WO2024018243A1 - Method for end-sealing of hollow membrane filter fibers - Google Patents
Method for end-sealing of hollow membrane filter fibers Download PDFInfo
- Publication number
- WO2024018243A1 WO2024018243A1 PCT/HU2023/050034 HU2023050034W WO2024018243A1 WO 2024018243 A1 WO2024018243 A1 WO 2024018243A1 HU 2023050034 W HU2023050034 W HU 2023050034W WO 2024018243 A1 WO2024018243 A1 WO 2024018243A1
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- WO
- WIPO (PCT)
- Prior art keywords
- sealing material
- filter fibers
- fibers
- filter
- auxiliary liquid
- Prior art date
Links
- 239000000835 fiber Substances 0.000 title claims abstract description 103
- 239000012528 membrane Substances 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000007789 sealing Methods 0.000 title claims abstract description 15
- 239000003566 sealing material Substances 0.000 claims abstract description 75
- 239000007788 liquid Substances 0.000 claims abstract description 41
- 238000007711 solidification Methods 0.000 claims abstract description 5
- 230000008023 solidification Effects 0.000 claims abstract description 5
- 239000000853 adhesive Substances 0.000 claims description 14
- 230000001070 adhesive effect Effects 0.000 claims description 14
- 239000003292 glue Substances 0.000 claims description 14
- 239000012466 permeate Substances 0.000 claims description 9
- 238000013461 design Methods 0.000 claims description 4
- 229920003002 synthetic resin Polymers 0.000 claims description 4
- 239000000057 synthetic resin Substances 0.000 claims description 4
- 229920000728 polyester Polymers 0.000 claims description 3
- 239000004593 Epoxy Substances 0.000 claims description 2
- 239000005662 Paraffin oil Substances 0.000 claims description 2
- 229920002635 polyurethane Polymers 0.000 claims description 2
- 239000004814 polyurethane Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 239000012510 hollow fiber Substances 0.000 description 6
- 238000000926 separation method Methods 0.000 description 5
- 239000000565 sealant Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 235000004879 dioscorea Nutrition 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000002706 hydrostatic effect Effects 0.000 description 2
- 238000005192 partition Methods 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000005273 aeration Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009940 knitting Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000005374 membrane filtration Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000012465 retentate Substances 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000004065 wastewater treatment Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
- C09J175/04—Polyurethanes
- C09J175/06—Polyurethanes from polyesters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
- B01D63/02—Hollow fibre modules
- B01D63/021—Manufacturing thereof
- B01D63/022—Encapsulating hollow fibres
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G2190/00—Compositions for sealing or packing joints
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
Definitions
- the invention relates to a method for end-sealing of hollow membrane filter fibers.
- one end of the hollow filter fibers is immersed in a low-viscosity hardening sealing material, preferably in glue filled in a container, to a given depth.
- a low-viscosity hardening sealing material preferably in glue filled in a container
- filter fibers with end seals are used to create membrane filter modules with a one-sided permeate head design.
- membrane is a technological term. It denotes a technological barrier which, due to its selective permeability, enables the separation of the components of the materials to be processed mostly without chemical transformation.
- the essence of membrane separation or membrane filtration is that selective transport takes place through a membrane under the influence of some driving force.
- the membrane which is the essence of the operation, is a partition wall that, due to its selective permeability, enables the separation of substances mostly without chemical transformation.
- the membrane serves as an intermediate phase when separating two phases and/or participates as an active or passive partition wall in the material transfer between the phases in contact with it.
- the supplied liquid is not flowed perpendicular to the filter medium, but parallel to the membrane (cross-flow), while a part of the components of the material to be filtered passes through the membrane under the influence of the driving force and leaves on the permeate side.
- the components retained by the membrane are enriched on the feed side of the membrane, this is the retentate or concentrate.
- Membranes are increasingly used to solve separation problems in the food industry, healthcare, chemical industry, wastewater treatment, etc.
