into the turbine during 

this phase. Once the hydraulic energy 

at the inlet to the HPRT is sufficient, the 

turbine runs up to the motor speed. The 

overrunning clutch now ensures that the 

HPRT cannot run faster and supplies its 

hydraulic energy to the drive train. 

Amine 

contactor 

Startup 

pump 

Level controller 

Sour gas 

Startup 

motor 

Sweet gas stream 

Pump Motor 

Bypass 

Lean amine stream 

7 A gas-scrubbing HPRT application can recover more than 2 MW. 

Clutch 

Short payback times 

In many industrial processes, hydraulic 

power recovery turbines (HPRTs 8 ) 

can provide substantial savings with a 

short payback period. It is not uncommon 

to find that over 1.5MW can be re - 

covered. Careful attention to process 

conditions and HPRT controls assures 

reliable, useful operation for years of 

service. 

HPRT 

PANORAMA 

Stripper 

Ron Adams 

Sulzer Pumps 

800 Koomey Road 

Brookshire, TX 77423 

USA 

Phone +1 281 934 6029 

ron.adams@sulzer.com 

John Parker 

Sulzer Pumps 

800 Koomey Road 

Brookshire, TX 77423 

USA 

Phone +1 281 934 6011 

johns.parker@sulzer.com 


29

PANORAMA 

Characterization of arbitrary 

distributions—a new method 

For a realistic evaluation of an arbitrary distribution, the fluctuations of the 

magnitudes as well as its spatial distribution have to be considered. Therefore, 

a new key figure (CoD—coefficient of distribution) has been found that is able 

to cover both attributes of the distribution/mixture. First tests with artificial tracer 

distributions as well as with tracer distributions gained from CFD-calculations 

show reasonable results. The new key figure provides a realistic evaluation of 

any arbitrary distribution. The use of this powerful tool can, therefore, improve 

the possibilities in the design and development phase of products as well as 

help create more precise definitions for the requirements of the customers. 


The mixing of components is one of the 

oldest processes within mechanical 

process engineering. Industrial mixing 

processes are challenging—especially 

for liquids and, in particular, for liquids 

with high viscosities. Since more mixing 

effort is necessary to achieve better 

homogeneity, the characterization of the 

state of the mixture is of special interest. 

The homogeneity, or the degree of 

mixing, is commonly evaluated with 

figures that are based on statistical 

methods. A well-introduced and 

commonly accepted value is the CoV, 

the coefficient of variation, which 

describes the ratio between standard 

deviation and expectation. 

Since the CoV value is an averaged 

quantity over a region (area or space) 

and, therefore, not sensitive to spatial 

differences, a quantification of mixtures 

only with the CoV can sometimes lead 

to less expressiveness or to misconstructions. 

Mixtures that only differ within 

the spatial distribution of the describing 

quantities will lead to the same CoV 

value even though the properties of the 

mixtures are obviously different 1. In 

case of, e.g., chemical reactions, the 

different mixing states can lead to 

enormous differences in yield and composition. 

Two mechanisms of mixing 

Two mechanisms are able to increase the 

quality of the mixing—one is distributive 

mixing and the other is the diffusive 

equalization of differences within a con- 

1 Two mixtures with different spatial distribution patterns but nearly identical CoV values. 

centration field. The latter is a spontaneous, 

unsolicited process that needs no 

additional energy to take place. 

The result of the diffusive transport 

can be measured directly via the CoV 

value. However, as important as diffusive 

equalization is distributive mixing—the 

second mechanism for mixing processes. 

It is a requirement for effective mixing 

because it enlarges the contact area 

between higher and lower concentrated 

regions. Since diffusive transport is proportional 

to that contact area and to the 

concentration gradient, an increasing 

spatial distribution has a direct positive 

impact on the quality of the mixture and 

should, therefore, additionally have an 

impact on the quantity of the mixing 

quality. 

