A papermaking wastewater sedimentation recovery device

Abstract

The present application relates to wastewater treatment technical field, propose a kind of papermaking wastewater precipitation recovery device, including air floatation equipment and filter tank, still include filter cartridge, wastewater pipe, backwashing recovery component, biological filter and biological filtration component, filter cartridge two ends are respectively sealed and rotationally sleeved with bearing support, two bearing supports are symmetrically arranged, filter tank is installed on installation rack, bearing support is fixedly installed in installation rack interior, wastewater pipe is fixedly installed on installation rack, backwashing recovery component is installed in filter cartridge interior, biological filter is internally provided with water distribution groove, filter area and overflow area, biological filtration component is installed in biological filter interior, by the above technical scheme, for solving the problem that small fiber, colloid and mixed impurities in wastewater in prior art are prone to block filter structure, leading to the process of wastewater treatment is discontinuous, frequent shutdown cleaning filter structure is needed, leading to the problem of low overall processing efficiency and stability.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a sedimentation and recovery device for papermaking wastewater. Background Technology

[0002] Papermaking wastewater mainly originates from the two major process stages of pulping and papermaking. In the pulping stage, steps such as material preparation, cooking, washing, screening, and bleaching generate a large amount of wastewater, which generally contains lignin, hemicellulose, and other recalcitrant organic matter, as well as alkaline substances. In the bleaching stage, toxic wastewater containing chlorinated organic compounds is generated. In the papermaking stage, the wastewater from the papermaking stage also contains fibers, fillers, and additives. In addition, equipment cleaning water is also a source of wastewater.

[0003] In existing technologies, the wastewater generated during these papermaking processes generally needs to be treated by a combination of processes to remove pollutants. During treatment, the pollutants in a suspended state are first removed through physical filtration and sedimentation, which mainly include coarse bark, wood chips and fibers, as well as some fine fibers, fillers (such as calcium carbonate and talc) and colloidal substances in the water, in order to reduce the turbidity and most of the solid content of the wastewater. For dissolved biodegradable organic matter in the wastewater (such as hemicellulose, sugars, organic acids and alcohols), biological treatment is required.

[0004] Microorganisms (mainly bacteria) use these pollutants as a nutrient source and decompose them into carbon dioxide, water and sludge through metabolic activities. In the specific treatment process, the pretreated wastewater is first discharged into an aerobic bioreactor. Under oxygenated conditions, the microbial community (activated sludge) adsorbs and oxidizes and decomposes dissolved organic matter. Then the mixed liquid enters the secondary sedimentation tank for sludge-water separation. The supernatant is discharged, while most of the settled sludge is recycled to maintain the biomass in the reactor, and a small portion is discharged from the system as excess sludge.

[0005] During the recycling and treatment of papermaking wastewater, the large amount of fine fibers and colloidal substances present in the wastewater, along with impurities such as ink and adhesives in addition to fibers, can easily clog the pores of screens or filter cloths. This leads to a rapid increase in filtration resistance, resulting in a reduction in treatment capacity and the need for frequent shutdowns for cleaning, making it difficult to ensure the continuity of wastewater treatment. Summary of the Invention

[0006] This invention proposes a papermaking wastewater sedimentation and recovery device to solve the problem in the prior art where fine fibers, colloids and mixed impurities in wastewater easily clog the filter structure, resulting in discontinuous wastewater treatment process, frequent shutdowns to clean the filter structure, and low overall treatment efficiency and stability.

[0007] The technical solution of the present invention is as follows: A papermaking wastewater sedimentation and recovery device includes an air flotation unit and a filter tank, and further includes: A filter cartridge, with sealed and rotatably fitted support brackets at both ends, two support brackets arranged symmetrically, and an installation frame installed on the filter tank, with the support brackets fixedly installed inside the installation frame; Wastewater pipe, which is fixedly installed on the mounting frame, with the output end of the wastewater pipe located inside the filter cylinder; A backwashing and recovery assembly is installed inside the filter cartridge to filter solids in the wastewater and collect the filtered substances. A biological filter, wherein the biological filter is provided with a water distribution tank, a filtration zone and an overflow zone, and the overflow zone is connected to a drain pipe; A biological filtration assembly is installed inside the biological filter tank to treat organic matter in wastewater through the degradation effect of biofilm and microorganisms.