- Patent application CN 10197266 describes a method for manufacturing a hollow fiber membrane module. The method comprises the following steps: the first ends of the equally long hollow fiber membrane yams are bundled by a conventional method, and preparing sealant in a container, immersing the second ends of the hollow fiber membrane yams in the sealant in the container in a depth of 2-15 mm.
- a vacuum pump is coupled to he first ends of the membrane fibers of the membrane bundle, and the pressure is decreased by 500-1000 Pa inside the membrane fibers thereby the level of the sealant is increased. The vacuum is maintained till the sealant solidifies. Finally, the second ends of the membrane fibers are cut off by 5-20 mm so that the second ends remain sealed. In this solution, no auxiliary liquid, but a vacuum pump is used, which makes the procedure more complicated and more expensive.
- US patent No. US 7,950,528 B2 relates to a through-one-end water collection type hollow fiber membrane and a method for manufacturing the same. According to the invention, an internal sealing part is formed in the hollow part of the membrane at its free end. The internal sealing part is surrounded by an external sealing part from its outer surface, so this solution aims to improve the efficiency of the entire sealing part.
- US Patent No. 8852438 B2 relates to a membrane filter device. The device contains a number of hollow membrane fibers standing free from each other. The device also contains a first header and a second header disposed in vertically spaced-apart relationship.
- each fiber of the first header and the second header are sealingly secured, and all open ends of the fibers open to a permeate-discharging face of at least one header.
- the device further contains permeate collection means to collect the permeate, sealingly connected in open fluid communication with a permeatedischarging face of at least one of the headers; and means to withdraw said permeate.
- the fibers, the headers and the permeate collection means together form an integrated unit wherein the fibers are essentially vertically disposed and ends of the individual fibers are potted in closely spaced-apart relationship in cured resin at a fixed distance.
- the fibers are individually immersed in glue, essentially an adhesive that binds to UV light, then illuminated, and depending on the viscosity and other physical properties of the glue, the glue penetrates the inner cavity of the fiber to a small extent, but mostly solidifies outside the end of the fibers in the form of a drop. This slightly increases the dimensions of the fiber. Furthermore, no auxiliary liquid is used in any of them.
- the filter modules consist of a large number of fibers, and the separate dipping and/or curing with a UV lamp requires a lot of work and time.
- the glue cannot penetrate the fiber to a sufficient depth and the glue cannot penetrate the membrane structure without pressure (there is no time for it), so the glue on the outside does not ensure a proper seal for a long term.
- Another problem is that the glue increases the cross-section of the end of the fiber, which makes it more difficult for impurities to be removed from the filter module, and it also partially blocks air evaporation. If the UV light-hardening glue penetrates very deeply into the inner cavity, it will not be exposed to enough UV light and will not bond. In this case, toxic substances may remain in the fiber, which may later enter the water to be filtered.
- Our aim is to develop a manufacturing process that enables the simultaneous sealing of one end of a large number of filter fibers so that after sealing the filter fibers remain separable from each other and are also suitable for creating a single-sided suction head during the production of membrane filter modules.
- the present invention is a method for end-sealing of hollow membrane filter fibers.
- one end of the hollow filter fibers is immersed in a low-viscosity hardening sealing material, preferably in glue filled in a container, to a given depth.
- a low-viscosity hardening sealing material preferably in glue filled in a container
- filter fibers with end seals are used to create membrane filter modules with a one-sided permeate head design.
- the filter fibers are arranged in bundles to form their end seals, and then one end of the bundled filter fibers is immersed together into the liquid or gel state sealing material filled in the container to a maximum depth of 20 mm.
- auxiliary liquid with a specific weight lower than the specific weight of the sealing material is filled on the sealing material, which forces the sealing material to a certain extent into one end of the filter fibers.
- the auxiliary liquid is removed and the bundled filter fibers are separated from the sealing material remaining in the container above the level of the solidified sealing material.
