RO water purifier with double-membrane positive and negative dynamic flushing function

Abstract

The utility model relates to water purification equipment field provides a RO reverse osmosis water purifier with double membrane positive and negative dynamic flushing function. It contains ultrafiltration membrane subassembly, activated carbon subassembly, booster pump, RO reverse osmosis filter subassembly and pressure bucket. Pressure bucket is connected RO reverse osmosis filter subassembly water inlet through the positive flushing branch of first flush valve with first check valve, and RO membrane is back-flushed with pressure bucket pure water, and the concentrated water outlet of RO reverse osmosis filter subassembly is connected water outlet of ultrafiltration membrane subassembly through the reverse flushing branch of second flush valve with second check valve, and the outside pollution of ultrafiltration membrane is back-flushed with RO concentrated water. The water outlet of RO reverse osmosis filter subassembly is equipped with pressure sensor, and when reaching threshold value, triggers flushing, and the second flush valve of reverse flushing branch is pulse control solenoid valve, forms pulse water flow and enhances cleaning effect. The water purifier realizes efficient self-cleaning, prevents concentrated water penetration, prolongs filter core life through double membrane collaborative flushing, accurate control and pulse flushing, saves water and electricity, and low maintenance cost.

Description

Technical Field

[0001] This utility model relates to the field of water purification equipment technology, specifically to an RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function. Background Technology

[0002] If an external pressure ultrafiltration membrane is added before a traditional RO reverse osmosis water purifier, the external pressure ultrafiltration membrane, with its high filtration precision of 0.01 microns, can effectively intercept tiny pollutants such as colloids and bacteria. However, the intercepted impurities tend to accumulate on the outside of the membrane, and traditional one-way flushing technology is difficult to clean thoroughly, resulting in rapid flow decay, short filter life, and in severe cases, manual cleaning of the filter cartridge is required to restore performance. This leads to high maintenance costs and a poor user experience, which greatly limits the widespread application of ultrafiltration membranes in RO machines. In addition, after shutdown, the concentrated water in front of the membrane inside the RO membrane housing will seep into the pure water side behind the membrane over time, causing the TDS value to increase and the water quality to decline when used again.

[0003] Taking a Chinese ultrafiltration water purifier with a reverse osmosis module (publication number CN212151810U) as an example, it uses a booster pump with an RO membrane, a reverse osmosis filter cartridge, and a post-activated carbon filter cartridge module between the ultrafiltration water purifier's outlet and the water-using device. While it effectively filters bacteria, viruses, and other heavy metal ions from the water, it lacks an effective flushing method, resulting in a short filter cartridge lifespan and frequent replacements. Furthermore, it cannot address the issue of increased TDS (Total Dissolved Solids) water from the interpermeation of concentrated and pure water within the membrane housing after shutdown. Therefore, there is an urgent need to develop a new type of water purifier with a dual-membrane high-efficiency self-cleaning function to extend filter cartridge lifespan, effectively prevent RO membrane concentrated water from permeating to the pure water side, and precisely control the electrical equipment through pressure sensors to reduce frequent start-stop cycles and achieve water and energy savings. Utility Model Content

[0004] The purpose of this application is to provide an RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function, which has the advantages of efficient self-cleaning, extended filter life, prevention of concentrated water from seeping into the pure water side, and precise control to reduce frequent start-stop.

[0005] This application provides an RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function, the technical solution of which is as follows:

[0006] The system comprises, in sequence, an ultrafiltration membrane module 1, an activated carbon module 2, a booster pump 3, an RO reverse osmosis filter module 4, and a pressure tank 5, characterized in that:

[0007] The outlet of the pressure tank 5 is connected to the inlet of the RO reverse osmosis filter assembly 4 through the forward flushing branch 11. The forward flushing branch 11 is provided with a first one-way valve 111 and a first flushing valve 112 in sequence. The flow direction of the first one-way valve 111 is configured to allow only the pure water in the pressure tank 5 to flow back into the RO reverse osmosis filter assembly 4.

[0008] The wastewater outlet of the RO reverse osmosis filtration component 4 is connected to the clean water outlet of the ultrafiltration membrane component 1 through a backwash branch 12. The backwash branch 12 is equipped with a second one-way valve 121 and a pulse-controlled solenoid valve 122. The flow direction of the second one-way valve 121 is configured to allow only RO reverse osmosis concentrate to flow into the clean water outlet of the ultrafiltration membrane component 1.

