A nanofiltration membrane separation device for water treatment

Abstract

The application belongs to the technical field of water treatment devices, and particularly relates to a nanofiltration membrane separation device for water treatment, which comprises a base, a pre-filter, a PLC controller, multiple groups of membrane filtration assemblies, an outer driving assembly, an inner cleaning assembly and a separation assembly, and each structure cooperates with each other to complete raw water pretreatment, pressure filtration, automatic membrane surface cleaning and convenient device maintenance operation; raw water fine filtration is realized through pressure water supply and the nanofiltration membrane body, and a gas-liquid cooperation cleaning mode is formed through micro-pressure aeration; the inner cleaning assembly is reciprocally rotated and wiped on the membrane surface through magnetic driving, so that the attached dirt on the membrane surface can be effectively removed, and the problems of incomplete water flow cleaning and existence of cleaning dead angles of the existing nanofiltration membrane separation device are solved; in cooperation with the quick-release cylinder and the separation assembly, the separation and disassembly and deep maintenance of the cleaning assembly are realized, the operation and maintenance difficulty is reduced, the nanofiltration membrane pollution is effectively delayed, and long-term stable and efficient operation of the device is ensured.

Description

Technical Field

[0001] This invention belongs to the technical field of water treatment devices, specifically a nanofiltration membrane separation device for water treatment. Background Technology

[0002] Nanofiltration membrane separation devices for water treatment are widely used in water purification and impurity removal processes. They mainly rely on the sieving performance of nanofiltration membranes to separate and remove large molecular organic matter, salts, and colloidal impurities in water, and have the advantages of high filtration accuracy and stable effluent quality.

[0003] Most existing nanofiltration membrane separation devices are equipped with simple rinsing structures to clean the membrane surface, which can meet basic membrane surface impurity removal requirements, but still have the following shortcomings: Firstly, the existing nanofiltration membrane separation devices generally use pure water rinsing, chemical solution circulation rinsing, or backwashing to clean nanofiltration membranes. The devices lack internal mechanical wiping structures and rely solely on water flow to remove loose impurities from the membrane surface. This cleaning method can only achieve a general, overall rinsing and cannot perform a close-fitting, full-coverage, and precise cleaning of the outer wall of the membrane tube. Compacted dirt is easily left in localized areas of the membrane tube, and after long-term operation, the dirt accumulates layer by layer, causing increased membrane fouling and affecting the filtration effect. Secondly, the existing nanofiltration membrane separation devices mostly use a single external water flow to clean the existing nanofiltration membranes. The cleaning method is limited and can only remove loose impurities on the membrane surface. It is difficult to remove stubborn salt scale and colloidal deposits that are compacted and attached to the membrane surface. It cannot effectively break the concentration polarization boundary layer on the membrane surface. There are many cleaning dead spots, poor cleaning uniformity, and poor membrane fouling delay effect, which can easily lead to rapid decline in membrane flux. Third, existing nanofiltration membrane separation devices are only equipped with pipeline flushing structures, lacking built-in detachable cleaning and isolation structures. The internal structure of the device is fixed and highly integrated. When the nanofiltration membrane becomes severely clogged and conventional hydraulic and chemical cleaning fails to remove the contaminants, it is impossible to isolate, disassemble, and perform in-depth maintenance on the internal cleaning structure. The only option is to shut down the entire device for disassembly and repair, which is cumbersome, difficult, and costly. In addition, existing nanofiltration membrane separation devices lack dedicated storage and isolation structures, resulting in poor convenience for cleaning and maintenance operations and low overall maintenance efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a nanofiltration membrane separation device for water treatment. By setting up a magnetic linkage internal and external cleaning method, combined with gas-liquid cleaning, it can perform all-round non-destructive descaling of the nanofiltration membrane surface. At the same time, it is equipped with an detachable maintenance structure to solve the problems of large cleaning dead corners, rapid membrane fouling, and cumbersome operation and maintenance of existing nanofiltration membrane separation devices, thereby improving the stability of water treatment and the service life of the device.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A nanofiltration membrane separation device for water treatment includes: a base, a pre-filter and two supports at the top of the base, a PLC controller at the other end of each support, the two supports being located at opposite ends of the pre-filter, and multiple membrane filtration assemblies mounted on the supports; each membrane filtration assembly includes a filter cartridge, an inlet end at one end of the filter cartridge, an outlet end at the other end of the filter cartridge, a first sealing disc at the outlet end, a limiting rod and a threaded rod on the outer side of the filter cartridge, both ends of the limiting rod and the threaded rod being connected to opposite ends of the filter cartridge, an external drive assembly threadedly connected to the threaded rod, an internal cleaning assembly that drives the external drive assembly within the inner cavity of the filter cartridge, and a quick-release cylinder detachably mounted at the other end of the filter cartridge, the quick-release cylinder being equipped with an isolation assembly.