- Figure 1 shows a side view section of the bundled filter fibers placed in the container, where one end of the filter fibers is filled with the sealing material and the auxiliary liquid is filled on the sealing material,
- Figure 2 shows the top view of the bundled filter fibers placed in the container, one end of the filter fibers is filled with the sealing material and the auxiliary liquid is filled on the sealing material,
- Figure 3 shows the side view section of the remaining adhesive material with the ends of the filter fibers where the bundled filter fibers are separated from the remaining adhesive material
- Figure 4 shows the top view of the already sealed, ready-to-use bundled filter fibers
- Figure 5 is a perspective view of the bundled filter fibers, partially in section.
- the membrane filter fiber 1 is designed in a known manner. It is based on a flexible structure made of polyester material made using a woven (braid) or knitted (knitting) process (similar to shoelaces). This structure is coated from the outside with plastic, the surface of which has micropores of 0.01 -0.03 micrometers.
- One end 3 of the bundled filter fibers 6 is immersed into the sealing material 5 filled in the container 4, which is still in liquid or gel state, to a maximum depth of 20 mm, then an auxiliary liquid 7 with a specific weight lower than the specific weight of the sealing material 5 is poured onto the sealing material 5.
- the auxiliary liquid 7 is a liquid that does not react with the sealing material 5.
- the sealing material 5 is forced into one end 3 of the filter fibers 1 to a given extent, and on the other hand, it is also ensured that the individual filter fibers 1 do not stick together, and that the end seal 2 does not increase the circumference of the filter fibers 1 at the end seal 2 (1., Figure 2).
- the auxiliary liquid 7 is removed, and the bundled filter fibers 6 are separated from the sealing material 5 remaining in the container 4 above the level of the solidified sealing material 5 ( Figures 3, 4).
- the auxiliary liquid 7 is preferably paraffin oil.
- the auxiliary liquid 7 can be any liquid which, on the one hand, has a lower specific weight than the specific weight of the sealing material 5, and on the other hand, does not enter into any chemical reaction with the sealing material 5.
- the filter fibers 1 are immersed in the sealing material 5 for a maximum of 10 mm before the auxiliary liquid 7 is filled, and then the auxiliary liquid 7 is filled into the container 4. Afterwards, the filter fibers 1 are immersed in the sealing material 5 to a maximum depth of 20 mm. In this case, the outer side of the filter fibers 1 will be less coated with the sealing material 5, because it is prevented by the auxiliary liquid 7. At the same time, it will be deep enough so that the end of the filter fiber 1 remains below the level of the sealing material 5. This is achieved even if, due to the hydrostatic pressure generated by the auxiliary fluid 7, the sealing material 5 has already penetrated inside the filter fiber 1 , and because of this, the level of the sealing material 5 in the container 4 has decreased.
- the filter fibers 1 cut to the given length are bundled, thus preparing the bundled filter fibers 6.
- the sealing material 5 is filled in the container. If it is multi-component, it is in already mixed state. After that, the ends of the bundled filter fibers 6 are immersed (for example 7 mm deep) into the sealing material 5.
- the auxiliary liquid 7 is slowly poured on top of the sealing material 5. After that, the bundled filter fibers 6 are immersed deeper, approx. 10-20 mm deep into the sealing material 5. Due to its hydrostatic pressure, the auxiliary liquid 7 forces a part of the sealing material 5 inside the filter fibers 1 . Then, of course, the level of the sealing material 5 will be lower than before the auxiliary liquid 7 was applied to the adhesive.
- the outer side of the filter fibers 1 is surrounded by the auxiliary liquid 7 and does not allow the sealing material 5 to cover it. This ensures that the filter fibers 1 can be separated later.
- the auxiliary liquid 7 is removed.
- the bundled filter fibers 6 fixed in the sealing material 5 are taken out of the container 4.
- the bundled filter fibers 6 are cut directly above the level of the sealing material 5 or a few millimeters above the level of the sealing material 5.
