Composite reverse osmosis membrane assembly and water purifier having the same

Abstract

The present invention provides a composite reverse osmosis membrane assembly and a water purifier having the same. The composite reverse osmosis membrane assembly comprises: first and second reverse osmosis membrane elements and a central tube. The first reverse osmosis membrane element is formed by rolling a first reverse osmosis membrane sheet onto the central tube, and the second reverse osmosis membrane element is formed by rolling a second reverse osmosis membrane sheet onto the central tube. The first reverse osmosis membrane element and the second reverse osmosis membrane element are rolled onto the same or different central tubes. The first reverse osmosis membrane element has a first raw water flow channel, and the second reverse osmosis membrane element has a second raw water flow channel. The first concentrate outlet of the first raw water flow channel is connected to the second water inlet of the second raw water flow channel, and the flow cross-sectional area s1 of the first raw water flow channel is greater than the flow cross-sectional area s2 of the second raw water flow channel. According to the present invention, the membrane surface flow velocity on the concentrate side can be increased, the concentration polarization on the concentrate side can be slowed down, the anti-fouling performance of the reverse osmosis membrane can be improved, and the service life of the reverse osmosis membrane filter element can be extended.

Description

Technical Field

[0001] The present invention relates to the technical field of water purifiers, and in particular to a composite reverse osmosis membrane assembly and a water purifier having the same. Background Art

[0002] A spiral wound reverse osmosis membrane element is a water purification element formed by rolling an inlet screen, reverse osmosis membrane, and pure water guide onto a central water production pipe. Utilizing the osmotic properties of the reverse osmosis membrane, water molecules in the raw water, under pressure, permeate the membrane and converge on the pure water side to form pure water, while the raw water gradually forms concentrate on the concentrate side. Ultimately, concentrate flows out of the concentrate outlet, and pure water flows out of the concentrate outlet. As the raw water flows through the raw water flow path toward the concentrate outlet, the fluid velocity on the reverse osmosis membrane surface in the raw water flow path gradually decreases, with the fluid velocity on the concentrate side being the lowest. Due to the gradual decrease in fluid velocity and the increase in solute content, concentration polarization is most severe on the concentrate side, making it the most susceptible to fouling and clogging. Conventional reverse osmosis membrane elements exhibit significant concentration polarization on the concentrate side, shortening the membrane element's service life.

[0003] Since the water flow rate on the membrane surface in the raw water flow channel of the roll-type reverse osmosis membrane element in the prior art gradually decreases with the flow process, the concentration polarization in the downstream section of the flow direction is the most serious, which is most likely to cause technical problems such as fouling and blockage. Therefore, the present invention studies and designs a roll-type reverse osmosis membrane element and a water purifier having the same. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that the concentration polarization in the raw water flow channel of the rolled reverse osmosis membrane element is most serious in the downstream section in the flow direction, which is easy to cause fouling and blockage, thereby providing a composite reverse osmosis membrane assembly and a water purifier having the same.

[0005] In order to solve the above problems, the present invention provides a composite reverse osmosis membrane assembly, which comprises:

[0006] A first reverse osmosis membrane element, a second reverse osmosis membrane element and a central tube, wherein the first reverse osmosis membrane element is formed by rolling a first reverse osmosis membrane sheet on the central tube, and the second reverse osmosis membrane element is formed by rolling a second reverse osmosis membrane sheet on the central tube, the first reverse osmosis membrane element and the second reverse osmosis membrane element are rolled on the same central tube or on different central tubes, the first reverse osmosis membrane element has a first raw water flow channel, the second reverse osmosis membrane element has a second raw water flow channel, the first concentrated water outlet of the first raw water flow channel is connected to the second water inlet of the second raw water flow channel, and the flow cross-sectional area s1 of the first raw water flow channel is greater than the flow cross-sectional area s2 of the second raw water flow channel.

[0007] In some embodiments, 1.5≤s1 / s2≤4.

[0008] In some embodiments, there are at least two central tubes, including a first central tube and a second central tube, the first reverse osmosis membrane is rolled around the periphery of the first central tube to form the first reverse osmosis membrane element, the second reverse osmosis membrane is rolled around the periphery of the second central tube to form the second reverse osmosis membrane element, the second reverse osmosis membrane element is arranged inside the first central tube, the pure water purified by the second reverse osmosis membrane element enters the first central tube, and the pure water purified by the first reverse osmosis membrane element also enters the first central tube.

[0009] In some embodiments, the outer diameter of the second central tube is smaller than the inner diameter of the first central tube.

[0010] The first reverse osmosis membrane sheet is folded to form the first raw water flow channel between the front surfaces of the two membrane leaves, and to form a first opening and a first folded edge facing each other, the first folded edge facing the first central tube and being connected to the first central tube during rolling, and the first opening being away from the first central tube;

[0011] The second reverse osmosis membrane sheet is folded to form the second raw water flow channel between the front sides of its two membrane leaves, and to form a second opening and a second folded edge opposite to each other. The second opening faces the second central tube and is connected to the second central tube for rolling, and the second folded edge is away from the second central tube.

[0012] In some embodiments, the first pure water flow channel is formed between the back sides of the two membrane pages of the first reverse osmosis membrane, and the first pure water flow channel is connected to the interior of the first central tube; the second pure water flow channel is formed between the back sides of the two membrane pages of the second reverse osmosis membrane, and the second pure water flow channel is also connected to the interior of the first central tube, and a pure water outlet is formed at one axial end of the first central tube.

[0013] In some embodiments, the first reverse osmosis membrane includes a first side long side and a second side long side that are perpendicular to the first folded edge after folding, the first side long side and the second side long side are arranged opposite to each other, and a first water inlet is provided on the first side long side, the first water inlet is connected to the first raw water flow channel, and the first concentrated water outlet is provided on the second side long side;

[0014] The second reverse osmosis membrane includes a third side long side and a fourth side long side which are perpendicular to the second folded edge after folding. The third side long side is arranged opposite to the fourth side long side, and the second water inlet is arranged on the third side long side. One end of the second water inlet is connected to the first concentrated water outlet, and the other end is connected to the second raw water flow channel. The second raw water flow channel is connected to the interior of the second central tube through the second opening, and one axial end of the second central tube is formed as the second concentrated water outlet.

[0015] In some embodiments, the first long side is open along its length direction, forming the first water inlet, and the second long side is open along its length direction, forming the first concentrated water outlet.

[0016] The third side is partially sealed at its long edge, and the second water inlet is formed at a position relative to the second opening and close to the second folded edge. The fourth side is completely sealed at its long edge.

[0017] In some embodiments, a first sealing structure is provided at the long side of the third side, and the first sealing structure extends from the second opening to a position at a preset distance from the second folded edge, and the preset distance between the two positions forms the second water inlet. A second sealing structure is provided at the long side of the fourth side, and the second sealing structure extends from the second opening to the second folded edge.

[0018] In some embodiments, there is at least one central tube, including a first central tube, the first reverse osmosis membrane is rolled around the outer periphery of the first central tube to form the first reverse osmosis membrane element, the second reverse osmosis membrane is also rolled around the outer periphery of the first central tube to form the second reverse osmosis membrane element, and the first reverse osmosis membrane and the second reverse osmosis membrane are arranged at intervals along the axial direction of the first central tube.

[0019] In some embodiments, the first reverse osmosis membrane sheet is folded to form the first raw water flow channel between the front surfaces of its two membrane leaves, and to form a first opening and a first folded edge facing each other, wherein the first folded edge faces the first central tube and is connected to the first central tube during rolling, and the first opening is away from the first central tube;

[0020] The second reverse osmosis membrane sheet is folded to form the second raw water flow channel between the front sides of its two membrane leaves, and to form a second opening and a second folded edge relative to each other. The second folded edge is rolled toward the first central tube and connected to the first central tube, and the second opening is away from the first central tube.

