A water purification system

Abstract

The application discloses a water purification system, which comprises a water inlet pipe and a water purification module. The water purification module is provided with a water inlet, a deep water purification outlet communicated with a deep water purification discharge valve and a concentrated water outlet. The deep water purification outlet is communicated with the deep water purification discharge valve through a deep water purification pipeline. The water purification system further comprises a first liquid-operated valve and a second liquid-operated valve. The liquid-operated valve comprises a liquid inlet, a liquid outlet and a control port for communicating with a control liquid. The liquid pressure of the control port is controlled to control the on-off between the liquid inlet and the liquid outlet. The liquid inlet of the first liquid-operated valve is communicated with the water inlet pipe, and the liquid outlet is communicated with the water inlet of the water purification module. The water purification control filter module enters and the two liquid-operated valves of the concentrated water pipeline can simultaneously close the tap water inlet and the concentrated water outlet, which is safe and reliable, and cannot appear the phenomenon that the water cannot be closed and the concentrated water outlet continuously discharges concentrated water.

Description

Technical Field

[0001] This invention relates to the field of water purification technology, and in particular to a water purification system. Background Technology

[0002] Most reverse osmosis water purifiers use a series of electrical components, including solenoid valves, high-pressure switches, and electronic control systems, to pressurize the water using a booster pump. This pressurizes the reverse osmosis membrane to separate tap water, producing highly purified water and concentrated water. This control method is costly, wasteful of electricity, and unusable in locations without electricity. Pump-free water purifiers on the market have the following disadvantages: they use a four-way valve to control the machine's start and stop, which has a high failure rate, sometimes failing to completely shut off the water supply, resulting in continuous discharge of concentrated water and wasting water resources, and potentially causing flooding; due to the lack of a booster pump, the tap water pressure is low each time the purified water is drawn, resulting in a small initial flow rate and poor user experience; and the reverse osmosis membrane filter cannot be flushed, making it prone to clogging and shortening its lifespan. Summary of the Invention

[0003] To solve the problem of incomplete closure of machine pipelines, this invention utilizes two hydraulic valves in the water purification control filter module inlet and concentrate pipeline, which can simultaneously shut off the tap water inlet and concentrate outlet, ensuring safety and reliability and preventing the phenomenon of water not being shut off and the concentrate outlet continuously discharging concentrate.

[0004] The technical solution adopted in this invention is to design a water purification system, including an inlet pipe and a water purification module. The water purification module has an inlet, a deep purified water outlet connected to a deep purified water discharge valve, and a concentrated water outlet. The deep purified water outlet is connected to the deep purified water discharge valve through a deep purified water pipeline. The system also includes two hydraulic valves, a first and a second. Each hydraulic valve has an inlet, an outlet, and a control port for connecting and controlling liquids. The connection between the inlet and outlet is controlled by controlling the liquid pressure at the control port. The inlet of the first hydraulic valve is connected to the inlet pipe, and its outlet is connected to the inlet of the water purification module. The inlet of the second hydraulic valve is connected to the concentrated water outlet of the water purification module. The deep purified water outlet is simultaneously connected to the control ports of both hydraulic valves.

[0005] In some embodiments, the outlet of the second hydraulic valve is connected to a concentrate proportioner.

[0006] In some embodiments, the concentrated water outlet of the water purification module is connected to the purified water discharge valve through a purified water pipeline; the purified water pipeline is connected to the control port of the first hydraulic valve through a second check valve, and the second check valve prevents the concentrated water from the purified water pipeline from flowing into the deep purified water pipeline.

[0007] In some embodiments, a third check valve is connected between the second check valve and the concentrate outlet, and the purified water discharge valve is connected between the second check valve and the third check valve to prevent purified water from the deep purification pipeline from flowing into the concentrate outlet.

[0008] In some embodiments, the deep water purification outlet is connected to the deep water purification discharge valve and the two hydraulic valves via a first check valve, wherein the first check valve prevents external water from flowing back into the deep water purification outlet.

