Patent ID: 8667974

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 filter chamber; a rotating filter located within the filter chamber and having an upstream surface and a downstream surface and located within the recirculation flow path such that the sprayed liquid passes through the filter from the upstream surface to the downstream surface to effect a filtering of the sprayed liquid; and a first artificial boundary spaced apart from at least a portion of the upstream surface to form a gap between the first artificial boundary and the upstream surface such that the proximity of the first artificial boundary to the rotating filter causes an increase in the angular velocity of liquid passing through the gap to form an increased shear force zone adjacent the filter; wherein the rotating filter fluidly divides the filter chamber into a first part that contains filtered soil particles and a second part that excludes filtered soil particles and where liquid passing between the first artificial boundary and the rotating filter applies a greater shear force on the upstream surface than liquid in an absence of the first artificial boundary.