- the filter fibers 1 and one of their ends 3 are already separate.
- the sealing material 5 introduced into them seals the ends of the filter fibers 1 .
- the bundled filter fibers 6 prepared in this way must be immersed in the liquid to be cleaned.
- the open fiber ends of the bundled filter fibers 6 are connected to the suction side of the pump.
- a vacuum is created in the filter fibers 1 through the open fiber ends, and the clean liquid flows into the fiber through the small pores on the outer superficies of the filter fibers 1 , and the dirt remains outside. Contamination can be removed with a counter flow.
- the bundled filter fibers 6 are surrounded by a closed shell.
- the filter consists of a filtrate outlet, a filter space de-aerate hole, and an inlet-cleaning hole. This latter opening serves for the introduction of air in the cleaning cycle, and of the purified liquid in normal operation.
- the advantage of our invention is that the filter fibers become more suitable for mass production, a large number of filter fibers can be produced simultaneously in one step, no manual labor is required, regardless of the number and size of the fibers. Specifically, less adhesive is required.
- the level of the adhesive/sealing material that enters the filter fiber can be limited by the level of the upper auxiliary liquid, i.e. , how deep the sealing/adhesive material should go into the cavity. Deeper penetration into the inner part of the filter fiber can be provided.
- the sealing material has a longer time to set, so its penetration into the spongy membrane structure is better.
- the glue sets completely on all parts, even on parts blocked from light.
- the geometry of the filter fiber does not change, so pollutants are more easily removed from the formed module, or aeration also cleans more effectively.
- Even a flexible sealing can be created, which also does not cause damage in the superficies of the filter fiber.
- glue that solidifies without the use of an external energy source.
- the labor required for its production is lower.
- the auxiliary liquid can be used several times.
- the filter fibers according to the method of the present invention are equally suitable for the production of filters consisting of membrane fibers with or without a carrier. Furthermore, the amount of adhesive flowing into one end of the filter fiber can be controlled together with the level of the auxiliary liquid and the degree of immersion of the filter fiber.
Abstract
Method for end-sealing of hollow membrane filter fibers. During the method one end of the hollow filter fibers is immersed in a low-viscosity hardening sealing material. After the sealing material solidifies, filter fibers with end seals are used to create membrane filter modules. The filter fibers (1) are arranged in bundles. One end (3) of the bundled filter fibers (6) is immersed together into the liquid or gel state sealing material (5) filled in the container (4). Then an auxiliary liquid (7) is filled on the sealing material (5). After solidification of the sealing material (5), the auxiliary liquid (7) is removed. The bundled filter fibers (6) are separated from the sealing material (5) remaining in the container (4) above the level of the solidified sealing material (5).
Description
METHOD FOR END-SEALING OF HOLLOW MEMBRANE FILTER FIBERS
The invention relates to a method for end-sealing of hollow membrane filter fibers. During the method, one end of the hollow filter fibers is immersed in a low-viscosity hardening sealing material, preferably in glue filled in a container, to a given depth. After the sealing material solidifies, filter fibers with end seals are used to create membrane filter modules with a one-sided permeate head design.
In the chemical industry, membrane is a technological term. It denotes a technological barrier which, due to its selective permeability, enables the separation of the components of the materials to be processed mostly without chemical transformation. The essence of membrane separation or membrane filtration is that selective transport takes place through a membrane under the influence of some driving force. The membrane, which is the essence of the operation, is a partition wall that, due to its selective permeability, enables the separation of substances mostly without chemical transformation. The membrane serves as an intermediate phase when separating two phases and/or participates as an active or passive partition wall in the material transfer between the phases in contact with it. During the membrane separation operations, in contrast to the traditional filtration process, the supplied liquid is not flowed perpendicular to the filter medium, but parallel to the membrane (cross-flow), while a part of the components of the material to be filtered passes through the membrane under the influence of the driving force and leaves on the permeate side. The components retained by the membrane are enriched on the feed side of the membrane, this is the retentate or concentrate.
