An ultra-micro filtration water membrane filtering device using air-water collaborative backwashing

Abstract

The embodiment of the application provides a kind of ultrafiltration water membrane filter device using air-water collaborative backwashing, it is related to water treatment membrane separation technical field.It includes filter membrane component, linkage switching valve, backwashing gas branch, backwashing water branch, drainage branch, water inlet branch, water production branch and control unit.Linkage switching valve includes valve body and valve core, and the valve core is equipped with air path channel and water path channel, and control unit drives valve core rotation to make air path channel and water path channel alternate conduction, realize gas washing and water washing linkage switching.The application uses single linkage switching valve to replace multiple independent valves, and has simple structure, convenient control, high backwashing efficiency and reliable operation.

Description

Technical Field

[0001] This invention relates to the field of water treatment membrane separation technology, and in particular to an ultra-micro water filtration membrane filtration device employing air-water synergistic backwashing. Background Technology

[0002] Ultrafiltration membrane filtration devices are widely used in water treatment scenarios such as water purification, industrial wastewater treatment, and reclaimed water reuse. Their core component is the membrane module, which consists of multiple hollow fiber membrane filaments encapsulated within a membrane housing. During filtration, raw water passes through the membrane under pressure differential, and contaminants are trapped on the membrane surface. Product water is collected from the inner cavity of the membrane filaments and discharged. As operating time increases, the trapped contaminants gradually accumulate on the membrane surface, forming a filter cake layer that continuously compacts, leading to increased filtration resistance and decreased product water flux. Therefore, periodic backwashing is necessary to restore membrane flux.

[0003] Common backwashing methods include water backwashing and air scrubbing. Water backwashing uses backwash water to flow backward through the membrane pores, using the scouring effect of the water flow to remove contaminants from the membrane surface. Air scrubbing, on the other hand, introduces compressed air into the membrane module, using the shearing and turbulence generated by the rising air bubbles to loosen the filter cake layer on the membrane surface. In practical applications, both methods are often used in combination to achieve both effective contaminant removal and cleaning. In existing systems, air scrubbing and water scrubbing are usually controlled by two separate sets of valves, and the switching sequence depends on a separate programmable control system.

[0004] This method of controlling air and water independently has the following shortcomings: First, the switching sequence between air washing and water washing depends on the control links, and the switching action is delayed. If the filter cake layer is not switched to water washing in time after the air washing loosens it, the loosened pollutants will be re-compacted on the membrane surface, resulting in incomplete backwashing. Second, there is no linkage and interlock between the air and water circuits. At the moment of switching, backwash water may flow back into the air circuit, or gas may enter the product water branch and the inlet water branch, which will not only contaminate the product water, but may also damage the air source equipment. Third, the air and water switching involves a large number of valves and control links, making the overall structure of the device complex and increasing the number of failure points.

[0005] To address the problems of separate and independent control of air washing and water washing in the backwashing process of existing ultra-micro water filtration devices, uncoordinated switching timing, easy crosstalk between air and water branches, and complex switching structure, those skilled in the art have attempted to coordinate air washing and water washing by optimizing the control timing program of two independent valves. However, this method relies on the accuracy and response speed of the control system and still has the risk of erroneous switching and crosstalk between air and water. Therefore, this application provides an ultra-micro water filtration device that adopts air-water coordinated backwashing, which realizes coordinated switching of air washing and water washing through a linkage switching valve driven by a single drive component in a mechanical linkage manner. Summary of the Invention

[0006] This application provides an ultra-micro water filtration membrane device employing air-water coordinated backwashing, which solves the problems of separate and independent control of air washing and water washing in the prior art, uncoordinated switching timing, easy crosstalk between air and water branches, and complex switching structure. It includes a filter membrane assembly, a linkage switching valve, a backwashing air branch, a backwashing water branch, a drainage branch, a water inlet branch, a product water branch, and a control unit. The linkage switching valve includes a valve body and a valve core rotatably disposed within the valve body. The valve core has air passages and water passages. The valve body has an air interface, a water interface, and a media interface. The backwashing air branch is connected to the air interface, the backwashing water branch is connected to the water interface, and the media interface is connected to the backwashing media inlet of the filter membrane assembly. The control unit drives the valve core to rotate, so that the air passages and water passages are alternately connected, realizing the linkage switching of air washing and water washing.

