Kubota Corporation

Yasunobu Okajima

Hidetoshi Masutani

Tomokazu Kitano

Tadao Shinkai

Yoshio Asakura

Youichirou Hirose

Kazuo Nanri

Kiyoshi Izumi

Tetsuya Uenaka

Tatsuya Uejima

Masaaki Nagano

Yutaka Yamada

Kimihiro Ishikawa

Makoto Takahashi

Taichi Uesaka

Ken Tanaka

Motofumi Tajima

Yuji Otsuka

Kenichi Ohnishi

Yuki Kawashima

Yukako Morita

Yuji Ohtsuka

A method for operating a membrane separation device includes (a) setting a flow amount M(t) of permeated water and extracting the permeated water from the membrane separation device by the set flow amount M(t), and (b) temporarily stopping the extracting the permeated water, when a water level of a first water tank in which the membrane separation device is immersed, a water level of a second water tank in communication with the first tank, or a water level of a third water tank receiving overflowing water from the first water tank becomes lower than a predetermined halt water level. M(t), which is the flow amount of the permeated water during a time period t, satisfies a equation M(t)=KQ(t&#x2212;1), where K is a gain (K&#x3e;1), and Q(t&#x2212;1) is an amount of inflow of the water-to-be-treated during a time period t&#x2212;1 immediately prior to the time period t.

Method for operating membrane separation device with halt process

Provided is a method for cleaning a filtration membrane provided in a membrane filtration device that is immersed in a liquid to be treated and performs solid-liquid separation on the liquid to be treated. When a transmembrane pressure difference exceeds a first predetermined pressure difference P, a first cleaning step Wfor cleaning a filtration membrane is performed using a first chemical solution; when the transmembrane pressure difference immediately after performing the first cleaning step Wexceeds a second predetermined pressure difference Pthat is lower than the first predetermined pressure difference, a second cleaning step Wfor cleaning the filtration membrane is performed using a second chemical solution having a concentration higher than the first chemical solution; and when the second cleaning step Wis performed, the concentration of the second chemical solution and/or the cleaning time is changed according to the temperature of the liquid to be treated.

Filtering membrane cleaning method

A lifting set includes a lifting apparatus and a water treatment device. In lifting the water treatment device, an engaging member attached to a first attaching position of a frame of the lifting apparatus pivots in a first direction by sliding along a corresponding engageable portion of the water treatment device as the lifting apparatus approaches the water treatment device, and then automatically engages with the engageable portion by pivoting back to a vertical position by weight thereof while the lifting apparatus is further lowered. In installing the water treatment device, the engaging member attached to a second attaching position engages with the engageable portion at a pivoted position pivoted in a second direction, and when the lifting apparatus is further lowered after installation, the engaging member automatically disengages from the corresponding engageable portion by pivoting back from the second pivoted position to the vertical position by weight thereof.

Method for operating lifting set including lifting apparatus and water device

A low-cost membrane cartridge and a low-cost method for producing a membrane cartridge, in which fatigue durability can be increased with a simple structure, are provided by focusing on a bonding position of the filtration membrane onto the filtration plate. The membrane cartridge includes a filtration membrane disposed on both faces of a filtration plate made of a thermoplastic resin, such that a joining portion provided at the periphery of the filtration membrane is joined to the filtration plate. At least an inner edge portion of the joining portion has a downward inclination with respect to the surface of the filtration plate inside of the inner edge portion at an angle in a range of 10 to 45 degrees toward an outer peripheral edge of the filtration membrane. The joining portion is pressed and welded using a heating plate or an ultrasonic horn having such an inclined surface.

Membrane cartridge and membrane-cartridge production method

A membrane separation device is provided with membrane modules comprising multiple membrane elements, a frame body accommodating the membrane modules stacked in multiple stages, a stopper for closing an end portion of the frame body to prevent the membrane modules accommodated in the frame from being released, and elastic members which, arranged in a state of elastic deformation in the vertical direction in the frame with the end portion of the frame being closed, suppress vertical vibration of the membrane modules accommodated in the frame, whereby making it possible to avoid vibration of the membrane modules inside the frame body even if the volume of the membrane modules accommodated in the frame body varies.

