Abstract: A self-uprighting aeration device that minimizes turbulence and disruption of any sediment layer in a tank. The device includes a float positioned about a first position on a longitudinal axis of the aeration device, a ballast positioned about a second position on the longitudinal axis, and a diffuser. The float and the ballast are configured to orient the aeration device in a liquid with the longitudinal axis substantially aligned with a gravitational vector to dispose the diffuser above the sediment layer. The aeration device can be configured to rest on a support surface in the tank or float above such a support surface. Methods for aerating liquid in tanks with the aeration device are also provided.

Abstract: A diffuser for mixing and oxygenating water or other liquid with an airstrip employs a self supporting microporous tubular membrane, arranged in a spiral or grid configuration, with openings between proximate elements which, are at least equal to the diameter of the membrane. Gas, when forced through the tubular membrane, forms fine bubbles which agitate, oxygenate and entrain the surrounding liquid as it slowly passes through the openings. The tubular membrane is flexible and is to be mounted on a manifold which connects it to a source of air or gas, and which may also impart buoyancy or serve as anchor in the liquid.

Abstract: A system for improving the efficiency of the cooling system for a compressor for air or other compressible gas, involving the use of the condensate produced by the compression, which is presented for evaporation at the point of entry of the stream of coolant gas into heat exchangers, whereby the heat required for evaporation of the condensate is taken from such coolant gas to precool the same before it enters the heat exchanger.