|
|
 |
|
|
|
|
|
|
|
|
2009.01.20
Rotative cooling “made in BMI”
The renown of the range of B8_T type vacuum furnaces dedicated to gas quenching is partly down to and thanks to the rotating volute, which offers unequalled quenching uniformity. Developed from the B7_T series, this rotative cooling process has proved itself in many integrated or sub-contracted heat treatment units that use vacuum furnaces from the B8_T range for their main vacuum heat treatments (steel quenching and tempering, stainless steel hyperquenching, bright annealing, ageing, soldering, special alloy degassing...according to the options selected in a wide range).
Working at the centre of the volute, the cooling turbine distributes its flow according to the rotation of the volute (up to 10rpm). The gas is cooled on intake and discharge by passing through the exchanger. The cooled gas, guided by the volute, is blown into the circular treatment chamber via diffusers which are supplied from the beginning of the cooling phase. The diffusers distributed regularly around the heating chamber permit optimal cooling of the load, sparing no zone from the latter. At each instant of the cooling phase, half the load is directly blown by the cool gas flow, while the heated gas is extracted then cooled by the opposed side diffusers.
The high performance turbine, driven by an inverter, is located at the heart of a short and rational convection circuit and therefore provides effective and homogeneous load ventilation. The cooling circuit is entirely integrated into the airtight chamber, which limits floor space needs and reduces inert gas consumption and cycle time. In order to adapt to all load and part typologies, cooling can be carried out either in rotative mode, or fixed mode according to a volute stop position.
Finally, as needs vary from one project to another, BMI offers different cooling speeds/pressures for its equipments, for different types of inert gas. As standard, a B84T type vacuum furnace has a pressure of 5 bar abs for nitrogen, and we are offering alternative cooling pressure of 6, 10 and 12 bar abs, for nitrogen and/or argon (other speeds on request and subject to agreement). These higher cooling pressures will prevent certain distortion problems in sensitive parts (tapered parts for example) or make it possible to harden “intermediate” grades which are more commonly treated in an oil quenching vacuum furnace.
The whole BMI sales team is at your service to provide you with any further information on our range of B8_T type vacuum furnaces or our rotative cooling process and its advantages.
|
|
|
|
