CN115779693A

CN115779693A - Composite reverse osmosis membrane assembly and water purifier with same

Info

Publication number: CN115779693A
Application number: CN202211501487.2A
Authority: CN
Inventors: 陈静; 吴伟利; 李一然; 陈子斌; 詹婷; 宁贵勇
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2022-11-28
Filing date: 2022-11-28
Publication date: 2023-03-14

Abstract

The invention provides a composite reverse osmosis membrane component and a water purifier with the same, wherein the composite reverse osmosis membrane component comprises: the membrane comprises a first reverse osmosis membrane element, a second reverse osmosis membrane element and a central pipe, wherein the first reverse osmosis membrane element is formed by rolling a first reverse osmosis membrane on the central pipe, the second reverse osmosis membrane element is formed by rolling a second reverse osmosis membrane on the central pipe, the first reverse osmosis membrane element and the second reverse osmosis membrane element are rolled on the same or different central pipes, the first reverse osmosis membrane element is provided with a first raw water flow channel, the second reverse osmosis membrane element is provided with a second raw water flow channel, a first concentrated water outlet of the first raw water flow channel is communicated with a 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 larger than the flow cross-sectional area s2 of the second raw water flow channel. According to the invention, the membrane surface flow rate of the concentrated water side can be increased, the concentration polarization of the concentrated water side is slowed down, the anti-pollution performance of the reverse osmosis membrane is improved, and the service life of the reverse osmosis membrane filter element is prolonged.

Description

Composite reverse osmosis membrane assembly and water purifier with same

Technical Field

The invention relates to the technical field of water purifiers, in particular to a composite reverse osmosis membrane assembly and a water purifier with the same.

Background

The roll type reverse osmosis membrane element forms a water purification element by rolling the water inlet separation net, the reverse osmosis membrane and the pure water diversion part on the central water production pipe. By utilizing the permeation function of the reverse osmosis membrane, water molecules in the raw water permeate through the reverse osmosis membrane under the pressurization condition and are gathered at the pure water side to form pure water, the raw water gradually forms concentrated water at the concentrated water side, finally the concentrated water flows out from the concentrated water outlet, and the pure water flows out from the pure water outlet. Along with the flowing of the raw water in the raw water channel to the concentrated water outlet, because part of the raw water is filtered by the reverse osmosis membrane and then is changed into pure water for output, the flow velocity of the fluid on the surface of the reverse osmosis membrane in the raw water channel is gradually reduced, and the flow velocity of the fluid on the membrane surface of the concentrated water side is the lowest. Because the flow velocity of the fluid on the membrane surface is gradually reduced and the solute in the fluid on the membrane surface is gradually increased, the concentration polarization on the concentrated water side is the most serious, and the pollution blockage is most easily caused. The concentration polarization phenomenon of a common reverse osmosis membrane element on the concentrated water side is obvious, and the service life of the membrane element is influenced.

The invention provides a roll type reverse osmosis membrane element and a water purifier with the same, which are researched and designed because the membrane surface water flow speed in a raw water flow channel of the roll type reverse osmosis membrane element in the prior art is gradually reduced along with the flow process, the concentration polarization of the downstream section in the flow direction is the most serious, the pollution blockage is most easily caused, and the like.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects that concentration polarization is most serious and pollution blockage is easily caused in the downstream section in the flow direction in the raw water flow channel of the roll type reverse osmosis membrane element in the prior art, so that the composite reverse osmosis membrane element and the water purifier with the same are provided.

In order to solve the above problems, the present invention provides a composite reverse osmosis membrane module comprising:

first reverse osmosis membrane element, second reverse osmosis membrane element and center tube, first reverse osmosis membrane element is formed for rolling up the system on the center tube through first reverse osmosis diaphragm, second reverse osmosis membrane element is formed for rolling up the system on the center tube through second reverse osmosis diaphragm, first reverse osmosis membrane element with second reverse osmosis membrane element is rolled up and is made on the same center tube or is rolled up the system on the center tube of difference, first reverse osmosis membrane element has first raw water runner, second reverse osmosis membrane element has second raw water runner, the first dense water export of first raw water runner with the second water inlet intercommunication of second raw water runner, just the flow cross sectional area s1 of first raw water runner is greater than the flow cross sectional area s2 of second raw water runner.

In some embodiments, 1.5. Ltoreq. S1/s 2. Ltoreq.4.

In some embodiments, the number of the central pipes is at least two, and the central pipes include a first central pipe and a second central pipe, the first reverse osmosis membrane is rolled around the periphery of the first central pipe to form the first reverse osmosis membrane element, the second reverse osmosis membrane is rolled around the periphery of the second central pipe to form the second reverse osmosis membrane element, the second reverse osmosis membrane element is disposed inside the first central pipe, the purified pure water of the second reverse osmosis membrane element enters the first central pipe, and the purified pure water of the first reverse osmosis membrane element also enters the first central pipe.

In some embodiments, the second base pipe has an outer diameter less than an inner diameter of the first base pipe,

the first reverse osmosis membrane is folded to form the first raw water flow channel between the front surfaces of the two membrane leaves, and a first opening and a first folding edge which are opposite are formed, the first folding edge faces the first central pipe and is connected with the first central pipe for rolling, and the first opening is far away from the first central pipe;

the second reverse osmosis membrane sheet is folded to form a second raw water flow channel between the front surfaces of the two membrane sheets, and a second opening and a second folding edge are formed, wherein the second opening faces the second central pipe and is connected with the second central pipe for rolling, and the second folding edge is far away from the second central pipe.

In some embodiments, the first pure water flow channel is formed between the back sides of the two membrane leaves of the first reverse osmosis membrane sheet, and the first pure water flow channel is communicated with the interior of the first central tube; and a second pure water flow channel is formed between the back surfaces of the two membrane pages of the second reverse osmosis membrane, is also communicated with the inside of the first central pipe, and forms a pure water port at one axial end of the first central pipe.

In some embodiments, the first reverse osmosis membrane comprises a first long side and a second long side which are perpendicular to the first folding side after being folded, the first long side is opposite to the second long side, a first water inlet is arranged on the first long side, the first water inlet is communicated with the first raw water flow passage, and a first concentrated water outlet is arranged on the second long side;

the second reverse osmosis membrane comprises a third side long edge and a fourth side long edge which are perpendicular to the second folded edge after being folded, the third side long edge and the fourth side long edge are arranged oppositely, the third side long edge is provided with the second water inlet, one end of the second water inlet is communicated with the first concentrated water outlet, the other end of the second water inlet is communicated with the second raw water flow channel, the second raw water flow channel is communicated with the inside of the second central tube through the second opening, and one axial end of the second central tube is formed into a second concentrated water outlet.