[0006] According to some embodiments of the present invention, a micro-pressure air pump is connected to the outside of the filter cartridge via a flexible tube, the micro-pressure air pump is connected to a micro-pressure air inlet pipe, and the end of the micro-pressure air inlet pipe is connected to a central purified water pipe for introducing micro-pressure gas into the central purified water pipe.

[0007] According to some embodiments of the present invention, a water supply pipe is connected to the side wall of the pre-filter. Both the water supply pipe and the micro-pressure air inlet pipe are equipped with electromagnetic valves controlled by a PLC controller. The other end of the water supply pipe is connected to a booster pump, and the other end of the booster pump is connected to multiple filter cartridges via multiple water supply pipes. A central purified water pipe runs through the inner cavity of each filter cartridge. A multi-layer nanofiltration membrane body is fitted onto the outer wall of the central purified water pipe. A closed pipe is provided at the output end of the central purified water pipe, located inside a quick-release cylinder. Detachable valve sections are detachably installed at both the input end of the central purified water pipe and the other end of the closed pipe. A drain pipe is inserted into the outer wall of the filter cartridge. A flange mounting plate is detachably installed at the other end of the closed pipe.

[0008] According to some embodiments of the present invention, the external drive assembly includes a bearing seat slidably sleeved on the outside of the filter cartridge. The bearing seat has multiple limiting holes that slide with the limiting rod. The bearing seat also has a threaded collar that rotatably engages with the threaded rod. The outer side of the threaded collar has a toothed groove. Both ends of the bearing seat are provided with protective frames. A first motor and a second motor are respectively provided on the side walls of the two protective frames. The power output end of the first motor is provided with a first gear. The first gear meshes with a winding ring. The winding ring is rotatably connected to the inner cavity of the bearing. Multiple electromagnetic blocks are arranged in an array in the inner cavity of the winding ring. A conductive slip ring electrically connected to the electromagnetic blocks is provided on the outer wall of the winding ring. A conductive collar that slides in contact with the conductive slip ring is fixed on the inner side of the bearing seat. Both the conductive slip ring and the conductive collar are electrically connected to the PLC controller. The power output end of the second motor is provided with a second gear, which meshes with the threaded collar.

[0009] According to some embodiments of the present invention, the internal cleaning assembly includes two annular grooves formed on the outer wall of the quick-release cylinder, wherein a plurality of metal balls are slidably disposed in the inner cavity of the annular grooves, and the other ends of the plurality of metal balls slide against the inner side wall of the filter cylinder; the inner cavity of the quick-release cylinder is provided with a plurality of annularly arranged rubber fibers, one end of the plurality of rubber fibers contacting the outer wall of the nanofiltration membrane body.

[0010] According to some embodiments of the present invention, the outer wall of the quick-release cylinder is also arranged in a circumferential array with a plurality of magnetic blocks that magnetically cooperate with the electromagnet.

[0011] According to some embodiments of the present invention, the quick-release cylinder is provided with a second sealing disc that is detachably connected to the first sealing disc, and a sealing ring is provided between the first sealing disc and the second sealing disc, and a mounting groove is provided on the outer side of both the first sealing disc and the second sealing disc.

[0012] According to some embodiments of the present invention, the isolation assembly includes a nested frame sealed on the outer wall of a quick-release cylinder. One end of the nested frame is provided with a gate communicating with a second sealing disc. Both ends of the nested frame are provided with electric cylinders. The output ends of the two electric cylinders extend into the inner cavity of the nested frame. The power output ends of the electric cylinders are provided with gates. Both sides of the gates are provided with sliders. The sliders are slidably connected to the inner sidewall of the nested frame. One end of the gate is provided with an arc-shaped opening that fits tightly against the outer wall of the sealing tube. The inner cavity of the arc-shaped opening is provided with an elastic sealing ring. A transversely sealed through-hole is provided on the nested frame. A magnetic strip adsorption rod slides through the through-hole. One end of the magnetic strip adsorption rod is provided with a permanent magnet block that magnetically cooperates with the magnetic block.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention, by setting up a first motor, a second motor, an external drive assembly, and an internal cleaning assembly, utilizes the magnetic force of an electromagnetic block and a magnetic block to drive the quick-release cylinder and rubber bristles to rotate and wipe. Simultaneously, through the threaded engagement of a threaded rod and a threaded collar, combined with the limiting action of a limiting rod, the external drive assembly and the internal cleaning assembly move horizontally back and forth along the filter cylinder axis, performing a circumferential, all-around mechanical cleaning of the outer wall of the central purified water pipe and the entire length of the nanofiltration membrane body. This overcomes the shortcomings of existing nanofiltration membrane separation devices, such as incomplete cleaning by pure water rinsing and easy accumulation of impurities, improves the surface decontamination capability of the nanofiltration membrane body, and ensures long-term continuous and stable operation of the device.

