Air diffusers

Air diffusion apparatus for aerating bodies of water such as reservoirs or sewage or waste treatment lagoons, comprising:

• an air manifold;
• pumping means for supplying air to said air manifold;
• and
• a plurality of flexible diffuser tubes, each tube being connected to receive air from said manifold and to release air in bubble form along substantially its entire length;
• each of said diffuser tubes comprising an inner conduit connected to receive air from said manifold, said inner conduit having perforations spaced along its length to release air to its exterior, a foraminous fabric tube surrounding said inner conduit and being of a size such as to provide a space at least between the perforations of said inner conduit and the interior of said fabric tube, means securing the ends of said fabric tube to said inner conduit in order to enclose the ends of said space so that escape of air from the fabric tube is essentially limited to the foramina thereof, and means comprising a quantity of loose pellets filling said space and providing resistance to the flow of air within said space.

Air diffusion apparatus for aerating bodies of water such as reservoirs or sewage or waste treatment lagoons comprising:

• an air manifold;
• pumping means for supplying air to said air manifold;
• and
• a plurality of flexible diffuser tubes adapted to release air in bubble form along substantially its entire length, each diffuser tube being connected at one end to receive air from said manifold,
• each diffuser tube being adapted to lie horizontally in said body of water with well defined upper and lower portions and being provided with transverse openings in its wall, said openings being confined to the upper part of the tube when said tube is in its horizontal position in a body of water, and
• each diffuser tube having slit valve means located at its opposite end, said slit valve being positioned to release water from said tube during start-up.

A system for aeration comprising:

• a lagoon having a substantially flat bottom portion and at least one sloping side extending upwardly and outwardly from said bottom portion;
• an air manifold located on said bottom portion of said body;
• pumping means for supplying air to said air manifold;
• and
• an array of at least four flexible diffuser tubes also located on and essentially confined to said bottom portion of said lagoon, and arranged adjacent said sloping side, each tube in said array being connected to receive air from said manifold and to release said air in bubble form along substantially its entire length;
• the connections of the diffuser tubes in said array to said manifold, all being projectable into a horizontal circle having a radius less than approximately one-tenth of the average length of said diffuser tubes;
• and
• the diffuser tubes in said array extending substantially radially outwardly from said manifold in horizontal directions below the lowest normal liquid level in said lagoon, there being at least one of said diffuser tubes in each quadrant whereby an outwardly directed radial flow is produced at the surface of the liquid in said lagoon by reason of the interaction of the flows produced by adjacent diffuser tubes, and at least two of the flexible tubes of said array being arranged to diverge from each other in the direction from the manifold thereof toward said sloping side, whereby a resultant outwardly directed radial surface flow is produced above said sloping side.