Circulating sewage treatment device and method thereof

Abstract

The application relates to the technical field of sewage treatment, in particular to a circulating sewage treatment device and method thereof, which comprises a pretreatment unit, a biological reaction unit, a sedimentation unit, a filtering unit, a water outlet pipe and a circulating pipeline, the pretreatment unit is connected with the biological reaction unit, the biological reaction unit is connected with the sedimentation unit through a pipeline, the sedimentation unit is connected with the filtering unit through a pipeline, and the filtering unit is connected with the water outlet pipe. The circulating sewage treatment device and method thereof can intercept large-particle impurities through the pretreatment unit, can treat the silt by cooperating with a cyclone sand remover, and can ensure that one of the two sets of grid interception mechanisms can work normally when the other one is cleaned, and can adjust the angle of the partition sheet during cleaning, can increase the angle during cleaning, and can facilitate cleaning of the grid interception mechanism.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, and in particular to a circulating wastewater treatment device and method thereof. Background Technology

[0002] Wastewater treatment technology is a systematic engineering process that uses physical, chemical, and biological methods to purify wastewater. Its core objective is to remove pollutants and achieve water reuse.

[0003] Wastewater treatment technology has been widely applied and developed in recent years, especially in the treatment of industrial wastewater and domestic sewage. With increasingly stringent environmental regulations, traditional wastewater treatment methods can no longer meet the demands for efficient and low-cost treatment. Currently, common wastewater treatment technologies include physical, chemical, and biological methods. Physical methods mainly remove suspended solids through sedimentation and filtration; chemical methods use chemical agents to neutralize and perform oxidation-reduction reactions; and biological methods utilize microorganisms to degrade organic pollutants. Existing wastewater treatment equipment mainly includes pretreatment tanks, sedimentation tanks, aeration tanks, and filtration devices. In small-scale wastewater treatment systems, the screens in the wastewater treatment tanks are prone to clogging. While screens are typically cleaned manually, some impurities become trapped inside, requiring manual removal one by one, making cleaning inconvenient after clogging.

[0004] Therefore, this application provides a circulating wastewater treatment device and method. Summary of the Invention

[0005] The purpose of this application is to solve at least one technical problem raised in the background art.

[0006] This application provides a circulating wastewater treatment device, including a pretreatment unit, a biological reaction unit, a sedimentation unit, a filtration unit, an effluent pipe, and a circulation pipe.

[0007] The pretreatment unit is connected to the bioreactor unit, which is connected to the sedimentation unit via a pipe. The sedimentation unit is connected to the filtration unit via a pipe, and the filtration unit is connected to the effluent pipe. One end of the circulation pipe is connected to the effluent pipe, and the other end is connected to the bioreactor unit, which is used to return part of the treated water to the bioreactor unit.

[0008] By adopting the above technical solution, the pretreatment unit is used to receive the wastewater to be treated, the biological reaction unit is an MBR membrane bioreactor or an activated sludge reactor, the filtration unit includes a quartz sand filter or an activated carbon filter, and the circulation pipeline is equipped with a flow control valve and a return pump. The wastewater is treated by removing large particulate impurities in the pretreatment unit, and the pretreated water enters the biological reaction unit for biochemical degradation. The water after the biological reaction is separated into mud and water by the sedimentation unit, and the supernatant is discharged from the effluent pipe after further treatment in the filtration unit. 20%-50% of the effluent is returned to the biological reaction unit through the circulation pipeline. The microorganisms carried by the returned liquid can replenish the activated sludge concentration in the biological reaction unit and ensure the efficiency of the biochemical reaction.

[0009] Preferably, the pretreatment unit consists of a water storage tank, a bar screen interception mechanism, and a cyclone sand separator. The water storage tank is divided into two chambers by a partition. The bar screen interception mechanism adopts a mesh structure with rotatable partitions. Two sets of the bar screen interception mechanism are provided and are respectively installed in the two chambers. Water supply pipes are provided in both chambers and are connected to the cyclone sand separator through a T-junction.

