CN115738729A

CN115738729A - Roll type reverse osmosis membrane element and water purifier with same

Info

Publication number: CN115738729A
Application number: CN202211501254.2A
Authority: CN
Inventors: 陈静; 詹婷; 李一然; 陈子斌; 宁贵勇; 李文灿
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: 2023-03-07

Abstract

The invention provides a roll-type reverse osmosis membrane element and a water purifier with the same, wherein the roll-type reverse osmosis membrane element comprises N filtering sections consisting of M reverse osmosis membranes, N is more than or equal to 2 and less than or equal to M, the number of raw water flow channels of an Nth filtering section is less than that of raw water flow channels of an N-1 th filtering section, a water inlet of the roll-type reverse osmosis membrane element is arranged in a first filtering section, a concentrated water outlet of the roll-type reverse osmosis membrane element is arranged in the Nth filtering section, and the M reverse osmosis membranes are independent membranes. According to the invention, the scheme that the number of the raw water channels is reduced along the flowing direction of the raw water is formed by arranging the water inlet at the first filtering section and the water outlet at the Nth filtering section, so that the number of the raw water channels can be reduced along the flowing direction of the raw water, the membrane surface flow rate of the concentrated water side is improved, 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

Roll type reverse osmosis membrane element and water purifier with same

Technical Field

The invention relates to the technical field of water purifiers, in particular to a roll type reverse osmosis membrane element 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 cloth 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 flow of the raw water in the raw water channel to the concentrated water outlet, the flow velocity of the water film surface in the raw water channel is smaller and smaller, the flow velocity of the film surface on the concentrated water side is minimum, the concentration polarization is most serious, and the pollution blockage is most easily caused. From the raw water side to the concentrated water side, since 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 is gradually reduced. Since the flow velocity of the membrane surface fluid is gradually reduced and the solute in the membrane surface fluid is gradually increased, the concentration polarization on the concentrated water side is the most severe. The concentration polarization phenomenon of a general 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 in the prior art, because the membrane surface water flow speed on the concentrated water side in the roll type reverse osmosis membrane element is gradually reduced along with the flowing process, the concentration polarization of the downstream section in the flowing 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 defect that the concentration polarization of the roll-type reverse osmosis membrane element in the downstream section of the flow direction is the most serious and the pollution blockage is easily caused in the prior art, thereby providing the roll-type reverse osmosis membrane element and the water purifier with the same.

In order to solve the above problems, the present invention provides a roll type reverse osmosis membrane element, comprising: n filtering sections are formed by M reverse osmosis membranes, N is more than or equal to 2 and less than or equal to M, the number of raw water flow channels of the N-th filtering section is less than that of the raw water flow channels of the N-1 th filtering section, a water inlet of the roll type reverse osmosis membrane element is arranged at the first filtering section, a concentrated water outlet of the roll type reverse osmosis membrane element is arranged at the N-th filtering section, and the M reverse osmosis membranes are independent membranes.

In some embodiments, the reverse osmosis membrane element further comprises:

the M reverse osmosis membranes comprise a first reverse osmosis membrane, a second reverse osmosis membrane, a third reverse osmosis membrane and a fourth reverse osmosis membrane, the first reverse osmosis membrane is bent to form a first long page, a first folding edge and a first short page which are sequentially connected, the first long page is longer than the first short page, the second reverse osmosis membrane is bent to form a second long page, a second folding edge and a second short page which are sequentially connected, the second long page is longer than the second short page, the third reverse osmosis membrane is bent to form a third long page, a third folding edge and a third short page which are sequentially connected, the third long page is longer than the third short page, the fourth reverse osmosis membrane is bent to form a fourth long page, a fourth folding edge and a fourth short page which are sequentially connected, the fourth long page is longer than the fourth short page, the first short page and the second short page are oppositely arranged, the third short page and the fourth short page are oppositely arranged, the first reverse osmosis membrane, the fourth reverse osmosis membrane, the third reverse osmosis membrane, the fourth short page and the fourth reverse osmosis membrane are integrally arranged after being folded;

and the subsection of the first long page is opposite to the first short page and forms a first raw water runner between the two, the subsection of the second long page is opposite to the second short page and forms a second raw water runner between the two, the subsection of the first long page is longer than the subsection of the second long page is opposite to the subsection of the second short page and forms a third raw water runner between the two, the first raw water runner and the second raw water runner are communicated with a raw water interface so as to be capable of being introduced with raw water, water in the first raw water runner and water in the second raw water runner respectively flow into the third raw water runner, and the sum of the flow cross-sectional areas of the first raw water runner and the second raw water runner is greater than the flow cross-sectional area of the third raw water runner.

In some embodiments, the third long sheet section is opposite to the third short sheet and forms a fourth raw water channel therebetween, the fourth long sheet section is opposite to the fourth short sheet and forms a fifth raw water channel therebetween, the third long sheet section from which the third short sheet is extended is opposite to the fourth long sheet section from which the fourth short sheet is extended and forms a sixth raw water channel therebetween, the fourth raw water channel and the fifth raw water channel are connected to a raw water port so that raw water can be introduced, and water in the fourth raw water channel and water in the fifth raw water channel flow into the sixth raw water channel, respectively, and the sum of the flow cross-sectional areas of the fourth raw water channel and the fifth raw water channel is greater than the flow cross-sectional area of the sixth raw water channel;

the first long page is longer than the second long page and the fourth long page is longer than the third long page, a seventh raw water channel is formed between the first long page and the fourth long page, water in the third raw water channel and water in the sixth raw water channel flow to the seventh raw water channel respectively, and the sum of the flow cross-sectional areas of the third raw water channel and the sixth raw water channel is larger than the flow cross-sectional area of the seventh raw water channel.

The first raw water channel, the second raw water channel, the fourth raw water channel and the fifth raw water channel are all first filtering sections, the third raw water channel and the sixth raw water channel are all second filtering sections, and the seventh raw water channel is a third filtering section.

In some embodiments, in a projection plane within the axial end face of the central tube, the first short pages and the second short pages are equal in length and both L2, the length L1 of the first long page is greater than the length L3 of the second long page, L1 > L3 > L2; the third short page and the fourth short page are equal in length and are both L2, the third long page is equal in length and is both L3, and the fourth long page is equal in length and is both L1;

the first folded edge, the second folded edge, the third folded edge and the fourth folded edge are all located on the same side and are arranged at intervals in sequence.

In some embodiments, the first raw water flow passage, the second raw water flow passage, the fourth raw water flow passage, and the fifth raw water flow passage are each provided with a water inlet on an axial end surface in the axial direction of the central tube, a length of the water inlet in a projection plane within the axial end surface of the central tube is L0, and L0 < L2.

In some embodiments, 1/3 ≦ L3/L1 ≦ 3/4; L2/L3 is more than or equal to 1/3 and less than or equal to 3/4; L0/L2 is more than or equal to 1/10 and less than or equal to 1/2.

In some embodiments, a first water inlet screen is disposed in the first raw water channel, a second water inlet screen is further disposed in the second raw water channel, a third water inlet screen is disposed in the fourth raw water channel, a fourth water inlet screen is disposed in the fifth raw water channel, at least one of the first water inlet grid, the second water inlet screen, the third water inlet screen and the fourth water inlet screen extends into the seventh raw water channel, and at least one of the remaining water inlet grids extends into the third raw water channel and at least one of the remaining water inlet grids extends into the sixth raw water channel.

In some embodiments, the first raw water channel, the third raw water channel and the seventh raw water channel are further provided with a first water inlet separation net, one end of the first water inlet separation net is connected with the first folded edge, and the other end of the first water inlet separation net extends to a position opposite to the end of the first long sheet, so that the first water inlet separation net extends from the first raw water channel to the third raw water channel and further extends to the seventh raw water channel; a second water inlet separation net is further arranged in the second raw water flow channel, one end of the second water inlet separation net is connected with the second folded edge, and the other end of the second water inlet separation net extends to a position opposite to the end part of the second short leaf, so that the second water inlet separation net extends in the second raw water flow channel;

a third water inlet separation net is further arranged in the fourth raw water flow channel and the sixth raw water flow channel, one end of the third water inlet separation net is connected with the third folded edge, and the other end of the third water inlet separation net extends to a position opposite to the end part of the third long leaf, so that the third water inlet separation net extends from the fourth raw water flow channel to the sixth raw water flow channel; and a second water inlet separation net is further arranged in the second raw water flow channel, one end of the fourth water inlet separation net is connected with the fourth folded edge, and the other end of the fourth water inlet separation net extends to a position opposite to the end part of the fourth short leaf, so that the fourth water inlet separation net extends in the fifth raw water flow channel.

In some embodiments, in a plane of projection within the axial end face of the central tube, the first influent spacer has a length greater than a length of the first long page, the second influent spacer has a length greater than a length of the second short page, the third influent spacer has a length greater than a length of the third long page, and the fourth influent spacer has a length greater than a length of the fourth short page.

