Membrane element aging on-line detection method

Abstract

The invention discloses a membrane element aging on-line detection method. The method comprises the following steps: S1, pre-replenishing water to a constant-temperature water tank; s2, performing constant-temperature and uniform mixing on the detection liquid; s3, weighing and metering; s4, cleaning the weighing container: starting a cleaning assembly to move a suction pipe downwards into the weighing container, starting a self-priming pump to pump filtrate in the weighing container through the suction pipe to a water pan to be discharged, and cleaning the interior of the weighing container by using the cleaning assembly to prevent residues from affecting the weighing operation; and S5, performing periodic cycle test and data acquisition. After weighing is completed, the weighing container is cleaned, crystallization and wall-hanging pollution of residual filtrate on the inner wall of the container can be avoided, concentration deviation caused by mixing of the residual filtrate and subsequent filtrate is prevented, corrosion or interference of the residual medium to the weight sensor is eradicated, the initial state of weighing and metering each time is ensured to be consistent, and the weighing accuracy is improved. Core detection parameters such as flow conversion data and cumulative flow statistics truly reflect the permeability of the membrane element, and accurate data support is provided for aging evaluation.

Description

Technical Field

[0001] This invention belongs to the field of membrane element testing technology, and particularly relates to an online detection method for membrane element aging. Background Technology

[0002] As a core separation component in water treatment, chemical separation, biomedicine, and food processing, filtration membrane elements rely on membrane structures with different pore sizes to achieve solid-liquid, liquid-liquid, or ion-level separation. They are key components for media purification, impurity removal, and water purification. During long-term operation, filtration membrane elements can become clogged due to physical fouling caused by suspended solids and colloids in the raw water medium, chemically degraded by acids, alkalis, and oxidants, and biofouling due to microbial growth. Simultaneously, aging issues such as membrane pore structure wear and delamination occur over time, ultimately manifesting as decreased filtration flux, reduced separation and retention capacity, and abnormal fluctuations in operating pressure.

[0003] When using online detection methods to test the aging degree of membrane elements, the weight of the permeate water is measured by weighing, and the aging degree of the membrane element is calculated based on parameters such as the permeate flow rate and the conductivity of the medium. However, the weighing container is generally not equipped with a dedicated cleaning component. After a single measurement, the test liquid remaining on the inner wall of the container will be directly included in the next measurement data, forming a systematic measurement error. Moreover, the error will continue to accumulate with the cycle of testing, causing distortion of core test data such as filtration flux and separation performance, thereby affecting the test results of membrane element aging. Summary of the Invention

[0004] To address the problems in the prior art, the present invention proposes the following technical solution: The online aging detection method for membrane elements includes the following steps: S1. Pre-filling of constant temperature water tank: After injecting pure water into the buffer solution tank, add concentrated solution according to the test ratio to prepare the test solution. Then, the water replenishment pump pumps the test solution in the buffer solution tank into the constant temperature water tank. S2. Temperature control and mixing of the test solution: Stop when the liquid level reaches the set level. Start the temperature control host to exchange heat with the test solution in the temperature control water tank. Then open the second solenoid valve. The constant pressure pump delivers the temperature-controlled test solution to the inlet of the filter membrane element of multiple test stations. Water molecules pass through the membrane pores to form filtrate and flow out from the product water end of the filter membrane. The concentrate that does not pass through is discharged from the concentrate end of the filter membrane. The touch screen displays the test solution pressure, concentrate pressure, flow rate, conductivity and temperature parameters of each test station in real time. S3. Weighing and Metering: The filtered liquid is guided to the weighing container by the diversion funnel. The weighing timer is started, and the weighing module collects the weight of the water in the weighing container in real time. It is automatically converted into flow data through a preset formula. At the same time, the real-time flow and cumulative flow data of the test liquid and the filtrate are collected simultaneously. After the timer ends, the single measurement is completed and the data is uploaded to the control system. Then the second solenoid valve is closed and the first solenoid valve is opened. The filtrate flows back to the constant temperature water tank for the next weighing operation. S4. Weighing container cleaning: Activate the cleaning component to lower the suction tube into the weighing container, activate the self-priming pump to extract the filtrate from the weighing container through the suction tube to the water collection tray for discharge, and use the cleaning component to clean the inside of the weighing container to avoid residue affecting the weighing operation. S5. Cyclic Test and Data Acquisition: The system continuously collects data by repeating steps S3 to S4 according to the set cycle. During the test, pressure, flow rate, conductivity, and temperature parameters are monitored in real time. If the flow rate / conductivity exceeds the set range, the system triggers an alarm to indicate aging or abnormal status.

