A screening device for biological flocs and a semi-submerged sludge treatment system

Abstract

The utility model discloses a screening device for biological flocs and a semi-submerged sludge treatment system, which relates to the technical field of sewage treatment, and includes a backflow prevention cone, a fixing mechanism, and a cyclone cylinder with a cyclone separation chamber, wherein the backflow prevention cone is arranged in the cyclone separation chamber, the top small-diameter end of the backflow prevention cone is arranged upward, the fixing mechanism is arranged on the cyclone cylinder, and the backflow prevention cone is arranged on the fixing mechanism. The screening device for biological flocs of the utility model prevents the biological flocs and carriers that have been separated from each other from being mixed again by positively setting the backflow prevention cone in the cyclone cone.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a screening device for biological flocs and a semi-submerged sludge treatment system. Background Art

[0002] Existing cyclones are mostly used for mineral processing and separation or classification of materials with large density differences, and cannot be effectively applied to lightweight sludge and carriers with low density differences, small particle sizes, and easy dispersion.

[0003] In existing sewage treatment, the cyclone separator for separating light sludge and carrier has the technical problem of poor separation effect. Utility Model Content

[0004] The utility model provides a screening device for biological flocs, which solves the technical problem of poor separation effect of the existing cyclone separator.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] A screening device for biological flocs comprises a backflow prevention cone, a fixing mechanism and a cyclone cylinder with a cyclone separation chamber. The backflow prevention cone is arranged in the cyclone separation chamber, the top small-diameter end of the backflow prevention cone is arranged upward, the fixing mechanism is arranged on the cyclone cylinder, and the backflow prevention cone is arranged on the fixing mechanism.

[0007] Furthermore, a gap is left between the backflow prevention cone and the inner wall surface of the cyclone cylinder.

[0008] Furthermore, the anti-backflow cone is a solid cone.

[0009] Furthermore, the backflow prevention cone is a hollow cone, and the hollow cone is a thin-walled cone with an opening at the bottom.

[0010] Furthermore, the cyclone cylinder body comprises a coaxially arranged cyclone cone, a cyclone straight cylinder and a tail cone. The cyclone straight cylinder is arranged at the top opening position of the cyclone cone and is connected to the cyclone cone through a flange. A water inlet is arranged on the side wall surface of the cyclone straight cylinder. A central overflow pipe is arranged in the cyclone straight cylinder. The central overflow pipe is coaxially arranged with the cyclone straight cylinder. The tail cone is arranged at the bottom opening position of the cyclone cone and is connected to the cyclone cone through a flange. A heavy outlet is opened on the bottom center axis of the tail cone, and an anti-backflow cone is arranged in the cyclone cone.

[0011] Furthermore, the cone angle of the cyclone cone is 2 to 15 degrees.

[0012] Furthermore, a first end of the fixing mechanism is fixedly connected to the cyclone cone, a second end of the fixing mechanism is fixedly connected to the anti-backflow cone, the fixing mechanism comprises a fixed horizontal frame and a fixed vertical frame, the fixed horizontal frame is laterally erected on the cyclone cone, the fixed vertical frame is in the cyclone separation chamber, a first end of the fixed vertical frame is connected to the fixed horizontal frame, and a second end of the fixed vertical frame is fixedly connected to the anti-backflow cone.

[0013] Furthermore, the fixed horizontal frame is transversely erected at the top opening position of the cyclone cone, and the second end of the fixed vertical frame is fixedly connected to the top small-diameter end of the anti-backflow cone.

[0014] Furthermore, the fixing mechanism includes a bottom support fixing frame and a center support frame, the bottom support fixing frame is fixedly arranged on the tail cone, the center support frame is coaxially arranged with the cyclone cone, the first end of the center support frame passes through the cyclone straight cylinder and is supported on the cyclone straight cylinder, the second end of the center support frame passes through the bottom support fixing frame and is supported on the bottom support fixing frame, the center support frame is movably arranged along the height, and the movably adjusted center support frame is fixed to the bottom support fixing frame by tightening bolts, the center support frame passes through the anti-backflow cone, and the anti-backflow cone is fixed on the center support frame.