In some embodiments, the face of the first long page opposite to the first short page is the front face of the first long page, the face of the first short page opposite to the first long page is the front face of the first short page, and the first raw water channel is formed between the front face of the first long page and the front face of the first short page;

the surface of the second long page, which is opposite to the second short page, is the front surface of the second long page, the surface of the second short page, which is opposite to the second long page, is the front surface of the second short page, and a second raw water channel is formed between the front surface of the second long page and the front surface of the second short page;

the front surface of the partial section of the first long page, which is longer than the first short page, is opposite to the front surface of the partial section of the second long page, which is longer than the second short page, and a third raw water flow channel is formed between the front surfaces;

the surface of the third long sheet opposite to the third short sheet is the front surface of the third long sheet, the surface of the third short sheet opposite to the third long sheet is the front surface of the third short sheet, and the fourth raw water channel is formed between the front surface of the third long sheet and the front surface of the third short sheet;

the surface of the fourth long sheet opposite to the fourth short sheet is the front surface of the third long sheet, the surface of the fourth short sheet opposite to the fourth long sheet is the front surface of the fourth short sheet, and the fifth raw water channel is formed between the front surface of the fourth long sheet and the front surface of the fourth short sheet;

the front surface of the partial section of the third long page, which is longer than the third short page, is opposite to the front surface of the partial section of the fourth long page, which is longer than the fourth short page, and a sixth raw water flow channel is formed between the front surfaces;

the front surface of the partial section of the first long page, from which the second long page extends, is opposite to the front surface of the partial section of the fourth long page, from which the third long page extends, and a seventh raw water channel is formed between the front surfaces.

In some embodiments, a first pure water flow passage is formed between the back surface of the first short page and the back surface of the second short page, the back surface of the first short page is the side opposite to the first long page, the raw water in the first raw water flow passage is filtered and purified by the first short page to form pure water which can enter the first pure water flow passage, and the raw water in the second raw water flow passage is filtered and purified by the second short page to form pure water which can also enter the first pure water flow passage;

after the first reverse osmosis membrane and the second reverse osmosis membrane are stacked into a whole and are rolled on the central tube, a second pure water flow channel is formed between the back surface of the first long page and the back surface of the second long page, pure water formed by filtering and purifying raw water in the first raw water flow channel through the first long page can enter the second pure water flow channel, pure water formed by filtering and purifying raw water in the second raw water flow channel through the second long page can enter the second pure water flow channel, and pure water formed by filtering and purifying raw water in the third raw water flow channel through the first long page and the second long page respectively can enter the second pure water flow channel;

a second pure water flow passage is formed between the back surface of the second long page and the back surface of the third long page, raw water in the second raw water flow passage forms pure water after being filtered and purified by the second long page and can enter the second pure water flow passage, and raw water in the fourth raw water flow passage forms pure water after being filtered and purified by the third long page and can also enter the second pure water flow passage;

a third pure water flow channel is formed between the back surface of the third short sheet and the back surface of the fourth short sheet, pure water is formed after raw water in the fourth raw water flow channel is filtered and purified by the third short sheet and can enter the third pure water flow channel, and pure water formed after raw water in the fifth raw water flow channel is filtered and purified by the fourth short sheet can also enter the third pure water flow channel;

the first reverse osmosis membrane, the second reverse osmosis membrane, the third reverse osmosis membrane and the fourth reverse osmosis membrane are stacked into a whole and rolled on the central pipe, a fourth pure water flow channel is formed between the back of the first long page and the back of the fourth long page, raw water in the first raw water flow channel, in the third raw water flow channel and in the seventh raw water flow channel respectively passes through the first long page and is filtered and purified to form pure water and can enter the fourth pure water flow channel, and raw water in the fifth raw water flow channel, in the sixth raw water flow channel and in the seventh raw water flow channel respectively passes through the fourth long page and is filtered and purified to form pure water and can enter the fourth pure water flow channel.

In some embodiments, a first pure water guide cloth is further arranged in the first pure water flow passage, and a second pure water guide cloth is further arranged in the second pure water flow passage; a third pure water flow guide cloth is also arranged in the third pure water flow passage, and a fourth pure water flow guide cloth is also arranged in the fourth pure water flow passage;

in a projection plane in the axial end face of the central tube, the length of the first pure water diversion cloth is larger than that of the first short page, and the length of the first short page is equal to that of the second short page; the length of the second pure water flow guide cloth is greater than that of the second long page, the length of the third pure water flow guide cloth is greater than that of the third short page, the length of the fourth pure water flow guide cloth is greater than that of the first long page, and the length of the first long page is equal to that of the fourth long page.

In some embodiments, a first sealing piece is connected between the back surface of the first short page and the back surface of the second short page, so that the pure water outlet of the first pure water flow channel faces the first folding edge; a second sealing element is connected between the back of the second short leaf and the back of the third long leaf, so that a pure water outlet of the second pure water flow channel faces the second folded edge; a third sealing element is connected between the back surface of the third short sheet and the back surface of the fourth short sheet, so that a pure water outlet of a third pure water flow channel faces a third folded edge; and a fourth sealing element is connected between the back surface of the first long page and the back surface of the fourth long page, so that the pure water outlet of the fourth pure water flow channel faces the fourth folded edge.

In some embodiments, the end of the first folded edge, the second folded edge, the third folded edge and the fourth folded edge after being folded is a starting end rolled onto the outer peripheral wall of the central tube, the open end formed between the end of the first long sheet and the end of the fourth long sheet is a terminal end rolled onto the central tube, the starting end is connected with the outer peripheral wall of the central tube, and the terminal end is located at the radial outer side of the starting end; the first pure water flow channel and the second pure water flow channel, and the third pure water flow channel and the fourth pure water flow channel are communicated with the inside of the central tube, so that pure water after filtration and purification is discharged through the inside of the central tube, and concentrated water after filtration and purification flows out through an opening end formed between the end part of the first long page and the end part of the fourth long page.

In some embodiments, the open end formed between the end of the first long sheet and the end of the fourth long sheet is folded to be a starting end rolled onto the outer peripheral wall of the central tube, and the end of the first folded edge, the second folded edge, the third folded edge and the fourth folded edge is a terminal end rolled onto the central tube, the starting end is connected with the outer peripheral wall of the central tube, and the terminal end is located at the radial outer side of the starting end; an open end between the end of the first long page and the end of the fourth long page is communicated with the inside of the central tube, so that the filtered and purified concentrated water flows to the inside of the central tube through the open end between the end of the first long page and the end of the fourth long page, and the first pure water flow channel, the second pure water flow channel, the third pure water flow channel and the fourth pure water flow channel are respectively communicated to the outside of the roll-type reverse osmosis membrane element, so that the filtered and purified pure water is discharged through the first pure water flow channel, the second pure water flow channel, the third pure water flow channel and the fourth pure water flow channel respectively.

In some embodiments, the first reverse osmosis membrane sheet and the second reverse osmosis membrane sheet form a reverse osmosis unit, and the reverse osmosis unit comprises at least two reverse osmosis units, wherein at least two reverse osmosis units are stacked and integrally rolled on the central pipe.

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

The roll type reverse osmosis membrane element and the water purifier with the same have the following beneficial effects:

1. the roll-type reverse osmosis membrane element comprises N filtering sections consisting of M reverse osmosis membranes, wherein N is more than or equal to 2 and less than or equal to M, the number of raw water flow channels of the N-th filtering section is less than that of the raw water flow channels of the N-1-th filtering section, a water inlet of the roll-type reverse osmosis membrane element is arranged in the first filtering section, a concentrated water outlet of the roll-type reverse osmosis membrane element is arranged in the N-th filtering section, and the M reverse osmosis membranes are independent membranes. According to the invention, the scheme that the number of the raw water channels is reduced along the flowing direction of raw water is formed by arranging the water inlet at the first filtering section and arranging the water outlet at the Nth filtering section, namely the number of the raw water channels of the Nth filtering section is smaller than that of the raw water channels of the (N-1) th filtering section, so that the number of the raw water channels can be reduced along the flowing direction of the raw water, the membrane surface flow rate of a concentrated water side is increased, the concentration polarization of the concentrated water side is slowed down, the anti-pollution performance of a reverse osmosis membrane is improved, and the service life of a reverse osmosis membrane filter element is prolonged.

2. The invention also folds the first reverse osmosis membrane into a first long page and a first short page which are different in length, folds the second reverse osmosis membrane into a second long page and a second short page which are different in length, and enables the two short pages to be oppositely arranged, a first raw water flow channel is formed between the opposite surfaces of the first long page and the first short page, a second raw water flow channel is formed between the opposite surfaces of the second long page and the second short page, a third raw water flow channel is formed by the surface of the first long page, which is between the first short page and the first short page, which is between the second long page and the second short page, which is between the second short page and the second short page, which is between the first long page and the second short page, and the water flow direction is from the first raw water flow channel to the third raw water flow channel and from the second raw water flow channel to the third water flow channel, and further folds the third reverse osmosis membrane into a third long page and a third short page which are different in length, and folds the fourth reverse osmosis membrane into a fourth long page and a short page which are different in length, the two short pages are oppositely arranged, a fourth raw water flow channel is formed between the opposite surfaces of the third long page and the third short page, a fifth raw water flow channel is formed between the opposite surfaces of the fourth long page and the fourth short page, a sixth raw water flow channel is formed between the part of the fourth long page, which is longer than the fourth short page, and the part of the third long page, which is longer than the third short page, and the surface of the fourth long page, which is directly opposite to the surface of the third long page, which is longer than the third short page, and the water flow direction is from the fourth raw water flow channel to the sixth raw water flow channel, so that the two original raw water flow channels are combined into a sixth raw water flow channel along the flow direction, furthermore, the part of the first long page, which is longer than the second long page, is opposite to the part of the fourth long page, which is longer than the third long page, and a seventh raw water flow channel is formed between the first long page and the fourth long page, and the water in the sixth raw water flow channel respectively flows towards the seventh raw water flow channel, therefore, the scheme that at least 4 raw water channels are changed into 2 raw water channels and then changed into one raw water channel is effectively formed, so that the number of the raw water channels is reduced along the flowing direction of raw water, the flow cross section area of water flow is effectively reduced, the flow velocity of fluid can be increased, the concentration polarization of a concentrated water side is slowed down, the anti-pollution performance of a reverse osmosis membrane is improved, and the service life of a reverse osmosis membrane filter element is prolonged; the invention effectively reduces the size of the inlet channel of the concentrated water side by folding the long and short pages and rolling the membrane, effectively improves the membrane surface flow rate of the concentrated water side, further slows down the concentration polarization of the concentrated water side, improves the anti-pollution performance of the reverse osmosis membrane, and prolongs the service life of the reverse osmosis membrane filter element. The raw water flow channel is divided into N sections along the advancing direction of water flow, and the quantity of the raw water flow channels of the N section of filtering section is smaller than that of the raw water flow channels of the N-1 section of filtering section, namely, the size of the raw water flow channel is narrowed by reducing the quantity of the flow channels along the advancing direction of the water flow, so that the flow velocity of the side membrane surface can be increased section by section, the polarization and pollution of the concentration difference of the membrane surface caused by the deterioration of the raw water concentration of the membrane surface are relieved, the pollution resistance 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 schematic structural view (a view in a projection plane of an axial end face of a center pipe, that is, a view in a cross section of the center pipe) of example 1 of a rolled reverse osmosis membrane element of the present invention;

