JPH047277B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an aeration device used for water treatment and the like.

[Prior art]

In activated sludge treatment, raw water and activated sludge are mixed and aerated in an aeration tank to decompose organic matter, but sludge and treated water are generally separated by solid-liquid separation in a settling tank. Some sedimentation tanks are installed completely separate from the aeration tank, and the dirt is returned using a pump, but since this sedimentation tank is placed two-dimensionally outside the aeration tank, the installation area of the entire treatment equipment is reduced. Sedimentation tanks account for a large proportion of the total.

In order to improve these points, an aeration system has been proposed in which the solid-liquid separation section is installed on the side of the aeration section, but in this device, the sludge is returned by the swirling flow in the aeration section. Aeration cannot be performed in the area where sludge is returned, so a full-scale aeration method cannot be used, and the installation area becomes large.
The drawback was that energy-saving operation was not possible.

[Purpose of the invention]

This invention is intended to improve the above drawbacks,
Two partition plates are provided at the top of the aeration tank to divide it into a mixed liquid section consisting of an ascending section and a descending section, and a solid-liquid separation section, and a rectifying plate extending from the bottom of the solid-liquid separation section to the mixed liquid section is provided. The purpose of this invention is to provide an energy-saving aeration device that allows the aeration tank to be of a full-surface aeration system, has a small installation area, and is energy-saving.

[Structure of the invention]

This invention includes: an aeration tank having an aeration device on the bottom; a first partition plate extending from above the liquid level of the aeration tank into the liquid and dividing the upper part of the aeration tank into a mixed liquid section and a solid-liquid separation section; The upper end is located below the liquid level of the mixed liquid part, and the lower part is a downwardly inclined part that maintains a distance from the tip of the first partition plate, and extends to the lower part of the solid-liquid separation part, and allows the mixed liquid part to rise and fall. a second partition plate that extends from the lower part of the solid-liquid separation part to the mixed liquid part, slanting downward in a direction intersecting the second partition plate and keeping a distance from the lower end of the second partition plate; This is an aeration device characterized by comprising a current plate.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to embodiments of the drawings. The drawing is a vertical sectional view of an aeration device according to an embodiment of the present invention. In the drawings, reference numeral 1 denotes an aeration tank consisting of a rectangular parallelepiped-shaped container with an open top, and an aeration device 2 is uniformly provided over the entire bottom surface. At the top of the aeration tank 1, there is a first partition plate 3 extending from above the liquid level into the liquid.
The upper part of the aeration tank 1 is divided by the partition plate 3 into a mixed liquid section 4 and a solid-liquid separation section 5.

A second partition plate 6 is provided below the liquid level of the mixed liquid part 4, and its lower part becomes a downwardly inclined part 6a, keeping a distance from the lower end of the partition plate 3. It extends to the bottom. The mixed liquid section 4 is divided into an ascending section 7 and a descending section 8 by the partition plate 6 . The inclination angle α of the inclined portion 6a is set to 45° or more, and the cross-sectional area of the opening 9 at the lower part of the first and second partition plates 3, 6 is larger than the cross-sectional area of the rising portion 7.

At the bottom of the solid-liquid separator 5, a rectifying plate 10 is installed, which is inclined downward from one side wall 1a of the aeration tank 1 in a direction that intersects the inclined part 6a of the partition plate 6, while maintaining a distance from the lower end of the partition plate 6. It extends to the mixed liquid part 4. The inclination angle β of the current plate 10 is set to 45° or more, and the opening 11 between the rectifying plate 10 and the partition plate 6 is made larger than the cross-sectional area of the rising portion 7. The lower part of the current plate 10 forms an inclined part 10a that is inclined in the opposite direction and extends to the side wall 1a, and the lower side thereof forms an aeration part 12. The slope angle γ of the slope portion 10a is set to be 15° or more. 13 is aeration section 1
2, 14 is a treated liquid pipe connected to solid-liquid separation section 5, 15 is an air supply pipe connected to aeration device 2, 16 is a sludge pit provided at the bottom of aeration tank 1, and 17 is a It is a sludge drainage pipe.

In the above configuration, when a undiluted solution such as waste water is supplied from the undiluted solution pipe 13 and air (oxygen) is supplied from the air supply pipe 15 and aeration is performed by the aeration device 2, the undiluted solution is mixed with activated sludge in the aeration section 12. Mixed and aerated. The mixed liquid in the aeration part 12 rises from the mixed liquid part 4 through the rising part 7, and during this time, organic matter is decomposed by oxygen in the air. The mixed liquid from which air has been separated at the upper part of the mixed liquid section 4 descends through the descending section 8, and a part of the liquid flows into the solid-liquid separation section 5.
Most of the liquid is circulated from the lower part of the solid-liquid separation section 5 to the mixed liquid section 4 along the baffle plate 10, where it is aerated.