In some embodiments, the first side long edge is open along the length direction thereof and is formed as the first water inlet, the second side long edge is open along the length direction thereof and is formed as the first concentrated water outlet,

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

In some embodiments, a first sealing structure is disposed at the third side long edge, the first sealing structure extending from the second opening to a position spaced apart from the second flange by a predetermined distance, the spaced apart predetermined distance being formed as the second water inlet, and a second sealing structure is disposed at the fourth side long edge, the second sealing structure extending from the second opening to the second flange.

In some embodiments, the number of the central pipes is at least one, and the central pipes include a first central pipe, the first reverse osmosis membrane is rolled on the outer periphery of the first central pipe to form the first reverse osmosis membrane element, the second reverse osmosis membrane is also rolled on the outer periphery of the first central pipe 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 pipe.

In some embodiments, the first reverse osmosis membrane sheet is folded to form the first raw water flow channel between the front faces of the two membrane sheets, and forms a first opening and a first folding edge which are opposite, the first folding edge faces to the first central tube and is connected with the first central tube for rolling, and the first opening is far away from the first central tube;

the second reverse osmosis membrane forms a second raw water flow channel between the front surfaces of the two membrane pages through folding, and forms a second opening and a second folded edge which are opposite, the second folded edge faces the first central pipe and is connected with the first central pipe for rolling, and the second opening is far away from the first central pipe.

the second reverse osmosis membrane comprises a third long side and a fourth long side which are vertical to the second folded side after being folded, the third long side and the fourth long side are arranged oppositely, the third long side and the second long side are opposite, the third long side is provided with the second water inlet, one end of the second water inlet is communicated with the first concentrated water outlet, the other end of the second water inlet is communicated with the second raw water flow passage, and the fourth long side is provided with a second concentrated water outlet.

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

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

In some embodiments, a first sealing structure is disposed at the first side long edge, the first sealing structure extending from the first opening to a position spaced apart from the first fold edge by a first predetermined distance, the spaced apart first predetermined distance forming the first water inlet;

a second sealing structure is arranged between the second side long edge and the third side long edge, the second sealing structure extends from the first central pipe to a position spaced from the first opening by a second preset distance, and the spaced second preset distance is formed into the first concentrated water outlet; the second seal structure extends from the first center tube to a location spaced a third predetermined distance from the second opening, the spaced third predetermined distance forming the second water inlet;

and a third sealing structure is arranged at the long side of the fourth side, the third sealing structure extends from the second opening to a position which is spaced from the second folded edge by a fourth preset distance, and the spaced fourth preset distance is formed into the second concentrated water outlet.

In some embodiments, the first side long edge is partially sealed, 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;

the third side long edge is partially sealed, 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.

In some embodiments, a first sealing structure is disposed at the first side long edge, the first sealing structure extending from the first fold edge to a location spaced a first predetermined distance from the first opening, the spaced first predetermined distance forming the first water inlet;

a second sealing structure is arranged between the second side long edge and the third side long edge, the second sealing structure extends from the first opening to a position spaced from the first central tube by a second preset distance, and the spaced second preset distance is formed into the first concentrated water outlet; the second seal structure extends from the second opening to a location spaced a third predetermined distance from the first center tube, the spaced third predetermined distance forming the second water inlet;

and a third sealing structure is arranged at the long side of the fourth side, the third sealing structure extends from the second folded edge to a position which is spaced from the second opening by a fourth preset distance, and the spaced fourth preset distance is formed into the second concentrated water outlet.

In some embodiments, the first side long edge is open along the length direction thereof and forms the first water inlet, and the second side long edge is open along the length direction thereof and forms the first concentrated water outlet;

In some embodiments, a first sealing structure is disposed at the third side long edge, the first sealing structure extending from the second fold edge to a location spaced a first predetermined distance from the second opening, the spaced first predetermined distance forming the second water inlet;

and a second sealing structure is arranged at the long side of the fourth side, the second sealing structure extends from the second opening to a position which is spaced from the second folded edge by a second preset distance, and the second preset distance is formed as the second concentrated water outlet.

In some embodiments, the first opening and the second opening are positioned in axial alignment of the first center tube.

The invention also provides a water purifier which comprises the composite reverse osmosis membrane module.

The composite reverse osmosis membrane module and the water purifier with the same have the following beneficial effects:

according to the invention, the first reverse osmosis membrane element is formed by coiling the first reverse osmosis membrane on the central pipe, the second reverse osmosis membrane element is formed by coiling the second reverse osmosis membrane on the central pipe, the first raw water flow channel of the first reverse osmosis membrane element is communicated with the second raw water of the second reverse osmosis membrane element, and the flow cross section area s1 of the first raw water flow channel positioned at the upstream of the raw water flow direction is set to be larger than the flow cross section area s2 of the second raw water flow channel positioned at the downstream of the raw water flow direction, so that the flow cross section area of the fluid can be effectively reduced along the flow direction of the raw water, the flow velocity of the fluid can be increased, the concentration polarization at the concentrated water side can be slowed down, the anti-pollution performance of the reverse osmosis membrane is improved, and the service life of the reverse osmosis membrane filter element is prolonged.

Drawings

FIG. 1 is a flow channel structure diagram of a composite roll type reverse osmosis membrane element of example 1 of the present invention;

FIG. 2 is a schematic flow path diagram of a composite roll-up reverse osmosis membrane element of example 2 of the present invention;

FIG. 3 is a flow channel structure diagram of the composite roll type reverse osmosis membrane element of example 1 of the present invention;

fig. 4 is a flow channel schematic diagram of the composite roll type reverse osmosis membrane element of embodiment 2 of the invention.

The reference numerals are represented as:

101. a first center tube; 102. a second center tube; 200. a first reverse osmosis membrane element; 201. a first reverse osmosis membrane; 202. a first opening; 203. a first folded edge; 204. a first side long edge; 205. a second side long edge; 300. a second reverse osmosis membrane element; 301. a second reverse osmosis membrane; 302. a second opening; 303. a second folded edge; 304. a third side long side; 305. a fourth side long side; 401. a first raw water flow passage; 402. a second raw water flow passage; 501. a first water inlet; 502. a first concentrated water outlet; 503. a second water inlet; 504. a second concentrated water outlet; 505. a pure water port; 601. a first pure water flow passage; 602. a second pure water flow passage; 701. a first seal structure; 702. a second seal structure; 703. and a third seal structure.

Detailed Description

As shown in fig. 1 to 4, the present invention provides a composite reverse osmosis membrane module comprising:

the membrane module comprises a first reverse osmosis membrane element 200, a second reverse osmosis membrane element 300 and a central pipe, wherein the first reverse osmosis membrane element 200 is formed by coiling a first reverse osmosis membrane 201 on the central pipe, the second reverse osmosis membrane element 300 is formed by coiling a second reverse osmosis membrane 301 on the central pipe, the first reverse osmosis membrane element 200 and the second reverse osmosis membrane element 300 are coiled on the same central pipe or different central pipes, the first reverse osmosis membrane element 200 is provided with a first raw water flow passage 401, the second reverse osmosis membrane element 300 is provided with a second raw water flow passage 402, a first concentrated water outlet 502 of the first raw water flow passage 401 is communicated with a second water inlet 503 of the second raw water flow passage 402, and the flow cross-sectional area s1 of the first raw water flow passage 401 is larger than the flow cross-sectional area s2 of the second raw water flow passage 402.

