Cleaning system for ultrafiltration membrane

Abstract

The utility model discloses a cleaning system of an ultrafiltration membrane. The cleaning system comprises a cleaning pump; the enhanced cleaning unit can be used for performing forward washing and reverse washing on the ultrafiltration membrane, and comprises an enhanced cleaning water tank; one end of the first valve is connected with the reinforced cleaning water tank and the other end is connected with an inlet of the cleaning pump; the chemical cleaning unit can be used for performing forward washing on the ultrafiltration membrane and comprises a chemical cleaning water tank; one end of the second valve is connected with the chemical cleaning water tank and the other end is connected with an inlet of the cleaning pump; the conventional washing pipeline is connected with an outlet of the washing pump, and reinforced washing liquid or chemical washing liquid in the conventional washing pipeline enters from a water inlet of the ultrafiltration membrane and is discharged from a concentrated water port of the ultrafiltration membrane and / or a water producing port of the ultrafiltration membrane; and the backwashing pipeline is connected with an outlet of the washing pump, and reinforced washing liquid in the backwashing pipeline enters from a water producing port of the ultrafiltration membrane and is discharged from a concentrated water port of the ultrafiltration membrane and / or a water inlet of the ultrafiltration membrane. The system can improve the cleaning effect of the ultrafiltration membrane, reduce energy consumption and save cost.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrafiltration membrane cleaning, in particular to an ultrafiltration membrane cleaning system. Background Art

[0002] With the rapid development of society and the improvement of industrial manufacturing levels, wastewater treatment emission standards are becoming increasingly stringent. This is especially true for the design requirements of water treatment systems in concentrated brine industries, such as the chemical industry. They must maintain stable water output and ensure the system operates stably and autonomously. Column-type hollow fiber ultrafiltration membranes, in particular, are widely used in various industrial wastewater treatment industries. However, they suffer from rapid fouling and clogging, resulting in short operating times and frequent cleaning. However, offline chemical cleaning of ultrafiltration membranes, without spare membrane modules, often halts the entire water treatment system, disrupting normal production at the plant site – an unacceptable situation for businesses.

[0003] At present, the cleaning of ultrafiltration membranes mainly includes online enhanced backwashing and offline chemical cleaning. Online enhanced backwashing is carried out when the transmembrane pressure difference of the ultrafiltration membrane increases and the water production flow rate decreases. At this time, the pollution of the ultrafiltration membrane is not very serious. It is mainly carried out by adding about 0.1% NaClO+0.05% NaOH or 0.1% HCl and other cleaning reagents (the type of cleaning reagent is selected according to the pollution situation) to perform backwashing to restore the ultrafiltration membrane to a certain water production flux. Generally, the frequency of online enhanced backwashing is about once a day.

[0004] Offline chemical cleaning is performed when the ultrafiltration membrane's permeate flow rate has significantly decreased, the transmembrane pressure has exceeded the design pressure, and online enhanced backwashing has been ineffective. Furthermore, offline chemical cleaning typically requires a separate, complete set of chemical cleaning equipment (e.g., dosing pumps, cleaning pumps, filters, etc.), and enhances cleaning effectiveness by using a high-concentration cleaning agent such as approximately 0.1% NaClO + 0.2% NaOH or 0.2% HCl (the type of cleaning agent is selected based on the contamination situation). Offline chemical cleaning is typically performed approximately once a month, or once a week in special circumstances, and is typically performed manually on-site.

[0005] Therefore, how to improve the continuous operation time of ultrafiltration membrane and the automatic cleaning ability of the cleaning system is very important for the water treatment system. Utility Model Content

[0006] In order to solve the above technical problems, the utility model provides an ultrafiltration membrane cleaning system.

[0007] The embodiment of the present utility model discloses a cleaning system for an ultrafiltration membrane, the cleaning system comprising:

[0008] A cleaning pump, comprising a cleaning pump inlet and a cleaning pump outlet;

[0009] The enhanced cleaning unit is capable of forward and backwashing the ultrafiltration membrane. The enhanced cleaning unit includes:

[0010] Enhanced cleaning water tank, used to store enhanced cleaning fluid;

[0011] A first valve, one end of which is connected to the enhanced cleaning water tank and the other end of which is connected to the inlet of the cleaning pump;

[0012] The chemical cleaning unit can perform positive cleaning on the ultrafiltration membrane. The chemical cleaning unit includes:

[0013] Chemical cleaning water tank, used to store chemical cleaning liquid;

[0014] The second valve has one end connected to the chemical cleaning water tank and the other end connected to the cleaning pump inlet;

[0015] The forward washing pipeline is connected to the outlet of the washing pump. The enhanced washing liquid or chemical washing liquid in the forward washing pipeline enters from the water inlet of the ultrafiltration membrane and is discharged from the concentrated water outlet and / or the water outlet of the ultrafiltration membrane;

[0016] The backwash pipeline is connected to the outlet of the cleaning pump. The enhanced cleaning liquid in the backwash pipeline enters from the water outlet of the ultrafiltration membrane and is discharged from the concentrate outlet of the ultrafiltration membrane and / or the water inlet of the ultrafiltration membrane.

[0017] The adoption of the above technical solution not only improves the cleaning effect of the enhanced cleaning unit and extends the operating time of the ultrafiltration membrane, but also improves the utilization efficiency of the equipment itself, significantly reduces the number of equipment required for traditional ultrafiltration chemical cleaning, reduces energy consumption, and achieves effective cost savings.

[0018] Optionally, the cleaning system also includes a dosing device, a dosing pump, a third valve and a mixer, the dosing device is used to store cleaning agents, the dosing pump includes a dosing pump inlet and a dosing pump outlet, the dosing pump inlet is connected to the dosing device, the dosing pump outlet is connected to one end of the third valve, the input end of the mixer is respectively connected to the other end of the third valve and the cleaning pump outlet, and the output end of the mixer is respectively connected to the input end of the forward wash pipeline and the input end of the backwash pipeline.

