Variable-density self-circulation sludge granulating device

Abstract

The invention relates to the technical field of sewage treatment, and provides a variable-density self-circulation sludge granulating device which comprises an anoxic tank, an aerobic tank and a sedimentation tank which are arranged along a water body flowing path, the water body accelerating device is arranged in the anoxic tank; the inlet end of the backflow header pipe is provided with a sludge backflow branch pipe extending into the sedimentation tank and / or a nitrification liquid backflow branch pipe extending into the aerobic tank, and the outlet end of the backflow header pipe is provided with a first pipe section extending into the anoxic tank and located in the throat pipe; the outlet end of the reflux header pipe is also provided with a second pipe section which extends to the anoxic tank and is positioned outside the throat pipe; one end of the ventilation pipe extends into the second pipe section, the other end of the ventilation pipe is suitable for being connected with a gas source, and gas is introduced into the second pipe section through the ventilation pipe. According to the device, double drainage is carried out by utilizing the negative pressure effect generated by water inlet jet flow and the gas stripping effect generated by ventilation of the ventilation pipe, so that nitrification liquid and / or sludge flow back to the anoxic tank, energy conservation and environmental protection are facilitated, and the burden of system maintenance is not increased.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a variable-density self-circulating sludge granulation device. Background Art

[0002] The existing aerobic reaction device mainly includes an anoxic zone, an aerobic zone and a sedimentation zone arranged in sequence along the flow path of the sewage. After the raw water of the sewage enters the anoxic zone, it mixes with the microorganisms inside it to undergo anoxic reaction. Then the sewage enters the aerobic zone for aerobic reaction to further remove pollutants in the sewage. Then the sewage enters the sedimentation zone for sedimentation separation. There is a large amount of nitrification liquid in the downstream aerobic zone and a large amount of sludge in the sedimentation zone. In order to improve the treatment effect of the water body in the prior art, a pump body is generally used in conjunction with a pipeline to reflux the nitrification liquid or sludge. However, such a design is not conducive to energy saving and environmental protection and will increase the burden of system maintenance. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is that the traditional aerobic reaction device uses a pump body and pipelines to return the nitrification liquid or sludge. However, such a design is not conducive to energy saving and environmental protection and will increase the burden of system maintenance, thereby providing a variable density self-circulating sludge granulation device.

[0004] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0005] The present invention provides a variable density self-circulating sludge granulation device, comprising: an anoxic tank, an aerobic tank and a sedimentation tank arranged along a water flow path; a water acceleration device arranged in the anoxic tank, comprising a throat and at least one first-level nozzle, the throat cover being arranged on the top of the nozzle, the external water enters the throat after being accelerated by the nozzle, and the water is then released from the top of the throat into the anoxic tank; a return main pipe, the inlet end of the return main pipe is provided with a sludge return branch pipe extending to the sedimentation tank and / or a nitrate return branch pipe extending to the aerobic tank; A liquid reflux branch pipe, the outlet end of the reflux main pipe is provided with a first pipe section extending to the anoxic tank and located in the throat, the first pipe section uses the negative pressure in the throat to introduce the sludge and / or nitrification liquid into the throat; the outlet end of the reflux main pipe is also provided with a second pipe section extending to the anoxic tank and located outside the throat; a ventilation pipe, one end of which extends into the second pipe section and the other end is suitable for being connected to a gas source, the ventilation pipe introduces gas into the second pipe section, and uses the gas lift effect to introduce the sludge and / or nitrification liquid into the anoxic tank.

[0006] Furthermore, the variable-density self-circulating sludge granulation device also includes a light sludge hopper; the light sludge hopper is arranged at one end of the sludge return branch pipe away from the return main pipe, and the opening of the light sludge hopper is arranged upward.

[0007] Furthermore, the variable density self-circulating sludge granulation device also includes an aerobic water inlet distribution tank, which is arranged between the aerobic tank and the anoxic tank. The water in the anoxic tank first enters the aerobic water inlet distribution tank and then enters the aerobic tank; the second pipe section is located in the aerobic water inlet distribution tank.

[0008] Furthermore, the variable density self-circulating sludge granulation device also includes a degassing channel; the degassing channel is arranged between the aerobic tank and the sedimentation tank, the channel cross-sectional area located downstream in the degassing channel is larger than the channel cross-sectional area located upstream, and the water in the aerobic tank enters the sedimentation tank after being degassed in the degassing channel; the nitrification liquid reflux branch pipe is located in the degassing channel.

[0009] Furthermore, the pipe opening of the nitrification liquid reflux branch pipe faces downward and is located in the downstream channel of the degassing channel.

[0010] Furthermore, a first water return port is provided between the degassing channel and the aerobic tank, a part of the water in the degassing channel enters the downstream sedimentation tank, and another part of the water flows back to the upstream aerobic tank through the first water return port.

[0011] Furthermore, an aeration device is provided in the aerobic tank, and the aeration device includes an aerator and an accelerator; the aerator is provided at the bottom of the aerobic tank to provide gas required for aerobic reaction; the accelerator includes a premixing hood and a speed-retaining component; the premixing hood is provided at the air outlet end of the aerator, and the space between the premixing hood and the aerator forms a first premixing zone; a gap is left between the premixing hood and the aerator to form a second water return port, and the second water return port connects the space inside and outside the first premixing zone; wherein the flow area of ​​the release port of the premixing hood is smaller than the flow area of ​​the water inlet of the premixing hood, so as to increase the pressure in the first premixing zone under the aeration state; one end of the speed-retaining component is connected to the release port of the premixing hood, and the other end extends in a direction away from the premixing hood.

