TPT September 2008

T echnology U pdate

Circular cold sawing machine with six-step shift transmission

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

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  The machine can cut solid material, single pipes or tubes in layers, and bundled materials

Fax : +49 2191 99 60-60 Website : www.lennartz.de

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 : inex@buffnet.net • Website : www.inexinc.net

 Cutting forces are absorbed by heavy-duty vices

 The Ohler circular sawing machine has six-step shift transmission

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S eptember 2008

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