A gas distribution structure and operation method of ultrafiltration membrane

Abstract

The present application provides an air distribution structure and operation method of an ultrafiltration membrane, comprising a columnar body, membrane filaments arranged in the columnar body, a water purification chamber arranged at the upper part of the columnar body, a concentrated water chamber arranged in the middle part of the columnar body, and a water distribution chamber arranged at the bottom of the columnar body. The device is provided with an air distribution chamber at the bottom of the concentrated water chamber, a plurality of water inlet channels are arranged in the air distribution chamber, and strip-shaped air inlet holes are symmetrically arranged at the position of each water inlet channel near the bottom of the air distribution chamber. Through the air distribution structure, after the compressed air enters the air distribution chamber from the air inlet, a stable air pressure is first formed in the air distribution chamber, and then the compressed air enters each water inlet channel uniformly through the strip-shaped air inlet holes, thereby achieving uniform distribution of air washing and improving the cleaning effect of the membrane filaments.

Description

Technical Field

[0001] The present application relates to the technical field of water treatment, and in particular to an air distribution structure and an operating method of an ultrafiltration membrane. Background Art

[0002] Column ultrafiltration membranes have been widely used in the field of water treatment. This technology can effectively remove suspended matter, colloids, bacteria, viruses and other macromolecular substances in water, while retaining minerals and trace elements that are beneficial to the human body. Therefore, it has significant advantages in water purification, drinking water production, industrial water treatment, etc.

[0003] During the ultrafiltration process, as the intercepted dirt continues to adhere to the surface of the membrane fibers, the water production of the ultrafiltration device will gradually decrease. In order to restore the water production flux of the ultrafiltration membrane, the ultrafiltration membrane needs to be automatically backwashed with air and water on a regular basis. However, the air distribution structure in the prior art has obvious defects: when the clean compressed air enters the water distribution chamber from the air inlet of the ultrafiltration membrane, most of the air volume will be concentrated into the concentrated water side of the ultrafiltration membrane from the water inlet channel near the air inlet, while the bottom of the membrane fibers far away from the air inlet cannot obtain sufficient air washing.

[0004] This uneven air distribution structure seriously affects the air washing effect. Since the bottom of the membrane fiber far from the air inlet cannot be effectively cleaned, the pollutants there cannot be completely removed. These residual pollutants will continue to accumulate during the operation of the equipment, which not only reduces the water flux of the membrane, but also increases the frequency of chemical cleaning of the membrane.

[0005] Therefore, it is necessary to propose a new technical solution to solve the above technical problems. Summary of the invention

[0006] The purpose of the present application is to provide an air distribution structure and an operating method for an ultrafiltration membrane, so as to solve the technical problem in the prior art of poor membrane filament cleaning effect caused by uneven air distribution.

[0007] An embodiment of the present application provides an ultrafiltration membrane device, comprising a columnar body, membrane filaments arranged in the columnar body, a clean water chamber arranged on the upper part of the columnar body, a concentrated water chamber arranged in the middle part of the columnar body, and a water distribution chamber arranged at the bottom of the columnar body, the ultrafiltration membrane device also includes: an air distribution chamber arranged at the bottom of the concentrated water chamber; a plurality of water inlet channels passing through the air distribution chamber, one end of the water inlet channel being connected to the water distribution chamber; strip-shaped air inlet holes symmetrically arranged at a position of each of the water inlet channels close to the bottom of the air distribution chamber; and a fixed plate, the fixed plate being installed at the bottom of the concentrated water chamber, the fixed plate being in a disc shape, the outer diameter of the fixed plate being matched with the inner diameter of the concentrated water chamber, the outer peripheral edge of the fixed plate being provided with an annular sealing groove, a sealing ring being arranged in the sealing groove, the fixed plate being fixedly connected to the bottom of the concentrated water chamber through a fixing ring, and the inner diameter of the fixing ring being equal to the outer diameter of the fixed plate.

[0008] In the above-mentioned ultrafiltration membrane device, the air distribution chamber is located between the water distribution chamber and the concentrated water chamber, the air distribution chamber is provided with an air inlet for introducing compressed air into the air distribution chamber, and the air distribution chamber is provided with a space for storing the compressed air.

[0009] In the above-mentioned ultrafiltration membrane device, the membrane filaments are arranged in the concentrated water chamber, the top of the concentrated water chamber is provided with a concentrated water outlet, and the top of the water purification chamber is provided with a water production outlet.

[0010] In the above-mentioned ultrafiltration membrane device, the ultrafiltration membrane device further comprises a supporting base, and the supporting base is arranged below the water distribution chamber.

[0011] In the above-mentioned ultrafiltration membrane device, the fixed plate includes a positioning hole group, and the positioning hole group is distributed on the fixed plate in a concentric circle manner. A plurality of concentric circles are arranged outward in sequence with the center of the fixed plate as a reference, and a plurality of positioning holes are evenly arranged on the circumference of each concentric circle. The number of positioning holes on the inner concentric circle is less than the number of positioning holes on the outer concentric circle, and the radial spacing between two adjacent concentric circles is equal.

[0012] In the above-mentioned ultrafiltration membrane device, each of the positioning holes includes a guide portion and a fixing portion, the guide portion is located above the fixing portion, the inner diameter of the guide portion is larger than the inner diameter of the fixing portion, the inner wall of the positioning hole is provided with an inclined surface, the inclined surface extends from the guide portion to the fixing portion, and the central axis of the positioning hole is perpendicular to the upper surface of the fixing plate.

[0013] In the above-mentioned ultrafiltration membrane device, the ultrafiltration membrane device also includes a guide assembly, which includes a plurality of guide plates, which are radially and evenly distributed with the center of the fixed plate as the reference, the upper end of each guide plate is fixedly connected to the lower surface of the fixed plate, the lower end of the guide plate is inclined toward the water inlet channel, and the surface of each guide plate is provided with a plurality of parallel guide grooves in the vertical direction, and the cross-section of the guide groove is V-shaped.

[0014] In the above-mentioned ultrafiltration membrane device, the ultrafiltration membrane device also includes an adjustment component and a protection component, the adjustment component includes a plurality of adjustment components, the adjustment components are evenly distributed along the circumference of the fixed plate, and are used to adjust the horizontality of the fixed plate, the protection component includes a protection net and a support frame, the mesh diameter of the protection net is equal to the diameter of the fixed plate, the support frame includes a plurality of support rods and an annular frame, the support rods are evenly distributed along the circumference, the lower end of each support rod is fixedly connected to the fixed plate, the upper end of the support rod is connected to the annular frame, and the edge of the protective net is fixedly connected to the annular frame.

