Reverse osmosis membrane element and water purifier

Abstract

The present invention provides a reverse osmosis membrane element and a water purifier. The reverse osmosis membrane element includes: a central tube, a first reverse osmosis membrane, a second reverse osmosis membrane, and a third reverse osmosis membrane. A first pure water flow channel is formed between the first reverse osmosis membrane and the second reverse osmosis membrane, a second pure water flow channel is formed between the second reverse osmosis membrane and the third reverse osmosis membrane, and a third pure water flow channel is formed between the first reverse osmosis membrane and the third reverse osmosis membrane. The third pure water flow channel is located downstream of both the first pure water flow channel and the second pure water flow channel. The flow cross-sectional area of ​​the third pure water flow channel is smaller than the sum of the flow cross-sectional area of ​​the first pure water flow channel and the flow cross-sectional area of ​​the second pure water flow channel. According to the present invention, the water flux of the membrane can be increased, thereby effectively reducing the phenomenon of shortening the life of the membrane element due to accumulation of impurities in the membrane element due to concentration polarization, improving the filtration effect of the membrane element, and extending its service life.

Description

Technical Field

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

[0002] A reverse osmosis membrane element consists of an inlet screen, reverse osmosis membrane, and pure water guide fabric wrapped around a central tube, all sealed and connected. Raw water enters through one end of the reverse osmosis membrane element. Under pressure, a portion of the raw water passes through the membrane surface, removing impurities such as inorganic ions, bacteria, viruses, organic matter, and colloids, resulting in high-quality pure water.

[0003] During the water production process of the reverse osmosis membrane element, raw water spreads across the membrane surface along the water inlet mesh, and under pressure, passes through the membrane to generate pure water, which is collected along the pure water guide cloth to the central tube and then flows out through one or both ends of the central tube; the concentrated water that fails to pass through the membrane continues to flow out from the other end of the membrane element along the water inlet mesh.

[0004] One of the core performance indicators of reverse osmosis membrane elements is service life. Traditional reverse osmosis membrane elements have the disadvantages of low water flux and short service life.

[0005] The main factor affecting the lifespan of reverse osmosis membrane elements is the phenomenon of concentration polarization that occurs during their operation. Specifically, three types of movement occur during reverse osmosis membrane operation: First, raw water, driven by pressure, flows through the reverse osmosis membrane from the raw water side to the lower-concentration pure water side; second, solutes (impurities such as particulate matter) are carried by the raw water toward the membrane surface and then retained by the reverse osmosis membrane; and third, the concentration of the retained solute at the reverse osmosis membrane surface gradually increases above that in the bulk of the raw water solution. Under the influence of the concentration gradient, the solutes (impurities) diffuse from the membrane surface into the raw water. When the solute flow rate toward the membrane surface (the second factor) and the solute diffusion rate into the bulk raw water solution due to the concentration gradient (the third factor) reach equilibrium, a stable boundary layer corresponding to the concentration gradient forms on the membrane surface, forming a concentration-polarized boundary layer.

[0006] Concentration polarization can cause the following hazards to the stable operation of the water purification system:

[0007] 1) When the solute concentration on the membrane surface reaches its saturation, a deposition or gel layer will form on the membrane surface, increasing the permeation resistance and thus increasing the operating pressure of the system;

[0008] 2) Severe concentration polarization leads to crystallization, blocking the flow channel and causing deterioration of system operation.

[0009] Since the reverse osmosis membrane elements in the prior art have technical problems such as shortened membrane element life due to concentration polarization during operation, the present invention studies and designs a reverse osmosis membrane element and a water purifier. Summary of the Invention

[0010] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the reverse osmosis membrane element in the prior art that the life of the membrane element is shortened due to the concentration polarization phenomenon during operation, thereby providing a reverse osmosis membrane element and a water purifier.

[0011] In order to solve the above problems, the present invention provides a reverse osmosis membrane element, comprising:

[0012] A central tube, a first reverse osmosis membrane, a second reverse osmosis membrane and a third reverse osmosis membrane, the first reverse osmosis membrane, the second reverse osmosis membrane and the third reverse osmosis membrane are stacked in sequence as one, and rolled onto the central tube, a first pure water flow channel is formed between the first reverse osmosis membrane and the second reverse osmosis membrane, a second pure water flow channel is formed between the second reverse osmosis membrane and the third reverse osmosis membrane, a third pure water flow channel is formed between the first reverse osmosis membrane and the third reverse osmosis membrane, and the third pure water flow channel is located downstream of the first pure water flow channel and the second pure water flow channel at the same time, so that the water flowing from the first pure water flow channel to the third pure water flow channel is mixed with the water flowing from the second pure water flow channel to the third pure water flow channel, and the flow cross-sectional area of ​​the third pure water flow channel is smaller than the sum of the flow cross-sectional area of ​​the first pure water flow channel and the flow cross-sectional area of ​​the second pure water flow channel.

[0013] In some embodiments,

[0014] The flow cross-sectional area of ​​the third pure water flow channel is smaller than or equal to the flow cross-sectional area of ​​the first pure water flow channel, and the flow cross-sectional area of ​​the third pure water flow channel is smaller than or equal to the flow cross-sectional area of ​​the second pure water flow channel.

[0015] In some embodiments,

[0016] The first reverse osmosis membrane, the second reverse osmosis membrane and the third reverse osmosis membrane are each folded in half, the two opposite surfaces of the first reverse osmosis membrane are the front surfaces, and a first raw water flow channel is formed between the two opposite front surfaces of the first reverse osmosis membrane, the first pure water flow channel is formed between the back surface of the first reverse osmosis membrane opposite to the second reverse osmosis membrane and the back surface of the second reverse osmosis membrane opposite to the first reverse osmosis membrane, the second raw water flow channel is formed between the two opposite front surfaces of the second reverse osmosis membrane, the second pure water flow channel is formed between the back surface of the second reverse osmosis membrane opposite to the third reverse osmosis membrane and the back surface of the third reverse osmosis membrane opposite to the second reverse osmosis membrane, and the third pure water flow channel is formed between the back surface of the first reverse osmosis membrane opposite to the third reverse osmosis membrane and the back surface of the third reverse osmosis membrane opposite to the first reverse osmosis membrane.

