Concentrated water separation net, reverse osmosis membrane assembly and filter element
By using a concentrated water partition with an n-side mesh, the scaling problems and turbulent unevenness that are prone to occur in the reverse osmosis membrane module are solved, and the effect of improving the desalination rate and service life is achieved.
Patent Information
- Application Number
- CN202421414624.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-19
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-06-19
AI Technical Summary
Conventional quadrilateral mesh thick water partitions are prone to scaling problems during the operation of reverse osmosis membrane components, and the flow resistance at the angles is large, resulting in uneven turbulence, increasing the area of the stagnant water area, and aggravating the scaling phenomenon.
The dense water partition mesh with an n-side (n≥5) mesh is used to woven and molded by fiber wire. The mesh structure has many angles and a large angle, which reduces the flow resistance and stagnant area at the angle, improves the scaling phenomenon and improves the uniformity of turbulence.
By improving the grid structure of the concentrated water barrier network, the scale phenomenon and the area of the stagnant water area are reduced, and the desalination rate and service life of the reverse osmosis membrane module are improved.
Smart Images
Figure CN223027093U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of water treatment, and particularly relates to a concentrated water spacer grid, a reverse osmosis membrane module and a filter element. Background Art
[0002] The reverse osmosis membrane module is the core component of the reverse osmosis system. Generally, it is in a cylindrical shape. Specifically, it is a cylindrical long-tube-shaped spiral membrane element formed by winding membrane sheets for filtration, concentrated water spacer grids, etc. around a central collecting pipe, and can be used in water treatment and separation processes.
[0003] Among them, the concentrated water spacer grid is an important part of the reverse osmosis membrane module, and its main functions are to support the flow channel and slow down the concentration polarization phenomenon and membrane fouling. The conventional concentrated water spacer grid is formed by extrusion molding of polypropylene through a mold. The grid of the spacer grid is quadrilateral, and during operation, the scaling phenomenon is serious. Summary of the Utility Model
[0004] The main purpose of the utility model is to propose a concentrated water spacer grid, a reverse osmosis membrane module and a filter element, aiming to improve the scaling problem of the concentrated water spacer grid.
[0005] To achieve the above object, the grid of the concentrated water spacer grid proposed by the utility model is an n-sided polygon, where n≥5.
[0006] In one embodiment, the grid of the concentrated water spacer grid is a hexagon.
[0007] In one embodiment, the grid has a first wire and a second wire spaced along the a direction, a third wire and a fourth wire spaced along the b direction, and a fifth wire and a sixth wire spaced along the c direction; the first wire, the second wire, the third wire, the fourth wire, the fifth wire and the sixth wire enclose to form the grid.
[0008] In one embodiment, the wire densities of the wires in two of the a direction, the b direction and the c direction are the same.
[0009] In one embodiment, the grid has a first wire density and a second wire density, the first wire density is 20 - 24; and / or, the second wire density is 14 - 18.
[0010] In one embodiment, the thickness of the concentrated water spacer grid is 0.21 mm - 0.70 mm.
[0011] In one embodiment, the concentrated water spacer grid is woven by fiber filaments.
[0012] In one embodiment, the fiber filaments are selected from one of polypropylene and polyester.
[0013] The utility model also proposes a reverse osmosis membrane module, including a central pipe, a reverse osmosis membrane and the above-mentioned concentrated water spacer grid.
[0014] The present utility model further provides a filter element, which includes the reverse osmosis membrane module described above.
[0015] The grid of the concentrated water separation net of the present utility model is an n-sided polygon, where n≥5. Such a grid structure has a large number of included angles and large angles. During the operation of the reverse osmosis membrane module, the flow resistance at the included angles will be reduced, and the area of the dead water region will be reduced. On the one hand, the scaling phenomenon can be improved, and on the other hand, the effect of improving the turbulence uniformity can be achieved, thereby improving the desalination rate and service life of the reverse osmosis membrane module. Description of the Drawings
[0016] In order to more clearly illustrate the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.
[0017] Figure 1 It is a schematic structural diagram of the concentrated water separation net in an embodiment of the present utility model;
[0018] Figure 2 It is a schematic structural diagram of the concentrated water separation net in the comparative example.
[0019] Explanation of the Reference Numerals in the Drawings
[0020] 100, concentrated water separation net; 101, grid. Detailed Embodiments
[0021] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, such "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. Additionally, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously. "At least one" as used in the embodiments of the present utility model refers to one or more, and "multiple" refers to two or more.