[0007] Furthermore, the valve core is also provided with a drainage channel, and the valve body is also provided with a waste discharge interface; when the valve core rotates to the transition position, both the air passage and the water passage are closed, and the drainage channel connects the medium interface and the waste discharge interface to realize pressure relief and waste discharge.

[0008] Furthermore, the backwash air branch is equipped with an air one-way valve, the backwash water branch is equipped with a water one-way valve, the inlet water branch is equipped with an inlet valve, the product water branch is equipped with a product water valve, and the drain branch is equipped with a drain valve.

[0009] Furthermore, a gas-water mixer is provided on the pipeline between the medium interface and the backwash medium inlet. The backwash water and backwash gas are mixed in the gas-water mixer to form a two-phase flow of gas and water before entering the filter membrane assembly.

[0010] Furthermore, the filter membrane assembly includes a membrane shell and a hollow fiber membrane bundle disposed within the membrane shell. The two ends of the hollow fiber membrane bundle are fixed to the membrane shell through a casting layer, and a water collection cavity is formed above the casting layer. The membrane shell is provided with an inlet, a water outlet, a backwashing medium inlet, and a drain outlet.

[0011] Furthermore, an air and water distribution plate is provided at the inlet of the backwashing medium to ensure that the air and water two-phase flow is evenly distributed on the surface of the hollow fiber membrane bundle.

[0012] Furthermore, the linkage switching valve also includes a drive component, which is connected to the valve core in a transmission manner, and the control unit is electrically connected to the drive component; a sealing component is provided between the valve body and the valve core.

[0013] Furthermore, the outer wall of the valve core is provided with a positioning groove, and the valve body is provided with an elastic positioning element that cooperates with the positioning groove. When the valve core rotates to each working position, the elastic positioning element is engaged in the positioning groove to achieve positioning.

[0014] This invention provides an ultra-micro water filtration membrane device employing air-water synergistic backwashing, which, compared to existing technologies, offers the following advantages: This ultra-micro water membrane filtration device, which uses air-water synergistic backwashing, employs a single linkage switching valve. The valve core rotation enables alternating conduction of air and water channels, replacing multiple independent valves in the traditional system. This significantly simplifies the system structure and reduces equipment costs and failure rates.

[0015] This ultra-microfiltration membrane filtration device employs a combined air-water backwashing system. The valve core features a transition position, allowing for pressure relief and waste discharge between air and water washing via a drainage channel. This prevents direct air-water collisions and protects the membrane fibers from damage. This ultra-micro water filtration device employs air-water synergistic backwashing. The air-water mixer ensures thorough mixing of backwashing air and water, forming a uniform two-phase flow that enhances membrane fiber vibration and shearing scrubbing effects, thereby improving backwashing efficiency.

[0016] This ultra-micro water filtration device uses air-water synergistic backwashing. The air and water distribution plate ensures that the backwashing medium is evenly distributed across the membrane module cross section, avoiding uneven rinsing or dead zones in certain areas. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention; Figure 3 This is a schematic diagram of the linkage switching valve of the present invention; Figure 4 This is a schematic diagram of the orifice conduction state of the valve core of the linkage switching valve of the present invention at different working positions. Figure 5 This is a schematic diagram of the structure of the filter membrane assembly of the present invention; Figure 6 This is a schematic diagram of the gas-water mixer of the present invention; Figure 7 This is a schematic diagram of the connection structure of the gas-water mixer of the present invention.