[0015] An embodiment of the present application also provides a cleaning method for the above-mentioned ultrafiltration membrane device, comprising the following steps: step S1, open the water inlet solenoid valve and the concentrated water solenoid valve, start the raw water pump, and exhaust the air in the ultrafiltration concentrated water chamber; step S2, open the water inlet solenoid valve and the water production solenoid valve, start the raw water pump, and produce water; step S3, open the concentrated water solenoid valve and the air inlet solenoid valve, and adjust the raw water flow to half of the normal water production flow; step S4, open the concentrated water solenoid valve, the backwash water inlet solenoid valve and the air intake solenoid valve, and start the backwash pump; step S5, open the water inlet solenoid valve and the concentrated water solenoid valve, and adjust the raw water pump to half of the normal water production flow; and return to the step S1, and cyclically execute the above steps S1 to S5.

[0016] In the above cleaning method, the step S5 further comprises: using raw water to flush away the pollutants cleaned in step S4.

[0017] In the air distribution structure and operation method of the ultrafiltration membrane provided in the present application, a decentralized air distribution structure is formed by arranging a plurality of water inlet channels in the air distribution chamber, and symmetrically arranging strip air inlet holes at the position of each water inlet channel near the bottom of the air distribution chamber. When the compressed air enters the air distribution chamber from the air inlet, a stable air pressure is first formed in the air distribution chamber, and then evenly enters each water inlet channel through the strip air inlet holes. Since the strip air inlet holes are symmetrically arranged on both sides of the water inlet channel and the positions are relatively fixed, the air volume obtained by each water inlet channel is basically equal, which avoids the problem of insufficient air volume far away from the air inlet in the traditional air distribution method, significantly improves the uniformity and effectiveness of air washing, and solves the technical problem of poor membrane filament cleaning effect caused by uneven air distribution in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the operating environment of the ultrafiltration membrane device provided in the embodiment of the present application.

[0019] Figure 2 yes Figure 1 Schematic diagram of the ultrafiltration membrane device shown.

[0020] Figure 3 yes Figure 2 An enlarged view of area A in the ultrafiltration membrane device is shown. DETAILED DESCRIPTION

[0021] The specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0022] The terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different technical features. The term "plurality" and similar words mean two or more, unless otherwise clearly defined.

[0023] The embodiments of the present application may be combined with each other.

[0024] Reference Figures 1 to 3 , the present application provides an ultrafiltration membrane device 105 (air distribution structure of ultrafiltration membrane) and a cleaning method (operation method) thereof.

[0025] The water inlet 10503 of the ultrafiltration membrane device 105 is connected to the water inlet solenoid valve 103, the water inlet solenoid valve 103 is connected to the raw water pump 102, the raw water pump 102 is connected to the raw water tank 101, the air inlet 10504 of the ultrafiltration membrane device 105 is connected to the air inlet solenoid valve 104, and the concentrate water outlet 10509 of the ultrafiltration membrane device 105 is connected to the concentrate water solenoid valve 106.

[0026] The water outlet 10511 of the ultrafiltration membrane device 105 is connected to the water production solenoid valve 108 and the backwash water inlet solenoid valve 107, the backwash water inlet solenoid valve 107 is connected to the water inlet valve 109, the water inlet valve 109 is connected to the backwash water pump 110, and the backwash water pump 110 is connected to the ultrafiltration water production tank 111.

[0027] The ultrafiltration membrane device 105 includes a columnar body, in which a water purification chamber 10510, a concentrated water chamber 10508 and a water distribution chamber 10502 are arranged from top to bottom. A membrane filament 10507 is arranged in the concentrated water chamber 10508 for filtering impurities in water. A water production port 10511 is arranged at the top of the water purification chamber 10510, and a concentrated water port 10509 is arranged at the top of the concentrated water chamber 10508.

[0028] The ultrafiltration membrane device 105 of the present application is provided with an air distribution chamber 10505 at the bottom of the concentrated water chamber 10508. The air distribution chamber 10505 is provided with a space for storing compressed air. An air inlet 10504 is provided on one side of the air distribution chamber 10505 for introducing compressed air into the air distribution chamber 10505. A plurality of water inlet channels are provided in the air distribution chamber 10505, and one end of each water inlet channel is connected to the water distribution chamber 10502. Strip-shaped air inlet holes 10506 are symmetrically provided at a position near the bottom of each water inlet channel, and a support base 10501 is provided below the air distribution chamber 10505.

[0029] The cleaning method of the ultrafiltration membrane device 105 of the present application comprises the following steps:

[0030] First, the positive wash step is performed. This step lasts for 15-25 seconds, the water inlet solenoid valve and the concentrated water solenoid valve are opened, the raw water pump is started, and the air in the ultrafiltration concentrated water chamber 10508 is exhausted.

[0031] Then proceed to the normal operation step. This step lasts for 45-75 minutes, open the water inlet solenoid valve and the water production solenoid valve, start the raw water pump, and produce water.

[0032] Then, the first gas-water positive flushing step is performed. This step lasts for 15-25 seconds, and the concentrated water solenoid valve and the air inlet solenoid valve are opened to adjust the raw water flow rate to half of the normal water production flow rate. In this step, compressed air enters the water inlet channel through the air distribution chamber 10505 and the strip air inlet hole 10506, and the gas and water are mixed in the concentrated water chamber 10508 to remove pollutants on the surface of the ultrafiltration membrane and the concentrated water chamber 10508.

[0033] Then, the air-water washing step is performed. This step lasts for 25-35 seconds, and the concentrated water solenoid valve, the backwash water inlet solenoid valve and the air inlet solenoid valve are opened to start the backwash pump. In this step, compressed air also enters the water inlet channel through the air distribution chamber 10505 and the strip air inlet hole 10506.

[0034] Then the second gas-water positive flushing step is carried out. This step lasts for 10-20 seconds. The water inlet solenoid valve and the concentrated water solenoid valve are opened, and the raw water pump is adjusted to half of the normal water production flow rate. This step uses raw water flushing to remove the pollutants washed out in the gas-water washing step.

[0035] Finally, return to the forward washing step and repeat the above steps in a loop.