CoV for the diffusion—ffor the 

distribution 

The aim is to have a single method with 

which to evaluate both mixing mechanisms: 

diffusive transport and distributive 

mixing. To incorporate both mechanisms, 

several artificial tracer distributions 

have been analyzed. Figure 2 

shows nine different mixed situations 

differing in mixedness and spatial distribution. 

On the vertical axis, the CoV 

value decreases, since the state becomes 

more mixed due to an equalization of the 

values (simulating a diffusive transport 

mechanism). In these cases, the spatial 

4336

distribution remains constant. On the 

horizontal axis, the CoV value remains 

constant, but the length scale on which 

segregation occurs, decreases; therefore, 

the spatial distribution of the tracer increases 

in the horizontal direction (simulating 

distributive mixing processes). 

The diffusive equalization can be 

quantified with the coefficient of variation. 

Applied to the artificial distributions 

in figure 2, the mixedness in the first 

row has a CoV value of 100%, the second 

row of 60%, and the third of 20%. These 

values are independent of the spatial distribution. 

In this example, the size of the colored 

squares serves the purpose of characterizing 

the length scale on which these 

fluctuations occur. The smaller the individual 

squares are, the better the distribution 

is. A good measure of the size of 

these squares is the length of the contact 

line between regions of different concentrations. 

In real cases, this contact line 

(or contact area) is of special interest as 

well, since diffusive and dispersive 

equalization strongly depend on it. The 

length of contact line is made dimensionless 

by relating it to a characteristic 

length scale, e.g., the hydraulic diameter. 

Applied to the different distributions in 

figure 2, this dimensionless number f 

is 2 (=16/8) for the right column, 6 

(=48/8) for the middle column, and 14 

(=112/8) for the left column. The respective 

width of each square is 8. These 

values are independent of the degree of 

mixing or CoV. 

CoD for comparing distributions of different 

degrees and extents of mixing 

Here, two key figures are available to 

characterize different aspects of a scalar 

distribution—the commonly used CoV 

value, used to characterize the magnitude 

of the fluctuations, and the f value, used 

to characterize the spatial distribution. 

The combination of both values leads 

intuitively to the definition of the coefficient 

of distribution (CoD)—being the 

quotient of the CoV and the f value— 

and allows distributions of different 

mixing degrees and extents (diagonal 

directions within figure 2) to be 

compared. The value of the coefficient 

of distribution (combining diffusive and 

distributive mixing effects) in figure 2 

ranges from 50% for the worst mixing 

state down to approx. 1% for the best 

mixing state (bottom, left). 

In contrast to the situation in artificial 

distributions like this example, in real 

systems, the contact line is not necessarily 

easy to determine. Here, measure theory 

helps. It is known that for a completely 

segregated system, the integration of the 

norm of the gradient of a normalized 

value leads exactly to the length of its 

contact line (between value 0 and value 

1). Applied to real systems, the distributions 

will be made dimensionless and 

be scaled by a division by 2 s . The characteristic 

length scale is obtained as the 

ratio of cross section and hydraulic 

diameter. The fundamental formulas can 

be seen within figure 3. 

A restriction for the calculation of the 

length of the contact line appears for 

systems with a massive increasing diffusive 

equalization. There, the contact 

line loses its significance, but the values 

achieved get smaller, so the key value 

of the CoD is conservative. 

2 Sketches of different artificial tracer distributions. From top to bottom, the mixedness increases; 

from right to left, the spatial distribution increases. 

