Method and device for purifying and recycling industrial cleaning waste liquid

Abstract

The application provides an industrial cleaning waste liquid recycling purification and reuse method and device, which comprises the following steps: introducing the industrial cleaning waste liquid and inorganic flocculants into a tubular ceramic membrane assembly to separate primary permeate and recycling liquid; applying low pressure pulse to the recycling liquid to reduce the transmembrane pressure difference from the highest working pressure to a positive low pressure area, using the elastic recovery force of the dynamic floc layer to make the floc volume expand and crack to form a defibrillation state liquid; driving the defibrillation state liquid to flow through a static spiral flow guide element to form a stripped membrane surface and stripping liquid; under the action of steady-state cross-flow shear, supplementing the floc to the stripped membrane surface to maintain the thickness of the dynamic floc layer, transporting the stripping liquid forward with the main flow, separating secondary permeate and final concentrated liquid; performing multi-stage series filtration on the primary permeate and the secondary permeate to obtain purified and reused water, and discharging the final concentrated liquid as waste concentrated liquid. The application improves the purification and reuse stability of the industrial cleaning waste liquid and the water purification quality.

Description

Technical Field

[0001] This invention relates to the field of waste liquid recycling technology, and in particular to a method and apparatus for recycling, purifying and reusing industrial cleaning waste liquid. Background Technology

[0002] In the field of industrial cleaning, especially in industries such as precision parts manufacturing and semiconductor processing, a large amount of cleaning wastewater containing oil, solid particles, surfactants, and organic solvents is generated. To achieve water resource recycling and reduce environmental pollution, the purification and reuse of industrial cleaning wastewater has become an industry consensus. Current mainstream treatment methods typically employ a combination of "pretreatment + membrane separation," with cross-flow filtration being the core solid-liquid separation method. In traditional cross-flow filtration, the feed liquid flows parallel to the membrane surface, the permeate passes perpendicularly through the membrane pores, and the concentrate that does not permeate is discharged along the membrane surface. This flow pattern aims to use shear force to flush the membrane surface, thereby slowing down the deposition of contaminants and maintaining a certain flux.

[0003] However, membrane fouling leads to severe irreversible flux degradation, and the cleaning recovery efficiency is low. Specifically, in the traditional unidirectional continuous cross-flow filtration mode, the hydrodynamic boundary layer is relatively stable, and colloidal particles and large organic molecules easily form a dense gel layer or filter cake layer on the membrane surface. As the operating time increases, pollutants gradually embed into the membrane pores, causing pore blockage. This deep fouling is difficult to completely remove by conventional backwashing or chemical cleaning alone, resulting in a continuous reduction in the effective filtration area of ​​the membrane module and a significant decrease in permeate flux. This makes it impossible for the purified water quality to consistently meet reuse standards, forcing the system to frequently shut down for high-intensity chemical cleaning or membrane module replacement, affecting the stability of industrial cleaning wastewater purification and reuse and the quality of water purification. Summary of the Invention

[0004] This invention provides a method and apparatus for recycling and purifying industrial cleaning wastewater. It aims to achieve controllable reconstruction and efficient removal of the fouling layer on the membrane surface through a synergistic mechanism of structured film formation, elastic dissipation, and eddy current stripping, thereby improving the stability of industrial cleaning wastewater purification and reuse and the quality of water purification.

[0005] In a first aspect, the present invention provides a method for recycling, purifying, and reusing industrial cleaning wastewater, applied to a tubular ceramic membrane module with a built-in static spiral flow guiding element; the method includes: Industrial cleaning wastewater and inorganic flocculant are introduced into a tubular ceramic membrane module, and transmembrane pressure differential filtration is performed using a gradient increase to separate the primary permeate and the circulating feed liquid; the endpoint of the gradient increase is the maximum working pressure. Apply a low-pressure pulse to the circulating feed liquid to reduce the transmembrane pressure difference from the highest working pressure to the positive low-pressure zone, cut off the transmembrane driving force, and use the elastic recovery force of the dynamic floc layer to make the floc volume expand and generate cracks, forming a dissipated feed liquid. The disintegrating liquid is driven to flow through the static spiral guide element, and the Dean vortex generated by the fluid is used to entrain and remove the surface flocs with cracks from the membrane surface, forming the stripped membrane surface and stripping liquid. Under steady-state cross-flow shearing, flocs are added to the stripped membrane surface to maintain the dynamic floc layer thickness, and the stripping liquid is transported forward with the mainstream to separate the secondary permeate and the final concentrate. The primary and secondary permeate are subjected to multi-stage series filtration to obtain purified reclaimed water, and the final concentrate is discharged as waste concentrate.

[0006] In a second aspect, the present invention also provides an industrial cleaning wastewater recycling and reuse device for implementing the industrial cleaning wastewater recycling and reuse method as described in the first aspect; the device includes: The gradient differential pressure filtration unit is used to introduce industrial cleaning waste liquid and inorganic flocculant into a tubular ceramic membrane module, and use the gradient increase to perform transmembrane differential pressure filtration to separate the primary permeate and the circulating feed liquid; the endpoint of the gradient increase is the maximum working pressure. The low-pressure pulse disintegration unit is used to apply low-pressure pulses to the circulating feed liquid, reduce the transmembrane pressure difference from the highest working pressure to the positive low-pressure zone, cut off the transmembrane driving force, and use the elastic recovery force of the dynamic floc layer to make the floc volume expand and generate cracks, forming a disintegrated feed liquid. The vortex floc stripping unit is used to drive the disintegrated liquid to flow through the static spiral guide element. The Dean vortex generated by the fluid will entrain and remove the surface flocs with cracks from the membrane surface, forming the stripped membrane surface and stripping liquid. The cross-flow circulation separation unit is used to replenish flocs to the stripped membrane surface under steady-state cross-flow shearing action to maintain the dynamic floc layer thickness, transport the stripping liquid forward with the mainstream, and separate the secondary permeate and the final concentrate. The filtrate multi-stage purification unit is used to perform multi-stage series filtration of the primary permeate and the secondary permeate to obtain purified reclaimed water, and to discharge the final concentrate as waste concentrate.

[0007] Thirdly, the present invention also provides an electronic device, comprising: a memory for storing a computer program; and a processor for reading and executing the computer program, thereby realizing the industrial cleaning waste liquid recycling, purification and reuse method as described above.

[0008] Fourthly, the present invention also provides a non-transitory computer-readable storage medium storing a computer program, which, when executed by a processor, implements the industrial cleaning waste liquid recycling, purification, and reuse method described above.

[0009] Fifthly, the present invention also provides a computer program product, including a computer program, which, when executed by a processor, implements the industrial cleaning waste liquid recycling, purification, and reuse method described above.

[0010] The industrial cleaning wastewater recycling and reuse method provided in this invention introduces industrial cleaning wastewater and inorganic flocculant into a tubular ceramic membrane module and uses gradient increasing transmembrane pressure difference filtration to obtain a stable primary permeate and a circulating feed liquid carrying flocculent impurities, resulting in a stable dynamic floc layer based on gradient pressurization filtration. Applying a low-pressure pulse to the circulating feed liquid and rapidly reducing the transmembrane pressure difference creates a disintegrated feed liquid, causing elastic expansion and cracking of the dense floc layer. This overcomes the problem of fouling layer hardening and solidification caused by continuous high-pressure operation in traditional membrane filtration. The resulting cracked disintegrated feed liquid creates the prerequisite for precise removal of the flocculent fouling layer from the membrane surface. Driving the disintegrated feed liquid through a static spiral guide element and using a Dean vortex suction to remove the surface flocs and the resulting stripped membrane surface and stripping liquid achieve directional and complete removal of the membrane fouling layer, avoiding the problems of residual fouling and filtration fragmentation associated with single filtration methods. Based on the clean membrane surface after stripping while preserving the basic floc structure, steady-state cross-flow shearing replenishes the flocs to maintain the dynamic floc layer thickness, and transports and separates the secondary permeate and the final concentrate, ensuring the continuity and stability of membrane filtration operations and avoiding operational fluctuations caused by frequent abrupt changes in membrane surface state during operation. Multi-stage series filtration of the primary and secondary permeates yields purified reclaimed water and discharged waste concentrate as the final treatment result. Therefore, this embodiment of the invention, through the synergistic mechanism of structured membrane formation, elastic disintegration, and eddy current stripping, achieves controllable reconstruction and efficient removal of the fouling layer on the membrane surface, improving the stability of industrial cleaning wastewater purification and reuse, and the quality of water purification. Attached Figure Description

[0011] Figure 1 This is a flowchart of the industrial cleaning waste liquid recycling, purification, and reuse method provided in the embodiments of the present invention; Figure 2 This is a structural diagram of the industrial cleaning waste liquid recycling, purification, and reuse device provided in an embodiment of the present invention; Figure 3 An embodiment diagram of the electronic device provided in this invention; Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with the present invention. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0014] In the description of this invention, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0015] Optionally, see Figure 1 , Figure 1 This is a flowchart of the industrial cleaning wastewater recycling, purification, and reuse method provided by the present invention. In this embodiment of the invention, the executing entity of the industrial cleaning wastewater recycling, purification, and reuse method is a wastewater purification device. Therefore, the industrial cleaning wastewater recycling, purification, and reuse method includes: Step 10: The industrial cleaning waste liquid and inorganic flocculant are introduced into the tubular ceramic membrane module, and the transmembrane pressure difference is used for filtration by gradient increase to separate the primary permeate and the circulating feed liquid.

