A centrifugal solid-liquid separation device
The centrifugal solid-liquid separation device, with its non-central shaft water inlet design and dynamic balance adjustment, solves the problems of easy filter clogging and unstable dynamic balance, achieving efficient solid-liquid separation and disinfection, and improving the safety and filtration efficiency of the device.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANCHONG YINGYU AQUATIC TECH CO LTD
- Filing Date
- 2025-07-15
- Publication Date
- 2026-06-09
AI Technical Summary
Existing solid-liquid separation devices suffer from problems such as easy clogging of the filter screen, unstable dynamic balance, contradiction between flow rate and filtration efficiency, high water consumption, and difficulty in achieving both anti-clogging and flushing effects.
It adopts a non-central shaft water inlet design, uses a flexible coupling and tie rod structure to achieve dynamic balance adjustment, combines a 90° bend water inlet and backwashing system, and uses a variable speed motor to control centrifugal force to achieve efficient solid-liquid separation and backwashing. It is also equipped with ultraviolet lamps for disinfection.
It improves the stability and filtration efficiency of the filter, reduces the risk of clogging, lowers water consumption, enhances dynamic balance and safety, and improves the disinfection effect.
Smart Images
Figure CN224331679U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of liquid filtration technology, and in particular relates to a solid-liquid separation device. Background Technology
[0002] In aquaculture, livestock and poultry farming, food processing, industrial manufacturing, and sewage treatment, there are a large amount of particulate solids and residues in water bodies. If they are not removed in time, they will damage water quality, pollute the environment, affect the recycling and reuse of liquids, and even lead to diseases and accidents. Therefore, solid particulates and residues in water bodies must be separated and removed in a timely manner.
[0003] Currently, there are numerous commonly used solid-liquid separation devices, with drum filters being the most prevalent. When using drum filters, a mesh size that is too large will affect filtration accuracy and effectiveness, while a mesh size that is too small will easily cause clogging. Once the filter screen becomes clogged, drainage is impeded, and a large amount of water that needs filtration remains inside the filter drum, causing the water level to rise. When the weight of the water and solid waste exceeds the load-bearing capacity of the filter and filter screen, it will crush the filter and damage the filter screen, leading to equipment failure. Furthermore, due to the ellipticity of the drum itself and the eccentricity during installation, vibrations caused by dynamic imbalance occur during drum rotation, limiting the drum's speed and size.
[0004] To address the problem of filter clogging, some researchers have adopted conical drum filters. These filters utilize centrifugal force to eject the liquid from the filter cylinder, achieving filtration. Solid waste trapped on the inner wall of the cylinder is flushed to the outlet side by the inclined surface of the conical drum. This structure offers good filtration and anti-clogging effects. However, due to the central shaft inlet, the inlet hole cannot be too large to ensure the shaft's strength, limiting the filter's flow rate. Flow rate and strength become contradictory. The trapped solid waste is also subject to centrifugal force and cannot be promptly discharged as the filter cylinder rotates. While the conical drum can provide some rinsing effect through the inclined surface, its large cone angle and high water volume result in good rinsing, but they are also energy-intensive. While backwashing offers advantages like large water volume, small cone angle, low water distribution, and low water consumption, it also results in poor rinsing performance. The balance between clogging prevention and filtration efficiency has become a contradiction. To prevent clogging, some researchers have adopted backwashing devices. These devices use reverse rinsing to remove deposits from the filter screen and then use the inclined surface of the conical drum to distribute the water, flushing the impurities out from the large end of the drum. However, this type of structure requires a densely packed pipe arrangement for uniform rinsing, resulting in a large number of nozzles. The total cross-sectional area of these nozzles exceeds the cross-sectional area of the water supply pipe, leading to a decrease in water flow velocity, reduced backwashing effectiveness, and increased water consumption. The only alternative is to use flat-nozzle nozzles to accumulate flow and increase the backwash water flow velocity. However, these nozzles have very narrow pores, making them prone to clogging and difficult to clean. Widening the pores negates the flow accumulation effect. Therefore, flow accumulation and clogging prevention have become a contradiction in backwashing devices. Utility Model Content
[0005] In order to overcome the shortcomings of the prior art, this utility model provides a centrifugal solid-liquid separation device with non-central shaft water inlet, adjustable dynamic balance, timely solid waste removal, higher safety, and disinfection effect.