CoV 100.0 (%) 

f 14.0 (–) 

CoD 7.1 (%) 

CoV 60.0 (%) 

f 14.0 (–) 

CoD 4.3 (%) 

CoV 20.0 (%) 

f 14.0 (–) 

CoD 1.4 (%) 

CoV 100.0 (%) 

f 6.0 (–) 

CoD 16.7 (%) 

CoV 60.0 (%) 

f 6.0 (–) 

CoD 10.0 (%) 

CoV 20.0 (%) 

f 6.0 (–) 

CoD 3.3 (%) 

CoV 100.0 (%) 

f 2.0 (–) 

CoD 50.0 (%) 

CoV 60.0 (%) 

f 2.0 (–) 

CoD 30.0 (%) 

CoV 20.0 (%) 

f 2.0 (–) 

CoD 10.0 (%) 

PANORAMA 


31

PANORAMA 

Formula Scalar quantity Vectorial quantity 

Mean value 

Standard deviation 

Coefficient of variation 

Norm of the gradient 

Length scale 

Coefficient of distribution 

3 Formulas that are necessary in order to calculate the new key value 

for characterizing a mixture, the coefficient of distribution. 

Application to industrial relevant cases 

The applicability of the theory developed 

above can be tested using results gained 

form CFD calculations. In figure 4, left, 

tracer distributions gained from mixing 

processes with alternative Contour- 

Mixer™ designs (by Sulzer Chemtech) 

can be seen. The starting distribution of 

the tracer was the same in both cases: a 

totally segregated system with tracer 

concentration of unity in the left half of 

the channel and zero in the right half 

(1 left). 4 (right, top and bottom) shows 

the distributions on a cross section of 


the channel at some distance behind the 

mixing devices. Although the CoV value 

is nearly identical in both cases (70%), 

one would intuitively think that the 

bottom one is better mixed. By incorporating 

the concept of length of the 

contact line, one can calculate that the 

quality of these two distributions differs 

by a factor of three. 

The concept of evaluating the distribution 

of magnitudes together with the 

spatial distributions of the quantity of a 

given distribution is not limited to scalar 

distributions like concentration or tem- 

4 Different designs have been tested for the Sulzer Chemtech Contour™ Mixer (left), a static mixer for high turbulent 

gas flows. For two of the designs, tracer distributions after the mixer are shown (right). In both cases, there was a start 

configuration of left/red – right/blue. 

perature fields, but can also be applied 

to vectorial distributions like velocity 

fields. 

The new key figure, the coefficient of 

distribution (CoD) is a powerful tool to 

be able to give a realistic evaluation of 

any arbitrary distribution. This advancement 

opens new possibilities in the 

design and development phase of 

products and helps create more precise 

definitions for the requirements of the 

customers. 

Carsten Stemich 

Sulzer Markets and Technology Ltd. 





Phone +41 52 262 21 96 

carsten.stemich@sulzer.com

SULZER WORLD 

Welcome to Sulzer Pumps in Suzhou 

Sulzer strengthens its pumps facilities network in China with a 

significant investment in a new state-of-the-art factory for engineered 

pumps for the industries oil and gas and power generation. 

In 2010, Sulzer invested around CHF30 

million in the expansion of its global 

manufacturing network with a new fac - 

tory in Suzhou, China. As part of this 

investment, Sulzer is bringing its most 

advanced engineered-pump technology 

to China. The new state-of-the-art 

factory for engineered pumps mainly 

focuses on meeting the growing demand 

in the oil and gas and the power generation 

markets segments in China. 

Suzhou is one of the most vibrant 

industrial cities in China and is located 

about 100 kilometers west of Shanghai. 

The new, wholly owned pump factory 

was officially opened November 24, 2010 

with more than 300 customers, government 

officials, and employees present at 

the ceremony. 

Extensive testing capabilities 

As part of the Sulzer global network, 

employees in the Suzhou factory 

manufacture engineered pumps on 

23 000 m 2 of total floor space with 

state-of-the-art machine tools. The new 

factory integrates best practices from 

other major Sulzer Pumps factories, 

ensuring operational excellence by com- 

Outside view of the new state-of-art facility in Suzhou, China. 

Opening ceremony at Suzhou factory in China in November 2010. 

bining Sulzer’s global standards for 

quality with reliable delivery times. 

The plant has extensive testing capabilities 

with two closed-loop test beds, 

one test well for vertical pumps and a 

hot test area. Variable frequency drives 

(VFDs) are provided to allow motor softstarts 

and to run parallel tests in all four 

test areas with a total power supply 

of 15 MW. The test bed was designed 

incorporating the most advanced testing 

technologies of Sulzer Pumps. 

