A sludge sieve

Abstract

The present application discloses a sludge sieve, belonging to the technical field of wastewater treatment, which is used to separate activated sludge from the sludge mixture. It includes a primary separation pipe and a secondary separation pipe. The primary feed port is used to pump the sludge mixture into the primary separation pipe, and the sludge mixture flows along the wall of the primary separation pipe in a spiral flow towards the primary discharge port, achieving preliminary separation during the flow process. The sludge sieve further includes a secondary separation member, which can transport separation liquid to the secondary separation pipe and form a separation eddy current on the outer periphery of the sludge mixture. The separation eddy current draws down the middle air pressure during the spiral flow process, providing a pressure difference for the sludge mixture and its outer space. This part of the pressure difference enhances the centrifugal force of the sludge mixture, and part of the high-quality activated sludge in the sludge mixture moves towards the outer separation eddy current under the drive of a stronger centrifugal force, realizing the further separation of the activated sludge in the sludge mixture.

Description

Technical Field

[0001] This application belongs to the technical field of wastewater treatment, and particularly relates to a sludge sieve. Background Art

[0002] The activated sludge process is a wastewater treatment technology with activated sludge as the main body. It is a bioengineering technology that enables the microorganisms in the activated sludge to fully exert their physiological functions of oxidizing and decomposing organic pollutants by taking a series of artificially strengthened and controlled technical measures to purify wastewater.

[0003] And the activated sludge usually contains light sludge or particulate matter such as filaments. The poor sludge sedimentation characteristics result in biomass loss, leading to sludge bulking, high sludge production, and thus affecting the water purification effect. Therefore, screening high-quality sludge is of great significance to the normal operation of the activated sludge process wastewater treatment system.

[0004] Traditional sludge sieves usually use gravitational sedimentation to separate the denser particulate matter or filamentous sludge inside the activated sludge to achieve the purification of the activated sludge. However, this screening method can usually only separate some coarser particles of high-quality activated sludge, and cannot effectively screen some finer particles of low-quality activated sludge, and the screening efficiency of high-quality activated sludge cannot be effectively guaranteed. Summary of the Invention

[0005] This application provides a sludge sieve to solve the technical problem of poor separation effect of the traditional sludge sieve on the activated sludge in the sludge mixture.

[0006] The technical solution adopted in this application is as follows:

[0007] A sludge sieve for separating the activated sludge in the sludge mixture, including a primary separation pipe and a secondary separation pipe. The primary separation pipe includes a primary feed port and a primary discharge port. The secondary separation pipe has a secondary feed port communicating with the primary separation pipe. The primary feed port is used to pump the sludge mixture into the primary separation pipe, and the sludge mixture flows along the wall of the primary separation pipe in a spiral flow towards the primary discharge port to achieve preliminary separation during the flow process; a return area is provided on the flow path of the sludge mixture in the primary separation pipe towards the primary discharge port, so that the sludge mixture changes its movement direction through the return area during the flow towards the primary discharge port and enters the secondary separation pipe in a spiral flow through the secondary feed port; the sludge sieve further includes a secondary separation member, and the secondary separation member can transport the separation liquid to the secondary separation pipe and form a separation eddy current for increasing the centrifugal force of the sludge mixture on the outer periphery of the sludge mixture.

[0008] The sludge sieve described in this application further includes the following additional technical features:

[0009] The secondary separation member includes a liquid pumping assembly and a closed housing. The closed housing cooperates with the secondary separation pipe to form a liquid supply chamber. A plurality of liquid infusion ports communicating with the liquid supply chamber are formed in the pipe wall of the secondary separation pipe, and the liquid pumping assembly can transport separation liquid to the liquid supply chamber.

[0010] The included angle α between the plane where the opening direction of the liquid infusion port is located and the plane where the tangent of the cross-sectional circle of the secondary separation pipe is located satisfies 0° < α ≤ 30°, and / or the included angle β between the plane where the opening direction of the liquid infusion port is located and the pipe wall of the secondary separation pipe satisfies 70° ≤ β ≤ 85°.

[0011] The secondary separation member further includes an infusion pipe communicating with the liquid infusion port. The extending direction of the infusion pipe is the same as the opening direction of the liquid infusion port, and the separation liquid in the liquid supply chamber is transported to the secondary separation pipe through the infusion pipe.

[0012] A plurality of infusion groups are arranged at intervals along the extending direction of the secondary separation pipe. Each infusion group includes a plurality of liquid infusion ports whose projections in the direction of the axis of the secondary separation pipe coincide.

[0013] Both the primary separation pipe and the secondary separation pipe extend in the vertical direction, and the extension line of the axis of the primary separation pipe coincides with the extension line of the axis of the secondary separation pipe.

