Ulvac Service Corporation

Millipore Corporation

Erma Optical Works, Ltd.

Toru Yunoki

Masashi Kobayashi

Kozo Shirato

Kazuyasu Kawashima

Kazuo Hiraizumi

Shinya Okuyama

Yoshio Yamamoto

Akira Takeya

Minoru Tanaka

Satoshi Shinohara

Yasuo Koyama

A filtration system is disclosed which operates with a single supply pump to achieve backwashing in an expeditious manner. The system includes a fluid supply source for a feed fluid to be filtered, a feed pump in fluid communication with the source and a membrane filter module for separating the fluid into filtrate and retentate streams. A collection reservoir is also provided which has at least two isolated fluid compartments movably separated from one another, one compartment for accumulating filtrate, the other being in fluid communication with the supply pump. In a preferred embodiment the collection reservoir is in the form of a diaphragm unit. At appropriate times, valves are activated to divert the flow of feed material from the supply source to the other chamber of the diaphragm unit. At the same time, flow in the effluent conduit is restricted by suitable means such as a valve, restrictor, pumps or the like, thereby forcing the fluid in the filtrate chamber back through the filtrate conduit to the 'underside' of the membrane filter. The resultant pressure creates a back pulse which backwashes the filtration surface of the membrane to remove particular matter thereon.

Filtration system with improved backwashing capability

A measuring apparatus for measuring the number and size of impurities such as dust and bacteria in super-pure water includes a sealed container; a sample supply line which sealingly interconnects a source of super-pure water with the sealed container and supplies a sample mixture of super-pure water and electrolyte to the sealed container; an overflow pipe which sealingly connects with the side of the sealed container; a negative electrode which extends into the sample mixture in the sealed container; a hollow sensor which extends into the sample mixture in the sealed container, the hollow sensor containing a positive electrode surrounded by electrolyte and having a small hole at its lower end; and a detecting circuit connected to said negative and positive electrodes for supplying a certain DC current therebetween and detecting voltage pulses caused by impurities passing through the small hole into the hollow sensor.

Apparatus for measuring impurities in super-pure water without exposure

Apparatus for controlling an infinitesimal flow rate of fluid comprises at least one filter means (3, 3A, 3B, 3C, 3D, . . . ) provided in a fluid passage and capable of setting to a predetermined filtration amount, thereby regulating the flow rate of the fluid by controlling fluid supply to said filter means. The present apparatus may be used in a vacuum processing system.

Apparatus for controlling an infinitesimal flow rate of fluid

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Chigasaki, Japan

Toru Yunoki