A hollow fiber membrane cleaning system

Abstract

The application relates to a hollow fiber membrane cleaning system, which comprises a normal-temperature water tank, a heated water tank, a cleaning liquid original solution tank and a cleaning liquid preparation tank; water pipelines are arranged between the normal-temperature water tank and the cleaning liquid original solution tank and the heated water tank respectively, an original solution pipeline is arranged between the cleaning liquid original solution tank and the cleaning liquid preparation tank, a hot water pipeline is arranged between the heated water tank and the cleaning liquid preparation tank; the heated water tank and the cleaning liquid preparation tank share a cleaning liquid inlet pipeline leading to an ultrafiltration membrane system, the ultrafiltration membrane system is connected with a cleaning liquid outlet pipeline; an inlet monitoring assembly is arranged on the cleaning liquid inlet pipeline, and an outlet detecting assembly is arranged on the cleaning liquid outlet pipeline. The utility model can improve the cleaning efficiency, optimize the energy efficiency, prolong the equipment service life, improve the automatic control degree, reduce the wastewater discharge amount, and is economic and environment-friendly.

Description

Technical Field

[0001] This application relates to the field of water treatment technology, and more specifically, to a hollow fiber membrane cleaning system. Background Technology

[0002] Ultrafiltration membranes are widely used in drinking water purification, wastewater treatment, food industry and other processes. However, during operation, the membrane surface is easily contaminated by organic matter, microorganisms, colloids and other substances, which leads to a decrease in membrane flux and an increase in transmembrane pressure difference. Regular cleaning is required to restore performance.

[0003] Existing cleaning technologies mainly include physical cleaning (such as backwashing and water cleaning) and chemical cleaning (such as using chemical reagents like sodium hypochlorite and sodium hydroxide). In recent years, with increasing demands for automation, various integrated cleaning systems have emerged, but these often suffer from problems such as limited cleaning modes, inaccurate temperature control, and poor material corrosion resistance. Related technological developments include multi-tank chemical cleaning systems, thermal cleaning (such as pasteurization) systems, and PLC-based automatic control systems; however, existing systems still have shortcomings in terms of flexibility, energy efficiency, and durability.

[0004] 1. Limited cleaning modes: The system can only perform cleaning in a fixed sequence and cannot flexibly select pasteurization, alkaline washing, sodium hypochlorite washing or their combinations according to the type of contamination, resulting in low cleaning efficiency.

[0005] 2. Insufficient temperature control: The temperature of the water used for solution preparation is not adjustable, and high-temperature cleaning relies solely on a single heating tank, resulting in low energy efficiency and an inability to achieve the synergistic effect of high-temperature chemical cleaning.

[0006] 3. The material is not corrosion resistant: The tank and pipeline are made of ordinary metal materials, which are easily oxidized and corroded by long-term contact with sodium hypochlorite and alkaline solutions, shortening the service life of the equipment.

[0007] 4. Low level of automation: The lack of automatic control over liquid flow rate, transmembrane pressure difference and pipeline evacuation means that the cleaning process relies on manual operation, which is prone to operational errors and incomplete cleaning.

[0008] 5. Poor system integration: Insufficient separation between the raw solution and the working solution tank, and inaccurate solution preparation process, which can easily lead to waste of chemicals or substandard concentration.

[0009] Existing cleaning systems often have fixed cleaning modes that cannot be flexibly switched; the solution temperature is uncontrollable, affecting the cleaning effect; the material is ordinary carbon steel, which is prone to corrosion; and they lack automatic control functions, such as precise adjustment of flow rate and transmembrane pressure difference. Utility Model Content

[0010] The purpose of this application is to provide a hollow fiber membrane cleaning system that can improve cleaning efficiency, optimize energy efficiency, extend equipment life, improve the degree of automation control, and reduce wastewater discharge, making it economical and environmentally friendly.

