Ruhrgas Aktiengesellschaft

Loi Thermprocess Gmbh

Friedhelm Kuhn

Walter Scheuermann

Georg Velten

Method and device for the heat treatment of workpieces

Method and device for exchanging the atmosphere in a hood-shaped

A method is described for the heat treatment, preferably for the intermediate heat treatment, of workpieces, in which the workpieces coming from a heating apparatus are quenched in a fluidized bed under precise temperature and movement control, and then, if necessary, transferred to a structure transformation apparatus.

Method for the heat treatment of workpieces

To harden individual metal parts in a continuous low-energy heat treatment process consisting of clearly separate stages, the part to be heated is placed in a sealed heat treatment box consisting of two layers of porous material separated by a gas-tight barrier. A heat-releasing atmosphere is caused to enter into the material of the two layers during the heating stage, the atmosphere moving from the inner layer of porous material into the box chamber thereby heating the metal part being treated to a diffusion temperature above hardening temperature. An atmosphere releasing components for diffusion is caused to enter the box chamber through the inner layer of porous material during the diffusion stage, with the heat releasing atmosphere continuing to enter the outer layer of porous material. The entry of hot atmosphere into the outer layer of porous material is stopped during the cooling stage, and a cooling atmosphere is caused to enter the box chamber through the inner layer of porous material, to reduce the temperature of the part being heat-treated to the hardening temperature. The temperature having been thus reduced, the part is quenched during the quenching stage by means of a quenching agent preferably following the transfer of the part to a cooling box the hardening agent entering the cooling box through porous material lining the box. A rotating arrangement may be used to transport several heat treatment and cooling boxes through the different treatment stages.

Hardening metal parts

Method of operating an industrial furnace

A process for the surveillance of jacketed radiant heating tubes and recuperative burners using a detector responding to the oxygen partial pressure in the exhaust gas. At low exhaust gas temperatures down to 200.degree. to 300.degree. C., an abrupt change in the detector output signal occurring due to the transition from over-stoichiometric to under-stoichiometric combustion and vice-versa is detected and is reproduced as an actuating and/or alarm signal. The process can also be used for flame surveillance, for the determination of leaks and cracks in jackets, and for surveillance of the tightness of closed magnetic gas valves.

Growing community of inventors

Mulheim, Germany

Friedhelm Kuhn