[0017] In some embodiments,

[0018] The length of the second reverse osmosis membrane along the raw water flow direction after being folded in half is shorter than the length of the first reverse osmosis membrane along the raw water flow direction after being folded in half. The length of the second reverse osmosis membrane along the raw water flow direction after being folded in half is shorter than the length of the third reverse osmosis membrane along the raw water flow direction after being folded in half.

[0019] In some embodiments,

[0020] The length of the first reverse osmosis membrane sheet along the raw water flow direction after being folded in half is equal to the length of the third reverse osmosis membrane sheet along the raw water flow direction after being folded in half.

[0021] In some embodiments,

[0022] The first reverse osmosis membrane sheet is folded in half to form a first folded edge, the second reverse osmosis membrane sheet is folded in half to form a second folded edge, and the third reverse osmosis membrane sheet is folded in half to form a third folded edge. The first folded edge is adhered to the central tube and rolled, the third folded edge is opposite to the first folded edge, the second folded edge is not opposite to the first folded edge, and the second folded edge is spaced apart from the first folded edge by a preset distance L, that is, the second folded edge is arranged to move the preset distance L from the first folded edge toward the open end of the first reverse osmosis membrane sheet.

[0023] In some embodiments,

[0024] The first pure water flow channel, the second pure water flow channel and the third pure water flow channel form a pure water unit, the reverse osmosis membrane element includes N pure water units, where N≥1, and two adjacent pure water units share a reverse osmosis membrane and a raw water flow channel sharing the reverse osmosis membrane.

[0025] In some embodiments,

[0026] It includes a first-stage filter element and a second-stage filter element, the first-stage filter element includes a central tube, a first reverse osmosis membrane, a second reverse osmosis membrane and a third reverse osmosis membrane, the second-stage filter element also includes a central tube, a first reverse osmosis membrane, a second reverse osmosis membrane and a third reverse osmosis membrane, and the raw water flow channel of the first-stage filter element is connected to the raw water flow channel of the second-stage filter element, the raw water flow channel of the second-stage filter element is located downstream of the raw water flow channel of the first-stage filter element, so that the water in the raw water flow channel of the first-stage filter element can flow into the raw water flow channel of the second-stage filter element; and an inter-stage turbulence generator is provided between the raw water flow channel of the first-stage filter element and the raw water flow channel of the second-stage filter element, so that the water in the raw water flow channel of the first-stage filter element generates turbulence when flowing through the inter-stage turbulence generator, and then flows into the raw water flow channel of the second-stage filter element.

[0027] In some embodiments,

[0028] The central tube of the first filter element is the first filter element central tube, the central tube of the second filter element is the second filter element central tube, the reverse osmosis membrane of the first filter element is the first filter element roll membrane, and the reverse osmosis membrane of the second filter element is the second filter element roll membrane;

[0029] The inter-segment turbulence generator includes a two-way adapter and a two-way support. The two-way adapter is clamped between the first-section filter element center tube and the second-section filter element center tube to connect the first-section filter element center tube and the second-section filter element center tube; the two-way support is clamped on the outer periphery of the first-section filter element membrane and the second-section filter element membrane to connect the first-section filter element membrane and the second-section filter element membrane, so that a spacing space is formed between the first-section filter element membrane and the second-section filter element membrane along the axial direction.

[0030] In some embodiments,

[0031] The two-way adapter includes a cylinder, at least part of the structure of the cylinder is inserted into the inner circumference of the first-section filter element center tube, and at least part of the structure of the cylinder is inserted into the inner circumference of the second-section filter element center tube. The outer circumference of the cylinder is also provided with a first protrusion protruding radially outward, and the first protrusion is clamped between the first-section filter element center tube and the second-section filter element center tube. The two-way support is an annular cylinder structure, and its inner circumference is also provided with a second protrusion protruding radially inward, and the second protrusion is clamped between the first-section filter element roll membrane and the second-section filter element roll membrane to form the separation space.

[0032] In some embodiments,

[0033] The inter-segment turbulence generator also includes a first seal and a second seal. The first seal is arranged between the outer periphery of the cylinder of the two-way adapter and the inner periphery of the first-segment filter element center tube. The first seal is also arranged between the outer periphery of the cylinder of the two-way adapter and the inner periphery of the second-segment filter element center tube. The cylinder has a hollow connecting channel to connect the pure water inside the first-segment filter element center tube and the pure water inside the second-segment filter element center tube; the second seal is respectively arranged on the outer periphery of the two-way support and the outer periphery of the first-segment filter element roll membrane. The second seal is also respectively arranged on the outer periphery of the two-way support and the outer periphery of the second-segment filter element roll membrane.

[0034] In some embodiments,

[0035] Activated carbon particles are also arranged in the spacing space, and the activated carbon particles can be impacted by water flow and generate movement; the first sealing member is a sealing ring, and the second sealing member is a sealing tape; the first protrusion is a cylindrical ring structure, and the second protrusion is a plurality of structures arranged at intervals in the circumferential direction; the outer periphery of the bidirectional support member is also radially protruding outward and spaced apart with a plurality of third protrusions.

[0036] The present invention also provides a water purifier, which includes the aforementioned reverse osmosis membrane element.

