Sludge backflow control device for vertical flow type secondary sedimentation tank

Abstract

The utility model relates to the technical field of sewage treatment, and provides a vertical flow type secondary sedimentation tank sludge backflow control device which comprises a biochemical tank, a secondary sedimentation tank main body, a water outlet pipe, a backflow pipe, a lifting pump and a regulating valve, the secondary sedimentation tank main body and the biochemical tank are oppositely arranged, and the horizontal position of the secondary sedimentation tank main body is higher than that of the biochemical tank; two ends of the water outlet pipe are respectively communicated with the secondary sedimentation tank body and the biochemical tank; two ends of the return pipe are respectively communicated with the secondary sedimentation tank main body and the biochemical tank. According to the vertical flow type sludge backflow control device for the secondary sedimentation tank, the secondary sedimentation tank main body is arranged to be higher than the biochemical tank in horizontal position, the lifting pump is arranged for lifting and conveying sewage, and meanwhile, the regulating valve is arranged on the backflow pipe, so that when the sludge level is too high, the sewage conveying amount can be reduced through the lifting pump, and the opening degree of the regulating valve is increased; the sludge level can be rapidly adjusted under gravity pressure, the system cost is reduced, meanwhile, the possibility of the sludge running phenomenon is greatly reduced, and the running stability of the system is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a sludge return control device for a vertical flow secondary sedimentation tank. Background Art

[0002] The vertical flow secondary sedimentation tank is a sedimentation tank commonly used in sewage treatment processes. Its main function is to remove suspended matter and organic matter from sewage. The design feature of this type of sedimentation tank is that the water flow direction is vertically downward, and the suspended particles are settled to the bottom of the tank by gravity. The vertical flow secondary sedimentation tank is usually composed of a circular or square tank body, with a water inlet device in the center and an outlet weir around it. After the sewage enters the center of the tank, the suspended particles gradually settle under the action of gravity, and the clarified supernatant is discharged from the outlet weir. The advantages of this design are small footprint and high treatment efficiency, and it is suitable for sewage treatment plants of various sizes. The sediment at the bottom of the tank is regularly discharged through a scraper or a mud discharge pipe to prevent accumulation and clogging of the bottom of the tank. The vertical flow secondary sedimentation tank can be used in combination with other treatment units such as primary sedimentation tanks, aeration tanks, etc. to form a complete sewage treatment system, which plays an important role in improving the quality of effluent.

[0003] In the sewage treatment process, the vertical flow secondary sedimentation tank is not only used for solid-liquid separation, but also bears the important function of sludge return. Sludge return is a key link in the activated sludge treatment system, which aims to return the settled concentrated sludge to the aeration tank to maintain the required microbial concentration in the system. For example, the method for preventing the sludge return pump of the secondary sedimentation tank from being blocked is disclosed in the publication number CN108439581A. This scheme realizes the recycling of activated sludge by setting a return pump.

[0004] However, installing a reflux pump will increase the cost and energy consumption of the system, and there is also a risk of clogging. If only gravity is used to circulate the sludge, it will not be able to be processed in time when the mud level is too high, which will cause sludge leakage and affect the normal use and purification effect of the secondary sedimentation tank. Utility Model Content

[0005] In view of this, the utility model proposes a sludge return control device for a vertical flow secondary sedimentation tank, which sets the secondary sedimentation tank body in a horizontal position higher than the biochemical tank, and sets a lifting pump to lift and transmit the sewage, and sets a regulating valve on the return pipe. When the mud level is too high, the lifting pump can be used to reduce the sewage transmission volume, and the opening of the regulating valve can be increased, so that the mud level can be quickly adjusted under gravity pressure, which reduces the system cost and greatly reduces the possibility of mud leakage, effectively improving the stability of system operation.

