METHOD AND ARRANGEMENT FOR TREATING EXHAUST GASES FROM A SUSPENSION SMELTING FURNACE

摘要

The invention relates to a method and arrangement for treating exhaust gases from a suspension smelting furnace (1). In the method, exhaust gases are conducted from the uptake shaft (2) of a suspension smelting furnace (1) to a waste heat boiler (5), the flue dust contained in the exhaust gas is deactivated in the waste heat boiler (5) by deactivation gas, the exhaust gases are cooled and the thermal energy contained in the exhaust gases recovered, and the cooled exhaust gases are conducted from the waste heat boiler (5) to an electric filter (15). In the electric filter (15), flue dust is separated from the exhaust gas. The method employs a waste heat boiler (5) that comprises a radiation chamber (6) and an evaporation cooling unit (11). The method comprises steps where exhaust gas is received from the uptake shaft (2) of the suspension smelting furnace (1) by the radiation chamber (6) of the waste heat boiler, the flue dust contained in the exhaust gas is deactivated by deactivation gas in the radiation chamber (6) of the waste heat boiler, the exhaust gases are precooled in the radiation chamber (6) of the waste heat boiler, the precooled exhaust gases are conducted from the radiation chamber (6) of the waste heat boiler to the evaporation cooling unit (11) of the waste heat boiler, the exhaust gases are cooled by water mist in the evaporation cooling unit (11) of the waste heat boiler, and from the evaporation cooling unit (11) of the waste heat boiler, the aqueous vapor formed of the exhaust gas and water mist is conducted to the electric filter (15).