[0010] By adopting the above technical solution, the partition is a louver structure. The rotatable partition can increase the spacing between the partitions. In addition, a grid interception mechanism is set in both chambers. When the grid interception mechanism is cleaned regularly, one grid interception mechanism can be cleaned while the other grid interception mechanism can work normally.

[0011] Preferably, the pretreatment unit consists of a water storage tank, a rotating grid mechanism, and a cyclone desander. The rotating grid mechanism includes a cylindrical frame rotatably fitted on the inner wall of the water storage tank, multiple grids fixedly installed on the inner wall of the cylindrical frame in a circular pattern, and a drive assembly located on the right side of the water storage tank to drive the cylindrical frame to rotate. A water inlet pipe is fixedly installed at the left end of the water storage tank, and one end of the water inlet pipe extends into the interior of the cylindrical frame.

[0012] Preferably, the drive assembly includes a motor, a connecting shaft is fixedly mounted on the output end of the motor, a spur gear is fixedly mounted on the surface of the connecting shaft, and the right end of the cylindrical frame extends to the right end of the water storage tank and is fixedly mounted with an external gear disk that meshes with the spur gear for transmission.

[0013] By adopting the above technical solution, when the inlet pipe transports the sewage to be treated into the rotating screen mechanism, the drive motor can drive the spur gear to rotate. The spur gear meshes with the external gear disc to drive the cylindrical frame to rotate, thereby allowing multiple screens to contact the sewage evenly. This can intercept large particles in the sewage, and the wastewater will pass through the screen and enter the cavity between the screen and the storage cylinder.

[0014] Preferably, the cylindrical frame is provided with a slag discharge mechanism, which includes a conveying cylinder, a conveying auger rotatably fitted on the inner wall of the conveying cylinder, a slag inlet on the surface of the conveying cylinder, a conical hopper fixedly installed on the inner wall of the slag inlet, and the conveying cylinder rotatably fitted with the inside of the cylindrical frame. One end of the conveying cylinder extends to the left end of the water storage cylinder, and the other end of the conveying cylinder is fixedly installed on the right end of the water storage cylinder by a support frame.

[0015] By adopting the above technical solution, when the cylindrical frame rotates, the large particles in the grid will rotate to a higher position and enter the conveying cylinder along the slag inlet due to gravity. The conical hopper facilitates the entry of large particles into the slag inlet.

[0016] Preferably, the right end of the conveying auger is provided with a linkage control mechanism, which includes a first sprocket fixedly installed on the right end of the conveying auger, a second sprocket fixedly installed on the surface of the connecting shaft, and the first sprocket and the second sprocket are connected by chain drive.

[0017] By adopting the above technical solution, when the drive motor drives the cylindrical frame to rotate, the second sprocket will rotate synchronously. The chain transmission can drive the conveying auger to rotate, so that the rotating conveying auger can transport large particles of impurities in the conveying cylinder to the outside.

[0018] Preferably, the surface of the water storage tank is provided with a backwashing mechanism. The backwashing mechanism includes a protective cover fixedly installed on the outer surface of the water storage tank. The protective cover is in communication with the interior of the water storage tank. A flushing pipe is fixedly installed inside the protective cover. A high-pressure nozzle is fixedly installed on the inner wall of the flushing pipe, and the high-pressure nozzle is located directly above the slag inlet. One end of the flushing pipe is connected to the water outlet pipe through a booster pump.

[0019] By adopting the above technical solution, when the screen becomes clogged, the booster pump will pump the treated water into the flushing pipe, and the water will be sprayed out through the high-pressure nozzle to clean the screen. The cleaned wastewater and large particles will enter the conveying cylinder for discharge.

[0020] Preferably, one end of the water storage tank is connected to the cyclone desander via a water guide pipe, and the other end of the water guide pipe extends into the interior of the water storage tank and is located outside the rotating grid mechanism.

