Internally and externally cleanable filter assembly, dynamic membrane module, and cleaning method

Abstract

The present invention discloses a filter assembly capable of internal and external cleaning, a dynamic membrane module, and a cleaning method. The filter assembly comprises a membrane frame, a filter membrane, and a pressing plate. The pressing plate secures the filter membrane to the two outer sides of the membrane frame, so that the filter membrane and the membrane frame together enclose an internal space. The membrane frame has a top opening and a bottom opening communicating with the internal space, for cleaning the opposing inner sides of the filter membrane. The filter membrane comprises a nylon fiber membrane having a pore size of 50 to 350 mesh, a warp breaking force and a weft breaking force both exceeding 2200N, and a warp breaking elongation and a weft breaking elongation both exceeding 20%. The high-performance dynamic membrane module comprises several filter assemblies, an assembly rack, a cleaning and aeration system, and a control system. The control system controls the cleaning and aeration system to perform aeration operations within the pool, external cleaning of the filter assembly, and / or internal cleaning of the filter assembly based on test results.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a filter assembly capable of being cleaned inside and outside, a dynamic membrane module, and a cleaning method. Background Art

[0002] In wastewater treatment, dynamic membrane modules, which organically combine membrane separation technology and biological reaction processes, have become a key filtration device in this field. The performance and cleaning efficiency of their filter components play a crucial role in the efficiency and stability of the entire treatment system. However, the use of dynamic membrane modules also has limitations, such as the high cost of the membrane components, high operating costs, continuous retention of suspended matter on the membrane surface during the separation process, resulting in membrane fouling and significant attenuation of the effluent flux. Invention patent application CN1363526A discloses a method and apparatus for filtering a bioreactor mixture using a dynamic membrane. The filter component, fabricated from a conventional porous material substrate, is placed in a bioreactor with continuous inlet, biological reaction, and outlet, and is submerged so that the reactor liquid level is higher than the outlet, creating a water level difference. With cross-flow across the membrane surface, as filtration proceeds, microbial metabolites and the bacteria themselves form a biomass layer on the substrate surface through adsorption, adhesion, and deposition. Although this invention effectively reduces costs by selecting cheap materials, the dynamic membrane components produced are in a fixed state in the biochemical reactor, and it is difficult to solve the membrane fouling problem by relying solely on aeration to provide cross-flow shear force on the membrane surface.

[0003] During membrane filtration, colloids and suspended particles in the solution are trapped on the membrane surface under filtration pressure, forming a filter cake layer, which can cause phenomena such as decreased membrane flux. Regular cleaning is the primary means of reducing membrane fouling and ensuring membrane filtration effectiveness. Traditional cleaning processes primarily target the outer surface of the membrane (i.e., the filtration surface) through physical or chemical scrubbing, such as using rotating brushes, air-water backwashing, or chemical immersion. However, long-term practice has shown that conventional membranes have poor deformation resistance, are prone to wrinkling under the impact of high-speed water flow, and are extremely susceptible to wear, significantly shortening their service life. Invention patent application CN1807279A discloses a high-throughput flexible biomimetic dynamic membrane assembly, its fabrication method, and its application. The structure includes a membrane assembly, a valve, a flexible joint, a membrane frame, and a fixing card. The membrane assembly structure includes a curtain sheet composed of several types of porous material mesh or filter cloth, a diversion cavity, and a water collection pipe. The curtain sheet is assembled from a combination of several types of porous material mesh or filter cloth, and the surface of the membrane assembly is modified with collagen. The curtain sheet has a cavity with length and width dimensions, wherein the two sides in the length direction are bonded or sewn together and the two sides in the width direction are open. A flexible diversion grid is provided in the curtain sheet cavity to form a flexible diversion cavity. The two open ends of the curtain sheet with a flexible diversion cavity are respectively inserted into the grooves of two water collection pipes. One end of the water collection pipe is blocked, and the other end is connected to the main outlet pipe through a matching flexible joint and valve. Fixing cards are welded on the membrane frame, and the water collection pipes are respectively fixed to the fixing cards. However, this invention still uses hollow fibers as the base layer, and its membrane pore size is large, resulting in poor water quality during the dynamic membrane formation process. In addition, it is impossible to stably produce water during the filtration process, which limits the promotion and application of dynamic membranes.

[0004] Therefore, how to provide a filter membrane and its filter assembly, which has excellent comprehensive performance, simple and durable filter assembly structure, easy installation and maintenance, and can be used in a dynamic membrane module to achieve high filtration performance, no need for disassembly and cleaning, easy cleaning inside and outside, durability and low cost, has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0005] To address the shortcomings of the aforementioned prior art, the present invention aims to provide a more optimized filter assembly, dynamic membrane module, and cleaning method that can be cleaned both inside and outside. Specifically, the filter membrane utilizes a high-strength nylon fiber membrane as its base material, and a coordinated design of the membrane frame, rubber pads, and press discs achieves a stable and flexible connection. This, combined with the dynamic membrane module's cleaning system, effectively addresses technical issues such as membrane contamination, poor sealing, unstable filtration, and poor cleaning performance found in prior art.

[0006] In a first aspect, the present invention provides a filter assembly that can be cleaned inside and outside, comprising: a membrane frame, a filter membrane, and a pressing sheet;

[0007] The filter membrane is fixed on the two outer sides of the membrane frame by pressing, so that the filter membrane and the membrane frame together enclose the internal space;

[0008] The membrane frame has a top opening and a bottom opening communicating with the internal space, and is used for cleaning the inner side surfaces opposite to the filter membrane;

[0009] The filter membrane comprises a nylon fiber membrane having a pore size of 50 to 350 meshes, a warp breaking force and a weft breaking force both being above 2200N, and a warp breaking elongation and a weft breaking elongation both being above 20%.

[0010] Through material selection and structural optimization, the present invention provides a filter assembly with excellent filtering effect, long service life, and the filter membrane can be cleaned inside and outside without disassembling the filter membrane and the membrane frame. The membrane frame and the pressing plate are preferably made of stainless steel to enhance the overall quality and service life of the equipment. In addition, 1-5 top openings are provided at the top of the membrane frame, and 1-5 bottom openings are provided at the bottom, which facilitates high-pressure water flow to enter the internal space of the membrane frame from the above openings to clean the inner side of the filter membrane, and to flow out the sewage and dirt after internal cleaning from the bottom opening. The filter membrane uses a nylon fiber membrane, which has a long regeneration cycle (more than 30 days). The flux can be restored by high-intensity aeration without the consumption of chemical agents, saving costs and being beneficial to the environment. The nylon fiber membrane may include a single layer or multiple layers of nylon fiber layers, and is preferably composed of multiple nylon fiber layers laminated together, for example, through three-dimensional weaving to form an integrated structure. Compared with traditional nylon fiber membranes, it has higher strength and deformation resistance, and can reduce membrane wrinkles under the impact of high-speed water flow; the anti-fracture ability is adapted to the strength of the diaphragm's high-pressure backwashing, thereby improving the service life of the membrane.

