Pretreatment-free self-cleaning pull rod type ceramic membrane water treatment device and filtration and cleaning operation method

Abstract

This invention provides a pretreatment-free, self-cleaning, pull-rod type ceramic membrane water treatment device and filtration method, relating to the field of water treatment membrane separation technology. It solves the technical problem in existing water treatment membrane separation processes where dead zones exist in the membrane module structure, leading to easy fouling and membrane damage. The device includes a filter tank, ceramic membrane filter elements, and a partition plate. The partition plate divides the interior of the filter tank into an upper clear water chamber and a lower filtration chamber. All ceramic membrane filter elements are arranged side-by-side in the lower filtration chamber, and the hollow chambers of all ceramic membrane filter elements are connected to the upper clear water chamber. A hollow pull rod extends through the ceramic membrane tube along its axial direction. The lower end of the hollow pull rod is threaded to a cap nut, and the upper end of the hollow pull rod passes through the partition plate and is connected by a positioning nut. The inner diameter of the threads of both the positioning nut and the cap nut is no greater than the inner diameter of the ceramic membrane tube, and both the positioning nut and the cap nut are smoothly flush with the outer surface of the ceramic membrane tube end.

Description

Technical Field

[0001] This invention relates to the field of water treatment membrane separation technology, and in particular to a pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device and filtration method. Background Technology

[0002] Current mainstream water treatment membrane separation processes suffer from several inherent technical defects, forming a technical bottleneck in the industry and making it difficult to adapt to the development needs of green, efficient, and low-cost modern water treatment. The specific drawbacks are as follows:

[0003] 1. Dead zones exist in the membrane module structure, making it prone to fouling and membrane damage. Traditional membrane modules use an externally protruding bolt connection structure at the end, with the bolt outer diameter much larger than the membrane tube outer diameter. This results in numerous grooves, gaps, and structural dead zones at the connection point. During water treatment operation and equipment cleaning, these dead zones easily accumulate scale and trap impurities in the water, and conventional cleaning methods cannot completely remove residual contaminants. Long-term scale buildup will continuously exacerbate the fouling, clogging, and corrosion problems of the membrane module, significantly reducing the operational stability of the membrane module and drastically shortening the service life of the membrane elements.

[0004] Second, the process is complex and the construction and maintenance costs are high. Existing water treatment systems generally employ a two-stage treatment process: pre-treatment and membrane filtration. Before raw water enters the membrane module for filtration, a separate pre-treatment system must be built, and various chemical agents such as flocculants, scale inhibitors, and defoamers must be continuously added to complete pre-treatment processes such as impurity flocculation, membrane surface anti-scaling, and water defoaming. This process involves complex equipment configurations and large floor space requirements, resulting in high initial equipment investment and construction costs, as well as cumbersome daily operation and maintenance processes, high management difficulty, and poor overall economic efficiency.

[0005] Third, the cleaning process is outdated and inefficient, resulting in waste and contamination. Current industry-standard membrane module cleaning methods are highly dependent on and have significant limitations. They require additional cleaning agents and large amounts of clean water to complete the membrane surface cleaning operation, resulting in high cleaning material costs and the potential for secondary pollution from cleaning wastewater. Furthermore, existing cleaning processes lack a tiered and refined cleaning logic, and their processes are rigid and inflexible. This leads to either frequent chemical cleaning causing membrane module wear and aging, or incomplete cleaning preventing effective recovery of membrane flux. These practices exacerbate equipment wear and shorten equipment lifespan, while severely restricting overall water treatment operating efficiency.

[0006] In summary, existing water treatment membrane separation equipment and process systems cannot simultaneously achieve the core technical goals of no pretreatment, zero chemical reagent addition, no dead zone to prevent fouling residue, and efficient graded self-cleaning. They have multiple shortcomings in structure, process, and operation and maintenance, and can no longer meet the core development needs of the current water treatment industry for green environmental protection, high efficiency and energy saving, and low cost operation and maintenance. Summary of the Invention

[0007] The purpose of this invention is to provide a pretreatment-free, self-cleaning, lever-type ceramic membrane water treatment device and filtration method to solve the technical problem in existing water treatment membrane separation processes where dead zones exist in the membrane module structure, leading to easy fouling and membrane damage. The various technical effects of the preferred solutions among the many technical solutions provided by this invention are detailed below.