[0021] In some embodiments, the first pure water flow channel is formed between the back sides of the two membrane pages of the first reverse osmosis membrane, and the first pure water flow channel is connected to the interior of the first central tube; the second pure water flow channel is formed between the back sides of the two membrane pages of the second reverse osmosis membrane, and the second pure water flow channel is also connected to the interior of the first central tube, and a pure water outlet is formed at one axial end of the first central tube.

[0022] In some embodiments, the first reverse osmosis membrane includes a first side long side and a second side long side that are perpendicular to the first folded edge after folding, the first side long side and the second side long side are arranged opposite to each other, and a first water inlet is provided on the first side long side, the first water inlet is connected to the first raw water flow channel, and the first concentrated water outlet is provided on the second side long side;

[0023] The second reverse osmosis membrane includes a third side long side and a fourth side long side which are perpendicular to the second folded edge after folding. The third side long side is arranged opposite to the fourth side long side, and the third side long side is opposite to the second side long side. The second water inlet is arranged on the third side long side, one end of the second water inlet is connected to the first concentrated water outlet, and the other end is connected to the second raw water flow channel. The second concentrated water outlet is arranged on the fourth side long side.

[0024] In some embodiments, the first side is partially sealed at its long edge, forming the first water inlet at a position close to the first folded edge relative to the first opening; the second side is partially sealed at its long edge, forming the first concentrated water outlet at a position close to the first opening relative to the first folded edge;

[0025] The third side long edge is partially sealed, and the second water inlet is formed at a position close to the second opening relative to the second folded edge. The fourth side long edge is partially sealed, and the second concentrated water outlet is formed at a position close to the second folded edge relative to the second opening.

[0026] In some embodiments, a first sealing structure is provided at the long side of the first side, and the first sealing structure extends from the first opening to a position spaced a first preset distance from the first folded edge, and the first preset distance forms the first water inlet;

[0027] A second sealing structure is provided between the second long side and the third long side, the second sealing structure extending from the first central tube to a position spaced a second preset distance from the first opening, the first concentrated water outlet being formed at the second preset distance; the second sealing structure extends from the first central tube to a position spaced a third preset distance from the second opening, the second water inlet being formed at the third preset distance;

[0028] A third sealing structure is provided at the long side of the fourth side, and the third sealing structure extends from the second opening to a position spaced a fourth preset distance from the second folded edge, and the second concentrated water outlet is formed at the fourth preset distance.

[0029] In some embodiments, the first side long edge is partially sealed, and the first water inlet is formed at a position close to the first opening relative to the first folded edge; the second side long edge is partially sealed, and the first concentrated water outlet is formed at a position close to the first folded edge relative to the first opening;

[0030] The third side long edge is partially sealed, and the second water inlet is formed at a position close to the second folded edge relative to the second opening. The fourth side long edge is partially sealed, and the second concentrated water outlet is formed at a position close to the second opening relative to the second folded edge.

[0031] In some embodiments, a first sealing structure is provided at the long side of the first side, and the first sealing structure extends from the first folded edge to a position spaced a first preset distance from the first opening, and the first preset distance forms the first water inlet;

[0032] A second sealing structure is provided between the second long side and the third long side, the second sealing structure extending from the first opening to a position spaced a second preset distance from the first central tube, the first concentrated water outlet being formed at the second preset distance; the second sealing structure extending from the second opening to a position spaced a third preset distance from the first central tube, the second water inlet being formed at the third preset distance;

[0033] A third sealing structure is provided at the fourth long side, and the third sealing structure extends from the second folded edge to a position spaced a fourth preset distance from the second opening, and the second concentrated water outlet is formed at the fourth preset distance.

[0034] In some embodiments, the first long side is open along its length, forming the first water inlet, and the second long side is open along its length, forming the first concentrated water outlet;

[0035] The third side long edge is partially sealed, and the second water inlet is formed at a position close to the second opening relative to the second folded edge. The fourth side long edge is partially sealed, and the second concentrated water outlet is formed at a position close to the second folded edge relative to the second opening.

[0036] In some embodiments, a first sealing structure is provided at the long side of the third side, and the first sealing structure extends from the second folded edge to a position spaced a first preset distance from the second opening, and the first preset distance forms the second water inlet;

[0037] A second sealing structure is provided at the long side of the fourth side. The second sealing structure extends from the second opening to a position spaced a second preset distance from the second folded edge. The second preset distance forms the second concentrated water outlet.

[0038] In some embodiments, the first opening and the second opening are aligned in the axial direction of the first central tube.

[0039] The present invention also provides a water purifier, which includes the composite reverse osmosis membrane assembly described in any of the preceding items.

[0040] The composite reverse osmosis membrane assembly and the water purifier having the same provided by the present invention have the following beneficial effects:

[0041] The present invention forms a first reverse osmosis membrane element formed by rolling a first reverse osmosis membrane sheet on a central tube, and a second reverse osmosis membrane element formed by rolling a second reverse osmosis membrane sheet on the central tube, and makes the first raw water flow channel of the first reverse osmosis membrane element connected with the second raw water flow channel of the second reverse osmosis membrane element, and sets the flow cross-sectional area s1 of the first raw water flow channel located upstream in the raw water flow direction to be larger than the flow cross-sectional area s2 of the second raw water flow channel located downstream in the raw water flow direction, so that the flow cross-sectional area of ​​the fluid can be effectively reduced along the flow direction of the raw water, thereby increasing the flow velocity of the fluid, slowing down the concentration polarization on the concentrated water side, improving the anti-pollution performance of the reverse osmosis membrane, and extending the service life of the reverse osmosis membrane filter element. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 1 is a flow channel structure diagram of a composite spiral reverse osmosis membrane element embodiment 1 of the present invention;

[0043] Figure 2 Schematic diagram of the flow path of the composite spiral reverse osmosis membrane element embodiment 2 of the present invention;

[0044] Figure 3 1 is a flow channel structure diagram of a composite spiral reverse osmosis membrane element embodiment 1 of the present invention;

[0045] Figure 4 Schematic diagram of the flow path of the composite spiral reverse osmosis membrane element embodiment 2 of the present invention.

[0046] The reference numerals indicate:

[0047] 101. First central tube; 102. Second central tube; 200. First reverse osmosis membrane element; 201. First reverse osmosis membrane sheet; 202. First opening; 203. First folded edge; 204. First side long side; 205. Second side long side; 300. Second reverse osmosis membrane element; 301. Second reverse osmosis membrane sheet; 302. Second opening; 303. Second folded edge; 304. Third side long side; 305. Fourth side long side; 401. First raw water flow channel; 402. Second raw water flow channel; 501. First water inlet; 502. First concentrated water outlet; 503. Second water inlet; 504. Second concentrated water outlet; 505. Pure water inlet; 601. First pure water flow channel; 602. Second pure water flow channel; 701. First sealing structure; 702. Second sealing structure; 703. Third sealing structure. DETAILED DESCRIPTION

[0048] like Figure 1-4 As shown, the present invention provides a composite reverse osmosis membrane assembly, which includes:

[0049] A first reverse osmosis membrane element 200, a second reverse osmosis membrane element 300 and a central tube, wherein the first reverse osmosis membrane element 200 is formed by rolling a first reverse osmosis membrane sheet 201 on the central tube, and the second reverse osmosis membrane element 300 is formed by rolling a second reverse osmosis membrane sheet 301 on the central tube, the first reverse osmosis membrane element 200 and the second reverse osmosis membrane element 300 are rolled on the same central tube or on different central tubes, the first reverse osmosis membrane element 200 has a first raw water flow channel 401, the second reverse osmosis membrane element 300 has a second raw water flow channel 402, the first concentrated water outlet 502 of the first raw water flow channel 401 is connected to the second water inlet 503 of the second raw water flow channel 402, and the flow cross-sectional area s1 of the first raw water flow channel 401 is greater than the flow cross-sectional area s2 of the second raw water flow channel 402.

