In-situ capacity expansion method and device for sewage treatment system for improving flux of separated solids of secondary sedimentation tank, and sewage treatment system

Abstract

The invention discloses a sewage treatment system in-situ capacity expansion method and device for improving the flux of separated solids of a secondary sedimentation tank and a sewage treatment system. The method comprises the following steps: inputting activated sludge in a secondary sedimentation tank into a first separation cavity of a first-stage separation unit, so that the activated sludge is separated through spiral movement in the first separation cavity; according to the operation parameters of the secondary sedimentation tank and the performance of activated sludge in an aeration tank in the biochemical treatment unit, the activated sludge discharged from one of a first overflow port and a first underflow port of the first-stage separation unit is input into a second separation cavity of the second-stage separation unit, so that the activated sludge is separated through spiral movement in the second separation cavity; and the activated sludge discharged from one of the second overflow port and the second underflow port of the second-stage separation unit flows back to the biochemical treatment unit. According to the method, the solid load and the sludge settling performance of the secondary sedimentation tank can be regulated and controlled, the separated solid flux of the secondary sedimentation tank is increased, and in-situ synergy and capacity expansion of a sewage treatment system are realized.

Description

Technical Field

[0001] The present application relates to the technical field of water treatment, and in particular to an in-situ expansion method for a sewage treatment system for increasing the solid flux of a secondary sedimentation tank, an in-situ expansion device for a sewage treatment system for increasing the solid flux of a secondary sedimentation tank, and a sewage treatment system. Background Art

[0002] The activated sludge process is the most widely used biological treatment technology for sewage treatment in my country. It is mainly composed of an aeration tank, a secondary sedimentation tank, a sludge return system, etc. In order to ensure high-quality and clear effluent, the activated sludge not only needs to have the functions of adsorbing, oxidizing and decomposing organic matter, but also needs to have excellent coagulation and sedimentation properties. However, as emission standards become increasingly stringent, sewage plants usually need to maintain a high sludge concentration to ensure that the effluent quality meets the standards, resulting in the common problems of high solid load and poor solid-liquid separation in the secondary sedimentation tanks of most sewage plants. Summary of the invention

[0003] In response to the problems of high solid load and poor solid-liquid separation efficiency in the secondary sedimentation tank of the existing sewage treatment system, the embodiments of the present application provide a method and device for in-situ expansion of the sewage treatment system for improving the solid flux separated by the secondary sedimentation tank. The method can simultaneously regulate the solid load and sludge settling performance of the secondary sedimentation tank, increase the solid flux separated by the secondary sedimentation tank, enhance the solid-liquid separation efficiency of the secondary sedimentation tank, realize the in-situ expansion of the sewage treatment system, effectively improve the efficiency and resilience of the sewage treatment system, reduce the cost of sewage treatment, and help improve the quality and efficiency of the sewage treatment system.

[0004] The present application embodiment provides an in-situ capacity expansion method for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank, comprising:

[0005] The activated sludge in the secondary sedimentation tank of the sewage treatment system is fed into the first separation chamber of the first separation unit from the first feed port of the first separation unit, so that the activated sludge is separated by spiral motion in the first separation chamber;

[0006] According to the operating parameters of the secondary sedimentation tank and the performance of the activated sludge in the aeration tank in the biochemical treatment unit of the sewage treatment system, the activated sludge discharged from one of the first overflow port and the first underflow port of the first-stage separation unit is input into the second separation chamber of the second-stage separation unit from the second feed port of the second-stage separation unit, so that the activated sludge is separated by spiral motion in the second separation chamber, and the activated sludge discharged from one of the second overflow port and the second underflow port of the second-stage separation unit is returned to the biochemical treatment unit.

[0007] The present application also provides an in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank, comprising:

[0008] A first-stage separation unit comprises a first separation chamber, and a first feed port, a first underflow port and a first overflow port connected to the first separation chamber, wherein the first feed port is arranged to be connected to a secondary sedimentation tank of a sewage treatment system, and the first-stage separation unit is arranged to separate the activated sludge inputted from the first feed port into the first separation chamber through a spiral motion; and

[0009] The second-stage separation unit has a second separation chamber, and a second feed port, a second underflow port and a second overflow port connected to the second separation chamber, and one of the first overflow port and the first underflow port is connected to the second feed port. The second-stage separation unit is configured to separate the activated sludge input from the second feed port into the second separation chamber through spiral motion, and one of the second overflow port and the second underflow port is configured to be connected to a biochemical treatment unit of a sewage treatment system.

[0010] The present application also provides a sewage treatment system, including a biochemical treatment unit, a secondary sedimentation tank and the above-mentioned sewage treatment system in-situ expansion device for improving the solid separation flux of the secondary sedimentation tank, the first feed inlet of the sewage treatment system in-situ expansion device is connected to the secondary sedimentation tank, and the second underflow outlet and one of the second overflow outlet of the sewage treatment system in-situ expansion device are connected to the biochemical treatment unit.

[0011] Compared with the prior art, the embodiments of the present application have the following technical effects:

[0012] 1. The technical solution of the embodiment of the present application is based on the morphology and density difference between microbial aggregates, silt, and biomass-attached silt in activated sludge. The in-situ expansion device of the sewage treatment system used can perform gradient graded separation of different solid phase components in the activated sludge, thereby achieving precise control of the settling performance of the activated sludge in the aeration tank and the solid load of the secondary sedimentation tank;

[0013] 2. The technical solution of the embodiment of the present application can effectively improve the settling performance of activated sludge, increase the solid separation flux of the secondary sedimentation tank, increase the ability of the sewage treatment system to resist the impact of hydraulic fluctuations, and realize the in-situ expansion of the sewage treatment system;

[0014] 3. The in-situ expansion device of the sewage treatment system of the embodiment of the present application has good universality and can be applied to the secondary sedimentation tank of the existing urban sewage treatment system, and can improve the operating efficiency of the secondary sedimentation tank;

[0015] 4. The in-situ expansion device of the sewage treatment system of the embodiment of the present application has the advantages of simple structure, small footprint, high screening efficiency, low operation and maintenance costs, and no need to add chemicals. It is a low-consumption and high-efficiency secondary sedimentation tank operation efficiency enhancement technology.

[0016] Other features and advantages of the present application will be set forth in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0018] Figure 1 This is a schematic flow chart of an in-situ expansion method for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to an embodiment of the present application;

[0019] Figure 2 This is a schematic structural diagram of an in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to an embodiment of the present application;

[0020] Figure 3 This is a schematic diagram of the working principle of an in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to an embodiment of the present application;

[0021] Figure 4 This is a schematic structural diagram of an in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to another embodiment of the present application;

[0022] Figure 5 This is a schematic diagram of the working principle of an in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to another embodiment of the present application;

[0023] Figure 6 A schematic diagram of the structure of a sewage treatment system according to an embodiment of the present application;

[0024] Figure 7 It is a structural schematic diagram of a sewage treatment system according to another embodiment of the present application.

[0025] Reference numerals:

[0026] 100-first stage separation unit, 200-second stage separation unit, 300-in-situ expansion device for sewage treatment system;

[0027] 1-outer cylinder, 11-first end wall, 12-first separation chamber, 13-second separation chamber, 14-first feed port, 15-first underflow port, 16-first overflow port, 17-second feed port, 18-second underflow port, 19-second overflow port, 110-discharge port, 111-second end wall;

[0028] 2-first inner cone, 21-first conical section, 211-second connecting cavity, 22-first cylindrical section;

[0029] 3-second inner cone, 31-second conical section, 32-second cylindrical section;

[0030] 4-helical body, 41-columnar portion, 411-first communicating cavity, 42-spiral blade, 43-spiral flow channel;

[0031] 5-biochemical treatment unit, 51-anaerobic zone, 52-first anoxic zone, 53-first aerobic zone, 54-second anoxic zone, 55-second aerobic zone;

[0032] 6-second sedimentation tank, 71-first internal return pipeline, 72-second internal return pipeline, 73-external return pipeline, 8-primary sedimentation tank. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present application more clear, the embodiments of the present application will be described in detail below. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0034] The present application is further described in detail below in conjunction with specific examples, but the examples should not be construed as limiting the present application.

[0035] like Figure 1 As shown, the embodiment of the present application provides an in-situ expansion method for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank, comprising the following steps:

[0036] Step S102: The activated sludge in the secondary sedimentation tank of the sewage treatment system is fed into the first separation chamber of the first separation unit from the first feed port of the first separation unit, so that the activated sludge is separated by spiral motion in the first separation chamber;

[0037] Step S104: According to the operating parameters of the secondary sedimentation tank and the performance of the activated sludge in the aeration tank in the biochemical treatment unit of the sewage treatment system, the activated sludge discharged from one of the first overflow port and the first underflow port of the first-stage separation unit is input into the second separation chamber of the second-stage separation unit from the second feed port of the second-stage separation unit, so that the activated sludge is separated by spiral motion in the second separation chamber, and the activated sludge discharged from one of the second overflow port and the second underflow port of the second-stage separation unit is returned to the biochemical treatment unit.

