CN110787498A - Sludge discharge system of secondary sedimentation tank and operation method thereof - Google Patents

Abstract

The invention discloses a secondary sedimentation tank sludge discharge system and an operation method thereof, belonging to the technical field of sewage treatment. A secondary sedimentation tank sludge discharge system is mainly composed of a sludge return well, a sludge discharge main pipe, a sleeve valve, a sludge return pipe, a venting pipe, a pump barrel, a gate valve, a venting well and a drainage pipe. The operation method mainly includes opening the gate valve, reducing the liquid level in the pump barrel to below the top flange blind plate, opening the top of the pump barrel, putting the axial flow pump or submersible pump to the bottom of the pump barrel, starting the axial flow pump or submersible pump, and pumping out the remaining sewage. mud. The invention avoids the defect that the traditional secondary sedimentation tank can not be completely emptied, establishes a relatively good working environment for operation, operation and maintenance, saves the space occupied by the traditional valve well, and reduces the foundation pit in the construction process. The excavation depth reduces the difficulty and risk of construction and shortens the construction period.

Description

A kind of secondary sedimentation tank sludge discharge system and operation method thereof

technical field

The invention relates to the technical field of sewage treatment, in particular to a secondary sedimentation tank sludge discharge system and an operation method thereof.

Background technique

The secondary sedimentation tank is an important part of the activated sludge water treatment system. It is an important unit to realize the separation of sludge and water, clarifying the mixed liquid, concentrating the sludge and providing activated sludge for the biological tank. The quality of its work directly affects the effluent quality of the subsequent treatment unit of the sewage treatment plant and the overall process, and also affects the sludge concentration, sludge sedimentation ratio and dissolved oxygen in the biological pool.

During the production and operation of the sewage plant, the secondary sedimentation tank needs to be discharged, vented, and repaired regularly or when the equipment suddenly fails. Usually, the venting well of the secondary sedimentation tank includes the following three parts (see Figure 1):

1. Sludge return well: The sludge at the bottom of the secondary sedimentation tank enters the sludge return well through the sludge discharge main pipe. By adjusting the opening of the manual screw hoist of the sleeve valve in the sludge return well, combined with the adjustment of the biological pool sludge return pump , to realize the adjustment of the sludge return ratio, and the sludge flows to the sludge return pump station through the sludge return pipe;

2. Valve well: a gate valve is set in the valve well. Under normal circumstances, the valve is closed. When the secondary settling tank needs to be vented for maintenance, stop the water supply to the secondary settling tank, and the maintenance personnel go down to the well through the ladder in the valve well, open the gate valve, and the sludge flows into the venting pipe through the three-way in the sludge return well, and flows through the valve well and Subsequent venting wells. In addition, a sump is set in the valve well to realize the collection and discharge of rainwater or other sewage in the well and avoid immersion of the valve.

3. Vent well: The sludge flows into the vent well through the vent pipe, and finally merges into the sewage pipe in the plant through the drain pipe in the middle of the vent well to realize the venting of the secondary sedimentation tank.

However, conventional secondary sedimentation tank discharge wells have the following disadvantages:

1. The secondary sedimentation tank cannot be completely emptied, and the secondary sedimentation tank needs to be emptied in combination with other pumps, which increases energy consumption and is not conducive to the operation, operation and maintenance of the sewage plant;

2. The mud discharge well consists of three parts, covers a large area, and uses a large amount of excavation and concrete;

3. The depth of the sludge return well is large, and a deep foundation pit needs to be excavated during the construction process, which increases the construction period and construction difficulty;

4. The distance between the drain pipe of the venting well and the bottom of the well is large, and the excess sludge cannot be completely discharged.

SUMMARY OF THE INVENTION

The main technical problem solved by the present invention is to provide a secondary sedimentation tank sludge discharge system and an operation method thereof, which simplifies the structure of the sludge discharge system, can completely empty the secondary sedimentation tank, reduces the construction area and the excavation depth of the foundation pit, and reduces the construction cost. Difficulties and risks, shorten the construction period, and reduce the excess sludge during sludge discharge.

In order to achieve the above purpose, the first technical solution adopted in the present invention is: a sludge discharge system for a secondary sedimentation tank, which is characterized in that it includes a sludge return well, a sludge discharge main pipe, a sleeve valve, a sludge return pipe, and a vent pipe. , pump barrel, gate valve, venting well, drain pipe, the sludge return pipe is installed on the side wall of the lower part of the sludge return well, and one end of the sludge return pipe extends out of the sludge return well, and the sleeve The barrel valve is vertically installed in the sludge return well, the lower end of the sleeve valve passes through the bottom of the sludge return well, the lower end of the sleeve valve is connected to a vertical tee, and one end of the tee is connected to the In the mud discharging main pipe, the other end of the tee is connected to the venting pipe in the horizontal direction, and the other end of the venting pipe is located below the bottom of the venting well and communicates with the pump barrel in the vertical direction. The pump barrel passes through the bottom of the venting well, the side opening of the pump barrel is provided with the gate valve, the gate valve is located in the venting well, the drain pipe is installed on the side wall of the venting well, and the drain pipe is located in the venting well. The inner end of the venting well is lower than the gate valve, and the other end of the drain pipe extends out of the venting well to communicate with the external plant drainage pipe.

Preferably, the sludge return well and the venting well are vertically arranged in parallel and in parallel, and the bottom of the sludge return well and the bottom of the venting well are located on the same plane.

Preferably, the sludge return pipe is connected to an external sludge return pump station.

Preferably, a flange blind plate is installed at the top of the pump barrel.

Preferably, an axial flow pump seat ring is arranged at the bottom of the pump barrel, an axial flow pump is placed on the seat ring, and the pump barrel of the axial flow pump is opened laterally and connected to the gate valve.

Preferably, a submersible pump is placed at the bottom of the pump barrel, and the water outlet pipe of the submersible pump extends out of the pump barrel and communicates with the sewage pipe in the factory area.

Preferably, an extension rod is installed on the gate valve.

The second technical solution adopted in the present invention is: a method for operating a sludge discharge system in a secondary sedimentation tank, which is characterized in that

Method 1 includes the following steps:

Open the gate valve to lower the liquid level in the pump barrel to below the gate valve,

Open the flange blind plate at the top of the pump barrel, place an axial flow pump at the bottom of the pump barrel, the pump barrel opening of the axial flow pump is connected to the lateral gate valve, and close the flange blind plate at the top of the pump barrel. plate,

The axial flow pump is turned on, and the sludge in the pump barrel is drawn out along the gate valve opening, flows into the venting well, and flows into the sewage pipe in the factory area through the drain pipe opening.

Method 2 includes the following steps:

Open the gate valve to lower the liquid level in the pump barrel to below the flange blind plate at the top of the pump barrel,

Open the flange blind plate at the top of the pump barrel, place an axial flow pump at the bottom of the pump barrel, the pump barrel opening of the axial flow pump is connected to the lateral gate valve, and close the flange blind plate at the top of the pump barrel. plate,

The axial flow pump is turned on, and the sludge in the pump barrel is drawn out along the gate valve opening, flows into the venting well, and flows into the sewage pipe in the factory area through the drain pipe opening.

Method three includes the following steps:

Open the gate valve to lower the liquid level in the pump barrel to below the flange blind plate at the top of the pump barrel,

Open the flange blind plate at the top of the pump barrel, place a submersible pump at the bottom of the pump barrel, and connect the water outlet of the submersible pump to the sewage pipe in the factory area,

Turn on the submersible pump, and pump out the sludge in the pump barrel along the water outlet pipe of the submersible pump, and then flow into the sewage pipe in the factory area.

The beneficial effects of the invention are: through a secondary sedimentation tank sludge discharge system and its operation method, the secondary sedimentation tank can be completely emptied, the construction of valve wells can be reduced, the construction area of the secondary sedimentation tank sludge discharge system can be saved, and the foundation pit can be reduced. The depth of digging reduces the difficulty and risk of construction, shortens the construction period, and reduces excess sludge.

Description of drawings

Fig. 1 is a schematic diagram of the structure of a traditional secondary sedimentation tank sludge discharge system;

The components in the drawings are marked as follows: 101-drainage pipe, 102-sump, 103-gate valve, 104-venting pipe, 105-sludge main pipe, 106-tee, 107-sludge return pipe, 108- The lowest position of the valve port of the sleeve valve, 109-the highest position of the valve port of the sleeve valve, 110-sludge return well, 111-manual screw hoist, 112-sleeve valve, 113-valve well, 114-venting well, 115 -ground;

2 is a schematic structural diagram of the secondary sedimentation tank sludge discharge system of the present invention;

The symbols of the parts in the drawings are as follows: 201-axial flow pump, 202-pump barrel;

Fig. 3 is the cross-sectional structural schematic diagram of the right side of the secondary sedimentation tank sludge discharge system of the present invention;

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the protection scope of the present invention can be more clearly defined.