[0014] 2. This invention, by installing a micro-pressure air pump and a micro-pressure air inlet pipe on the outside of the central purified water pipe, allows for the introduction of stable micro-positive pressure gas into the central purified water pipe during cleaning. The gas penetrates the nanofiltration membrane body from the inside out, forming uniform microbubbles. This, combined with the external water flow, creates a gas-liquid cleaning process that disrupts the concentration polarization boundary layer on the surface of the nanofiltration membrane. This process lifts, loosens, and peels off stubborn dirt, scale, and colloidal impurities that are compacted and attached to the surface of the nanofiltration membrane. This solves the problems of uneven cleaning, local dead corner residue, and severe concentration polarization inherent in existing nanofiltration membrane separation devices that rely on a single water flow for rinsing. It improves the cleaning uniformity and effectiveness of the nanofiltration membrane body, slows down the fouling rate of the nanofiltration membrane body, and stabilizes the overall water treatment throughput of the device.

[0015] 3. By assembling a quick-release cylinder and an isolation component at the end of the filter cartridge, this invention allows for the rapid isolation and removal of the internal cleaning component for deep cleaning and maintenance when the nanofiltration membrane is severely clogged and conventional online cleaning fails to remove contaminants. The disassembly and assembly are simple, eliminating the need to disassemble the entire device, thus reducing the difficulty and cost of device inspection and maintenance. Simultaneously, the internal cleaning component can be stored away, preventing it from prolonged contact with the nanofiltration membrane, which could increase water flow resistance and cause membrane wear, effectively extending the service life of the nanofiltration membrane and the overall lifespan of the device.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the membrane filtration assembly structure of the present invention; Figure 4 This is a schematic cross-sectional view of the membrane filtration assembly of the present invention. Figure 5 This is a schematic diagram of the isolation component structure of the present invention; Figure 6 This is a schematic diagram of the gate opening and closing state structure of the present invention; Figure 7 This is a schematic diagram of the second sealing disc structure of the present invention; Figure 8 This is a schematic diagram of the first gear structure of the present invention; Figure 9 This is a schematic diagram of the second gear structure of the present invention; Figure 10 This is a schematic diagram of the exploded structure of the external drive component of the present invention; Figure 11 This is a schematic diagram of the first motor mounting position structure of the present invention; Figure 12 This is a schematic diagram of the internal cleaning component structure of the present invention.

[0019] In the diagram: 1. Base; 2. Pre-filter; 3. Bracket; 4. PLC controller; 5. Membrane filtration assembly; 51. Filter cartridge; 52. Limiting rod; 53. Threaded rod; 54. Inlet end; 55. Outlet end; 56. First sealing plate; 57. Sewage pipe; 6. Booster pump; 7. Water supply pipe; 71. Solenoid valve; 8. Micro-pressure air pump; 81. Micro-pressure air inlet pipe; 9. Central purified water pipe; 91. Nanofiltration membrane body; 92. Sealing pipe; 93. Detachable valve section; 94. Flange mounting plate; 10. External drive assembly; 101. Bearing 102. Seat; 103. Threaded collar; 104. Protective frame; 105. First motor; 106. First gear; 107. Wrapping ring; 108. Electromagnetic block; 109. Conductive slip ring; 11. Conductive collar; 11. Internal cleaning assembly; 110. Second motor; 111. Second gear; 113. Metal ball; 115. Rubber velvet; 116. Magnetic block; 12. Quick release cylinder; 121. Second sealing disc; 13. Isolation assembly; 131. Nested frame; 132. Electric cylinder; 133. Gate; 134. Magnetic strip adsorption rod; 135. Permanent magnet block. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] like Figures 1-12 As shown, a nanofiltration membrane separation device for water treatment includes: a base 1, which supports and houses the entire device, and works with the upper components to complete the overall assembly of the device, ensuring structural stability during operation and reducing the risk of vibration and displacement; a pre-filter 2 and two supports 3 are provided at the top of the base 1; the pre-filter 2 is used to pre-treat the incoming raw water, intercepting large particulate impurities in the raw water, providing pre-protection for the downstream water treatment structure, and reducing the treatment load on the downstream membrane; a PLC controller 4 is provided at the other end of the supports 3, which is used to uniformly control the electrical components, valves, water circuits, and air circuits of the entire device, realizing the automatic switching between filtration and cleaning modes; the two supports 3 are located at both ends of the pre-filter 2, and are used to install and raise the membrane filter assembly 5, reserving space for pipeline assembly and device maintenance; multiple membrane filter assemblies 5 are provided on the supports 3, and multiple sets of membrane filter assemblies 5 work together to complete the water treatment operation synchronously, improving the overall water treatment efficiency of the device.