[0022] The "range" disclosed in the present utility model is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all contemplated: 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5. In the present utility model, unless otherwise stated, the numerical range "a - b" represents an abbreviated representation of any real number combination between a and b, where both a and b are real numbers. For example, the numerical range "0 - 5" means that all real numbers between "0 - 5" have been fully listed herein, and "0 - 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
[0023] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.
[0024] The concentrated water spacer is an important part of the reverse osmosis membrane module. Its main function is to support the flow channel and mitigate the concentration polarization phenomenon and membrane fouling. Conventional concentrated water spacers are formed by extrusion molding of polypropylene through a mold. The grids of the spacer are quadrilateral, with a small number of grids and small angles. During operation, dead water areas are likely to form at the corners, leading to scaling problems. In addition, the flow resistance at the corners of the quadrilateral grids is large, resulting in uneven turbulent flow and further increasing the area of the dead water region, thereby exacerbating the scaling phenomenon.
[0025] Therefore, the present utility model proposes a concentrated water spacer, and the grids of the concentrated water spacer are n-sided polygons, where n ≥ 5.
[0026] The grid refers to the holes on the concentrated water spacer that allow water flow to pass through. The present utility model sets the number of sides of the grid ≥ 5. Such a grid structure has a large number of corners and large angles. During the operation of the reverse osmosis membrane module, the flow resistance at the corners will be reduced, and the area of the dead water region will be reduced. On the one hand, it can improve the scaling phenomenon, and on the other hand, it can also achieve the effect of improving the uniformity of turbulent flow, thereby increasing the desalination rate and service life of the reverse osmosis membrane module.
[0027] It should be noted that the n-sided polygon in the present utility model refers to a convex n-sided polygon, that is, the interior angles of the n-sided polygon are all inferior angles.
[0028] In an embodiment of the present utility model, the grid of the concentrated water separation net is a hexagon. The hexagonal grid can take into account the advantages of high performance and processability.
[0029] In an embodiment of the present utility model, the grid has a first wire and a second wire arranged at intervals in the a direction, a third wire and a fourth wire arranged at intervals in the b direction, and a fifth wire and a sixth wire arranged at intervals in the c direction; the first wire, the second wire, the third wire, the fourth wire, the fifth wire, and the sixth wire enclose to form the grid. That is, the first wire and the second wire in this embodiment are parallelly distributed, the third wire and the fourth wire are parallelly distributed, the fifth wire and the sixth wire are parallelly distributed, and the formed grid is an axisymmetric hexagon and has two axes of symmetry, which is easy to process.
[0030] In an embodiment of the present utility model, the linear densities of the wires in two of the a direction, the b direction, and the c direction are the same. That is, the linear densities of the first wire, the second wire, the third wire, and the fourth wire are the same, and the linear densities of the fifth wire and the sixth wire are the same; or, the linear densities of the first wire, the second wire, the fifth wire, and the sixth wire are the same, and the linear densities of the third wire and the fourth wire are the same; or, the linear densities of the third wire, the fourth wire, the fifth wire, and the sixth wire are the same, and the linear densities of the first wire and the second wire are the same.
[0031] The linear density of the wire refers to the number of such wires on the concentrated water separation net per inch of length. The level of the linear density reflects the density of the grid on the concentrated water separation net and also reflects the size of the holes allowing water flow through. Therefore, the linear density of the wire will affect the open area, water flow distribution, pressure loss, and membrane fouling of the concentrated water separation net.
[0032] Setting different linear densities in this embodiment is beneficial for the reverse osmosis membrane module to achieve better use effects and cost performance in different usage environments.
[0033] In an embodiment of the present utility model, the grid has a first wire density and a second wire density. The first wire density is 20 - 24; and / or, the second wire density is 14 - 18. That is, the wire density of the first wire, the second wire, the third wire, and the fourth wire can be set to 14 - 18, and the wire density of the fifth wire and the sixth wire is 20 - 24; or the wire density of the first wire, the second wire, the third wire, and the fourth wire is set to 20 - 24, and the wire density of the fifth wire and the sixth wire is 14 - 18; or the wire density of the first wire, the second wire, the fifth wire, and the sixth wire is set to 14 - 18, and the wire density of the third wire and the fourth wire is 20 - 24; or the wire density of the first wire, the second wire, the fifth wire, and the sixth wire is set to 20 - 24, and the wire density of the third wire and the fourth wire is 14 - 18; or the wire density of the third wire, the fourth wire, the fifth wire, and the sixth wire is set to 14 - 18, and the wire density of the first wire and the second wire is 20 - 24; or the wire density of the third wire, the fourth wire, the fifth wire, and the sixth wire is set to 20 - 24, and the wire density of the first wire and the second wire is 14 - 18.
