Treatment device for waste water containing PVA (Polyvinyl Alcohol) slurry

Abstract

The invention relates to the technical field of PVA-containing slurry wastewater treatment, in particular to a PVA-containing slurry wastewater treatment device which comprises a treatment barrel, a centrifugal filter barrel is rotationally connected into the treatment barrel, a dirt blocking frame is fixedly connected to the treatment barrel, an automatic dirt removing mechanism is rotationally connected to the dirt blocking frame, and a dirt pushing plate is arranged at the top end of the dirt blocking frame in a sliding fit mode. A secondary treatment seat is fixedly connected to one side of the top end of the dirt blocking frame, a discharging wheel is rotatably connected to the interior of the secondary treatment seat, and an extrusion transmission mechanism is arranged on the secondary treatment seat in a sliding fit mode. The dirt scraping plate is arranged on the dirt blocking frame, so that the dirt scraping plate can push filtered materials in the centrifugal filter barrel blocked by the dirt blocking frame out of the centrifugal filter barrel in time, shutdown treatment is not needed, blockage and efficiency reduction are avoided, the stability and continuity of the filtering process are ensured, meanwhile, manual cleaning work is reduced, the automation degree of the equipment is improved, and the equipment is more efficient and saves more energy.

Description

Technical Field

[0001] The invention relates to the technical field of treatment of wastewater containing PVA slurry, and in particular to a treatment device for wastewater containing PVA slurry. Background Art

[0002] PVA slurry, full name polyvinyl alcohol slurry, is a material made of polyvinyl alcohol (PVA) dissolved in water, usually in the form of a gel or viscous liquid. PVA is a water-soluble synthetic polymer widely used in various industrial and civilian products. PVA slurry is usually made by mixing PVA and water in a certain proportion, with good solubility and adjustable viscosity. PVA slurry is often used to make various types of adhesives, especially for bonding paper, wood, textiles, etc.

[0003] Application of PVA slurry: Coatings: PVA slurry can be used as one of the base materials for water-based coatings and is widely used in architectural coatings, paper coatings, printing and other fields. It has good adhesion and durability in coatings. Textiles: PVA slurry is used as a sizing agent in the textile industry to improve the flatness and glossiness of fabrics, especially in the weaving process. Paper processing: It is used for coating and surface treatment of paper to enhance the smoothness, water resistance and strength of paper.

[0004] The treatment of wastewater containing PVA (polyvinyl alcohol) slurry is a complex process. The main challenge is that PVA has poor water solubility and biodegradability, which makes it difficult to be naturally degraded or directly removed in wastewater. Therefore, it is necessary to combine multiple treatment methods to effectively treat wastewater containing PVA slurry and reduce environmental pollution. The treatment of wastewater containing PVA slurry needs to comprehensively consider the properties of the wastewater, the concentration of PVA and the treatment cost. Usually, physical, chemical, biological and membrane separation technologies need to be combined to effectively remove PVA and other organic pollutants. For wastewater containing PVA, common treatment solutions include: physical precipitation and filtration, oxidative degradation (such as ozone oxidation), biodegradation, reverse osmosis and other technologies.

[0005] In the process of treating wastewater containing PVA, centrifugal filtration is performed. During the centrifugal filtration process, the equipment needs to be shut down regularly to clean the filtrate, which will increase the downtime and affect the efficiency of the entire treatment process. Frequent shutdowns mean that the time of the filtration process is unstable, which may lead to a decrease in the overall treatment capacity. Untimely or incomplete cleaning may cause the accumulation of filter residues or pollutants in the system, thereby affecting the subsequent treatment efficiency and the normal operation of the equipment. Long-term accumulation may cause equipment damage or reduce the service life of the equipment.

[0006] In summary, the prior art lacks a technology for automated cleaning of PVA-containing wastewater during centrifugal treatment. Summary of the invention

[0007] The purpose of the present invention is to solve the shortcomings existing in the background technology and to propose a treatment device for wastewater containing PVA slurry.

