Filter cartridge assembly and filter including therein

Abstract

This invention discloses a filter element assembly and a filter including the same. The filter element assembly includes a central tube, a filter membrane assembly, a modified nonwoven fabric, an upper end cap, and a lower end cap. A water collection hole is formed on the side wall of the central tube. One end of the modified nonwoven fabric is fixed along the axial direction of the central tube and wound around the outer circumference of the central tube and fixed to the outer circumferential surface of the central tube. The other end of the modified nonwoven fabric covers the filter membrane assembly and is wound around it along the axial direction of the central tube and fixed to form a wound body. The upper end cap and the lower end cap are respectively fitted onto the two ends of the wound body. A long strip-shaped second through hole is formed on the lower end cap. The modified nonwoven fabric wound around the outer wall of the central tube of this invention can remove heavy metals and, in conjunction with the filter membrane assembly, remove some minerals. The long strip-shaped second through hole on the lower end cap can reduce the dead zone on the membrane surface and reduce the amount of pollutants deposited on the membrane surface, which not only improves the lifespan of the filter element assembly but also avoids reducing the filtration effect of the filter element assembly.

Description

Technical Field

[0001] This invention relates to the field of water purification and filtration technology, and in particular to a filter cartridge assembly and a filter including the same. Background Technology

[0002] Currently, spiral wound filter cartridges are widely used in industrial water treatment and household water purification. Conventional spiral wound filter cartridges generally employ an "end-to-end" flow pattern. However, this flow pattern, due to its wide flow channel and short flow path, results in low fluid velocity and severe concentration polarization on the membrane surface. Severe concentration polarization leads to three problems: First, increased salt concentration on the membrane surface, resulting in decreased desalination rate and reduced flow rate; second, increased contaminant concentration on the membrane surface, making it more susceptible to fouling, further reducing filter flow rate and lifespan; and third, the decreased fluid velocity makes it difficult to flush away contaminants deposited on the membrane surface, leading to contaminant enrichment and further shortening filter lifespan. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art in which the "end-to-end" flow mode of the filter element assembly easily leads to excessive salt concentration in the membrane, resulting in a decrease in the desalination rate of the filter element, a decrease in the flow rate of the filter element, and easy fouling of the membrane. The present invention provides a filter element assembly and a filter including the thereof.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] This invention provides a filter element assembly, which includes a central tube, a filter membrane assembly, a modified nonwoven fabric, an upper end cap, and a lower end cap.

[0006] The central tube has a water collection hole on its side wall and a clean water outlet at its upper end that communicates with the inner cavity of the central tube.

[0007] The filter membrane assembly includes multiple parallel stacked membrane units, each with the same opening. Each membrane unit includes two single membranes connected in sequence. Each single membrane is folded to form a first part and a second part, the length of the first part being greater than the length of the second part. The second parts of adjacent single membranes within each membrane unit are interconnected, and the first parts of adjacent single membranes within adjacent membrane units are interconnected. The inner surface of each single membrane is smooth, and the space between the smooth surface of the first part and the smooth surface of the second part of each single membrane forms a raw water channel. The space between the smooth surfaces of the first parts of the mating single membranes of each membrane unit forms a wastewater channel. The spaces between the outer surfaces of the two mating second parts of each membrane unit, and between the outer surfaces of the two mating first parts of adjacent membrane units, both form purified water channels.

[0008] The filter membrane assembly also includes multiple flow guide cloths, each of which is disposed in the water purification channel. Each flow guide cloth is inserted one-to-one between the outer surfaces of two adjacent second parts in each membrane unit, and between the outer surfaces of two adjacent first parts of adjacent membrane units.

[0009] The filter membrane assembly also includes multiple grids, which are respectively inserted between the smooth surfaces of the first part and the second part of each membrane unit;

[0010] The modified nonwoven fabric is disposed below the filter membrane assembly and is attached to the outer side of the first portion of the first membrane unit; one end of the modified nonwoven fabric is fixed along the axial direction of the central tube and is wound around the central tube at least once and fixed on the outer circumferential surface of the central tube; the other end of the modified nonwoven fabric extends outward to cover the filter membrane assembly and is wound around the central tube along the axial direction and fixed to form a wound body.