[0022] like Figure 3As shown, the membrane filtration assembly 5 includes a filter cartridge 51, which is a sealed cavity structure for water treatment filtration and membrane surface cleaning. It works in conjunction with various internal and external components to complete water filtration and dirt cleaning. One end of the filter cartridge 51 has an inlet end 54, which receives pre-treated raw water and introduces it into the filter cartridge 51. The other end of the filter cartridge 51 has an outlet end 55, which is used to output purified water. The outlet end 55 has a first sealing disc 56, which is used for end sealing and connection, ensuring a sealed environment inside the filter cartridge 51 and guaranteeing stable filtration and cleaning pressure. The outer side of the filter cartridge 51 has a limiting rod 52 and a threaded rod 53, both ends of which are connected to the two ends of the filter cartridge 51. The limiting rod 52 is used to cooperate with the moving structure to achieve axial limiting and guidance, restricting the rotation of the moving structure. The filter cartridge 51 has a threaded rod 53 for axial feed; an external drive assembly 10 is threadedly connected to the threaded rod 53 and the limiting rod 52 to achieve axial reciprocating movement, and at the same time, it provides rotational power for the internal cleaning structure in conjunction with the magnetic transmission relationship; the inner cavity of the filter cartridge 51 is also provided with an internal cleaning assembly 11 that is in transmission cooperation with the external drive assembly 10. The internal cleaning assembly 11 moves and rotates synchronously with the external drive assembly 10 to perform overall wiping and cleaning of the outer wall of the membrane; a quick-release cylinder 12 is detachably installed at the other end of the filter cartridge 51. The quick-release cylinder 12 is detachably assembled with the end of the filter cartridge 51 to facilitate the disassembly and maintenance of the internal components; an isolation assembly 13 is provided on the quick-release cylinder 12. The isolation assembly 13 is used in conjunction with the quick-release cylinder 12 to isolate, position and transfer the internal cleaning components, meeting the switching conditions between online operation and offline maintenance of the device.

[0023] A micro-pressure air pump 8 is connected to the outside of the filter cartridge 51 via a flexible hose. The micro-pressure air pump 8 is used to output stable micro-pressure gas, which, in conjunction with the air path structure, enables micro-pressure air ventilation and cleaning inside the membrane body. The micro-pressure air pump 8 is connected to a micro-pressure air inlet pipe 81, which is used to connect the micro-pressure air pump 8 to the central purified water pipe 9, enabling directional delivery of stable pressure gas. The end of the micro-pressure air inlet pipe 81 is connected to the central purified water pipe 9, which is used to introduce micro-pressure gas into the central purified water pipe 9. This, in conjunction with the membrane structure, enables micro-bubble disturbance from the inside out, assisting in the removal of dirt adhering to the membrane surface and enhancing the cleaning effect.

[0024] like Figures 1-4As shown, a water supply pipe 7 is connected to the side wall of the pre-filter 2. The water supply pipe 7 is used to connect the pre-filter 2 and the filter cartridge 51 to realize the raw water delivery and distribution. Both the water supply pipe 7 and the micro-pressure air inlet pipe 81 are equipped with solenoid valves 71 controlled by the PLC controller 4. The solenoid valves 71 work with the PLC controller 4 to realize the on / off control of the water and air circuits and complete the automatic switching of filtration and cleaning modes. The other end of the water supply pipe 7 is connected to a booster pump 6. The booster pump 6 is used to provide pressurization power for the raw water delivery and realize stable permeation filtration of raw water in conjunction with the pipeline pressure. The other end of the booster pump 6 is connected to multiple filter cartridges 51 through multiple water supply pipes 7, and works synchronously with multiple sets of membrane filtration components 5 to supply water.

[0025] A central purified water pipe 9 runs through the inner cavity of the filter cartridge 51. The central purified water pipe 9, in conjunction with the membrane structure, collects and transports filtered purified water. A multi-layer nanofiltration membrane body 91 is fitted onto the outer wall of the central purified water pipe 9. The nanofiltration membrane body 91 serves as the core filtration structure, working with water pressure to screen and remove impurities in the water, thus completing the purification and separation of the raw water. A closed pipe 92 is located at the output end of the central purified water pipe 9. The closed pipe 92, in conjunction with the central purified water pipe 9, completes the transport of purified water, isolates purified water from wastewater, and prevents secondary pollution of the purified water. The closed pipe 92 is located at a quick-release... Inside the cylinder 12, a quick-release cylinder 12 disassembly and assembly structure is adapted for overall assembly; both the input end of the central purified water pipe 9 and the other end of the closed pipe 92 are detachably equipped with a detachable opening and closing valve section 93, which, together with the pipeline, enables on / off control and disassembly and maintenance; a drain pipe 57 is inserted into the outer wall of the filter cylinder 51, which is used to discharge the filtered concentrated water and cleaning wastewater in conjunction with the cavity structure; a flange mounting plate 94 is detachably installed at the other end of the closed pipe 92, which, together with the pipeline end, enables sealed connection and detachable assembly.