[0037] The reverse osmosis membrane element and water purifier provided by the present invention have the following beneficial effects:

[0038] 1. The present invention optimizes the flow channel design in the filter element membrane rolling process through the unique setting relationship between the first, second and third reverse osmosis membranes, and effectively reduces the number of flow channels by merging several pure water flow channels of equal length. Since multiple reverse osmosis membranes are stacked, the flow cross-sectional area of ​​the third pure water flow channel located downstream in the direction of the pure water flow channel is effectively made smaller than the flow cross-sectional area of ​​the first and second pure water flow channels, thereby effectively increasing the membrane surface flow rate of pure water and achieving a doubling of the membrane surface flow rate at the pure water end (the merged rear flow channel can increase the membrane surface pure water flow rate by 100%), so that pure water can quickly flow through the central tube to the water outlet, which is beneficial to increase the pressure difference between raw water and pure water, making it easier for raw water to pass through the reverse osmosis membrane, and increasing the water flux of the membrane, thereby effectively reducing the phenomenon of shortening the life of the membrane element due to accumulation of impurities in the membrane element due to concentration polarization, improving the filtration effect of the membrane element, and extending its service life.

[0039] 2. The present invention also configures the reverse osmosis membrane element into a filter element structure of at least two sections, and arranges an inter-section turbulence generator between the raw water flow channels of the two sections of the filter element, thereby effectively affecting the water flow field distribution from the first section of the filter element into the second section of the filter element, disrupting / breaking the concentration polarization layer, thereby achieving the effect of increasing the solute diffusion coefficient, slowing down the scale formation rate and the membrane flow attenuation rate, thereby enhancing the filtration effect of the filter element and improving the service life of the membrane element. Under the same conditions, the service life of the membrane element can be increased by more than 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow channel structure diagram of the filter element membrane rolling process in the prior art;

[0041] Figure 2 is a flow channel structure diagram of the reverse osmosis membrane element of the present invention;

[0042] Figure 3 This is a waterway structure diagram of the reverse osmosis membrane element of the present invention;

[0043] Figure 4 Schematic diagram comparing the laminar flow and turbulent flow in resolving concentration polarization in the reverse osmosis membrane element of the present invention;

[0044] Figure 5 is a cross-sectional view of the structure of the reverse osmosis membrane element of the present invention;

[0045] Figure 6 This is a cross-sectional view of the structure of the first filter element in the reverse osmosis membrane element of the present invention;

[0046] Figure 7 It is a structural cross-sectional view of the second filter element in the reverse osmosis membrane element of the present invention;

[0047] Figure 8a is a partial cross-sectional view of an inter-segment turbulence generator in a reverse osmosis membrane element of the present invention;

[0048] Figure 8b is a three-dimensional structural diagram of the inter-segment turbulence generator in the reverse osmosis membrane element of the present invention;

[0049] Figure 8c yes Figure 8b A side view from left to right of an inter-segment turbulence generator in a reverse osmosis membrane element.

[0050] The accompanying drawings are:

[0051] 100. Central tube; 1. First reverse osmosis membrane; 2. Second reverse osmosis membrane; 3. Third reverse osmosis membrane; 101. First pure water flow channel; 102. Second pure water flow channel; 103. Third pure water flow channel; 201. First raw water flow channel; 202. Second raw water flow channel; 203. Third raw water flow channel; 11. First folded edge; 21. Second folded edge; 31. Third folded edge; 4. First section filter element; 41. Central tube of first section filter element; 42. First section filter element roll; 5. Second section filter element; 51. Central tube of second section filter element; 52. Second section filter element roll; 6. Inter-section turbulence generator; 61. Bidirectional adapter; 62. Bidirectional support; 63. Cylinder; 64. First protrusion; 65. Second protrusion; 66. First sealing member; 67. Second sealing member; 68. Third protrusion; 7. Spacing space. DETAILED DESCRIPTION

[0052] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0054] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0055] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0056] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0057] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0058] like Figure 1-8c As shown, the present invention provides a reverse osmosis membrane element, which includes:

[0059] A central tube 100, a first reverse osmosis membrane 1, a second reverse osmosis membrane 2 and a third reverse osmosis membrane 3, wherein the first reverse osmosis membrane 1, the second reverse osmosis membrane 2 and the third reverse osmosis membrane 3 are stacked in sequence and rolled onto the central tube 100, a first pure water flow channel 101 is formed between the first reverse osmosis membrane 1 and the second reverse osmosis membrane 2, a second pure water flow channel 102 is formed between the second reverse osmosis membrane 2 and the third reverse osmosis membrane 3, and the first reverse osmosis membrane 1 and the third reverse osmosis membrane are connected to each other. 3, and the third pure water flow channel 103 is formed between the first pure water flow channel 101 and the second pure water flow channel 102, so that the water flowing from the first pure water flow channel 101 to the third pure water flow channel 103 is mixed with the water flowing from the second pure water flow channel 102 to the third pure water flow channel 103, and the flow cross-sectional area of ​​the third pure water flow channel 103 is smaller than the sum of the flow cross-sectional area of ​​the first pure water flow channel 101 and the flow cross-sectional area of ​​the second pure water flow channel 102.

[0060] The present invention optimizes the flow channel design in the filter element membrane rolling process through the unique setting relationship between the first, second and third reverse osmosis membranes, and effectively reduces the number of flow channels by merging several pure water flow channels of equal length. Since multiple reverse osmosis membranes are stacked, the flow cross-sectional area of ​​the third pure water flow channel located downstream in the direction of the pure water flow channel is effectively made smaller than the flow cross-sectional area of ​​the first and second pure water flow channels, thereby effectively increasing the membrane surface flow rate of pure water and achieving a doubling of the membrane surface flow rate at the pure water end (the merged rear flow channel can increase the membrane surface pure water flow rate by 100%), so that pure water can quickly flow through the central tube to the water outlet, which is beneficial to increase the pressure difference between raw water and pure water, making it easier for raw water to pass through the reverse osmosis membrane, and increasing the water flux of the membrane, thereby effectively reducing the phenomenon of shortening the life of the membrane element due to accumulation of impurities in the membrane element due to concentration polarization, improving the filtration effect of the membrane element, and extending its service life.