[0008] In order to achieve the above objectives, the technical solution adopted by the present invention is: a treatment device for wastewater containing PVA slurry, comprising a treatment barrel, a centrifugal filter barrel is rotatably connected inside the treatment barrel, a dirt blocking frame is fixedly connected to the treatment barrel, an automatic dirt removal mechanism is rotatably connected to the dirt blocking frame, a dirt pushing plate is slidably provided on the top of the dirt blocking frame, a secondary treatment seat is fixedly provided on one side of the top of the dirt blocking frame, a discharge wheel is rotatably provided inside the secondary treatment seat, and an extrusion transmission mechanism is slidably provided on the secondary treatment seat.

[0009] Preferably, a water inlet pipe is fixedly installed on the top of the processing barrel, the other end of the water inlet pipe is connected to the top of the dirt retaining frame, and a drainage pipe is fixedly connected to the bottom of the processing barrel.

[0010] Preferably, a pin is fixedly connected to the bottom end of the centrifugal filter barrel, the other end of the pin passes through the inner wall of the processing barrel and extends to the outside and is fixedly connected to a motor, the motor is fixedly connected to the lower surface of the processing barrel, and an arc-shaped rack is fixedly connected to the top end of the centrifugal filter barrel.

[0011] Preferably, the automatic dirt removal mechanism includes two pulleys, the pulleys are rotatably connected to the dirt blocking frame, a pressure sensor is installed at the top of the dirt blocking frame, a belt is arranged for friction transmission between the two pulleys, a plurality of scraping plates are connected and fixedly arranged on the belt, the scraping plates are slidingly matched with the inner wall of the centrifugal filter barrel, one end of the pulley at the top is connected and fixedly arranged with a rotating shaft, one end of the rotating shaft passes through the inner wall of the dirt blocking frame and extends to the outside and is connected and fixedly arranged with a transmission wheel, and the transmission wheel is arranged for meshing transmission with an arc-shaped rack.

[0012] Preferably, the lower outer wall of the dirt pushing plate is arranged in sliding contact with the dirt scraping plate and the outer wall of the belt, the top of the dirt pushing plate is rotatably connected with a connecting rod group, the other end of the connecting rod group is rotatably connected with the top of the dirt blocking frame, one end of the connecting rod group connected to the dirt blocking frame is connected and fixedly provided with a gear, one side of the gear is meshingly transmitted with a rack, an electric push rod is connected and fixedly provided on the rack, and the electric push rod is fixedly connected to the dirt blocking frame.

[0013] Preferably, a water pipe is fixedly connected to one end of the secondary processing seat, and the other end of the water pipe is fixedly connected to the processing barrel. A filter is fixedly connected to the inner wall of the secondary processing seat at the position of the water pipe, and a material receiving seat is slidably provided at the opening at the bottom end of the secondary processing seat.

[0014] Preferably, one end of the discharge wheel passes through the secondary processing seat and the water pipe in sequence and is connected and fixed with a universal joint, one end of the universal joint is connected and fixed with a transmission rod, the transmission rod is rotatably connected to the secondary processing seat, and the top of the transmission rod is connected and fixed with an engaging wheel.

[0015] Preferably, the extrusion transmission mechanism includes a contact rod, one end of the contact rod is slidably matched with the top of the dirt blocking frame, the top of the contact rod is movably contacted with the dirt pushing plate, the bottom end of the contact rod is slidably matched with the secondary processing seat, the bottom end of the contact rod is connected and fixedly provided with an extrusion block, the extrusion block is slidably contacted with the secondary processing seat and the discharge wheel, a tension spring is connected and fixedly provided on the contact rod, and the other end of the tension spring is connected and fixedly provided with the secondary processing seat.

[0016] Preferably, a gear rack is fixedly connected to the contact rod, and the inner wall of the gear rack is rotatably connected with a plurality of meshing teeth in a linear structure, one end of the meshing teeth is fixedly connected to a spring, and the other end of the spring is fixedly connected to the inner wall of the gear rack, and the meshing teeth are meshed with a meshing wheel for transmission.

