Ultrafiltration membrane water purification system

Abstract

The present invention relates to an ultrafiltration membrane water purification system, in which an ultrafiltration membrane filtering device includes a membrane pool and a membrane treatment unit, a membrane pool liquid level sensor is arranged in the membrane pool, a raw water pipe is connected to a reaction precipitator through an inlet switch valve, a coarse filter, an inlet electric regulating valve, a flocculant dosing mixing unit, and an inlet flow meter, the reaction precipitator is connected to the membrane pool, water in the membrane pool enters the membrane treatment unit through the hollow ultrafiltration membrane surface, the membrane treatment unit outlet pipe is connected to a clear water tank through an outlet flow meter, an outlet electric regulating valve, and a disinfectant dosing unit, and is also connected to a water ring pump unit, a self-priming pump unit, and a backwash water system at the same time, the air outlet pipe of the fan unit enters the membrane pool and is connected to a gas distributor at the bottom of the membrane treatment unit; the control unit is electrically connected to the membrane pool liquid level sensor to control the outlet flow according to the membrane pool water level, and the control unit is electrically connected to each unit and each electric control valve to control the system operation. The system has not only good water purification effect, but also high automation and flexible adjustment.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to an ultrafiltration membrane water purification system. Background Art

[0002] Many existing small-scale drinking water purification equipment are inconvenient to manage, difficult to operate, and have poor water purification effects, and cannot meet the standards for drinking water. Some water purification equipment using activated carbon adsorption and ion exchange technology requires a high level of management and high operating costs, making it difficult to promote and apply in rural areas. Therefore, it is urgent to develop a small-scale micro-powered drinking water purification equipment with good water purification effect, high degree of automation, and flexible adjustment to meet the drinking water needs in rural areas. Summary of the invention

[0003] The object of the present invention is to provide an ultrafiltration membrane water purification system, which not only has a good water purification effect, but also has a high degree of automation and flexible regulation.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is: an ultrafiltration membrane water purification system, including an inlet switch valve, a coarse filter, an inlet electric regulating valve, a flocculant dosing mixing unit, an inlet flow meter, a reaction precipitator, an ultrafiltration membrane filtering device, an outlet flow meter, an outlet electric regulating valve, a disinfectant dosing unit, a clear water tank, a fan unit, a water ring pump unit, a self-priming pump unit, a backwash water system, various connecting pipelines and a control unit, the ultrafiltration membrane filtering device includes a membrane pool and a membrane treatment unit, a membrane pool liquid level sensor is provided in the membrane pool, and the membrane treatment unit is installed in the center of the membrane pool; the raw water pipe is connected to the inlet switch valve, the coarse filter, the inlet electric regulating valve, the flocculant dosing mixing unit, the inlet flow meter, the reaction precipitator, the ultrafiltration membrane filtering device, the outlet flow meter, the outlet electric regulating valve, the disinfectant dosing unit, the clear water tank, the fan unit, the water ring pump unit, the self-priming pump unit, the backwash water system, various connecting pipelines and a control unit The meter is connected to the inlet of the reaction precipitator, and the outlet of the reaction precipitator is connected to the inlet of the membrane pool. The water in the membrane pool passes through the surface of the hollow ultrafiltration membrane of the membrane treatment unit at a certain flow rate and enters the membrane treatment unit. The outlet pipe of the membrane treatment unit is connected to the clean water tank through the outlet flow meter, the outlet electric regulating valve, and the disinfectant addition unit in sequence. The outlet pipe of the membrane treatment unit is also connected to the water ring pump unit, the self-priming pump unit, and the backwash water system at the same time. The air outlet pipe of the fan unit enters the membrane pool and is connected to the gas distributor at the bottom of the membrane treatment unit; the control unit is electrically connected to the membrane pool liquid level sensor to control the water outlet flow rate according to the membrane pool water level, and the control unit is electrically connected to each unit and each electric control valve to control the operation of the entire system.

[0005] Furthermore, the flocculant adding and mixing unit includes a coagulant adding metering pump, a coagulant barrel, a coagulant aid adding metering pump, a coagulant aid barrel and a tubular static mixer. The outlet pipe of the coagulant barrel is connected to the connecting pipeline between the water inlet electric regulating valve and the tubular static mixer via the coagulant adding metering pump and a first ball valve. The outlet pipe of the coagulant aid barrel is connected to the middle inlet of the tubular static mixer via the coagulant aid adding metering pump and a second ball valve to improve the coagulation effect. The outlet of the tubular static mixer is connected to a water inlet flowmeter. The control unit is electrically connected to the coagulant adding metering pump and the coagulant aid adding metering pump to control the dosage of the coagulant and the coagulant aid.