[0061] In some embodiments,

[0062] The flow cross-sectional area of ​​the third pure water flow channel 103 is less than or equal to the flow cross-sectional area of ​​the first pure water flow channel 101, and the flow cross-sectional area of ​​the third pure water flow channel 103 is less than or equal to the flow cross-sectional area of ​​the second pure water flow channel 102. This is the relationship between the third pure water flow channel and the first and second pure water flow channels of the present invention. By making the flow cross-sectional area of ​​the third pure water flow channel smaller than the flow cross-sectional areas of the first and second pure water flow channels, the speed of pure water flowing into the third pure water flow channel can be further increased, further improving the water flux of the membrane, increasing the pure water production, further improving the filtration effect of the membrane element, and further improving the service life.

[0063] This invention addresses the problem of concentration polarization during membrane operation, which shortens membrane element lifespan. By proposing a novel reverse osmosis membrane element structure, the membrane element has one inlet (raw water) and two outlets (pure water and concentrated water). This invention optimizes both outlets to extend filter element lifespan.

[0064] 1. For the pure water outlet, the present invention optimizes the flow channel design through the filter element membrane rolling process, that is, through the optimization design of the long and short membrane flow channels, the common several equal-length flow channels are reduced by merging the flow channels, that is, several equal-length flow channels are changed into several front flow channels + (several / 2) rear flow channels, thereby increasing the pure water membrane surface flow rate, allowing pure water to flow quickly through the central tube to the water outlet, which is beneficial to increasing the pressure difference between raw water and pure water, making it easier for raw water to pass through the reverse osmosis membrane, and increasing the water flux of the membrane. The merged rear flow channels can increase the membrane surface flow rate by 100%.

[0065] 2. For the concentrated water outlet, the present invention designs the filter element into a two-stage one-stage filter element, including a first-stage filter element and a second-stage filter element. An inter-stage turbulence generator is added between the two sections. The inter-stage turbulence generator between the two sections of the filter element is used to generate turbulence, which affects the water flow field distribution from the first-stage filter element into the second-stage filter element, disrupts / breaks the concentration polarization layer, and achieves the effect of increasing the solute diffusion coefficient, slowing down the scale formation rate and the membrane flow attenuation rate.

[0066] The reverse osmosis membrane element structural solution of the present invention realizes a doubling of the pure water end membrane surface flow rate, and at the same time disrupts / breaks the concentration polarization layer through inter-segment turbulence, thereby increasing the service life of the membrane element by more than 20% under the same conditions.

[0067] In some embodiments,

[0068] The first reverse osmosis membrane 1, the second reverse osmosis membrane 2 and the third reverse osmosis membrane 3 are folded in half respectively. The two opposite faces of the first reverse osmosis membrane 1 are the front faces. The first raw water flow channel 201 is formed between the two opposite front faces of the first reverse osmosis membrane 1. The first pure water flow channel 101 is formed between the back face of the first reverse osmosis membrane 1 opposite to the second reverse osmosis membrane 2 and the back face of the second reverse osmosis membrane 2 opposite to the first reverse osmosis membrane 1. The first pure water flow channel 101 is formed between the two opposite front faces of the second reverse osmosis membrane 2. A second raw water flow channel 202 is formed between the two opposite front sides of the third reverse osmosis membrane 3, a third raw water flow channel 203 is formed between the two opposite front sides of the third reverse osmosis membrane 3, a second pure water flow channel 102 is formed between the back side of the second reverse osmosis membrane 2 opposite to the third reverse osmosis membrane 3 and the back side of the third reverse osmosis membrane 3 opposite to the second reverse osmosis membrane 2, and a third pure water flow channel 103 is formed between the back side of the first reverse osmosis membrane 1 opposite to the third reverse osmosis membrane 3 and the back side of the third reverse osmosis membrane 3 opposite to the first reverse osmosis membrane 1.

[0069] This is a further preferred relationship between the first, second and third reverse osmosis membranes of the present invention, that is, the second reverse osmosis membrane is located between the first and third reverse osmosis membranes, a first pure water flow channel is formed between the first and second reverse osmosis membranes, a first raw water flow channel is formed inside the first reverse osmosis membrane, a second pure water flow channel is formed between the second and third reverse osmosis membranes, a second raw water flow channel is formed inside the second reverse osmosis membrane, a third pure water flow channel is formed between the first and third reverse osmosis membranes, and a third raw water flow channel is formed inside the third reverse osmosis membrane, which effectively allows the pure water in the first and second pure water flow channels to flow to the third pure water flow channel for mixing while reducing the flow cross-sectional area, increasing the pure water flow rate, increasing the water flux of the membrane, reducing the reduction in water flux due to concentration polarization air induction, and further improving the service life of the membrane.

[0070] In some embodiments,

[0071] The length of the second reverse osmosis membrane 2 along the raw water flow direction after being folded in half is less than the length of the first reverse osmosis membrane 1 along the raw water flow direction after being folded in half, and the length of the second reverse osmosis membrane 2 along the raw water flow direction after being folded in half is less than the length of the third reverse osmosis membrane 3 along the raw water flow direction after being folded in half. This is the structural arrangement of the second reverse osmosis membrane of the present invention. By setting its length along the raw water flow direction to be less than the length of the first and third reverse osmosis membranes, a third pure water flow channel can be formed at the position where the length difference occurs, effectively reducing the flow cross-sectional area of ​​the third pure water flow channel (such as Figure 2As shown, after the three membranes are stacked, the third pure water flow channel is compressed to be smaller than the sum of the flow cross-sectional areas of the first and second pure water flow channels. Since there is no second reverse osmosis membrane blocking the first and third reverse osmosis membranes, the water flow rate of the membranes is increased, the filtering effect is improved, and the service life is increased.