FIG. 1-1 is a schematic view of a rolling process of the rolled reverse osmosis membrane element of FIG. 1 (a schematic view of a first and a second reverse osmosis membrane sheet being rolled);

FIGS. 1-2 are schematic views of a pure water flow path of the spiral wound reverse osmosis membrane element of FIG. 1;

FIGS. 1-3 are schematic views of a concentrate flow path of the spiral wound reverse osmosis membrane element of FIG. 1;

FIGS. 1-4 are schematic views of the rolled reverse osmosis membrane element of FIG. 1 after rolling;

fig. 2 is a schematic structural view (a view in a projection plane of an axial end face of a center pipe, i.e., a view in a cross section of the center pipe) of example 2 of the rolled reverse osmosis membrane element of the present invention;

fig. 3 is a schematic structural view (a view in a projection plane of an axial end face of a center pipe, i.e., a view in a cross section of the center pipe) of example 3 of the rolled reverse osmosis membrane element of the present invention.

The reference numbers are given as:

100. a central tube; 1. a first reverse osmosis membrane; 11. a first long page; 12. a first short page; 13. a first folded edge; 2. a second reverse osmosis membrane; 21. a second long page; 22. a second short page; 23. a second folded edge; 31. a first water inlet separation net; 32. a second water inlet separation net; 33. a third water inlet separation net; 34. a fourth water inlet separation net; 41. a first pure water guide cloth; 42. a second pure water guide cloth; 43. third pure water diversion cloth; 44. fourth pure water diversion cloth; 51. a first seal member; 52. a second seal member; 53. a third seal member; 54. a fourth seal member; 6. a third reverse osmosis membrane; 61. a third long page; 62. a third short page; 63. thirdly, folding; 7. a fourth reverse osmosis membrane; 71. a fourth long page; 72. a fourth short page; 73. a fourth folded edge; 201. a first raw water flow passage; 202. a second raw water flow passage; 203. a third raw water flow passage; 204. a fourth raw water flow path; 205. a fifth raw water flow passage; 206. a sixth raw water flow path; 207. a seventh raw water flow path; 301. a first pure water flow passage; 302. a second pure water flow passage; 303. a third pure water flow passage; 304. a fourth pure water flow passage; 401. a water inlet; 402. a concentrated water outlet; 403. and a pure water outlet.

Detailed Description

As shown in fig. 1 to 3, the present invention provides a roll type reverse osmosis membrane element comprising:

n filtering sections consisting of M reverse osmosis membranes, wherein N is more than or equal to 2 and less than or equal to M, and preferably N is more than or equal to 2 and less than or equal to log ₂ M +1 (i.e. M is greater than or equal to 2^ (N-1)), M is greater than 0 and is a natural number, and the number of raw water channels with the Nth filtering section is smallAccording to the quantity of raw water channels of the N-1 section of the filtering section, a water inlet of the roll type reverse osmosis membrane element is arranged at the first filtering section, a concentrated water outlet of the roll type reverse osmosis membrane element is arranged at the N filtering section, and the M reverse osmosis membrane pieces are independent membrane pieces. According to the invention, the scheme that the number of the raw water channels is reduced along with the flowing direction of raw water is formed by arranging the water inlet at the first filtering section and arranging the water outlet at the Nth filtering section, namely the number of the raw water channels of the Nth filtering section is smaller than that of the raw water channels of the N-1 th filtering section, so that the number of the raw water channels can be reduced along the flowing direction of the raw water, the membrane surface flow rate of a concentrated water side is increased, the concentration polarization of the concentrated water side is reduced, the anti-pollution performance of a reverse osmosis membrane is improved, and the service life of a reverse osmosis membrane filter element is prolonged.

In some embodiments, preferably N.gtoreq.3, the reverse osmosis membrane element comprises: a central tube 100, a first reverse osmosis membrane 1, a second reverse osmosis membrane 2, a third reverse osmosis membrane 6 and a fourth reverse osmosis membrane 7, wherein the first reverse osmosis membrane 1 is bent to form a first long sheet 11, a first folded edge 13 and a first short sheet 12 which are sequentially connected, the length of the first long sheet 11 is longer than that of the first short sheet 12, the second reverse osmosis membrane 2 is bent to form a second long sheet 21, a second folded edge 23 and a second short sheet 22 which are sequentially connected, the length of the second long sheet 21 is longer than that of the second short sheet 22, the third reverse osmosis membrane 6 is bent to form a third long sheet 61, a third folded edge 63 and a third short sheet 62 which are sequentially connected, the length of the third long sheet 61 is longer than that of the third short sheet 62, the fourth reverse osmosis membrane 7 is bent to form a fourth long sheet 71, a fourth folded edge 73 and a fourth short sheet 72 which are sequentially connected, the length of the fourth long sheet 71 is longer than that of the fourth short sheet 72, the fourth reverse osmosis membrane 7 and the fourth short sheet 72 are sequentially connected, the first long sheet 21, the second short sheet 21, the fourth short sheet 21 and the fourth short sheet 21 are integrally arranged with the fourth short sheet 72, the fourth reverse osmosis membrane 7 and the fourth short sheet 21 are stacked oppositely, the first reverse osmosis membrane 7 and the fourth short sheet 21 are stacked;

a partial section of the first long sheet 11 is opposite to the first short sheet 12 and forms a first raw water flow passage 201 therebetween, a partial section of the second long sheet 21 is opposite to the second short sheet 22 and forms a second raw water flow passage 202 therebetween, a partial section of the first long sheet 11 from which the first short sheet 12 is extended is opposite to a partial section of the second long sheet 21 from which the second short sheet 22 is extended and forms a third raw water flow passage 203 therebetween, the first raw water flow passage 201 and the second raw water flow passage 202 are communicated with a raw water interface to allow raw water to flow in, and water in the first raw water flow passage 201 and water in the second raw water flow passage 202 respectively flow into the third raw water flow passage 203, and the sum of the flow cross-sectional areas of the first raw water flow passage 201 and the second raw water flow passage 202 is larger than the flow cross-sectional area of the third raw water flow passage 203;

a partial section of the third long sheet 61 is opposite to the third short sheet 62 and forms a fourth raw water flow channel 204 therebetween, a partial section of the fourth long sheet 71 is opposite to the fourth short sheet 72 and forms a fifth raw water flow channel 205 therebetween, a partial section of the third long sheet 61 from which the third short sheet 62 is grown is opposite to a partial section of the fourth long sheet 71 from which the fourth short sheet 72 is grown and forms a sixth raw water flow channel 206 therebetween, the fourth raw water flow channel 204 and the fifth raw water flow channel 205 are communicated with a raw water interface so as to be capable of being introduced with raw water, and raw water in the fourth raw water flow channel 204 and raw water in the fifth raw water flow channel 205 respectively flow into the sixth raw water flow channel 206, and the sum of the flow cross-sectional areas of the fourth raw water flow channel 204 and the fifth raw water flow channel 205 is larger than the flow cross-sectional area of the sixth raw water flow channel 206;

the section of the first long sheet 11 extending out of the second long sheet 21 is opposite to the section of the fourth long sheet 71 extending out of the third long sheet 61, and a seventh raw water channel 207 is formed therebetween, water in the third raw water channel 203 and water in the sixth raw water channel 206 flow into the seventh raw water channel 207, respectively, and the sum of the flow cross-sectional areas of the third raw water channel 203 and the sixth raw water channel 206 is larger than the flow cross-sectional area of the seventh raw water channel 207.