[0019] Optionally, the cleaning pump includes a cleaning pump flowmeter, and the cleaning pump flowmeter is used to measure the flow of the cleaning pump; the dosing pump includes a dosing pump flowmeter, and the dosing pump flowmeter is used to measure the flow of the dosing pump.

[0020] Optionally, the cleaning system further comprises a filter, one end of the filter is connected to the outlet of the cleaning pump, and the other end of the filter is connected to the input end of the mixer.

[0021] Optionally, the cleaning system further includes an air intake pipeline and a fourth valve, the air intake pipeline is connected to the ultrafiltration membrane, the fourth valve is arranged on the air intake pipeline, and the gas in the air intake pipeline flows through the fourth valve into the ultrafiltration membrane.

[0022] Optionally, the cleaning system also includes a circulation pipeline, a fifth valve and a sixth valve, one end of the fifth valve is connected to the concentrated water outlet of the ultrafiltration membrane, the other end of the fifth valve is connected to the input end of the circulation pipeline, one end of the sixth valve is connected to the water outlet of the ultrafiltration membrane, the other end of the sixth valve is connected to the input end of the circulation pipeline, and the output end of the circulation pipeline is connected to the chemical cleaning water tank.

[0023] Optionally, the first valve, the second valve, the third valve, the fourth valve, the fifth valve and the sixth valve are pneumatic control valves.

[0024] Optionally, the cleaning system also includes a filtration pipeline, which includes a first collection unit and a second collection unit; the first collection unit is connected to the water inlet of the ultrafiltration membrane, and the first collection unit is used to collect the flow rate and pressure of the water inlet of the ultrafiltration membrane; the second collection unit is connected to the water production port of the ultrafiltration membrane, and the second collection unit is used to collect the flow rate and pressure of the water production port of the ultrafiltration membrane.

[0025] Optionally, the cleaning system further includes a control unit, which is connected to the first collection unit and the second collection unit, and is used to turn on or off the enhanced cleaning unit.

[0026] Optionally, the cleaning system further comprises a temperature transmitter, which is provided in the forward washing pipeline and located between the mixer and the water inlet of the ultrafiltration membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of an ultrafiltration membrane cleaning system provided by the present invention is shown.

[0028] 1. Ultrafiltration membrane, 2. Chemical cleaning water tank, 3. Cleaning pump, 4. Dosing device, 5. Dosing pump, 6. Second pressure transmitter, 7. Mixer, 8. First flow meter, 9. Second flow meter, 10. First pressure transmitter, 11. First valve, 12. Second valve, 13. Third valve, 14. Forward wash line valve, 15. Backwash line valve, 16. Water production valve, 17. Concentrate valve, 18. Inlet valve, 19. Fourth valve, 20. Inlet drain valve, 21. Concentrate drain valve, 22. Air intake line, 23. Enhanced cleaning water tank, 24. Fifth valve, 25. Sixth valve, 26. Seventh valve, 27. Forward wash line, 28. Circulation line, 29. Backwash line, 30. Filter DETAILED DESCRIPTION

[0029] The following is an explanation of the implementation of the present invention by means of specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation. On the contrary, the purpose of introducing the utility model in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0030] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0031] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0032] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0034] like Figure 1 As shown, the utility model discloses a cleaning system for an ultrafiltration membrane 1, the cleaning system comprising:

[0035] A cleaning pump 3, comprising a cleaning pump inlet and a cleaning pump outlet;

[0036] The enhanced cleaning unit is capable of performing forward and backwashing on the ultrafiltration membrane 1. The enhanced cleaning unit includes: an enhanced cleaning water tank 23 for storing an enhanced cleaning solution, which may include water, 0.1-0.3% NaClO + 0.1-0.2% NaOH, or 0.1-0.2% HCl; a first valve 11, one end of which is connected to the enhanced cleaning water tank 23 and the other end is connected to the cleaning pump inlet;

[0037] The chemical cleaning unit can perform positive washing on the ultrafiltration membrane 1. The chemical cleaning unit includes: a chemical cleaning water tank 2 for storing a chemical cleaning liquid, which may include desalted water, clean water, 0.1-0.3% NaClO+0.1-0.2% NaOH or 0.1-0.2% HCl; a second valve 12, one end of which is connected to the chemical cleaning water tank 2 and the other end is connected to the inlet of the cleaning pump.

[0038] The positive washing pipeline 27 is connected to the outlet of the cleaning pump. The enhanced cleaning liquid or chemical cleaning liquid in the positive washing pipeline 27 enters from the water inlet of the ultrafiltration membrane 1 and is discharged from the concentrated water outlet of the ultrafiltration membrane 1 and / or the water production outlet of the ultrafiltration membrane 1; that is, the enhanced cleaning liquid or chemical cleaning liquid flows out from the outlet of the cleaning pump and enters the positive washing pipeline 27, then enters from the water inlet of the ultrafiltration membrane 1, and is discharged from the concentrated water outlet of the ultrafiltration membrane 1 and / or the water production outlet of the ultrafiltration membrane 1.

[0039] The backwash pipeline 29 is connected to the outlet of the cleaning pump. The enhanced cleaning liquid in the backwash pipeline 29 enters from the water production port of the ultrafiltration membrane 1 and is discharged from the concentrate port of the ultrafiltration membrane 1 and / or the water inlet of the ultrafiltration membrane 1; that is, the enhanced cleaning liquid flows out from the outlet of the cleaning pump and enters the backwash pipeline 29, then enters from the water production port of the ultrafiltration membrane 1, and is discharged from the concentrate port of the ultrafiltration membrane 1 and / or the water inlet of the ultrafiltration membrane 1.

