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ALUMINIUM SMELTING INDUSTRY
with the low investment costs makes this
technology ideal for small scale production of
foundry ingot, forging rod or extrusion billet.
The technology is especially useful when producing
rods/billets of smaller diameters (normally
less than 3”) as no undesired bending
effects can occur, as opposed to such risks in
a vertical casting process. On the other hand,
casting larger diameters (normally more than
8”) can result in segregation zones within the
billet, because heavier alloying elements tend
to sink to the bottom of the billet.
Recently, Gautschi has designed the so
called smart caster. This casting system is designed
to offer very low investment costs and
short lead times. It is basically shop-assembled
and shipped in one unit. Thus it does not
need extensive installation on site, and this
further minimises time and cost. It is designed
as a dual strand standard caster for rod and
billet in a diameter range of 2 to 6”.
Both the primary and the secondary aluminium
industry have always counted on
Gautschi for the supply of reliable ingot casting
and stacking machines.
A wide variety of production lines allow
the production of ingots from 6 to 23 kg, with
a maximum output of 28 t/h. The latest development
in this field is an improved, partially
submerged pouring system. A plug and spout
system, in combination with a casting wheel,
successfully avoids turbulence and reduces
the generation of oxides.
Automatic speed control has been a standard
feature of Gautschi casting lines for years.
It ensures excellent weight consistency of the
ingots (which is necessary to ensure compact
stacks). Variation in the metal level of the feed
launder is compensated by the speed control
system, which ensures uniform filling of the
moulds.
Heavy-duty industrial robots have been
used in Gautschi ingot stacking lines for over
ten years. They can build rigid ingot stacks
weighing between 500 and 1,000 kg, depending
on customer requirements. Recent installations
have been equipped with a special sensor
measuring the distance between the ingot
layer in the robots handling system and the
previous layer of the stack. This allows the robot
release the ingots at a minimal fall height,
which increases the integrity of the stacks.
Heat treatment technology
The pre-heating and annealing processes are
some of the major steps in the production of
aluminium products, and they are of critical
importance for the quality of the final product.
Based on its long tradition of engineering,
Gautschi designs and supplies the full range
of equipment in the field of heat treatment.
These includes single and multi coil furnaces,
chamber homogenising furnaces as well as
pit type furnaces. Gautschi is also one of the
leading suppliers of pusher type furnaces,
having been involved in this technology for
more than 60 years.
This success is based on continuous product
development to improve productivity, temperature
uniformity and energy efficiency. As a
result, all components are carefully evaluated
and chosen to perfectly match each other. This
applies to the combustion systems, air guidance
and nozzle systems, recirculation fans,
insulation materials and temperature control.
It also applies to the complete handling system,
allowing short cycle times.
In 2007, Gautschi designed a new ingot
travel car for pusher type furnaces. As commonly
done, several pusher furnaces are installed
at the entry side of a hot rolling mill.
The ingot travel car allows for the installation
of some of the handling systems which often
serve more than one furnace. This car needs
just one unit for the up-ender and rail bridges
on the entry side, as well as single extraction
Gautschi pusher furnace
54 ALUMINIUM · 1-2/2013