Composite filter element

Abstract

The application provides a composite filter core, belonging to the technical field of sewage treatment equipment, comprising a diaphragm, a water inlet screen, a water production flow guide cloth, a scale inhibitor and a center pipe with a cavity structure; one end of the inside of the center pipe is provided with a screen, and the inside of the center pipe is further provided with a sealing part; the scale inhibitor is placed between the screen and the sealing part; a plurality of desalination layers are wrapped on the center pipe, each desalination layer is formed by folding the diaphragm and arranging the water inlet screen in the middle of the diaphragm, and the adjacent two desalination layers are separated by the water production flow guide cloth; a plurality of water collecting holes are formed on the center pipe. The application utilizes the structural characteristics of the existing roll type reverse osmosis / nanofiltration membrane element, combines the performance advantages that the PE-based diaphragm is thin in thickness, high in desalination rate and large in flux, ensures the functions of scale inhibition, filtration and purification and the performances of water production and desalination rate, effectively reduces the volume of the water purification filter core, makes the water purification treatment equipment more portable, and makes the filter core installation more convenient.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment equipment technology, specifically to a composite filter element based on PE-based reverse osmosis membrane or PE-based nanofiltration membrane. Background Technology

[0002] Current water purification equipment generally suffers from drawbacks such as large size, large footprint, and complex and cumbersome structure. Due to the characteristics of water purification technology, existing reverse osmosis / nanofiltration water purification equipment typically consists of membrane elements and pre- and post-filter cartridges with functions such as scale inhibition and filtration. Existing composite filter cartridges on the market usually consist of a reverse osmosis / nanofiltration membrane cartridge and a post-activated carbon filter cartridge connected in series; or an activated carbon filter cartridge, a reverse osmosis / nanofiltration membrane cartridge, and a sterilization / bacteriostatic filter cartridge connected in series sequentially; or a pre-filter cartridge, an RO filter cartridge (with a scale inhibition unit below), and a post-filter cartridge integrated into a single filter bottle to achieve the water purification function. By stacking activated carbon fiber cotton on top of the reverse osmosis membrane sheet, a spiral wound membrane element with built-in activated carbon is produced, solving the problem of its own inability to improve the taste of the produced water. Replacing ordinary produced water guide cloth with a layered structure of carbon fiber sheets spliced ​​together achieves the same goal of improving the taste of the produced water.

[0003] The existing series-connected filter cartridges mentioned above, while maintaining a fixed volume, all sacrifice the effective membrane area of ​​the spiral-wound reverse osmosis / nanofiltration membrane cartridge. It is known that the effective membrane area of ​​the reverse osmosis / nanofiltration membrane in a water purification filter cartridge directly affects the filter cartridge's water purification efficiency and total water volume. Furthermore, filter cartridges produced by stacking activated carbon fiber cotton on top of the membrane introduce an additional step in the production process, increasing the difficulty of winding and making the element's production more complex, while also reducing the effective membrane area of ​​the membrane element.

[0004] Spiral reverse osmosis / nanofiltration membrane cartridges prepared by splicing carbon fiber sheets onto the permeate flow cloth may also increase the thickness of the permeate flow cloth, resulting in a loss of the effective membrane area of ​​the membrane element. Furthermore, the simple splicing method of combining carbon fiber sheets and permeate flow cloth will increase the thickness of the permeate flow cloth and destroy the grooved flow channels of the permeate flow cloth itself, increasing the resistance during permeate water transportation and reducing the water purification efficiency of the cartridge. Summary of the Invention

[0005] The purpose of this invention is to provide a composite filter element based on PE-based membrane or nanofiltration membrane to solve at least one of the technical problems existing in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] On one hand, the present invention provides a composite filter element, comprising: a membrane, an inlet screen, a product water guiding cloth, a scale inhibitor, and a central tube with a cavity structure; a screen is provided at one end of the central tube, and a sealing part is also provided inside the central tube; a scale inhibitor is placed between the screen and the sealing part; multiple desalination layers are wrapped on the central tube, each desalination layer is formed by the inlet screen being placed in the middle of the folded membrane, and adjacent desalination layers are separated by the product water guiding cloth; multiple water collection holes are provided on the central tube.

[0008] Optionally, the membrane is a PE-based reverse osmosis membrane.

[0009] Optionally, the membrane is a PE-based nanofiltration membrane.

[0010] Furthermore, the edge of the strainer is provided with multiple cards; the wall of the central tube is provided with a groove; the strainer is detachably disposed at one end inside the central tube by inserting the cards into the groove.

