Pleated, tapered, and spiral-wound cross-flow filter elements are described. The filter elements have pleated and tapered membrane leaves. The pleated and tapered membrane leaves maintain retentate fluid velocity in high permeate flux applications.

The present invention relates to a separation membrane element for use in separation of ingredients contained in fluids such as liquid and gas. An object of the present invention is to provide a separation membrane element which, even when used in a high-recovery ratio operation, has high fresh-water production performance and high removal performance and is less apt to suffer scaling.

The present invention provides a method for manufacturing a separation membrane suitable for transferring a separation functional layer and an intermediate layer from a release liner to a porous support member. The manufacturing method of the present invention is a method for manufacturing a separation membrane 10 including a separation functional layer 1, a porous support member 3, and an intermediate layer 2. The manufacturing method includes: forming the intermediate layer 2 on a first laminate 15 having a release liner 5 and the separation functional layer 1; bonding the intermediate layer 2 of a second laminate 16 having the release liner 5, the separation functional layer 1, and the intermediate layer 2 in this order to the porous support member 3 and thereby forming a third laminate 17; and removing the release liner 5 from the third laminate 17. In the manufacturing method, the intermediate layer 2 is formed in such a manner that a ratio R of an adhesive strength A2 (N/50 mm) between the intermediate layer 2 and the porous support member 3 with respect to an adhesive strength A1 (N/50 mm) between the release liner 5 and the separation functional layer 1 is 3.1 or more.

The present invention provides a filter element (500) having a radial permeate discharge path (550). The filter element generally includes a closed membrane structure (510) wrapped about a core (530) in reciprocating clockwise and counterclockwise directions, forming semicircular folds of membrane about the core. The semicircular folds of membrane have opposingly situated apical ends (560) separated by a gap. The interior of the closed membrane structure (510) defines a feed channel and the exterior of the closed membrane structure defines at least one permeate channel (522). A radial permeate discharge path (550) extends through the gap between the apical ends of the semicircular folds of membrane. Systems containing, and methods of using, filter elements including radial permeate discharge paths are also provided.

In at least one embodiment, a membrane filtration element is provided. The element may include at least one feed spacer including a first set of parallel strands extending in a first direction and including a plurality of first strands having a first thickness and a plurality of second strands having a second thickness that is smaller than the first thickness. A second set of parallel strands may extend in a second direction that is transverse to the first direction. The second set of parallel strands may include a plurality of third strands having a third thickness and a plurality of fourth strands having a fourth thickness that is smaller than the third thickness. In one embodiment, the first and second sets of strands include alternating thick and thin strands, which reduce pressure drop in membrane filtration systems.

A spiral wound membrane module adapted for hyperfiltration and including at least one membrane envelope and feed spacer sheet wound about a central permeate tube to form an inlet and outlet scroll face and an outer periphery, wherein the feed spacer sheet includes: i) a feed entrance section extending along the permeate collection tube from the inlet scroll face toward the outlet scroll face, ii) a feed exit section extending along the outer periphery from the outlet scroll face toward the inlet scroll face, and iii) a central feed section located between the feed entrance section and the feed exit section; and wherein the feed entrance section has a median resistance to flow in a direction parallel to the permeate collection tube that is less than 25% of the median resistance to flow of the central feed section in a direction perpendicular to the permeate collection tube.

Provided is a compression bar apparatus for applying pressure to desired areas of a thin film composite (TFC) membrane, such as spiral wound TFC membranes and elements, including membranes and elements used for nanofiltration, reverse osmosis or forward osmosis to purify water, such as tap water, seawater, and brackish water. Application of pressure to a spiral wound element by the apparatus produces a membrane with increased sealant penetration, reduced osmotic blistering, and minimal damage to the active area of the membrane. Also provided are methods of using the apparatus.

Provided are reverse-osmosis-membrane device capable of treating raw water including a large amount of membrane foulants, such as MBR-treated water, with stability while preventing a reduction in the amount of permeate, and a method for operating the reverse-osmosis-membrane device. The raw water includes a high-molecular organic substance having a molecular weight of 10,000 or more at a concentration of 0.01 ppm or more. The reverse-osmosis-membrane device includes a reverse-osmosis-membrane element including a membrane unit, the membrane unit including a reverse osmosis membrane having a thickness of 0.1 mm or less, a feed spacer disposed on a surface of the reverse osmosis membrane, and a permeate spacer disposed on the other surface of the reverse osmosis membrane. The reverse-osmosis-membrane device is operated at a permeation flux of 0.6 m/d or less.

Filter elements for perfusion systems and methods are provided. A filter element sheet includes a microporous membrane having a mean pore size of at least about 0.65 ?m and a feed spacer comprising woven fibers and having an open area of at least about 35%. The filter element sheet can be arranged within a filter element, for example, in a spiral-wound format or in a cassette format. A perfusion system includes at least one filter element and a pump configured to control flow of a liquid feed through the at least one filter element.

A separation membrane element of the present invention includes: a separation membranes each having a feed-side face and a permeate-side face and forming a separation membrane pair by being arranged so that the permeate-side faces face each other; and a permeate-side channel material provided between the permeate-side faces of the separation membranes, the permeate-side channel material includes a sheet and a plurality of projections formed on the sheet, the sheet is a porous sheet having pores on a surface thereof, and has densely fused parts, coarsely fused parts and non-fused parts on the surface, and the projections contain a resin, and a part of the resin is impregnated into the pores of the sheet.