Apparatus and method for treating cement kiln combustion exhaust gas

TLDR: In this article, an apparatus for treating a cement kiln combustion exhaust gas includes a probe, a heat reclaimer, a spray tower, and a dust collector, where the slaked lime slurry is separated by a thickener.

Abstract: PROBLEM TO BE SOLVED: To treat the exhaust gas of a chlorine bypass system without using a large amount of water.SOLUTION: An apparatus 1 for treating a cement kiln combustion exhaust gas includes a probe 3 which extracts a part G of combustion exhaust gas while cooling it from a kiln exhaust gas passage ranging from the kiln bottom of a cement kiln 2 to a lowest step cyclone of a preheater, a heat reclaimer 6 which makes extraction gas G2 subjected to heat exchange and temperature decrease, a spray tower 7 which sprays extraction gas G3 with water, allows slaked lime produced from quick lime in extraction gas and water react with SOin the extraction gas, and removes SOin the extraction gas, and a dust collector 8 which recovers dust D2 contained in the exhaust gas G4 of the spray tower. The apparatus may includes a thickener 9 which separates slurry containing the dust recovered by the dust collector into slaked lime slurry S produced from quick lime contained in the dust, gypsum G, and salt water SW, wherein the slaked lime slurry separated by the thickener is sprayed on the extraction gas by the probe in the spray tower.