[0008] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a pretreatment-free self-cleaning pull-rod type ceramic membrane water treatment device, comprising a filter tank, ceramic membrane filter elements, and a partition plate. The partition plate is fixedly disposed in the upper region of the filter tank and divides the interior of the filter tank into an upper clear water chamber and a lower filtration chamber. There are multiple ceramic membrane filter elements, all of which are arranged side by side in the lower filtration chamber. All of the ceramic membrane filter elements are connected to the partition plate, and the hollow chambers of all the ceramic membrane filter elements are connected to the upper clear water chamber. The ceramic membrane filter element includes a ceramic membrane tube, a hollow tie rod, a cap nut, and a positioning nut. The hollow tie rod passes through the ceramic membrane tube along its axial direction. The lower end of the hollow tie rod is threaded to the cap nut, and the cap nut is sealed to the lower end face of the ceramic membrane tube. The upper end of the hollow tie rod passes through the partition plate and is connected to it through the positioning nut. The inner diameter of the threads of both the positioning nut and the cap nut is not greater than the inner diameter of the ceramic membrane tube, and both the positioning nut and the cap nut are smoothly flush with the outer circular surface of the end of the ceramic membrane tube.

[0009] Optionally, the hollow tie rod has a hollow cavity inside, and the circumferential sidewall of the hollow tie rod has a plurality of through holes, all of which are connected to the hollow cavity. The hollow tie rod has threads at its end.

[0010] Optionally, the number of positioning nuts on one of the ceramic membrane filter elements is two, and the two positioning nuts are respectively located on the upper and lower sides of the partition plate.

[0011] Optionally, a sealing ring is provided between the cap nut and the ceramic membrane tube, between the positioning nut and the ceramic membrane tube, and between the positioning nut and the partition plate.

[0012] Optionally, the partition plate is provided with a plurality of connection holes, the number of which is consistent with the number of ceramic membrane filter elements and are connected one-to-one.

[0013] Optionally, a drain pipe is provided at the bottom center of the filter tank, and a drain valve is provided on the drain pipe; An air inlet pipe is provided at the eccentric position at the bottom of the filter tank, and an air inlet valve is provided on the air inlet pipe; The filter tank is provided with an air outlet pipe, a water inlet pipe and a pressure gauge interface on its circumferential side wall. An air outlet valve is provided on the air outlet pipe, a water inlet valve is provided on the water inlet pipe, and a pressure gauge is installed on the pressure gauge interface. The top of the filter tank is equipped with a clean water production pipe and a clean water inlet pipe. The clean water production pipe is equipped with a production valve, and the clean water inlet pipe is equipped with a clean water valve.

[0014] Optionally, the cap nut and the positioning nut are made of engineering plastic.

[0015] The present invention provides a filtration and washing method for a pretreatment-free self-cleaning pull-rod type ceramic membrane water treatment device, comprising the following steps: Step S1: Open the inlet valve and let the raw water flow into the lower filter chamber through the inlet pipe. The raw water undergoes external pressure dead-end filtration through the ceramic membrane filter element in the lower filter chamber. The clean water produced by filtration passes through the ceramic membrane filter element and enters the upper clear water chamber. During the filtration process, keep the product water valve open so that the clean water in the upper clear water chamber is continuously transported out through the clean water product water pipe. Step S2: Since the ceramic membrane filter element adopts a suspended installation structure, some suspended solids and colloidal pollutants in the raw water adhere to the outer surface of the ceramic membrane filter element. Large particulate pollutants with a density greater than water in the raw water naturally settle to the collection area at the bottom of the filter tank under the action of gravity. At the same time, the pollutant layer on the outer surface of the ceramic membrane filter element gradually thickens, and the transmembrane pressure difference gradually increases. When the transmembrane pressure difference of the ceramic membrane filter element increases to the preset cleaning threshold or the water production drops to the preset lower limit, the filtration operation is stopped and the cleaning process begins. Step S3: Close the water inlet valve, open the air inlet valve and the air outlet valve, and introduce compressed air into the lower filter chamber through the air inlet pipe; the compressed air mixes with the raw water remaining in the lower filter chamber to form a high-speed gas-liquid two-phase flow, which generates a high-intensity shearing effect on the outer surface of the ceramic membrane filter element; at the same time, driven by the compressed air, the raw water remaining in the lower filter chamber continues to pass through the ceramic membrane filter element to complete the filtration and produce water, further concentrating the retentate in the lower filter chamber, and the excess gas is discharged from the air outlet pipe; Step S4: As the retentate continues to concentrate, the concentration of retentate particles in the lower filtration chamber continues to increase; the high concentration of retentate particles, under the influence of the high-speed gas-liquid two-phase flow, forms a strong particle scrubbing effect on the outer surface of the ceramic membrane filter element, causing the attached pollutants to be quickly detached; after the gas-water scrubbing is completed, the drain valve is opened to drain all the concentrated wash liquid containing the detached pollutants. Step S5: After the backwash liquid is drained, close the drain valve and open the clean water valve. Inject the backwash water into the upper clean water chamber through the clean water inlet pipe, allowing the backwash water to pass through the ceramic membrane filter element in reverse and enter the lower filtration chamber to backwash the inner surface of the membrane and the internal channels of the filter element. During the backwashing process, compressed air is simultaneously introduced through the air inlet pipe to form a two-phase flow of air and water to jointly scrub the outer surface of the ceramic membrane filter element. Repeat the above air-water combined backwashing operation at least twice, then open the drain valve to drain all the backwash liquid, and normal filtration production can be resumed.