[0036] In the ultrafiltration membrane device 105 of the present application, the arrangement of the air distribution chamber 10505 allows the compressed air to form an air cushion layer in the air distribution chamber 10505 before entering the water inlet channel. As the compressed air continues to enter, the lower surface of the air cushion layer gradually drops. When the air cushion layer drops to the position of the strip air inlet holes 10506, the compressed air will evenly enter each water inlet channel through the strip air inlet holes 10506 on each water inlet channel, and then enter the concentrated water chamber 10508, achieving uniform air distribution. This air distribution method allows the gas and water to be fully mixed in the concentrated water chamber 10508, and the water in the entire concentrated water chamber 10508 can roll more evenly, making it easier to clean the pollutants on the surface of the membrane filament 10507.

[0037] The system of the ultrafiltration membrane device 105 of the present application also includes a raw water tank, a raw water pump, a pressure gauge, an ultrafiltration water production tank, a backwash water pump and related valves. The ultrafiltration membrane device 105 of the present application is equipped with multiple solenoid valves for controlling the water flow direction under different working conditions, and is provided with a compressed air intake device, which is controlled by the air intake solenoid valve, and each pipeline is interconnected through valves.

[0038] An embodiment of the present application provides an ultrafiltration membrane device 105, comprising a columnar body, membrane filaments 10507 arranged in the columnar body, a water purification chamber 10510 arranged at the upper part of the columnar body, a concentrated water chamber 10508 arranged in the middle part of the columnar body, and a water distribution chamber 10502 arranged at the bottom of the columnar body.

[0039] The ultrafiltration membrane device 105 also includes an air distribution chamber 10505 , a plurality of water inlet channels and strip-shaped air inlet holes 10506 .

[0040] The gas distribution chamber 10505 is arranged at the bottom of the concentrated water chamber 10508.

[0041] A plurality of water inlet channels are provided in the air distribution chamber 10505 , and one end of the water inlet channel is connected to the water distribution chamber 10502 .

[0042] The strip-shaped air inlet holes 10506 are symmetrically arranged at a position near the bottom of the air distribution chamber 10505 in each of the water inlet channels.

[0043] The membrane filaments 10507 are arranged in the concentrated water chamber 10508 .

[0044] The air distribution chamber 10505 is provided with an air inlet 10504 for introducing compressed air into the air distribution chamber 10505 .

[0045] The air distribution chamber 10505 is provided with a space for storing compressed air.

[0046] The ultrafiltration membrane device 105 also includes a supporting base 10501 , and the supporting base 10501 is arranged below the water distribution chamber 10502 .

[0047] The gas distribution chamber 10505 is located between the water distribution chamber 10502 and the concentrated water chamber 10508 .

[0048] The top of the water purification chamber 10510 is provided with a water outlet 10511. The top of the concentrated water chamber 10508 is provided with a concentrated water outlet 10509. The bottom of the water distribution chamber 10502 is provided with a water inlet 10503.

[0049] The columnar body is cylindrical. The membrane filaments 10507 are vertically arranged in the concentrated water chamber 10508, and a plurality of the membrane filaments 10507 are evenly distributed in bundles.

[0050] The cross section of the air distribution chamber 10505 is circular, and its diameter is equal to the inner diameter of the columnar body. The height of the air distribution chamber 10505 is 5%-15% of the height of the columnar body. The air distribution chamber 10505 is fixedly connected to the inner wall of the columnar body through a sealing connector.

[0051] The number of the water inlet channels is 6-12, and the multiple water inlet channels are distributed in a circular array in the gas distribution chamber 10505. Each of the water inlet channels is a round tube with a diameter of 10-30 mm, and the axial direction of the water inlet channel is parallel to the axial direction of the columnar body. The upper end of the water inlet channel is connected to the concentrated water chamber 10508, and the lower end is connected to the water distribution chamber 10502 to form a water flow channel.

[0052] The strip-shaped air inlet hole 10506 on each of the water inlet channels is arranged at a position 5-15 mm away from the bottom of the air distribution chamber 10505. The strip-shaped air inlet hole 10506 is a long strip through hole structure, and its length direction is perpendicular to the axial direction of the water inlet channel. Two strip-shaped air inlet holes 10506 are symmetrically arranged on each of the water inlet channels, and the opening directions of the two strip-shaped air inlet holes 10506 are opposite. The length of the strip-shaped air inlet hole 10506 is 5-15 mm, and the width is 1-3 mm.

[0053] In the ultrafiltration membrane device 105 and the cleaning method thereof provided in the present application, a decentralized air distribution structure is formed by arranging a plurality of water inlet channels in the air distribution chamber 10505, and symmetrically arranging strip air inlet holes 10506 at the position of each water inlet channel near the bottom of the air distribution chamber 10505. When the compressed air enters the air distribution chamber 10505 from the air inlet 10504, a stable air pressure is first formed in the air distribution chamber 10505, and then the compressed air enters each water inlet channel uniformly through the strip air inlet holes 10506. Since the strip air inlet holes 10506 are symmetrically arranged on both sides of the water inlet channel and the positions are relatively fixed, the air volume obtained by each water inlet channel is basically equal, thus avoiding the problem of insufficient air volume far away from the air inlet 10504 in the traditional air distribution method, significantly improving the uniformity and effectiveness of air washing, and solving the technical problem of poor cleaning effect of membrane filaments 10507 due to uneven air distribution in the prior art.

[0054] In practical applications, the distribution of the bundles of membrane filaments 10507 may not be uniform enough, resulting in poor air washing effect in some areas. To solve this technical problem, the ultrafiltration membrane device 105 of this embodiment also includes a fixing plate and a guide assembly to optimize the fixing structure of the bundles of membrane filaments 10507.

[0055] The fixing plate is installed on the bottom end face of the concentrated water chamber 10508. The fixing plate is made of metal material and has an overall disc-shaped structure. Its outer diameter is adapted to the inner diameter of the concentrated water chamber 10508. An annular sealing groove is provided on the outer peripheral edge of the fixing plate, and a sealing ring is provided in the sealing groove. The fixing plate is connected to the bottom of the concentrated water chamber 10508 through an annular fixing ring. The inner diameter of the fixing ring is equal to the outer diameter of the fixing plate. A plurality of connecting holes are provided on the fixing ring at equal intervals along the circumferential direction. The number of these connecting holes is 8-12, and each connecting hole is provided with an internal thread. Bolts are passed through the mounting holes at the bottom of the concentrated water chamber 10508 in turn, and are threadedly connected to the connecting holes on the fixing ring to fasten the fixing ring to the bottom of the concentrated water chamber 10508.