[0006] The technical solution of this utility model is: a centrifugal solid-liquid separation device, comprising: a motor, a flexible coupling, a spindle, a long tie rod, a conical drum, a duckbill rubber valve, a backwash pipe, a backwash outlet pipe, a top cover, an inlet pipe, bearings, a clean water pipe, a baffle plate, a short tie rod, a right ultraviolet lamp, a drain pipe, a left ultraviolet lamp, a housing, a backwash pump, a backwash inlet pipe, a changeover switch, and a bypass switch. The top cover is located above the housing, and the two are movably connected. The housing partition P and the top cover partition T separate their inner cavities into left and right cavities. The partition P and partition T have mirror-symmetrical semi-holes. The left and right ends of the housing and the top cover have mirror-symmetrical semi-holes for connecting bearings. The drain pipe at the bottom of the left cavity of the housing is connected to a sludge collection tank, and the left ultraviolet lamp is located on the lower side of the left cavity. The clean water pipe on the lower right side of the right cavity of the housing is connected to an aquaculture tank. The clean water pipe is higher than the bottom of the housing, and the right ultraviolet lamp is located on the lower side of the right cavity. Located on the lower side of the right cavity; the motor is connected to the left end of the spindle via a flexible coupling, and the spindle is sleeved on both sides to the bearings at the left and right ends of the housing; the long tie rod is at the left end of the conical drum, connecting the conical drum and the spindle; the short tie rod is between the long tie rod and the water inlet pipe, connecting the conical drum and the spindle; the large end of the conical drum is on the left side of the half hole of the housing partition P and the upper cover partition T, and the small end is fixedly connected to the baffle plate; the water outlet at the left end of the water inlet pipe is located in the inner cavity of the conical drum, on the left side of the baffle plate, and the right end is located on the outside of the housing and the upper cover; the backwash pipe is located on the inner side of the upper cover, in the center above the conical drum, and the left end is located in the half hole clearance groove of the upper cover partition plate, with the nozzle facing down, sleeved to the upper water inlet of the duckbill rubber valve, and the lower lip of the duckbill rubber valve is directly opposite the conical drum; the right end of the backwash pipe is connected to the backwash pump outlet via the backwash outlet pipe, and the backwash pump inlet is connected to the cleaning water via the backwash inlet pipe;
[0007] The half-holes at the left and right ends of the housing are located in the center of the upper ends, and the half-hole of the partition P is located in the center of the upper side of the partition P.
[0008] The half-holes at both ends of the upper cover are located in the center of the lower side, the half-hole of the partition T is located in the center of the lower side of the partition T, and there is a centering clearance groove on the upper side of the half-hole of the partition T.
[0009] Both the right and left ultraviolet lamps are waterproof ultraviolet disinfection lamps.
[0010] The conical roller is a conical annular filter screen, with the left side larger than the right side.
[0011] The short tie rod and the long tie rod have the same structure and connection method, only the length is different. Both are three pieces, and they are evenly distributed around the circumference with the mandrel as the center.
[0012] The long tie rod consists of an adjusting nut connecting a screw and a connecting rod; the inner side of the screw is fixedly connected to the spindle, and the outer side is threaded into the adjusting nut's screw hole; the inner side of the connecting rod is a limiting step located inside the adjusting nut's screw hole, which mutually limits the adjusting nut's inner limiting step, and the outer side is fixedly connected to the conical roller.
[0013] The screw has an external thread on the outside and a smooth rod on the inside.
[0014] The adjusting nut has a screw hole on the inside and an inner limiting step on the outside. The inner hole of the inner limiting step is larger than the small end of the outer side of the connecting rod and smaller than the outer limiting step on the inner side of the connecting rod.
[0015] The outer side of the connecting rod's outer limiting step is the small end, and the inner side of the outer limiting step is the large end. The outer diameter of the outer limiting step is larger than the inner hole of the inner limiting step of the adjusting nut, but smaller than the small diameter of the adjusting nut's screw hole.
[0016] The water inlet pipe has a 90° bend structure. The water outlet at the left end of the water inlet pipe is located on the right side of the inner cavity of the conical roller, on the left side of the baffle plate, on the right side of the short pull rod, and is located at the upper right position. The nozzle is angled downward toward the inner wall of the right side of the conical roller. The right end is outside the right side of the conical roller, extending out to the right side of the upper cover, and is connected to the aquaculture pond water pump.