[0011] The upper end cap and the lower end cap are respectively sleeved on both ends of the winding body, and the lower end of the central tube is sealed to the lower end cap;

[0012] The upper end cover has an annular first through hole, the central tube passes through the first through hole and forms a gap with the inner circumferential surface of the first through hole, the gap forms a raw water inlet, and the inner top surface of the upper end cover is sealed to the upper end surface of the winding body.

[0013] The lower end cap has a long strip-shaped second through hole, which extends radially outward along the outer wall of the modified nonwoven fabric. The inner bottom surface of the lower end cap is sealed to the lower end surface of the winding body.

[0014] The filter assembly also includes a tape arranged circumferentially along the outer periphery of the winding body, and the tape is uniformly provided with concentrated water outlets for concentrated water to flow out.

[0015] In this design, a modified non-woven fabric is wound around the outer wall of the central tube. This not only reduces the size of the filter element assembly, optimizes the water flow path, and reduces flow resistance, but also removes heavy metals and, by combining with the filter membrane assembly, removes some minerals, achieving the effect of removing heavy metals while retaining minerals. The elongated second through-hole on the lower end cap reduces dead zones on the membrane surface, decreasing the amount of contaminants deposited on the membrane surface. This not only improves the lifespan of the filter element assembly but also prevents a reduction in its filtration efficiency. Furthermore, the elongated second through-hole simplifies the molding and assembly process. When sealing the lower end cap and the winding body, only the inner bottom surface of the lower end cap needs to be coated with adhesive; there is no need to apply adhesive to the winding body. This prevents the concentrated water outlet on the winding body from aligning with the water outlet on the lower end cap, which could lead to blockage of the second through-hole.

[0016] Preferably, there are multiple second through holes, which are spaced apart along the circumference of the central tube.

[0017] Preferably, the distance between the second through hole and the outer wall surface of the modified nonwoven fabric is no greater than 5% of the lay-up length of the wound body.

[0018] Preferably, the flat length of the raw water inlet accounts for 10% to 50% of the flat length of the wound body.

[0019] Preferably, the lay-up length of the second through hole accounts for 10% to 30% of the lay-up length of the wound body;

[0020] And / or, the tiling length of the second through hole accounts for 0.01% to 1% of the tiling length of the first portion.

[0021] Preferably, the length of the second portion in each of the single membranes is 10%-50% of the length of the first portion.

[0022] Preferably, the single membrane in the filter membrane assembly is one or a combination of nanofiltration membranes or reverse osmosis membranes.

[0023] Preferably, both single membranes in each membrane unit are nanofiltration membranes;

[0024] Alternatively, both individual membranes in each membrane unit may be reverse osmosis membranes;

[0025] Alternatively, the two individual membranes in each membrane unit may be a nanofiltration membrane and a reverse osmosis membrane, respectively.

[0026] Preferably, the inner top surface of the upper end cover is coated with sealant;

[0027] And / or, the inner bottom surface of the lower end cap is coated with sealant.

[0028] The present invention also provides a filter comprising the filter element assembly as described above.

[0029] The positive and progressive effects of this invention are as follows:

[0030] 1. The modified non-woven fabric wrapped around the outer wall of the central tube can not only reduce the volume of the filter element, optimize the water flow path, and reduce flow resistance; but also remove heavy metals and, combined with the filter membrane, remove some minerals, thus achieving the effect of removing heavy metals while retaining minerals.

[0031] 2. The elongated second through-hole on the lower end cap reduces dead zones on the membrane surface, decreasing the amount of contaminants deposited. This not only extends the lifespan of the filter element assembly but also prevents a reduction in its filtration efficiency. Furthermore, the elongated second through-hole simplifies the molding and assembly process. When sealing the lower end cap and the winding body, only the entire inner bottom surface of the lower end cap needs to be coated with adhesive; there's no need to apply adhesive to the winding body. This prevents the concentrated water outlet on the winding body from aligning with the water outlet on the lower end cap, which could lead to blockage of the second through-hole. Attached Figure Description

[0032] Figure 1 This is a three-dimensional structural diagram of the filter element assembly according to Embodiment 1 of the present invention.

[0033] Figure 2 This is a schematic diagram of the structure of the filter element assembly before winding according to Embodiment 1 of the present invention.

[0034] Figure 3 This is a schematic diagram of the wound structure of the filter element assembly according to Embodiment 1 of the present invention. Figure 1 .

[0035] Figure 4 This is a schematic diagram of the wound structure of the filter element assembly according to Embodiment 1 of the present invention. Figure 2 .

