Patent ID: 8002975
Filing Date: 2011-08-23
Classification: B01D,Y10T

Abstract:
1. A serial-flow filtration device comprising a housing, a fluid inlet, a fluid outlet, and a stack of serially-arranged filter layers including at least an upper and a rearmost filter layer, and an additional filter layer or layers between said upper and rearmost layers, each filter layer comprised of a filter medium, the filter layers being made of the same or different selectively-permeable filtration material each adjacent filter layer being separated proximately either by an air space or by a spacer comprising a screen capable of allowing substantially non-selective passage of fluid therethrough and laterally: the upper filter layer dividing the interior of the housing into an upstream zone and a downstream zone, said fluid inlet capable of introducing fluid into said upstream zone, said fluid outlet capable of releasing fluid from said downstream zone out of said housing; the upper filter layer is held by a substantially rigid framework, said upper filter layer and said substantially rigid framework combining to form an upper filter component, said upper filter layer comprising a pressure-activated gate integrated into only the upper filter layer, wherein the pressure-activated gate is a switchable gate capable of opening and closing comprising a plug and a gate, the plug is located within the lumen such that the aperture is open upon attainment of a first predetermined pressure range, and the aperture is closed when the pressure falls below a second predetermined pressure range the rearmost filter layer being positioned in said downstream zone, wherein a rearmost filter layer does not include a pressure activated gate.