[0056] The fixing plate is provided with a positioning hole group, and the positioning hole group is distributed in a concentric circle manner. Taking the center of the fixing plate as a reference, multiple concentric circles are arranged outward in sequence, and the number of concentric circles is 4-6. Multiple positioning holes are evenly arranged on the circumference of each concentric circle, and the number of positioning holes on the inner concentric circle is less than the number of positioning holes on the outer concentric circle. The radial spacing between two adjacent concentric circles is equal, and the spacing value is 30-50 mm. On the same circumference, the arc length between two adjacent positioning holes is equal. Through this distribution method, the positioning holes on the fixing plate form a regular array distribution in the radial and circumferential directions.

[0057] Each positioning hole adopts a double-layer stepped hole structure, including a guide section located at the top and a fixed section located at the bottom. The inner diameter of the guide section is larger than the inner diameter of the fixed section, and an annular step surface is formed at the transition between the guide section and the fixed section. An inclined surface with an angle of 15-30 degrees to the vertical direction is provided on the inner wall of the positioning hole, and the inclined surface extends from the upper guide section to the lower fixed section. The central axis of the positioning hole is perpendicular to the upper surface of the fixed plate to ensure that the membrane filament 10507 bundle can remain in a vertical state after being inserted into the positioning hole. The inner diameter of the guide section is 10-15 mm, the inner diameter of the fixed section is 5-8 mm, the depth of the guide section is 8-12 mm, and the depth of the fixed section is 15-20 mm.

[0058] A guide assembly is provided between the fixed plate and the water inlet channel. The guide assembly includes a plurality of guide plates, which are evenly distributed radially with the center of the fixed plate as the reference. Each guide plate is made of stainless steel, and its upper end is connected to the lower surface of the fixed plate by screws, and its lower end is inclined at an angle of 45-60 degrees toward the water inlet channel. A plurality of parallel guide grooves are provided on the surface of each guide plate in the vertical direction, and the cross section of the guide groove is V-shaped, and these guide grooves are used to guide the water flow in a specific direction.

[0059] In order to facilitate the adjustment of the horizontality of the fixed plate, an adjustment component is arranged around the fixed plate. The adjustment component includes a plurality of adjustment screws and fixing nuts. The inclination of the fixed plate can be changed by adjusting the screws, and the fixing nuts are used to lock it after the adjustment is completed to prevent the position from changing.

[0060] The protection assembly includes a circular protection net and an annular support frame. The protection net is made of stainless steel wire mesh, and the diameter of the mesh is equal to the diameter of the fixed plate. The support frame is composed of multiple support rods and annular frames, and these support rods are evenly distributed along the circumference. The lower end of each support rod is fixedly connected to the fixed plate through a threaded connector, and the upper end is welded to the annular frame. The edge of the protection net is fixed to the annular frame by a buckle to intercept impurities with a diameter greater than 1 mm in the water to prevent impurities from entering the membrane filament 10507 area and causing damage.

[0061] During installation, first divide the membrane wires 10507 into multiple groups, and each group of membrane wires 10507 passes through the positioning holes and is fixed in turn. Then install the guide assembly, adjust the levelness of the fixing plate, and finally install the protection assembly. After the installation is completed, it is necessary to test to ensure that all parts are installed in place and working properly.

[0062] The above technical solution ensures uniform distribution of the membrane filaments 10507 bundles through the special distribution of the positioning hole groups, optimizes the water flow distribution through the guide components, and improves the air washing effect.

[0063] In practical applications, since the position of the air inlet 10504 is fixed, the compressed air in the air distribution chamber 10505 may be unevenly distributed, affecting the air washing effect. To solve this technical problem, this embodiment provides an annular air flow guide groove, multiple guide blades and a pressure equalization component in the air distribution chamber 10505.

[0064] The annular airflow guide groove is arranged along the inner wall of the air distribution chamber 10505. Specifically, the cross section of the annular airflow guide groove is U-shaped, the groove depth is 15-25 mm, and the groove width is 20-30 mm. The surface roughness of the inner surface of the annular airflow guide groove is not greater than 0.8 microns to reduce airflow resistance. The function of this groove is to guide and evenly distribute the compressed air entering from the air inlet 10504 so that it flows evenly along the inner wall of the air distribution chamber 10505.

[0065] A plurality of guide blades are arranged on the annular airflow guide groove. The guide blades are evenly distributed along the circumference of the annular airflow guide groove, and an equal distance is maintained between adjacent guide blades. Each guide blade is an arc-shaped plate-like structure, and its length direction is parallel to the axial direction of the annular airflow guide groove. The height of the guide blade is adapted to the groove depth of the annular airflow guide groove. These guide blades are installed in the annular airflow guide groove at the same inclination angle, and all guide blades are installed in an inclination along the annular airflow guide groove in sequence, forming a spiral structure as a whole. The inclination angle is 30-60 degrees, preferably 45 degrees.

[0066] The guide blade adopts a detachable installation structure. A plurality of mounting seats are arranged at the bottom of the annular airflow guide groove, and each mounting seat is provided with a positioning groove. A positioning block matching with the positioning groove is arranged at the bottom of the guide blade, and the guide blade is fixed by the matching of the positioning block and the positioning groove.

[0067] The pressure equalization assembly includes a plurality of splitter plates and guide vanes. The splitter plates are vertically mounted on the inner side of the annular airflow guide groove to divide the airflow into multiple streams. The guide vanes are mounted between the splitter plates in an arc-shaped arrangement. The splitter plates and the guide vanes form a plurality of airflow channels, and the cross-sectional areas of these airflow channels are equal, and are used to guide the airflow to flow evenly along the inner wall of the air distribution chamber 10505. This ensures that the compressed air can be evenly distributed in the air distribution chamber 10505 even if the position of the air inlet 10504 is fixed.

[0068] The flow process of compressed air after entering the air distribution chamber 10505 from the air inlet 10504 is as follows:

[0069] The first stage: the compressed air enters the annular airflow guide groove, which guides the compressed air entering from a fixed position to the entire annular area to achieve preliminary dispersion of the airflow.

[0070] The second stage: The compressed air forms a directional flow under the action of the guide vanes. When the airflow passes through these inclined guide vanes, a spiral flow path is formed under the guidance of the vanes. This spiral flow enables the airflow to be evenly distributed downward.