[0005] As a preferred embodiment of the above technical solution, it also includes: S6, system shutdown and cleanup: triggering a shutdown command on the touch screen to sequentially shut down the constant pressure pump, constant temperature host, and buffer solution tank replenishment pump, and clean the system pipeline as needed.

[0006] As a preferred embodiment of the above technical solution, step S5 further includes data storage and export: the system periodically and automatically saves all test data, and during or after the test, the data can be exported as a table or graph via a touch screen for analysis and evaluation of the aging performance of the filter membrane.

[0007] As a preferred embodiment of the above technical solution, step S2 further includes pre-drainage before testing: the cylinder pushes the hose to move to one side of the diversion funnel, guides the filtrate to the water receiving tray to remove any possible residues, and after the pre-drainage is completed, the cylinder drives the hose to reset so that it switches to the position of diversion funnel guiding the weighing container.

[0008] As a preferred embodiment of the above technical solution, the cleaning assembly includes a rinsing pipe, a mounting frame, and a conversion component. The mounting frame reciprocates vertically. One end of the rinsing pipe is mounted on the mounting frame, and the other end of the rinsing pipe is connected to an external distilled water supply device. The conversion component includes a plug tube and a replacement tube, which are located at the upper and lower ends of the suction tube, respectively. A sleeve tube fixedly connected to the mounting frame is fitted onto the outer surface of the plug tube. An air blowing pipe and a water suction pipe are respectively provided on both sides of the sleeve tube. The air blowing pipe is connected to an external air blowing device, and the water suction pipe is connected to a self-priming pump. After the self-priming pump draws the filtrate from the weighing container through the suction pipe, the external distilled water supply device flushes distilled water into the weighing container through the flushing pipe. After the self-priming pump draws the filtrate from the container multiple times and washes it with distilled water, the residual filtrate is removed. Then, the external air blowing device blows air into the suction pipe through the air blowing pipe, and the inside of the weighing container is quickly dried by the rotation of the replacement cylinder.

[0009] As a preferred embodiment of the above technical solution, a first sealing plug is provided at the bottom of the replacement cylinder. One end of the first sealing plug gradually decreases in size towards the bottom of the sleeve cylinder. Multiple through holes are provided circumferentially on the outer side of the replacement cylinder. A second sealing plug is provided inside the through holes. The second sealing plug gradually decreases in size towards the center of the sleeve cylinder. A spring is provided between the first sealing plug and the second sealing plug and the replacement cylinder. When the self-priming pump draws liquid from the weighing container, the second sealing plug closes and the first sealing plug opens to perform the drawing operation. When the external air blowing device is working, the first sealing plug closes and the second sealing plug opens, allowing airflow to pass through the multiple through holes for air drying.

[0010] As a preferred embodiment of the above technical solution, the end of the through hole is inclined, and the inclined center line of the through hole is tangent to the outer surface of the replacement cylinder. When the airflow passes through, the suction tube drives the insertion cylinder to rotate inside the sleeve cylinder.

[0011] As a preferred embodiment of the above technical solution, the first and second sealing plugs are made of fluororubber. When the external blowing device introduces compressed air of 0.4-0.8MPa into the blowing pipe, the second sealing plug overcomes the spring force and moves to the outside of the replacement cylinder, the through hole is fully opened, the airflow velocity through the through hole is 15-25m / s, and the drying time is 20-40 seconds.