[0038] The in-situ capacity expansion method of the sewage treatment system for increasing the solid separation flux of the secondary sedimentation tank according to the embodiment of the present application can be achieved by Figure 2-Figure 5 The sewage treatment system in-situ expansion device 300 for increasing the solid separation flux of the secondary sedimentation tank is implemented Figure 6 and Figure 7In the process of realizing the in-situ expansion of the sewage treatment system, first, the activated sludge in the secondary sedimentation tank 6 can be input into the first separation unit 100, and the activated sludge can perform spiral motion in the first separation chamber 12 of the first separation unit 100 to separate the activated sludge, so that part of the activated sludge can be discharged from the first overflow port 16 of the first separation unit 100, and part of the activated sludge can be discharged from the first underflow port 15; then, according to the operating parameters of the secondary sedimentation tank 6 in the sewage treatment system and the performance of the activated sludge in the aeration tank in the biochemical treatment unit 5, the activated sludge from the first separation unit 100 can be discharged from the first overflow port 16 of the first separation unit 100. The activated sludge discharged from an overflow port 16 or a first underflow port 15 is input into the second-stage separation unit 200. The activated sludge can perform spiral motion in the second separation chamber 13 of the second-stage separation unit 200 for separation, so that the activated sludge discharged from the second overflow port 19 and the second underflow port 18 of the second-stage separation unit 200 have different performance parameters. The activated sludge discharged from the second overflow port 19 or the second underflow port 18 of the second-stage separation unit 200 can be returned to the biochemical treatment unit 5 according to the operating parameters of the secondary sedimentation tank 6 and the performance of the activated sludge in the aeration tank in the biochemical treatment unit 5.

[0039] The in-situ expansion method of a sewage treatment system for improving the solid flux of the secondary sedimentation tank provided in the embodiment of the present application is based on the morphology and density differences among microbial aggregates, silt, and biomass-attached silt in the activated sludge, and adopts a two-stage separation unit (a first-stage separation unit 100 and a second-stage separation unit 200) to perform gradient separation on different solid phase components in the activated sludge, thereby adjusting the performance of the activated sludge, and further achieving precise control of the sedimentation properties of the activated sludge in the aeration tank in the biochemical treatment unit 5 and the solid load of the secondary sedimentation tank 6.

[0040] The in-situ expansion method of a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank provided in the embodiment of the present application can effectively improve the settling performance of activated sludge, increase the solid separation flux of the secondary sedimentation tank 6, increase the ability of the sewage treatment system to resist the impact of hydraulic fluctuations, and realize the in-situ expansion of the sewage treatment system.

[0041] In some exemplary embodiments, the operating parameters of the secondary settling tank include the solid load of the secondary settling tank, and the performance of the activated sludge in the aeration tank includes the settling performance of the activated sludge in the aeration tank.

[0042] Based on this, the step S104 of "according to the operating parameters of the secondary sedimentation tank and the performance of the activated sludge in the aeration tank in the biochemical treatment unit of the sewage treatment system, the activated sludge discharged from the first overflow port and the first underflow port of the first separation unit is input into the second separation chamber of the second separation unit from the second feed port of the second separation unit, so that the activated sludge is separated by spiral motion in the second separation chamber, and the activated sludge discharged from the second overflow port and the second underflow port of the second separation unit is returned to the biochemical treatment unit" includes:

[0043] Based on the fact that the settling performance of the activated sludge in the aeration tank of the biochemical treatment unit 5 is lower than the set settling performance, and the solid load of the secondary sedimentation tank 6 is not higher than the set solid load, as Figure 3 As shown, the activated sludge discharged from the first underflow port 15 of the first separation unit 100 is fed into the second separation chamber 13 of the second separation unit 200 from the second feed port 17 of the second separation unit 200 for separation, and the activated sludge discharged from the second underflow port 18 of the second separation unit 200 is returned to the biochemical treatment unit 5;

[0044] Based on the fact that the solid load in the secondary sedimentation tank 6 is higher than the set solid load, and the sedimentation performance of the activated sludge in the aeration tank in the biochemical treatment unit 5 is not lower than the set sedimentation performance, as Figure 5 As shown, the activated sludge discharged from the first overflow port 16 of the first separation unit 100 is fed into the second separation chamber 13 of the second separation unit 200 from the second feed port 17 of the second separation unit 200 for separation, and the activated sludge discharged from the second overflow port 19 of the second separation unit 200 is returned to the biochemical treatment unit 5;

[0045] When the settling performance of the activated sludge in the aeration tank of the biochemical treatment unit 5 is lower than the set settling performance and the solid load of the secondary sedimentation tank 6 is higher than the set solid load, Figure 5 As shown, the activated sludge discharged from the first overflow port 16 of the first-stage separation unit 100 is input into the second separation chamber 13 of the second-stage separation unit 200 from the second feed port 17 of the second-stage separation unit 200 for separation, and the activated sludge discharged from the second underflow port 18 of the second-stage separation unit 200 is returned to the biochemical treatment unit 5.

[0046] When the sedimentation performance of the activated sludge in the aeration tank of the biochemical treatment unit 5 is poor (lower than the set sedimentation performance), but the solid load of the secondary sedimentation tank 6 is not higher than the set solid load, the underflow sludge discharged from the first underflow port 15 of the first-stage separation unit 100 can be used as the feed sludge of the second-stage separation unit 200, and the underflow sludge discharged from the second underflow port 18 of the second-stage separation unit 200 is returned to the biochemical treatment unit 5 to provide fine sand (coagulation nuclei) for the biochemical treatment unit 5 to improve the sedimentation performance of the activated sludge and improve the solid-liquid separation capacity of the secondary sedimentation tank 6. The overflow sludge discharged from the first overflow port 16 of the first-stage separation unit 100 and the second overflow port 19 of the second-stage separation unit 200 can be discharged to the sludge thickening tank.

[0047] When the solid load of the secondary sedimentation tank 6 is high (higher than the set solid load), but the sedimentation performance of the activated sludge in the aeration tank of the biochemical treatment unit 5 is not lower than the set sedimentation performance, the overflow sludge discharged from the first overflow port 16 of the first-stage separation unit 100 is used as the feed sludge of the second-stage separation unit 200, and the overflow sludge discharged from the second overflow port 19 of the second-stage separation unit 200 is returned to the biochemical treatment unit 5 to increase the ratio of mixed liquor volatile suspended solids (MLVSS) to mixed liquid suspended solids (MLSS), increase the microbial share of the activated sludge, reduce the sludge concentration of the biochemical treatment unit 5, and further reduce the solid load of the secondary sedimentation tank 6. The underflow sludge discharged from the first underflow port 15 of the first-stage separation unit 100 and the second underflow port 18 of the second-stage separation unit 200 are both discharged to the sludge thickening tank.

[0048] When the settling property of the activated sludge in the aeration tank of the biochemical treatment unit 5 is poor and the solid load of the secondary sedimentation tank 6 is high, the overflow sludge discharged from the first overflow port 16 of the first-stage separation unit 100 is used as the feed sludge of the second-stage separation unit 200, and the underflow sludge discharged from the second underflow port 18 of the second-stage separation unit 200 is returned to the biochemical treatment unit 5 to increase MLVSS / MLSS, reduce the solid load, and improve the settling property of the activated sludge. The underflow sludge discharged from the first underflow port 15 of the first-stage separation unit 100 and the second overflow port 19 of the second-stage separation unit 200 is discharged to the sludge thickening tank.

[0049] The method of the embodiment of the present application is based on the morphology and density differences among microbial aggregates, silt, and biomass-attached silt in activated sludge, and adopts a two-stage separation unit to perform gradient graded separation of different solid phase components of the sludge, thereby achieving precise regulation of the settling properties of the activated sludge in the aeration tank in the biochemical treatment unit 5 and the solid load of the secondary sedimentation tank 6; the method of the embodiment of the present application can effectively improve the settling properties of the activated sludge, enhance the solid separation flux of the secondary sedimentation tank 6, increase the ability of the sewage treatment system to resist the impact of hydraulic fluctuations, and achieve in-situ expansion of the sewage treatment system.

[0050] In some exemplary embodiments, the method for in-situ expansion of a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank further includes:

[0051] The other sludge discharged from the first overflow port and the first underflow port of the first-stage separation unit is transported to the sludge thickening tank, and the other sludge discharged from the second overflow port and the second underflow port of the second-stage separation unit is transported to the sludge thickening tank.