[0016] Optionally, industrial cleaning wastewater is mixed with an inorganic flocculant and then introduced into a tubular ceramic membrane module for filtration, utilizing a gradient increase in transmembrane pressure difference. During this process, solid particles, colloidal substances, and oil in the industrial cleaning wastewater form flocs under the action of the inorganic flocculant. Driven by the transmembrane pressure difference, some of the liquid passes through the membrane pores of the tubular ceramic membrane module to form primary permeate, while the liquid that does not pass through serves as circulating feed, flowing along the membrane surface and being recycled back.

[0017] As the transmembrane pressure difference gradually increases, flocs gradually accumulate on the membrane surface of the tubular ceramic membrane module to form a dynamic floc layer until the transmembrane pressure difference reaches the maximum working pressure, at which point the gradient increase process ends, completing one filtration separation, as described in steps 101 to 104.

[0018] Industrial cleaning wastewater refers to cleaning wastewater containing oil, solid particles, surfactants, and organic solvents generated in industries such as precision parts manufacturing and semiconductor processing. Inorganic flocculants are inorganic chemical agents that can aggregate suspended particles and colloidal substances in industrial cleaning wastewater to form flocs, such as polyaluminum chloride and polyferric sulfate. Tubular ceramic membrane modules are membrane separation elements with a tubular structure made of inorganic ceramic materials, used to achieve solid-liquid separation. Gradient escalation refers to the process of gradually increasing the transmembrane pressure difference according to a preset gradient; that is, the transmembrane pressure difference starts from an initial pressure value and gradually increases to the maximum working pressure according to a preset increment. The transmembrane pressure difference is the pressure difference between the inside and outside of the tubular ceramic membrane module, serving as the driving force for the fluid to pass through the membrane pores. Primary permeate is the liquid that passes through the filtration membrane pores after being filtered by the tubular ceramic membrane module. Circulating feed is the liquid that does not permeate the tubular ceramic membrane module but flows along the membrane surface and circulates back. The maximum operating pressure is the maximum transmembrane pressure difference that the tubular ceramic membrane module can withstand during the gradient increase process, and it is preset according to the material and structural characteristics of the tubular ceramic membrane module. The dynamic floc layer is a floc layer with a certain thickness and structure formed by the accumulation of flocs on the membrane surface of the tubular ceramic membrane module during the filtration process. This floc layer is in a dynamic equilibrium state under the action of fluid shear force.

[0019] Step 20: Apply a low-pressure pulse to the circulating feed liquid to reduce the transmembrane pressure difference from the highest working pressure to the positive low-pressure zone, cut off the transmembrane driving force, and use the elastic recovery force of the dynamic floc layer to make the floc volume expand and generate cracks, forming a dissipated feed liquid.

[0020] Optionally, by applying low-pressure pulses to the circulating feed liquid, the transmembrane pressure difference is rapidly reduced from the maximum operating pressure to the positive low-pressure zone, thereby cutting off the transmembrane driving force. After the transmembrane driving force disappears, the dynamic floc layer, due to the loss of external pressure compression, undergoes volume expansion under the action of elastic restoring force, and cracks are generated during the expansion process, thus transforming the dense dynamic floc layer into a loose feed liquid with a cracked structure, as described in steps 201 to 204. The low-pressure pulse refers to the periodically changing low-pressure fluctuations applied to the circulating feed liquid by the waste liquid purification device, with a pressure value lower than the maximum operating pressure, used to change the fluid dynamic state inside the tubular ceramic membrane module. The positive low-pressure zone is the pressure range after the transmembrane pressure difference is reduced; its pressure value is positive but lower than the maximum operating pressure, insufficient to drive fluid through the membrane pores, but able to maintain the basic flow state of the fluid. The transmembrane driving force is the force generated by the transmembrane pressure difference that drives the fluid through the membrane pores of the tubular ceramic membrane module; when the transmembrane pressure difference is reduced to the positive low-pressure zone, this driving force is cut off. Elastic recovery force refers to the force exerted by flocs in a dynamic floc layer to restore their original volume after the loss of external pressure compression, due to their inherent elastic properties. Disintegrated state refers to the state of the filtrate after low-pressure pulse treatment, where the flocs in the dynamic floc layer expand in volume and develop cracks; the floc layer structure in this state is relatively loose.

[0021] Step 30: Drive the disintegrated feed liquid through the static spiral guide element, and use the Dean vortex generated by the fluid to entrain and detach the surface flocs with cracks from the membrane surface, forming the stripped membrane surface and stripping liquid.

[0022] Optionally, the disintegrated feed liquid is driven to flow through a static spiral guide element, wherein the static spiral guide element is fixedly installed in the internal flow channel of the tubular ceramic membrane module, and its surface has a spiral guide structure. When the disintegrated feed liquid flows through the static spiral guide element, the fluid generates rotational motion under the guidance of the spiral guide structure. Due to the inertia and centrifugal effect of the fluid, Dean vortices are formed on the cross-section of the tubular ceramic membrane module. Dean vortices are a secondary flow phenomenon, and their rotation direction is perpendicular to the mainstream direction, which can generate strong shearing and entrainment effects on the membrane surface of the tubular ceramic membrane module. Since the dynamic floc layer has developed cracks, the bonding force between the surface flocs and the membrane surface is reduced. The entrainment effect of Dean vortices can entrain and detach the surface flocs with cracked surfaces from the membrane surface, thereby forming a stripped membrane surface and stripping liquid. The stripped membrane surface refers to the membrane surface state after the Dean vortex stripping action, where the amount of residual flocs on the membrane surface is reduced. The stripping liquid refers to the liquid containing the stripped surface flocs.

[0023] Step 40: Under steady-state cross-flow shearing action, flocs are added to the stripped membrane surface to maintain the dynamic floc layer thickness, and the stripping liquid is transported forward with the mainstream to separate the secondary permeate and the final concentrate.

[0024] Optionally, under steady-state cross-flow shearing, flocs in the circulating feed are continuously replenished to the membrane surface after stripping to maintain the thickness of the dynamic floc layer and keep the filtration performance of the tubular ceramic membrane module stable. Simultaneously, the waste liquid purification device transports the stripped liquid forward with the main flow. Driven by the transmembrane pressure difference, some liquid passes through the membrane pores of the tubular ceramic membrane module to form secondary permeate, while the liquid that does not pass through is discharged as the final concentrate, completing the secondary filtration separation, as described in steps 401 to 403.

[0025] Steady-state cross-flow shear refers to the shearing action generated when fluid flows parallel to the membrane surface of the tubular ceramic membrane module under steady-state flow conditions. This shearing action can scour the membrane surface and slow down the deposition of pollutants. Dynamic floc layer thickness refers to the thickness of the dynamic floc layer accumulated on the membrane surface of the tubular ceramic membrane module. This thickness needs to be maintained within a preset range during filtration to ensure stable filtration performance. Secondary permeate is the liquid that passes through the pores of the tubular ceramic membrane module after filtration. Final concentrate is the liquid that does not permeate the tubular ceramic membrane module but flows along the membrane surface and is eventually discharged; its concentration is higher than that of the circulating feed.

[0026] Step 50: The primary permeate and secondary permeate are subjected to multi-stage series filtration to obtain purified reclaimed water, and the final concentrate is discharged as waste concentrate.

[0027] Optionally, the primary and secondary permeate solutions can be subjected to multi-stage series filtration. Multi-stage series filtration refers to connecting multiple filtration units in series, allowing the liquid to flow through each filtration unit sequentially to gradually remove residual contaminants from the liquid. Although most solid particles and colloidal substances have been removed from the primary and secondary permeate solutions, they still contain small amounts of fine particles, dissolved organic matter, and surfactants, requiring further purification through multi-stage series filtration to meet the reuse standards for industrial cleaning wastewater. For example, the multi-stage series filtration in [example description] includes three filtration units. The first-stage filtration unit uses an ultrafiltration membrane module with a pore size of 100 nanometers to remove fine particles and large organic molecules from the primary and secondary permeate solutions; the second-stage filtration unit uses a nanofiltration membrane module with a pore size of 10 nanometers to remove dissolved organic matter and surfactants from the liquid after the first-stage filtration; and the third-stage filtration unit uses a reverse osmosis membrane module with a pore size of 1 nanometer to remove dissolved salts and small organic molecules from the liquid after the second-stage filtration. The primary and secondary permeate flows sequentially through the first, second, and third filtration units to obtain purified reclaimed water.

[0028] The waste liquid purification device discharges the final concentrated liquid as waste concentrate, which is enriched with most of the pollutants from the industrial cleaning waste liquid.

[0029] The embodiments of the present invention realize the controllable reconstruction and efficient removal of the fouling layer on the membrane surface, thereby improving the stability of industrial cleaning wastewater purification and reuse and the water purification quality.

[0030] Optionally, the processes of steps 101 to 104 include: Step 101: Start the feed pump, control the frequency of the variable frequency drive to 20-25Hz, drive the mixture of industrial cleaning waste liquid and inorganic flocculant into the tubular ceramic membrane module, and control the electric regulating valve to be fully open, so that the mixture forms a low shear force circulating flow field with an axial flow velocity of 0.5-1m / s in the membrane tube.

[0031] Optionally, the feed pump provides initial power to the mixture of industrial cleaning wastewater and inorganic flocculant, while a variable frequency drive controls the output frequency of the feed pump within the range of 20 to 25 Hz to achieve precise adjustment of the feed pump speed. Within this frequency range, the feed pump operates at a lower speed, resulting in a relatively small output flow rate of the mixture. The wastewater purification device simultaneously controls the electric regulating valve to be fully open (100% opening), allowing the mixture to enter the tubular ceramic membrane module with minimal resistance. Due to the low feed pump speed and the fully open electric regulating valve, the axial velocity of the mixture within the membrane tube of the tubular ceramic membrane module is low, maintained between 0.5 and 1 m / s. This axial velocity range results in low fluid shear force, creating a low-shear circulating flow field.