[0009] Furthermore, this application also proposes that the other end of the forward flushing branch 11 is connected to the inlet of the RO reverse osmosis filter assembly 4 through a first tee connector T1; the other end of the reverse flushing branch 12 is connected to the clean water outlet of the ultrafiltration membrane assembly 1 through a second tee connector T2; and the concentrate outlet of the ultrafiltration membrane assembly 1 is connected to a wastewater discharge pipe 13 through a third tee connector T3, in order to form a water path that can simultaneously flush the ultrafiltration membrane assembly 1 and the RO reverse osmosis filter assembly 4.

[0010] Furthermore, this application also proposes that the concentrate outlet of the RO reverse osmosis filter assembly 4 is connected to the third end of the third tee connector T3 through the fourth tee connector T4, the first end of the fourth tee connector T4 is connected to the concentrate outlet of the RO reverse osmosis filter assembly 4, the second end is connected to the reverse flushing branch 12, and the third end is connected to the wastewater discharge pipeline 13 through the third tee connector T3.

[0011] Furthermore, this application also proposes that a water-making solenoid valve 401 is provided between the fourth tee connector T4 and the third tee connector T3.

[0012] Furthermore, this application also proposes that the wastewater discharge pipeline 13 is equipped with a wastewater solenoid valve 131 for controlling the unified discharge of wastewater from the forward flushing branch 11 and the reverse flushing branch 12.

[0013] Furthermore, this application also proposes that the inlet of the ultrafiltration membrane module 1 is provided with an inlet solenoid valve 101, and its concentrate outlet is provided with an ultrafiltration wastewater solenoid valve 102.

[0014] Furthermore, this application proposes that the RO reverse osmosis filter assembly 4 is equipped with a pressure sensor 402 at its water inlet to detect the pressure at the water inlet of the RO reverse osmosis filter assembly 4 and trigger a flushing action when the pressure reaches a threshold. In particular, the system will only activate the flushing function when the pressure drops to the user's usable minimum low pressure threshold, thereby achieving intelligent energy-saving and water-saving optimization effects while ensuring water demand.

[0015] Furthermore, this application also proposes that the second flushing valve 122 of the backwash branch 12 is a pulse-controlled solenoid valve, used to form a pulse water flow to flush the ultrafiltration membrane assembly 1.

[0016] As can be seen from the above, the RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function provided in this application can achieve efficient self-cleaning of dual membranes, extend the service life of filter elements, and prevent concentrated water from seeping into the pure water side after shutdown by the synergistic effect of the forward flushing branch and the reverse flushing branch, combined with the precise control of pressure sensor and solenoid valve. At the same time, it reduces frequent start and stop, and has the advantages of water saving, power saving and low maintenance cost.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. Dual-membrane self-cleaning: The RO reverse osmosis filter module flushing wastewater is guided to the ultrafiltration membrane module through the reverse flushing branch. The water flow back washes the surface of the ultrafiltration membrane module, removing deep-seated blockages, effectively reducing the flux decline rate of the ultrafiltration membrane module and greatly extending its lifespan. At the same time, the RO reverse osmosis filter module is flushed forward to remove contaminants from its surface, improving the flux and filtration efficiency of the RO reverse osmosis filter module, thus achieving highly efficient self-cleaning of the dual-membrane module.

[0019] 2. Zero residual water ensures stable water quality: The RO reverse osmosis membrane module is flushed with pressurized pure water stored in the pressure tank, completely replacing the high concentration of residual wastewater in the membrane housing. This design ensures that the pure water entering the pressure tank after the equipment is restarted always maintains ultra-high purity, thus ensuring that users can obtain clean and safe drinking water at any time.

[0020] 3. Water-saving and efficient: The wastewater from both forward and reverse flushing is recycled and used for cleaning the ultrafiltration membrane module. This method is more water-saving than the traditional one-way flushing solution, combining environmental protection and economy, reducing water waste and conforming to the concept of green environmental protection. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the water circuit for the forward flushing of the RO reverse osmosis filter module and the reverse flushing of the ultrafiltration membrane module in this case.

[0022] Figure 2 This is a schematic diagram of the water supply system in this case;

[0023] Figure 3 This is a schematic diagram of the forward flushing water path for the ultrafiltration membrane module in this case; Detailed Implementation

[0024] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] Figure 1 In the middle, the dashed arrow indicates the dual-mode flushing water flow path: pressure tank 5 → forward flushing branch 11 → RO reverse osmosis filter module 4 → reverse flushing branch 12 → ultrafiltration membrane module 1 → wastewater discharge pipeline 13.

[0026] Figure 2 In the diagram, the dashed arrows indicate the water flow path: Ultrafiltration membrane module 1 → Activated carbon module 2 → RO reverse osmosis filter module 4 → Pressure tank 5 / Wastewater discharge pipeline 13.