[0011] Furthermore, the membrane frame includes a top cover hinged to the top of the membrane frame, and a bottom cover hinged to the bottom of the membrane frame;

[0012] The top cover rotates to open or close the top opening, and the bottom cover rotates to open or close the bottom opening.

[0013] The top of the membrane frame of the present invention can be provided with a single top opening or multiple top openings, and the bottom can be provided with a single bottom opening or multiple bottom openings. Accordingly, the top cover and the bottom cover can be provided with a single or multiple openings for each opening, or an integral top cover that can cover the top of the membrane frame and an integral bottom cover that can cover the bottom of the membrane frame can be provided to respectively complete the opening or closing of all top openings and all bottom openings, thereby improving the overall sealing performance of the membrane frame.

[0014] Furthermore, a top cover seal is provided on the inner surface of the top cover facing the top of the membrane frame, and / or a bottom cover seal is provided on the inner surface of the bottom cover facing the bottom of the membrane frame, and the top cover seal and the bottom cover seal meet at least one of the following conditions:

[0015] 1) Thickness: 1-5mm, foaming density: 0.1-0.6g / m 3 ;

[0016] 2) Tear strength is above 3KN / m and elongation is above 200%;

[0017] 3) Including foam latex, selected from at least one of foam silica gel, foam EPDM (ethylene propylene diene monomer), foam EVA (ethylene-vinyl acetate copolymer), foam PU (polyurethane), foam CR (chloroprene rubber), and foam NBR (nitrile butadiene rubber).

[0018] The top cover seal on the inner surface of the top cover and the bottom cover seal on the inner surface of the bottom cover effectively prevent liquid from leaking from the top and bottom of the membrane frame during the filtration process, ensuring a tight seal during the filtration operation. The seal can be made of at least one of rubber, latex, and foamed latex, with foamed latex being preferred as it has good compressibility and resilience. When the top / bottom cover is closed, the foamed latex can fill the gap between the membrane frame and the top / bottom cover, providing a better seal.

[0019] The selection of different sealing materials can be based on specific working conditions or optimized in combination. For example, foamed CR or foamed NBR can be selected in high-temperature, oil-containing or organic solvent-containing environments, and foamed EPDM can be selected in outdoor environments with strong UV or ozone exposure. This can specifically improve the environmental adaptability and long-term stability of the equipment, thereby extending its service life.

[0020] Preferably, the top cover seal and the bottom cover seal are made of foamed silicone, which has a tear strength of about 3-8 KN / m, a ductility of about 200-600%, and a compressive strength of about 0.1-0.5 MPa.

[0021] More preferably, 1-10 wt% of nano-silicon dioxide is added to the foamed silica gel. The addition of nano-silicon dioxide improves the density and wear resistance of the foamed silica gel pore structure, which is beneficial to improving the sealing performance and durability of the top cover seal and the bottom cover seal.

[0022] Furthermore, the filter membrane may further include a rubber pad disposed on an edge region of at least one side of the filter membrane, and the pressing sheet fixes the filter membrane to the membrane frame via the rubber pad; the rubber pad may satisfy at least one of the following conditions:

[0023] 1) The thickness of the rubber pad is 0.5-1.5mm, the Shore hardness is 50-70A, and the water absorption rate is ≤1%;

[0024] 2) The rubber pad includes an inner rubber pad and an outer rubber pad. The inner rubber pad is set on the side of the filter membrane facing the membrane frame, and the thickness of the inner rubber pad is 0.5-1.2mm; the outer rubber pad is set on the side of the filter membrane facing the pressing sheet, and the thickness of the outer rubber pad is 0.8-1.5mm;

[0025] 3) The material of the rubber pad is selected from at least one of silicone rubber, fluororubber, CR (chloroprene rubber), NBR (nitrile rubber), EPDM (ethylene propylene diene monomer rubber), and IIR (butyl rubber).

[0026] The design of the rubber pad can effectively protect the filter membrane and prevent it from being damaged by the membrane frame, pressing piece or fixing screws during installation and use. It also provides sufficient friction for the fixation of the filter membrane and can enhance the sealing performance of the non-diaphragm area of ​​the filter assembly.

[0027] Preferably, the rubber pad is made of silicone rubber, forming a solid strip. During use, the rubber pad is stacked between the filter membrane and the membrane frame and / or between the filter membrane and the pressing plate. Alternatively, a rubber pad layer can be preformed around the edge of the filter membrane by coating, impregnation, or other methods. This not only improves the bonding strength between the rubber pad material and the filter membrane, but also prevents subsequent displacement during installation, which could damage the filter membrane and affect its filtration performance and service life.

[0028] Furthermore, the filter membrane includes multiple laminated nylon fiber layers. From the water inlet side to the water outlet side of the membrane frame, the pore size of the multiple nylon fiber layers in the filter membrane decreases step by step. The pore size of the nylon fiber layer on the water inlet side is 80-120 mesh, the pore size of the nylon fiber layer on the water outlet side is 280-320 mesh, and the pore size of the middle nylon fiber layer is greater than 120 mesh and less than 280 mesh.

[0029] Furthermore, the nylon fiber layer on the water inlet side (film-forming surface) has a twisted warp of 80-120 mesh, the middle nylon fiber layer has a twill weave greater than 120 mesh and less than 280 mesh, and the nylon fiber layer on the water outlet side (clear water surface) has a plain weave of 280-320 mesh. The twisted warp nylon fiber layer on the water inlet side has excellent elasticity and ductility, and its relatively loose pores enable rapid film formation. The middle twill weave nylon fiber layer is relatively compact, offering high wear resistance and strength, and can be composed of 1-3 individual layers. The plain weave nylon fiber layer on the water outlet side is more compact and uniform, with moderate wear resistance and strength, strong structural stability, and resistance to deformation. The filter membrane of the present invention utilizes a combination of different weave methods while designing a pore size gradient, fully leveraging the wear resistance, strength, and filtration performance advantages of the various weave fiber layers, resulting in a filter membrane with excellent overall performance. Furthermore, the multiple nylon fiber layers are preferably integrated into a filter membrane using a three-dimensional gradient weave. Through the above-mentioned single layers and overall design, it can be ensured that the warp breaking force and weft breaking force of the nylon fiber membrane of a single filter membrane are both above 2200N, and the warp breaking elongation and weft breaking elongation are both above 20%. Preferably, the warp breaking force is above 2450N, the warp breaking elongation is above 30%, the weft breaking force is above 2500N, and the weft breaking elongation is above 25%.