[0026] like Figures 8-11As shown, the external drive assembly 10 includes a bearing seat 101 slidably sleeved on the outside of the filter cartridge 51. The bearing seat 101 is slidably assembled with the filter cartridge 51 and works with various transmission structures to complete power output and movement. The bearing seat 101 is provided with multiple limiting holes that slide with the limiting rod 52. The limiting holes work with the limiting rod 52 to achieve sliding limitation, ensuring that the bearing seat 101 can only move axially and preventing rotational deviation. The bearing seat 101 is also rotatably provided with a threaded collar 102 that is threadedly engaged with the threaded rod 53. The threaded collar 102 works with the threaded rod 53 to form a threaded transmission engagement, which drives the rotational movement of the filter cartridge 51. Rotational force is converted into axial movement force; the outer side of the threaded collar 102 is provided with toothed grooves, which cooperate with the gear structure to achieve power meshing transmission; both ends of the bearing housing 101 are provided with protective frames 103, which cooperate with the bearing housing 101 to protect and adapt the motor and transmission structure; the side walls of the two protective frames 103 are respectively provided with a first motor 104 and a second motor 110, which respectively cooperate with the corresponding transmission structure to provide rotational power, respectively meeting the power requirements of cleaning rotation and component translation; the power output end of the first motor 104 is provided with The first gear 105, in conjunction with the first motor 104, outputs power to achieve meshing transmission. A ring 106 meshes with the first gear 105, and the ring 106, in conjunction with the first gear 105, achieves rotational motion. The ring 106 is rotatably connected to the inner cavity of the bearing to meet the requirements of rotational motion. Multiple electromagnetic blocks 107 are arranged in an array within the inner cavity of the ring 106. The electromagnetic blocks 107, in conjunction with the energized structure, generate a magnetic field, forming a magnetic transmission connection with the internal structure. A conductive slip ring 108, electrically connected to the electromagnetic blocks 107, is provided on the outer wall of the ring 106. The bearing seat 10... A conductive collar 109 is fixedly provided on the inner side and slides in contact with the conductive slip ring 108. The conductive slip ring 108 and the conductive collar 109 slide and conduct in a coordinated manner to ensure continuous energization during rotation and maintain stable magnetic transmission. Both the conductive slip ring 108 and the conductive collar 109 are electrically connected to the PLC controller 4 to achieve precise control of energization and excitation in cooperation with the PLC controller 4. The power output end of the second motor 110 is provided with a second gear 111, which meshes with the threaded collar 102 to transmit the power of the second motor 110 and drive the threaded collar 102 to rotate and feed.

[0027] like Figure 2As shown, the internal cleaning component 11 includes two annular grooves formed on the outer wall of the quick-release cylinder 12. Multiple metal balls 113 are slidably arranged in the inner cavity of the annular grooves, and the other ends of the multiple metal balls 113 slide against the inner side wall of the filter cylinder 51. The metal balls 113 slide with the filter cylinder 51, which plays a role in the rotational adaptation and stable positioning of the quick-release cylinder 12, ensuring that the rotation operation is stable and without shaking. Multiple annularly arranged rubber bristles 115 are provided in the inner cavity of the quick-release cylinder 12, and one end of the multiple rubber bristles 115 contacts the outer wall of the nanofiltration membrane body 91. The rubber bristles 115 cooperate with the rotational movement of the quick-release cylinder 12 to adhere to the outer wall of the nanofiltration membrane body 91 for comprehensive wiping and descaling.

[0028] The outer wall of the quick-release cylinder 12 is also surrounded by a plurality of magnetic blocks 116 that magnetically cooperate with the electromagnetic block 107. The magnetic blocks 116 and the electromagnetic block 107 form a magnetic attraction cooperation. By utilizing the magnetic field penetration cooperation relationship, the power from the outside to the inside is transmitted without contact, which drives the quick-release cylinder 12 to rotate stably. There is no need for cavity opening transmission, which ensures the airtightness of the filter cartridge 51.

[0029] The quick-release cylinder 12 is provided with a second sealing disc 121 that is detachably connected to the first sealing disc 56. The second sealing disc 121 and the first sealing disc 56 are mated together to achieve a sealed and detachable assembly of the filter cartridge 51 and the quick-release cylinder 12. A sealing ring is provided between the first sealing disc 56 and the second sealing disc 121. The sealing ring, together with the two sealing discs, further improves the sealing performance of the mating and prevents air pressure and water leakage. The outer side of the first sealing disc 56 and the second sealing disc 121 are provided with mounting slots. The mounting slots, together with the assembly structure, enable quick alignment and disassembly, improving the convenience of maintenance.