In some embodiments, 1.5. Ltoreq. S1/s 2. Ltoreq.4. The sectional area of the first raw water flow passage of the invention is s1 larger than that of the second raw water flow passage of the invention, and s1/s2 is preferably more than or equal to 1.5 and less than or equal to 4. The relation is 1.5 to 4:1, namely the flow cross section area of the raw water flow channel of the first reverse osmosis membrane element is always larger than that of the second reverse osmosis membrane element. Through the arrangement of the size relation, the invention can effectively ensure that the flow cross-sectional area is reduced in the flowing process of raw water, thereby increasing the flow velocity of the membrane surface, further reducing concentration polarization, having better effect, and improving the water purification rate (preventing the situation that the flow velocity is too large and the water purification effect is not good) on the basis.

The invention provides a composite reverse osmosis membrane assembly, which comprises a first reverse osmosis membrane element with a raw water flow passage sectional area of s1 and a second reverse osmosis membrane element with a raw water flow passage sectional area of s 2; the device is characterized in that a first concentrated water port of a first reverse osmosis membrane unit is communicated with a second water port of a second reverse osmosis membrane unit, and the cross section area of a raw water flow passage of the first reverse osmosis membrane element is s1 and is larger than the cross section area of a raw water flow passage of the second reverse osmosis membrane element is s2. Preferably 1.5. Ltoreq. S1/s 2. Ltoreq.4. The size of the raw water channel on the concentrated water side can be effectively reduced, the membrane surface flow rate on the concentrated water side is improved, the concentration polarization on the concentrated water side is slowed down, the pollution resistance of the reverse osmosis membrane is improved, and the service life of the reverse osmosis membrane filter element is prolonged.

Example 1, as shown in fig. 1, in some embodiments, there are at least two central pipes, including a first central pipe 101 and a second central pipe 102, the first reverse osmosis membrane 201 is wound around the outer periphery of the first central pipe 101 to form the first reverse osmosis membrane element 200, the second reverse osmosis membrane 301 is wound around the outer periphery of the second central pipe 102 to form the second reverse osmosis membrane element 300, the second reverse osmosis membrane element 300 is disposed inside the first central pipe 101, purified pure water of the second reverse osmosis membrane element 300 enters the first central pipe 101, and purified pure water of the first reverse osmosis membrane element 200 also enters the first central pipe 101.

This is a preferable structure form of the first reverse osmosis membrane element and the second reverse osmosis membrane element in embodiment 1 of the present invention, that is, the first and second reverse osmosis membrane sheets are respectively rolled on different central pipes, and the rolled second reverse osmosis membrane element is disposed inside the first central pipe, so that the first reverse osmosis membrane element is located at the periphery of the second reverse osmosis membrane element.

In some embodiments, the outer diameter of the second base pipe 102 is less than the inner diameter of the first base pipe 101,

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 forms a first opening 202 and a first folding edge 203 which are opposite, the first folding edge 203 faces the first central tube 100 and is connected with the first central tube 101 for rolling, the first opening 202 is far 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 faces of the two membrane leaves, and a second opening 302 and a second folded edge 303 are formed, wherein the second opening 302 faces the second central tube 102 and is connected with the second central tube 102 for rolling, and the second folded edge 303 is far away from the second central tube 100.

The first reverse osmosis membrane is preferably rolled in the first rolling mode of embodiment 1 of the invention, a first folded edge and a first opening are formed by folding the first reverse osmosis membrane, and the first folded edge is connected with a first central pipe to be rolled, so that a first raw water flow channel is formed between the front sides of the membrane sheets formed by folding the first reverse osmosis membrane, the first raw water flow channel needs to be filtered and purified by the first reverse osmosis membrane, pure water can be formed only by penetrating from the front side to the back side of the first reverse osmosis membrane, and the pure water is introduced into the first central pipe, so that the purification and the flow guide effect of the pure water are effectively realized; the second reverse osmosis membrane is folded to form a second folded edge and a second opening, and the second opening is connected with a second central pipe to be rolled, so that a second raw water flow channel is formed between the front surfaces of the membrane leaves formed by folding the second reverse osmosis membrane, the second raw water flow channel needs to be filtered and purified by the second reverse osmosis membrane, pure water can be formed only by penetrating from the front surface to the back surface of the second reverse osmosis membrane, and the pure water is introduced into the first central pipe to effectively realize the purification and the flow guide effect of the pure water; and the second opening guides the concentrated water which does not pass through the second reverse osmosis membrane to the inside of the second central pipe, so that the flow guide effect of the concentrated water is realized.

In some embodiments, the first pure water flow channel 601 is formed between the back surfaces of the two membrane sheets of the first reverse osmosis membrane sheet 201, and the first pure water flow channel 601 is communicated with the inside of the first central tube 101; the second pure water flow passage 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 passage 602 is also communicated with the inside of the first central pipe 101, and forms a pure water port 505 at one axial end of the first central pipe 101. This is a preferable configuration of the two pure water flow passages of embodiment 1 of the present invention, that is, the raw water flow passage is formed between the front surfaces of the two reverse osmosis membranes, and the pure water filtered by passing through the membranes is formed between the rear surfaces, and the pure water port at one axial end of the first central tube is used for discharging the pure water.

In some embodiments, the first reverse osmosis membrane 201 includes a first long side 204 and a second long side 205 perpendicular to the first folding side 203 after being folded, the first long side 204 is disposed opposite to the second long side 205, the first long side 204 is provided with a first water inlet 501, the first water inlet 501 is communicated with the first raw water channel 401, and the second long side 205 is provided with the first concentrated water outlet 502;

the second reverse osmosis membrane 301 includes a third long side 304 and a fourth long side 305 perpendicular to the second folded side 303 after being folded, the third long side 304 is disposed opposite to the fourth long side 305, the third long side 304 is disposed with the second water inlet 503, one end of the second water inlet 503 is communicated with the first concentrated water outlet 502, the other end is communicated with the second raw water channel 402, the second raw water channel 402 is communicated with the inside of the second central tube 102 through the second opening 302, and one axial end of the second central tube 102 is formed as a second concentrated water outlet 504.