[0030] Furthermore, the nylon fiber layer on the water inlet side contains 1-3 wt% of hydroxylated carbon nanotubes;

[0031] The nylon fiber surface of the nylon fiber layer on the water outlet side is provided with a polytetrafluoroethylene anti-fouling layer, and the polytetrafluoroethylene anti-fouling layer is formed by electrostatic spraying, including the following steps:

[0032] S1: charging polytetrafluoroethylene particles (preferably with a particle size of <50 μm) through a high-voltage electrostatic field (e.g., 50-100 kV);

[0033] S2: The nylon fiber layer on the outlet side is grounded and preheated to 60-100°C;

[0034] S3: PTFE is sprayed and adsorbed onto the surface of nylon fiber to form a PTFE anti-fouling layer.

[0035] Preferably, the nylon fiber layer on the outlet side runs at a speed of 1-10 m / min, the amount of polytetrafluoroethylene used is 5-10% of the total mass of the nylon fiber layer on the outlet side, and the thickness of the anti-fouling layer formed is about 1-50 μm.

[0036] Through modification, spraying, and other treatments, the inlet-side nylon fiber layer (outer layer) is easier to form a membrane, while the outlet-side nylon fiber layer (inner layer) is less susceptible to contamination. This combined effect reduces the dynamic membrane's film-forming time, extends high-throughput operation time, and prolongs the chemical cleaning cycle. The electrostatic spraying process to form the anti-fouling polytetrafluoroethylene layer can be performed on the outlet-side nylon fiber layer alone, either before lamination or after lamination.

[0037] In a second aspect, the present invention provides a dynamic membrane module with coordinated internal and external cleaning of the above-mentioned filter assembly, comprising: a plurality of the above-mentioned filter assemblies, an assembly rack, a cleaning aeration system and a control system;

[0038] Several of the filtering components and cleaning and aeration systems are detachably fixed on the assembly frame;

[0039] Cleaning the aeration system, including the air supply pipe and the aeration head with variable spray direction connected to the air supply pipe;

[0040] The control system includes a treatment pool detection unit, a filter membrane detection unit and a control unit. The control unit controls the aeration head to perform aeration operation in the pool, external cleaning of the filter component and / or internal cleaning of the filter component according to feedback results from the treatment pool detection unit and / or the filter membrane detection unit.

[0041] Through structural combination design and optimization, the dynamic membrane module of the present invention integrates filtration, aeration and intelligent internal and external self-cleaning functions, and through the detachable installation method of the filter component, it can flexibly adapt to various application scenarios and processing intensities, effectively improving the versatility and maintenance convenience of the equipment.

[0042] Furthermore, the dynamic membrane module includes a plurality of filter assemblies arranged in parallel on an assembly rack, and the filter membranes of the filter assemblies meet at least one of the following conditions:

[0043] 1) Each filter membrane consists of multiple laminated nylon fiber layers, and the pore size of the multiple nylon fiber layers decreases step by step from the water inlet to the water outlet;

[0044] 2) The nylon fiber layer on the water inlet side of the filter membrane contains hydroxylated carbon nanotubes in the nylon fiber;

[0045] 3) The nylon fiber surface of the nylon fiber layer on the outlet side of the filter membrane has a polytetrafluoroethylene anti-fouling layer.

[0046] The present invention incorporates a functional filter membrane on a membrane frame. By designing the pore size gradient of the filter membrane's multiple nylon fiber layers, the membrane's overall resistance to fracture and deformation is ensured. Furthermore, through treatments such as modification and spraying, the outer layer is easily formed and the inner layer is less susceptible to contamination. This combined effect reduces the dynamic membrane's film formation time, extends high-throughput operation time, and prolongs the chemical cleaning cycle. In particular, when filter membranes are fixed to the two outer surfaces of the membrane frame, the inner surface of the internal space between the two filter membranes is difficult to clean, while conventional filter membranes require frequent cleaning. The treated filter membrane exhibits long-lasting durability and contamination resistance, significantly reducing operational and maintenance costs. Furthermore, by providing top and bottom openings on the membrane frame, the filter assembly of the present invention can open the aforementioned internal space, allowing for high-pressure cleaning with an aeration head. Sewage and contaminants are then discharged through the bottom opening, allowing the filter membrane to quickly return to optimal filtration conditions, further reducing operational and maintenance costs.

[0047] Furthermore, it also includes a drive system and a reset system, wherein the drive system is used to synchronously open a top cover hinged to the top of the membrane frame and a bottom cover hinged to the bottom of the membrane frame to cooperate with the aeration head to clean the interior of the filter assembly from the top opening and the bottom opening;

[0048] The reset system is used to close the top cover and the bottom cover synchronously or step by step after the interior is cleaned, so as to close the top opening and the bottom opening.

[0049] The drive system and reset system of the present invention have multiple options. Optionally, the drive system can adopt at least one of motor drive, cylinder drive, and hydraulic drive to provide driving force, and cooperate with transmission methods such as pulley drive, gear drive, and screw drive to provide opening force to the top cover and bottom cover. The reset system can adopt a configuration similar to the drive system, or simply use a spring structure to utilize the elastic reset force of the spring to drive the top cover and bottom cover. Through the coordinated cooperation of the drive system and the reset system, automated cleaning is achieved, and the thoroughness of cleaning and the maintenance efficiency of the equipment are improved. When multiple filter assemblies are set on the assembly rack, the top covers and bottom covers of the multiple filter assemblies can be linked to open or close.

[0050] In a third aspect, the present invention further provides a method for coordinated cleaning of the inside and outside of a dynamic membrane module using the aforementioned dynamic membrane module, comprising the following steps:

[0051] S1. Real-time detection of at least one of the following parameters: treatment pool water parameters, treatment pool liquid level, filter membrane outlet turbidity, filter membrane flux, and filter membrane pressure difference;

[0052] S2. Based on the detection results, the control unit controls the dynamic membrane module to enter at least one of the following operating modes:

[0053] (1) Aeration mode in the pond;

[0054] (2) External cleaning mode of filter components;

[0055] (3) Internal cleaning mode of the filter component.

[0056] The dynamic membrane module internal and external coordinated cleaning method provided by this invention achieves precise triggering and dynamic coordinated cleaning by monitoring various data such as water parameters and liquid levels in the treatment tank in real time. The control unit intelligently selects mode switching based on the detection results. This method can match the optimal cleaning strategy for different contamination types, effectively improving membrane flux recovery rate, extending membrane module life, and reducing energy consumption and maintenance costs, achieving multiple goals at one stroke.

