STACK GAS DESULFURIZING APPARATUS

摘要

PURPOSE:To prevent white smoke and to improve utilizing efficiency of an absorbent by branching a waste gas, feeding the branched gases to a spray dryer type absorption column and wet type absorption column, joining the waste gases from both absorption columns and introducing the absorbent used in the spray dryer type absorption column into the wet type absorption column. CONSTITUTION:A waste gas duct 1 is branched and the boiler waste gas is conducted to the spray dryer type absorption column 2 and the spray wet type absorption column 18. The absorbent such as Ca(OH)2 from an absorbent hopper 3 is prepd. into a slurry in a suspension tank 4 and is fed from a absorbent slurry supply line 7 to the absorp tion column 2 to absorb the SOx in the waste gas. The waste gas from the absorption column 2 is subjected to removal of the absorbent powder incorporated therein by an electrical dust precipitator 9 and is fed to a chimney 10. The absorbent slurry in the bottom of the absorption column 2 is fed together with the absorbent powder captured in the precipitator 9 through discharge pipes 14-16 and a transfer pipe 17 to the absorption column 18 where water is added to the slurry to prepare the absorbent liquid. The remaining SOx in the waste gas is thus wet absorbed. The waste gas from the absorption column 18 is joined with the waste gas from the absorp tion column 2 in a duct 27.