摘要 |
A filter consisting of a housing, a rigid, porous filtering element, means for forming a primary filter path along the filtering element, and a non-rigid expanding element, wherein when a solution to be filtered flows through the primary flow path, filtrate passes through the rigid filtering element and particulate matter is retained on or in the filtering element. When the filter surface becomes clogged, the incoming solution is bypassed, reduced, or discontinued and the non-rigid expanding element expanded to first form discrete compartments of filtrate between the expanding element and the filtering element and secondly to force the discrete volumes of filtrate back through the filtering element into the flow path for removal. In one embodiment, the housing and filtering element consist of hollow cylinders and the expanding element extends lengthwise through the interior of the filtering element, expanding outwardly to expel particulate matter. In another embodiment, the housing and filtering element also consist of hollow cylinders but the expanding element surrounds the filtering element and is pressed inwardly against the filtering element surface by pressure exerted between the housing and the filtering element. Both embodiments provide rapid, uniform clearing of the filtering element.
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