[0030] like Figures 3-6As shown, the isolation assembly 13 includes a nested frame 131 sealed on the outer wall of the quick-release cylinder 12. The nested frame 131 works with the quick-release cylinder 12 to achieve overall sealing assembly, providing assembly adaptation for each isolation structure. One end of the nested frame 131 is provided with a gate communicating with the second sealing disc 121. The gate works with the cavity structure to realize the passage and isolation of the internal components. Both ends of the nested frame 131 are provided with electric cylinders 132. The output ends of the two electric cylinders 132 extend into the inner cavity of the nested frame 131. The electric cylinders 132 work with the cavity structure to realize the extension and retraction power output. The power output ends of the electric cylinders 132 are provided with gates 133. The gates 133 work with the electric cylinders 132 to realize the opening and closing of the gates to seal, completing the switching between cavity isolation and conduction. Both sides of the gates 133 are provided with sliders. The sliding block is connected to the inner wall of the nested frame 131, and the slider slides with the nested frame 131 to ensure smooth opening and closing of the gate 133. One end of the gate 133 has an arc-shaped opening that fits tightly with the outer wall of the sealing tube 92. The inner cavity of the arc-shaped opening is equipped with an elastic sealing ring. The elastic sealing ring fits tightly with the outer wall of the sealing tube 92 to achieve a seal, balancing pipeline passage and cavity sealing. The nested frame 131 has a horizontally sealed through-hole. A magnetic strip adsorption rod 134 slides through the through-hole. The magnetic strip adsorption rod 134 cooperates with the through-hole to achieve horizontal sliding displacement. One end of the magnetic strip adsorption rod 134 is equipped with a permanent magnet 135 that magnetically cooperates with the magnetic block 116. The permanent magnet 135 and the magnetic block 116 magnetically attract each other to achieve adsorption, transfer and isolation storage of the inner cleaning component 11.

[0031] Working principle: First, the raw water is filtered by the pre-filter 2, which removes large particles of silt, suspended impurities, and fibrous debris, preventing hard particles from directly scouring and scratching the surface of the nanofiltration membrane 91. Then, the pressurized water pump 6 is started to deliver the pretreated raw water to the inner cavity of the filter cartridge 51. Under the pressure of the pressurized water pump 6, the raw water penetrates the outer layers of the nanofiltration membrane 91 from the outside in. Small molecules such as water molecules and monovalent salts can pass through the membrane layers smoothly and flow into the central purified water pipe 9 inside the filter tube, forming purified water, which is then transported outward from the product water end of the central purified water pipe 9. However, large organic molecules, divalent salts, colloids, and fine suspended solids in the water cannot pass through the nanofiltration membrane 91 and are trapped on the outer surface of the nanofiltration membrane 91, forming concentrated wastewater, which is continuously discharged through the concentrated water outlet of the membrane filtration module 5. During long-term operation of the device, pollutants trapped on the membrane surface accumulate continuously, which can easily cause local concentration polarization and membrane fouling. Therefore, the device needs to be switched to the cleaning process after a certain period of operation.

[0032] Cleaning process: The first motor 104 is started, and the power output end of the first motor 104 drives the first gear 105 to rotate. The first gear 105 drives the meshing ring 106 to rotate inside the bearing seat 101. During the rotation, the electromagnetic block 107 contacts and conducts electricity through the outer wall conductive slip ring 108 and the inner side conductive sleeve 109 of the bearing seat 101, generating a magnetic field that attracts the magnetic block 116. The magnetic field can penetrate the wall of the filter cartridge 51 and drive the inner quick-release cylinder 12 to rotate synchronously. When the quick-release cylinder 12 rotates, the multiple sets of rubber floss 115 arranged on its inner wall can comprehensively clean the large molecular organic matter, divalent salt scale, colloids and suspended impurities attached to the outer wall of the central water purification pipe 9. The cleaning process involves a surrounding mechanical wiping process. During cleaning, the pressurized water pump 6 is turned off, the pipeline solenoid valve 71 is opened, and the micro-pressure air pump 8 is started. The micro-pressure air pump 8 delivers regulated gas through the micro-pressure air inlet pipe 81 to the interior of the central purified water pipe 9. The micro-pressure air pump 8 maintains the air pressure inside the central purified water pipe 9 at a slightly positive pressure that is slightly higher than the flushing water pressure outside the inner cavity of the filter cartridge 51. This ensures that the gas permeates evenly and slowly from the inside of the nanofiltration membrane body 91 to the outside, forming dense and uniform microbubbles on the membrane surface. It also avoids problems such as bulging, peeling, and permanent damage to the membrane pores caused by excessive pressure, while avoiding situations where the pressure is too low to form effective bubble disturbance and cleaning failure occurs. During the process of microbubbles permeating from the inside out, they can lift, loosen, and peel off the stubborn dirt, colloidal deposits, and salt particles that are compacted and attached to the outer wall of the membrane. Combined with the external circulating flushing water flow and the mechanical wiping action of the rubber bristles 115, this solves the problems of uneven cleaning and local dead corner residue in existing nanofiltration membrane separation devices with unilateral water flow flushing. It also breaks the concentration polarization boundary layer on the membrane surface, achieving a gas-liquid combination enhanced cleaning effect and improving the overall cleanliness of the membrane surface.