[0014] The primary separation pipe includes a cylindrical section and a conical section. The primary feed port is arranged on the cylindrical section. One end of the conical section is connected to the cylindrical section, and the other end extends away from the cylindrical section and the cross-sectional area gradually decreases. At least part of the area inside the conical section constitutes the return area.

[0015] It further includes a reflection plate arranged in the return area. There is a flow-through gap between the reflection plate and the pipe wall of the primary separation pipe, and the reflection plate has a reflection surface facing the secondary feed port.

[0016] The ratio of the width of the flow-through gap to the width of the reflection surface is 11% - 25%.

[0017] It further includes a pumping assembly. The pumping assembly includes a variable-frequency pump and a feed pipe. The variable-frequency pump transports the sludge mixture to the primary feed port through the feed pipe, and the variable-frequency pump can adjust the pumping power to adjust the speed of the sludge mixture entering the primary separation pipe.

[0018] Due to the adoption of the above technical solutions, the beneficial effects obtained by this application are:

[0019] 1. The sludge sieve of the present application includes a primary separation tube. When screening and purifying the sludge mixture, the sludge mixture is first transported to the primary separation tube through the primary feed port. Under the combined action of centrifugal force and its own gravity, the sludge mixture will flow spirally along the inner wall of the primary separation tube towards the primary discharge port. Due to the different densities of the components inside the sludge mixture, during the spiral flow of the sludge mixture, the activated sludge with higher density and better sedimentation performance will be subjected to a greater centrifugal force and be separated to the outside of the sludge mixture. And as the sludge mixture spirals, the air pressure at the central axis of its spiral flow will decrease, forming a low-pressure area or even a negative-pressure area. While the filamentous sludge with relatively lower density, poorer activity and sedimentation characteristics is subjected to a smaller centrifugal force, so it will continuously move towards the middle under the action of the pressure difference during the spiral flow, thus realizing the primary separation of the activated sludge in the sludge mixture. When the sludge mixture moves to the turning area, the low-density sludge mixture mainly composed of filamentous sludge in the middle will be affected by the turning force in the turning area and change its movement direction, move towards the secondary feed port and enter the secondary separation tube through the secondary feed port. The high-quality activated sludge separated is discharged through the primary discharge port. The sludge mixture entering the secondary separation tube from the secondary feed port will flow spirally under the action of centrifugal force, and the separation liquid conveyed by the secondary separation part forms a spiral separation eddy on the outside of the sludge mixture under the combined action of its own centrifugal force and gravity. During the spiral flow of the separation eddy, the air pressure in the middle is pumped down, causing the air pressure outside the sludge mixture to decrease, and then providing a greater pressure difference for the sludge mixture and the space outside it. This part of the pressure difference enhances the centrifugal force of the sludge mixture, and drives some of the fine-particle activated sludge with lower density in the sludge mixture to move towards the outer separation eddy under the action of a stronger centrifugal force and be adsorbed by the separation eddy, thus realizing the further separation of the activated sludge in the sludge mixture; in addition, the low-density fine-particle sludge in the sludge mixture is driven by the separation eddy to return to the primary separation tube through the secondary feed port and is discharged through the primary discharge port together with the separation eddy. The separation eddy can also scour the activated sludge separated by the preliminary separation in the primary separation tube during this process, and carry the separated activated sludge by the preliminary separation out through the primary discharge port together, reducing the possibility of the separated activated sludge by the preliminary separation being adsorbed on the inner wall of the primary separation tube, so as to reduce the possibility of the activated sludge blocking the primary discharge port and providing a stability guarantee for the smooth separation of the activated sludge.

[0020] 2. As a preferred embodiment of the present application, the secondary separation member includes a liquid pumping assembly and a closed casing. The closed casing cooperates with the secondary separation tube to form a liquid supply chamber. A plurality of liquid injection ports communicating with the liquid supply chamber are formed in the tube wall of the secondary separation tube. The liquid pumping assembly can transport the separation liquid to the liquid supply chamber. By pumping the separation liquid into the liquid supply chamber through the liquid pumping assembly, the separation liquid in the liquid supply chamber is then transported into the secondary separation tube through a plurality of liquid injection ports. The liquid flows of the separation liquid output from the plurality of liquid injection ports jointly form a separation vortex, improving the uniformity of the composition of the separation vortex and helping to maintain the flow power of the separation vortex. In addition, the design of the liquid supply chamber enables the liquid pumping assembly to fill the liquid supply chamber first when pumping the separation liquid into the secondary separation tube, and then the pumping assembly continues to inject the separation liquid into the liquid supply chamber. The separation liquid in the liquid supply chamber is evenly injected into the secondary separation tube through each liquid injection port, so that the separation liquid input into the secondary separation tube through each liquid injection port has the same transport kinetic energy, that is, the same initial velocity, thus jointly forming a stable separation vortex and avoiding the occurrence of unstable separation vortex caused by the kinetic energy difference of the separation liquid transported by the liquid injection ports. Moreover, by providing the closed casing and the liquid supply chamber, only one set of liquid pumping assembly is required to transport the separation liquid to multiple liquid injection ports, without the need to set up multiple sets of liquid pumping assemblies to transport the separation liquid to the liquid injection ports respectively, optimizing the structural design of the secondary separation member.