[0032] Under the action of a low-shear-force circulating flow field, the inorganic flocculant in the mixture comes into full contact with the suspended particles and colloidal substances in the industrial cleaning wastewater and begins to undergo a flocculation reaction, forming tiny floc particles. Due to the low shear force, the floc particles are not destroyed and can gradually grow and circulate with the mixture in the membrane tube, creating conditions for the uniform adsorption of flocs on the membrane surface.

[0033] For example, taking industrial cleaning wastewater generated in a semiconductor processing workshop as an example, the feed pump in the wastewater purification device is a centrifugal pump with a rated flow rate of 50 cubic meters per hour and a rated power of 15 kilowatts. The frequency converter driver uses a vector control type frequency converter, which can accurately control the output frequency of the feed pump within the range of 20 to 25 Hz. The electric regulating valve is a pneumatic butterfly valve with a diameter of 100 mm and a maximum working pressure of 1.6 MPa. After the feed pump of the wastewater purification device is started, the output frequency of the frequency converter driver is set to 22 Hz, and the electric regulating valve is controlled to be fully open. At this time, the mixture of industrial cleaning wastewater and polyaluminum chloride circulates in the membrane tube of the tubular ceramic membrane module at an axial flow velocity of 0.8 m / s, forming a low shear force circulating flow field. The polyaluminum chloride in the mixture reacts with the suspended particles in the industrial cleaning wastewater to form tiny flocculent particles with a particle size of 50 to 100 micrometers.

[0034] Step 102: Monitor the turbidity change rate of the online turbidity meter. When the turbidity change rate is below 0.5 NTU / min for 300 consecutive seconds, linearly increase the feed pump frequency to 45-50 Hz within 10-30 seconds to raise the axial flow velocity inside the membrane tube to a high shear force flow field of 2.5-3.5 m / s. The high shear force flow field is used to suppress the disordered accumulation of large particles, so that the flocs are uniformly adsorbed on the inner wall of the tubular ceramic membrane module to form a primary adsorption layer.

[0035] Optionally, the turbidity value of the circulating feed liquid is monitored in real time using an online turbidity meter, and the turbidity change rate is calculated. The turbidity change rate refers to the change in turbidity value per unit time, reflecting the rate of floc formation and aggregation in the circulating feed liquid. When the online turbidity meter detects a turbidity change rate below 0.5 NTU per minute for 300 consecutive seconds, it indicates that the floc formation and aggregation process in the circulating feed liquid has stabilized, and the size and distribution of floc particles have reached a relative equilibrium. Under these conditions, the waste liquid purification device linearly increases the output frequency of the feed pump within a time range of 10 to 30 seconds, that is, uniformly increasing the output frequency of the frequency converter from 20 to 25 Hz to 45 to 50 Hz. As the feed pump frequency increases, the feed pump speed increases accordingly, the output flow rate of the mixed liquid increases, and the axial velocity in the membrane tube increases from 0.5 to 1 m / s to 2.5 to 3.5 m / s. The fluid shear force formed in this axial velocity range increases, belonging to a high-shear flow field. Under the influence of a high-shear flow field, larger floc particles in the mixture are dispersed due to the strong shear force, inhibiting the disorderly accumulation of large particles. Simultaneously, smaller floc particles, carried by the high-shear flow field, are uniformly adsorbed onto the inner surface of the tubular ceramic membrane module, forming a primary adsorption layer. This primary adsorption layer is a thin layer structure formed by the initial adsorption of floc particles on the membrane surface.

[0036] For example, the online turbidity meter in the system uses the principle of light scattering to measure turbidity, with a measurement range of 0 NTU to 1000 NTU and a measurement accuracy of ±0.1 NTU. After the waste liquid purification device is started, the online turbidity meter monitors the turbidity value of the circulating feed liquid in real time. When the online turbidity meter detects that the turbidity change rate is below 0.5 NTU per minute for 300 consecutive seconds, the output frequency of the frequency converter driver is linearly increased from 22 Hz to 48 Hz within 20 seconds. As the feed pump frequency increases, the axial flow velocity in the membrane tube increases from 0.8 m / s to 3 m / s, forming a high shear force flow field. Under the action of the high shear force flow field, large particle flocs with a particle size greater than 150 micrometers in the mixture are dispersed, and small particle flocs with a particle size of 50 to 100 micrometers are uniformly adsorbed on the inner wall surface of the tubular ceramic membrane module, forming a primary adsorption layer with a thickness of 0.1 to 0.2 mm.

[0037] Step 103: Control the electric regulating valve to reduce its opening from 100% to 30-40% within 5-8 seconds, thereby increasing the transmembrane pressure difference to 0.2-0.3 MPa and maintaining the transmembrane pressure difference at a constant level for 30-60 seconds. This densifies the flocs inside the primary adsorption layer, forming a high-density rigid support core.

[0038] Optionally, after the primary adsorption layer is formed, the electric regulating valve is rapidly reduced in opening within a time range of 5 to 8 seconds, that is, the opening of the electric regulating valve is uniformly reduced from 100% to 30% to 40%. As the opening of the electric regulating valve decreases, the resistance of the mixed liquid through the electric regulating valve increases, resulting in an increase in liquid pressure inside the tubular ceramic membrane module, and the transmembrane pressure difference correspondingly increases to 0.2 to 0.3 MPa. After the transmembrane pressure difference reaches 0.2 to 0.3 MPa, the waste liquid purification device maintains this transmembrane pressure difference constant for 30 to 60 seconds. Under this constant transmembrane pressure difference, the flocs inside the primary adsorption layer are subjected to continuous pressure, the gaps between floc particles gradually decrease, and the floc structure gradually becomes denser. At the same time, the transmembrane pressure difference drives some liquid to pass through the membrane pores of the tubular ceramic membrane module, forming the primary permeate, while the floc particles are retained on the membrane surface. As the primary permeate continues to be produced, the flocs inside the primary adsorption layer become further densified under the combined action of pressure and liquid permeation force, forming a high-density rigid support core. This high-density rigid support core is a hard structure formed by the densified floc particles, which can provide stable support for the dynamic floc layer and prevent it from collapsing or deforming under the action of fluid shear force.

[0039] For example, after the primary adsorption layer is formed, the electrically controlled regulating valve is reduced from 100% opening to 35% opening within 6 seconds. As the valve opening decreases, the liquid pressure inside the tubular ceramic membrane module increases, and the transmembrane pressure difference rises from the initial 0.05 MPa to 0.25 MPa. The wastewater purification device maintains a constant transmembrane pressure difference of 0.25 MPa for 45 seconds. During this process, the flocs inside the primary adsorption layer gradually densify under the combined action of pressure and liquid permeation force, forming a high-density rigid support core with a thickness of 0.05 to 0.1 mm. The porosity of the high-density rigid support core is 20% to 30%, and its compressive strength can withstand pressures of over 0.5 MPa without deformation. Simultaneously, the wastewater purification device separates the primary permeate, which has a turbidity of 5 NTU and a total solids content of 0.1%.

[0040] Step 104: Construct a dynamic floc layer based on a high-density rigid support core to separate the primary permeate and the circulating feed liquid.

[0041] Optionally, a dynamic floc layer is constructed based on a high-density rigid support core to separate the primary permeate and the circulating feed liquid, as described in steps 1041 to 1044.

[0042] This invention relates to a dynamic floc layer constructed based on a high-density rigid support core. This allows the flocs to form a filter layer with a gradient structure on the membrane surface. Specifically, the inner side is a dense, high-density rigid support core, while the outer side is a relatively loose dynamic floc layer. This gradient structure can effectively trap pollutants in industrial cleaning wastewater and maintain a high permeability. At the same time, the presence of the dynamic floc layer can protect the membrane pores of the tubular ceramic membrane module from direct fouling, delay the flux decline caused by membrane fouling, and improve the stability of industrial cleaning wastewater purification and reuse, as well as the water purification quality.

[0043] Optionally, the process of steps 1041 to 1044 includes: Step 1041: Control the electric regulating valve to increase the opening from 30-40% to 80-90% within 3-5 seconds, so that the transmembrane pressure difference drops back to 0.05-0.1MPa. Maintain the feed pump frequency at 45-50Hz. Utilize the reverse diffusion of pore water caused by the sudden drop in pressure difference to cause the outer flocs to expand and form an outer loose layer with a compressive stress gradient.

[0044] Optionally, after forming the high-density rigid support core, the waste liquid purification device controls the electric regulating valve to rapidly increase its opening within a time range of 3 to 5 seconds, that is, to uniformly increase the opening of the electric regulating valve from 30% to 40% to 80% to 90%. As the opening of the electric regulating valve increases, the resistance of the mixed liquid through the electric regulating valve decreases, the liquid pressure inside the tubular ceramic membrane module decreases, and the transmembrane pressure difference correspondingly drops from the highest working pressure in step 103 to 0.05 to 0.1 MPa. During this process, the waste liquid purification device keeps the output frequency of the feed pump constant within the range of 45 to 50 Hz, that is, the speed and output flow of the feed pump remain stable, and the axial flow velocity in the membrane tube remains in the high shear force flow field state formed in step 102.