[0027] Figure 3 In the image, the dashed arrow indicates the forward flushing water flow path of the ultrafiltration membrane module: Ultrafiltration membrane module 1 → Wastewater discharge pipeline 13.

[0028] In existing technologies, traditional reverse osmosis water purification systems can intercept minute contaminants through ultrafiltration membrane pretreatment. However, impurities trapped on the outside of the ultrafiltration membrane are difficult to remove through unidirectional flushing, leading to flow rate reduction and shortened filter cartridge life. During shutdown, the concentrate inside the reverse osmosis membrane housing can permeate into the pure water side, causing a decline in water quality upon reuse. Existing technologies do not effectively solve the self-cleaning problem of dual membranes and lack a synergistic control mechanism for membrane fouling and permeation issues.

[0029] To address the aforementioned issues, traditional unidirectional flushing technology cannot simultaneously handle the removal of contaminants from the outer side of the ultrafiltration membrane and the permeation of concentrate from the RO reverse osmosis membrane. Therefore, independent and complementary flushing paths need to be designed. One approach is to utilize the pressure of the water stored in the pressure tank to backwash the RO reverse osmosis membrane, while simultaneously directing the high-pressure flow of RO reverse osmosis concentrate to the outer side of the ultrafiltration membrane to form a reverse flush. By installing a directional flow guide device to avoid water flow interference, synchronous flushing control is achieved, thus overcoming the limitations of unidirectional flushing.

[0030] Therefore, this application proposes a water purification device including an ultrafiltration membrane module, an activated carbon module, a booster pump, an RO reverse osmosis filter module, and a pressure tank. The pressure tank is connected to the inlet of the RO reverse osmosis filter module via a forward flushing branch, which is equipped with a first check valve and a first flushing valve, with the water flow direction from the pressure tank towards the RO reverse osmosis module. The concentrate outlet of the RO reverse osmosis module is connected to the ultrafiltration membrane filter outlet via a reverse flushing branch, which is equipped with a second check valve and a second flushing valve, with the water flow direction from the reverse osmosis module towards the ultrafiltration membrane module.

[0031] The forward flushing branch refers to the piping system connecting the pressure tank and the RO reverse osmosis module inlet, which can be implemented using a combination of pressure-resistant hoses and quick-connect fittings. Its function is to use the pure water stored in the pressure tank to backwash the surface of the reverse osmosis membrane, removing deposited contaminants. The first one-way valve is a valve that only allows unidirectional flow from the pressure tank to the RO reverse osmosis module, which can be implemented using a spring-loaded check valve to prevent raw water from entering the pressure tank directly without RO membrane filtration and to prevent backflow of reverse osmosis feed water into the pressure tank. The reverse flushing branch refers to the piping structure connecting the RO reverse osmosis module concentrate inlet and the ultrafiltration membrane module filter inlet, which can be implemented using a three-way distributor and reducer to achieve reverse flushing of the ultrafiltration membrane by high-pressure concentrate. The second one-way valve is a valve that only allows unidirectional flow from the RO reverse osmosis module to the ultrafiltration membrane module, which can be implemented using a membrane-type one-way valve to prevent raw water from entering the RO membrane directly without passing through activated carbon and to prevent backflow of ultrafiltration membrane module permeate into the RO reverse osmosis module, thus affecting the RO membrane's lifespan.

[0032] Specifically, during forward flushing, the pure water stored in the pressure tank forms a reverse flow through the forward flushing branch, flushing away impurities adhering to the surface of the reverse osmosis membrane and squeezing out the high-concentration water from the membrane concentrate. The first one-way valve ensures a constant water flow direction. During reverse flushing, the concentrate produced by the RO reverse osmosis module forms a high-pressure water flow through the reverse flushing branch, flushing away colloidal contaminants trapped on the outside of the ultrafiltration membrane module from the clean water outlet. The second one-way valve prevents the ultrafiltration membrane module's product water from flowing backward. The booster pump 3 is shut off in flushing mode, utilizing the pressure stored in the pressure tank 5 to drive the water flow, ensuring independent and controllable flushing pressure for both membranes. Each valve is independently controlled, allowing for individual or simultaneous operation, avoiding interference between the two-way water flows. The reverse flushing of the water stored in the pressure tank effectively removes blockages from the reverse osmosis membrane pores, while the high-pressure characteristics of the reverse osmosis concentrate provide power for flushing the outside of the ultrafiltration membrane, achieving synergistic self-cleaning of both membranes.