The invention folds a first reverse osmosis membrane into a first long page and a first short page with different lengths, folds a second reverse osmosis membrane into a second long page and a second short page with different lengths, and makes the two short pages oppositely arranged, a first raw water channel is formed between the opposite surfaces of the first long page and the first short page, a second raw water channel is formed between the opposite surfaces of the second long page and the short page, a third raw water channel is formed between the part of the first long page between the first short pages and the part of the second long page between the second short pages, and the water flow direction is from the first raw water channel to the third raw water channel and from the second raw water channel to the third raw water channel, thereby combining the two original raw water channels into a third raw water channel along the flow direction, and folds the third reverse osmosis membrane into a third long page and a third short page with different lengths, folds a fourth reverse osmosis membrane into a fourth long page with different lengths and a fourth short page, two short pages are oppositely arranged, a fourth raw water flow channel is formed between opposite surfaces of a third long page and the third short page, a fifth raw water flow channel is formed between opposite surfaces of the fourth long page and the fourth short page, a sixth raw water flow channel is formed by a surface of the fourth long page, which is directly opposite to a surface of the third long page, which is directly opposite to a part of the third long page, which is between the fourth short page and the third short page, the water flowing direction is from the fourth raw water flow channel to the sixth raw water flow channel and from the fifth raw water flow channel to the sixth raw water flow channel, so that the original two raw water flow channels are combined into the sixth raw water flow channel along the flowing direction, furthermore, a part section of the first long page, which is longer than the second long page, is opposite to a part section of the fourth long page, which is longer than the third long page, and a seventh raw water flow channel is formed between the two parts, water in the third raw water flow channel and water in the sixth raw water flow channel respectively flow towards the seventh raw water flow channel, therefore, the scheme that at least 4 raw water channels are changed into 2 raw water channels and then changed into one raw water channel is effectively formed, so that the number of the raw water channels is reduced along the flowing direction of raw water, the flow area of water flow can be effectively reduced, the flow rate of fluid can be increased, the concentration polarization of a concentrated water side is slowed down, the anti-pollution performance of a reverse osmosis membrane is improved, and the service life of a reverse osmosis membrane filter element is prolonged; the invention effectively reduces the size of the inlet channel of the concentrated water side by folding the long and short pages and rolling the membrane, effectively improves the membrane surface flow rate of the concentrated water side, further slows down the concentration polarization of the concentrated water side, improves the anti-pollution performance of the reverse osmosis membrane, and prolongs the service life of the reverse osmosis membrane filter element. The raw water flow channel is divided into N sections along the advancing direction of water flow, the number of the raw water flow channels of the N section of filtering section is smaller than that of the raw water flow channels of the N-1 section of filtering section, namely, the size of the raw water flow channel is narrowed by reducing the number of the flow channels along the advancing direction of the water flow, the flow velocity of the side membrane surface can be increased section by section, further, the polarization and pollution of membrane surface concentration caused by the deterioration of the raw water concentration quality of the membrane surface are relieved, the pollution resistance of the reverse osmosis membrane is improved, and the service life of the reverse osmosis membrane filter element is prolonged.

The roll type reverse osmosis membrane element comprises a central pipe, a first reverse osmosis membrane, a second reverse osmosis membrane, a first water inlet grid, a second water inlet grid and first pure water guide cloth, wherein the first reverse osmosis membrane, the second reverse osmosis membrane, the first water inlet grid, the second water inlet grid and the first pure water guide cloth are rolled on the central pipe. The front sides of the first reverse osmosis membrane and the second reverse osmosis membrane are folded in half to form a folded edge, and a long page and a short page which are distinguished by the folded edge are formed, a first raw water channel is formed between the long page and the short page of the first reverse osmosis membrane, a second raw water channel is formed between the long page and the short page of the second reverse osmosis membrane, a third raw water channel is formed between the long page of the first reverse osmosis membrane and the front side of the long page of the second reverse osmosis membrane, the first water inlet grid is inserted into the first raw water channel and the third raw water channel, and the second water inlet grid is inserted into the second raw water channel; or the first water inlet grid is inserted in the second raw water flow channel and the third raw water flow channel, and the second water inlet grid is inserted in the first raw water flow channel. The main function of the water inlet grid is to form a water passing gap and a water passing flow channel between the reverse osmosis membrane and the front surface of the reverse osmosis membrane, so that raw water can smoothly flow through the surface of the reverse osmosis membrane. The size of the concentrated water side water inlet flow channel is reduced by folding and pasting the long and short page rolling membranes, the membrane surface flow rate of the concentrated water side is improved, the concentration polarization of 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.

In some embodiments, the first raw water channel 201, the second raw water channel 202, the fourth raw water channel 204, and the fifth raw water channel 205 are all first filter stages, the third raw water channel 203 and the sixth raw water channel 206 are all second filter stages, and the seventh raw water channel 207 is a third filter stage. According to the invention, the raw water flow channel is divided into N filter sections along the advancing direction of water flow, and the number of the raw water flow channels of the Nth filter section is smaller than that of the raw water flow channels of the (N-1) th filter section, namely, the size of the raw water flow channel is narrowed by reducing the number of the flow channels along the advancing direction of water flow, so that the flow velocity of the side membrane surface can be increased section by section, further, the polarization and pollution of the concentration difference of the membrane surface caused by the deterioration of the raw water concentration of the membrane surface are relieved, the pollution resistance of the reverse osmosis membrane is improved, and the service life of the reverse osmosis membrane filter element is prolonged.

Preferably, the raw water flow channel is divided into a first section raw water flow channel and a second section raw water flow channel along the advancing direction of water flow, and the number of the second section raw water flow channels is less than that of the first section raw water flow channels;

preferably, the raw water flow channel can be further divided into a first section raw water flow channel, a second section raw water flow channel and a third section raw water flow channel along the advancing direction of the water flow, and the number of the third section raw water flow channels is less than that of the second section raw water flow channels, and the number of the second section raw water flow channels is less than that of the first section raw water flow channels;

preferably, the raw water channel can be further divided into a first section raw water channel, a second section raw water channel and a third section raw water channel, wherein the first section raw water channel, the second section raw water channel and the third section raw water channel are 8230, the third section raw water channel is 8230, the nth raw water channel is provided, and the number of the raw water channels is reduced in sequence.

In some embodiments, in a projection plane in the axial end face of the central tube 100, the first short leaf 12 and the second short leaf 22 are equal in length and both L2, and the length L1 of the first long leaf 11 is greater than the length L3 of the second long leaf 21, i.e., L1 > L3 > L2; the third short page 62 and the fourth short page 72 have the same length and are both L2, the third long page 61 has the same length and are both L3 as the second long page 21, and the fourth long page 71 has the same length as the first long page 11 and are both L1;

the first folded edge 13, the second folded edge 23, the third folded edge 63 and the fourth folded edge 73 are located on the same side and are sequentially arranged at intervals.

The optimal position relationship and the size relationship among the first long page, the first short page, the second long page, the second short page, the third long page, the third short page, the fourth long page and the fourth short page are that the lengths of the first long page and the second long page are equal, the lengths of the first short page and the second short page are equal, and the lengths of the two long pages are longer than the lengths of the two short pages.

In some embodiments, the first and second raw water flow passages 201 and 202, the fourth raw water flow passage 204 and the fifth raw water flow passage 205 are each provided with a water inlet 401 (i.e., a raw water inlet) on an axial end surface along the axial direction of the central tube 100, and a length of the water inlet 401 in a projection plane within the axial end surface of the central tube 100 is L0, and L0 < L2. The invention is a further preferable structure form, namely the length of the water inlet is less than that of the short page, so that the condition that the direction of the flow channel is changed due to too large length can be effectively prevented. The length of the raw water inlet influencing the design performance is L0. The raw water inlet is used for enabling raw water to enter a flow channel between the front faces of the reverse osmosis membranes, the length needs to be proper, too small length can cause overlarge resistance and unsmooth water inflow, and too large length can cause the direction of the flow channel to be changed, so that the design performance is influenced.

In some embodiments, a first water inlet screen 31 is disposed in the first raw water channel 201, a second water inlet screen 32 is disposed in the second raw water channel 202, a third water inlet screen 33 is disposed in the fourth raw water channel 204, a fourth water inlet screen 34 is disposed in the fifth raw water channel 205, at least one of the first water inlet screen 31, the second water inlet screen 32, the third water inlet screen 33 and the fourth water inlet screen 34 extends into the seventh raw water channel 207, and at least one of the remaining water inlet screens extends into the third raw water channel 203 and at least one of the remaining water inlet screens extends into the sixth raw water channel 206. The raw water channels with the membrane structures of the first section and the second section can be simultaneously supported by extending at least one of the first water inlet separation net, the second water inlet grid, the fourth water inlet grid and the fifth water inlet grid into the seventh raw water channel, the raw water channels with the membrane structures of the first section, the second section and the third section can be simultaneously supported by extending at least one of the remaining water inlet grids into the third raw water channel, the raw water channels with the membrane structures of the first section and the second section can be simultaneously supported by extending at least one of the remaining water inlet grids into the sixth raw water channel, the raw water channels with the membrane structures of the first section and the second section can be simultaneously supported, and the remaining water inlet grids only support the corresponding raw water channels of the first section; thereby improving the effective utilization rate of the water inlet grid.

Example 1, in some embodiments, a first water inlet separation net 31 is further disposed in the first raw water channel 201 and the third raw water channel 203 and the seventh raw water channel 207, one end of the first water inlet separation net 31 is connected to the first folded edge 13, and the other end of the first water inlet separation net 31 extends to a position opposite to the end of the first long leaf 11, so that the first water inlet separation net 31 extends from the first raw water channel 201 to the third raw water channel 203 and further extends to the seventh raw water channel 207; a second water inlet separation net 32 is further arranged in the second raw water flow channel 202, one end of the second water inlet separation net 32 is connected with the second folded edge 23, and the other end of the second water inlet separation net 32 extends to a position opposite to the end of the second short leaf 22, so that the second water inlet separation net 32 extends in the second raw water flow channel 202;

a third water inlet screen 33 is further disposed in the fourth raw water channel 204 and the sixth raw water channel 206, one end of the third water inlet screen 33 is connected to the third folded edge 63, and the other end thereof extends to a position opposite to the end of the third long leaf 61, so that the third water inlet screen 33 extends from the fourth raw water channel 204 to the sixth raw water channel 206; a second water inlet separation net 32 is further disposed in the second raw water flow channel 202, one end of the fourth water inlet separation net 34 is connected to the fourth folded edge 73, and the other end of the fourth water inlet separation net 34 extends to a position opposite to the end of the fourth short leaf 72, so that the fourth water inlet separation net 34 extends in the fifth raw water flow channel 205.