[0008] Based on the aforementioned scheme, the backwashing and recovery assembly includes: The toothed rings are rotatably installed inside both of the two bearing brackets, and the toothed rings are fixedly fitted onto the filter cylinder. The gears are rotatably mounted inside both of the two bearing brackets, and the two gears mesh with the two gear rings respectively. The two gears are coaxially connected by a connecting shaft. A driving component is fixedly mounted on the mounting frame, and the output end of the driving component is fixedly connected to one of the gears; The filter structure is provided on the filter cylinder for filtering and collecting solid substances in wastewater. A backwash collection unit, installed inside the mounting frame, is used to collect the filtered solid material and transport it out.

[0009] Based on the aforementioned scheme, the filtering structure includes: The filter cylinder has several sets of filter holes arranged in a circular shape at equal angles inside. Each set of filter holes has several holes, and the several filter holes in each set are arranged at intervals along the axial direction of the filter cylinder. The filter cylinder has several partition plates fixedly installed in a circular shape at equal angles inside, and the partition plates are arranged alternately with several sets of filter holes.

[0010] Based on the aforementioned scheme, the backwash collection unit includes: A water supply pipe, which is installed inside the mounting frame; A drainage rack is fixedly installed between two of the supporting supports. Each drainage rack has a water spray groove at its bottom. The drainage rack is sealed and slidably fitted with the filter cylinder. Each drainage rack is connected to the water supply pipe by a branch pipe. A collection hopper is fixedly installed inside the mounting frame. The collection hopper is located inside the filter cylinder, and there is space between the two sides of the collection hopper and the inner wall of the filter cylinder. A screw conveyor is installed inside the mounting frame. The input end of the screw conveyor is connected to the output end of the collection hopper for conveying collected solid materials.

[0011] Based on the aforementioned scheme, a first water pump is also included. The input end of the first water pump is connected to the filter tank through an input pipe, and the output end of the first water pump is connected to an output pipe. The output end of the output pipe is located in the reaction zone of the air flotation device.

[0012] Based on the aforementioned solution, the biofiltration component includes: Aeration pipes: Several aeration pipes are installed inside the biological filter, and the aeration pipes are located at the bottom of the filtration zone. An air supply pipe, several aeration pipes are all connected to the air supply pipe, and the air supply pipe is connected to the air supply equipment; Aeration discs, several aeration discs are fixedly installed on each aeration pipe, and an assembly cylinder is installed on each aeration disc; The water distribution section is installed inside the biological filter tank and is used to pass the wastewater that has passed through the air flotation device into the assembly cylinder and into the filtration zone. The primary mixing section is provided inside each of the assembly cylinders to mix the discharged wastewater and air bubbles together.

[0013] Based on the aforementioned scheme, the water distribution unit includes: The filter area is provided with a plurality of water distribution pipes, each of which corresponds one-to-one with a plurality of aeration pipes, and the water distribution pipes are connected to the water distribution tank. An annular cavity is provided inside each of the assembly cylinders, and a connecting pipe is installed on each assembly cylinder. The connecting pipe is connected to the annular cavity and the water distribution pipe. Drainage holes: Each of the annular cavities has a number of drainage holes arranged in a circular shape at equal angles.

[0014] Based on the aforementioned scheme, a second water pump is also included. The input end of the second water pump is connected to the clear water tank of the air flotation device through an inlet pipe, and the output end of the second water pump is connected to the water distribution tank through an outlet pipe.

[0015] Based on the aforementioned scheme, the initial mixing section includes: A mesh plate bracket is fixedly installed on the top of each assembly cylinder; A hybrid fan is rotatably mounted on the bottom of each of the mesh plate supports.

[0016] Based on the aforementioned scheme, the biological filter is provided with a support layer and a filter media layer inside. The support layer is laid at the bottom of the filtration zone, and the filter media layer is laid on the support layer.

[0017] The working principle and beneficial effects of this invention are as follows: 1. In this invention, as the filter cylinder rotates, when the two adjacent partition plates containing impurities are rotated to the bottom of the drainage frame, the water supply pipe is turned on, and water is introduced into the corresponding drainage frame through the branch pipe. The water is then sprayed out through the spray trough, and the sprayed water backwashes the filter holes, thereby flushing out the impurities attached around the filter holes and between the two adjacent partition plates, causing them to fall into the collection hopper. Then, the screw conveyor can be turned on to transport the impurities that have entered the collection hopper out and recycle them. This achieves continuous operation without stopping the machine, improves the online rate and processing capacity of the equipment, and reduces the intensity and cost of manual maintenance.