[0033] Compared to existing technologies, traditional solutions only flush ultrafiltration or reverse osmosis membranes in one direction, failing to address the dual-membrane fouling problem simultaneously. For example, patent CN212151810U lacks an independent bidirectional flushing branch, leading to the accumulation of contaminants on the outer side of the ultrafiltration membrane that cannot be removed. This solution, through a physically isolated forward and reverse water path design combined with directional flow control, ensures that the two flushing branches do not interfere with each other and complement each other. Backflushing with water stored in the pressure tank solves the problem of concentrate leakage during shutdown, while the reuse of reverse osmosis concentrate improves flushing efficiency and reduces additional energy consumption.

[0034] Through the above technical solution, this application achieves bidirectional dynamic flushing of the outer side of the ultrafiltration membrane and the surface of the reverse osmosis membrane, effectively removing pollutant buildup that is difficult to handle with traditional unidirectional flushing. The pressure tank stores water for reverse flushing to prevent the TDS value from increasing due to concentrate seepage when the reverse osmosis membrane is shut down, thus maintaining stable effluent quality. The two flushing branches are independently controlled, allowing for flexible adjustment of the flushing frequency based on water quality changes, reducing the frequency of booster pump start-stop cycles and lowering system energy and water consumption.

[0035] This application further proposes that the other end of the forward flushing branch is connected to the inlet of the RO reverse osmosis filter module through a first tee connector, the other end of the reverse flushing branch is connected to the clean water outlet of the ultrafiltration membrane module through a second tee connector, and the concentrate outlet of the ultrafiltration membrane module is connected to a wastewater discharge pipeline through a third tee connector.

[0036] The first tee connector refers to a pipe fitting with three connection ports, specifically a Y-type or T-type tee valve, used to divert the purified water from the pressure tank to the RO reverse osmosis filter module to form a reverse flushing water flow. The second tee connector is a fluid distribution device located at the purified water inlet of the ultrafiltration membrane module, specifically a tee fitting with an anti-backflow structure, used to introduce the concentrated water from the RO reverse osmosis membrane module into the ultrafiltration membrane module for reverse flushing. The third tee connector is a transitional connection between the concentrated water inlet of the ultrafiltration membrane module and the wastewater discharge pipeline, specifically a tee interface with a wastewater guide channel, used to directionally discharge contaminants generated during dual-membrane flushing. The wastewater discharge pipeline refers to a drainage channel with an independent control valve, used to simultaneously collect flushing wastewater from both the ultrafiltration and reverse osmosis membranes.

[0037] Specifically, when the flushing procedure is triggered, the purified water stored in the pressure tank is injected into the inlet of the RO reverse osmosis filter module through the first three-way connector, forming a reverse flushing water flow from back to front. This flushes the RO reverse osmosis membrane and drives the RO reverse osmosis membrane concentrate to enter the ultrafiltration membrane module's clean water inlet through the second three-way connector. At this time, the contaminants trapped by the ultrafiltration membrane module are flushed to the concentrate outlet by the reverse water flow and discharged into the wastewater discharge pipeline through the third three-way connector. Through the topological connection of the three-way connectors, the wastewater generated by the ultrafiltration membrane module during forward flushing and the wastewater from the reverse flushing of the RO reverse osmosis filter module form a combined discharge mechanism.

[0038] Compared to existing technologies, traditional devices only perform unidirectional flushing through a single branch, failing to achieve simultaneous counter-current flushing of both membranes. This solution constructs a bidirectional counter-current channel through the spatial layout of a three-way connector, allowing the permeate and concentrate sides of the ultrafiltration membrane to form independent flushing paths. In existing technologies, ultrafiltration membrane flushing wastewater needs to be discharged separately, while this solution combines the flushing wastewater from both membranes into a unified pipeline through a third three-way connector, avoiding structural redundancy caused by multiple drainage paths.

[0039] Through the above technical solution, this application achieves simultaneous operation of forward flushing of the reverse osmosis membrane and reverse flushing of the ultrafiltration membrane, effectively removing colloidal contaminants accumulated on the surfaces of both membranes. The integrated design of the wastewater discharge pipeline allows impurities generated during the flushing process to be discharged centrally, preventing secondary pollution. The topological connection of the three-way connector enables the flushing water flow of the two membranes to form a closed loop, solving the problem of filter clogging caused by incomplete unidirectional flushing in traditional water purifiers, and extending the service life of both the ultrafiltration and reverse osmosis membranes.

[0040] This application further proposes that the concentrate outlet of the reverse osmosis filter module is connected to the third end of the third tee connector via a fourth tee connector. The first end of the fourth tee connector is connected to the concentrate outlet of the reverse osmosis filter module, the second end is connected to the backwash branch, and the third end is connected to the wastewater discharge pipeline via the third tee connector.

