Filtration units and assembly, and methods of making and using same

A tangential flow filtration cassette having a first cassette end along an inlet of a feedstream into the tangential flow filtration cassette and a second cassette end along an outlet for permeate of the feedstream, said tangential flow filtration cassette comprising:

• at least one membrane having a feed-port-defining zone adjacent the first cassette end, a retentate-port-defining zone adjacent the second cassette end, and a permeate-port-defining zone along the sides thereof between the first cassette end and the second cassette end;
• at least one feed spacer defining a feed channel along an upstream side of said membrane, and having a feed-port-defining zone adjacent the first cassette end, a retentate-port-defining zone adjacent the second cassette end, and a permeate-port-defining zone along the sides thereof between the first end and the second end;
• and
• at least one permeate spacer defining a permeate channel along a downstream side of said membrane, and having a feed-port-defining zone adjacent the first cassette end and with sealant extending around the perimeter thereof, a retentate-port-defining zone adjacent the second cassette end thereof and with sealant extending around the perimeter thereof, and a permeate-port-defining zone along the sides thereof between the first end and the second end;
• wherein:
• each of said at least one membrane, said at least one feed spacer, and said at least one permeate spacer has substantially the same shape about their respective perimeters;
• said feed-port-defining zones of said at least one membrane, said at least one feed spacer, and said at least one permeate spacer are aligned to define a feed inlet path extending along the first cassette end;
• said retentate-port-defining zones of said at least one membrane, said at least one feed spacer, and said at least one permeate spacer are aligned to define a retentate outlet path extending along the second cassette end;
• said permeate-port-defining zones of said at least one membrane, said at least one feed spacer, and said at least one permeate spacer are aligned to define a permeate outlet path extending along at least one of the sides of said tangential flow filtration cassette between the first cassette end and the second cassette end;
• a sealant extends around the perimeter of said at least one feed spacer to fluidly isolate feed channels from permeate channels within said tangential flow filtration cassette, whereas the permeate-port-defining zones of said at least one permeate spacer are unsealed and in fluid communication with the permeate outlet path;
• the tangential flow filtration cassette defines a flow path between the feed-port-defining zones and the retentate-port-defining zones;
• and
• a clamp assembly extends through a housing that houses the tangential flow filtration cassette and said tangential flow filtration cassette, the clamp assembly having a cross-sectional shape elongated in the direction of the flow path through said tangential flow filtration cassette.