[0018] 2. In this invention, as aeration continues, the wastewater in the distribution tank enters the corresponding annular cavity through the distribution pipe and the connecting pipe on the distribution pipe. At this time, the wastewater enters the assembly cylinder through the drain hole. When the wastewater and air are discharged into the assembly cylinder at the same time, they are initially mixed together and then discharged from the top of the assembly cylinder by the mixing fan. At this time, the mixing fan rotates, thereby promoting the mixing of the two, which facilitates the full contact between oxygen in the air and wastewater, improves oxygen transfer efficiency and biofilm degradation rate of organic matter, and makes the biological treatment section more efficient and energy-saving.

[0019] 3. In this invention, by setting up the backwashing and recovery component, the clogging fibers can be automatically removed without stopping the machine, thereby solving the clogging problem in the filtration process and allowing the fibers to be continuously recovered. By setting up the biological filtration component, the mass transfer efficiency of oxygen and pollutants is improved before the wastewater enters the filter media layer, thereby enhancing the ability of microorganisms to degrade dissolved organic matter, making the microbial treatment more thorough and energy-efficient. Attached Figure Description

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 2 This is a three-dimensional structural diagram from another angle in the present invention; Figure 3 This is a three-dimensional structural diagram of the backwashing and recovery component in this invention; Figure 4 This is a three-dimensional structural schematic diagram of the backwashing and recovery component in this invention. Figure 5 This is a cross-sectional three-dimensional structural diagram showing the cooperation between the backwash recovery component and the backwash collection section in this invention; Figure 6 This is a cross-sectional three-dimensional structural diagram showing the cooperation between the backwashing and recovery component and the filter structure in this invention. Figure 7 This is a three-dimensional structural diagram of the biological filtration component in this invention; Figure 8 This is a cross-sectional three-dimensional structural diagram of the biological filtration component in this invention; Figure 9 This is a cross-sectional planar structural diagram of the biological filtration component in this invention; Figure 10 This is a three-dimensional structural diagram showing the cross-sectional view of the water distribution section and the initial mixing section in this invention. Figure 11 This is a three-dimensional structural diagram of the water distribution section in this invention.

[0022] In the diagram: 1. Air flotation equipment; 2. Filter tank; 3. Filter cartridge; 4. Support bracket; 5. Mounting frame; 6. Wastewater pipe; 7. Biological filter; 701. Water distribution trough; 702. Filtration zone; 703. Overflow zone; 8. Drainage pipe; 9. Gear ring; 10. Gear; 11. Connecting shaft; 12. Drive component; 13. Filter hole; 14. Partition plate; 15. Water supply pipe; 16. Drainage frame; 17. Spray trough; 18. Branch pipe; 19. Collection... 20. Screw conveyor; 21. First water pump; 22. Inlet pipe; 23. Outlet pipe; 24. Aeration pipe; 25. Air supply pipe; 26. Air supply equipment; 27. Aeration disc; 28. Assembly cylinder; 29. ​​Water distribution pipe; 30. Annular cavity; 31. Connecting pipe; 32. Drain hole; 33. Second water pump; 34. Water inlet pipe; 35. Water outlet pipe; 36. Mesh plate support; 37. Mixing fan; 38. Support layer; 39. Filter media layer. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] like Figures 1 to 11 As shown, this embodiment proposes a papermaking wastewater sedimentation and recovery device, including an air flotation device 1 and a filter tank 2, as well as a filter cylinder 3, a wastewater pipe 6, a backwashing and recovery assembly, a biological filter tank 7, and a biological filtration assembly. The filter cylinder 3 has sealed and rotatably mounted support brackets 4 at both ends, with the two support brackets 4 arranged symmetrically. An installation frame 5 is mounted on the filter tank 2, and the support brackets 4 are fixedly installed inside the installation frame 5. The wastewater pipe 6 is fixedly installed on the installation frame 5, with its output end located inside the filter cylinder 3. The backwashing and recovery assembly is installed inside the filter cylinder 3 to filter solids in the wastewater and collect the filtered substances. The backwashing and recovery assembly includes a gear ring 9 and a gear 1. 0. Drive component 12, filter structure and backwash collection unit. Gear rings 9 are rotatably installed inside the two support brackets 4. The gear rings 9 are fixedly fitted on the filter cylinder 3. Gears 10 are rotatably installed inside the two support brackets 4. The two gears 10 mesh with the two gear rings 9 respectively. The two gears 10 are coaxially connected by a connecting shaft 11. Drive component 12 is fixedly installed on the mounting frame 5. Drive component 12 is a motor. The output end of drive component 12 is fixedly connected to one of the gears 10. The filter cylinder 3 is provided with a filter structure for filtering and collecting solid matter in wastewater. The backwash collection unit is installed inside the mounting frame 5 for collecting the filtered solid matter and conveying it out.

