Radiant heat emitter has space between electrical resistance and refractory matrix produced by sleeve removed by pyrolysis

摘要

A radiant heat emitter comprises a matrix of electrically resistive refractory material (2), a space (5) around the resistance. The spaces formed after compacting the refractory powder used to make the matrix, or during a subsequent fritting process by enclosing the resistance in a sleeve of a material that can be removed by pyrolysis. The resistance and the space surrounding it have diameters in a ratio of between 0.8 and 1.2:1, and the space has constrictions at intervals formed by projections (7,8).