[0041] The fourth tee connector is a connecting component that connects the concentrate outlet of the reverse osmosis filter module, the backwash branch, and the wastewater discharge pipeline. It can be implemented using a pipe fitting structure with three ports, used to direct concentrate to the wastewater discharge pipeline during normal water production and to switch the water flow path during backwashing. The third tee connector is a connecting component that connects the concentrate outlet of the ultrafiltration membrane module, the concentrate discharge pipeline of the reverse osmosis filter module, and the wastewater discharge pipeline. It can be a tee valve or a fixed tee structure, used to integrate the wastewater discharge channels of the ultrafiltration and reverse osmosis systems.

[0042] Specifically, under normal water production conditions, wastewater from the concentrate outlet of the reverse osmosis filter module enters the third end through the first end of the fourth three-way connector, and then is discharged into the wastewater pipeline through the third end of the third three-way connector, preventing concentrate residue in the pipeline from causing leakage. When flushing is required, pure water stored in the pressure tank enters the reverse flushing branch from the concentrate outlet of the reverse osmosis filter module through the second end of the fourth three-way connector, flowing in the reverse direction across the surface of the ultrafiltration membrane module to flush away contaminants. Subsequently, the wastewater carrying contaminants is discharged uniformly through the third three-way connector. This connection structure allows the reverse osmosis flushing water flow and the ultrafiltration flushing wastewater to share a discharge channel, while utilizing the fluid guiding characteristics of the three-way connector to achieve automatic switching of the dual membrane flushing paths.

[0043] Compared to existing technologies, traditional dual-membrane water purifiers require separate wastewater discharge pipelines for the ultrafiltration and reverse osmosis systems, resulting in complex pipeline structures and low flushing efficiency. Existing technologies, such as the CN212151810U patent, only employ a unidirectional flow design, failing to block the concentrated water permeation path during shutdown. This solution integrates the reverse osmosis concentrated water discharge and ultrafiltration wastewater discharge into a single path through a three-way connector topological connection, while simultaneously establishing the hydraulic loop required for backflushing, achieving synergistic flushing of both membranes while simplifying the pipeline layout.

[0044] Through the above technical solution, this application achieves centralized discharge of flushing wastewater from both ultrafiltration and reverse osmosis membranes, reducing pressure drop losses caused by pipeline branches and improving the utilization rate of flushing water flow. In the shutdown state, the connection structure between the fourth and third tee connectors can block the permeation path of concentrated water from the reverse osmosis membrane housing to the pure water side, effectively preventing an increase in TDS value. The closed loop formed by the reverse water flow during flushing can simultaneously remove deposits on the outside of the ultrafiltration membrane and contaminants on the surface of the reverse osmosis membrane, solving the problems of asynchronous flushing of the two membranes and dispersed wastewater discharge in traditional technologies.

[0045] This application further proposes to install a water-making solenoid valve between the fourth tee connector and the third tee connector.

[0046] The water-purifying solenoid valve is a valve device that controls the opening and closing of a pipeline via an electrical signal. Specifically, it can be implemented using a normally open solenoid valve, which opens the pipeline when de-energized and closes it when energized, used to control the connectivity of the concentrate discharge path of the reverse osmosis filter module. The fourth tee connector is a branch pipe fitting with three connection ports, specifically a Y-type tee structure. Its first end connects to the concentrate port of the reverse osmosis filter module, the second end connects to the backwash branch, and the third end connects to the third tee connector via a pipeline. The third tee connector is a manifold fitting with three connection ports, specifically a T-type tee structure. Its first end connects to the concentrate port of the ultrafiltration membrane module, the second end connects to the wastewater discharge pipeline, and the third end connects to the fourth tee connector via a pipeline.

[0047] Specifically, during normal water production, the water production solenoid valve is open, allowing the concentrated water from the reverse osmosis filtration module to flow sequentially through the fourth three-way connector, the water production solenoid valve, and the third three-way connector before entering the wastewater discharge pipe. When entering flushing mode, the water production solenoid valve closes, blocking the direct connection between the reverse osmosis filtration module and the wastewater discharge pipe. At this time, the water output from the pressure tank flows sequentially through the forward flushing branch into the reverse osmosis filtration module, forming a reverse flow of flushing water that flows into the reverse flushing branch. Simultaneously, impurities trapped on the outside of the ultrafiltration membrane module are flushed away by the reverse flow and discharged through the wastewater discharge pipe. Compared to existing technologies, traditional reverse osmosis water purifiers control concentrated water discharge only through a single wastewater valve, failing to distinguish the water flow paths during water production and flushing, resulting in the flushing water flow not being able to directionally flush the membrane surface. This solution, by adding a combination structure of a water production solenoid valve and a three-way connector, achieves dynamic switching of the concentrated water discharge path while maintaining the original wastewater discharge function. This allows the reverse osmosis membrane to form a closed-loop water path during flushing, improving the efficiency of the flushing water flow in removing impurities from the membrane surface.

