Patent ID: 7682511

Claim:
A method for filtering a liquid feed comprising: continuously supplying the feed stream at a specific feed flow rate of less than about 200 lmh into a separation module and having at least one channel having specific membrane area greater than about 40 cm-1; operating the separation module in a single pass tangential flow filtration mode; wherein the separation module comprises: a stacked configuration comprising: a first plurality of cassettes, each cassette having a feed manifold, a retentate manifold, at least one permeate channel, and at least one flow channel fluidly coupled to the feed manifold and to the retentate manifold, the flow channels of the plurality of cassettes fluidly coupled in parallel; a staging plate disposed adjacent the first plurality of cassettes; at least one second cassette having a feed manifold and a retentate manifold, the staging plate disposed between the first plurality of cassettes and the at least one second cassette; and wherein the staging plate fluidly couples the retentate manifold of one of the cassettes of the first plurality of cassettes to the feed manifold of the second cassette and blocks the flow from the feed manifold of one of the cassettes of the first plurality of cassettes, thereby serializing the retentate flow through the system.