[0040] It should be noted that the ultrafiltration membrane 1 includes a water inlet of the ultrafiltration membrane 1, a water outlet of the ultrafiltration membrane 1 and a concentrate outlet of the ultrafiltration membrane 1. The so-called forward washing means that the flow direction of the cleaning liquid is the same as the direction of filtration during normal operation of the ultrafiltration membrane 1, that is, the flow direction of the cleaning liquid enters from the water inlet of the ultrafiltration membrane 1 and is discharged from the concentrate outlet of the ultrafiltration membrane 1 and / or the water outlet of the ultrafiltration membrane 1; the so-called backwash means that the flow direction of the cleaning liquid is opposite to the direction of filtration during normal operation of the ultrafiltration membrane 1, that is, the flow direction of the cleaning liquid enters from the water outlet of the ultrafiltration membrane 1 and is discharged from the concentrate outlet of the ultrafiltration membrane 1 and / or the water inlet of the ultrafiltration membrane 1.

[0041] Specifically, when the enhanced cleaning unit is started, the cleaning system will open the first valve 11 while keeping the second valve 12 closed. At this time, the enhanced cleaning liquid in the enhanced cleaning water tank 23 flows into the cleaning pump inlet through the first valve 11, and then flows out of the cleaning pump outlet through the backwash pipeline 29 to or the forward cleaning pipeline 27. In the backwash mode, the enhanced cleaning liquid enters the water outlet of the ultrafiltration membrane 1 through the backwash pipeline 29, and is discharged from the concentrate outlet of the ultrafiltration membrane 1 and / or the water inlet of the ultrafiltration membrane 1 to the cleaning drain pipe. Among them, a concentrate end drain valve 21 is provided between the concentrate outlet of the ultrafiltration membrane 1 and the cleaning drain pipe, for discharging the cleaning waste liquid from the concentrate outlet of the ultrafiltration membrane 1 through the concentrate end drain valve 21 to the cleaning drain pipe. A water inlet end drain valve 20 is provided between the water inlet of the ultrafiltration membrane 1 and the cleaning drain pipe, for discharging the cleaning waste liquid from the water inlet of the ultrafiltration membrane 1 through the water inlet end drain valve 20 to the cleaning drain pipe to prevent contamination. In the forward washing mode, the enhanced washing liquid enters the water inlet of the ultrafiltration membrane 1 through the forward washing pipeline 27 and is discharged from the concentrate outlet of the ultrafiltration membrane 1 and / or the water inlet of the ultrafiltration membrane 1 .

[0042] When the chemical cleaning unit is started, the cleaning system opens the second valve 12 while keeping the first valve 11 closed. The chemical cleaning liquid in the chemical cleaning water tank 2 flows into the cleaning pump inlet through the second valve 12 and flows out of the cleaning pump outlet to the forward cleaning pipeline 27. The chemical cleaning liquid in the forward cleaning pipeline 27 enters the water inlet of the ultrafiltration membrane 1 and is discharged from the concentrate outlet and / or the water outlet of the ultrafiltration membrane 1.

[0043] Compared with the prior art, the present invention improves the cleaning effect of the enhanced cleaning unit by adding a forward wash line 27 to the enhanced cleaning unit and cooperating with the backwash line 29, thereby extending the operating time of the ultrafiltration membrane. In addition, by adjusting the position of the chemical cleaning water tank 2, the chemical cleaning unit and the enhanced cleaning unit can share the cleaning pump 3 and the forward wash line 27, and through different valve configurations, the appropriate cleaning mode (i.e., enhanced cleaning mode or chemical cleaning mode) can be easily switched according to the degree and type of ultrafiltration membrane contamination. This not only improves the utilization efficiency of the equipment itself, significantly reduces the number of equipment required for traditional ultrafiltration chemical cleaning, reduces energy consumption, and achieves effective cost savings, but also improves operational flexibility, thereby improving cleaning efficiency.

[0044] In this embodiment, the cleaning system also includes a dosing device 4, a dosing pump 5, a third valve 13, and a mixer 7. The dosing device 4 is used to store cleaning agents. The dosing pump 5 includes a dosing pump inlet and a dosing pump outlet. The dosing pump inlet is connected to the dosing device 4, and the dosing pump outlet is connected to one end of the third valve 13. The input end of the mixer 7 is respectively connected to the other end of the third valve 13 and the cleaning pump outlet. The output end of the mixer 7 is respectively connected to the input end of the forward wash pipeline and the input end of the backwash pipeline. The cleaning agents include NaClO, NaOH, and HCl. These cleaning agents can be selected and added by technicians according to the specific situation of membrane fouling. The function of the dosing pump 5 is to transport the cleaning agents stored in the dosing device 4 to the mixer 7 as needed. The input end of the mixer 7 is also connected to the cleaning pump outlet, so that the cleaning agents and the enhanced cleaning solution or chemical cleaning solution are fully mixed in the mixer 7 to form the enhanced cleaning solution or chemical cleaning solution of the required concentration. The output end of the mixer 7 is connected to the input end of the forward wash pipeline 27 and the backwash pipeline 29, respectively. In this way, whether forward wash or backwash is performed, the cleaning agent can be effectively transported to the ultrafiltration membrane 1 and clean the ultrafiltration membrane 1. In particular, in the chemical cleaning unit, considering the risk of acid and alkali leakage and production cost issues, the existing technology still requires manual addition of cleaning agents. The above-mentioned design of this embodiment avoids the tedious operation of traditional manual dosing, reduces the risk of acid and alkali leakage, and is also beneficial to the automation level of the cleaning system, making the cleaning process safer, more efficient, and easier to control.