This is a preferable configuration of the first and second water inflow spacers of embodiment 1 of the present invention, that is, the first water inflow spacer extends from the first raw water flow path into the third raw water flow path while supporting the raw water flow path between the first short leaf and the first long leaf and supporting the third raw water flow path between the first and second long leaves, and the second water inflow spacer is used only for effectively supporting the second raw water flow path between the second long leaf and the second short leaf.

In some embodiments, the length of the first water-inlet spacer 31 is greater than the length of the first long leaf 11, the length of the second water-inlet spacer 32 is greater than the length of the second short leaf 22, the length of the third water-inlet spacer 33 is greater than the length of the third long leaf 61, and the length of the fourth water-inlet spacer 34 is greater than the length of the fourth short leaf 72 in a plane of projection into the axial end face of the central tube 100. The length of the first water inlet separation net in embodiment 1 of the present invention is greater than that of the first long sheet, so that the first water inlet separation net can extend from the first raw water channel to the third raw water channel, and can support all the length sections of the first long sheet, and the length of the second water inlet separation net is greater than that of the second short sheet, so that the second water inlet separation net can effectively support all the length sections of the second short sheet.

Preferably, the length of the first water inlet grid is 1-10mm longer than the length of the side edge of the long page perpendicular to the folded edge (namely the length L1 of the first long page); the length of the graticule mesh of intaking is longer than diaphragm length slightly, can guarantee that all diaphragm surfaces have the graticule mesh of intaking, and all diaphragm surfaces of make full use of are used for filtering, avoid diaphragm and the direct laminating of diaphragm surface to lead to the fluid can't pass through.

Embodiments 1 and 2, the roll type reverse osmosis membrane element of the present invention includes a central tube, and a first reverse osmosis membrane sheet, a second reverse osmosis membrane sheet, a first water inlet mesh, a second water inlet mesh, and a first pure water guide cloth which are rolled on the central tube. The front faces of the first reverse osmosis membrane and the second reverse osmosis membrane are folded in half to form a folded edge, and a long sheet and a short sheet which are distinguished by the folded edge, a first raw water channel is formed between the long sheet and the short sheet of the first reverse osmosis membrane, a second raw water channel is formed between the long sheet and the short sheet of the second reverse osmosis membrane, a third raw water channel is formed between the long sheet of the first reverse osmosis membrane and the front face of the long sheet of the second reverse osmosis membrane, the first water inlet grid is inserted into the first raw water channel and the third raw water channel, and the second water inlet grid is inserted into the second raw water channel (embodiment 1); or the first water inlet grid is inserted in the second raw water flow passage and the third raw water flow passage, and the second water inlet grid is inserted in the first raw water flow passage (embodiment 2).

Preferably, the back surfaces of the first reverse osmosis membrane short sheet and the second reverse osmosis membrane short sheet are partially sealed to form a pure water channel with one end close to the folded edge being a pure water outlet, and the first pure water guide cloth is laminated between the back surfaces of the first reverse osmosis membrane short sheet and the second reverse osmosis membrane short sheet.

In some embodiments, the surface of the first long sheet 11 opposite to the first short sheet 12 is the front surface of the first long sheet 11, the surface of the first short sheet 12 opposite to the first long sheet 11 is the front surface of the first short sheet 12, and the first raw water channel 201 is formed between the front surface of the first long sheet 11 and the front surface of the first short sheet 12;

the surface of the second long sheet 21 opposite to the second short sheet 22 is the front surface of the second long sheet 21, the surface of the second short sheet 22 opposite to the second long sheet 21 is the front surface of the second short sheet 22, and the second raw water channel 202 is formed between the front surface of the second long sheet 21 and the front surface of the second short sheet 22;

the front surface of the partial section of the first long sheet 11 longer than the first short sheet 12 is opposite to the front surface of the partial section of the second long sheet 21 longer than the second short sheet 22, and the third raw water channel 203 is formed therebetween;

the surface of the third long sheet 61 opposite to the third short sheet 62 is the front surface of the third long sheet 61, the surface of the third short sheet 62 opposite to the third long sheet 61 is the front surface of the third short sheet 62, and the fourth raw water channel 204 is formed between the front surface of the third long sheet 61 and the front surface of the third short sheet 62;

the surface of the fourth long sheet 71 opposite to the fourth short sheet 72 is the front surface of the fourth long sheet 71, the surface of the fourth short sheet 72 opposite to the fourth long sheet 71 is the front surface of the fourth short sheet 72, and the fifth raw water channel 205 is formed between the front surface of the fourth long sheet 71 and the front surface of the fourth short sheet 72;

the front surface of the section of the third long sheet 61 from which the third short sheet 62 is extended is opposite to the front surface of the section of the fourth long sheet 71 from which the fourth short sheet 72 is extended, and the sixth raw water flow passage 206 is formed therebetween;

the front surface of the section of the first long sheet 11 from which the second long sheet 21 is extended is opposite to the front surface of the section of the fourth long sheet 71 from which the third long sheet 61 is extended, and the seventh raw water flow passage 207 is formed therebetween.

The first long page, the first short page, the second long page, the second short page, the first raw water channel and the third raw water channel are arranged in parallel, the first raw water channel is formed between the first long page and the front surface of the first short page, the second raw water channel is formed between the second long page and the front surface of the second short page, the third raw water channel is formed in a space opposite to the front surfaces of the first long page and the second long page, and the first raw water channel and the second raw water channel are arranged in parallel.

In some embodiments, a first pure water flow channel 301 is formed between the back surface of the first short sheet 12 and the back surface of the second short sheet 22, the back surface of the first short sheet 12 is the side opposite to the first long sheet 11, pure water formed by filtration and purification of raw water in the first raw water flow channel 201 through the first short sheet 12 can enter the first pure water flow channel 301, and pure water formed by filtration and purification of raw water in the second raw water flow channel 202 through the second short sheet 22 can also enter the first pure water flow channel 301;

a second pure water flow passage 302 is formed between the back surface of the second long sheet 21 and the back surface of the third long sheet 61, the raw water in the second raw water flow passage 202 forms pure water after being filtered and purified by the second long sheet 21 and can enter the second pure water flow passage 302, and the raw water in the fourth raw water flow passage 204 also can enter the second pure water flow passage 302 after being filtered and purified by the third long sheet 61 to form pure water;

a third pure water flow channel 303 is formed between the back surface of the third short sheet 62 and the back surface of the fourth short sheet 72, pure water is formed after raw water in the fourth raw water flow channel 204 is filtered and purified by the third short sheet 62 and can enter the third pure water flow channel 303, and pure water formed after raw water in the fifth raw water flow channel 205 is filtered and purified by the fourth short sheet 72 can also enter the third pure water flow channel 303;

after the first reverse osmosis membrane 1, the second reverse osmosis membrane 2, the third reverse osmosis membrane 6 and the fourth reverse osmosis membrane 7 are stacked and rolled onto the central tube 100, a second pure water flow channel 302 is formed between the back surface of the first long leaf 11 and the back surface of the fourth long leaf 71, pure water formed by the raw water in the first raw water flow channel 201, the raw water in the third raw water flow channel 203 and the raw water in the seventh raw water flow channel 207 after being filtered and purified by the first long leaf 11 can enter the fourth pure water flow channel 304, and the raw water in the fifth raw water flow channel 205, the raw water in the sixth raw water flow channel 206 and the raw water in the seventh raw water flow channel 207 respectively forms pure water after being filtered and purified by the fourth long leaf 71 and can enter the fourth pure water flow channel 304.

The first pure water flow channel and the second pure water flow channel are formed in the invention, namely the first pure water flow channel is formed between the back surfaces of the first short page and the second short page, and the two short pages are used for filtering and purifying water in the respective raw water flow channels, so that the purified pure water obtained by passing through the short pages enters the first pure water flow channel; and a second pure water flow channel is formed between the back surfaces of the first long page and the second long page, so that the water in the first raw water flow channel and the second raw water flow channel is filtered and purified respectively through the two long pages, the water in the third raw water flow channel is filtered and purified respectively through the two long pages, and the formed pure water enters the second pure water flow channel and can be discharged in different modes finally.

In some embodiments, a first pure water guide cloth 41 is further disposed in the first pure water flow passage 301, and a second pure water guide cloth 42 is further disposed in the second pure water flow passage 302; a third pure water guide cloth 43 is further disposed in the third pure water flow passage 303, and a fourth pure water guide cloth 44 is further disposed in the fourth pure water flow passage 304;

in a projection plane in the axial end face of the central tube 100, the length of the first pure water guide cloth 41 is greater than that of the first short sheet 12, and the length of the first short sheet 12 is equal to that of the second short sheet 22; the length of the second pure water guide cloth 42 is greater than that of the second long sheet 21, the length of the third pure water guide cloth 43 is greater than that of the third short sheet 62, the length of the fourth pure water guide cloth 44 is greater than that of the first long sheet 11, and the length of the first long sheet 11 is equal to that of the fourth long sheet 71.

The reverse osmosis membrane water purifier further comprises a first pure water flow guide cloth, a second pure water flow guide cloth and a membrane, wherein the first pure water flow guide cloth is arranged in the first pure water flow channel and can provide space and flow guide for the flow of pure water, the second pure water flow guide cloth is arranged in the second pure water flow channel and can provide space and flow guide for the flow of pure water, the length of the pure water flow guide cloth is slightly longer than that of the membrane, the reverse osmosis membrane water can be guided out smoothly, and the phenomenon that pure water cannot flow out effectively due to the fact that reverse osmosis membranes are directly attached to the reverse osmosis membranes is avoided.