[0006] Furthermore, a first butterfly valve is provided on the connecting pipeline between the water inlet flowmeter and the inlet of the reaction precipitator, and the connecting pipeline of the outlet of the reaction precipitator is divided into three routes. The first route is connected to the membrane pool inlet via the second butterfly valve, the second route is connected to the medicinal water pipeline via the first gate valve, which is used for medicinal water for coagulants and coagulant aids, and the third route is connected to the clear water tank via a bypass electric butterfly valve.

[0007] Furthermore, the position of the membrane pool is higher than the clean water pool, so as to produce water without power based on the siphon principle by utilizing the height difference between the membrane pool and the clean water pool.

[0008] Furthermore, a water production constant current control module is provided in the control unit, and a corresponding relationship table between the linear change of the water outlet flow rate and the nonlinear opening of the water outlet electric regulating valve is provided in the water production constant current control module, and the maximum value and the minimum value of the membrane pool water level are stored in the water production constant current control module. The membrane pool liquid level sensor detects the membrane pool water level in real time and sends it to the control unit, and the control unit transmits the received data to the water production constant current control module. When the water production constant current control module monitors that the membrane pool water level is higher than the maximum value of the membrane pool water level or lower than the minimum value of the membrane pool water level, the water outlet flow that needs to be adjusted is intelligently calculated. The amount is measured, and then the opening of the outlet electric regulating valve that needs to be opened or closed is found from the corresponding relationship table according to the outlet water flow rate that needs to be adjusted; if the membrane pool water level remains stable between the highest value and the lowest value of the membrane pool water level after adjustment, the adjustment of the opening of the outlet electric regulating valve is stopped; if after a certain period of adjustment, the membrane pool water level drops from the highest value to the lowest value or rises from the lowest value to the highest value of the membrane pool water level, the outlet electric regulating valve is closed or opened in reverse to a certain degree, so that the membrane pool water level remains stable between the highest value and the lowest value of the membrane pool water level.

[0009] Furthermore, a pressure sensor is provided on the outlet pipe of the membrane treatment unit, and the pressure sensor detects the outlet water pressure of the membrane treatment unit in real time and sends it to the control unit; the control unit stores the membrane pool inlet pipe diameter, the membrane treatment unit outlet pipe diameter, the membrane treatment unit related structural parameters, the time since the last backwashing, and the membrane treatment unit outlet water pressure data;

[0010] The water production constant flow control module is provided with an outlet flow automatic adjustment model based on a neural network model, and the water production constant flow control module trains the neural network model through historical adjustment data to obtain a trained outlet flow automatic adjustment model, and the historical adjustment data include the membrane pool inlet diameter, the membrane treatment unit outlet diameter, the membrane treatment unit related structural parameters, the time since the last backwashing, the membrane treatment unit outlet pressure, the membrane treatment unit outlet flow, the membrane pool water level rise or fall speed, the outlet flow adjustment amount and the adjustment result feedback data, and the adjustment result feedback data include whether the membrane pool water level is stable after adjustment, and if it is not stable, the time for the membrane pool water level to drop from the highest value to the lowest value or rise from the lowest value to the highest value, the reverse adjustment amount and the subsequent adjustment result feedback data;

[0011] When the water production constant flow control module monitors that the real-time membrane pool water level is higher than the maximum value of the membrane pool water level or lower than the minimum value of the membrane pool water level, the water outlet flow automatic adjustment model is called according to the current relevant data to predict and output the water outlet flow that needs to be adjusted this time, so that the adjusted membrane pool water level can reach stability as soon as possible; after this adjustment, the water production constant flow control module trains and updates the water outlet flow automatic adjustment model through the adjustment data of this time.

[0012] Furthermore, it includes at least two disinfectant dosing units, the drug outlet pipe of the first disinfectant dosing unit is connected to the connecting pipeline between the water outlet electric regulating valve and the clean water tank to add sodium hypochlorite disinfectant to the clean water after ultrafiltration membrane filtration, and the drug outlet pipe of the second disinfectant dosing unit is connected to the membrane tank to add sodium hypochlorite disinfectant to the water in the membrane tank.