[0017] Compared with the prior art, the present invention has the following beneficial effects: When using a centrifugal filter barrel to treat wastewater containing PVA slurry, the rotating centrifugal filter barrel can drive the automatic dirt removal mechanism to rotate intermittently, so that the belt drives multiple scraping plates to rotate, so that the scraping plates can push the filtered materials in the centrifugal filter barrel blocked by the dirt blocking frame out of the centrifugal filter barrel in time, without stopping the machine for treatment, avoiding blockage and efficiency reduction, ensuring the stability and continuity of the filtration process, and reducing manual cleaning work, improving the automation level of the equipment, making it more efficient and energy-saving; By setting a dirt-pushing plate, when the pressure sensor detects that the dirt-pushing plate rotates to the top opening of the dirt-blocking frame, it can drive the dirt-pushing plate to move, and automatically push the filtered material scraped from the centrifugal filter barrel by the dirt-pushing plate into the secondary treatment seat, thereby ensuring the cleanliness of the dirt-pushing plate and not affecting the working efficiency of the dirt-pushing plate. It is suitable for the treatment of wastewater containing PVA slurry that requires long-term continuous operation; By arranging an extrusion block in the secondary treatment seat, when the dirt pushing plate pushes the filtered material into the secondary treatment seat, the extrusion block can be driven to move, and the filtered material can be extruded to achieve secondary treatment. At the same time, when the extrusion block is reset, the discharge wheel can be driven to rotate. After the filter material is extruded, it can not only reduce the volume but also effectively remove moisture, thus preparing for subsequent treatment or resource recovery. The discharge wheel ensures that the treated material can be automatically discharged and collected, further improving the processing efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a schematic diagram of the overall structure of a treatment device for PVA slurry wastewater according to the present invention; Figure 2 It is a schematic cross-sectional view of the overall structure of a treatment device for PVA slurry wastewater according to the present invention; Figure 3 It is a schematic cross-sectional view of the treatment barrel structure of a treatment device for PVA slurry wastewater according to the present invention; Figure 4 This is a schematic diagram of the structure of a centrifugal filter barrel of a device for treating wastewater containing PVA slurry according to the present invention; Figure 5 It is a partial cross-sectional schematic diagram of the structure of a dirt retaining frame and an automatic dirt removal mechanism of a treatment device for wastewater containing PVA slurry according to the present invention; Figure 6 This is a schematic diagram of the structure of a dirt pusher plate of a treatment device for wastewater containing PVA slurry according to the present invention; Figure 7 It is a cross-sectional expansion schematic diagram of a secondary treatment seat and a discharge wheel structure of a treatment device for PVA slurry wastewater of the present invention; Figure 8 The present invention is a schematic diagram of the structure of an extrusion transmission mechanism of a treatment device for wastewater containing PVA slurry.

[0019] The following are marked in the figure: 1. treatment barrel; 2. centrifugal filter barrel; 3. dirt retaining frame; 4. automatic dirt removal mechanism; 5. dirt pushing plate; 6. secondary treatment seat; 7. discharge wheel; 8. extrusion transmission mechanism; 101. water inlet pipe; 102. drain pipe; 201. motor; 202. arc-shaped rack; 203. pin shaft; 401. pulley; 402. belt; 403. dirt scraping plate; 404. rotating shaft; 405. Transmission wheel; 501, connecting rod group; 502, gear; 503, rack; 504, electric push rod; 601, water pipe; 602, filter screen; 603, material receiving seat; 701, universal joint; 702, transmission rod; 703, meshing wheel; 801, contact rod; 802, extrusion block; 803, tension spring; 804, gear rack; 805, meshing teeth; 806, spring; 301, pressure sensor. DETAILED DESCRIPTION

[0020] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0021] like Figure 1-Figure 8The treatment device for wastewater containing PVA slurry shown in the figure comprises a treatment barrel 1, a centrifugal filter barrel 2 is rotatably connected to the treatment barrel 1, a dirt blocking frame 3 is fixedly connected to the treatment barrel 1, an automatic dirt removal mechanism 4 is rotatably connected to the dirt blocking frame 3, a dirt pushing plate 5 is slidably provided on the top of the dirt blocking frame 3, a secondary treatment seat 6 is fixedly provided on one side of the top of the dirt blocking frame 3, a discharge wheel 7 is rotatably connected to the secondary treatment seat 6, and an extrusion transmission mechanism 8 is slidably provided on the secondary treatment seat 6.

[0022] like Figure 3 As shown, a water inlet pipe 101 is fixedly installed on the top of the treatment barrel 1, and the other end of the water inlet pipe 101 is connected to the top of the dirt retaining frame 3, and a drainage pipe 102 is fixedly connected to the bottom of the treatment barrel 1.