[0012] Furthermore, the variable density self-circulating sludge granulation device also includes a partition plate, which is arranged in the lower half of the aerobic tank, and the partition plate divides the lower half of the aerobic tank into multiple aeration zones, and the aeration device is arranged in the aeration zone; the space between two adjacent aeration zones forms an internal recirculation channel, and a gap connecting the aeration zone and the internal recirculation channel is left between the bottom of the partition plate and the bottom of the aerobic tank, and the flow direction of water in the internal recirculation channel is opposite to that of the water in the aeration zone; a guide cone is arranged at the bottom of the internal recirculation channel to guide the water in the internal recirculation channel to flow back into the aeration zone.

[0013] Furthermore, a sludge filter layer is formed in the sedimentation tank, the lower layer of the sludge filter layer is a nitrification filter layer, and the upper layer of the sludge filter layer is a denitrification filter layer; while the sludge filter layer filters the passing water, the nitrification filter layer is used to remove ammonia nitrogen in the water, and the denitrification filter layer is used to remove total nitrogen and COD in the water.

[0014] Furthermore, the variable density self-circulating sludge granulation device also includes a sludge discharge pipe, one end of which is connected to the light collection bucket and the other end of which extends to the outside of the aerobic tank.

[0015] Furthermore, along the water flow path in the anoxic pool, there are a mixing zone, an upflow anoxic zone, an anaerobic backflow channel and an upflow anaerobic reaction zone in sequence; the nozzle and the throat are both located in the mixing zone, and a third water return port is left between the nozzle and the throat, and a portion of the water in the mixing zone flows back into the throat through the third water return port; another portion of the water in the mixing zone flows out from the bottom and enters the upflow anoxic zone, the water flows upward to the top in the upflow anoxic zone and then enters the anaerobic diversion channel, the water in the anaerobic diversion channel flows downward to the bottom and then enters the upflow anaerobic reaction zone, the water in the upflow anaerobic reaction zone flows upward to the top and then enters the aerobic water inlet distribution tank.

[0016] Furthermore, the variable density self-circulating sludge granulation device also includes an anaerobic effluent weir and an anaerobic water distribution pipe; the anaerobic effluent weir is arranged at the top of the upflow anaerobic reaction zone, and the water body enters the anaerobic effluent weir and is then transported to the aerobic water inlet distribution tank; the water inlet end of the anaerobic water distribution pipe is connected to the anaerobic backflow channel, and the water outlet end of the anaerobic water distribution pipe is arranged parallel to the bottom of the upflow anaerobic reaction zone so that the inlet water is evenly distributed at the bottom of the upflow anaerobic reaction zone.

[0017] Furthermore, the variable density self-circulating sludge granulation device also includes an anoxic return pipe, one end of which extends into the throat and the other end is located in the upflow anaerobic reaction zone; the mouth of the anoxic return pipe faces upward and extends to the upper half of the upflow anaerobic reaction zone, so that the anaerobic sewage in the upflow anaerobic reaction zone can flow back to the mixing zone.

[0018] Furthermore, the anoxic tank, aerobic tank and sedimentation tank are integrated into one tank body, and different areas divided in the tank body form the anoxic tank, aerobic tank and sedimentation tank; or one or more of the anoxic tank, aerobic tank and sedimentation tank are composed of separate tank bodies.

[0019] Furthermore, the variable-density self-circulating sludge granulation device also includes a lifting agitator, which is arranged in the mixing zone and is used to accelerate the rise of the water in the throat.

[0020] The technical solution of the present invention has the following advantages:

[0021] The variable density self-circulating sludge granulation device provided by the present invention utilizes the negative pressure effect generated by the inlet water jet and the air lift effect generated by the ventilation pipe to perform double drainage, so that the nitrification liquid and / or sludge are returned to the anoxic tank. Compared with the use of a pump body and a pipeline to return the nitrification liquid and / or sludge, it is beneficial to energy saving and environmental protection and will not increase the burden of system maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A top view of a variable density self-circulating sludge granulation device in an embodiment of the present invention;

[0024] Figure 2 For along Figure 1 The cross-sectional view along the AA direction;

[0025] Figure 3 It is a schematic diagram of the partial structure of the aerobic tank in the variable density self-circulating sludge granulation device in the embodiment of the present invention;

[0026] Figure 4 For along Figure 1 The cross-sectional view along the BB direction;

[0027] Figure 5 is a schematic diagram of an aeration device in one embodiment of the present invention;

[0028] Figure 6 is a schematic diagram of an aeration device in another embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of an aeration device in another embodiment of the present invention;

[0030] Figure 8 is a schematic diagram of an aeration device in another embodiment of the present invention;

[0031] Fig. 9 This is a schematic diagram of the placement of an aerator in one embodiment of the present invention;

[0032] Fig.10 It is a schematic diagram of a lifting agitator in a variable density self-circulating sludge granulation device in one embodiment of the present invention;

[0033] Fig.11 It is a schematic diagram of a lifting agitator in a variable density self-circulating sludge granulation device in another embodiment of the present invention;

[0034] Fig.12 It is a schematic diagram of a lifting agitator in a variable density self-circulating sludge granulation device in another embodiment of the present invention;

[0035] Fig.13 It is a schematic diagram of a lifting agitator in a variable density self-circulating sludge granulation device in another embodiment of the present invention;

[0036] Fig.14 It is a schematic diagram of a lifting agitator in a variable density self-circulating sludge granulation device in another embodiment of the present invention;

[0037] Fig.15 It is a schematic diagram of a lifting agitator in a variable density self-circulating sludge granulation device in another embodiment of the present invention;

[0038] Fig.16 This is a schematic diagram of a lifting agitator in a variable density self-circulating sludge granulation device in another embodiment of the present invention.