[0036] Figure 5 This is a front view of the upper cover of Embodiment 1 of the present invention.

[0037] Figure 6 This is a schematic diagram showing the position of the first through hole in Embodiment 1 of the present invention.

[0038] Figure 7 This is a front view of the lower end cap of Embodiment 1 of the present invention.

[0039] Figure 8 This is a schematic diagram showing the position of the second through hole in Embodiment 3 of the present invention.

[0040] Figure 9 This is a schematic diagram of the filter element of the present invention as a comparative example.

[0041] Figure 10This is a schematic diagram of the structure of the filter element before winding, which is a comparative example of the present invention.

[0042] Figure 11 This is a schematic diagram showing the position of the second through hole in Embodiment 4 of the present invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] Central tube 100

[0045] Water collection hole 101

[0046] Water purification outlet 102

[0047] Filter membrane module 200

[0048] Single membrane 210

[0049] Flow guide cloth 211

[0050] Grid 212

[0051] Top cover 220

[0052] First through hole 221

[0053] Lower end cap 230

[0054] Second through hole 231

[0055] 240 tape

[0056] Concentrate outlet 241

[0057] Modified nonwoven fabric 250 Detailed Implementation

[0058] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0059] Example 1

[0060] like Figure 1-7 As shown, this embodiment provides a filter element assembly, which includes a central tube 100, a filter membrane assembly 200, a modified nonwoven fabric 250, an upper end cap 220, and a lower end cap 230.

[0061] A water collection hole 101 is provided on the side wall of the central pipe 100, and a clean water outlet 102 communicating with the inner cavity of the central pipe 100 is provided at the upper end of the central pipe 100.

[0062] The filter membrane module 200 includes multiple parallel stacked membrane units, each with the same opening and located away from the central tube 100. Each membrane unit includes two single membranes 210 connected in sequence. Each single membrane 210 is folded to form a first part and a second part, with the length of the first part being greater than the length of the second part. The second parts of adjacent single membranes 210 within each membrane unit are interconnected, and the first parts of adjacent single membranes 210 within adjacent membrane units are interconnected. The inner surface of each single membrane 210 is smooth, and the space between the smooth surface of the first part and the smooth surface of the second part of each single membrane 210 forms a raw water channel. The space between the smooth surfaces of the first parts of the mating single membranes 210 within each membrane unit forms a wastewater channel. The spaces between the outer surfaces of the two mating second parts of each membrane unit, and between the outer surfaces of the two mating first parts of adjacent membrane units, both form purified water channels.

[0063] The filter membrane module 200 also includes a plurality of flow guide cloths 211, each flow guide cloth 211 being disposed in the water purification channel. Each flow guide cloth 211 is inserted one-to-one between the outer surfaces of the two adjacent second parts in each membrane unit, and between the outer surfaces of the two adjacent first parts of adjacent membrane units.

[0064] The filter membrane module 200 also includes a plurality of grids 212, which are respectively inserted between the smooth surfaces of the first and second portions of each membrane unit.

[0065] The modified nonwoven fabric 250 is wrapped around the circumference of the central tube 100 and fixed to the outer circumferential surface of the central tube 100.

[0066] The modified nonwoven fabric 250 is disposed below the filter membrane assembly 200 and is attached to the outer side of the first part of the first membrane unit; one end of the modified nonwoven fabric 250 is fixed on the central tube 100 along the axial direction of the central tube 100, and the other end of the modified nonwoven fabric 250 covers the filter membrane assembly 200 and is wound and fixed along the axial direction of the central tube 100 to form a wound body.

[0067] The upper end cap 220 and the lower end cap 230 are respectively fitted onto the two ends of the winding body, and the lower end of the center tube 100 is sealed to the lower end cap 230.

[0068] The upper end cover 220 has an annular first through hole 221. The central tube 100 passes through the first through hole 221 and forms a gap with the inner circumferential surface of the first through hole 221. The gap forms the raw water inlet. The inner top surface of the upper end cover 220 is sealed to the upper end surface of the winding body.

[0069] The lower end cover 230 has a long strip-shaped second through hole 231. The second through hole 231 extends radially outward along the outer wall of the modified nonwoven fabric 250. The inner bottom surface of the lower end cover 230 is sealed to the lower end surface of the winding body.