The main function of the pure water flow guide cloth is to form a water passing gap and a water production flow passage between the reverse side and the reverse side of the reverse osmosis membrane, raw water on the raw water side of the reverse osmosis membrane permeates through the reverse osmosis membrane to the reverse side of the reverse osmosis membrane under the action of pressure, and the produced water flows out along the pure water flow passage formed by the pure water flow guide cloth. Therefore, the pure water diversion cloth is slightly longer than the membrane, so that the water produced on the reverse sides of all the reverse osmosis membranes can be smoothly guided out, and the phenomenon that the pure water cannot effectively flow out due to the fact that the reverse sides of the reverse osmosis membranes are directly attached is avoided.

Preferably, the length of the first pure water guide cloth is 1-10mm longer than the length of the side edge of the short sheet perpendicular to the folded edge (i.e. the first short sheet 12).

In some embodiments, a first sealing member 51 is connected between the back of the first short sheet 12 and the back of the second short sheet 22, so that the pure water outlet of the first pure water flow passage 301 faces the first folding edge 13; a second sealing element 52 is connected between the back surface of the second long sheet 21 and the back surface of the third long sheet 61, so that the pure water outlet of the second pure water flow channel 302 faces the second flange 23; a third sealing member 53 is connected between the back surface of the third short sheet 62 and the back surface of the fourth short sheet 72, so that the pure water outlet of the third pure water flow passage 303 faces the third folding edge 63; a fourth sealing member 54 is connected between the back surface of the first long sheet 11 and the back surface of the fourth long sheet 71 so that the pure water outlet of the fourth pure water flow passage 304 faces the fourth folded edge 73.

The sealing elements with different structures in the two pure water flow passages are in the structural form, and the first sealing element can effectively prevent water in the first pure water flow passage from being mixed with raw water in the raw water flow passage and the outside; the third sealing member can effectively prevent the water in the second pure water flow passage from being mixed with the raw water in the raw water flow passage and the outside; the third sealing member can effectively prevent the water in the third pure water flow passage from being mixed with the raw water in the raw water flow passage and the outside; the fourth sealing member can effectively prevent the water in the fourth pure water flow passage from being mixed with the raw water in the raw water flow passage and with the outside; the pure water after filtration is ensured not to be mixed with the raw water, and the purification effect is improved.

Example 1, in some embodiments, the end of the first folded edge 13, the second folded edge 23, the third folded edge 63 and the fourth folded edge 73 after being folded is a starting end rolled onto the outer peripheral wall of the central tube 100, the open end formed between the end of the first long sheet 11 and the end of the fourth long sheet 71 is a terminal end rolled onto the central tube 100, the starting end is connected with the outer peripheral wall of the central tube 100, and the terminal end is located at the radial outer side of the starting end; the first pure water flow passage 301, the second pure water flow passage 302, the third pure water flow passage 303, and the fourth pure water flow passage 304 are all communicated with the inside of the center pipe 100, so that pure water after filtration and purification is discharged through the inside of the center pipe 100, and concentrated water after filtration and purification flows out through an open end formed between the end of the first long sheet 11 and the end of the fourth long sheet 71.

The structure of the invention can lead the folded edge to be connected with the central pipe and rolled, the opening end is positioned at the radial outer side of the rolling, the raw water inlet enters the first, second, third and fourth raw water flow passages, the raw water can enter the first, second, third and fourth pure water flow passages after being filtered and purified by the reverse osmosis membrane and is communicated with the inside of the central pipe so as to flow into the central pipe for leading out and conveying the pure water, and the concentrated water flows to the opening end formed at the end part of the first and fourth long pages and is discharged, thereby effectively realizing normal filtering and purification and simultaneously improving the speed of the raw water flowing process (especially at the position where the flow passages are combined), further increasing the flow speed in the seventh raw water flow passage, reducing the concentration polarization in the seventh raw water flow passage and improving the antifouling and blocking capacity.

Preferably, the short side of the first pure water flow guide cloth, which is close to the pure water outlet, is connected with the central pipe, and then the adhered reverse osmosis membrane, the water inlet grid and the pure water flow guide cloth are rolled on the central pipe, so that the pure water outlet of the rolled pure water flow channel faces the central pipe;

preferably, the raw water flow channel part is sealed by applying glue to the end surface of the rolled reverse osmosis membrane and the water inlet grid, and the glue applying position is a part far away from the central pipe, so that a raw water inlet (a water inlet 401) is formed at a position close to the central pipe on the end surface.

Preferably, the length of the raw water inlet accounts for 1/3-1/10 of the length of the side edge of the first long page adjacent to the folded edge. The raw water inlet is used for enabling raw water to enter a flow channel between the front faces of the reverse osmosis membranes, the length needs to be appropriate, too small length can cause too large resistance and unsmooth water inflow, too large length can cause the direction of the flow channel to be changed, and design performance is affected.

Example 2, as shown in fig. 2, in some embodiments, the end of the first long sheet 11 that is overlapped with the end of the fourth long sheet 71 is a starting end rolled onto the outer circumferential wall of the central tube 100, and the end of the first folded edge 13, the second folded edge 23, the third folded edge 63, and the fourth folded edge 73 that is overlapped is a terminal end rolled onto the central tube 100, the starting end is adjacent to the outer circumferential wall of the central tube 100, and the terminal end is located radially outside the starting end; an opening between the end of the first long sheet 11 and the end of the fourth long sheet 71 communicates with the inside of the central tube 100 so that the filtered and purified concentrated water flows to the inside of the central tube 100 through the opening between the ends of the first long sheet 11 and the fourth long sheet 71, and the first pure water flow channel 301, the second pure water flow channel 302, the third pure water flow channel 303 and the fourth pure water flow channel 304 communicate with the outside of the spiral reverse osmosis membrane element, respectively, so that the filtered and purified pure water is discharged through the first pure water flow channel 301, the second pure water flow channel 302, the third pure water flow channel 303 and the fourth pure water flow channel 304, respectively.

The structure of the invention can lead the opening end to be connected with the central pipe and rolled, the folded edge is positioned at the radial outer side of the rolling, the raw water inlet enters the first, second, third and fourth raw water flow passages, the filtered and purified water passing through the reverse osmosis membrane can enter the first, second, third and fourth pure water flow passages and is discharged to the radial outer side for exporting and conveying the pure water, and the concentrated water flows to the opening end formed by the end parts of the first and fourth long pages and is discharged into the central pipe to flow into the central pipe, thereby effectively realizing normal filtering and purifying, improving the speed of the raw water flowing process (especially at the position where the flow passages are combined), further increasing the flow speed of the raw water in the seventh raw water flow passage, reducing the concentration polarization in the seventh raw water flow passage and improving the antifouling capacity.

Example 3, as shown in fig. 3, in some embodiments, the number of the reverse osmosis membranes is 8, and 8 reverse osmosis membranes are stacked and integrally rolled on the central pipe 100.

The utility model provides a formula of book reverse osmosis membrane element, includes a diaphragm group at least, the interior raw water runner that forms by reverse osmosis membrane openly relative that contains of diaphragm group, its characterized in that raw water runner is divided into N section and the quantity of each section raw water runner reduces along the direction that rivers go forward gradually along the direction that rivers go forward of rivers direction.

Preferably, the raw water flow channel is divided into a first section raw water flow channel, a second section raw water flow channel, a third section raw water flow channel and a fourth section raw water flow channel along the advancing direction of water flow, the number of the second section raw water flow channels is less than that of the first section raw water flow channels, the number of the third section raw water flow channels is less than that of the second section raw water flow channels, and the number of the fourth section raw water flow channels is less than that of the third section raw water flow channels;

preferably, the membrane set at least comprises a first reverse osmosis membrane, a second reverse osmosis membrane, a third reverse osmosis membrane, a fourth reverse osmosis membrane, a fifth reverse osmosis membrane, a sixth reverse osmosis membrane, a seventh reverse osmosis membrane and an eighth reverse osmosis membrane, and is characterized in that the front sides of the first reverse osmosis membrane, the second reverse osmosis membrane, the third reverse osmosis membrane, the fourth reverse osmosis membrane, the fifth reverse osmosis membrane, the sixth reverse osmosis membrane, the seventh reverse osmosis membrane and the eighth reverse osmosis membrane are folded to form a folded edge, and a long page and a short page which are distinguished by the folded edge are formed. A first section of raw water flow channel is formed among the front faces of the long page and the short page of the first reverse osmosis membrane, the second reverse osmosis membrane, the third reverse osmosis membrane, the fourth reverse osmosis membrane, the fifth reverse osmosis membrane, the sixth reverse osmosis membrane, the seventh reverse osmosis membrane and the eighth reverse osmosis membrane; a second section of raw water flow channel is formed between the long page of the first reverse osmosis membrane and the long page front face of the second reverse osmosis membrane, between the long page of the third reverse osmosis membrane and the long page front face of the fourth reverse osmosis membrane, between the long page of the fifth reverse osmosis membrane and the long page front face of the sixth reverse osmosis membrane, and between the long page of the seventh reverse osmosis membrane and the long page front face of the eighth reverse osmosis membrane; a third section of raw water flow channel is formed between the long page of the first reverse osmosis membrane and the long page of the fourth reverse osmosis membrane, between the long page of the fifth reverse osmosis membrane and the long page of the eighth reverse osmosis membrane, and a fourth section of raw water flow channel is formed between the long page of the first reverse osmosis membrane and the long page of the eighth reverse osmosis membrane.