[0012] The beneficial effects of this invention are: 1. Cleaning the weighing container after weighing can prevent residual filtrate from crystallizing and adhering to the inner wall of the container, thus preventing concentration shifts caused by mixing with subsequent filtrate and eliminating corrosion or interference of residual media with the weight sensor. This ensures that the initial state of each weighing is consistent, allowing core detection parameters such as flow conversion data and cumulative flow statistics to accurately reflect the permeation performance of the membrane element, providing accurate data support for aging assessment. Furthermore, it reduces the corrosion of the container material caused by long-term residual filtrate adhesion, thereby reducing equipment maintenance frequency and replacement costs. 2. Distilled water is sprayed out through the rinsing tube at a specific pressure to break down the adsorption force between the residual liquid and the container wall, thoroughly removing trace contaminants that are invisible to the naked eye. Meanwhile, the airflow is sprayed out through multiple through holes in the replacement tube to quickly remove residual water, preventing concentration shifts caused by water mixing with subsequent filtrate. This ensures that the initial state of each weighing is absolutely clean, minimizing the error rate of core data such as flow conversion and cumulative flow statistics, and providing reliable data support for the accurate assessment of membrane element aging. 3. Because the center line of the through hole, which is set at the end, is tangent to the outer surface of the replacement tube, the airflow leaves the through hole and generates thrust, which drives the straw and the insertion tube to rotate. The resulting rotating airflow can evenly cover areas that are difficult to reach by traditional unidirectional airflow, such as the corners of the container and the gaps in the inner wall, ensuring that there is no residual medium or moisture on the inner wall of the container. At the same time, due to the efficient coverage of the rotating airflow, drying can be completed in only 20-40 seconds, which greatly shortens the cleaning cycle and avoids affecting the continuity of online detection due to excessive cleaning time. Attached Figure Description

[0013] Figure 1 The diagram shown is a schematic representation of the overall structure of the embodiment; Figure 2 The diagram shown is a front sectional view of the converter in the embodiment; Figure 3 The diagram shown is a top sectional view of the alternative cylinder in the embodiment.

[0014] In the diagram: 11. Constant temperature water tank; 12. First solenoid valve; 13. Second solenoid valve; 14. Cylinder; 15. Hoses; 16. Diverting funnel; 17. Weighing module; 18. Weighing container; 19. Water receiving tray; 20. Self-priming pump; 21. Filter membrane element; 30. Flushing pipe; 40. Mounting bracket; 51. Connecting sleeve; 52. Socket sleeve; 521. Air blowing pipe; 522. Water suction pipe; 53. Replacement sleeve; 54. First sealing plug; 55. Second sealing plug; 56. Through hole; 57. Spring; 60. Suction tube. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings.

[0016] Figure 1 The online aging detection method for membrane elements includes the following steps: S1. Pre-filling of constant temperature water tank 11: After injecting pure water into the buffer solution preparation tank, add concentrated solution according to the test ratio to prepare the test solution. Then, the water replenishment pump pumps the test solution in the buffer solution preparation tank into the constant temperature water tank 11. S2. Temperature control and mixing of the test solution: Stop when the liquid level reaches the set level. Start the temperature control host to exchange heat with the test solution in the temperature control water tank 11. Then open the second solenoid valve 13. The constant pressure pump delivers the temperature-controlled test solution to the inlet of the filter membrane element 21 of multiple test stations. Water molecules pass through the membrane pores to form filtrate and flow out from the water production end of the filter membrane. The concentrated water that does not pass through is discharged from the concentrated water end of the filter membrane. The touch screen displays the test solution pressure, concentrated water pressure, flow rate, conductivity and temperature parameters of each test station in real time. S3. Weighing and Metering: The filtered test liquid is guided into the weighing container 18 by the diversion funnel 16. The weighing timer is started, and the weighing module 17 collects the weight of the water in the weighing container 18 in real time. The weight is automatically converted into flow data by a preset formula. At the same time, the real-time flow and cumulative flow data of the test liquid and the filtrate are collected simultaneously. After the timer ends, the single measurement is completed and the data is uploaded to the control system. Then the second solenoid valve 13 is closed and the first solenoid valve 12 is opened. The filtrate flows back to the constant temperature water tank 11 to prepare for the next weighing operation. S4. Cleaning the weighing container 18: Start the cleaning assembly and move the suction tube 60 into the weighing container 18. Start the self-priming pump 20 to draw out the filtrate in the weighing container 18 through the suction tube 60 and discharge it into the water receiving tray 19. Use the cleaning assembly to clean the inside of the weighing container 18 to avoid residue affecting the weighing operation. S5. Cyclic Test and Data Acquisition: The system continuously collects data by repeating steps S3 to S4 according to the set cycle. During the test, pressure, flow rate, conductivity, and temperature parameters are monitored in real time. If the flow rate / conductivity exceeds the set range, the system triggers an alarm to indicate aging or abnormal status.

