CN111035970A

CN111035970A - Sedimentation tank with bottom aeration stirring function

Info

Publication number: CN111035970A
Application number: CN201911277710.8A
Authority: CN
Inventors: 朱超; 侯洪峰; 丁武斌
Original assignee: Lianyungang Dagu Water Treatment Engineering Co ltd
Current assignee: Lianyungang Dagu Water Treatment Engineering Co ltd
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2020-04-21

Abstract

The invention discloses a sedimentation tank with aeration stirring at the bottom, which comprises a return pipe, a water inlet pipe, a sludge discharge pipe, a water outlet weir, a circulating pipe, a central cylinder, water distribution holes, a skirt board and an aeration pipe. The reflux pipe, the sludge discharge pipe and the circulating pipe are positioned in the central cylinder, the 3 aeration pipes are respectively positioned in the reflux pipe, the sludge discharge pipe and the circulating pipe, the water inlet pipe is communicated with the central cylinder, the bottom side of the central cylinder is provided with water distribution holes, the bottom end of the central cylinder is provided with a skirt board, the circulating pipe is fixed on a central cylinder bottom plate and is communicated with the sedimentation zone, the reflux pipe and the sludge discharge pipe penetrate through the central cylinder bottom plate and are inserted into the sedimentation zone, a certain distance is reserved between the reflux pipe and the bottom of the tank, and the upper end. The sedimentation tank with aeration and stirring at the bottom can improve the sewage sedimentation efficiency and sedimentation effect and prevent sludge from silting and floating.

Description

Sedimentation tank with bottom aeration stirring function

Technical Field

The invention relates to the field of sewage treatment, in particular to a sedimentation tank with aeration and stirring at the bottom.

Background

The sedimentation tank is a mud-water separation structure for removing suspended matters in water by means of natural sedimentation or coagulating sedimentation of water. The sedimentation tank is divided into a horizontal sedimentation tank and a vertical sedimentation tank according to the water flow direction, and the sedimentation tank has a plurality of types of horizontal flow type, vertical flow type, radial flow type and inclined tube type.

Aeration is a means of making air strongly contact with water, and can play a role in stirring and mixing to prevent sludge at the bottom of the tank from silting up. The aeration can also ensure that sufficient dissolved oxygen exists in the tank, and prevent sludge from floating upwards and waste water from being decomposed.

In the sludge-water separation process of sewage treatment, the design of a sedimentation tank is crucial, and if the design is unreasonable, the quality of effluent water can be influenced. The problems to be solved mainly include the following aspects:

1. anoxic denitrification phenomena. The biological denitrification process refers to the process of microbial nitrate Nitrogen (NO) under the condition of NO oxygen or low oxygen₃-N) and nitrite Nitrogen (NO)₂-N) reduction to gaseous nitrogen. The oxygen content in water is too low, so that the anoxic denitrification phenomenon can be caused, and the sludge floats upwards.

2. The fluidity of the sludge is poor. In the traditional sedimentation technology, the sedimented mud is static and is directly discharged out of the sedimentation tank through backflow, the mud has low mobility on the whole, and the mud at the bottom of the tank is easy to silt up.

3. The precipitation efficiency is low. The settling efficiency of the settling pond determines the removal rate of suspended matters in water, so the design of the settling pond aims at improving the settling efficiency of the settling pond. The sedimentation efficiency of the sedimentation tank is determined by factors such as the content of dissolved oxygen, the activity of sludge, the flocculation effect and the like.

4. The quality of the effluent water does not reach the standard. The factors of the failure of effective sedimentation of sludge, low sludge activity, poor flocculation effect, sludge sedimentation at the bottom of the tank, algae breeding, unreasonable design of the sedimentation tank and the like are all reasons for causing the quality of the effluent to fail to reach the standard. Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a sedimentation tank with aeration stirring at the bottom. The device can increase the dissolved oxygen content in the sewage, increase the sludge circulation flow at the bottom of the tank, prevent sludge deposition, accelerate the speed of attaching and depositing suspended matters in the sewage, and effectively improve the depositing efficiency and the water quality of the effluent.

In order to achieve the purpose, the invention adopts the technical scheme that:

a sedimentation tank with aeration stirring at the bottom comprises a backflow pipe, a water inlet pipe, a sludge discharge pipe, a water outlet weir, a circulating pipe, a central cylinder, water distribution holes, a skirtboard and three aeration pipes, wherein the water inlet pipe is communicated with the central cylinder, the backflow pipe, the sludge discharge pipe and the circulating pipe are positioned in the central cylinder, and the three aeration pipes are respectively positioned in the backflow pipe, the circulating pipe and the sludge discharge pipe.

Furthermore, the return pipe and the sludge discharge pipe penetrate through the central cylinder bottom plate to be inserted into the sedimentation area, and have a certain distance with the bottom of the pool.

Further, the circulating pipe is fixed on the bottom plate of the central cylinder and is communicated with the sedimentation zone.

