METHOD FOR PREVENTING FLOATING SLUDGE OF HOPPER TYPE SLUDGE THICKENER

摘要

PROBLEM TO BE SOLVED: To make it possible to separate and settle air bubbles sticking to floating sludge by agitating the sludge in a vessel by the floating effect of the air injected into a sludge layer, then allowing the sludge to stand still and restarting the charging of the excess sludge. ;SOLUTION: The amts. of supernatant water and the thick sludge are balanced and the position of the sludge boundary is stabilized by repeating the cycle motion of charging the excess sludge, then allowing the sludge to stand still and executing thickening, removing the thick sludge in the bottom and executing the next charging. In a high-water temp. season, such as summer or hot season, however, gaseous nitrogen and anaerobic gases are formed and is adhered in the form of the air bubbles to the sludge. The sludge partly floats, giving rise to the formation of the floating sludge (b). The air is injected from the air discharge port 6a of an air piping 6 by opening an actuator valve 7 at such time. As a result, the inside of the vessel is agitated and the high-concn. floating sludge (b) and the intermediate water (c) are mixed. The concn. of the floating sludge (b) is thinned and the air bubbles sticking to the sludge is made easily partable. The settlement in the form of the sludge not contg. the air bubbles is thus accelerated.;COPYRIGHT: (C)1998,JPO