[0021] 3. As a preferred embodiment of the present application, the included angle α between the extension line of the opening direction of the liquid delivery pipe and the tangent of the cross-sectional circle of the secondary separation tube is set to satisfy 0° < α ≤ 30°, so that the opening direction of the liquid delivery pipe is kept close to the tube wall of the secondary separation tube to a certain extent. In this way, when the separation liquid enters the secondary separation tube from the liquid delivery pipe, the separation liquid can quickly adhere to the tube wall of the secondary separation tube and flow spirally along the tube wall under the guiding action of the tube wall, reducing the probability that the separation liquid collides violently with the tube wall of the secondary separation tube and cannot quickly form a separation vortex, and at the same time reducing the kinetic energy loss of the separation liquid after colliding with the tube wall of the secondary separation tube, which helps to improve the spiral flow rate of the separation vortex and enhance the adsorption efficiency of the activated sludge in the sludge mixture. And the included angle β between the extension line of the opening direction of the liquid delivery pipe and the tube wall of the secondary separation tube satisfies 70° ≤ β ≤ 85°, providing an initial velocity along the length direction of the secondary separation tube for the separation liquid entering the secondary separation tube, so that the separation liquid can quickly move along the tube wall of the secondary separation tube in a spiral flow form towards the secondary feed port, thereby realizing the rapid transfer of the adsorbed activated sludge.

[0022] 4. As a preferred embodiment of the present application, by providing an infusion tube, when the separation liquid in the liquid supply chamber enters the secondary separation tube through the infusion port, it will first enter the infusion tube. When it moves to the front of the infusion port, the separation liquid in the infusion tube has adjusted its flow direction after colliding with the inner wall of the infusion tube during the flow process, so that the separation liquid enters the secondary separation tube along the opening direction of the infusion port together; that is, by providing the infusion tube, it provides a guiding effect for the separation liquid entering the secondary separation tube, reducing the probability of the phenomenon of collision and dispersion inside the liquid caused by different flow directions at the initial stage when the separation liquid enters the secondary separation tube, thereby effectively ensuring the kinetic energy intensity of the separation liquid after entering the secondary separation tube and providing guarantee for the stability of the formed separation eddy current. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0024] Figure 1 is a cross-section of the sludge screen under an embodiment of the present application Figure 1 ;

[0025] Figure 2 is a cross-section of the sludge screen under an embodiment of the present application Figure 2 ;

[0026] Figure 3 is Figure 2 an enlarged view of part A of

[0027] Figure 4 is a cross-section of part of the structure of the sludge screen under an embodiment of the present application Figure 1 ;

[0028] Figure 5 is a cross-section of part of the structure of the sludge screen under an embodiment of the present application Figure 2 ;

[0029] Figure 6 is a schematic structural view of part of the structure of the sludge screen under an embodiment of the present application.

[0030] Wherein:

[0031] 1, primary separation tube; 11, primary feed port; 12, primary discharge port; 13, cylindrical section; 14, conical section;

[0032] 2, secondary separation tube; 21, secondary feed port; 22, secondary discharge port; 23, infusion port;

[0033] 3. Secondary separation component; 31. Enclosed housing; 311. Liquid inlet channel; 32. Liquid pumping component; 321. Infusion pump; 322. Transfer pipe; 33. Liquid supply chamber; 34. Infusion tube;

[0034] 4. Reflector; 41. Reflective surface;

[0035] 5. Flow-through gap;

[0036] 6. Pumping component; 61. Variable-frequency pump; 62. Feeding pipe. Detailed implementation manner

[0037] For a clearer explanation of the overall concept of this application, the following will be described in detail by way of examples in conjunction with the accompanying drawings of the specification.

[0038] In the following description, many specific details are set forth in order to fully understand this application. However, this application can also be implemented in other ways different from those described herein. Therefore, the protection scope of this application is not limited by the specific embodiments disclosed below. It should be noted that, without conflict, the embodiments of this application and the features in each embodiment can be combined with each other.

[0039] In addition, in the description of this application, it should be understood that the orientation or positional relationships indicated by the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application 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 construed as a limitation to this application.

