A filter membrane packet and a packaging method thereof

Abstract

The application discloses a filter membrane package and a packaging method thereof, and relates to the technical field of filter materials, which comprises a liquid inlet guide screen, a filter unit, a filter layer arranged on the side of the filtrate guide screen, and a plurality of filter membranes stacked to form a radial misalignment area at the packaging hole. The packaging hole is at least partially communicated with the first through hole, and the plurality of filter membranes at least comprises a first filter membrane with the largest packaging hole inner diameter and a second filter membrane with the smallest packaging hole inner diameter. The ring-shaped glue sealing layer covers the inner wall of the first through hole, the inner wall of the first filter membrane packaging hole, and the radial misalignment area between the adjacent packaging holes. The adhesive structure between the filter membranes is simple and effective, the processing method is simple, the processing cost is low, the feed liquid cannot flow out from the gap between the filter membranes, and the packaging effect of the ring-shaped glue sealing layer is good.

Description

Technical Field

[0001] This invention belongs to the field of filter material technology, and in particular relates to a filter membrane pack and its encapsulation method. Background Technology

[0002] In the biopharmaceutical industry, filtration membrane packs are commonly used for filtering or concentrating fluids containing large protein molecules. In the tangential flow process, the filtration membrane pack is usually composed of a filter layer and a flow guide screen. During use, the fluid flows tangentially from the surface of the membrane through the flow guide screen. A portion of the fluid passes through the membrane surface under pressure to form permeate and is discharged, while the large molecules are retained by the filter layer.

[0003] To ensure the stability of the filter membrane pack stack structure and meet the design requirements of the filter flow channel, potting adhesives (such as epoxy resin, polyurethane, or silicone) are typically used to solvent bond or directly heat seal the membrane pack. Since the potting adhesive can penetrate into the flow guide screen, the penetrated potting adhesive can ensure a strong bond between the flow guide screen and the filter layer.

[0004] In the process of filtering virus-containing liquids, the filter layer needs to use a virus-removing filter membrane. However, the virus removal rate is not sufficient after using a single-layer virus-removing filter membrane. Therefore, multiple filter membranes are usually stacked. However, since the filter membrane cannot be permeated by potting adhesive, the multiple filter membranes in the filter layer cannot be well bonded. During the use of the filter membrane pack, the liquid will flow through the gaps with low resistance instead of passing through the filter membrane. Therefore, the filter membrane cannot perform the filtering effect. At the same time, the poorly bonded filter membrane is also easily loosened and wrinkled by fluid impact during use, which affects the overall filtration effect and lifespan of the filter membrane pack.

[0005] Furthermore, Chinese patent CN104321133A discloses a "Virus Filter," which employs a porous hollow fiber membrane to achieve virus filtration. Its background section also mentions several prior art documents, most of which also utilize hollow fiber membranes, differing only in their membrane composition and the variation in pore size from the membrane wall center to the two surfaces. No one has yet proposed a design concept for virus filtration using a multi-layered, flat-sheet filter membrane stacked and encapsulated to form a membrane package. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a filter membrane package and its encapsulation method that can stack multiple filter membranes to achieve effective virus filtration, has a simple structure, and excellent filtration effect.

[0007] The technical solution adopted by this invention to solve its technical problem is: a filter membrane package, comprising at least:

[0008] The liquid inlet guide screen has a liquid inlet and through holes, which is used to guide the fluid to be filtered to permeate in a tangential direction;

[0009] A filtration unit is located downstream of the liquid inlet guiding screen, and includes at least a filtrate guiding screen and a filter layer located on the side of the filtrate guiding screen.

[0010] The filtrate guiding screen is provided with a first through hole and a filtrate outlet;

[0011] The filter layer is a multi-layer filter membrane, each of which has an encapsulation hole and a through hole. The encapsulation hole is at least partially opposite to and connected to the first through hole. The multi-layer filter membrane includes at least a first filter membrane with the largest inner diameter of the encapsulation hole and a second filter membrane with the smallest inner diameter of the encapsulation hole. The multi-layer filter membranes are stacked to form a radial misalignment region at the encapsulation hole.

[0012] An annular adhesive layer is formed inside the encapsulation hole. This annular adhesive layer covers the inner wall of the first through hole, the inner wall of the first filter membrane encapsulation hole, and the radial misalignment area between adjacent encapsulation holes, so as to form a sealed connection between each filter membrane layer and between the filtrate guiding screen and the filter layer.

[0013] This invention differs from traditional methods that filter viruses by altering the composition of the filter layer. Instead, it solves the virus filtration problem by increasing the number of filter membranes in the filter layer. Multiple filter membranes are sealed within encapsulation pores using an annular adhesive layer. This annular adhesive layer fills the radial misalignment areas between adjacent filter membranes, the inner wall of the first through-hole, and the inner sidewall of the first filter membrane located within the encapsulation pore. Specifically, some adhesive permeates into the filtrate guiding screen, filling its mesh. Filter membranes near the filtrate guiding screen are directly bonded to it, while the annular adhesive layer covers the inner wall of the first through-hole of the filtrate guiding screen. Since the filter membranes do not permeate with adhesive, the remaining filter membranes pass through the radial misalignment areas between the encapsulation pores. The adhesive filling the area forms an encapsulation, firmly adhering adjacent filter membranes. Simultaneously, an annular adhesive sealant layer is also adhered to the inner sidewall of the encapsulation pore of the first filter membrane. This indicates that the sidewall of the first filter membrane, with the largest encapsulation pore inner diameter, must be encapsulated with an annular adhesive sealant layer to adhere multiple filter membranes together through radially misaligned adhesion. Therefore, the annular adhesive sealant layer ensures a stable bond between all filter membranes and the filtrate guide screen, preventing liquid from seeping through gaps and guaranteeing good filtration performance. The sides of the annular adhesive sealant layer seal the filter membrane, and its upper and lower sides firmly adhere adjacent filter membranes, thereby sealing the encapsulation pores and ensuring that the liquid to be filtered enters from the inlet during filtration, covering the entire inlet guide screen.