[0013] Furthermore, the water ring pump unit comprises a first electric gate valve, a water ring pump and a water ring pump water tank, the outlet pipe of the membrane treatment unit is connected to the water ring pump inlet through the first electric gate valve, and the water ring pump outlet is connected to the water ring pump water tank.

[0014] Furthermore, the self-priming pump unit includes a first electric butterfly valve, a self-priming pump, a first check valve and a second gate valve, and the backwash water system includes a third gate valve, a second electric butterfly valve, a second check valve, a backwash pump, a third butterfly valve, a backwash water tank and a third disinfectant dosing unit; one of the outlet pipes of the membrane treatment unit is connected to the self-priming pump inlet through the first electric butterfly valve, and the self-priming pump outlet pipe extends into the backwash water tank after passing through the first check valve and the second gate valve; the backwash pump inlet pipe is connected to the backwash water tank through the third butterfly valve, and the backwash pump outlet pipe is connected to the outlet pipe of the membrane treatment unit through the second check valve, the second electric butterfly valve and the third gate valve; the drug outlet pipe of the third disinfectant dosing unit is connected to the connecting pipeline between the backwash pump and the second check valve.

[0015] Furthermore, the fan unit includes a third electric butterfly valve, a third check valve and a fan, and the air outlet pipe of the fan passes through the third check valve and the third electric butterfly valve, enters the membrane pool and is connected to the gas distributor at the bottom of the membrane treatment unit.

[0016] Compared with the prior art, the present invention has the following beneficial effects: it provides an ultrafiltration membrane water purification system, which combines conventional water purification technologies such as flocculation reaction and precipitation with submerged membrane filtration technology, and automatically controls the operation of the equipment through a control unit, which not only has a good water purification effect, but also has flexible adjustment, and can achieve stable and reliable constant flow water production with less power, meeting the demand for safe drinking water in rural areas. Therefore, the present invention has strong practicality and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a system implementation principle of an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0021] like Figure 1As shown, this embodiment provides an ultrafiltration membrane water purification system, including an inlet switch valve 1, a coarse filter 42, an inlet electric regulating valve 2, a flocculant dosing mixing unit, an inlet flowmeter 3, a reaction precipitator 4, an ultrafiltration membrane filtering device, an outlet flowmeter 5, an outlet electric regulating valve 6, a disinfectant dosing unit 7, a clear water tank 8, a fan unit, a water ring pump unit, a self-priming pump unit, a backwash water system, various connecting pipelines and a control unit, the ultrafiltration membrane filtering device includes a membrane pool 9 and a membrane treatment unit 10, the membrane pool 9 is provided with a membrane pool liquid level sensor 11, and the membrane treatment unit 10 is installed in the center of the membrane pool 9; the raw water pipe is connected to the inlet of the reaction precipitator 4 in turn through the inlet switch valve 1, the coarse filter 42, the inlet electric regulating valve 2, the flocculant dosing mixing unit, and the inlet flowmeter 3, and the reaction precipitator The outlet of the precipitator 4 is connected to the inlet of the membrane pool 9. The water in the membrane pool 9 passes through the hollow ultrafiltration membrane surface of the membrane treatment unit 10 at a certain flow rate and enters the membrane treatment unit 10. The outlet pipe of the membrane treatment unit 10 is connected to the clean water pool 8 through the outlet flow meter 5, the outlet electric regulating valve 6, and the disinfectant addition unit 7 in sequence. The outlet pipe of the membrane treatment unit 10 is also connected to the water ring pump unit, the self-priming pump unit, and the backwash water system. The air outlet pipe of the fan unit enters the membrane pool and is connected to the gas distributor at the bottom of the membrane treatment unit. Many gas distribution holes are evenly arranged on the gas distributor, which are used to achieve gas-water mixed flushing during backwashing; the control unit is electrically connected to the membrane pool liquid level sensor to control the water outlet flow according to the membrane pool water level. The control unit is electrically connected to each unit and each electric control valve to control the operation of the entire system.

[0022] In this embodiment, the valve body of the water inlet switch valve 1 is a gate valve, and the valve bodies of the water inlet electric regulating valve 2 and the water outlet electric regulating valve 6 are both butterfly valves.