The first reverse osmosis membrane is further optimized in structural form and the forming mode of the first water inlet and the first concentrated water outlet, namely the first water inlet is arranged on the first side long edge, the first concentrated water outlet is arranged on the second side long edge, so that raw water can enter the first raw water channel through the first water inlet for purification and filtration, and concentrated water generated by purification is guided to the second reverse osmosis membrane through the first concentrated water outlet; the second reverse osmosis membrane further preferably has a second water inlet arranged on the third side long edge, a second concentrated water outlet arranged on the fourth side long edge, so that raw water can enter a second raw water channel through the second water inlet to be purified and filtered, and the second opening is communicated with the second central pipe and is used for guiding concentrated water into the second central pipe and further guiding the concentrated water out through the second concentrated water outlet.

In some embodiments, the first long side 204 is open along the length direction thereof and is formed as the first water inlet 501, the second long side 205 is open along the length direction thereof and is formed as the first concentrated water outlet 502,

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

The first water inlet and the first concentrated water inlet are further preferably in structural form, namely the first side long edge and the second side long edge are both in normally open structures, so that raw water can enter the first raw water flow channel through the whole length direction of the first side long edge and concentrated water is discharged through the whole length direction of the second side long edge; and the long limit of third side of second reverse osmosis membrane forms the part sealed, only forms the second water inlet in the position (being circumference outer end) that is close to the second hem, avoids the second water inlet too close to the second opening and leads to the length of second raw water runner shorter and can't form effective purification filterable effect to further improve and purify the precision.

In some embodiments, a first sealing structure 701 is disposed at the third long side 304, the first sealing structure 701 extends from the second opening 302 to a position spaced apart from the second flange 303 by a predetermined distance, the spaced apart predetermined distance is formed as the second water inlet 503, a second sealing structure 702 is disposed at the fourth long side 305, and the second sealing structure 702 extends from the second opening 302 to the second flange 303. The first sealing structure is arranged on the long side of the third side and forms a gap with the second flange for feeding concentrated water, namely the second water inlet, so that the effects of increasing the purification path and distance are achieved, and the purification precision is improved.

Example 1:

the invention provides a composite reverse osmosis membrane assembly, which at least comprises two reverse osmosis membrane units, wherein each reverse osmosis membrane unit is formed by superposing and winding a reverse osmosis membrane, a water inlet grid and a pure water guide cloth on a central water production pipe, and the water inlet grid and the pure water guide cloth are respectively positioned in a water inlet flow passage formed by the front surface of the folded reverse osmosis membrane and a water production flow passage formed by the adjacent back surface. Wherein, the first dense water port of the first reverse osmosis membrane unit is communicated with the second water port of the second reverse osmosis membrane unit, and the cross section of the water inlet flow passage s1 of the first reverse osmosis membrane unit is larger than the cross section of the water inlet flow passage s2 of the second reverse osmosis membrane unit.

The 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 being folded and rolled, the folding length L and the number n of the folded water inlet flow channels.

The first reverse osmosis membrane unit is provided with a first water inlet, a first concentrated water port and a first pure water port, the second reverse osmosis membrane unit is provided with a second water inlet, a second concentrated water port and a second pure water port, the first water inlet of the first reverse osmosis membrane unit is a water inlet of the composite reverse osmosis membrane assembly, and the second concentrated water outlet of the second reverse osmosis membrane unit is a concentrated water outlet of the composite reverse osmosis membrane assembly. And a first concentrated water outlet of the first reverse osmosis membrane unit is connected with a second water inlet of the second reverse osmosis membrane unit.

Preferably, the two reverse osmosis membrane units are assembled in a concentric circle mode. The first reverse osmosis membrane unit has a first center tube and the second reverse osmosis membrane unit has a second center tube. The assembly mode is that the first central pipe is concentrically sleeved on the outer side of the second reverse osmosis membrane unit, and a gap formed between one end of the first central pipe and the outer side of the second reverse osmosis membrane unit is sealed.

Preferably, the first reverse osmosis membrane unit is provided with a first pure water outlet, the second reverse osmosis membrane unit is provided with a second pure water outlet, and the first pure water outlet and the second pure water outlet are communicated with a common pure water outlet channel inside the composite reverse osmosis membrane module and are connected to the pure water outlet of the composite reverse osmosis membrane module.

The first reverse osmosis membrane unit is characterized by comprising a first central pipe, and a pure water diversion cloth, a reverse osmosis membrane and a water inlet separation net which are rolled on the first central pipe, wherein the water inlet grid and the pure water diversion cloth are respectively positioned in a raw water flow channel formed by the front surface of the reverse osmosis membrane after being folded and a water production flow channel formed by the adjacent back surface. An opening formed by folding the reverse osmosis membrane back to the first central pipe, a raw water inlet is formed on the first side long edge of the raw water flow channel, which is vertical to the folded edge, and a concentrated water outlet is formed on the second side long edge; the short side of pure water conservancy diversion cloth with first center tube is connected, two long limits after the reverse osmosis diaphragm is folding with keep away from the short side of first center tube all with the pure water conservancy diversion cloth is connected and is formed the pure water runner, the pure water export of pure water runner with first center tube intercommunication, first center tube is used for collecting the pure water of first reverse osmosis membrane list output.

The second reverse osmosis membrane unit is characterized by comprising a second central pipe and pure water guide cloth, a reverse osmosis membrane and a water inlet separation net which are rolled on the second central pipe, wherein the water inlet grid and the pure water guide cloth are respectively positioned in a water inlet flow channel formed by the front surface of the reverse osmosis membrane after being folded and a water production flow channel formed by the adjacent back surface. An opening formed by folding the reverse osmosis membrane in half faces to the second central pipe, the opening is communicated with the second central pipe, and the second central pipe is used for collecting concentrated water produced by a second reverse osmosis membrane unit; a first long edge of the raw water channel, which is vertical to the folded edge, is partially sealed, a raw water inlet is formed at one end close to the folded edge, and a second long edge of the raw water channel, which is vertical to the folded edge, is completely sealed; the short sides of the pure water flow guide cloth are connected with the concentrated water pipe, the two long sides of the reverse osmosis membrane after being folded and the short sides close to the concentrated water pipe are connected with the pure water flow guide cloth to form a pure water flow passage, and a pure water outlet of the pure water flow passage is positioned on the outer side surface of the rolled reverse osmosis membrane element.

Because the first central pipe is concentrically sleeved outside the second reverse osmosis membrane element, the first central pipe can simultaneously collect pure water produced by the second reverse osmosis membrane unit, and the pure water of the first reverse osmosis membrane unit and the pure water of the second reverse osmosis membrane unit are converged in the first central pipe;

the first central tube is provided with 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, and the second end face and the circumference of one end of the raw water inlet of the second reverse osmosis membrane unit are sealed in a gluing mode.

The cross section of the water inlet channel at the concentrated water side is reduced by compounding membrane elements with different water inlet channel cross sections, the membrane surface flow rate at the concentrated water side is improved, the concentration polarization at the concentrated water side is slowed down, the anti-pollution performance of the reverse osmosis membrane is improved, and the service life of a reverse osmosis membrane filter element is prolonged.