[0039] Description of reference numerals:

[0040] 1. Anoxic tank; 2. Aerobic tank; 3. Sedimentation tank; 4. Return main pipe; 5. Sludge return branch pipe; 6. Nitrate return branch pipe; 7. First pipe section; 8. Second pipe section; 9. Ventilation pipe; 10. Light sludge hopper; 11. Aerobic water inlet distribution tank; 12. Degassing channel; 13. First water return port; 14. Aerator; 15. Premixing hood; 16. Speed-retaining parts; 17. First premixing zone; 18. Second water return port; 19. Divider plate; 20. Internal return channel; 21. Aeration zone; 22. Guide cone; 23. Sludge filter layer; 2 4. Denitrification filter layer; 25. Nitrification filter layer; 26. Mud discharge pipe; 27. Throat; 28. Spray pipe; 29. ​​Third water return port; 30. Mixing zone; 31. Inclined tube separation device; 32. Water outlet trough; 33. Upflow anoxic zone; 34. Anaerobic diversion channel; 35. Upflow anaerobic reaction zone; 36. Anaerobic water outlet weir; 37. Anaerobic water distribution pipe; 38. Anoxic return pipe; 39. Drain pipe; 40. Fairing; 41. Baffle; 42. Second premixing zone; 43. Diversion port; 44. Tooth-shaped port; 45. Lifting agitator. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] like Figure 1 , Figure 2 As shown, the present invention provides a variable density self-circulating sludge granulation device, comprising: an anoxic tank 1, an aerobic tank 2 and a sedimentation tank 3 arranged along the flow path of the water body; for example, the anoxic tank 1, the aerobic tank 2 and the sedimentation tank 3 can be integrated into one tank body, and different areas divided into the tank body form the anoxic tank 1, the aerobic tank 2 and the sedimentation tank 3. Alternatively, one or more of the anoxic tank 1, the aerobic tank 2 and the sedimentation tank 3 are composed of separate tank bodies, for example, the anoxic tank 1 is composed of a separate tank body, and the aerobic tank 2 and the sedimentation tank 3 are integrated into another tank body; for another example, the anoxic tank 1, the aerobic tank 2 and the sedimentation tank 3 are all composed of separate tank bodies.

[0046] Among them, in some scenarios, there may be more than one anoxic tank 1, aerobic tank 2 and sedimentation tank 3, but multiple to multiple, or one to multiple. For example, in some scenarios, there may be one anoxic tank 1 corresponding to multiple aerobic tanks 2 and sedimentation tanks 3, etc. Moreover, as long as the upstream and downstream relationship of the anoxic tank 1, aerobic tank 2 and sedimentation tank 3 remains unchanged, the positional relationship of the anoxic tank 1, aerobic tank 2 and sedimentation tank 3 can be designed as needed. For example, from left to right, they may be anoxic tank 1, aerobic tank 2 and sedimentation tank 3. For another example, from left to right, they may be sedimentation tank 3, aerobic tank 2, anoxic tank 1, aerobic tank 2 and sedimentation tank 3, etc.

[0047] The anoxic tank 1, the aerobic tank 2 and the sedimentation tank 3 may be formed of a steel structure or a concrete structure, and the cross-sectional shape of each tank may be circular, rectangular or other polygonal.

[0048] like Figure 1 As shown, in order to more clearly reflect the inventive concept of the present application, the following embodiments take the anoxic tank 1, the aerobic tank 2 and the sedimentation tank 3 in the same tank body as an example, and in the tank body along the first direction (left-right direction) there are the sedimentation tank 3, the aerobic tank 2, the anoxic tank 1, the aerobic tank 2 and the sedimentation tank 3 in sequence.

[0049] The water acceleration device is arranged in the anoxic tank 1, and includes a throat 27 and at least one level of nozzle 28, that is, the nozzle 28 can be arranged in one level or multiple levels according to the acceleration needs of the water body. The throat 27 cover is arranged at the top of the nozzle 28, and the external water enters the throat 27 after being accelerated by the nozzle 28, and the water is then released into the anoxic tank 1 from the top of the throat 27. The return main pipe 4, the inlet end of the return main pipe 4 is provided with a sludge return branch pipe 5 extending into the sedimentation tank 3 and / or a nitrification liquid return branch pipe 6 extending into the aerobic tank 2, and the outlet end of the return main pipe 4 is provided with a first pipe section 7 extending into the anoxic tank 1 and located in the throat 27, and the first pipe section 7 uses the negative pressure in the throat 27 to introduce the sludge and / or nitrification liquid into the throat 27; the outlet end of the return main pipe 4 is also provided with a second pipe section 8 extending into the anoxic tank 1 and located outside the throat 27.

[0050] When the amount of water to be treated is large, multiple water acceleration devices can be set in the anoxic pool 1 at the same time, and multiple water acceleration devices can be filled with water at the same time to increase the water intake.

[0051] The vent pipe 9 has one end extending into the second pipe section 8 and the other end being suitable for being connected to the air source. The vent pipe 9 introduces gas into the second pipe section 8, and uses the air lift effect to introduce the sludge and / or nitrification liquid into the anoxic tank 1. For example, the air inlet of the vent pipe 9 is located at the top of the vent pipe 9, and the air inlet of the vent pipe 9 extends outside the anoxic tank 1 and is connected to an air pump or other air source device. The air outlet of the vent pipe 9 is located at the bottom of the pipe body, and the gas is released at the bottom of the pipe. The outlet and inlet ends of the reflux main pipe 4 produce a concentration difference, and then the fluid at the inlet end of the reflux main pipe 4 is drained to the outlet end for release. For example, the nitrification liquid reflux branch pipe 6 and the sludge reflux branch pipe 5 can be arranged at the same time, or only one of them can be arranged.

[0052] The variable density self-circulating sludge granulation device provided by the present invention utilizes the negative pressure effect generated by the inlet water jet and the air lift effect generated by the ventilation of the vent pipe 9 to perform double drainage, so that the nitrification liquid and / or sludge are returned to the anoxic tank 1. Compared with the use of a pump body and a pipeline to return the nitrification liquid and / or sludge, it is beneficial to energy saving and environmental protection and will not increase the burden of system maintenance.