[0014] During the use of the filter membrane pack, the liquid to be filtered enters from the inlet on one side. A portion of the liquid permeates through multiple filter membranes and flows out from the filtrate guide screen. The remaining unfiltered liquid forms permeate and is discharged from the inlet on the other side of the inlet guide screen. The annular sealant can block the flow channels in the sealing holes, preventing liquid from flowing out and ensuring the effectiveness of the flow path. At the same time, the inlet on the other side of the inlet guide screen can also be completely sealed, allowing all the liquid to be filtered from the inlet to pass through multiple filter membranes to form permeate before flowing out from the filtrate outlet.

[0015] The ring-shaped adhesive sealant layer completes the sealing connection between each layer of filter membrane, as well as between the filtrate guide screen and the filter layer. The entire connection structure is simple and effective, the processing method is simple, and the processing cost is low. The ring-shaped adhesive sealant layer solves the problem of poor sealing after multiple filter membranes are stacked, so that a stable bond can be achieved no matter how many filter membranes are used to form the filter layer. It can adapt to different filtration scenarios and has high flexibility of use.

[0016] Furthermore, the second filter membrane is located on the side of the filter layer away from the filtrate guiding screen; or, the second filter membrane is located on the side of the filter layer closer to the filtrate guiding screen.

[0017] The second filter membrane with the largest inner diameter of the encapsulation hole is located on the outside, allowing the adhesive to flow from the larger inner diameter encapsulation hole to the relatively smaller inner diameter encapsulation hole. This simplifies the fabrication of the annular seal and makes the adhesive structure more stable. The second filter membrane with the largest inner diameter of the encapsulation hole is located on the inside, preventing the second filter membrane with the smallest inner diameter from being located on the inside. This would prevent the adhesive layer on the inner wall of the encapsulation hole from being scraped off during the adhesive scraping process, which would prevent the annular seal from achieving a good seal. At the same time, it also allows the adhesive to flow down the steps to achieve a better seal.

[0018] Furthermore, the inner diameter of the encapsulation hole varies in a stepped manner, gradually decreasing from the side closest to the filtrate guiding screen outwards, or gradually increasing from the side closest to the filtrate guiding screen outwards.

[0019] The adhesive flows along the steps to ensure coverage of every area, meaning the annular sealant layer covers all radially misaligned areas. This structural design results in stronger adhesion between all the filter membranes in the filter layer. Because the inner diameter of the encapsulation hole changes in a stepped manner, all adjacent filter membranes not only have annular sealant layers on their sidewalls but also on the steps of the radially misaligned areas. This makes the adhesion between the filter membranes more stable. Due to the stable adhesion in both directions, liquid is less likely to break through the annular sealant layer and penetrate into the encapsulation hole, allowing the filtrate to be discharged from the filtrate outlet of the filtrate guide screen or from the inlet on the other side of the inlet guide screen.

[0020] Furthermore, the inner diameter of the first filter membrane encapsulation hole is d1, the inner diameter of the second filter membrane encapsulation hole is d2, the inner diameter of the first through hole is l, and 1.2d1≥l≥0.8d2.

[0021] The above numerical settings avoid excessive differences in the inner diameter of the encapsulation holes of the first and second filter membranes. They also prevent the first through-hole area of ​​the filtrate guiding screen from being too large, which would prevent the filtrate after filtration from being quickly and smoothly discharged, and would also prevent it from providing adequate support to the filter layer. Furthermore, they avoid situations where the radial misalignment area is too small, resulting in insufficient adhesion between adjacent filter membranes, or where the radial misalignment area is too large, leading to incomplete filling of this area by the adhesive, which in turn causes gaps in the annular sealant layer, allowing liquid to leak out and affecting the final filtration effect.

[0022] Furthermore, if the width of the radial misalignment region is h, the inner diameter of the second filter membrane encapsulation hole is d2, and the thickness of the filter membrane is s, then s < h ≤ 0.5d2.

[0023] Since adjacent filter membranes are covered with annular adhesive sealant in the radial misalignment area, satisfying s < h ensures sufficient adhesive strength between adjacent filter membranes and guarantees the stability of the bonded and fixed connection between multiple filter membranes. Satisfying h ≤ 0.5d2 avoids the radial misalignment area being too wide, which would not only require a large amount of adhesive but may also cause the adhesive to fail to completely fill the radial misalignment area, and adversely affect the filtration efficiency of the filter layer. It also avoids blocking too much flow surface of the encapsulation hole and the first through hole.

[0024] Furthermore, the width of the annular sealant layer is n, and the width of the radial misalignment region is h, where n = 1 - 1.5h.

[0025] Ensure that the width of the annular seal layer corresponding to each radial misalignment region is not too large, which would result in an excessively thick annular seal layer and insufficient flow of filtrate, nor too small, which would result in an excessively thin annular seal layer and unstable adhesion to adjacent filter membranes.

[0026] Furthermore, the radial misalignment region width h between adjacent encapsulation holes is greater than 1 mm; the inner diameter of the encapsulation hole is 10-18 mm; and the inner diameter of the first through hole is 10-18 mm.

[0027] The radial misalignment area width is set to ensure that the width of the annular sealant layer can play a stable adhesive bonding role; the inner diameter of the first filter membrane encapsulation hole is set to 14.2mm, the inner diameter of the second filter membrane encapsulation hole is set to 11.7mm, and the inner diameter of the first through hole is set to 13.2mm.

