A small size membrane element and filter cartridge
Patent Information
- Application Number
- CN202521875427.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2035-09-01
AI Technical Summary
[0006]为解决现有技术中使用较薄过滤膜时膜袋被水流冲击容易产生褶皱的问题，本实用新型的目的是提供一种小尺寸膜元件及滤芯
[0028]本实用新型提出的膜元件，使用较薄的PE反渗透膜片制成膜袋，不仅能够满足制得小尺寸但膜面积相同的膜元件这一要求，并且克服较软膜片更加容易起皱的技术偏见，使用的PE反渗透膜片也较软(弹性模量为635MPa～1170MPa)，同时设计原水流向与膜袋长度延伸方向大致平行的原水流道，由于水流流向与膜袋卷绕方向大致平行，因此水流的冲击力与膜袋卷绕方向也大致平行。当收卷状态的膜袋受到与卷绕方向大致平行的作用力时，会卷紧或放松，而不会形成如图1所示的褶皱。
Smart Images
Figure CN224812323U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water purification technology, specifically to a small-sized membrane element and filter cartridge. Background Technology
[0002] With increasing emphasis on drinking water quality, water purifiers have become a highly sought-after product in the market. For water purifiers, the filter cartridge is a crucial component for water filtration. It typically consists of a base membrane that can be rolled up, a raw water channel, and a pure water channel located on opposite sides of the base membrane. During use, raw water flows into the raw water channel through its inlet, then passes through the membrane to become pure water, which then enters the pure water channel. Through the reverse osmosis effect of the membrane, impurities are filtered out, producing the pure water that people need.
[0003] In industrial water treatment equipment, the commonly used filter element sizes are 8040 and 4040. Due to the limitations of filter element size, the existing industrial water treatment equipment is relatively large.
[0004] To reduce the size of industrial water treatment equipment, or to install more filter cartridges in industrial water treatment equipment of the same volume, existing technologies have proposed technical solutions that reduce the axial length of the filter cartridges. In such existing technical solutions, because the axial length of the filter cartridge is reduced, more membrane bags need to be wound around the filter cartridge to avoid reducing the membrane area.
[0005] To meet equipment compatibility requirements, the outer diameter of the filter element must remain constant. This is because when winding more membrane bags, thinner membrane sheets are needed to avoid increasing the outer diameter of the filter element. However, further research and use have revealed that when the filter membrane is thin, wrinkles easily form on the surface of the membrane bag, both during winding and use, which adversely affects the filtration performance of the filter element. Utility Model Content
[0006] To address the problem that membrane bags are prone to wrinkling when subjected to water flow impact when using thinner filter membranes in existing technologies, the purpose of this invention is to provide a small-sized membrane element and filter cartridge.
[0007] The technical solution provided by this utility model is as follows:
[0008] In one aspect, a small-sized membrane element includes a membrane bag and a central tube:
[0009] One side of the membrane bag is connected to the central tube and is wound around the central tube along the length of the membrane bag, forming a raw water flow channel inside the membrane bag and a pure water flow channel outside the membrane bag;
[0010] The membrane bag is formed by folding and bonding PE reverse osmosis membrane sheets;
[0011] The PE reverse osmosis membrane has a thickness of 0.01 mm to 0.03 mm and an elastic modulus of 635 MPa to 1170 MPa.
[0012] The original water flow channel is equipped with a flow guide, and the thickness of the membrane bag at the location of the flow guide is 0.25mm to 0.72mm;
[0013] The density of the membrane bag wound on the central tube is 11-22 turns / cm;
[0014] Within the raw water flow channel, the direction of the raw water flow is approximately parallel to the length extension direction of the membrane bag. The raw water can wash the surface of the membrane bag, smooth out the wrinkles on the surface of the membrane bag, and make the surface of the membrane bag smooth.
[0015] As one of the optional technical solutions in the first aspect, the tensile strength of the PE reverse osmosis membrane is 79MPa to 142MPa.
