Sewage treatment system

Abstract

The utility model discloses a sewage treatment system which is characterized in that a biochemical pool of the system is communicated with a sedimentation pool through a pipeline A, the sedimentation pool is positioned at the downstream of the biochemical pool, and a pipeline B is arranged at the downstream of the sedimentation pool; the sewage treatment system further comprises a heat pump; a compressor and a throttle valve of the heat pump are connected with the condenser and the evaporator through a refrigerant pipeline to form a refrigerant loop; the sewage treatment system further comprises a pipeline C, one end of the pipeline C is communicated with the pipeline B, and the other end of the pipeline C is communicated with an inlet of the evaporator; the sewage treatment system further comprises a pipeline D, one end of the pipeline D is communicated with the pipeline C, and the other end of the pipeline D is communicated with an inlet of the condenser; the sewage treatment system also comprises a mixing tank which is positioned at the upstream of the biochemical tank and is communicated with the biochemical tank through a pipeline E; and an outlet of the condenser is communicated with the mixing tank through a pipeline F. According to the sewage treatment system, a heat exchange structure does not need to be arranged in the biochemical pool, the equipment investment is reduced, and the heating efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment technology, and in particular relates to a wastewater treatment system. Background Technology

[0002] In the wastewater treatment process, wastewater enters a biological treatment tank after passing through a pretreatment unit. Bacterial cultures are added to the biological treatment tank for further purification. In northern regions, especially during winter, the temperature of the wastewater entering the biological treatment tank after pretreatment is relatively low, typically around 7°C. The activity of the bacterial cultures in the biological treatment tank is relatively weak at low temperatures, resulting in a slower purification rate.

[0003] The bacteria exhibit the strongest activity and the fastest purification speed in the biological treatment tank at 15℃-20℃. Heating the wastewater in the biological treatment tank can effectively solve this problem.

[0004] In existing technologies, the heating technology for sewage in biological treatment tanks mostly involves installing heat exchange coils inside the biological treatment tank, and passing hot water or steam through the coils for indirect heat exchange; or drawing sewage out of the biological treatment tank, indirectly heating it through a heat exchanger, and then injecting it back into the biological treatment tank.

[0005] The wastewater in the biological treatment tank contains many impurities, most of which are corrosive. The heat exchange coils installed inside the biological treatment tank or the heat exchangers outside the tank are easily corroded and fouled, which seriously affects the service life and heat exchange efficiency of the heat exchangers. At the same time, heat exchange coils and indirect heat exchangers are indirect heat exchange equipment, and there is a heat exchange temperature difference, so the heating efficiency is lower than that of direct heating. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to provide a sewage treatment system that eliminates the need for heat exchange coils or heat exchangers in the biological treatment tank, thereby reducing equipment investment and improving heating efficiency.

[0007] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0008] A wastewater treatment system includes a biological treatment tank and a sedimentation tank. The biological treatment tank and the sedimentation tank are connected via pipe A. The sedimentation tank is located downstream of the biological treatment tank, and pipe B is installed downstream of the sedimentation tank. The wastewater treatment system also includes a heat pump, which includes a compressor, a throttling valve, a condenser, and an evaporator. The compressor and the throttling valve are connected to the condenser and the evaporator via a refrigerant pipeline to form a refrigerant circuit. The wastewater treatment system also includes a pipe C, one end of which is connected to pipe B, and the other end of which is connected to the inlet of the evaporator. The wastewater treatment system also includes a pipe D, one end of which is connected to pipe C, and the other end of which is connected to the inlet of the condenser. The wastewater treatment system also includes a mixing tank, located upstream of the biological treatment tank, which is connected to the biological treatment tank via pipe E. The outlet of the condenser is connected to the mixing tank via pipe F.

[0009] Furthermore, valve A is installed on the pipeline B.

[0010] Furthermore, a valve B is installed on the pipeline C, and the valve B is located between the pipeline D and the pipeline B.

[0011] Furthermore, a valve C is installed on the pipeline D.

[0012] Furthermore, the wastewater treatment system also includes a post-treatment device located downstream of the sedimentation tank, which is connected to the sedimentation tank via pipeline B.

[0013] Furthermore, the wastewater treatment system also includes a pipeline G, one end of which is connected to the outlet of the evaporator, and the other end of which is connected to the pipeline B. The other end of the pipeline G is located between the valve A and the post-treatment device.

[0014] Furthermore, the wastewater treatment system also includes a pretreatment device located upstream of the mixing tank, and the pretreatment device and the mixing tank are connected by a pipeline H.

[0015] Furthermore, the temperature of the wastewater in the biochemical tank is 15°C.

[0016] Furthermore, the temperature of the wastewater in pipe C and pipe D is 12°C.

[0017] Furthermore, the temperature of the sewage in the pipeline F is 28°C.

