Aerator

Abstract

An aerator comprises a centrifugal pump including a rotary impeller with a plurality of blades defining an upwardly opening, axially oriented eye, inwardly of the inner ends of the blades, the blades also defining a plurality of flow passages therebetween extending generally radially outwardly from the eye. The pump further comprises an impeller housing generally surrounding the impeller and including an upper wall closely overlying a major portion of the blades, radially outermost, and defining an axially upwardly opening inlet over the impeller eye, the housing further defining at least one laterally opening outlet communicating with the radially outer extremities of the flow passages. The housing is adapted to resist rotation with respect to a container of liquid in which a pump may be disposed. The pump is also adapted to stay in a given depth range in such container. A housing extension conduit, fixed with respect to the impeller housing, extends upwardly with respect to the impeller housing. A throughway of the conduit has its lower end aligned with the inlet of the impeller housing. The length of the conduit is sufficient to position an upper end of the throughway above the liquid. A lower portion of the conduit at least partially defines a liquid intake disposed below the surface of the liquid and opening above the upper wall of the impeller housing. This liquid intake is sized to pass less liquid per unit time than the pump can handle.