METHOD FOR REMOVING SULFUR DIOXIDE FROM GAS FLOW AND APPARATUS FOR IT

摘要

PURPOSE: To improve removal of SO2 from a low-volume flue gas containing high concentration of SO2 by agitating an aqueous SO2 absorbent with rotating impellers consisting of an upper and lower impellers and injecting the gas containing SO2 with pressure at a point lower than a surface of the aqueous SO2 absorbent and approaching a space between the upper and lower impellers. CONSTITUTION: An aqueous SO2 absorbent is added to a tank 4 with an amount keeping a pH of an SO2 absorbent stream 10 at least pH 4.5. The SO2 absorbent stream 10 is agitated by using impellers consisting of an upper impeller 6 and a lower impeller 8, where the upper impeller 6 having at least one shroud 7 prevents gas bypass. The gas containing SO2 is injected with pressure into the absorbent from a nozzle 3 at a point below a surface of the aqueous absorbent stream 10 and close to a space between the upper impeller and the lower impeller. Furthermore, the surface of the stream 10 is maintained at a specific height by extracting the stream 10 from a line 15. A desulfurized gas is removed from the tank 4 through a line 14.