Abstract: Disclosed is a method for manufacturing a composite porous film having a stable film quality and a desired hollow shape by controlling the entrance of a film-forming resin solution into a hollow part of a hollow reinforcement support. The method is provided with a step of adhering a film-forming resin solution to the outer peripheral surface of the hollow reinforcement support and thereby forming a film intermediate, a step of adhering a coagulating liquid to the outer peripheral surface of the film intermediate, and a step of flowing the coagulating liquid along the outer peripheral surface of the film intermediate so that at least a part of the outermost interface of the coagulating liquid in the circumferential direction is a free surface and thereby coagulating the film-forming resin solution adhering to the outer peripheral surface of the hollow reinforcement support.

Abstract: A method of manufacturing a porous film includes a decomposition step of introducing a porous film precursor which is formed by coagulating an undiluted film forming solution containing a hydrophilic polymer and a hydrophobic polymer, into a decomposition container; bringing a heated chemical containing an oxidizing agent into contact with the porous film precursor in the decomposition container; warming the porous film precursor in contact with the chemical; and decomposing the hydrophilic polymer remaining inside the porous film precursor using the oxidizing agent. An apparatus for manufacturing a porous film includes a decomposition device provided with the decomposition container.

Abstract: The present invention of a method for producing a porous membrane including a solidification step of forming a porous membrane, and a heating step of drying the porous membrane, wherein the heating step includes at least a water reduction step of the porous membrane, the water reduction step uses a heating medium, and the temperature of the heating medium (Tgh) satisfies a relation of tgh>Td, when Td represents the heat deformation temperature of a membrane material. The present invention of a drying device of a porous membrane including a water reduction unit, and a final drying unit, wherein the drying device includes a membrane-surface-temperature measurement means for measuring the surface temperature of the porous membrane and the final drying unit, and a control means for controlling the temperature and/or the flow speed of the heating medium of the water reduction unit.

Abstract: A method of manufacturing a porous film includes a decomposition step of introducing a porous film precursor which is formed by coagulating an undiluted film forming solution containing a hydrophilic polymer and a hydrophobic polymer, into a decomposition container; bringing a heated chemical containing an oxidizing agent into contact with the porous film precursor in the decomposition container; warming the porous film precursor in contact with the chemical; and decomposing the hydrophilic polymer remaining inside the porous film precursor using the oxidizing agent. An apparatus for manufacturing a porous film includes a decomposition device provided with the decomposition container.

Abstract: Disclosed is a drying device for a hollow fiber membrane, including: a tubular drying member that is formed with an opening portion through which a hollow fiber membrane is input and output at at least one end thereof in a length direction, the hollow fiber membrane passing inside the tubular drying member while forming a gap between the hollow fiber membrane and an inner circumferential surface of the tubular drying member; and a gas supply unit that is formed on a side surface of the tubular drying member and supplies a drying gas into the tubular drying member. Thus, it is possible to dry the hollow fiber membrane in a short time at a low cost without the necessity of large equipment.

Abstract: This disclosure relates to a porous hollow fiber membrane production method that is capable of reducing the concentration of residual substances in membrane retained water and preventing reattachment of a hydrophilic polymer while suppressing the usage amount of a washing liquid. The production method includes a coagulation process of coagulating a membrane forming dope in a coagulating liquid to form a porous hollow fiber membrane, and a hydrophobic polymer removal process to remove hydrophilic polymer that remains in the porous hollow fiber membrane.

Abstract: The present invention of a method for producing a porous membrane including a solidification step of forming a porous membrane, and a heating step of drying the porous membrane, wherein the heating step includes at least a water reduction step of the porous membrane, the water reduction step uses a heating medium, and the temperature of the heating medium (Tgh) satisfies a relation of tgh>Td, when Td represents the heat deformation temperature of a membrane material. The present invention of a drying device of a porous membrane including a water reduction unit, and a final drying unit, wherein the drying device includes a membrane-surface-temperature measurement means for measuring the surface temperature of the porous membrane and the final drying unit, and a control means for controlling the temperature and/or the flow speed of the heating medium of the water reduction unit.

Abstract: The purpose of the present invention is to provide a method for manufacturing a porous hollow fiber membrane in which the amount of a hypochlorite used during pore forming agent removal treatment can be reduced and the facilities cost can be minimized, and in which the post-treatment waste liquid can be readily treated. This method for manufacturing a porous hollow fiber membrane has: coagulating a membrane forming material liquid containing a membrane forming resin and a pore forming agent by a coagulating liquid, to thereby form a porous hollow fiber membrane precursor; and removing the porous hollow fiber membrane precursor impregnated at least with a liquid into contact with ozone gas in a vapor phase, to thereby decompose and remove the pore forming agent present in the membrane.

