Compact spiral-wound filter elements, modules and systems
The present invention provides compact spiral-wound filter elements having cassette-like performance. The invention further provides filtration systems (e.g., TFF systems) and processes (e.g., SPTFF processes) employing compact spiral-wound filter elements having cassette-like performance.
1. A spiral-wound filter element comprising:
a) a feed channel having a height of less than about 450 μm and a length that is less than about 800 times the feed channel height, the feed channel including a mesh fiber feed screen;
b) a permeate channel having a height of less than about 300 μm, the permeate channel including a mesh fiber permeate screen; and
c) a filtration membrane having a pore size in the range of about 1 nm to about 100 nm.
2. The filter element of claim 1 , wherein the feed channel has a length of about 18 inches (45.72 cm) or less.
3. The filter element of claim 1 , comprising two or more spiral-wound filter sub-elements.
4. The filter element of claim 1 , wherein the mesh fiber permeate screen is a woven fiber screen having flattened or removed tangent points along an outer surface of the woven fiber screen.
5. The filter element of claim 1 , wherein the mesh fiber feed screen has an uncompressed height of about 600 μm or less.
6. The filter element of claim 1 , wherein the mesh fiber permeate screen is configured to compress less than about 130 μm under compression at about 50 psi at an operating temperature of about 15° C. to about 30° C.
7. The filter element of claim 1 , comprising an outermost feed channel layer that is blocked.
8. The filter element of claim 1 , wherein the mesh fiber feed screen is imprinted into the membrane, precompressed, or a combination thereof.
9. The filter element of claim 1 , wherein the mesh fiber feed screen is capable of expanding and maintaining contact with a surface of a membrane during operation.
10. The filter element of claim 1 , wherein the filter element is in a housing, sleeve, or liner.
11. A tangential flow filtration (TFF) system comprising at least one filter element claim 1 .
12. The TFF system of claim 11 , wherein the TFF system can be operated in a single-pass mode.
13. The TFF system of claim 11 , comprising at least two filter elements of claim 1 , and wherein the filter elements are fluidly connected in series, in parallel, or in a configuration having both serial and parallel connections.
14. The TFF system of claim 11 , further comprising a reservoir for diafiltration solution and a conduit for delivering diafiltration to a feed reservoir.
15. The filter element of claim 1 , wherein the mesh fiber permeate screen is compressible.
16. The filter element of claim 1 , wherein the mesh fiber permeate screen has an uncompressed height of 300 μm or less.
17. The filter element of claim 1 , wherein the mesh fiber permeate screen is woven.
18. A process for filtering a liquid, comprising:
providing at least one spiral-wound filter element comprising:
a feed channel having a height of less than about 450 μm and a length that is less than about 800 times the feed channel height, the feed channel including a mesh fiber feed screen,
a permeate channel having a height of less than about 300 μm, the permeate channel including a mesh fiber permeate screen, and
a filtration membrane having a pore size in the range of about 1 nm to about 100 nm;
passing a liquid feed through the at least one filter element;
separating the liquid feed into permeate and retentate in the filter element; and
recovering the permeate and at least a portion of the retentate from the filter element.
19. The process of claim 18 , wherein the process is a tangential flow filtration (TFF) process.