[0034] Theoretically, the higher the wire density, the better the turbulent flow effect of the concentrated water, the smaller the concentration polarization phenomenon, and the better the anti-scaling effect. However, the higher the wire density, the more precise the production mold requirements and the higher the cost. Therefore, when the concentrated water separation grid of the present utility model is applied to a household water purifier, setting the first wire density to 20 - 24 and the second wire density to 14 - 18 can achieve a longer service life and price competitiveness.
[0035] In an embodiment of the present utility model, the thickness of the concentrated water separation grid is 0.21 mm - 0.70 mm.
[0036] The thickness of the concentrated water separation grid affects the distribution of water flow on the membrane surface, the pressure loss during water passage, and the membrane fouling rate. The thickness range of this embodiment can achieve a more uniform water flow distribution, avoid pressure loss caused by high water flow resistance, and reduce membrane fouling.
[0037] In an embodiment of the present utility model, the concentrated water separation grid is woven by fiber filaments.
[0038] The concentrated water separation grid is woven by fiber filaments. Compared with the separation grid formed by extrusion molding, it has a lower overall strength. When the reverse osmosis membrane module operates, it can improve the situation where the membrane is damaged by being squeezed by the separation grid, thereby improving the desalination rate.
[0039] In an embodiment of the present utility model, the fiber filaments are selected from one of polypropylene and polyester.
[0040] The polyesters include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycarbonate (PC), and polyarylate (PAR). The concentrated water separation net made of polypropylene or polyester material has good chemical stability, anti-pollution property, and mechanical properties.
[0041] The present utility model also proposes a reverse osmosis membrane module, which includes a central tube, a reverse osmosis membrane, and the above-mentioned concentrated water separation net. For the specific setting of the concentrated water separation net, refer to the above-mentioned embodiments. Since the reverse osmosis membrane module of the present utility model adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.
[0042] In order to improve the water treatment efficiency and water quality of the reverse osmosis membrane module, multiple groups of reverse osmosis membranes can be specifically set, and a concentrated water separation net is arranged between each adjacent two groups of reverse osmosis membranes. Arranging the concentrated water separation net between the reverse osmosis membranes can help maintain a certain flow channel space, prevent the reverse osmosis membranes from fitting due to pressure, thereby ensuring smooth water flow. In addition, arranging the concentrated water separation net between the reverse osmosis membranes can also prevent direct contact between the reverse osmosis membranes, reducing pollution and scaling on the surface of the membrane sheets.
[0043] The present utility model also proposes a filter element, which includes the above-mentioned reverse osmosis membrane module. For the specific setting of the reverse osmosis membrane module, refer to the above-mentioned embodiments. Since the filter element of the present utility model adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.
[0044] The following will be described in conjunction with specific embodiments.
[0045] Embodiment 1
[0046] The concentrated water separation net 100 is woven from polyethylene terephthalate fibers, and its thickness is 0.34 mm. The structure of the concentrated water separation net 100 refers to Figure 1 As shown, the grid 101 of the concentrated water separation net 100 is hexagonal, and the grid 101 is formed by enclosing a first wire, a second wire arranged at intervals in the a direction, a third wire, a fourth wire arranged at intervals in the b direction, a fifth wire, and a sixth wire arranged at intervals in the c direction. The linear densities of the first wire, the second wire, the third wire, and the fourth wire are the same, all being 18, and the linear densities of the fifth wire and the sixth wire are the same, all being 22.
[0047] Comparative Example
[0048] The concentrated water separation net of the comparative example is formed by polypropylene extrusion molding, referring to Figure 2As shown, the thickness of the concentrated water separation net is 0.34 mm, its mesh is quadrilateral, specifically rhombic, and the linear density of the four wire meshes of the concentrated water separation net is 24. Other structures of the filter element are the same as those in the embodiment.