[0028] Furthermore, an encapsulation layer is provided between adjacent filter membranes at the outer edge of the encapsulation hole.

[0029] The encapsulation layer effectively fills the gaps between adjacent filter membranes, making the adhesion between them stronger and preventing them from being loose. At the same time, during filtration, the liquid can only continue to impact the annular sealant layer between the radially misaligned areas after it breaks through the encapsulation layer, which extends the sealing length that the liquid needs to impact to bypass the filter membrane, ensuring that the liquid can pass through the filter membrane.

[0030] Furthermore, the width of the encapsulation layer is m, and the thickness of the filter membrane is s, where m = 0.5-4s.

[0031] The above ratio setting avoids the effective filtration area of ​​the filter membrane being reduced due to the excessive width of the encapsulation layer, which can easily lead to filtration dead corners. It also avoids the adhesion being insufficient due to the excessive width of the encapsulation layer.

[0032] Furthermore, an isolation layer is provided between the filtrate guiding screen and the filter layer to prevent the filter membrane from embedding into the filtrate guiding screen.

[0033] The isolation layer prevents the filter membrane from getting trapped in the filtrate guiding screen, which would reduce its filtration performance.

[0034] Furthermore, the air permeability of the isolation layer is 80-140cc / cm2 / sec, and the thickness is 90-140μm.

[0035] The air permeability and thickness of the isolation layer are limited to allow the adhesive to penetrate, ensuring that the adhesive can smoothly enter the filtrate guiding screen and achieve a firm adhesion between the filtrate guiding screen, the isolation layer, and the inner filter membrane. If the air permeability is too small and the thickness is too large, the adhesive will not be able to penetrate to the target area. If the air permeability is too large, it means that the pores of the isolation layer are too large or too numerous. If the thickness is too small, the support effect on the filter membrane will be poor.

[0036] Furthermore, the filtrate port is located close to the first through hole, and the guide port is at least partially directly opposite and connected to the filtrate port. A vacuum is drawn over the filtrate port and the guide port, and the adhesive injected into the first through hole and the sealing hole flows circumferentially to form the annular sealant layer.

[0037] The formation of the ring-shaped sealant is simple, the ring-shaped sealant is relatively uniform throughout, and the radially misaligned areas can be effectively filled.

[0038] Furthermore, a first groove structure is provided around the first through hole to guide the flow of adhesive; a second groove structure is provided around the through hole to guide the penetration of adhesive.

[0039] The first groove structure facilitates the penetration of the adhesive into the filtrate guiding screen, and ensures that the adhesive is distributed around the first through hole, so that a solid bond is formed between the filtrate guiding screen and the filter membrane adjacent to it, ensuring the production quality of the annular adhesive seal. Moreover, the setting of the first groove structure also helps to accurately control the width of the adhesive layer formed after the adhesive solidifies.

[0040] The second groove structure facilitates the penetration of the adhesive into the filtrate guide screen, and the adhesive is distributed around the circumference of the through hole, which makes it possible to form a strong bond between the inlet guide screen and the filter membrane adjacent to it. Moreover, the setting of the second groove structure also helps to accurately control the width of the adhesive layer formed after the adhesive solidifies.

[0041] Furthermore, the thickness s of the filter membrane is 80-120μm; the filtration accuracy of the outer filter membrane is less than that of the inner filter membrane; the porosity of the filtrate guiding screen is 25-35%, and its thickness is 400-650μm.

[0042] The filtration precision of the outer filter membrane is lower than that of the inner filter membrane, creating a filtration gradient and ensuring good filtration effect; this meets the requirements of a filter membrane for virus removal, ensuring effective filtration and removal of viruses.

[0043] The present invention also discloses a method for packaging the above-mentioned filter membrane package, comprising the following steps:

[0044] At least two filter layers and a filtrate guiding screen are stacked, with the sealing hole and the first through hole facing each other, and the guide port and the filtrate port facing each other. Adhesive is injected from the sealing hole, and a vacuum is drawn from the guide port to form an annular adhesive sealant layer in the sealing hole, thereby achieving a sealed connection between at least two filter layers and the filtrate guiding screen and completing the encapsulation of a single filter unit.

[0045] A ring-shaped sealing layer is formed in the through holes of the liquid inlet guide screen;

[0046] Stack the filter unit and the liquid inlet guide screen, with the sealing hole facing the liquid inlet and the guide port facing the through hole. Apply external force to press the filter unit and the liquid inlet guide screen together, and apply adhesive to the outside. Vacuum is drawn at the liquid inlet and through hole of the liquid inlet guide screen. The adhesive on the outside forms a coating layer, completing the encapsulation of the filter membrane.

[0047] A packaging structure with an annular adhesive layer is prepared by vacuuming. The packaging structure of the filter membrane package is simple and the adhesive structure is stable. Any number of filter membranes can be used as needed.

[0048] Furthermore, the method for encapsulating the filter membrane package includes the following steps:

[0049] Multiple filter units are stacked one on top of the other, and adjacent filter units are separated by a first spacer membrane. The first spacer membrane has a first opening and a second opening at the corresponding encapsulation hole and the through port.

[0050] An annular adhesive layer is formed within the encapsulation holes of all filter units to achieve encapsulation of multiple filter units and multiple first spacer membranes;

[0051] Multiple liquid inlet guide screens are stacked one on top of the other, and adjacent liquid inlet guide screens are separated by a second spacer membrane. The second spacer membrane has a third opening and a fourth opening corresponding to the liquid inlet and the through hole.

[0052] A ring-shaped sealing layer is formed in all the through holes of the liquid inlet guide screen;

[0053] Stack the above-mentioned filter unit and the liquid inlet guide screen to complete the encapsulation of the filter membrane package.