[0019] icon: 1. Filter membrane module; 11. Membrane housing; 12. Hollow fiber membrane bundle; 13. Permeate collection chamber; 14. Inlet; 15. Permeate outlet; 16. Backwash media inlet; 17. Drain outlet; 18. Casting layer; 19. Air and water distribution plate; 2. Linkage switching valve; 21. Valve body; 22. Valve core; 221. Air passage; 222. Water passage; 223. Drain channel; 23. Air interface; 24. Water interface; 25. Media interface; 26. Drive component; 3. Backwash air branch; 31. Air one-way valve; 4. Backwash water branch; 41. Water one-way valve; 5. Drain branch; 51. Drain valve; 6. Inlet branch; 61. Inlet valve; 7. Permeate branch; 71. Permeate valve; 8. Control unit; 9. Air-water mixer; 27. Seal; 28. Positioning groove; 29. ​​Elastic positioning component. Detailed Implementation

[0020] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0021] Please refer to Figures 1-7 This invention provides an ultra-micro water filtration membrane device using air-water synergistic backwashing, comprising a filter membrane assembly 1, a linkage switching valve 2, a backwashing air branch 3, a backwashing water branch 4, a drainage branch 5, a water inlet branch 6, a water production branch 7, and a control unit 8.

[0022] The linkage switching valve 2 includes a valve body 21 and a valve core 22 rotatably disposed within the valve body 21. The valve core 22 has an air passage 221 and a water passage 222. The valve body 21 has an air inlet 23, a water inlet 24, and a media inlet 25. The backwash air branch 3 connects to the air inlet 23, the backwash water branch 4 connects to the water inlet 24, and the media inlet 25 connects to the backwash media inlet 16 of the filter membrane assembly 1 via a pipeline.

[0023] The linkage switching valve 2 also includes a drive component 26, which is connected to the valve core 22 via a transmission connection. The control unit 8 is electrically connected to the drive component 26. A sealing component 27 is provided between the valve body 21 and the valve core 22 to prevent leakage between the interfaces. The outer wall of the valve core 22 is provided with a positioning groove 28, and the valve body 21 is provided with an elastic positioning component 29 that cooperates with the positioning groove 28. When the valve core 22 rotates to each position, the elastic positioning component 29 engages with the positioning groove 28 to achieve precise positioning.

[0024] The valve core 22 is also provided with a drain channel 223, and the valve body 21 is also provided with a waste discharge port. For example... Figure 3 As shown, valve core 22 has four positions: Filtration station: Air passage 221, water passage 222, and drain passage 223 are all shut off, and the device is filtering and producing water normally; Air washing station: Air passage 221 connects air interface 23 and medium interface 25, and backwash gas enters filter membrane module 1 for air washing; Transition station: Gas passage 221 and water passage 222 are both closed, and drainage passage 223 connects medium interface 25 with waste discharge interface to relieve pressure and discharge waste; Water washing station: Water channel 222 connects water interface 24 and medium interface 25, and backwash water enters the filter membrane module 1 for water washing.

[0025] The backwash air branch 3 is equipped with an air one-way valve 31 to prevent backwash water from flowing back into the air source; the backwash water branch 4 is equipped with a water one-way valve 41 to prevent backwash gas from flowing back into the water source; the water inlet branch 6 is equipped with a water inlet valve 61; the water production branch 7 is equipped with a water production valve 71; and the drainage branch 5 is equipped with a drainage valve 51.

[0026] An air-water mixer 9 is installed on the pipeline between the media interface 25 and the backwash media inlet 16. For example... Figure 6 As shown, the gas-water mixer 9 is a Venturi injector, including a converging section, a throat, and a diffuser section, with the gas inlet located at the throat. After the backwash water is accelerated in the converging section, a negative pressure is formed at the throat, entraining the backwash gas. The gas and water phases are fully mixed in the mixing chamber and then decelerated and pressurized in the diffuser section, forming a uniform gas-water two-phase flow output.