[0021] By adopting the above technical solution, the water treated by the bar screen will enter the cavity between the water storage tank and the rotating bar screen mechanism, and then be fed into the cyclone desander through the water guide pipe.

[0022] Preferably, a support rod is fixedly installed on the inner wall of the water storage cylinder, and multiple hammers are rotatably connected at equal intervals on the surface of the support rod. A torsion spring for driving the hammers to contact the grid is provided on the surface of the support rod, and multiple arc-shaped protrusions are fixedly installed at equal intervals on the outer surface of the cylindrical frame.

[0023] By adopting the above technical solution, when the cylindrical frame rotates, it will drive the arc-shaped protrusion to rotate synchronously. When the arc-shaped protrusion rotates to the position of the hammer, it will drive the hammer to rotate away from the cylindrical frame. At this time, the torsion spring is in a stored state. When the arc-shaped protrusion rotates to disengage from the hammer, the torsion spring resets and drives the hammer to strike the grid. The vibration generated by the strike can help large particles of impurities stuck in the grid to disengage from the grid.

[0024] A circulating wastewater treatment method includes the following steps:

[0025] The wastewater to be treated enters the pretreatment unit to remove large suspended solids and gravel;

[0026] The pretreated water enters the biological reactor unit via pipelines for biochemical treatment;

[0027] The effluent from the biological reaction enters the sedimentation unit through pipelines to achieve mud-water separation;

[0028] The supernatant from the sedimentation unit enters the filtration unit for further treatment via pipeline;

[0029] The water produced by the filtration unit is discharged through the outlet pipe, while 20-50% of the treated water is returned to the biological reactor unit through the circulation pipe.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. The circulating sewage treatment device and method described in this application can intercept large particulate impurities through a pretreatment unit, and treat silt and sand in conjunction with a cyclone sand separator. The bar screen interception mechanism is designed as a mesh structure with rotatable baffles, and two sets are designed so that when one bar screen interception mechanism is cleaned, the other bar screen interception mechanism can work normally. At the same time, the angle of the baffles can be adjusted during cleaning, and the angle can be increased during cleaning to facilitate cleaning of the bar screen interception mechanism.

[0032] 2. The circulating sewage treatment device and method described in this application drive a motor to drive a spur gear to rotate. The spur gear meshes with an external gear disc to drive a cylindrical frame to rotate. The rotatable cylindrical frame, in conjunction with a screen, can increase the filtration area of ​​the device. When the cylindrical frame rotates, large particles in the screen will rotate to a higher position and enter the conveying cylinder along the slag inlet due to gravity, thus preventing excessive blockage of the screen by large particles.

[0033] 3. The circulating sewage treatment device and method described in this application, through the linkage control mechanism and the backwashing mechanism, when large particles of impurities enter the conveying cylinder, the motor drives the cylindrical frame to rotate, and the second sprocket will rotate synchronously. The chain drive can drive the conveying auger to rotate, so that the rotating conveying auger can transport the large particles of impurities in the conveying cylinder to the outside. When the impurities are stuck on the screen and cannot fall due to gravity, the backwashing mechanism is driven in conjunction with the hammer to wash and knock the screen, so as to flush the impurities stuck on the screen out of the screen, reducing the frequency of manual maintenance. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application;

[0035] Figure 2 This is a schematic diagram of the overall structure of Embodiment 2 of this application;

[0036] Figure 3 This is a partial structural diagram of the preprocessing unit in Embodiment 2 of this application;

[0037] Figure 4 This is a schematic diagram of the front section structure of the preprocessing unit in Embodiment 2 of this application;

[0038] Figure 5 yes Figure 4 Enlarged structural diagram at point A in the middle;

[0039] Figure 6 This is a three-dimensional structural diagram of the slag discharge mechanism according to Embodiment 2 of this application;

[0040] Figure 7 This is a schematic diagram of the three-dimensional structure of the tubular frame according to Embodiment 2 of this application.