[0071] The third stage: the compressed air is distributed through the splitter assembly. The splitter plate in the splitter assembly divides the airflow into multiple streams, and each stream flows through the airflow channel between the splitter plates. Since the cross-sectional areas of these airflow channels are equal and the guide vanes are arranged in an arc shape, it can ensure that the airflow in each direction is basically equal.

[0072] The fourth stage: the compressed air that has undergone multi-stage distribution is evenly distributed in the air distribution chamber 10505. Through the circumferential guidance of the annular airflow guide groove, the spiral guidance of the guide blades and the uniform diversion of the diversion assembly, the compressed air is finally evenly distributed in the air distribution chamber 10505.

[0073] In the above technical solution, after the compressed air enters from the air inlet 10504, it is first received and initially guided by the annular airflow guide groove, and then guided by the guide blades to form a spiral downward flow path. At the same time, the coordination of the splitter plate and the guide vane enables the airflow to be evenly distributed in the air distribution chamber 10505. This can solve the problem of uneven distribution of compressed air in the air distribution chamber 10505 and improve the air washing effect.

[0074] During long-term operation, the strip-shaped air inlet holes 10506 may be clogged due to the deposition of impurities in the water. To solve this technical problem, the ultrafiltration membrane device 105 of this embodiment further includes a tapered channel, an anti-blocking component, and a cleaning component.

[0075] The strip-shaped air inlet hole 10506 adopts a tapered channel structure, wherein the diameter of the opening at the air inlet end is larger than the diameter of the opening at the air outlet end, and the entire channel gradually narrows from the air inlet end to the air outlet end. The cross section of the tapered channel is elliptical, and the inner wall of the channel gradually tilts inward along the air inlet direction. This allows the airflow to pass smoothly, and because the inner wall of the channel is inclined, impurities in the water are difficult to stay and accumulate on the inner wall.

[0076] An anti-blocking assembly is arranged at the periphery of the tapered channel. The anti-blocking assembly includes a guide plate group and a baffle plate group. The guide plate group includes a plurality of annular guide plates, which are arranged in sequence along the axial direction of the tapered channel. The inner diameter of each annular guide plate is larger than the outer diameter of the tapered channel, and an annular space is formed between the annular guide plate and the tapered channel. The surface of the annular guide plate is provided with a plurality of inclined guide surfaces, which guide the water flow to change direction.

[0077] The baffle group is arranged in the annular space between the annular guide plate and the conical channel. The baffle group includes a plurality of radial baffles, which are evenly distributed along the circumference of the annular space. Interval chambers are formed between adjacent radial baffles, and the interval chambers are used to block and collect impurities in the water.

[0078] The cleaning assembly is arranged outside the tapered channel, and includes a flushing unit and a control unit. The flushing unit includes a plurality of flushing nozzles, which are evenly arranged along the circumference of the tapered channel. The outlet of each flushing nozzle faces the inner wall of the tapered channel, and the axis of the flushing nozzle forms an angle of 30-45 degrees with the axis of the tapered channel, so that the flushing liquid can cover the inner wall of the tapered channel.

[0079] The control unit is connected to the flushing unit. The control unit includes a solenoid valve assembly, a detection assembly and a processing assembly. The pressure sensor of the detection assembly is installed near the air inlet end of the conical channel to detect the air pressure change at the air inlet hole. The processing assembly is electrically connected to the pressure sensor to receive and analyze the pressure signal. The inlet of the solenoid valve assembly is connected to the cleaning liquid source, and the outlet is connected to the flushing nozzle.

[0080] When the detection component detects that the air pressure at the air inlet increases, the processing component controls the solenoid valve component to open, so that the cleaning liquid is sprayed to the inner wall of the tapered channel through the flushing nozzle to remove impurities attached to the inner wall. After the cleaning is completed, the processing component controls the solenoid valve component to close and stop the supply of cleaning liquid.

[0081] Through the above technical solution, not only the problem of easy clogging of the strip air inlet hole 10506 is solved, but also automated maintenance is achieved, manual intervention is reduced, and the operating efficiency of the equipment is improved.

[0082] The sealing connection between the air distribution chamber 10505 and the columnar body may age after long-term use, causing air leakage. To solve this technical problem, the ultrafiltration membrane device 105 of this embodiment further includes an inner sealing ring, an outer sealing ring, an annular sealing groove group and a pressing assembly.

[0083] The inner sealing ring is arranged at the connection between the upper end surface of the air distribution chamber 10505 and the lower end surface of the columnar body. The cross section of the inner sealing ring is in an "X" shape, including an upper protrusion and a lower protrusion, which are in contact with the upper end surface of the air distribution chamber 10505 and the lower end surface of the columnar body respectively. The inner sealing ring is installed in the first annular installation groove on the upper end surface of the air distribution chamber 10505, and the depth of the installation groove matches the height of the inner sealing ring. The inner wall of the first annular installation groove is tightly fitted with the outer side surface of the inner sealing ring, and the bottom surface of the first annular installation groove is in tight contact with the bottom surface of the inner sealing ring.

[0084] The outer sealing ring is arranged radially outside the inner sealing ring. The cross section of the outer sealing ring is in an "O" shape and is installed in the second annular mounting groove on the upper end surface of the air distribution chamber 10505. The position of the second annular mounting groove is arranged concentrically with the first annular mounting groove. An annular gap is formed between the outer sealing ring and the inner sealing ring, and the annular gap constitutes a sealing buffer area. The upper surface of the outer sealing ring contacts the lower end surface of the columnar body, and the lower surface of the outer sealing ring contacts the bottom surface of the second annular mounting groove.

[0085] The annular sealing groove group is arranged on the upper end surface of the air distribution chamber 10505. The annular sealing groove group includes a plurality of concentric annular grooves, which are arranged in sequence from the inside to the outside. The cross section of each annular groove is rectangular, including a groove bottom surface and two side walls. An isolation step is arranged between adjacent annular grooves, and the upper surface of the isolation step is flush with the upper end surface of the air distribution chamber 10505. The annular sealing groove group is located on the outer side of the outer sealing ring, and a multiple sealing structure is formed by the arrangement of multiple annular grooves.