[0050] The present invention forms a first reverse osmosis membrane element formed by rolling a first reverse osmosis membrane sheet on a central tube, and a second reverse osmosis membrane element formed by rolling a second reverse osmosis membrane sheet on the central tube, and makes the first raw water flow channel of the first reverse osmosis membrane element connected with the second raw water flow channel of the second reverse osmosis membrane element, and sets the flow cross-sectional area s1 of the first raw water flow channel located upstream in the raw water flow direction to be larger than the flow cross-sectional area s2 of the second raw water flow channel located downstream in the raw water flow direction, so that the flow cross-sectional area of ​​the fluid can be effectively reduced along the flow direction of the raw water, thereby increasing the flow velocity of the fluid, slowing down the concentration polarization on the concentrated water side, improving the anti-pollution performance of the reverse osmosis membrane, and extending the service life of the reverse osmosis membrane filter element.

[0051] In some embodiments, 1.5≤s1 / s2≤4. The cross-sectional area of ​​the first raw water flow channel of the present invention is s1, which is greater than the cross-sectional area of ​​the second raw water flow channel is s2, preferably 1.5≤s1 / s2≤4. This relationship is 1.5:1~4:1, that is, the cross-sectional area of ​​the raw water flow channel of the first reverse osmosis membrane element is always greater than the cross-sectional area of ​​the flow of the second reverse osmosis membrane element. The present invention, through the setting of the above-mentioned dimensional relationship, can effectively ensure that the cross-sectional area of ​​the flow is reduced during the flow of raw water, thereby increasing the flow velocity of the membrane surface, and then reducing concentration polarization, and the effect is better. On this basis, the water purification rate can also be improved (to prevent the occurrence of poor water purification effect due to excessive flow velocity).

[0052] The present invention provides a composite reverse osmosis membrane assembly, comprising a first reverse osmosis membrane element having a raw water flow channel cross-sectional area of ​​s1 and a second reverse osmosis membrane element having a raw water flow channel cross-sectional area of ​​s2. The assembly is characterized in that the first concentrate inlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit, and the raw water flow channel cross-sectional area s1 of the first reverse osmosis membrane element is greater than the raw water flow channel cross-sectional area s2 of the second reverse osmosis membrane element. Preferably, 1.5 ≤ s1 / s2 ≤ 4. This effectively reduces the size of the raw water flow channel on the concentrate side, increases the membrane surface flow velocity on the concentrate side, and thereby slows concentration polarization on the concentrate side, improving the anti-fouling performance of the reverse osmosis membrane and extending the service life of the reverse osmosis membrane filter element.

[0053] Example 1, as Figure 1 In some embodiments, there are at least two central tubes, including a first central tube 101 and a second central tube 102. The first reverse osmosis membrane sheet 201 is rolled around the periphery of the first central tube 101 to form the first reverse osmosis membrane element 200. The second reverse osmosis membrane sheet 301 is rolled around the periphery of the second central tube 102 to form the second reverse osmosis membrane element 300. The second reverse osmosis membrane element 300 is arranged inside the first central tube 101. The pure water purified by the second reverse osmosis membrane element 300 enters the first central tube 101, and the pure water purified by the first reverse osmosis membrane element 200 also enters the first central tube 101.

[0054] This is the preferred structural form of the first reverse osmosis membrane element and the second reverse osmosis membrane element of Example 1 of the present invention, that is, the first and second reverse osmosis membrane sheets are respectively rolled on different central tubes, and the rolled second reverse osmosis membrane element is arranged inside the first central tube, so that the first reverse osmosis membrane element is located on the periphery of the second reverse osmosis membrane element. Such an arrangement can reasonably utilize space, effectively reduce the space in the length direction, and improve space utilization. Moreover, through a reasonable membrane arrangement, the pure water of the first and second reverse osmosis membrane elements flows into the first central tube, is mixed into one, and then discharged.

[0055] In some embodiments, the outer diameter of the second central tube 102 is smaller than the inner diameter of the first central tube 101.

[0056] The first reverse osmosis membrane 201 is folded to form the first raw water flow channel 401 between the front sides of the two membrane leaves, and to form a first opening 202 and a first folded edge 203 opposite to each other. The first folded edge 203 faces the first central tube 100 and is connected to the first central tube 101 during rolling. The first opening 202 is away from the first central tube 101.

[0057] The second reverse osmosis membrane 301 is folded to form the second raw water flow channel 402 between the front sides of its two membrane leaves, and to form opposite second openings 302 and second folded edges 303. The second opening 302 faces the second central tube 102 and is connected to the second central tube 102 for rolling, and the second folded edge 303 is away from the second central tube 100.

[0058] This is the preferred rolling method of the first reverse osmosis membrane of Example 1 of the present invention. By folding it to form a first folded edge and a first opening, and connecting the first folded edge with the first central tube for rolling, a first raw water flow path is formed between the front sides of the membrane pages formed by folding the first reverse osmosis membrane. The first raw water flow path needs to be filtered and purified by the first reverse osmosis membrane, and penetrates from the front side to the back side of the first reverse osmosis membrane to form pure water, and the pure water is introduced into the first central tube, effectively achieving the purification and pure water diversion effect; the second reverse osmosis membrane passes through it The second folded edge and the second opening are folded to form a second folded edge and a second opening, and the second opening is connected to the second central tube for rolling, so that a second raw water flow channel is formed between the front sides of the membrane pages formed by the folding of the second reverse osmosis membrane. The second raw water flow channel needs to be filtered and purified by the second reverse osmosis membrane, and penetrates from the front side to the back side of the second reverse osmosis membrane to form pure water, and the pure water is introduced into the first central tube to effectively achieve the purification and pure water diversion effect; and the second opening guides the concentrated water that has not passed through the second reverse osmosis membrane to the interior of the second central tube, thereby achieving the concentrated water diversion effect.

[0059] In some embodiments, a first pure water flow channel 601 is formed between the back surfaces of the two membrane leaves of the first reverse osmosis membrane 201, and the first pure water flow channel 601 is connected to the interior of the first central tube 101. A second pure water flow channel 602 is formed between the back surfaces of the two membrane leaves of the second reverse osmosis membrane 301, and the second pure water flow channel 602 is also connected to the interior of the first central tube 101, and a pure water port 505 is formed at one axial end of the first central tube 101. This is the preferred structural form of the two pure water flow channels of Example 1 of the present invention, i.e., a raw water flow channel is formed between the front surfaces of the two reverse osmosis membranes, while pure water filtered through the membranes is formed between the back surfaces. The pure water port at one axial end of the first central tube is used to discharge the pure water.

[0060] In some embodiments, the first reverse osmosis membrane 201 includes a first side long side 204 and a second side long side 205 that are perpendicular to the first folded edge 203 after folding. The first side long side 204 and the second side long side 205 are arranged opposite to each other, and a first water inlet 501 is provided on the first side long side 204. The first water inlet 501 is connected to the first raw water flow channel 401, and the first concentrated water outlet 502 is provided on the second side long side 205.

[0061] The second reverse osmosis membrane 301 includes a third side long side 304 and a fourth side long side 305 which are perpendicular to the second folded edge 303 after folding. The third side long side 304 is arranged opposite to the fourth side long side 305, and the second water inlet 503 is arranged on the third side long side 304. One end of the second water inlet 503 is connected to the first concentrated water outlet 502, and the other end is connected to the second raw water flow channel 402. The second raw water flow channel 402 is connected to the interior of the second central tube 102 through the second opening 302, and one axial end of the second central tube 102 is formed as the second concentrated water outlet 504.