[0017] The baffle plate is a circular ring with a central hole, which separates the mandrel and the water inlet pipe.
[0018] The backwash pipe is equipped with parallel circular nozzles located directly above the conical drum and equidistant from the outer side of the conical drum. The circular nozzles are perpendicular to the outer side of the conical drum and are fitted with duckbill rubber valves. The left side of the backwash pipe is located in the clearance groove of the upper cover partition T, and the right side is located on the left side of the baffle plate. The backwash outlet pipe connected to its right end passes through the right side of the upper cover.
[0019] The upper end of the duckbill rubber valve is the water inlet, and the lower end is a rounded lip.
[0020] The right ultraviolet lamp, left ultraviolet lamp, and high-speed motor are connected to the power supply via a changeover switch; the low-speed motor and backwash pump are connected to the power supply via a bypass switch.
[0021] The motor is a variable speed motor, with a selector switch connected to the high-speed end and a bypass switch connected to the low-speed end. It can output different speeds according to the different centrifugal force requirements of the filtration and backwashing states.
[0022] The selector switch is a three-position selector switch.
[0023] The working principle of this utility model is as follows:
[0024] During centrifugal separation, the aquaculture tank water pump sprays water onto the inner wall of the right side of the conical drum through the inlet pipe. The spraying water helps to propel the conical filter cylinder. When the bypass switch is off and the selector switch is on the right, the high-speed motor is engaged. The motor drives the spindle to rotate through the flexible coupling. The spindle is connected to the conical drum through the long and short tie rods. Centrifugal force is used to throw the water out. The separated water falls through the mesh into the right cavity of the shell and then flows back to the aquaculture tank through the clear water pipe. The clear water pipe is higher than the bottom of the shell to prevent sediment from flowing back into the aquaculture tank. Through the gravity water separation effect of the conical inclined surface of the conical drum, the residue and waste liquid are diverted to the outside of the large end opening and fall into the left cavity of the shell, flowing to the sludge collection tank through the sewage pipe.
[0025] After centrifugal separation, during backwashing, the changeover switch is in the middle position, the bypass switch is closed, the motor is in low speed mode, the centrifugal force is reduced, the backwash pump is turned on, and the water flows through the duckbill rubber valve at the backwash nozzle of the backwash outlet pipe and backwashes the conical drum. The inlet pipe continues to supply water to the inside of the conical drum. The two-way rinsing utilizes the gravity separation effect of the cone angle of the conical drum to wash the solid waste residue attached to the conical drum to the outside of the large end opening, fall into the left cavity of the shell, and flow to the sludge collection tank through the sewage pipe.
[0026] After backwashing is completed, the water supply to the inlet pipe stops, the bypass switch is turned off, the selector switch is set to the left, the motor and backwash pump are de-energized, and the left and right ultraviolet lamps are turned on, simultaneously disinfecting the left and right cavities of the top cover and the housing; after disinfection is completed, the selector switch is set to the middle, the entire device is de-energized, and it stops working.
[0027] This utility model has the following advantages compared with the prior art:
[0028] The mandrel support of this invention has better stability. The left and right sides of the mandrel are located at the center of the bearings at both ends of the housing, forming a simply supported beam structure for the conical roller, which effectively improves stability.
[0029] This invention has good dynamic balance stability. The flexible coupling and short tie rod of this invention together with the long tie rod form a dynamic balance stabilization mechanism, which can adjust the parallelism and eccentricity of the conical roller and the mandrel, and can buffer and reduce shock, so as to achieve dynamic balance adjustment and stability, and solve the bottleneck problems of roller speed and large size.
[0030] The water inlet pipe of this utility model has a 90° bend structure, which occupies less space and can provide more installation space for tie rods or other support components, thereby improving the support effect of the support components.
[0031] This invention features high filtration efficiency. The motor drives the conical drum to rotate via a spindle, outputting different centrifugal forces according to the needs of filtration and rinsing: during filtration, the motor is switched to high speed, increasing the centrifugal force, improving water flow, reducing water separation, and improving filtration efficiency.
