JPS6337119Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is a batch-type activated sludge treatment that treats wastewater by repeating the steps of aeration, precipitation, and discharge in a single treatment tank. Concerning the decanter used.

[Prior art]

Conventionally, in batch-type activated sludge treatment, a decanter for discharging supernatant liquid has been raised and lowered using a dedicated hydraulic device or the like. However, this hydraulic system has the drawbacks of being very expensive and having a complicated mechanism.

[Summary of the idea]

This invention was made to eliminate the above-mentioned drawbacks, and by installing a check valve in a water collection container supported by a float floating on the liquid surface and connected to a pump, suspended solids can be removed. It is an object of the present invention to provide a decanter which does not contain scum, can effectively discharge a supernatant liquid, and has a simplified device.

[Example of idea]

An embodiment of this invention will be described below with reference to the drawings.

As shown in FIG. 1, an aeration pipe 2 is arranged in the treatment tank 1 for blowing air into the wastewater from an aeration blower (not shown) during the aeration process. Also, processing tank 1
A decanter 3 for discharging the supernatant liquid is arranged movably up and down at the liquid level, and this decanter 3 is connected to a pump 4.

As shown in FIGS. 1 and 2, the decanter 3 is engaged with and guided by a guide wire 6 suspended from a support member 5 fixed to the wall surface of the processing tank 1 so as to be movable in the vertical direction. . As shown in FIGS. 1 to 3, the decanter 3 includes a plurality of floats 7 floating on the liquid surface, a water collection container 8 supported by the floats 7, and a lower part of the water collection container 8. The pump suction pipe 10 has one end opened in the water collection container 8 and the other end connected to the pump 4. Here, this pump suction pipe 10
A part of the decanter 3 is formed with a bellows 10a which can be expanded and contracted, allowing the decanter 3 to move up and down smoothly.

Next, the operation of this invention will be explained.

In the treatment tank 1, there is an aeration process in which air is blown into the liquid from the aeration pipe 2, a settling process in which the air blowing is stopped and the sludge in the liquid is precipitated, and the separated supernatant liquid is discharged above the sludge. The discharge process is repeated as one cycle, and the inflowing sewage that is continuously or arbitrarily supplied is treated with activated sludge. Further, excess sludge in the treatment tank 1 is extracted at an appropriate time through a extraction pipe (not shown).

The decanter 3 that discharges the supernatant liquid is used for the aeration process,
The self-priming pump 4, which has been stopped up to now, is operated during the discharge process following the precipitation process to operate as follows. As shown in FIGS. 2 and 3, the supernatant liquid pushes aside the check valve 9 and enters the water collection container 8,
It is discharged to the outside of the tank 1 through the pump suction pipe 10 and the pump 4. The decanter 3 descends to a predetermined position as shown in FIG. 1 as the liquid level falls due to this discharge. At this time, since a part of the pump suction pipe 10 is formed of a flexible bellows 10a,
The decanter 3 can be moved up and down extremely smoothly. Moreover, a check valve 9 provided below the water surface of the water collection container 8
scum floating on the water surface will not be mixed in.

Next, the pump 4 is stopped, the discharge process is completed, and the aeration process and precipitation process are started again.
Since the check valve 9 is pressed against the inner wall of the water collection container 8 and performs a backflow prevention function, the water collection container 8 is filled with the remainder of the previously discharged supernatant liquid. Therefore, the activated sludge in the treatment tank 1 will not mix into the water collection container 8 through the check valve 9.

[Effect of idea]

As described above, according to this invention, by providing a check valve in the water collection container supported by a float above the liquid surface and connected to the pump, the supernatant can be removed while preventing the contamination of suspended solids and scum. This method has extremely excellent effects such as effective discharge of liquid and simplification of the device.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of this invention, FIG. 2 is a front view of the same, and FIG. 3 is an enlarged front view of the same. 3...Decanter, 7...Float, 8...Water collection container, 9...Check valve, 10...Pump suction pipe.

Claims (1)

[Scope of utility model registration request] A float floating on a liquid surface, a water collection container supported by the float, a check valve provided at the bottom of the water collection container to allow liquid to flow into the water collection container, and a check valve provided in the water collection container to allow the liquid to flow into the water collection container. A decanter is provided with a pump suction pipe that is open and discharges the liquid that has flowed into the interior.