[0062] This is a further preferred structural form of the first reverse osmosis membrane of the present invention and a forming method of the first water inlet and the first concentrated water outlet, that is, the first water inlet is arranged on the first side long side, and the first concentrated water outlet is arranged on the second side long side, so that the raw water can enter the first raw water channel through the first water inlet for purification and filtration, and the purified concentrated water can be guided to the second reverse osmosis membrane through the first concentrated water outlet; the second reverse osmosis membrane further preferably has the second water inlet arranged on the third side long side, and the second concentrated water outlet arranged on the fourth side long side, so that the raw water can enter the second raw water channel through the second water inlet for purification and filtration, and the second opening is connected to the second central tube for guiding the concentrated water into the second central tube, and further guiding the concentrated water out through the second concentrated water outlet.

[0063] In some embodiments, the first long side 204 is open along its length, forming the first water inlet 501, and the second long side 205 is open along its length, forming the first concentrated water outlet 502.

[0064] The third long side 304 is partially sealed, and the second water inlet 503 is formed at a position relative to the second opening 302 and close to the second folded edge 303 . The fourth long side 305 is completely sealed.

[0065] This is a further preferred structural form of the first water inlet and the first concentrate water inlet of the present invention, that is, the first side long side and the second side long side are both normally open structures, which can enable the raw water to enter the first raw water flow channel through the entire length direction of the first side long side, and discharge the concentrate water through the entire length direction of the second side long side; and the third side long side of the second reverse osmosis membrane forms a partial seal, and the second water inlet is formed only at a position close to the second folded edge (that is, the circumferential outer end), avoiding the second water inlet being too close to the second opening, resulting in a shorter length of the second raw water flow channel and unable to form an effective purification and filtration effect, thereby further improving the purification accuracy.

[0066] In some embodiments, a first sealing structure 701 is provided on the third long side 304. The first sealing structure 701 extends from the second opening 302 to a position spaced a preset distance from the second folded edge 303. The spaced preset distance forms the second water inlet 503. A second sealing structure 702 is provided on the fourth long side 305. The second sealing structure 702 extends from the second opening 302 to the second folded edge 303. This is a preferred structural form for forming a partial seal on the second reverse osmosis membrane of the present invention, i.e., the first sealing structure is provided on the third long side and forms a gap with the second folded edge for the intake of concentrated water, i.e., the second water inlet, thereby increasing the purification path and distance, thereby improving purification accuracy.

[0067] Example 1:

[0068] The present invention provides a composite reverse osmosis membrane assembly comprising at least two reverse osmosis membrane units. Each reverse osmosis membrane unit is formed by stacking and winding a reverse osmosis membrane sheet, a water inlet grid, and a pure water guide cloth around a central water production pipe. The water inlet grid and the pure water guide cloth are respectively located in the water inlet channel formed by the front face of the folded reverse osmosis membrane sheet and the water production channel formed by the adjacent back face. The first concentrate inlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit, and the cross-sectional area s1 of the water inlet channel of the first reverse osmosis membrane unit is greater than the cross-sectional area s2 of the water inlet channel of the second reverse osmosis membrane unit.

[0069] The cross-sectional area of ​​the water inlet flow channel of the reverse osmosis membrane element is equal to the product of the distance H between the front faces of the reverse osmosis membrane after folding and rolling, the folding position length L and the number n of water inlet flow channels after folding.

[0070] The first reverse osmosis membrane unit has a first water inlet, a first concentrate outlet, and a first pure water outlet. The second reverse osmosis membrane unit has a second water inlet, a second concentrate outlet, and a second pure water outlet. The first water inlet of the first reverse osmosis membrane unit is the water inlet of the composite reverse osmosis membrane assembly, and the second concentrate outlet of the second reverse osmosis membrane unit is the concentrate outlet of the composite reverse osmosis membrane assembly. The first concentrate outlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit.

[0071] Preferably, the two reverse osmosis membrane units are assembled in a concentric manner. The first reverse osmosis membrane unit comprises a first central tube, and the second reverse osmosis membrane unit comprises a second central tube. The assembly is performed by concentrically sleeved the first central tube on the outside of the second reverse osmosis membrane unit, and sealing the gap formed between one end of the first central tube and the outside of the second reverse osmosis membrane unit.

[0072] Preferably, the first reverse osmosis membrane unit has a first pure water outlet, the second reverse osmosis membrane unit has a second pure water outlet, the first pure water outlet and the second pure water outlet are connected inside the composite reverse osmosis membrane assembly and share a pure water outlet channel, which is connected to the pure water outlet of the composite reverse osmosis membrane assembly.

[0073] The first reverse osmosis membrane unit is characterized by comprising a first central tube and a pure water guide cloth rolled onto the first central tube, a reverse osmosis membrane, and a water inlet grid. The water inlet grid and the pure water guide cloth are respectively located in the raw water flow channel formed by the front side and the produced water flow channel formed by the adjacent back side after the reverse osmosis membrane is folded. The opening formed by the folded reverse osmosis membrane faces away from the first central tube. The first long side of the raw water flow channel, which is perpendicular to the folded edge, forms the raw water inlet, and the second long side forms the concentrated water outlet. The short side of the pure water guide cloth is connected to the first central tube. The two long sides of the folded reverse osmosis membrane and the short side away from the first central tube are both connected to the pure water guide cloth to form a pure water flow channel. The pure water outlet of the pure water flow channel is connected to the first central tube. The first central tube is used to collect the pure water produced by the first reverse osmosis membrane.

[0074] The second reverse osmosis membrane unit is characterized by comprising a second central tube and a pure water guide cloth, a reverse osmosis membrane and a water inlet grid rolled on the second central tube, wherein the water inlet grid and the pure water guide cloth are respectively located in the water inlet channel formed by the front side and the water production channel formed by the adjacent back side after the reverse osmosis membrane is folded. The opening formed by the folded reverse osmosis membrane faces the second central tube and is connected to the second central tube. The second central tube is used to collect the concentrated water produced by the second reverse osmosis membrane unit; the first long side of the raw water channel perpendicular to the folded edge is partially sealed and forms a raw water inlet at one end near the folded edge, and the second long side of the raw water channel perpendicular to the folded edge is completely sealed; the short side of the pure water guide cloth is connected to the concentrated water pipe, and the two long sides of the folded reverse osmosis membrane and the short side near the concentrated water pipe are both connected to the pure water guide cloth to form a pure water channel, and the pure water outlet of the pure water channel is located on the outer side of the rolled reverse osmosis membrane element.

[0075] Because the first central tube is concentrically sleeved outside the second reverse osmosis membrane element, the first central tube can simultaneously collect the pure water produced by the second reverse osmosis membrane unit, and the pure water of the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are collected in the first central tube;

[0076] The first central tube has a first end face close to the raw water inlet of the first reverse osmosis membrane unit and a second end face close to the concentrated water outlet of the first reverse osmosis membrane unit. The second end face and the circumference of one end of the raw water inlet of the second reverse osmosis membrane unit are sealed by gluing.

[0077] The present invention reduces the cross-sectional area of ​​the water inlet flow channel on the concentrated water side by combining membrane elements with different water inlet flow channel cross-sectional areas, thereby increasing the membrane surface flow rate on the concentrated water side, thereby slowing down the concentration polarization on the concentrated water side, improving the anti-pollution performance of the reverse osmosis membrane, and extending the service life of the reverse osmosis membrane filter element.

[0078] The present invention also includes a water purifier having the composite filter element.

[0079] Example 2-4, as Figure 2-4 ,

[0080] In some embodiments, there is at least one central tube, including a first central tube 101, the first reverse osmosis membrane 201 is rolled on the outer periphery of the first central tube 101 to form the first reverse osmosis membrane element 200, and the second reverse osmosis membrane 301 is also rolled on the outer periphery of the first central tube 101 to form the second reverse osmosis membrane element 300, and the first reverse osmosis membrane 201 and the second reverse osmosis membrane 301 are arranged at intervals along the axial direction of the first central tube 101.