[0015] The utility model also provides a semi-submerged sludge treatment system, comprising the above-mentioned screening device for biological flocs.

[0016] The utility model has the following beneficial effects:

[0017] The utility model discloses a screening device for biological flocs, comprising a backflow prevention cone, a fixing mechanism and a cyclone cylinder. The backflow prevention cone is arranged in a cyclone separation chamber of the cyclone cylinder through the fixing mechanism, the top small-diameter end of the backflow prevention cone is arranged upward, and the bottom large-diameter end of the backflow prevention cone is arranged downward. By arranging the backflow prevention cone, the backflow of biological flocs and carriers that have been separated can be prevented from causing re-mixing. After the backflow prevention cone is installed, the generation of backmixing can be effectively suppressed, and the cyclone separator has a good separation effect.

[0018] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0020] Figure 1 It is a cross-sectional three-dimensional structural schematic diagram of a screening device for biological flocs in one embodiment of the utility model;

[0021] Figure 2 yes Figure 1 One of the structural schematic diagrams of the anti-reflux cone in FIG.

[0022] Figure 3 yes Figure 1 The second structural diagram of the anti-backflow cone;

[0023] Figure 4 It is a structural schematic diagram of a screening device for biological flocs in one embodiment of the utility model;

[0024] Figure 5 It is a cross-sectional view of a screening device for biological flocs in one embodiment of the utility model;

[0025] Figure 6 It is a structural schematic diagram of a screening device for biological flocs in another embodiment of the utility model;

[0026] Figure 7 It is a cross-sectional view of a screening device for biological flocs in another embodiment of the utility model;

[0027] Figure 8 It is a cross-sectional view of a screening device for biological flocs in yet another embodiment of the utility model.

[0028] Description of Figure Numbers:

[0029] 100. Screening device for biological flocs; 10. Anti-backflow cone; 20. Fixing mechanism;

[0030] 21. Fixed horizontal frame; 22. Fixed vertical frame; 23. Bottom support fixed frame; 24. Center support frame;

[0031] 30. Cyclone cone; 40. Cyclone straight cylinder; 50. Center overflow pipe; 60. Tail cone. DETAILED DESCRIPTION

[0032] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0036] Through research, it was found that in the existing sewage treatment, the cyclone separator that separates light sludge and carriers has already completed the separation of biological flocs and carriers inside the cyclone. It is easy to form an air column under high-speed hydraulic conditions near the underflow outlet of the cyclone, which produces backflow and back mixing, causing the central overflow pipe to discharge heavy biological flocs and complete carriers that should have been discharged from the underflow, resulting in poor separation effect.

[0037] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, the utility model provides a screening device 100 for biological flocs, including a backflow prevention cone 10, a fixing mechanism 20 and a cyclone cylinder with a cyclone separation chamber, the backflow prevention cone 10 is arranged in the cyclone separation chamber, the top small diameter end of the backflow prevention cone 10 is arranged upward, the fixing mechanism 20 is arranged on the cyclone cylinder, and the backflow prevention cone 10 is arranged on the fixing mechanism 20.

[0038] It can be understood that the fixing mechanism 20 can be completely arranged in the cyclone cone 30, or partially arranged in the cyclone cone 30; the fixing mechanism 20 and the cyclone cone 30 can be detachably connected or fixedly connected. The screening device 100 for biological flocs provided by the utility model includes an anti-backflow cone 10, a fixing mechanism 20 and a cyclone cylinder. The anti-backflow cone 10 is arranged in the cyclone separation chamber of the cyclone cylinder through the fixing mechanism 20. The top small diameter end of the anti-backflow cone 10 is arranged upward, and the bottom large diameter end of the anti-backflow cone 10 is arranged downward. The bottom surface of the anti-backflow cone 10 is set to block and prevent the separated biological flocs and carriers from flowing back and causing re-mixing. After the anti-backflow cone is installed, the generation of backmixing can be effectively suppressed, and the cyclone separator has a good separation effect.