[0048] Through the above technical solution, this application can discharge the concentrated water generated by the reverse osmosis filtration module in a timely manner during the water production stage, avoiding the deposition of impurities on the membrane surface; during the flushing stage, by cutting off the concentrated water discharge path and forming a reverse water flow, the pollutants accumulated on the outside of the ultrafiltration membrane and the dissolved solids trapped on the surface of the reverse osmosis membrane are effectively removed, thereby simultaneously extending the service life of the dual membrane filter element and maintaining the stability of the effluent water quality.

[0049] This application further proposes that the wastewater discharge pipeline is equipped with a wastewater solenoid valve to control the unified discharge of wastewater from the forward flushing branch and the reverse flushing branch.

[0050] The wastewater discharge pipeline refers to the channel for collecting and discharging wastewater generated during the flushing process. Specifically, it can be implemented using polypropylene pipes connected to tee fittings. Its function is to combine the wastewater generated from forward and reverse flushing into the same discharge path. The wastewater solenoid valve is an actuator that controls the flow of fluid via electrical signals. Its function is to synchronously regulate the timing of flushing wastewater discharge by controlling the valve's opening and closing state, avoiding the problems of pipeline cross-cutting and timing coordination caused by separate discharge valves.

[0051] Specifically, during the dual-membrane forward and reverse dynamic flushing, water stored in the pressure tank enters the RO reverse osmosis filter module through the first one-way valve to flush the membrane surface. At this time, the wastewater solenoid valve is configured to be open, and the wastewater generated during forward flushing backwashes the ultrafiltration membrane module. During this time, the wastewater solenoid valve remains open, and the wastewater generated during reverse flushing is discharged synchronously through the same pipeline. When the ultrafiltration membrane is forward flushed, raw water flows through the inlet of the ultrafiltration membrane module to flush the ultrafiltration membrane, and the wastewater generated during flushing is discharged through the same wastewater pipeline. By synchronously controlling the two wastewater streams through a single wastewater solenoid valve, impurities generated by the forward and reverse flushing actions can be continuously discharged along a unified path, avoiding the redundancy of pipeline branch structures and fluid stagnation during flushing stage switching caused by separate discharge valves in traditional systems.

[0052] Compared to existing technologies, traditional flushing systems require separate wastewater discharge valves for forward and reverse flushing, resulting in complex piping structures and the need to independently control the opening and closing sequence of the two valves, leading to low flushing efficiency and the risk of wastewater residue. This solution, however, integrates a wastewater solenoid valve at the end of the merged discharge pipeline, allowing both flushing wastewater streams to be controlled synchronously by a single valve. This simplifies the pipeline layout and eliminates discharge conflicts caused by asynchronous valve operation.

[0053] Through the above technical solution, this application realizes the unified discharge control of wastewater from dual-membrane forward and reverse rinsing, effectively reducing the number of pipeline connection nodes, reducing the risk of impurity deposition caused by incomplete wastewater discharge during the rinsing stage, and reducing system energy consumption and maintenance costs by reducing the number of control components.

[0054] This application further proposes a technical solution of installing an inlet solenoid valve at the inlet of the ultrafiltration membrane module and an ultrafiltration wastewater solenoid valve at the concentrate outlet.

[0055] The inlet solenoid valve is an electrically controlled device installed at the inlet end of the ultrafiltration membrane. Specifically, it can be a normally closed 2-position 2-way solenoid valve used to block or open the channel through which raw water enters the membrane. The wastewater solenoid valve is an electrically controlled device installed at the concentrate outlet end of the ultrafiltration membrane. It can also be a normally closed 2-position 2-way solenoid valve used to control the opening and closing status of the concentrate discharge channel.

[0056] Specifically, when the system enters the flushing mode, the inlet solenoid valve cuts off the raw water supply to eliminate continuous sources of contamination, while the ultrafiltration wastewater solenoid valve remains open to create a discharge path. At this time, the pressure generated by the pressure tank acts on the outer surface of the membrane, forcibly discharging colloids, bacteria, and other trapped substances adhering to the 0.01-micron pore size membrane structure through the concentrate outlet. This process, by independently controlling the inlet and outlet paths, overcomes the technical limitation of traditional unidirectional flushing in cleaning the outer surface of external pressure ultrafiltration membranes, achieving periodic removal of impurities from the membrane surface.