[0053] Among them, under normal circumstances, under the action of sludge backflow, its own gravity and the push flow of incoming water, a sludge filter layer 23 will be formed in the sedimentation tank 3, the lower layer of the sludge filter layer 23 is a nitrification filter layer 25, and the upper layer of the sludge filter layer 23 is a denitrification filter layer 24; while the sludge filter layer 23 filters the suspended matter in the passing water, the nitrification filter layer 25 is used to remove ammonia nitrogen in the water, and the denitrification filter layer 24 is used to remove total nitrogen and COD (Chemical Oxygen Demand) in the water. Among them, the variable density self-circulating sludge granulation device also includes a light sludge hopper 10; the light sludge hopper 10 is arranged at one end of the sludge return branch pipe 5 away from the return main pipe 4, and the opening of the light sludge hopper 10 is arranged upward, and the opening position of the light sludge hopper 10 can be kept flush with the upper denitrification filter layer 24, and the sludge in the denitrification filter layer 24 is returned to carry out denitrification reaction in the anoxic tank 1, thereby removing COD and total nitrogen in the water body.

[0054] Among them, the variable density self-circulating sludge granulation device also includes an aerobic water inlet distribution tank 11, which is arranged between the aerobic tank 2 and the anoxic tank 1. The water in the anoxic tank 1 first enters the aerobic water inlet distribution tank 11, and then enters the aerobic tank 2; the second pipe section 8 is located in the aerobic water inlet distribution tank 11, and the top of the second pipe section 8 is bent and extended into the upper half of the anoxic tank 1, one end of the ventilation pipe 9 extends into the aerobic water inlet distribution tank 11 and is inserted in the second pipe section 8, and the other end extends to the outside of the aerobic water inlet distribution tank 11 and can be connected to the air source.

[0055] Among them, the variable density self-circulating sludge granulation device also includes a degassing channel 12; the degassing channel 12 is arranged between the aerobic tank 2 and the sedimentation tank 3, and the channel cross-sectional area of ​​the degassing channel 12 located downstream is larger than the channel cross-sectional area of ​​the upstream, and the water in the aerobic tank 2 enters the sedimentation tank 3 after being degassed in the degassing channel 12; the nitrification liquid return branch pipe 6 is located in the degassing channel 12. For example, the pipe mouth of the nitrification liquid return branch pipe 6 can be downward and located in the channel downstream of the degassing channel 12. Since the channel cross-section downstream of the degassing channel 12 is enlarged, the water flow rate is low, so that the sludge and water have time to separate, and the low speed can make the degassing more thorough.

[0056] A first water return port 13 is provided between the degassing channel 12 and the aerobic tank 2. For example, the first water return port 13 can be located at the bottom of the degassing channel 12. A portion of the water in the degassing channel 12 enters the downstream sedimentation tank 3, and the other portion of the water flows back to the upstream aerobic tank 2 through the first water return port 13. A guide plate can be provided on the inner wall of the degassing channel 12, and the guide plate is inclined toward the position where the first water return port 13 is located. Under the guidance of the guide plate, the water flows back to the aerobic tank 2 first, and then the remaining water enters the downstream sedimentation tank 3. Moreover, since the water inlet level of the degassing channel 12 is at the top of the aerobic tank 2, the sludge can be sunk in the aerobic tank 2 depending on the height.

[0057] The middle part of the degassing channel 12 may be inclined toward the sedimentation tank 3 to block the sludge in the aerobic tank 2 from ascending, so that the sludge in the aerobic tank 2 can enter the aeration zone 21 more conveniently and reduce the amount of sludge entering the degassing channel 12 .

[0058] like Figure 3As shown, an aeration device is provided in the aerobic pool 2, and the aeration device includes an aerator 14 and an accelerator; the aerator 14 is arranged at the bottom of the aerobic pool 2, and is used to provide the gas required for the aerobic reaction; the accelerator includes a premixing hood 15 and a speed-retaining member 16; the premixing hood 15 is provided at the gas outlet end of the aerator 14, and the space between the premixing hood 15 and the aerator 14 forms a first premixing zone 17; a gap is left between the premixing hood 15 and the aerator 14 to form a second water return port 18, and the second water return port 18 connects the space inside and outside the first premixing zone 17; wherein, the flow area of ​​the release port of the premixing hood 15 is smaller than the flow area of ​​the water inlet of the premixing hood 15, so as to increase the pressure in the first premixing zone 17 under the aeration state; one end of the speed-retaining member 16 is connected to the release port of the premixing hood 15, and the other end extends in a direction away from the premixing hood 15. For example, the premixing hood 15 can be a truncated cone structure, with both ends open, the large end at the bottom, the small end at the top, and the small end used as a release port. For another example, the premixing hood 15 can also be a prism structure, with both ends open, the large end at the bottom, the small end at the top, and the small end used as a release port. Among them, the premixing hood 15 can be welded to the side wall of the aerobic tank 2 by setting a connecting rod on the side wall; it can also be installed as an integrated structure with the trachea bracket of the aerator 14 and fixed on the trachea bracket of the aerator 14. Among them, the speed-keeping component 16 can be a round tube or a square tube, which can be selected according to needs. Because the speed-keeping component 16 increases the release port height of the premixing hood 15, the gas-water mixture flow rate outside the premixing hood 15 is low, and the speed difference with the gas-water mixture in the first premixing zone 17 is large, so the pressure difference is large. Compared with the absence of the speed-keeping component 16, the speed difference between the two is greater, so the drainage effect is better.