[0027] The filter membrane module 1 includes a membrane housing 11 and a hollow fiber membrane bundle 12 disposed within the membrane housing 11. The hollow fiber membrane bundle 12 is fixed to the membrane housing 11 at both ends by a casting layer 18, and a product water collection chamber 13 is formed above the casting layer 18. The membrane housing 11 is provided with an inlet 14, a product water outlet 15, a backwash media inlet 16, and a drain outlet 17. An air and water distribution plate 19 is provided at the backwash media inlet 16, and the air and water distribution plate 19 has multiple air and water distribution holes to ensure uniform distribution of the air and water two-phase flow on the surface of the hollow fiber membrane bundle 12.

[0028] In specific use, according to this embodiment of the invention: raw water enters the inner cavity of the membrane housing 11 of the filter membrane assembly 1 through the inlet branch 6, the inlet valve 61, and the inlet 14. Under pressure, it passes through the membrane wall of the hollow fiber membrane bundle 12 and enters the inner cavity of the membrane fibers. The produced water is collected in the produced water collection chamber 13 and output through the produced water outlet 15, the produced water valve 71, and the produced water branch 7. At this time, the valve core 22 of the linkage switching valve 2 is in the filtration position, and both the air passage 221 and the water passage 222 are closed.

[0029] Backwashing status: When the membrane flux drops to the set value or reaches the set operating cycle, the control unit 8 starts the backwashing program, closes the inlet water branch 6 and the product water branch 7, and opens the drain valve 51.

[0030] Air washing stage: Control unit 8 drives drive component 26 to rotate valve core 22 to the air washing position, and air passage 221 connects air interface 23 and medium interface 25. Backwash gas enters the inner cavity of membrane housing 11 through backwash gas branch 3, air one-way valve 31, air interface 23, air passage 221, medium interface 25, air-water mixer 9, backwash medium inlet 16, and air and water distribution plate 19. The gas rises in the form of bubbles, violently shaking the hollow fiber membrane bundles 12, causing contaminants attached to the membrane surface to loosen and fall off. At the same time, the gas shearing action removes contaminants from the membrane pores. The detached contaminants are discharged with the gas through drain port 17, drain valve 51, and drain branch 5.

[0031] Transition phase: After the air washing is completed, the control unit 8 drives the valve core 22 to rotate to the transition position. The air passage 221 and water passage 222 are both closed. The drain passage 223 connects the medium interface 25 with the waste discharge interface. The residual gas and wastewater in the pipeline are discharged through the waste discharge interface. The system is depressurized to avoid direct air and water collision that could damage the membrane fibers.

[0032] Water washing stage: Control unit 8 drives valve core 22 to rotate to the water washing position, and water channel 222 connects water interface 24 and medium interface 25. Backwash water enters air-water mixer 9 through backwash water branch 4, water one-way valve 41, water interface 24, water channel 222, and medium interface 25. At the Venturi throat of air-water mixer 9, high-speed water flow creates negative pressure to entrain a small amount of gas, forming a two-phase flow of gas and water. After being evenly distributed by air and water distribution plate 19, it passes in reverse through hollow fiber membrane bundle 12, thoroughly flushing loose and detached contaminants away from the membrane surface, and is discharged through drain outlet 17, drain valve 51, and drain branch 5.

[0033] Air washing and water washing can be alternated for multiple cycles until the membrane flux recovers to the set value. After backwashing, the control unit 8 drives the valve core 22 back to the filtration position, closes the drain valve 51, and opens the inlet branch 6 and the product water branch 7, and the device resumes normal filtration and water production.

[0034] During the rotation of the valve core 22, the elastic positioning element 29 cooperates with the positioning groove 28 to ensure that the valve core 22 is accurately positioned at each station; the sealing element 27 ensures the seal between each interface to prevent leakage. Each check valve prevents backflow of the medium and ensures the safe operation of the system.