Figure 2 shows a schematic structural diagram of a secondary sedimentation tank sludge discharge system. The secondary sedimentation tank system includes a drain pipe 101, a gate valve 103, a vent pipe 104, a sludge discharge main pipe 105, a tee 106, a sludge return pipe 107, The lowest position of the sleeve valve valve port 108, the highest position of the sleeve valve valve port 109, the sludge return well 110, the manual screw hoist 111, the sleeve valve 112, the venting well 114, the ground 115, the axial flow pump 201, the pump barrel 202.

An extension rod is installed on the gate valve 103 so that the technician can open the gate valve 103 without entering the venting well.

It can be seen from FIG. 2 that the sludge return well 110 and the venting well 114 are adjacent to each other, and they are arranged vertically in parallel, and the bottom of the sludge return well 110 and the bottom of the venting well 114 are located on the same plane.

A sludge return pipe 107 is installed on the lower side wall of the sludge return well 110. One end of the sludge return pipe 107 extends out of the sludge return well 110 and is connected to an external sludge return pump station. The sleeve valve 112 is vertically installed in the sludge return well 110. Inside, the lower end of the sleeve valve 112 passes through the bottom of the sludge return well 110, the lower end of the sleeve valve 112 is connected to a vertical tee 106, one end of the tee 106 is connected to the sludge discharge main 105, and the other end of the tee 106 is connected to the horizontal discharger. Empty pipe 104, the other end of the venting pipe 104 is located below the bottom of the venting well 114 and is connected to the vertical pump barrel 202, the pump barrel 202 passes through the bottom of the venting well 114, and a flange and a flange blind plate are installed on the top of the pump barrel 202 , the top opening of the pump barrel 202 is closed by the flange blind plate, the side opening of the pump barrel 202 is provided with a gate valve 103, the gate valve 103 is located in the venting well 114, and a drain pipe 101 is installed on the side wall of the venting well 114, and the drain pipe 101 Its end is lower than the gate valve 103, and the drainage pipe 103 extends out of the venting well 114 to communicate with the drainage pipe of the external sewage treatment plant.

The pump barrel 202 has different designs depending on the type of pump selected for sludge emptying. For example, when the axial flow pump 201 is used to discharge mud, the bottom of the pump barrel 202 needs to be provided with a seat ring of the axial flow pump.

When the sewage treatment system is in normal operation, the sludge from the secondary sedimentation tank enters the sleeve valve 112 through the sludge discharge main pipe 105, and the sludge return flow is controlled by adjusting the opening of the sleeve valve 112, and the sludge passes through the sludge in the sludge return well 110. The return pipe 107 returns to the sludge return pump room.

When the secondary settling tank needs to be repaired and vented, first open the gate valve 103 in the venting well 114, the secondary settling tank sludge flows through the venting pipe 104 and the gate valve 103 in turn, and flows into the venting well 114, and then flows through the drain pipe 101 in the venting well. Sewage pipes in sewage treatment plants;

When the liquid level in the pump cylinder drops below the gate valve 103, open the flange blind plate at the top of the pump cylinder 202, lift the axial flow pump 201 into the axial flow pump seat ring of the pump cylinder 202, and connect the pump cylinder with the gate valve 103, Close the flange blind plate at the top of the pump barrel 202, turn on the axial flow pump 201, and the excess sludge flows into the venting well 114 through the opening of the side gate valve 103 of the pump barrel, and finally flows into the sewage pipe of the sewage treatment plant through the drain pipe 101 of the venting well 114;

Or when the liquid level in the pump barrel drops below the flange blind plate at the top of the pump barrel 202, open the flange blind plate at the top of the pump barrel 202, hoist the axial flow pump 201 into the axial flow pump seat ring of the pump barrel 202, and put the The pump barrel is connected to the gate valve 103, close the flange blind plate at the top of the pump barrel 202, start the axial flow pump 201, discharge the sludge into the venting well 114 through the opening of the side gate valve 103 of the pump barrel, and then flow into the sewage treatment plant through the drain pipe 101 Sewage pipe, so as to achieve the purpose of quickly emptying the secondary sedimentation tank.

When the liquid level in the pump barrel drops below the flange blind plate at the top of the pump barrel 202, open the flange blind plate at the top of the pump barrel 202, hoist a submersible pump, and connect the outlet pipe of the submersible pump to the sewage from the sewage treatment plant. Tube. Close the gate valve 103, start the submersible pump, and the submersible pump outlet pipe will pump the sludge into the sewage pipe of the sewage treatment plant, so as to realize the purpose of quickly emptying the secondary sedimentation tank.

The application of the present invention can improve the sludge return well and the venting well as a whole, can completely vent the secondary sedimentation tank, reduce the construction of valve wells, thus save the construction area of the secondary sedimentation tank sludge discharge system, reduce the excavation depth of the foundation pit, and reduce the construction cost. Difficulty and risk, shorten the construction period, reduce the construction cost, reduce the excess sludge, and improve the efficiency of the sludge discharge system.

The above descriptions are only the embodiments of the present invention, and are not intended to limit the scope of the patent of the present invention. Any equivalent structural transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied to other related technical fields, are the same as The principles are included in the scope of patent protection of the present invention.

Claims (10)

1. a secondary sedimentation tank sludge discharge system is characterized in that comprising sludge return well, sludge discharge main pipe, sleeve valve, sludge return pipe, emptying pipe, pump barrel, gate valve, emptying well, drain pipe, described The sludge return pipe is installed on the side wall of the lower part of the sludge return well, one end of the sludge return pipe extends out of the sludge return well, and the sleeve valve is vertically installed in the sludge return well, so The lower end of the sleeve valve passes through the bottom of the sludge return well, the lower end of the sleeve valve is connected to a vertical tee, one end of the tee is connected to the sludge discharge main pipe, and the other end of the tee is connected to the horizontal direction the vent pipe, the other end of the vent pipe is located below the bottom of the vent well and communicates with the vertical direction of the pump barrel, the pump barrel passes through the bottom of the vent well, and the side of the pump barrel The gate valve is arranged to the opening, the gate valve is located in the venting well, the drain pipe is installed on the side wall of the venting well, and the end of the drain pipe located in the venting well is lower than the gate valve, the The other end of the drain pipe extends out of the venting well and communicates with the external plant area drain pipe. 2. The secondary sedimentation tank sludge discharge system according to claim 1, characterized in that the sludge return well and the venting well are vertically arranged in close proximity and in parallel, and the bottom of the sludge return well and the venting well are on the same plane. 3. The secondary sedimentation tank sludge discharge system according to claim 1, wherein the sludge return pipe is connected to an external sludge return pump station. 4. The secondary sedimentation tank sludge discharge system according to claim 1, characterized in that a flange blind plate is installed at the top of the pump barrel. 5. The secondary sedimentation tank sludge discharge system according to claim 4, wherein an axial flow pump seat ring is arranged at the bottom of the pump barrel, an axial flow pump is placed on the seat ring, and the The pump barrel is opened laterally and is connected with the gate valve. 6 . The secondary sedimentation tank sludge discharge system according to claim 4 , wherein a submersible pump is placed at the bottom of the pump barrel, and the outlet pipe of the submersible pump extends out of the pump barrel and communicates with the sewage pipe in the factory area. 7 . 7. The secondary sedimentation tank sludge discharge system according to any one of claims 1 to 6, characterized in that an extension rod is installed on the gate valve. 8. a secondary settling tank sludge discharge system operating method according to claim 5, is characterized in that comprising the following steps: Open the gate valve to lower the liquid level in the pump barrel to below the gate valve, Open the flange blind plate on the top of the pump barrel, place an axial flow pump on the axial flow pump seat ring, the pump barrel opening of the axial flow pump is connected with the lateral gate valve, and close the top of the pump barrel flange blind, The axial flow pump is turned on, and the sludge in the pump barrel is drawn out along the gate valve opening, flows into the venting well, and flows into the sewage pipe in the factory area through the drain pipe opening. 9. A method for operating a secondary settling tank sludge discharge system according to claim 5, characterized in that it comprises the following steps: Open the gate valve to lower the liquid level in the pump barrel to below the flange blind plate at the top of the pump barrel, Open the flange blind plate on the top of the pump barrel, place an axial flow pump on the axial flow pump seat ring, the pump barrel opening of the axial flow pump is connected with the lateral gate valve, and close the top of the pump barrel flange blind, The axial flow pump is turned on, and the sludge in the pump barrel is drawn out along the gate valve opening, flows into the venting well, and flows into the sewage pipe in the factory area through the drain pipe opening. 10. A method for operating a secondary settling tank sludge discharge system according to claim 6, characterized in that it comprises the following steps: Open the gate valve to lower the liquid level in the pump barrel to below the flange blind plate at the top of the pump barrel, Open the flange blind plate at the top of the pump barrel, place a submersible pump at the bottom of the pump barrel, and connect the water outlet of the submersible pump to the sewage pipe in the factory area, Turn on the submersible pump, and pump out the sludge in the pump barrel along the water outlet pipe of the submersible pump, and then flow into the sewage pipe in the factory area.

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