[0039] It can be understood that the anti-backflow cone 10 can be a cone or a truncated cone, as long as the large-diameter end of the bottom of the anti-backflow cone 10 is arranged below the small-diameter end of the top so that the anti-backflow cone 10 is placed upright, the radial dimension of the anti-backflow cone 10 gradually shrinks from the bottom to the top, and the anti-backflow cone 10 can suppress the generation of back mixing; optionally, the fixing mechanism 20 can be a bolt fixing part, a welding part or other connecting fixing parts, as long as the anti-backflow cone 10 is fixed in the cyclone cylinder through the fixing mechanism 20; it can be understood that in the present utility model, the anti-backflow cone 10 can be an upper suspension installation, or an upper suspension plus lower support installation.

[0040] It can be understood that in the present invention, the cyclone cylinder includes a coaxially arranged cyclone cone 30, a cyclone straight cylinder 40 and a tail cone 60, and a bottom flow port is provided at the bottom of the cyclone cone 30, and the bottom flow port is connected to the tail cone 60; the anti-backflow cone 10 and the cyclone cone 30 can be coaxially arranged or offset. In a preferred embodiment of the present invention, the anti-backflow cone 10 and the cyclone cone 30 are coaxially arranged to improve the efficiency of suppressing back mixing.

[0041] Furthermore, a gap is left between the anti-backflow cone 10 and the inner wall surface of the cyclone cylinder. It can be understood that in the present invention, the fixed height of the anti-backflow cone 10 can be adjusted, the position of the back-mixing can be adjusted, and the size of the gap can be adjusted.

[0042] Further, the anti-backflow cone 10 is a solid cone, or the anti-backflow cone 10 is a hollow cone, and the hollow cone is a thin-walled cone with an opening at the bottom. In the utility model, the anti-backflow cone 10 can be a solid cone or a hollow cone, as long as the bottom surface of the anti-backflow cone 10 can be set to block, and it can be set according to specific circumstances.

[0043] Please refer to Figure 4 and Figure 5Furthermore, the cyclone cylinder body includes a coaxially arranged cyclone cone 30, a cyclone straight cylinder 40 and a tail cone 60. The cyclone straight cylinder 40 is arranged at the top opening position of the cyclone cone 30 and is connected to the cyclone cone 30 through a flange. A water inlet is provided on the side wall surface of the cyclone straight cylinder 40. A central overflow pipe 50 is provided in the cyclone straight cylinder 40. The central overflow pipe 50 is coaxially arranged with the cyclone straight cylinder 40. The tail cone 60 is arranged at the bottom opening position of the cyclone cone 30 and is connected to the cyclone cone 30 through a flange. A heavy outlet (sand settling port) is opened on the bottom center axis of the tail cone 60. The anti-backflow cone 10 is arranged in the cyclone cone 30. In a specific embodiment of the present invention, the fixed horizontal frame 21 is radially mounted on the cyclone cone 30, an internal thread hole is provided on the fixed horizontal frame 21, and the first end of the fixed vertical frame 22 is an external thread connection section, and the first end of the fixed vertical frame 22 is fixedly connected to the fixed horizontal frame 21 through threaded matching connection. Optionally, the fixed horizontal frame 21 is a cross, or a cross or a cross arranged in a cross shape.

[0044] Furthermore, the cone angle of the cyclone cone 30 is 2 to 15 degrees.