[0011] To achieve the above objectives, this utility model provides a hollow fiber membrane cleaning system, comprising: a normal temperature water tank, a heated water tank, a cleaning solution stock tank, and a cleaning solution mixing tank; Water supply pipelines are respectively provided between the ambient temperature water tank, the cleaning solution stock tank, and the heating water tank; a stock pipeline is provided between the cleaning solution stock tank and the cleaning solution mixing tank; and a hot water pipeline is provided between the heating water tank and the cleaning solution mixing tank. The heating water tank and the cleaning solution mixing tank share a cleaning inlet pipeline leading to the ultrafiltration membrane system, and the ultrafiltration membrane system is connected to a cleaning outlet pipeline. The cleaning inlet pipeline is equipped with an inlet monitoring component, and the cleaning outlet pipeline is equipped with an outlet detection component.

[0012] In an optional embodiment, the cleaning solution stock tank includes a sodium hypochlorite tank and a sodium hydroxide tank, and the cleaning solution mixing tank includes a sodium hypochlorite solution tank and a sodium hydroxide solution tank. The sodium hypochlorite tank, the sodium hydroxide tank, the sodium hypochlorite solution tank, the sodium hydroxide solution tank, and the heating water tank are each provided with a return pipeline.

[0013] In an optional embodiment, the ambient temperature water tank and the heated water tank are made of stainless steel; The cleaning solution stock tank and the cleaning solution mixing tank are made of the same material, namely stainless steel, PTFE, PVC, PP or FRP.

[0014] In an optional embodiment, the water supply pipeline, the raw liquid pipeline, the hot water pipeline, the cleaning liquid inlet pipeline, and the cleaning liquid outlet pipeline are all made of stainless steel or PVDF.

[0015] In an optional embodiment, each tank is equipped with a liquid transfer pump for liquid transportation. The liquid transfer pump includes a centrifugal pump or a metering pump. Both the centrifugal pump and the metering pump are variable frequency pumps, and the pump bodies are made of corrosion-resistant materials.

[0016] In an optional embodiment, control valves are respectively installed on the water supply pipeline, the raw liquid pipeline, the hot water pipeline, the cleaning liquid inlet pipeline, the cleaning liquid outlet pipeline, and the return pipeline. The control valves include butterfly valves or ball valves made of corrosion-resistant materials.

[0017] In an optional embodiment, each tank is provided with a drain line on its outlet pipe, and a drain valve is provided on the drain line. Each tank is equipped with a corresponding liquid outlet valve, and the venting pipeline is located upstream of the liquid outlet valve.

[0018] In an optional embodiment, the liquid inlet monitoring component includes an inlet pressure gauge and an inlet flow meter; The liquid discharge detection component includes a pH meter, a conductivity meter, and a residual chlorine detector; The hollow fiber membrane cleaning system also includes a control unit, and the liquid inlet monitoring component, the liquid outlet detection component, the control valve and the infusion pump are electrically connected to the control unit.

[0019] In an optional embodiment, the ultrafiltration membrane system includes multiple ultrafiltration membranes, each of which is provided with a corresponding cleaning outlet branch pipe, and the cleaning outlet branch pipe is provided with a branch pipe control valve and an outlet pressure gauge. Each of the ultrafiltration membranes is provided with a corresponding outlet branch pipe, which is connected to the cleaning outlet pipeline and is equipped with an outlet flow meter. The branch pipe control valve, the outlet pressure gauge, and the outlet flow meter are all electrically connected to the control unit.

[0020] In an optional embodiment, the heating water tank is equipped with an electric heating module, and a hot water cleaning pipeline is provided between the cleaning liquid outlet pipeline and the heating water tank.

[0021] The hollow fiber membrane cleaning system of this invention enables multi-mode cleaning of the ultrafiltration membrane system through the liquid supply pipelines set between different tanks and the cleaning liquid inlet pipeline set between the tanks and the ultrafiltration membrane system. The heating water tank not only directly provides high-temperature cleaning water, but also serves as the liquid preparation water for the cleaning liquid mixing tank, thereby improving the efficiency of chemical cleaning.