The application and construction of membranes is described in detail in the article entitled Membranos muveletek (Membrane Operations) by Katalin Belafine Bako and Nandor Nemestothy, which was published in 2020 by Pannon University and is available on the following website https://moodle2.mk.uni-pannon .hu/pluginfile.php/35982/mod_resource/content/0/Membr%C3%A1 nos%20m%C5%B 1veletek.pdf.
Membranes are increasingly used to solve separation problems in the food industry, healthcare, chemical industry, wastewater treatment, etc.
Patent application CN 10197266 describes a method for manufacturing a hollow fiber membrane module. The method comprises the following steps: the first ends of the equally long hollow fiber membrane yams are bundled by a conventional method, and
preparing sealant in a container, immersing the second ends of the hollow fiber membrane yams in the sealant in the container in a depth of 2-15 mm.
A vacuum pump is coupled to he first ends of the membrane fibers of the membrane bundle, and the pressure is decreased by 500-1000 Pa inside the membrane fibers thereby the level of the sealant is increased. The vacuum is maintained till the sealant solidifies. Finally, the second ends of the membrane fibers are cut off by 5-20 mm so that the second ends remain sealed. In this solution, no auxiliary liquid, but a vacuum pump is used, which makes the procedure more complicated and more expensive.
The American patent No. US 9498753 B2 describes a method for sealing the free end of a hollow fiber membrane and for use in a filter module. According to the patent, one end of the membrane is immersed in a low-viscosity, light-curing adhesive and the adhesive is cured. The invention also covers the resulting sealed hollow fiber membrane, the diameter of which is only slightly larger than the diameter of the unsealed membrane.
US patent No. US 7,950,528 B2 relates to a through-one-end water collection type hollow fiber membrane and a method for manufacturing the same. According to the invention, an internal sealing part is formed in the hollow part of the membrane at its free end. The internal sealing part is surrounded by an external sealing part from its outer surface, so this solution aims to improve the efficiency of the entire sealing part. US Patent No. 8852438 B2 relates to a membrane filter device. The device contains a number of hollow membrane fibers standing free from each other. The device also contains a first header and a second header disposed in vertically spaced-apart relationship. Opposed ends of each fiber of the first header and the second header are sealingly secured, and all open ends of the fibers open to a permeate-discharging face of at least one header. The device further contains permeate collection means to collect the permeate, sealingly connected in open fluid communication with a permeatedischarging face of at least one of the headers; and means to withdraw said permeate. The fibers, the headers and the permeate collection means together form an integrated unit wherein the fibers are essentially vertically disposed and ends of the individual fibers are potted in closely spaced-apart relationship in cured resin at a fixed distance. In most known solutions, the fibers are individually immersed in glue, essentially an adhesive that binds to UV light, then illuminated, and depending on the viscosity and other physical properties of the glue, the glue penetrates the inner cavity of the fiber to a small extent, but mostly solidifies outside the end of the fibers in the form of a drop.
This slightly increases the dimensions of the fiber. Furthermore, no auxiliary liquid is used in any of them.
Their disadvantage is that the filter modules consist of a large number of fibers, and the separate dipping and/or curing with a UV lamp requires a lot of work and time. In addition, the glue cannot penetrate the fiber to a sufficient depth and the glue cannot penetrate the membrane structure without pressure (there is no time for it), so the glue on the outside does not ensure a proper seal for a long term. Another problem is that the glue increases the cross-section of the end of the fiber, which makes it more difficult for impurities to be removed from the filter module, and it also partially blocks air evaporation. If the UV light-hardening glue penetrates very deeply into the inner cavity, it will not be exposed to enough UV light and will not bond. In this case, toxic substances may remain in the fiber, which may later enter the water to be filtered.