[0009] In some implementations, the check valve and the hydraulic valve are integrated on the same valve body.

[0010] In some embodiments, a post-filter is connected between the deep water purification outlet of the water purification module and the deep water purification discharge valve.

[0011] In some embodiments, a pre-filter is connected between the outlet of the first hydraulic valve and the inlet of the water purification module.

[0012] In some embodiments, the valve chamber of the hydraulic valve includes a connecting channel located between the inlet and the outlet, and a pressure control chamber communicating with the control port. The connecting channel and the pressure control chamber are connected by a telescopic cavity. The valve core is telescopically disposed within the telescopic cavity. The valve core of the hydraulic valve has a first end and a second end opposite to each other in the telescopic direction. The first end corresponds to the connecting channel, and the second end corresponds to the pressure control chamber. The pressure-bearing area of ​​the first end is smaller than that of the second end. When the second end is pressed, the first end extends, thereby closing the connecting channel.

[0013] In some embodiments, the water purification module is an RO membrane or an NF membrane filter.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. With a dual-outlet water structure, the permeate membrane is flushed when using purified water. The water path passes through the surface of the permeate membrane, thus realizing the function of automatically flushing the permeate membrane.

[0016] 2. Utilizing two hydraulic valves in the water purification control filter module inlet and concentrate pipeline, the system can simultaneously shut off both the tap water inlet and concentrate outlet, ensuring safety and reliability. This prevents the inability to shut off the water supply and avoids continuous discharge of concentrate from the concentrate outlet. Even if either the first or second hydraulic valve malfunctions or occasionally fails, the entire unit functions normally. The probability of both valves failing simultaneously is very low, thus achieving dual protection and resolving the issue of water loss caused by occasional malfunctions or failures of traditional four-way valves.

[0017] 3. The first hydraulic valve and the second hydraulic valve can simultaneously close the water circuit, so that the pipeline between the two control valve units maintains the same pre-pressure as the tap water. When the tap is turned on to draw water, the initial water output will be increased due to the pre-pressure, thus improving the water usage experience. Attached Figure Description

[0018] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. To illustrate the details and facilitate understanding of its principles, the drawings are not necessarily to scale, and similar reference numerals may describe similar components in different views. The accompanying drawings generally illustrate the embodiments discussed herein by way of example and not limitation. Wherein:

[0019] Figure 1 This is a schematic diagram of a water purification system.

[0020] Figure 2 This is a schematic diagram of a water purification system with water purification pipelines.

[0021] Figure 3 This is a schematic diagram of a water purification system equipped with pre- and post-filters.

[0022] Figure 4 This is a 3D schematic diagram of the integrated valve used in a water purification system.

[0023] Figure 5 This is a front view schematic diagram of an integrated valve.

[0024] Figure 6 yes Figure 5 A schematic diagram of the AA section.

[0025] Figure 7 yes Figure 5 A schematic diagram of the BB cross section.

[0026] Figure 8 yes Figure 5 A schematic diagram of the CC section.

[0027] In the diagram, 1. First hydraulic valve; 2. Second hydraulic valve; 3. Inlet pipe; 4. Water purification module; 41. Inlet; 42. Deep purified water outlet; 43. Concentrate outlet; 5. Deep purified water pipeline; 6. Deep purified water discharge valve; 7. Concentrate pipeline; 8. Concentrate proportioner; 9. First check valve; 10. Purified water pipeline; 11. Purified water discharge valve; 12. Second check valve; 13. Third check valve; 14. Post-filter; 15. Pre-filter; 16. Pressure control chamber; 17. Telescopic chamber; 18. Valve core; 19. First end; 20. Second end; 21. Flexible diaphragm; 22. Connecting channel. Detailed Implementation

[0028] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments, and the following embodiments do not limit the invention covered by the claims. Furthermore, not all combinations of the features described in the embodiments are necessary for the inventive solution.