[0059] When in use, the aerator 14 releases air in the first premixing zone 17. Due to the rapid rise of the bubbles, the water outside the first premixing zone 17 will be driven into the first premixing zone 17 through the second water return port 18. In addition, the reduction in diameter of the release port just above the premixing hood 15 causes the pressure in the first premixing zone 17 to rise, so that the bubbles are further mixed with the water flowing back through the second water return port 18. Due to the increase in pressure, the effect of gas dissolving into the water will be better. The mixed gas-water mixture is ejected through the release port and rises to the aerobic area outside the first premixing zone 17. The speed retaining member 16 can prolong the time of high-speed movement of the water body and delay the release. With this arrangement, when the aeration device is in use, the concentration of dissolved oxygen is increased by recirculating, mixing and pressurizing dissolved gas, which is more efficient and energy-saving under the same aeration conditions. The variable density self-circulating sludge granulation device further includes a partition plate 19, which is arranged in the lower half of the aerobic tank 2. The partition plate 19 divides the lower half of the aerobic tank 2 into a plurality of aeration zones 21, and the aeration device is arranged in the aeration zone 21; the space between two adjacent aeration zones 21 forms an inner reflux channel 20, and a gap connecting the aeration zone 21 and the inner reflux channel 20 is left between the bottom of the partition plate 19 and the bottom of the aerobic tank 2, and the flow direction of the water in the inner reflux channel 20 is opposite to that of the water in the aeration zone 21. When in use, the gas effect of the aerator 14 can be used to speed up the water diversion, so that the amount of refluxed water is more, thereby accelerating the circulation and reflux of the inner reflux channel 20 and the aeration zone 21, and the water can be mixed quickly. Moreover, under the action of aeration, the water flow in the aeration zone 21 rises rapidly, and the heavy sludge will flow down from the internal recirculation channel 20, and then participate in the rising process of aeration again, so that the sludge particles are formed more efficiently. In addition, through this high-speed rise and fall, air and water scrubbing, the granular sludge is more stable and the ball diameter ratio of the granular sludge is better.

[0060] A guide cone 22 is provided at the bottom of the inner recirculation channel 20 to guide the water in the inner recirculation channel 20 to flow back into the aeration zone 21. This arrangement can prevent mud accumulation in the inner recirculation channel 20 and is conducive to the guidance of air lift drainage.

[0061] like Figure 5 As shown, in one embodiment, the release port of the premixing cover 15 may not be provided with the speed retaining member 16 .

[0062] like Figure 6As shown, the aeration device further comprises a fairing 40, which is arranged at the release port of the premixing hood 15, and the end of the fairing 40 away from the premixing hood 15 is a sealing structure, and the inner diameter of the fairing 40 gradually decreases in the direction away from the premixing hood 15; the space between the fairing 40 and the premixing hood 15 forms a second premixing zone 42; a gap is left between the fairing 40 and the premixing hood 15 to form a diversion port 43, and the diversion port 43 connects the second premixing zone 42 with the space outside the second premixing zone 42. Wherein, the fairing 40 can be welded to the side wall of the aeration zone 21 by arranging a connecting rod on the side wall. For example, the fairing 40 can be a conical structure with the top of the cone on the top. For another example, the premixing hood 15 can also be a prismatic structure with a smaller top surface on the top. Wherein, the shape of the fairing 40 is adapted to the shape of the premixing hood 15, for example, when the premixing hood 15 is a truncated cone structure, the fairing 40 can be a conical structure. For example, when the premixing cover 15 is a prism-shaped structure, the fairing 40 can be a prism-shaped structure. When in use, the gas-water mixture in the first premixing zone 17 enters the second premixing zone 42 through the release port of the premixing cover 15, and the gas-water mixture in the second premixing zone 42 flows out through the diversion port 43 and is divided into a first branch and a second branch. The gas-water mixture in the first branch moves toward the direction of the second water return port 18, thereby forming a cycle, and the gas-water mixture in the second branch flows over the fairing 40 toward the downstream. Moreover, since the side wall of the fairing 40 is an inclined surface, a slope can be formed, and a part of the gas-water mixture will slide down along the slope (the reason is that the acceleration of the edge fluid forms a flow velocity difference and slides down) and counter-mixes with the gas-water mixture that rises rapidly in the second branch, thereby improving the mixing effect. In this way, there is reflux, mixing, and pressurized dissolved gas in the aeration zone 21, which increases the concentration of dissolved oxygen. Under the same aeration conditions, the efficiency is improved and more energy-saving.

[0063] like Figure 7 As shown, in one embodiment, the fairing 40 may also be disposed on an end of the speed-retaining member 16 away from the premixing cover 15 .

[0064] like Fig. 9 As shown, a plurality of tooth-shaped openings 44 can be provided at the edge of the fairing 40, and the plurality of tooth-shaped openings 44 are distributed along the circumference of the fairing 40. Such a setting has two advantages: first, the mixing effect can be increased through the tooth-shaped openings 44, because the flow velocities through the concave area and the convex area of ​​the tooth-shaped openings 44 are different, which can increase the disturbance mixing effect; second, it has the function of cutting bubbles, which can make large bubbles become smaller bubbles, increase the area of ​​contact with water, and increase dissolved oxygen. In addition, the mixing effect can be further increased by making the gas-water mixture have horizontal and downward reflux diversion momentum, and the downward diversion of the gas-water mixture will increase the extension of the mixing, so that the effective contact time is prolonged, and it will not rise directly to the liquid surface. Such a setting increases the extension, prolongs the reaction time, and increases the concentration of dissolved oxygen. Under the same aeration conditions, the efficiency is improved and more energy-saving is achieved.

[0065] like Figure 8 As shown, the aeration device further includes a baffle 41, which is arranged inside the fairing 40, and the plate surface of the baffle 41 is arranged opposite to the outlet of the speed-retaining member 16. When in use, the gas-water mixture released from the outlet at the top of the speed-retaining member 16 hits the baffle 41 and then diffuses to the surroundings. Such a setting can prevent the accumulation of bubbles on the top of the fairing 40, so that the gas is smoothly released into the water, thereby improving the gas-water mixing effect.

[0066] The variable density self-circulating sludge granulation device further includes a sludge discharge pipe 26, one end of which is connected to the light sludge collection bucket, and the other end of which extends to the outside of the aerobic tank 2. For example, a control valve can be provided on the sludge discharge pipe 26, and the control valve is closed during water treatment; when the nozzle 28 stops taking in water and the ventilation pipe 9 stops supplying air, the control valve is opened to discharge the sludge in the light sludge bucket 10 through the sludge discharge pipe 26.