[0072] In some embodiments,

[0073] The length of the first reverse osmosis membrane 1 along the raw water flow direction after being folded in half is equal to the length of the third reverse osmosis membrane 3 along the raw water flow direction after being folded in half. This is a further preferred structural form of the first and third reverse osmosis membranes of the present invention. It is preferred that the lengths of the first and third reverse osmosis membranes are equal, thereby forming Figure 2 The third pure water flow channel 103 shown prevents the flow cross-sectional area of ​​the third pure water flow channel from increasing.

[0074] In some embodiments,

[0075] The first reverse osmosis membrane sheet 1 is folded in half to form a first folded edge 11, the second reverse osmosis membrane sheet 2 is folded in half to form a second folded edge 21, and the third reverse osmosis membrane sheet 3 is folded in half to form a third folded edge 31. The first folded edge 11 is rolled in contact with the central tube 100, the third folded edge 31 is opposite to the first folded edge 11, the second folded edge 21 is not opposite to the first folded edge 11, and a preset distance L is spaced between the second folded edge 21 and the first folded edge 11, that is, the second folded edge 21 is arranged to move the preset distance L from the first folded edge 11 toward the open end of the first reverse osmosis membrane sheet 1.

[0076] This is a further preferred structural relationship between the second reverse osmosis membrane and the first and third reverse osmosis membranes of the present invention. By setting the second folded edge of the second reverse osmosis membrane to be retracted toward the opening end of the membrane relative to the first and third folded edges, it is possible to effectively form a Figure 2 The third pure water flow channel shown makes the length of the second reverse osmosis membrane smaller than the lengths of the first and third reverse osmosis membranes, respectively, so that the flow cross-sectional area of ​​the third pure water flow channel is smaller than the sum of the flow cross-sectional areas of the first and second pure water flow channels, thereby improving the pure water flow rate, increasing the water flow rate, and improving the filtering effect and service life of the membrane.

[0077] In some embodiments,

[0078] The first pure water flow channel 101, the second pure water flow channel 102, and the third pure water flow channel 103 form a pure water unit. The reverse osmosis membrane element includes N pure water units, where N ≥ 1, and two adjacent pure water units share a reverse osmosis membrane and a raw water flow channel sharing the reverse osmosis membrane. This is a further preferred structural form of the reverse osmosis membrane element of the present invention, that is, it can include multiple pure water units to form multiple structures with reduced flow cross-sectional areas along the pure water flow direction, forming multiple structures with increased pure water flow rates, further increasing the water flow rate of the membrane, and further improving the overall filtration effect and service life of the membrane.

[0079] In some embodiments,

[0080] It includes a first-stage filter element 4 and a second-stage filter element 5. The first-stage filter element 4 includes a central tube 100, a first reverse osmosis membrane 1, a second reverse osmosis membrane 2 and a third reverse osmosis membrane 3. The second-stage filter element 5 also includes a central tube 100, a first reverse osmosis membrane 1, a second reverse osmosis membrane 2 and a third reverse osmosis membrane 3. The raw water flow channel of the first-stage filter element 4 is connected to the raw water flow channel of the second-stage filter element 5. The raw water flow channel of the second-stage filter element 5 is located downstream of the raw water flow channel of the first-stage filter element 4 so that water in the raw water flow channel of the first-stage filter element 4 can flow into the raw water flow channel of the second-stage filter element 5; and an inter-stage turbulence generator 6 is provided between the raw water flow channel of the first-stage filter element 4 and the raw water flow channel of the second-stage filter element 5 so that the water in the raw water flow channel of the first-stage filter element 4 generates turbulence when flowing through the inter-stage turbulence generator 6, and then flows into the raw water flow channel of the second-stage filter element 5.

[0081] The present invention also arranges the reverse osmosis membrane element into a filter element structure of at least two sections, and arranges an inter-section turbulence generator between the raw water flow channels of the two sections of the filter element, thereby effectively affecting the water flow field distribution from the first section of the filter element into the second section of the filter element, disrupting / breaking the concentration polarization layer, achieving the effect of increasing the solute diffusion coefficient, slowing down the scale formation rate and the membrane flow attenuation rate, thereby enhancing the filtration effect of the filter element and improving the service life of the membrane element. Under the same conditions, the service life of the membrane element can be increased by more than 20%.

[0082] like Figure 2As shown, the optimized flow channel design diagram of the filter element membrane rolling process of the present invention explains: the first-stage filter element and the second-stage filter element both adopt optimized flow channel design in the membrane rolling process, and the number of common equal-length flow channels is reduced by merging the flow channels, that is, several equal-length flow channels are changed into several front flow channels + (several / 2) rear flow channels. The merged rear flow channels can increase the membrane surface flow rate by 100%. The high flow rate enables pure water to quickly flow through the central tube to the water outlet, which is beneficial to increase the pressure difference between raw water and pure water, making it easier for raw water to pass through the reverse osmosis membrane and increasing the water flux of the membrane.

[0083] like Figure 3 、 Figure 4 As shown, the reverse osmosis membrane element of the present invention is composed of two filter elements, front and rear. Since an appropriate inter-segment turbulence generator is set between the filter elements, the raw water flowing out of the first filter element generates turbulence, disrupting / breaking the concentration polarization layer, thereby increasing the solute diffusion coefficient and slowing down the scale formation rate and the membrane flow attenuation rate.

[0084] like Figure 5 As shown, a reverse osmosis membrane element in one embodiment includes a first-stage filter element, a second-stage filter element and an inter-stage turbulence generator.