[0045] When the transmembrane pressure difference drops sharply, the pressure inside the membrane pores of the tubular ceramic membrane module is higher than the pressure on the membrane surface. Driven by the pressure difference, the liquid inside the membrane pores flows in the opposite direction to the membrane surface, forming a phenomenon called pore water back diffusion. The reverse water flow generated by the back diffusion impacts the flocs outside the high-density rigid support core, causing the flocs to absorb water and expand in volume, increasing the gaps between the floc particles and making the structure looser. Due to the sudden drop in transmembrane pressure difference, a pressure distribution that gradually decreases from the inside to the outside is formed on the membrane surface. During the expansion process, the outer flocs form a compressive stress gradient with gradually decreasing compressive stress from the inside to the outside. That is, the compressive stress is higher on the side closer to the high-density rigid support core and lower on the side farther away from the high-density rigid support core, ultimately forming an outer loose layer with a compressive stress gradient.

[0046] For example, after step 103 is completed, the electric regulating valve is at 35% opening, the transmembrane pressure difference is 0.25 MPa, the feed pump frequency is 48 Hz, and the axial flow velocity in the membrane tube is 3 m / s. The waste liquid purification device controls the electric regulating valve to increase from 35% opening to 85% opening within 4 seconds, the transmembrane pressure difference drops from 0.25 MPa to 0.08 MPa, the feed pump frequency remains unchanged at 48 Hz, and the axial flow velocity in the membrane tube remains at 3 m / s.

[0047] A sudden drop in transmembrane pressure causes the liquid inside the membrane pores of the tubular ceramic membrane module to diffuse back towards the membrane surface at a velocity of 0.02 m / s. This back-diffusion of pore water impacts the flocs outside the high-density rigid support core, causing the flocs to expand in volume and the interparticle spacing to increase from 10 μm to 30 μm, forming a loose outer layer with a thickness of 0.3 to 0.5 mm. The compressive stress of this loose outer layer gradually decreases from 0.08 MPa near the high-density rigid support core to 0.02 MPa further away.

[0048] Step 1042: Linearly adjust the opening of the electric regulating valve within 60-120 seconds to increase the transmembrane pressure difference to 0.15-0.25 MPa, and calculate the flux change rate in real time based on the instantaneous permeate flux of the flow meter.

[0049] Optionally, after the outer loose layer is formed, the opening of the electric regulating valve is linearly adjusted within a time range of 60 to 120 seconds, that is, the opening of the electric regulating valve is uniformly reduced from 80% to 90% to the preset target opening, so that the transmembrane pressure difference is gradually increased from 0.05 to 0.1 MPa to 0.15 to 0.25 MPa. As the opening of the electric regulating valve decreases linearly, the resistance of the mixed liquid through the electric regulating valve increases linearly, the liquid pressure inside the tubular ceramic membrane module increases linearly, and the transmembrane pressure difference increases linearly accordingly. During the linear increase of the transmembrane pressure difference, the waste liquid purification device monitors the permeate flow rate produced by the tubular ceramic membrane module in real time through a flow meter, and calculates the instantaneous permeate flux based on the effective membrane area of ​​the tubular ceramic membrane module. The instantaneous permeate flux refers to the volume of permeate passing through a unit membrane area per unit time, reflecting the filtration performance of the tubular ceramic membrane module under the current transmembrane pressure difference. The waste liquid purification device calculates the flux change rate based on the instantaneous through-flux at two adjacent sampling times. The flux change rate is calculated as follows: subtract the instantaneous through-flux at the previous sampling time from the current sampling time to obtain the flux difference; then divide the flux difference by the time interval between the two sampling times to obtain the flux change per unit time, which is the flux change rate. The flux change rate reflects the trend of instantaneous through-flux change over time and is used to determine whether the construction of the dynamic floc layer tends to stabilize.

[0050] For example, after the outer loose layer forms, the opening of the electrically controlled regulating valve is linearly reduced from 85% to 45% within 90 seconds, and the transmembrane pressure difference is linearly increased from 0.08 MPa to 0.2 MPa. During this process, the waste liquid purification device monitors the permeate flow rate in real time through an electromagnetic flowmeter installed on the permeate pipeline. The electromagnetic flowmeter has a measurement accuracy of ±0.5% and a sampling interval of 10 seconds. The instantaneous permeate flux is calculated based on the effective membrane area of ​​the tubular ceramic membrane module, which is 10 square meters. At the 10th second, the permeate flow rate is 0.5 cubic meters per hour, and the instantaneous permeate flux is 50 liters per square meter per hour; at the 20th second, the permeate flow rate is 0.55 cubic meters per hour, and the instantaneous permeate flux is 55 liters per square meter per hour. To calculate the flux change rate, subtract 50 liters per square meter per hour from 55 liters per square meter per hour to obtain a flux difference of 5 liters per square meter per hour. Then, divide 5 liters per square meter per hour by 10 minutes to obtain a flux change rate of 0.5 liters per square meter per hour per minute. Continue to calculate the flux change rate for each sampling interval in the above manner.

[0051] Step 1043, when the flux change rate is below 0.5 L / (m³) for 180 consecutive seconds 2 When the temperature reaches ·h·min), the high-density rigid support core and the outer loose layer covering the high-density rigid support core form a dynamic flocculent layer.

[0052] Optionally, during the continuous calculation of the flux change rate in step 1042, it is determined in real time whether the flux change rate is below 0.5 liters per square meter per hour per minute for 180 consecutive seconds. When the flux change rate is below 0.5 liters per square meter per hour per minute for 180 consecutive seconds, it indicates that the change in instantaneous permeate flux is very small, and the filtration performance of the tubular ceramic membrane module tends to be stable. This indicates that the high-density rigid support core and the outer loose layer covering it have reached a dynamic equilibrium state under the combined action of transmembrane pressure difference and fluid shear force. In the dynamic equilibrium state, the flocs on the surface of the outer loose layer are continuously washed away and detached under the action of fluid shear force. At the same time, the flocs in the circulating feed liquid continuously migrate to the membrane surface and are adsorbed and replenished under the drive of transmembrane pressure difference. The detachment rate and replenishment rate of the flocs are basically equal, and the thickness and structure of the outer loose layer remain relatively stable. At this point, the high-density rigid support core, as a dense rigid support structure, provides stable mechanical support for the outer loose layer, preventing it from collapsing under fluid shear force. The outer loose layer, as a loose filter layer with a compressive stress gradient, effectively traps suspended particles and colloidal substances in the circulating feed while maintaining a high permeability. Together, the high-density rigid support core and the outer loose layer constitute a dynamic floc layer with a gradient structure. This dynamic floc layer is in a dynamic equilibrium state during filtration, enabling it to continuously and stably perform its filtration function.

[0053] For example, during the continuous monitoring of flux change rate in step 1042, it was found that after the transmembrane pressure difference stabilized at 0.2 MPa, the flux change rate gradually decreased. At 120 seconds, the flux change rate was 0.8 L / m² / h / min; at 150 seconds, it was 0.6 L / m² / h / min; and at 180 seconds, it was 0.4 L / m² / h / min. Starting from 180 seconds, the waste liquid purification device continuously monitored the flux change rate and found that the flux change rate remained between 0.3 L / m² / h / min and 0.4 L / m² / h / min for 180 consecutive seconds, all below the threshold of 0.5 L / m² / h / min. The waste liquid purification device determined that the high-density rigid support core and the outer loose layer covering it had reached a dynamic equilibrium state, forming a dynamic floc layer. The total thickness of the dynamic floc layer is 0.5 to 0.7 mm, of which the thickness of the high-density rigid support core is 0.05 to 0.1 mm and the thickness of the outer loose layer is 0.4 to 0.6 mm, and the instantaneous permeability is stable at 60 liters per square meter per hour.

[0054] Step 1044: Based on the dynamic floc layer, the feed liquid is continuously separated for 5-10 minutes. When the turbidity of the permeate is less than 1 NTU and the flow pressure difference of the feed liquid fluctuates less than ±0.01 MPa, the primary permeate and the circulating feed liquid are obtained.

[0055] Optionally, after the formation of the dynamic floc layer, the circulating feed liquid is continuously separated based on the dynamic floc layer for 5 to 10 minutes. During this continuous separation process, driven by the transmembrane pressure difference, some of the circulating feed liquid passes through the membrane pores of the dynamic floc layer and the tubular ceramic membrane module to form permeate, while the liquid that does not pass through flows along the membrane surface and circulates back. The turbidity of the permeate is monitored in real time using an online turbidity meter. When the turbidity of the permeate is below 1 NTU, it indicates that the membrane pores of the dynamic floc layer and the tubular ceramic membrane module have a good retention effect on suspended particles and colloidal substances in the circulating feed liquid, and the water quality of the permeate meets the preset standard. At the same time, the pressure difference between the inlet and outlet of the tubular ceramic membrane module, i.e., the flow pressure difference, is monitored in real time using a pressure sensor, and the flow pressure difference fluctuation is calculated. The flow pressure difference fluctuation refers to the change in the flow pressure difference during the continuous separation process, reflecting the stability of the dynamic floc layer during the filtration process. When the flow pressure difference fluctuation is less than ±0.01 MPa, it indicates that the thickness and structure of the dynamic floc layer remain stable, with no obvious floc shedding or accumulation, and the filtration performance of the tubular ceramic membrane module is stable. Under the conditions that the turbidity of the permeate is less than 1 NTU and the flow pressure difference fluctuation is less than ±0.01 MPa, the waste liquid purification device collects the permeate as the primary permeate and uses the liquid flowing along the membrane surface and circulating back as the circulating feed liquid to complete the filtration and separation process in step 10.