Our aim is to develop a manufacturing process that enables the simultaneous sealing of one end of a large number of filter fibers so that after sealing the filter fibers remain separable from each other and are also suitable for creating a single-sided suction head during the production of membrane filter modules.
It has been realized that if the filter fibers are immersed in a low-viscosity, one- or several-component adhesive sealing material, and a liquid with a lower specific weight than the sealing material is poured on top of the sealing material, due to the phenomenon of the communicating vessels, the sealing material pushes inside the membrane and hardens there. Then the auxiliary liquid with a lower specific weight can be removed, and then the external adhesive residue outside the fibers is cut off, so the fibers will become separate, but each one will be sealed one by one. Due to the low viscosity of the sealing material, the sealing material penetrates not only into the inner cavity, but also into the structure of the membrane filter, but does not affect its external geometry, or only to a negligible extent.
The present invention is a method for end-sealing of hollow membrane filter fibers. During the method, one end of the hollow filter fibers is immersed in a low-viscosity hardening sealing material, preferably in glue filled in a container, to a given depth. After the sealing material solidifies, filter fibers with end seals are used to create membrane filter modules with a one-sided permeate head design. The filter fibers are arranged in bundles to form their end seals, and then one end of the bundled filter
fibers is immersed together into the liquid or gel state sealing material filled in the container to a maximum depth of 20 mm. An auxiliary liquid, with a specific weight lower than the specific weight of the sealing material is filled on the sealing material, which forces the sealing material to a certain extent into one end of the filter fibers. After solidification of the sealing material, the auxiliary liquid is removed and the bundled filter fibers are separated from the sealing material remaining in the container above the level of the solidified sealing material.
Advantageous embodiments of the present invention are described in the dependent claims.
The method according to the present invention will be described with reference to the accompanying drawings in which:
Figure 1 shows a side view section of the bundled filter fibers placed in the container, where one end of the filter fibers is filled with the sealing material and the auxiliary liquid is filled on the sealing material,
Figure 2 shows the top view of the bundled filter fibers placed in the container, one end of the filter fibers is filled with the sealing material and the auxiliary liquid is filled on the sealing material,
Figure 3 shows the side view section of the remaining adhesive material with the ends of the filter fibers where the bundled filter fibers are separated from the remaining adhesive material,
Figure 4 shows the top view of the already sealed, ready-to-use bundled filter fibers, and
Figure 5 is a perspective view of the bundled filter fibers, partially in section.
The membrane filter fiber 1 is designed in a known manner. It is based on a flexible structure made of polyester material made using a woven (braid) or knitted (knitting) process (similar to shoelaces). This structure is coated from the outside with plastic, the surface of which has micropores of 0.01 -0.03 micrometers.
Our method relates to the formation of end seals 2 of hollow, bundled filter fibers 6. During bundling, filter fibers 1 are cut to a given length and tied together. In this process, we can create membrane filter modules with a one-sided permeate head design (Figure 5). During the method, one end 3 of the hollow filter fibers 1 is immersed to a given depth in a low-viscosity, hardening, sealing material 5 filled in a container 4.
The sealing material 5 is a one- or two-component adhesive preferably synthetic resin that solidifies independently of an external energy source. The sealing material 5 is advantageously a polyurethane, polyester or epoxy based synthetic resin. During the method, the filter fibers 1 are arranged in bundles to form their end seals 2. One end 3 of the bundled filter fibers 6 is immersed into the sealing material 5 filled in the container 4, which is still in liquid or gel state, to a maximum depth of 20 mm, then an auxiliary liquid 7 with a specific weight lower than the specific weight of the sealing material 5 is poured onto the sealing material 5. The auxiliary liquid 7 is a liquid that does not react with the sealing material 5. In this way, on the one hand, the sealing material 5 is forced into one end 3 of the filter fibers 1 to a given extent, and on the other hand, it is also ensured that the individual filter fibers 1 do not stick together, and that the end seal 2 does not increase the circumference of the filter fibers 1 at the end seal 2 (1., Figure 2). After solidification of the sealing material 5, the auxiliary liquid 7 is removed, and the bundled filter fibers 6 are separated from the sealing material 5 remaining in the container 4 above the level of the solidified sealing material 5 (Figures 3, 4).