[0052] The other sludge discharged from the first underflow port 15 and the first overflow port 16 of the first-stage separation unit 100 is transported to the sludge thickening tank of the sewage treatment system, and the other sludge discharged from the second underflow port 18 and the second overflow port 19 of the second-stage separation unit 200 is transported to the sludge thickening tank of the sewage treatment system to reduce the volume of the sludge, thereby reducing the subsequent treatment cost of the sludge and the impact on the environment.

[0053] In some exemplary embodiments, the pressure of the activated sludge input into the first feed port 14 of the first-stage separation unit 100 is 0.2 MPa to 0.5 MPa, such as 0.3 MPa.

[0054] The pressure of the activated sludge input into the first-stage separation unit 100 is between 0.2 MPa and 0.5 MPa. The two-stage separation unit can achieve efficient and effective treatment of the activated sludge, so as to improve the performance of the activated sludge after treatment by the two-stage separation unit.

[0055] In some exemplary embodiments, the concentration of the activated sludge input into the first feed port 14 of the first-stage separation unit 100 is in a range of 2.0 g / L to 50.0 g / L.

[0056] Of course, the pressure and concentration range of the activated sludge input into the first-stage separation unit 100 are not limited to the above ranges, and can also be adjusted according to actual needs.

[0057] like Figure 2-Figure 5 As shown, the embodiment of the present application also provides an in-situ expansion device 300 for a sewage treatment system for improving the solid separation flux of a secondary sedimentation tank, including a first-stage separation unit 100 and a second-stage separation unit 200.

[0058] The first-stage separation unit 100 has a first separation chamber 12, and a first feed port 14, a first underflow port 15 and a first overflow port 16 connected to the first separation chamber 12. The first feed port 14 is configured to be connected to the secondary sedimentation tank 6 of the sewage treatment system. The first-stage separation unit 100 is configured to separate the activated sludge input into the first separation chamber 12 from the first feed port 14 through spiral motion.

[0059] The second-stage separation unit 200 has a second separation chamber 13, and a second feed port 17, a second underflow port 18 and a second overflow port 19 connected to the second separation chamber 13, and one of the first overflow port 16 and the first underflow port 15 is connected to the second feed port 17. The second-stage separation unit 200 is configured to separate the activated sludge input into the second separation chamber 13 from the second feed port 17 through spiral motion, and one of the second overflow port 19 and the second underflow port 18 is configured to be connected to the biochemical treatment unit 5 of the sewage treatment system.

[0060] In the in-situ expansion device 300 of the sewage treatment system, the first overflow port 16 or the first underflow port 15 of the first separation unit 100 can be connected to the second feed port 17 of the second separation unit 200, so that the first separation unit 100 and the second separation unit 200 are connected in series.

[0061] When the in-situ expansion device 300 of the sewage treatment system is working, the activated sludge in the secondary sedimentation tank 6 can be input into the first separation chamber 12 of the first-stage separation unit 100 from the first feed port 14, and the activated sludge can perform spiral motion in the first separation chamber 12 to separate the activated sludge and discharge it from the first underflow port 15 and the first overflow port 16 respectively.

[0062] like Figure 3 As shown, the activated sludge discharged from the first underflow port 15 can be fed into the second separation chamber 13 of the second separation unit 200 from the second feed port 17, and can perform spiral motion in the second separation chamber 13 to separate the activated sludge and discharge it from the second overflow port 19 and the second underflow port 18 respectively. Figure 5 As shown, the activated sludge discharged from the first overflow port 16 can be input into the second separation chamber 13 of the second-stage separation unit 200 from the second feed port 17, and can perform spiral motion in the second separation chamber 13 to separate the activated sludge and then discharge it from the second overflow port 19 and the second underflow port 18 respectively.

[0063] The activated sludge discharged from the second overflow port 19 and the second underflow port 18 has different performance parameters. According to the parameters of the secondary sedimentation tank 6 and the performance of the activated sludge in the aeration tank in the biochemical treatment unit 5, the activated sludge discharged from the second overflow port 19 or the second underflow port 18 of the second-stage separation unit 200 can be returned to the biochemical treatment unit 5 to improve the settling performance of the activated sludge in the aeration tank in the biochemical treatment unit 5, improve the solid separation flux of the secondary sedimentation tank 6, increase the ability of the sewage treatment system to resist the impact of hydraulic fluctuations, and realize the in-situ expansion of the sewage treatment system.

[0064] In some exemplary embodiments, Figure 2-Figure 5 As shown, the in-situ expansion device 300 for the sewage treatment system further includes: an outer cylinder 1, a first inner cone 2 and a second inner cone 3.

[0065] A partition is provided inside the outer cylinder 1 to separate the space inside the outer cylinder 1 into a first separation chamber 12 and a second separation chamber 13. The outer cylinder 1 may be a cylindrical cylinder. Of course, the outer cylinder 1 may also be a non-cylindrical cylinder.

[0066] The first inner cone 2 is disposed in the first separation chamber 12 , with the small end of the first inner cone 2 facing the side where the first feed port 14 and the first overflow port 16 are located, and the first underflow port 15 is close to the large end of the first inner cone 2 .

[0067] The second inner cone 3 is disposed in the second separation chamber 13 , with the small end of the second inner cone 3 facing the side where the second feed port 17 and the second overflow port 19 are located, and the second underflow port 18 is close to the large end of the second inner cone 3 .

[0068] like Figure 2-Figure 5 As shown, when the in-situ expansion device 300 of the sewage treatment system is working, the activated sludge enters the first separation chamber 12 from the first feed port 14 and performs spiral motion. The activated sludge rotates in the first separation chamber 12 to generate a spiral flow. Under the action of the first inner cone 2, the spiral flow is divided into two parts. One part of the spiral flow (such as Figure 3 and Figure 5 The outer spiral flow (shown as M1 in FIG. 1 ) moves toward the first bottom flow port 15 and is discharged from the first bottom flow port 15. The other part of the spiral flow (shown as M1 in FIG. 1 ) moves toward the first bottom flow port 15 and is discharged from the first bottom flow port 15. Figure 3 and Figure 5 The inner spiral flow M2 in the first separation chamber 12 flows toward the first overflow port 16 and is discharged from the first overflow port 16. In the first separation chamber 12, there are both the outer spiral flow M1 and the inner spiral flow M2 to achieve separation of the activated sludge.

[0069] like Figure 2 and Figure 3As shown, after the first stage separation of the first stage separation unit 100, the activated sludge discharged from the first underflow port 15 enters the second separation chamber 13 through the second feed port 17 and performs spiral motion. The activated sludge rotates in the second separation chamber 13 to generate a spiral flow. Under the action of the second inner cone 3, the spiral flow is divided into two parts. One part of the spiral flow (such as Figure 3 The outer spiral flow (shown as M3 in FIG. 1 ) moves toward the second bottom flow port 18 and is discharged from the second bottom flow port 18, and the other part of the spiral flow (shown as M3 in FIG. 1 ) moves toward the second bottom flow port 18 and is discharged from the second bottom flow port 18. Figure 3 The inner spiral flow M4 shown in FIG. 1 moves toward the second overflow port 19 and is discharged from the second overflow port 19. In the second separation chamber 13, there are both the outer spiral flow M3 and the inner spiral flow M4 to achieve the re-separation of the activated sludge.

[0070] Or, if Figure 4 and Figure 5 As shown, after the primary separation of the first-stage separation unit 100, the activated sludge discharged from the first overflow port 16 enters the second separation chamber 13 through the second feed port 17 and performs spiral motion. The activated sludge rotates in the second separation chamber 13 to generate a spiral flow. Under the action of the second inner cone 3, the spiral flow is divided into two parts. One part of the spiral flow (such as Figure 5 The outer spiral flow (shown as M3 in FIG. 1 ) moves toward the second bottom flow port 18 and is discharged from the second bottom flow port 18, and the other part of the spiral flow (shown as M3 in FIG. 1 ) moves toward the second bottom flow port 18 and is discharged from the second bottom flow port 18. Figure 5 The inner spiral flow M4 shown in FIG. 1 moves toward the second overflow port 19 and is discharged from the second overflow port 19. In the second separation chamber 13, there are both the outer spiral flow M3 and the inner spiral flow M4 to achieve the re-separation of the activated sludge.

[0071] After two-stage separation in the first-stage separation unit 100 and the second-stage separation unit 200, the activated sludge discharged from the second underflow port 18 or the second overflow port 19 of the second-stage separation unit 200 can flow back into the biochemical treatment unit 5 as needed.