[0032] This invention has a good rinsing effect. During backwashing, the motor is switched to a low speed, which reduces centrifugal force, decreases water flow, and increases water distribution. Under the two-way rinsing of the inlet pipe and the backwash drain pipe, the gravity water distribution effect of the cone angle of the conical roller is used to rinse the solid waste residue attached to the conical roller to the outside of the large end opening, effectively improving the rinsing efficiency.
[0033] This invention has good safety features. The top cover and the shell of this invention form a closed shell, which can prevent accidents from occurring when the dynamic balance is lost.
[0034] This invention has a good isolation effect. The top cover and the shell of this invention form a closed shell, which prevents water from being thrown out of the closed shell when the conical drum rotates. The shell partition P and the top cover partition T isolate the inner cavity into left and right cavities. This can effectively prevent solid waste residue thrown out of the large end opening of the conical drum from colliding with the shell and the left cavity of the top cover during centrifugal separation and splashing back into the right cavity, thus contaminating the filtered water in the right cavity.
[0035] This utility model's backwash nozzle has excellent flow accumulation and anti-clogging effects; the duckbill rubber valve of this utility model has a rounded lip, which can not only accumulate flow, but also widen the water flow width, making backwashing more uniform and effectively reducing the number of backwash nozzles; when the duckbill rubber valve is blocked, the internal pressure increases, the lip opens wider, and the blockage is automatically discharged; if the blockage is severe, the lip can also be manually opened for manual cleaning.
[0036] This invention has a good disinfection effect. The ultraviolet lamp, motor and backwash pump work at different times to avoid power superposition. The top cover and shell form a closed shell, which can effectively prevent ultraviolet leakage. It can be equipped with a high-efficiency ultraviolet lamp to improve the disinfection effect and shorten the disinfection time. It can effectively kill bacteria and viruses and prevent the formation of biological adhesion and accumulation in the inner cavity of the top cover and shell.
[0037] This utility model has a wide range of applications. It is mainly applicable to aquaculture filtration, but it is also applicable to solid-liquid separation systems in other fields, such as wastewater treatment in livestock and poultry farming, food processing, and industrial manufacturing. Attached Figure Description
[0038] Figure 1 This is a schematic diagram of the structure of this utility model;
[0039] Figure 2 This is the left view of the present invention;
[0040] Figure 3 This is a schematic diagram of the long tie rod assembly structure of this utility model;
[0041] Figure 4 This is a schematic diagram of the duckbill rubber valve structure of this utility model;
[0042] Figure 5This is a schematic diagram of the backwashing system of this utility model;
[0043] Figure 6 This is the circuit schematic diagram of this utility model. Detailed Implementation
[0044] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, a centrifugal solid-liquid separation device includes: a motor 1, a flexible coupling 2, a spindle 3, a long tie rod 4, a conical drum 5, a duckbill rubber valve 6, a backwash drain pipe 7, a backwash outlet pipe 8, a top cover 9, an inlet pipe 10, a bearing 11, a clean water pipe 12, a baffle plate 13, a short tie rod 14, a right ultraviolet lamp 15, a drain pipe 16, a left ultraviolet lamp 17, a housing 18, a backwash pump 19, a backwash inlet pipe 20, a changeover switch 21, and a bypass switch 22. Cover 9 is located above shell 18, and the two are movably connected. Partition P of shell 18 and partition T of cover 9 divide their inner cavities into left and right chambers. Partition P and partition T have mirror-symmetrical semi-holes. Shell 18 and cover 9 have mirror-symmetrical semi-holes at their left and right ends, connecting to bearings 11. A sewage pipe 16 at the bottom of the left chamber of shell 18 is connected to a sludge collection tank, and a left ultraviolet lamp 17 is located on the lower side of the left chamber. A clear water pipe 12 on the lower right side of the right chamber of shell 18 is connected to a breeding tank. The clear water pipe 12 is higher than the bottom of shell 18, and a right ultraviolet lamp 17 is located on the lower side of the right chamber. Lamp 15 is located on the lower side of the right cavity; motor 1 is connected to the left end of spindle 3 via flexible coupling 2, and the spindle 3 is sleeved on both sides of bearings 11 at the left and right ends of housing 18; long pull rod 4 is at the left end of conical roller 5, connecting conical roller 5 and spindle 3; short pull rod 14 is between long pull rod 4 and water inlet pipe 10, connecting conical roller 5 and spindle 3; the large end of conical roller 5 is on the left side of the half hole of housing partition P and upper cover partition T, and the small end is fixedly connected to baffle plate 13; the water outlet at the left end of water inlet pipe 10 is located on the conical roller 5. The inner cavity of the roller 5 is located on the left side of the baffle plate 13, and the right end is located outside the shell 20 and the upper cover 9. The backwash pipe 7 is located inside the upper cover 9, directly above the center of the conical roller 5, with its left end located in the half-hole clearance groove of the upper cover partition plate T. The nozzle faces downward and is connected to the upper inlet of the duckbill rubber valve 6. The lower lip of the duckbill rubber valve 6 is directly opposite the conical roller 5. The right end of the backwash pipe 7 is connected to the outlet of the backwash pump 19 via the backwash outlet pipe 8. The inlet of the backwash pump 19 is connected to the external cleaning water via the backwash inlet pipe 20.