[0041] Figure 8 This is a side sectional view of the water storage cylinder according to Embodiment 2 of this application.

[0042] Explanation of reference numerals in the attached drawings: 100, Pretreatment unit; 101, Water storage tank; 102, Bar screen interception mechanism; 103, Cyclone sand separator; 104, Baffle plate; 105, Water supply pipe; 106, Water storage cylinder; 107, Water guide pipe; 108, Cylindrical frame; 109, Water inlet pipe; 110, Motor; 111, Connecting shaft; 112, Spur gear; 113, External gear disc; 114, Bar screen; 115, Support rod; 116, Hammer; 117, Arc-shaped protrusion;

[0043] 200. Bioreaction Unit;

[0044] 300. Precipitation unit;

[0045] 400. Filter unit;

[0046] 500. Water outlet pipe;

[0047] 600. Circulation pipeline;

[0048] 700. Slag discharge mechanism; 701. Conveying cylinder; 702. Conveying auger; 703. Slag inlet; 704. Conical hopper; 705. Support frame;

[0049] 800. Linkage control mechanism; 801. First sprocket; 802. Second sprocket; 803. Chain;

[0050] 900. Backwashing mechanism; 901. Protective cover; 902. Flushing pipe; 903. High-pressure nozzle. Detailed Implementation

[0051] The following combination Figures 1 to 8 This application will be described in further detail below.

[0052] Example 1

[0053] Please refer to the following carefully. Figure 1 A circulating wastewater treatment device includes a pretreatment unit 100, a biological reactor unit 200, a sedimentation unit 300, a filtration unit 400, an effluent pipe 500, and a circulation pipe 600. The pretreatment unit 100 is connected to the biological reactor unit 200. The biological reactor unit 200 is connected to the sedimentation unit 300 through a pipe. The sedimentation unit 300 is connected to the filtration unit 400 through a pipe. The filtration unit 400 is connected to the effluent pipe 500 at one end and to the biological reactor unit 200 at the other end, for returning part of the treated water to the biological reactor unit 200.

[0054] Specifically, the pretreatment unit 100 is used to receive wastewater to be treated, the bioreactor 200 is an MBR membrane bioreactor or an activated sludge reactor, the filtration unit 400 includes a quartz sand filter or an activated carbon filter, and the circulation pipe 600 is equipped with a flow control valve and a return pump. The wastewater is treated by removing large particulate impurities and silt in the pretreatment unit 100. The pretreated water enters the bioreactor 200 for biochemical degradation. The water after the bioreactor enters the sedimentation unit 300 to achieve sludge-water separation. The supernatant enters the filtration unit 400 for further treatment and is discharged from the effluent pipe 500. 20%-50% of the effluent is returned to the bioreactor 200 through the circulation pipe 600. The microorganisms carried by the returned water can replenish the activated sludge concentration in the bioreactor 200 and ensure the efficiency of the biochemical reaction.

[0055] Please refer to this carefully. Figure 1The pretreatment unit 100 consists of a water storage tank 101, a bar screen interception mechanism 102, and a cyclone sand separator 103. The water storage tank 101 is divided into two chambers by a partition 104. The bar screen interception mechanism 102 adopts a mesh structure with rotatable partitions. Two sets of the bar screen interception mechanism 102 are provided and are respectively installed in the two chambers. A water supply pipe 105 is provided in each of the two chambers. The water supply pipe 105 is connected to the cyclone sand separator 103 through a tee pipe.

[0056] Specifically, a valve is installed on the surface of the water pipe 105, and the partition is a louver structure. The louver control mechanism drives its rotation (the louver control mechanism is a louver linkage control mechanism). The rotatable partition can increase the spacing between the partitions. A grid interception mechanism 102 is installed in both chambers. When the grid interception mechanism 102 is cleaned regularly, cleaning one grid interception mechanism 102 can ensure that the other grid interception mechanism 102 can work normally.