[0072] In some embodiments, such as Figure 2 and Figure 3 As shown, the separator includes a spiral body 4, which includes a cylindrical portion 41 and a spiral blade 42. The spiral blade 42 is arranged between the outer wall of the cylindrical portion 41 and the inner wall of the outer cylinder 1 to form a spiral flow channel 43. The inlet of the spiral flow channel 43 is connected to the first bottom flow port 15, and the outlet of the spiral flow channel 43 is connected to the second feed port 17.

[0073] The partition inside the outer cylinder 1 includes a spiral body 4, and an annular cavity is provided between the cylindrical portion 41 of the spiral body 4 and the inner wall of the outer cylinder 1. The annular cavity is divided into a spiral flow channel 43 by spiral blades 42, and the inlet of the spiral flow channel 43 is connected to the first bottom flow port 15, and the outlet of the spiral flow channel 43 is connected to the second feed port 17, so that the activated sludge discharged from the first bottom flow port 15 first enters the spiral flow channel 43 to perform spiral motion, and then enters the second separation chamber 13 from the second feed port 17, so that the activated sludge can be spirally separated in the second separation chamber 13.

[0074] In some embodiments, Figure 2 and Figure 3 As shown, the cylindrical portion 41 is provided with a first connecting cavity 411, the first inner cone 2 includes a first conical section 21, the cylindrical portion 41 is provided at the large end of the first conical section 21, the first conical section 21 is provided with a second connecting cavity 211, the outer cylinder 1 is provided with a discharge port 110, the second overflow port 19 is provided at one end of the cylindrical portion 41 away from the first inner cone 2, and the second overflow port 19, the first connecting cavity 411, the second connecting cavity 211 and the discharge port 110 are sequentially connected. Among them, the first conical section 21 and the second connecting cavity 211 therein can be conical, and the cylindrical portion 41 and the first connecting cavity 411 therein can be cylindrical.

[0075] The cylindrical portion 41 of the spiral body 4 is arranged at the large head end of the first conical section 21 of the first inner cone 2, and the cylindrical portion 41 and the first conical section 21 are respectively provided with a first connecting cavity 411 and a second connecting cavity 211, and the second overflow port 19 is arranged on the cylindrical portion 41 of the spiral body 4, and the second overflow port 19 can be connected with the discharge port 110 on the outer cylinder 1 through the first connecting cavity 411 and the second connecting cavity 211, so that the sludge overflowing from the second overflow port 19 passes through the first connecting cavity 411 and the second connecting cavity 211 and is discharged from the discharge port 110.

[0076] In some embodiments, Figure 2 and Figure 3 As shown, the first overflow port 16 and the discharge port 110 are both arranged on the first end wall 11 of the outer cylinder 1 opposite to the small end of the first conical section 21, and the first overflow port 16 surrounds the outside of the discharge port 110. The first end wall 11 may be the upper end wall of the outer cylinder 1, and the small end of the first conical section 21 faces upward.

[0077] The first overflow port 16 surrounds the outside of the discharge port 110 and is arranged compactly, which is beneficial to reducing the size of the first end wall 11 and is convenient for discharging the sludge discharged from the first overflow port 16 and the second overflow port 19 into the sludge thickening tank together when the solid load of the secondary sedimentation tank 6 is high but the sedimentation performance of the activated sludge in the aeration tank in the biochemical treatment unit 5 is not lower than the set sedimentation performance.

[0078] Of course, the discharge port 110 and the first overflow port 16 surrounding the outside thereof can also be connected to different pipelines to discharge the sludge discharged from the first overflow port 16 and the second overflow port 19 into the sludge thickening tank and the biochemical treatment unit 5 respectively.

[0079] In some embodiments, Figure 2 and Figure 3 As shown, the second inner cone 3 includes a second conical section 31 and a second cylindrical section 32, the small end of the second conical section 31 faces the partition, one end of the second cylindrical section 32 is connected to the large end of the second conical section 31, and the other end of the second cylindrical section 32 is connected to the second end wall 111 of the outer cylinder 1, and the second end wall 111 of the outer cylinder 1 is arranged opposite to the first end wall 11. Among them, the second conical section 31 can be conical, and the second cylindrical section 32 can be cylindrical.

[0080] The first feed port 14 and the second underflow port 18 are both arranged on the side wall of the outer cylinder 1 , and the first feed port 14 is close to the first end wall 11 of the outer cylinder 1 , and the second underflow port 18 is close to the second end wall 111 of the outer cylinder 1 .

[0081] In the in-situ expansion device 300 of the sewage treatment system, the first inner cone 2, the partition and the second inner cone 3 can be arranged in sequence from top to bottom, and the small heads of the first inner cone 2 and the second inner cone 3 are both facing upward, the first feed port 14 can be located at the upper part of the side wall of the outer cylinder 1, the first overflow port 16 and the discharge port 110 are both arranged on the upper end wall (first end wall 11) of the outer cylinder 1, and the second bottom flow port 18 can be located at the lower part of the side wall of the outer cylinder 1, and close to the second end wall 111 of the outer cylinder 1 (the second end wall 111 can be the lower end wall).

[0082] The in-situ expansion device 300 of the sewage treatment system has the advantages of simple and compact structure, small footprint, high screening efficiency, low operation and maintenance costs, and no need to add chemicals, thus realizing low-consumption and high-efficiency secondary sedimentation tank 6 operation efficiency enhancement technology.

[0083] In some embodiments, Figure 2 As shown, the size of the sewage treatment system in-situ expansion device 300 satisfies at least one of the following:

[0084] The inner diameter D of the outer cylinder 1 is: 50mm≤D≤250mm;

[0085] The diameter d of the first feed port 14 is: d≤0.25D;

[0086] The diameter O of the first overflow port 16 1 For: 1 ≤0.25D, diameter O of the second overflow port 19 2 For: 2 ≤0.25D;

[0087] One end of the first overflow port 16 extends into the first separation chamber 12, and the length l of the first overflow port 16 extending into the first separation chamber 12 1 =0.4D≤l 1 ≤0.8D, one end of the second overflow port 19 extends into the second separation chamber 13, and the length l extending into the second separation chamber 13 2 =0.4D≤l 2 ≤0.8D;

[0088] The diameter U of the second underflow port 18 2 For: U 2 ≤0.15D;

[0089] The diameter F of the discharge port 110 is: F ≥ O 2 ;

[0090] The distance L between the first end wall 11 of the outer cylinder 1 and the large end of the first conical section 21 is 1 3.0D≤L 1 ≤6.0D, the distance L between the partition and the large end of the second tapered section 31 2 3.0D≤L 2 ≤6.0D;

[0091] The diameter D of the large end of the first tapered section 21 1 For: D 1 ≤0.80D, the diameter D of the large end of the second tapered section 31 2 For: D 2 ≤0.80D;

[0092] The height h of the first tapered section 21 1 =2.0D≤h 1 ≤3.5D, height h of the second tapered section 31 2 =2.0D≤h 2 ≤3.5D, height G of the second cylindrical section 32 2 =0.5D 2 ≤G 2 ≤1.5D 2 ;

[0093] The cone angle θ of the first cone section 21 1 =16°≤θ 1 ≤24°, the cone angle θ of the second cone section 31 2 =16°≤θ 2 ≤24°;

[0094] The number of turns of the spiral blade 42 is: 2-6;

[0095] The helical angle β of the helical blade 42 is: 0°≤β≤30°;

[0096] The outer diameter of the cylindrical portion 41 is set to be equal to the diameter D of the large end of the first conical section 21. 1 equal.

[0097] Of course, the dimensions of the sewage treatment system in-situ expansion device 300 are not limited to the above ranges and can be adjusted according to actual needs.

[0098] It should be understood that the above-mentioned "diameter" may refer to the diameter when the components, structures, etc. are cylindrical or circular, or may refer to the equivalent diameter when the components, structures, etc. are non-cylindrical or non-circular.

[0099] In other embodiments, Figure 4 and Figure 5 As shown, the separator includes a spiral body 4, which includes a cylindrical portion 41 and a spiral blade 42. The spiral blade 42 is arranged between the outer wall of the cylindrical portion 41 and the inner wall of the outer cylinder 1 to form a spiral flow channel 43. The inlet of the spiral flow channel 43 is connected to the first overflow port 16, and the outlet of the spiral flow channel 43 is connected to the second feed port 17.

[0100] The partition inside the outer cylinder 1 includes a spiral body 4, and an annular cavity is provided between the cylindrical portion 41 of the spiral body 4 and the inner wall of the outer cylinder 1. The annular cavity is divided into a spiral flow channel 43 by spiral blades 42, and the inlet of the spiral flow channel 43 is connected to the first overflow port 16, and the outlet of the spiral flow channel 43 is connected to the second feed port 17, so that the activated sludge discharged from the first overflow port 16 first enters the spiral flow channel 43 to perform spiral motion, and then enters the second separation chamber 13 from the second feed port 17, so that the activated sludge can be spirally separated in the second separation chamber 13.