[0022] The tank and pipelines are made of corrosion-resistant materials such as 316L stainless steel or PVDF, and key components are treated with anti-oxidation to extend the equipment's lifespan.

[0023] The PLC or DCS system with integrated control unit can automatically adjust the liquid flow rate and transmembrane pressure difference, and can also drain the pipeline, ensuring a precise and safe cleaning process.

[0024] The cleaning solution mixing tank is used as the actual tank and is separated from the original solution tank. The concentration of the solution can be adjusted, reducing chemical residues.

[0025] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the process structure of the hollow fiber membrane cleaning system in this application.

[0028] icon: 1-Ambient temperature water tank; 2-Sodium hypochlorite tank; 3-Sodium hydroxide tank; 4-Heating water tank; 5-Sodium hypochlorite solution tank; 6-Sodium hydroxide solution tank; 7-Water supply line; 8-Solid solution line; 9-Hot water line; 10-Cleaning inlet line; 11-Cleaning outlet line; 12-Return line; 13-Drain line; 14-Drain valve; 15-Outlet valve; 16-Inlet pressure gauge; 17-Inlet flow meter; 18-pH meter; 19-Conductivity meter; 20-Residual chlorine detector; 21-Hot water cleaning line; 22-Electric heating module. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] See Figure 1 The hollow fiber membrane cleaning system in this application has a main structure including a tank system and a pipeline system. The tank system mainly includes a water tank unit, a raw liquid tank unit, and a cleaning solution mixing tank unit.

[0033] The water tank unit includes an ambient temperature water tank 1 and a heated water tank 4, which provide ambient temperature cleaning water and hot water for cleaning. The stock solution tank unit includes a sodium hypochlorite tank 2 and a sodium hydroxide tank 3, which provide the stock solution for cleaning, and are used to store the sodium hypochlorite stock solution and sodium hydroxide stock solution, respectively. The cleaning solution mixing tank unit specifically includes a sodium hypochlorite solution tank 5 and a sodium hydroxide solution tank 6, which are used to store the sodium hypochlorite cleaning solution and sodium hydroxide cleaning solution, respectively, which are prepared by mixing hot water with the stock solution.

[0034] By installing water supply lines 7 between the ambient temperature water tank 1 and the cleaning solution stock tank and the heating water tank 4, a stock solution line 8 between the cleaning solution stock tank and the cleaning solution mixing tank, and a hot water line 9 between the heating water tank 4 and the cleaning solution mixing tank, and by combining the cleaning inlet line 10 connecting the heating water tank 4 and the cleaning solution mixing tank to the ultrafiltration membrane system, and by connecting the ultrafiltration membrane system to the cleaning outlet line 11, different cleaning solutions can be prepared, and different cleaning modes can be adjusted.

[0035] This application enables flexible switching between pasteurization, room temperature water cleaning, high temperature alkaline solution cleaning, high temperature sodium hypochlorite cleaning, and different mixing modes through the interconnection of different tanks and valve control.

[0036] The heating water tank 4 can not only provide heated high-temperature hot water for cleaning the ultrafiltration membrane in pasteurization mode, but also serve as the water for preparing the cleaning solution in the mixing tank, thereby improving the efficiency of chemical cleaning.

[0037] Sodium hypochlorite solution tank 5 and sodium hydroxide solution tank 6 can provide the cleaning solution used in the actual cleaning process. By separating them from the original solution tank, the concentration of the solution can be adjusted, reducing chemical residues.

[0038] The inlet monitoring component installed on the cleaning inlet pipeline 10 and the outlet detection component installed on the cleaning outlet pipeline 11, together with the control unit, can automatically adjust the liquid flow rate and transmembrane pressure difference, and realize pipeline evacuation, ensuring the cleaning process is accurate and safe.