[0081] This is the preferred structural form of the first reverse osmosis membrane element and the second reverse osmosis membrane element of Example 2 of the present invention, that is, the first and second reverse osmosis membrane sheets are respectively rolled on the same central tube, and the rolled second reverse osmosis membrane element and the first reverse osmosis membrane element are axially spaced apart, so that the first reverse osmosis membrane element is located at one axial end of the second reverse osmosis membrane element. Such an arrangement can reasonably utilize space, effectively reduce the space in the radial direction, and do not need to make the first central tube very large, thereby improving space utilization. Moreover, through a reasonable arrangement of the membrane sheets, the pure water of the first and second reverse osmosis membrane elements can flow into the first central tube, be mixed into one, and then be discharged.

[0082] In some embodiments, the first reverse osmosis membrane 201 is folded to form the first raw water flow channel 401 between the front surfaces of the two membrane leaves, and to form a first opening 202 and a first folded edge 203 opposite to each other. The first folded edge 203 faces the first central tube 100 and is connected to the first central tube 100 during rolling. The first opening 202 is away from the first central tube 100.

[0083] The second reverse osmosis membrane 301 is folded to form the second raw water flow channel 402 between the front sides of its two membrane leaves, and to form a second opening 302 and a second folded edge 303 opposite to each other. The second folded edge 303 is rolled toward the first central tube 100 and connected to the first central tube 101, and the second opening 302 is away from the first central tube 101.

[0084] This is the preferred rolling method of the first reverse osmosis membrane of Example 2 of the present invention, which is formed by folding it to form a first folded edge and a first opening, and connecting the first folded edge to the first central tube for rolling, so that a first raw water flow path is formed between the front sides of the membrane pages formed by folding the first reverse osmosis membrane. The first raw water flow path needs to be filtered and purified by the first reverse osmosis membrane, and penetrates from the front side to the back side of the first reverse osmosis membrane to form pure water, and the pure water is introduced into the first central tube, effectively achieving the purification and pure water diversion effect; the second reverse osmosis membrane is formed by folding it to form a second A folded edge and a second opening are formed, and the second folded edge is connected to the first central tube and rolled, so that a second raw water flow channel is formed between the front sides of the membrane pages formed by the folding of the second reverse osmosis membrane. The second raw water flow channel needs to be filtered and purified by the second reverse osmosis membrane, and penetrates from the front side to the back side of the second reverse osmosis membrane to form pure water, and the pure water is introduced into the first central tube to effectively achieve the purification and pure water diversion effect; and the second opening seals the concentrated water that has not passed through the second reverse osmosis membrane without excluding the concentrated water, and the concentrated water is discharged through the second concentrated water outlet at the long side of the fourth side.

[0085] In some embodiments, a first pure water flow channel 601 is formed between the back surfaces of the two membrane leaves of the first reverse osmosis membrane 201, and the first pure water flow channel 601 is connected to the interior of the first central tube 101. A second pure water flow channel 602 is formed between the back surfaces of the two membrane leaves of the second reverse osmosis membrane 301, and the second pure water flow channel 602 is also connected to the interior of the first central tube 101, and a pure water port 505 is formed at one axial end of the first central tube 101. This is the preferred structural form of the two pure water flow channels of Example 2 of the present invention, i.e., the raw water flow channel is formed between the front surfaces of the two reverse osmosis membranes, while the pure water after passing through the membranes and being filtered is formed between the back surfaces. The pure water port at one axial end of the first central tube is used to discharge the pure water.

[0086] In some embodiments, the first reverse osmosis membrane 201 includes a first side long side 204 and a second side long side 205 that are perpendicular to the first folded edge 203 after folding. The first side long side 204 and the second side long side 205 are arranged opposite to each other, and a first water inlet 501 is provided on the first side long side 204. The first water inlet 501 is connected to the first raw water flow channel 401, and the first concentrated water outlet 502 is provided on the second side long side 205.

[0087] The second reverse osmosis membrane 301 includes a third side long side 304 and a fourth side long side 305 which are perpendicular to the second folded edge 303 after folding. The third side long side 304 is arranged opposite to the fourth side long side 305, and the third side long side 304 is opposite to the second side long side 205. The second water inlet 503 is set on the third side long side 304. One end of the second water inlet 503 is connected to the first concentrated water outlet 502 and the other end is connected to the second raw water flow channel 402. The second concentrated water outlet 504 is set on the fourth side long side 305.

[0088] This is a further preferred structural form of the first reverse osmosis membrane and the forming method of the first water inlet and the first concentrated water outlet of Examples 2-4 of the present invention, that is, the first water inlet is arranged on the first side long side, and the first concentrated water outlet is arranged on the second side long side, so that the raw water can enter the first raw water channel through the first water inlet for purification and filtration, and the purified concentrated water can be guided to the second reverse osmosis membrane through the first concentrated water outlet; the second reverse osmosis membrane further preferably has the second water inlet arranged on the third side long side, and the second concentrated water outlet arranged on the fourth side long side, so that the raw water can enter the second raw water channel through the second water inlet for purification and filtration, and the second opening is connected to the second central tube for guiding the concentrated water into the second central tube, and further guiding the concentrated water out through the second concentrated water outlet.

[0089] Example 2, as Figure 2 ,

[0090] In some embodiments, the first long side 204 is partially sealed, and the first water inlet 501 is formed at a position close to the first folded edge 203 relative to the first opening 202; the second long side 205 is partially sealed, and the first concentrated water outlet 502 is formed at a position close to the first opening 202 relative to the first folded edge 203;

[0091] The third side long edge 304 is partially sealed, and the second water inlet 503 is formed at a position close to the second opening 302 relative to the second folded edge 303. The fourth side long edge 305 is partially sealed, and the second concentrated water outlet 504 is formed at a position close to the second folded edge 303 relative to the second opening 302.

[0092] This is a further preferred structural form of the first water inlet and the first concentrated water outlet of embodiment 2 of the present invention, that is, the first side long side is partially sealed, so that the first water inlet is formed near the first folded edge position, and the second side long side is partially sealed, forming the first concentrated water outlet near the first opening position, which can effectively increase the Figure 2 The length of the water flow in the lateral direction shown can increase the flow length in the first raw water flow channel, thereby improving the water purification rate; and the third side long edge of the second reverse osmosis membrane forms a partial seal, and only forms a second water inlet at a position close to the second opening (i.e., the circumferential outer end), so that the second water inlet is arranged opposite to the first concentrated water outlet, and the second concentrated water outlet is located at the fourth side long edge close to the second folded edge, which can increase the flow length of the raw water in the second raw water flow channel, avoid the second concentrated water outlet being too close to the second opening, resulting in a shorter length of the second raw water flow channel and unable to form an effective purification and filtration effect, thereby further improving the purification accuracy.

[0093] In some embodiments, a first sealing structure 701 is provided at the first long side 204 , and the first sealing structure 701 extends from the first opening 202 to a position spaced a first preset distance from the first folded edge 203 , and the first preset distance forms the first water inlet 501 ;

[0094] A second sealing structure 702 is provided between the second long side 205 and the third long side 304. The second sealing structure 702 extends from the first central tube 101 to a position spaced a second preset distance from the first opening 202. The second preset distance forms the first concentrated water outlet 502. The second sealing structure 702 extends from the first central tube 101 to a position spaced a third preset distance from the second opening 302. The third preset distance forms the second water inlet 503.

[0095] A third sealing structure 703 is provided at the fourth long side 305 . The third sealing structure 703 extends from the second opening 302 to a position spaced a fourth preset distance from the second folded edge 303 . The fourth preset distance forms the second concentrated water outlet 504 .

