Asahi Kasei Kabushiki Kaisha

Asahi Kasei Kogyo Kabushiki Kaisha

Sumitomo Mitsubishi Silicon Corporation

Asahi Kasei Chemicals Corporation

Tohru Taniguchi

Yuzuru Ishibashi

Nobuhiko Suga

Kazushige Takaishi

Sakae Koyata

Takehiko Otoyo

Kazuo Fujimaki

Masashi Norimoto

Akihiro Kudo

A hollow fiber membrane modulehas a hollow fiber membrane bundleand a housing case. The housing casehas first molding membersand a second molding member. At each first molding member, a tubular portionand a nozzle portionare integrally molded. The second molding memberhas a tubular shape coaxially continuous from the tubular portion. Values obtained by dividing, by the wall thickness of the second molding member, the wall thicknesses of the housing caseat positions separated in the axial direction from a connecting position toward the first molding memberside by distances of 3 times and 5 times the wall thickness of the second molding memberare 1.0 to 1.3 and 1.0 to 1.5, respectively.

Hollow fiber membrane module and manufacturing method therefor

In a hollow fiber membrane module including a housing case, potting material loaded into the housing case, a cap attached to each of both ends of the housing case, and an O-ring closely held by the potting material and the cap, a whole area of the O-ring between a first contact point and a second contact point is exposed when the area is viewed from a central axis passing through a center of the ring shape of the O-ring, the first contact point being a point of contact between the O-ring and the cap, which faces inner cavity defined by an end surface of the potting material facing the cap, an inner circumferential surface of the O-ring and an inner circumferential surface of the cap, and the second contact point being a point of contact between the O-ring and the potting material, which faces the inner cavity.

Hollow fiber membrane module

A hollow fiber membrane module characterized by having a tubular module case; a bundle of a multiplicity of hollow fiber membranes housed in the module case; adhesively fixing parts for fixing both side edge portions of the bundle in the module case in such a fashion that raw fluid can pass through the interior of the hollow fiber membranes; a permeated fluid communication part adapted for passable connection between both end faces outside the adhesively fixing parts by a pipe of diameter significantly larger than that of the hollow fiber membranes; and a raw fluid distribution supply part capable of feeding the raw fluid into the module case at one of the adhesively fixing parts, wherein the raw fluid distribution supply part has multiple raw fluid introduction holes made in hollow fiber membrane interspaces so as to be able to supply the raw fluid along the longitudinal direction of the hollow fiber membranes.

Hollow fiber membrane module, process for manufacturing the same, hollow fiber membrane module assembly and method of purifying suspended water with use thereof

Provided is a method for producing a silicon wafer whose surfaces exhibit precise flatness and minute surface roughness, and which allows one to visually discriminate between the front and rear surfaces, the method comprising a slicing step of slicing a single-crystal ingot into thin disc-like wafers, a chamfering step of chamfering the wafer, a lapping step for flattening the chamfered wafer, a mild lapping step for abrading away part of processing distortions on the rear surface of the wafer left after chamfering and lapping, a rear-surface mild polishing step for abrading away part of roughness on the rear surface of the wafer, an etching step for alkali-etching the remains of processing distortions on the front and rear surfaces of the wafer, a front-surface mirror-polishing step for mirror-polishing the front surface of the etched wafer, and a cleaning step for cleaning the mirror-polished wafer.

Method for producing a silicon wafer

Provided is an improved method for producing a silicon wafer whose surfaces exhibit precise flatness and minute surface roughness, and which allows one to visually discriminate between the front and rear surfaces, the method comprising a slicing step of slicing a single-crystal ingot into thin disc-like wafers, a chamfering step of chamfering the wafer, a lapping step for flattening the wafer, an etching step for removing processing distortions on the wafer surfaces, a mirror-polishing step for mirror-polishing the surface of the wafer, and a cleaning step for cleaning the wafer. The etching step further comprises a first acid-etching phase and a second alkali-etching phase, and a rear surface mild polishing step is introduced between the first and second etching phases in order to abrade part of roughness formed on the rear surface of the wafer as a result of the first etching phase.

A hollow fiber membrane module comprising a module housing, a hollow fiber membrane bundle comprising a plurality of hollow fiber membranes, at least one end portion of the bundle being fixed on the housing through a flexible potting material, and a rib or ring embedded in the potting portion, the rib or ring being fixed on an inner wall of the housing, and the rib or ring being embedded in the potting portion without directly contacting the hollow fiber membrane, and the filtration method using the same. The hollow fiber membrane module can maintain a practical pressure resistance.

Liquid filter cap

A method and apparatus for purifying an aqueous suspension comprising feeding an aqueous suspension containing fine particles comprising an inorganic component from the outer surface of a wavy hollow fiber membrane having an outer diameter of from 0.5 to 3.1 mm to filter, followed by physical wash of the hollow fiber membrane. The purifying method can reduce the damage of the membrane outer surface during the physical wash step, prevent open pores on the surface from covering and achieve stable filtration. The hollow fiber membrane bundle can be produced by having a pulsation flow contacted with the hollow fiber material being extruded from the double spinning nozzle under specific conditions and cooling and solidifying or coagulating it while shaking.

Method for purifying aqueous suspension

A hollow fiber membrane module comprising a module case and a hollow fiber membrane bundle comprising a plurality of hollow fiber membranes, at least one end of the bundle being bonded to and fixed on the module case, wherein the bonding portions of the hollow fiber membrane bundle and the module case comprise a silicone type resin and in at least one of the bonding portions, a reinforcing rib for reinforcing the bonding portions is directly fixed on the module case. According to the hollow fiber membrane module of this invention, the membrane filtration treatment of water containing ozone over a long period of time and the repeating washing with water containing ozone are made possible.

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Tokyo, Japan

Tohru Taniguchi