Abstract: Provided is a spiral membrane element that has a restricted outer diameter and is capable of being decreased in operation energy therefor. The element is a spiral membrane element including plural membrane leaves in each of which a permeation-side flow-channel member is interposed between opposed separation membranes a supply-side flow-channel member interposed between any two of the membrane leaves a perforated central pipe on which the membrane leaves and the supply-side flow-channel member are wound and a sealing part that prevents a supply-side flow-channel member from being mixed with a permeation-side flow-channel member. This element has an efficiency index E of 0.005 to 0.10, and the thickness of the supply-side flow-channel member is from 10 to 110 mil.

Abstract: Provided is a spiral membrane element that has a restricted outer diameter and is capable of being decreased in operation energy therefor. The element is a spiral membrane element including plural membrane leaves in each of which a permeation-side flow-channel member is interposed between opposed separation membranes a supply-side flow-channel member interposed between any two of the membrane leaves a perforated central pipe on which the membrane leaves and the supply-side flow-channel member are wound and a sealing part that prevents a supply-side flow-channel member from being mixed with a permeation-side flow-channel member. This element has an efficiency index E of 0.005 to 0.10, and the thickness of the supply-side flow-channel member is from 10 to 110 mil.

Abstract: Provided is a spiral membrane element that has a restricted outer diameter and is capable of being decreased in operation energy therefor. The element is a spiral membrane element including plural membrane leaves in each of which a permeation-side flow-channel member is interposed between opposed separation membranes a supply-side flow-channel member interposed between any two of the membrane leaves a perforated central pipe on which the membrane leaves and the supply-side flow-channel member are wound and a sealing part that prevents a supply-side flow-channel member from being mixed with a permeation-side flow-channel member. This element has an efficiency index E of 0.005 to 0.10, and the thickness of the supply-side flow-channel member is from 10 to 110 mil.

Abstract: 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 ?m.

Abstract: 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.

Abstract: Provided is a spiral membrane element that has a restricted outer diameter and is capable of being decreased in operation energy therefor. The element is a spiral membrane element including plural membrane leaves in each of which a permeation-side flow-channel member is interposed between opposed separation membranes; a supply-side flow-channel member interposed between any two of the membrane leaves; a perforated central pipe on which the membrane leaves and the supply-side flow-channel member are wound; and a sealing part that prevents a supply-side flow-channel member from being mixed with a permeation-side flow-channel member. This element has an efficiency index E of 0.005 to 0.10, the index being calculated in accordance with an expression described below, and the thickness of the supply-side flow-channel member is from 10 to 110 mil. Efficiency index: E=0.0024×X?0.

Abstract: 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 ?m.

Abstract: 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.

Abstract: The objective of the present invention is to provide a porous support that is unlikely to curl (the incidence of MD curling is low). This porous support has a polymer porous layer on one surface of a nonwoven cloth layer, the nonwoven cloth layer having an MD bend stiffness of 1.2 to 2.1 g·cm2/cm, and an MD bend recovery of 0.3 to 0.6 g·cm/cm. The nonwoven cloth layer is impregnated with a polymer that is the material for forming the polymer porous layer, the impregnation ratio of the polymer impregnated in the nonwoven cloth layer being 25 to 34% by weight of the total weight of the polymer in the polymer porous layer and the polymer impregnated in the nonwoven cloth layer.

Abstract: An object of the present invention is to provide a composite membrane support composed of a dry process thermoplastic resin filaments nonwoven fabric having a significantly high uniformity to enable formation of a porous layer free from strike-through or a defect such as pinhole at the film formation, producing no skin layer defect at the formation of a skin layer, and being excellent in the mechanical strength and dimensional stability at high temperatures, and a high-performance composite membrane and a composite membrane element each using the composite membrane support. The composite membrane support of the present invention is a laminate dry process thermoplastic resin filaments nonwoven fabric comprising three or more layers containing at least a meltblown fiber layer as an interlayer and spunbond fiber layers on both sides of the interlayer, wherein the average value of air flow resistance is from 2.0 to 30.

Abstract: An object of the present invention is to provide a composite membrane support composed of a dry process thermoplastic resin filaments nonwoven fabric having a significantly high uniformity to enable formation of a porous layer free from strike-through or a defect such as pinhole at the film formation, producing no skin layer defect at the formation of a skin layer, and being excellent in the mechanical strength and dimensional stability at high temperatures, and a high-performance composite membrane and a composite membrane element each using the composite membrane support. The composite membrane support of the present invention is a laminate dry process thermoplastic resin filaments nonwoven fabric comprising three or more layers containing at least a meltblown fiber layer as an interlayer and spunbond fiber layers on both sides of the interlayer, wherein the average value of air flow resistance is from 2.0 to 30.