[0057] The beneficial effects of the above technical solution of the present invention include at least:

[0058] (1) The present invention utilizes a filter membrane with excellent mechanical properties and an integrated laminated structure, combined with a stainless steel pressing sheet and membrane frame, to provide a smoother surface. During operation, the membrane will not become concave or convex due to water flow, resulting in a filter assembly with both high filtration performance and high mechanical properties. Furthermore, through the design of the pore size gradient of the filter membrane and the preferred functionalization of the double-sided nylon fiber layer, the filter assembly can be optimized to ensure filtration efficiency while extending the regeneration cycle and reducing the cleaning frequency, thereby improving the overall durability of the filter assembly and reducing operating costs.

[0059] (2) The present invention provides a top opening on the top frame of the membrane frame that connects the interior of the membrane frame with the external environment, and a bottom opening on the bottom frame that connects the interior of the membrane frame with the external environment, thereby achieving vertical internal and external communication of the membrane frame. High-pressure water flows into the internal space of the membrane frame from the top opening and / or the bottom opening to clean the inner surfaces of the two filter membranes, and flows out of the bottom opening to remove the sewage and dirt after internal cleaning. The cleaning of the inner and outer surfaces of each filter membrane can be completed without removing the filter components or the filter membranes. On this basis, the spacing between the membranes can also be reduced, and more filter components can be accommodated on the assembly rack under the same space, thereby improving the processing capacity and processing efficiency of the dynamic membrane module.

[0060] (3) In addition to the membrane frame, filter membrane, and pressing plate, the present invention also includes foam latex seals on the inner surfaces of the top and bottom covers, which are used to effectively seal the top and bottom openings during filtration operations, thereby improving the filtration effect of the filter assembly. Furthermore, an inner rubber pad facing the side of the membrane frame and / or an outer rubber pad facing the pressing plate are provided on the side edge areas of the filter membrane to protect the edge areas of the filter membrane, which is particularly beneficial for preventing the filter membrane from being damaged by the membrane frame, pressing plate, or fixing screws during installation and use.

[0061] (4) The filter assembly of the present invention can be integrated with the cleaning and aeration system, control system, etc. to form a dynamic membrane module. The intelligent control system monitors the water parameters of the treatment pool and the status parameters of the filter membrane in real time, and switches the cleaning mode according to the detection results, taking into account the realization of aeration in the pool and coordinated cleaning of the inside and outside of the filter assembly, dynamically and comprehensively improving the cleaning effect, and enhancing the intelligence and pertinence of the cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an illustrative and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0063] Figure 1 It is a schematic structural diagram of the filter assembly of the present invention;

[0064] Figure 2 It is a structural schematic diagram of the upper part of the membrane frame of the present invention;

[0065] Figure 3 It is a structural schematic diagram of the lower part of the membrane frame of the present invention;

[0066] Figure 4 Schematic diagram of the structure of each nylon fiber layer in the filter membrane of the present invention;

[0067] Figure 5 It is a structural schematic diagram of the dynamic membrane module of the present invention.

[0068] Explanation of the accompanying drawings: 1-top cover, 2-bottom cover, 3-membrane frame, 4-filter membrane, 5-rubber pad, 6-assembly frame, 7-air supply pipe, 9-drive system, 9.1-upper linkage, 9.2-lower linkage, 10-reset system, 11-pressing sheet, 1.1-top cover seal, 2.1-bottom cover seal, 3.1-top opening of membrane frame, 3.2-bottom opening of membrane frame. DETAILED DESCRIPTION

[0069] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0070] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a," "an," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, and unless the context clearly indicates otherwise, "a plurality" generally includes at least two.

[0071] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or device. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or device comprising the element.

[0072] like Figure 1-5 As shown, the dynamic membrane module with coordinated internal and external cleaning provided by the present invention includes several filter components that can be cleaned inside and outside, an assembly frame 6, a cleaning aeration system and a control system, etc., specifically including:

[0073] (1) The filter assembly can be cleaned inside and outside, the membrane frame 3, the filter membrane 4, the pressing piece 11, the optional top cover seal 1.1 and the bottom cover seal 2.1 and the rubber pad 5. The specific structure is as follows:

[0074] (1.1) Membrane frame 3, see attached Figure 1-3 , preferably made of stainless steel, with a top opening 3.1 on the top frame and a bottom opening 3.4 on the bottom frame. The top opening 3.1 and the bottom opening 3.2 connect the internal space enclosed by the membrane frame and the filter membrane 4 with the external environment. The membrane frame 3 also has a top cover 1 hinged to the top of the membrane frame 3 and a bottom cover 2 hinged to the bottom. The top cover 1 and the bottom cover 2 can rotate to open and close the top opening 3.1 / bottom opening 3.2 of the membrane frame;

[0075] (1.2) Filter membrane 4. Each filter assembly has at least two filter membranes 4, wherein one filter membrane 4 is fixed on each of the two outer sides of the membrane frame 3. Each filter membrane 4 comprises a plurality of laminated nylon fiber layers. From the water inlet side to the water outlet side of the membrane frame 3 (along the thickness direction of the filter membrane 4), the pore size of the plurality of nylon fiber layers in the filter membrane decreases step by step. See the attached figure. Figure 4 :

[0076] a. The nylon fiber layer on the water inlet side has a pore size of 80-120 mesh, and the film-forming surface on the water inlet side is preferably twisted; the nylon fiber layer on the water inlet side preferably contains 1-3wt% hydroxylated carbon nanotubes to increase the surface Zeta potential of the material, promote the adsorption of positively charged bacterial colloids, and reduce the dynamic membrane formation time;

[0077] b. The middle nylon fiber layer has a pore size greater than 120 mesh and less than 280 mesh, preferably the middle layer is twill, more preferably 1-3 single layers are used. When multiple single layers are used, the pore size of each single layer decreases from the water inlet side to the water outlet side;

[0078] c. The nylon fiber layer on the water outlet side has a pore size of 280-320 mesh, and the clear water surface on the water outlet side is preferably plain weave; the nylon fiber layer on the water outlet side preferably contains a polytetrafluoroethylene anti-fouling layer formed by electrostatic spraying to improve the anti-fouling performance of the material.

[0079] The warp breaking force and weft breaking force of the nylon fiber membrane of a single filter membrane are both above 2200N, and the warp breaking elongation and weft breaking elongation are both above 20%. Preferably, the warp breaking force is above 2450N, the warp breaking elongation is above 30%, the weft breaking force is above 2500N, and the weft breaking elongation is above 25%.