[0039] The sodium hypochlorite tank 2, sodium hydroxide tank 3, sodium hypochlorite solution tank 5, sodium hydroxide solution tank 6, and heating water tank 4 are each equipped with a reflux pipe 12, which can realize the mixing and circulation of different solutions.

[0040] The tanks and pipes in this application are made of corrosion-resistant materials, and key components are treated with anti-oxidation to extend the service life of the equipment.

[0041] Specifically, the ambient temperature water tank 1 provides ambient temperature rinsing water and is made of stainless steel 304 or 316L.

[0042] The heating water tank 4 is a high-temperature water tank with electric heating. The heating method includes electric heating tubes or coils. The temperature is usually adjusted in the range of 30-100℃. The material is 316L stainless steel and is equipped with a heat insulation layer.

[0043] Sodium hypochlorite tank 2 stores high-concentration sodium hypochlorite stock solution and is made of chlorine-resistant stainless steel, PTFE, PVC, PP, or FRP. Sodium hydroxide tank 3 stores high-concentration alkaline solution and is made of stainless steel, PTFE, PVC, PP, or FRP.

[0044] Sodium hypochlorite solution tank 5 provides sodium hypochlorite solution for actual cleaning, receives the original sodium hypochlorite solution from the sodium hypochlorite stock tank and the high-temperature water from the heating water tank 4, and prepares a sodium hypochlorite solution with a working concentration such as 0.1-0.5%. The material is the same as that of sodium hypochlorite tank 2.

[0045] Sodium hydroxide solution tank 6 provides the alkaline solution for actual cleaning, receives the original sodium hydroxide solution from tank 3 and high-temperature water from heating water tank 4, and prepares an alkaline solution with a working concentration such as 0.1-1.0%. The material is the same as that of sodium hydroxide tank 3.

[0046] To reduce corrosion of equipment, pipes, and valves, the water supply line 7, raw liquid line 8, hot water line 9, cleaning inlet line 10, and cleaning outlet line 11 are all made of stainless steel or PVDF.

[0047] Each tank is equipped with a corresponding infusion pump for liquid transfer. The infusion pumps include centrifugal pumps or metering pumps. Both centrifugal pumps and metering pumps are variable frequency pumps, and the pump bodies are made of corrosion-resistant materials.

[0048] Control valves are installed on the water supply line 7, raw liquid line 8, hot water line 9, cleaning liquid inlet line 10, cleaning liquid outlet line 11, and return line 12. These control valves include butterfly valves or ball valves made of corrosion-resistant materials. This arrangement extends the service life of the equipment, pipelines, and valves.

[0049] Each tank is equipped with a drain line 13 on its outlet pipe, and a drain valve 14 is installed on the drain line 13 to facilitate the emptying of the tank. Each tank is also equipped with a corresponding outlet valve 15. By placing the drain line 13 upstream of the outlet valve 15, the complete emptying of the tank can be ensured.

[0050] The liquid inlet monitoring component includes a liquid inlet pressure gauge 16 and a liquid inlet flow meter 17. The liquid outlet detection component includes a pH meter 18, a conductivity meter 19 and a residual chlorine detector 20. The hollow fiber membrane cleaning system also includes a control unit. The liquid inlet monitoring component, the liquid outlet detection component, the control valve and the infusion pump are electrically connected to the control unit.

[0051] The ultrafiltration membrane system includes multiple ultrafiltration membranes, each of which is equipped with a corresponding cleaning outlet branch pipe. The cleaning outlet branch pipe is equipped with a branch pipe control valve and an outlet pressure gauge.

[0052] Each ultrafiltration membrane is equipped with a corresponding outlet branch pipe, which is connected to the cleaning outlet pipeline 11. An outlet flow meter is installed on the outlet branch pipe. The branch pipe control valve, outlet pressure gauge, and outlet flow meter are electrically connected to the control unit. This configuration enables automatic control of the cleaning system. From an automatic control perspective, this mainly includes: Liquid flow rate control: The flushing flow rate can be adjusted through feedback from the variable frequency pump and flow meter to avoid membrane damage.