[0056] For example, after the formation of the dynamic floc layer, the circulating feed liquid is continuously separated based on the dynamic floc layer for 8 minutes. During this process, the turbidity of the permeate is monitored in real time using an online turbidimeter with a measurement accuracy of ±0.1 NTU. At the 2nd minute, the turbidity of the permeate is 1.2 NTU; at the 4th minute, it is 0.9 NTU; at the 6th minute, it is 0.7 NTU; and at the 8th minute, it is 0.6 NTU. The turbidity of the permeate remains below 1 NTU from the 4th minute onwards. The waste liquid purification device simultaneously monitors the flow pressure difference in real time using pressure sensors installed at the inlet and outlet of the tubular ceramic membrane module, with a measurement accuracy of ±0.001 MPa. During the 8 minutes of continuous separation, the flow pressure difference fluctuates between 0.18 and 0.2 MPa, with a fluctuation of ±0.01 MPa, which is less than the threshold of ±0.01 MPa. The waste liquid purification device determines that the permeate water quality meets the standards and the dynamic floc layer is stable. The permeate is collected as the primary permeate, with a total output of 8 cubic meters, a turbidity of 0.6 NTU, and a total solids content of 0.05%. The liquid flowing along the membrane surface and circulating back is used as the circulating feed liquid, with a volume of 42 cubic meters.

[0057] The dynamic floc layer formed in this embodiment of the invention has a gradient structure from the inside to the outside. The inner side is a dense, high-density rigid support core that provides mechanical support, while the outer side is a loose filter layer with a compressive stress gradient that effectively intercepts pollutants and maintains high water permeability. This gradient structure of the dynamic floc layer delays the flux decay caused by membrane fouling and improves the stability of industrial cleaning wastewater purification and reuse and the water purification quality.

[0058] Optionally, the processes of steps 201 to 204 include: Step 201: Control the feed cut-off electric ball valve to close, and control the bypass pressure relief electric ball valve to open fully, so that the liquid side pressure of the tubular ceramic membrane module drops to 0.02-0.05MPa within 1-3 seconds.

[0059] Optionally, the control system issues a command to rapidly close the feed shut-off electric ball valve, thereby cutting off the physical channel for the feed pump to deliver circulating liquid to the tubular ceramic membrane module and stopping the continuous input of high-pressure liquid. Simultaneously, the waste liquid purification device controls the bypass pressure relief electric ball valve to open fully, directly connecting the liquid side of the tubular ceramic membrane module to the low-pressure relief pipeline. Because the bypass pressure relief electric ball valve is fully open, the flow area is at its maximum, and the high-pressure circulating liquid on the liquid side is rapidly discharged through the bypass pressure relief pipeline under the drive of the pressure difference. This causes the pressure on the liquid side of the tubular ceramic membrane module to rapidly drop to 0.02 to 0.05 MPa within a very short time of 1 to 3 seconds, achieving rapid pressure relief on the liquid side.

[0060] For example, the feed shut-off electric ball valve with a control orifice diameter of 100 mm is fully closed within 0.5 seconds, while the bypass pressure relief electric ball valve with a control orifice diameter of 100 mm is fully open within 0.5 seconds. The feed side pressure of the tubular ceramic membrane module drops from 0.2 MPa at the end of step 104 to 0.03 MPa within 2 seconds.

[0061] Step 202: After detecting that the feed liquid side pressure drops to 0.02-0.05MPa, control the back pressure linkage regulating valve to throttle synchronously, so that the permeate side pressure of the tubular ceramic membrane module drops to 0.01-0.04MPa, and control the feed liquid side pressure to be greater than or equal to the permeate side pressure, so that the transmembrane pressure difference approaches 0MPa.

[0062] Optionally, the feed liquid side pressure is monitored in real time by a pressure sensor. When the feed liquid side pressure drops to 0.02 to 0.05 MPa, the back pressure linkage regulating valve installed on the permeate side pipeline is controlled to synchronously perform a throttling operation. The back pressure linkage regulating valve increases the fluid resistance of the permeate discharge by reducing the valve opening. As the back pressure linkage regulating valve throttles, the liquid discharge on the permeate side is obstructed, but because the feed liquid side pressure has been significantly reduced, the permeate side pressure also decreases to 0.01 to 0.04 MPa. During this adjustment process, the waste liquid purification device compares the values ​​of the feed liquid side pressure and the permeate side pressure in real time and dynamically fine-tunes the opening of the back pressure linkage regulating valve to ensure that the feed liquid side pressure is always greater than or equal to the permeate side pressure, so as to prevent the permeate from flowing back to the feed liquid side under the reverse action of the pressure difference and contaminating the membrane pores. Through the above synchronous adjustment, the difference between the feed liquid side pressure and the permeate side pressure, i.e., the transmembrane pressure difference, gradually decreases and approaches 0 MPa, thereby completely cutting off the transmembrane driving force for the driving fluid to pass through the membrane pores.

[0063] For example, after a pressure sensor with an accuracy of ±0.001 MPa detects that the feed liquid side pressure has dropped to 0.03 MPa, the back pressure linkage regulating valve is controlled to reduce its opening from 100% to 20% within 1 second for synchronous throttling. The permeate side pressure of the tubular ceramic membrane module drops from 0.05 MPa to 0.02 MPa. The waste liquid purification device controls the feed liquid side pressure (0.03 MPa) to always be greater than the permeate side pressure (0.02 MPa), causing the transmembrane pressure difference to decrease from 0.15 MPa to 0.01 MPa, approaching 0 MPa.

[0064] Step 203: Maintain the transmembrane pressure difference at 0 MPa for 5-10 seconds to allow the dynamic floc layer to rehydrate and swell under no compressive load, increasing its thickness by 10% to 25%.

[0065] Optionally, after the transmembrane pressure difference approaches 0 MPa, this state without transmembrane driving force is maintained for 5 to 10 seconds. Since the transmembrane pressure difference is 0 MPa, the dynamic floc layer is no longer subjected to transmembrane compressive loads directed towards the membrane pores. In this state without compressive load, the floc particles in the dynamic floc layer, due to their hydrophilic groups and porous network structure, begin to absorb a large amount of water from the surrounding circulating feed, undergoing rehydration and swelling. Rehydration and swelling causes the polymer chains inside the floc particles to extend, significantly expanding the volume of the floc particles and increasing the gaps between them, resulting in an increase in the overall macroscopic thickness of the dynamic floc layer of 10% to 25%. For example, at the end of step 104, the initial total thickness of the dynamic floc layer is 0.6 mm. The state of maintaining a transmembrane pressure difference of 0 MPa is maintained for 8 seconds. During these 8 seconds, the floc particles in the dynamic floc layer absorb water and undergo rehydration and swelling, increasing the thickness of the dynamic floc layer from 0.6 mm to 0.72 mm, an increase of 20%.

[0066] Step 204: Based on the cracks generated by shear stress, the circulating liquid penetrates into the cracks to form a flaked liquid.

[0067] Optionally, based on the cracks generated by shear stress, the circulating liquid is driven to penetrate into the cracks to form a flaked liquid, as in steps 2041 to 2044.

[0068] The loose, cracked liquid structure formed in the embodiments of the present invention reduces the hydrodynamic energy required for eddy current stripping and improves the removal efficiency of the fouling layer on the membrane surface, thereby ensuring the long-term stable operation of the industrial cleaning wastewater purification and reuse system and the water purification quality.

[0069] Optionally, the process of steps 2041 to 2044 includes: Step 2041: Maintain the transmembrane pressure difference at 0 MPa. Utilize the fixed constraint on the bottom of the floc and the free boundary at the top of the tubular ceramic membrane to generate a non-uniform displacement increasing from bottom to top within the dynamic floc layer, forming shear stress on the surface of the dynamic floc layer.

[0070] Optionally, when the transmembrane pressure difference is 0 MPa, the dynamic floc layer is no longer subjected to compressive load perpendicular to the membrane surface. The bottom of the dynamic floc layer is in direct contact with the inner surface of the tubular ceramic membrane, and is subject to physical friction and intermolecular adsorption on the inner surface of the tubular ceramic membrane, forming a fixed constraint, which greatly restricts the displacement of the bottom floc particles. However, the top of the dynamic floc layer is in direct contact with the circulating feed liquid, which is a free boundary. Under the influence of the expansion force generated by the rehydration swelling in step 203 and the weak fluid disturbance, the top floc particles can undergo relatively free displacement. This difference in boundary conditions, with the bottom constrained and the top free, results in a gradient distribution of displacement from bottom to top during the expansion and stress process of the dynamic floc layer, i.e., a non-uniform displacement increasing from bottom to top. This non-uniform displacement leads to relative sliding and slippage between adjacent layers within the dynamic floc layer, thereby accumulating shear stress on the surface of the dynamic floc layer. Shear stress refers to the internal force parallel to the cross-section generated due to uneven deformation within an object.

[0071] For example, the transmembrane pressure difference is maintained at 0 MPa. The total thickness of the dynamic floc layer is 0.72 mm. Its bottom is in close contact with the inner surface of the tubular ceramic membrane, with a displacement of 0 mm; its top is a free boundary, and the displacement reaches 0.05 mm under swelling. Non-uniform displacement increasing from bottom to top is generated inside the dynamic floc layer, and a shear stress of 15 Pa is formed on the surface of the dynamic floc layer.

[0072] Step 2042: Maintain the transmembrane pressure difference at 0 MPa, causing the surface of the dynamic floc layer to undergo physical fracture due to shear stress exceeding the bonding force threshold, resulting in network cracks with a depth of 0.1-0.3 mm.