[0101] In other embodiments, Figure 4 and Figure 5 As shown, a first communication cavity 411 is provided in the cylindrical portion 41 , a discharge port 110 is provided in the outer cylinder 1 , a second overflow port 19 is provided in the cylindrical portion 41 , and the second overflow port 19 is connected to the discharge port 110 through the first communication cavity 411 .

[0102] A first connecting cavity 411 is provided in the cylindrical portion 41 of the spiral body 4, and the second overflow port 19 can be connected with the discharge port 110 on the outer cylinder 1 through the first connecting cavity 411, so that the sludge overflowing from the second overflow port 19 can be discharged from the discharge port 110 after passing through the first connecting cavity 411.

[0103] In other embodiments, Figure 4 and Figure 5As shown, the first inner cone 2 includes a first conical section 21 and a first cylindrical section 22, the small end of the first conical section 21 faces the partition, one end of the first cylindrical section 22 is connected to the large end of the first conical section 21, and the other end of the first cylindrical section 22 is connected to the second end wall 111 of the outer cylinder 1; the second inner cone 3 includes a second conical section 31 and a second cylindrical section 32, the small end of the second conical section 31 faces the partition, one end of the second cylindrical section 32 is connected to the large end of the second conical section 31, and the other end of the second cylindrical section 32 is connected to the first end wall 11 of the outer cylinder 1, and the first end wall 11 and the second end wall 111 of the outer cylinder 1 are arranged opposite to each other. Among them, the first conical section 21 and the second conical section 31 can be conical, the first cylindrical section 22 and the second cylindrical section 32 can be cylindrical; the first end wall 11 and the second end wall 111 of the outer cylinder 1 can be the upper end wall and the lower end wall, respectively.

[0104] The first feed port 14 , the first bottom flow port 15 and the second bottom flow port 18 are all arranged on the side wall of the outer cylinder 1 , and the first feed port 14 and the discharge port 110 are both close to the partition and arranged opposite to each other, the first bottom flow port 15 is close to the second end wall 111 of the outer cylinder 1 , and the second bottom flow port 18 is close to the first end wall 11 of the outer cylinder 1 .

[0105] In the in-situ expansion device 300 of the sewage treatment system, the second inner cone 3, the partition and the first inner cone 2 can be arranged in sequence from top to bottom, and the small end of the first inner cone 2 faces upward, the small end of the second inner cone 3 faces downward, and the small ends of the first inner cone 2 and the second inner cone 3 are both facing the partition wall, so that the first inner cone 2 and the second inner cone 3 can be basically arranged symmetrically. The first feed port 14 and the discharge port 110 can be located in the middle of the side wall of the outer cylinder 1 and are arranged oppositely; the first underflow port 15 can be located at the lower part of the side wall of the outer cylinder 1 and close to the lower end wall (second end wall 111) of the outer cylinder 1; the second underflow port 18 can be located at the upper part of the side wall of the outer cylinder 1 and close to the upper end wall (first end wall 11) of the outer cylinder 1.

[0106] The sewage treatment system in-situ expansion device 300 has a simple and compact structure, a small size and a low cost.

[0107] In other embodiments, Figure 4 As shown, the size of the sewage treatment system in-situ expansion device 300 satisfies at least one of the following:

[0108] The inner diameter D of the outer cylinder 1 is: 50mm≤D≤250mm;

[0109] The diameter d of the first feed port 14 is: d≤0.25D;

[0110] The diameter O of the first overflow port 16 1 For: 1 ≤0.25D, diameter O of the second overflow port 192 For: 2 ≤0.25D;

[0111] One end of the first overflow port 16 extends into the first separation chamber 12, and the length l of the first overflow port 16 extending into the first separation chamber 12 1 =0.4D≤l 1 ≤0.8D, one end of the second overflow port 19 extends into the second separation chamber 13, and the length l extending into the second separation chamber 13 2 =0.4D≤l 2 ≤0.8D;

[0112] Diameter U of the first bottom flow port 15 1 For: U 1 ≤0.15D, diameter U of the second underflow port 18 2 For: U 2 ≤0.15D;

[0113] The diameter F of the discharge port 110 is: F ≥ O 2 ;

[0114] The distance L between the partition and the large end of the first tapered section 21 1 3.0D≤L 1 ≤6.0D, the distance L between the partition and the large end of the second tapered section 31 2 3.0D≤L 2 ≤6.0D;

[0115] The diameter D of the large end of the first tapered section 21 1 For: D 1 ≤0.80D, the diameter D of the large end of the second tapered section 31 2 For: D 2 ≤0.80D;

[0116] The height h of the first tapered section 21 1 =2.0D≤h 1 ≤3.5D, height h of the second tapered section 31 2 =2.0D≤h 2 ≤3.5D;

[0117] The cone angle θ of the first cone section 21 1 The cone angle θ of the second cone section 31 is: 16°≤θ1≤24°. 2 16°≤θ2≤24°;

[0118] The height G of the first cylindrical section 22 1 =0.5D 1 ≤G 1 ≤1.5D 1, the height G of the second cylindrical section 32 2 =0.5D 2 ≤G 2 ≤1.5D 2 ;

[0119] The number of turns of the spiral blade 42 is: 2-6;

[0120] The helical angle β of the helical blade 42 is: 0°≤β≤30°;

[0121] The outer diameter N of the columnar portion 41 is: N≦0.80D.

[0122] Of course, the dimensions of the sewage treatment system in-situ expansion device 300 are not limited to the above ranges and can be adjusted according to actual needs.

[0123] It should be understood that the above-mentioned "diameter" may refer to the diameter when the components, structures, etc. are cylindrical or circular, or may refer to the equivalent diameter when the components, structures, etc. are non-cylindrical or non-circular.

[0124] In some exemplary embodiments, Figure 2-Figure 5 As shown, the first feed port 14 is arranged tangentially to the first separation chamber 12 so that the activated sludge forms a spiral motion in the first separation chamber 12 to achieve separation of the activated sludge.

[0125] Of course, the first feed port 14 and the first separation chamber 12 may also be arranged to be non-tangential, and the spiral movement of the activated sludge in the first separation chamber 12 is achieved by arranging a spiral flow channel in the first separation chamber 12 (such as: similar to the spiral flow channel 43 in the second separation chamber 13).

[0126] In some exemplary embodiments, Figure 2 and Figure 3 As shown, the second underflow port 18 can be arranged tangentially to the second separation chamber 13, and the axes of the first overflow port 16 and the discharge port 110 can coincide, that is, the first overflow port 16 and the discharge port 110 can be arranged coaxially; or, as Figure 4 and Figure 5 As shown, the first underflow port 15 and the second underflow port 18 may be arranged tangentially to the first separation chamber 12 and the second separation chamber 13 respectively.

[0127] In some exemplary embodiments, the in-situ expansion device 300 for the sewage treatment system further includes a delivery pump (not shown), the outlet of the delivery pump is connected to the first feed port 14, and the delivery pump is configured to make the pressure of the activated sludge input into the first feed port 14 be 0.2 MPa to 0.5 MPa. The delivery pump device for applying working pressure to the activated sludge may be a mechanical device for conveying fluids, such as a submersible pump and a rotor pump.

[0128] In some exemplary embodiments, each outlet (e.g. Figure 2 and Figure 3 The first overflow port 16, the second underflow port 18 and the discharge port 110, or as Figure 4 and Figure 5 The first underflow port 15, the second underflow port 18 and the discharge port 110 are all equipped with electric valves to adjust the sludge discharge flow rate.

[0129] In some exemplary embodiments, the material of the sewage treatment system in-situ expansion device 300 is cast iron or stainless steel. Of course, according to actual conditions, the sewage treatment system in-situ expansion device 300 can also be made of other materials.

[0130] In some exemplary embodiments, the axis of the outer cylinder 1 may be perpendicular to the horizontal plane to achieve the normal installation of the in-situ expansion device 300 for the sewage treatment system, such as Figure 2-Figure 5 As shown; or, the axis of the outer cylinder 1 is inclined relative to the horizontal plane to achieve oblique installation of the in-situ expansion device 300 for the sewage treatment system; or, the axis of the outer cylinder 1 is parallel to the horizontal plane to achieve flat installation of the in-situ expansion device 300 for the sewage treatment system.

[0131] like Figure 6 and Figure 7 As shown, an embodiment of the present application also provides a sewage treatment system, including a biochemical treatment unit 5, a secondary sedimentation tank 6 and an in-situ expansion device 300 for a sewage treatment system for improving the solid flux separated by the secondary sedimentation tank according to any of the above embodiments, and the first feed port 14 of the in-situ expansion device 300 of the sewage treatment system is connected to the secondary sedimentation tank 6, and the second underflow port 18 and one of the second overflow port 19 of the in-situ expansion device 300 of the sewage treatment system are connected to the biochemical treatment unit 5.