[0049] Performance Test
[0050] The concentrated water separation nets in Example 1 and the comparative example were respectively assembled with components such as reverse osmosis membranes according to conventional methods to form a reverse osmosis membrane (RO membrane) module, and the performance of the RO membrane module was tested.
[0051] Test method for the new water efficiency flux: Test the pure water production of the RO membrane module within 1 minute, with the unit of L / min, and then convert it to the flux expressed in GPD. GPD represents gallons per day, and the conversion method is: 1 L / min = 2.6286 × 1 GPD.
[0052] Test method for the new water efficiency desalination rate: Test the total amount of all dissolved solids (TDS value) in the influent and pure water of the RO membrane module respectively, and calculate the desalination rate through formula (I):
[0053] (Influent TDS value - Pure water TDS value) / Influent TDS value × 100% Formula (I).
[0054] Test method for the new water efficiency life attenuation rate: Test the initial flux of the RO membrane module as the background value A1, and the flux during the operation under working conditions as A2, and calculate the attenuation rate through formula (II):
[0055] (A1 - A2) / A1 × 100% Formula (II).
[0056] The above test methods were all carried out under the conditions of the influent water quality being the new water efficiency water quality (GB 34914-2021 Water Efficiency Limit and Water Efficiency Grade for Water Purifiers), the pre-membrane pressure of 0.7 MPa, and the recovery rate of 70% - 75%.
[0057] Test Results
[0058] The new water efficiency initial flux of the filter element in this embodiment is 939 GPD, and the new water efficiency 4T life flux (the water production of 4000 L of pure water) is 890 GPD. The new water efficiency initial flux of the filter element in the comparative example is 937 GPD, and the new water efficiency 4T life flux is 837 GPD. Although there is no significant difference in the initial flux between the filter element in this embodiment and the filter element in the comparative example, the new water efficiency 4T life flux of the filter element in this embodiment is significantly higher than that in the comparative example, indicating that the concentrated water separation net of the present invention can improve the 4T life flux of the filter element.
[0059] The initial desalination rate of the filter element in this embodiment under the new water efficiency is 92.64%, and the desalination rate of the filter element under the new water efficiency during its service life is 96.33%. While for the filter element of the comparative example, the initial desalination rate under the new water efficiency is 90.62%, and the desalination rate under the new water efficiency during its service life is 94.56%. This shows that the concentrated water spacer of the present invention can improve the desalination rate of the filter element.
[0060] On the basis of configuring a pre-filter for scale inhibition, the attenuation rate of the service life of the filter element of the present invention under the new water efficiency is only 5.20%, while the attenuation rate of the service life of the filter element of the comparative example under the new water efficiency is 10.67%. This shows that the concentrated water spacer of the present invention can reduce the attenuation rate of the filter element, thereby improving the service life of the filter element.
[0061] The above are only exemplary embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present utility model.
Claims
1. A concentrated water screen, characterized in that: The grid of the concentrated water separator is an n-gon, wherein n≥5, and the concentrated water separator is woven by fiber filaments.
2. The concentrated water screen according to claim 1, characterized in that: The grid of the concentrated water separator is hexagonal.
3. The concentrated water screen as claimed in claim 2, characterized in that: The grid comprises first and second mesh wires spaced apart in direction a, third and fourth mesh wires spaced apart in direction b, and fifth and sixth mesh wires spaced apart in direction c; The first mesh, the second mesh, the third mesh, the fourth mesh, the fifth mesh and the sixth mesh together form the grid.
4. The concentrated water screen as claimed in claim 3, characterized in that: The linear density of the mesh fibers in two directions among the a direction, the b direction, and the c direction is the same.
5. The concentrated water screen as claimed in claim 4, characterized in that: The grid has a first line density and a second line density, the first line density being 20-24; And / or, the second linear density is 14-18.
6. The concentrated water screen according to any one of claims 1 to 5, characterized in that: The thickness of the concentrated water separator is 0.21mm-0.70mm.
7. The concentrated water screen according to claim 1, characterized in that: The fiber filaments are selected from one of polypropylene and polyester.
8. A reverse osmosis membrane assembly, characterized in that: The invention comprises a central tube, a reverse osmosis membrane and the concentrated water separator according to any one of claims 1 to 7.
9. A filter element, characterized in that: Comprising the reverse osmosis membrane assembly according to claim 8.