[0067] Among them, Figure 1 , Figure 4 As shown, along the second direction (up and down direction), along the water flow path in the anoxic tank 1, there are a mixing zone 30, an upflow anoxic zone 33, an anaerobic diversion channel 34 and an upflow anaerobic reaction zone 35 in sequence, and the upflow anoxic zone 33, the anaerobic diversion channel 34 and the upflow anaerobic reaction zone 35 are symmetrically distributed on both sides of the mixing zone 30 along the second direction.

[0068] The nozzle 28 and the throat 27 are both located in the mixing zone 30, and a third water return port 29 is reserved between the nozzle 28 and the throat 27. A portion of the water in the mixing zone 30 flows back to the throat 27 through the third water return port 29; another portion of the water in the mixing zone 30 flows out from the bottom and enters the upflow anoxic zone 33, and the water flows upward to the top in the upflow anoxic zone 33 and then enters the anaerobic diversion channel 34, and the water in the anaerobic diversion channel 34 flows downward to the bottom and then enters the upflow anaerobic reaction zone 35, and the water in the upflow anaerobic reaction zone 35 flows upward to the top and then enters the aerobic water inlet distribution tank 11. Among them, a guide plate is arranged on the inner wall of the mixing zone 30, and the guide plate is inclined toward the position where the third water return port 29 is located. Under the guidance of the guide plate, the water body is preferentially returned to the mixing zone 30, and then the remaining water body enters the upstream anoxic zone 33 downstream, and the sludge can be kept in the mixing zone 30 as much as possible. In this way, the water bodies in the upstream anoxic zone 33 and the upstream anaerobic reaction zone 35 both flow upward, and the microorganisms can be suspended through hydraulic rise, which is conducive to the nutrition acquisition of the microorganisms and a more thorough reaction.

[0069] Among them, the variable density self-circulating sludge granulation device also includes an anaerobic effluent weir 36 and an anaerobic water distribution pipe 37; the anaerobic effluent weir 36 is arranged at the top of the upflow anaerobic reaction zone 35, and the anaerobic effluent weir 36 connects the upflow anaerobic reaction zone 35 with the aerobic inlet distribution tank 11. After the water enters the anaerobic effluent weir 36, it is transported to the aerobic inlet distribution tank 11; the water inlet end of the anaerobic water distribution pipe 37 is connected to the anaerobic diversion channel 34, and the water outlet end of the anaerobic water distribution pipe 37 is arranged parallel to the bottom of the upflow anaerobic reaction zone 35. A water spray hole is arranged on the pipe section corresponding to the water outlet end of the anaerobic water distribution pipe 37, and the water spray hole sprays water toward the bottom of the upflow anaerobic reaction zone 35, so that the inlet water is evenly distributed at the bottom of the upflow anaerobic reaction zone 35.

[0070] The variable density self-circulating sludge granulation device further includes an anoxic return pipe 38, one end of which extends into the throat pipe 27 and the other end is located in the upflow anaerobic reaction zone 35; the mouth of the anoxic return pipe 38 faces upward and extends to the upper half of the upflow anaerobic reaction zone 35, so that the anaerobic sewage in the upflow anaerobic reaction zone 35 can be returned to the mixing zone 30. For example, the mouth of the anoxic return pipe 38 can also be a bucket-shaped structure to increase the water intake during the return flow. In this way, the water volume in the mixing zone 30 is increased, the rising flow rate is increased, the sludge is suspended, and the sludge in the mixing zone 30 is supplemented and inoculated by returning part of the anaerobic sludge.

[0071] When in use, before the raw water enters the mixing zone 30, it is accelerated by the spray of the nozzle and the fusion return water, and a circulating mixing reaction is carried out in the mixing zone 30 with the center upward and the surrounding downward. In this section, there is anaerobic sewage return from the upflow anaerobic reaction zone 35, sludge return from the sedimentation tank 3, and nitrification liquid return from the degassing channel 12. These return waters are mixed with the raw water to carry out denitrification reaction, and COD and total nitrogen are removed. The water in the mixing zone 30 enters the bottom of the upflow anoxic zone 33, rises and enters the anaerobic diversion channel 34, and then enters the upflow anaerobic reaction zone 35 (because this section of oxygen is gradually consumed, it is called the upflow anaerobic reaction zone 35). There is a water distribution pipe at the bottom of the upflow anaerobic reaction zone 35, which can evenly distribute the water at the bottom and then rise. An anaerobic effluent weir 36 is provided at the upper part of the upflow anaerobic reaction zone 35 , and water is fed into the aerobic water distribution tanks 11 on both sides. Below the anaerobic effluent weir 36 is an anoxic return pipe 38 , which returns the water to the mixing zone 30 .

[0072] Among them, an inclined tube separation device 31 can also be set in the sedimentation tank 3 to further precipitate and separate the escaped small suspended matter. A water outlet trough 32 is set downstream of the inclined tube separation device 31, and the water outlet trough 32 is connected to a water outlet pipe. After the clean water enters the water outlet trough 32, it is discharged from the water outlet pipe. An emptying pipe 39 can also be set at the bottom of the sedimentation tank 3 to empty the sludge and water in the sedimentation tank 3.

[0073] like Fig.10As shown, in one embodiment, the variable density self-circulating sludge granulation device also includes a lifting agitator 45, the base of which can be installed on the top of the mixing zone 30, and the connecting rod and the spiral blades of the lifting agitator 45 are both extended into the throat 27. When in use, the lifting agitator 45 can promote the rise of the water body in the throat 27. For example, the lifting agitator 45 can be controlled by frequency conversion so that the speed of the spiral blades can be adjusted. At this time, the flow rate of the rising water body can also be adjusted, and then the amount of water reflux will also change with the change of speed. Among them, the lifting agitator 45 can be used alone, or it can be used in conjunction with injection and air lift.