[0025] Specifically, when papermaking wastewater needs to be treated, the wastewater is first introduced into the filter cylinder 3 through the wastewater pipe 6. After entering the filter cylinder 3, the wastewater undergoes physical filtration through the filtration structure to remove larger fibers. The filtered wastewater then enters the filter tank 2, where it undergoes preliminary sedimentation. The wastewater in the filter tank 2 is then sent to the air flotation device 1 for further treatment. Microbubbles are used to remove fine fibers, colloids, some pigments, and recalcitrant organic matter, forming scum that is scraped off. The wastewater treated by the air flotation device 1 is then introduced into the biological filter tank 7, where it is treated by the biological filtration components to remove dissolved pollutants that are difficult to remove by physical methods. The treated wastewater can then be introduced into the next stage.

[0026] When filtering wastewater through the filter structure, the drive unit 12 is activated. Under the action of the connecting shaft 11, the drive unit 12 synchronously drives the two gears 10 to rotate, thereby stably driving the filter cylinder 3 to rotate through the two gear rings 9. This prevents impurities (referring to solid substances, fibers, etc., hereinafter collectively referred to as impurities) from clogging the filter structure, which would make effective filtration difficult. The filtered impurities will adhere to the filter structure. As the filter cylinder 3 rotates, when the corresponding area of ​​the filter cylinder 3 with attached impurities moves to the position of the backwash collection section, the backwash collection section is activated to wash the impurities off the filter structure and transport them out. Then, the fibers and other impurities can be recovered.

[0027] It should be noted that after the wastewater undergoes physical filtration, it enters the filter tank 2, where it will settle. This allows some unfiltered impurities to settle to the bottom of the filter tank 2, facilitating wastewater treatment. The settled wastewater will then be transported to the reaction zone of the air flotation device 1.

[0028] When treating the pre-filtered wastewater using the flotation equipment 1, the wastewater is first introduced into the reaction zone, and then flocculants and coagulants are continuously added to the reaction zone. The wastewater, flocculants, and coagulants are mixed together by a stirring device. After effective flocculation reaction, the wastewater enters the flotation contact zone. In the contact zone, microbubbles in the dissolved air water adhere to the flocculated suspended solids and then enter the separation zone together. At this time, the overall density of the suspended solids with a large number of microbubbles is less than 1. The flocs and bubbles rise to the liquid surface together to form scum, thereby achieving solid-liquid separation. These scum are scraped to the sludge zone by a skimmer, while the clear water at the bottom flows to the clear water tank through a water collection pipe and other structures. Part of the clear water in the clear water tank is returned to the dissolved air system for use, and the other part enters the next stage for treatment.

[0029] like Figures 4 to 6 As shown above, the filter structure includes filter holes 13 and partition plates 14. The filter cylinder 3 has several sets of filter holes 13 arranged in a circumferential shape at equal angles inside. Each set of filter holes 13 has several holes, and the several filter holes 13 in each set are arranged at intervals along the axis of the filter cylinder 3. Several partition plates 14 are fixedly installed in a circumferential shape at equal angles inside the filter cylinder 3. The several partition plates 14 and the several sets of filter holes 13 are arranged alternately.