[0057] The working principle of this embodiment is as follows: The pretreatment unit 100 can intercept large particles of impurities, and the cyclone separator 103 can treat silt and sand. The grid interception mechanism 102 is designed as a mesh structure with rotatable baffles, and two sets are designed so that cleaning one grid interception mechanism 102 ensures the other can work normally. The baffle angle can be adjusted during cleaning; the angle can be increased to facilitate cleaning of the grid interception mechanism 102. During operation, wastewater enters the primary grid interception mechanism 102 through the storage tank 101. The louvered baffles are initially closed. The louvered baffle opening is adjusted to a suitable angle via the louvered linkage control mechanism, allowing large particles of impurities to pass through. After interception, the wastewater is transported to the cyclone sand separator 103. The sand separator 103 centrifuges the sand and gravel to settle. The pretreated water is then degraded for COD / BOD in the MBR membrane bioreactor. The sedimentation unit 300 achieves a MLSS removal rate of 95%. The supernatant is filtered by an activated carbon filter to adsorb trace organic matter. The return pump proportionally returns the water produced by the filtration unit 400 to the bioreactor unit 200 to replenish nitrifying bacteria. When the primary screen interception mechanism 102 becomes clogged, it automatically switches to the B-chamber screen interception mechanism 102. After that, the primary screen interception mechanism 102 is removed. The louver linkage mechanism drives the partition to rotate through the double rocker arm, achieving stepless adjustment from 0 to 30°. This allows the spacing between the partitions to be increased, making cleaning easier.

[0058] Example 2

[0059] Based on Example 1, refer to Figures 2 to 8 And unlike Example 1, the following is true:

[0060] Please refer to this carefully. Figures 2 to 5The pretreatment unit 100 consists of a water storage tank 106, a rotating screen mechanism, and a cyclone desander 103. The rotating screen mechanism includes a cylindrical frame 108 rotatably fitted on the inner wall of the water storage tank 106, multiple screens 114 circumferentially fixed on the inner wall of the cylindrical frame 108, and a drive assembly located on the right side of the water storage tank 106 to drive the cylindrical frame 108 to rotate. A water inlet pipe 109 is fixedly installed at the left end of the water storage tank 106, and one end of the water inlet pipe 109 extends into the interior of the cylindrical frame 108. The drive assembly includes a motor 110, a connecting shaft 111 is fixedly installed at the output end of the motor 110, and a spur gear 112 is fixedly installed on the surface of the connecting shaft 111. The right end of the cylindrical frame 108 extends to the right end of the water storage tank 106 and is fixedly installed with an external gear disk 113 that meshes with the spur gear 112 for transmission.

[0061] Specifically, when the inlet pipe 109 transports the sewage to be treated into the rotating screen mechanism, the drive motor 110 can drive the spur gear 112 to rotate. The spur gear 112 meshes with the external gear disk 113 to drive the cylindrical frame 108 to rotate, thereby allowing multiple screens 114 to contact the sewage evenly, thus intercepting large particles in the sewage. The wastewater will pass through the screens 114 and enter the cavity between the screens 114 and the water storage cylinder 106.

[0062] Please refer to this carefully. Figures 4 to 6 The cylindrical frame 108 is equipped with a slag discharge mechanism 700. The slag discharge mechanism 700 includes a conveying cylinder 701 and a conveying auger 702 rotatably fitted on the inner wall of the conveying cylinder 701. A slag inlet 703 is opened on the surface of the conveying cylinder 701. A conical hopper 704 is fixedly installed on the inner wall of the slag inlet 703. The conveying cylinder 701 is rotatably fitted with the inside of the cylindrical frame 108. One end of the conveying cylinder 701 extends to the left end of the water storage cylinder 106, and the other end of the conveying cylinder 701 is fixedly installed on the right end of the water storage cylinder 106 through a support frame 705.