[0045] Further, the first end of the fixing mechanism 20 is fixedly connected to the cyclone cone 30, the second end of the fixing mechanism 20 is fixedly connected to the anti-backflow cone 10, the fixing mechanism 20 includes a fixing horizontal frame 21 and a fixing vertical frame 22, the fixing horizontal frame 21 is horizontally erected on the cyclone cone 30, the fixing vertical frame 22 is in the cyclone separation chamber, the first end of the fixing vertical frame 22 is connected to the fixing horizontal frame 21, and the second end of the fixing vertical frame 22 is fixedly connected to the anti-backflow cone 10

[0046] More preferably, the fixed horizontal frame 21 is a cross with a through hole in the center. The fixed horizontal frame 21 is horizontally arranged at the top opening position of the cyclone cone 30. The first end of the fixed vertical frame 22 is arranged through the through hole, and the second end of the fixed vertical frame 22 is fixedly connected to the top small-diameter end of the anti-backflow cone 10.

[0047] Furthermore, the fixed vertical frame 22 is adjustable in height direction, and the fixed vertical frame 22 is fixed to the fixed horizontal frame 21 by connecting fasteners, and the through holes are threaded holes.

[0048] Furthermore, the water inlet is arranged near the top of the cyclone cylinder 40, and the first end of the central overflow pipe 50 extends downward to be below the water inlet.

[0049] Further, a first end of the fixing mechanism 20 is fixedly connected to the cyclone cone 30, a second end of the fixing mechanism 20 is fixedly connected to the anti-backflow cone 10, the fixing mechanism 20 comprises a fixed horizontal frame 21 and a fixed vertical frame 22, the fixed horizontal frame 21 is horizontally erected on the cyclone cone 30, the fixed vertical frame 22 is in the cyclone separation chamber, a first end of the fixed vertical frame 22 is connected to the fixed horizontal frame 21, and a second end of the fixed vertical frame 22 is fixedly connected to the anti-backflow cone 10.

[0050] Furthermore, the water inlet is arranged near the top of the cyclone cylinder 40, and the first end of the central overflow pipe 50 extends downward to be below the water inlet.

[0051] For further information, please refer to Figure 6 and Figure 7 In another embodiment of the utility model, the fixing mechanism 20 includes a bottom support frame 23 and a center support frame 24. The bottom support frame is fixedly arranged on the tail cone 60. The center support frame 24 is coaxially arranged with the cyclone cone 30. The first end of the center support frame 24 passes through the cyclone straight tube 40 and is supported on the cyclone straight tube 40. The second end of the center support frame 24 passes through the bottom support frame 23 and is supported on the bottom support frame 23. The center support frame 24 is movably arranged along the height. The center support frame 24 after movable adjustment is fixed to the bottom support frame 23 by tightening bolts. The center support frame 24 passes through the anti-backflow cone 10, and the anti-backflow cone 10 is fixed on the center support frame 24. By setting the bottom support frame 23 to be arranged on the periphery of the cyclone cylinder, and the center support frame 24 to be arranged to penetrate the cyclone cylinder along the axial direction, the cyclone flow field in the cyclone cylinder will not be disturbed, and the cyclone effect is guaranteed. At the same time, the center support frame 24 is also conducive to eliminating the air column.

[0052] Furthermore, the bottom support fixing frame 23 includes at least two cross-arranged U-shaped frames, the top of the U-shaped frame is fixedly connected to the flange of the tail cone 60, and a central mounting hole for the central support frame 24 to pass through is provided at the intersection of the U-shaped frames.

[0053] For further information, please refer to Figure 8 A pressure monitor 70 is provided at the bottom opening of the central overflow pipe 50, a sand settling port is provided at the bottom of the tail cone 60, and a flow regulating shuttle 80 is also arranged on the central support frame 24. The flow regulating shuttle 80 is a shuttle body with a gradually changing cross section. The flow regulating shuttle is movably arranged along the axial direction of the central support frame 24 and is fixed by a top screw. The gap between the flow regulating shuttle 80 and the inner wall surface of the tail cone 60 is adjusted by adjusting the axial height of the flow regulating shuttle 80 to finally adjust the diameter of the sand settling port.