[0030] Specifically, when the wastewater entering the filter cylinder 3 is physically filtered, the wastewater will be discharged into the filter tank 2 through the filter hole 13, while the impurities in the wastewater will remain in the filter cylinder 3. As the wastewater continuously enters the filter cylinder 3, these impurities will also remain between the two adjacent partition plates 14 under the flushing of the wastewater. As the filter cylinder 3 rotates, the two adjacent partition plates 14 containing the impurities will be rotated to the collection position, and the impurities can be recovered.

[0031] like Figures 3 to 6 As shown above, the backwash collection unit includes a water supply pipe 15, a drain rack 16, a collection hopper 19, and a screw conveyor 20. The water supply pipe 15 is installed inside the mounting frame 5. Several drain racks 16 are fixedly installed between the two support brackets 4. Each drain rack 16 has a spray channel 17 at its bottom. The spray channel 17 is designed as a long and thin strip to facilitate water spraying. The drain rack 16 is sealed and slidably fitted with the filter cylinder 3. Each drain rack 16 is connected to the water supply pipe 15 by a branch pipe 18. The collection hopper 19 is fixedly installed. Inside the mounting frame 5, the collection hopper 19 is located inside the filter cylinder 3. There is space between the two sides of the collection hopper 19 and the inner wall of the filter cylinder 3. The mounting frame 5 is equipped with a screw conveyor 20. The input end of the screw conveyor 20 is connected to the output end of the collection hopper 19 for conveying the collected solid material. It also includes a first water pump 21. The input end of the first water pump 21 is connected to the filter tank 2 through the input pipe 22. The output end of the first water pump 21 is connected to the output pipe 23. The output end of the output pipe 23 is located in the reaction zone of the air flotation device 1.

[0032] Specifically, before treating the wastewater, the water source is connected to the water supply pipe 15. As the filter cylinder 3 rotates, when the two adjacent partition plates 14 containing impurities are rotated to the bottom of the drainage rack 16, the water supply pipe 15 is turned on, and water is introduced into the corresponding drainage rack 16 through the branch pipe 18. The water is then sprayed out through the water spray trough 17. The sprayed water backwashes the filter holes 13, thereby flushing out the impurities attached to the filter holes 13 and between the two adjacent partition plates 14, causing them to fall into the collection hopper 19. At this time, the screw conveyor 20 can be turned on to transport the impurities that have entered the collection hopper 19 out and recycle them.

[0033] When it is necessary to transport the wastewater in the filter tank 2 to the reaction zone of the air flotation device 1, the first water pump 21 is turned on, the wastewater is drawn out through the input pipe 22, and then sent into the reaction zone through the output pipe 23.

[0034] like Figures 7 to 11As shown, the biological filter 7 is internally equipped with a water distribution trough 701, a filtration zone 702, and an overflow zone 703. The overflow zone 703 is connected to a drain pipe 8. A biological filtration assembly is installed inside the biological filter 7 to treat organic matter in wastewater through the degradation action of biofilm and microorganisms. The biological filtration assembly includes an aeration pipe 24, an air supply pipe 25, an aeration disc 27, a water distribution section, and a primary mixing section. Several aeration pipes 24 are installed inside the biological filter 7, and the aeration pipes 24 are located in the filtration zone 7. At the bottom of 02, several aeration pipes 24 are connected to air supply pipes 25, and air supply pipes 25 are connected to air supply equipment 26. Several aeration discs 27 are fixedly installed on each aeration pipe 24, and an assembly cylinder 28 is installed on each aeration disc 27. The water distribution part is installed inside the biological filter 7 and is used to pass the wastewater that has passed through the air flotation device 1 into the assembly cylinder 28 and into the filtration zone 702. Each assembly cylinder 28 is equipped with a primary mixing part, which is used to mix the discharged wastewater and air bubbles together.

[0035] Specifically, when treating the wastewater after it has been treated by the air flotation device 1, the wastewater is sent into the distribution tank 701. The wastewater entering the distribution tank 701 enters the filtration zone 702 through the distribution section. At the same time, the air supply device 26 is turned on to supply air into the air supply pipe 25. The air in the air supply pipe 25 enters the aeration pipe 24 and is discharged through the aeration disc 27. Meanwhile, the wastewater in the distribution tank 701 enters the primary mixing zone through the distribution section, thereby uniformly mixing the wastewater and air together in the assembly cylinder 28. Then, the biofilm attached to the surface of the filter media layer 39 inside the biological filter tank 7 reacts with the wastewater to remove the dissolved pollutants in the wastewater. The wastewater passing through the filter media layer 39 flows into the overflow zone 703. At this time, the treated wastewater is transported to the next stage through the drainage pipe 8.