[0073] Optionally, the transmembrane pressure difference is maintained at 0 MPa, allowing shear stress to continuously accumulate on the surface of the dynamic floc layer. The binding force threshold refers to the maximum intermolecular force and mechanical interlocking force that maintains the structural integrity of floc particles in the dynamic floc layer without relative slippage. When the shear stress on the surface layer continuously increases and exceeds this binding force threshold, the bonds between floc particles are broken, the floc structure loses stability, and physical fracture occurs. Due to the non-uniform distribution of shear stress on the surface layer and the anisotropy of the floc structure itself, physical fracture does not occur along a single plane, but rather propagates intersectingly along multiple directions of stress concentration, thus generating an interwoven network of cracks on the surface of the dynamic floc layer. The depth of the network cracks is controlled between 0.1 and 0.3 mm. This depth range is sufficient to destroy the dense structure of the surface layer without penetrating the entire dynamic floc layer, thereby ensuring the integrity of the bottom floc layer.

[0074] For example, when the transmembrane pressure difference is maintained at 0 MPa, the shear stress on the surface of the dynamic floc layer gradually accumulates from 15 Pascals to 25 Pascals, exceeding the binding force threshold of 20 Pascals for the floc material. Physical fracture occurs between the floc particles, resulting in a network of cracks with a depth of 0.2 mm and an average crack width of 0.05 mm on the surface of the dynamic floc layer.

[0075] Step 2043: After the formation of network cracks is detected, the circulating pump is controlled to run at a linear flow rate of 0.5-1 m / s, so that the linear flow rate of the circulating liquid in the tubular ceramic membrane module is maintained at 0.5-1 m / s, and the liquid side pressure is maintained at 0.02-0.05 MPa, driving the circulating liquid to penetrate into the interior of the network cracks.

[0076] Optionally, after the formation of network cracks is detected by sensors, the circulation pump is started or adjusted. The circulation pump provides fluid power to the system, and its output is controlled to maintain the linear flow velocity of the circulating feed liquid within the tubular ceramic membrane module at 0.5 to 1 m / s. This linear flow velocity range falls within a low-shear crossflow state, providing sufficient fluid kinetic energy to force the circulating feed liquid into the cracks while preventing excessively high velocities from causing the entire floc layer to be washed away and peeled off. Simultaneously, the control system maintains the feed liquid side pressure at 0.02 to 0.05 MPa, providing a stable hydrostatic driving force for the circulating feed liquid. Under the combined action of fluid dynamic pressure and hydrostatic pressure, the circulating feed liquid is forced into the network cracks with a depth of 0.1 to 0.3 mm. After the circulating feed liquid penetrates the cracks, it not only hydrates the flocs on both sides of the cracks but also produces a fluid wedging effect, further weakening the binding force between the floc particles deep within the cracks.

[0077] For example, after a visual sensor detects the formation of a network crack with a depth of 0.2 mm, the circulation pump is controlled to maintain the linear flow velocity of the circulating liquid within the tubular ceramic membrane module at 0.8 m / s and the liquid-side pressure at 0.03 MPa. Driven by dynamic and static pressure, the circulating liquid fully penetrates into the 0.2 mm deep network crack, reaching a penetration depth of 0.18 mm.

[0078] Step 2044: Maintain the circulating pump at a linear flow rate of 0.5-1 m / s to flush the material, causing the weakened loose flocs to detach and suspend from the cracks, while retaining the main body attachment layer with network cracks, forming a loosened liquid.

[0079] Optionally, after the circulating feed solution penetrates into the network cracks, the circulating pump continues to flush the membrane surface at a linear flow rate of 0.5 to 1 m / s. As the circulating feed solution flows through the edges and surface of the network cracks, local micro-eddies and shear forces are generated due to the abrupt change in the flow channel cross-section. The flocs located on the surface of the dynamic floc layer and at the crack edges, due to the physical fracture caused by shear stress in the early stage and the weakening effect of hydration and wedging after the circulating feed solution penetrates, have become extremely loose in structure, becoming weakened, loose floc fragments. These loose floc fragments cannot resist the local shear forces generated by the fluid flushing, thus detaching from the cracks and suspending in the circulating feed solution. Simultaneously, the main body of the bottom of the dynamic floc layer, due to the strong constraint of the inner surface of the tubular ceramic membrane and the absence of crack penetration damage, remains firmly attached to the membrane surface, forming a main attachment layer with network cracks. The main attachment layer refers to the floc structure at the bottom of the dynamic floc layer that is not damaged by crack penetration and remains on the membrane surface due to strong constraint. The loose, detached flocculent debris, together with the main adhering layer with network cracks, constitutes the disintegrated liquid, realizing the structural disintegration and controlled peeling preparation of the contamination layer.

[0080] For example, the circulating pump maintains a linear flow rate of 0.8 m / s to flush the membrane surface. The local shear force generated by the fluid flushing causes a 0.05 mm thick layer of weakened, loose flocculent debris to detach from the cracks and suspend in the circulating feed solution, with a suspended debris concentration of 50 mg / L. Simultaneously, a 0.67 mm thick main adhesion layer with a 0.2 mm deep network of cracks remains on the membrane surface, ultimately forming a disintegrated feed solution.

[0081] The embodiments of the present invention ultimately form a loosely structured, easily detached liquid material that is easy to peel off by subsequent eddy currents, which reduces the overall bonding strength of the fouling layer on the membrane surface, thereby improving the stability of industrial cleaning wastewater purification and reuse and the water purification quality.

[0082] Optionally, the processes of steps 401 to 403 include: Step 401: After detecting that the inner surface of the tubular ceramic membrane module is in a peeled state, the floc addition pump is started to inject inorganic flocculant solution into the main stream of circulating liquid, so that the floc concentration in the circulating liquid is maintained at 50mg / L to 100mg / L, and the circulating pump is controlled to increase the linear velocity of the circulating liquid in the tubular ceramic membrane module to 2.0-3.0m / s, and a steady-state cross-flow shear environment is established.

[0083] Optionally, if a sensor detects that the inner surface of the tubular ceramic membrane module is in a post-stripping state (a membrane surface state where the amount of residual flocs on the membrane surface is significantly reduced after the Dean vortex stripping action), the floc addition pump (a pump used to accurately meter and deliver chemical agents to the system) is started to inject an inorganic flocculant solution (a liquid agent with a specific concentration prepared by dissolving inorganic flocculants in water) into the main stream of the circulating feed liquid, maintaining the floc concentration in the circulating feed liquid at 50 to 100 mg / L. The purpose of replenishing the inorganic flocculant solution is to regenerate a sufficient amount of micro-flocs in the circulating feed liquid to compensate for the floc loss caused by stripping in step 30.

[0084] The waste liquid purification device simultaneously controls the operation of the circulating pump (a power device used to drive the circulating feed liquid to circulate within the system), adjusting its output frequency or valve opening to increase the linear velocity of the circulating feed liquid within the tubular ceramic membrane module (the average velocity of fluid flowing axially within a pipe or membrane tube) to 2 to 3 meters per second. This establishes a steady-state cross-flow shear environment (a shear environment generated when fluid flows parallel to the membrane surface of the tubular ceramic membrane module under steady-state flow conditions; this shearing action can scour the membrane surface and slow down the deposition of pollutants). Under this steady-state cross-flow shear environment, the supplemented flocs can be evenly distributed with the mainstream, preventing excessive accumulation of flocs on the membrane surface.

[0085] For example, after the turbidity sensor detects that the inner surface of the tubular ceramic membrane module is in a delamination state, the metering pump is started as a flocculant injection pump to inject a 10% (w / w) polyaluminum chloride solution as an inorganic flocculant solution into the main stream of the circulating feed liquid, maintaining the floc concentration in the circulating feed liquid at 80 mg / L. Simultaneously, the waste liquid purification device controls the centrifugal pump to operate as a circulation pump, and adjusts the frequency converter to increase the linear velocity of the circulating feed liquid within the tubular ceramic membrane module to 2.5 m / s, establishing a steady-state cross-flow shear environment.

[0086] Step 402: Maintain a linear flow rate of 2.0-3.0 m / s for 30-60 seconds to drive the selective deposition of flocs on the inner surface of the tubular ceramic membrane, forming a new dynamic floc layer with a thickness of 10-50 μm.

[0087] Optionally, the wastewater purification device maintains a linear flow velocity of 2 to 3 meters per second for 30 to 60 seconds. Under the steady-state cross-flow shearing action generated by this linear flow velocity, the flocs in the circulating feed liquid are selectively deposited as they migrate towards the membrane surface of the tubular ceramic membrane module due to the filtering effect of fluid shear force (referring to the phenomenon that, under the combined action of fluid shear force and transmembrane pressure difference, smaller, denser flocs preferentially deposit on the membrane surface, while larger, looser flocs are carried away by fluid shear force). Due to the high surface energy and permeability of the membrane surface after peeling, the flocs can quickly attach to and grow on its surface. As the deposition process proceeds, the wastewater purification device controls the transmembrane pressure difference to drive some liquid through the membrane pores, causing the deposited flocs to gradually compact, ultimately forming a new dynamic floc layer with a thickness of 1 to 50 micrometers (the floc accumulation layer reconstructed in step 40 and in a dynamic equilibrium state under the action of fluid shear force). This thickness range ensures effective retention of minute contaminants in the circulating feed solution while maintaining a high water flux, avoiding excessive mass transfer resistance due to excessive thickness, thus enabling controllable reconstruction of the fouling layer on the membrane surface.