The invention also comprises a water purifier with the composite filter element.

Examples 2-4, as shown in figures 2-4,

in some embodiments, there is at least one central tube, and the central tube includes a first central tube 101, the first reverse osmosis membrane 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 301 is also rolled around the 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 spaced along the axial direction of the first central tube 101.

This is the preferred structure form of the first reverse osmosis membrane element and the second reverse osmosis membrane element in embodiment 2 of the present invention, that is, the first and second reverse osmosis membranes 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 arranged at an interval, so that the first reverse osmosis membrane element is located at one axial end of the second reverse osmosis membrane element.

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 sheets, and to form a first opening 202 and a first folding edge 203 which are opposite, the first folding edge 203 faces the first central tube 100 and is connected with the first central tube 100 to be rolled, the first opening 202 is far away from the first central tube 100,

the second reverse osmosis membrane 301 is folded to form the second raw water flow channel 402 between the front surfaces of the two membrane leaves, and to form a second opening 302 and a second folded edge 303 which are opposite to each other, the second folded edge 303 faces the first central tube 100 and is connected with the first central tube 101 to be rolled, and the second opening 302 is far away from the first central tube 101.

The first reverse osmosis membrane is preferably rolled in the first reverse osmosis membrane of embodiment 2 of the invention, a first folded edge and a first opening are formed by folding the first reverse osmosis membrane, and the first folded edge is connected with a first central tube to roll the first reverse osmosis membrane, so that a first raw water flow channel is formed between the front surfaces of the membrane sheets formed by folding the first reverse osmosis membrane, the first raw water flow channel needs to be filtered and purified by the first reverse osmosis membrane, pure water can be formed only by penetrating from the front surface to the back surface of the first reverse osmosis membrane, and the pure water is introduced into the first central tube, so that the purifying and pure water guiding effects are effectively realized; the second reverse osmosis membrane is folded to form a second folded edge and a second opening, and the second folded edge is connected with the first central pipe to be rolled, so that a second raw water flow channel is formed between the front surfaces of the membrane leaves formed by folding the second reverse osmosis membrane, the second raw water flow channel needs to be filtered and purified by the second reverse osmosis membrane, pure water can be formed only by penetrating from the front surface to the back surface of the second reverse osmosis membrane, and the pure water is guided into the first central pipe to effectively realize purification and pure water diversion effects; and the second opening seals the concentrated water which does not pass through the second reverse osmosis membrane without discharging the concentrated water, and the concentrated water is discharged through a second concentrated water outlet at the long side of the fourth side.

In some embodiments, the first pure water flow channel 601 is formed between the back surfaces of the two membrane sheets of the first reverse osmosis membrane sheet 201, and the first pure water flow channel 601 is communicated with the inside of the first central tube 101; the second pure water flow passage 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 passage 602 is also communicated with the inside of the first central pipe 101, and forms a pure water port 505 at one axial end of the first central pipe 101. This is a preferable configuration of the two pure water flow passages of embodiment 2 of the present invention, that is, the raw water flow passage is formed between the front surfaces of the two reverse osmosis membranes, and the pure water filtered by passing through the membranes is formed between the rear surfaces, and the pure water port at one axial end of the first central tube is used for discharging the pure water.

the second reverse osmosis membrane 301 includes a third long side 304 and a fourth long side 305 perpendicular to the second folded side 303 after being folded, the third long side 304 is opposite to the fourth long side 305, the third long side 304 is opposite to the second long side 205, the third long side 304 is provided with the second water inlet 503, one end of the second water inlet 503 is communicated with the first concentrated water outlet 502, the other end of the second water inlet is communicated with the second raw water channel 402, and the fourth long side 305 is provided with a second concentrated water outlet 504.

This is a further preferable structural form of the first reverse osmosis membrane and a molding manner of the first water inlet and the first concentrated water outlet in embodiments 2 to 4 of the present invention, that is, the first water inlet is disposed on the first side long edge, and the first concentrated water outlet is disposed on the second side long edge, so that raw water enters the first raw water channel through the first water inlet to be purified and filtered, and concentrated water generated by purification is guided to the second reverse osmosis membrane through the first concentrated water outlet; the second reverse osmosis membrane further prefers the second water inlet setting on the long edge of third side, and the second dense water export sets up on the long edge of fourth side, can make the raw water pass through the second water inlet and get into in the second raw water passageway and purify the filtration, and the second opening communicates with the second center tube for with the leading-in second center tube of dense water, and further export the dense water through the second dense water.

Example 2 the process of example 2, as shown in figure 2,

in some embodiments, the first side long edge 204 is partially sealed, 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 side long edge 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;

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

This is a further preferable structural form of the first water inlet and the first concentrate inlet in embodiment 2 of the present invention, that is, the first side long side portion is sealed, so that the first water inlet is formed near the first folding edge position, the second side long side portion is sealed, and the first concentrate outlet is formed near the first opening position, which can effectively increase the length of the water flow in the transverse direction shown in fig. 2, can increase the flow length in the first raw water flow passage, and thus can improve the water purification rate; and the long limit of third side of second reverse osmosis membrane piece forms the part sealed, only forms the second water inlet in the position (circumference outer end promptly) that is close to the second open-ended, make the second water inlet set up with first dense water export relatively, and the dense water export of second is located the second hem department that is close to on the long limit of fourth side, can increase the flow length of raw water in the raw water runner of second, avoid the dense water export of second too close to the second open-ended and lead to the raw water runner of second length shorter and can't form effective purification and filtration's effect, thereby further improve the purification precision.

In some embodiments, a first sealing structure 701 is disposed at the first long side 204, and the first sealing structure 701 extends from the first opening 202 to a position spaced apart from the first folding edge 203 by a first preset distance, where the first preset distance is formed as the first water inlet 501;

a second sealing structure 702 is arranged 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 apart from the first opening 202 by a second preset distance, and the second preset distance is formed as the first concentrated water outlet 502; the second sealing structure 702 extends from the first center tube 101 to a position spaced a third predetermined distance from the second opening 302, the third predetermined distance being formed as the second water inlet 503;

a third sealing structure 703 is disposed on the fourth side long edge 305, and the third sealing structure 703 extends from the second opening 302 to a position spaced apart from the second folded edge 303 by a fourth predetermined distance, where the fourth predetermined distance is formed as the second concentrated water outlet 504.

The first reverse osmosis membrane and the second reverse osmosis membrane form partial sealing, namely, the first sealing structure is arranged on the first side long edge and forms a gap with the first folding edge for feeding raw water, namely, a first water inlet, and the second sealing structure is arranged between the second side long edge and the third side long edge and forms a gap with the first opening for discharging first concentrated water, so that the effects of increasing purification paths and distances can be realized, and the purification precision is improved; the second seal structure sets up between second side long limit and third side long limit and forms the breach with the second opening and be used for advancing first dense water, second water inlet promptly, and the third seal structure sets up on fourth side long limit and forms the breach with the second flange and be used for discharging the second dense water, can realize increasing the effect of purifying path and distance, improves and purifies the precision.