[0096] This is the preferred structural form for forming partial seals on the first reverse osmosis membrane and the second reverse osmosis membrane in Example 2 of the present invention, that is, the first sealing structure is arranged on the long side of the first side and forms a gap with the first folded edge for the intake of raw water, that is, the first water inlet, the second sealing structure is arranged between the long side of the second side and the long side of the third side and forms a gap with the first opening for the discharge of the first concentrated water, which can achieve the effect of increasing the purification path and distance and improve the purification accuracy; the second sealing structure is arranged between the long side of the second side and the long side of the third side and forms a gap with the second opening for the intake of the first concentrated water, that is, the second water inlet, the third sealing structure is arranged on the long side of the fourth side and forms a gap with the second folded edge for the discharge of the second concentrated water, which can achieve the effect of increasing the purification path and distance and improve the purification accuracy.

[0097] In some embodiments, the positions of the first opening 202 and the second opening 302 are aligned in the axial direction of the first central tube 101 (ie, Figure 2 (The first opening 202 and the second opening 302 are shown flush at the right end of the figure, making the second predetermined distance equal to the third predetermined distance.) This is the preferred positioning of the first and second openings in Example 2 of the present invention. They are positioned opposite each other, so that the first concentrate outlet and the second water inlet face each other. This effectively drains concentrate from the first raw water flow channel into the second raw water flow channel, achieving two-stage filtration.

[0098] Example 2:

[0099] The present invention provides a composite reverse osmosis membrane assembly comprising at least two reverse osmosis membrane units. Each reverse osmosis membrane unit is formed by stacking and winding a reverse osmosis membrane sheet, a water inlet grid, and a pure water guide cloth around a central water production pipe. The water inlet grid and the pure water guide cloth are respectively located in the water inlet channel formed by the front face of the folded reverse osmosis membrane sheet and the water production channel formed by the adjacent back face. The first concentrate inlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit, and the cross-sectional area s1 of the water inlet channel of the first reverse osmosis membrane unit is greater than the cross-sectional area s2 of the water inlet channel of the second reverse osmosis membrane unit.

[0100] The cross-sectional area of ​​the water inlet flow channel of the reverse osmosis membrane element is equal to the product of the distance H between the front faces of the reverse osmosis membrane after folding and rolling, the folding position length L and the number n of water inlet flow channels after folding.

[0101] The first reverse osmosis membrane unit has a first water inlet, a first concentrate outlet, and a first pure water outlet. The second reverse osmosis membrane unit has a second water inlet, a second concentrate outlet, and a second pure water outlet. The first water inlet of the first reverse osmosis membrane unit is the water inlet of the composite reverse osmosis membrane assembly, and the second concentrate outlet of the second reverse osmosis membrane unit is the concentrate outlet of the composite reverse osmosis membrane assembly. The first concentrate outlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit.

[0102] Preferably, the two reverse osmosis membrane units are combined by rolling them on the same central tube, wherein the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled together on the central tube.

[0103] Preferably, the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled onto the central tube at one time. The first reverse osmosis membrane unit is close to the first end of the central tube, and the second reverse osmosis membrane unit is close to the second end of the central tube. The outlet of the second end of the central tube is sealed, and the outlet of the first end is open.

[0104] The water inlet grid and pure water guide cloth are respectively located in the water inlet channel formed by the front side and the water production channel formed by the adjacent back side after the reverse osmosis membrane is folded. The opening formed by the folded reverse osmosis membrane faces away from the central tube, which is used to collect the pure water produced by the first reverse osmosis membrane unit and the second reverse osmosis membrane unit. The first long side of the raw water channel of the first reverse osmosis membrane unit, which is perpendicular to the fold, is sealed, and a raw water inlet is formed at the end near the fold. The second long side of the raw water channel of the first reverse osmosis membrane unit, which is perpendicular to the fold, is sealed, and a concentrated water outlet is formed at the end away from the fold. The third long side of the raw water channel of the second reverse osmosis membrane unit, which is perpendicular to the fold, is sealed, and a raw water inlet is formed at the end away from the fold. The fourth long side of the raw water channel of the second reverse osmosis membrane unit, which is perpendicular to the fold, is sealed, and a concentrated water outlet is formed at the end near the fold.

[0105] The first long side, the second long side, the third long side and the fourth long side of the raw water flow channel, which are perpendicular to the folded edge, are partially sealed by gluing.

[0106] The present invention reduces the size of the water inlet flow channel on the concentrated water side by combining membrane elements with different water inlet flow channel cross-sectional areas, thereby increasing the membrane surface flow rate on the concentrated water side, thereby slowing down the concentration polarization on the concentrated water side, improving the anti-pollution performance of the reverse osmosis membrane, and extending the service life of the reverse osmosis membrane filter element.

[0107] The present invention also includes a water purifier having the composite filter element.

[0108] Example 3, as Figure 3 ,

[0109] In some embodiments, the first long side 204 is partially sealed, forming the first water inlet 501 at a position close to the first opening 202 relative to the first folded edge 203, and the second long side 205 is partially sealed, forming the first concentrated water outlet 502 at a position close to the first folded edge 203 relative to the first opening 202;

[0110] The third side long edge 304 is partially sealed, and the second water inlet 503 is formed at a position close to the second folded edge 303 relative to the second opening 302. The fourth side long edge 305 is partially sealed, and the second concentrated water outlet 504 is formed at a position close to the second opening 302 relative to the second folded edge 303.

[0111] This is a further preferred structural form of the first water inlet and the first concentrated water outlet of embodiment 3 of the present invention, that is, the first side long side is partially sealed, so that the first water inlet is formed near the first opening position, and the second side long side is partially sealed, and the first concentrated water outlet is formed near the first fold position, which can effectively increase the Figure 3 The length of the water flow in the lateral direction shown can increase the flow length in the first raw water flow channel, thereby improving the water purification rate; and the third side long edge of the second reverse osmosis membrane forms a partial seal, and only forms a second water inlet at a position close to the second folded edge (i.e., the circumferential outer end), so that the second water inlet is arranged opposite to the first concentrated water outlet, and the second concentrated water outlet is located near the second opening on the fourth side long edge, which can increase the flow length of the raw water in the second raw water flow channel, avoid the second concentrated water outlet being too close to the second folded edge, resulting in a shorter length of the second raw water flow channel and unable to form an effective purification and filtration effect, thereby further improving the purification accuracy.

[0112] In some embodiments, a first sealing structure 701 is provided at the first long side 204 , and the first sealing structure 701 extends from the first folded edge 203 to a position spaced a first preset distance from the first opening 202 , and the first preset distance forms the first water inlet 501 ;

[0113] A second sealing structure 702 is provided between the second long side 205 and the third long side 304. The second sealing structure 702 extends from the first opening 202 to a position spaced a second preset distance from the first central tube 101. The second preset distance forms the first concentrated water outlet 502. The second sealing structure 702 extends from the second opening 302 to a position spaced a third preset distance from the first central tube 101. The third preset distance forms the second water inlet 503.

[0114] A third sealing structure 703 is provided at the fourth long side 305 . The third sealing structure 703 extends from the second folded edge 303 to a position spaced a fourth preset distance from the second opening 302 . The fourth preset distance forms the second concentrated water outlet 504 .

[0115] This is the preferred structural form for forming partial seals on the first reverse osmosis membrane and the second reverse osmosis membrane in Example 3 of the present invention, that is, the first sealing structure is arranged on the long side of the first side and forms a gap with the first opening for the intake of raw water, that is, the first water inlet, the second sealing structure is arranged between the long side of the second side and the long side of the third side and forms a gap with the first folded edge for the discharge of the first concentrated water, which can achieve the effect of increasing the purification path and distance and improve the purification accuracy; the second sealing structure is arranged between the long side of the second side and the long side of the third side and forms a gap with the second folded edge for the intake of the first concentrated water, that is, the second water inlet, the third sealing structure is arranged on the long side of the fourth side and forms a gap with the second opening for the discharge of the second concentrated water, which can achieve the effect of increasing the purification path and distance and improve the purification accuracy.