[0040] In this application, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] In this application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the 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. In the description of this specification, descriptions with reference to terms such as "an embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0042] As Figures 1 to 6 shown, a sludge sieve for separating activated sludge from a sludge mixture includes a primary separation pipe 1 and a secondary separation pipe 2. The primary separation pipe 1 includes a primary feed port 11 and a primary discharge port 12. The secondary separation pipe 2 has a secondary feed port 21 communicating with the primary separation pipe 1. The primary feed port 11 is used to pump the sludge mixture into the primary separation pipe 1, and during the process of the sludge mixture flowing along the pipe wall of the primary separation pipe 1 in a spiral flow towards the primary discharge port 12, preliminary separation is achieved. A turning area is provided on the flow path of the sludge mixture in the primary separation pipe 1 towards the primary discharge port 12, so that during the process of the sludge mixture flowing towards the primary discharge port 12, the movement direction is changed through the turning area and enters the secondary separation pipe 2 in a spiral flow through the secondary feed port 21. The sludge sieve further includes a secondary separation member 3, and the secondary separation member 3 can convey separation liquid to the secondary separation pipe 2 and form a separation eddy current for increasing the centrifugal force of the sludge mixture on the outer periphery of the sludge mixture.

[0043] The sludge sieve of the present application includes a primary separation tube 1. When screening and purifying the sludge mixture, first, the sludge mixture is transported to the primary separation tube 1 through the primary feed port 11. Under the combined action of centrifugal force and its own gravity, the sludge mixture will flow spirally along the inner wall of the primary separation tube 1 towards the primary discharge port. Due to the different densities of the components inside the sludge mixture, during the spiral flow of the sludge mixture, the activated sludge with a higher density and better sedimentation performance will be subjected to a greater centrifugal force and be separated to the outside of the sludge mixture. And as the sludge mixture spirals, the air pressure at the central axis of its spiral flow will decrease, forming a low-pressure area or even a negative-pressure area. While the filamentous sludge with relatively low density, poor activity and sedimentation characteristics is subjected to less centrifugal force, so it will continuously move towards the middle under the action of the pressure difference during the spiral flow, thus realizing the primary separation of the activated sludge in the sludge mixture. When the sludge mixture moves to the turning area, the low-density sludge mixture mainly composed of filamentous sludge in the middle will be affected by the turning force in the turning area and change its movement direction, move towards the secondary feed port 21 and enter the secondary separation tube 2 through the secondary feed port 21. The high-quality activated sludge separated is discharged through the primary discharge port 12. The sludge mixture entering the secondary separation tube 2 from the secondary feed port 21 will flow spirally under the action of centrifugal force, and the separation liquid transported by the secondary separation member 3 forms a spiral separation eddy on the outside of the sludge mixture under the combined action of its own centrifugal force and gravity. The separation eddy draws down the air pressure in the middle during the spiral flow, causing the air pressure on the outside of the sludge mixture to decrease, and then providing a greater pressure difference for the sludge mixture and the space outside it. This part of the pressure difference enhances the centrifugal force of the sludge mixture, and drives some fine-particle activated sludge with relatively low density in the sludge mixture to move towards the separation eddy on the outside under the drive of the stronger centrifugal force and be adsorbed by the separation eddy, thus realizing the further separation of the activated sludge in the sludge mixture; in addition, the low-density fine-particle sludge in the sludge mixture is driven by the separation eddy to return to the primary separation tube 1 through the secondary feed port 21 and is discharged from the primary discharge port 12 together with the separation eddy. The separation eddy can also scour the activated sludge separated under the preliminary separation action in the primary separation tube 1 during this process, and carry the separated activated sludge under the preliminary separation action out through the primary discharge port 12 together, reducing the possibility of the separated activated sludge under the preliminary separation action being adsorbed on the inner wall of the primary separation tube 1, so as to reduce the possibility of the primary discharge port 12 being blocked by the activated sludge and providing a stability guarantee for the smooth separation of the activated sludge.

[0044] Specifically, the working process of the sludge sieve of the present application is as follows: Figure 2Schematically shows the movement trajectories of the sludge mixture and the separation eddy current. When the sludge mixture enters the first-stage separation tube 1 through the first-stage feed port 11, due to its certain initial velocity, it will flow spirally along the inner wall of the first-stage distribution tube 1 towards the first-stage discharge port 12 according to the travel trajectory of curve S1. During the spiral flow of the sludge mixture, it will be subjected to centrifugal force, thus throwing the coarser particles of high-quality activated sludge with a higher density to the outside of the sludge mixture. When the sludge mixture moves to the turning area, the sludge mixture with a lower density in the middle is affected by the turning force and changes its travel direction, and enters the second-stage separation tube 2 in a suspended spiral flow manner along the travel trajectory shown by curve S2 through the second-stage feed port 21. During this process, the sludge mixture does not come into contact with the inner walls of the first-stage separation tube 1 and the second-stage separation tube 2, and the separated activated sludge is discharged from the first-stage separation tube 1 through the first-stage discharge port 12, thus realizing the primary separation of the sludge mixture; when the sludge mixture enters the second-stage separation tube 2, it still remains in a suspended state without contacting the inner wall of the second-stage separation tube 2 and spirally ascends along curve S2. The separation eddy current formed by the separation liquid on the outside of the sludge mixture adsorbs the finer particles of activated sludge with a lower density in the sludge mixture through the drag force generated by its spiral flow along the inner wall of the second-stage separation tube 2 along the trajectory of curve S3. This part of the activated sludge is adsorbed into the separation eddy current under the action of the drag force. The separation eddy current carries the activated sludge and spirally enters the first-stage separation tube 1 along the inner wall of the second-stage separation tube 2, and is discharged through the first-stage discharge port 12, thus realizing the secondary separation of the sludge.