[0063] Specifically, when the cylindrical frame 108 rotates, the conveying cylinder 701 will not rotate. At the same time, the large particles in the grid 114 will rotate to a higher position and enter the conveying cylinder 701 along the slag inlet 703 due to gravity. The conical hopper 704 facilitates the entry of large particles into the slag inlet 703.

[0064] Please refer to this carefully. Figures 4 to 7 The right end of the conveying auger 702 is provided with a linkage control mechanism 800. The linkage control mechanism 800 includes a first sprocket 801 fixedly installed on the right end of the conveying auger 702, and a second sprocket 802 fixedly installed on the surface of the connecting shaft 111. The first sprocket 801 and the second sprocket 802 are connected by a chain 803.

[0065] Specifically, when the drive motor 110 drives the cylindrical frame 108 to rotate, the second sprocket 802 will rotate synchronously. The chain 803 can drive the conveying auger 702 to rotate, so that the rotating conveying auger 702 can transport large particles of impurities in the conveying cylinder 701 to the outside.

[0066] Please refer to this carefully. Figures 2 to 3 The surface of the water storage cylinder 106 is provided with a backwashing mechanism 900. The backwashing mechanism 900 includes a protective cover 901 fixedly installed on the outer surface of the water storage cylinder 106. The protective cover 901 is connected to the interior of the water storage cylinder 106. A flushing pipe 902 is fixedly installed inside the protective cover 901. A high-pressure nozzle 903 is fixedly installed on the inner wall of the flushing pipe 902, and the high-pressure nozzle 903 is located directly above the slag inlet 703. One end of the flushing pipe 902 is connected to the water outlet pipe 500 through a booster pump.

[0067] Specifically, a water level sensor can be added inside the water storage tank 106. When the grille 114 is blocked, the grille 114 cannot drain water in time, and the water level in the water storage tank 106 will rise. When the alarm value of the water level sensor is reached, the booster pump is driven to pump the treated water into the flushing pipe 902. The water is then sprayed out through the high-pressure nozzle 903 to clean the grille 114. The cleaned sewage and large particles will enter the conveying cylinder 701 and be discharged.

[0068] Please refer to this carefully. Figures 2 to 3 One end of the water storage tank 106 is connected to the cyclone sand separator 103 through the water guide pipe 107, and the other end of the water guide pipe 107 extends into the interior of the water storage tank 106 and is located outside the rotating grid mechanism.

[0069] Specifically, the water treated by the bar screen 114 will enter the cavity between the water storage tank 106 and the rotating bar screen mechanism, and then be fed into the cyclone desander 103 by the water guide pipe 107.

[0070] Please refer to this carefully. Figure 8 A support rod 115 is fixedly installed on the inner wall of the water storage cylinder 106. Multiple hammers 116 are rotatably connected at equal intervals on the surface of the support rod 115. A torsion spring is provided on the surface of the support rod 115 to drive the hammers 116 to contact the grid 114. Multiple arc-shaped protrusions 117 are fixedly installed at equal intervals on the outer surface of the cylindrical frame 108.

[0071] Specifically, when the cylindrical frame 108 rotates, it will drive the arc-shaped protrusion 117 to rotate synchronously. When the arc-shaped protrusion 117 rotates to the position of the hammer 116, the hammer 116 will rotate away from the cylindrical frame 108 due to the force. At this time, the torsion spring is in a stored state. When the arc-shaped protrusion 117 rotates to disengage from the hammer 116, the torsion spring will reset and drive the hammer 116 to strike the grid 114. The vibration generated by the strike can help large particles of impurities stuck in the grid 114 to be removed from the grid 114.