[0086] The clamping assembly is arranged on the outer periphery of the air distribution chamber 10505, and is used to apply axial pressure to the inner sealing ring and the outer sealing ring. The clamping assembly includes an annular clamping ring, a plurality of fixing screws and an annular pressure ring. The inner diameter of the clamping ring is larger than the outer diameter of the air distribution chamber 10505, and the clamping ring is connected to the outer peripheral wall of the air distribution chamber 10505 through a plurality of fixing screws. These fixing screws are evenly spaced along the circumference of the clamping ring, and the screw of each fixing screw passes through the through hole on the clamping ring and is connected to the threaded hole on the outer peripheral wall of the air distribution chamber 10505. The pressure ring is arranged on the inner side of the clamping ring, and the cross section of the pressure ring is an "L"-shaped structure, including a vertical portion and a horizontal portion. The vertical portion of the pressure ring contacts the inner wall of the clamping ring, and the horizontal portion extends above the inner sealing ring and the outer sealing ring. When the clamping ring applies pressure downward through the fixing screws, the horizontal portion of the pressure ring evenly transfers the pressure to the inner sealing ring and the outer sealing ring.

[0087] The installation process is carried out according to the following steps: first, the inner sealing ring is installed into the first annular installation groove on the upper end surface of the air distribution chamber 10505, so that the bottom surface of the inner sealing ring is completely in contact with the bottom surface of the installation groove; second, the outer sealing ring is installed into the second annular installation groove on the upper end surface of the air distribution chamber 10505, so that the bottom surface of the outer sealing ring is completely in contact with the bottom surface of the installation groove; third, the pressure ring is placed above the inner sealing ring and the outer sealing ring, so that the horizontal part of the pressure ring is in contact with the upper surface of the sealing ring; fourth, the clamping ring is placed on the outer periphery of the air distribution chamber 10505, so that the inner wall of the clamping ring is in contact with the vertical part of the pressure ring; fifth, the fixing screws are inserted into the through holes on the clamping ring in sequence, and connected with the threaded holes on the outer peripheral wall of the air distribution chamber 10505. The tightening order of the fixing screws is to tighten the screws in relative positions alternately to ensure that the clamping force is evenly distributed in the circumferential direction. After the installation is completed, compressed air is introduced into the air distribution chamber 10505 to perform a sealing test to detect whether there is any leakage at each connection.

[0088] In this multiple sealing structure, the inner sealing ring is arranged in the first innermost annular installation groove as the main sealing component; the outer sealing ring is arranged in the second annular installation groove, located outside the inner sealing ring, as a backup sealing component; the annular sealing groove group is arranged outside the outer sealing ring, and is composed of multiple concentric annular grooves; the clamping assembly is arranged on the outermost side, and uniform pressure is applied to the inner and outer sealing rings through the cooperation of the clamping ring, fixing screws and pressure ring. Each component is distributed in sequence in the radial direction, and a compression fit is formed in the axial direction, so that a stable and reliable sealing effect is achieved through the multiple sealing structure.

[0089] In the above technical scheme, the inner sealing ring is located at the innermost side as the main sealing component, the outer sealing ring is located at the outer side as the backup sealing component, the annular sealing groove group is distributed in the sealing area, and the clamping assembly is located at the outermost side, which effectively solves the sealing problem between the air distribution chamber 10505 and the columnar body, extends the service life of the seal, and improves the operating reliability of the equipment.

[0090] In practical applications, the water flow rates of multiple water inlet channels may be different, affecting the filtering effect. To solve this technical problem, this embodiment provides a regulating valve, a flow detection component, a pressure sensor and a control component at the entrance of each water inlet channel.

[0091] The regulating valve is installed at the entrance of each water inlet channel to control the opening of the water inlet channel. The regulating valve includes a cylindrical valve body and a valve plate arranged in the valve body. The two ends of the valve body are respectively provided with a water inlet 10503 and a water outlet, and an annular sealing ring is provided on the inner wall of the valve body. The valve plate is installed in the valve body through a transversely arranged rotating shaft, and the two ends of the rotating shaft pass through the side walls of the valve body respectively. Bearing seats are respectively provided on the outer surfaces of the two side walls of the valve body, and bearings are provided in the bearing seats. The two ends of the rotating shaft are respectively connected to the bearing seats through bearings. One end of the rotating shaft extends to the outside of the bearing seat and is connected to the output shaft of the driving assembly. The driving assembly includes a stepping motor and a reducer. The stepping motor drives the rotating shaft to rotate through the reducer, thereby adjusting the angle of the valve plate and changing the opening of the water inlet channel.

[0092] The flow detection assembly is arranged downstream of the water outlet of the regulating valve. The flow detection assembly includes a detection body and a display unit. The detection body is a cylindrical structure, and a rotor cavity is arranged inside it, and an impeller-shaped rotor is arranged inside the rotor cavity. The central axis of the rotor is connected to the detection body through a bearing, and a gap is left between the blades of the rotor and the inner wall of the rotor cavity. A magnetic sensor is arranged on the outer wall of the detection body for detecting the rotation speed of the rotor. The display unit is connected to the magnetic sensor through a data cable, and the display screen of the display unit displays the flow value in real time, and transmits the flow data to the control assembly through the communication interface.

[0093] The pressure sensors are respectively arranged at the water inlet end and the water outlet end of the water inlet channel. Each pressure sensor includes a detection element and a signal conversion unit. The detection element adopts a piezoresistive sensor, and its pressure-sensitive diaphragm is in direct contact with the water flow. The signal conversion unit includes a signal amplification circuit and an analog-to-digital conversion circuit to convert the pressure signal output by the detection element into a standard electrical signal. The pressure sensor is installed on the wall of the water inlet channel through a threaded connector, and the signal output end of the pressure sensor is connected to the control component through a shielded cable. By detecting the pressure difference between the water inlet end and the water outlet end, the control component can monitor the working status of the water inlet channel in real time.

[0094] The control component includes a drive unit, a processing unit and an execution unit. The drive unit is arranged outside the regulating valve, and includes a stepper motor and a reducer. The output shaft of the stepper motor is connected to the input shaft of the reducer through a coupling, and the output shaft of the reducer is connected to the rotating shaft of the regulating valve through a coupling. The processing unit is arranged in the control box, and is electrically connected to the flow detection component and the pressure sensor through the data acquisition interface, and receives the digital signals transmitted by each detection element. The processing unit has a built-in control program, and calculates the required adjustment amount according to the preset control parameters. The execution unit is arranged in the control box, and is electrically connected to the processing unit and the drive unit through a signal line, and converts the adjustment instruction output by the processing unit into a control signal of the drive unit.