[0045] Furthermore, the cleaning pump 3 includes a cleaning pump flowmeter for measuring the flow rate of the cleaning pump 3; the dosing pump 5 includes a dosing pump flowmeter for measuring the flow rate of the dosing pump 5. Thus, when a chemical cleaning agent is required, the cleaning pump flowmeter and the dosing pump flowmeter are used to calculate the corresponding agent volume concentration, thereby directly controlling the flow rates of the cleaning pump 3 and the dosing pump 5 to configure the cleaning agent of the desired concentration. This not only improves the accuracy of agent concentration control in the cleaning solution, but also reduces the risk of overdosage or underdosage, helping to optimize the cleaning effect and further extend the service life of the ultrafiltration membrane. It also further improves the automation level of the cleaning system, reduces manual intervention, and improves operational safety.

[0046] Continue to refer Figure 1 As shown, the cleaning system also includes a filter 30, one end of which is connected to the outlet of the cleaning pump, and the other end is connected to the input end of the mixer 7. That is, the filter 30 is arranged between the outlet of the cleaning pump and the mixer 7, forming an effective barrier. Therefore, whether it is the enhanced cleaning liquid from the enhanced cleaning water tank 23 or the chemical cleaning liquid in the chemical cleaning water tank 2, after being transported by the cleaning pump 5, it must first pass through the filtering effect of the filter 30 before it can be transported to the mixer 7. It effectively intercepts particulate matter that may cause damage to the internal structure of the ultrafiltration membrane 1 and effectively prevents impurities from entering the ultrafiltration membrane 1, thereby extending the service life of the ultrafiltration membrane 1 and reducing the frequency of maintenance and replacement. At the same time, it also ensures that the cleaning liquid flowing into the mixer 7 has a higher purity and is more effectively mixed with the cleaning agent, thereby improving the cleaning effect.

[0047] In this embodiment, the cleaning system further includes an air inlet line 22 and a fourth valve 19. The air inlet line 22 is connected to the ultrafiltration membrane 1. The fourth valve 19 is provided on the air inlet line 22. The gas in the air inlet line 22 flows through the fourth valve 19 and enters the ultrafiltration membrane 1. That is, the fourth valve 19 is provided on the air inlet line 22 to control the opening and closing of the air inlet line 22. When the fourth valve 19 is opened, the gas in the air inlet line 22 directly enters the ultrafiltration membrane 1, thereby achieving air washing of the ultrafiltration membrane 1 and improving the cleaning effect of the ultrafiltration membrane 1. Specifically, the ultrafiltration membrane 1 further includes an air inlet of the ultrafiltration membrane 1. Furthermore, after the gas in the air inlet line 22 flows through the fourth valve 19, it enters the ultrafiltration membrane 1 from the air inlet of the ultrafiltration membrane 1 and / or the water inlet of the ultrafiltration membrane 1.

[0048] Furthermore, the forward wash pipeline 27 is provided with a forward wash pipeline valve 14, and the backwash pipeline 29 is provided with a backwash pipeline valve 15. After opening the first valve 11 and the fourth valve 19 and starting the cleaning pump 3, the forward wash pipeline valve 14 or the backwash pipeline valve 15 is opened to strengthen the flow of cleaning liquid and gas into the ultrafiltration membrane 1, thereby achieving gas-water washing of the ultrafiltration membrane 1. Alternatively, after opening the second valve 12 and the fourth valve 19 and starting the cleaning pump 3, the forward wash pipeline valve 14 is opened to allow the chemical cleaning liquid and gas to flow into the ultrafiltration membrane 1, thereby achieving gas-water washing of the ultrafiltration membrane 1. The turbulent state generated by the gas-liquid mixing performs gas-water washing on the ultrafiltration membrane 1. By utilizing the combined effects of gas-liquid mixed cleaning and high-flow rate flushing, the ultrafiltration membrane 1 is cleaned more thoroughly, and the flux recovery rate of the filter element and membrane element is higher.

[0049] In this embodiment, the cleaning system further includes a circulation pipeline 28, a fifth valve 24, and a sixth valve 25. One end of the fifth valve 24 is connected to the concentrate outlet of the ultrafiltration membrane 1, and the other end of the fifth valve 24 is connected to the input end of the circulation pipeline 28. One end of the sixth valve 25 is connected to the water outlet of the ultrafiltration membrane 1, and the other end of the sixth valve 25 is connected to the input end of the circulation pipeline 28. The output end of the circulation pipeline 28 is connected to the chemical cleaning water tank 2. Thus, the provision of the circulation pipeline 28 enables the recycling of the cleaning fluid and improves cleaning efficiency.

[0050] Specifically, the first valve 11 is opened, the cleaning pump 3 and the forward cleaning line 27 are started, and the fifth valve 24 and the sixth valve 25 are opened, so that the chemical cleaning water tank 2, the cleaning pump 3, the forward cleaning line 27, and the circulation line 28 form a loop. The chemical cleaning liquid in the chemical cleaning water tank 2 is filtered by the cleaning pump 3 through the filter 30 and mixed by the mixer 7 before reaching the forward cleaning line 27. The chemical cleaning liquid enters the water inlet of the ultrafiltration membrane 1 through the forward cleaning line 27, is discharged from the concentrated water outlet of the ultrafiltration membrane 1, flows through the fifth valve 24, and returns to the chemical cleaning water tank 2 through the circulation line 28; and / or the chemical cleaning liquid is discharged from the water outlet of the ultrafiltration membrane 1, flows through the sixth valve 25, and returns to the chemical cleaning water tank 2 through the circulation line 28. This achieves the cleaning of the ultrafiltration membrane 1 by soaking and circulating, which not only reduces the waste of cleaning liquid but also ensures the continuity of the cleaning effect, facilitates deep cleaning of dirt on the membrane surface and within the membrane pores, and further improves the cleaning effect.