[0080] (1.3) Tablet 11, see attached Figure 2-3 , preferably made of stainless steel, the pressing piece has multiple mounting holes corresponding to the membrane frame, which are used to screw in fixing screws to squeeze and fix the pressing piece together with the filter membrane on the side of the membrane frame.

[0081] (1.4) Rubber pad 5, see attached Figure 3 , arranged in the edge area of ​​at least one side of the filter membrane 4, the pressing sheet 11 fixes the filter membrane 4 on the membrane frame 3 through the rubber pad 5; the rubber pad 5 meets at least one of the following conditions:

[0082] 1) The thickness of the rubber pad 5 is 0.5-1.5mm, the Shore hardness is 50-70A, and the water absorption rate is ≤1%;

[0083] 2) The rubber pad 5 includes an inner rubber pad and an outer rubber pad. The inner rubber pad is arranged on the side of the filter membrane 4 facing the membrane frame 3, and the thickness of the inner rubber pad is 0.5-1.2 mm; the outer rubber pad is arranged on the side of the filter membrane 4 facing the pressing sheet 11, and the thickness of the outer rubber pad is 0.8-1.5 mm.

[0084] 3) The material of the rubber pad 5 is selected from at least one of silicone rubber, fluororubber, CR (chloroprene rubber), NBR (nitrile rubber), EPDM (ethylene propylene diene monomer rubber), and IIR (butyl rubber).

[0085] An inner rubber pad facing the side of the membrane frame and an outer rubber pad facing the pressing sheet are provided on the edge areas of both sides of the filter membrane 4. The pressing sheet 11 fixes the outer rubber pad, the filter membrane 4 and the inner rubber pad to the outer side of the membrane frame 3.

[0086] Inner rubber pad, thickness 0.5-1.2mm, Shore hardness 50-70A, water absorption ≤1%, preferably made of silicone rubber pad;

[0087] The outer rubber pad has a thickness of 0.8-1.5mm, a Shore hardness of 50-70A, a water absorption rate of ≤1%, and is made of the same material as the inner rubber pad. Other rubbers can also be used.

[0088] (1.5) Top cover seal 1.1 / bottom cover seal 2.1, see attached Figure 1-3 To ensure the tightness of the filter assembly, a top cover seal 1.1 is provided on the inner surface of the top cover 1 facing the top of the membrane frame 3, and a bottom cover seal 2.1 is provided on the inner surface of the bottom cover 2 facing the bottom of the membrane frame 3. These seals are used to fill the gap between the membrane frames 3 when the top cover 1 and the bottom cover 2 close the top / bottom of the membrane frame 3, thereby better sealing the top opening 3.1 / bottom opening 3.2. The top cover seal 1.1 and the bottom cover seal 2.1 meet at least one of the following conditions:

[0089] 1) Thickness: 1-5mm, foaming density: 0.1-0.6g / m 3 ;

[0090] 2) Tear strength is above 3KN / m and elongation is above 200%;

[0091] 3) The foam latex is selected from at least one of foamed silica gel, foamed EPDM, foamed EVA, foamed PU, foamed CR (chloroprene rubber), and foamed NBR (nitrile rubber).

[0092] (2) Assembly rack 6, used for detachably fixing filter components, cleaning aeration system and other equipment to form an integrated dynamic membrane module, and facilitate the use and maintenance of each device;

[0093] (3) Cleaning the aeration system, including the air supply pipe 7 and the aeration head with variable injection direction;

[0094] (4) A control system, including a treatment pool detection unit, a filter membrane detection unit, and a control unit. The control unit controls the aeration head to perform aeration operations in the pool, external cleaning of the filter assembly, and internal cleaning of the filter assembly based on feedback from the treatment pool detection unit and the filter membrane detection unit.

[0095] (5) A drive system 9 for synchronously opening the top cover 1 hinged to the top of the membrane frame 3 and the bottom cover 2 hinged to the bottom of the membrane frame of each filter assembly, so as to cooperate with the aeration head to clean the inside of the filter assembly from the top opening 3.1 and / or the bottom opening 3.2, and discharge the sewage and dirt cleaned inside from the opened bottom opening 3.2; optionally, the power equipment of the drive system can adopt at least one of motor drive, cylinder drive, and hydraulic drive to provide driving force, and cooperate with pulley drive, gear drive, screw drive and other transmission methods to provide opening force to the top cover and the bottom cover. When multiple filter assemblies are provided, a linkage can be set to synchronously open multiple top covers 1 and / or multiple bottom covers 2;

[0096] (6) A reset system 10, for closing the top cover 1 and the bottom cover 2 synchronously or step by step after the interior is cleaned, so as to close the top opening 3.1 and the bottom opening 3.2. The reset system can adopt a configuration similar to that of the drive system, preferably using a spring structure to provide a restoring force.

[0097] Preferably, Figure 5 The figure shows the drive system, reset system, and their automated working process, using a dynamic membrane module without a filter membrane as an example. The power device of the drive system 9 drives the linkage, causing the top cover 1 and bottom cover 2 to open synchronously. The reset system cooperates with this to achieve automated pre- and post-cleaning operations. These include, but are not limited to, the following drive and reset operation methods:

[0098] The drive system 9 includes a power device, an upper linkage 9.1 connected to each top cover 1, and a lower linkage 9.2 connected to each bottom cover 2. The power device includes a motor fixed to the assembly frame 6 and a telescopic rod driven by the motor. The free end of the telescopic rod is fixed with a transmission rope, which passes over the top fixed pulley and extends downward to be fixed to the upper linkage 9.1. After further extending downward and passing over the bottom fixed pulley, the transmission rope extends upward to be fixed to the lower linkage 9.2. The top fixed pulley is fixed to the top of the assembly frame 6, and the bottom fixed pulley is fixed to the bottom of the assembly frame 6.

[0099] When driving to open each top cover 1 and each bottom cover 2, the power equipment contracts the telescopic rod, and the transmission rope causes the upper linkage 9.1 to move upward, thereby opening each top cover 1 relative to the top of the membrane frame 3; the transmission rope further utilizes the steering action of the bottom fixed pulley to synchronously drive the lower linkage 9.2 to move downward, thereby opening each bottom cover 2 relative to the bottom of the membrane frame 3.