Abstract: A hollow porous membrane with a reduced cost and excellent separation characteristic, water permeability, and mechanical strength and a process of producing the hollow porous membrane with an excellent adhesive property between a support and a porous membrane layer at a low cost are provided. The hollow porous membrane includes a porous membrane layer in which dense layers are disposed in the vicinities of an outer surface and an inner surface. In the process of producing the hollow porous membrane, membrane-forming dopes of a first membrane-forming dope and a second membrane-forming dope, which contain the material of the porous membrane layer and a solvent, are successively applied and stacked onto the outer circumferential surface of a hollow support and the applied membrane-forming dopes are simultaneously coagulated.

Abstract: A method of manufacturing a porous film includes a decomposition step of introducing a porous film precursor which is formed by coagulating an undiluted film forming solution containing a hydrophilic polymer and a hydrophobic polymer, into a decomposition container; bringing a heated chemical containing an oxidizing agent into contact with the porous film precursor in the decomposition container; warming the porous film precursor in contact with the chemical; and decomposing the hydrophilic polymer remaining inside the porous film precursor using the oxidizing agent. An apparatus for manufacturing a porous film includes a decomposition device provided with the decomposition container.

Abstract: The present invention is a device that is for cleaning a porous hollow fiber membrane by running the porous hollow fiber membrane through a cleaning tank containing a cleaning liquid, thus eliminating residual substances in the porous hollow fiber membrane, wherein the inside of the cleaning tank is provided with a duct structure having a hollow fiber membrane running path at which the porous hollow fiber membrane can be continuously run through from an entrance at one end towards an exit at the other end; the duct structure comprises at least two structures that can separate; the duct structure has a running groove, which is formed to at least one structure of the at least two structures, and a branched duct, which pumps or sucks the cleaning fluid to cause the cleaning fluid to flow through; and the branched duct is a duct that is connected to the running groove.

Abstract: This invention relates to a washing device for a porous hollow fiber membrane, including: n (n is an integer of 2 or greater) washing tanks that contain a washing liquid, through which the porous hollow fiber membrane sequentially passes; and at least one pressure applying unit that pressurizes or de-pressurizes the washing liquid on the outer side of the porous hollow fiber membrane immersed in the washing liquid to force the washing liquid to pass through a membrane part of the porous hollow fiber membrane, in which the pressure applying unit is accommodated in at least one of the first to (n?1)-th washing tanks. According to the invention, it is possible to provide a porous hollow fiber membrane production method that is capable of reducing the concentration of residual substances in membrane retained water and preventing reattachment of a hydrophilic polymer.

Abstract: A tubular storage package which stores a string-like material includes a tubular core rod which is mounted in a center of a bottom of the storage container, the string-like material is a plurality of continuous loop shapes, a storage starting end of the string-like material protrudes, and a winding center of each loop of the plurality of loops is deviated around an axis of the storage container and the loop is laminated.

Abstract: Disclosed is a drying device for a hollow fiber membrane, including: a tubular drying member that is formed with an opening portion through which a hollow fiber membrane is input and output at at least one end thereof in a length direction, the hollow fiber membrane passing inside the tubular drying member while forming a gap between the hollow fiber membrane and an inner circumferential surface of the tubular drying member; and a gas supply unit that is formed on a side surface of the tubular drying member and supplies a drying gas into the tubular drying member. Thus, it is possible to dry the hollow fiber membrane in a short time at a low cost without the necessity of large equipment.

Abstract: Disclosed is a method for manufacturing a composite porous film having a stable film quality and a desired hollow shape by controlling the entrance of a film-forming resin solution into a hollow part of a hollow reinforcement support. The method is provided with a step of adhering a film-forming resin solution to the outer peripheral surface of the hollow reinforcement support and thereby forming a film intermediate, a step of adhering a coagulating liquid to the outer peripheral surface of the film intermediate, and a step of flowing the coagulating liquid along the outer peripheral surface of the film intermediate so that at least a part of the outermost interface of the coagulating liquid in the circumferential direction is a free surface and thereby coagulating the film-forming resin solution adhering to the outer peripheral surface of the hollow reinforcement support.

Abstract: A hollow porous membrane with a reduced cost and excellent separation characteristic, water permeability, and mechanical strength and a process of producing the hollow porous membrane with an excellent adhesive property between a support and a porous membrane layer at a low cost are provided. The hollow porous membrane includes a porous membrane layer in which dense layers are disposed in the vicinities of an outer surface and an inner surface. In the process of producing the hollow porous membrane, membrane-forming dopes of a first membrane-forming dope and a second membrane-forming dope, which contain the material of the porous membrane layer and a solvent, are successively applied and stacked onto the outer circumferential surface of a hollow support and the applied membrane-forming dopes are simultaneously coagulated.