[0023] like Figure 4 As shown, a pin shaft 203 is fixedly connected to the bottom end of the centrifugal filter barrel 2, and the other end of the pin shaft 203 passes through the inner wall of the processing barrel 1 and extends to the outside and is fixedly connected to a motor 201, which is fixedly connected to the lower surface of the processing barrel 1, and an arc-shaped rack 202 is fixedly connected to the top end of the centrifugal filter barrel 2. The motor 201 drives the connected pin shaft 203 to rotate, so that the pin shaft 203 drives the connected centrifugal filter barrel 2 to rotate.

[0024] like Figure 5 As shown, the automatic dirt removal mechanism 4 includes two pulleys 401, which are rotatably connected to the dirt blocking frame 3, a pressure sensor 301 is installed on the top of the dirt blocking frame 3, a belt 402 is frictionally transmitted between the two pulleys 401, a plurality of scraping plates 403 are connected and fixedly arranged on the belt 402, and the scraping plates 403 are slidingly matched with the inner wall of the centrifugal filter barrel 2, one end of the pulley 401 at the top is connected and fixedly arranged with a rotating shaft 404, one end of the rotating shaft 404 passes through the inner wall of the dirt blocking frame 3 and extends to the outside and is connected and fixedly arranged with a transmission wheel 405, and the transmission wheel 405 is meshed with the arc rack 202 for transmission. When the centrifugal filter barrel 2 rotates, the filtered material will be blocked by the dirt blocking frame 3, and then when the centrifugal filter barrel 2 rotates, the connected arc-shaped rack 202 can drive the transmission wheel 405 to rotate, so that the transmission wheel 405 drives the connected rotating shaft 404 to rotate, and the rotating shaft 404 drives the connected pulley 401 to rotate, so that the pulley 401 drives the belt 402 to rotate, and then the belt 402 drives the scraper plate 403 to move, and the filtered material blocked by the dirt blocking frame 3 is pushed out of the centrifugal filter barrel 2.

[0025] like Figure 6As shown, the lower outer wall of the dirt-pushing plate 5 is arranged in sliding contact with the outer wall of the dirt-scraping plate 403 and the belt 402, the top of the dirt-pushing plate 5 is rotatably connected with a connecting rod group 501, the other end of the connecting rod group 501 is rotatably connected with the top of the dirt-blocking frame 3, one end of the connecting rod group 501 connected to the dirt-blocking frame 3 is connected and fixed with a gear 502, one side of the gear 502 is meshingly driven with a rack 503, and an electric push rod 504 is connected and fixed on the rack 503, and the electric push rod 504 is connected and fixed with the dirt-blocking frame 3. The electric push rod 504 drives the connected rack 503 to move, so that the rack 503 drives the connecting rod group 501 connected to the gear 502 to rotate, so that the connecting rod group 501 drives the dirt-pushing plate 5 to move, and pushes the filtered material on the dirt-scraping plate 403 into the secondary treatment seat 6.

[0026] like Figure 7 As shown, one end of the secondary processing seat 6 is connected and fixed with a water pipe 601, and the other end of the water pipe 601 is connected and fixed with the processing barrel 1, a filter screen 602 is connected and fixed at the position of the water pipe 601 on the inner wall of the secondary processing seat 6, and a material receiving seat 603 is slidably provided at the opening at the bottom end of the secondary processing seat 6.

[0027] like Figure 7 As shown, one end of the discharge wheel 7 passes through the secondary processing seat 6 and the water pipe 601 in sequence and is connected and fixed with a universal joint 701, one end of the universal joint 701 is connected and fixed with a transmission rod 702, the transmission rod 702 is rotatably connected with the secondary processing seat 6, and the top of the transmission rod 702 is connected and fixed with a meshing wheel 703. The meshing teeth 805 mesh with the meshing wheel 703, so that the meshing wheel 703 rotates, thereby driving the universal joint 701 connected to the transmission rod 702 to rotate, so that the universal joint 701 drives the connected discharge wheel 7 to rotate, discharges the extruded PVA residue, and drops it into the receiving seat 603 for collection.