At the plant opening the new legal 

entity had already an order backlog of 

more than CHF 30 million. Engineering 

and procurement teams have already 

been working on several major orders 

for quite some time while manufacturing 

has just started recently. The ISO 9001 

certification process is ongoing, and the 

certification is expected in the second 

quarter of 2011. 

Continuous expansion 

The various divisions of Sulzer have continuously 

expanded their collective 

presence in China over the last few years 

and currently employ over 1000 people. 

Sulzer has a range of sales and service 

locations in China and is now active 

with four main manufacturing plants: 

in Shanghai for Sulzer Chemtech’s separation 

technology and Sulzer Metco’s 

surface coating technology, in Dalian for 

Sulzer Pumps serving the hydrocarbon 

processing and the pulp and paper 

markets, and, now, in Suzhou. 

Based on its strong growth over the 

last two decades, China has become 

one of Sulzer’s key markets. It offers 

excellent prospects for further expansion 

for the local market as well as a manufacturing 

platform to supply the rest of 

the world. 

Martin Tempus 

4337 Sulzer Technical Review 1/2011 | 

33

INTERVIEW 

John Allen: “Scope of work for Sulzer’s customers expanded” 

34 


When was Dowding & Mills founded 

and how did the company develop 

over the years? 

Dowding & Mills was founded in 1911, 

starting with one branch in Birmingham, 

UK, in a terrace house in Camp Hill. 

Over the years, this location has grown— 

gradually acquiring properties around 

it. It currently occupies a five-acre site 

with 128000sq ft of buildings on the 

premises. 

Early in the 1960s, a second branch 

was acquired in London, and the 

number of branches doubled in 1965 

with the acquisition of Southampton & 

Nottingham. Branch network growth 

was steady through late 60s and 70s with 

the addition of around two branches per 

year throughout the UK. In the 1980s 

the company expanded significantly 

with the acquisitions of electro-mechanical 

repair facilities, Hamilton & Dickson 

(Australia), EMS (USA), Geha (Netherlands), 

AEW (Luxembourg), EMS 

(Germany), Manning Marine (UK) and 

the UK Calibration businesses. 

Company growth continued into the 

1990s with acquisitions of electronic and 

servo repair companies, then Peebles 

Field Services, and then the gear cutting 

companies (R W Gear & Banner). At 

its peak, Dowding & Mills had circa 

With the acquisition of Dowding & Mills, Sulzer has 

expanded its technical competencies, and it has 

complemented the current activities of Sulzer Turbo 

Services with repair and maintenance services for 

generators and motors. John Allen—technical director 

of Sulzer Dowding & Mills—spoke to us about the 

opportunities our customers will experience through 

our expanded service business. 

40 branches in the UK, 5 in Europe, 5 in 

USA, and 6 in Australia. 

As a result of closures, consolidation, 

and disposals the network shrank 

between 2000–2010, but over the last 

four years the branch network has 

been reinforced with the acquisition 

of two small businesses in the UK 

(Middlesbrough and Daventry) and a 

50% interest in a facility in Dubai. 

Why is the service business of 

Dowding & Mills attractive to the 

customers of Sulzer? 

Dowding & Mills’ core area of expertise 

is in the rewinding of rotating electrical 

machines. Therefore, Sulzer’s customers 

can now have their turbine-driven generators 

or their motor-driving pumps or 

compressors repaired by Sulzer. 

The scope of work available to 

Sulzer’s customers when their plant fails 

or needs maintaining has been expanded 

by the acquisition of the electromechanical 

capability of Dowding & Mills. 

Sulzer will now have in-house capability, 

whereas, in the past, it had to outsource 

this work to subcontractors. As a result, 

the quality and customer service culture 

of Sulzer will extend from the mechanical 

equipment itself to include motors and 

generators. 