[0054] Multiple filter units are stacked and packaged, allowing any number of filter units to be used as needed, and making them easy to access.

[0055] Furthermore, the duration of the vacuuming process is 20-30 seconds, and the vacuum level is -0.2 to -0.4 bar.

[0056] Vacuum treatment results in a more uniform distribution of the adhesive, forming a closed ring, and the process is simple and controllable. The duration of vacuum treatment ensures the closed structure of the ring-shaped sealant layer, avoiding voids.

[0057] The beneficial effects of this invention are: by increasing the number of filter membranes in the filter layer to achieve the purpose of virus transition, there is no need to change the composition of the filter layer, and the solution is simple and effective; the bonding structure between each filter membrane is simple and effective, the processing method is simple, and the processing cost is low; the liquid will not flow out from the gaps between the filter membranes, the sealing effect of the annular adhesive layer is good, ensuring that the liquid flows according to the set flow path, and the filtration effect is good; any number of filter membranes can be selected to form a filter unit, and the adaptability is high. Attached Figure Description

[0058] Figure 1 This is an exploded structural diagram of the filter membrane package provided in Embodiment 1 of the present invention.

[0059] Figure 2This is a partial cross-sectional view of the filter unit (excluding the annular sealant layer) provided in Embodiment 1 of the present invention.

[0060] Figure 3 This is a partial cross-sectional view of the filtering unit provided in Embodiment 1 of the present invention.

[0061] Figure 4 This is a partial cross-sectional view of the filter membrane package provided in Embodiment 1 of the present invention.

[0062] Figure 5 This is a partial schematic diagram of the filtrate guiding screen (with a first groove structure) provided in Embodiment 1 of the present invention.

[0063] Figure 6 This is a partial schematic diagram of the liquid inlet guide screen (with a second groove structure) provided in Embodiment 1 of the present invention.

[0064] Figure 7 This is a partial cross-sectional view of the filter units with a first spacer membrane provided in Embodiment 1 of the present invention.

[0065] Figure 8 This is a partial cross-sectional view of the filter unit (excluding the annular sealant layer) provided in Embodiment 2 of the present invention.

[0066] Figure 9 This is a partial cross-sectional view of the filter unit (including an annular sealant layer) provided in Embodiment 2 of the present invention.

[0067] Figure 10 This is a partial cross-sectional view of the filter unit (excluding the annular sealant layer) provided in Embodiment 3 of the present invention.

[0068] Figure 11 This is a partial cross-sectional view of the filter unit (including an annular sealant layer) provided in Embodiment 3 of the present invention.

[0069] Figure 12 This is a partial cross-sectional view of the filter unit (excluding the annular sealant layer) provided in Embodiment 4 of the present invention.

[0070] Figure 13 This is a partial cross-sectional view of the filter unit (including an annular sealant layer) provided in Embodiment 4 of the present invention.

[0071] Figure 14 This is a partial cross-sectional view of the filter unit (excluding the annular sealant layer) provided in Embodiment 5 of the present invention.

[0072] Figure 15 This is a partial cross-sectional view of the filter unit (including an annular sealant layer) provided in Embodiment 5 of the present invention.

[0073] Figure 16This is a partial cross-sectional view of the filter unit (excluding the annular sealant layer) provided in Embodiment Six of the present invention.

[0074] Figure 17 This is a partial cross-sectional view of the filter unit (including an annular sealant layer) provided in Embodiment Six of the present invention.

[0075] Figure 18 This is a partial cross-sectional view of the filter unit (with isolation layer) provided in Embodiment 7 of the present invention.

[0076] Figure 19 This is a partial cross-sectional view of the filter layer provided in Embodiment 8 of the present invention.

[0077] Among them, 1-liquid inlet guide screen, 11-liquid inlet, 12-through hole, 121-second groove structure, 2-filtration unit, 3-filtrate guide screen, 31-first through hole, 311-first groove structure, 32-filtrate inlet, 4-filtration layer, 41-filtration membrane, 411-encapsulation hole, 412-conducting port, 413-first filtration membrane, 414-second filtration membrane, 415-third filtration membrane, 5-radial misalignment area, 6-annular sealant layer, 7-encapsulation layer, 8-isolation layer, 9-first spacer membrane, 91-first opening. Detailed Implementation

[0078] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0079] Example 1

[0080] like Figure 1 , Figure 2 As shown, a filter membrane package includes at least:

[0081] The liquid inlet guide screen 1 has a liquid inlet 11 and a through hole 12, which is used to guide the fluid to be filtered to permeate along the tangential direction;

[0082] In this embodiment, the liquid inlet guide screen 1 is provided with a liquid inlet 11 and a through hole 12 at both ends;

[0083] The filter unit 2 is located downstream of the liquid inlet guide screen 1. It includes at least a filtrate guide screen 3 and a filter layer 4 located on the side of the filtrate guide screen. If the filter unit 2 is stacked inside, the filter layer 4 is provided on both sides of the filtrate guide screen. If the filter unit is located on the outermost side, the filtrate guide screen can only have a filter layer on the inner side.

[0084] The filtrate guiding screen 3 has a first through hole 31 and a filtrate port 32, and is opened at both ends respectively; in this embodiment, the porosity of the filtrate guiding screen 3 is 25-35%, and its thickness is 400-650μm;

[0085] The filter layer 4 is a multi-layer filter membrane 41. Each filter membrane 41 has an encapsulation hole 411 and a through-hole 412 at both ends. The encapsulation hole 411 is at least partially connected to the first through-hole 31 of the filtrate guiding screen 3. The multi-layer filter membrane 41 includes at least a first filter membrane 413 with the largest encapsulation hole inner diameter and a second filter membrane 414 with the smallest encapsulation hole inner diameter. The multi-layer filter membranes 41 are stacked to form a radial misalignment region 5 at the encapsulation hole.