[0017] It also includes: S6, system shutdown and cleanup: triggering a shutdown command on the touch screen will sequentially shut down the constant pressure pump, constant temperature host, buffer solution tank replenishment pump, and clean the system pipeline as needed.

[0018] The S5 step also includes data storage and export: the system periodically and automatically saves all test data. During or after the test, the data can be exported as a table or graph via the touch screen for analysis and evaluation of the aging performance of the filter membrane.

[0019] The S2 step also includes pre-drainage before testing: cylinder 14 pushes hose 15 to move to one side of diversion funnel 16, guides the filtrate to water receiving tray 19 to remove any possible residue. After the pre-drainage is completed, cylinder 14 drives hose 15 to reset so that it switches to the position of diversion funnel 16 guiding the weighing container 18.

[0020] After weighing, the weighing container 18 is cleaned to prevent residual filtrate from crystallizing and adhering to the inner wall of the container, thus preventing concentration shifts caused by mixing with subsequent filtrate and eliminating corrosion or interference from residual media to the weight sensor. This ensures that the initial state of each weighing is consistent, allowing core detection parameters such as flow conversion data and cumulative flow statistics to accurately reflect the permeation performance of the membrane element, providing precise data support for aging assessment. Furthermore, it reduces the corrosion of the container material caused by long-term residual filtrate adhesion, thereby reducing equipment maintenance frequency and replacement costs.

[0021] Figures 1-3 In the process, the cleaning assembly includes a rinsing pipe 30, a mounting frame 40, and a conversion component. The mounting frame 40 reciprocates vertically. One end of the rinsing pipe 30 is mounted on the mounting frame 40, and the other end of the rinsing pipe 30 is connected to an external distilled water supply device. The conversion component includes a plug tube 51 and a replacement tube 53. The plug tube 51 and the replacement tube 53 are located at the upper and lower ends of the suction tube 60, respectively. A sleeve tube 52, which is fixedly connected to the mounting frame 40, is sleeved on the outer surface of the plug tube 51. An air blowing pipe 521 and a water suction pipe 522 are respectively provided on both sides of the sleeve tube 52. The air blowing pipe 521 is connected to an external air blowing device, and the water suction pipe 522 is connected to a self-priming pump 20. After the self-priming pump 20 draws the filtrate from the weighing container 18 through the suction pipe 60, the external distilled water supply device flushes distilled water into the weighing container 18 through the flushing pipe 30. After the self-priming pump 20 draws the filtrate from the container multiple times and washes it with distilled water, the residual filtrate inside is removed. Then, the external air blowing device blows air into the suction pipe 60 through the air blowing pipe 521. The air is then quickly dried inside the weighing container 18 by the direction of the replacement cylinder 53.

[0022] The bottom of the replacement cylinder 53 is provided with a first sealing plug 54, one end of which gradually decreases in size towards the bottom of the sleeve cylinder 52. Multiple through holes 56 are provided circumferentially on the outer side of the replacement cylinder 53. A second sealing plug 55 is provided inside the through holes 56, and the second sealing plug 55 gradually decreases in size towards the center of the sleeve cylinder 52. A spring 57 is provided between the first sealing plug 54 and the second sealing plug 55 and the replacement cylinder 53. When the self-priming pump 20 draws liquid from the weighing container 18, the second sealing plug 55 closes and the first sealing plug 54 opens to perform the drawing operation. When the external air blowing device is working, the first sealing plug 54 closes and the second sealing plug 55 opens to allow airflow to pass through the multiple through holes 56 for the drying operation.