[0053] Transmembrane pressure differential control: Pressure sensors monitor the pressure differential between the membrane inlet and outlet, and automatically adjust the flow rate or trigger an alarm when the pressure differential is abnormal.

[0054] Pipeline evacuation control: After cleaning, the valve automatically switches to use compressed air or gravity to drain the residual liquid in the pipeline into the wastewater pool to prevent crystallization or corrosion.

[0055] Solution concentration control: Sodium hypochlorite solution tank 5 and sodium hydroxide solution tank 6 are equipped with level gauges and concentration sensors to automatically control the mixing ratio of the stock solution and water.

[0056] The heating water tank 4 is equipped with an electric heating module 22, which can heat hot water. A hot water cleaning pipeline 21 is installed between the cleaning outlet pipeline 11 and the heating water tank 4, which can perform circulating hot cleaning. The heating element of the electric heating module 22 of the heating water tank 4 is made of titanium to avoid high-temperature oxidation, and the system is grounded to prevent static electricity.

[0057] All components that come into contact with chemicals are made of corrosion-resistant materials, welds are passivated, and pipe inner walls are smooth to reduce residue. The system is equipped with overflow and leakage sensors and an emergency shutdown function.

[0058] In the specific layout, the pipeline is designed with an inclination to facilitate drainage. The infusion pump can be frequency-controlled to adjust the flow rate. The control unit is a PLC-based automatic control system that integrates a human-machine interface (HMI), programmable cleaning process, and real-time monitoring of parameters such as transmembrane pressure difference, flow rate, and temperature.

[0059] The different cleaning modes mainly include the following modes: 1. Sodium hypochlorite solution preparation: Sodium hypochlorite tank 2 contains high-concentration sodium hypochlorite and supplies sodium hypochlorite to sodium hypochlorite solution tank 5 for solution preparation. Sodium hypochlorite solution tank 5 preparation: With valves V8 and V28 closed, water from heating water tank 4 at a certain temperature enters sodium hypochlorite solution tank 5 through valve V5, pump 2, valve V7, flow meter F7, and valve V27. With valves V10 and V12 closed, high-concentration sodium hypochlorite flows from sodium hypochlorite tank 2 through valve V11, pump 3, flow meter F4, and valve V13 into sodium hypochlorite solution tank 5. The flow rates of water and sodium hypochlorite solution entering sodium hypochlorite solution tank 5 are controlled by flow meters F4 and F7. With valves V14 and V17 closed, internal mixing is achieved through valve V15, pump 4, thermometer T2, valve V16, and flow meter F7 in return pipe 12, resulting in a sodium hypochlorite solution with a concentration of 500–2000 mg / L.

[0060] 2. Sodium hydroxide solution preparation: Same as in Implementation Scheme 1. Sodium hydroxide tank 3 contains high-concentration sodium hydroxide, which is used to supply sodium hydroxide solution tank 6 for solution preparation. Sodium hydroxide solution tank 6 solution preparation: With valves V8 and V27 closed, water from heating water tank 4 at a certain temperature enters sodium hydroxide solution tank 6 through valve V5, pump 2, valve V7, flow meter F7, and valve V28; with valves V19 and V21 closed, high-concentration sodium hydroxide flows from sodium hydroxide tank 3 through valve V20, pump 5, flow meter F5, and valve V22 into sodium hydroxide solution tank 6. The flow rates of water and sodium hydroxide solution entering sodium hydroxide solution tank 6 are controlled by flow meters F5 and F7; with valves V14 and V17 closed, internal mixing is achieved through valve V24, pump 6, thermometer T3, valve V25, and flow meter F9 in return pipe 12 to obtain a sodium hydroxide solution of a certain concentration.