[0016] Optionally, after completing the combined air-water backwash in step S5, if the transmembrane pressure difference of the ceramic membrane filter element has not recovered to 80% to 90% of the initial operating value or the preset normal operating threshold, the chemical cleaning component is activated, and the ceramic membrane filter element is subjected to cyclic immersion-type restorative chemical cleaning by sequentially using acidic and alkaline cleaning agents.

[0017] This invention provides a pretreatment-free, self-cleaning, tie-rod type ceramic membrane water treatment device. It abandons the traditional external protruding bolt connection structure of membrane modules, adopting an internal assembly scheme with a hollow tie rod penetrating the ceramic membrane tube. Combined with a cap nut and a positioning nut, the ceramic membrane filter element is fixedly assembled. Simultaneously, the thread inner diameter of the positioning nut and cap nut is strictly limited to not exceeding the inner diameter of the ceramic membrane tube, and both the positioning nut and cap nut are smoothly flush with the outer circular surface of the ceramic membrane tube end. This reduces the grooves, gaps, and structural dead zones caused by the traditional external protruding bolt structure. Therefore, during water treatment operation and equipment cleaning, it can reduce the points where impurities and pollutants accumulate and adhere to the water, effectively reducing the problem of dirt retention and accumulation. This greatly improves the operational stability of the ceramic membrane filter element, effectively delays the performance degradation of the membrane element, and significantly extends the overall service life of the equipment.

[0018] The preferred technical solution of the present invention can also produce at least the following technical effects: Breaking through the limitations of existing two-stage, segmented water treatment processes involving pretreatment and membrane filtration, this device integrates both water pretreatment and ceramic membrane filtration. It eliminates the need for separate pretreatment systems, chemical dosing equipment, reaction sedimentation, and filtration facilities. During daily operation, raw water can directly enter the device for filtration without the addition of any chemical agents such as flocculants, scale inhibitors, defoamers, or corrosion inhibitors. This eliminates the need for chemical pretreatment and membrane protection, overcoming the industry's technical barrier of requiring pretreatment followed by chemical dosing and membrane treatment. It significantly simplifies the water treatment process, reduces equipment footprint, lowers investment costs, and eliminates significant expenses related to manual chemical dosing and equipment maintenance. This integrated, one-stop, and minimally invasive water treatment approach eliminates chemical pollution at its source. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the internal structure of the pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the external structure of the pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device provided in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device provided in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the ceramic membrane filter element of the self-cleaning pull-rod type ceramic membrane water treatment device without pretreatment provided in an embodiment of the present invention.