[0033] It should be noted that during the cleaning operation, the second motor 110 is started simultaneously. The second motor 110 drives the meshing second gear 111 to rotate, which drives the threaded collar 102 to rotate and feed on the threaded rod 53. Utilizing the threaded transmission and the limiting and guiding effect of the limiting rod 52, the outer drive component 10 is driven to move horizontally back and forth, thereby driving the inner cleaning component 11 to rotate and translate at the same time, realizing a comprehensive, dead-angle-free cleaning of the entire length of the outer wall of the central water purification pipe 9. This solves the defects of the existing fixed-point cleaning method of nanofiltration membrane separation devices, such as incomplete local cleaning and accumulation of dirt residue. At the same time, with the continuous water flow rinsing, the impurities and residues removed by wiping can be quickly transported with the rinsing wastewater to the sewage pipe 57 for centralized discharge, preventing the detached impurities from being re-adsorbed and adhered to the surface of the nanofiltration membrane body 91, and ensuring the cleaning effect.

[0034] When the nanofiltration membrane body 91 becomes clogged and the internal cleaning component 11 needs to be disassembled, inspected, and cleaned, the magnetic attraction of the external drive component 10 drives the internal cleaning component 11 to move towards the isolation component 13. After the component moves to the gate position, the electromagnetic block 107 of the external drive component 10 is de-energized and demagnetized, so that the internal cleaning component 11 is temporarily stored in the inner area of ​​the filter cartridge 51 near the isolation component 13. Then, the magnetic strip adsorption rod 134 is manually pushed so that the permanent magnet block 135 on the magnetic strip adsorption rod 134 is magnetically attracted to the magnetic block 116 of the internal cleaning component 11. Then, the two sets of electric cylinders 132 are activated. The extension and retraction power of the electric cylinders 132 pulls the two sets of gates 133 that are tightly attached to the closed tube 92 to open. The magnetic strip adsorption rod 134 is manually pulled to smoothly move the magnetically attracted internal cleaning component 11 into the quick-release cylinder 12. Then, the gates 133 are closed. Workers can remove the entire internal cleaning component 11 by disassembling the flange mounting plate 94 and the detachable opening and closing valve section 93 of the quick-release cylinder 12, and clean and maintain it. After maintenance, the component is put back into place to ensure the stable operation of the device in the future.

[0035] It should be noted that the closed tube 92 is only used to transport filtered purified water and has no filtration or cleaning function. When the device is producing water normally and no membrane cleaning is required, the inner cleaning component 11 can be moved to the inner cavity of the nested frame 131 for isolation and sealing through the above manual operation to avoid the problem of increased water flow resistance and membrane wear caused by the inner cleaning component 11 being in contact with the membrane surface for a long time.

[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A nanofiltration membrane separation device for water treatment, characterized in that, include: The base (1) is provided with a pre-filter (2) and two brackets (3) at the top end of the base (1). A PLC controller (4) is provided at the other end of the brackets (3). The two brackets (3) are located at both ends of the pre-filter (2). Multiple membrane filter components (5) are provided on the brackets (3). The membrane filtration assembly (5) includes a filter cartridge (51), one end of which is provided with an inlet end (54), and the other end of which is provided with an outlet end (55). The outlet end (55) is provided with a first sealing disc (56). The outer side of the filter cartridge (51) is provided with a limiting rod (52) and a threaded rod (53). The two ends of the limiting rod (52) and the threaded rod (53) are respectively connected to the two ends of the filter cartridge (51). An external drive assembly (10) is threadedly connected to the threaded rod (53). The inner cavity of the filter cartridge (51) is also provided with an internal cleaning assembly (11) that drives the external drive assembly (10). The other end of the filter cartridge (51) is detachably installed with a quick-release cylinder (12), and an isolation assembly (13) is provided on the quick-release cylinder (12).

2. The nanofiltration membrane separation device for water treatment according to claim 1, characterized in that, The filter cartridge (51) is connected to a micro-pressure air pump (8) via a flexible hose. The micro-pressure air pump (8) is connected to a micro-pressure air inlet pipe (81). The end of the micro-pressure air inlet pipe (81) is connected to the central purified water pipe (9) for introducing micro-pressure gas into the central purified water pipe (9).

