SNDOTHERMIC PROCESSES IN A SHAFT FURNACE OF KILN AND MORE PARTICULARLY TO A PROCESS FOR CALCINING LINE.

摘要

A process involving an endothermic reaction in a furnace or kiln having first and second vertical shafts each shaft having, from -top to bottom, a preheating zone, a combustion zone and a cooling zone, the shafts being joined together at the lower end of the combustion zone, which process comprises introducing the material required to undergo reaction into the shaft heating the material in the preheating zone, introducing a current of primary air in to the top of the first shaft, feeding in cooling air in counter-flow from the bottom of the cooling zone in one or both shafts and feeding fuel gas into the combustion zone at more than one position so that a portion of the fuel gas burin only with the cooling air.