The auxiliary liquid 7 is preferably paraffin oil. Of course, the auxiliary liquid 7 can be any liquid which, on the one hand, has a lower specific weight than the specific weight of the sealing material 5, and on the other hand, does not enter into any chemical reaction with the sealing material 5.
During the formation of the end seal 2 according to our method, it is advantageous if the filter fibers 1 are immersed in the sealing material 5 for a maximum of 10 mm before the auxiliary liquid 7 is filled, and then the auxiliary liquid 7 is filled into the container 4. Afterwards, the filter fibers 1 are immersed in the sealing material 5 to a maximum depth of 20 mm. In this case, the outer side of the filter fibers 1 will be less coated with the sealing material 5, because it is prevented by the auxiliary liquid 7. At the same time, it will be deep enough so that the end of the filter fiber 1 remains below the level of the sealing material 5. This is achieved even if, due to the hydrostatic pressure generated by the auxiliary fluid 7, the sealing material 5 has already penetrated inside the filter fiber 1 , and because of this, the level of the sealing material 5 in the container 4 has decreased.
During the procedure the following steps are made. The filter fibers 1 cut to the given length are bundled, thus preparing the bundled filter fibers 6. The sealing material 5 is filled in the container. If it is multi-component, it is in already mixed state. After that, the ends of the bundled filter fibers 6 are immersed (for example 7 mm deep) into the
sealing material 5. The auxiliary liquid 7 is slowly poured on top of the sealing material 5. After that, the bundled filter fibers 6 are immersed deeper, approx. 10-20 mm deep into the sealing material 5. Due to its hydrostatic pressure, the auxiliary liquid 7 forces a part of the sealing material 5 inside the filter fibers 1 . Then, of course, the level of the sealing material 5 will be lower than before the auxiliary liquid 7 was applied to the adhesive. The outer side of the filter fibers 1 is surrounded by the auxiliary liquid 7 and does not allow the sealing material 5 to cover it. This ensures that the filter fibers 1 can be separated later. After solidification of the sealing material 5, the auxiliary liquid 7 is removed. The bundled filter fibers 6 fixed in the sealing material 5 are taken out of the container 4. The bundled filter fibers 6 are cut directly above the level of the sealing material 5 or a few millimeters above the level of the sealing material 5. Thus, the filter fibers 1 and one of their ends 3 are already separate. At the same time, the sealing material 5 introduced into them seals the ends of the filter fibers 1 .
In the case of a suction system, the bundled filter fibers 6 prepared in this way must be immersed in the liquid to be cleaned. The open fiber ends of the bundled filter fibers 6 are connected to the suction side of the pump. As a result, a vacuum is created in the filter fibers 1 through the open fiber ends, and the clean liquid flows into the fiber through the small pores on the outer superficies of the filter fibers 1 , and the dirt remains outside. Contamination can be removed with a counter flow.
In a pressurized system, the bundled filter fibers 6 are surrounded by a closed shell. In this case, the filter consists of a filtrate outlet, a filter space de-aerate hole, and an inlet-cleaning hole. This latter opening serves for the introduction of air in the cleaning cycle, and of the purified liquid in normal operation.
The use of the bundled filter fibers 6 formed with end seals 2 in different filter systems will not be described in more detail, considering that this must be within knowledge of a person skilled in the art.
