CN-122006492-A - Online detection method for ageing of membrane element

CN122006492ACN 122006492 ACN122006492 ACN 122006492ACN-122006492-A

Abstract

The invention discloses an online detection method for ageing of a membrane element, which comprises the following steps of S1, pre-supplementing water in a constant-temperature water tank, S2, keeping the temperature of detection liquid constant and uniformly mixing, S3, weighing and metering, S4, cleaning a weighing container, namely starting a cleaning assembly to move a suction pipe downwards into the weighing container, starting a self-sucking pump to suck filtered liquid in the weighing container through the suction pipe to a water receiving disc for discharging, and cleaning the interior of the weighing container by using the cleaning assembly to avoid residues from influencing weighing operation, and S5, periodically testing and collecting data. After weighing, 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 residual media to a weighing sensor is avoided, consistency of initial states of weighing and metering each time is ensured, core detection parameters such as flow conversion data, accumulated flow statistics and the like truly reflect the permeability of the membrane element, and accurate data support is provided for ageing evaluation.

Inventors

Yin Xianhu
LI ZHIFENG
ZHANG FEIHU

Assignees

安徽智泓净化科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260227

Claims (8)

1. The online detection method for the aging of the membrane element is characterized by comprising the following steps of: S1, pre-supplementing water to a constant-temperature water tank (11), namely, after pure water is injected into the buffer solution preparation water tank, adding concentrated solution according to a test proportion to prepare detection solution, and then pumping the detection solution in the buffer solution preparation water tank into the constant-temperature water tank (11) by a water supplementing pump; S2, stopping after the liquid level reaches a set liquid level, starting a constant-temperature host machine to exchange heat with the detection liquid in a constant-temperature water tank (11), then opening a second electromagnetic valve (13), conveying the detection liquid subjected to constant temperature to a water inlet end of a filtering membrane element (21) of a plurality of sets of test tables by a constant-pressure pump, enabling water molecules to permeate through membrane holes to form filtered liquid to flow out from a water producing end of the filtering membrane, and discharging non-permeated concentrated water from a concentrated water end of the filtering membrane, wherein the touch screen displays parameters of the detection liquid pressure, the concentrated water pressure, the flow, the conductivity and the temperature of each test table in real time; S3, weighing and metering, namely guiding the filtered detection liquid into a weighing container (18) by a splitting funnel (16), starting weighing and timing, collecting the weight of water in the weighing container (18) in real time by a weighing module (17), automatically converting the weight into flow data by a preset formula, synchronously collecting the real-time flow and accumulated flow data of the detection liquid and the filtrate, finishing single metering after timing, uploading the data to a control system, closing and opening a first electromagnetic valve (12) by a second electromagnetic valve (13), and refluxing the filtrate to a constant-temperature water tank (11) for next weighing operation; s4, cleaning the weighing container (18), namely starting a cleaning assembly to move a suction pipe (60) downwards into the weighing container (18), starting a self-priming pump (20) to pump out filtrate in the weighing container (18) through the suction pipe (60) to a water receiving disc (19) for discharging, and cleaning the inside of the weighing container (18) by using the cleaning assembly to avoid residue from influencing weighing operation; And S5, periodically and circularly testing and collecting data, wherein the system continuously collects data according to the process from the step S3 to the step S4 according to a set period, monitors pressure, flow, conductivity and temperature parameters in real time in the test process, and if the flow/conductivity exceeds a set range, the system triggers an alarm to prompt an aging state or an abnormal state.
2. The method for on-line detection of membrane element aging according to claim 1, further comprising S6, system shutdown and ending, wherein a shutdown command is triggered on a touch screen, a constant pressure pump, a constant temperature host machine and a buffer liquid distribution water tank water supplementing pump are sequentially closed, and system pipelines are cleaned as required.
3. The method for online detection of aging of a membrane element according to claim 1, wherein the step S5 further comprises data storage and derivation, wherein the system periodically and automatically stores all test data, and the data can be derived into a table or a graph through a touch screen during or after the test process is finished for analysis and evaluation of aging performance of the filtering membrane.
4. The method for online detection of aging of a membrane element according to claim 1, wherein the step S2 further comprises pre-draining before testing, wherein the air cylinder (14) pushes the hose (15) to move to one side of the diversion funnel (16), the filtrate is guided to the water receiving disc (19) to remove residues possibly existing, and after the pre-draining is completed, the air cylinder (14) drives the hose (15) to reset so that the hose is switched to the diversion funnel (16) to guide the weighing container (18).
5. The online detection method for aging of the membrane element according to claim 1, wherein the cleaning assembly comprises a flushing pipe (30), a mounting frame (40) and a conversion piece, the mounting frame (40) moves reciprocally in the vertical direction, one end of the flushing pipe (30) is mounted on the mounting frame (40), the other end of the flushing pipe (30) is connected with external distilled water supply equipment, the conversion piece comprises an inserting cylinder (51) and a replacing cylinder (53), the inserting cylinder (51) and the replacing cylinder (53) are respectively positioned at the upper end and the lower end of a suction pipe (60), a sleeve joint cylinder (52) fixedly connected with the mounting frame (40) is sleeved on the outer surface of the inserting cylinder (51), a gas blowing pipe (521) and a gas pumping pipe (522) are respectively arranged at two sides of the sleeve joint cylinder (52), the gas blowing pipe (521) is connected with external gas blowing equipment, and the gas pumping pipe (522) is connected with a self-sucking pump (20). After the self-priming pump (20) sucks the filtrate in the weighing container (18) through the suction pipe (60), the external distilled water supply equipment blows distilled water into the weighing container (18) through the flushing pipe (30), the residual filtrate in the weighing container (18) is removed after the self-priming pump (20) sucks and washes the distilled water for a plurality of times, then the external blowing equipment blows air flow into the suction pipe (60) through the air blowing pipe (521), and the interior of the weighing container (18) is rapidly air-dried through the steering of the replacing cylinder (53).
6. The online detection method for ageing of membrane elements according to claim 5, wherein a first sealing block (54) is arranged at the bottom of the replacing cylinder (53), one end of the first sealing block (54) gradually decreases towards the bottom of the sleeving cylinder (52), a plurality of through holes (56) are circumferentially formed in the outer side of the replacing cylinder (53), a second sealing block (55) is arranged in the through holes (56), the second sealing block (55) gradually decreases towards the center of the sleeving cylinder (52), a spring (57) is arranged between the first sealing block (54) and the second sealing block (55) and the replacing cylinder (53), when the self-priming pump (20) sucks liquid in the weighing container (18), the second sealing block (55) is sealed, the first sealing block (54) is opened for sucking, when the external blowing device works, the first sealing block (54) is sealed, the second sealing block (55) is opened for enabling air flow to be air-dried from the plurality of through holes (56).
7. The online detection method for aging of the membrane element according to claim 6, wherein the end part of the through hole (56) is obliquely arranged, the oblique central line of the through hole (56) is tangential to the outer surface of the replacing cylinder (53), and the suction pipe (60) drives the plug cylinder (51) to rotate in the sleeve cylinder (52) when the air flow passes through the through hole.
8. The on-line detection method for aging of membrane elements according to claim 6, wherein the first closing plug (54) and the second closing plug (55) are made of fluororubber, when compressed air of 0.4-0.8MPa is introduced into the air blowing pipe (521) by an external air blowing device, the second closing plug (55) moves to the outside of the replacing cylinder (53) against the elastic force of the spring (57), the through hole (56) is completely opened, the flow rate of air ejected through the through hole (56) is 15-25m/s, and the air drying duration is 20-40 seconds.