[0100] The reset system 10 includes a top cover spring and a bottom cover spring, wherein one end of the top cover spring is connected to the inner side of the top cover 1, and the other end is fixed on the membrane frame 3 or fixed on the support of the membrane frame 3. The fixed position is preferably lower than the top of the membrane frame 3 to provide sufficient elastic deformation and restoring force. When the top cover 1 is opened by the power loaded by the drive system 9, the top cover spring is stretched to accumulate restoring force. When the drive system 9 unloads the driving force, the restoring force of the top cover spring pulls the top cover 1 toward the top of the membrane frame 3 to close the top opening. Similarly, one end of the bottom cover spring is connected to the inner side of the bottom cover 2, and the other end is fixed on the membrane frame 3 or fixed on the support of the membrane frame 3. The fixed position is preferably higher than the bottom of the membrane frame 3. In addition, considering that the spring's telescopic movement is prone to wear or damage to the filter membrane, a soft rope can be preferably used for connection at the position where it may contact the filter membrane, that is, a structure combining a rope and a spring is used to provide a reset drive, see the attached. Figure 3 .

[0101] By using the above-mentioned dynamic membrane module, the internal and external coordinated cleaning operations of the dynamic membrane module can be realized while the aeration operation in the pool is being performed simultaneously or in steps. The process is as follows:

[0102] S1. Real-time detection of at least one of the following parameters: water parameters, liquid level, turbidity of effluent from the filter membrane, membrane flux, and membrane pressure difference in the treatment pool;

[0103] S2. Based on the detection results, the control unit controls the dynamic membrane module to switch the operation mode so as to perform aeration in the pool or internal / external cleaning of the filter assembly.

[0104] To further illustrate the present invention, the following describes in detail the filter assembly capable of internal and external cleaning, the dynamic membrane module, and the internal and external coordinated cleaning method provided by the present invention in conjunction with the embodiments:

[0105] Example 1

[0106] The filter assembly capable of internal and external cleaning of Example 1 comprises a membrane frame 3, a filter membrane 4, a pressing sheet 11, a top cover seal 1.1, a bottom cover seal 2.1, and a rubber pad 5. The specific structure is as follows:

[0107] (1.1) A membrane frame 3, made of stainless steel, having a top opening 3.1 on the top frame and a bottom opening 3.4 on the bottom frame. The top opening 3.1 and the bottom opening 3.2 connect the interior space enclosed by the membrane frame and the filter membrane 4 to the external environment. The membrane frame 3 also has a top cover 1 hinged to the top of the membrane frame 3 and a bottom cover 2 hinged to the bottom. The top cover 1 and the bottom cover 2 are rotatable to open and close the top opening 3.1 and the bottom opening 3.2 of the membrane frame respectively.

[0108] (1.2) Filter membrane 4. A filter membrane 4 is fixed to each of the two outer sides of the membrane frame 3 in the filter assembly via a pressing sheet 11. Each filter membrane 4 comprises three nylon fiber layers woven and laminated in a three-dimensional gradient manner. Along the thickness direction of the filter membrane 4, the following components are sequentially included:

[0109] a. Nylon fiber layer on the water inlet side, twisted warp 100 mesh;

[0110] b. Middle nylon fiber layer, twill 200 mesh;

[0111] d. Nylon fiber layer on the outlet side, plain weave 300 mesh.

[0112] The warp breaking force of a single filter membrane is about 2750N, the warp breaking elongation is about 36%, the weft breaking force is about 2850N, and the weft breaking elongation is about 27.5%.

[0113] (1.3) The pressing piece 11 is made of stainless steel and has multiple mounting holes corresponding to the membrane frame for screwing in fixing screws to squeeze and fix the pressing piece together with the filter membrane on the side of the membrane frame.

[0114] (1.4) Rubber pad 5 . The rubber pad 5 is made of silicone rubber with a thickness of 1.0 mm, a Shore hardness of approximately 60A, and a water absorption rate of ≤1%. The rubber pad 5 is disposed on the side edge area of ​​the filter membrane 4 facing the pressing plate 11 . The pressing plate 11 fixes the filter membrane 4 to the membrane frame 3 through the rubber pad 5 .

[0115] (1.5) Top cover seal 1.1 and bottom cover seal 2.1. The top cover seal 1.1 is set on the inner surface of the top cover 1 facing the top of the membrane frame 3, and the bottom cover seal 2.1 is set on the inner surface of the bottom cover 2 facing the bottom of the membrane frame 3. They are used to fill the gap between the membrane frame 3 when the top cover 1 and bottom cover 2 close the membrane frame 3, better sealing the top opening 3.1 and bottom opening 3.2. The top cover seal 1.1 and bottom cover seal 2.1 are made of foamed silicone with a thickness of 2.5mm and a foam density of approximately 0.4g / m 3 , the tearing strength is about 4.5KN / m and the elongation is above 400%.

[0116] (1.6) The reset system 10 includes a top cover spring and a bottom cover spring, wherein one end of the top cover spring is connected to the inner side of the top cover 1, and the other end is fixed on the support member of the membrane frame 3, and the fixed position is lower than the top of the membrane frame 3, providing sufficient elastic deformation and restoring force. When the top cover 1 is opened, the top cover spring is stretched to accumulate restoring force. When the top cover 1 is restored, the restoring force of the top cover spring pulls the top cover 1 toward the top of the membrane frame 3 to close the top opening. Similarly, one end of the bottom cover spring is connected to the inner side of the bottom cover 2, and the other end is fixed on the support member of the membrane frame 3, and the fixed position is higher than the bottom of the membrane frame 3. In addition, considering that the spring's telescopic movement is prone to wear or damage to the filter membrane, a soft rope is used to connect at the position where it may contact the filter membrane, that is, a structure combining a rope and a spring is used to provide a reset drive, see Appendix. Figure 3 .

[0117] Example 2

[0118] The difference between the internal and external washable filter assembly of Example 2 and Example 1 is that the filter membrane of Example 2 has been functionalized and includes, in sequence, the following components along the thickness direction of the filter membrane 4:

[0119] a. The nylon fiber layer on the water inlet side is twisted through 100 mesh, and the nylon fiber layer on the water inlet side contains about 1.5wt% hydroxylated carbon nanotubes;

[0120] b. Middle nylon fiber layer, twill 200 mesh;

[0121] c. The nylon fiber layer on the water outlet side is plain weave 300 mesh, and the nylon fiber surface of the nylon fiber layer on the water outlet side has a polytetrafluoroethylene anti-fouling layer, and the polytetrafluoroethylene anti-fouling layer is formed by electrostatic spraying, comprising the following steps:

[0122] S1: Charge polytetrafluoroethylene particles (screened particle size is about 30 μm or less) through a 75 kV high voltage electrostatic field;

[0123] S2: The nylon fiber layer on the outlet side is grounded and preheated to 80±2℃;

[0124] S3: The nylon fiber layer on the outlet side runs at a speed of 5m / min. Polytetrafluoroethylene is sprayed and adsorbed onto the surface of the nylon fiber to form a polytetrafluoroethylene anti-fouling layer. The amount of polytetrafluoroethylene is 6% of the total mass of the nylon fiber layer on the outlet side. The thickness of the anti-fouling layer is about 25±5μm.