The advantage of our invention is that the filter fibers become more suitable for mass production, a large number of filter fibers can be produced simultaneously in one step, no manual labor is required, regardless of the number and size of the fibers. Specifically, less adhesive is required. The level of the adhesive/sealing material that enters the filter fiber can be limited by the level of the upper auxiliary liquid, i.e. , how deep the sealing/adhesive material should go into the cavity. Deeper penetration into the inner part of the filter fiber can be provided. The sealing material has a longer time
to set, so its penetration into the spongy membrane structure is better. The glue sets completely on all parts, even on parts blocked from light. The geometry of the filter fiber does not change, so pollutants are more easily removed from the formed module, or aeration also cleans more effectively. Depending on the hardness of the glue, even a flexible sealing can be created, which also does not cause damage in the superficies of the filter fiber. It is cheaper to use glue that solidifies without the use of an external energy source. The labor required for its production is lower. The auxiliary liquid can be used several times. The filter fibers according to the method of the present invention are equally suitable for the production of filters consisting of membrane fibers with or without a carrier. Furthermore, the amount of adhesive flowing into one end of the filter fiber can be controlled together with the level of the auxiliary liquid and the degree of immersion of the filter fiber.
Claims
1 . Method for end-sealing of hollow membrane filter fibers, during the method one end of the hollow filter fibers is immersed in a low-viscosity hardening sealing material, preferably in glue, filled in a container, to a given depth, and after the sealing material solidifies, filter fibers with end seals are used to create membrane filter modules with a one-sided permeate head design, the filter fibers are arranged in bundles to form their end seals, characterized in that one end (3) of the bundled filter fibers (6) is immersed together into the liquid or gel state sealing material (5) filled in the container
(4) to a maximum depth of 20 mm, then an auxiliary liquid (7), with a specific weight lower than the specific weight of the sealing material (5) is filled on the sealing material
(5), which forces the sealing material (5) to a certain extent into one end (3) of the filter fibers (1 ), and after solidification of the sealing material (5), the auxiliary liquid (7) is removed and the bundled filter fibers (6) are separated from the sealing material (5) remaining in the container (4) above the level of the solidified sealing material (5).
2. Method according to claim 1 characterized in that the filter fibers (1 ) are immersed in the sealing material (5) for a maximum of 10 mm before the auxiliary liquid (7) is filled, and then the auxiliary liquid (7) is filled into the container (4), and after that, the filter fibers (1 ) are immersed in the sealing material (5) to a maximum depth of 20 mm.
3. Method according to claims 1 or 2 characterized in that the sealing material (5) is a one- or two-component adhesive that solidifies independently of an external energy source.
4. Method according to any of claims 1 - 3 characterized in that the sealing material (5) is synthetic resin.
5. Method according to any of claims 1 - 4 characterized in that the sealing material (5) is polyurethane, polyester or epoxy based synthetic resin.
6. Method according to any of claims 1 - 5 characterized in that the auxiliary liquid (7) is paraffin oil.
Applications Claiming Priority (2)
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HU2200299 | 2022-07-20 | ||
HUP2200299 | 2022-07-20 |
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WO2024018243A1 true WO2024018243A1 (en) | 2024-01-25 |
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101972606A (en) * | 2010-11-23 | 2011-02-16 | 武汉艾科滤膜技术有限公司 | Manufacturing method of hollow fiber membrane component |
CN102806015A (en) * | 2011-05-30 | 2012-12-05 | 海南立昇净水科技实业有限公司 | Manufacturing method for hollow fiber membrane assembly |
US20130240436A1 (en) * | 2012-03-15 | 2013-09-19 | Taylour Johnson | Method for Sealing Hollow Fiber Membranes |
-
2023
- 2023-06-13 WO PCT/HU2023/050034 patent/WO2024018243A1/en unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101972606A (en) * | 2010-11-23 | 2011-02-16 | 武汉艾科滤膜技术有限公司 | Manufacturing method of hollow fiber membrane component |
CN102806015A (en) * | 2011-05-30 | 2012-12-05 | 海南立昇净水科技实业有限公司 | Manufacturing method for hollow fiber membrane assembly |
US20130240436A1 (en) * | 2012-03-15 | 2013-09-19 | Taylour Johnson | Method for Sealing Hollow Fiber Membranes |
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