Description

Online detection method for ageing of membrane element Technical Field The invention belongs to the technical field of membrane element detection, and particularly relates to an online detection method for aging of a membrane element. Background The filtering membrane element is used as a core separation component in the fields of water treatment, chemical separation, biological medicine, food processing and the like, and solid-liquid, liquid-liquid or ion-level separation is realized by depending on membrane structures with different apertures, so that the filtering membrane element is a key core component for realizing medium purification, impurity interception and water quality purification. In the long-term actual operation process, the filtering membrane element can be blocked by physical pollution caused by suspended matters and colloid in raw water medium, chemical degradation of membrane materials is caused by mediums such as acid and alkali, oxidant and the like, biological pollution is formed by microorganism breeding, and meanwhile, the aging problems of abrasion, delamination and the like of a membrane pore structure brought by long-term operation are finally represented as phenomena of filtration flux reduction, separation interception capacity attenuation, abnormal operation pressure fluctuation and the like of the membrane element. When the aging degree of the membrane element is detected by adopting an online detection method, the aging degree of the membrane element is calculated by weighing the weight of produced water and carrying parameters such as the flow rate of produced water and the conductivity of a medium, a weighing container is generally not provided with a special cleaning component, the residual test liquid on the inner wall of the container after single metering can be directly counted into the next metering data to form systematic metering errors, and the errors can be continuously accumulated along with the periodic cycle test, so that the core detection data such as the filtration flux, the separation performance and the like are distorted, thereby influencing the detection result of the aging of the membrane element. Disclosure of Invention Aiming at the problems in the prior art, the invention provides the following technical scheme: The online detection method for the aging of the membrane element comprises the following steps: s1, pre-replenishing water in a constant-temperature water tank, namely after pure water is injected into a buffer solution preparation water tank, adding concentrated solution according to a test proportion to prepare detection solution, and then pumping the detection solution in the buffer solution preparation water tank into the constant-temperature water tank by a water replenishing pump; S2, stopping after the liquid level reaches a set liquid level, starting a constant-temperature host machine to exchange heat with the detection liquid in the constant-temperature water tank, then opening a second electromagnetic valve, conveying the detection liquid subjected to constant temperature to the water inlet ends of the filtering membrane elements of the multiple sets of test tables by the constant-pressure pump, enabling water molecules to permeate through membrane holes to form filtered liquid to flow out from the water producing end of the filtering membrane, and discharging non-permeated concentrated water from the concentrated water end of the filtering membrane, wherein the touch screen displays parameters of the detection liquid pressure, the concentrated water pressure, the flow, the conductivity and the temperature of each test table in real time; S3, weighing and metering, namely guiding filtered filtrate into a weighing container by a splitting funnel, starting weighing and timing, collecting the weight of water in the weighing container in real time by a weighing module, automatically converting the weight into flow data by a preset formula, synchronously collecting real-time flow and accumulated flow data of detection liquid and filtrate, finishing single metering after timing, uploading the data to a control system, closing a second electromagnetic valve, opening the first electromagnetic valve, and refluxing the filtrate to a constant-temperature water tank for next weighing operation; S4, cleaning the weighing container, namely starting a cleaning component to move a suction pipe downwards into the weighing container, starting a self-sucking pump to suck filtered liquid in the weighing container through the suction pipe and discharge the filtered liquid to a water receiving disc, and cleaning the interior of the weighing container by using the cleaning component to avoid residues from influencing weighing operation; And S5, periodically and circularly testing and collecting data, wherein the system continuously collects data according to the process from the step S3 to the step S4 according to a set period, monitors pressure, flow,