[0036] like Figures 7 to 11 As shown above, the water distribution section includes a water distribution pipe 29, an annular cavity 30, and a drain hole 32. Several water distribution pipes 29 are arranged inside the filtration zone 702. The several water distribution pipes 29 correspond one-to-one with several aeration pipes 24. The water distribution pipes 29 are connected to the water distribution tank 701. Each assembly cylinder 28 is provided with an annular cavity 30. Each assembly cylinder 28 is equipped with a connecting pipe 31. The connecting pipe 31 is connected to the annular cavity 30 and the water distribution pipe 29. Several drain holes 32 are opened in a circular shape at equal angles inside each annular cavity 30. The section also includes a second water pump 33. The input end of the second water pump 33 is connected to the clear water tank of the air flotation device 1 through the water inlet pipe 34. The output end of the second water pump 33 is connected to the water distribution tank 701 through the water outlet pipe 35.

[0037] Specifically, as aeration continues, the wastewater in the distribution tank 701 enters the corresponding annular cavity 30 through the distribution pipe 29 and the connecting pipe 31 on the distribution pipe 29. At this time, the wastewater will enter the assembly cylinder 28 through the drain hole 32 and initially mix with the air discharged from the aeration disc 27. Then, the wastewater passes through the support layer 38 from the bottom of the filter tank and enters the filter media layer 39. Through the setting of the filter media layer 39, organic matter is oxidized and decomposed by microorganisms.

[0038] It should be noted that as filtration proceeds, the amount of new microorganisms generated on the surface of the filter media increases, and the amount of impurities trapped continuously increases. In the initial stage, the head loss of the filter bed increases slowly. When the accumulation of solid matter reaches a certain level, the filter bed needs to be backwashed to remove the aging biofilm and impurities. The aging biofilm and impurities are discharged from the biological filter bed 7 with the backwash water, restoring its treatment capacity.

[0039] When it is necessary to send the wastewater from the clear water tank of the flotation device 1 into the distribution tank 701, the second water pump 33 is turned on, the wastewater is drawn out through the inlet pipe 34, and then sent into the distribution tank 701 through the outlet pipe 35.

[0040] like Figure 10 As shown above, the primary mixing section includes a mesh plate bracket 36 and a mixing fan 37. A mesh plate bracket 36 is fixedly installed on the top of each assembly cylinder 28, and a mixing fan 37 is rotatably installed on the bottom of each mesh plate bracket 36.

[0041] Specifically, when wastewater and air are discharged into the assembly cylinder 28 at the same time, they will initially mix together and enter the filtration zone 702 from the top of the assembly cylinder 28 as the wastewater and air are continuously discharged. When the wastewater and air pass through the mixing fan 37, the mixing fan 37 will rotate, thereby promoting the mixing of the two. The mesh plate bracket 36 provides support for the mixing fan 37 and prevents the support layer 38 from affecting the discharge of wastewater and air.

[0042] like Figure 9 As shown above, the biological filter 7 is internally provided with a support layer 38 and a filter media layer 39. The support layer 38 is laid at the bottom of the filtration zone 702 and is generally composed of pebbles of a certain gradation. It is mainly used to support the filter media and prevent the filter media from being lost during filtration. At the same time, it allows the backwash water to be evenly distributed to the filter layer. The filter media layer 39 is laid on the support layer 38 and is composed of special filter media with a single particle size. It is the main area for biological attachment and growth. The filter media is used to adsorb dissolved and colloidal organic pollutants in wastewater and to provide a surface for the growth and reproduction of microorganisms, thereby carrying out biochemical reactions.