[0018] Due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0019] The wastewater treatment system includes a biological treatment tank and a sedimentation tank, which are connected by pipe A. The sedimentation tank is located downstream of the biological treatment tank, and pipe B is located downstream of the sedimentation tank. The system also includes a heat pump, which comprises a compressor, a throttling valve, a condenser, and an evaporator. The compressor and throttling valve are connected to the condenser and evaporator via refrigerant piping to form a refrigerant circuit. The system further includes pipe C, one end of which is connected to pipe B, and the other end of which is connected to the inlet of the evaporator. Pipe D is also included, one end of which is connected to pipe C, and the other end of which is connected to the inlet of the condenser. Finally, the system includes a mixing tank, located upstream of the biological treatment tank, connected to it via pipe E. The outlet of the condenser is connected to the mixing tank via pipe F. This wastewater treatment system eliminates the need for heat exchange coils or heat exchangers within the biological treatment tank, reducing equipment investment and improving heating efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the wastewater treatment system of this utility model;

[0021] In the diagram, the direction of the arrows indicates the direction of fluid flow;

[0022] In the diagram, 1. Biological treatment tank; 2. Sedimentation tank; 3. Mixing tank; 4. Post-treatment device; 5. Pre-treatment device; 6. Evaporator; 7. Compressor; 8. Throttling valve; 9. Condenser; 10. Pipeline A; 11. Pipeline B; 12. Pipeline C; 13. Pipeline D; 14. Pipeline E; 15. Pipeline F; 16. Pipeline G; 17. Pipeline H; 18. Pipeline I; 19. Pipeline J; 20. Pipeline K; 21. Valve A; 22. Valve B; 23. Valve C. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Combination Figure 1 As shown, a sewage treatment system includes a biological treatment tank 1 and a sedimentation tank 2. The biological treatment tank 1 and the sedimentation tank 2 are connected by a pipeline A10. The sedimentation tank 2 is located downstream of the biological treatment tank 1, and a pipeline B11 is installed downstream of the sedimentation tank 2.

[0025] The wastewater treatment system also includes a heat pump, which comprises a compressor 7, a throttle valve 8, a condenser 9, and an evaporator 6. The compressor 7 and the throttle valve 8 are connected to the condenser 9 and the evaporator 6 via refrigerant pipelines to form a refrigerant circuit. The working principle and process of the heat pump are the same as those of an air conditioner. The working principle and process of an air conditioner are common knowledge to those skilled in the art and will not be described in detail here.

[0026] The wastewater treatment system also includes pipe C12, one end of which is connected to pipe B11, and the other end of which is connected to the inlet of evaporator 6.

[0027] The wastewater treatment system also includes pipe D13, one end of which is connected to pipe C12, and the other end of which is connected to the inlet of condenser 9.

[0028] The wastewater treatment system also includes a mixing tank 3, which is located upstream of the biological treatment tank 1 and is connected to the biological treatment tank 1 via pipeline E14.

[0029] The outlet of condenser 9 is connected to mixing tank 3 via pipe F15.

[0030] The wastewater treatment system also includes a post-treatment device 4, which is located downstream of the sedimentation tank 2 and is connected to the sedimentation tank 2 via pipeline B11.

[0031] The wastewater treatment system also includes pipe G16, one end of which is connected to the outlet of evaporator 6, and the other end of which is connected to pipe B11. A valve A21 is also installed on pipe B11, and the other end of pipe G16 is located between valve A21 and the after-treatment device 4.

[0032] The wastewater treatment system also includes a pretreatment device 5, which is located upstream of the mixing tank 3. The pretreatment device 5 and the mixing tank 3 are connected by a pipeline H17.

[0033] A valve B 22 is installed on pipeline C12, and the valve B 22 is located between pipeline D13 and pipeline B11.

[0034] Valve C23 is installed on pipeline D13.

[0035] The temperature of the wastewater in biological treatment tank 1 is 15℃.

[0036] The temperature of the sewage in pipes C12 and D13 is 12℃.

[0037] The temperature of the sewage in pipe F15 is 28℃.

[0038] A pipeline I18 is installed upstream of the pretreatment device 5. The pipeline I18 is connected to the pretreatment device 5, and the wastewater to be treated enters the pretreatment device 5 through the pipeline I18.

[0039] Downstream of the post-treatment device 4, there is a pipeline J19 connected to the post-treatment device 4, and the greywater discharged from the post-treatment device 4 is discharged through the pipeline J19.

[0040] The wastewater treatment system also includes pipe K 20, which is located below the sedimentation tank 2 and is connected to the bottom of the sedimentation tank 2. The sludge deposited at the bottom of the sedimentation tank 2 is discharged through pipe K 20.