[0086] An annular sealant layer 6 is formed inside the encapsulation hole. The annular sealant layer 6 covers the inner wall of the first through hole 31, the inner wall of the first filter membrane 413, and the radial misalignment area 5 between adjacent encapsulation holes, so that a sealed connection is formed between each filter membrane 41 and between the filtrate guiding screen 3 and the filter layer 4.

[0087] Specifically, such as Figure 2 , Figure 3 As shown, in this embodiment, the filter layer 4 includes two filter membranes 41, specifically a first filter membrane 413 with a larger inner diameter of the encapsulation hole and a second filter membrane 414 with a smaller inner diameter of the encapsulation hole. The first filter membrane 413 is located on the inner side close to the filtrate guiding screen 3, and the second filter membrane 414 is located on the outer side away from the filtrate guiding screen 3.

[0088] like Figure 3 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. The annular sealant layer 6 covers the inner wall of the first through hole 31, the inner wall of the first filter membrane 413, and the radial misalignment area 5 of the first filter membrane 413 and the second filter membrane 414, so that a sealed connection is formed between the first filter membrane 413 and the second filter membrane 414, as well as between the filtrate guiding screen 3 and the first filter membrane 413.

[0089] Let d1 be the inner diameter of the encapsulation hole of the first filter membrane 413, d2 be the inner diameter of the encapsulation hole of the second filter membrane 414, and l be the inner diameter of the first through hole 31. Then, 1.2d1 ≥ l ≥ 0.8d2. These numerical settings avoid excessive differences between the inner diameters of the encapsulation holes of the first filter membrane 413 and the second filter membrane 414, which would prevent the adhesive from completely covering the radial misalignment area 5. Simultaneously, they prevent the area of ​​the first through hole 31 of the filtrate guiding screen 3 from being too large, thus hindering the rapid and smooth discharge of the filtrate after filtration by the filter layer 4, and also preventing the filter layer 4 from receiving adequate support.

[0090] Let h be the width of the radial misalignment region 5 and s be the thickness of the filter membrane 41, then s < h ≤ 0.5d². In this embodiment, the difference between the inner diameters of the encapsulation holes of the first filter membrane 413 and the second filter membrane 414 is the width h of the radial misalignment region 5. The width must satisfy the condition s < h ≤ 0.5d². Since adjacent filter membranes 41 are covered by an annular adhesive layer 6 in the radial misalignment region, satisfying s < h ensures sufficient adhesive strength between adjacent filter membranes 41, guaranteeing the stability of the bonded connection between the multiple filter membranes 41. Satisfying h ≤ 0.5d² avoids an excessively large width of the radial misalignment region, which would require a large amount of adhesive and adversely affect the filtration efficiency of the filter layer 4. It also avoids blocking too much flow surface of the encapsulation hole 411 and the first through hole 31.

[0091] Under the above conditions, the inner diameter of the encapsulation hole 411 is 10-18 mm, specifically, the inner diameter of the encapsulation hole of the first filter membrane 413 can be set to 14.2 mm, and the inner diameter of the encapsulation hole of the second filter membrane 414 can be set to 11.7 mm; the inner diameter of the first through hole 31 is 10-18 mm, specifically 13.2 mm, and the width h of the radial misalignment region between adjacent encapsulation holes 411 is greater than 1 mm. The thickness s of the filter membrane is 80-120 μm.

[0092] The annular sealant layer 6 covers the inner wall of the first through hole 31, the inner wall of the first filter membrane 413, and the radially misaligned area of ​​the first filter membrane 413 and the second filter membrane 414.

[0093] Define the width of the annular sealant 6 as n, then n = 1 - 1.5h. This ensures that the width of the annular sealant 5 corresponding to the radial misalignment region 5 is not too large, which would prevent the adhesive from completely filling all the transverse planes of the radial misalignment region 5, or cause the annular sealant 5 to be too thick, resulting in too small a flow rate of filtrate. It also prevents the annular sealant 5 from being too thin, resulting in an unstable adhesion to the adjacent filter membrane 41.

[0094] The filtrate port 32 is located close to the first through hole 31. The guide port 412 and the filtrate port 32 are at least partially connected. A vacuum is drawn on the filtrate port 32 and the guide port 412. The adhesive injected into the first through hole 31 and the sealing hole 411 flows circumferentially under the action of negative pressure to form an annular adhesive sealant layer 6.

[0095] like Figure 5As shown, in order to facilitate the flow of adhesive, a first groove structure 311 is provided around the first through hole 31. It is used to guide the flow of adhesive and helps to distribute adhesive around the first through hole 31, so that a solid bond is formed between the filtrate guiding screen 3 and the filter membrane 41, which is the third filter membrane 415, which is close to it. Moreover, the setting of the first groove structure 311 also helps to accurately control the width of the adhesive layer formed after the adhesive solidifies.

[0096] like Figure 6 As shown, a second groove structure 121 is also provided around the through hole 12, which is used to guide the adhesive to penetrate and help to distribute the adhesive around the through hole 12, so that a solid bond is formed between the liquid inlet guide screen 1 and the filter membrane 41, which is the second filter membrane 414, which is close to it.

[0097] Since the liquid to be filtered enters through inlet 11, the liquid fills the inlet guide screen 1. A portion of the liquid permeates into the filtrate guide screen 3 after being filtered by multiple filter membranes 41, and flows out from the filtrate outlet 32 ​​of the filtrate guide screen 3. The remaining unfiltered liquid forms permeate, which is discharged from the inlet 11 on the other side of the inlet guide screen 1. At the same time, the inlet 11 on the other side of the inlet guide screen 1 can also be completely sealed, so that all the liquid to be filtered entering through inlet 11 can pass through multiple filter membranes to form permeate before flowing out from the filtrate outlet 32. Therefore, to ensure the filtration effect, the filtration accuracy of the outer filter membrane 41 is less than that of the inner filter membrane. Here, the side closer to the filtrate guide screen 3 is considered the inner side.