Furthermore, a circle of water distribution holes are formed in the bottom of the central cylinder, and the arrangement mode of the water distribution holes is equal interval arrangement.

Furthermore, an apron board is arranged on the outer side of the bottom of the central cylinder, and a limited space is formed between the apron board and the inner wall of the sedimentation tank.

Furthermore, a circle of effluent weir is arranged at the upper end inside the sedimentation tank.

Furthermore, an aeration pipe in the circulating pipe penetrates through the central cylinder bottom plate and is inserted into the fixed air pipe, and the depth of the aeration pipe is lower than that of the return pipe and the sludge discharge pipe.

Compared with the prior art, the invention has the beneficial effects that:

1. through aeration, the air is continuously contacted with the sewage, the content of dissolved oxygen in the sewage is increased, the phenomenon of anoxic denitrification is prevented, and the quality of effluent water is ensured to reach the national first-class A standard (ss is less than or equal to 5).

2. By steam stripping, the sludge at the bottom of the tank is in a state circulation, the circulation flow of the sludge at the bottom of the tank is increased, and the sludge sedimentation is prevented. The middle part of the sedimentation tank is a static sedimentation area, and the sludge is dynamically circulated after naturally sedimentating to a dynamic area.

3. A high-concentration sludge layer is formed at the bottom of the tank, so that the speed of attaching and precipitating suspended matters in raw water is increased, and the precipitation efficiency is improved.

Description of the drawings: FIG. 1 is a schematic structural view of a bottom aeration-agitation type sedimentation tank.

The invention is further described below with reference to the accompanying drawings.

The specific implementation mode is as follows:

a sedimentation tank with aeration stirring at the bottom comprises a return pipe 1, a water inlet pipe 2, a sludge discharge pipe 3, a water outlet pipe 4, a water outlet weir 5, a circulating pipe 6, a central cylinder 7, a water distribution hole 8, a skirt board 9, an aeration pipe 10, an aeration pipe 11 and an aeration pipe 12.

When the sewage treatment device operates, sewage enters the central cylinder 7 through the water inlet pipe 2, water flows downwards and flows out through the water distribution holes 8 at the bottom end of the central cylinder 7, water flows upwards, sludge flows into the sedimentation zone through the limited space between the apron board 9 and the inner wall of the sedimentation tank, the aeration pipe 11 inflates the sedimentation zone, gas drives water and sludge in the sedimentation zone to ascend, the water and the sludge enter the central cylinder 7 through the circulating pipe 6 to provide sufficient dissolved oxygen for the central cylinder 7, the sludge sinks in the central cylinder 7 and flows out to the sedimentation zone again through the water distribution holes 8 to form dynamic circulation of the sludge at the bottom of the tank, the sludge at the bottom of the tank is prevented from silting up, when the clear water level is higher than the water outlet weir 5, the clear water is discharged from the water outlet pipe 4, the aeration pipe 10 inflates the return pipe 1, the sludge at the bottom of the tank ascend.

Claims

1. The utility model provides a sedimentation tank of bottom aeration stirring, includes back flow (1), inlet tube (2), mud pipe (3), outlet pipe (4), play water weir (5), circulating pipe (6), a center section of thick bamboo (7), water distribution hole (8), skirtboard (9), aeration pipe (10), aeration pipe (11), aeration pipe (12), its characterized in that, inlet tube (2) communicate with each other with a center section of thick bamboo (7), back flow (1), mud pipe (3), circulating pipe (6) are located a center section of thick bamboo (7), aeration pipe (10), aeration pipe (11), aeration pipe (12) are located back flow (1), circulating pipe (6), mud pipe (3) respectively.

2. A bottom-aerated stirred sedimentation tank according to claim 1, wherein the return pipe (1) and the sludge discharge pipe (3) are inserted into the sedimentation zone through the bottom plate of the central cylinder (7) at a distance from the bottom of the tank.

3. A bottom-aerated stirred sedimentation tank according to claim 1, characterized in that the circulation pipe (6) is fixed to the bottom plate of the central drum (7) and communicates with the sedimentation zone.

4. A bottom-aeration stirring sedimentation tank according to claim 1, wherein the bottom of the central cylinder (7) is provided with a circle of water distribution holes (8), and the arrangement of the water distribution holes (8) is arranged at equal intervals.

5. A bottom-aerated stirred sedimentation tank according to claim 1, wherein an apron (9) is provided outside the bottom of the central drum (7), the apron (9) defining a space with the inner wall of the sedimentation tank.

6. A bottom-aerated stirred tank according to claim 1 wherein the interior of the tank is provided at its upper end with a ring of weir (5).

7. A bottom-aerated stirred sedimentation tank according to claim 1, characterized in that the aeration pipe (11) is inserted through the bottom plate of the central drum (7) into the sedimentation zone at a depth lower than the depth of the return pipe (1) and the sludge discharge pipe (3).