[0132] The sewage treatment system of the embodiment of the present application can utilize the sewage treatment system in-situ expansion device 300 to effectively improve the sedimentation performance of the activated sludge in the aeration tank in the biochemical treatment unit 5, increase the solid separation flux of the secondary sedimentation tank 6, increase the sewage treatment system's ability to resist hydraulic fluctuations, and realize in-situ expansion of the sewage treatment system.

[0133] In some embodiments, such as Figure 6 As shown, the sewage treatment system is a system adopting an anaerobic-anoxic-aerobic activated sludge method, in which an anaerobic zone 51, a first anoxic zone 52 and a first aerobic zone 53 are sequentially arranged in the biochemical treatment unit 5, and one of the second underflow port 18 and the second overflow port 19 of the sewage treatment system in-situ expansion device 300 is connected to the anaerobic zone 51.

[0134] like Figure 6As shown, the sewage treatment system further includes a primary sedimentation tank 8, the primary sedimentation tank 8, the biochemical treatment unit 5 and the secondary sedimentation tank 6 are sequentially connected, the biochemical treatment unit 5 is sequentially provided with an anaerobic zone 51, a first anoxic zone 52 and a first aerobic zone 53, a first internal return pipeline 71 may be provided between the first aerobic zone 53 and the first anoxic zone 52, and an external return pipeline 73 may be provided between the secondary sedimentation tank 6 and the anaerobic zone 51. The sewage treatment system in-situ expansion device 300 may be provided in the external return pipeline 73.

[0135] In some other exemplary embodiments, Figure 7 As shown, the sewage treatment system is a system adopting a two-stage anoxic-aerobic activated sludge method, in which a first anoxic zone 52, a first aerobic zone 53, a second anoxic zone 54 and a second aerobic zone 55 are sequentially arranged in the biochemical treatment unit 5, and one of the second underflow port 18 and the second overflow port 19 of the in-situ expansion device 300 of the sewage treatment system is connected to the first anoxic zone 52.

[0136] like Figure 7 As shown, the sewage treatment system also includes a primary sedimentation tank 8, the primary sedimentation tank 8, the biochemical treatment unit 5 and the secondary sedimentation tank 6 are connected in sequence, and the first anoxic zone 52, the first aerobic zone 53, the second anoxic zone 54 and the second aerobic zone 55 are sequentially arranged in the biochemical treatment unit 5. A first internal return pipeline 71 may be arranged between the first aerobic zone 53 and the first anoxic zone 52, a second internal return pipeline 72 may be arranged between the second aerobic zone 55 and the second anoxic zone 54, an external return pipeline 73 may be arranged between the secondary sedimentation tank 6 and the first anoxic zone 52, and the sewage treatment system in-situ expansion device 300 may be arranged on the external return pipeline 73.

[0137] The in-situ expansion device 300 of the sewage treatment system of the embodiment of the present application has good universality and can be applied to the secondary sedimentation tank 6 of the existing urban sewage treatment system, such as: it can be applied to the system using biochemical treatment processes such as the anaerobic-anoxic-aerobic activated sludge method and the two-stage anoxic-aerobic activated sludge method, and can improve the operating efficiency of the secondary sedimentation tank 6.

[0138] In some exemplary embodiments, a plurality of in-situ expansion devices 300 for the sewage treatment system are provided, and the plurality of in-situ expansion devices 300 for the sewage treatment system are connected in parallel.

[0139] According to the processing capacity of activated sludge, multiple in-situ expansion devices 300 of the sewage treatment system can be operated in parallel to increase the processing capacity of activated sludge, thereby improving the sewage treatment performance of the sewage treatment system.

[0140] In some exemplary embodiments, the operating time and frequency of the in-situ expansion device 300 of the sewage treatment system can be adjusted in conjunction with the parameters of the sewage treatment system.

[0141] In some exemplary embodiments, the sewage treatment system may further include a detection device (not shown in the figure), which is configured to detect the operating parameters of the secondary sedimentation tank 6 (e.g., the solid load of the secondary sedimentation tank) and the performance of the activated sludge in the aeration tank in the biochemical treatment unit 5 (e.g., the settling performance of the activated sludge in the aeration tank). According to the detection results of the detection device, one of the first underflow port 15 and the first overflow port 16 of the sewage treatment system in-situ expansion device 300 may be connected to the second feed port 17, and one of the second underflow port 18 and the second overflow port 19 of the sewage treatment system in-situ expansion device 300 may be connected to the biochemical treatment unit 5.

[0142] The following three specific embodiments are used to illustrate the effect of the in-situ expansion method and device of the sewage treatment system of the present application for improving the solid separation flux of the secondary sedimentation tank.

[0143] Embodiment 1:

[0144] like Figure 2 and Figure 3 As shown, this embodiment provides an in-situ expansion method and device for a sewage treatment system for increasing the solid separation flux in a secondary sedimentation tank, mainly to solve the problem of poor settling performance of activated sludge.

[0145] In this embodiment, the structural parameters of the in-situ expansion device 300 of the sewage treatment system are as follows: the inner diameter D of the outer cylinder 1 is 60 mm; the diameter d of the first feed port 14 is 15 mm; the diameter D of the large end of the first conical section 21 is 1 The diameter D of the large end of the second tapered section 31 is 48 mm. 2 The diameter O of the first overflow port 16 is 44 mm; 1 is 14 mm, and the diameter O of the second overflow port 19 is 2 The overflow discharge port 110 has a diameter F of 8 mm; the diameter U of the second bottom flow port 18 is 2 The length of the first overflow port 16 extending into the first separation chamber 12 is l 1 The length l of the second overflow port 19 extending into the second separation chamber 13 is 40 mm. 2 The length L of the first separation chamber 12 is 35 mm; 1 is 220 mm, and the length L of the second separation chamber 13 is 2 The height h of the first conical section 21 is 190 mm; 1 is 145 mm, and the height h of the second tapered section 31 is 2 The cone angle θ of the first conical section 21 is 125 mm; 1 is 16°, and the cone angle θ of the second cone section 31 is 2 The number of turns of the spiral blade 42 is 4; the helical angle β of the spiral blade 42 is 10°; the height G of the second cylindrical section 32 2It is 30mm.

[0146] In this embodiment, the pressure of the activated sludge input into the first feed port 14 of the first-stage separation unit 100 is 0.3 MPa.

[0147] In this embodiment, the sewage treatment system in-situ expansion device 300 is made of stainless steel.

[0148] In this embodiment, the installation method of the in-situ expansion device 300 of the sewage treatment system is normal installation.

[0149] In this embodiment, the concentration of activated sludge input into the first feed port 14 of the first-stage separation unit 100 is 6.5 g / L, and each discharge port of the in-situ expansion device 300 of the sewage treatment system is equipped with an electric valve. The underflow flow rate (sludge flow discharged from the first underflow port 15) / overflow flow rate (sludge flow overflowing from the first overflow port 16) of the first-stage separation unit 100 is 0.7, and the underflow flow rate (sludge flow discharged from the second underflow port 18) / overflow flow rate (sludge flow overflowing from the second overflow port 19) of the second-stage separation unit 200 is 0.5. After two-stage separation treatment, the original activated sludge (MLVSS / MLSS=65.68%, SVI (Sludge Volume Index)=137mL / g) had an MLVSS / MLSS of 68.27% and an SVI of 154mL / g in the sludge discharged into the thickening tank; the MLVSS / MLSS of the activated sludge discharged into the biochemical treatment unit 5 was 45.49% and the SVI was 106mL / g. According to the results, the SVI value of the activated sludge discharged into the biochemical treatment unit 5 is low, and the inorganic matter content of the activated sludge is high (inorganic matter can be used as coagulation nuclei), so the sedimentation performance of the activated sludge in the biochemical treatment unit 5 can be effectively improved.

[0150] Embodiment 2:

[0151] This embodiment provides an in-situ expansion method and device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank, mainly to solve the problem of high sludge solid load in the secondary sedimentation tank 6.

