WCA January 2014

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22 Wire & Cable ASIA – January/February 2014
Industrynews
AUSTRIAN high-quality wire machinery
manufacturer CPA Wire Technologies
uses the gentle but efficient water
quenching system AEOX STS, which
helps to save energy without being
harmful to workers and nature.
AEOX STS is part of the elaborate
AEOX Heat Treatment Technology
consisting of energy-efficient
recirculation convection furnaces for
austenitisation and cross-flow
convection furnaces for diffusion, stress
relieving, soft annealing and tempering
of wires and strips. With the entire
AEOX heat treatment technology
operators can save up to 40 per cent of
energy.
Traditionally, the quenching systems
used in the steel wire industry are lead
baths. In a technical point of view, these
systems are very well suited for
achieving the desired thermal
procedure, but there are major
disadvantages which must not be
neglected. First of all, lead is an
environmental poison. Additionally,
residues of lead will always adhere to
the wire which might require additional
chemical cleaning. Finally, heating up
and controlling the temperature of tons
of wire requires valuable energy.
As an alternative to lead baths, fluidised
bed systems have been introduced.
These systems make use of small solid
particles impacting on the wire which
extract heat from the product by direct
contact. Compared to lead baths, these
systems are environmentally
compatible and have less power
consumption. Still, these systems have
some disadvantages. They are usually
operated with sand of 100 to 200μm
particle size. This is a size where dust
can enter the respiratory system and
lead to irritations. Particle sizes below
approximately 5μm, which may be
produced during operation, can even
get into the lungs and cause severe
health problems. In a technical point of
view, these systems only allow a very
narrow dimension range of wires at the
same time, since it is not possible to
adjust the bed corresponding to the
wires individually.
To overcome the described problems,
CPA developed a water-based
quenching system. The quenching fluid
is a mixture of water and organic
polymers. These fluids are
environmentally friendly and easy to
handle. Because of the polymer
properties, the vapour film phase at the
beginning of the quenching is very
stable. The comparably long-lasting
vapour film phase results in a
controllable quenching process. The
transformation temperature is reached
before the bulk boiling phase starts.
The AEOX Structural Transformation
Systems by CPA (international patent
pending) is designed to run different wire
dimensions at the same time. For that
reason, the cooling section is divided
into individually adjustable sections
according to the customer’s request.
The quenching section is directly
connected to the soaking zone, without
leading the wires through surrounding
atmosphere. The soaking zone consists
of two individually adjustable,
electrically heated sections. In that way
it is possible to introduce a temperature
gradient from the entrance to the exit in
order to minimise wire temperature
changes during pearlite transformation.
CPA Wire Technologies – Austria
Website:
Gentle but efficient from CPA
❍ The AEOX system from CPA