The reverse osmosis membrane element further comprises a first water inlet grid, a second water inlet grid, a third water inlet grid, a fourth water inlet grid, a fifth water inlet grid, a sixth water inlet grid, a seventh water inlet grid, an eighth water inlet grid, first pure water guide cloth, second pure water guide cloth, third pure water guide cloth, fourth pure water guide cloth, fifth pure water guide cloth, sixth pure water guide cloth and seventh pure water guide cloth. The first water inlet grid is inserted in a first section raw water flow channel, a second section raw water flow channel, a third section raw water flow channel and a fourth section raw water flow channel of the first reverse osmosis membrane; the second water inlet grid is inserted in the first section of raw water flow channel of the second reverse osmosis membrane; the third water inlet grid is inserted in the first section of raw water flow channel and the second section of raw water flow channel of the third reverse osmosis membrane; the fourth water inlet grid is inserted in the first section of raw water flow channel of the fourth reverse osmosis membrane; the fifth water inlet grid is inserted in the first section raw water flow channel, the second section raw water flow channel and the third section raw water flow channel of the fifth reverse osmosis membrane; the sixth water inlet grid is inserted in the first section of raw water flow channel of the sixth reverse osmosis membrane; the seventh water inlet grid is inserted in the first section of raw water flow channel and the second section of raw water flow channel of the seventh reverse osmosis membrane; the eighth water inlet grid is inserted in the first section of the raw water flow channel of the eighth reverse osmosis membrane. The first pure water diversion cloth is laminated between the reverse sides of the first reverse osmosis membrane short leaf and the second reverse osmosis membrane short leaf; the second pure water diversion cloth is laminated between the reverse sides of the second long reverse osmosis membrane sheet and the third long reverse osmosis membrane sheet; the third pure water diversion cloth is laminated between the reverse sides of the third reverse osmosis membrane short sheet and the fourth reverse osmosis membrane short sheet; the fourth pure water diversion cloth is laminated between the reverse sides of the fourth long reverse osmosis membrane sheet and the fifth long reverse osmosis membrane sheet; the fifth pure water flow guide cloth is laminated between the reverse sides of the fifth reverse osmosis membrane short sheet and the sixth reverse osmosis membrane short sheet, and the sixth pure water flow guide cloth is laminated between the reverse sides of the sixth reverse osmosis membrane long sheet and the seventh reverse osmosis membrane long sheet; and the seventh pure water guide cloth is laminated between the reverse sides of the seventh reverse osmosis membrane short sheet and the eighth reverse osmosis membrane short sheet.

The invention provides a water purifier containing the reverse osmosis membrane element.

According to the invention, the size of the raw water flow channel is narrowed by reducing the number of the flow channels along the advancing direction of the water flow, and the flow velocity of the side membrane surface is increased section by section, so that the membrane surface concentration polarization and pollution caused by the deterioration of the raw water concentration of the membrane surface are relieved, the pollution resistance of the reverse osmosis membrane is improved, and the service life of the reverse osmosis membrane filter element is prolonged.

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 roll-type reverse osmosis membrane element is characterized in that: the device comprises N filtering sections consisting of M reverse osmosis membranes, wherein N is more than or equal to 2 and less than or equal to M, the number of raw water channels of an Nth filtering section is less than that of raw water channels of an N-1 th filtering section, a water inlet (401) of the rolled reverse osmosis membrane element is arranged at the first filtering section, and a concentrated water outlet (402) of the rolled reverse osmosis membrane element is arranged at the Nth filtering section; and the M reverse osmosis membranes are independent membranes.

2. The rolled reverse osmosis membrane element of claim 1, wherein:

further comprising: a central tube (100), M reverse osmosis membranes including a first reverse osmosis membrane (1), a second reverse osmosis membrane (2), a third reverse osmosis membrane (6) and a fourth reverse osmosis membrane (7), the first reverse osmosis membrane (1) being bent to form a first long sheet (11), a first folded edge (13) and a first short sheet (12) which are connected in sequence, the first long sheet (11) being longer than the first short sheet (12), the second reverse osmosis membrane (2) being bent to form a second long sheet (21), a second folded edge (23) and a second short sheet (22) which are connected in sequence, the second long sheet (21) being longer than the second short sheet (22), the third reverse osmosis membrane (6) being bent to form a third long sheet (61), a third folded edge (63) and a third short sheet (62) which are connected in sequence, the third long sheet (61) being longer than the third short sheet (62), the fourth reverse osmosis membrane (7) being bent to form a fourth long sheet (71), the fourth short sheet (71) and the fourth short sheet (71) being arranged opposite to the fourth short sheet (71), the fourth short sheet (71) and the fourth short sheet (71) being longer than the fourth short sheet (71), the second long sheet (21) and the third long sheet (61) are oppositely arranged, so that the first long sheet (11), the first short sheet (12), the second short sheet (22), the second long sheet (21), the third long sheet (61), the third short sheet (62), the fourth short sheet (72) and the fourth long sheet (71) are sequentially arranged, and the first reverse osmosis membrane (1), the second reverse osmosis membrane (2), the third reverse osmosis membrane (6) and the fourth reverse osmosis membrane (7) are stacked into a whole and then rolled onto the central pipe (100);

the partial section of the first long sheet (11) is opposite to the first short sheet (12) and forms a first raw water flow passage (201) therebetween, the partial section of the second long sheet (21) is opposite to the second short sheet (22) and forms a second raw water flow passage (202) therebetween, the partial section of the first long sheet (11) from which the first short sheet (12) is grown is opposite to the partial section of the second long sheet (21) from which the second short sheet (22) is grown and forms a third raw water flow passage (203) therebetween, the first raw water flow passage (201) and the second raw water flow passage (202) are communicated with a raw water interface so as to be capable of passing raw water, and the water in the first raw water flow passage (201) and the water in the second raw water flow passage (202) respectively flow toward the third raw water flow passage (203), and the sum of the flow cross-sectional areas of the first raw water flow passage (201) and the second raw water flow passage (202) is larger than the flow-through cross-sectional area of the third raw water flow passage (203).

3. The rolled reverse osmosis membrane element of claim 2, wherein:

a partial section of the third long sheet (61) is opposite to the third short sheet (62) and forms a fourth raw water flow channel (204) therebetween, a partial section of the fourth long sheet (71) is opposite to the fourth short sheet (72) and forms a fifth raw water flow channel (205) therebetween, a partial section of the third long sheet (61) from which the third short sheet (62) is grown is opposite to a partial section of the fourth long sheet (71) from which the fourth short sheet (72) is grown and forms a sixth raw water flow channel (206) therebetween, the fourth raw water flow channel (204) and the fifth raw water flow channel (205) are connected to an interface so as to allow raw water to flow therein, and water in the fourth raw water flow channel (204) and water in the fifth raw water flow channel (205) respectively flow into the sixth raw water flow channel (206), and a sum of cross-sectional areas of the fourth raw water flow channel (204) and the fifth raw water flow channel (205) is larger than a cross-sectional area of the sixth raw water flow channel (206);

the section of the first long sheet (11) from which the second long sheet (21) is extended is opposite to the section of the fourth long sheet (71) from which the third long sheet (61) is extended, and a seventh raw water channel (207) is formed between the first long sheet and the fourth long sheet, water in the third raw water channel (203) and water in the sixth raw water channel (206) respectively flow into the seventh raw water channel (207), and the sum of the flow cross-sectional areas of the third raw water channel (203) and the sixth raw water channel (206) is larger than the flow cross-sectional area of the seventh raw water channel (207);

the first raw water channel (201), the second raw water channel (202), the fourth raw water channel (204) and the fifth raw water channel (205) are both first filter sections, the third raw water channel (203) and the sixth raw water channel (206) are both second filter sections, and the seventh raw water channel (207) is a third filter section.

4. The rolled reverse osmosis membrane element of claim 3, wherein:

in a projection plane in the axial end face of the central tube (100), the first short page (12) and the second short page (22) are equal in length and are L2, and the length L1 of the first long page (11) is greater than the length L3 of the second long page (21), namely L1 is greater than L3 and greater than L2; the third short page (62) and the fourth short page (72) are equal in length and are both L2, the third long page (61) is equal in length and are both L3, and the fourth long page (71) is equal in length and are both L1;

the first folding edge (13), the second folding edge (23), the third folding edge (63) and the fourth folding edge (73) are located on the same side and are arranged at intervals in sequence.

5. The rolled reverse osmosis membrane element of claim 4, wherein:

the first raw water flow channel (201), the second raw water flow channel (202), the fourth raw water flow channel (204) and the fifth raw water flow channel (205) are respectively provided with a water inlet (401) on the axial end face along the axial direction of the central tube (100), the length of the water inlet (401) in the projection plane in the axial end face of the central tube (100) is L0, and L0 is less than L2.

6. The rolled reverse osmosis membrane element of claim 5, wherein:

1/3≤L3/L1≤3/4；1/3≤L2/L3≤3/4；1/10≤L0/L2≤1/2。

7. the rolled reverse osmosis membrane element according to any one of claims 3-6, wherein:

the water purifier is characterized in that a first water inlet separation net (31) is arranged in the first raw water flow channel (201), a second water inlet separation net (32) is further arranged in the second raw water flow channel (202), a third water inlet separation net (33) is arranged in the fourth raw water flow channel (204), a fourth water inlet separation net (34) is arranged in the fifth raw water flow channel (205), at least one of the first water inlet grid net (31), the second water inlet separation net (32), the third water inlet separation net (33) and the fourth water inlet separation net (34) extends into the seventh raw water flow channel (207), and at least one of the rest water inlet grid nets extends into the third raw water flow channel (203) and at least one of the rest water inlet grid extends into the sixth raw water flow channel (206).