[0006] The technical solution of the utility model is implemented as follows: The utility model provides a vertical flow secondary sedimentation tank sludge return control device, including a biochemical tank, a secondary sedimentation tank body, an outlet pipe, a return pipe, a lifting pump and a regulating valve, wherein:

[0007] The main body of the secondary sedimentation tank is arranged opposite to the biochemical tank, and the horizontal position of the main body of the secondary sedimentation tank is higher than that of the biochemical tank;

[0008] The two ends of the outlet pipe are connected to the main body of the secondary sedimentation tank and the biochemical tank respectively;

[0009] The two ends of the return pipe are connected to the main body of the secondary sedimentation tank and the biochemical tank respectively, and the return pipe is used to return the sludge in the main body of the secondary sedimentation tank to the biochemical tank;

[0010] The lifting pump is arranged on the outlet pipe, and the lifting pump is used to transport the sewage in the biochemical pool to the main body of the secondary sedimentation tank through the outlet pipe;

[0011] The regulating valve is arranged on the return pipe, and the regulating valve is used to control the flow rate of the sludge.

[0012] On the basis of the above technical solution, preferably, the main body of the secondary sedimentation tank includes a tank body and a mud hopper, wherein:

[0013] The pool body and the biochemical pool are arranged opposite to each other;

[0014] The mud bucket is arranged in the pool body, the water outlet pipe extends to the top end of the mud bucket, and the return pipe is communicated with the bottom end of the mud bucket.

[0015] On the basis of the above technical solution, preferably, a water outlet flow meter is provided on the water outlet pipe, and the water outlet flow meter is used to detect the sewage flow in the water outlet pipe.

[0016] On the basis of the above technical solution, preferably, a reflux flowmeter is provided on the reflux pipe, and the reflux flowmeter is used to detect the sludge flow in the reflux pipe.

[0017] On the basis of the above technical solution, preferably, it also includes a water pump inverter, the water pump inverter is electrically connected to the lift pump, and the water pump inverter is used to adjust the rotation speed of the lift pump.

[0018] Further preferably, a control host is also included, wherein the control host is electrically connected to the water pump inverter, and the control host is used to send a control signal to the water pump inverter.

[0019] On the basis of the above technical solution, preferably, it also includes a mud level meter, which is arranged on the main body of the secondary sedimentation tank and is used to detect the mud level height in the main body of the secondary sedimentation tank.

[0020] Further preferably, the water outlet pipe also includes a water outlet elbow, which is connected to the biochemical pool and is located in the mud bucket. The end of the water outlet elbow away from the lift pump extends to above the mud bucket and bends toward the mud bucket.

[0021] The vertical flow secondary sedimentation tank sludge return control device of the utility model has the following beneficial effects compared with the prior art:

[0022] (1) By setting the main body of the secondary sedimentation tank to a higher horizontal position than the biochemical tank, and setting a lifting pump to lift and transfer sewage, and setting a regulating valve on the return pipe, when the mud level is too high, the sewage transmission volume can be reduced by the lifting pump, and the opening of the regulating valve can be increased, so that the mud level can be quickly adjusted under gravity pressure, which reduces the system cost and greatly reduces the possibility of mud leakage, effectively improving the stability of system operation;

[0023] (2) By setting up a water outlet flow meter, a return flow meter and a mud level meter, the water supply, mud return and mud level detection of the device are realized, which provides a good foundation for the overall automated feedback control, mud level and flow adjustment of the device. At the same time, the operation of the entire device can be visually monitored, further improving the operating stability and sewage treatment capacity of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of a sludge return control device for a vertical flow secondary sedimentation tank of the utility model. DETAILED DESCRIPTION

[0026] The following will be combined with the implementation of the utility model to clearly and completely describe the technical solutions in the implementation of the utility model. Obviously, the described implementation is only a part of the implementation of the utility model, not all of the implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] like Figure 1 As shown, the vertical flow secondary sedimentation tank sludge return control device of the utility model comprises a biochemical tank 1, a secondary sedimentation tank body 2, an outlet pipe 3, a return pipe 4, a lift pump 5 and a regulating valve 6.