[0021] In the diagram: 1. Filter tank; 11. Upper clear water chamber; 12. Lower filter chamber; 13. Sewage discharge pipe; 14. Air inlet pipe; 15. Air outlet pipe; 16. Water inlet pipe; 17. Pressure gauge interface; 18. Clean water production pipe; 19. Clear water inlet pipe; 2. Ceramic membrane filter element; 21. Ceramic membrane tube; 22. Hollow tie rod; 221. Through hole; 23. Cap nut; 24. Positioning nut; 3. Divider. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] This invention provides a pretreatment-free self-cleaning pull-rod type ceramic membrane water treatment device, including a filter tank 1, ceramic membrane filter elements 2, and a partition plate 3. The partition plate 3 is fixedly installed in the upper region of the filter tank 1, and the partition plate 3 divides the interior of the filter tank 1 into an upper clear water chamber 11 and a lower filtration chamber 12. There are multiple ceramic membrane filter elements 2, all of which are arranged side by side in the lower filtration chamber 12. All ceramic membrane filter elements 2 are connected to the partition plate 3, and the hollow chambers of all ceramic membrane filter elements 2 are connected to the upper clear water chamber 11. The ceramic membrane filter element 2 includes a ceramic membrane tube 21, a hollow tie rod 22, a cap nut 23, and a positioning nut 24. The hollow tie rod 22 passes through the ceramic membrane tube 21 along the axial direction. The lower end of the hollow tie rod 22 is threadedly connected to the cap nut 23, and the cap nut 23 is sealed to the lower end face of the ceramic membrane tube 21. The upper end of the hollow tie rod 22 passes through the partition plate 3 and is connected to it through the positioning nut 24. The inner diameter of the threads of both the positioning nut 24 and the cap nut 23 is no greater than the inner diameter of the ceramic membrane tube 21. Both the positioning nut 24 and the cap nut 23 are smoothly flush with the outer circular surface of the end of the ceramic membrane tube 21. The end connection position of the ceramic membrane tube 21 has no unevenness, no dead zone gap, and no siltation blind zone. Water and circulating scrubbing fluid can flow smoothly through the outer wall and end of the ceramic membrane tube 21. The water flow is highly turbulent and without stagnation. There is no dirt trapping or impurity residue during the cleaning process. This solves the problems of dead zone fouling, incomplete cleaning, and secondary pollution of traditional membrane modules from the structural root, continuously keeping the membrane tube clean, delaying membrane fouling, significantly extending the service life of the ceramic membrane tube, and reducing the frequency of equipment maintenance. The present invention provides a pretreatment-free self-cleaning tie rod type ceramic membrane water treatment device, which abandons the traditional external protruding bolt connection structure of membrane modules. It adopts an internal assembly scheme in which a hollow tie rod 22 passes through the ceramic membrane tube 21, and together with the cap nut 23 and the positioning nut 24, the ceramic membrane filter element 2 is fixedly assembled as a whole. At the same time, the inner diameter of the threads of the positioning nut 24 and the cap nut 23 is strictly limited to not being greater than the inner diameter of the ceramic membrane tube 21. Furthermore, the positioning nut 24 and the cap nut 23 are both smoothly flush with the outer circular surface of the end of the ceramic membrane tube 21. This reduces the grooves, gaps, and dead zones caused by the traditional external protruding bolt structure. Consequently, during water treatment operation and equipment cleaning, it can reduce the points where water impurities and pollutants accumulate and adhere, effectively reducing the problem of dirt retention and accumulation. This can greatly improve the operational stability of the ceramic membrane filter element, effectively delay the performance degradation of the membrane element, and significantly extend the overall service life of the equipment.

[0026] As an optional implementation, the hollow tie rod 22 has a hollow chamber inside, and multiple through holes 221 are provided on the circumferential sidewall of the hollow tie rod 22, all of which are connected to the hollow chamber; the end of the hollow tie rod 22 is provided with threads. The hollow chamber and through holes 221, together with the smooth integrated filter element structure without dead zones, can realize a full-channel flushing passage from the inside to the outside, without relying on traditional special cleaning agents and large amounts of cleaning water. Water and air can be evenly distributed through the hollow chamber and through holes 221 of the hollow tie rod 22 to perform all-round, dead-zone-free flushing and cleaning of the inner and outer walls of the ceramic membrane tube 21, realizing a purely physical self-cleaning operation without the intervention of chemical agents, greatly reducing the cost of cleaning materials, and avoiding the problem of secondary water pollution caused by chemical cleaning waste liquid.

[0027] As an optional implementation, a ceramic membrane filter element 2 has two positioning nuts 24, located on the upper and lower sides of the partition plate 3 respectively. By symmetrically arranging two sets of positioning nuts 24 on the upper and lower sides of the partition plate 3, the ceramic membrane filter element 2 and the partition plate 3 are clamped and fixed in both directions, resulting in a stable and reliable assembly structure. Sealing rings are provided between the cap nut 23 and the ceramic membrane tube 21, between the positioning nut 24 and the ceramic membrane tube 21, and between the positioning nut 24 and the partition plate 3, achieving multi-position all-round sealing and compensating for temperature deformation. The cap nut 23 and the positioning nut 24 are made of engineering plastic material, possessing excellent corrosion resistance, wear resistance, and aging resistance, effectively adapting to complex water treatment conditions, avoiding the problems of easy rusting, scaling, and corrosion failure of metal fasteners, and further eliminating the adhesion of rust impurities and the phenomenon of scale accumulation at points.

