Abstract: A method for manufacturing a hollow fiber membrane has a spinning step of applying a first membrane forming stock solution and a second membrane forming stock solution for forming a porous membrane layer to the outer peripheral surface of a hollow porous base material using a nozzle for hollow fiber membrane spinning and solidifying these membrane forming stock solutions, wherein a draft ratio (VB/VA), which is the ratio of feed velocity VB for hollow porous base material fed out from a base material feed opening to linear velocity VA for the first membrane forming stock solution and the second membrane forming stock solution discharged from a membrane forming stock solution discharge opening of the nozzle for hollow fiber membrane spinning, is set to 1-6.

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: The present invention provides a defect inspection apparatus and a defect inspection method that allows easy and efficient inspection of a defect of a porous hollow fiber membrane.

Abstract: A hollow fiber membrane-spinning nozzle that spins a hollow fiber membrane having a porous membrane layer and a support is provided in which the nozzle includes a resin flow channel through which a membrane-forming resin solution forming the porous membrane layer flows, the resin flow channel includes a liquid storage section that stores the membrane-forming resin solution and a shaping section that shapes the membrane-forming resin solution in a cylindrical shape and satisfies at least one of conditions (a) to (c): (a) the resin flow channel is disposed to cause the membrane-forming resin solution to branch and merge; (b) a delay means for delaying the flow of the membrane-forming resin solution is disposed in the resin flow channel; and (c) the liquid storage section or the shaping section includes branching and merging means for the membrane-forming resin solution therein.

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 present invention relates to a device for producing a hollow porous film, the device comprising a spinning nozzle that discharges/shapes a film-forming resin solution dissolved to at least a hydrophobic polymer to a favorable solvent, a processing vessel that houses a processing gas containing a nonsolvent of the hydrophobic polymer and includes a first opening through which the film-forming resin solution discharged/shaped from the spinning nozzle is introduced, and a second opening from which the film-forming resin solution having come into contact with the gas containing the nonsolvent of the hydrophobic polymer is led, a solidification tank which houses a solidification solution and into which the film-forming resin solution led from the second opening is introduced; and gas elimination means for eliminating the processing gas, which flows out of the first opening, from the vicinity of the spinning nozzle.

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 relates to a defect inspection apparatus including: a container storing a fluid; a passage member that is configured such that a hollow fiber membrane travel passage, which allows the porous hollow fiber membrane to pass therethrough continuously, is formed thereinside and the passage member being disposed in the fluid to thereby fill the passage with the fluid; a restrictor that restricts travel of the porous hollow fiber membrane such that the porous hollow fiber membrane passes through the fluid in the hollow fiber membrane travel passage of the passage member; a fluid suction device that flows the fluid in the hollow fiber membrane travel passage to thereby lower the pressure of the fluid in the hollow fiber membrane travel passage; and an air bubble detector that detects an air bubble that is released into the fluid from a defect of the porous hollow fiber membrane.

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: The present invention relates to a method of producing a porous membrane, including a coagulation step of coagulating a membrane-forming raw material solution to form a porous membrane; a washing step of washing the porous membrane to remove material remaining in the porous membrane; a removal step of removing a hydrophilic polymer remaining in the porous membrane, in which the washing step includes transporting a porous membrane so as to contact with a falling washing solution. According to the present invention, it is possible to provide a method of producing a porous membrane capable of efficiently removing a solvent from a porous membrane within a short period of time at a low cost without large facilities; and a washing apparatus used for the production process.

Abstract: A hollow fiber membrane-spinning nozzle that spins a hollow fiber membrane having a porous membrane layer and a support is provided in which the nozzle includes a resin flow channel through which a membrane-forming resin solution forming the porous membrane layer flows, the resin flow channel includes a liquid storage section that stores the membrane-forming resin solution and a shaping section that shapes the membrane-forming resin solution in a cylindrical shape and satisfies at least one of conditions (a) to (c): (a) the resin flow channel is disposed to cause the membrane-forming resin solution to branch and merge; (b) a delay means for delaying the flow of the membrane-forming resin solution is disposed in the resin flow channel; and (c) the liquid storage section or the shaping section includes branching and merging means for the membrane-forming resin solution therein.

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.