[0072] The working principle of this embodiment is as follows: During operation, the inlet pipe 109 first transports the wastewater to be treated into the rotating screen mechanism. Then, the drive motor 110 drives the cylindrical frame 108 to rotate, thereby allowing multiple screens 114 to contact the wastewater evenly, thus intercepting large particles in the wastewater. The wastewater passes through the screens 114 and enters the cavity between the screens 114 and the storage tank 106. Then, it is input into the hydrocyclone desander 103 through the guide pipe 107. After centrifugal separation by the hydrocyclone desander 103, the large particles of impurities in the screens 114 are transported to a higher position by the cylindrical frame 108. When the large particles of impurities are directly above the slag inlet 703, they enter the conveying cylinder 701 due to gravity along the slag inlet 703. At the same time, when the motor 110 rotates, it drives the second sprocket 802 to rotate. The transmission of the chain 803 drives the conveying auger 702 to rotate, thereby utilizing the rotating conveying auger... Dragon 702 transports large particles of impurities in the conveying cylinder 701 to the outside. At the same time, when the cylindrical frame 108 rotates, it will drive the arc-shaped protrusion 117 to rotate synchronously. When the arc-shaped protrusion 117 contacts the hammer 116, the hammer 116 will rotate away from the cylindrical frame 108 due to the force. At this time, the torsion spring is in a stored state. When the arc-shaped protrusion 117 rotates to disengage from the hammer 116, the torsion spring will reset and drive the hammer 116 to strike the grid 114. The vibration generated by the strike can help the large particles of impurities stuck in the grid 114 to be removed from the grid 114. The booster pump is turned on periodically to pump the treated water into the flushing pipe 902. The water is sprayed out through the high-pressure nozzle 903 to flush the grid 114. Combined with the vibration generated by the hammer 116, the large particles of impurities stuck in the grid 114 can be washed off, preventing the large particles of impurities stuck in the grid 114 from clogging the grid 114 due to gravity.

[0073] A circulating wastewater treatment method includes the following steps:

[0074] The wastewater to be treated enters the pretreatment unit 100 to remove large suspended solids and sand;

[0075] The pretreated water enters the biological reactor 200 through pipelines for biochemical treatment;

[0076] The effluent from the biological reaction enters the sedimentation unit 300 through pipelines to achieve mud-water separation;

[0077] The supernatant from sedimentation unit 300 enters filtration unit 400 for further treatment via pipeline;

[0078] The water produced by the filtration unit 400 is discharged through the outlet pipe 500, while 20-50% of the treated water is returned to the biological reactor unit 200 through the circulation pipe 600.

Claims

1. A circulating sewage treatment device, characterized in that, include: The pretreatment unit (100), the bioreactor unit (200), the sedimentation unit (300), the filtration unit (400), the effluent pipe (500), and the circulation pipe (600). The pretreatment unit (100) is connected to the bioreactor unit (200), the bioreactor unit (200) is connected to the sedimentation unit (300) through a pipe, the sedimentation unit (300) is connected to the filtration unit (400) through a pipe, the filtration unit (400) is connected to the effluent pipe (500), and the circulation pipe (600) is connected to the effluent pipe (500) at one end and to the bioreactor unit (200) at the other end, for returning part of the treated water to the bioreactor unit (200).

2. The circulating sewage treatment device according to claim 1, characterized in that, The pretreatment unit (100) consists of a water storage tank (101), a bar screen interception mechanism (102), and a cyclone sand separator (103). The water storage tank (101) is divided into two chambers by a partition (104). The bar screen interception mechanism (102) adopts a mesh structure with rotatable partitions. There are two sets of the bar screen interception mechanism (102), which are respectively installed in the two chambers. A water supply pipe (105) is installed in each of the two chambers. The water supply pipe (105) is connected to the cyclone sand separator (103) through a three-way pipe.

3. The circulating sewage treatment device according to claim 1, characterized in that, The pretreatment unit (100) consists of a water storage tank (106), a rotating grid mechanism, and a cyclone sand remover (103). The rotating grid mechanism includes a cylindrical frame (108) rotatably fitted on the inner wall of the water storage tank (106), a plurality of grids (114) circumferentially fixed on the inner wall of the cylindrical frame (108), and a drive assembly located on the right side of the water storage tank (106) for driving the cylindrical frame (108) to rotate. A water inlet pipe (109) is fixedly installed on the left end of the water storage tank (106), and one end of the water inlet pipe (109) extends into the interior of the cylindrical frame (108).