[0116] In some embodiments, the positions of the first opening 202 and the second opening 302 are aligned in the axial direction of the first central tube 101 (ie, Figure 3 (The first opening 202 and the second opening 302 are shown flush at the right end of the figure, making the second predetermined distance equal to the third predetermined distance.) This is the preferred positioning of the first and second openings in Example 3 of the present invention. They are positioned opposite each other, so that the first concentrate outlet and the second concentrate inlet face each other. This effectively drains concentrate from the first raw water flow channel into the second raw water flow channel, achieving two-stage filtration.

[0117] Example 3:

[0118] The present invention provides a composite reverse osmosis membrane assembly comprising at least two reverse osmosis membrane units. Each reverse osmosis membrane unit is formed by stacking and winding a reverse osmosis membrane sheet, a water inlet grid, and a pure water guide cloth around a central water production pipe. The water inlet grid and the pure water guide cloth are respectively located in the water inlet channel formed by the front face of the folded reverse osmosis membrane sheet and the water production channel formed by the adjacent back face. The first concentrate inlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit, and the cross-sectional area s1 of the water inlet channel of the first reverse osmosis membrane unit is greater than the cross-sectional area s2 of the water inlet channel of the second reverse osmosis membrane unit.

[0119] The cross-sectional area of ​​the water inlet flow channel of the reverse osmosis membrane element is equal to the product of the distance H between the front faces of the reverse osmosis membrane after folding and rolling, the folding position length L and the number n of water inlet flow channels after folding.

[0120] The first reverse osmosis membrane unit has a first water inlet, a first concentrate outlet, and a first pure water outlet. The second reverse osmosis membrane unit has a second water inlet, a second concentrate outlet, and a second pure water outlet. The first water inlet of the first reverse osmosis membrane unit is the water inlet of the composite reverse osmosis membrane assembly, and the second concentrate outlet of the second reverse osmosis membrane unit is the concentrate outlet of the composite reverse osmosis membrane assembly. The first concentrate outlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit.

[0121] Preferably, the two reverse osmosis membrane units are combined by rolling them on the same central tube, wherein the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled together on the central tube.

[0122] Preferably, the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled onto the central tube at one time. The first reverse osmosis membrane unit is close to the first end of the central tube, and the second reverse osmosis membrane unit is close to the second end of the central tube. The outlet of the second end of the central tube is sealed, and the outlet of the first end is open.

[0123] The water inlet grid and pure water guide cloth are respectively located in the water inlet channel formed by the front side and the water production channel formed by the adjacent back side after the reverse osmosis membrane is folded. The opening formed by the folded reverse osmosis membrane faces away from the central tube, which is used to collect the pure water produced by the first reverse osmosis membrane unit and the second reverse osmosis membrane unit. The first long side of the raw water channel of the first reverse osmosis membrane unit, which is perpendicular to the fold, is sealed and forms a raw water inlet at the end away from the fold. The second long side of the raw water channel of the first reverse osmosis membrane unit, which is perpendicular to the fold, is sealed and forms a concentrate outlet at the end near the fold. The third long side of the raw water channel of the second reverse osmosis membrane unit, which is perpendicular to the fold, is sealed and forms a raw water inlet at the end near the fold. The fourth long side of the raw water channel of the second reverse osmosis membrane unit, which is perpendicular to the fold, is sealed and forms a concentrate outlet at the end away from the fold.

[0124] The first long side, the second long side, the third long side and the fourth long side of the raw water flow channel, which are perpendicular to the folded edge, are partially sealed by gluing.

[0125] The present invention reduces the size of the water inlet flow channel on the concentrated water side by combining membrane elements with different water inlet flow channel cross-sectional areas, thereby increasing the membrane surface flow rate on the concentrated water side, thereby slowing down the concentration polarization on the concentrated water side, improving the anti-pollution performance of the reverse osmosis membrane, and extending the service life of the reverse osmosis membrane filter element.

[0126] The present invention also includes a water purifier having the composite filter element.

[0127] Example 4, as Figure 4 ,

[0128] In some embodiments, the first long side 204 is open along its length, forming the first water inlet 501, and the second long side 205 is open along its length, forming the first concentrated water outlet 502.

[0129] The third side long edge 304 is partially sealed, and the second water inlet 503 is formed at a position close to the second opening 302 relative to the second folded edge 303. The fourth side long edge 305 is partially sealed, and the second concentrated water outlet 504 is formed at a position close to the second folded edge 303 relative to the second opening 302.

[0130] This is a further preferred structural form of the first water inlet and the first concentrated water outlet of Example 4 of the present invention, that is, the first side long side and the second side long side are both normally open structures, which can enable the raw water to enter the first raw water flow channel through the entire length direction of the first side long side, and discharge the concentrated water through the entire length direction of the second side long side; and the third side long side of the second reverse osmosis membrane forms a partial seal, and only forms a second water inlet at a position close to the second opening (that is, the circumferential outer end), and opens a second concentrated water outlet near the second folded edge position, so that the distance between the first water inlet and the second concentrated water outlet is effectively increased, avoiding the second water inlet being too close to the second concentrated water outlet, resulting in a shorter length of the second raw water flow channel and unable to form an effective purification and filtration effect, thereby further improving the purification accuracy.

[0131] In some embodiments, a first sealing structure 701 is provided at the third long side 304 , and the first sealing structure 701 extends from the second folded edge 303 to a position spaced a first preset distance from the second opening 302 , and the first preset distance forms the second water inlet 503 ;

[0132] A second sealing structure 702 is provided at the fourth long side 305 . The second sealing structure 702 extends from the second opening 302 to a position spaced a second preset distance from the second folded edge 303 . The second preset distance forms the second concentrated water outlet 504 .

[0133] This is the preferred structural form for forming partial sealing on the second reverse osmosis membrane of the present invention, that is, the first sealing structure is arranged on the third side long side and forms a gap with the second opening for the intake of the first concentrated water, that is, the second water inlet, and the second sealing structure is arranged on the fourth side long side and forms a gap with the second folded edge for the discharge of the second concentrated water, that is, the second concentrated water outlet, thereby achieving the effect of increasing the purification path and distance and improving the purification accuracy.

[0134] In some embodiments, the positions of the first opening 202 and the second opening 302 are aligned in the axial direction of the first central tube 101 (ie, Figure 4 (The first opening 202 and the second opening 302 are shown flush at the right end of the figure.) This is the preferred position of the first opening and the second opening of Example 4 of the present invention. The first opening and the second opening are positioned opposite each other, such that the first concentrate outlet and the second water inlet are opposite each other, effectively draining the concentrate from the first raw water flow channel into the second raw water flow channel, forming a two-stage filtration system.

[0135] Example 4:

[0136] The present invention provides a composite reverse osmosis membrane assembly comprising at least two reverse osmosis membrane units. Each reverse osmosis membrane unit is formed by stacking and winding a reverse osmosis membrane sheet, a water inlet grid, and a pure water guide cloth around a central water production pipe. The water inlet grid and the pure water guide cloth are respectively located in the water inlet channel formed by the front face of the folded reverse osmosis membrane sheet and the water production channel formed by the adjacent back face. The first concentrate inlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit, and the cross-sectional area s1 of the water inlet channel of the first reverse osmosis membrane unit is greater than the cross-sectional area s2 of the water inlet channel of the second reverse osmosis membrane unit.