[0054] More preferably, the outer edge surface area of ​​the anti-backflow cone 10 is 1 / 2 of the cross-sectional area of ​​the cyclone straight cylinder 40; the moving range of the anti-backflow cone is 1 / 8-1 / 3 of the height of the entire cone cylinder from the height of the sand settling port; specifically, the lowest point of the anti-backflow cone 10 is 1 / 10 of the height of the cyclone cone cylinder 30 from the sand settling port, and the highest point is 1 / 3 of the height of the cyclone cone cylinder 30 from the sand settling port; the central support frame 24 adopts a central support shaft, the shaft diameter of the central support shaft is 20-50mm, a thicker central shaft is used to occupy the central air column and the back mixing is suppressed by the anti-backflow cone 10, and the separation effect is good.

[0055] In the scheme of the utility model, the elimination methods of the air column specifically include: 1. adopting a semi-submerged operation mode to eliminate the air column by water pressure; 2. adopting a central support shaft with a shaft diameter of 20ˉ50mm to replace the position of the air column, that is, eliminating the air column by occupying the space; 3. adding an anti-backflow cone 10 to eliminate the air column by the blocking effect of the anti-backflow cone section. The combination of the three methods allows the cyclone to achieve a good separation and dilution effect, while effectively reducing the operating energy consumption.

[0056] In the solution of the utility model, a semi-submerged operation mode is adopted, an anti-backflow cone 10 is added, and the final device shape after multiple structural adjustments can achieve an effective dilution effect under low-pressure conditions. The specific test results are shown in Table 1.

[0057] Table 1

[0058]

[0059] Among them, the dilution multiple is: overflow mud sample concentration / inlet mud sample concentration. The dilution multiple index is used to evaluate the dilution effect of the cyclone on the mixed liquid mud sample. The lower the dilution multiple, the better the cyclone effect. It can be seen that the screening device for biological flocs provided by the utility model has a cyclone effect far higher than other conventional cyclones at a pressure of 0.15MPa to 0.25MPa in a semi-submerged operation mode.

[0060] The functions of the various structures of the screening device 100 for biological flocs proposed in the utility model patent are as follows: the material (biochemical pool sludge) enters the hydrocyclone straight cylinder 40 tangentially from the water inlet after being pressurized by a water pump; the biochemical pool sludge enters tangentially and is centrifugally concentrated in the straight cylinder part, and sludge and carriers with different characteristics generate vortexes in this part; the biochemical pool sludge enters the hydrocyclone cone 30 after being centrifugally concentrated in the hydrocyclone straight cylinder 40, and the heavy biological flocs and complete carriers move to the wall surface under the action of centrifugal force, and the light biological flocs and broken carriers are squeezed to the center position, and the cone part area of ​​the hydrocyclone cone 30 gradually shrinks, increasing the centrifugal force, generating a hydraulic squeezing effect, and discharging the light biological flocs and broken carriers through the central overflow pipe 50; the anti-backflow cone is placed upright and installed on the central axis, and is also fixed to the vertical frame through threaded or bolted cooperation. 22 Synchronous movement realizes up and down adjustment to prevent the separated biological flocs and carriers from re-mixing at the bottom. After installing the anti-backflow cone, the backmixing can be effectively suppressed. The anti-backflow cone can be set as a hollow structure or a solid structure; the anti-backflow cone can be adjusted up and down inside the cyclone through the installation axis, which can adapt to materials of different properties, different water inlet pressures and different installation heights; the installation of the anti-backflow cone can achieve effective separation under low-pressure conditions (the operating pressure of the conventional cyclone is above 0.2MPa, and the cyclone can achieve effective separation between 0.04MPaˉ0.2MPa), because the upright design of the anti-backflow cone can form an upward thrust that gradually weakens from the center to the surroundings for the separated light biological flocs and broken carriers inside, thereby reducing the inlet pressure; when installing a conventional cyclone, the bottom of the cyclone cannot be directly submerged in the material. The design of the anti-backflow cone can ensure that even if there is static pressure outside, it will not have a significant impact on the inside of the cyclone, so the cyclone can be installed in a submerged manner to reduce the installation height; the anti-backflow cone can be adjusted up and down inside the cyclone through the installation shaft, and can adapt to materials of different properties, different water inlet pressures and different installation heights. The bottom flow outlet is used to discharge heavy biological flocs and complete carriers. The screening device for biological flocs proposed by the utility model installs an upright anti-backflow cone in the cone section of the cyclone, which can effectively separate sludge flocs of different sludge ages and characteristics as well as broken and complete carriers. At the same time, due to its special structure, it can effectively reduce the installation height and greatly reduce the operating energy consumption.