[0070] The filter assembly also includes a tape 240 arranged circumferentially along the outer periphery of the winding body, and a concentrated water outlet 241 uniformly opened on the tape 240 for concentrated water to flow out.

[0071] When the filter assembly is working, a portion of the raw water enters the winding body from the raw water inlet on the upper end cover 220 and flows along the adjacent raw water channels, thus presenting a side-flow pattern. This side-flow pattern can reduce the channel width, increase the channel length, and improve the fluid velocity on the membrane surface, thereby enhancing the performance and extending the life of the filter assembly. Another portion of the raw water enters the winding body from the raw water inlet and flows directly out from the second through hole 231 at the lower end of the winding body, which can avoid and reduce the deposition of contaminants on the membrane surface and prevent the formation of a flow dead zone at the bottom of the raw water inlet. Clean water is generated from the clean water channel between the outer surfaces of two adjacent single membranes 210 and flows into the central tube 100, and flows into the inner cavity of the central tube 100 through the water collection hole 101 on the side wall of the central tube 100, and finally flows out through the clean water outlet 102 at the upper end of the central tube 100.

[0072] In this embodiment, the raw water entering the winding body and flowing out from the second through-hole 231 can reduce the deposition of pollutants on the membrane surface, thereby reducing the fluid dead zone on the membrane surface. This not only improves the lifespan of the filter element assembly but also avoids reducing the filtration efficiency of the filter element assembly. At the same time, the elongated second through-hole 231 simplifies the molding and assembly process. When sealing the lower end cover 230 and the winding body, the entire inner bottom surface of the lower end cover 230 can be coated with adhesive, eliminating the need to apply adhesive to the winding body. This prevents the outlet on the winding body from not aligning with the second through-hole 231 on the lower end cover 230, which could lead to the second through-hole 231 being blocked.

[0073] The modified nonwoven fabric 250 wound on the outer wall of the central tube 100 in this embodiment can not only reduce the volume of the filter element assembly, optimize the water flow path, and reduce flow resistance, but also remove heavy metals and remove some minerals by combining with the filter membrane assembly 200, thus achieving the effect of removing heavy metals while retaining minerals.

[0074] The second through-hole 231 is designed as an elongated strip. This serves two purposes: firstly, it connects the second through-hole 231 to each individually wound membrane sheet 210, ensuring that each membrane sheet 210 has a second through-hole 231, and that the size of the second through-hole 231 on each membrane sheet 210 is consistent; secondly, the elongated design simplifies machining accuracy and mold requirements compared to the annular water outlet design. However, due to potential deviations in the stacking of the membrane sheets 210 during the winding process, it is difficult to align the annular water outlet with the membrane sheets 210, making it difficult to guarantee that raw water can flow out from each membrane sheet 210. Furthermore, it is difficult to ensure that the size of the water outlets between each membrane sheet 210 is consistent, thus also making it impossible to guarantee that the flow rate of raw water flowing out from each membrane sheet 210 is the same. The elongated second through-hole 231 can reduce the dead zone on the membrane surface and reduce the amount of pollutants deposited on the membrane surface. This not only improves the lifespan of the filter element assembly but also prevents a reduction in the filtration efficiency of the filter element assembly.

[0075] In this embodiment, as Figure 6 As shown, the distance between the second through hole 231 and the outer wall of the first nonwoven fabric 250 is 0. The fact that some raw water flows out from the second through hole 231 can prevent pollutants from depositing on the inner side of the membrane.

[0076] In this embodiment, as Figure 5 As shown, the flat length of the raw water inlet accounts for 30% of the flat length of the winding body. By limiting the flat length of the raw water inlet, on the one hand, it can ensure that the size of the raw water inlet is large enough, ensuring that the water resistance of the raw water inlet is small and avoiding the risk of the raw water inlet being blocked by pollutants; on the other hand, it ensures that most of the fluid in the raw water channel is in a side flow state, that is, flowing from the central pipe 100 to the direction of the concentrated water outlet 241, so that most of the raw water is in a high-speed flow state.

[0077] In other embodiments, the lay-up length of the raw water inlet is any value between 10% and 50% of the lay-up length of the winding.