[0043] The working principle or usage process of this application is as follows: Before treating the wastewater, the water source is connected to the water supply pipe 15. When papermaking wastewater needs treatment, it is fed into the filter cylinder 3 through the wastewater pipe 6 to remove larger fibers. After filtration, the wastewater enters the filter tank 2, while impurities remain in the filter cylinder 3. As wastewater continuously enters the filter cylinder 3, these impurities are also flushed out and retained between two adjacent partition plates 14. During filtration, the drive unit 12 is activated. Under the action of the connecting shaft 11, the drive unit 12 synchronously drives two gears 10 to rotate, thereby stably rotating the filter cylinder 3 through two gear rings 9 to prevent impurities from entering. (Referring to solid substances, fibers, etc., hereinafter collectively referred to as impurities) clogging affects the filtration effect. As the filter cylinder 3 rotates, when the two adjacent partition plates 14 containing impurities are rotated to the bottom of the drain rack 16, the water supply pipe 15 is turned on, and water is introduced into the corresponding drain rack 16 through the branch pipe 18. The water is sprayed out through the water spray trough 17, and the sprayed water backwashes the filter holes 13, thereby flushing out the impurities attached to the filter holes 13 and between the two adjacent partition plates 14, causing them to fall into the collection hopper 19. At this time, the screw conveyor 20 can be turned on to transport the impurities that have entered the collection hopper 19 out and recycle them.

[0044] When it is necessary to transport the wastewater in the filter tank 2 to the reaction zone of the flotation equipment 1, the first water pump 21 is turned on, the wastewater is drawn out through the input pipe 22, and then sent into the reaction zone through the output pipe 23. The flotation equipment 1 uses microbubbles to scrape off the scum formed by fine fibers, colloids, some pigments and recalcitrant organic matter. When it is necessary to send the wastewater in the clear water tank of the flotation equipment 1 into the distribution tank 701, the second water pump 33 is turned on, the wastewater is drawn out through the inlet pipe 34, and then sent into the distribution tank 701 through the outlet pipe 35.

[0045] When treating the wastewater after it has been treated by the air flotation device 1, the air supply device 26 is turned on to supply air into the air supply pipe 25. The air in the air supply pipe 25 enters the aeration pipe 24 and is discharged through the aeration disc 27. As aeration continues, the wastewater in the water distribution tank 701 enters the corresponding annular cavity 30 through the water distribution pipe 29 and the connecting pipe 31 on the water distribution pipe 29. At this time, the wastewater will enter the assembly cylinder 28 through the drain hole 32. When the wastewater and air are discharged into the assembly cylinder 28 at the same time, they will initially mix together and enter the filtration zone 702 from the top of the assembly cylinder 28. When the wastewater and air pass through the mixing fan 37, the mixing fan 37 rotates, thereby promoting the mixing of the two. The screen plate bracket 36 provides support for the mixing fan 37 and prevents the support layer 38 from affecting the discharge of wastewater and air.