[0045] Preferably, the diameter of the first-stage separation tube 1 is larger than the diameter of the second-stage separation tube 2, and the density of the separation liquid is greater than the density of the sludge mixture.

[0046] Preferably, the first-stage separation tube 1 is cylindrical at the position corresponding to the first-stage feed port 11, and the opening direction of the first-stage feed port 11 is parallel to the tangential direction of the cross-section of the first-stage separation tube 1.

[0047] Preferably, the second-stage separation tube 2 further includes a second-stage discharge port 22, and the sludge mixture entering the second-stage separation tube 2 through the second-stage feed port 21 is discharged through the second-stage discharge port 22.

[0048] As a preferred embodiment of the present application, as Figure 1 、 Figure 4 shown, the second-stage separation member 3 includes a liquid pumping assembly 32 and a closed housing 31. The closed housing 31 and the second-stage separation tube 2 cooperate to form a liquid supply chamber 33. A plurality of liquid infusion ports 23 communicating with the liquid supply chamber 33 are opened on the inner wall of the second-stage separation tube 2, and the liquid pumping assembly 32 can transport the separation liquid to the liquid supply chamber 33.

[0049] The separation liquid is pumped into the liquid supply chamber 33 through the liquid pumping assembly 32. The separation liquid in the liquid supply chamber 33 is then transported into the secondary separation tube 2 through a plurality of liquid infusion ports 23. The liquid flows of the separation liquid output from the plurality of liquid infusion ports 23 jointly form a separation eddy current, improving the uniformity of the composition of the separation eddy current and helping to maintain the flow power of the separation eddy current. In addition, the design of the liquid supply chamber 33 enables the liquid pumping assembly 32 to be filled first when pumping the separation liquid into the secondary separation tube 2. The liquid pumping assembly 32 continues to inject the separation liquid into the liquid supply chamber 33, and the separation liquid in the liquid supply chamber 33 is evenly injected into the secondary separation tube 2 through each liquid infusion port 23, so that the separation liquid input into the secondary separation tube 2 from each liquid infusion port 23 has the same transport kinetic energy, that is, the same initial velocity, thus jointly forming a stable separation eddy current and avoiding the occurrence of unstable separation eddy current caused by the kinetic energy difference of the separation liquid transported by the liquid infusion ports 23. Furthermore, by providing the closed housing 31 and the liquid supply chamber 33, only one set of liquid pumping assembly 32 is required to achieve the transportation of the separation liquid to the plurality of liquid infusion ports 23, without the need to set up multiple sets of liquid pumping assemblies 32 to transport the separation liquid to the liquid infusion ports 23 respectively, optimizing the structural design of the secondary separation member 3.

[0050] Preferably, the liquid pumping assembly 32 includes an infusion pump 321 and a transmission pipe 322 connecting the infusion pump 321 and the liquid supply chamber 33. The infusion pump 321 transports the separation liquid into the liquid supply chamber 33 through the transmission pipe 322. The closed housing 31 is provided with a liquid inlet channel 311 communicating with the transmission pipe 322.

[0051] Specifically, the secondary separation tube 2 is cylindrical. The opening direction of the liquid infusion port 23 in this embodiment is not limited, and any of the following embodiments can be adopted:

[0052] Embodiment 1: As Figure 4 shown, the included angle α between the plane where the opening direction of the liquid infusion port 23 is located and the plane where the tangent of the cross-sectional circle of the secondary separation tube 2 is located satisfies 0° < α ≤ 30°.

[0053] Embodiment 2: As Figure 3 shown, the included angle β between the plane where the opening direction of the liquid infusion port 23 is located and the tube wall of the secondary separation tube 2 satisfies 70° ≤ β ≤ 85°.

[0054] Embodiment 3: As Figures 2 to 4 shown, the included angle α between the plane where the opening direction of the liquid infusion port 23 is located and the plane where the tangent of the cross-sectional circle of the secondary separation tube 2 is located satisfies 0° < α ≤ 30°, and the included angle β between the plane where the opening direction of the liquid infusion port 23 is located and the tube wall of the secondary separation tube 2 satisfies 70° ≤ β ≤ 85°.