[0152] like Figure 4 and Figure 5 As shown, in this embodiment, the structural parameters of the in-situ expansion device 300 of the sewage treatment system are: the inner diameter D of the outer cylinder 1 is 80 mm; the diameter d of the first feed port 14 is 20 mm; the diameter D of the large end of the first conical section 21 is 1 The diameter D of the large end of the second tapered section 31 is 64 mm. 2 The diameter of the first overflow port 16 is 60 mm; 1 is 16 mm, and the diameter O of the second overflow port 19 is 2The overflow discharge port 110 has a diameter F of 20 mm; the diameter U of the first bottom flow port 15 is 1 is 8 mm, and the diameter U of the second bottom flow port 18 is 2 The length of the first overflow port 16 extending into the first separation chamber 12 is l 1 The length l of the second overflow port 19 extending into the second separation chamber 13 is 55 mm. 2 The length L of the first separation chamber 12 is 35 mm; 1 is 320 mm, and the length L of the second separation chamber 13 is 2 The height h of the first conical section 21 is 250 mm; 1 is 230 mm, and the height h of the second tapered section 31 is 2 The cone angle θ of the first conical section 21 is 170 mm; 1 is 16°, and the cone angle θ of the second cone section 31 is 2 The number of turns of the spiral blade 42 is 4; the spiral angle β of the spiral blade 42 is 10°; the outer diameter N of the cylindrical portion 41 is 64 mm; the height G of the first cylindrical section 22 1 is 40 mm, and the height G of the second cylindrical section 32 is 2 It is 35mm.

[0153] In this embodiment, the pressure of the activated sludge input into the first feed port 14 of the first-stage separation unit 100 is 0.25 MPa.

[0154] In this embodiment, the sewage treatment system in-situ expansion device 300 is made of stainless steel.

[0155] In this embodiment, the installation method of the in-situ expansion device 300 of the sewage treatment system is normal installation.

[0156] In this embodiment, the concentration of the activated sludge input into the first feed port 14 of the first separation unit 100 is 10.3 g / L, each discharge port of the sewage treatment system in-situ expansion device 300 is equipped with an electric valve, the underflow flow / overflow flow of the first separation unit 100 is 0.2, and the underflow flow / overflow flow of the second separation unit 200 is 0.2. After the original activated sludge (MLVSS / MLSS=38.28%) is treated by two-stage separation, the MLVSS / MLSS of the sludge discharged into the thickening tank is 31.22%; the MLVSS / MLSS of the activated sludge discharged into the biochemical treatment unit 5 is 43.71%. According to the results, the MLVSS / MLSS value of the activated sludge discharged into the biochemical treatment unit 5 is high, and the MLVSS / MLSS value of the sludge discharged into the thickening tank is low, so it can ensure that the concentration of the activated sludge is reduced under the same microbial content in the biochemical treatment unit 5, and then gradually reduce the sludge solid load of the secondary sedimentation tank 6.

[0157] Embodiment three:

[0158] This embodiment provides an in-situ expansion method and device for a sewage treatment system for improving the solid separation flux of a secondary sedimentation tank, which mainly solves the problem of poor settling performance of activated sludge and high solid load of the secondary sedimentation tank 6.

[0159] like Figure 4 and Figure 5 As shown, in this embodiment, the angle β of the spiral flow channel 43 of the in-situ expansion device 300 of the sewage treatment system is 8°, and other structural parameters of the in-situ expansion device 300 of the sewage treatment system are consistent with those in the second embodiment.

[0160] In this embodiment, the pressure of the activated sludge input into the first feed port 14 of the first-stage separation unit 100 is 0.4 MPa.

[0161] In this embodiment, the sewage treatment system in-situ expansion device 300 is made of stainless steel.

[0162] In this embodiment, the installation method of the in-situ expansion device 300 of the sewage treatment system is normal installation.

[0163] In this embodiment, the concentration of the activated sludge input into the first feed port 14 of the first separation unit 100 is 8.4g / L, each discharge port of the sewage treatment system in-situ expansion device 300 is equipped with an electric valve, the underflow flow / overflow flow of the first separation unit 100 is 0.08, and the underflow flow / overflow flow of the second separation unit 200 is 0.5. Among them, the first separation unit 100 mainly removes inorganic sand particles in the activated sludge, and the second separation unit 200 mainly selects to enrich the activated sludge with high organic matter content and low SVI. After the original activated sludge (MLVSS / MLSS=45.16%, SVI=128mL / g) is treated by two-stage separation, the MLVSS / MLSS of the sludge discharged into the thickening tank is 40.53%, and the SVI is 136mL / g; the MLVSS / MLSS of the activated sludge discharged into the biochemical treatment unit 5 is 47.01%, and the SVI is 109mL / g. According to the results, the SVI value of the activated sludge discharged into the biochemical treatment unit 5 is low, and the organic matter content of the activated sludge is high (high microbial content), so the sedimentation performance of the activated sludge can be gradually improved and the solid load of the secondary sedimentation tank 6 can be reduced.

[0164] In the description of the present application, it should be understood that the terms "length", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 a limitation on the present application.

[0165] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0166] In the description of the present application, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0167] In this application, unless otherwise clearly specified and limited, the terms "installation", "connection" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0168] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0169] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0170] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for in-situ expansion of a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank, characterized in that: include: The activated sludge in the secondary sedimentation tank of the sewage treatment system is fed into the first separation chamber of the first separation unit from the first feed port of the first separation unit, so that the activated sludge is separated by spiral motion in the first separation chamber; According to the operating parameters of the secondary sedimentation tank and the performance of the activated sludge in the aeration tank in the biochemical treatment unit of the sewage treatment system, the activated sludge discharged from one of the first overflow port and the first underflow port of the first-stage separation unit is input into the second separation chamber of the second-stage separation unit from the second feed port of the second-stage separation unit, so that the activated sludge is separated by spiral motion in the second separation chamber, and the activated sludge discharged from one of the second overflow port and the second underflow port of the second-stage separation unit is returned to the biochemical treatment unit.

2. The method for in-situ expansion of a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 1, characterized in that: The operating parameters of the secondary sedimentation tank include the solid load of the secondary sedimentation tank, and the performance of the activated sludge in the aeration tank includes the settling performance of the activated sludge in the aeration tank; According to the operating parameters of the secondary sedimentation tank and the performance of the activated sludge in the aeration tank in the biochemical treatment unit of the sewage treatment system, the activated sludge discharged from one of the first overflow port and the first underflow port of the first-stage separation unit is input into the second separation chamber of the second-stage separation unit from the second feed port of the second-stage separation unit, so that the activated sludge is separated by spiral motion in the second separation chamber, and the activated sludge discharged from one of the second overflow port and the second underflow port of the second-stage separation unit is returned to the aeration tank, comprising: Based on the fact that the settling performance of the activated sludge in the aeration tank is lower than the set settling performance and the solid load of the secondary settling tank is not higher than the set solid load, the activated sludge discharged from the first underflow port of the first-stage separation unit is fed into the second separation chamber of the second-stage separation unit from the second feed port of the second-stage separation unit for separation, and the activated sludge discharged from the second underflow port of the second-stage separation unit is returned to the biochemical treatment unit; Based on the fact that the solid load in the secondary sedimentation tank is higher than the set solid load and the settling performance of the activated sludge in the aeration tank is not lower than the set settling performance, the activated sludge discharged from the first overflow port of the first-stage separation unit is input from the second feed port of the second-stage separation unit into the second separation chamber of the second-stage separation unit for separation, and the activated sludge discharged from the second overflow port of the second-stage separation unit is returned to the biochemical treatment unit; When the settling performance of the activated sludge in the aeration tank is lower than the set settling performance and the solid load of the secondary sedimentation tank is higher than the set solid load, the activated sludge discharged from the first overflow port of the first-stage separation unit is input into the second separation chamber of the second-stage separation unit from the second feed port of the second-stage separation unit for separation, and the activated sludge discharged from the second underflow port of the second-stage separation unit is returned to the biochemical treatment unit.

3. The method for in-situ expansion of a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 1 or 2, characterized in that: The pressure of the activated sludge input into the first feed inlet of the first-stage separation unit is 0.2 MPa to 0.5 MPa; and / or The in-situ capacity expansion method of the sewage treatment system for improving the solid flux separated in the secondary sedimentation tank also includes: transporting the activated sludge discharged from the first overflow port and the first underflow port of the first-stage separation unit to a sludge thickening tank, and transporting the activated sludge discharged from the second overflow port and the second underflow port of the second-stage separation unit to a sludge thickening tank.

4. An in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank, characterized in that: include: A first-stage separation unit comprises a first separation chamber, and a first feed port, a first underflow port and a first overflow port connected to the first separation chamber, wherein the first feed port is configured to be connected to a secondary sedimentation tank of a sewage treatment system, and the first-stage separation unit is configured to separate the activated sludge inputted from the first feed port into the first separation chamber through a spiral motion; and The second-stage separation unit has a second separation chamber, and a second feed port, a second underflow port and a second overflow port connected to the second separation chamber, and one of the first overflow port and the first underflow port is connected to the second feed port. The second-stage separation unit is configured to separate the activated sludge input from the second feed port into the second separation chamber through spiral motion, and one of the second overflow port and the second underflow port is configured to be connected to a biochemical treatment unit of a sewage treatment system.

