Implantation system, fluid treatment system, membrane aeration biofilm reactor, membrane supported biofilm reactor, membrane bioreactor, membrane contactor or membrane filtration unit

Abstract

The implant system includes an implant unit having an integral compression seal formed from the same material from which it is constructed.

Description

[Technical field]

[0001] The present invention relates to seals used in implanting or holding hollow fiber membranes together. [Background technology]

[0002] A membrane aerated biofilm reactor (MABR) or membrane supported biofilm reactor (MSBR) is one of several types of reactors that use submerged membrane modules. In an MABR, gas (usually oxygen in the form of air) is fed to the inside of a hollow fiber membrane to grow a biofilm on the other side of the membrane. The biofilm is then used to treat water and / or wastewater. The biofilm does so by removing carbonaceous contaminants, nitrifying / denitrifying nitrogenous contaminants, and / or performing xenobiotic biotreatment of wastewater components. The membrane used in an MABR is an air / oxygen / hydrogen (gas) permeable membrane (often a hollow fiber membrane) that provides an interface between the fluid to be treated (liquid phase) and the air / oxygen / hydrogen supply (gas phase). Typically, a biofilm consisting of a heterogeneous population of bacteria (microorganisms) (generally including nitrifying, denitrifying, and heterotrophic bacteria) grows on the liquid phase side of the membrane. MABR can achieve less bubble aeration and higher oxygen utilization efficiency (up to 100%).

[0003] The membrane forms a barrier between two fluids but allows certain molecules or particles of a certain size to pass between them. When manufacturing membrane modules, it is very important that the two fluids are kept separate and that the membrane or the implants that hold the membrane together and seal the membrane to keep the fluids on either side of the membrane separate are free of defects.

[0004] Membranes are found in one of three configurations: hollow fiber, flat sheet, and spiral. Membrane modules are generally found in either tubular or submerged configurations. In submerged membrane modules, the membranes are generally configured in hollow fiber or flat sheet configurations. In hollow fiber modules, various implantation techniques are used to ensure that the membranes are held together and that there is no direct fluid communication between the inside and outside of the membrane. In some implantation techniques, several hollow fiber membranes are bundled together in a bundle or array, and wax or similar material is placed inside the ends of the hollow fibers. The sealed ends are dipped into a potting agent, typically a liquid polymer, or the potting agent is poured or placed over and around the ends of the hollow fiber membranes in a mold that gives them the shape required for implantation. As described in U.S. Pat. No. 5,639,373, the polymer must be allowed to solidify and bond well with the membrane material so that the membrane does not come loose and compromise the integrity of the membrane module. The solidified potting agent holds the membranes together so that they can be assembled into modules. It is important to ensure that the potting agent wets each hollow fiber membrane. The liquid polymer must have a low enough viscosity to flow between the hollow fibers and bond to the surface. The potting agent must also be chemically compatible with the membrane so that it will actively bond to the surface. Membrane potting is the most difficult part of membrane module manufacturing and is the cause of most membrane module failures.

[0005] In immersed modules, these potted membranes are connected to a header or manifold by being fastened or glued to ensure there is a good seal between the potted membrane and the header or manifold to prevent cross contamination between the two fluids. To ensure a good seal is achieved, an adhesive is used that bonds with both the polymer of the potting agent and the material of the header, even though it is another material such as a polymer or metal. The use of an adhesive is to ensure that leakage does not occur over time. In many cases, the adhesive is the only way to bond the potted membrane to the header. Over time, the adhesive can weaken or be chemically attacked by chemicals or contaminants in the water or wastewater, compromising the integrity of the module. The addition of an adhesive also introduces another step into the manufacturing process. In other examples, a seal or gasket can be placed between the potted membrane and the header. The use of an additional seal creates two material interfaces, between the potted membrane and the seal, and between the seal and the header. This creates leakage and, as explained above when using adhesives, over time the integrity is lost and the module fails.