[0028] The biochemical pool 1 is used to receive sewage entering the system. Activated sludge is spread on the bottom of the biochemical pool 1. In the biochemical pool 1, the sewage is fully mixed with the activated sludge rich in microorganisms. These microorganisms decompose organic matter in the sewage through biodegradation. Microorganisms metabolize under aerobic conditions and decompose complex organic pollutants, such as carbohydrates, fats, and proteins, into simple inorganic substances, such as carbon dioxide, water, and new microbial cells. The microbial population of the activated sludge in the biochemical pool 1 continues to proliferate, forming a large amount of activated sludge. These sludges not only contribute to the degradation of organic matter, but also contribute to solid-liquid separation in the secondary sedimentation tank. A part of the proliferated activated sludge will be returned to the biochemical pool 1 to maintain an appropriate microbial concentration, and the other part will be discharged through the sludge discharge system.

[0029] The secondary sedimentation tank body 2 is arranged opposite to the biochemical tank 1, and the horizontal position of the secondary sedimentation tank body 2 is higher than that of the biochemical tank 1. The secondary sedimentation tank body 2 is a vertical flow secondary sedimentation tank. In the sewage treatment process, it is not only used for solid-liquid separation, but also bears the important function of sludge return. Sludge return is a key link in the activated sludge treatment system, which aims to return the settled concentrated sludge to the aeration tank, which is the biochemical tank 1, to maintain the required microbial concentration in the system.

[0030] When the horizontal height of the secondary sedimentation tank body 2 is set higher than that of the biochemical tank 1, the sludge precipitated in the secondary sedimentation tank body 2 can be returned to the biochemical tank 1 under the action of gravity without the need to specially set up a reflux pump. The setting of a single pump is more conducive to the control operation of the system, while reducing system costs and energy consumption, and is more energy-saving and environmentally friendly.

[0031] Both ends of the outlet pipe 3 are connected to the secondary sedimentation tank body 2 and the biochemical tank 1 respectively. After the outlet pipe 3 is connected to the secondary sedimentation tank body 2 and the biochemical tank 1, the sewage can be transferred from the biochemical tank 1 to the secondary sedimentation tank body 2 to realize the sewage transfer operation.

[0032] Both ends of the return pipe 4 are connected to the secondary sedimentation tank body 2 and the biochemical tank 1 respectively, and the return pipe 4 is used to return the sludge in the secondary sedimentation tank body 2 to the biochemical tank 1 .

[0033] The lifting pump 5 is arranged on the outlet pipe 3, and the lifting pump 5 is used to transport the sewage in the biochemical pool 1 to the secondary sedimentation tank body 2 through the outlet pipe 3. Since the horizontal position of the secondary sedimentation tank body 2 is higher than the biochemical pool 1, the lifting pump 5 is mainly used for the upward transmission of sewage, so that the sewage can overcome the influence of gravity and be transmitted to the secondary sedimentation tank body 2 for sedimentation.

[0034] The regulating valve 6 is arranged on the return pipe 4 , and the regulating valve 6 is used to control the flow rate of the sludge. The regulating valve 6 controls the mud level height in the secondary sedimentation tank body 2 by controlling the flow rate of the sludge.

[0035] When the sediment mud level rises, the amount of mud flowing back can be increased by increasing the opening of the regulating valve 6 and reducing the speed of the lifting pump 5. Conversely, when the mud level drops, the opening of the regulating valve 6 can be reduced and the speed of the lifting pump 5 can be increased, thereby ensuring that the mud level in the secondary sedimentation tank body 2 always remains within a certain range.

[0036] In this embodiment, the secondary sedimentation tank body 2 includes a tank body 21 and a mud hopper 22. The tank body 21 is arranged opposite to the biochemical tank 1. The mud hopper 22 is arranged in the tank body 21. The outlet pipe 3 extends to the top of the mud hopper 22, and the return pipe 4 is connected to the bottom of the mud hopper 22.