[0088] For example, the linear flow rate is maintained at 2.5 m / s for 45 seconds. During this process, flocs in the circulating feed solution selectively deposit on the inner surface of the tubular ceramic membrane module. Dense flocs smaller than 20 micrometers are preferentially deposited, while loose flocs larger than 20 micrometers are carried away by the fluid. The waste liquid purification device controls the transmembrane pressure difference at 0.15 MPa, driving some liquid to permeate through the membrane pores, gradually compacting the deposited flocs, and ultimately forming a new dynamic floc layer with a thickness of 30 micrometers.

[0089] Step 403: Separate the secondary permeate and the final concentrate based on the new dynamic floc layer.

[0090] Optionally, the secondary permeate and the final concentrate are separated based on the new dynamic floc layer, as described in steps 4031 to 1033.

[0091] The embodiments of the present invention maintain the optimal thickness and filtration performance of the dynamic floc layer through dynamic replenishment and selective deposition mechanisms, thereby improving the stability of industrial cleaning wastewater purification and reuse and the continuity of water purification quality.

[0092] Optionally, the processes of steps 4031 to 1033 include: Step 4031: Control the feed regulating valve to open, add new industrial cleaning waste liquid to the inlet of the tubular ceramic membrane module, and control the circulation pump to maintain a linear flow rate of 2.0-3.0 m / s, so that the new industrial cleaning waste liquid mixes with the circulating feed liquid and flows through the surface of the new dynamic floc layer.

[0093] Optionally, the feed regulating valve is opened to allow new industrial cleaning wastewater to continuously enter the system and mix with the existing circulating feed liquid to replenish the volume of the separated permeate and maintain the material balance within the system. Simultaneously, the wastewater purification device controls the operation of the circulating pump, adjusting its output frequency or valve opening to maintain a stable linear velocity of 2 to 3 meters per second within the tubular ceramic membrane module. At this velocity, the mixture forms a stable cross-flow field within the tubular ceramic membrane module and flows at high speed across the surface of the new dynamic floc layer. As the mixture flows across the surface of the new dynamic floc layer, the shear force generated by the fluid continuously flushes the surface, preventing excessive deposition and compaction of contaminants. This also provides stable hydrodynamic conditions for subsequent transmembrane filtration, ensuring the continuity and stability of the filtration process.

[0094] For example, the pneumatic butterfly valve is controlled to open as a feed regulating valve to replenish the tubular ceramic membrane module with a new industrial cleaning waste liquid with a flow rate of 5 cubic meters per hour. The centrifugal pump is controlled as a circulation pump to maintain a linear flow velocity of 2.5 meters per second, so that the new industrial cleaning waste liquid is mixed with the circulating feed liquid and flows through the surface of a new dynamic floc layer with a thickness of 30 micrometers.

[0095] Step 4032: Control the opening of the back pressure regulating valve to stabilize the feed liquid side pressure of the tubular ceramic membrane module at 0.3-0.5MPa and the permeate side pressure at 0.1-0.2MPa, thereby establishing a stable transmembrane pressure difference of 0.2-0.3MPa.

[0096] Optionally, by adjusting the opening of the back pressure regulating valve, the fluid resistance of the permeate discharge is changed, thereby precisely controlling the permeate-side pressure to stabilize it within the range of 0.1 to 0.2 MPa. Simultaneously, the wastewater purification device stabilizes the feed liquid-side pressure within the range of 0.3 to 0.5 MPa through system piping and pump control. By stabilizing the feed liquid-side pressure and the permeate-side pressure respectively, the wastewater purification device establishes a stable transmembrane pressure difference of 0.2 to 0.3 MPa. This stable transmembrane pressure difference provides a continuous and constant driving force for water molecules and small molecule solutes to permeate through the membrane pores, effectively preventing the destruction of the new dynamic floc layer structure or mechanical blockage of the tubular ceramic membrane pores due to drastic pressure difference fluctuations, thus ensuring the long-term stability of the permeate flux.

[0097] For example, by controlling the back pressure regulating valve opening to 40%, the feed liquid side pressure of the tubular ceramic membrane module is stabilized at 0.4 MPa, the permeate liquid side pressure is stabilized at 0.15 MPa, and a stable transmembrane pressure difference of 0.25 MPa is established.

[0098] Step 4033: Under the action of steady-state transmembrane pressure difference, water molecules and small molecule solutes pass through the new dynamic floc layer and the tubular ceramic membrane pores and are discharged from the permeate outlet to form secondary permeate. The large molecule pollutants and suspended solids intercepted by the new dynamic floc layer are transported forward with the mainstream and returned to the circulating feed tank through the circulation pipeline, so that the concentration of pollutants in the circulating feed gradually increases to form the final concentrate.

[0099] Optionally, driven by the steady-state transmembrane pressure difference, water molecules and small-molecule solutes in the mixture overcome mass transfer resistance and sequentially pass through the pores of the new dynamic floc layer and the membrane pores of the tubular ceramic membrane module, exiting from the permeate outlet to form secondary permeate. Large-molecule pollutants and suspended solids, due to their larger size than the pore size of the new dynamic floc layer and membrane pores, are physically trapped on the surface of the new dynamic floc layer. Under the shearing action of the cross-flowing fluid, the trapped pollutants cannot form a dense filter cake layer on the membrane surface, but are instead transported forward with the main flow and returned to the feed tank through the circulation pipeline. As the filtration process continues, water in the feed tank is continuously discharged from the system as secondary permeate, causing the mass of large-molecule pollutants and suspended solids in the feed tank to conserve mass and decrease in volume, thus gradually increasing the pollutant concentration in the feed, ultimately forming a high-concentration final concentrate.

[0100] For example, under a steady-state transmembrane pressure difference of 0.25 MPa, water molecules and small molecule solutes permeate through a new dynamic floc layer with a thickness of 30 micrometers and tubular ceramic membrane pores, and are discharged from the permeate outlet to form a secondary permeate with a turbidity of 0.5 NTU. The macromolecular pollutants and suspended solids trapped by the new dynamic floc layer are transported forward with the mainstream and returned to the circulating feed tank with a volume of 50 cubic meters through the circulation pipeline, so that the total solids concentration in the circulating feed gradually increases from 2% to 8%, forming the final concentrate.

[0101] The embodiments of the present invention realize the controllable reconstruction and efficient removal of the fouling layer on the membrane surface, thereby improving the stability of industrial cleaning wastewater purification and reuse and the water purification quality.

[0102] Furthermore, the industrial cleaning waste liquid recycling, purification and reuse device provided by the present invention will be described below. The industrial cleaning waste liquid recycling, purification and reuse device described below can be referred to in correspondence with the industrial cleaning waste liquid recycling, purification and reuse method described above.

[0103] Optionally, refer to Figure 2 , Figure 2 This is a structural diagram of the industrial cleaning wastewater recycling, purification, and reuse device provided by the present invention. The industrial cleaning wastewater recycling, purification, and reuse device includes: The gradient differential pressure filtration unit 210 is used to introduce industrial cleaning wastewater and inorganic flocculant into a tubular ceramic membrane module, and to separate the primary permeate and the circulating feed liquid by using a gradient increase in transmembrane differential pressure filtration. The endpoint of the gradient increase is the maximum operating pressure.

[0104] The low-pressure pulse disintegration unit 220 is used to apply low-pressure pulses to the circulating feed liquid, reduce the transmembrane pressure difference from the highest working pressure to the positive low-pressure zone, cut off the transmembrane driving force, and use the elastic recovery force of the dynamic floc layer to make the floc volume expand and generate cracks, forming a disintegrated feed liquid.

[0105] The vortex floc stripping unit 230 is used to drive the disintegrated liquid to flow through the static spiral guide element. The vortex generated by the fluid entrains and removes the surface flocs with cracks from the membrane surface, forming the stripped membrane surface and stripping liquid.

[0106] The cross-flow circulation separation unit 240 is used to replenish flocs to the stripped membrane surface under steady-state cross-flow shearing action to maintain the dynamic floc layer thickness, transport the stripping liquid forward with the mainstream, and separate the secondary permeate and the final concentrate.

[0107] The filtrate multi-stage purification unit 250 is used to perform multi-stage series filtration of the primary and secondary permeate to obtain purified reclaimed water, and discharge the final concentrate as waste concentrate.

[0108] The embodiments of the present invention improve the stability of industrial cleaning wastewater purification and reuse, as well as the water purification quality.

[0109] Please see Figure 3 , Figure 3 An embodiment diagram of an electronic device provided in accordance with the present invention. For example... Figure 3 As shown, an embodiment of the present invention provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor 320. When the processor 320 executes the computer program 311, it implements the processes of steps 10 to 50.

[0110] Please see Figure 4 , Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with an embodiment of the present invention is shown. Figure 4 As shown, this embodiment provides a computer-readable storage medium 400 on which a computer program 311 is stored. When the computer program 311 is executed by a processor, it implements the processes of steps 10 to 50.

[0111] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the industrial cleaning waste liquid recycling, purification and reuse method provided by the above methods, which includes steps 10 to 50.

[0112] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0113] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for recycling, purifying, and reusing industrial cleaning wastewater, characterized in that, A tubular ceramic membrane module with a built-in static helical flow guiding element; the method includes: Industrial cleaning wastewater and inorganic flocculant are introduced into a tubular ceramic membrane module, and transmembrane pressure differential filtration is performed using a gradient increase to separate the primary permeate and the circulating feed liquid; the endpoint of the gradient increase is the maximum working pressure. Apply a low-pressure pulse to the circulating feed liquid to reduce the transmembrane pressure difference from the highest working pressure to the positive low-pressure zone, cut off the transmembrane driving force, and use the elastic recovery force of the dynamic floc layer to make the floc volume expand and generate cracks, forming a dissipated feed liquid. The disintegrating liquid is driven to flow through the static spiral guide element, and the Dean vortex generated by the fluid is used to entrain and detach the surface flocs with cracks from the membrane surface, forming the stripped membrane surface and stripping liquid. Under steady-state cross-flow shearing, flocs are added to the stripped membrane surface to maintain the dynamic floc layer thickness, and the stripping liquid is transported forward with the mainstream to separate the secondary permeate and the final concentrate. The primary and secondary permeates are subjected to multi-stage series filtration to obtain purified reclaimed water, and the final concentrate is discharged as waste concentrate.