[0023] The flocculant adding and mixing unit includes a coagulant adding metering pump 12, a coagulant medicine barrel 13, a coagulant aid adding metering pump 14, a coagulant aid medicine barrel 15 and a tubular static mixer 16. The medicine outlet pipe of the coagulant medicine barrel 13 is connected to the connecting pipeline between the water inlet electric regulating valve 2 and the tubular static mixer 16 through the coagulant adding metering pump 12 and the first ball valve 17. The medicine outlet pipe of the coagulant aid medicine barrel 15 is connected to the middle inlet of the tubular static mixer 16 through the coagulant aid adding metering pump 14 and the second ball valve 18 to improve the coagulation effect. The outlet of the tubular static mixer 16 is connected to the water inlet flowmeter 3; the control unit is electrically connected to the coagulant adding metering pump 12 and the coagulant aid adding metering pump 14 to control the dosage of the coagulant and the coagulant aid.

[0024] A first butterfly valve 19 is provided on the connecting pipeline between the water inlet flowmeter 3 and the inlet of the reaction precipitator 4. The connecting pipeline of the outlet of the reaction precipitator 4 is divided into three routes. The first route is connected to the inlet of the membrane pool 9 through the second butterfly valve 20, the second route is connected to the medicinal water pipeline through the first gate valve 21, which is used for the medicinal water of the coagulant and the coagulant aid, and the third route is connected to the clear water tank through the bypass electric butterfly valve 22. The side of the bottom of the reaction precipitator is led to the drainage ditch through the fourth electric butterfly valve 43, which is used for the timed mud discharge of the reaction precipitator. An overwater overflow pipe is led out from the side of the top of the reaction precipitator to realize the overwater overflow of the reaction precipitator.

[0025] The position of the membrane pool 9 is higher than the clean water pool 8, so as to produce water without power based on the siphon principle by utilizing the drop between the membrane pool 9 and the clean water pool 8. The side of the bottom of the membrane pool is led to the drainage ditch through the fifth electric butterfly valve 44 for timed mud discharge of the membrane pool. An over-water level overflow pipe is also led out from the side of the top of the membrane pool to achieve over-water level overflow of the membrane pool.

[0026] When the system is working on water purification, according to the turbidity, pH value and temperature of the raw water, the coagulant dosing pump 12 and the coagulant aid dosing pump 14 are adjusted to control the dosing of the coagulant and the coagulant aid, so that the flocculant added to the raw water is optimized. The flocculant is added to the raw water, and the raw water and the flocculant are quickly mixed by the tubular static mixer 16, and the flocculant is fully and evenly diffused in the water body, creating favorable conditions for the subsequent flocculation reaction.

[0027] The mixed raw water enters the reaction sedimentator 4, and forms uniform, dense and easy-to-precipitate alum flocs through flocculation reaction, and then precipitates, thereby forming a 200-300mm stable flocculent suspension layer below the sedimentation area. The suspension layer has an excellent filtering effect on the fine alum flocs generated by low-temperature and low-turbidity raw water and the light alum flocs generated by algae-containing raw water. The flocculent suspension layer can also accelerate the sedimentation of alum flocs in high-turbidity raw water to ensure that the turbidity of the water after precipitation is lower than 5NTU.

[0028] The water production method of the submerged ultrafiltration membrane filtration device is siphon constant flow water production (using the membrane pool drop to produce water without power). The precipitated water body is passed into the membrane pool 9 of the ultrafiltration membrane filtration device. The membrane treatment unit is mainly composed of a hollow fiber ultrafiltration membrane with an average pore size of 0.03μm and a material of PVDF. Under the action of pressure, the water body passes through the membrane surface at a certain flow rate. Substances smaller than the membrane pore size pass through the membrane fiber wall, while material particle impurities, colloids, etc. larger than the membrane pore size are intercepted by the membrane fiber wall. The ultrafiltration membrane filtration device has good water quality, and the removal rate of turbidity, suspended solids, total bacteria and Escherichia coli in the water is high. The turbidity of the effluent is ≤0.2NTU for a long time. The equipment investment and operating costs are low, and the cost performance is high. The service life of the PVDF membrane is more than 5 years, ensuring the long-term stable operation of the ultrafiltration membrane filtration device. At the same time, the energy saving filtration membrane pressure is small, and the liquid level difference between the membrane pool and the clear water pool can be used to siphon water.