[0028] As an optional implementation, the partition plate 3 is provided with multiple connection holes, the number of which is consistent with the number of ceramic membrane filter elements 2 and they are connected one by one, so that each ceramic membrane filter element 2 can be accurately aligned and independently assembled, with a neat layout and convenient disassembly and maintenance. It can also realize the suspended installation structure of the ceramic membrane filter element 2, without any other support structure that would create a dead zone where pollutants can remain.

[0029] As an optional implementation, the present invention provides a comprehensive pipeline integration layout for the filter tank 1. A drain pipe 13 is provided at the center of the bottom of the filter tank 1, and a drain valve is provided on the drain pipe 13 to quickly and thoroughly discharge the sludge, impurities, and cleaning waste liquid deposited in the filter tank 1, avoiding the accumulation of dirt and secondary pollution, and ensuring a clean water environment in the filter tank 1. An air inlet pipe 14 is provided at the eccentric position of the bottom of the filter tank 1, and an air inlet valve is provided on the air inlet pipe 14 to accurately connect to the air source. Combined with the through-hole structure of the hollow tie rod 22, air and water combined physical cleaning is achieved, enhancing the membrane rinsing and cleaning effect. An air outlet pipe 15, a water inlet pipe 16, and a pressure gauge interface are provided on the circumferential side wall of the filter tank 1. 17. An air outlet valve is installed on the air outlet pipe 15. The air outlet pipe 15 is located in the upper area of ​​the circumferential side wall of the filter tank 1. The diameters of the air inlet pipe 14 and the air outlet pipe 15 are both DN15~32. An inlet valve is installed on the water inlet pipe 16. A pressure gauge is installed on the pressure gauge interface 17. This can realize stable water intake of raw water and orderly discharge of gas in the tank. Real-time monitoring of the internal operating pressure of the equipment is convenient for timely adjustment of the operating conditions and avoidance of overpressure operation risk. A clean water production pipe 18 and a clean water inlet pipe 19 are installed on the top of the filter tank 1. A production valve is installed on the clean water production pipe 18 and a clean water valve is installed on the clean water inlet pipe 19. This can realize the stable output of filtered clean water and the precise replenishment of cleaning water, respectively. The entire pipeline and valve system is clearly divided into zones, has complete functions, and is scientifically laid out. It achieves integrated control of water inlet, filtration, venting, sewage discharge, pressure monitoring, purified water output, and clean water replenishment. The equipment has strong automation adaptability, convenient operation and control, and safe and stable operation, further reducing the difficulty of manual operation and maintenance and improving the working condition adaptability and continuous stable operation capability of the entire water treatment device.

[0030] This invention provides a filtration and washing method for a pretreatment-free, self-cleaning, lever-type ceramic membrane water treatment device, comprising the following steps: Step S1: Open the inlet valve and let the raw water flow into the lower filter chamber 12 through the inlet pipe 16. The raw water undergoes external pressure dead-end filtration in the lower filter chamber 12 through the ceramic membrane filter element 2. The clean water produced by filtration passes through the ceramic membrane filter element 2 and enters the upper clear water chamber 11. During the filtration process, keep the product water valve open so that the clean water in the upper clear water chamber 11 is continuously transported out through the clean water product water pipe 18. Step S2: Because the ceramic membrane filter element 2 adopts a suspended installation structure and external pressure filtration, the inlet liquid space is large and the turbulence is strong, making it difficult for pollutants to adhere to the membrane surface. Some suspended solids and colloidal pollutants in the raw water adhere to the outer surface of the ceramic membrane filter element 2. Large particulate pollutants with a density greater than water in the raw water naturally settle to the dirt collection area at the bottom of the filter tank 1 under the action of gravity. At the same time, the pollutant layer on the outer surface of the ceramic membrane filter element 2 gradually thickens, and the transmembrane pressure difference gradually increases. When the transmembrane pressure difference of the ceramic membrane filter element 2 increases to the preset cleaning threshold or the water production drops to the preset lower limit, the filtration operation is stopped and the cleaning process begins. Step S3: Close the water inlet valve, open the air inlet valve and the air outlet valve, and introduce 0.6MPa compressed air into the lower filter chamber 12 through the air inlet pipe. The compressed air mixes with the raw water remaining in the lower filter chamber 12 to form a high-speed gas-liquid two-phase flow, which generates a high-intensity shearing effect on the outer surface of the ceramic membrane filter element 2. At the same time, driven by the compressed air, the raw water remaining in the lower filter chamber 12 continues to pass through the ceramic membrane filter element 2 to complete the filtration and produce water, further concentrating the retentate in the lower filter chamber 12. Excess gas is discharged from the air outlet pipe 15. Step S4: As the retentate continues to concentrate, the concentration of retentate particles in the lower filtration chamber 12 continues to increase; under the influence of the high-speed gas-liquid two-phase flow, the high concentration of retentate particles forms a strong particulate scrubbing effect on the outer surface of the ceramic membrane filter element 2, causing the attached contaminants to be quickly detached. The gas-water scrubbing time is about 5-10 seconds. Close the air inlet valve and the air outlet valve, and repeat 2-3 times; after the gas-water scrubbing is completed, open the drain valve to drain all the concentrated wash liquid containing the detached contaminants. Step S5: After the backwash liquid is drained, close the drain valve and open the clean water valve. Inject the backwash water into the upper clean water chamber 11 through the clean water inlet pipe 19, allowing the backwash water to pass through the ceramic membrane filter element 2 in reverse and enter the lower filtration chamber 12 to backwash the inner surface of the membrane and the internal channels of the filter element. During the backwashing process, compressed air is simultaneously introduced from the air inlet pipe 14 to form a two-phase flow of air and water to jointly scrub the outer surface of the ceramic membrane filter element 2. Repeat the above air-water combined backwashing operation at least twice, then open the drain valve to drain all the backwash liquid, and normal filtration production can be resumed.