3. A nanofiltration membrane separation device for water treatment according to claim 2, characterized in that, A water supply pipe (7) is connected to the side wall of the pre-filter (2). The water supply pipe (7) and the micro-pressure air inlet pipe (81) are equipped with electromagnetic valves (71) controlled by the PLC controller (4). The other end of the water supply pipe (7) is connected to a pressurized water pump (6). The other end of the pressurized water pump (6) is connected to multiple filter cartridges (51) through multiple water supply pipes (7). The filter cartridge (51) has a central purified water pipe (9) running through its inner cavity. The outer wall of the central purified water pipe (9) is fitted with a multi-layer nanofiltration membrane body (91). The output end of the central purified water pipe (9) is provided with a closed pipe (92). The closed pipe (92) is located inside the quick-release cylinder (12). The input end of the central purified water pipe (9) and the other end of the closed pipe (92) are both detachably equipped with a detachable opening and closing valve section (93). A drain pipe (57) is inserted into the outer wall of the filter cartridge (51). A flange mounting plate (94) is detachably installed at the other end of the closed pipe (92).

4. A nanofiltration membrane separation device for water treatment according to claim 3, characterized in that, The external drive assembly (10) includes a bearing seat (101) slidably sleeved on the outside of the filter cartridge (51). The bearing seat (101) is provided with a plurality of limiting holes that slide with the limiting rod (52). The bearing seat (101) is also rotatably provided with a threaded collar (102) that is threaded with the threaded rod (53). The outer side of the threaded collar (102) is provided with a toothed groove. Both ends of the bearing seat (101) are provided with protective frames (103). The side walls of the two protective frames (103) are respectively provided with a first motor (104) and a second motor (110). The power output end of the first motor (104) is provided with a first gear (105). The first gear (105) meshes with the first motor (104). A winding ring (106) is provided, which is rotatably connected to the inner cavity of the bearing. Multiple electromagnetic blocks (107) are arranged in an array in the inner cavity of the winding ring (106). A conductive slip ring (108) electrically connected to the electromagnetic blocks (107) is provided on the outer wall of the winding ring (106). A conductive collar (109) that slides in contact with the conductive slip ring (108) is fixed on the inner side of the bearing seat (101). Both the conductive slip ring (108) and the conductive collar (109) are electrically connected to the PLC controller (4). A second gear (111) is provided at the power output end of the second motor (110). The second gear (111) meshes with the threaded collar (102).

5. A nanofiltration membrane separation device for water treatment according to claim 4, characterized in that, The internal cleaning component (11) includes two annular slots formed on the outer wall of the quick-release cylinder (12). The inner cavity of the annular slots is provided with a plurality of metal balls (113), and the other end of the plurality of metal balls (113) slides against the inner side wall of the filter cylinder (51). The inner cavity of the quick-release cylinder (12) is provided with a plurality of annularly arranged rubber fibers (115), and one end of the plurality of rubber fibers (115) contacts the outer wall of the nanofiltration membrane body (91).

6. A nanofiltration membrane separation device for water treatment according to claim 5, characterized in that, The outer wall of the quick-release cylinder (12) is also surrounded by a plurality of magnetic blocks (116) that magnetically cooperate with the electromagnetic block (107).

7. A nanofiltration membrane separation device for water treatment according to claim 6, characterized in that, The quick-release cylinder (12) is provided with a second sealing disc (121) that is detachably connected to the first sealing disc (56). A sealing ring is provided between the first sealing disc (56) and the second sealing disc (121). An installation slot is provided on the outer side of both the first sealing disc (56) and the second sealing disc (121).

8. A nanofiltration membrane separation device for water treatment according to claim 1, characterized in that, The isolation assembly (13) includes a nested frame (131) sealed on the outer wall of the quick-release cylinder (12). One end of the nested frame (131) is provided with a gate communicating with the second sealing disc (121). Both ends of the nested frame (131) are provided with electric cylinders (132). The output ends of the two electric cylinders (132) extend into the inner cavity of the nested frame (131). The power output ends of the electric cylinders (132) are provided with gates (133). Both sides of the gates (133) are... A slider is provided, which is slidably connected to the inner wall of the nested frame (131). One end of the gate (133) is provided with an arc-shaped opening that fits tightly against the outer wall of the closed tube (92). The inner cavity of the arc-shaped opening is provided with an elastic sealing ring. A transversely sealed through-hole is provided on the nested frame (131). A magnetic strip adsorption rod (134) slides through the through-hole. One end of the magnetic strip adsorption rod (134) is provided with a permanent magnet block (135) that magnetically cooperates with the magnetic block (116).

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