[0037] The mud hopper 22 is arranged in a bucket shape and has an opening at the top. The sewage sent into the secondary sedimentation tank body 2 through the outlet pipe 3 will first enter the mud hopper 22 and then enter the tank body 21 through overflow. In this process, the particles in the sewage settle downward to form activated sludge, and enter the biochemical tank 1 through the return pipe 4 in a continuous cycle. The sludge returned to the biochemical tank 1 contains a large number of active microorganisms, which continue to decompose organic matter in the biochemical tank 1 and purify the sewage. In this way, the appropriate microbial concentration and sludge age in the biochemical tank 1 are maintained through the return flow, ensuring the efficiency and stability of the biological treatment.

[0038] The appropriate amount of sludge return can maintain the balance of the system, prevent excessive accumulation of sludge in the secondary sedimentation tank, and ensure that there is enough activated sludge in the biochemical tank 1 for sewage treatment.

[0039] As a preferred embodiment, an outlet flow meter 31 is provided on the outlet pipe 3, and the outlet flow meter 31 is used to detect the sewage flow in the outlet pipe 3. After the power of the lifting pump 5 is changed, the sewage flow in the outlet pipe 3 can be detected by the outlet flow meter 31, and then the opening of the regulating valve 6 can be determined to achieve an inflow and outflow balance of the sewage in the secondary sedimentation tank main body 2.

[0040] Correspondingly, a reflux flowmeter 41 is provided on the reflux pipe 4, and the reflux flowmeter 41 is used to detect the sludge flow in the reflux pipe 4. When the mud level in the mud hopper 22 is high, it is necessary to increase the opening of the regulating valve 6 to avoid the mud level being too high. Conversely, when the mud level is low, it is necessary to reduce the opening of the regulating valve 6 to keep the mud level within a certain range. After the opening of the regulating valve 6 is changed, the flow in the reflux pipe 4 is detected by the reflux flowmeter 41 to provide adjustment reference data for the lifting pump 5.

[0041] In this embodiment, in order to adjust the transmission flow of the lifting pump 5, a water pump inverter 7 is also provided. The water pump inverter 7 is electrically connected to the lifting pump 5. The water pump inverter 7 is used to adjust the rotational speed of the lifting pump 5. The rotational speed of the lifting pump 5 is controlled by the provided water pump inverter 7 to realize the transmission flow control of the lifting pump 5, so as to cooperate with the system to perform sewage transmission operations.

[0042] Correspondingly, a control host 8 is also provided, and the control host 8 is electrically connected to the water pump inverter 7. The control host 8 is used to send a control signal to the water pump inverter 7. In order to realize automatic adjustment of the system, the reflux flow meter 41 and the water outlet flow meter 31 are electrically connected to the control host 8, so that the detected flow is fed back to the control host 8 for judgment, and the control host 8 adjusts the water pump inverter 7. For the regulating valve 6, an electromagnetic valve can be selected, so that the regulating valve 6 is also connected to the control host 8, and the control host 8 directly controls the opening of the regulating valve 6.

[0043] As a preferred embodiment, a mud level meter 9 is further provided. The mud level meter 9 is provided on the secondary sedimentation tank body 2 . The mud level meter 9 is used to detect the mud level height in the secondary sedimentation tank body 2 .

[0044] Specifically, the mud level meter 9 detects the mud level height by emitting ultrasonic waves. The mud level meter 9 is electrically connected to the control host 8. After detecting the mud level height, it is fed back to the control host 8 through an electrical signal. By setting the highest and lowest mud level thresholds on the control host 8, it is possible to determine whether the mud level needs to be adjusted, and then the control host 8 adjusts the speed of the lift pump 5 and the opening of the regulating valve 6.