[0051] In this embodiment, the cleaning system also includes a filtration pipeline, which includes a first collection unit and a second collection unit; the first collection unit is connected to the water inlet of the ultrafiltration membrane, and the first collection unit is used to collect the flow rate and pressure of the water inlet of the ultrafiltration membrane; the second collection unit is connected to the water outlet of the ultrafiltration membrane, and the second collection unit is used to collect the flow rate and pressure of the water outlet of the ultrafiltration membrane. Specifically, the first collection unit includes a first flowmeter 8 and a first pressure transmitter 10, and the second collection unit includes a second pressure transmitter 6 and a second flowmeter 9. The first flowmeter 8 and the second flowmeter 9 can be electromagnetic flowmeters. The first flowmeter 8 and the first pressure transmitter 10 are used to measure the flow rate and pressure of the water inlet of the ultrafiltration membrane 1, and the second pressure transmitter 6 and the second flowmeter 9 are used to measure the flow rate and pressure of the water outlet of the ultrafiltration membrane 1, thereby measuring the transmembrane pressure difference and flow rate of the ultrafiltration membrane 1 to monitor the working status of the ultrafiltration membrane 1 and facilitate operation.

[0052] Among them, the filtration pipeline includes an inlet pipeline, a production water pipeline and a concentrated water pipeline. The inlet pipeline is connected to the water inlet of the ultrafiltration membrane 1, that is, the first collection unit is arranged in the inlet pipeline, that is, the first flowmeter 8 and the first pressure transmitter 10 are arranged in the inlet pipeline, and the first flowmeter 8 and the first pressure transmitter 10 are located between the mixer 7 and the water inlet of the ultrafiltration membrane 1. The inlet pipeline is also provided with an inlet valve 18 and an inlet pipe (i.e., an inlet pool). Water in the inlet pipe enters the ultrafiltration membrane 1 through the inlet valve 18 and the water inlet of the ultrafiltration membrane 1. The production water pipeline is connected to the water production port of the ultrafiltration membrane 1. The production water pipeline is provided with a production water valve 16 and a production water pipe (i.e., a production water pool). Water flows out of the water production port of the ultrafiltration membrane 1 and is discharged to the production water pipe through the production water valve 16. The water in the production water pipe (i.e., the production water pool) can be reused and used as enhanced cleaning liquid for the enhanced cleaning water tank 23. The second data acquisition unit can be installed in the production water pipeline; the second pressure transmitter 6 can also be installed in the backwash pipeline 29. The second pressure transmitter 6 is located between the backwash pipeline valve 15 and the production water outlet of the ultrafiltration membrane 1. One end of the second flowmeter 9 is connected to one end of the second pressure transmitter 6 and the production water outlet of the ultrafiltration membrane 1, respectively, and the other end of the second flowmeter 9 is connected to the production water pipeline. In addition, the concentrate pipeline is equipped with a concentrate valve 17 and a concentrate pipe (i.e., a concentrate tank). Concentrate is discharged from the concentrate outlet of the ultrafiltration membrane 1 through the concentrate valve 17 to the concentrate pipe. The water in the concentrate pipe can be reused as water for the inlet pipe (i.e., the inlet tank).

[0053] Specifically, the water production valve 16, the concentrated water valve 17 and the water inlet valve 18 are opened, and the water in the water inlet pipe enters the ultrafiltration membrane 1 through the water inlet valve 18 and the water inlet of the ultrafiltration membrane 1, and is filtered by the ultrafiltration membrane 1 and discharged from the concentrated water outlet of the ultrafiltration membrane 1 and the water production outlet of the ultrafiltration membrane 1. The water discharged from the water production outlet of the ultrafiltration membrane 1 is discharged to the water production pipe through the water production valve 16, and the water discharged from the concentrated water outlet of the ultrafiltration membrane 1 is discharged to the concentrated water pipe through the concentrated water valve 17, thus completing the normal operating mode (that is, the filtration mode) of the ultrafiltration membrane 1.

[0054] Furthermore, the cleaning system also includes a control unit (i.e., a DCS or PCL), which is connected to the first acquisition unit and the second acquisition unit, and is used to turn on or off the enhanced cleaning unit. That is, the control unit is connected to the first flow meter 8, the first pressure transmitter 10, the second pressure transmitter 6, and the second flow meter 9, and the above connection can be understood as an electrical connection. When the control unit detects that the flow difference measured by the first flow meter 8 and the second flow meter 9 is too small or the pressure difference measured by the first pressure transmitter 10 and the second pressure transmitter 6 is too large, the control unit automatically starts the enhanced cleaning unit, that is, the cleaning system automatically enters the enhanced cleaning mode.

[0055] The inventors also realized that since the chemical cleaning unit and the enhanced cleaning unit share the cleaning pump 3, and the chemical cleaning unit and the enhanced cleaning unit have different flow requirements, the flow requirement of the chemical cleaning unit is less than the flow of the enhanced cleaning unit, and the flow regulation of the cleaning pump 3 itself is limited. Therefore, the chemical cleaning unit also includes a seventh valve 26, one end of the seventh valve 26 is connected to the outlet of the cleaning pump, and the other end is connected to the chemical cleaning water tank 2. In this way, flow regulation of the chemical cleaning process is achieved. That is, when the seventh valve 26 is closed or even shut down, most of the chemical cleaning liquid is used to clean the ultrafiltration membrane 1, ensuring the cleaning effect; when the seventh valve 26 is opened, most of the chemical cleaning liquid is directly returned to the chemical cleaning water tank 2, avoiding excessive fluid causing damage to the cleaning system or reducing the cleaning effect due to uneven mixing of the chemical cleaning liquid.