[0074] like Fig.11 As shown, in one embodiment, the bottom of the mixing zone 30 uses pressure water inlet, and after the water inlet, there is jet acceleration, and the ascending section has multiple acceleration devices for drainage; in addition to the nozzle acceleration, there is also a lifting stirrer 45 on the upper part to assist the upstream flow, and the speed of the spiral fan blades can change the drainage force and flow rate. The throat 27 drainage has two or more layers, which can reflux and mix the water that needs to be refluxed in the anoxic zone, aerobic zone and sedimentation zone.

[0075] like Fig.12 As shown, in one embodiment, the bottom of the mixing zone 30 uses gravity water inlet. Since the lifting speed of the lifting stirrer 45 is increased, the reflux required in the middle of the rise can be drained by changing the diameter to accelerate the flow. All the rising flow rates are channel spiral blades. The number of layers of the spiral blades can be calculated to make two or more layers; the speed of the spiral blades can change the force and flow of the drainage. The throat 27 has two or more layers of drainage, which can reflux and mix the water that needs to be refluxed in the anoxic zone, aerobic zone and sedimentation zone.

[0076] like Fig.13 As shown, in one embodiment, the bottom of the mixing zone 30 uses gravity water inlet, and the water first enters an annular water distribution bin, and the bottom of the bin has an annular gap for uniform water distribution; after the water is distributed, it enters the central rising zone, and is lifted by the lifting stirrer 45. The speed of the spiral blades can change the force and flow of the drainage; during the lifting process, the points that need to reflux are reduced in diameter and accelerated, and then connected to the reflux pipe. The throat 27 needs to have two or more layers of drainage, and the diameter is reduced, so that the anoxic zone, aerobic zone and sedimentation zone that need to reflux can be refluxed and mixed.

[0077] like Fig.14 As shown, in one embodiment, the bottom of the mixing zone 30 uses gravity water inlet, and the water first enters an annular water distribution bin, and the bottom of the bin has an annular gap to evenly distribute the water; after the water is distributed, it enters the central rising area and is lifted by the lifting agitator 45. The speed of the spiral blades can change the force and flow of the drainage; during the lifting process, the point where the reflux is required is reduced in diameter and accelerated, and then connected to the reflux pipe. The impeller is mainly arranged in the upper area.

[0078] like Fig.15 As shown, in one embodiment, gravity water is fed into the bottom of the mixing zone 30, and the spiral blades are arranged with unequal diameters.

[0079] like Fig.16 As shown, in one embodiment, water is fed into the bottom of the mixing zone 30 by gravity, and after bouncing off the bottom plate, it rises due to the lifting action of the lifting agitator 45; after the water is distributed, it enters the central rising zone, and is lifted upstream by the lifting agitator 45. The speed of the spiral blades can change the force and flow of the drainage; and then the return pipe is connected. The spiral blades are arranged in an independent bucket, and the bucket is connected to a return pipe, so that the water that needs to be returned in the anoxic zone, aerobic zone, sedimentation zone and other areas returns to the central mixing zone. Obviously, the above embodiments are only examples for clear explanation, and are not limitations on the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. And the obvious changes or modifications derived from this are still within the scope of protection of the invention.

Claims

1. A variable density self-circulating sludge granulation device, characterized in that: include: Anoxic tank (1), aerobic tank (2) and sedimentation tank (3) are arranged along the flow path of the water body; A water acceleration device is arranged in the anoxic pool (1), comprising a throat (27) and at least one first-stage nozzle (28), wherein the throat (27) is covered at the top of the nozzle (28), and the external water enters the throat (27) after being accelerated by the nozzle (28), and the water is then released from the top of the throat (27) into the anoxic pool (1); a return main pipe (4), wherein the inlet end of the return main pipe (4) is provided with a sludge return branch pipe (5) extending into the sedimentation tank (3) and / or a nitrification liquid return branch pipe (6) extending into the aerobic tank (2); the outlet end of the return main pipe (4) is provided with a first pipe section (7) extending into the anoxic tank (1) and located in the throat pipe (27); the first pipe section (7) utilizes the negative pressure in the throat pipe (27) to introduce the sludge and / or nitrification liquid into the throat pipe (27); The outlet end of the reflux main pipe (4) is also provided with a second pipe section (8) extending toward the anoxic pool (1) and located outside the throat pipe (27); a vent pipe (9), one end of which extends into the second pipe section (8) and the other end of which is suitable for being connected to a gas source, wherein the vent pipe (9) introduces gas into the second pipe section (8) to introduce sludge and / or nitrification liquid into the anoxic tank (1) by utilizing gas lift effect; The drain pipe (39) has one end extending inwardly into the bottom of the sedimentation tank (3) and the other end extending outwardly to the outside of the sedimentation tank (3).

2. The variable density self-circulating sludge granulation device according to claim 1 is characterized in that: Also includes a light sludge hopper (10); The light sludge hopper (10) is arranged at one end of the sludge return branch pipe (5) away from the return main pipe (4), and the opening of the light sludge hopper (10) is arranged upward.

3. The variable density self-circulating sludge granulation device according to claim 1 is characterized in that: It also includes an aerobic water inlet distribution tank (11) disposed between the aerobic tank (2) and the anoxic tank (1), wherein the water in the anoxic tank (1) first enters the aerobic water inlet distribution tank (11) and then enters the aerobic tank (2); The second pipe section (8) is located in the aerobic water inlet distribution tank (11).

4. The variable density self-circulating sludge granulation device according to claim 1 is characterized in that: Also includes a degassing channel (12); The degassing channel (12) is arranged between the aerobic tank (2) and the sedimentation tank (3); the cross-sectional area of ​​the channel located downstream in the degassing channel (12) is larger than the cross-sectional area of ​​the channel located upstream; the water in the aerobic tank (2) enters the sedimentation tank (3) after being degassed in the degassing channel (12); The nitrification liquid reflux branch pipe (6) is located in the degassing channel (12).