[0078] In this embodiment, the length of the second through hole 231 accounts for 20% of the flat length of the wound body. By limiting the flat length of the second through hole 231, the fluid flow becomes poor or a dead zone appears at the corner due to the second through hole 231 being too short, thereby avoiding the risk of serious pollution and scaling at the corner; it also prevents a large amount of raw water from flowing directly out of the second through hole 231 due to the second through hole 231 being too long, thereby avoiding a reduction in the water flow area and a decrease in the purified water flow rate of the filter element assembly.

[0079] In other embodiments, the lay-up length of the second through-hole 231 is any value between 10% and 30% of the lay-up length of the winding.

[0080] In this embodiment, the flat length of the second through hole 231 is 0.05% of the flat length of the first part, which can prevent the opening of the second through hole 231 from being too large, causing a large amount of raw water to flow directly out of the second through hole 231, thereby avoiding the reduction of the water flow area and the decrease of the water flow rate of the filter element assembly.

[0081] In this embodiment, the length of the second part in each single membrane sheet is 30% of the length of the first part. On the one hand, it can combine the two streams of raw water in the two single membrane sheets 210 into one stream of raw water, which can significantly increase the fluid flow rate to reduce the concentration polarization phenomenon on the membrane surface, slow down the deposition rate and amount of pollutants, and improve the performance and life of the filter element assembly. Specifically, it can increase the raw water flow rate by 100%. On the other hand, it can ensure the feasibility of the filter element assembly manufacturing process and the stability of the filter element assembly operation, and prevent the raw water flow rate from being too high, which would reduce the stability of the inlet and outlet water during the filtration of the filter element assembly.

[0082] In other embodiments, the ratio of the length of the second portion to the length of the first portion in each single membrane can be any value between 10% and 50%.

[0083] In this embodiment, the single membrane sheet in the filter membrane assembly is one or a combination of nanofiltration membranes or reverse osmosis membranes. Specifically, the two single membrane sheets 210 in each membrane unit are a nanofiltration membrane and a reverse osmosis membrane, respectively. By overlapping the nanofiltration membrane and the reverse osmosis membrane and sharing a single inlet channel, the fouling of the reverse osmosis membrane surface can be effectively reduced, the degradation of the reverse osmosis membrane's lifespan can be slowed down, and the lifespans of the nanofiltration membrane and the reverse osmosis membrane can be made more consistent, thereby extending the lifespan of the entire filter cartridge. By adjusting the ratio of the number of reverse osmosis membranes to nanofiltration membranes, the desalination rate of the filter cartridge can be adjusted.

[0084] In other embodiments, both single membranes 210 in each membrane unit are either reverse osmosis membranes or both are nanofiltration membranes.

[0085] In this embodiment, sealant is applied to the inner top surface of the upper end cover 220 and the inner bottom surface of the lower end cover 230.

[0086] The manufacturing method of the filter element assembly in this embodiment includes: S1, folding multiple single membrane sheets 210 in half, and sealing the second part of adjacent single membrane sheets 210 with the side of the second part parallel to the axis of the central tube, and sealing the first part with the side of the first part parallel to the axis of the central tube. Specifically, sealing is performed by applying glue (not shown in the figure) to the outer surface of the single membrane sheet 210; S2, fixing one end of the modified nonwoven fabric 250 to the outer wall of the central tube 100 and wrapping it around twice and fixing it; S3, inserting the guide cloth 211 one-to-one between the outer surfaces of the two adjacent second parts in each membrane unit, and between the outer surfaces of the two adjacent first parts of adjacent membrane units; S4, inserting the grid 212 one-to-one into the adjacent single membrane sheets 210. S5. Between the smooth surfaces of the first and second parts of 10; S6. Fix one end of the modified nonwoven fabric 250 to the outer wall of the central tube 100; and wind and fix the layer structure formed by stacking the modified nonwoven fabric 250, single membrane 210, flow guide cloth 211, and grid 212 along the central tube 100 to form a wound body; S7. Use tape 240 with concentrated water outlet 241 to fix the outer peripheral surface of the wound body; S8. Apply glue to the inner top surface of the upper end cover 220 and the inner bottom surface of the lower end cover 230, avoiding the first through hole 221 and the second through hole 231 respectively when applying glue, and clamp the upper end cover 220 and the lower end cover 230 to the two ends of the wound body to achieve a seal, so that the raw water can enter the wound body from the first through hole 221 and then flow out of the wound body from the second through hole 231.

[0087] This embodiment also provides a filter, which includes the filter element assembly described above.