[0125] The warp breaking force of a single filter membrane is about 2810N, the warp breaking elongation is about 32.3%, the weft breaking force is about 2900N, and the weft breaking elongation is about 26.0%.

[0126] Example 3

[0127] The difference between the filter assembly capable of internal and external cleaning of Example 3 and Example 2 is that the rubber pad of Example 3 uses an inner rubber pad and an outer rubber pad, including:

[0128] The rubber pad includes an inner rubber pad and an outer rubber pad made of silicone rubber. The inner rubber pad is arranged on the side of the filter membrane facing the membrane frame, and the thickness of the inner rubber pad is 0.5mm; the outer rubber pad is arranged on the side of the filter membrane facing the pressing sheet, and the thickness of the outer rubber pad is 1.0mm.

[0129] Application Example 1

[0130] Five groups of filter components of Example 1 are fixed in parallel on an assembly rack of a dynamic membrane module. The dynamic membrane module includes: a group of filter components, an assembly rack, a cleaning and aeration system, a control system, a driving system, and a reset system.

[0131] An assembly frame, which can detachably fix the filtering components, cleaning aeration system and other equipment to form an integral dynamic membrane module;

[0132] The cleaning aeration system includes an air supply pipe and an aeration head with variable injection direction. The air supply pipe includes an air supply main pipe and an air supply branch pipe that branches from the air supply main pipe to supply air. The air supply branch pipes are arranged at the upper and lower parts of the assembly rack, corresponding to the arrangement of each filter component. Three aeration heads are set on each air supply branch pipe, corresponding to the three top openings and three bottom openings of the filter component respectively. When the aeration head changes the injection direction, other positions can also be cleaned and the pool can be aerated.

[0133] A control system includes a treatment pool detection unit, a filter membrane detection unit, and a control unit. The control unit controls the aeration head to perform aeration operations in the pool, external cleaning of the filter assembly, and internal cleaning of the filter assembly based on feedback from the treatment pool detection unit and the filter membrane detection unit.

[0134] The drive system is configured to synchronously open the top and bottom covers to facilitate the aeration head's cleaning of the opposing inner surfaces of the filter assembly from the top and bottom openings, and to discharge the cleaned sewage and dirt from the bottom opening. The drive system comprises a power unit, an upper linkage connected to each top cover, and a lower linkage connected to each bottom cover. The power unit comprises a motor secured to the assembly frame and a telescopic rod driven by the motor. A transmission rope is secured to the free end of the telescopic rod. The transmission rope passes over a top fixed pulley, extends downward, and is secured to the upper linkage. The transmission rope further extends downward, passes over a bottom fixed pulley, and then extends upward to be secured to the lower linkage. The top fixed pulley is secured to the top of the assembly frame, while the bottom fixed pulley is secured to the bottom of the assembly frame. To open each top and bottom cover, the power unit retracts the telescopic rod, causing the transmission rope to move the upper linkage upward, opening each top cover relative to the top of the membrane frame. The transmission rope further utilizes the steering action of the bottom fixed pulley to synchronously drive the lower linkage downward, opening each bottom cover relative to the bottom of the membrane frame.

[0135] The reset system uses a spring structure to provide restoring force. It includes a top cover spring and a bottom cover spring. One end of the top cover spring is connected to the inner side of the top cover, and the other end is fixed to the membrane frame support. The fixed position is lower than the top of the membrane frame. One end of the bottom cover spring is connected to the inner side of the bottom cover, and the other end is fixed to the membrane frame support. The fixed position is higher than the bottom of the membrane frame. When the top and bottom covers are opened by the power applied by the drive system, the top cover spring is stretched and accumulates restoring force. After the internal cleaning is completed, the drive system unloads the driving force. The restoring force of the top cover spring pulls the top cover toward the top of the membrane frame to close the top opening, and the restoring force of the bottom cover spring pulls the bottom cover toward the bottom of the membrane frame to close the bottom opening.

[0136] The dynamic membrane module can provide an internal and external coordinated cleaning method, including the following steps:

[0137] S1. Real-time detection of at least one of the following parameters: treatment pool water parameters, treatment pool liquid level, filter membrane outlet turbidity, filter membrane flux, and filter membrane pressure difference;

[0138] S2. Based on the detection results, the control unit controls the dynamic membrane module to enter at least one of the following operating modes:

[0139] (1) In the aeration mode, the top and bottom covers of the filter assembly are closed, and the aeration head sprays aeration into the pool;

[0140] (2) External cleaning mode of the filter assembly: the top cover and bottom cover of the filter assembly are in the closed state, and the aeration head sprays and washes the membrane frame and the outer surface of the filter assembly;

[0141] (3) In the internal cleaning mode of the filter assembly, the top cover and the bottom cover of the filter assembly are in the open state. The aeration head sprays into the internal space of the membrane frame from the top opening and the bottom opening respectively and flushes the inner side of each filter membrane. The flushed sewage and dirt are discharged from the bottom opening. After cleaning, the top cover and the bottom cover are closed.

[0142] Application Example 2-3

[0143] Application Examples 2 and 3 have the same overall structure as Application Example 2, except that: Application Example 2 fixes five groups of filter components of Example 2 in parallel on the assembly rack of the dynamic membrane module, and Application Example 3 fixes five groups of filter components of Example 3 in parallel on the assembly rack of the dynamic membrane module.

[0144] Dynamic membrane modules from Examples 1-3 were simultaneously placed in an aerobic tank and operated normally. On the 31st day, the filter membrane detection unit in Example 1 reported a water turbidity of less than 10 NTU, initiating the internal cleaning mode for the filter module in Example 1. On the 38th day, the filter membrane detection unit in Example 2 reported a water turbidity of less than 10 NTU, initiating the internal cleaning mode for the filter module in Example 2. On the 40th day, the filter membrane detection unit in Example 3 reported a water turbidity of less than 10 NTU, initiating the internal cleaning mode for the filter module in Example 3. Over a three-month period, the internal cleaning of Example 1 was performed three times, and of Examples 2 and 3 twice. Upon opening each dynamic membrane module for inspection, three of the ten filter membranes in Example 1 showed slight unevenness; two of the ten filter membranes in Example 2 showed slight unevenness; and the surfaces of all ten filter membranes in Example 3 remained smooth, with no signs of concavity or convexity due to water erosion.

[0145] Improving the durability, stain resistance and ease of cleaning of the filter membrane, combined with a stable assembly method and automatic detection and control system, are important factors for the dynamic membrane module to achieve high filtration performance, easy cleaning, stable and durable, and intelligent and low-cost operation.