[0046] Then, the wastewater and air will pass through the support layer 38 from the bottom of the filter tank and enter the filter media layer 39. Through the filter media layer 39, the organic matter is oxidized and decomposed by microorganisms. The wastewater passing through the filter media layer 39 will flow into the overflow area 703. At this time, the treated wastewater can be transported to the next stage through the drain pipe 8.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sedimentation and recovery device for papermaking wastewater, comprising an air flotation unit (1) and a filter tank (2), characterized in that, Also includes: The filter cylinder (3) is sealed at both ends and rotatably fitted with a support bracket (4). The two support brackets (4) are arranged symmetrically. The filter tank (2) is equipped with an installation frame (5). The support bracket (4) is fixedly installed inside the installation frame (5). Wastewater pipe (6), the wastewater pipe (6) is fixedly installed on the mounting frame (5), and the output end of the wastewater pipe (6) is located inside the filter cylinder (3); A backwashing and recovery assembly is installed inside the filter cylinder (3) to filter solid substances in wastewater and collect the filtered substances. The biological filter (7) is provided with a water distribution tank (701), a filtration zone (702) and an overflow zone (703) inside, and the overflow zone (703) is connected to a drain pipe (8). A biological filtration assembly is installed inside the biological filter (7) to treat organic matter in wastewater through degradation by biofilm and microorganisms. The backwashing and recovery assembly includes: Toothed ring (9), the toothed ring (9) is rotatably installed inside both of the two bearing brackets (4), and the toothed ring (9) is fixedly fitted on the filter cylinder (3); Gear (10), both of the two bearing brackets (4) are rotatably mounted with the gear (10), the two gears (10) mesh with the two gear rings (9) respectively, and the two gears (10) are coaxially connected by a connecting shaft (11); A drive unit (12) is fixedly mounted on the mounting frame (5), and the output end of the drive unit (12) is fixedly connected to one of the gears (10); The filter structure is provided on the filter cylinder (3) for filtering and collecting solid substances in wastewater; A backwash collection unit is installed inside the mounting frame (5) to collect the filtered solid material and transport it out. The filtering structure includes: The filter cylinder (3) has several sets of filter holes (13) arranged in a circular shape at equal angles inside. Each set of filter holes (13) has several holes, and the several filter holes (13) in each set are arranged at intervals along the axis of the filter cylinder (3). The filter cylinder (3) has several partition plates (14) fixedly installed in a circular shape at equal angles inside the filter cylinder (3). The several partition plates (14) and several sets of filter holes (13) are arranged alternately. The backwash collection unit includes: Water supply pipe (15), the water supply pipe (15) is installed inside the mounting frame (5); A drainage rack (16) is fixedly installed between two support brackets (4). Each drainage rack (16) has a water spray groove (17) at its bottom. The drainage rack (16) is sealed and slidably fitted with the filter cylinder (3). Each drainage rack (16) is connected to the water supply pipe (15) by a branch pipe (18). Collection hopper (19) is fixedly installed inside the mounting frame (5). The collection hopper (19) is located inside the filter cylinder (3). There is space between the two sides of the collection hopper (19) and the inner wall of the filter cylinder (3). The screw conveyor (20) is installed inside the mounting frame (5). The input end of the screw conveyor (20) is connected to the output end of the collection bucket (19) for conveying the collected solid material. The biofiltration component includes: Aeration pipe (24): Several aeration pipes (24) are installed inside the biological filter (7), and the aeration pipes (24) are located at the bottom of the filtration zone (702). Aeration discs (27), several aeration discs (27) are fixedly installed on each aeration pipe (24), and each aeration disc (27) is equipped with an assembly cylinder (28). The primary mixing section is provided inside each of the assembly cylinders (28) for mixing the discharged wastewater and air bubbles together; Water distribution section, which is installed inside the biological filter (7), is used to pass the wastewater that has passed through the air flotation device (1) into the assembly cylinder (28) and into the filtration zone (702). The water distribution unit includes: Water distribution pipe (29), a plurality of water distribution pipes (29) are provided inside the filtration zone (702), the plurality of water distribution pipes (29) correspond one-to-one with the plurality of aeration pipes (24), and the water distribution pipes (29) are connected to the water distribution tank (701); An annular cavity (30) is provided inside each of the assembly cylinders (28), and a connecting pipe (31) is installed on each of the assembly cylinders (28). The connecting pipe (31) is connected to the annular cavity (30) and the connecting pipe (31) is connected to the water distribution pipe (29). Drainage holes (32): Each of the annular cavities (30) has a number of drainage holes (32) arranged in a circular shape at equal angles. The initial mixing section includes: Mesh plate bracket (36), each of the assembly cylinders (28) is fixedly installed with the mesh plate bracket (36) on its top; A hybrid fan (37) is rotatably mounted on the bottom of each of the mesh plate supports (36).

2. The papermaking wastewater sedimentation and recovery device according to claim 1, characterized in that, It also includes a first water pump (21), the input end of the first water pump (21) is connected to the filter tank (2) through the input pipe (22), the output end of the first water pump (21) is connected to the output pipe (23), and the output end of the output pipe (23) is located in the reaction zone of the air flotation device (1).

3. The papermaking wastewater sedimentation and recovery device according to claim 2, characterized in that, The biofiltration assembly also includes: The air supply pipe (25) and several aeration pipes (24) are connected to the air supply pipe (25), and the air supply pipe (25) is connected to the air supply equipment (26).

4. The papermaking wastewater sedimentation and recovery device according to claim 3, characterized in that, It also includes a second water pump (33), the input end of which is connected to the clear water tank of the air flotation device (1) through a water inlet pipe (34), and the output end of the second water pump (33) is connected to the water distribution tank (701) through a water outlet pipe (35).

5. The papermaking wastewater sedimentation and recovery device according to claim 4, characterized in that, The biological filter (7) is provided with a support layer (38) and a filter media layer (39). The support layer (38) is laid at the bottom of the filtration zone (702), and the filter media layer (39) is laid on the support layer (38).

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