[0045] The half-holes at the left and right ends of the housing 18 are located in the center of the upper ends, and the half-hole of the partition P is located in the center of the upper side of the partition P.
[0046] The upper cover 9 has half holes at both ends located in the center of the lower side, the partition T has half holes located in the center of the lower side, and there is a centering clearance groove on the upper side of the half holes of the partition T.
[0047] Both the right ultraviolet lamp 15 and the left ultraviolet lamp 17 are waterproof ultraviolet disinfection lamps.
[0048] The conical roller 5 is a conical annular filter screen, with the left side larger than the right side.
[0049] The short tie rod 14 and the long tie rod 4 have the same structure and connection method, only the length is different. Both are three pieces, and they are evenly distributed around the circumference with the spindle 3 as the center.
[0050] The long tie rod 4 is composed of an adjusting nut 4-2 connecting a screw 4-1 and a connecting rod 4-3; the inner side of the screw 4-1 is fixedly connected to the spindle 3, and the outer side is threaded into the screw hole of the adjusting nut 4-2; the inner side of the connecting rod 4-3 is a limiting step located in the screw hole of the adjusting nut 4-2, and mutually limits the inner side of the adjusting nut 4-2, and the outer side is fixedly connected to the conical roller 5.
[0051] The screw 4-1 has an external thread on the outside and a smooth rod on the inside.
[0052] The inner side of the adjusting nut 4-2 is a screw hole, and the outer side is an inner limiting step. The inner hole of the inner limiting step is larger than the small end of the outer side of the connecting rod 4-3, but smaller than the outer limiting step on the inner side of the connecting rod 4-3.
[0053] The outer side of the outer limiting step of the connecting rod 4-3 is the small end, and the inner side of the outer limiting step is the large end. The outer diameter of the outer limiting step is larger than the inner hole of the inner limiting step of the adjusting nut 4-2, but smaller than the small diameter of the screw hole of the adjusting nut 4-2.
[0054] The water inlet pipe 10 has a 90° bend structure. The water outlet at the left end of the water inlet pipe 10 is located on the right side of the inner cavity of the conical roller 5, on the left side of the baffle plate 13, on the right side of the short pull rod 14, and is located at the upper right position. The nozzle is angled downward toward the inner wall of the right side of the conical roller 5. The right end is outside the right side of the conical roller 5, extending out to the right side of the upper cover 9, and is connected to the aquaculture pond water pump.
[0055] The baffle plate 13 is a circular ring with a central hole, which separates the mandrel 3 and the water inlet pipe 10.
[0056] The backwash pipe 7 is equipped with parallel circular nozzles located directly above the conical roller 5 and equidistant from the outer side of the conical roller 5. The circular nozzles are perpendicular to the outer side of the conical roller 5 and are fitted with duckbill rubber valves 6. The left side of the backwash pipe 7 is located in the relief groove of the partition T of the upper cover 9, and the right side is located on the left side of the baffle plate 13. The backwash water outlet pipe 8 connected to its right end passes through the right side of the upper cover 9.
[0057] The upper end of the duckbill rubber valve 6 is the water inlet, and the lower end is a rounded lip.