[0011] Optionally, the water-generating guide cloth is woven from activated carbon fibers.

[0012] Furthermore, the water-producing guide fabric is woven with multiple rows of intersecting protrusions, and the grooves between two adjacent rows of protrusions serve as guide channels.

[0013] Secondly, the present invention provides a method for preparing the composite filter element as described above, wherein one end of the water-producing guide cloth is glued to the central tube, a folded membrane is placed on the water-producing guide cloth, and an inlet screen is placed in the middle of the folded membrane; the two folded membranes are glued together to fix the three sides except for the folds; then, before the glue is cured, the membrane coated with glue is evenly rolled onto the central tube and fixed with tape, and cut to size to become the finished composite filter element.

[0014] The beneficial effects of this invention are as follows: by utilizing the structural characteristics of existing spiral wound reverse osmosis / nanofiltration membrane elements, and combining the performance advantages of thin PE-based membrane sheets with high desalination rate and large flux, the volume of water purification filter cartridges is effectively reduced while ensuring functions such as scale inhibition, filtration and purification, and water production and desalination rate. This makes water purification equipment lighter and filter cartridges easier to install.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the composite filter element structure according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the circular mesh structure with buckles described in an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the central tube structure containing scale inhibitor according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of a flow-guiding cloth structure with flow-guiding channels woven from activated carbon fiber filaments, as described in an embodiment of the present invention.

[0021] Figure 5 This is an unfolded diagram of the composite filter element structure according to an embodiment of the present invention.

[0022] Wherein: 501-Membrane; 502-Inlet screen; 503-Product water flow guide cloth; 504-Scale inhibitor; 505-Center tube; 201-Card; 202-Screw mesh; 301-Groove; 302-Sealing part; 303-Water collection hole; 401-Protrusion; 402-Flow guide channel. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as here.

[0026] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0027] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0028] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In the description of this specification, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this technology.

[0030] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of these terms in this art according to the specific circumstances.

[0031] To facilitate understanding of the present invention, the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0032] Those skilled in the art should understand that the accompanying drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0033] like Figures 1 to 5 As shown, this embodiment provides a composite filter element. The main raw materials of this composite filter element include: a membrane 501, such as a thin PE-based reverse osmosis / PE-based nanofiltration membrane; an inlet water separator 502; and a product water guiding cloth 503 woven from activated carbon fiber with guiding channels 402. The membrane 501, inlet water separator 502, and product water guiding cloth 503 are all rolled onto a central tube 505. The interior of the central tube 505 is hollow, with a strainer 202 at one end. A sealing part 302 is also provided inside the central tube 505, which mainly serves to separate the internal space of the central tube 505. A scale inhibitor 504 is placed between the strainer 202 and the sealing part 302.

[0034] The aforementioned composite filter element, by placing a scale inhibitor inside the central tube 505, has a scale-inhibiting function and can improve the taste of the produced water. It is not only small in size but also has a high flow rate. Its structure is as follows: Figure 1 As shown, a calculated amount of FOF scale inhibitor 504 is placed inside a cavity structure with a mesh 202 in the upper part of the central tube 505. The mesh 202 at the top of this cavity structure is attached to the central tube 505 via a snap-fit ​​mechanism, enabling the removal and addition of scale inhibitor. This snap-fit ​​is a circular mesh 202 with three clips 201. The clips 201 are snapped into corresponding grooves 301 on the central tube 505. By pressing and rotating, the mesh 202 can be removed from the grooves 301, thus completing the addition of scale inhibitor.

[0035] In a specific embodiment, during filter cartridge operation, the flushing action of the influent water on the scale inhibitor 504 enables the scale inhibitor 504 to perform its scale-inhibiting function, increasing the stability of calcium and magnesium ions and preventing scale formation. For example... Figure 3 As shown, a sealing section 302 is provided at one-quarter of the cavity of the central tube 505 from top to bottom, dividing the central tube 505 into upper and lower parts, with the water in the two parts completely isolated from each other. Water collection holes 303 are evenly distributed on the lower three-quarters of the central tube wall. Specifically, in this embodiment, two rows of water collection holes 303 are provided, with six holes in each row.

[0036] In practical applications, the number of rows of water collection holes 303 and the number of holes in each row are not limited by the above-mentioned quantity. Those skilled in the art can set the number of rows of water collection holes and the number of water collection holes in each row according to the actual situation.