[0095] The working process of the control component specifically includes the following steps:

[0096] The processing unit collects the flow data and pressure data of each water inlet channel every 100 milliseconds through the data acquisition interface;

[0097] The processing unit compares the collected data with the last data stored in the memory and calculates the flow difference between each water inlet channel;

[0098] When the flow difference between any two water inlet channels exceeds a preset threshold, the processing unit calculates the angle value that needs to be adjusted according to the control program;

[0099] The processing unit sends the calculated angle value to the execution unit;

[0100] The execution unit converts the angle value into a pulse signal of the stepper motor;

[0101] The execution unit sends a pulse signal to the stepper motor through the drive circuit to control the stepper motor to rotate a specified angle;

[0102] The stepper motor drives the shaft of the regulating valve to rotate through the reducer to change the valve plate opening;

[0103] The processing unit continuously monitors flow changes until the flow difference of each water inlet channel drops below a preset threshold.

[0104] When the flow detection component or pressure sensor fails and the output signal is abnormal, the processing unit immediately sends a stop signal to the execution unit. After receiving the stop signal, the execution unit immediately cuts off the driving power of the stepper motor to keep the valve plate of the regulating valve in the current position. At the same time, the processing unit sends a fault alarm signal to the upper computer through the communication interface to indicate that the detection component is abnormal. This ensures the stable operation of the equipment when the detection system is abnormal.

[0105] Through the above technical solution, the flow of multiple water inlet channels is automatically balanced. The regulating valve controls the water flow, the flow detection component and the pressure sensor provide real-time data, and the control component automatically adjusts the flow of each channel based on this data, ultimately keeping the flow of all water inlet channels consistent.

[0106] During the long-term operation of the device, the support base 10501 may be deformed due to excessive load. To solve this technical problem, the present embodiment improves the structure of the support base 10501, which mainly includes a bottom plate component, a reinforcement component and a shock absorbing component.

[0107] The base assembly includes a base body and an edge baffle. The base body is square, with edge baffles extending upwards around it, which are used to prevent the equipment from moving horizontally. Adjustable feet are set at the four corners of the base body, and the height of the adjustable feet can be changed to adjust the levelness of the base.

[0108] The reinforcement assembly adopts a cross structure, including a main support plate and a secondary support plate. The main support plate is set along the diagonal direction of the bottom plate, and its cross section is "T" shaped. The vertical part of the "T" cross section provides the main support force, and the horizontal part increases the structural stability. The secondary support plate is set perpendicular to the main support plate, and its structure is the same as the main support plate, but its size is smaller.

[0109] A connection node is set at the intersection of the main support plate and the auxiliary support plate. The connection node adopts an integral structure to form a smooth transition. A reinforcement plate is set at the connection node, and the reinforcement plate is arranged in an inclined shape to increase the node strength.

[0110] The shock-absorbing assembly includes a cushion, a shock absorber and a limit assembly. The cushion is arranged below the base plate assembly to absorb vibration. The upper and lower surfaces of the cushion are provided with anti-slip patterns to prevent displacement during use. Positioning protrusions are arranged around the cushion, which can limit the range of movement of the cushion.

[0111] The shock absorber adopts a piston structure, including an outer shell and an internal piston. The piston is provided with multiple through holes, which are used to produce a damping effect. The space between the outer shell and the piston is filled with damping fluid, and the damping effect is achieved through the flow of the damping fluid.

[0112] The limit assembly consists of a limit rod and a limit sleeve. The limit rod passes through the limit sleeve, and a buffer layer is provided on the inner wall of the limit sleeve. This structure can prevent the device from excessive displacement and reduce impact.

[0113] The embodiment of the present application also provides a method for cleaning the ultrafiltration membrane device 105, the cleaning method comprising the following steps:

[0114] Step S1, open the water inlet solenoid valve and the concentrated water solenoid valve, start the raw water pump, and exhaust the air in the ultrafiltration concentrated water chamber 10508. Step S1 lasts for 15-25 seconds. Specifically, first open the water inlet solenoid valve set on the water inlet pipeline and the concentrated water solenoid valve set on the concentrated water pipeline, and start the raw water pump connected to the water inlet pipeline. In this process, raw water enters the ultrafiltration concentrated water chamber 10508 from the water inlet pipeline, and the air in the concentrated water chamber 10508 is exhausted from the concentrated water pipeline. This step lasts for 15-25 seconds to ensure that the air in the concentrated water chamber 10508 is completely exhausted.

[0115] Step S2, open the water inlet solenoid valve and the water production solenoid valve, start the raw water pump, and produce water. Step S2 lasts for 45-75 minutes. Specifically, keep the water inlet solenoid valve open, close the concentrated water solenoid valve, and open the water production solenoid valve set on the water production pipeline at the same time, and continue to run the raw water pump. At this time, the raw water is filtered by the membrane filament 10507 set in the columnar body, and the filtered water flows out from the water production pipeline. This step lasts for 45-75 minutes.

[0116] Step S3, open the concentrated water solenoid valve and the air intake solenoid valve, adjust the raw water flow rate to half of the normal water production flow rate, and step S3 lasts for 15-25 seconds; specifically, close the water production solenoid valve, open the concentrated water solenoid valve and the air intake solenoid valve set on the air intake pipeline, and reduce the output flow rate of the raw water pump to half of the normal water production flow rate. At this time, the raw water and gas enter the ultrafiltration concentrated water chamber 10508 at the same time. This step lasts for 15-25 seconds and is used to pretreat the surface of the membrane filament 10507.

[0117] Step S4, open the concentrated water solenoid valve, the backwash water inlet solenoid valve and the air inlet solenoid valve, start the backwash pump, and step S4 lasts for 25-35 seconds; specifically, close the water inlet solenoid valve, keep the concentrated water solenoid valve and the air inlet solenoid valve open, and at the same time open the backwash water inlet solenoid valve set on the backwash water inlet pipeline, and start the backwash pump connected to the backwash water inlet pipeline. At this time, the backwash water and gas reversely flush the surface of the membrane filament 10507 from the water production side of the membrane filament 10507. This step lasts for 25-35 seconds and is used to remove pollutants on the surface of the membrane filament 10507.

[0118] Step S5, open the water inlet solenoid valve and the concentrated water solenoid valve, adjust the raw water pump to half of the normal water production flow rate, and step S5 lasts for 10-20 seconds; specifically, close the backwash water inlet solenoid valve and the air inlet solenoid valve, open the water inlet solenoid valve, keep the concentrated water solenoid valve open, and adjust the output flow rate of the raw water pump to half of the normal water production flow rate. At this time, the raw water enters from the water inlet pipeline, and the pollutants cleaned in step S4 are discharged from the system through the concentrated water pipeline. This step lasts for 10-20 seconds.

