Abstract: An electrical resistance ceramic heating element comprises: a) three or more ceramic legs comprising regions of the element in which at least the majority of the electrical heating occurs (hot zones), at least one of the legs being effectively entirely a hot zone and at least two of the legs each comprising a hot zone and a cold zone; b) a number of leg terminal portions less than the number of legs, for connection to a power supply; and, c) ceramic bridging portions providing electrical connectivity between the legs.
Abstract: A heating panel includes an electrical heating element fully embedded in a base of refractory material, the element being embedded in a region of high thermal conductivity refractory material integrally backed by low thermal conductivity refractory material. The element and surrounding high-thermal conductivity refractory may be fully or partially raised above the general surface of the base. In another aspect, a heating device is in the form of an electrical heating element coil supported and retained on a base of castable refractory material by ribs molded with the base and around part of the periphery of the coil, the material of the base being molded between adjacent turns of the coil, the core of the coil being free of refractory and open to the surface of the device, and at least part of the coil periphery is raised above the surrounding surface of the panel. Methods of making the heating device are disclosed.
Type:
Grant
Filed:
June 19, 1987
Date of Patent:
December 4, 1990
Assignee:
Kanthal Limited
Inventors:
Peter H. A. Roebuck, Stanley B. Moug, Adrian G. Howgate