[0037] The composite filter cartridge described in this embodiment mainly achieves the functions of water purification and improving the taste of the produced water. The main membrane element that achieves these two functions includes a water distribution cloth 503 (such as...) woven from activated carbon fibers and featuring grooved flow channels 402. Figure 4 As shown in the image, the membrane consists of a PE-based reverse osmosis / nanofiltration membrane with a thickness of approximately 20 μm, characterized by high desalination and high flux, an inlet water separator 502, and a central tube 505 with a cavity. The product water guiding cloth 503 is primarily composed of activated carbon fiber filaments woven using existing weaving techniques, forming a grooved activated carbon fiber product water guiding cloth on one side. Figure 4 As shown, in the water production guide fabric 503, the cross-shaped protrusions 401 formed by weaving are the edges of the grooves. The depth of the grooves is determined by the height of the cross-weaving of the protrusions. The grooves formed by two adjacent rows of protrusions 401 are the guide channels 402, which provide a flow channel for the water produced by the membrane and accelerate the flow of the water.

[0038] The membrane element is composed of an activated carbon fiber guide cloth pre-bonded to the central tube 505, and a PE-based membrane sheet 501 with a desalination layer folded on one side and an inlet water separator 502 placed in the middle (see...). Figure 5 Adjacent folded membrane sheets are separated by grooved activated carbon fiber guide cloth, and the two membrane sheets are glued together, fixing them on three sides except for the folds. Then, before the glue cures, the membrane sheets are evenly rolled onto the central tube 505 and secured with tape. After being cut to size, they become the finished composite filter element. Figure 1 The composite filter element is infused with a metered amount of scale inhibitor 504. Raw water flows into the central tube cavity through the snap-on disc-type strainer, flushing the FOF scale inhibitor. The raw water containing the scale inhibitor then enters the main body of the filter element, participating in the water production process of the membrane element and achieving the scale inhibition effect.

[0039] In the composite filter cartridge, a grooved flow-guiding cloth woven from activated carbon fibers is sealed between two adjacent folded membrane sheets. Its inherent grooved structure provides a flow channel 402 for the collection and flow of produced water. The activated carbon fiber filaments themselves have the function of adsorbing and purifying water. The produced water from adjacent membrane sheets flows through the flow-guiding cloth and then collects at the central tube 505 through the water collection holes 303. During this process, impurities affecting the taste remaining in the produced water are adsorbed and purified. The water flowing out of the central tube is purified and has improved taste. The composite filter cartridge uses a woven cloth with water-guiding grooves made of activated carbon fibers with adsorption properties as the flow-guiding cloth. This flow-guiding cloth, which simultaneously has adsorption, purification, and water-guiding functions, can replace pre- and post-activated carbon filter cartridges, improving taste while saving space. The composite filter cartridge uses a central tube with a sealing section at one-quarter of the way down, dividing the central tube cavity into two parts. The upper quarter section, when used in conjunction with a snap-fit ​​circular mesh screen, forms a cavity of a certain volume, into which FOF scale inhibitor with scale inhibition function is placed.

[0040] In summary, the composite filter element of this embodiment includes: a membrane 501, an inlet screen 502, a product water guiding cloth 503, a scale inhibitor 504, and a central tube 505 with a cavity structure; a strainer 202 is provided at one end of the interior of the central tube 505, and a sealing part 302 is also provided inside the central tube 505; the scale inhibitor 504 is placed between the strainer 202 and the sealing part 302; multiple desalination layers are wrapped on the central tube 505, each desalination layer is formed by the inlet screen 502 in the middle of the folded membrane 501, and adjacent desalination layers are separated by the product water guiding cloth 503; multiple water collection holes 303 are provided on the central tube 505. In the manufacturing process of this composite filter element, one end of the water production guide cloth 503 is first glued to the central tube 505. A folded membrane 501 is placed on the water production guide cloth 503, and an inlet mesh 502 is placed in the middle of the folded membrane 501. The two folded membranes 501 are glued together to fix the three sides except for the folds. Then, before the glue is cured, the membrane with glue is evenly rolled onto the central tube 505 and fixed with tape. After being cut to size, it becomes the finished composite filter element.

[0041] The composite filter element described in this embodiment of the invention uses a PE-based membrane sheet with a thickness of only about 20μm, a high desalination rate, and a large flux as one of the main raw materials for achieving the water purification function. Compared with a non-woven fabric-based membrane sheet with a thickness of 140μm, the thinner PE-based membrane sheet can reduce the size of the membrane element while ensuring the water production flux.

