A system, method and device are disclosed for bio-processing a feed stream and providing a constant output by operating a continuous single-pass tangential-flow process. The single-pass process provides high conversion concentration while operating at relatively low feed flow rates, and the process can also be used to provide constant output diafiltration.

A spiral-wound membrane structure includes a central pipe and a film roll. The central pipe comprises a filter body and end covers separately connected to two ends of the filter body. A passage is formed in the center of the filter body, and two ends of the filter body are embedded in the end covers to be bonded on and sealed by the end covers. The film roll includes a guide cloth, a membrane and a mesh. The film roll is wound on the central pipe. The central pipe is directly made of a filter material, can be used as a pre-filter or post-filter, and can be matched with the film roll in the spiral-wound membrane structure to form a highly-integrated two-in-one composite filter. The composite filter can be mounted on a water purifier.

A central tube assembly for a filter cartridge and a manufacturing method for the central tube assembly are provided. The central tube assembly includes a first half-tube defines a first flow passage, and having a first water inlet at an end thereof and a water output hole in a side wall thereof, a filtering membrane bent to form a first membrane layer and a second membrane layer, the first half-tube being disposed between the first membrane layer and the second membrane layer; an input-water filtering net connected to the first half-tube and disposed between the first membrane layer and the second membrane layer, a second half-tube disposed outside of a bending of the filtering membrane, defining a second flow passage, and having a water input hole in a side wall thereof and a first water outlet at an end thereof, and a produced-water filtering net.

The object of the present invention is to provide a spiral membrane element that can make a composite semipermeable membrane high in effective membrane area, and that can restrain the composite semipermeable membrane from being lowered in rejection ratio by a deformation of this membrane while ensuring the flow rate of a permeation liquid flowing in a permeation-side flow-channel sufficiently. The spiral membrane element comprises a layered body which comprises a composite semipermeable membrane, a supply-side flow-channel member, and a permeation-side flow-channel member; and the permeation-side flow-channel member comprises a tricot knitted fabric having a plurality of ribs each formed by repeating loops in a linear form in a longitudinal direction, and a plurality of grooves present between the ribs; has a membrane support index of 60 to 135, the membrane support index being calculated in accordance with the specified numerical relationship.

A spiral membrane element is provided which has a restricted outer diameter but is heightened in effective membrane area, and further which can be decreased in operation energy therefor. The spiral membrane element is an element including plural membrane leaves L in each of which a permeation-side flow-channel member 3 is interposed between opposed separation membranes 1; a supply-side flow-channel member 2 interposed between any two of the membrane leaves L; a perforated central pipe 5 on which the membrane leaves L and the supply-side flow-channel member 2 are wound; and sealing parts that prevent a supply-side flow-channel from being mixed with a permeation-side flow-channel. The sealing parts include both-end sealing parts 11 in which an adhesive is used to seal two-side end parts of each of the membrane leaves L on both sides of the leaf in an axial direction A1 of the leaf. The thickness T1 of the both-end sealing parts 11 is 390 to 540 μm.

The present invention provides a spiral membrane element in which the effective membrane area of a composite semi-permeable membrane can be increased and any decrease in rejection rate is less likely to occur. The spiral membrane element includes: a laminate including a permeation-side flow path material, a supply-side flow path material, and a composite semi-permeable membrane having a separation function layer on a surface of a porous support; a perforated central tube around which the laminate is wound; and a sealing member for preventing mixing between the supply-side flow path and a permeation-side flow path, the spiral membrane element being characterized in that the thickness of the porous support of the composite semi-permeable membrane is 80 m to 100 m, the permeation-side flow path material is formed from a tricot knit fabric, and the width of a groove that continues in a straight line is 0.05 mm to 0.40 mm.

A full-effective reverse osmosis membrane element and a water purification machine are provided. The reverse osmosis membrane element includes a reverse osmosis membrane (20) and a central tube (10) provided with several water-inlet holes (11). The reverse osmosis membrane (20) is wound around the central tube (10) and covers each water-inlet hole (11) and forms a raw water flow channel. Two sides of the reverse osmosis membrane (20) are sealed by first and second water division bands (21) (22). The first water division band (21) and the central tube (10) form a first concentrated water-outlet (211). The first water division band (21) and the reverse osmosis membrane (20) form a second concentrated water-outlet (212). The second water division band (22) and the reverse osmosis membrane (20) form a first raw water-inlet (221). The second water division band (22) and the central tube (10) form a second raw water-inlet (222).

Provided is a membrane module which has a simple and easy structure to restrain its vessel from being increased in costs, and which allows to fabricate the vessel by a simple and easy work, and further to locate an inlet for a fluid, and others at respective predetermined positions of the membrane module.

Provided is a separation membrane leaf and a spiral wound module and an apparatus including the same, the separation membrane leaf comprising a separator, a supply-side flow channel material, and a permeation-side flow channel material comprising a tricot, the tricot comprising an adhesive part, and at least a part of the adhesive part being a low density part of the tricot, compared to the rest, wherein the tricot comprises at least one wale, at least one course, and an intersection point at which the at least one wale and the at least one course intersect, and the average distance between two intersection points arranged in parallel in the direction in which the wale of the low-density part is arranged is at least 1.25 times the average distance between two intersection points arranged in parallel in the direction in which the wale of the part other than the low-density part is arranged.

A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the porous support comprises less than 10 mg/m.sup.2 of monovalent metal ions; and (b) the discriminating layer has an average thickness of at least 0.7 m.