[0057] Compared to existing technologies, the ultrafiltration module in patent CN212151810U lacks an active control device, resulting in continuous inflow of raw water into the outer side of the membrane and repeated deposition of contaminants. This solution, through the coordinated control of dual solenoid valves, enables the ultrafiltration membrane module to independently initiate backwashing during non-water production periods, effectively avoiding flux reduction caused by impurity accumulation during shutdown.

[0058] Through the above technical solution, this application realizes the timed cleaning of contaminants on the outside of the external pressure ultrafiltration membrane, effectively extending the cleaning cycle of the filter element, while avoiding manual maintenance operations of disassembling the filter element. Moreover, the flushing process only consumes the system's remaining pressurized water and requires no additional energy supply.

[0059] This application further proposes to install a pressure sensor at the water inlet of the RO reverse osmosis filter assembly to detect the water inlet pressure and trigger a flushing action when the pressure reaches a threshold.

[0060] The pressure sensor refers to a pressure detection device installed at the product water end of the RO reverse osmosis filter component. It can be implemented using a piezoresistive sensor or a piezoelectric ceramic sensor, and monitors the pressure value on the pure water side in real time through electrical signal conversion. The threshold trigger mechanism refers to using a preset pressure threshold as a judgment condition. This can be implemented using microcontroller or PLC programming. When the sensor detection value exceeds the set threshold, the flushing program is automatically started.

[0061] Specifically, the pressure sensor collects real-time pressure data at the RO reverse osmosis filter assembly's clean water inlet. During normal use, if contaminant deposits on the RO membrane surface increase the resistance in the pre-membrane flow channel, the pressure at the permeate end will abnormally drop. When the pressure reaches a preset threshold, it indicates that the RO membrane is in a critical fouling state. At this point, the sensor triggers the electronic control unit to activate the flushing solenoid valve, using the water flow stored in the pressure tank to backwash the RO membrane surface and discharge the concentrate into the wastewater pipeline. By setting the detection point at the clean water inlet, it directly reflects changes in the pure water side pressure. Compared to traditional inlet monitoring solutions, this allows for earlier identification of permeation risks and precise control of the flushing timing.

[0062] Compared to existing technologies, current water purification equipment typically uses timed flushing or manual control modes, which cannot detect the permeation state inside the membrane housing, resulting in low flushing efficiency and an inability to prevent TDS from rising. For example, patent CN212151810U does not include a pressure monitoring device, allowing concentrated water to continuously permeate to the pure water side after shutdown, requiring frequent filter replacements and leading to water quality degradation. This solution uses a pressure detection and threshold triggering mechanism at the water outlet to achieve dynamic matching between flushing action and permeation state, avoiding resource waste caused by ineffective flushing.

[0063] Through the above technical solution, this application effectively prevents the increase of TDS value caused by the reverse osmosis of concentrate after the RO membrane is shut down, ensuring stable water quality when it is used again; at the same time, by precisely controlling the flushing action through pressure threshold, unnecessary system start-ups and shutdowns are reduced, energy consumption and water waste are reduced, and the service life of the filter element is extended.

[0064] This application further proposes that the second flushing valve of the backwash branch is a pulse-controlled solenoid valve, used to form a pulsed water flow to flush the ultrafiltration membrane module.

[0065] Among them, the pulse-controlled solenoid valve refers to a fluid control device that drives the valve core to open and close at high frequency through an electromagnetic coil. Specifically, it can be implemented using a solenoid valve with a preset frequency switching function, such as a high-frequency solenoid valve with a programmable controller to adjust the switching cycle. This feature enhances the removal effect of contaminants on the membrane surface through periodic water flow impact.

[0066] The pulsed water flow refers to the impact water flow formed by water pressure fluctuations generated by the intermittent opening and closing of a solenoid valve. Specifically, different impact intensities can be achieved by adjusting the on / off frequency of the solenoid valve, for example, a frequency range of 2-5 times per second. This feature enhances the shearing effect on impurities on the membrane surface through the characteristics of the water flow fluctuations.

[0067] Specifically, during the backwashing of the ultrafiltration membrane module, the pulse-controlled solenoid valve performs periodic opening and closing actions according to a preset frequency. When the solenoid valve opens, the concentrate discharged from the RO reverse osmosis filter module 4 is converted into a pulsed water flow, with the flow direction opposite to the normal filtration direction. The water pressure acts on the contaminant layer accumulated on the outside of the ultrafiltration membrane. When the solenoid valve closes, the water flow is cut off, causing a sudden drop in pressure. At this time, the deposits on the membrane surface undergo a peeling effect due to the pressure difference. Through the alternating high-pressure impact and pressure release process, a dynamic shearing action is formed on the contaminants on the membrane surface, which can more effectively remove colloids, bacteria, and other small particles compared to constant water flow flushing. In addition, the pulse frequency can be adjusted according to the degree of water pollution. For example, when a decrease in the permeate flow rate of the membrane module is detected, the pulse frequency can be increased to enhance the flushing intensity.