2. The method for recycling, purifying, and reusing industrial cleaning wastewater according to claim 1, characterized in that, The process of separating the primary permeate and the circulating feed liquid includes: Start the feed pump, control the frequency converter to output frequency of 20-25Hz, drive the mixture of industrial cleaning waste liquid and inorganic flocculant into the tubular ceramic membrane module, control the electric regulating valve to be fully open, so that the mixture forms a low shear force circulating flow field with an axial flow velocity of 0.5-1m / s in the membrane tube; Monitor the turbidity change rate of the online turbidity meter. When the turbidity change rate is below 0.5 NTU / min for 300 consecutive seconds, linearly increase the feed pump frequency to 45-50 Hz within 10-30 seconds to raise the axial flow velocity inside the membrane tube to a high shear force flow field of 2.5-3.5 m / s. Use the high shear force flow field to suppress the disordered accumulation of large particles, so that the flocs are uniformly adsorbed on the inner wall of the tubular ceramic membrane module to form a primary adsorption layer. The electric regulating valve is controlled to decrease from 100% opening to 30-40% opening within 5-8 seconds, so that the transmembrane pressure difference is increased to 0.2-0.3MPa. The transmembrane pressure difference is maintained at a constant level for 30-60 seconds, which makes the flocs inside the primary adsorption layer denser and forms a high-density rigid support core. A dynamic floc layer is constructed based on the high-density rigid support core to separate the primary permeate and the circulating feed liquid.

3. The method for recycling, purifying, and reusing industrial cleaning wastewater according to claim 2, characterized in that, The process of constructing a dynamic floc layer based on the high-density rigid support core to separate the primary permeate and the circulating feed liquid includes: The electric regulating valve is controlled to increase from 30-40% opening to 80-90% opening within 3-5 seconds, so that the transmembrane pressure difference drops back to 0.05-0.1MPa. The feed pump frequency is kept at 45-50Hz. The reverse diffusion of pore water caused by the sudden drop in pressure difference causes the outer flocs to expand, forming an outer loose layer with a compressive stress gradient. The opening of the electric regulating valve is linearly adjusted within 60-120 seconds to increase the transmembrane pressure difference to 0.15-0.25 MPa, and the flux change rate is calculated in real time based on the instantaneous permeate flux of the flow meter. When the flux change rate is below 0.5 L / (m³) for 180 consecutive seconds 2 At hmin), the high-density rigid support core and the outer loose layer covering the high-density rigid support core form a dynamic flocculent layer; Based on the dynamic floc layer, the feed liquid is continuously separated for 5-10 minutes. When the turbidity of the permeate is less than 1 NTU and the flow pressure difference fluctuation of the feed liquid is less than ±0.01 MPa, the primary permeate and the circulating feed liquid are obtained.

4. The method for recycling, purifying, and reusing industrial cleaning wastewater according to claim 1, characterized in that, The process of forming the disintegrated liquid includes: Control the feed cut-off electric ball valve to close, and control the bypass pressure relief electric ball valve to open fully, so that the liquid pressure on the feed side of the tubular ceramic membrane module drops to 0.02-0.05MPa within 1-3 seconds; After detecting that the feed liquid side pressure drops to 0.02-0.05MPa, the back pressure linkage regulating valve is controlled to throttle synchronously, so that the permeate side pressure of the tubular ceramic membrane module drops to 0.01-0.04MPa, and the feed liquid side pressure is controlled to be greater than or equal to the permeate side pressure, so that the transmembrane pressure difference approaches 0MPa. Maintaining a transmembrane pressure difference of 0 MPa for 5-10 seconds allows the dynamic floc layer to rehydrate and swell under no compressive load, increasing its thickness by 10% to 25%. Based on the cracks generated by shear stress, the circulating liquid penetrates into the cracks, forming a dissipated liquid state.

5. The method for recycling, purifying, and reusing industrial cleaning wastewater according to claim 4, characterized in that, Based on the cracks caused by shear stress, the circulating feed liquid penetrates into the crack interior, forming a dissipated feed liquid, including: Maintaining a transmembrane pressure difference of 0 MPa, the inner surface of the tubular ceramic membrane provides fixed constraints on the bottom of the flocs and a free boundary at the top, causing a non-uniform displacement that increases from bottom to top within the dynamic floc layer, resulting in shear stress on the surface of the dynamic floc layer. Maintaining a transmembrane pressure difference of 0 MPa causes the surface of the dynamic floc layer to undergo physical fracture due to shear stress exceeding the bonding force threshold, resulting in network cracks with a depth of 0.1-0.3 mm. After the formation of network cracks is detected, the circulating pump is controlled to run at a linear flow rate of 0.5-1 m / s, so that the linear flow rate of the circulating liquid in the tubular ceramic membrane module is maintained at 0.5-1 m / s, and the liquid side pressure is maintained at 0.02-0.05 MPa, driving the circulating liquid to penetrate into the interior of the network cracks. Maintain the circulating pump at a linear flow rate of 0.5-1 m / s to flush the material, causing the weakened loose flocs to detach and suspend from the cracks, while retaining the main body with network cracks to form a loosened liquid.

6. The method for recycling, purifying, and reusing industrial cleaning wastewater according to claim 1, characterized in that, The process of separating the secondary permeate and the final concentrate includes: When the inner surface of the tubular ceramic membrane module is detected to be in a peeled state, the floc addition pump is started to inject inorganic flocculant solution into the main stream of circulating liquid, so that the floc concentration in the circulating liquid is maintained at 50mg / L to 100mg / L, and the circulating pump is controlled to increase the linear velocity of the circulating liquid in the tubular ceramic membrane module to 2.0-3.0m / s, and establish a steady-state cross-flow shear environment. Maintaining a linear flow rate of 2.0-3.0 m / s for 30-60 seconds drives the selective deposition of flocs on the inner surface of the tubular ceramic membrane, forming a new dynamic floc layer with a thickness of 10-50 μm. The secondary permeate and final concentrate are separated based on the new dynamic floc layer.

7. The method for recycling, purifying, and reusing industrial cleaning wastewater according to claim 6, characterized in that, The separation of secondary permeate and final concentrate based on the new dynamic floc layer includes: The feed regulating valve is opened to replenish the tubular ceramic membrane module with new industrial cleaning waste liquid. The circulating pump is controlled to maintain a linear flow rate of 2.0-3.0 m / s, so that the new industrial cleaning waste liquid is mixed with the circulating feed liquid and flows through the surface of the new dynamic floc layer. Control the opening of the back pressure regulating valve to stabilize the feed liquid side pressure of the tubular ceramic membrane module at 0.3-0.5MPa and the permeate side pressure at 0.1-0.2MPa, thereby establishing a stable transmembrane pressure difference of 0.2-0.3MPa. Under the action of steady-state transmembrane pressure difference, water molecules and small molecule solutes pass through the new dynamic floc layer and tubular ceramic membrane pores and are discharged from the permeate outlet to form secondary permeate. Large molecule pollutants and suspended solids trapped by the new dynamic floc layer are transported forward with the mainstream and returned to the circulating feed tank through the circulation pipeline, so that the concentration of pollutants in the circulating feed gradually increases, forming the final concentrate.

8. An industrial cleaning wastewater recycling and purification device, characterized in that, A tubular ceramic membrane module with a built-in static spiral flow guiding element, used to realize the industrial cleaning wastewater recycling and reuse method as described in any one of claims 1 to 7; the device includes: The gradient differential pressure filtration unit is used to introduce industrial cleaning waste liquid and inorganic flocculant into a tubular ceramic membrane module, and use the gradient increase to perform transmembrane differential pressure filtration to separate the primary permeate and the circulating feed liquid; the endpoint of the gradient increase is the maximum working pressure. The low-pressure pulse disintegration unit is used to apply low-pressure pulses to the circulating feed liquid, reduce the transmembrane pressure difference from the highest working pressure to the positive low-pressure zone, cut off the transmembrane driving force, and use the elastic recovery force of the dynamic floc layer to make the floc volume expand and generate cracks, forming a disintegrated feed liquid. The vortex floc stripping unit is used to drive the disintegrated liquid to flow through the static spiral guide element. The Dean vortex generated by the fluid will entrain and remove the surface flocs with cracks from the membrane surface, forming the stripped membrane surface and stripping liquid. The cross-flow circulation separation unit is used to replenish flocs to the stripped membrane surface under steady-state cross-flow shearing action to maintain the dynamic floc layer thickness, transport the stripping liquid forward with the mainstream, and separate the secondary permeate and the final concentrate. The filtrate multi-stage purification unit is used to perform multi-stage series filtration of the primary permeate and the secondary permeate to obtain purified reclaimed water, and to discharge the final concentrate as waste concentrate.

9. An electronic device, comprising: A memory for storing a computer program; a processor for reading and executing the computer program, characterized in that, when the processor executes the computer program, it implements the industrial cleaning waste liquid recycling, purification, and reuse method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the industrial cleaning waste liquid recycling, purification and reuse method as described in any one of claims 1 to 7.

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