APPARATUS AND METHOD FOR TREATING GAS DISCHARGED FROM CEMENT KILN

摘要

A gas bled from a discharge gas passage of a cement kiln is treated while inhibiting the occurrence of a loss of thermal energy or the generation of an organic pollutant and efficiently recovering heavy metals from chlorine bypass dust. An apparatus (1) for treating a gas discharged from a cement kiln is provided which includes: a probe (42) which bleeds part of a combustion gas from a kiln discharge passage extending from the end of the cement kiln (41) to the lowermost-stage cyclone; a cyclone (44) in which the bleed gas (G1) is classified to separate coarse particles (D1) therefrom; and a high-temperature bag filter (2) which has a heat resistance of at least 300 °C and in which a discharge gas (G2) discharged from the cyclone (44) and containing fine particles (D2) is subjected to solid-gas separation at a temperature of 300-700 °C.  There is no need of cooling the bleed gas in the course of the gas treatment, and a loss of thermal energy is hence inhibited.  Throughout the period to dust removal in the solid-gas separator (2), a temperature exceeding resynthesis temperatures for dioxins is maintained.  The resyntheses of dioxins can hence be inhibited.