[0031] The innovative process employs a combined raw water and liquid gas-water scrubbing technique, eliminating the need for any external cleaning aids or agents. It directly utilizes the concentrated raw liquid produced by the equipment itself, combined with the introduced gas to form a high-speed gas-liquid two-phase flow, to repeatedly and powerfully scrub the membrane surface. The suspended solids and colloidal impurities in the concentrated raw liquid have extremely strong physical adsorption and entrainment capabilities, and the gas-liquid linkage scrubbing force is even stronger, which can quickly remove contaminants and pore-clogging impurities adhering to the membrane surface. Water production, concentration, and scrubbing operate simultaneously, without the need for machine shutdown, external cleaning media, or secondary pollution. It automatically completes primary and efficient cleaning online, with cleaning efficiency far exceeding that of traditional single water washing processes.

[0032] As an optional implementation, after completing the combined air-water backwash in step S5, if the transmembrane pressure difference of the ceramic membrane filter element 2 has not recovered to 80% to 90% of the initial operating value or the preset normal operating threshold, the chemical cleaning component is activated, and the ceramic membrane filter element 2 is subjected to cyclic soaking recovery chemical cleaning with acidic cleaning agent and alkaline cleaning agent in sequence.

[0033] This invention is matched with a dedicated pretreatment-free, graded self-cleaning operation method. Relying on the unique structure of the device and the integrated layout of multiple pipelines, it constructs a stepped fine filtration and cleaning system of gas-liquid shear scrubbing, gas-water combined backwashing, and selective chemical fine cleaning. It abandons the technical drawbacks of traditional processes that rely on pretreatment, continuous addition of chemical agents, and a single and crude cleaning mode.

[0034] This invention employs an external pressure dead-end filtration mode, utilizing the suspended structure of the ceramic membrane filter element 2 to achieve stratified separation of pollutants. When the contamination of the ceramic membrane filter element 2 approaches the threshold, a high-speed gas-liquid two-phase flow is formed through bottom eccentric air intake. Utilizing high-intensity fluid shear force and high-concentration particle scrubbing action, the dense contamination layer on the membrane surface is quickly peeled off. Combined with the all-area permeable flushing effect of the built-in hollow tie rod 22, physical cleaning without dead zones is achieved on the outer surface of the membrane. Then, reverse water permeation flushing is achieved through the top water inlet pipe 19, combined with synchronous air washing to complete the combined regeneration of the membrane channels inside and outside. The entire process of pure physical cleaning does not require the addition of cleaning agents, fundamentally eliminating secondary pollution caused by chemical cleaning waste liquid and significantly reducing operation and maintenance consumable costs.

[0035] This invention also incorporates a tiered cleaning logic. For routine contamination, membrane flux can be restored through multi-stage physical air-water combined cleaning, significantly reducing the frequency of chemical cleaning and avoiding problems such as membrane aging, pore damage, and shortened lifespan caused by frequent chemical immersion. Only when physical cleaning is ineffective is selective acid-base immersion chemical cleaning initiated, achieving precise, on-demand cleaning that balances thorough cleaning with membrane element protection. The entire process is highly automated with clear logical steps, adaptable to different water pollution conditions, effectively stabilizing equipment permeate output, restoring transmembrane pressure differential to normal operating range, and ensuring long-term, efficient, continuous, and stable operation of the water treatment system.