[0016] As an optional technical solution in the first aspect, in the raw water channel, the inlet flow velocity V1 ≥ 6 cm / s and the outlet flow velocity V2 ≥ 3 cm / s.
[0017] As one optional technical solution in the first aspect, the membrane bag has a first short side, a second short side, a first long side, and a second long side; wherein the first short side corresponds to the second short side, and the first long side corresponds to the second long side; the central tube is connected to the first short side.
[0018] Optionally, the raw water inlet is located on the first short side, and the concentrate outlet is located on the second short side;
[0019] Alternatively: the raw water inlet is located on the first or second long side near the end of the central pipe, and the concentrate outlet is located on the second short side.
[0020] Alternatively: the raw water inlet is located on the second short side, and the concentrate outlet is located on the first or second long side near the end of the central pipe.
[0021] Optionally, the pure water outlet is located on the first long side or the second long side; or: the pure water outlet is located on the first short side.
[0022] As an optional technical solution in the first aspect, each of the original water channels is provided with a flow guide;
[0023] Alternatively: The guide element is installed in the raw water flow channel near the raw water inlet.
[0024] As an optional technical solution in the first aspect, the thickness of the guide element is 0.25mm to 0.7mm.
[0025] As an optional technical solution in the first aspect, a flow guide cloth is provided in the pure water flow channel.
[0026] In a second aspect, a filter element includes the small-sized membrane element described in the first aspect or any of the optional technical solutions of the first aspect.
[0027] Compared with the prior art, the technical solution provided by this utility model has the following advantages:
[0028] The membrane element proposed in this invention uses a thinner PE reverse osmosis membrane sheet to make the membrane bag. This not only meets the requirement of producing a small-sized membrane element with the same membrane area, but also overcomes the technical bias that softer membrane sheets are more prone to wrinkling. The PE reverse osmosis membrane sheet used is also relatively soft (elastic modulus of 635MPa~1170MPa). Simultaneously, a raw water flow channel is designed with the raw water flow direction approximately parallel to the length extension direction of the membrane bag. Because the water flow direction is approximately parallel to the winding direction of the membrane bag, the impact force of the water flow is also approximately parallel to the winding direction of the membrane bag. When the membrane bag in the winding state is subjected to a force approximately parallel to the winding direction, it will tighten or loosen, without forming a wrinkled shape. Figure 1 The folds shown.
[0029] In addition, wrinkles may also occur during the process of winding the membrane bag into the central tube. This application uses a softer membrane sheet and designs a raw water flow channel that is approximately parallel to the length extension direction of the membrane bag. During the use of the filter element, the membrane bag can be straightened and wrinkles eliminated by the flushing action of the water flow that is approximately parallel to the winding direction. Attached Figure Description
[0030] Figure 1 This is a schematic diagram illustrating the wrinkling process of a membrane bag in the prior art.
[0031] Figure 2 This is a schematic diagram of the membrane element after winding in one embodiment of this application;
[0032] Figure 3 This is a schematic diagram of one embodiment of the present application where the pure water outlet is located on the second long side;
[0033] Figure 4 This is a schematic diagram of one embodiment of the present application when the pure water outlet is located on the first short side;
[0034] Figure 5 This is a schematic diagram of one embodiment of the present application when the raw water inlet is located on the first short side;
[0035] Figure 6 This is a schematic diagram of one embodiment of the present application, showing the raw water inlet located at the end of the first or second long side near the center pipe;
[0036] Figure 7 This is a schematic diagram of one embodiment of the present application when the raw water inlet is located on the second short side;
[0037] Figure 8This is a schematic diagram of diaphragm folding in one embodiment of this application, where the pure water outlet is located on the second long side and the raw water inlet is located on the first long side;
[0038] Figure 9 This is a schematic diagram of diaphragm folding in one embodiment of this application, where the pure water outlet is located on the first short side and the raw water inlet is located on the first long side;
[0039] Figure 10 This is a schematic diagram of diaphragm folding in one embodiment of this application, where the pure water outlet is located on the second long side and the raw water inlet is located on the second short side;
[0040] Figure 11 This is a schematic diagram of diaphragm folding in one embodiment of this application, where the pure water outlet is located on the first short side and the raw water inlet is located on the second short side;
[0041] Figure 12 This is a schematic diagram of a filter element in one embodiment of this application.