[0028] like Figure 8 As shown, the extrusion transmission mechanism 8 includes a contact rod 801, one end of which is slidably matched with the top of the dirt blocking frame 3, the top of the contact rod 801 is movably contacted with the dirt pushing plate 5, the bottom of the contact rod 801 is slidably matched with the secondary processing seat 6, the bottom of the contact rod 801 is connected and fixedly provided with an extrusion block 802, the extrusion block 802 is slidably contacted with the secondary processing seat 6 and the discharge wheel 7, and the contact rod 801 is connected and fixedly provided with a tension spring 803, and the other end of the tension spring 803 is connected and fixedly provided with the secondary processing seat 6. The dirt pushing plate 5 will contact the contact rod 801, so that the contact rod 801 can drive the extrusion block 802 to move, so that the extrusion block 802 squeezes the PVA residues that fall into the secondary processing seat 6.

[0029] A gear rack 804 is fixedly connected to the contact rod 801, and the inner wall of the gear rack 804 is linearly structured and rotatably connected with a plurality of meshing teeth 805. A spring 806 is fixedly connected to one end of the meshing tooth 805, and the other end of the spring 806 is fixedly connected to the inner wall of the gear rack 804. The meshing tooth 805 is meshed with the meshing wheel 703 for transmission.

[0030] Working principle: When the wastewater containing PVA slurry needs to be treated, the wastewater containing PVA slurry is injected into the centrifugal filter barrel 2 through the water inlet pipe 101, and the motor 201 is used to drive the connected pin shaft 203 to rotate, so that the pin shaft 203 drives the connected centrifugal filter barrel 2 to rotate for centrifugal treatment; When the centrifugal filter barrel 2 rotates, the filtered material will be blocked by the dirt blocking frame 3, and then when the centrifugal filter barrel 2 rotates, the connected arc-shaped rack 202 can drive the transmission wheel 405 to rotate, so that the transmission wheel 405 drives the connected rotating shaft 404 to rotate, so that the rotating shaft 404 drives the connected pulley 401 to rotate, so that the pulley 401 drives the belt 402 to rotate, and then the belt 402 drives the scraper 403 to move, and the filtered material blocked by the dirt blocking frame 3 is pushed out of the centrifugal filter barrel 2; Then, when the scraper plate 403 moves to the top opening of the dirt retaining frame 3, it contacts the pressure sensor 301. At this time, the device uses the electric push rod 504 to drive the connected rack 503 to move, so that the rack 503 drives the connecting rod group 501 connected to the gear 502 to rotate, so that the connecting rod group 501 drives the dirt pushing plate 5 to move, and pushes the filtered material on the scraper plate 403 into the secondary treatment seat 6; At this time, the dirt-pushing plate 5 will contact the contact rod 801, so that the contact rod 801 can drive the squeezing block 802 to move, so that the squeezing block 802 squeezes the PVA residue that falls into the secondary treatment seat 6, so that the water in the PVA residue passes through the filter screen 602 and falls into the water guide pipe 601, and flows back to the treatment barrel 1; Then, under the action of the tension spring 803, the extrusion block 802 connected to the contact rod 801 will be retracted and reset. At this time, the contact rod 801 will drive the gear rack 804 to move. At this time, the spring 806 will cause the meshing teeth 805 to mesh with the meshing wheel 703, so that the meshing wheel 703 rotates, thereby driving the universal joint 701 connected to the transmission rod 702 to rotate, so that the universal joint 701 drives the connected discharge wheel 7 to rotate, and the PVA residue after extrusion is discharged and falls into the receiving seat 603 for collection.

[0031] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A treatment device for wastewater containing PVA slurry, comprising a treatment tank (1), characterized in that: A centrifugal filter barrel (2) is rotatably connected to the processing barrel (1), a dirt blocking frame (3) is fixedly connected to the processing barrel (1), an automatic dirt removal mechanism (4) is rotatably connected to the dirt blocking frame (3), a dirt pushing plate (5) is slidably provided at the top end of the dirt blocking frame (3), a secondary processing seat (6) is fixedly provided at one side of the top end of the dirt blocking frame (3), a discharge wheel (7) is rotatably connected to the secondary processing seat (6), and an extrusion transmission mechanism (8) is slidably provided on the secondary processing seat (6).

2. The device for treating wastewater containing PVA slurry according to claim 1, characterized in that: A water inlet pipe (101) is fixedly installed at the top of the treatment barrel (1), the other end of the water inlet pipe (101) is connected to the top of the dirt retaining frame (3), and a drainage pipe (102) is fixedly connected to the bottom of the treatment barrel (1).