[0006] Submerged membrane modules are often used in wastewater applications where the types of contaminants can vary significantly depending on whether the application is municipal or industrial wastewater, and the concentrations of contaminants can change from hour to hour depending on environmental or upstream conditions. Conditions can be harsh with temperatures ranging from 4°C to 40°C, and chemicals such as hypochlorites, acids, and bases used in the cleaning procedures. These contaminants in the wastewater and the chemicals used in the cleaning procedures can attack the chemical bond between the potting material and the header, weakening or compromising the bond over time.

[0007] One object of the present invention is to overcome at least one of the above problems. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention relates to an implantation system used to hold hollow fiber membranes together with an integrated compression seal. When a mechanical force is used to press the compression seal against a header or manifold, the fluids inside and outside the hollow fiber membrane are completely separated. The implantation system can be used to manufacture membrane modules suitable for transferring dissolved components from one fluid to another. [Means for solving the problem]

[0009] In one aspect, there is provided an implantation system (1) comprising an implant unit (2) having a body (3) including a distal end (5), an intermediate portion (6) and a proximal end (7), the body (3) further comprising an integral compression seal (4) that is continuous and perpendicular with the body (3) and that is constructed from the same material as the implantation unit (2), as recited in the appended claims.

[0010] In one aspect, the material is an elastomer. Preferably, the elastomer is selected from polysiloxane, polyurethane, natural rubber, nitrile rubber, polyisoprene, fluoroelastomer. Ideally, the elastomer is a polysiloxane selected from silicone, silicone rubber, silicone resin, silicone foam, silicone caulk.

[0011] In one embodiment, the integral compression seal (4) is located at the base (9) of the body (3).

[0012] In one embodiment, the distal end (5) is adapted to receive the hollow fiber membrane (10), which is potted in the distal end (5) with a potting agent of the same material as the implantation unit (2). Preferably, the distal end (5) can be of any shape selected from a circle, a chevron, a cross, a line, a square, a rectangle, a triangle, a hexagon, other polygonal or circular cross-sectional shapes, an ellipse, a three-pointed star, a four-pointed star, a five-pointed star, etc.

[0013] In one embodiment, the implant unit (2) is a single piece.

[0014] In one embodiment, the implantation system (1) further comprises a fastener (20).

[0015] In one aspect, the fastener (20) includes a first portion (21) and a second portion (22) configured to engage and maintain a downward force with the integrated compression seal (4) of the implant unit (2). Preferably, the first portion (21) includes a series of spaced apart recesses (24) adapted to receive the integrated compression seal (4) of the implant unit (2).

[0016] In one embodiment, the second portion (22) includes a series of corresponding spaced apart recesses (25) adapted to receive and engage the intermediate portion (6) of the body (3).

[0017] In one embodiment, the first portion (21) includes a series of male / female connectors (26) adapted to mate with a corresponding series of male / female connectors (27) included in the second portion (22).

[0018] In one embodiment, the first and second parts (21, 22) each have additional fastening means (28) at their ends (29).

[0019] In one aspect, the implantation system (1) further comprises a securing means (30) adapted to engage the fastener (20) and maintain a downward force on the integrated compression seal (4) of the implantation unit 2. Preferably, the securing means (30) engages the fastening means (28) at the end (29) of the first portion (21) or the second portion (22).

[0020] In one embodiment, the body (2) tapers from the distal end (5) to the proximal end (7).

[0021] In one embodiment, the proximal end (7) is adapted to engage a header (50) of a fluid treatment system.

[0022] In one aspect, a fluid treatment system is provided that includes the implantation system (1) described above.

[0023] In one aspect, there is provided a membrane aeration biofilm reactor (MABR), membrane supported biofilm reactor (MSBR), membrane bioreactor (MBR), membrane contactor or membrane filtration unit comprising the implantation system (1) as described above.

[0024] In one aspect, the implantation system further includes a fastener including a first portion adapted to engage with the body of the implantation unit and a second portion adapted to engage with the integrated compression seal of the implantation unit.

