Patent ID: 7520988
Filing Date: 2009-04-21
Classification: B01D,Y02A

Abstract:
1. A cross-flow filtration cassette having a feed inlet and feed flow channel; a permeate flow channel and a permeate outlet; a retentate outlet; and at least one two-ply microporous separation membrane having a front side ply facing said feed channel and a back side ply facing said permeate channel wherein said plies physically lie on top of one another and are joined at their peripheries by spacers but are not bonded together in the area between said spacers, wherein the flow of liquid feed through said separation membrane is tangential over the surface of said separation membrane and the flow of permeate through said separation membrane is from the front side ply to the back side ply, and wherein the pores of said separation membrane are sized such that the average pore size of said front side ply is from about 1.4 to about 5 times the average pore size of said back side ply.