Method for controlling rapid stirrer, and rapid stirrer

Patent metadata

Field	Value
Publication number	US-10654015-B2
Application number	US-201515559519-A
Country	US
Kind code	B2
Filing date	Dec 18, 2015
Priority date	Mar 31, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

In a rapid stirrer that stirs sludge and a flocculant in a tank with a stirring blade, the rotation speed of the stirring blade is increased at a set rate with an increase in the amount of charged sludge, the rotation speed of the stirring blade is reduced at the set rate with a decrease in the amount of charged sludge, and flocculated flocs having a fixed floc diameter are stably generated even when operating conditions change so as to fluctuate the amount of charged sludge.

First claim

Having described the invention, the following is claimed:

1. A flocculating-mixing apparatus, comprising:
a slow stirring machine comprising a slow stirring tank with a tank bottom;
a sludge supply system configured to supply sludge;
a flocculant supply system configured to charge flocculant into the supplied sludge;
a rapid stirring machine on which the slow stirring machine is disposed and to which the flocculant-charged sludge is supplied, the rapid stirring machine comprising a rapid stirring tank and a rapid stirring blade disposed in the rapid stirring tank, the rapid stirring blade being configured to rotate around an axis of a drive shaft disposed in the rapid stirring tank to stir the supplied flocculant-charged sludge, the rapid stirring tank having a tank ceiling, the tank ceiling being configured to communicate with the tank bottom of the slow stirring tank through an opening having a diameter that is less than an inside diameter of the rapid stirring tank, the tank ceiling having a circular shape; and
a stirrer controller configured to control a rotation speed of the rapid stirring blade, the stirrer controller being further configured to increase the rotation speed of the rapid stirring blade at a set rate with an increase in an amount of the sludge charged by the sludge supply system or an amount of a solid, and reduce the rotation speed of the rapid stirring blade at the set rate with a decrease in the amount of the sludge charged by the sludge supply system.

2. A flocculating-mixing apparatus according to claim 1 , wherein the rapid stirring blade has a rotating plate and edged turbine blades radially disposed on an outer edge of the rotating plate.

3. The flocculating-mixing apparatus according to claim 2 , wherein each of the sludge supply system and the flocculant supply system includes a pump and a flowmeter, and
wherein the stirrer controller controls the rotation speed of the rapid stirring blade according to a flow rate measured by the flowmeter or a rotation speed of the pump.

4. A sludge treatment system, comprising:
the flocculating-mixing apparatus according to claim 3 ; and
a dewatering machine disposed in a downstream process of the flocculating-mixing apparatus,
wherein the slow stirring machine communicates with the rapid stirring machine.

5. A sludge treatment system, comprising:
the flocculating-mixing apparatus according to claim 1 ; and
a thickener disposed in a downstream process of the flocculating-mixing apparatus,
wherein the slow stirring machine communicates with the rapid stirring machine.

6. The flocculating-mixing apparatus according to claim 1 , wherein each of the sludge supply system and the flocculant supply system includes a pump and a flowmeter, and
wherein the stirrer controller controls the rotation speed of the rapid stirring blade according to a flow rate measured by the flowmeter or a rotation speed of the pump.

7. A sludge treatment system, comprising:
the flocculating-mixing apparatus according to claim 1 ; and
a dewatering machine disposed in a downstream process of the flocculating-mixing apparatus
wherein the slow stirring machine communicates with the rapid stirring machine.

8. A sludge treatment system, comprising:
the flocculating-mixing apparatus according to claim 2 ; and
a dewatering machine disposed in a downstream process of the flocculating-mixing apparatus,
wherein the slow stirring machine communicates with the rapid stirring machine.

9. A sludge treatment system, comprising:
the flocculating-mixing apparatus according to claim 2 ; and
a thickener disposed in a downstream process of the flocculating-mixing apparatus,
wherein the slow stirring machine communicates with the rapid stirring machine.

10. A sludge treatment system, comprising:
the flocculating-mixing apparatus according to claim 3 ; and
a thickener disposed in a downstream process of the flocculating-mixing apparatus,
wherein the slow stirring machine communicates with the rapid stirring machine.

Assignees

• Kubota Kk

Inventors

• Tamura Takashi
• Higashi Ryuji

Classifications

• B01F2215/0431

  Numerical size values, e.g. diameter of a hole or conduit, area, volume, length, width, or ratios thereof · CPC title

• B01D21/30

  Control equipment · CPC title

• C02F2209/40

  Liquid flow rate · CPC title

• B01D21/01

  using flocculating agents (for purifying water C02F1/52; for liquid radioactive waste G21F9/10) · CPC title

• B01F15/00389 Primary

  Operations & Transport · mapped topic