TPT September 2008

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September 2008 46
Technology Update
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Gebr Lennartz GmbH & Co KG, Germany,
is the provider of an advanced range of
Ohler heavy-duty circular sawing machines.
With a long standing tradition, Ohler circular
sawing machines have been used over
decades with success.
The machines are able to cope with the
stringent demands of the material being
cut, cutting parameters and the circular
cutting tools employed. The machine
frame consists of a solid cast iron base,
two columns with a crosshead and the saw
carriage, which is guided vertically between
the cylindrical column guides.
The saw blade and feeding cylinders are
located in the centre line of the machine.
The cutting forces are absorbed by heavy-
duty vices and are distributed evenly within
the closed system. Vibrations are optimally
absorbed by the sturdy cast iron body of
the machine and the ideally dimensioned,
helical spur gear drive in combination with a
worm gear. The cutting forces are absorbed
Circular cold sawing machine
with six-step shift transmission
by extremely large-surface carriage guides,
which have a long life.
Two synchronous hydraulic cylinders
produce the vertical down feed cutting
force. The weight of the saw carriage is
adequately compensated. The centrical
clamping of the material is carried out at the
inlet and outlet side. A kerf opening system
guarantees a contact free return of the saw
blade.
A unique feature of the Ohler circular
sawing machine is that it can work with
six-step shift transmission. It is possible to
achieve transmission ratios at low cutting
speeds with high torque.
Both carbide tipped circular saw blades and
circular segmental saw blades can be used
on the machine. A frequency converter can
also be implemented to achieve all cutting
speeds between gear steps. It is therefore
possible to cut material up to 1,500N/mm²
and even stainless steel can be cut due to
the low revolution and the use of circular
segmental saw blades. This is not possible
with a conventional sawing machine when
using carbide tipped saw blades.
Ohler machines can cut solid material,
single pipes or tubes in layer and material
in bundles. Much lower motor powers are
required due to the shift transmission. The
Ohler K/KA 1000 is equipped with a 37KW
motor, providing a remarkable saving in
energy. A comparable sawing machine
for carbide tipped saw blades would need
approximately 90KW.
Gebr Lennartz GmbH & Co KG –
Germany
Fax: +49 2191 99 60-60
Website:
 Cutting forces are absorbed by heavy-duty vices
 The Ohler circular sawing machine has six-step
shift transmission
 The machine can cut solid material, single pipes
or tubes in layers, and bundled materials
From straight, open-ended tubes
to internally finned tubes
Inex Incorporated, USA, established in 1983, is the manufacturer of composite radiant
tubes. In addition to straight, open-ended tubes, the company offers SER (closed
ended and flanged), burner nozzles, U-tubes, and segmented tubes.
Silicon/silicon carbide tubes offer creep resistance, thermal shock resistance, high
emissivity, high thermal conductivity, high temperature capability, long tube life, and
are chemically inert. These properties may make them a suitable choice for furnace
operators who are dissatisfied with the performance or life of metal alloy tubes. The
material attributes provide heat treaters with a means to improve furnace uptime,
reduce tube replacement costs, reduce recovery time, and improve temperature
uniformity.
The company also produces internally finned tubes. The fins cause turbulence, which
eliminates laminar gas flow and enhances heat transfer. The turbulence also improves
combustion, which in turn reduces emissions and improves efficiency. The fins also
provide increased surface area to capture the heat in the combustion gas stream.
Inex Inc – USA
Fax: +1 716 537 3218 • Email: • Website: