A secondary sedimentation tank sludge discharge system and operation method thereof

Abstract

The present invention discloses a secondary sedimentation tank sludge discharge system and an operation method thereof, and belongs to the technical field of sewage treatment. A secondary sedimentation tank sludge discharge system mainly consists of a sludge return well, a sludge discharge main pipe, a sleeve valve, a sludge return pipe, a vent pipe, a pump barrel, a gate valve, a vent well, and a drain pipe. The operation method mainly includes opening the gate valve to lower the liquid level in the pump barrel to below the top flange blind plate, opening the top of the pump barrel, putting an axial flow pump or a submersible pump to the bottom of the pump barrel, starting the axial flow pump or the submersible pump, and pumping out the remaining sludge. The present invention avoids the defect that the traditional secondary sedimentation tank sludge discharge vent well cannot be completely emptied, establishes a better operation, operation and maintenance working environment, and at the same time saves the space occupied by the traditional valve well, reduces the foundation pit excavation depth during the construction process, reduces the construction difficulty and risk, and shortens the construction period.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, in particular to a secondary sedimentation tank sludge discharge system and an operating method thereof. Background Art

[0002] The secondary sedimentation tank is a crucial component of the activated sludge water treatment system. It is a crucial unit for sludge-water separation, clarifying the mixed liquor, concentrating the sludge, and providing activated sludge for the biological pool. Its performance directly impacts the effluent quality of subsequent treatment units and the overall process, as well as influencing indicators such as sludge concentration, sludge settling ratio, and dissolved oxygen in the biological pool.

[0003] During the production and operation of the sewage treatment plant, the secondary sedimentation tank needs to be drained, emptied and repaired regularly or when there is a sudden failure of the equipment. Generally, the secondary sedimentation tank drain well consists of the following three parts (see attached Figure 1 ):

[0004] 1. Sludge return well: The sludge at the bottom of the secondary sedimentation tank enters the sludge return well through the sludge main pipe. By adjusting the opening of the manual screw hoist of the sleeve valve in the sludge return well and combining the adjustment of the sludge return pump of the biological pool, the sludge return ratio can be adjusted. The sludge flows to the sludge return pump station through the sludge return pipe;

[0005] 2. Valve Well: A gate valve is installed in the valve well, and under normal circumstances, this valve is closed. When the secondary sedimentation tank needs to be emptied for maintenance, the water supply is stopped, and maintenance personnel descend into the well via a ladder inside the valve well. They open the gate valve, and sludge flows through the tee in the sludge return well into the vent pipe, flowing through the valve well and subsequent vent wells. In addition, a sump is installed in the valve well to collect and discharge rainwater or other sewage in the well, preventing the valve from being soaked.

[0006] 3. Drain well: The sludge flows into the drain well through the drain pipe, and finally flows into the sewage pipe of the factory through the drainage pipe in the middle of the drain well, thus realizing the emptying of the secondary sedimentation tank.

[0007] However, conventional secondary sedimentation tank sludge discharge wells have the following disadvantages:

[0008] 1. The secondary sedimentation tank cannot be completely emptied. It needs to be emptied by other pumps, which increases energy consumption and is not conducive to the operation, operation and maintenance of the sewage treatment plant;

[0009] Second, the mud discharge well consists of three parts, which occupies a large area and requires a large amount of excavation and concrete for construction;

[0010] 3. The sludge return well is deep, and a deep foundation pit needs to be excavated during the construction process, which increases the construction period and construction difficulty;

[0011] 4. The drainage pipe outlet of the drain well is far away from the bottom of the well, and a large amount of residual sludge cannot be completely discharged. Summary of the Invention

[0012] The main technical problem solved by the present invention is to provide a secondary sedimentation tank sludge discharge system and its operation method, which simplifies the sludge discharge system structure, can completely empty the secondary sedimentation tank, and at the same time reduce the construction footprint and foundation pit excavation depth, reduce construction difficulty and risk, shorten the construction period, and reduce residual sludge during sludge discharge.

[0013] In order to achieve the above-mentioned purpose, the first technical solution adopted by the present invention is: a secondary sedimentation tank sludge discharge system, characterized in that it includes a sludge return well, a sludge discharge main pipe, a sleeve valve, a sludge return pipe, a vent pipe, a pump barrel, a gate valve, a vent well, and a drain pipe. The sludge return pipe is installed on the lower side wall of the sludge return well, one end of the sludge return pipe extends out of the sludge return well, the sleeve 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, and the lower end of the sleeve valve is connected to a vertical three-way One end of the tee is connected to the mud discharge main pipe, and the other end of the tee is connected to the horizontal drain pipe. The other end of the drain pipe is located below the bottom of the drain well and is connected to the vertical pump barrel. The pump barrel passes through the bottom of the drain well. The gate valve is set at the side opening of the pump barrel. The gate valve is located in the drain well. The drain pipe is installed on the side wall of the drain well. The end of the drain pipe located in the drain well is lower than the gate valve. The other end of the drain pipe extends out of the drain well and is connected to the external factory drainage pipe.

[0014] Preferably, the sludge return well and the drain well are adjacent to each other and arranged vertically in parallel, and the bottom of the sludge return well and the bottom of the drain well are located on the same plane.

[0015] Preferably, the sludge return pipe is connected to an external sludge return pump station.

[0016] Preferably, a flange blind plate is installed at the top end of the pump barrel.

[0017] Preferably, an axial flow pump seat ring is provided 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 open laterally and connected to the gate valve.

[0018] Preferably, 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 is connected to the factory sewage pipe.

[0019] Preferably, an extension rod is installed on the gate valve.

[0020] The second technical solution adopted by the present invention is: a method for operating a secondary sedimentation tank sludge discharge system, characterized in that

[0021] Method 1 includes the following steps:

[0022] Open the gate valve to lower the liquid level in the pump barrel to below the gate valve.

[0023] Open the blind flange on the top of the pump barrel, place an axial flow pump at the bottom of the pump barrel, connect the pump barrel opening of the axial flow pump to the side gate valve, close the blind flange on the top of the pump barrel,

[0024] The axial flow pump is turned on to pump out the sludge in the pump barrel along the gate valve opening, flow into the drain well, and flow into the factory sewage pipe through the drainage pipe opening.

[0025] Method 2 includes the following steps:

[0026] Open the gate valve to lower the liquid level in the pump barrel to below the blind flange at the top of the pump barrel.

[0027] Open the blind flange on the top of the pump barrel, place an axial flow pump at the bottom of the pump barrel, connect the pump barrel opening of the axial flow pump to the side gate valve, close the blind flange on the top of the pump barrel,

[0028] The axial flow pump is turned on to pump out the sludge in the pump barrel along the gate valve opening, flow into the drain well, and flow into the factory sewage pipe through the drainage pipe opening.

[0029] Method 3 includes the following steps:

[0030] Open the gate valve to lower the liquid level in the pump barrel to below the blind flange at the top of the pump barrel.

[0031] Open the blind flange on the top of the pump barrel, place a submersible pump at the bottom of the pump barrel, and connect the outlet of the submersible pump to the factory sewage pipe.

[0032] The submersible pump is turned on to pump out the sludge in the pump barrel along the outlet pipe of the submersible pump and into the factory sewage pipe.

[0033] The beneficial effects of the present 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, thereby saving the construction area of the secondary sedimentation tank sludge discharge system, reducing the excavation depth of the foundation pit, reducing the construction difficulty and risk, shortening the construction period, and reducing residual sludge. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the structure of the traditional secondary sedimentation tank sludge discharge system;

[0035] The components in the accompanying drawings are marked as follows: 101 - drain pipe, 102 - sump, 103 - gate valve, 104 - vent pipe, 105 - sludge main pipe, 106 - tee, 107 - sludge return pipe, 108 - sleeve valve port at lowest position, 109 - sleeve valve port at highest position, 110 - sludge return well, 111 - manual screw hoist, 112 - sleeve valve, 113 - valve well, 114 - vent well, 115 - ground;

[0036] Figure 2 This is a schematic structural diagram of the secondary sedimentation tank sludge discharge system of the present invention;

[0037] The components in the drawings are marked as follows: 201 - axial flow pump, 202 - pump barrel;

[0038] Figure 3 It is a schematic diagram of the right side cross-sectional structure of the secondary sedimentation tank sludge discharge system of the present invention; DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention are 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, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0040] Figure 2 The figure shows a schematic diagram of the structure of the secondary sedimentation tank sludge discharge system, which 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, a sleeve valve at the lowest position 108, a sleeve valve at the highest position 109, a sludge return well 110, a manual screw opening and closing machine 111, a sleeve valve 112, a vent well 114, a ground 115, an axial flow pump 201, and a pump barrel 202.