[0055] The included angle α between the extension line of the opening direction of the infusion tube 34 and the tangent line of the cross-sectional circle of the secondary separation tube 2 is set to satisfy 0° < α ≤ 30°, so that the opening direction of the infusion tube 34 is kept close to the tube wall of the secondary separation tube 2 to a certain extent. In this way, when the separation liquid enters the secondary separation tube 2 from the infusion tube 34, the separation liquid can quickly adhere to the tube wall of the secondary separation tube 2 and flow spirally along the tube wall under the guiding action of the tube wall, reducing the probability that the separation liquid collides violently with the tube wall of the secondary separation tube 2 and cannot quickly form a separation eddy current. At the same time, the kinetic energy loss of the separation liquid after colliding with the tube wall of the secondary separation tube 2 is reduced, which helps to increase the spiral flow rate of the separation eddy current and enhance the adsorption efficiency of the activated sludge in the sludge mixture; and the included angle β between the extension line of the opening direction of the infusion tube 34 and the tube wall of the secondary separation tube 2 satisfies 70° ≤ β ≤ 85°, providing an initial velocity along the length direction of the secondary separation tube 2 for the separation liquid entering the secondary separation tube 2, so that the separation liquid can quickly move towards the secondary feed port 21 in the form of spiral flow along the tube wall of the secondary separation tube 2, thereby realizing the rapid transfer of the adsorbed activated sludge.

[0056] As another preferred embodiment under this embodiment, as Figures 1 to 4 shown, the secondary separation member 3 further includes an infusion tube 34 communicated with the infusion port 23, and the extending direction of the infusion tube 34 is consistent with the opening direction of the infusion port 23. The separation liquid in the liquid supply chamber 33 is conveyed to the secondary separation tube 2 through the infusion tube 34.

[0057] By providing the infusion tube 34, when the separation liquid in the liquid supply chamber 33 enters the secondary separation tube 2 through the infusion port 23, it will first enter the infusion tube 34. When moving to the front of the infusion port 23, the separation liquid in the infusion tube 34 has adjusted its flow direction after colliding with the inner wall of the infusion tube 34 during the flow process, so that the separation liquid enters the secondary separation tube 2 together along the opening direction of the infusion port 23; that is, by providing the infusion tube 34, a guiding effect is provided for the separation liquid entering the secondary separation tube 2, reducing the probability of the phenomenon that the liquid collides and collapses inside due to different flow directions at the initial stage when the separation liquid enters the secondary separation tube 2, thereby effectively ensuring the kinetic energy intensity of the separation liquid after entering the secondary separation tube 2 and providing a guarantee for the stability of the formation of the separation eddy current.

[0058] As yet another preferred embodiment under this embodiment, as Figure 1 、 Figure 2As shown in the figure, a plurality of infusion groups are provided at intervals along the extending direction of the secondary separation tube 2. Each infusion group includes a plurality of infusion ports 23 whose projections coincide in the axial direction of the secondary separation tube 2. With this arrangement, when the separation eddy current moves along the inner wall of the secondary separation tube 2 towards the secondary feed port 21, there are infusion groups on its flow path to supplement the separation liquid. Because as the separation eddy current continuously flows along the inner wall of the secondary separation tube 2, it will suffer kinetic energy loss under the influence of the frictional force of the inner wall of the secondary separation tube 2 and other effects during the flow, which will in turn affect its spiral flow efficiency. By setting the infusion groups, the separation liquid with sufficient kinetic energy can continuously supplement the separation eddy current, effectively improving the kinetic energy uniformity of the separation eddy current on the spiral flow path and ensuring the separation function of the separation eddy current.

[0059] As a preferred embodiment of the present application, as Figure 1 , Figure 2 shown, both the primary separation tube 1 and the secondary separation tube 2 extend along the vertical direction, and the axial extension line of the primary separation tube 1 coincides with the axial extension line of the secondary separation tube 2. When the sludge mixture is subjected to the first separation of activated sludge in the primary distribution pipe, it will spiral upward into the secondary separation tube 2 with the axis of the primary separation tube 1 as the rotation axis under the action of the return force in the return area, avoiding the possibility of the travel trajectory deviation caused by gravity deviation during the movement of the sludge mixture from the primary separation tube 1 to the secondary separation tube 2. In addition, the activated sludge separated in the primary separation tube 1 can slide down along the inner wall of the primary separation tube 1 under its own weight and be discharged from the primary discharge port 12, reducing the possibility of the activated sludge gathering and blocking in the primary separation tube 1; furthermore, the separation eddy current in the secondary separation tube 2 rotates downward after adsorbing part of the activated sludge and enters the primary separation tube 1, and is close to the inner wall of the primary separation tube 1 under the action of centrifugal force, playing an auxiliary scouring role on the activated sludge separated in the primary separation tube 1 and further reducing the probability of the activated sludge separated during the first separation blocking in the primary separation tube 1.