5. The variable density self-circulating sludge granulation device according to claim 4 is characterized in that: The pipe opening of the nitrification liquid reflux branch pipe (6) faces downward and is located in the downstream channel of the degassing channel (12).

6. The variable density self-circulating sludge granulation device according to claim 4 is characterized in that: A first water return port (13) is provided between the degassing channel (12) and the aerobic pool (2); a portion of the water in the degassing channel (12) enters the sedimentation pool (3) at the downstream, and another portion of the water flows back to the aerobic pool (2) at the upstream through the first water return port (13).

7. The variable density self-circulating sludge granulation device according to claim 6 is characterized in that: An aeration device is provided in the aerobic pool (2), and the aeration device comprises an aerator (14) and an accelerator; The aerator (14) is arranged at the bottom of the aerobic tank (2) to provide gas required for aerobic reaction; The accelerating component comprises a premixing cover (15) and a speed-retaining component (16); The premixing hood (15) is arranged at the outlet end of the aerator (14), and the space between the premixing hood (15) and the aerator (14) forms a first premixing zone (17); a gap is left between the premixing hood (15) and the aerator (14) to form a second water return port (18), and the second water return port (18) communicates the space inside and outside the first premixing zone (17); wherein the flow area of ​​the release port of the premixing hood (15) is smaller than the flow area of ​​the water inlet of the premixing hood (15), so as to increase the pressure in the first premixing zone (17) under the aeration state; One end of the speed-retaining member (16) is connected to the release port of the premixing cover (15), and the other end extends in a direction away from the premixing cover (15).

8. The variable density self-circulating sludge granulation device according to claim 7 is characterized in that: It also includes a partition plate (19) disposed in the lower half of the aerobic tank (2), the partition plate (19) divides the lower half of the aerobic tank (2) into a plurality of aeration zones (21), and the aeration device is disposed in the aeration zone (21); The space between two adjacent aeration zones (21) forms an internal recirculation channel (20), a gap connecting the aeration zones (21) and the internal recirculation channel (20) is left between the bottom of the partition plate (19) and the bottom of the aerobic tank (2), and the water flow direction in the internal recirculation channel (20) is opposite to that in the aeration zones (21); A guide cone (22) is provided at the bottom of the inner recirculation channel (20) to guide the water in the inner recirculation channel (20) to flow back into the aeration zone (21).

9. The variable density self-circulating sludge granulation device according to claim 1, characterized in that: A sludge filter layer (23) is formed in the sedimentation tank (3), the lower layer of the sludge filter layer (23) is a nitrification filter layer (25), and the upper layer of the sludge filter layer (23) is a denitrification filter layer (24); The sludge filter layer (23) filters the water passing through it, while the nitrification filter layer (25) removes ammonia nitrogen in the water, and the denitrification filter layer (24) removes total nitrogen and COD in the water.

10. The variable density self-circulating sludge granulation device according to claim 2, characterized in that: It also comprises a mud discharge pipe (26), one end of which is connected to the light collection bucket and the other end of which extends to the outside of the aerobic pool (2).

11. The variable density self-circulating sludge granulation device according to claim 3, characterized in that: The anoxic pool (1) includes a mixing zone (30), an upflow anoxic zone (33), an anaerobic diversion channel (34) and an upflow anaerobic reaction zone (35) in sequence along the water flow path; The nozzle (28) and the throat (27) are both located in the mixing zone (30), and a third water return port (29) is reserved between the nozzle (28) and the throat (27), so that a portion of the water in the mixing zone (30) flows back into the throat (27) through the third water return port (29); Another part of the water in the mixing zone (30) flows out from the bottom and enters the upflow anoxic zone (33). The water flows upward to the top of the upflow anoxic zone (33) and then enters the anaerobic diversion channel (34). The water in the anaerobic diversion channel (34) flows downward to the bottom and then enters the upflow anaerobic reaction zone (35). The water in the upflow anaerobic reaction zone (35) flows upward to the top and then enters the aerobic water inlet distribution tank (11).

12. The variable density self-circulating sludge granulation device according to claim 11, characterized in that: It also includes an anaerobic water outlet weir (36) and an anaerobic water distribution pipe (37); The anaerobic effluent weir (36) is arranged at the top of the upflow anaerobic reaction zone (35), and the water enters the anaerobic effluent weir (36) and is then transported to the aerobic inlet distribution tank (11); The water inlet end of the anaerobic water distribution pipe (37) is connected to the anaerobic diversion channel (34), and the water outlet end of the anaerobic water distribution pipe (37) is arranged parallel to the bottom of the upflow anaerobic reaction zone (35) so that the inlet water is evenly distributed at the bottom of the upflow anaerobic reaction zone (35).

13. The variable density self-circulating sludge granulation device according to claim 11, characterized in that: It also includes an anoxic return pipe (38), one end of which extends into the throat pipe (27) and the other end of which is located in the upflow anaerobic reaction zone (35); The pipe opening of the anoxic return pipe (38) faces upward and extends to the upper half of the upflow anaerobic reaction zone (35), so that the anaerobic sewage in the upflow anaerobic reaction zone (35) can be returned to the mixing zone (30).

14. The variable density self-circulating sludge granulation device according to claim 1, characterized in that: The anoxic tank (1), the aerobic tank (2) and the sedimentation tank (3) are integrated into a tank body, and different areas divided in the tank body form the anoxic tank (1), the aerobic tank (2) and the sedimentation tank (3); Or one or more of the anoxic tank (1), the aerobic tank (2) and the sedimentation tank (3) are composed of a separate tank body.

15. The variable density self-circulating sludge granulation device according to claim 11, characterized in that: It also includes a lifting agitator (45) disposed in the mixing zone (30) for accelerating the rise of the water in the throat (27).

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