[0085] like Figure 6 、 Figure 7 As shown, the first filter element and the second filter element are both formed by winding the water inlet screen, reverse osmosis membrane and pure water guide cloth on the central tube and sealingly connecting them.

[0086] In some embodiments,

[0087] The central tube of the first filter element 4 is the first filter element central tube 41, the central tube of the second filter element 5 is the second filter element central tube 51, the reverse osmosis membrane of the first filter element 4 is the first filter element roll membrane 42, and the reverse osmosis membrane of the second filter element 5 is the second filter element roll membrane 52;

[0088] The inter-segment turbulence generator 6 includes a two-way adapter 61 and a two-way support 62. The two-way adapter 61 is clamped between the first-segment filter element center tube 41 and the second-segment filter element center tube 51 to connect the first-segment filter element center tube 41 with the second-segment filter element center tube 51; the two-way support 62 is clamped on the outer periphery of the first-segment filter element membrane 42 and the second-segment filter element membrane 52, and connects the first-segment filter element membrane 42 with the second-segment filter element membrane 52, so that an interval space 7 is formed between the first-segment filter element membrane 42 and the second-segment filter element membrane 52 along the axial direction.

[0089] This is the preferred structural form of the inter-segment turbulence generator of the present invention, that is, a structure including a bidirectional adapter and a bidirectional support. The bidirectional adapter is used to connect the two sections of the central tube and define a gap between the two sections. The bidirectional support is used to connect the two sections of the filter element membrane and effectively define the interval space between the two sections of the membrane. When the raw water flows out of the first section of the membrane and enters the interval space, a turbulent effect is generated due to the sudden change in the flow area, etc., which effectively disrupts / breaks the concentration polarization layer, effectively increases the solute diffusion coefficient, slows down the scale formation rate and the membrane flow attenuation rate, thereby enhancing the filtering effect of the filter element and improving the service life of the membrane element.

[0090] like Figures 8a-8c As shown in Figure 1, the inter-segment turbulence generator is composed of a bidirectional adapter and a bidirectional support, which are connected to the first and second filter elements at the same time. The sealing method of the connection parts is as follows: (1) Sealing rings are set at both ends of the bidirectional adapter to achieve a sealed connection with the central tube of the two filter elements; (2) The connection between the bidirectional support and the filter element is sealed by wrapping salt water sealing tape.

[0091] In some embodiments,

[0092] The bidirectional adapter 61 includes a cylindrical body 63, at least part of which is inserted into the inner circumference of the first-stage filter core tube 41 and at least part of which is inserted into the inner circumference of the second-stage filter core tube 51. A first protrusion 64 is provided on the outer circumference of the cylindrical body 63, projecting radially outward. The first protrusion 64 is positioned between the first-stage filter core tube 41 and the second-stage filter core tube 51. The bidirectional support 62 is an annular cylindrical structure, and a second protrusion 65 is provided on the inner circumference of the cylindrical body 63, projecting radially inward. The second protrusion 65 is positioned between the first-stage filter core membrane 42 and the second-stage filter core membrane 52 to form the separation space 7. Preferably, the bidirectional adapter 61 and the bidirectional support 62 are separate structures, with the bidirectional adapter engaging and assembling with the two-stage core tube and the bidirectional support engaging and assembling with the two-stage membrane roll.

[0093] This is a further preferred structural form of the inter-segment turbulence generator of the present invention. The two-way adapter of the cylindrical structure can be respectively inserted into the first and second sections of the central tube to form a connection between the two. The setting of the first protrusion effectively defines a gap between the two sections of the central tube. The two-way support of the annular cylindrical structure can be wrapped around the outer periphery of the partial structure of the first and second sections of the filter element roll membrane. The second protrusion can effectively define the spacing space between the first and second sections of the filter element roll membrane.

[0094] In some embodiments,

[0095] The inter-segment turbulence generator 6 also includes a first seal 66 and a second seal 67. The first seal 66 is arranged between the outer periphery of the cylinder 63 of the two-way adapter 61 and the inner periphery of the first-segment filter element center tube 41. The first seal 66 is also arranged between the outer periphery of the cylinder 63 of the two-way adapter 61 and the inner periphery of the second-segment filter element center tube 51. The cylinder 63 has a hollow connecting channel to connect the pure water inside the first-segment filter element center tube 41 and the pure water inside the second-segment filter element center tube 51; the second seal 67 is respectively arranged on the outer periphery of the two-way support 62 and the outer periphery of the first-segment filter element membrane 42. The second seal is also respectively arranged on the outer periphery of the two-way support 62 and the outer periphery of the second-segment filter element membrane 52 to seal the joints between the second seal 67 and the first-segment filter element membrane 42 and the second-segment filter element membrane 52.

[0096] The present invention can effectively seal the pure water inside the two sections of the central tube and the raw water outside the central tube through the first seal to prevent mixing. The present invention can effectively seal the raw water on the outer periphery of the first and second sections of the filter element membrane and the concentrated water on the inner periphery through the second seal to prevent the two from mixing, effectively ensure the filtering effect, and increase the service life of the membrane.

[0097] In some embodiments,

[0098] Activated carbon particles are also provided in the separation space 7, and the activated carbon particles can be impacted by the water flow to generate movement, thereby increasing the turbulence effect; the first sealing member 66 is a sealing ring, and the second sealing member 67 is a sealing tape; the first protrusion 64 is a cylindrical ring structure, and the second protrusion 65 is a plurality of structures arranged at intervals in the circumferential direction; the outer periphery of the bidirectional support member 62 is also radially outwardly protruding and spaced apart with a plurality of third protrusions 68.

