Tangential flow filter with combined permeate outputs and method of filtering

A tangential flow filter for filtration of a fluid, comprising:

• first and second endcaps, a fluid feed inlet, a retentate outlet and a permeate outlet on said first or second endcaps;
• a plurality of pairs of plates between said first and second endcaps;
• each of said pairs of said plurality of plates comprising at least first and second plates, each of said first and second plates having a first side and an opposite second side, said first side of said first plate having a first effective filtration area, said second side of said first plate facing said first side of said second plate and having a second effective filtration area;
• filtration media on said first side and second side of each of said first and second plates;
• a first series of spaced openings through said first plate;
• a second series of openings through said second plate;
• a third series of spaced openings through said first plate spaced from said first series of spaced openings;
• a fourth series of openings through said second plate in fluid communication with said third series of openings in said first plate;
• wherein said third and fourth series of spaced openings are positioned in respective permeate channels in respective regions of said second side of said first plate and said first side of said second plate that are devoid of filtration media, said regions being opposite respective filtration media on said first side of said first plate and said second side of said second plate;
• said permeate channel being in fluid communication with said permeate outlet.

A method of filtering a fluid sample, comprising:

• introducing said fluid sample into a feed inlet of a first endcap;
• causing said introduced fluid sample to:
• (a) contact a first membrane attached to said first endcap to form a first permeate flow and a first retentate flow, the first permeate flow flowing to a first permeate outlet of said first endcap or to a second permeate outlet of a second endcap, and said first retentate flow flowing to a first retentate outlet of said first endcap or a second retentate outlet of a second endcap;
• (b) contact a second membrane attached to a first side of a first plate attached to said first endcap to form a second permeate flow and a second retentate flow, said second permeate flow flowing to a first spaced plurality of permeate ports formed in said first plate that are in fluid communication with a permeate channel and said first or second permeate outlet, said second retentate flow flowing to said first or second retentate outlet;
• (c) contact a third membrane attached to a second side of said first plate to form a third permeate flow and a third retentate flow, said third permeate flow flowing to a second spaced plurality of permeate ports formed in said first plate and combining with said second permeate flow prior to said second permeate flow entering said first spaced plurality of permeate ports that are in fluid communication with said permeate channel and said first or second permeate outlet, said third retentate flow flowing to said first or second retentate outlet;
• (d) contact a fourth membrane attached to a first side of a second plate attached to said first plate to form a fourth permeate flow and a fourth retentate flow, said fourth permeate flow flowing to a third spaced plurality of ports formed in said second plate and in fluid communication with a fourth spaced plurality of ports in fluid communication with said permeate channel and said permeate outlet, and said fourth retentate flow flowing to said first or second retentate outlet;
• and
• (e) contact a fifth membrane attached to a second side of said second plate to form a fifth permeate flow and a fifth retentate flow, said fifth permeate flow flowing to said fourth spaced plurality of permeate ports formed in said second plate that are in fluid communication with said permeate channel and said first or second permeate outlet, said fifth retentate flow flowing to said first or second retentate outlet;
• and
• (f) contact a sixth membrane attached to a second endcap to form a sixth permeate flow and a sixth retentate flow, the sixth permeate flow flowing to a permeate pipe in fluid communication with said permeate channel and said first or second permeate outlet and said sixth retentate flow flowing to said first or second retentate outlet;
• and
• collecting permeate flow from said permeate outlet.