Dowding & Mills has always been 

a service-driven business delivering a 

quality product with fast response and 

a minimum of outage time. With our inhouse 

copper-rolling mill and world- 

class HV coil-manufacturing facility, 

Dowding & Mills is able to manufacture 

high-quality HV coils for rewinds faster 

than almost any rewind competitor in 

the world. These services are further 

complemented by our in-house highspeed 

balancing and overspeed facility. 

How can the customers of Dowding 

& Mills profit from the merger with 

Sulzer? 

Dowding & Mills customers will profit 

through Sulzer’s capability to repair the 

mechanical parts driving or being driven 

by the motors and generators—which 

have historically been repaired by 

Dowding & Mills. In other words, 

Dowding & Mills customers now have 

a one-stop service shop for their turbines, 

pumps, and compressors. 

They will also profit from the culture 

of continuous improvement in personnel 

development, management systems, performance, 

quality, safety, and environment 

that is part of Sulzer’s culture and 

that Sulzer will foster within Dowding 

& Mills. 

How many service centers does 

Dowding & Mills have around the 

world and what are their capabilities? 

Currently, we have 27 branches in the 

UK, 3 in USA, 5 in Australia, and 1 in 

Dubai. 

The capabilities of branches vary 

greatly. Each is specialized in meeting 

the needs of its customer base. Several 

4338

anches serve niche markets and, therefore, 

specialize in the needs of particular 

industries as well as serving local customers. 

Others serve only their local 

customer base. 

Several branches work globally to 

provide services for their customers. The 

Birmingham branch, in particular, will 

rewind machines of any size anywhere 

in the world where it is safe to operate. 

It repairs motors and generators up to 

and including 16500V, 400MW (generally, 

air cooled), from two-pole turbine to 

multi-pole hydro generators with stator 

core lengths up to 7 m, and rotor diameters 

up to 16m. When the equipment 

is too large to transport back to UK it 

is rewound in situ, which includes on 

board vessels while they are in service. 

How do you make sure you know the 

needs of your customers? 

Our primary method of understanding 

the needs of our customers is through 

our 80 strong sales team and our branch 

managers, who maintain regular personal 

contact with their key account customers. 

This is supported by contact between 

project manager and technical liaison 

with the customers. 

We also review our customer needs 

during contract review, and customer 

feedback is recorded though our QA 

system. In our quest to better understand 

our customers’ needs, we have periodically 

conducted customer satisfaction 

surveys. 

Can you give us a recent example? 

One UK customer in 2010 had a premature 

failure of a 12MW gas compressor 

motor. This disruption created a significant 

risk that that customer would not 

be able to meet contracted delivery 

requirements. A prolonged outage was 

not tolerable from an operational point 

of view. 

The failure necessitated a complete 

stator rewind. However, a temporary 

repair that involved cutting out the 

failed coils as well as some good coils 

to balance the winding, performing a 

splice repair to one coil, and repairing 

core damage, allowed the machine to be 

put back into service at a reduced output 

of 75% load (9 MW). 

During the repair, engineers noted 

that the rotor also needed rewinding. As 

a result, when the stator was rewound 

some months later (when the risks to 

the customer were lower), a spare rotor 

was refurbished and fitted, which permitted 

rewinding of the original rotor. 

Unfortunately, the spare rotor limited 

output to 70%. 

When the rewound rotor is completed, 

it will be fitted into the rewound stator 

taking the capability back up to 12 MW. 

This machine will continue in service 

until a replacement machine is procured 

and installed in 2012—after which, it 

will be maintained as an essential spare. 

A final question: Are there technological 

developments (e.g., renewable 

energy) to which you are paying 

increased attention? 

Wind power generation is an area where 

we have become more active. This is a 

challenging area, since these machines 

operate in a relatively hostile environment 

and are engineered to keep the 

mass of the equipment as low as 

possible. 