[0042] Explanation of the labels in the diagram:
[0043] Central tube 101, membrane bag 102, pure water through hole 103, raw water through hole 104, flow guide 105;
[0044] First short side 201, second short side 202;
[0045] First long side 301, second long side 302;
[0046] 401 housing, 402 water outlet, 403 first end cap, 404 second end cap. Detailed Implementation
[0047] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.
[0048] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.
[0049] In one embodiment, such as Figures 2 to 11As shown, a small-sized membrane element includes a membrane bag 102 and a central tube 101. In this application, the membrane bag 102 is made of a PE reverse osmosis membrane sheet. Specifically, the PE reverse osmosis membrane sheet can be made into a rectangular shape, for example, with a length and width of 2m and 0.5m respectively. The PE reverse osmosis membrane sheet is then folded into a membrane bag with a length and width of 1m and 0.5m respectively. Adhesive is applied to the inner and outer edges of the membrane bag, and then it is bonded and wound onto the central tube 101. Figures 3-7 As shown in the figure, the thick black solid line represents the location where the adhesive is applied.
[0050] After adhesive bonding and winding, relatively closed raw water channels and pure water channels are formed on the inner and outer sides of the membrane bag 101, respectively. The relative closedness here means that except for the various inlets and outlets of the channels, all other positions are closed, so that after the raw water enters the raw water channel, it is filtered by the PE reverse osmosis membrane, and the pure water enters the pure water channel and flows out from the outlet of the pure water channel. The concentrated water remaining in the raw water channel flows out from the outlet of the raw water channel, and the pure water and concentrated water will not mix.
[0051] Regarding the winding method of the membrane bag 102, as an optional implementation, one side of the membrane bag 102 can be connected to the central tube 101, for example, by adhesive bonding, or other connection methods suitable for membrane elements in the prior art can be used, which are not limited or elaborated here. In this embodiment, when the length and width of the membrane bag 101 are 1m and 0.5m respectively, the 0.5m wide side of the membrane bag 102 can be connected to the central tube 101, and then wound around the central tube 101 along the length extension direction of the membrane bag, thereby forming a membrane element.
[0052] In this application, the membrane bag 102 is a PE (polyethylene) reverse osmosis membrane. How the PE reverse osmosis membrane is prepared is in the prior art and will not be described or limited here.
[0053] The PE reverse osmosis membrane used in this application has a thickness of 0.01mm to 0.03mm, for example, 0.01mm, 0.012mm, 0.014mm, 0.015mm, 0.016mm, 0.017mm, 0.018mm, 0.019mm, 0.02mm, 0.022mm, 0.024mm, 0.025mm, 0.026mm, 0.027mm, 0.028mm, 0.029mm, or 0.03mm, etc. The elastic modulus ranges from 635 MPa to 1170 MPa, for example, 635 MPa, 637.4 MPa, 670.41 MPa, 775.26 MPa, 872.19 MPa, 1143.59 MPa, 1166.29 MPa, or 1170 MPa, etc. Furthermore, within the raw water flow channel, the raw water flow direction is set approximately parallel to the length extension direction of the membrane bag, such as... Figures 3 to 11 As shown, in the raw water channel, the flow direction of water from the raw water inlet to the concentrate outlet needs to be mostly parallel to the length extension direction of the membrane bag (i.e. the winding direction of the membrane bag). The water flow in the raw water channel can wash the surface of the membrane bag, smooth the wrinkles on the surface of the membrane bag, and make the surface of the membrane bag smooth.
[0054] Compared to existing membrane elements wound with membrane bags of 1m in length and 1m in width, this embodiment uses membrane bags made of thinner and softer PE reverse osmosis membrane sheets, with lengths of 1m and 0.5m in width. The length of the membrane element obtained by winding is half that of the existing membrane elements. Moreover, this application can wind more membrane bags with the same outer diameter, thereby meeting the requirements of the same or larger membrane area.