[0061] 3. Room temperature water flushing (10-30℃): Room temperature water is supplied to the ultrafiltration membrane system and flushed at a certain flow rate to remove loose contaminants from the ultrafiltration membrane surface. Specific implementation: Water is introduced into room temperature water tank 1. Valves V2, V3, V6, and V7 are closed, while valves V1, V4, V5, V8, V29, V30, V31, V32, V33, and V34 are opened. Purified water enters through room temperature water tank 1 and heated water tank 4, and exits through the inlet of the hollow fiber membrane module, the concentrate outlet, and the product water outlet. It can be discharged to the floor drain through valve V35. The membrane module pressure differential and product water flow rate can be adjusted through valves V30, V32, and V34. The inlet and product water flow rates can be observed through flow meters F10, F11, F12, and F13.

[0062] 4. Pasteurization and High-Temperature Water Rinsing (30-95℃): Conventional pasteurization involves supplying high-temperature water from heating tank 4 through pipelines to the membrane system, maintaining a specific temperature and time to pasteurize the ultrafiltration membrane, killing bacteria and microorganisms on the membrane surface. Specific parameters can be adjusted according to actual conditions, such as controlling the temperature at 80-90℃ and the disinfection time at 30-60 minutes. Specific implementation: The water source for heating tank 4 can be externally connected or connected through ambient temperature water tank 1. Heating tank 4 can provide high-temperature water to the entire system through its own electric heating module 22. When heating water in heating tank 4, the water level should be higher than the electric heating module 22 to prevent dry burning. Close valves V6 and V8, and open valves V5 and V7. Pump 2 and return pipeline 12 enable self-circulation heating of heating tank 4. Thermometer T1 displays the water temperature inside the tank. When the water temperature reaches the set temperature, the electric heating automatically stops. Set the electric heating temperature to 80-90℃, close valves V6 and V7. High-temperature water flows into the membrane module through valves V5 and V8, pressure gauge P1, and flow meter F10. It then flows through valves V30, flow meter F11, V32, F12, V34, and F13, and finally returns to the heating water tank 4 through valve V38, circulating for 30-60 minutes to achieve the pasteurization process. If only rinsing is required, the water can flow into the floor drain through valve V35.

[0063] 5. Sodium hypochlorite cleaning: The sodium hypochlorite stock solution in sodium hypochlorite tank 2 is mixed with high-temperature water in heating water tank 4 in sodium hypochlorite solution tank 5 to prepare a high-temperature sodium hypochlorite solution. This solution is then transferred to the membrane system to flush the membrane, removing biological contaminants and some recalcitrant organic contaminants from the membrane surface. The temperature is generally controlled at 35-55℃, the sodium hypochlorite concentration is controlled at 500-2000 mg / L, and the flushing time is 30-120 min. Detailed Implementation: Valves V8, V14, V16, and V36 are closed. Sodium hypochlorite at a specific temperature, prepared in sodium hypochlorite solution tank 5, flows into the membrane module through valve V15, pump 4, thermometer T2, valve V17, pressure gauge P1, and flow meter F10. The sodium hypochlorite then returns to sodium hypochlorite solution tank 5 through valves V30, V32, V34, and flow meters F11, F12, and F13, via valve V37, thus achieving a cleaning cycle. The influent flow rate can be controlled by valves at both ends of the membrane module. Multiple membrane modules M1, M2, M3… can be cleaned individually or in combination. When sodium hypochlorite solution tank 5 needs cleaning or re-preparation, valve V14 can be opened for discharge. The sodium hypochlorite solution tank 5 can be cleaned using a normal temperature water tank 1 and a heated water tank 4.

