Patent attributes
A dishwasher includes a pump assembly which functions to chop all fluid entrained soil prior to directing fluid to upper and lower wash arms. A flow conduit leading to the upper wash arm is provided with a sampling port which directs a percentage of the fluid flow into a filter chamber having one or more fine mesh filter screens that open into the dishwasher tub basin. The filter chamber is exposed to a collection chamber that leads to a flapper valve and then to a drain port. A sealing chamber joins the filter chamber with the collection chamber. A sealing member is positioned in the sealing chamber to selectively seal the filter chamber after a portion of the fluid is drained. Once sealed, a drain pump expels the fluid from the washing tub. After the tub is empty, the remainder of the fluid is drained from the filter chamber.