Apparatus for removing soil from the wash and rinse waters of an

Abstract

A food soil separation apparatus for cleaning the wash and rinse waters of an automatic dishwasher. The apparatus comprises a reversible motor and a lower pump housing with a lower impeller surmounted by an upper pump housing with an upper impeller. The lower and upper impellers are connected to the motor shaft and are driven in one direction during a wash or rinse operation and in the other direction during a drain operation. An annular separation chamber surrounds and defines the upper pump housing. The lower pump housing has a pump cavity containing the lower impeller and having a first passage connected to spray devices in the dishwasher vat, a second passage connected to a check valve-controlled wash and rinse water inlet tube extending into the separation chamber, and a third passage connected to a drain water inlet tube extending into the separation chamber. The separation chamber has an outlet tube connected to drain. During wash and rinse operations, a majority of the water entering the lower pump housing cavity passes through the first outlet with a lesser amount entering the second outlet and the wash and rinse water inlet to the separation chamber, wherein food soils precipitate therefrom. The supernatant wash or rinse water is returned from the separation chamber to the vat. During a drain operation, water from the lower pump housing cavity enters the third passage and the drain water inlet tube to the separation chamber, exiting the separation chamber via its outlet tube to drain, and carrying the precipitated food soil with it.