Ebara Corporation

Sakae Kosanda

Koichi Masuda

Ken Suzuki

Yuichi Fuchu

Kenji Hata

Yutaka Niida

Hirotoshi Hinuma

Seiichi Tsuda

Naohiro Tateishi

Tomoichi Fujihashi

The present invention has an object to provide a compact aggregation precipitation method and an apparatus therefor which prevent the outflow of flocs and do not deteriorate the turbidity elimination performance even in start-up early stages. As the means to accomplish such an object, the present invention provides a method of adding an inorganic flocculant and, optionally, an organic polymer flocculent to the water to be treated and agitating the resulting mixture to effect aggregation precipitation treatment which comprises introducing the agitated solution into a first chamber of a separation tank where flocs are allowed to grow to effect solid-liquid separation and, simultaneously, the separated water is discharged out of the separation tank.

Aggregation precipitation method

A solid-liquid separator including a separation tank, a treated water outlet ( ) at the top of the tank, a sludge outlet ( ) at the bottom of the tank, a draft tube ( ) near the center in an upper inner zone of the tank and connected to a raw water inlet pipe ( ), horizontally rotatable multistage stirring blades A ( ) in the draft tube, horizontally rotatable multistage stirring blades B ( ) immediately below the draft tube, a horizontal baffle ( ) below the stirring blades B, a floating filter medium layer ( ) around the outside of the draft tube above the stirring blades B, and a screen ( ) fixed below the water level above the filter medium layer, and optionally, a filter medium-receiving screen ( ) around the lower outside of the tube in combination with stirring rods ( ) above the screen or aeration nozzles.

Solid-liquid separator

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Kanagawa, Japan

Sakae Kosanda