8. The rolled reverse osmosis membrane element of claim 7, wherein:

a first water inlet separation net (31) is further arranged in the first raw water runner (201), the third raw water runner (203) and the seventh raw water runner (207), one end of the first water inlet separation net (31) is connected with the first folded edge (13), and the other end of the first water inlet separation net extends to a position opposite to the end part of the first long leaf (11), so that the first water inlet separation net (31) extends from the first raw water runner (201) into the third raw water runner (203) and further extends into the seventh raw water runner (207); a second water inlet separation net (32) is further arranged in the second raw water flow channel (202), one end of the second water inlet separation net (32) is connected with the second flange (23), and the other end of the second water inlet separation net extends to a position opposite to the end part of the second short leaf (22), so that the second water inlet separation net (32) extends in the second raw water flow channel (202);

a third water inlet separation net (33) is further arranged in the fourth raw water flow channel (204) and the sixth raw water flow channel (206), one end of the third water inlet separation net (33) is connected with the third folding edge (63), and the other end of the third water inlet separation net extends to a position opposite to the end part of the third long sheet (61), so that the third water inlet separation net (33) extends from the fourth raw water flow channel (204) to the sixth raw water flow channel (206); a fourth water inlet separation net (34) is further arranged in the fifth raw water flow channel (205), one end of the fourth water inlet separation net (34) is connected with the fourth folded edge (73), and the other end of the fourth water inlet separation net extends to a position opposite to the end part of the fourth short leaf (72), so that the fourth water inlet separation net (34) extends in the fifth raw water flow channel (205).

9. The rolled reverse osmosis membrane element of claim 8, wherein:

in a projection plane in the axial end face of the central tube (100), the length of the first water inlet screen (31) is greater than that of the first long leaf (11), the length of the second water inlet screen (32) is greater than that of the second short leaf (22), the length of the third water inlet screen (33) is greater than that of the third long leaf (61), and the length of the fourth water inlet screen (34) is greater than that of the fourth short leaf (72).

10. The rolled reverse osmosis membrane element of any one of claims 3-9, wherein:

the surface of the first long sheet (11) opposite to the first short sheet (12) is the front surface of the first long sheet (11), the surface of the first short sheet (12) opposite to the first long sheet (11) is the front surface of the first short sheet (12), and the first raw water flow channel (201) is formed between the front surface of the first long sheet (11) and the front surface of the first short sheet (12);

the surface of the second long sheet (21) opposite to the second short sheet (22) is the front surface of the second long sheet (21), the surface of the second short sheet (22) opposite to the second long sheet (21) is the front surface of the second short sheet (22), and the second raw water flow passage (202) is formed between the front surface of the second long sheet (21) and the front surface of the second short sheet (22);

the front surface of the partial section of the first long page (11) which is longer than the first short page (12) is opposite to the front surface of the partial section of the second long page (21) which is longer than the second short page (22), and a third raw water flow channel (203) is formed between the front surfaces;

the surface of the third long sheet (61) opposite to the third short sheet (62) is the front surface of the third long sheet (61), the surface of the third short sheet (62) opposite to the third long sheet (61) is the front surface of the third short sheet (62), and the fourth raw water channel (204) is formed between the front surface of the third long sheet (61) and the front surface of the third short sheet (62);

the surface of the fourth long sheet (71) opposite to the fourth short sheet (72) is the front surface of the fourth long sheet (71), the surface of the fourth short sheet (72) opposite to the fourth long sheet (71) is the front surface of the fourth short sheet (72), and the fifth raw water flow channel (205) is formed between the front surface of the fourth long sheet (71) and the front surface of the fourth short sheet (72);

the front surface of the subsection of the third long sheet (61) from which the third short sheet (62) is grown is opposite to the front surface of the subsection of the fourth long sheet (71) from which the fourth short sheet (72) is grown, and the sixth raw water flow channel (206) is formed between the front surfaces;

the front surface of the partial section of the first long sheet (11) from which the second long sheet (21) is grown is opposite to the front surface of the partial section of the fourth long sheet (71) from which the third long sheet (61) is grown, and the seventh raw water flow passage (207) is formed therebetween.

11. The rolled reverse osmosis membrane element of claim 10, wherein:

a first pure water flow channel (301) is formed between the back of the first short sheet (12) and the back of the second short sheet (22), the back of the first short sheet (12) is the side opposite to the first long sheet (11), pure water formed by filtering and purifying raw water in the first raw water flow channel (201) through the first short sheet (12) can enter the first pure water flow channel (301), and pure water formed by filtering and purifying raw water in the second raw water flow channel (202) through the second short sheet (22) can also enter the first pure water flow channel (301);

a second pure water flow channel (302) is formed between the back surface of the second long page (21) and the back surface of the third long page (61), the raw water in the second raw water flow channel (202) forms pure water after being filtered and purified by the second long page (21) and can enter the second pure water flow channel (302), and the raw water in the fourth raw water flow channel (204) forms pure water after being filtered and purified by the third long page (61) and can also enter the second pure water flow channel (302);

a third pure water flow channel (303) is formed between the back surface of the third short sheet (62) and the back surface of the fourth short sheet (72), pure water is formed after raw water in the fourth raw water flow channel (204) is filtered and purified by the third short sheet (62) and can enter the third pure water flow channel (303), and pure water formed after raw water in the fifth raw water flow channel (205) is filtered and purified by the fourth short sheet (72) can also enter the third pure water flow channel (303);

the first reverse osmosis membrane (1), the second reverse osmosis membrane (2), the third reverse osmosis membrane (6) and the fourth reverse osmosis membrane (7) are stacked into a whole and rolled on the central tube (100), a fourth pure water flow channel (304) is formed between the back of the first long leaf (11) and the back of the fourth long leaf (71), pure water is formed in the first raw water flow channel (201), the raw water in the third raw water flow channel (203) and the raw water in the seventh raw water flow channel (207) after being filtered and purified by the first long leaf (11) respectively and can enter the fourth pure water flow channel (304), and pure water is formed in the fifth raw water flow channel (205), the raw water in the sixth raw water flow channel (206) and the raw water in the seventh raw water flow channel (207) after being filtered and purified by the fourth long leaf (71) respectively and can enter the fourth pure water flow channel (304).

12. The rolled reverse osmosis membrane element of claim 11, wherein:

a first pure water guide cloth (41) is further arranged in the first pure water flow passage (301), and a second pure water guide cloth (42) is further arranged in the second pure water flow passage (302); a third pure water guide cloth (43) is further arranged in the third pure water flow passage (303), and a fourth pure water guide cloth (44) is further arranged in the fourth pure water flow passage (304);

in a projection plane in an axial end face of the central pipe (100), the length of the first pure water diversion cloth (41) is larger than that of the first short page (12), and the length of the first short page (12) is equal to that of the second short page (22); the length of the second pure water guide cloth (42) is greater than that of the second long sheet (21), the length of the third pure water guide cloth (43) is greater than that of the third short sheet (62), the length of the fourth pure water guide cloth (44) is greater than that of the first long sheet (11), and the length of the first long sheet (11) is equal to that of the fourth long sheet (71).

13. The rolled reverse osmosis membrane element of claim 11, wherein:

a first sealing element (51) is connected and arranged between the back surface of the first short sheet (12) and the back surface of the second short sheet (22) so that a pure water outlet of the first pure water flow channel (301) faces the first folding edge (13); a second sealing element (52) is connected and arranged between the back surface of the second long page (21) and the back surface of the third long page (61) so that the pure water outlet of the second pure water flow passage (302) faces the second flange (23); a third sealing element (53) is connected and arranged between the back surface of the third short sheet (62) and the back surface of the fourth short sheet (72) so that a pure water outlet of the third pure water flow channel (303) faces a third folded edge (63); and a fourth sealing element (54) is connected between the back surface of the first long sheet (11) and the back surface of the fourth long sheet (71) so that the pure water outlet of the fourth pure water flow passage (304) faces a fourth folded edge (73).

14. The rolled reverse osmosis membrane element of claim 11, wherein:

the end part of the first folded edge (13), the second folded edge (23), the third folded edge (63) and the fourth folded edge (73) after being folded is a starting end rolled on the outer peripheral wall of the central tube (100), the opening end formed between the end part of the first long leaf (11) and the end part of the fourth long leaf (71) is a tail end rolled on the central tube (100), the starting end is connected with the outer peripheral wall of the central tube (100), and the tail end is positioned on the radial outer side of the starting end; the first pure water flow passage (301), the second pure water flow passage (302), the third pure water flow passage (303) and the fourth pure water flow passage (304) are all communicated with the inside of the central tube (100), so that pure water after filtration and purification is discharged through the inside of the central tube (100), and concentrated water after filtration and purification flows out through an opening end formed between the end part of the first long leaf (11) and the end part of the fourth long leaf (71).

15. The rolled reverse osmosis membrane element of claim 11, wherein:

an opening end formed between the end of the first long sheet (11) and the end of the fourth long sheet (71) is a starting end rolled onto the outer peripheral wall of the central tube (100) after being folded, the end of the first folded edge (13), the second folded edge (23), the third folded edge (63) and the fourth folded edge (73) after being folded is a tail end rolled onto the central tube (100), the starting end is connected with the outer peripheral wall of the central tube (100), and the tail end is positioned on the radial outer side of the starting end; an opening between the end of the first long leaf (11) and the end of the fourth long leaf (71) is communicated with the inside of the central tube (100), so that the filtered and purified concentrated water flows to the inside of the central tube (100) through an opening end between the end of the first long leaf (11) and the end of the fourth long leaf (71), and the first pure water flow passage (301), the second pure water flow passage (302), the third pure water flow passage (303) and the fourth pure water flow passage (304) are respectively communicated to the outside of the roll type reverse osmosis membrane element, so that the filtered and purified pure water is discharged through the first pure water flow passage (301), the second pure water flow passage (302), the third pure water flow passage (303) and the fourth pure water flow passage (304), respectively.

16. A water purifier, which is characterized in that: comprising a rolled reverse osmosis membrane element according to any one of claims 1-15.