[0029] In this embodiment, the control unit is provided with a water production constant current control module, and the water production constant current control module is provided with a corresponding relationship table between the linear change of the water outlet flow rate and the nonlinear opening of the water outlet electric regulating valve, and the water production constant current control module stores the maximum value of the membrane pool water level and the minimum value of the membrane pool water level. The membrane pool liquid level sensor detects the membrane pool water level in real time and sends it to the control unit, and the control unit transmits the received data to the water production constant current control module. When the water production constant current control module monitors that the membrane pool water level is higher than the maximum value of the membrane pool water level or lower than the minimum value of the membrane pool water level, it intelligently calculates the water outlet that needs to be adjusted. Flow rate, and then find the opening of the outlet electric regulating valve that needs to be opened or closed from the corresponding relationship table according to the outlet water flow rate to be adjusted; if the membrane pool water level remains stable between the highest value and the lowest value of the membrane pool water level after adjustment, stop adjusting the opening of the outlet electric regulating valve; if after a certain period of adjustment, the membrane pool water level drops from the highest value to the lowest value or rises from the lowest value to the highest value, then the outlet electric regulating valve is closed or opened in reverse to a certain degree, so that the membrane pool water level remains stable between the highest value and the lowest value of the membrane pool water level.

[0030] A pressure sensor 23 is also provided on the outlet pipe of the membrane treatment unit. The pressure sensor 23 detects the outlet water pressure of the membrane treatment unit in real time and sends it to the control unit; the control unit stores the membrane pool inlet pipe diameter, membrane treatment unit outlet pipe diameter, membrane treatment unit related structural parameters, the time since the last backwashing and the membrane treatment unit outlet water pressure data.

[0031] The water production constant flow control module is provided with an automatic water flow control model constructed based on a neural network model. The water production constant flow control module trains the neural network model through historical adjustment data to obtain a trained automatic water flow control model. The historical adjustment data include the membrane pool inlet pipe diameter, the membrane treatment unit outlet pipe diameter, the membrane treatment unit related structural parameters, the time since the last backwashing, the membrane treatment unit outlet water pressure, the membrane treatment unit outlet flow, the membrane pool water level rising or falling speed, the water flow adjustment amount and the adjustment result feedback data. The adjustment result feedback data includes whether the membrane pool water level is stable after adjustment, and if it is not stable, the time for the membrane pool water level to drop from the highest value to the lowest value or rise from the lowest value to the highest value, the reverse adjustment amount and the subsequent adjustment result feedback data.

[0032] When the water production constant flow control module monitors that the real-time membrane pool water level is higher than the maximum value of the membrane pool water level or lower than the minimum value of the membrane pool water level, the water outlet flow automatic adjustment model is called according to the current relevant data to predict and output the water outlet flow that needs to be adjusted this time, so that the adjusted membrane pool water level can reach stability as soon as possible; after this adjustment, the water production constant flow control module trains and updates the water outlet flow automatic adjustment model through the adjustment data of this time.

[0033] In this embodiment, the system includes three disinfectant dosing units. The drug outlet pipe of the first disinfectant dosing unit 7 is connected to the connecting pipeline between the water outlet electric regulating valve 6 and the clean water tank 8 to add sodium hypochlorite disinfectant to the clean water after ultrafiltration membrane filtration. The drug outlet pipe of the second disinfectant dosing unit 24 is connected to the membrane tank 9 to add sodium hypochlorite disinfectant to the water in the membrane tank 9. The setting of the third disinfectant dosing unit 25 will be further described below.

[0034] This system uses ultrafiltration membrane filtration technology to effectively remove solid particles, algae, bacteria, viruses, Giardia, Cryptosporidium, bloodworms and other harmful substances in the water. Adding sodium hypochlorite disinfectant can further effectively kill bacteria and viruses in the water, and maintain a certain amount of residual chlorine in the water outlet of the equipment to prevent secondary bacterial growth and ensure that the water quality meets drinking water standards.

[0035] The water ring pump unit includes a first electric gate valve 26 , a water ring pump 27 and a water ring pump water tank 28 . The outlet pipe of the membrane treatment unit 10 is connected to the inlet of the water ring pump 27 through the first electric gate valve 26 , and the outlet of the water ring pump 27 is connected to the water ring pump water tank 28 .