[0042] In this embodiment, membrane elements of the same type (e.g., 3113) were fabricated using both PE-based and conventional non-woven fabric-based membrane sheets. The thickness of the separator and permeate flow guide fabric was the same (both using the thinnest products currently available on the market: inlet separator 0.28mm; permeate flow guide fabric 0.17mm). Calculations showed that the effective area of ​​the two types of membrane elements with the same diameter was 3.61m². 2 and 2.3m 2 The same effective film area (0.35m²) was produced by rolling the PE base film of this invention and the conventional nonwoven base film, respectively. 2 The membrane elements used were of the same thickness, with the same separator and permeate flow guide cloth. The final diameters of the rolled membrane elements were 45 mm and 48 mm, respectively. Performance data at 60 psi pressure, 50% recovery, and 500 ppm sodium chloride as feed water are shown in Table 1.

[0043]

[0044] In summary, this invention utilizes activated carbon fibers with adsorption properties woven into a composite filter element to improve the taste of the produced water without increasing the difficulty of the winding process or compromising the water-guiding channels of the filter element, thus reducing the resistance to water flow on the filter element. No new raw materials are added between the two membrane sheets, maintaining a minimum thickness between them and not increasing the diameter of the composite filter element. To avoid adding front and rear antiscalant devices, FOF antiscalant is placed in the upper cavity of the central tube, improving and delaying scaling on the membrane element and increasing its lifespan. The introduction of thin, high-performance PE-based membrane sheets further reduces the volume of the composite filter element.

[0045] The FOF scale inhibitor placed in the upper cavity of the central tube of this invention primarily functions to allow the incoming water carrying scale inhibitor molecules to participate in the water purification process of the composite filter element, delaying or preventing scale formation without increasing the overall volume of the composite filter element. Therefore, composite filter elements made by placing any scale inhibitor in any form in other parts of the central tube cavity are all within the scope of this patent. The activated carbon fiber woven water-guiding cloth with flow channels mainly achieves the functions of guiding water and improving taste. Compared with existing water-guiding cloths, it adds the function of improving the taste of the produced water without introducing other disadvantages. Other water-guiding cloths woven with activated carbon fibers with any form of flow channels, when applied to composite filter elements, are also within the scope of this patent.

[0046] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solutions disclosed in the present invention, various modifications or variations that can be made by those skilled in the art without creative effort should be included within the scope of protection of the present invention.

Claims

1. A composite filter cartridge, characterized by, The application relates to a composite filter core, which comprises a film sheet (501), a water inlet screen (502), a water production guide cloth (503), a scale inhibitor (504) and a center tube (505) with a cavity structure; one end of the center tube (505) is provided with a screen (202), and the center tube (505) is further provided with a sealing part (302); the scale inhibitor (504) is arranged between the screen (202) and the sealing part (302); the center tube (505) is wrapped with multiple desalination layers, each of the desalination layers is formed by folding the film sheet (501) and arranging the water inlet screen (502) in the middle of the film sheet (501), and the adjacent two desalination layers are separated by the water production guide cloth (503); multiple water collecting holes (303) are formed in the center tube (505); multiple clamping cards (201) are arranged at the edge of the screen (202); a groove (301) is arranged on the wall of the center tube (505); the screen (202) is detachably arranged at one end of the center tube (505) by clamping the clamping card (201) into the groove (301); the water production guide cloth (503) is woven by active carbon fibers; multiple rows of cross-shaped protrusions (401) are woven on the water production guide cloth (503), and the grooves between the adjacent two rows of protrusions (401) are guide channels (402). The film sheet (501) is a PE-based reverse osmosis membrane.

2. The composite filter cartridge of claim 1, wherein, The film sheet (501) is a PE-based nanofiltration membrane sheet.

3. The composite filter cartridge of claim 1, wherein, One end of the water production guide cloth (503) is bonded to the center tube (505), the folded film sheet (501) is arranged on the water production guide cloth (503), and the water inlet screen (502) is arranged in the middle of the folded film sheet (501); the two film sheets (501) are fixed by adhesive except for the three edges of the folds; then the film sheet coated with the adhesive is uniformly rolled on the center tube (505) before the adhesive is solidified, and the film sheet is fixed by winding with adhesive tape; and the composite filter core product is obtained after cutting according to the size.

4. A method of producing a composite filter element according to any one of claims 1 to 3, characterized in that ​

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