[0099] The present invention further preferably arranges activated carbon particles that can move with the water flow in the interval space, which can further increase the disturbing effect on the water flow, further improve the turbulent effect, further slow down the scale generation rate and the membrane flow attenuation rate, further enhance the filtering effect of the filter element and improve the service life of the membrane element; the first sealing member of the present invention is preferably a sealing ring, preferably a plurality of sealing rings, which are sleeved on the outer periphery of the cylinder; the second sealing member is preferably a sealing tape (further preferably a brine sealing tape), which is wrapped around the outer periphery of the bidirectional support and the outer periphery of part of the first and second sections of the filter element membrane, which can further enhance the sealing effect; the second protrusion is preferably a structure with multiple intervals, which can separate the two sections of the membrane without excessively affecting the filtration area of ​​the membrane; the third protrusion can be connected and fixed with the external shell, thereby effectively fixing the reverse osmosis membrane element.

[0100] The present invention also provides a water purifier, which includes the aforementioned reverse osmosis membrane element.

[0101] The specific implementation steps of the present invention are as follows:

[0102] 1. The first and second filter element membrane rolling operations are as follows

[0103] 1. First, cut the diaphragm (the raw material is a roll) into sheets of specified size;

[0104] 2. Such as Figure 2 As shown, the sheet membrane is folded in half according to the specified size and equal length;

[0105] 3. Place the water inlet spacer in the middle of the long membrane group; (Long membrane group: long membrane sheet folded in half + water inlet spacer, the long module group is the first or third reverse osmosis membrane);

[0106] 4. Place the water inlet spacer in the middle of the short membrane group; (short membrane group: short membrane folded in half + water inlet spacer, the short module group is the second reverse osmosis membrane);

[0107] 5. Lay out the long membrane group 1 flatly, then lay a pure water guide cloth on it, and then apply glue along the three sides of the membrane;

[0108] 6. Place the short film group 1 on the long film group 1, aligning the open end of the short film group 1 with the open end of the long film group 1, and bond the short and long film groups together with adhesive;

[0109] 7. Take another piece of pure water guide cloth and lay it on the short membrane group 1, then apply glue along the three sides of the membrane;

[0110] 8. Take another long film group 2 and lay it on the short film group 1, making sure that the long film group 2 is aligned with the long film group 1. Use adhesive to bond the long and short film groups together.

[0111] 9. Take another short film set 2 and repeat steps 6;

[0112] 10. The number of long film groups and short film groups depends on the product design, and the laying operation of the long film group and the short film group is repeated.

[0113] 11. Roll the laid diaphragm around the central tube and guide cloth to form a filter element.

[0114] 2. The assembly operation of the first and second filter elements is as follows

[0115] 1. Install the two-way connector into the sealing ring;

[0116] 2. Such as Figure 5As shown, a two-way connector and a two-way support are used to connect the first filter element and the second filter element, and then a salt water sealing tape is wrapped around the junction of the two-way support and the filter element to seal it, forming a membrane element with a one-stage two-stage structure.

[0117] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A reverse osmosis membrane element, characterized in that: include: A central tube (100), a first reverse osmosis membrane (1), a second reverse osmosis membrane (2) and a third reverse osmosis membrane (3), wherein the first reverse osmosis membrane (1), the second reverse osmosis membrane (2) and the third reverse osmosis membrane (3) are sequentially stacked as a whole and rolled onto the central tube (100), a first pure water flow channel (101) is formed between the first reverse osmosis membrane (1) and the second reverse osmosis membrane (2), a second pure water flow channel (102) is formed between the second reverse osmosis membrane (2) and the third reverse osmosis membrane (3), and the first reverse osmosis membrane (1) and the third reverse osmosis membrane (3) are connected to each other. A third pure water flow channel (103) is formed between the diaphragms (3), and the third pure water flow channel (103) is located downstream of both the first pure water flow channel (101) and the second pure water flow channel (102), so that water flowing from the first pure water flow channel (101) to the third pure water flow channel (103) is mixed with water flowing from the second pure water flow channel (102) to the third pure water flow channel (103), and a flow cross-sectional area of ​​the third pure water flow channel (103) is smaller than the sum of the flow cross-sectional area of ​​the first pure water flow channel (101) and the flow cross-sectional area of ​​the second pure water flow channel (102); The flow cross-sectional area of ​​the third pure water flow channel (103) is smaller than or equal to the flow cross-sectional area of ​​the first pure water flow channel (101), and the flow cross-sectional area of ​​the third pure water flow channel (103) is smaller than or equal to the flow cross-sectional area of ​​the second pure water flow channel (102).

2. The reverse osmosis membrane element according to claim 1, characterized in that: The first reverse osmosis membrane (1), the second reverse osmosis membrane (2) and the third reverse osmosis membrane (3) are folded in half respectively, the two opposite faces of the first reverse osmosis membrane (1) are front faces, a first raw water flow channel (201) is formed between the two opposite front faces of the first reverse osmosis membrane (1), the first pure water flow channel (101) is formed between the back face of the first reverse osmosis membrane (1) opposite to the second reverse osmosis membrane (2) and the back face of the second reverse osmosis membrane (2) opposite to the first reverse osmosis membrane (1), and the second pure water flow channel (101) is formed between the two opposite front faces of the second reverse osmosis membrane (2). Two raw water flow channels (202), a third raw water flow channel (203) is formed between two opposite front faces of the third reverse osmosis membrane (3), the second pure water flow channel (102) is formed between the back face of the second reverse osmosis membrane (2) opposite to the third reverse osmosis membrane (3) and the back face of the third reverse osmosis membrane (3) opposite to the second reverse osmosis membrane (2), and the third pure water flow channel (103) is formed between the back face of the first reverse osmosis membrane (1) opposite to the third reverse osmosis membrane (3) and the back face of the third reverse osmosis membrane (3) opposite to the first reverse osmosis membrane (1).