[0061] The utility model also provides a semi-submerged sludge treatment system, including the above-mentioned screening device 100 for biological flocs.

[0062] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A screening device for biological flocs, characterized in that: It includes a backflow prevention cone, a fixing mechanism and a cyclone cylinder with a cyclone separation chamber. The anti-backflow cone is arranged in the cyclone separation chamber, and the top small-diameter end of the anti-backflow cone is arranged upward. The fixing mechanism is arranged on the cyclone cylinder, and the anti-backflow cone is arranged on the fixing mechanism.

2. The screening device for biological flocs according to claim 1, characterized in that: A gap is left between the anti-backflow cone and the inner wall surface of the cyclone cylinder.

3. The screening device for biological flocs according to claim 1, characterized in that: The anti-backflow cone is a solid cone.

4. The screening device for biological flocs according to claim 1, characterized in that: The anti-backflow cone is a hollow cone, and the hollow cone is a thin-walled cone with an opening at the bottom.

5. The screening device for biological flocs according to any one of claims 1 to 4, characterized in that: The cyclone cylinder body comprises a cyclone cone, a cyclone straight cylinder and a tail cone which are coaxially arranged. The cyclone straight cylinder is arranged at the top opening position of the cyclone cone and is connected to the cyclone cone through a flange. A water inlet is arranged on the side wall surface of the cyclone straight cylinder. A central overflow pipe is arranged in the cyclone straight cylinder. The central overflow pipe is coaxially arranged with the cyclone straight cylinder. The tail cone is arranged at the bottom opening position of the cyclone cone and is connected to the cyclone cone through a flange. A heavy outlet is opened on the bottom center axis of the tail cone. The anti-backflow cone is arranged in the cyclone cone.

6. The screening device for biological flocs according to claim 5, characterized in that: The cone angle of the cyclone cone is 2 to 15 degrees.

7. The screening device for biological flocs according to claim 5, characterized in that: The first end of the fixing mechanism is fixedly connected to the cyclone cone, and the second end of the fixing mechanism is fixedly connected to the anti-backflow cone. The fixing mechanism comprises a fixed horizontal frame and a fixed vertical frame, wherein the fixed horizontal frame is horizontally erected on the cyclone cone, the fixed vertical frame is located in the cyclone separation chamber, the first end of the fixed vertical frame is connected to the fixed horizontal frame, and the second end of the fixed vertical frame is fixedly connected to the anti-backflow cone.

8. The screening device for biological flocs according to claim 7, characterized in that: The fixed horizontal frame is horizontally erected at the top opening position of the cyclone cone, and the second end of the fixed vertical frame is fixedly connected to the top small-diameter end of the anti-backflow cone.

9. The screening device for biological flocs according to claim 5, characterized in that: The fixing mechanism comprises a bottom support fixing frame and a center support frame, wherein the bottom support fixing frame is fixedly arranged on the tail cone. The central support frame is coaxially arranged with the cyclone cone, the first end of the central support frame passes through the cyclone straight cylinder and is supported on the cyclone straight cylinder, the second end of the central support frame passes through the bottom support fixing frame and is supported on the bottom support fixing frame, the central support frame is movably arranged along the height, and the movably adjusted central support frame is fixed to the bottom support fixing frame by tightening bolts, The central support frame is arranged through the anti-backflow cone, and the anti-backflow cone is fixed on the central support frame.

10. A semi-submerged sludge treatment system, characterized in that: It comprises the screening device for biological flocs as described in any one of claims 1 to 9.

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