[0029] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0030] Example

[0031] like Figure 1 As shown, a water purification system includes an inlet pipe 3 and a water purification module 4. The water purification module 4 has an inlet 41, a deep water purification outlet 42 connected to a deep water purification discharge valve 6, and a concentrated water outlet 43. The deep water purification outlet 42 is connected to the deep water purification discharge valve 6 through a deep water purification pipeline 5.

[0032] The inlet pipe 3 is, for example, a tap water pipe, and the water purification module 4 is, for example, an RO membrane or NF membrane filter.

[0033] Inlet 41 is the inlet for the RO or NF membrane filter to receive the raw water source. It connects to the inlet pipe 3, and the raw water enters the RO membrane filter system through inlet 41 for filtration and treatment. Deep purified water outlet 42, also known as the product water outlet, is the outlet for the RO or NF membrane filter. Through this outlet, the purified water (product water) that has passed through the membrane filter is output from the system. Concentrate outlet 43 is the concentrate discharge outlet. The concentrate discharge outlet is used to discharge the concentrate that has not passed through the RO or NF membrane, which contains filtered impurities and concentrated solutes. This concentrate is discharged from the system through the discharge outlet.

[0034] Deep water purification discharge valve 6, for example, is a faucet that supplies deep purified water.

[0035] It also includes two hydraulic valves, namely the first hydraulic valve and the second hydraulic valve. A hydraulic valve is a valve that uses the pressure of an externally applied liquid to control the opening and closing of the valve or to regulate the flow rate. It uses liquid pressure as a power source to control the movement of the valve. The main components of the hydraulic valve include the valve body and the valve core 18. The valve body is the outer shell of the valve, which is used to support and fix the internal components of the valve. The valve core 18 is the moving part of the valve. The movement of the valve core 18 is driven by hydraulic force to realize the opening, closing or regulation of the valve.

[0036] The hydraulic valve includes an inlet, an outlet, and a control port for connecting to an external control liquid. By controlling the liquid pressure at the control port, the valve core 18 is moved to control the connection between the inlet and the outlet, thus opening or closing the valve.

[0037] like Figure 4 , 5 As shown in Figures 6, 7, and 8, the hydraulic valve in this embodiment operates on a principle similar to that of a four-way valve. Both valves open or close the flow channel on the other side by controlling the movement of the valve core through liquid pressure on one side. The valve chamber of the hydraulic valve includes a connecting channel 22 located between the inlet a and the outlet b, and a pressure control chamber 16 connected to the control port c. The connecting channel 22 and the pressure control chamber 16 are connected through a telescopic chamber 17. The valve core 18 of the hydraulic valve is telescopically disposed within the telescopic chamber 17. The valve core 18 has a first end 19 and a second end 20 opposite to each other in the telescopic direction. The first end 19 corresponds to the connecting channel 22, and the second end 20 corresponds to the pressure control chamber 16. The pressure-bearing area of ​​the first end 19 is smaller than that of the second end 20. When the second end 20 is pressed, the first end 19 extends, thereby closing the connecting channel 22. The telescopic cavity 17 in this embodiment includes a first port and a second port, the first port being smaller than the second port. Flexible diaphragms 21 are fixed to both the first and second ports. In this embodiment, the flexible diaphragm 21 on the first port corresponds to the inlet. The end faces of the first end 19 and the second end 20 of the valve core 18 are respectively connected to the flexible diaphragms 21 on the corresponding ports, thus preventing the first and second ports from communicating. The valve core 18 can still telescopically move within the telescopic cavity 17 under the hydraulic pressure of the pressure control cavity 16 and the connecting channel 22. Because the first port is smaller than the second port, when the hydraulic pressure in the pressure control cavity 16 and the connecting channel 22 is the same, the pressure on the first end 19 of the valve core 18 is less than that on the second end 20. This causes the valve core 18 to move towards the connecting channel 22, blocking the connecting channel 22 with the flexible diaphragm 21 at the first port, thereby closing the communication between the inlet and the outlet.