[0064] 6. Sodium hydroxide cleaning: First, the sodium hydroxide stock solution in sodium hydroxide tank 3 and the high-temperature water in heating water tank 4 are transferred to sodium hydroxide solution tank 6 in a certain proportion to prepare a high-temperature alkaline solution. Then, the high-temperature alkaline solution is transferred to the ultrafiltration membrane system for rinsing under certain temperature, pressure, and time conditions to remove organic contaminants and grease from the membrane surface. For example, the temperature is controlled at 50-80℃, the transmembrane pressure difference is controlled at 0.1-0.3MPa, and the rinsing time is 30-90min. Specific implementation method: Close valves V8, V23, V25, and V37. The sodium hydroxide prepared at a certain temperature in sodium hydroxide solution tank 6 flows into the membrane module through valve V24, pump 6, thermometer T3, valve V26, pressure gauge P1, and flow meter F10. The sodium hydroxide can return to sodium hydroxide solution tank 6 through valves V30, V32, V34, and flow meters F11, F12, and F13, and then through valve V36 to achieve a cleaning cycle. The feed rate can be controlled by valves at both ends of the membrane module. Multiple membrane module control units M1, M2, M3, etc., can be cleaned individually or in combination. When the sodium hydroxide solution tank 6 needs to be cleaned or re-prepared, valve V23 can be opened for discharge. The sodium hydroxide solution tank 6 can be cleaned using room temperature water tank 1 and heated water tank 4.

[0065] 7. Cleaning Modes: Depending on the fouling level of the ultrafiltration membrane, a combination of the above cleaning methods can be selected automatically or manually to achieve the best cleaning effect.

[0066] ① For membranes that require regular pasteurization, step 4 can be performed separately; ② Alkaline cleaning: For slightly fouled membranes or those with biofilm, first perform step 3 to rinse the surface contaminants of the membrane module; then perform step 6 to remove biofouling from the membrane module using a high-temperature alkaline solution. The cleaning effect can be observed by comparing the membrane flux before and after cleaning, thereby determining the required concentration of cleaning solution and cleaning time. When the membrane module flux returns to its initial value, the alkaline cleaning is considered complete. After cleaning the membrane module to neutrality through step 3, and ensuring the conductivity is within the acceptable range, the membrane module cleaning is considered complete.

[0067] ③ Sodium hypochlorite cleaning: For severely fouled membrane modules, use high-temperature sodium hypochlorite for cleaning. First, perform step 4, softening the organic matter adhering to the membrane pores and surface with high-temperature water (30-80℃, 10-30 min). Then, perform step 5, removing organic pollutants with sodium hypochlorite at a specific temperature to restore membrane flux. Pay attention to the rinsing temperature, sodium hypochlorite concentration, and rinsing time in this step. A temperature of 35-55℃, a sodium hypochlorite concentration of 500-1000 mg / L, and a rinsing time of 30-120 min are recommended. Compare the membrane flux before and after cleaning to observe the cleaning effect. Cleaning is considered complete when the membrane module flux returns to its initial value. After cleaning the membrane module to neutrality using step 3, with conductivity and residual chlorine within acceptable ranges, the membrane module cleaning is considered complete.

[0068] In addition, it can also perform cleaning modes such as mixed cleaning with alkaline solution and sodium hypochlorite, and cleaning modes with high-temperature water and alkaline solution, which can be adjusted according to specific actual needs.

[0069] Compared with existing technologies, the cleaning system in this application has multiple modes that can be flexibly switched to adapt to different types of contamination and shorten the cleaning cycle; high-temperature liquid preparation enhances chemical reactions and improves the cleaning effect.

[0070] The water heater can be used for multiple purposes, reducing heating energy loss and improving energy efficiency.

[0071] Corrosion-resistant materials and venting design extend equipment life and reduce maintenance costs.

[0072] Fully automated control reduces human intervention, lowers operational errors, and ensures consistent cleaning.

[0073] Precise solution preparation reduces chemical consumption and wastewater discharge.

