Patent ID: 6221249
Filing Date: 2001-04-24
Classification: B01D

Abstract:
A tangential-flow filter for selectively transferring a species from a fluid mixture to a fluid medium, the filter comprising:a filtration membrane having a first surface and a second surface;a cassette formed with a first channel and a second channel, the first channel being disposed to establish a tangential flow of the fluid mixture over the first surface of the membrane, the first channel having a cross-sectional area with the cross-sectional area decreasing in the direction of the tangential flow, the second channel being disposed to establish a tangential flow of the fluid media over the second surface of the membrane;wherein the tangential flow is substantially constant over the length of the first channel and a pressure differential is substantially constant over the length of the filtration membrane; andwherein the pressure differential is maintained at a value which is between 5% and 100% of the transition point pressure (TPP) of the tangential-flow filter; andmeans for creating a pressure differential between the fluid mixture in the first channel and the fluid media in the second channel to cause the species to traverse the membrane from the fluid mixture to the fluid media.