[0060] The present application does not limit the structural forms of the primary separation tube 1 and the return area, and any one of the following implementation manners can be adopted:

[0061] Embodiment 1: As Figure 6 shown, the primary separation tube 1 includes a cylindrical section 13 and a conical section 14. The primary feed port 11 is arranged on the cylindrical section 13. One end of the conical section 14 is connected to the cylindrical section 13, and the other end extends away from the cylindrical section 13 and the cross-sectional area gradually decreases. At least part of the area inside the conical section 14 constitutes the return area.

[0062] Specifically, the primary discharge port 12 is located at one end of the conical section 14 away from the cylindrical section 13 and its projection toward the cylindrical section 13 falls within the secondary feed port 21. When the sludge mixture enters the primary separation tube 1 from the primary feed port 11, the sludge mixture is restricted by the wall of the primary separation tube 1, so that the sludge mixture rotates along the wall of the primary separation tube 1 toward the primary discharge port 12. When it moves to the conical section 14, the inner diameter of the conical section 14 gradually decreases, and the rotation speed of the sludge mixture will continue to accelerate. Due to the uneven pressure distribution along the radial direction when the sludge mixture flows in a spiral direction, the closer it is to the axis of the primary separation tube 1, the smaller it is and approaches zero when it reaches the axis, becoming a low-pressure area or even a vacuum area, causing the sludge mixture to move toward the axial direction. At the same time, due to the gradual reduction of the aperture at the bottom of the conical section 14, the sludge mixture cannot be quickly discharged from the primary discharge port 12, and the secondary feed port 21 is in a low-pressure area, forcing the sludge mixture to move from the high-pressure area to the secondary feed port 21 in the low-pressure area, thereby forming a return of the sludge mixture. Figure 6 As shown, taking the first-level separation tube 1 set vertically as an example, affected by the spiral flow of the sludge mixture, the air pressure in the area close to the axis is relatively low, and the sludge mixture gradually moves closer to the axis of the first-level separation tube 1 during the spiral movement from top to bottom, while the high-quality activated sludge in the sludge mixture has a relatively large density and is subjected to a relatively large centrifugal force. As the rotation speed increases, the centrifugal force continues to increase. When the centrifugal force is greater than the liquid resistance of the sludge mixture to it, the activated sludge will move toward the wall of the first-level separation tube 1 and separate from the sludge mixture; and the sludge mixture entering the conical section 14 has a continuously increasing rotation speed, and the more it moves downward, the faster its spiral flow speed is, and the space at the bottom of the conical section 14 is relatively small, so the sludge mixture cannot be discharged in time, so it spirals from bottom to top to the secondary feed port 21 in the low-pressure zone. That is, the return force of the lower return zone in this embodiment refers to the pressure from the high-pressure zone around the first-level separation tube 1 to the low-pressure zone at its axis.

[0063] Implementation method 2: Figure 1 As shown, it also includes a reflector 4 arranged in the return zone, a flow gap 5 is arranged between the reflector 4 and the tube wall of the first-stage separation tube 1, and the reflector 4 has a reflective surface 41 facing the second-stage feed port 21. Figure 1As shown in the figure, taking the case where the first - stage separation tube 1 is vertically arranged as an example, affected by the spiral flow of the sludge mixture, the air pressure in the area near the axis is relatively low. During the process of the sludge mixture spiraling downward, it gradually approaches the axis of the first - stage separation tube 1. The high - quality activated sludge in the sludge mixture has a relatively large density and is subject to a relatively large centrifugal force. When the centrifugal force is greater than the liquid resistance of the sludge mixture to it, the activated sludge will move towards the wall of the first - stage separation tube 1, separate from the sludge mixture, and slide down to the first discharge port 12 through the flow - through gap 5. When the sludge mixture moves to the turning - back area, its movement direction is changed by the reflection of the reflector 4, and then it spirals upward from bottom to top to the second - stage feed port 21 and enters the second - stage separation tube 2.

[0064] Preferably, the first - stage separation tube 1 is provided with a converging section. After the first - stage separation, the activated sludge converges to the first discharge port 12 under the action of the wall of the converging section.

[0065] As a preferred embodiment under the second implementation manner, as Figure 1 shown, the ratio of the width of the flow - through gap 5 to the width of the reflection surface 41 is 11% - 25%. With such a setting, the reflection surface 41 has a sufficient reflection width, so as to provide a turning - back force for the sludge mixture and reduce the probability that the sludge mixture flows out through the flow - through gap 5 without contacting the reflection surface 41. In addition, sufficient movement space is reserved for the separated activated sludge, reducing the probability of blockage of the separated activated sludge. Figure 1 The width of the flow - through gap 5 and the width of the reflection surface 41 are schematically drawn in the figure. L1 and L2 indicate the width of the flow - through gap, and L3 indicates the width of the reflection surface 41. 11% < L1 / L3 < 25%, 11% < L2 / L3 < 25%.

