Gas-fired tunnel kiln - with circular tunnel continuous belt conveyor and internal protective gas generator

摘要

The belt rests on a supporting table carried on an inverted "U" support resting on the base of the circular refractory lining around which the gas burners are curved and within this support are a pair of coaxial pipes lined with a catalyst for the dissociation of ammonia into hydrogen and nitrogen, the overall length of the path followed by the ammonia being increased by baffles so that dissociation is complete. Running costs are less than in kilns using electrical heating and operating temp. is attained quickly without damage to the tunnel lining. Es. for mass prodn. brazing of e.g. watch and clock cases.