Apparatus including a flow path formed by membrane compression

Cross-flow filtration apparatus for removing a preselected component from a fluid feedstock, which comprises:

• a first plate member having a plurality of closely spaced fixed projections, said projections having tips that are in a first plane;
• a second plate member having a plurality of closely spaced fixed projections, said projections of said second plate member having tips that are in a second plane;
• means supporting said first and second plate members in a fixed, spaced relationship to each other with the projections of said first plate member facing and in a fixed relationship to the projections of the second plate member;
• first and second compressible, resilient membranes of sheet material through which the preselected component can pass, each of said membranes having a first surface and an opposite surface;
• said first membrane having its first surface thereof in contact with the first surface of said second membrane when there is no flow of feedstock;
• said first membrane having its opposite surface in contact with the projections of said first plate member and said second membrane having its opposite surface in contact with the projections of said second plate member;
• said supporting means for said first and second plate members maintaining said first and second planes at a fixed distance from each other that is no greater than the non-compressed combined thickness of said first and second membranes located between said first and second planes;
• inlet means for introducing pressurized feedstock into the apparatus and between the first and second membranes to force the compressible, resilient menbranes themselves to become compressed against the fixed projections of said first and second plate members by the pressurized feedstock passing through the apparatus, and thus separate the membranes from each other as a result of the distance between the first and opposite surfaces of each membrane becoming smaller due to compression, to form a feedstock flow path between the membranes.