[0098] A method for encapsulating the above-mentioned filter membrane package includes the following steps:

[0099] At least two filter layers 4 and a filtrate guiding screen 3 are stacked. In this embodiment, a single filter layer 4 is composed of a second filter membrane 414 and a first filter membrane 413 stacked together. There are two filter layers 4. In other words, the second filter membrane 414, the first filter membrane 413, and the filtrate guiding screen 3 are stacked sequentially from top to bottom. The first filter membrane 413 and the second filter membrane 414 are stacked sequentially on the lower side of the filtrate guiding screen 3. All encapsulation holes 411 and the first through holes 31 are aligned, and the through ports 412 and the filtrate ports 32 are aligned. Adhesive is injected from the encapsulation holes 411, and a vacuum is drawn from the through ports 412. The vacuuming process lasts for 20-30 seconds, and the vacuum degree is -0.2 to -0.4 bar. Excess adhesive is removed, and after curing, an annular sealant layer 6 is formed in the encapsulation holes 411, realizing the sealed connection between the two filter layers 4 and the filtrate guiding screen 3, and completing the encapsulation of a single filter unit.

[0100] Multiple filter units are stacked vertically, with adjacent filter units separated by a first spacer membrane 9, such as... Figure 7As shown, the first spacer 9 has a first opening 91 and a second opening at the corresponding encapsulation hole 411 and the through port 412;

[0101] An annular adhesive layer 6 is formed within the encapsulation holes 411 of all filter units to encapsulate multiple filter units and multiple first spacer membranes 9.

[0102] Multiple liquid inlet guide screens 1 are stacked one on top of the other, and adjacent liquid inlet guide screens 1 are separated by a second spacer membrane. The second spacer membrane has a third opening and a fourth opening at the liquid inlet 11 and the through hole 12.

[0103] An annular sealing ring (not shown in the figure) is formed in the through holes 12 of all liquid inlet guide screens 1. The specific formation method is the same as that of the annular adhesive layer 6. Adhesive is injected into the through holes 12 and vacuum is drawn at the liquid inlet 11 to form the ring.

[0104] Stack the above-mentioned filter unit and the liquid inlet guide screen 1, with the sealing hole 411 facing the liquid inlet 11 and the guide port 412 facing the through hole 12. Apply external force to press the filter unit and the liquid inlet guide screen 1 together, and apply adhesive to the outside. Vacuum is drawn at the liquid inlet 11 and through hole 12 of the liquid inlet guide screen 1. The vacuuming process lasts for 20-30 seconds, and the vacuum degree is -0.2 to -0.4 bar. The outer adhesive forms a coating layer, completing the encapsulation of the filter membrane.

[0105] Example 2

[0106] like Figure 8 As shown, the difference between this embodiment and Embodiment 1 is that, of the two filter membranes 41 of the filter layer 4, the first filter membrane 413 with a larger inner diameter of the encapsulation hole is located on the outer side away from the filtrate guiding screen 3, and the second filter membrane 414 with a smaller inner diameter of the encapsulation hole is located on the inner side close to the filtrate guiding screen 3.

[0107] like Figure 9 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. The annular sealant layer 6 covers the inner wall of the first through hole 31, the inner wall of the first filter membrane 413, and the radial misalignment area 5 between adjacent encapsulation holes, so that a sealed connection is formed between each filter membrane 41 and between the filtrate guiding screen 3 and the filter layer 4.

[0108] Everything else is the same as in Example 1, and will not be repeated here.

[0109] Example 3

[0110] like Figure 10As shown, the difference between this embodiment and Embodiment 1 is that the filter layer 4 is a three-layer filter membrane 41. The first filter membrane 413 with the largest inner diameter of the encapsulation hole is set close to the filtrate guiding screen 3, the second filter membrane 414 with the smallest inner diameter of the encapsulation hole is located on the outermost side, and the third filter membrane 415 is located between the first filter membrane 413 and the second filter membrane 414. Its inner diameter of the encapsulation hole is also smaller than the inner diameter of the encapsulation hole of the first filter membrane 413 and larger than the inner diameter of the encapsulation hole of the second filter membrane 414.

[0111] In other words, the inner diameter of the encapsulation hole changes in a stepped manner, gradually decreasing from the side closest to the filtrate guide screen 3 outwards. This structural design results in stronger adhesion between all the filter membranes 41 in the filter layer 4.

[0112] like Figure 11 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. This annular sealant layer 6 covers the inner wall of the first through hole 31, the inner wall of the third filter membrane 415, the inner wall of the first filter membrane 413, and the radially misaligned areas of the third filter membrane 415 and the first filter membrane 413, as well as the radially misaligned areas of the first filter membrane 413 and the second filter membrane 414. This creates a sealed connection between the second filter membrane 414 and the third filter membrane 415, between the third filter membrane 415 and the first filter membrane 413, and between the filtrate guiding screen 3 and the first filter membrane 413.

[0113] Let h be the width of the radial misalignment region 5 and s be the thickness of the filter membrane 41, then s < h ≤ 0.5d². In this embodiment, the width h of the radial misalignment region 5 is a variable value, that is, the difference between the inner diameters of the encapsulation holes of the first filter membrane 413 and the second filter membrane 414 is the width of the radial misalignment region, the difference between the inner diameters of the encapsulation holes of the first filter membrane 413 and the third filter membrane 415 is also the width of the radial misalignment region, and the difference between the inner diameters of the encapsulation holes of the second filter membrane 414 and the third filter membrane 415 is also the width of the radial misalignment region. All of the above widths must satisfy the condition s < h ≤ 0.5d².