[0119] Return to step S1, and execute the above steps S1 to S5 cyclically. After completing step S5, return to step S1 and restart a new round of cleaning cycle. By cyclically executing steps S1 to S5, the membrane filaments 10507 in the ultrafiltration membrane device 105 are regularly cleaned and maintained.

[0120] The step S5 further comprises:

[0121] The pollutants cleaned in step S4 are removed by washing with raw water.

[0122] Specifically, in step S5, raw water enters the ultrafiltration concentrated water chamber 10508 from the water inlet pipeline, flows along the inner wall of the concentrated water chamber 10508, and washes off the pollutants attached to the wall of the concentrated water chamber 10508 and the surface of the membrane filaments 10507. These pollutants are discharged from the system through the concentrated water pipeline along with the raw water. This flushing method can effectively remove the pollutants cleaned in step S4 and prevent the pollutants from re-depositing in the system.

[0123] The embodiments of the present application are described in detail above, and the contents of this specification should not be construed as limiting the scope of protection of the present application.

Claims

1. An ultrafiltration membrane device, comprising a columnar body, membrane fibers arranged in the columnar body, a water purification chamber arranged at the upper part of the columnar body, a concentrated water chamber arranged in the middle part of the columnar body, and a water distribution chamber arranged at the bottom of the columnar body, characterized in that: The ultrafiltration membrane device also includes: A gas distribution chamber, arranged at the bottom of the concentrated water chamber; A plurality of water inlet channels are provided in the air distribution chamber, and one end of the water inlet channel is connected to the water distribution chamber; Strip-shaped air inlet holes are symmetrically arranged at a position of each of the water inlet channels close to the bottom of the air distribution chamber; and A fixed plate is installed at the bottom of the concentrated water chamber. The fixed plate is disc-shaped. The outer diameter of the fixed plate is matched with the inner diameter of the concentrated water chamber. An annular sealing groove is provided on the outer peripheral edge of the fixed plate. A sealing ring is provided in the sealing groove. The fixed plate is fixedly connected to the bottom of the concentrated water chamber through a fixing ring. The inner diameter of the fixing ring is equal to the outer diameter of the fixed plate.

2. The ultrafiltration membrane device according to claim 1, characterized in that: The air distribution chamber is located between the water distribution chamber and the concentrated water chamber. The air distribution chamber is provided with an air inlet for introducing compressed air into the air distribution chamber. The air distribution chamber is provided with a space for storing the compressed air.

3. The ultrafiltration membrane device according to claim 2, characterized in that: The membrane fibers are arranged in the concentrated water chamber, a concentrated water outlet is provided at the top of the concentrated water chamber, and a water production outlet is provided at the top of the purified water chamber.

4. The ultrafiltration membrane device according to claim 1, characterized in that: The ultrafiltration membrane device also includes a supporting base, and the supporting base is arranged below the water distribution chamber.

5. The ultrafiltration membrane device according to claim 1, characterized in that: The fixing plate includes a positioning hole group, which is distributed on the fixing plate in a concentric circle manner. A plurality of concentric circles are sequentially arranged outwardly with the center of the fixing plate as a reference, and a plurality of positioning holes are evenly arranged on the circumference of each concentric circle. The number of positioning holes on the inner concentric circle is less than the number of positioning holes on the outer concentric circle, and the radial spacing between two adjacent concentric circles is equal.

6. The ultrafiltration membrane device according to claim 5, characterized in that: Each of the positioning holes includes a guide portion and a fixing portion, the guide portion is located above the fixing portion, the inner diameter of the guide portion is larger than the inner diameter of the fixing portion, the inner wall of the positioning hole is provided with an inclined surface, the inclined surface extends from the guide portion to the fixing portion, and the central axis of the positioning hole is perpendicular to the upper surface of the fixing plate.

7. The ultrafiltration membrane device according to claim 5, characterized in that: The ultrafiltration membrane device also includes a guide assembly, which includes a plurality of guide plates, which are radially and evenly distributed with the center of the fixed plate as a reference, the upper end of each guide plate is fixedly connected to the lower surface of the fixed plate, and the lower end of the guide plate is inclined toward the water inlet channel. The surface of each guide plate is provided with a plurality of parallel guide grooves in the vertical direction, and the cross-section of the guide groove is V-shaped.

8. The ultrafiltration membrane device according to claim 5, characterized in that: The ultrafiltration membrane device also includes an adjustment component and a protection component. The adjustment component includes a plurality of adjustment parts, which are evenly distributed along the circumference of the fixed plate and are used to adjust the horizontality of the fixed plate. The protection component includes a protection net and a support frame. The mesh diameter of the protection net is equal to the diameter of the fixed plate. The support frame includes a plurality of support rods and an annular frame. The support rods are evenly distributed along the circumference, the lower end of each support rod is fixedly connected to the fixed plate, the upper end of the support rod is connected to the annular frame, and the edge of the protection net is fixedly connected to the annular frame.

9. A method for cleaning an ultrafiltration membrane device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1, opening the water inlet solenoid valve and the concentrate solenoid valve, starting the raw water pump, and exhausting the air in the ultrafiltration concentrate chamber, wherein the water inlet solenoid valve is connected to the water inlet of the ultrafiltration membrane device, the concentrate solenoid valve is connected to the concentrate outlet of the ultrafiltration membrane device, and the raw water pump is connected to the water inlet solenoid valve and the raw water tank of the ultrafiltration membrane device; Step S2, opening the water inlet solenoid valve and the water production solenoid valve, starting the raw water pump, and producing water, wherein the water production solenoid valve is connected to the water production port of the ultrafiltration membrane device; Step S3, opening the concentrated water solenoid valve and the air intake solenoid valve to adjust the raw water flow rate to half of the normal water production flow rate, wherein the air intake solenoid valve is connected to the air inlet of the ultrafiltration membrane device; Step S4, opening the concentrated water solenoid valve, the backwash water inlet solenoid valve and the air inlet solenoid valve, and starting the backwash pump, wherein the backwash water inlet solenoid valve is connected to the water outlet of the ultrafiltration membrane device; Step S5, opening the water inlet solenoid valve and the concentrated water solenoid valve, and adjusting the raw water pump to half of the normal water production flow rate; and Return to step S1 and execute the above steps S1 to S5 in a loop.

10. The cleaning method according to claim 9, characterized in that: The step S5 further comprises: The pollutants cleaned in step S4 are removed by washing with raw water.

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