In some embodiments, the first opening 202 and the second opening 302 are positioned in axial alignment with the first center tube 101 (i.e., the first opening 202 and the second opening 302 are flush at the right end of the figure as viewed in fig. 2) such that the second predetermined distance is equal to the third predetermined distance. This is the preferred position form of the first opening and the second opening in embodiment 2 of the present invention, that is, they are oppositely disposed, so that the first concentrated water outlet is opposite to the second water inlet, so as to effectively discharge the concentrated water in the first raw water channel to the second raw water channel, thereby forming a two-stage filtration.

Example 2:

Preferably, the two reverse osmosis membrane units are combined by rolling the reverse osmosis membrane units with a central pipe. The central tube is characterized in that the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled on the central tube together.

Preferably, the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are jointly rolled on the central pipe at one time. The first reverse osmosis membrane unit is close to the first end of center tube, the second reverse osmosis membrane unit is close to the second end of center tube, the second end export of center tube is sealed, and first end export is opened.

The water inlet grid and the pure water diversion cloth are respectively positioned in a water inlet flow passage formed by the front surface of the reverse osmosis membrane after being folded and a water production flow passage formed by the adjacent back surface. The opening that the reverse osmosis membrane fifty percent discount formed is dorsad the center tube, the center tube is used for collecting the pure water of first reverse osmosis membrane unit and second reverse osmosis membrane unit output. The long side part of the first side of the raw water channel of the first reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and a raw water inlet is formed at one end close to the folded edge; the long side part of the third side of the raw water channel of the second reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and one end, which is far away from the folded edge, is provided with a raw water inlet, and the long side part of the fourth side of the raw water channel of the second reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and one end, which is close to the folded edge, is provided with a concentrated water outlet.

The long edges of the first side, the second side, the third side and the fourth side of the raw water flow channel, which are perpendicular to the folded edge, are partially sealed in a glue bonding mode.

According to the invention, the size of the water inlet channel at the concentrated water side is reduced by compounding membrane elements with different water inlet channel sectional areas, the membrane surface flow rate at the concentrated water side is increased, the concentration polarization at the concentrated water side is slowed down, the pollution resistance of the reverse osmosis membrane is improved, and the service life of the reverse osmosis membrane filter element is prolonged.

Example 3 the process of example 3, as shown in figure 3,

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

the third long side 304 is partially sealed and forms the second water inlet 503 near the second folded edge 303 with respect to the second opening 302, and the fourth long side 305 is partially sealed and forms the second concentrated water outlet 504 near the second opening 302 with respect to the second folded edge 303.

The first water inlet and the first thick water outlet in embodiment 3 of the present invention are further preferable, that is, the first side long edge part is sealed, so that the first water inlet is formed near the first opening, the second side long edge part is sealed, and the first thick water outlet is formed near the first folding edge position, which can effectively increase the length of water flow in the transverse direction shown in fig. 3, can increase the flow length in the first raw water flow channel, and thus can improve the water purification rate; and the long limit of third side of second reverse osmosis membrane forms the part sealed, only forms the second water inlet in the position (circumference outer end promptly) that is close to the second hem, make the second water inlet set up with first dense water export relatively, and the dense water export of second is located the second opening part that is close to on the long limit of fourth side, can increase the flow length of raw water in the raw water runner of second, avoid the dense water export of second too close to the second hem and lead to the length of the raw water runner of second short and can't form effective purification and filtration's effect, thereby further improve the purification precision.

In some embodiments, a first sealing structure 701 is disposed at the first long side 204, and the first sealing structure 701 extends from the first folding edge 203 to a position spaced apart from the first opening 202 by a first preset distance, where the first preset distance is formed as the first water inlet 501;

a second sealing structure 702 is arranged 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 apart from the first central tube 101 by a second preset distance, and the second preset distance is formed as the first concentrated water outlet 502; the second sealing structure 702 extends from the second opening 302 to a position spaced a third predetermined distance from the first center tube 101, the third predetermined distance being formed as the second water inlet 503;

a third sealing structure 703 is disposed on the fourth long side 305, and the third sealing structure 703 extends from the second folded side 303 to a position spaced from the second opening 302 by a fourth predetermined distance, which is formed as the second concentrated water outlet 504.

The first reverse osmosis membrane and the second reverse osmosis membrane in embodiment 3 of the present invention form a partially sealed preferred structure, that is, the first sealing structure is disposed on the first side long edge and forms a gap with the first opening for feeding raw water, that is, the first water inlet, and the second sealing structure is disposed between the second side long edge and the third side long edge and forms a gap with the first folding edge for discharging the first concentrated water, so that an effect of increasing a purification path and distance can be achieved, and purification accuracy is improved; the second seal structure sets up and forms the breach with the second flange and be used for advancing first dense water between second side long limit and third side long limit, and the third seal structure sets up and forms the breach with the second opening on fourth side long limit and be used for the second dense water of discharging, can realize increasing the effect that purifies route and distance, improves and purifies the precision.

In some embodiments, the first opening 202 and the second opening 302 are positioned in axial alignment with the first center tube 101 (i.e., the first opening 202 and the second opening 302 are flush at the right end of the figure as viewed in fig. 3), such that the second predetermined distance is equal to the third predetermined distance. This is the preferred position form of the first opening and the second opening in embodiment 3 of the present invention, that is, they are oppositely disposed, so that the first concentrated water outlet is opposite to the second water inlet, so as to effectively discharge the concentrated water in the first raw water channel to the second raw water channel, thereby forming a two-stage filtration.

Example 3:

The water inlet grid and the pure water diversion cloth are respectively positioned in a water inlet flow passage formed by the front surface of the reverse osmosis membrane after being folded and a water production flow passage formed by the adjacent back surface. The opening that the reverse osmosis membrane fifty percent discount formed is dorsad the center tube, the center tube is used for collecting the pure water of first reverse osmosis membrane unit and second reverse osmosis membrane unit output. The long side part of the first side of the raw water channel of the first reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and a raw water inlet is formed at one end far away from the folded edge; the long side part of the third side of the raw water channel of the second reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and a raw water inlet is formed at one end close to the folded edge, and the long side part of the fourth side of the raw water channel of the second reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and a concentrated water outlet is formed at one end far away from the folded edge.

Example 4 the present invention, as shown in figure 4,

in some embodiments, the first long side 204 is open along the length direction thereof and is formed as the first water inlet 501, and the second long side 205 is open along the length direction thereof and is formed as the first concentrated water outlet 502;

the third side long side 304 is partially sealed and forms the second water inlet 503 at a position close to the second opening 302 relative to the second folding edge 303, and the fourth side long side 305 is partially sealed and forms the second concentrated water outlet 504 at a position close to the second folding edge 303 relative to the second opening 302.