[0038] The inlet of the first hydraulic valve 1 is connected to the inlet pipe 3, and the outlet is connected to the inlet 41 of the water purification module 4. That is, the raw water enters the water purification module 4 after passing through the first hydraulic valve 1. The inlet of the second hydraulic valve 2 is connected to the concentrated water outlet 43 of the water purification module 4. That is, the concentrated water can only be discharged after passing through the second hydraulic valve 2. The second hydraulic valve 2 is connected to the concentrated water pipeline 7. The deep purified water outlet 42 is connected to the control ports of both hydraulic valves. The deep purified water outlet 42 is connected to the deep purified water discharge valve 6 via the deep purified water pipeline 5. The deep purified water is connected to the control ports of the first and second hydraulic valves through two water control pipelines respectively.

[0039] The deep purified water outlet 42 is connected to the deep purified water discharge valve 6 and the two hydraulic valves via a first one-way valve 9. The first one-way valve 9 prevents external water from flowing back into the deep purified water outlet 42. The first one-way valve 9 is a deep purified water check valve, ensuring that the deep purified water can only flow unidirectionally to the deep purified water pipeline 5 and cannot return to the tap water pipeline. In this embodiment, the one-way valve and the two hydraulic valves are integrated valves on the same valve body.

[0040] When deep purified water needs to be discharged, such as when drinking, the deep purified water faucet can be opened, and the pressure in the deep purified water pipeline 5 will be released. That is, the pressure in the pressure control chamber 16 of the hydraulic valve will be relieved, and the pressure in the connecting channel 22 between the inlet and the outlet will be the pressure of tap water. Under this pressure, the connecting channel 22 will be in a connected state, so that the water purification module 4 is connected to the tap water circuit and the concentrated water circuit, thereby allowing water from the tap water to enter the water purification module 4, and allowing the concentrated water produced by the water purification module 4 to be discharged in a timely manner. Thus, the water purification module 4 can continuously produce deep purified water, which is continuously discharged from the deep purified water outlet 42.

[0041] In standby mode, i.e. when the water purification system is not in use, the deep water purifier faucet is closed. Driven by the tap water pressure, the pressure in the deep water purification pipeline 5 increases, and subsequently the pressure in the pressure control chamber 16 of the hydraulic valve increases. Since the first port is smaller than the second port, when the hydraulic pressure in the pressure control chamber 16 and the connecting channel 22 is the same, the pressure on the first end 19 of the valve core 18 is less than that on the second end 20. This causes the valve core 18 to move toward the connecting channel 22, causing the flexible diaphragm 21 at the first port to block the connecting channel 22. This closes the connection between the inlet and the outlet, i.e., the first hydraulic valve 1 and the second hydraulic valve 2 close the tap water path and the concentrated water path respectively, preventing tap water from entering the water purification module 4 and preventing the concentrated water produced by the water purification module 4 from being discharged, thus putting the machine into standby mode.

[0042] In this way, the water inlet and concentrated water outlet of the water purification module 4 can be controlled simultaneously by opening and closing the deep water purifier faucet. When any one of the control valves (hydraulic valve) fails, the other control valve (hydraulic valve) can still close the water circuit, which can provide double leakage protection for the system and prevent the phenomenon of water leakage due to failure to close the valve, making it safe and reliable.

[0043] Once water purification is complete, close the deep water purifier faucet. Both hydraulic valves will close simultaneously. The first hydraulic valve 1 shuts off the system's tap water source, and the second hydraulic valve 2 shuts off the concentrated water outlet. This closes both the system's inlet and outlet, while maintaining the same pre-pressure as the tap water within the system pipeline. When the deep water purifier faucet is opened, the pre-pressure ensures rapid water flow, increasing the initial water output and improving the user experience. This addresses the problem of slow water flow and low water volume caused by insufficient initial pressure when the faucet is opened in traditional water purification systems.

