Abstract

A fluid diffuser for dispersing gas bubbles or liquid droplets into a body of receiving liquid in a tank. The diffuser includes a fluid-emitting member for communication with the body of receiving liquid, which member defines a fluid plenum. A portion of at least one of the walls of the fluid-emitting member is porous and has a foraminous outer surface, to permit the passage of fluid from the plenum into the body of liquid. A slot-forming chamber has a wall that defines a narrow, elongated slot extending parallel to the foraminous outer surface of the plenum-defining wall of the fluid-emitting member, with the foraminous outer surface lying primarily outside the slot. Fluid supplied under pressure to the plenum flows out through the porous wall portion to produce small nascent fluid spheroids on the foraminous surface of that portion. Shearing liquid introduced into the slot-forming chamber under pressure exits through the narrow, elongated slot to form a stream of liquid that sweeps across and in contact with the foraminous outer surface just mentioned and shears the nascent spheroids off to form fine gas bubbles or fine liquid droplets. These are carried into the body of receiving liquid by the stream of shearing liquid as it exits from the slot and moves into the body of receiving liquid.