[0036] Advantages of this invention: 1. No dead zones or residues in the structure: The hollow tie rod is used for flush fixing. The inner diameter of the threads of the plastic positioning nut 24 and the plastic cap nut 23 is no greater than the inner diameter of the ceramic membrane tube 21. There are no dead zones at the end of the membrane tube, the water flows smoothly without stagnation, and dirt and impurities are completely eliminated. This reduces membrane pollution at the source and extends the service life of the ceramic membrane.

[0037] 2. Highly efficient and environmentally friendly cleaning process: The unique original liquid gas-water combined scrubbing process directly uses the concentrated original liquid of the product water for cleaning, without the need for any external cleaning aids. The physical cleaning is highly efficient and has no secondary pollution. The graded cleaning process adopts physical scrubbing first, then backwashing with clean water, and finally chemical cleaning as needed. This greatly reduces the frequency of chemical cleaning, reduces the corrosion of membrane tubes by acid and alkali agents, and achieves excellent membrane flux recovery.

[0038] 3. Eliminates pretreatment process and requires zero chemical addition: Breaking through the limitations of traditional processes, no pretreatment equipment is needed. No flocculants, scale inhibitors, or defoamers are added throughout the water treatment process, eliminating the need for dosing equipment, chemical costs, and pretreatment maintenance procedures. This simplifies the process flow, reduces the footprint, and eliminates secondary pollution from chemical agents at the source, making it extremely environmentally friendly.

[0039] 4. Simple operation and wide applicability: It is easy to operate and stable. It can directly treat various water sources such as seawater, domestic sewage, industrial wastewater, tap water, and surface water. It is applicable to a wide range of scenarios, greatly reduces the overall operation and maintenance costs, and has strong practical value and market promotion value.

[0040] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A pre-treatment free self-cleaning pull rod type ceramic membrane water treatment device, characterized in that, It includes a filter tank (1), a ceramic membrane filter element (2), and a separator plate (3), wherein, The partition plate (3) is fixedly installed in the upper region of the filter tank (1), and the partition plate (3) divides the interior of the filter tank (1) into an upper clear water chamber (11) and a lower filter chamber (12). There are multiple ceramic membrane filter elements (2), and all the ceramic membrane filter elements (2) are arranged side by side in the lower filter chamber (12). All the ceramic membrane filter elements (2) are connected to the partition plate (3), and the hollow chambers of all the ceramic membrane filter elements (2) are connected to the upper clear water chamber (11). The ceramic membrane filter element (2) includes a ceramic membrane tube (21), a hollow pull rod (22), a cap nut (23), and a positioning nut (24). The hollow pull rod (22) passes through the ceramic membrane tube (21) along the axial direction. The lower end of the hollow pull rod (22) is threaded to the cap nut (23), and the cap nut (23) is sealed to the lower end face of the ceramic membrane tube (21). The upper end of the hollow pull rod (22) passes through the partition plate (3) and is connected to the positioning nut (24). The inner diameter of the threads of the positioning nut (24) and the cap nut (23) is not greater than the inner diameter of the ceramic membrane tube (21). The positioning nut (24) and the cap nut (23) are both smoothly flush with the outer circular surface of the end of the ceramic membrane tube (21).

2. The pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device according to claim 1, characterized in that, The hollow tie rod (22) has a hollow cavity inside, and a plurality of through holes (221) are provided on the circumferential sidewall of the hollow tie rod (22), all of which are connected to the hollow cavity; The hollow tie rod (22) has a threaded end.

3. The pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device according to claim 1, characterized in that, The number of positioning nuts (24) on a ceramic membrane filter element (2) is two, and the two positioning nuts (24) are located on the upper and lower sides of the partition plate (3), respectively.

4. The pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device according to claim 3, characterized in that, A sealing ring is provided between the cap nut (23) and the ceramic membrane tube (21), between the positioning nut (24) and the ceramic membrane tube (21), and between the positioning nut (24) and the partition plate (3).

5. The pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device according to claim 1, characterized in that, The partition plate (3) is provided with a plurality of connection holes, the number of which is consistent with the number of the ceramic membrane filter element (2) and they are connected one by one.