[0044] The outlet of the second hydraulic valve 2 is connected to the concentrate proportioner 8 via the concentrate pipeline 7. This allows for the rational utilization of permeate and concentrate, improving system efficiency and reducing environmental impact. The concentrate proportioner 8 is a device used to adjust the ratio between permeate and concentrate in a reverse osmosis (RO) system. When the RO system is running, the pressure difference causes concentrate to flow from one side of the RO membrane to the concentrate proportioner 8. The regulating valve in the concentrate proportioner 8 automatically adjusts its opening degree according to changes in the pressure difference, controlling the concentrate flow rate. By adjusting the valve opening degree, the ratio between permeate and concentrate can be controlled. A higher valve opening degree will result in more concentrate discharge, while a lower valve opening degree will increase the permeate flow.

[0045] When either the first hydraulic valve 1 or the second hydraulic valve 2 malfunctions or occasionally fails, the whole machine functions normally. The probability of both valves malfunctioning at the same time is very low, thus achieving a dual protection function and solving the problem of water loss caused by occasional failure or malfunction of traditional four-sided valves.

[0046] like Figure 2 As shown, furthermore, the concentrated water outlet 43 of the water purification module 4 is connected to the purified water discharge valve 11 through the purified water pipeline 10, so that the concentrated water of the water purification module 4 can be discharged through the purified water pipeline 10; the purified water pipeline 10 is connected to the control port of the first hydraulic valve 1 through the second one-way valve 12, the second one-way valve 12 is a pressure relief check valve, the pressure relief check valve prevents the concentrated water of the purified water pipeline 10 from flowing into the deep purified water pipeline 5. Since there is no concentrated water proportioner 8 on the purified water pipeline 10, the resistance of this pipeline is less than that of the concentrated water pipeline 7.

[0047] When the purified water discharge valve 11 is opened, the deep purified water pipeline 5 is connected to the purified water pipeline 10 through the second one-way valve 12. The pressure in the deep purified water pipeline 5 is released, that is, the pressure control chamber 16 of the hydraulic valve is released. Driven by the pressure on the tap water side, the connecting channel 22 is opened, thereby making the inlet and outlet connected. The purified water module 4 is connected to the tap water circuit. Since there is no concentrate proportioner 8 on the purified water pipeline 10, the purified water pipeline 10 is open and in a depressurized state. The two sides of the permeate membrane need to be... A certain pressure difference is required for operation. Because the purified water pipeline 10 keeps the concentrated water outlet 43 in a depressurized state, the deep water purification will not start water production, i.e., there is no water-transparent permeation membrane. Due to the high water resistance of the concentrated water proportioner 8, no water will flow out of the concentrated water outlet. Therefore, driven by the tap water pressure, the raw water flows out quickly from the purified water discharge valve 11 between the membranes of the purified water module 4, which washes the membrane surface and carries away impurities to achieve membrane rinsing. In this way, the membrane can be cleaned when using purified water without the need for additional electricity, which has a good energy-saving effect.

[0048] like Figure 3 As shown, a post-filter 14 is connected between the deep purified water outlet 42 of the water purification module 4 and the deep purified water discharge valve 6. A pre-filter 15 is connected between the outlet of the first hydraulic valve 1 and the inlet 41 of the water purification module 4.

[0049] A third check valve 13 is connected between the second check valve 12 and the concentrated water outlet 43. The purified water discharge valve 11 is connected between the second check valve 12 and the third check valve 13 to prevent purified water from the deep purified water pipeline 5 from flowing into the concentrated water outlet 43, ensuring that purified water can only flow unidirectionally to the outlet of the purified water pipeline 10 and cannot return to the tap water pipeline. The setting of the third check valve 13 is beneficial to maintaining the pressure of the entire system. When the purified water discharge valve 11 is closed, although the deep purified water pipeline 5 closes the first hydraulic valve 1 and the second hydraulic valve 2, the membrane in the purified water module 4 will slowly absorb some of the water in the purified water pipeline 10, thereby causing the pressure of the purified water pipeline 10 to drop. Without the third check valve 13, water from the deep purified water pipeline 5 would enter the purified water pipeline 10, causing the deep purified water pipeline 5 to depressurize, causing the first hydraulic valve 1 and the second hydraulic valve 2 to fail, and failing to achieve the function of shutting down the system.

