Patent ID: 8627832

Claim:
A dishwasher comprising: a tub at least partially defining a washing chamber; a liquid spraying system supplying a spray of liquid to the washing chamber; a liquid recirculation system recirculating the sprayed liquid from the washing chamber to the liquid spraying system to define a recirculation flow path; and a liquid filtering system comprising: a shroud defining an interior and having an inlet opening facing downstream to the recirculation flow path; a rotating filter having an upstream surface and a downstream surface and located within the interior relative to the recirculation flow path such that the recirculation flow path passes through the filter from the upstream surface to downstream surface to effect a filtering of the sprayed liquid; and a first artificial boundary spaced apart from at least a portion of the downstream surface of the filter to form a gap between the first artificial boundary and the filter to form a high pressure zone that creates a backflow zone where the liquid flows from the downstream surface to the upstream surface; wherein the first artificial boundary is located such that the backflow zone is positioned relative to the inlet opening to retard entry of foreign objects in the liquid into the inlet opening along the recirculation flow path.