Abstract: A submersible seal that operates in a substantially frictionless manner is provided for protecting a motor from liquid intrusion along the shaft. Motors of this type are commonly used, for example, in aerators, pumps, mixers, flow developers, and the like. The submersible seal of the present invention includes a stationary seal element and a rotating seal element. The stationary seal element is in the form of a tubular section which is attached to the motor casing, surrounding but spaced from the rotating shaft. The rotating seal element, is a cylindrical section which is attached to the rotatable shaft and inter-engages the stationary seal element to form a labyrinth passageway having a first end at the casing of the motor, a second end opposite the first end, and at least one reverse bend therebetween. Liquid from the body of liquid in which the motor is immersed attempts to enter the first end of the labyrinth passage, and in so doing compresses an air cushion in the labyrinth passage.

Abstract: A motor-driven propeller is disposed within a draft tube beneath a buoyant float and is adapted to pump water upwardly through the draft tube. In one mode of operation, the pumping device functions as an aerator in that the water pumped upwardly through the draft tube flows upwardly through an opening in the float and is deflected across the upper side of the float and into the atmosphere by a diffuser plate spaced above the opening. The pumping device can be converted into a flow developer by positioning the diffuser plate beneath the opening in the float and, when the plate is so positioned, water pumped upwardly through the draft tube strikes the plate and is deflected outwardly beneath the lower side of the float.

Abstract: The separating apparatus includes a cartridge-type separator disposed in a tank and having a series of vertically extending and horizontally spaced baffles which cause still channels to exist downstream of the baffles. Rows of vertically spaced vanes are located in the spaces between the baffles with the vanes in alternate rows being inclined downwardly in opposite directions. Water flowing to the separator is deflected to the vanes by the baffles and, as the water flows between the vanes, flotable and settleable substances in the water contact the vanes and are directed into the still channels so as to either float or sink from the separator. Every other still channel serves exclusively as an escape duct for flotable substances while the intervening still channels serve exclusively as escape ducts for settleable substances.

Abstract: A floating liquid aerator includes an axial flow impeller rotated by an electric motor and disposed within a tubular throat to pump water from a pond upwardly through the throat and against a rotatable diffuser which slings the water outwardly for interface contact with the surrounding atmosphere. Being rotatable, the diffuser slings the water into the atmosphere with considerable turbulence thereby exposing more of the water droplets to the atmosphere and resulting in a higher transfer of oxygen to the water. The impeller comprises a series of angularly spaced blades formed with a rectangular cross-section to reduce power losses caused by drag and to increase the volume of water capable of being displaced by the impeller. Each blade is twisted longitudinally with a progressively decreasing attack angle from its root to its tip and, in addition, all of the blades are twisted identically to provide a statically, dynamically and hydrodynamically balanced impeller. .Iadd.