3. The device for treating wastewater containing PVA slurry according to claim 1, characterized in that: A pin shaft (203) is fixedly connected to the bottom end of the centrifugal filter barrel (2), the other end of the pin shaft (203) passes through the inner wall of the processing barrel (1) and extends to the outside and is fixedly connected to a motor (201), the motor (201) is fixedly connected to the lower surface of the processing barrel (1), and an arc-shaped rack (202) is fixedly connected to the top end of the centrifugal filter barrel (2).

4. The device for treating wastewater containing PVA slurry according to claim 1, characterized in that: The automatic dirt removal mechanism (4) comprises two pulleys (401), the pulleys (401) being rotatably connected to the dirt blocking frame (3), a pressure sensor (301) being installed at the top of the dirt blocking frame (3), a belt (402) being frictionally driven between the two pulleys (401), a plurality of dirt scraping plates (403) being connected and fixedly arranged on the belt (402), the dirt scraping plates (403) being slidably matched with the inner wall of the centrifugal filter barrel (2), one end of the pulley (401) at the top being connected and fixedly arranged with a rotating shaft (404), one end of the rotating shaft (404) passing through the inner wall of the dirt blocking frame (3) and extending to the outside and being connected and fixedly arranged with a transmission wheel (405), the transmission wheel (405) being meshed and driven with the arc-shaped rack (202).

5. The device for treating wastewater containing PVA slurry according to claim 1, characterized in that: The lower outer wall of the dirt pushing plate (5) is arranged in sliding contact with the outer wall of the dirt scraping plate (403) and the belt (402); the top end of the dirt pushing plate (5) is rotatably connected to a connecting rod group (501); the other end of the connecting rod group (501) is rotatably connected to the top end of the dirt blocking frame (3); one end of the connecting rod group (501) connected to the dirt blocking frame (3) is connected and fixedly provided with a gear (502); one side of the gear (502) is meshingly provided with a rack (503); an electric push rod (504) is connected and fixedly provided on the rack (503); and the electric push rod (504) is connected and fixedly provided with the dirt blocking frame (3).

6. The device for treating wastewater containing PVA slurry according to claim 1, characterized in that: A water pipe (601) is fixedly provided through one end of the secondary processing seat (6), and the other end of the water pipe (601) is fixedly provided through the processing barrel (1). A filter screen (602) is fixedly provided on the inner wall of the secondary processing seat (6) at a position connected to the water pipe (601), and a material receiving seat (603) is slidably provided at the bottom opening of the secondary processing seat (6).

7. The device for treating wastewater containing PVA slurry according to claim 1, characterized in that: One end of the discharge wheel (7) passes through the secondary processing seat (6) and the water guide pipe (601) in sequence and is connected and fixedly provided with a universal joint (701); one end of the universal joint (701) is connected and fixedly provided with a transmission rod (702); the transmission rod (702) is rotatably connected to the secondary processing seat (6); and a meshing wheel (703) is connected and fixedly provided at the top end of the transmission rod (702).

8. The device for treating wastewater containing PVA slurry according to claim 1, characterized in that: The extrusion transmission mechanism (8) comprises a contact rod (801), one end of which is slidably matched with the top end of the dirt blocking frame (3), the top end of which is movably contacted with the dirt pushing plate (5), the bottom end of which is slidably matched with the secondary processing seat (6), the bottom end of which is connected and fixedly provided with an extrusion block (802), the extrusion block (802) is slidably contacted with the secondary processing seat (6) and the discharge wheel (7), the contact rod (801) is connected and fixedly provided with a tension spring (803), the other end of which is connected and fixedly provided with the secondary processing seat (6).

9. The device for treating wastewater containing PVA slurry according to claim 8, characterized in that: A gear rack (804) is fixedly connected to the contact rod (801); the inner wall of the gear rack (804) is provided with a plurality of meshing teeth (805) in a linear structure and rotatably connected thereto; one end of the meshing teeth (805) is fixedly connected to a spring (806); the other end of the spring (806) is fixedly connected to the inner wall of the gear rack (804); and the meshing teeth (805) are meshed with the meshing wheel (703) for transmission.

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