[0066] As a preferred implementation manner of the present application, as Figure 1 shown, it further includes a pumping assembly 6. The pumping assembly 6 includes a variable - frequency pump 61 and a feeding pipe 62. The variable - frequency pump 61 conveys the sludge mixture to the first - stage feed port 11 through the feeding pipe 62, and the variable - frequency pump 61 can adjust the pumping power to adjust the speed of the sludge mixture entering the first - stage separation tube 1. Since the centrifugal force of the sludge mixture during the spiral flow process is proportional to the movement speed, by setting the variable - frequency pump 61, the sludge mixture can be conveyed into the first - stage separation tube 1 at different speeds, providing different initial speeds for the sludge mixture, and adjusting the centrifugal force of the sludge mixture according to the separation needs for sludge mixtures with different components and different separation requirements.

[0067] Preferably, the primary discharge port is communicated with the activated sludge tank. After separation, the activated sludge is discharged into the activated sludge tank through the primary discharge port. The material conveying pipe 62 is communicated with the activated sludge tank, and the activated sludge in the activated sludge tank is conveyed to the sludge screening device through the pumping assembly 6 for separation and purification.

[0068] In the present application, those not described can be implemented by adopting or referring to the existing technologies.

[0069] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments.

[0070] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A sludge sieve for separating activated sludge from a sludge mixture, characterized in that, It includes a primary separation pipe and a secondary separation pipe. The primary separation pipe includes a primary feed inlet and a primary discharge outlet. The secondary separation pipe has a secondary feed inlet communicating with the primary separation pipe. The primary feed inlet is used to pump a sludge mixture into the primary separation pipe, and the sludge mixture is preliminarily separated during the process of flowing along the inner wall of the primary separation pipe in a spiral flow towards the primary discharge outlet. A return zone is provided on the flow path of the sludge mixture in the primary separation pipe towards the primary discharge outlet, so that the sludge mixture changes its movement direction through the return zone during the process of flowing towards the primary discharge outlet and enters the secondary separation pipe in a spiral flow through the secondary feed inlet. The sludge sieve further includes a secondary separation member, and the secondary separation member can convey a separation liquid to the secondary separation pipe and form a separation eddy current for increasing the centrifugal force of the sludge mixture on the outer periphery of the sludge mixture. The secondary separation member includes a liquid pumping assembly and a closed housing. The closed housing and the secondary separation pipe cooperate to form a liquid supply chamber. A plurality of liquid infusion ports communicating with the liquid supply chamber are provided on the inner wall of the secondary separation pipe, and the liquid pumping assembly can convey the separation liquid to the liquid supply chamber. The secondary separation member further includes an infusion pipe communicating with the liquid infusion port. The extending direction of the infusion pipe is the same as the opening direction of the liquid infusion port, and the separation liquid in the liquid supply chamber is conveyed to the secondary separation pipe through the infusion pipe. A plurality of liquid infusion groups are provided at intervals along the extending direction of the secondary separation pipe. Each liquid infusion group includes a plurality of liquid infusion ports whose projections towards the axis direction of the secondary separation pipe coincide. The primary separation pipe includes a cylindrical section and a conical section. The primary feed inlet is arranged on the cylindrical section. One end of the conical section is connected to the cylindrical section, and the other end extends away from the cylindrical section and its cross-sectional area gradually decreases. At least part of the area in the conical section constitutes the return zone. It further includes a reflecting plate arranged in the return zone. There is a flow-through gap between the reflecting plate and the inner wall of the primary separation pipe, and the reflecting plate has a reflecting surface facing the secondary feed inlet.

2. The sludge sieve according to claim 1, wherein The included angle α between the plane where the opening direction of the liquid infusion port is located and the plane of the tangent line of the cross-sectional circle of the secondary separation pipe satisfies 0° < α ≤ 30°, and / or the included angle β between the plane where the opening direction of the liquid infusion port is located and the inner wall of the secondary separation pipe satisfies 70° ≤ β ≤ 85°.

3. The sludge sieve according to claim 1, wherein Both the primary separation pipe and the secondary separation pipe extend in the vertical direction, and the axial extension line of the primary separation pipe coincides with the axial extension line of the secondary separation pipe.

4. The sludge sieve according to claim 1, wherein The ratio of the width of the flow-through gap to the width of the reflecting surface is 11% - 25%.

5. The sludge sieve according to claim 1, wherein It further includes a pumping assembly, the pumping assembly includes a variable-frequency pump and a material conveying pipe, the variable-frequency pump conveys the sludge mixture to the primary feed inlet through the material conveying pipe, and the variable-frequency pump can adjust the pumping power to adjust the speed at which the sludge mixture enters the primary separation pipe.

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