[0056] In the above embodiments, the first valve 11, second valve 12, third valve 13, fourth valve 19, fifth valve 24, and sixth valve 25 are pneumatically controlled valves. This allows technicians to automatically operate and clean the ultrafiltration membrane 1 simply by pre-configuring the control unit. Furthermore, the seventh valve 26, the inlet drain valve 20, the concentrate drain valve 21, the forward wash line valve 14, the backwash line valves, the product water valve 15, the product water valve 16, the concentrate valve 17, and the inlet valve 18 are also pneumatically controlled valves, further achieving full automation, significantly reducing the risk of human error and improving efficiency.

[0057] Specifically, in this embodiment, all valves, pumps, dosing devices 4, etc. are electrically connected to the control unit, and the control unit controls the operating sequence of each structure throughout the entire process.

[0058] In addition, the cleaning system of the present invention also includes a temperature transmitter (not shown), which is provided in the forward washing pipeline 27, between the mixer 7 and the water inlet of the ultrafiltration membrane 1. That is, when the cleaning liquid in the mixer 7 flows into the ultrafiltration membrane 1 from the input end of the forward washing pipeline, it passes through the temperature transmitter and enters the ultrafiltration membrane 1 from the water inlet of the ultrafiltration membrane 1. The temperature of the temperature transmitter is set to 33-35°C. The temperature control function of the temperature transmitter ensures that the cleaning liquid in the forward washing pipeline 27 cleans the ultrafiltration membrane 1 within the optimal temperature range of 33-35°C, which can effectively improve the cleaning liquid's ability to dissolve dirt on the membrane, thereby improving the cleaning efficiency and extending the operation time of the ultrafiltration membrane 1.

[0059] The cleaning system of the present invention will be described below in conjunction with the following embodiments.

[0060] Specifically, in this embodiment, the enhanced cleaning mode includes the following steps:

[0061] Soaking: Open the first valve 11, cleaning pump 3, dosing pump 5, third valve 13, backwash line valve 15, and concentrate drain valve 21. Water in the enhanced cleaning water tank 23 (from the production water pipe) first passes through the filter 30 to the mixer 7. Then, along with the cleaning agent in the dosing device 4, it reaches the mixer 7 via the dosing pump 5. After thorough mixing in the mixer 7, the water and cleaning agent form an enhanced cleaning solution with a concentration of 0.1% NaClO + 0.2% NaOH or 0.2% HCl. This solution enters the production water outlet of the ultrafiltration membrane tube 1 through the backwash line 29 and is discharged from the concentrate outlet of the ultrafiltration membrane 1 through the concentrate drain valve 21. Continue flushing for 60 seconds, allowing the enhanced cleaning solution to flush the interior of the ultrafiltration membrane 1 at a high flow rate and fill the entire membrane element. After 60 seconds, close the cleaning pump 3, dosing pump 5, and all valves, and allow the membrane to soak for 30-60 minutes. Then open the water inlet drain valve 20 for 10 seconds to drain the cleaning waste liquid in the ultrafiltration membrane 1, and close the water inlet drain valve 20 after 10 seconds. In this embodiment, technicians can choose the number of soaking times according to the degree of contamination of the ultrafiltration membrane 1, and soak it at least once.

[0062] Air washing: open the drain valve 21 on the concentrated water side and the fourth valve 19, and the air in the air inlet pipe 22 flows through the fourth valve 19 into the ultrafiltration membrane 1 for air washing. The process lasts for 30 seconds, then close the fourth valve 19 and the drain valve 21 on the concentrated water side, open the drain valve 20 on the water inlet side, discharge the cleaning waste liquid, and close the drain valve 20 on the water inlet side after 10 seconds.

[0063] Backwash: Open the first valve 11, the backwash pipeline valve 15 and the concentrate end drain valve 21, turn on the cleaning pump 3, and the water reaches the backwash pipeline 29 through the cleaning pump 5, the filter 30 and the mixer 7. The enhanced cleaning liquid in the backwash pipeline 29 enters from the water outlet of the ultrafiltration membrane 1 and is discharged from the concentrate outlet of the ultrafiltration membrane 1 through the concentrate end drain valve 21, and backwashing is continued.

[0064] Air-water washing: After backwashing continues for 15 seconds, the fourth valve 19 is opened to allow the air in the air inlet pipe 22 to flow through the fourth valve 19 into the ultrafiltration membrane 1, and the gas and liquid are mixed in the ultrafiltration membrane 1 to perform air-water washing. After backwashing continues for 30 seconds, the fourth valve 19 is closed.

[0065] Forward wash: After 5 seconds, forward wash line valve 14 is opened, and after 5 seconds, backwash line valve 15 is closed. Water in the enhanced wash water tank 23 flows through the first valve 11 into the wash pump inlet, then out of the wash pump outlet into the forward wash line 27. The enhanced wash liquid enters the water inlet of the ultrafiltration membrane 1 through the forward wash line 27 and is discharged from the concentrate outlet of the ultrafiltration membrane 1 through the concentrate end drain valve 21, performing forward wash of the ultrafiltration membrane for 30 seconds. The wash pump 3 and all valves are then closed, completing the enhanced wash mode and preparing the ultrafiltration membrane 1 for normal operation.