[0146] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A filter assembly that can be cleaned inside and outside, characterized in that: The filter assembly comprises: a membrane frame (3), a filter membrane (4) and a pressing sheet (11); The pressing sheet (11) fixes the filter membrane (4) on the two outer sides of the membrane frame (3) respectively, so that the filter membrane (4) and the membrane frame (3) together enclose an internal space; The membrane frame has a top opening (3.1) and a bottom opening (3.2) communicating with the internal space, and is used for cleaning the inner side surfaces opposite to the filter membrane (4); The filter membrane (4) comprises a nylon fiber membrane, wherein the pore size of the nylon fiber membrane is 50 mesh to 350 mesh, the longitudinal breaking force and the latitudinal breaking force are both above 2200N, and the longitudinal breaking elongation and the latitudinal breaking elongation are both above 20%; The filter membrane (4) comprises a plurality of laminated nylon fiber layers, and the pore sizes of the plurality of nylon fiber layers in the filter membrane (4) decrease gradually from the water inlet side to the water outlet side of the membrane frame (3). The nylon fiber layer on the water inlet side is a twisted warp of 80-120 mesh, the nylon fiber layer on the water outlet side is a plain weave of 280-320 mesh, and the middle nylon fiber layer is a twill weave of greater than 120 mesh and less than 280 mesh. The nylon fiber layer on the water inlet side contains 1-3 wt% of hydroxylated carbon nanotubes, the nylon fiber surface of the nylon fiber layer on the water outlet side has a polytetrafluoroethylene anti-fouling layer, and the multiple nylon fiber layers are woven into an integrated filter membrane (4) through three-dimensional gradient weaving.

2. The filter assembly according to claim 1, wherein The membrane frame (3) comprises a top cover (1) hinged to the top of the membrane frame, and a bottom cover (2) hinged to the bottom of the membrane frame; The top cover (1) rotates to open or close the top opening (3.1), and the bottom cover (2) rotates to open or close the bottom opening (3.2).

3. The filter assembly according to claim 2, wherein A top cover seal (1.1) is provided on the inner surface of the top cover (1) facing the top of the membrane frame (3), and / or a bottom cover seal (2.1) is provided on the inner surface of the bottom cover (2) facing the bottom of the membrane frame (3); The top cover seal (1.1) and the bottom cover seal (2.1) meet at least one of the following conditions: 1) Thickness: 1-5mm, foaming density: 0.1-0.6g / m 3 ; 2) Tear strength is above 3KN / m and elongation is above 200%; 3) The foamed latex is selected from at least one of foamed silica gel, foamed EPDM, foamed EVA, foamed PU, foamed CR, and foamed NBR.

4. The filter assembly according to any one of claims 1 to 3, characterized in that: It also includes a rubber pad (5) arranged in an edge region of at least one side of the filter membrane (4), and the pressing sheet (11) fixes the filter membrane (4) to the membrane frame (3) via the rubber pad (5); the rubber pad (5) meets at least one of the following conditions: 1) The thickness of the rubber pad (5) is 0.5-1.5 mm, the Shore hardness is 50-70A, and the water absorption rate is ≤1%; 2) The rubber pad (5) includes an inner rubber pad and an outer rubber pad, wherein the inner rubber pad is arranged on the side of the filter membrane (4) facing the membrane frame (3), and the thickness of the inner rubber pad is 0.5-1.2 mm; the outer rubber pad is arranged on the side of the filter membrane (4) facing the pressing sheet (11), and the thickness of the outer rubber pad is 0.8-1.5 mm; 3) The material of the rubber pad (5) is selected from at least one of silicone rubber, fluororubber, CR, NBR, EPDM, and IIR.

5. The filter assembly according to any one of claims 1 to 3, characterized in that: The polytetrafluoroethylene antifouling layer is formed by electrostatic spraying, comprising the following steps: S1: Charge the polytetrafluoroethylene particles through a high-voltage electrostatic field; S2: The nylon fiber layer on the outlet side is grounded and preheated; S3: PTFE is sprayed and adsorbed onto the surface of nylon fiber to form a PTFE anti-fouling layer.

6. A dynamic membrane module with coordinated internal and external cleaning of the filter assembly according to any one of claims 1 to 5, characterized in that: include: Several of the filter components, assembly racks (6), cleaning and aeration systems, and control systems; Several of the filtering components and cleaning aeration systems are detachably fixed on the assembly frame (6); A cleaning aeration system, comprising an air supply pipe (7) and an aeration head (8) with a variable spray direction connected to the air supply pipe; The control system comprises a treatment pool detection unit, a filter membrane detection unit and a control unit. The control unit controls the aeration head (8) to perform aeration operation in the pool, external cleaning of the filter assembly and / or internal cleaning of the filter assembly according to feedback results from the treatment pool detection unit and / or the filter membrane detection unit.

7. The dynamic membrane module according to claim 6, characterized in that: The dynamic membrane module comprises a plurality of filter assemblies arranged in parallel on an assembly rack (6), wherein the filter membranes (4) of the filter assemblies meet the following conditions: 1) Each filter membrane (4) comprises a plurality of laminated nylon fiber layers, and the pore sizes of the plurality of nylon fiber layers decrease step by step from the water inlet to the water outlet; 2) The nylon fiber layer on the water inlet side of the filter membrane contains hydroxylated carbon nanotubes in the nylon fiber; 3) The nylon fiber surface of the nylon fiber layer on the outlet side of the filter membrane has a polytetrafluoroethylene anti-fouling layer.

8. The dynamic membrane module according to claim 6 or 7, characterized in that: It also includes a drive system (9) and a reset system (10), wherein the drive system (9) is used to synchronously open a top cover (1) hinged to the top of the membrane frame (3) and a bottom cover (2) hinged to the bottom of the membrane frame, so as to cooperate with the aeration head (8) to clean the inside of the filter assembly from the top opening (3.1) and the bottom opening (3.2); The reset system (10) is used to close the top cover (1) and the bottom cover (2) synchronously or step by step after the interior is cleaned, so as to close the top opening (3.1) and the bottom opening (3.2).

9. A method for coordinated cleaning of the inside and outside of a dynamic membrane module according to any one of claims 6 to 8, comprising the following steps: S1, real-time detection of at least one parameter among the water parameters of the treatment pool, the liquid level of the treatment pool, the turbidity of the water outlet of the filter membrane (4), the membrane flux of the filter membrane (4), and the membrane pressure difference of the filter membrane (4); S2. Based on the detection results, the control unit controls the dynamic membrane module to enter at least one of the following operating modes: (1) Aeration mode in the pond; (2) External cleaning mode of filter components; (3) Internal cleaning mode of the filter component.

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