[0036] The self-priming pump unit includes a first electric butterfly valve 29, a self-priming pump 30 for a backwashing water tank, a first check valve 31 and a second gate valve 32. The backwashing water system includes a third gate valve 33, a second electric butterfly valve 34, a second check valve 35, a backwashing pump 36, a third butterfly valve 37, a backwashing water tank 38 and a third disinfectant dosing unit 25 (containing sodium hypochlorite disinfectant). The outlet pipe of the membrane treatment unit 10 is connected to the inlet of the self-priming pump 30 through the first electric butterfly valve 29, and the outlet pipe of the self-priming pump 30 extends into the backwashing water tank 38 after passing through the first check valve 31 and the second gate valve 32. The inlet pipe of the backwashing pump 36 is connected to the backwashing water tank 38 through the third butterfly valve 37, and the outlet pipe of the backwashing pump 36 is connected to the outlet pipe of the membrane treatment unit 10 through the second check valve 35, the second electric butterfly valve 34 and the third gate valve 33. The drug outlet pipe of the third disinfectant dosing unit 25 is connected to the connecting pipeline between the backwash pump 36 and the second check valve 35 .

[0037] The fan unit includes a third electric butterfly valve 39 , a third check valve 40 and a fan 41 . The air outlet pipe of the fan 41 passes through the third check valve 40 and the third electric butterfly valve 39 , enters the membrane pool 9 and is connected to the gas distributor at the bottom of the membrane treatment unit 10 .

[0038] This system adopts cross-flow filtration and intermittent automatic cleaning (gas and water washing process), and adopts gas-water linkage process. The gas blown out from the fan blows out from the gas distributor at the bottom of the membrane treatment unit 10 from bottom to top. The blowing air drives the fiber membrane to vibrate and rub, and then the backwash water rushes out from the inner cavity of the membrane to bring the outer membrane dirt out of the system. The whole process is automatically controlled and operated by the control unit.

[0039] When the system starts running, open the water inlet switch valve 1. When the water level in the membrane pool reaches a certain height, open the first electric gate valve 26, open the water ring pump 27 to run for a set time (within 10 minutes) or shut down when the pressure sensor 23 detects that the pressure on the outlet pipe of the membrane treatment unit is negative pressure, close the first electric gate valve 26, and open the water outlet electric regulating valve 6 to discharge water. When the liquid level in the backwash water tank 38 is lower than the set low liquid level, open the first electric butterfly valve 29 and start the self-priming pump 30. When the liquid level in the backwash water tank 38 rises to the set high liquid level, close the first electric butterfly valve 29 and turn off the self-priming pump 30.

[0040] When backwashing the membrane pool, the working process of the fan unit and backwash water system is as follows.

[0041] Fan unit: open the third electric butterfly valve 39, open the fan 41 (it can only run when the self-priming pump 30, backwashing pump 36, and water ring pump 27 are stopped and the membrane pool water level reaches a certain height, and wait to run if it does not meet the requirements), shut down the fan 41 after it runs for a set time (within 2 minutes), and start running again after an interval of 10 to 100 minutes. Repeat the cycle.

[0042] Backwash water system: During the interval when the fan 41 is shut down, close the outlet electric regulating valve 6, open the fifth electric butterfly valve 44 beside the bottom of the membrane pool 9 to discharge sewage, open the second electric butterfly valve 34, start the backwash pump 36 (it can only run when the self-priming pump 30, the fan 41, and the water ring pump 27 are shut down and the liquid level of the backwash water tank 38 reaches a certain height, and wait for operation if it does not meet the requirements), open the third disinfectant dosing unit 25 to add sodium hypochlorite disinfectant, and after running for a set time (within 10 minutes), close the fifth electric butterfly valve 44. When the water level of the membrane pool rises to a certain height, close the third disinfectant dosing unit 25, close the second electric butterfly valve 34, open the outlet electric regulating valve 6, and start running again after an interval of 10 to 500 minutes. Repeat the cycle.

[0043] The ultrafiltration membrane water purification system provided by the present invention utilizes flocculation reaction and precipitation technology to preliminarily treat raw water, reduce the turbidity, chromaticity and other indicators of the source water, thereby effectively improving the adaptability of the overall equipment to high turbidity water, enhancing the load bearing capacity of the system, and extending the service life of the equipment and the membrane; then, through the membrane filtration technology, with a low membrane pressure and high flux immersed hollow ultrafiltration membrane as the filtration core, solid particles, algae, bacteria, viruses, Giardia, Cryptosporidium, red worms and other harmful substances in the water body are effectively removed, the turbidity, chromaticity and other indicators of the water body are reduced, and the effluent water quality meets the relevant requirements of the "Sanitary Standard for Drinking Water" (GB 5749-2006), and has the advantages of high-quality water production, effluent turbidity of ≤1 NTU for a long time, energy-saving low membrane pressure, siphoning water production by using the liquid level difference between the membrane pool and the clear water pool, stable operation, wide applicability, full-automatic control, high degree of automation, simple operation and operation, etc., thereby meeting the drinking water needs of various application scenarios such as remote rural areas and small and medium-sized units far away from cities.

