DISCHARGE VALVE FOR DISSOLVED AIR FLOTATION

摘要

2106084 9216459 PCTABS00016 A self cleaning valve (10) for discharge of a pressurized dissolved air flotation aqueous treatment liquid from a high pressure reservoir (76) to a low pressure body of liquid (70) is provided. The valve (10) includes a discharge head body (12) adapted to be attached to a conduit (18) supplied with pressurized treatment liquid which is provided with a central opening (22) for discharge of a treatment liquid. The opening (22) is controllable by a reciprocable cap (32) positioned to reciprocate from a position wherein it restricts flow of liquid through the opening (22) to a position wherein flow is unrestricted. The cap (32) is attached to a reciprocable piston rod (36) attached at its opposite end to a piston (38) that is movable within an enclosed cylinder (14). The cylinder (14) is provided with a port (60, 62) on each side of said piston (38) into which a source of pressurized air (95) connectable to cause movement of the piston (38) and thus opening and closing the valve (10).