PROCEDE DE GRILLAGE DU CALCAIRE DANS UN FOUR A CUVES

摘要

1314791 Shaft furnaces H HOFER and A SCHMID 27 April 1971 [20 May 1970] 11587/71 Heading F4B Endothermic reactions, particularly limeburning, are carried out in a pair of shaft furnaces, 1, 2 each having a preheating zone V, a combustion zone B and a cooling zone K, the furnaces being connected by a duct 3 at the bottom of the combustion zone, primary air L1 in an amount insufficient for complete combastion, being introduced at the top of one shaft and cooling air L2, L3 being introduced at the bottom of the shafts and fuel gas being introduced in at least two streams, and the operation of the shafts is periodically reversed. The two streams of fuel gas may be introduced at the top of the combustion zone of one shaft, Fig, 1, one gas stream, B1 burning completely in the cocurrent shaft, and the other gas stream, A1, providing gas to burn in the combustion zone of counter current shaft. Additional gas may be supplied into the duct 3 to give combustion in the counter current shaft. In an arrangement comprising two shafts connected by lateral ducts 4, 5, Fig. 4, gas for combustion in the counter current shaft II is supplied at C below the side ducts 4, 5. The proportion of fuel supplied at each point, and the fuel/air ratio at each fuel supply point is determined in accordance with the desired temperatures, and to avoid combustion in the side flues.