[0055] Furthermore, this embodiment overcomes the technical bias that thinner, softer membrane sheets are more prone to wrinkling by using a thinner, softer PE reverse osmosis membrane sheet. Simultaneously, it designs a raw water flow channel with the raw water flow direction roughly parallel to the membrane bag's length extension direction. Because the water flow direction is roughly parallel to the membrane bag's winding direction, the impact force of the water flow is also roughly parallel to the membrane bag's winding direction. When the membrane bag is wound up, it is not completely tightened; the membrane roll can tighten or loosen to a certain extent. Therefore, this application utilizes this characteristic to design a raw water flow channel with the water flow direction roughly parallel to the membrane bag's winding direction. When the wound membrane bag is subjected to a force roughly parallel to the winding direction, the scouring effect of the water flow and the membrane roll's ability to tighten or loosen to a certain extent eliminate wrinkles on the membrane bag's surface.
[0056] In addition, wrinkles may also occur during the winding process of the membrane bag being wound around the central tube. This application uses a softer, thinner membrane sheet and designs a raw water flow channel that is roughly parallel to the length extension direction of the membrane bag. During the use of the filter element, the membrane bag can be straightened and wrinkles eliminated by the flushing action of the water flow that is roughly parallel to the winding direction.
[0057] However, if such a method is adopted Figure 1 As shown in the diagram, the raw water flow direction is roughly perpendicular to the membrane bag winding direction. Therefore, the water flow in the raw water flow channel cannot straighten the membrane bag. Under the impact of the water flow in the channel, wrinkles will form at one end of the membrane bag.
[0058] In this application, a guide element 105, such as a raw water guide net, is provided in the raw water flow channel. The thickness of the guide element 105 needs to meet the following conditions: after the guide element 105 is arranged in the raw water flow channel of the membrane bag 102, the thickness of the membrane bag 102 at the location where the guide element 105 is provided is 0.25mm to 0.72mm, for example, 0.25mm, or 0.28mm, or 0.33mm, or 0.37mm, or 0.44mm, or 0.48mm, or 0.53mm, or 0.57mm, or 0.65mm, or 0.68mm, or 0.7mm, or 0.72mm, etc.
[0059] It should be noted that even if the flow channel proposed in the embodiments of this application is adopted, the softer and thinner PE reverse osmosis membrane may be prone to wrinkling due to collapse under the influence of gravity and other factors. In order to eliminate this defect, it is also necessary to support the membrane bag 102 made of the softer and thinner PE reverse osmosis membrane.
[0060] In this application, the flow guide 105 not only has the function of guiding flow, but also the membrane bag has a thickness of 0.25mm to 0.72mm after the flow guide 105 is installed. At this time, the membrane element has a certain degree of anti-collapse ability.
[0061] like Figure 2 As shown, the membrane element obtained after winding the membrane bag is roughly cylindrical. Within a radius of length L, the number of layers wound on the membrane bag 102 is the winding density. Preferably, the winding density of the membrane bag 102 on the central tube 101 is 11-22 turns / cm, that is, within a radius of 1 cm, the membrane bag 102 is wound with 11-22 layers. At this time, the membrane roll is not completely tightened, and the membrane roll can be tightened or loosened to a certain extent. In this application, the direction of the raw water flow is roughly parallel to the direction of the membrane bag's length extension. Under the flushing action of the raw water flow, the membrane bag has a certain degree of ability to tighten or loosen, so that the water flow can be used to smooth the membrane bag and eliminate wrinkles.
[0062] As an optional implementation, the tensile strength of the PE reverse osmosis membrane in this application is 79 MPa to 142 MPa, for example, 79 MPa, 79.35 MPa, 102.83 MPa, 113.84 MPa, 119.38 MPa, 129.24 MPa, or 141.31 MPa. Ensuring the tensile strength of the PE reverse osmosis membrane meets the above requirements not only satisfies the requirements for membrane roll winding but also allows the wound membrane roll to have a certain degree of tightness or looseness.