Membrane separation device

A diffusion pipe is provided in which the air diffusion efficiency can be quickly recovered just after conducting a cleaning process for the diffusion pipe with a cleaning solution supplied into the membrane support body, and in which air diffusion is evenly and constantly provided. The diffusion pipe includes a membrane body made of a viscoelastic material and formed in a tubular shape having an inner surface and an outer surface, and a tubular membrane support body that supports the membrane body from inside of the membrane body. The membrane body has a plurality of diffusion slits cutting therethrough between the outer surface and the inner surface. The membrane support body has through-holes on an upper side and a lower side thereof. The diffusion slits are not provided in a region of the membrane body corresponding to the through-holes.

Diffusion pipe and method for cleaning diffusion pipe

A membrane separation device includes a plurality of membrane elements each having a separation membrane arranged on front and back sides of a flat filter plate, wherein the membrane elements are oriented vertically and arranged in an array separated by a fixed distance such that the separation membranes are facing one another. A narrowing member is provided outside of the membrane element arranged at the outermost position along the arrangement direction, the narrowing member being disposed at least in a vicinity of a bonding portion of the filter plate and the separation membrane along the vertical direction thereof so as to be separated from the outermost membrane element by a predetermined distance smaller than the fixed distance T, thereby avoiding rupture of the separation membrane provided on outer side of the outermost membrane element even if aeration is continued in a state in which the filtering operation is stopped.

A method for lifting a membrane separation device immersed in liquid to be treated so as to obtain permeated liquid passed through a filtration membrane provides a method for lifting the membrane separation device in a visible state without lowering the liquid level of a treatment tank. The method includes injecting a gas into a predetermined region of the membrane separation device, thereby raising the membrane separation device by a buoyancy generated by the injected gas through the liquid to be treated, and engaging an engaging portion of a lifting apparatus with an engageable portion provided to an upper portion of the membrane separation device, thereby lifting up the membrane separation device. The predetermined region may be a space constituting a flow path for the permeated liquid permeated through the filtration membrane.

Method for lifting membrane separation apparatus

Disclosed is a membrane separation device comprising a plurality of flat membrane elements () arranged in parallel to one another so as to form channels for a solution to be treated therebetween, and a collecting case () having a collecting space that is formed internally and communicates with filtrate flow channels of the membrane elements (). The collecting case () includes a membrane element holder () having a plurality of slits, into which the sides of respective membrane elements () are inserted, and a stopper () which abuts on the membrane element holder () in the collecting case (), and a filler () is provided in the slits to attach and watertightly seal between the membrane elements () and the membrane element holder ().

The wall member of a water collecting case forms a projecting portion projecting to the outer side and recessed portions recessed to the inner side.

Membrane separator and membrane cassette

A membrane element is provided between a pair of water collecting cases. Water collecting spaces in which permeate having penetrated through the membrane element is collected are formed in the water collecting cases. The water collecting case of one membrane module and the water collecting case of the other membrane module are coupled via coupling portions. The coupling portions have flow holes. The water collecting space of the water collecting case of the one membrane module and the water collecting space of the water collecting case of the other membrane module communicate with each other via the flow holes of the coupling portions.

Membrane module and membrane cassette

A diffuser tube is capable of preventing sludge from entering the tube when a diffusion operation is not performed, thereby preventing clogging of diffusion holes and inside of the tube and reducing a pressure loss during the diffusion operation. The diffuser tube is formed of an elastic tubular body, and slit cutting surfaces of a diffusion slit are slanted with respect to a radial direction of a membrane member in a slanted surface portion.

Diffuser tube

A membrane elementincludes filtration membraneson the flat part of the membrane element. Spacing memberskeep spacing S between the filtration membranesbetween the membrane elementswhen the membrane elementsare arranged with the filtration membranesopposed to each other. The spacing memberseach have spacer sectionsandthat keep the spacing S between the filtration membranesbetween the membrane elementsin the direction of a membrane surface cleaning stream that flows along the surface of the filtration membrane

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Amagasaki, Japan

Yasunobu Okajima