[0114] The width of the annular sealant layer 6 is defined as n, then n = 1-1.5h. In this embodiment, because the width of the radial misalignment region is a variable value, the width n of the annular sealant layer 6 is also a variable value, and the width of the annular sealant layer 6 corresponding to all filter membranes 41 is within the range of 1-1.5h.

[0115] Everything else is the same as in Example 1, and will not be repeated here.

[0116] Example 4

[0117] like Figure 12As shown, the difference between this embodiment and Embodiment 3 is that the first filter membrane 413 with the largest encapsulation hole inner diameter is located on the outermost side away from the filtrate guiding screen 3, the second filter membrane 414 with the smallest encapsulation hole inner diameter is located close to the filtrate guiding screen 3, and the third filter membrane 415 is located between the first filter membrane 413 and the second filter membrane 414, and its encapsulation hole inner diameter is smaller than that of the first filter membrane 413 and larger than that of the second filter membrane 414.

[0118] In other words, the inner diameter of the encapsulation hole changes in a stepped manner, gradually increasing in size from the side closest to the filtrate guide screen 3 outwards. This structural design results in stronger adhesion between all the filter membranes 41 in the filter layer 4.

[0119] like Figure 13 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. This annular sealant layer 6 covers the inner wall of the third filter membrane 415, the inner wall of the first filter membrane 413, the radially misaligned areas of the third filter membrane 415 and the first filter membrane 413, and the radially misaligned areas of the third filter membrane 415 and the second filter membrane 414. This creates a sealed connection between the second filter membranes 414, between the third filter membrane 415, between the third filter membrane 415 and the first filter membrane 413, and between the filtrate guiding screen 3 and the second filter membrane 414.

[0120] Everything else is the same as in Example 3, and will not be repeated here.

[0121] Example 5

[0122] like Figure 14 As shown, the difference between this embodiment and Embodiment 3 is that the second filter membrane 414 with the smallest encapsulation hole inner diameter is located on the outermost side away from the filtrate guiding screen 3, the first filter membrane 413 with the largest encapsulation hole inner diameter is arranged adjacent to the first filter membrane 413, and the third filter membrane 415 is located on the innermost side close to the filtrate guiding screen 3, and its encapsulation hole inner diameter is also smaller than the encapsulation hole inner diameter of the first filter membrane 413 and larger than the encapsulation hole inner diameter of the second filter membrane 414.

[0123] like Figure 15 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. This annular sealant layer 6 covers the inner wall of the first through hole 31, the inner wall of the third filter membrane 415, the inner wall of the first filter membrane 413, and the radially misaligned areas of the third filter membrane 415 and the first filter membrane 413, as well as the radially misaligned areas of the first filter membrane 413 and the second filter membrane 414. This creates a sealed connection between the second filter membrane 414 and between the first filter membrane 413, between the third filter membrane 415 and the first filter membrane 413, and between the filtrate guiding screen 3 and the second filter membrane 414.

[0124] Everything else is the same as in Example 3, and will not be repeated here.

[0125] Example 6

[0126] like Figure 16 As shown, the difference between this embodiment and Embodiment 3 is that the first filter membrane 413 with the largest encapsulation hole inner diameter is arranged close to the filtrate guiding screen 3, the second filter membrane 414 with the smallest encapsulation hole inner diameter is arranged adjacent to the first filter membrane 413, and the third filter membrane 415 is located on the outermost side, and its encapsulation hole inner diameter is smaller than that of the first filter membrane 413 and larger than that of the second filter membrane 414.

[0127] like Figure 17 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. This annular sealant layer 6 covers the inner wall of the first through hole 31, the inner wall of the third filter membrane 415, the inner wall of the first filter membrane 413, and the radially misaligned areas of the third filter membrane 415 and the second filter membrane 414, as well as the radially misaligned areas of the first filter membrane 413 and the second filter membrane 414. This creates a sealed connection between the second filter membranes 414, between the first filter membrane 413, between the third filter membrane 415 and the second filter membrane 414, and between the filtrate guiding screen 3 and the first filter membrane 413.

[0128] Everything else is the same as in Example 3, and will not be repeated here.

[0129] Example 7

[0130] like Figure 18 As shown, based on the structure of Embodiment 1, an isolation layer 8 is provided between the filtrate guiding screen 3 and the filter layer 4 to prevent the filter membrane 41 from embedding into the filtrate guiding screen 3. Specifically, this isolation layer can be a non-woven fabric layer. The air permeability of the isolation layer 8 is 80-140 cc / cm² / sec, and its thickness s² is 90-140 μm. In other embodiments, the isolation layer can also be a woven fabric or a porous membrane, and the material can be a polymer material, such as PP, PE, PES, etc.

[0131] Everything else is the same as in Example 1, and will not be repeated here.

[0132] Example 8

[0133] like Figure 19 As shown, an encapsulation layer 7 is formed between adjacent filter membranes 41 at the outer edge of the encapsulation hole 411. The width of the encapsulation layer 7 is m, and its relationship with the thickness of the filter membrane 41 is m = 0.5-4s. The above values ​​ensure that the encapsulation layer 7 forms a stable connection to all filter membranes 41.