[0063] Preferably, in the raw water channel, the inlet flow velocity V1 ≥ 6 cm / s and the outlet flow velocity V2 ≥ 3 cm / s. At this time, the water flow velocity in the raw water channel can smooth out the wrinkles and also have a flushing and cleaning effect on the surface of the membrane bag in the raw water channel.
[0064] When the PE reverse osmosis membrane sheet is folded, the membrane bag 102 has a first short side 201, a second short side 202, a first long side 301, and a second long side 302, wherein the first short side 201 corresponds to the second short side 202, and the first long side 301 corresponds to the second long side 302. In this embodiment, the central tube 101 is connected to the first short side 201, and the membrane bag is wound up along its length extension direction (i.e., the length extension direction of the first long side 301 and the second long side 302).
[0065] Regarding the arrangement of the raw water channel, in one embodiment, such as... Figure 5 As shown, an independent raw water channel is provided inside the central tube 101, and a raw water through hole 104 is opened on the central tube 101. The raw water through hole 104 is connected to the raw water flow channel. The raw water inlet is located on the first short side 201, and the concentrate outlet is located on the second short side 202. In this embodiment, the wound membrane bag 102 has a tendency to unwind under the impact of the water flow in the raw water flow channel.
[0066] Regarding the arrangement of the raw water channel, in one embodiment, such as... Figure 6 , Figure 8 , Figure 9 As shown, the raw water inlet is located at the end of the first long side 301 or the second long side 302 near the center tube 101 (i.e., the membrane bag is not glued here), and the concentrate outlet is located at the second short side 202. In this embodiment, the raw water flow direction is roughly "L"-shaped, but the raw water flow direction is mostly still parallel to the membrane bag winding direction. At this time, the wound membrane bag 102 has a tendency to loosen under the impact of the water flow in the raw water channel.
[0067] Regarding the arrangement of the raw water channel, in one embodiment, such as... Figure 7 , Figure 10 , Figure 11As shown, the raw water inlet is located on the second short side 202, and the concentrate outlet is located on the first long side 301 or the second long side 302 near the end of the central tube 101. In this embodiment, the raw water flow direction is roughly "L" shaped, but the raw water flow direction is mostly still parallel to the membrane bag winding direction. At this time, the wound membrane bag 102 has a tendency to tighten the membrane roll under the impact of the water flow in the raw water channel.
[0068] Regarding the configuration of the pure water flow channel, in one embodiment, such as... Figure 3 , Figure 8 , Figure 10 As shown, the pure water outlet is located on the first long side 301 or the second long side 302.
[0069] Regarding the configuration of the pure water flow channel, in another embodiment, such as... Figure 4 , Figure 9 , Figure 11 As shown, the pure water outlet is located on the first short side 201. At this time, an independent pure water channel is provided in the central pipe 101, and a pure water through-hole 103 connecting the pure water channel and the pure water flow path is provided on the central pipe 101. Pure water in the pure water flow path flows into the pure water channel through the pure water through-hole 103.
[0070] Regarding the arrangement of the flow guides in the raw water channel, in one embodiment, flow guides 105 are provided throughout the entire raw water channel, meaning the flow guides 105 are distributed throughout the raw water channel. In another embodiment, the flow guides 105 are only provided in the raw water channel near the raw water inlet, meaning the flow guides 105 are only located in a portion of the raw water channel. In this case, the flow guides 105 only serve to guide and support the membrane bag 102 at the center of the membrane element.
[0071] Furthermore, the thickness of the guide element 105 is 0.25mm to 0.7mm, for example, 0.25mm, 0.3mm, 0.35mm, 0.42mm, 0.46mm, 0.55mm, 0.58mm, 0.6mm, 0.64mm, 0.66mm, or 0.7mm.