[0023] Distilled water is sprayed directionally through the rinsing pipe 30, using specific pressure to break down the adsorption force between the residual liquid and the container wall, thoroughly removing trace contaminants invisible to the naked eye. Meanwhile, airflow is sprayed through multiple through holes 56 in the replacement cylinder 53, quickly carrying away residual moisture and preventing concentration shifts caused by the mixing of moisture with subsequent filtrate. This ensures that the initial state of each weighing is absolutely clean, minimizing the error rate of core data such as flow conversion and cumulative flow statistics, and providing reliable data support for the accurate assessment of membrane element aging.

[0024] The end of the through hole 56 is inclined, and the inclined center line of the through hole 56 is tangent to the outer surface of the replacement cylinder 53. When the airflow passes through, the suction tube 60 drives the insertion cylinder 51 to rotate inside the sleeve cylinder 52.

[0025] The first sealing plug 54 and the second sealing plug 55 are made of fluororubber. When the external blowing device introduces compressed air of 0.4-0.8MPa into the blowing pipe 521, the second sealing plug 55 overcomes the elastic force of the spring 57 and moves to the outside of the replacement cylinder 53, the through hole 56 is fully opened, the airflow velocity ejected through the through hole 56 is 15-25m / s, and the drying time is 20-40 seconds.

[0026] Because the center line of the through hole 56, which is inclined at the end, is tangent to the outer surface of the replacement tube 53, the airflow leaves the position of the through hole 56 and generates thrust, thereby driving the straw 60 and the insertion tube 51 to rotate. The resulting rotating airflow can evenly cover areas that are difficult to reach by traditional unidirectional airflow, such as the corners of the container and the gaps in the inner wall, ensuring that there is no residual medium or moisture on the inner wall of the container. At the same time, due to the efficient coverage of the rotating airflow, drying can be completed in only 20-40 seconds, which greatly shortens the cleaning cycle and avoids affecting the continuity of online detection due to excessive cleaning time.

[0027] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. An online aging detection method for membrane elements, characterized in that, Includes the following steps: S1. Pre-filling water in constant temperature water tank (11): After injecting pure water into the buffer solution tank, add concentrated solution according to the test ratio to prepare the test solution. Then, the water replenishment pump pumps the test solution in the buffer solution tank into the constant temperature water tank (11). S2. Constant temperature and mixing of test liquid: Stop when the liquid level reaches the set level. Start the constant temperature host to exchange heat with the test liquid in the constant temperature water tank (11). Then open the second solenoid valve (13). The constant pressure pump delivers the constant temperature test liquid to the inlet of the filter membrane element (21) of multiple test stations. Water molecules pass through the membrane pores to form filtrate and flow out from the water production end of the filter membrane. The concentrated water that does not pass through is discharged from the concentrated water end of the filter membrane. The touch screen displays the test liquid pressure, concentrated water pressure, flow rate, conductivity and temperature parameters of each test station in real time. S3, Weighing and Metering: The filtered test liquid is guided into the weighing container (18) by the diversion funnel (16), and the weighing timer is started. The weighing module (17) collects the weight of the water in the weighing container (18) in real time and automatically converts it into flow data through a preset formula. At the same time, the real-time flow and cumulative flow data of the test liquid and the filtrate are collected simultaneously. After the timer ends, the single measurement is completed and the data is uploaded to the control system. Then the second solenoid valve (13) is closed and the first solenoid valve (12) is opened. The filtrate flows back to the constant temperature water tank (11) for the next weighing operation. S4. Cleaning the weighing container (18): Start the cleaning assembly and move the suction tube (60) down into the weighing container (18). Start the self-priming pump (20) to draw out the filtrate in the weighing container (18) through the suction tube (60) and discharge it into the water tray (19). Use the cleaning assembly to clean the inside of the weighing container (18) to avoid residue affecting the weighing operation. S5. Cyclic Test and Data Acquisition: The system continuously collects data by repeating steps S3 to S4 according to the set cycle. During the test, pressure, flow rate, conductivity, and temperature parameters are monitored in real time. If the flow rate / conductivity exceeds the set range, the system triggers an alarm to indicate aging or abnormal status.