5. The in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 4, characterized in that: Also includes: An outer cylinder body, in which a partition is provided to divide the space inside the outer cylinder body into the first separation chamber and the second separation chamber; A first inner cone is disposed in the first separation chamber, with a small end of the first inner cone facing the side where the first feed port and the first overflow port are located, and the first underflow port is close to a large end of the first inner cone; and A second inner cone is disposed in the second separation chamber, with the small end of the second inner cone facing the side where the second feed port and the second overflow port are located, and the second underflow port is close to the large end of the second inner cone; Wherein, the axis of the outer cylinder is perpendicular to the horizontal plane; or, the axis of the outer cylinder is inclined relative to the horizontal plane; or, the axis of the outer cylinder is parallel to the horizontal plane.

6. The in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 5, characterized in that: The separator comprises a spiral body, the spiral body comprises a cylindrical portion and a spiral blade, the spiral blade is arranged between the outer wall surface of the cylindrical portion and the inner wall surface of the outer cylinder to form a spiral flow channel, the inlet of the spiral flow channel is communicated with the first bottom flow port, and the outlet of the spiral flow channel is communicated with the second feed port; A first connecting cavity is provided in the cylindrical portion, the first inner cone includes a first conical section, the cylindrical portion is arranged at the large end of the first conical section, the first conical section is provided with a second connecting cavity, the outer cylinder is provided with a discharge port, the second overflow port is arranged at an end of the cylindrical portion away from the first inner cone, and the second overflow port, the first connecting cavity, the second connecting cavity and the discharge port are connected in sequence.

7. The in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 6, characterized in that: The first overflow port and the discharge port are both arranged on the first end wall of the outer cylinder body opposite to the small end of the first conical section, and the first overflow port surrounds the outside of the discharge port; The second inner cone includes a second conical section and a second cylindrical section, the small end of the second conical section faces the partition, one end of the second cylindrical section is connected to the large end of the second conical section, the other end of the second cylindrical section is connected to the second end wall of the outer cylinder, and the second end wall of the outer cylinder is arranged opposite to the first end wall; The first feed port and the second underflow port are both arranged on the side wall of the outer cylinder, and the first feed port is close to the first end wall of the outer cylinder, and the second underflow port is close to the second end wall of the outer cylinder.

8. The in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 7, characterized in that: The size of the in-situ expansion device of the sewage treatment system meets at least one of the following requirements: The inner diameter D of the outer cylinder is: 50mm≤D≤250mm; The diameter d of the first feed port is: d≤0.25D; The diameter O1 of the first overflow port is: O1≤0.25D, and the diameter O2 of the second overflow port is: O2≤0.25D; One end of the first overflow port extends into the first separation chamber, and the length l1 extending into the first separation chamber is: 0.4D≤l1≤0.8D; one end of the second overflow port extends into the second separation chamber, and the length l2 extending into the second separation chamber is: 0.4D≤l2≤0.8D; The diameter U2 of the second bottom flow outlet is: U2≤0.15D; The diameter F of the discharge port is: F ≥ O2; The distance L1 between the first end wall of the outer cylinder and the large end of the first tapered section is: 3.0D≤L1≤6.0D, and the distance L2 between the partition and the large end of the second tapered section is: 3.0D≤L2≤6.0D; The diameter D1 of the large end of the first tapered section is: D1≤0.80D, and the diameter D2 of the large end of the second tapered section is: D2≤0.80D; The height h1 of the first conical section is: 2.0D≤h1≤3.5D, the height h2 of the second conical section is: 2.0D≤h2≤3.5D, and the height G2 of the second cylindrical section is: 0.5D2≤G2≤1.5D2; The cone angle θ1 of the first cone section is: 16°≤θ1≤24°, and the cone angle θ2 of the second cone section is: 16°≤θ2≤24°; The number of turns of the spiral blade is: 2-6; The helical angle β of the spiral blade is: 0°≤β≤30°; The outer diameter of the cylindrical portion is set to be equal to the diameter D1 of the large head end of the first conical section.

9. The in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 5, characterized in that: The separator comprises a spiral body, the spiral body comprises a cylindrical portion and a spiral blade, the spiral blade is arranged between the outer wall surface of the cylindrical portion and the inner wall surface of the outer cylinder to form a spiral flow channel, the inlet of the spiral flow channel is communicated with the first overflow port, and the outlet of the spiral flow channel is communicated with the second feed port; A first communication cavity is provided in the columnar portion, a discharge port is provided in the outer cylinder, the second overflow port is provided in the columnar portion, and the second overflow port is communicated with the discharge port through the first communication cavity.

10. The in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 9, characterized in that: The first inner cone includes a first conical section and a first cylindrical section, the small end of the first conical section faces the partition, one end of the first cylindrical section is connected to the large end of the first conical section, and the other end of the first cylindrical section is connected to the second end wall of the outer cylinder; The second inner cone includes a second conical section and a second cylindrical section, the small end of the second conical section faces the partition, one end of the second cylindrical section is connected to the large end of the second conical section, the other end of the second cylindrical section is connected to the first end wall of the outer cylinder, and the first end wall of the outer cylinder is arranged opposite to the second end wall; The first feed port, the first bottom flow port and the second bottom flow port are all arranged on the side wall of the outer cylinder, and the first feed port and the discharge port are both close to the partition and arranged opposite to each other, the first bottom flow port is close to the second end wall of the outer cylinder, and the second bottom flow port is close to the first end wall of the outer cylinder.

11. The in-situ expansion device for a sewage treatment system for increasing the solid separation flux of a secondary sedimentation tank according to claim 10, characterized in that: The size of the in-situ expansion device of the sewage treatment system meets at least one of the following requirements: The inner diameter D of the outer cylinder is: 50mm≤D≤250mm; The diameter d of the first feed port is: d≤0.25D; The diameter O1 of the first overflow port is: O1≤0.25D, and the diameter O2 of the second overflow port is: O2≤0.25D; One end of the first overflow port extends into the first separation chamber, and the length l1 extending into the first separation chamber is: 0.4D≤l1≤0.8D; one end of the second overflow port extends into the second separation chamber, and the length l2 extending into the second separation chamber is: 0.4D≤l2≤0.8D; The diameter U1 of the first underflow port is: U1≤0.15D, and the diameter U2 of the second underflow port is: U2≤0.15D; The diameter F of the discharge port is: F ≥ O2; The distance L1 between the partition and the large end of the first tapered section is: 3.0D≤L1≤6.0D, and the distance L2 between the partition and the large end of the second tapered section is: 3.0D≤L2≤6.0D; The diameter D1 of the large end of the first tapered section is: D1≤0.80D, and the diameter D2 of the large end of the second tapered section is: D2≤0.80D; The height h1 of the first tapered section is: 2.0D≤h1≤3.5D, and the height h2 of the second tapered section is: 2.0D≤h2≤3.5D; The cone angle θ1 of the first cone section is: 16°≤θ1≤24°, and the cone angle θ2 of the second cone section is: 16°≤θ2≤24°; The height G1 of the first columnar segment is: 0.5D1≤G1≤1.5D1, and the height G2 of the second columnar segment is: 0.5D2≤G2≤1.5D2; The number of turns of the spiral blade is: 2-6; The helical angle β of the spiral blade is: 0°≤β≤30°; The outer diameter N of the columnar portion is: N≤0.80D.

12. A sewage treatment system, characterized in that: The invention comprises a biochemical treatment unit, a secondary sedimentation tank and an in-situ expansion device for a sewage treatment system for improving the solid separation flux of the secondary sedimentation tank as described in any one of claims 4 to 11, wherein a first feed inlet of the in-situ expansion device for the sewage treatment system is connected to the secondary sedimentation tank, and a second underflow outlet and one of a second overflow outlet of the in-situ expansion device for the sewage treatment system are connected to the biochemical treatment unit.

13. The sewage treatment system according to claim 12, characterized in that: The sewage treatment system is a system using an anaerobic-anoxic-aerobic activated sludge process, wherein an anaerobic zone, a first anoxic zone and a first aerobic zone are sequentially arranged in the biochemical treatment unit, and one of the second underflow port and the second overflow port of the in-situ expansion device of the sewage treatment system is connected to the anaerobic zone; or The sewage treatment system is a system adopting a two-stage anoxic-aerobic activated sludge method, wherein a first anoxic zone, a first aerobic zone, a second anoxic zone and a second aerobic zone are sequentially arranged in the biochemical treatment unit, and one of the second underflow port and the second overflow port of the in-situ expansion device of the sewage treatment system is connected to the first anoxic zone.

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