[0088] Example 2

[0089] This embodiment has the same structure as Embodiment 1, except that the length of the second through hole 231 is 1% of the length of the first part. This can avoid the fluid flow becoming poor or dead zones appearing at the fluid corner due to the second through hole 231 being too narrow, thereby avoiding the risk of serious pollution and scaling at the fluid flow corner.

[0090] Example 3

[0091] This embodiment has the same structure as Embodiment 1, the difference being: Figure 8 As shown, there are four second through holes 231, which are evenly spaced on the bottom surface of the lower end cover 230. This can enhance the flow guiding effect of the filter element, allowing some raw water to enter from the raw water inlet and flow along the smooth surface of the single membrane 210, while the other part of the raw water flows out from the end of the winding body after passing through the second through holes 231, thus discharging the raw water at the bottom of the winding body. This can prevent the raw water that enters the winding body vertically from depositing at the bottom of the filter element when it flows circumferentially towards the winding body, thereby avoiding a reduction in the service life of the filter element.

[0092] Comparative Example

[0093] The filter cartridge assembly of this comparative example includes a central tube and a filter membrane assembly. A water collection hole is provided on the side wall of the central tube, and a clean water outlet communicating with the inner cavity of the central tube is provided at the upper end of the central tube.

[0094] like Figure 10 As shown, the filter membrane module includes multiple parallel stacked membrane sheets; the opening directions of each membrane sheet after folding are the same, and a raw water channel is formed between the two opposing smooth surfaces formed after each membrane sheet is folded. The sides of two adjacent membrane sheets are sealed to form a purified water channel between the outer surfaces of the two adjacent membrane sheets. The folded membrane sheets are fixedly connected to the outer wall of the central tube at the fold, and the multiple membrane sheets are arranged sequentially at intervals along the circumference of the central tube and the winding direction to form a wound body.

[0095] The filter membrane module also includes multiple flow guide cloths, each of which is located in the water purification channel and is inserted between the outer surfaces of adjacent membrane sheets in a corresponding manner. The first flow guide cloth is attached to the outer surface of the first membrane sheet.

[0096] The filter membrane module also includes multiple grids, each of which is located in the raw water channel and is inserted one-to-one between the two opposing inner surfaces formed after each membrane sheet is folded in half.

[0097] The filter assembly also includes a tape arranged circumferentially along the outer periphery of the winding body.

[0098] No water-permeable holes are provided on the surface of the tape on the outer surface of the winding body; that is, the outer circumference of the winding body is sealed. Figure 9 As shown, raw water enters through the raw water inlet at one end of the winding body, flows through the raw water channel between the inner surfaces of two adjacent single membranes, and forms concentrated water at the other end of the winding body, flowing out. Its specific flow path is relatively short, only the width of the winding body. Purified water is generated from the purified water channel between the outer surfaces of two adjacent single membranes and flows into the central tube. It then flows into the inner cavity of the central tube through the water collection holes on the side wall of the central tube, and finally flows out through the purified water outlet at the upper end of the central tube.

[0099] The table below compares the performance data of the filter cartridges from Examples 1 to 3 with those of the comparative example filter cartridges:

[0100] Comparative Example Example 1 Example 2 Example 3 flow 2L / min 2L / min 2L / min 2L / min Desalination rate 75％ 83％ 78％ 81％ life 8t 12t 9.5t 11t

[0101] Under the same flow rate, the filter cartridge of Example 1 has a higher desalination rate and a longer service life compared to the filter cartridge of the comparative example.

[0102] Under the same flow rate, compared with the comparative example filter element, the filter element of Example 2 has a higher desalination rate and a longer lifespan; compared with Example 1, the filter element of Example 2 has a lower desalination rate and a shorter lifespan.

[0103] Under the same flow rate, compared with the comparative example filter element, the filter element of Example 3 has a higher desalination rate and a longer lifespan; compared with Example 1, the filter element of Example 3 has a lower desalination rate and a shorter lifespan.

[0104] Example 4

[0105] This embodiment has the same structure as Embodiment 1, the difference being: Figure 11 As shown, there is a gap between the second through hole 231 and the outer wall of the central tube 100. The second through hole 231 can also prevent the raw water flow from creating a dead zone at the bottom of the filter element near the outer wall of the central tube 100, thereby reducing the deposition of pollutants on the membrane surface. This not only improves the lifespan of the filter element assembly but also prevents a reduction in the filtration effect of the filter element assembly.