The first water inlet and the first thick water inlet in embodiment 4 of the present invention are further preferred, that is, the first side long edge and the second side long edge are both normally open structures, so that raw water can enter the first raw water channel through the whole length direction of the first side long edge, and thick water is discharged through the whole length direction of the second side long edge; and the long limit of third side of second reverse osmosis membrane forms the part sealed, only forms the second water inlet in the position (circumference outer end promptly) that is close to the second open-ended, offers the dense water export of second in the position that is close to the second hem for the distance between the dense water export of first water inlet to second effectively increases, avoids the second water inlet too close to the dense water export of second and leads to the length of second raw water runner shorter and can't form effective purification filterable effect, thereby further improves and purifies the precision.

In some embodiments, a first sealing structure 701 is disposed at the third side long edge 304, the first sealing structure 701 extends from the second folded edge 303 to a position spaced apart from the second opening 302 by a first predetermined distance, the spaced apart first predetermined distance being formed as the second water inlet 503;

a second sealing structure 702 is arranged at the fourth long side 305, and the second sealing structure 702 extends from the second opening 302 to a position spaced apart from the second fold 303 by a second preset distance, which is formed as the second concentrated water outlet 504.

The first sealing structure is arranged on the third side long edge and forms a gap with the second opening for feeding the first concentrated water, namely the second water inlet, and the second sealing structure is arranged on the fourth side long edge and forms a gap with the second flange for discharging the second concentrated water, namely the second concentrated water outlet.

In some embodiments, the first opening 202 and the second opening 302 are positioned in axial alignment with the first center tube 101 (i.e., the first opening 202 and the second opening 302 are flush at the right end of the figure as shown in fig. 4). This is the preferred position form of the first opening and the second opening in embodiment 4 of the present invention, that is, they are oppositely disposed, so that the first concentrated water outlet is opposite to the second water inlet, so as to effectively discharge the concentrated water in the first raw water channel to the second raw water channel, thereby forming a two-stage filtration.

Example 4:

Preferably, the two reverse osmosis membrane units are combined in a way of being rolled with a central pipe. The central tube is characterized in that the first reverse osmosis membrane unit and the second reverse osmosis membrane unit are rolled on the central tube together.

The water inlet grid and the pure water diversion cloth are respectively positioned in a water inlet flow passage formed by the front surface of the reverse osmosis membrane after being folded and a water production flow passage formed by the adjacent back surface. The opening that the reverse osmosis membrane fifty percent discount formed is dorsad the center tube, the center tube is used for collecting the pure water of first reverse osmosis membrane unit and second reverse osmosis membrane unit output. A first side long edge of the raw water channel of the first reverse osmosis membrane unit, which is vertical to the folded edge, forms a raw water inlet, and a second side long edge of the raw water channel of the first reverse osmosis membrane unit, which is vertical to the folded edge, forms a concentrated water outlet; the long side part of the third side of the raw water channel of the second reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and one end, which is far away from the folded edge, is provided with a raw water inlet, and the long side part of the fourth side of the raw water channel of the second reverse osmosis membrane unit, which is vertical to the folded edge, is sealed, and one end, which is close to the folded edge, is provided with a concentrated water outlet.

The long sides of the third side and the fourth side of the raw water flow channel, which are perpendicular to the folded edges, are partially sealed in a glue bonding mode.

The invention also provides a water purifier which comprises the roll type reverse osmosis membrane element. Namely, the invention also comprises a water purifier with the reverse osmosis membrane element.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention. The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A composite reverse osmosis membrane component is characterized in that: the method comprises the following steps:

the membrane comprises a first reverse osmosis membrane element (200), a second reverse osmosis membrane element (300) and a central pipe, wherein the first reverse osmosis membrane element (200) is formed by coiling a first reverse osmosis membrane (201) on the central pipe, the second reverse osmosis membrane element (300) is formed by coiling a second reverse osmosis membrane (301) on the central pipe, the first reverse osmosis membrane element (200) and the second reverse osmosis membrane element (300) are coiled on the same central pipe or on different central pipes, the first reverse osmosis membrane element (200) is provided with a first raw water flow passage (401), the second reverse osmosis membrane element (300) is provided with a second raw water flow passage (402), a first concentrated water outlet (502) of the first raw water flow passage (401) is communicated with a second water inlet (503) of the second raw water flow passage (402), and the flow cross-sectional area s1 of the first raw water flow passage (401) is larger than the flow-sectional area s2 of the second raw water flow passage (402).

2. The composite reverse osmosis membrane module of claim 1, wherein:

1.5≤s1/s2≤4。

3. the composite reverse osmosis membrane module of claim 1 or 2, wherein:

the number of the central pipes is at least two, the central pipes comprise a first central pipe (101) and a second central pipe (102), the first reverse osmosis membrane (201) is rolled on the periphery of the first central pipe (101) to form the first reverse osmosis membrane element (200), the second reverse osmosis membrane (301) is rolled on the periphery of the second central pipe (102) to form the second reverse osmosis membrane element (300), the second reverse osmosis membrane element (300) is arranged inside the first central pipe (101), purified pure water of the second reverse osmosis membrane element (300) enters the first central pipe (101), and purified pure water of the first reverse osmosis membrane element (200) also enters the first central pipe (101).

4. The composite reverse osmosis membrane module of claim 3, wherein:

the second base pipe (102) having an outer diameter smaller than the inner diameter of the first base pipe (101),

the first reverse osmosis membrane (201) forms the first raw water flow channel (401) between the front surfaces of the two membrane pages through folding, and forms a first opening (202) and a first folded edge (203) which are opposite, the first folded edge (203) faces the first central tube (100) and is connected with the first central tube (101) for rolling, and the first opening (202) is far 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 faces of the two membrane leaves, and a second opening (302) and a second folded edge (303) which are opposite are formed, the second opening (302) faces the second central tube (102) and is connected with the second central tube (102) for rolling, and the second folded edge (303) is far away from the second central tube (100).

5. The composite reverse osmosis membrane module of claim 4, wherein:

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 communicated with the inside of the first central pipe (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), the second pure water flow channel (602) is also communicated with the inside of the first central pipe (101), and a pure water port (505) is formed at one axial end of the first central pipe (101).