[0035] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An ultra-micro water filtration membrane device employing air-water synergistic backwashing, characterized in that: The system includes a filter membrane assembly (1), a linkage switching valve (2), a backwash air branch (3), a backwash water branch (4), a drainage branch (5), a water inlet branch (6), a water production branch (7), and a control unit (8). The linkage switching valve (2) includes a valve body (21) and a valve core (22) rotatably disposed within the valve body (21). The valve core (22) is provided with an air passage (221) and a water passage (222). The valve body (21) is provided with an air interface (23), a water interface (24), and a media interface (25). The backwash air branch (3) is connected to the air interface (23), the backwash water branch (4) is connected to the water interface (24), and the media interface (25) is connected to the backwash media inlet (16) of the filter membrane assembly (1). The control unit (8) drives the valve core (22) to rotate, so that the air passage (221) and the water passage (222) are alternately connected, thereby realizing the linkage switching between air washing and water washing.

2. The ultra-micro water filtration membrane filtration device using air-water synergistic backwashing according to claim 1, characterized in that: The valve core (22) is also provided with a drainage channel (223), and the valve body (21) is also provided with a waste discharge interface; when the valve core (22) rotates to the transition position, the air channel (221) and the water channel (222) are both cut off, and the drainage channel (223) connects the medium interface (25) and the waste discharge interface.

3. The ultra-micro water filtration membrane device employing air-water synergistic backwashing according to claim 2, characterized in that: The backwash air branch (3) is equipped with an air one-way valve (31), the backwash water branch (4) is equipped with a water one-way valve (41), the water inlet branch (6) is equipped with a water inlet valve (61), the water production branch (7) is equipped with a water production valve (71), and the drainage branch (5) is equipped with a drainage valve (51).

4. The ultra-micro water filtration membrane filtration device using air-water synergistic backwashing according to claim 1, characterized in that: A gas-water mixer (9) is provided on the pipeline between the media interface (25) and the backwash media inlet (16). The gas-water mixer (9) includes a liquid inlet, a gas inlet and an outlet. The backwash water and backwash gas are mixed in the gas-water mixer (9) and then enter the filter membrane assembly (1).

5. The ultra-micro water filtration membrane filtration device using air-water synergistic backwashing according to claim 1, characterized in that: The filter membrane assembly (1) includes a membrane shell (11) and a hollow fiber membrane bundle (12) disposed in the membrane shell (11). The two ends of the hollow fiber membrane bundle (12) are fixed in the membrane shell (11) through a casting layer (18). A water collection chamber (13) is formed above the casting layer (18). The membrane shell (11) is provided with an inlet (14), a water outlet (15), a backwashing medium inlet (16), and a drain outlet (17).

6. The ultra-micro water filtration membrane filtration device using air-water synergistic backwashing according to claim 5, characterized in that: The backwashing medium inlet (16) is provided with an air and water distribution plate (19), which has multiple air and water distribution holes to ensure that the mixture is evenly distributed on the surface of the hollow fiber membrane bundle (12).

7. The ultrafine water membrane filtration device employing air-water synergistic backwashing according to claim 1, characterized in that: The linkage switching valve (2) also includes a drive component (26), which is connected to the valve core (22) in a transmission manner, and the control unit (8) is electrically connected to the drive component (26); a sealing component (27) is provided between the valve body (21) and the valve core (22).

8. The ultra-micro water filtration membrane filtration device using air-water synergistic backwashing according to claim 1, characterized in that: The valve core (22) has a positioning groove (28) on its outer wall, and the valve body (21) has an elastic positioning element (29) that cooperates with the positioning groove (28). When the valve core (22) rotates to each station, the elastic positioning element (29) is inserted into the positioning groove (28) to achieve positioning.

9. The ultrafine water membrane filtration device employing air-water synergistic backwashing according to claim 3, characterized in that: The control unit (8) controls backwashing in the following sequence: first, it drives the valve core (22) to the air washing station to open the air passage (221) for air washing, then rotates to the transition station, and finally rotates to the water washing station to open the water passage (222) for water washing; air washing and water washing are alternated for at least one cycle.

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