Ishigaki Company Limited

Masayoshi Katayama

Manabu Yamashita

Atsushi Yanai

Hiroyuki Mino

Ryosuke Tamauchi

Masaharu Miyawaki

Yasuaki Nishihara

Masakazu Morita

Yasutaka Suetsugu

Hiroichi Kawasaki

Kenzou Sugaya

Eiichi Ishigaki

Kunio Fujita

Masafumi Nasu

Tooru Mori

A sludge dehydration method includes a recovery process of recovering specific material as a dewatering aid from sludge generated in a sewage treatment process and a dewatering process of performing solid-liquid separation on sludge in which the dewatering aid recovered in the recovery process and dewatering target sludge are mixed.

Sludge dehydration system and sludge dehydration method

A recovery device is configured to recover specific material as a dewatering aid from sludge generated in a sewage treatment process. The recovery device includes: a grinder configured to fragment a solid in the sludge to obtain prepared sludge; a separator configured to separate hardly decomposable organic matter and easily decomposable organic matter from the prepared sludge; and an extractor configured to continuously extract hardly decomposable organic matter having specific properties as the dewatering aid from the hardly decomposable organic matter separated by the separator.

Recovery device and recovery method for recovering specific material from sludge

A concentrator-integrated screw press includes: a continuous concentrator configured to continuously concentrate sludge and discharge the sludge as concentrated sludge, and including a discharge amount equalization unit configured to equalize an amount of concentrated sludge to be discharged per unit time; a positive displacement pump installed consecutively to the concentrator, and configured to continuously transport the concentrated sludge discharged from the concentrator; and a screw press installed consecutively to a discharge side of the positive displacement pump, and configured to compress and dewater the concentrated sludge.

Concentrator-integrated screw press

A differential rate rotary thickener; a power detector which is disposed in a sludge receiver tank for thickened sludge thickened in the differential rate rotary thickener; a discriminator which receives an electric signal for a thickened sludge concentration detected by the power detector and which calculates and discriminate the data; a first controller which receives an instruction signal being a discriminated result in the discriminator and which operates an outer cylinder driving machine and a screw driving machine; a ratio setter which receives a discriminated signal of the discriminator and which increases or decreases a chemical feed rate of flocculant stepwise; and a second controller which receives an instruction signal from the ratio setter and which operates a flocculant-feeding pump are provided. Thickening of sludge is performed by controlling the chemical feed rate, a rotational speed of a screw, and a rotational speed of an outer cylinder screen.

Sludge thickening method

A differential rate rotary thickener; a power detector which is disposed in a sludge receiver tank for thickened sludge thickened in the differential rate rotary thickener; a discriminator which receives an electric signal for a thickened sludge concentration (X) detected by the power detector and which calculates and discriminate the data; a first controller which receives an instruction signal being a discriminated result in the discriminator and which operates an outer cylinder driving machine and a screw driving machine; a ratio setter which receives a discriminated signal of the discriminator and which increases or decreases a chemical feed rate (&#x3b1;) of flocculant stepwise; and a second controller which receives an instruction signal from the ratio setter and which operates a flocculant-feeding pump are provided. Thickening of sludge is performed by controlling the chemical feed rate (&#x3b1;), a rotational speed (S) of a screw, and a rotational speed (C) of an outer cylinder screen.

Sludge thickening device

A continuous compression-type dewatering apparatus has a filter chamber ( ), a drive shaft ( ), a vane ( ), and a supply path ( ). The filter chamber ( ) is delineated by an annular plate ( ) and two side plates ( ). The drive shaft ( ) passes through the center axis of the annular plate ( ) and through the inside of the filter chamber ( ), and is free to rotate with respect to the filter chamber ( ). The vane ( ) is disposed within the filter chamber ( ), is fixed with respect to the drive shaft ( ), and rotates in concert with the drive shaft ( ). The supply path ( ) passes through the drive shaft ( ) and supplies raw fluid to the filter chamber ( ). The vane ( ) as two side edges ( ) facing the side plates ( ) and an end edge ( ) facing the annular plate ( ). The side plates ( ) include a screen ( ) for separating the raw fluid into a filtered fluid and a cake. The annular plate ( ) includes an ejection port ( ) for the cake. Inflow pressure of the raw fluid from the supply path ( ) into the filter chamber ( ) and rotation of the vane ( ) causes the filtered fluid to flow out from the filter element ( ) to the outside of the filter chamber ( ), a cake that remains inside the filter chamber ( ) being pushed to the outside of the filter chamber ( ) via the ejection port ( ).

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Kagawa, Japan

Masayoshi Katayama