[0058] like Figure 6As shown, the right ultraviolet lamp 15, the left ultraviolet lamp 17, and the high-speed end of motor 1 are connected to the power supply via changeover switch 21; the low-speed end of motor 1 and the backwash pump 19 are connected to the power supply via bypass switch 22; the right ultraviolet lamp 15 and the left ultraviolet lamp 17 can be connected in series or in parallel, in this example they are connected in series; the low-speed end of motor 1 and the backwash pump 19 are connected in parallel; when bypass switch 22 is open and changeover switch 21 is on the right, the high-speed setting of motor 1 is turned on; when changeover switch 21 is in the middle and bypass switch 22 is closed, the low-speed setting of motor 1 is turned on and the backwash pump 19 is turned on; when bypass switch 22 is open and changeover switch 21 is on the left, motor 1 and backwash pump 19 are de-energized, and the left ultraviolet lamp 17 and the right ultraviolet lamp 15 are turned on.
[0059] The motor 1 is a variable speed motor, with the high-speed end connected to the changeover switch 21 and the low-speed end connected to the bypass switch 22. It can output different speeds according to the different centrifugal force requirements of the filtration state and the backwashing state.
[0060] The selector switch 21 is a three-position selector switch.
Claims
1. A centrifugal solid-liquid separation device, comprising: The components include: motor, flexible coupling, spindle, long tie rod, conical roller, duckbill rubber valve, backwash drain pipe, backwash outlet pipe, top cover, inlet pipe, bearing, clean water pipe, baffle plate, short tie rod, right ultraviolet lamp, drain pipe, left ultraviolet lamp, housing, backwash pump, backwash inlet pipe, changeover switch, and bypass switch. The top cover is located above the housing. The housing partition P and the top cover partition T separate the inner cavity into left and right chambers. The housing and top cover have symmetrical half-holes at both ends for connecting bearings. The drain pipe connects to the sludge collection tank. The clean water pipe connects to the aquaculture tank. Bearings are connected to both sides of the spindle. The large end of the conical roller is on the left side of the half-holes in partition P and partition T, and the small end is connected to the baffle plate. The outlet of the inlet pipe is on the left side of the baffle plate, and the right end is located outside the housing and top cover. The backwash drain pipe is inside the top cover. At the top center of the conical drum, a backwash pipe is connected to a backwash pump via a backwash outlet pipe, and the backwash pump is connected to cleaning water via a backwash inlet pipe. The features include: partitions P and T having mirror-symmetrical semi-holes; a left ultraviolet lamp on the lower side of the left cavity and a right ultraviolet lamp on the lower side of the right cavity; a motor connected to the left end of the spindle via a flexible coupling; a long tie rod at the left end of the conical drum connecting the conical drum and the spindle; a short tie rod between the long tie rod and the inlet pipe connecting the conical drum and the spindle; the left end of the backwash pipe is in the semi-hole clearance groove of the upper cover partition, with the nozzle facing downwards, and is fitted with the inlet of a duckbill rubber valve, the lip of which faces the conical drum; the right ultraviolet lamp, left ultraviolet lamp, and high-speed motor are connected to the power supply via a changeover switch; the low-speed motor and backwash pump are connected to the power supply via a bypass switch.
2. The centrifugal solid-liquid separation device according to claim 1, characterized in that: The upper cover partition plate has a centering clearance groove on the upper side of the T-shaped half hole.
3. A centrifugal solid-liquid separation device according to claim 1 or 2, characterized in that: Both the short and long tie rods consist of three pieces, each evenly distributed around the mandrel.
4. A centrifugal solid-liquid separation device according to claim 3, characterized in that: The long tie rod consists of an adjusting nut connecting a screw and a connecting rod; the inner side of the screw is fixedly connected to the spindle, and the outer side is threaded into the adjusting nut's screw hole; the inner side of the connecting rod is a limiting step located inside the adjusting nut's screw hole, which mutually limits the adjusting nut's inner limiting step, and the outer side is fixedly connected to the conical roller.
5. A centrifugal solid-liquid separation device according to claim 4, characterized in that: The backwash pipe is equipped with parallel circular nozzles located directly above the conical drum and equidistant from the outer side of the conical drum. The circular nozzles are perpendicular to the outer side of the conical drum and are fitted with duckbill rubber valves. The left side of the backwash pipe is located in the clearance groove of the upper cover partition T, and the right side is located on the left side of the baffle plate. The right end is connected to the backwash outlet pipe.