[0137] The cross-sectional area of ​​the water inlet flow channel of the reverse osmosis membrane element is equal to the product of the distance H between the front faces of the reverse osmosis membrane after folding and rolling, the folding position length L and the number n of water inlet flow channels after folding.

[0138] The first reverse osmosis membrane unit has a first water inlet, a first concentrate outlet, and a first pure water outlet. The second reverse osmosis membrane unit has a second water inlet, a second concentrate outlet, and a second pure water outlet. The first water inlet of the first reverse osmosis membrane unit is the water inlet of the composite reverse osmosis membrane assembly, and the second concentrate outlet of the second reverse osmosis membrane unit is the concentrate outlet of the composite reverse osmosis membrane assembly. The first concentrate outlet of the first reverse osmosis membrane unit is connected to the second water inlet of the second reverse osmosis membrane unit.

[0139] Preferably, the two reverse osmosis membrane units are combined by rolling them on the same central tube, wherein the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled together on the central tube.

[0140] Preferably, the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled onto the central tube at one time. The first reverse osmosis membrane unit is close to the first end of the central tube, and the second reverse osmosis membrane unit is close to the second end of the central tube. The outlet of the second end of the central tube is sealed, and the outlet of the first end is open.

[0141] The water inlet grid and pure water guide cloth are respectively located in the water inlet channel formed by the front side and the water production channel formed by the adjacent back side after the reverse osmosis membrane is folded. The opening formed by the folded reverse osmosis membrane faces away from the central tube, and the central tube is used to collect the pure water produced by the first reverse osmosis membrane unit and the second reverse osmosis membrane unit. The first side long side of the raw water channel of the first reverse osmosis membrane unit, which is perpendicular to the fold, forms a raw water inlet, and the second side long side of the raw water channel of the first reverse osmosis membrane unit, which is perpendicular to the fold, forms a concentrated water outlet; the third side long side of the raw water channel of the second reverse osmosis membrane unit, which is perpendicular to the fold, is partially sealed and forms a raw water inlet at the end away from the fold. The fourth side long side of the raw water channel of the second reverse osmosis membrane unit, which is perpendicular to the fold, is partially sealed and forms a concentrated water outlet at the end close to the fold.

[0142] The third long side and the fourth long side of the raw water flow channel, which are perpendicular to the folded edge, are partially sealed by gluing.

[0143] The present invention reduces the size of the water inlet flow channel on the concentrated water side by combining membrane elements with different water inlet flow channel cross-sectional areas, thereby increasing the membrane surface flow rate on the concentrated water side, thereby slowing down the concentration polarization on the concentrated water side, improving the anti-pollution performance of the reverse osmosis membrane, and extending the service life of the reverse osmosis membrane filter element.

[0144] The present invention further provides a water purifier comprising the spiral reverse osmosis membrane element as described in any of the preceding items. That is, the present invention also includes a water purifier comprising the reverse osmosis membrane element.

[0145] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A composite reverse osmosis membrane assembly, characterized in that: include: A first reverse osmosis membrane element (200), a second reverse osmosis membrane element (300) and a central tube, wherein the first reverse osmosis membrane element (200) is formed by rolling a first reverse osmosis membrane sheet (201) on the central tube, and the second reverse osmosis membrane element (300) is formed by rolling a second reverse osmosis membrane sheet (301) on the central tube, the first reverse osmosis membrane element (200) and the second reverse osmosis membrane element (300) are rolled on the same central tube or on different central tubes, the first reverse osmosis membrane element (200) has a first raw water flow channel (401), the second reverse osmosis membrane element (300) has a second raw water flow channel (402), a first concentrated water outlet (502) of the first raw water flow channel (401) is connected to a second water inlet (503) of the second raw water flow channel (402), and a flow cross-sectional area s1 of the first raw water flow channel (401) is greater than a flow cross-sectional area s2 of the second raw water flow channel (402); There are at least two central tubes, including a first central tube (101) and a second central tube (102); the first reverse osmosis membrane sheet (201) is rolled around the outer periphery of the first central tube (101) to form the first reverse osmosis membrane element (200); the second reverse osmosis membrane sheet (301) is rolled around the outer periphery of the second central tube (102) to form the second reverse osmosis membrane element (300); the second reverse osmosis membrane element (300) is arranged inside the first central tube (101); pure water purified by the second reverse osmosis membrane element (300) enters the first central tube (101); and pure water purified by the first reverse osmosis membrane element (200) also enters the first central tube (101); The outer diameter of the second central tube (102) is smaller than the inner diameter of the first central tube (101), The first reverse osmosis membrane (201) is folded to form the first raw water flow channel (401) between the front sides of the two membrane leaves, and to form a first opening (202) and a first folded edge (203) facing each other, wherein the first folded edge (203) faces the first central tube (100) and is connected to the first central tube (101) for rolling, and the first opening (202) is away from the first central tube (101). The second reverse osmosis membrane (301) is folded to form the second raw water flow channel (402) between the front sides of the two membrane leaves, and to form a second opening (302) and a second folded edge (303) opposite to each other, wherein the second opening (302) faces the second central tube (102) and is connected to the second central tube (102) for rolling, and the second folded edge (303) is away from the second central tube (100).

2. The composite reverse osmosis membrane assembly according to claim 1, characterized in that: 1.5≤s1 / s2≤4.

3. The composite reverse osmosis membrane assembly according to claim 1, characterized in that: A first pure water flow channel (601) is formed between the back surfaces of the two membrane pages of the first reverse osmosis membrane (201), and the first pure water flow channel (601) is connected to the interior of the first central tube (101); a second pure water flow channel (602) is formed between the back surfaces of the two membrane pages of the second reverse osmosis membrane (301), and the second pure water flow channel (602) is also connected to the interior of the first central tube (101), and a pure water outlet (505) is formed at one axial end of the first central tube (101).

4. The composite reverse osmosis membrane assembly according to claim 1, characterized in that: The first reverse osmosis membrane (201) comprises a first side long side (204) and a second side long side (205) which are perpendicular to the first folded edge (203) after folding, the first side long side (204) and the second side long side (205) being arranged opposite to each other, and a first water inlet (501) is provided on the first side long side (204), the first water inlet (501) being connected to the first raw water flow channel (401), and the first concentrated water outlet (502) is provided on the second side long side (205); The second reverse osmosis membrane (301) comprises a third side long side (304) and a fourth side long side (305) which are perpendicular to the second folded edge (303) after folding. The third side long side (304) and the fourth side long side (305) are arranged opposite to each other, and the second water inlet (503) is arranged on the third side long side (304). One end of the second water inlet (503) is connected to the first concentrated water outlet (502), and the other end is connected to the second raw water flow channel (402). The second raw water flow channel (402) is connected to the interior of the second central tube (102) through the second opening (302). One axial end of the second central tube (102) is formed as the second concentrated water outlet (504).

5. The composite reverse osmosis membrane assembly according to claim 4, characterized in that: The first long side (204) is an open structure along its length direction, forming the first water inlet (501), and the second long side (205) is an open structure along its length direction, forming the first concentrated water outlet (502). The third side long edge (304) is partially sealed, and the second water inlet (503) is formed at a position relative to the second opening (302) and close to the second folded edge (303). The fourth side long edge (305) is completely sealed.

6. The composite reverse osmosis membrane assembly according to claim 5, characterized in that: A first sealing structure (701) is provided at the third long side (304), and the first sealing structure (701) extends from the second opening (302) to a position spaced a preset distance from the second folded edge (303), and the spaced preset distance forms the second water inlet (503). A second sealing structure (702) is provided at the fourth long side (305), and the second sealing structure (702) extends from the second opening (302) to the second folded edge (303).

7. A water purifier, characterized in that: The invention comprises the composite reverse osmosis membrane assembly according to any one of claims 1 to 6.

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