[0044] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. An ultrafiltration membrane water purification system, characterized in that: It includes an inlet switch valve, a coarse filter, an inlet electric regulating valve, a flocculant dosing mixing unit, an inlet flow meter, a reaction precipitator, an ultrafiltration membrane filtration device, an outlet flow meter, an outlet electric regulating valve, a disinfectant dosing unit, a clear water tank, a fan unit, a water ring pump unit, a self-priming pump unit, a backwash water system, various connecting pipelines and a control unit. The ultrafiltration membrane filtration device includes a membrane pool and a membrane treatment unit. A membrane pool liquid level sensor is provided in the membrane pool, and the membrane treatment unit is installed in the center of the membrane pool; the raw water pipe is connected to the reaction precipitator inlet in turn through the inlet switch valve, the coarse filter, the inlet electric regulating valve, the flocculant dosing mixing unit, and the inlet flow meter. The reaction The outlet of the sedimentation tank should be connected to the inlet of the membrane pool. The water in the membrane pool passes through the surface of the hollow ultrafiltration membrane of the membrane treatment unit at a certain flow rate and enters the membrane treatment unit. The outlet pipe of the membrane treatment unit is connected to the clean water tank through the outlet flow meter, the outlet electric regulating valve, and the disinfectant dosing unit in sequence. The outlet pipe of the membrane treatment unit is also connected to the water ring pump unit, the self-priming pump unit, and the backwash water system at the same time. The air outlet pipe of the fan unit enters the membrane pool and is connected to the gas distributor at the bottom of the membrane treatment unit; the control unit is electrically connected to the membrane pool liquid level sensor to control the outlet water flow according to the membrane pool water level. The control unit is electrically connected to each unit and each electric control valve to control the operation of the entire system; The control unit is provided with a water production constant current control module, and the water production constant current control module is provided with a corresponding relationship table between the linear change of the water outlet flow and the nonlinear opening of the water outlet electric regulating valve. The water production constant current control module stores the maximum value and the minimum value of the membrane pool water level. The membrane pool liquid level sensor detects the membrane pool water level in real time and sends it to the control unit. The control unit transmits the received data to the water production constant current control module. When the water production constant current control module monitors that the membrane pool water level is higher than the maximum value of the membrane pool water level or lower than the minimum value of the membrane pool water level, it intelligently calculates the water outlet flow that needs to be adjusted. Then, according to the outlet water flow rate to be adjusted, find the opening of the outlet electric regulating valve to be opened or closed from the corresponding relationship table; if the membrane pool water level remains stable between the highest value and the lowest value of the membrane pool water level after adjustment, stop adjusting the opening of the outlet electric regulating valve; if after a certain period of adjustment, the membrane pool water level drops from the highest value to the lowest value or rises from the lowest value to the highest value, then the outlet electric regulating valve is reversely closed or opened by a certain degree, so that the membrane pool water level remains stable between the highest value and the lowest value of the membrane pool water level; The outlet pipe of the membrane treatment unit is also provided with a pressure sensor, which detects the outlet water pressure of the membrane treatment unit in real time and sends it to the control unit; the control unit stores the membrane pool inlet pipe diameter, the membrane treatment unit outlet pipe diameter, the membrane treatment unit related structural parameters, the time since the last backwashing and the membrane treatment unit outlet water pressure data; The water production constant flow control module is provided with an outlet flow automatic adjustment model based on a neural network model, and the water production constant flow control module trains the neural network model through historical adjustment data to obtain a trained outlet flow automatic adjustment model, and the historical adjustment data include the membrane pool inlet diameter, the membrane treatment unit outlet diameter, the membrane treatment unit related structural parameters, the time since the last backwashing, the membrane treatment unit outlet pressure, the membrane treatment unit outlet flow, the membrane pool water level rise or fall speed, the outlet flow adjustment amount and the adjustment result feedback data, and the adjustment result feedback data include whether the membrane pool water level is stable after adjustment, and if it is not stable, the time for the membrane pool water level to drop from the highest value to the lowest value or rise from the lowest value to the highest value, the reverse adjustment amount and the subsequent adjustment result feedback data; When the water production constant flow control module monitors that the real-time membrane pool water level is higher than the maximum value of the membrane pool water level or lower than the minimum value of the membrane pool water level, the water outlet flow automatic adjustment model is called according to the current relevant data to predict and output the water outlet flow that needs to be adjusted this time, so that the adjusted membrane pool water level can reach stability as soon as possible; after this adjustment, the water production constant flow control module trains and updates the water outlet flow automatic adjustment model through the adjustment data of this time.