A sludge blanket 5a is formed in the solid-liquid separation section 5, and while the mixed liquid flowing in portions from the descending section 8 rises through the sludge blanket 5a, the sludge solids are captured in the sludge blanket 5a. ,
The separated liquid is taken out from the processing liquid pipe 14 as a processing liquid. When the cross-sectional area of the opening 9 is larger than the cross-sectional area of the rising portion 7, the sludge blanket 5a is less disturbed and solid-liquid separation is improved. A portion of the sludge blanket 5a flows into the mixed liquid section 4 from the opening 11 together with the mixed liquid as returned sludge, but if the opening 11 is larger than the cross-sectional area of the rising part 7, the sludge flows smoothly. be exposed. Providing the inclined plate 18 in the solid-liquid separation section 5 increases the solid separation effect. Excess sludge is concentrated in a sludge pit 16 provided at the bottom of the aeration tank 1, and is drained from a sludge pipe 17.

Although not shown, a sludge draining pipe that opens below the solid-liquid separation section 5, that is, into the sludge blanket 5a, is provided to drain an appropriate amount of sludge and maintain the sludge blanket tank at an optimal position. Do it like this.

In the above aeration device, the air diffused from the aeration device 2 flows into the mixed liquid section 4 through the rectifying plate 10,
Since it does not flow into the solid-liquid separation section 5, the sludge blanket 5a is not disturbed, and even when the solid-liquid separation section 5 is disposed above the aeration section 12, solid-liquid separation can be performed sufficiently. Therefore, the aeration tank 1 can be of a full-surface aeration type, and the installation area can be reduced to achieve energy-saving operation. Current plate 1
When there is no inclined portion 10a of 0, the upper part of the current plate 10 blocks air from flowing into the solid-liquid separation section 5, and the same effect as described above can be obtained.

In the above embodiments, a rectangular parallelepiped aeration tank 1 is shown, but it may be cylindrical or other shape. In the case of a cylindrical shape, the solid-liquid separation section 5 is provided in the center with the center axis 1a in the drawing. Also 1b
The rising portion 7 may be provided in the center with the center axis being the center axis.
The aeration section 12 can also be aerated by installing or charging fillers inside and adhering sludge to them to form a fixed bed or a fluidized bed. Furthermore, a DO meter can be installed in the aeration section 12 to adjust the amount of ventilation according to the DO. The position of the stock solution tube 13 can also be changed, for example, the upper part 13 of the mixed liquid section 4
It may be a.

〔Effect of the invention〕

According to the present invention, two partition plates are provided in the upper part of the aeration tank to divide it into a mixed liquid part and a solid-liquid separation part consisting of an ascending part and a descending part, and also to separate the mixed liquid part from the lower part of the solid-liquid separating part. Since the extending baffle plate is provided, the aeration tank can be of a full-surface aeration type, and the installation area is small and energy-saving operation can be performed.

[Brief explanation of drawings]

The drawing is a cross-sectional view of the embodiment, where 1 is an aeration tank, 2 is
is an aeration device, 3 and 6 are partition plates, 4 is a mixed liquid section, 5
1 is a solid-liquid separation section, 7 is a rising section, 8 is a descending section, 10 is a rectifying plate, 12 is an aeration section, 13 is a stock solution pipe, and 14 is a processing liquid pipe.

Claims (1)

[Claims] 1. An aeration tank having an aeration device on the bottom, and a first partition extending from above the liquid level of the aeration tank into the liquid and dividing the upper part of the aeration tank into a mixed liquid section and a solid-liquid separation section. plate, the upper end is located below the liquid level of the mixed liquid part, and the lower part is the first
a second partition plate that forms a downwardly sloped part maintaining a distance from the tip of the partition plate and extends to the bottom of the solid-liquid separation part and divides the mixed liquid part into an ascending part and a descending part; An aeration device comprising: a rectifier plate that is inclined downward in a direction intersecting with the second partition plate and extends from the lower part of the solid-liquid separation part to the mixed liquid part while keeping a distance from the lower end of the second partition plate. 2. The aeration device according to claim 1, wherein the inclined portion of the second partition plate and the angle of inclination of the rectifying plate are 45° or more. 3 The cross-sectional area of the opening formed between the first and second partition plates and between the second partition plate and the current plate is larger than the cross-sectional area of the rising part. Aeration equipment. 4. The aeration device according to any one of claims 1 to 3, wherein the current plate has a sloped part inclined in the opposite direction at the lower part. 5. The aeration device according to any one of claims 1 to 4, wherein the aeration device is uniformly arranged over the entire bottom surface of the aeration tank.