[0072] In an optional embodiment, a flow guide cloth can also be provided in the pure water flow channel. That is, a flow guide net or the like is provided as a flow guide 105 in the raw water flow channel, while a flow guide cloth is provided in the pure water flow channel. The flow guide 105 and the flow guide cloth not only play a guiding role, but also support the membrane bag 102 to prevent wrinkling and deformation.
[0073] In one embodiment, this application proposes a filter element comprising the aforementioned small-sized membrane element.
[0074] For filter elements, preferably, such as Figure 12As shown, the filter element includes a housing 401, a first end cap 403, and a second end cap 404. The housing 401 has an outlet 402, meaning the concentrate outlet of the raw water flow channel is located on the second short side 202. Furthermore, the pure water outlet and the raw water inlet are located at the same end of the filter element. For example, the second end cap 404 can have separate channels for raw water inflow and pure water outflow. In this case, the first end cap 403 of the filter element does not need any outlet. When replacing the membrane element, it can be replaced simply by removing the membrane housing cover at this point, without needing to disassemble the pipeline, thus achieving convenient membrane element replacement.
[0075] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.
Claims
1. A small-sized membrane element, comprising a membrane bag (102) and a central tube (101): One side of the membrane bag (102) is connected to the central tube (101) and is wound around the central tube (101) along the length of the membrane bag, forming a raw water flow channel inside the membrane bag (102) and a pure water flow channel outside the membrane bag (102); Its features are: The membrane bag (102) is formed by folding and bonding PE reverse osmosis membrane sheets; The PE reverse osmosis membrane has a thickness of 0.01 mm to 0.03 mm and an elastic modulus of 635 MPa to 1170 MPa. A guide (105) is installed in the original water flow channel, and the thickness of the membrane bag (102) at the location where the guide (105) is installed is 0.25mm to 0.72mm; The density of the membrane bag (102) wound on the central tube (101) is 11 to 22 turns / cm; Within the raw water flow channel, the direction of the raw water flow is approximately parallel to the length extension direction of the membrane bag. The raw water can wash the surface of the membrane bag, smooth out the wrinkles on the surface of the membrane bag, and make the surface of the membrane bag smooth.
2. The small-sized membrane element according to claim 1, characterized in that: The tensile strength of PE reverse osmosis membranes is 79MPa to 142MPa.
3. The small-sized membrane element according to claim 1, characterized in that: In the raw water channel, the inlet flow velocity V1 ≥ 6 cm / s and the outlet flow velocity V2 ≥ 3 cm / s.
4. The small-sized membrane element according to claim 1, characterized in that: The membrane bag (102) has a first short side (201), a second short side (202), a first long side (301), and a second long side (302); Among them, the first short side (201) corresponds to the second short side (202), and the first long side (301) corresponds to the second long side (302); The central tube (101) is connected to the first short side (201).
5. The small-sized membrane element according to claim 4, characterized in that, In the raw water channel: The raw water inlet is located on the first short side (201), and the concentrated water outlet is located on the second short side (202); or: The raw water inlet is located on the first long side (301) or the second long side (302) near the end of the central pipe (101), and the concentrated water outlet is located on the second short side (202); or: The raw water inlet is located on the second short side (202), and the concentrated water outlet is located on the first long side (301) or the second long side (302) near the end of the central pipe (101).
6. The small-sized membrane element according to claim 4, characterized in that, In the pure water flow channel: The pure water outlet is located on the first long side (301) or the second long side (302); or: The pure water outlet is located on the first short side (201).
7. The small-sized membrane element according to claim 1, characterized in that: Each of the original water channels is equipped with a flow guide (105); or: The guide (105) is installed in the raw water channel near the raw water inlet.
8. The small-sized membrane element according to claim 1 or 7, characterized in that: The thickness of the flow guide (105) is 0.25mm to 0.7mm.
9. The small-sized membrane element according to claim 1, characterized in that: A flow guide cloth is provided in the pure water flow channel.
10. A filter element, characterized in that: Includes small-sized membrane elements as described in any one of claims 1 to 9.