4. A circulating sewage treatment device according to claim 3, characterized in that, The drive assembly includes a motor (110), a connecting shaft (111) is fixedly installed at the output end of the motor (110), a spur gear (112) is fixedly installed on the surface of the connecting shaft (111), and the right end of the cylindrical frame (108) extends to the right end of the water storage tank (106) and is fixedly installed with an external gear disk (113) that meshes with the spur gear (112).

5. A circulating sewage treatment device according to claim 4, characterized in that, The cylindrical frame (108) is provided with a slag discharge mechanism (700). The slag discharge mechanism (700) includes a conveying cylinder (701) and a conveying auger (702) rotatably fitted on the inner wall of the conveying cylinder (701). A slag inlet (703) is opened on the surface of the conveying cylinder (701). A conical hopper (704) is fixedly installed on the inner wall of the slag inlet (703). The conveying cylinder (701) is rotatably fitted with the inside of the cylindrical frame (108). One end of the conveying cylinder (701) extends to the left end of the water storage cylinder (106), and the other end of the conveying cylinder (701) is fixedly installed on the right end of the water storage cylinder (106) through a support frame (705).

6. A circulating sewage treatment device according to claim 5, characterized in that, The right end of the conveying auger (702) is provided with a linkage control mechanism (800). The linkage control mechanism (800) includes a first sprocket (801) fixedly installed on the right end of the conveying auger (702), and a second sprocket (802) fixedly installed on the surface of the connecting shaft (111). The first sprocket (801) and the second sprocket (802) are connected by a chain (803).

7. A circulating sewage treatment device according to claim 4, characterized in that, The surface of the water storage tank (106) is provided with a backwashing mechanism (900). The backwashing mechanism (900) includes a protective cover (901) fixedly installed on the outer surface of the water storage tank (106). The protective cover (901) is connected to the interior of the water storage tank (106). A flushing pipe (902) is fixedly installed inside the protective cover (901). A high-pressure nozzle (903) is fixedly installed on the inner wall of the flushing pipe (902). The high-pressure nozzle (903) is located directly above the slag inlet (703). One end of the flushing pipe (902) is connected to the water outlet pipe (500) through a booster pump.

8. A circulating sewage treatment device according to claim 7, characterized in that, One end of the water storage cylinder (106) is connected to the cyclone separator (103) via a water guide pipe (107), and the other end of the water guide pipe (107) extends into the interior of the water storage cylinder (106) and is located outside the rotating grid mechanism.

9. A circulating sewage treatment device according to claim 3, characterized in that, The inner wall of the water storage cylinder (106) is fixedly installed with a support rod (115), and a plurality of hammers (116) are equidistantly rotatably connected to the surface of the support rod (115). The surface of the support rod (115) is provided with a torsion spring for driving the hammers (116) to contact the grid (114). A plurality of arc-shaped protrusions (117) are fixedly installed at equal intervals on the outer surface of the cylindrical frame (108).

10. A circulating wastewater treatment method, applied to a circulating wastewater treatment device as described in any one of claims 1-9, characterized in that, Includes the following steps: The wastewater to be treated enters the pretreatment unit (100) to remove large suspended solids and gravel; The pretreated water enters the bioreactor (200) through pipelines for biochemical treatment; The effluent from the biological reaction enters the sedimentation unit (300) through pipelines to achieve mud-water separation; The supernatant from the sedimentation unit (300) enters the filtration unit (400) for further treatment via a pipeline; The water produced by the filtration unit (400) is discharged through the outlet pipe (500), while 20-50% of the treated water is returned to the bioreactor unit (200) through the circulation pipe (600).

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