Directing gas flows for heating and cooling - in tunnel kiln with ceramic ware suspended from travelling roof wagons

摘要

Ceramic material being fired in a tunnel kiln is suspended from insulated wagons which form the kiln roof and more on wheels along lateral channels. The material travels through a warming-up zone, a fining zone with heaters and a final coollinq zone. In the firing zone the combination gases enter transversely and then flow oppositely to the moving ceramic ware. In the warming -up zone gas enters from the side walls, near the roof and obliquely to the movement direction, while in the cooling zone the gas enters obliquely against that movement, near the kiln roof and floor. Cooling gas is also supplied near the roof in the central firing zone and flows adjacent the wagon channels. The firing process is made more uniform, with local overheating avoided, and the rapid cooling helps to avoid distortion of the ware. The cooling gas adjacent the firing zone protects the seals.