[0041] The process of treating sewage using the sewage treatment system of this utility model is described in detail below:

[0042] In winter, wastewater from the wastewater treatment plant in the north enters the pretreatment unit 5 through pipeline I18. The temperature of the wastewater after pretreatment in the pretreatment unit 5 is approximately 5°C. Valve A 21 is closed, and valves B 22 and C 23 are opened. The wastewater treated in the biological treatment tank 1 enters the sedimentation tank 2 through pipeline A10. The temperature of the wastewater in the biological treatment tank 1, pipeline A10, and sedimentation tank 2 is approximately 12°C. After the wastewater flows out of the sedimentation tank 2, part of the wastewater flows into pipeline B11 and then into the evaporator 6 through pipeline C12. At the same time, another part of the wastewater flows into the condenser 9 through pipeline D13. The refrigerant absorbs heat from the wastewater in the evaporator 6, and the wastewater temperature drops to about 5°C before being discharged into the post-treatment device 4 through pipe G16. After being compressed by the compressor 7, the refrigerant condenses and releases heat in the condenser 9, heating the wastewater at about 12°C after biochemical treatment that enters the condenser 9 through pipe D13. The wastewater at about 28°C after biochemical treatment, after being heated by the condenser 9, enters the mixing tank 3 through pipe F15. At the same time, the wastewater at about 5°C, which enters the pretreatment device 5 through pipe I18 and is pretreated by the pretreatment device 5, enters the mixing tank 3 through pipe H17. The wastewater entering the mixing tank 3 through pipe F15 and the wastewater entering the mixing tank 3 through pipe H17 are mixed in the mixing tank 3, and the temperature of the mixture is raised to about 15°C. The heated wastewater then enters the biochemical tank 1 through pipe E14.

[0043] Open valve C 23, and the sewage in sedimentation tank 2 will directly enter the post-treatment device 4.

[0044] After a period of time, valve D (not shown in the figure) installed on pipeline K 20 is opened, and the sludge deposited at the bottom of sedimentation tank 2 is discharged through pipeline K 20.

[0045] The wastewater treatment system of this invention effectively improves the shortcomings of the traditional method where wastewater at 5°C directly enters the biological treatment tank 1, resulting in weak activity and reproduction of bacteria at this temperature and long wastewater treatment time.

[0046] The heat pump recirculates and heats the biochemically treated wastewater. The heated wastewater is then mixed with the pretreated wastewater in mixing tank 3 for direct heating. This direct heating method eliminates the need for heat exchange coils or heat exchangers in the heat exchange system, reducing equipment investment and eliminating the technical defects of heat exchange coil corrosion and fouling that weaken heat exchange, as well as the problem of low heat exchange efficiency in indirect heat exchange.

[0047] The technical features with serial numbers mentioned in this manual (such as pipeline A, pipeline B, pipeline C, pipeline D, pipeline E, pipeline F, pipeline G, pipeline H, pipeline I, pipeline J, pipeline K, valve A, valve B, valve C, etc.) are only for distinguishing the technical features and do not represent the positional relationship, installation sequence, or working sequence of the technical features.

[0048] In the description of this specification, it should be understood that the orientation or positional relationship described by terms such as "below" or "bottom" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0049] While specific embodiments of this utility model have been described above, those skilled in the art should understand that the described embodiments are merely some, not all, embodiments of this utility model. These are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model and without any inventive effort, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A wastewater treatment system, comprising a biological treatment tank and a sedimentation tank, wherein the biological treatment tank and the sedimentation tank are connected via a pipeline A, the sedimentation tank is located downstream of the biological treatment tank, and a pipeline B is provided downstream of the sedimentation tank; characterized in that, The wastewater treatment system also includes a heat pump, which includes a compressor, a throttle valve, a condenser, and an evaporator; the compressor and the throttle valve are connected to the condenser and the evaporator through refrigerant pipelines to form a refrigerant circuit; The wastewater treatment system also includes a pipeline C, one end of which is connected to the pipeline B, and the other end of which is connected to the inlet of the evaporator; The wastewater treatment system also includes a pipeline D, one end of which is connected to the pipeline C, and the other end of which is connected to the inlet of the condenser; The wastewater treatment system also includes a mixing tank, which is located upstream of the biological treatment tank and is connected to the biological treatment tank via pipeline E. The outlet of the condenser is connected to the mixing tank via pipe F.

2. The wastewater treatment system as described in claim 1, characterized in that, Valve A is installed on pipeline B.

3. The wastewater treatment system as described in claim 1, characterized in that, A valve B is installed on the pipeline C, and the valve B is located between the pipeline D and the pipeline B.

4. The wastewater treatment system as described in claim 1, characterized in that, A valve C is installed on the pipeline D.

5. The wastewater treatment system as described in claim 2, characterized in that, The wastewater treatment system also includes a post-treatment device located downstream of the sedimentation tank, which is connected to the sedimentation tank via pipeline B.

6. The wastewater treatment system as described in claim 5, characterized in that, The wastewater treatment system also includes a pipeline G, one end of which is connected to the outlet of the evaporator, and the other end of which is connected to the pipeline B. The other end of the pipeline G is located between the valve A and the post-treatment device.

7. The wastewater treatment system as described in claim 1, characterized in that, The wastewater treatment system also includes a pretreatment device located upstream of the mixing tank, and the pretreatment device and the mixing tank are connected by a pipeline H.

8. The wastewater treatment system as described in claim 1, characterized in that, The temperature of the wastewater in the biochemical tank is 15℃.

9. The wastewater treatment system as described in claim 1, characterized in that, The temperature of the sewage in pipes C and D is 12°C.

10. The wastewater treatment system as described in claim 1, characterized in that, The temperature of the sewage in pipeline F is 28°C.

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