6. The composite reverse osmosis membrane module of claim 4, wherein:

the first reverse osmosis membrane (201) comprises a first side long edge (204) and a second side long edge (205) which are perpendicular to the first folding edge (203) after being folded, the first side long edge (204) and the second side long edge (205) are arranged oppositely, a first water inlet (501) is formed in the first side long edge (204), the first water inlet (501) is communicated with the first raw water flow channel (401), and a first concentrated water outlet (502) is formed in the second side long edge (205);

the second reverse osmosis membrane (301) comprises a third side long edge (304) and a fourth side long edge (305) which are perpendicular to the second folded edge (303) after being folded, the third side long edge (304) and the fourth side long edge (305) are arranged oppositely, the third side long edge (304) is provided with a second water inlet (503), one end of the second water inlet (503) is communicated with the first concentrated water outlet (502), the other end of the second water inlet is communicated with the second raw water flow channel (402), the second raw water flow channel (402) is communicated with the inside of the second central tube (102) through the second opening (302), and one axial end of the second central tube (102) is formed into a second concentrated water outlet (504).

7. The composite reverse osmosis membrane module of claim 6, wherein:

the first side long edges (204) are all open structures along the length direction and form the first water inlet (501), the second side long edges (205) are all open structures along the length direction and form the first concentrated water outlet (502),

the third side long edge (304) is partially sealed, the second water inlet (503) is formed at a position close to the second folding edge (303) relative to the second opening (302), and the fourth side long edge (305) is completely sealed.

8. The composite reverse osmosis membrane module of claim 7, wherein:

a first sealing structure (701) is arranged at the third long side (304), the first sealing structure (701) extends from the second opening (302) to a position spaced from the second flange (303) by a preset distance, the second water inlet (503) is formed at the spaced preset distance, a second sealing structure (702) is arranged at the fourth long side (305), and the second sealing structure (702) extends from the second opening (302) to the second flange (303).

9. The composite reverse osmosis membrane module of any one of claims 1-8, wherein:

the number of the central pipes is at least one, and the central pipes comprise a first central pipe (101), the first reverse osmosis membrane (201) is rolled on the periphery of the first central pipe (101) to form the first reverse osmosis membrane element (200), the second reverse osmosis membrane (301) is also rolled on the periphery of the first central pipe (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 pipe (101).

10. The composite reverse osmosis membrane module of claim 9, wherein:

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 a first opening (202) and a first folding edge (203) which are opposite are formed, the first folding edge (203) faces the first central tube (100) and is connected with the first central tube (100) for rolling, and the first opening (202) is far away from the first central tube (100),

the second reverse osmosis membrane (301) is folded to form the second raw water flow channel (402) between the front faces of the two membrane leaves, and a second opening (302) and a second folded edge (303) which are opposite are formed, the second folded edge (303) faces the first central pipe (100) and is connected with the first central pipe (101) for rolling, and the second opening (302) is far away from the first central pipe (101).

11. The composite reverse osmosis membrane module of claim 10, wherein:

12. The composite reverse osmosis membrane module of claim 10, wherein:

the second reverse osmosis membrane (301) comprises a third side long edge (304) and a fourth side long edge (305) which are perpendicular to the second folded edge (303) after being folded, the third side long edge (304) and the fourth side long edge (305) are arranged oppositely, the third side long edge (304) is opposite to the second side long edge (205), the third side long edge (304) is provided with the second water inlet (503), one end of the second water inlet (503) is communicated with the first concentrated water outlet (502), the other end of the second water inlet is communicated with the second raw water flow channel (402), and the fourth side long edge (305) is provided with a second concentrated water outlet (504).

13. The composite reverse osmosis membrane module of claim 12, wherein:

-a partial seal at said first long side (204), said first inlet opening (501) being formed close to said first flap (203) with respect to said first opening (202), and a partial seal at said second long side (205), said first concentrate outlet opening (502) being formed close to said first opening (202) with respect to said first flap (203);

the third side long edge (304) is partially sealed, 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).

14. The composite reverse osmosis membrane module of claim 13, wherein:

a first sealing structure (701) is arranged at the first side long edge (204), the first sealing structure (701) extends from the first opening (202) to a position which is separated from the first folding edge (203) by a first preset distance, and the first water inlet (501) is formed at the first separated preset distance;

-a second sealing structure (702) is arranged between the second long side (205) and the third long side (304), the second sealing structure (702) extending from the first central tube (101) to a position spaced a second predetermined distance from the first opening (202), the second predetermined distance being formed as the first concentrate outlet (502); the second sealing structure (702) extending from the first central tube (101) to a position spaced a third predetermined distance from the second opening (302), the spaced third predetermined distance forming the second water inlet (503);

a third sealing structure (703) is arranged at the fourth side long edge (305), the third sealing structure (703) extends from the second opening (302) to a position spaced apart from the second fold edge (303) by a fourth preset distance, and the spaced fourth preset distance is formed as the second concentrated water outlet (504).

15. The composite reverse osmosis membrane module of claim 12, wherein:

-the first long side (204) is partially sealed, the first inlet opening (501) is formed close to the first opening (202) relative to the first folded edge (203), the second long side (205) is partially sealed, the first concentrate outlet (502) is formed close to the first folded edge (203) relative to the first opening (202);

the third side long edge (304) is partially sealed, 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).

16. The composite reverse osmosis membrane module of claim 15, wherein:

a first sealing structure (701) is arranged at the first side long edge (204), the first sealing structure (701) extends from the first folding edge (203) to a position which is separated from the first opening (202) by a first preset distance, and the first water inlet (501) is formed at the first separated preset distance;

-a second sealing structure (702) is arranged between the second long side (205) and the third long side (304), the second sealing structure (702) extending from the first opening (202) to a position spaced apart from the first central tube (101) by a second predetermined distance, the second predetermined distance being formed as the first concentrate outlet (502); the second sealing structure (702) extending from the second opening (302) to a position spaced a third predetermined distance from the first center tube (101), the spaced third predetermined distance forming the second water inlet (503);

a third sealing structure (703) is arranged at the fourth side long edge (305), the third sealing structure (703) extends from the second folded edge (303) to a position spaced from the second opening (302) by a fourth preset distance, and the spaced fourth preset distance is formed as the second concentrated water outlet (504).

17. The composite reverse osmosis membrane module of claim 12, wherein:

the first side long edges (204) are all open structures along the length direction thereof to form the first water inlet (501), and the second side long edges (205) are all open structures along the length direction thereof to form the first concentrated water outlet (502);

18. The composite reverse osmosis membrane module of claim 17, wherein:

a first sealing structure (701) is arranged at the third side long edge (304), the first sealing structure (701) extends from the second folded edge (303) to a position which is separated from the second opening (302) by a first preset distance, and the separated first preset distance is formed as the second water inlet (503);

a second sealing structure (702) is arranged at the fourth side long edge (305), the second sealing structure (702) extends from the second opening (302) to a position spaced apart from the second fold edge (303) by a second preset distance, and the second preset distance is formed as the second concentrated water outlet (504).

19. The composite reverse osmosis membrane module of any one of claims 12-18, wherein:

the first opening (202) and the second opening (302) are positioned in axial alignment of the first center pipe (101).

20. A water purifier, which is characterized in that: comprising the composite reverse osmosis membrane module of any one of claims 1-19.