2. The ultrafiltration membrane water purification system according to claim 1, characterized in that: The flocculant adding and mixing unit includes a coagulant adding metering pump, a coagulant barrel, a coagulant aid adding metering pump, a coagulant aid barrel and a tubular static mixer. The outlet pipe of the coagulant barrel is connected to the connecting pipeline between the water inlet electric regulating valve and the tubular static mixer via the coagulant adding metering pump and the first ball valve. The outlet pipe of the coagulant aid barrel is connected to the middle inlet of the tubular static mixer via the coagulant aid adding metering pump and the second ball valve to improve the coagulation effect. The outlet of the tubular static mixer is connected to the water inlet flowmeter. The control unit is electrically connected to the coagulant adding metering pump and the coagulant aid adding metering pump to control the dosage of the coagulant and the coagulant aid.

3. The ultrafiltration membrane water purification system according to claim 1, characterized in that: A first butterfly valve is provided on the connecting pipeline between the water inlet flowmeter and the inlet of the reaction precipitator. The connecting pipeline of the outlet of the reaction precipitator is divided into three routes. The first route is connected to the membrane pool inlet via the second butterfly valve, the second route is connected to the dissolving water pipeline via the first gate valve, which is used for dissolving water for coagulants and coagulant aids, and the third route is connected to the clear water tank via a bypass electric butterfly valve.

4. The ultrafiltration membrane water purification system according to claim 1, characterized in that: The membrane pool is located higher than the clean water pool, so as to produce water without power based on the siphon principle by utilizing the height difference between the membrane pool and the clean water pool.

5. The ultrafiltration membrane water purification system according to claim 1, characterized in that: It comprises at least two disinfectant dosing units, wherein the drug outlet pipe of the first disinfectant dosing unit is connected to the connecting pipeline between the water outlet electric regulating valve and the clean water tank so as to add sodium hypochlorite disinfectant to the clean water filtered by the ultrafiltration membrane, and the drug outlet pipe of the second disinfectant dosing unit is connected to the membrane tank so as to add sodium hypochlorite disinfectant to the water in the membrane tank.

6. The ultrafiltration membrane water purification system according to claim 1, characterized in that: The water ring pump unit comprises a first electric gate valve, a water ring pump and a water ring pump water tank. The outlet pipe of the membrane treatment unit is connected to the water ring pump inlet through the first electric gate valve, and the water ring pump outlet is connected to the water ring pump water tank.

7. The ultrafiltration membrane water purification system according to claim 1, characterized in that: The self-priming pump unit includes a first electric butterfly valve, a self-priming pump, a first check valve and a second gate valve, and the backwash water system includes a third gate valve, a second electric butterfly valve, a second check valve, a backwash pump, a third butterfly valve, a backwash water tank and a third disinfectant dosing unit; one outlet pipe of the membrane treatment unit is connected to the self-priming pump inlet through the first electric butterfly valve, and the self-priming pump outlet pipe extends into the backwash water tank after passing through the first check valve and the second gate valve; the backwash pump inlet pipe is connected to the backwash water tank through the third butterfly valve, and the backwash pump outlet pipe is connected to the outlet pipe of the membrane treatment unit through the second check valve, the second electric butterfly valve and the third gate valve; the medicine outlet pipe of the third disinfectant dosing unit is connected to the connecting pipeline between the backwash pump and the second check valve.

8. The ultrafiltration membrane water purification system according to claim 1, characterized in that: The fan unit comprises a third electric butterfly valve, a third check valve and a fan. The air outlet pipe of the fan passes through the third check valve and the third electric butterfly valve, enters the membrane pool and is connected to the gas distributor at the bottom of the membrane treatment unit.

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