6. The pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device according to claim 1, characterized in that, A drain pipe (13) is provided at the bottom center of the filter tank (1), and a drain valve is provided on the drain pipe (13); An air inlet pipe (14) is provided at the bottom eccentric position of the filter tank (1), and an air inlet valve is provided on the air inlet pipe (14); The filter tank (1) is provided with an air outlet pipe (15), a water inlet pipe (16) and a pressure gauge interface (17) on its circumferential side wall. An air outlet valve is provided on the air outlet pipe (15), a water inlet valve is provided on the water inlet pipe (16), and a pressure gauge is installed on the pressure gauge interface (17). The top of the filter tank (1) is provided with a clean water production pipe (18) and a clean water inlet pipe (19). A water production valve is provided on the clean water production pipe (18), and a clean water valve is provided on the clean water inlet pipe (19).

7. The pretreatment-free self-cleaning tie-rod type ceramic membrane water treatment device according to claim 1, characterized in that, The cap nut (23) and the positioning nut (24) are made of engineering plastic.

8. A filtration and washing method for a self-cleaning, pull-rod type ceramic membrane water treatment device without pretreatment as described in any one of claims 1-7, characterized in that, The following steps are included: Step S1: Open the inlet valve and let the raw water pass through the inlet pipe (16) into the lower filter chamber (12). The raw water in the lower filter chamber (12) is filtered by the ceramic membrane filter element (2) under external pressure. The clean water produced by filtration passes through the ceramic membrane filter element (2) and enters the upper clear water chamber (11). During the filtration process, keep the product water valve open so that the clean water in the upper clear water chamber (11) is continuously transported out through the clean water product water pipe (18). Step S2: Since the ceramic membrane filter element (2) adopts a suspended installation structure, some suspended solids and colloidal pollutants in the raw water adhere to the outer surface of the ceramic membrane filter element (2). Large particulate pollutants with a density greater than water in the raw water naturally settle to the collection area at the bottom of the filter tank (1) under the action of gravity. At the same time, the pollutant layer on the outer surface of the ceramic membrane filter element (2) gradually thickens, and the transmembrane pressure difference gradually increases. When the transmembrane pressure difference of the ceramic membrane filter element (2) increases to the preset cleaning threshold or the water production decreases to the preset lower limit, the filtration operation is stopped and the cleaning process begins. Step S3: Close the water inlet valve, open the air inlet valve and the air outlet valve, and introduce compressed air into the lower filter chamber (12) through the air inlet pipe (14); the compressed air mixes with the raw water remaining in the lower filter chamber (12) to form a high-speed gas-liquid two-phase flow, which generates a high-intensity shearing action on the outer surface of the ceramic membrane filter element (2); at the same time, driven by the compressed air, the raw water remaining in the lower filter chamber (12) continues to pass through the ceramic membrane filter element (2) to complete the filtration and produce water, further concentrating the entrapment liquid in the lower filter chamber (12), and the excess gas is discharged from the air outlet pipe (15); Step S4: As the retentate continues to concentrate, the concentration of retentate particles in the lower filtration chamber (12) continues to increase; the high concentration of retentate particles, under the influence of the high-speed gas-liquid two-phase flow, forms a violent particle scrubbing effect on the outer surface of the ceramic membrane filter element (2), causing the attached pollutants to be quickly detached; after the gas-water scrubbing is completed, the drain valve is opened to drain all the concentrated wash liquid containing the detached pollutants. Step S5: After the backwash liquid is drained, close the drain valve and open the clean water valve. Inject the backwash water into the upper clean water chamber (11) through the clean water inlet pipe (19), so that the backwash water passes through the ceramic membrane filter element (2) in reverse and enters the lower filter chamber (12) to backwash the inner surface of the membrane and the internal channels of the filter element. During the backwashing process, compressed air is simultaneously introduced from the air inlet pipe (14) to form a two-phase flow of air and water to jointly scrub the outer surface of the ceramic membrane filter element (2). After repeating the above air-water combined backwashing operation at least twice, open the drain valve to drain all the backwash liquid and resume normal filtration production.

9. The filtration and washing method according to claim 8, characterized in that, After completing the combined air-water backwash in step S5, if the transmembrane pressure difference of the ceramic membrane filter element (2) has not recovered to 80% to 90% of the initial operating value or the preset normal operating threshold, the chemical cleaning component is activated, and the ceramic membrane filter element (2) is subjected to cyclic soaking recovery chemical cleaning by sequentially using acidic cleaning agent and alkaline cleaning agent.

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