[0106] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A filter element assembly, characterized in that, The filter element assembly includes a central tube, a filter membrane module, a modified nonwoven fabric, an upper end cap, and a lower end cap. The central tube has a water collection hole on its side wall and a clean water outlet at its upper end that communicates with the inner cavity of the central tube. The filter membrane assembly includes multiple parallel stacked membrane units, each with the same opening. Each membrane unit includes two single membranes connected in sequence. Each single membrane is folded to form a first part and a second part, the length of the first part being greater than the length of the second part. The second parts of adjacent single membranes within each membrane unit are interconnected, and the first parts of adjacent single membranes within adjacent membrane units are interconnected. The inner surface of each single membrane is smooth, and the space between the smooth surface of the first part and the smooth surface of the second part of each single membrane forms a raw water channel. The space between the smooth surfaces of the first parts of the mating single membranes of each membrane unit forms a wastewater channel. The spaces between the outer surfaces of the two mating second parts of each membrane unit, and between the outer surfaces of the two mating first parts of adjacent membrane units, both form purified water channels. The filter membrane assembly also includes multiple flow guide cloths, each of which is disposed in the water purification channel. Each flow guide cloth is inserted one-to-one between the outer surfaces of two adjacent second parts in each membrane unit, and between the outer surfaces of two adjacent first parts of adjacent membrane units. The filter membrane assembly further includes multiple grids, which are respectively inserted one-to-one between the smooth surfaces of the first part and the second part of each membrane unit; The modified nonwoven fabric is disposed below the filter membrane assembly and is attached to the outer side of the first portion of the first membrane unit; one end of the modified nonwoven fabric is fixed along the axial direction of the central tube and is wound around the central tube at least once and fixed on the outer circumferential surface of the central tube; the other end of the modified nonwoven fabric extends outward to cover the filter membrane assembly and is wound around the central tube along the axial direction and fixed to form a wound body. The upper end cap and the lower end cap are respectively sleeved on both ends of the winding body, and the lower end of the central tube is sealed to the lower end cap; The upper end cover has an annular first through hole, the central tube passes through the first through hole and forms a gap with the inner circumferential surface of the first through hole, the gap forms a raw water inlet, and the inner top surface of the upper end cover is sealed to the upper end surface of the winding body. The lower end cap has a long strip-shaped second through hole, which extends radially outward along the outer wall of the modified nonwoven fabric. The inner bottom surface of the lower end cap is sealed to the lower end surface of the winding body. The filter assembly also includes a tape arranged circumferentially along the outer periphery of the winding body, and the tape is uniformly provided with concentrated water outlets for concentrated water to flow out.

2. The filter element assembly according to claim 1, characterized in that, The second through hole is provided in multiple ways, and the multiple second through holes are arranged at intervals along the circumference of the central tube.

3. The filter element assembly according to claim 1, characterized in that, The distance between the second through hole and the outer wall of the modified nonwoven fabric is no greater than 5% of the lay-up length of the wound body.

4. The filter element assembly according to claim 1, characterized in that, The flat length of the raw water inlet accounts for 10% to 50% of the flat length of the wound body.

5. The filter element assembly according to claim 1, characterized in that, The lay-up length of the second through hole accounts for 10% to 30% of the lay-up length of the wound body; And / or, the tiling length of the second through hole accounts for 0.01% to 1% of the tiling length of the first portion.

6. The filter element assembly according to claim 1, characterized in that, In each of the single membranes, the length of the second portion is 10%-50% of the length of the first portion.

7. The filter element assembly according to claim 1, characterized in that, The single membrane in the filtration membrane assembly is one or a combination of nanofiltration membranes or reverse osmosis membranes.

8. The filter element assembly according to claim 7, characterized in that, Both single membranes in each membrane unit are nanofiltration membranes; Alternatively, both individual membranes in each membrane unit may be reverse osmosis membranes; Alternatively, the two individual membranes in each membrane unit may be a nanofiltration membrane and a reverse osmosis membrane, respectively.

9. The filter element assembly according to claim 1, characterized in that, The inner top surface of the upper end cover is coated with sealant; And / or, the inner bottom surface of the lower end cap is coated with sealant.

10. A filter, characterized in that, Includes the filter element assembly as described in any one of claims 1-9.

Images