[0050] Although this document uses a number of technical terms, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention. The order of actions, steps, etc., in the apparatus and methods shown in the specification and drawings can be implemented in any order unless otherwise expressly specified, and provided that the output of a preceding process is not used in a subsequent process. Similar sequential terms used for descriptive convenience (e.g., "firstly," "next," "secondly," "again," "then," etc.) do not imply that the actions must be performed in such an order.

[0051] Those skilled in the art will understand that all directional references (e.g., above, below, up, up, down, down, top, bottom, left, right, vertical, horizontal, etc.) are used descriptively in the drawings to aid the reader's understanding and do not imply (e.g., a limitation on the scope of the invention as defined by the appended claims) a limitation on the scope of the invention as defined by the appended claims. They are merely for the purpose of facilitating the description of this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation. The directional terms "inside" and "outside" refer to inside or outside relative to the outline of the respective component itself.

[0052] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0053] Additionally, some vague terms (e.g., substantially, certain, generally, etc.) may refer to slight inaccuracies or minor deviations in conditions, quantities, values, or dimensions, some of which are within manufacturing tolerances or limits. It should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components; unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0054] The specific embodiments described herein are merely illustrative examples illustrating the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A water purification system, comprising an inlet pipe and a water purification module, wherein the water purification module has an inlet, a deep purified water outlet connected to a deep purified water discharge valve, and a concentrated water outlet, the deep purified water outlet being connected to the deep purified water discharge valve via a deep purified water pipeline, characterized in that: It also includes two hydraulic valves, each having an inlet, an outlet, and a control port. The connection between the inlet and the outlet is controlled by controlling the liquid pressure at the control port. The inlet of the first hydraulic valve is connected to the water inlet pipe, and the outlet of the first hydraulic valve is connected to the water inlet of the water purification module. The inlet of the second hydraulic valve is connected to the concentrated water outlet of the water purification module; The deep water purification outlet is simultaneously connected to the control ports of the first hydraulic valve and the second hydraulic valve; The valve chamber of the hydraulic valve includes a connecting channel between the inlet and the outlet, and a pressure control chamber communicating with the control port. The connecting channel and the pressure control chamber are connected by a telescopic cavity. The valve core of the hydraulic valve is telescopically disposed in the telescopic cavity. The valve core has a first end and a second end opposite to each other in the telescopic direction. The first end corresponds to the connecting channel, and the second end corresponds to the pressure control chamber. The pressure-bearing area of ​​the first end is smaller than that of the second end. When the second end is pressed, the first end extends, thereby closing the connecting channel.

2. The water purification system according to claim 1, characterized in that, The outlet of the second hydraulic valve is connected to the concentrate proportioner.

3. The water purification system according to claim 2, characterized in that, The concentrated water outlet of the water purification module is connected to the purified water discharge valve through a purified water pipeline; the purified water pipeline is connected to the control port of the first hydraulic valve through a second one-way valve, and the second one-way valve prevents the concentrated water from the purified water pipeline from flowing into the deep purified water pipeline.

4. The water purification system according to claim 3, characterized in that, The second check valve is connected to the concentrate outlet via a third check valve, and the purified water discharge valve is connected between the second check valve and the third check valve to prevent purified water from flowing into the concentrate outlet from the deep purification pipeline.

5. The water purification system according to claim 1, characterized in that, The deep water purification outlet is connected to the deep water purification discharge valve and the two hydraulic valves via a first one-way valve. The first one-way valve prevents external water from flowing back into the deep water purification outlet.

6. The water purification system according to claim 3, 4, or 5, characterized in that, Both the check valve and the hydraulic valve are integrated into the same valve body.

7. The water purification system according to claim 1, characterized in that, The deep water purification outlet of the water purification module is connected to the deep water purification discharge valve via a post-filter.

8. The water purification system according to claim 1, characterized in that, The outlet of the first hydraulic valve is connected to the inlet of the water purification module via a pre-filter.

9. The water purification system according to claim 1, characterized in that, The water purification module is an RO membrane or NF membrane filter.

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