2. The online aging detection method for membrane elements according to claim 1, characterized in that, Also includes: S6. System shutdown and cleanup: Trigger the shutdown command on the touch screen to shut down the constant pressure pump, constant temperature host, and buffer solution tank replenishment pump in sequence, and clean the system pipeline as needed.

3. The online aging detection method for membrane elements according to claim 1, characterized in that, The S5 step also includes data storage and export: the system periodically and automatically saves all test data. During or after the test, the data can be exported as a table or graph via the touch screen for analysis and evaluation of the aging performance of the filter membrane.

4. The online aging detection method for membrane elements according to claim 1, characterized in that, The S2 step also includes pre-drainage before testing: the cylinder (14) pushes the hose (15) to move to the side of the diversion funnel (16) to guide the filtrate to the water receiving tray (19) to remove any possible residue. After the pre-drainage is completed, the cylinder (14) drives the hose (15) to reset so that it switches to the position of diversion funnel (16) guiding the weighing container (18).

5. The online aging detection method for membrane elements according to claim 1, characterized in that, The cleaning assembly includes a rinsing pipe (30), a mounting bracket (40), and a conversion component. The mounting bracket (40) moves back and forth in the vertical direction. One end of the rinsing pipe (30) is mounted on the mounting bracket (40), and the other end of the rinsing pipe (30) is connected to an external distilled water supply device. The conversion component includes a plug tube (51) and a replacement tube (53). The plug tube (51) and the replacement tube (53) are located at the upper and lower ends of the suction tube (60), respectively. The outer surface of the plug tube (51) is fitted with a sleeve tube (52) that is fixedly connected to the mounting bracket (40). The sleeve tube (52) is provided with an air blowing pipe (521) and a water suction pipe (522) on both sides. The air blowing pipe (521) is connected to an external air blowing device, and the water suction pipe (522) is connected to a self-priming pump (20). After the self-priming pump (20) draws the filtrate inside the weighing container (18) through the suction pipe (60), the external distilled water supply device flushes distilled water into the weighing container (18) through the flushing pipe (30). After the self-priming pump (20) draws the filtrate inside multiple times and washes it with distilled water, the residual filtrate inside is removed. Then, the external air blowing device blows air into the suction pipe (60) through the air blowing pipe (521). The air is then quickly dried inside the weighing container (18) by the direction of the replacement cylinder (53).

6. The online aging detection method for membrane elements according to claim 5, characterized in that, The bottom of the substitute cylinder (53) is provided with a first sealing plug (54). One end of the first sealing plug (54) gradually decreases in size towards the bottom of the sleeve cylinder (52). Multiple through holes (56) are provided on the outer circumference of the substitute cylinder (53). A second sealing plug (55) is provided inside the through hole (56). The second sealing plug (55) gradually decreases in size towards the center of the sleeve cylinder (52). A spring (57) is provided between the first sealing plug (54) and the second sealing plug (55) and the substitute cylinder (53). When the self-priming pump (20) draws liquid from the weighing container (18), the second sealing plug (55) closes and the first sealing plug (54) opens to perform the drawing work. When the external blowing device is working, the first sealing plug (54) closes and the second sealing plug (55) opens to allow airflow to pass through the multiple through holes (56) for the drying work.

7. The online aging detection method for membrane elements according to claim 6, characterized in that, The end of the through hole (56) is inclined, and the inclined center line of the through hole (56) is tangent to the outer surface of the substitute tube (53). When the airflow passes through, the suction tube (60) drives the insertion tube (51) to rotate inside the sleeve tube (52).

8. The online aging detection method for membrane elements according to claim 6, characterized in that, The first sealing plug (54) and the second sealing plug (55) are made of fluororubber. When the external blowing device introduces 0.4-0.8MPa compressed air into the blowing pipe (521), the second sealing plug (55) overcomes the elastic force of the spring (57) and moves to the outside of the replacement cylinder (53). The through hole (56) is fully opened, and the airflow velocity ejected through the through hole (56) is 15-25m / s. The drying time is 20-40 seconds.

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