摘要 |
In a process of producing cement, the ground raw material is de-acidified in a calcinator and is subsequently burnt in a kiln and before being de-acidified in the calcinator is subjected to a multi-stage heat exchange with exhaust gas streams from the kiln and from the calcinator in two parallel series of heat exchange stages. The stream of ground raw material is delivered from heat exchange stages of each of said series to respective heat exchange stages of the other of said series. In order to improve the thermal efficiency and to reduce the equipment expenditure, the exhaust gas stream from the kiln is caused to deliver heat to the ground raw material in an additional heat exchange stage, which directly precedes the calcinator in the flow path of the ground raw material, and the exhaust gas stream from the kiln is subsequently mixed with the exhaust gas stream from the calcinator. The resulting stream of mixed exhaust gases is uniformly distributed to the two series of heat exchange stages. |