[0041] An extension rod is installed on the gate valve 103 to facilitate technicians to open the gate valve 103 without having to enter the drain well.

[0042] Depend on Figure 2 It can be seen that the sludge return well 110 and the drain well 114 are adjacent to each other and are arranged vertically in parallel. The bottom of the sludge return well 110 and the bottom of the drain well 114 are located on the same plane.

[0043] 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 to connect to the external sludge return pump station. A sleeve valve 112 is vertically installed in the sludge return well 110. 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 main pipe 105. The other end of the tee 106 is connected to the horizontal vent pipe 104. The other end of the vent pipe 104 is located in the vent well 11 4 is connected to the vertical pump barrel 202 below the bottom, the pump barrel 202 passes through the bottom of the drain well 114, a flange and a flange blind plate are installed on the top of the pump barrel 202, and the top opening of the pump barrel 202 is closed by the flange blind plate. A gate valve 103 is set at the side opening of the pump barrel 202, and the gate valve 103 is located in the drain well 114. A drain pipe 101 is installed on the side wall of the drain well 114, and the end of the drain pipe 101 is lower than the gate valve 103. The drain pipe 103 extends out of the drain well 114 and is connected to the drainage pipe of the external sewage treatment plant.

[0044] The pump barrel 202 has adopted different designs according to the type of pump selected when sludge is emptied. For example, when selecting axial flow pump 201 to discharge mud, it is necessary to set a seat ring of the axial flow pump at the bottom of the pump barrel 202. If a submersible pump is selected to discharge mud, the bottom of the pump barrel 202 may not be provided with a seat ring.

[0045] When the sewage treatment system operates normally, the sludge in the secondary sedimentation tank enters the sleeve valve 112 through the sludge discharge main pipe 105. The sludge return volume is controlled by adjusting the opening of the sleeve valve 112. The sludge flows back to the sludge return pump room through the sludge return pipe 107 in the sludge return well 110.

[0046] When the secondary sedimentation tank needs to be emptied for maintenance, the gate valve 103 in the emptied well 114 is first opened, and the sludge in the secondary sedimentation tank flows through the vent pipe 104 and the gate valve 103 in sequence, flows into the emptied well 114 by gravity, and then flows through the drainage pipe 101 in the emptied well to the sewage pipe of the sewage treatment plant;

[0047] When the liquid level in the pump barrel drops below the gate valve 103, open the blind flange on the top of the pump barrel 202, hang the axial flow pump 201 on the axial flow pump seat ring of the pump barrel 202, and connect the pump barrel to the gate valve 103. Close the blind flange on the top of the pump barrel 202, start the axial flow pump 201, and the remaining sludge flows into the drain well 114 through the opening of the pump barrel side gate valve 103, and finally flows into the sewage pipe of the sewage treatment plant through the outlet of the drain pipe 101 of the drain well 114;

[0048] Or when the liquid level in the pump barrel drops below the blind flange plate at the top of the pump barrel 202, open the blind flange plate at the top of the pump barrel 202, hoist the axial flow pump 201 onto the axial flow pump seat ring of the pump barrel 202, connect the pump barrel to the gate valve 103, close the blind flange plate at the top of the pump barrel 202, start the axial flow pump 201, and discharge the sludge into the drain well 114 through the opening of the pump barrel side gate valve 103, and then merge into the sewage pipe of the sewage treatment plant through the drain pipe 101, thereby achieving the purpose of quickly emptying the secondary sedimentation tank.