[0074] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0075] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hollow fiber membrane cleaning system, characterized in that, include: Ambient temperature water tank, heated water tank, cleaning solution concentrate tank, and cleaning solution mixing tank; Water supply pipelines are respectively provided between the ambient temperature water tank, the cleaning solution stock tank, and the heating water tank; a stock pipeline is provided between the cleaning solution stock tank and the cleaning solution mixing tank; and a hot water pipeline is provided between the heating water tank and the cleaning solution mixing tank. The heating water tank and the cleaning solution mixing tank share a cleaning inlet pipeline leading to the ultrafiltration membrane system, and the ultrafiltration membrane system is connected to a cleaning outlet pipeline. The cleaning inlet pipeline is equipped with an inlet monitoring component, and the cleaning outlet pipeline is equipped with an outlet detection component.

2. The hollow fiber membrane cleaning system according to claim 1, characterized in that, The cleaning solution stock tank includes a sodium hypochlorite tank and a sodium hydroxide tank, and the cleaning solution mixing tank includes a sodium hypochlorite solution tank and a sodium hydroxide solution tank. The sodium hypochlorite tank, the sodium hydroxide tank, the sodium hypochlorite solution tank, and the heating water tank are each equipped with a return pipeline.

3. The hollow fiber membrane cleaning system according to claim 1, characterized in that, The ambient temperature water tank and the heated water tank are made of stainless steel. The cleaning solution stock tank and the cleaning solution mixing tank are made of the same material, namely stainless steel, PTFE, PVC, PP or FRP.

4. The hollow fiber membrane cleaning system according to claim 1, characterized in that, The water supply pipeline, the raw liquid pipeline, the hot water pipeline, the cleaning liquid inlet pipeline, and the cleaning liquid outlet pipeline are all made of stainless steel or PVDF.

5. The hollow fiber membrane cleaning system according to claim 2, characterized in that, Each tank is equipped with a corresponding infusion pump for liquid transfer. The infusion pump includes a centrifugal pump or a metering pump. Both the centrifugal pump and the metering pump are variable frequency pumps, and the pump bodies are made of corrosion-resistant materials.

6. The hollow fiber membrane cleaning system according to claim 5, characterized in that, Control valves are respectively installed on the water supply pipeline, the raw liquid pipeline, the hot water pipeline, the cleaning liquid inlet pipeline, the cleaning liquid outlet pipeline, and the return pipeline. The control valves include butterfly valves or ball valves made of corrosion-resistant materials.

7. The hollow fiber membrane cleaning system according to claim 5, characterized in that, Each tank is equipped with a drain line on its outlet pipe, and a drain valve is installed on the drain line. Each tank is equipped with a corresponding liquid outlet valve, and the venting pipeline is located upstream of the liquid outlet valve.

8. The hollow fiber membrane cleaning system according to claim 6, characterized in that, The liquid inlet monitoring component includes a liquid inlet pressure gauge and a liquid inlet flow meter; The liquid discharge detection component includes a pH meter, a conductivity meter, and a residual chlorine detector; The hollow fiber membrane cleaning system also includes a control unit, and the liquid inlet monitoring component, the liquid outlet detection component, the control valve and the infusion pump are electrically connected to the control unit.

9. The hollow fiber membrane cleaning system according to claim 8, characterized in that, The ultrafiltration membrane system includes multiple ultrafiltration membranes, each of which is provided with a corresponding cleaning outlet branch pipe. The cleaning outlet branch pipe is equipped with a branch pipe control valve and an outlet pressure gauge. Each of the ultrafiltration membranes is provided with a corresponding outlet branch pipe, which is connected to the cleaning outlet pipeline, and an outlet flow meter is provided on the outlet branch pipe. The branch pipe control valve, the outlet pressure gauge, and the outlet flow meter are all electrically connected to the control unit.

10. The hollow fiber membrane cleaning system according to claim 9, characterized in that, The heating water tank is equipped with an electric heating module, and a hot water cleaning pipeline is installed between the cleaning liquid outlet pipeline and the heating water tank.

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