[0134] The above specific embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A filter membrane pack, comprising at least: The liquid inlet guide screen has a liquid inlet and through holes, which is used to guide the fluid to be filtered to permeate along the tangential direction; A filtration unit is located downstream of the liquid inlet guiding screen, and includes at least a filtrate guiding screen and a filter layer located on the side of the filtrate guiding screen. The filtrate guiding screen is provided with a first through hole and a filtrate outlet; The feature is that the filter layer is a multi-layer filter membrane, each filter membrane has an encapsulation hole and a through hole, the encapsulation hole is at least partially opposite to and connected to the first through hole, the multi-layer filter membrane includes at least a first filter membrane with the largest inner diameter of the encapsulation hole and a second filter membrane with the smallest inner diameter of the encapsulation hole, the multi-layer filter membrane is stacked to form a radial misalignment region at the encapsulation hole; An annular adhesive layer is formed inside the encapsulation hole. This annular adhesive layer covers the inner wall of the first through hole, the inner wall of the first filter membrane encapsulation hole, and the radial misalignment area between adjacent encapsulation holes, so as to form a sealed connection between each filter membrane layer and between the filtrate guiding screen and the filter layer.

2. The filter membrane pack according to claim 1, characterized in that: The second filter membrane is located on the side of the filter layer away from the filtrate guiding screen; or, the second filter membrane is located on the side of the filter layer closer to the filtrate guiding screen.

3. The filter membrane pack according to claim 2, characterized in that: The inner diameter of the encapsulation hole varies in a stepped manner, gradually decreasing from the side closest to the filtrate guiding screen outwards, or gradually increasing from the side closest to the filtrate guiding screen outwards.

4. The filter membrane pack according to claim 1, characterized in that: The inner diameter of the first filter membrane encapsulation hole is d1, the inner diameter of the second filter membrane encapsulation hole is d2, and the inner diameter of the first through hole is l, where 1.2d1≥l≥0.8d2.

5. The filter membrane pack according to claim 1, characterized in that: The width of the radial misalignment region is h, the inner diameter of the second filter membrane encapsulation hole is d2, and the thickness of the filter membrane is s, then s < h ≤ 0.5d2.

6. The filter membrane pack according to claim 1, characterized in that: The width of the annular sealant layer is n, and the width of the radial misalignment region is h, where n = 1 - 1.5h.

7. The filter membrane pack according to claim 1, characterized in that: The radial misalignment region width h between adjacent encapsulation holes is greater than 1 mm; the inner diameter of the encapsulation hole is 10-18 mm; the inner diameter of the first through hole is 10-18 mm.

8. The filter membrane pack according to claim 1, characterized in that: An encapsulation layer is present between adjacent filter membranes along the outer edge of the encapsulation hole.

9. The filter membrane pack according to claim 8, characterized in that: The width of the encapsulation layer is m, and the thickness of the filter membrane is s, where m = 0.5-4s.

10. The filter membrane pack according to claim 1, characterized in that: An isolation layer is provided between the filtrate guiding screen and the filter layer to prevent the filter membrane from embedding into the filtrate guiding screen.

11. The filter membrane pack according to claim 10, characterized in that: The air permeability of the isolation layer is 80-140cc / cm2 / sec, and the thickness is 90-140μm.

12. The filter membrane pack according to claim 1, characterized in that: The filtrate port is located near the first through hole, and the guide port is at least partially directly opposite and connected to the filtrate port. A vacuum is drawn over the filtrate port and the guide port, and the adhesive injected into the first through hole and the encapsulation hole flows circumferentially to form the annular sealant layer.

13. The filter membrane pack according to claim 12, characterized in that: The first through hole is surrounded by a first groove structure, which is used to guide the flow of adhesive; the through hole is surrounded by a second groove structure, which is used to guide the penetration of adhesive.

14. The filter membrane pack according to claim 1, characterized in that: The thickness s of the filter membrane is 80-120μm; the filtration accuracy of the outer filter membrane is less than that of the inner filter membrane; the porosity of the filtrate guiding screen is 25-35%, and its thickness is 400-650μm.

15. A method for encapsulating a filter membrane pack as described in any one of claims 1-14, comprising the following steps: At least two filter layers and a filtrate guiding screen are stacked, with the sealing hole and the first through hole facing each other, and the guide port and the filtrate port facing each other. Adhesive is injected from the sealing hole, and a vacuum is drawn from the guide port to form an annular adhesive sealant layer in the sealing hole, thereby achieving a sealed connection between at least two filter layers and the filtrate guiding screen and completing the encapsulation of a single filter unit. A ring-shaped sealing layer is formed in the through holes of the liquid inlet guide screen; Stack the filter unit and the liquid inlet guide screen, with the sealing hole facing the liquid inlet and the guide port facing the through hole. Apply external force to press the filter unit and the liquid inlet guide screen together, and apply adhesive to the outside. Vacuum is drawn at the liquid inlet and through hole of the liquid inlet guide screen. The adhesive on the outside forms a coating layer, completing the encapsulation of the filter membrane.

16. The method for encapsulating a filter membrane pack according to claim 15, characterized in that, Includes the following steps: Multiple filter units are stacked one on top of the other, and adjacent filter units are separated by a first spacer membrane. The first spacer membrane has a first opening and a second opening at the corresponding encapsulation hole and the through port. An annular adhesive layer is formed within the encapsulation holes of all filter units to achieve encapsulation of multiple filter units and multiple first spacer membranes; Multiple liquid inlet guide screens are stacked one on top of the other, and adjacent liquid inlet guide screens are separated by a second spacer membrane. The second spacer membrane has a third opening and a fourth opening corresponding to the liquid inlet and the through hole. A ring-shaped sealing layer is formed in all the through holes of the liquid inlet guide screen; Stack the above-mentioned filter unit and the liquid inlet guide screen to complete the encapsulation of the filter membrane package.

17. The method for encapsulating a filter membrane pack according to claim 15, characterized in that: The duration of the vacuuming process is 20-30 seconds, and the vacuum level is -0.2 to -0.4 bar.

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