[0066] In this embodiment, the chemical cleaning mode includes the following steps:

[0067] Desalted water washing: The chemical cleaning water tank 2 is replenished with desalted water to the required level. The second valve 12, the forward wash line valve 14, the fifth valve 24, and the sixth valve 25 are opened to form a passage between the ultrafiltration membrane 1 and the chemical cleaning water tank 2. The cleaning pump 3 is turned on for circulating washing. The desalted water in the chemical cleaning water tank 2 passes through the cleaning pump 3, the filter 30, and the pipeline mixer 7 to reach the forward wash line 27. It enters the water inlet of the ultrafiltration membrane 1 through the forward wash line 27, is discharged from the concentrated water outlet of the ultrafiltration membrane 1, flows through the fifth valve 24, and returns to the chemical cleaning water tank 2 through the circulation line 28; and is discharged from the water outlet of the ultrafiltration membrane 1, flows through the sixth valve 25, and returns to the chemical cleaning water tank 2 through the circulation line 28. After 5 minutes of washing, the chemical cleaning water tank 2 is emptied.

[0068] Acid Wash: Open third valve 13. Dosing pump 5 delivers HCl stored in dosing device 4 to mixer 7 as needed via the dosing pump flowmeter. The chemical cleaning solution in chemical cleaning tank 2 is delivered as needed via cleaning pump 3 via the cleaning pump flowmeter. It first passes through filter 30 and is thoroughly mixed with HCl in mixer 7, forming a chemical cleaning solution with a chemical concentration of 0.2% HCl. The chemical cleaning solution with a concentration of 0.2% HCl enters the water inlet of ultrafiltration membrane 1 via forward wash line 27, exits through the concentrate outlet of ultrafiltration membrane 1, flows through fifth valve 24, and returns to chemical cleaning tank 2 via circulation line 28. It then exits the water outlet of ultrafiltration membrane 1, flows through sixth valve 25, and returns to chemical cleaning tank 2 via circulation line 28. After cleaning pump 3 runs for 30 minutes, all pumps and valves are closed, allowing ultrafiltration membrane 1 to soak for 2 hours.

[0069] First water wash: Add clean water to the chemical cleaning water tank 2 to the required liquid level, open the second valve 12, the forward wash pipeline valve 14, the fifth valve 24, and the sixth valve 25, so that the ultrafiltration membrane 1 and the chemical cleaning water tank 2 form a passage, and start the cleaning pump 3 for circulating washing. The clean water in the chemical cleaning water tank 2 passes through the cleaning pump 3, the filter 30, and the pipeline mixer 7 to reach the forward wash pipeline 27, enters the water inlet of the ultrafiltration membrane 1 through the forward wash pipeline 27, is discharged from the concentrated water outlet of the ultrafiltration membrane 1, flows through the fifth valve 24, and returns to the chemical cleaning water tank 2 through the circulation pipeline 28; and is discharged from the water outlet of the ultrafiltration membrane 1, flows through the sixth valve 25, and returns to the chemical cleaning water tank 2 through the circulation pipeline 28. After 5 minutes of cleaning, the chemical cleaning water tank 2 is emptied.

[0070] Alkali Wash: Open third valve 13. Dosing pump 5 delivers the NaClO and NaOH stored in dosing device 4 to mixer 7 as needed via the dosing pump flowmeter. The chemical cleaning solution in chemical cleaning tank 2 is delivered as needed via cleaning pump 3 via the cleaning pump flowmeter. It first passes through filter 30 and is mixed with NaClO and NaOH in mixer 7 to form a chemical cleaning solution with a concentration of 0.1% NaClO and 0.2% NaOH. The chemical cleaning solution with a concentration of 0.1% NaClO and 0.2% NaOH enters the water inlet of ultrafiltration membrane 1 via forward wash line 27, exits through the concentrate outlet of ultrafiltration membrane 1, flows through fifth valve 24, and returns to chemical cleaning tank 2 via circulation line 28. It then exits the water outlet of ultrafiltration membrane 1, flows through sixth valve 25, and returns to chemical cleaning tank 2 via circulation line 28. After cleaning pump 3 runs for 30 minutes, all pumps and valves are closed, allowing ultrafiltration membrane 1 to soak for 2 hours.

[0071] Second water wash: Refill the chemical cleaning water tank 2 with clean water to the required level. Open the second valve 12, the forward wash line valve 14, the fifth valve 24, and the sixth valve 25 to form a passage between the ultrafiltration membrane 1 and the chemical cleaning water tank 2. Turn on the cleaning pump 3 for a circulating wash. The clean water in the chemical cleaning water tank 2 passes through the cleaning pump 3, the filter 30, and the pipeline mixer 7 to reach the forward wash line 27. It then enters the water inlet of the ultrafiltration membrane 1 through the forward wash line 27, is discharged from the concentrated water outlet of the ultrafiltration membrane 1, flows through the fifth valve 24, and returns to the chemical cleaning water tank 2 through the circulation line 28. It also flows out of the water outlet of the ultrafiltration membrane 1, flows through the sixth valve 25, and returns to the chemical cleaning water tank 2 through the circulation line 28. After 5 minutes of washing, the chemical cleaning water tank 2 is emptied. Turn off all pumps and valves, the chemical cleaning mode is complete, and the ultrafiltration membrane 1 is ready to enter the normal operation procedure.