[0045] In addition, in order to reduce the impact of water outlet, the water outlet pipe 3 also includes a water outlet elbow 32, which is connected to the biochemical pool 1 and is located in the mud bucket 22. The end of the water outlet elbow 32 away from the lifting pump 5 extends to the top of the mud bucket 22 and bends toward the mud bucket 22.

[0046] The outlet elbow 32 is provided with a curved arc to avoid the impact caused by direct sewage spraying and prevent the influence on the deposition of particles. In addition, at the end of the return pipe 4 located in the biochemical pool 1, a return elbow can also be provided to reduce the influence of the return sludge on the purification operation of the biochemical pool 1.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sludge return control device for a vertical flow secondary sedimentation tank, characterized in that: It comprises a biochemical pool (1), a secondary sedimentation tank body (2), a water outlet pipe (3), a return pipe (4), a lift pump (5) and a regulating valve (6), wherein: The secondary sedimentation tank body (2) is arranged opposite to the biochemical tank (1), and the horizontal position of the secondary sedimentation tank body (2) is higher than that of the biochemical tank (1); The two ends of the water outlet pipe (3) are respectively connected to the secondary sedimentation tank body (2) and the biochemical tank (1); The two ends of the return pipe (4) are respectively connected to the secondary sedimentation tank body (2) and the biochemical tank (1), and the return pipe (4) is used to return the sludge in the secondary sedimentation tank body (2) to the biochemical tank (1); The lifting pump (5) is arranged on the outlet pipe (3), and the lifting pump (5) is used to transport the sewage in the biochemical pool (1) to the secondary sedimentation tank body (2) through the outlet pipe (3); The regulating valve (6) is arranged on the return pipe (4), and the regulating valve (6) is used to control the flow rate of the sludge.

2. The sludge return control device for a vertical flow secondary sedimentation tank according to claim 1, characterized in that: The secondary sedimentation tank body (2) comprises a tank body (21) and a mud hopper (22), wherein: The pool body (21) is arranged opposite to the biochemical pool (1); The mud bucket (22) is arranged in the pool body (21), the water outlet pipe (3) extends to the top end of the mud bucket (22), and the return pipe (4) is connected to the bottom end of the mud bucket (22).

3. The sludge return control device for a vertical flow secondary sedimentation tank according to claim 1, characterized in that: The water outlet pipe (3) is provided with a water outlet flow meter (31), and the water outlet flow meter (31) is used to detect the flow rate of sewage in the water outlet pipe (3).

4. The sludge return control device for a vertical flow secondary sedimentation tank according to claim 1, characterized in that: A reflux flow meter (41) is provided on the reflux pipe (4), and the reflux flow meter (41) is used to detect the sludge flow in the reflux pipe (4).

5. The sludge return control device for a vertical flow secondary sedimentation tank according to claim 1, characterized in that: It also includes a water pump frequency converter (7), the water pump frequency converter (7) is electrically connected to the lift pump (5), and the water pump frequency converter (7) is used to adjust the rotation speed of the lift pump (5).

6. The sludge return control device for a vertical flow secondary sedimentation tank according to claim 5, characterized in that: It also includes a control host (8), the control host (8) is electrically connected to the water pump frequency converter (7), and the control host (8) is used to send a control signal to the water pump frequency converter (7).

7. The sludge return control device for a vertical flow secondary sedimentation tank according to claim 1, characterized in that: It also comprises a mud level meter (9), which is arranged on the secondary sedimentation tank body (2) and is used to detect the mud level height in the secondary sedimentation tank body (2).

8. The sludge return control device for a vertical flow secondary sedimentation tank according to claim 2, characterized in that: The water outlet pipe (3) further comprises a water outlet elbow (32), the water outlet elbow (32) being in communication with the biochemical pool (1) and being located in the mud bucket (22), the water outlet elbow (32) extending from one end of the lifting pump (5) to the top of the mud bucket (22) and bending towards the mud bucket (22).

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