[0068] In some specific implementations, the pulse-controlled solenoid valve works in conjunction with the pressure sensor. When the pressure sensor detects that the pressure at the RO reverse osmosis filter assembly's water inlet exceeds a set threshold, it triggers the pulse-controlled solenoid valve to execute a flushing procedure. The wastewater generated during the flushing process is discharged centrally through the wastewater discharge pipeline.

[0069] Compared to existing technologies, traditional backwashing uses continuous water flow, which results in insufficient shear force on the membrane surface due to stable water pressure, making it difficult to remove tightly attached contaminants. This solution, however, uses pulsed water flow to create intermittent high-pressure impacts, generating multiple pressure fluctuations per unit time, causing the force of the water flow on the membrane surface to change periodically. This dynamic rinsing mode not only improves the cleaning efficiency per unit water flow but also avoids the water waste caused by continuous high-pressure rinsing.

[0070] Through the above technical solution, this application can significantly improve the removal efficiency of pollutants on the outside of the ultrafiltration membrane, prevent the reduction of water production flow caused by membrane pore blockage, extend the service life of the ultrafiltration membrane module, and reduce the maintenance frequency caused by filter element fouling, thus ensuring the long-term stable operation of the water purification system.

[0071] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of 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 scope of protection of this application.

Claims

1. An RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function, comprising an ultrafiltration membrane module (1), an activated carbon module (2), a booster pump (3), an RO reverse osmosis filter module (4), and a pressure tank (5) connected in sequence, characterized in that: The outlet of the pressure tank (5) is connected to the inlet of the RO reverse osmosis filter assembly (4) through one end of the forward flushing branch (11). The forward flushing branch (11) is equipped with a first check valve (111) and a first flushing valve (112). The first check valve (111) is installed in the direction from the pressure tank (5) to the RO reverse osmosis filter assembly (4). The concentrate port of the RO reverse osmosis filter assembly (4) is connected to the clean water port of the ultrafiltration membrane assembly (1) through one end of the back flushing branch (12); the back flushing branch (12) is provided with a second check valve (121) and a second flushing valve (122), and the installation direction of the second check valve (121) is from the RO reverse osmosis filter assembly (4) to the ultrafiltration membrane assembly (1).

2. The RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function according to claim 1, characterized in that, The other end of the forward flushing branch (11) is connected to the inlet of the RO reverse osmosis filter assembly (4) through the first tee connector (T1); the other end of the reverse flushing branch (12) is connected to the clean water outlet of the ultrafiltration membrane assembly (1) through the second tee connector (T2); the concentrate outlet of the ultrafiltration membrane assembly (1) is connected to the wastewater discharge pipeline (13) through the third tee connector (T3) to form a water path that can simultaneously flush the ultrafiltration membrane assembly (1) and the RO reverse osmosis filter assembly (4).

3. The RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function according to claim 2, characterized in that, The concentrate port of the RO reverse osmosis filter assembly (4) is connected to the third end of the third tee connector (T3) through the fourth tee connector (T4). The first end of the fourth tee connector (T4) is connected to the concentrate port of the RO reverse osmosis filter assembly (4), the second end is connected to the reverse flushing branch (12), and the third end is connected to the wastewater discharge pipeline (13) through the third tee connector (T3).

4. The RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function according to claim 3, characterized in that, A water-making solenoid valve (401) is provided between the fourth tee connector (T4) and the third tee connector (T3).

5. An RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function according to claim 2, characterized in that, The wastewater discharge pipeline (13) is equipped with a wastewater solenoid valve (131) to control the unified discharge of wastewater from the forward flushing branch (11) and the reverse flushing branch (12).

6. The RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function according to claim 1, characterized in that, The inlet of the ultrafiltration membrane module (1) is equipped with an inlet solenoid valve (101), and the concentrate outlet is equipped with an ultrafiltration wastewater solenoid valve (102).

7. The RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function according to claim 1, characterized in that, The RO reverse osmosis filter assembly (4) is equipped with a pressure sensor (402) at the water outlet, which is used to detect the pressure at the water outlet of the RO reverse osmosis filter assembly (4) and trigger a flushing action when the pressure reaches a threshold.

8. The RO reverse osmosis water purifier with dual-membrane forward and reverse dynamic flushing function according to claim 1, characterized in that, The second flushing valve (122) of the backwash branch (12) is a pulse-controlled solenoid valve used to form a pulse water flow to flush the ultrafiltration membrane assembly (1).

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