[0072] In summary, the chemical cleaning unit of the present invention does not need to be equipped with a complete set of chemical cleaning system equipment (such as a dosing pump, a cleaning pump, a filter, etc.), which reduces the number of equipment and saves costs. A first pressure transmitter 10 and a first flow meter 8 are set at the water inlet of the ultrafiltration membrane 1, and a second pressure transmitter 6 and a second flow meter 9 are set at the water outlet of the ultrafiltration membrane 1. The control unit (i.e., DCS or PCL) automatically monitors and calculates the transmembrane pressure difference and flow rate of the ultrafiltration membrane 1. If the pressure difference is too large and the flow rate is too small, the cleaning system automatically enters the enhanced cleaning mode. When the chemical cleaning mode requires the configuration of chemical cleaning agents, the corresponding agent concentration is calculated through the cleaning pump flow meter and the dosing pump flow rate, and enters the chemical cleaning water tank 2 through the circulation line 28, which can reduce the workload of manual operation of the drug dispensing and the risk of acid and alkali leakage. All valves in the present invention can be pneumatically controlled valves, which can realize the complete automation of the ultrafiltration membrane operation to cleaning, greatly reducing the risk of manual misoperation and improving efficiency. A temperature transmitter can be added to the ultrafiltration membrane inlet to detect the concentration of the cleaning solution for online enhanced backwash or offline chemical cleaning, and maintained at 33-35°C to improve the cleaning effect. Conventional ultrafiltration membrane inlet pump flow selection takes into account the flow required for forward flushing. Therefore, the ultrafiltration inlet pump motor power will be one level higher than the motor power required for the actual operating water inflow. The utility model achieves the effect of forward flushing by utilizing the high flow rate of the cleaning pump 3 and the chemical enhanced forward flushing pipeline 27, thereby improving the cleaning effect, reducing the motor power of the ultrafiltration inlet pump, and achieving the effect of energy saving.

[0073] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above description is provided to further illustrate the present invention in conjunction with specific embodiments, and that the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make various changes in form and detail, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A cleaning system for an ultrafiltration membrane, characterized in that: The cleaning system comprises: A cleaning pump, comprising a cleaning pump inlet and a cleaning pump outlet; The enhanced cleaning unit is capable of performing forward and backwashing on the ultrafiltration membrane, and the enhanced cleaning unit comprises: Enhanced cleaning water tank, used to store enhanced cleaning fluid; a first valve, one end of which is connected to the enhanced cleaning water tank and the other end of which is connected to the inlet of the cleaning pump; A chemical cleaning unit capable of performing positive cleaning on the ultrafiltration membrane, the chemical cleaning unit comprising: Chemical cleaning water tank, used to store chemical cleaning liquid; a second valve, one end of which is connected to the chemical cleaning water tank and the other end of which is connected to the cleaning pump inlet; The forward wash pipeline is connected to the outlet of the cleaning pump, and the enhanced cleaning liquid or the chemical cleaning liquid in the forward wash pipeline enters from the water inlet of the ultrafiltration membrane and is discharged from the concentrated water outlet of the ultrafiltration membrane and / or the water production outlet of the ultrafiltration membrane; the backwash pipeline is connected to the outlet of the cleaning pump, and the enhanced cleaning liquid in the backwash pipeline enters from the water production outlet of the ultrafiltration membrane and is discharged from the concentrated water outlet of the ultrafiltration membrane and / or the water inlet of the ultrafiltration membrane.

2. The ultrafiltration membrane cleaning system according to claim 1, characterized in that: The cleaning system also includes a dosing device, a dosing pump, a third valve and a mixer. The dosing device is used to store cleaning agents. The dosing pump includes a dosing pump inlet and a dosing pump outlet. The dosing pump inlet is connected to the dosing device, and the dosing pump outlet is connected to one end of the third valve. The input end of the mixer is respectively connected to the other end of the third valve and the cleaning pump outlet, and the output end of the mixer is respectively connected to the input end of the forward wash pipeline and the input end of the backwash pipeline.

3. The ultrafiltration membrane cleaning system according to claim 2, characterized in that: The cleaning pump includes a cleaning pump flowmeter, and the cleaning pump flowmeter is used to measure the flow of the cleaning pump; the dosing pump includes a dosing pump flowmeter, and the dosing pump flowmeter is used to measure the flow of the dosing pump.

4. The ultrafiltration membrane cleaning system according to claim 2, characterized in that: The cleaning system further comprises a filter, one end of which is connected to the outlet of the cleaning pump, and the other end of which is connected to the input end of the mixer.

5. The ultrafiltration membrane cleaning system according to claim 2, characterized in that: The cleaning system further includes an air intake pipeline and a fourth valve. The air intake pipeline is connected to the ultrafiltration membrane. The fourth valve is arranged on the air intake pipeline. The gas in the air intake pipeline flows through the fourth valve and enters the ultrafiltration membrane.

6. The ultrafiltration membrane cleaning system according to claim 5, characterized in that: The cleaning system also includes a circulation pipeline, a fifth valve and a sixth valve, one end of the fifth valve is connected to the concentrated water outlet of the ultrafiltration membrane, the other end of the fifth valve is connected to the input end of the circulation pipeline, one end of the sixth valve is connected to the water outlet of the ultrafiltration membrane, the other end of the sixth valve is connected to the input end of the circulation pipeline, and the output end of the circulation pipeline is connected to the chemical cleaning water tank.

7. The ultrafiltration membrane cleaning system according to claim 6, characterized in that: The first valve, the second valve, the third valve, the fourth valve, the fifth valve and the sixth valve are pneumatic control valves.

8. The ultrafiltration membrane cleaning system according to claim 2, characterized in that: The cleaning system further includes a filtration pipeline, which includes a first collection unit and a second collection unit; the first collection unit is connected to the water inlet of the ultrafiltration membrane, and the first collection unit is used to collect the flow rate and pressure of the water inlet of the ultrafiltration membrane; The second collection unit is connected to the water outlet of the ultrafiltration membrane, and is used to collect the flow rate and pressure of the water outlet of the ultrafiltration membrane.

9. The ultrafiltration membrane cleaning system according to claim 8, characterized in that: The cleaning system further includes a control unit connected to the first collection unit and the second collection unit, and the control unit is used to turn on or off the enhanced cleaning unit.

10. The ultrafiltration membrane cleaning system according to claim 2, characterized in that: The cleaning system further comprises a temperature transmitter, which is arranged in the forward washing pipeline and located between the mixer and the water inlet of the ultrafiltration membrane.

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