[0049] Alternatively, when the liquid level in the pump barrel drops below the blind flange at the top of the pump barrel 202, the blind flange at the top of the pump barrel 202 can be opened, a submersible pump can be hoisted in, and the outlet pipe of the submersible pump can be connected to the sewage pipe of the sewage treatment plant. After closing the gate valve 103 and starting the submersible pump, the outlet pipe of the submersible pump can pump the sludge into the sewage pipe of the sewage treatment plant, thereby quickly emptying the secondary sedimentation tank.

[0050] The application of the present invention improves the sludge return well and the emptying well as a whole, can completely empty the secondary sedimentation tank, reduces the construction of valve wells, thereby saving the construction area of the secondary sedimentation tank sludge discharge system, reduces the excavation depth of the foundation pit, reduces the construction difficulty and risk, shortens the construction period, reduces the construction cost, reduces the residual sludge, and improves the efficiency of the sludge discharge system.

[0051] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A secondary sedimentation tank sludge discharge system, characterized in that It includes a sludge return well, a sludge discharge main pipe, a sleeve valve, a sludge return pipe, a vent pipe, a pump barrel, a gate valve, a vent well, and a drain pipe. The sludge return pipe is installed on the lower side wall of the sludge return well, one end of the sludge return pipe extends out of the sludge return well, the sleeve 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, one end of the tee is connected to the sludge discharge main pipe, the other end of the tee is connected to the vent pipe in the horizontal direction, the other end of the vent pipe is located below the bottom of the vent well and is connected to the vertical pump barrel, and the pump barrel passes through the bottom of the vent well The gate valve is provided at the lateral opening of the pump barrel, and the gate valve is located in the vent well. The drain pipe is installed on the side wall of the vent well, and the end of the drain pipe located in the vent well is lower than the gate valve, and the other end of the drain pipe extends out of the vent well and is connected with the external factory drainage pipe; the sludge return well and the vent well are adjacent and arranged vertically in parallel; a flange blind plate is installed on the top of the pump barrel; an axial flow pump seat ring is provided at the bottom of the pump barrel, and an axial flow pump is placed on the seat ring. The pump barrel of the axial flow pump opens laterally and is connected to the gate valve; 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 is connected to the factory sewage pipe.

2. The secondary sedimentation tank sludge discharge system according to claim 1, characterized in that The bottom of the sludge return well and the bottom of the drain well are located on the same plane.

3. The secondary sedimentation tank sludge discharge system according to claim 1, characterized in that The sludge return pipe is connected to an external sludge return pump station.

4. The secondary sedimentation tank sludge discharge system according to any one of claims 1 to 3, characterized in that An extension rod is installed on the gate valve.

5. A method for operating the secondary sedimentation tank sludge discharge system according to claim 1, characterized in that The following steps are involved: Open the gate valve to lower the liquid level in the pump barrel to below the gate valve. Open the blind flange on the top of the pump barrel, place an axial flow pump on the axial flow pump seat ring, connect the pump barrel opening of the axial flow pump to the side gate valve, close the blind flange on the top of the pump barrel, The axial flow pump is turned on to pump out the sludge in the pump barrel along the gate valve opening, flow into the drain well, and flow into the factory sewage pipe through the drainage pipe opening.

6. A method for operating the secondary sedimentation tank sludge discharge system according to claim 5, characterized in that The following steps are involved: Open the gate valve to lower the liquid level in the pump barrel to below the blind flange at the top of the pump barrel. Open the blind flange on the top of the pump barrel, place an axial flow pump on the axial flow pump seat ring, connect the pump barrel opening of the axial flow pump to the side gate valve, close the blind flange on the top of the pump barrel, The axial flow pump is turned on to pump out the sludge in the pump barrel along the gate valve opening, flow into the drain well, and flow into the factory sewage pipe through the drainage pipe opening.

7. A method for operating the secondary sedimentation tank sludge discharge system according to claim 6, characterized in that The following steps are involved: Open the gate valve to lower the liquid level in the pump barrel to below the blind flange at the top of the pump barrel. Open the blind flange on the top of the pump barrel, place a submersible pump at the bottom of the pump barrel, and connect the outlet of the submersible pump to the factory sewage pipe. The submersible pump is turned on to pump out the sludge in the pump barrel along the outlet pipe of the submersible pump and into the factory sewage pipe.

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