As the number of wind generators 

increases in the UK, we see this as an 

area of potential growth. With this in 

mind, we are currently developing a 

dedicated facility in order to control 

technical issues. 

As other renewable energy sources are 

developed, we will have to ensure that 

we will be able to meet the needs of 

those industries. 

Interview: Gabriel Barroso 

John Allen 

John Allen is a chartered electrical engineer. He started 

with 15 years in design of DC and AC rotating 

machines with a UK manufacturer, the last 7 years 

of which, he held the position of Chief Designer. As 

next a step, he moved to a diesel genset manufacturer 

(F G Wilson), where he spent 3 years in technical sales, 

this was followed by 6 years managing repair shops, 

and the last 16 years providing technical support to 

repair companies. For the last 12 years, he has been 

redesigning hydro generators to improve per formance. 

He has represented the UK at various IEC technical 

committees and at IECEx with particular expertise in 

the repair of hazardous-area equipment and competency 

of personnel repairing Ex equipment. 

The Sulzer Technical Review (STR) is a 

customer magazine produced by the 

Sulzer Corporation. It is published 

periodically in English and German 

and annually in Chinese. The articles 

are also available at: www.sulzer.com/str 

1/2011 

93rd year of the STR 

ISSN 1660-9042 

Publisher 

Sulzer Management Ltd. 

P. O. Box 

8401 Winterthur, Switzerland 

Editor-in-Chief 

Gabriel Barroso 

gabriel.barroso@sulzer.com 

Editorial Assistant 

Laura Gasperi 

sulzertechnicalreview@sulzer.com 

Advisory Board 

Mia Claselius 

Ralf Gerdes 

Thomas Gerlach 

Hans-Michael Höhle 

Sue Hudson 

Hans-Walter Schläpfer 

Heinz Schmid 

Shaun West 

Translations 

Interserv AG, Zürich 

Design Concept 

Partner & Partner AG, Winterthur 

Design 

Typografisches Atelier 

Felix Muntwyler, Winterthur 

Printers 

Mattenbach AG, Winterthur 

© March 2011 

Reprints of articles and illustrations are 

permitted subject to the prior approval of 

the editor. 

The Sulzer Technical Review (STR) has 

been compiled according to the best 

knowledge and belief of Sulzer Management 

Ltd. and the authors. However, 

Sulzer Management Ltd. and the authors 

cannot assume any responsibility for the 

quality of the information, and make no 

representations or warranties, explicit or 

implied, as to the accuracy or completeness 

of the information contained in this 

publication. 

Circulation: 16 000 copies. 

Magno Satin 135 g/m 2 

from sustainably managed forests. 

For readers in the United States of America only 

The Sulzer Technical Review is published periodically by 

Sulzer Management Ltd., P.O. Box, 8401 Winterthur, 

Switzerland. Periodicals postage paid at Folcroft, PA, 

by US Mail Agent – La Poste, 700 Carpenters Crossing, 

Folcroft PA 19032. 

Postmaster: Please send address changes to Sulzer 

Technical Review, P.O. Box 202, Folcroft PA 19032.

A More Efficient 

Surface 

To design a more efficient engine, vehicle engineers partnered 

with Sulzer for the answer. 

Let’s be frank. With the rising cost of fuel and the need to keep our planet clean, 

we want more efficient vehicles. So, when vehicle engineers challenged us to develop 

a better cylinder bore surface, we willingly took on the task. Together, we developed 

coating materials and application solutions to produce engines that use less fuel and 

oil, reduce emissions, and eliminate corrosion from poor-quality fuels, all without 

sacrificing power. The result? Hundreds of thousands of vehicles with this technology 

are now on the road, and that adds up to a lot less fuel and emissions. 

Working together, we can do great things. 

For further information: 

Sulzer Metco AG (Switzerland) 

Rigackerstrasse 16 

5610 Wohlen 


Phone +41 56 618 81 81 

Fax +41 56 618 81 00 

info@sulzermetco.com 

www.sulzermetco.com

Testing and quality

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