The present invention relates to a gas separation membrane including: a supporting membrane; and a separation functional layer which is provided on the supporting membrane and includes a crosslinked polyamide obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide, in which, in the crosslinked polyamide, the number A of terminal amino groups, the number B of terminal carboxy groups, and the number C of amide groups satisfy (A+B)/C0.66.

Disclosed are an integrated composite filter cartridge (200) and a water purifying system (300) having same. The integrated composite filter cartridge (200) comprises: an outer shell (20), wherein a chamber (21) is defined in the outer shell (20), and the outer shell (20) is provided with a raw water inlet (22), a pre-treated water outlet (23), a pre-treated water inlet (24), a purified water outlet (25) and a waste water outlet (26) which are in communication with the chamber (21); a pre-treatment filter cartridge (100); a central pipe (30); a filter membrane (40); and a control member, which is connected to the pre-treated water outlet (23) and the pre-treated water inlet (24). When the integrated composite filter cartridge (200) is used for the first time, the control member switches on the raw water inlet (22) and the pre-treated water outlet (23) and switches off the pre-treated water inlet (24).

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.

According to the present invention, even when a high recovery ratio operation is performed, the influence of concentration of ingredients to be separated in the feed fluid can be reduced, the concentration polarization can be prevented by increasing the turbulence effect on the membrane surface, and the fluid permeation performance and the separation performance of the separation membrane element can be maintained.

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.

The present invention provides a spiral membrane element suitable for suppressing a decrease in a permeation rate (or a permeation flux) of a permeated fluid from a separation membrane. A spiral membrane element of the present invention includes: a central tube; a membrane leaf that has a separation membrane and a permeation spacer and is wound around the central tube; and a flow passage spacer that is connected to the permeation spacer and is wound around the central tube on a side closer to the central tube than the membrane leaf is. A pressure loss of the flow passage spacer measured by a predetermined test is smaller than a pressure loss of the permeation spacer.

The gas separation membrane element contains a gas separation membrane, and a sealing portion for preventing mixture of a source gas and a specific gas permeated through a gas separation membrane. The gas separation membrane has a first porous layer including a porous membrane, and a hydrophilic resin composition layer disposed on the first porous layer. The sealing portion is a region in which a cured material of a sealant penetrates in at least the first porous layer in the gas separation membrane, and a thermal expansion coefficient A of the sealing portion and a thermal expansion coefficient B of a material forming the first porous layer satisfy a relation (I):

0.35A/B1.0 (I).

A spiral wound membrane element and a method for cleaning a spiral wound membrane sheet are provided. The spiral wound membrane element comprising a perforated central tube; one or more membrane sleeves, each sleeve comprising two membrane sheets enclosed at two edges around a feed spacer sheet and wrapped around the central tube; a permeate carrier sheet attached to the central tube at a first edge opposite a second edge; and a seal on third and fourth edges of the permeate carrier sheet. The method comprises introducing two solution with different solute concentration to two sides of the spiral wound membrane sheet; establishing a concentration gradient between the first and second sides; communicating a first solvent from the first side to the second side to remove a foulant located on the second side of the membrane sheet; and collecting a waste stream that contains the foulant.

Disclosed is a central tube set. The central tube set includes: a permeate tube, a peripheral wall of the permeate tube being arranged with a pure water influx hole communicating with an internal channel of the permeate tube; and a plurality of wastewater tubes arranged at intervals. The wastewater tubes are arranged around the permeate tube, a peripheral wall of each wastewater tube is arranged with a wastewater influx hole communicating with an internal channel of each wastewater tube. The plurality of the wastewater tubes and the permeate tube are arranged at intervals, to form a receiving space between each wastewater tube and the permeate tube, for receiving a portion of the reverse osmosis membrane sheet set which is extending into the central tube set. The present application further provides a spiral wound reverse osmosis membrane component and a reverse osmosis water purifier.

A reverse osmosis system includes a multi-element membrane array having a plurality of membrane elements disposed in series and a plurality of permeate pipes receiving permeate from a respective one of the plurality of membrane elements. Each of the plurality of elements has an inlet and an outlet. A plurality of connectors coupling successive permeate pipes together. Each of the plurality of connectors includes one of a plurality of flow restrictors. Each of the plurality of flow restrictors is sized to further restrict permeate flow into a subsequent permeate pipe of the plurality of permeate pipes.