3. The reverse osmosis membrane element according to claim 2, characterized in that: The length of the second reverse osmosis membrane (2) along the raw water flow direction after being folded in half is shorter than the length of the first reverse osmosis membrane (1) along the raw water flow direction after being folded in half, and the length of the second reverse osmosis membrane (2) along the raw water flow direction after being folded in half is shorter than the length of the third reverse osmosis membrane (3) along the raw water flow direction after being folded in half.

4. The reverse osmosis membrane element according to claim 3, characterized in that: The length of the first reverse osmosis membrane (1) along the raw water flow direction after being folded in half is equal to the length of the third reverse osmosis membrane (3) along the raw water flow direction after being folded in half.

5. The reverse osmosis membrane element according to claim 2, characterized in that: The first reverse osmosis membrane (1) is folded in half to form a first folded edge (11), the second reverse osmosis membrane (2) is folded in half to form a second folded edge (21), and the third reverse osmosis membrane (3) is folded in half to form a third folded edge (31). The first folded edge (11) is adhered to the central tube (100) and rolled. The third folded edge (31) is opposite to the first folded edge (11). The second folded edge (21) is not opposite to the first folded edge (11), and a preset distance L is spaced between the second folded edge (21) and the first folded edge (11). That is, the second folded edge (21) is arranged to move the preset distance L from the first folded edge (11) toward the open end of the first reverse osmosis membrane (1).

6. The reverse osmosis membrane element according to claim 1, characterized in that: The first pure water flow channel (101), the second pure water flow channel (102) and the third pure water flow channel (103) form a pure water unit, the reverse osmosis membrane element includes N pure water units, where N≥1, and two adjacent pure water units share a reverse osmosis membrane and a raw water flow channel sharing the reverse osmosis membrane.

7. A reverse osmosis membrane element, characterized in that: The invention comprises a first filter element (4) and a second filter element (5), wherein the first filter element (4) and the second filter element (5) both comprise a reverse osmosis membrane element as described in any one of claims 1 to 6, and the raw water flow channel of the first filter element (4) is connected to the raw water flow channel of the second filter element (5), and the raw water flow channel of the second filter element (5) is located downstream of the raw water flow channel of the first filter element (4), so that water in the raw water flow channel of the first filter element (4) can flow into the raw water flow channel of the second filter element (5); and an inter-segment turbulence generator (6) is provided between the raw water flow channel of the first filter element (4) and the raw water flow channel of the second filter element (5), so that water in the raw water flow channel of the first filter element (4) generates turbulence when flowing through the inter-segment turbulence generator (6), and then flows into the raw water flow channel of the second filter element (5).

8. The reverse osmosis membrane element according to claim 7, characterized in that: The central tube of the first-stage filter element (4) is the first-stage filter element central tube (41), the central tube of the second-stage filter element (5) is the second-stage filter element central tube (51), the reverse osmosis membrane of the first-stage filter element (4) is the first-stage filter element roll membrane (42), and the reverse osmosis membrane of the second-stage filter element (5) is the second-stage filter element roll membrane (52); The inter-segment turbulence generator (6) includes a bidirectional adapter (61) and a bidirectional support (62), wherein the bidirectional adapter (61) is clamped between the first-segment filter element central tube (41) and the second-segment filter element central tube (51) to connect the first-segment filter element central tube (41) and the second-segment filter element central tube (51); the bidirectional support (62) is clamped on the outer periphery of the first-segment filter element membrane (42) and the second-segment filter element membrane (52), and connects the first-segment filter element membrane (42) and the second-segment filter element membrane (52), so that an interval space (7) is formed between the first-segment filter element membrane (42) and the second-segment filter element membrane (52) along the axial direction.

9. The reverse osmosis membrane element according to claim 8, characterized in that: The bidirectional adapter (61) includes a cylinder (63), at least part of the structure of the cylinder (63) is inserted into the inner periphery of the first section filter element center tube (41), and at least part of the structure of the cylinder (63) is inserted into the inner periphery of the second section filter element center tube (51). The outer periphery of the cylinder (63) is also provided with a first protrusion (64) protruding radially outward, and the first protrusion (64) is clamped between the first section filter element center tube (41) and the second section filter element center tube (51). The bidirectional support (62) is an annular cylinder structure, and its inner periphery is also provided with a second protrusion (65) protruding radially inward, and the second protrusion (65) is clamped between the first section filter element roll membrane (42) and the second section filter element roll membrane (52) to form the separation space (7).

10. The reverse osmosis membrane element according to claim 9, characterized in that: The inter-segment turbulence generator (6) further includes a first seal (66) and a second seal (67), wherein the first seal (66) is arranged between the outer periphery of the cylinder (63) of the bidirectional adapter (61) and the inner periphery of the first-segment filter core center tube (41), and the first seal (66) is also arranged between the outer periphery of the cylinder (63) of the bidirectional adapter (61) and the inner periphery of the second-segment filter core center tube (51), and the cylinder (63) has a hollow connecting channel to connect the pure water inside the first-segment filter core center tube (41) and the pure water inside the second-segment filter core center tube (51); the second seal (67) is arranged on the outer periphery of the bidirectional support (62) and the outer periphery of the first-segment filter core membrane (42), and the second seal is also arranged on the outer periphery of the bidirectional support (62) and the outer periphery of the second-segment filter core membrane (52).

11. The reverse osmosis membrane element according to claim 10, characterized in that: Activated carbon particles are also provided in the spacing space (7), and the activated carbon particles can be moved by the impact of water flow; the first sealing member (66) is a sealing ring, and the second sealing member (67) is a sealing tape; the first protrusion (64) is a cylindrical ring structure, and the second protrusion (65) is a structure that is arranged at intervals in the circumferential direction; the outer periphery of the bidirectional support member (62) is also provided with a plurality of third protrusions (68) that protrude radially outward at intervals.

12. A water purifier, characterized in that: The reverse osmosis membrane element comprises the reverse osmosis membrane element according to any one of claims 1 to 11.

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