[0025] In one aspect, the material of construction of the fastener is suitably a durable, yet rigid material such as, for example, polypropylene, polyethylene (PE), polyethylene terephthalate copolymer (PETG), and amorphous polyethylene terephthalate (APET).

[0026] One advantage of the present invention is that it extends the life of fiber membrane bundles in systems such as MABRs and MSBRs or other submerged membrane modules, since the integrated seal of the implantation unit is a mechanical seal made of a material that resists any chemical attack. Another advantage is that the individual implantation configuration used to fasten individual fiber membrane bundles to the headers of such systems allows the user to remove a membrane bundle, whether it is a non-functioning or needed or under maintenance, without affecting other membrane bundles connected to the header in the same system or requiring solvents to remove adhesives or damage the header by cutting or drilling. Another advantage of the present invention is that it reduces the number of chemicals required in the manufacturing process. Reducing the number of chemicals used in manufacturing not only reduces the cost and complexity, but also reduces the environmental impact of manufacturing and the health and safety risks for personnel.

[0027] definition In this specification, the term "membrane aeration biofilm reactor (MABR)" should be understood to mean a membrane supported biofilm reactor (MSBR) for treating wastewater liquid and removing carbonaceous pollutants, removing pollutants, nitrification / denitrification, and / or performing xenobiotic biological treatment of wastewater components. Soluble organic compounds in the liquid are supplied to the biofilm from the biofilm-liquid interface, and gas supply to the biofilm is from the biofilm-membrane interface (by diffusion through the membrane). Typically, a biofilm consisting of a heterogeneous population of bacteria (generally including nitrifying bacteria, denitrifying bacteria, and heterotrophic bacteria) grows on the liquid phase side of the membrane. MABRs can achieve less bubble aeration and high oxygen utilization efficiency (up to 100%), and the biofilm can be divided into aerobic / anoxic / anaerobic zones to simultaneously achieve carbonaceous organic pollutant removal and nitrification and denitrification in a single biofilm. An example of a type of MABR having a lumen containing a gas phase, a liquid phase, and a gas-permeable membrane providing an interface between the gas and liquid phases is described in EP 2361367 (University College Dublin).

[0028] As used herein, the term "membrane bundle" should be understood to mean an assembly of 10-100,000, 10-10,000, 10-1,000, or 10-100 gas permeable hollow membrane fibers implanted at either end into a circular bundle or shaped element such that the fiber ends are open. The membranes can be aligned vertically within the MABR, in which case the resulting liquid flow is parallel to the membranes, or the membranes can be aligned horizontally within the MABR, in which case resulting in a cross-flow configuration.

[0029] As used herein, the term "implant unit" should be understood to mean a unit that can be used to fasten membranes together to form a membrane bundle, which can then be connected to a header or manifold of a fluid treatment system or membrane module. The implant unit is typically a single continuous piece made of the same material as the potting agent.

[0030] In this specification, the term "potting agent" should be understood to mean any polymer suitable for use in fixing the textile membrane within the implant unit. The implant unit may also be composed of the potting agent. Suitable polymers are elastomers.

[0031] In this specification, the term "elastomer" should be understood to mean a polymer that has viscoelastic properties (polymers that exhibit rubber-like elasticity) and has a high breaking strain compared to other non-elastic materials. Examples of elastomeric polymers include polysiloxanes (e.g., silicones, silicone rubbers, silicone resins, silicone foams or silicone caulks and their variants), polyurethanes and rubbers (natural or synthetic rubbers such as nitrile rubber, isoprene and fluoroelastomers). Elastomers typically have excellent sealing properties, stability over a wide temperature range, durability and corrosion resistance.

[0032] As used herein, the term "fastening means" should be understood to mean a device that closes or secures two or more objects together. Typically, fastening means create a non-permanent joint. Examples include cam locks, male / female fasteners, snap fasteners, threaded fasteners, snap fit joints, etc.

[0033] In this specification, the term "snap" should be understood to mean a mechanical joining system where the attachment between parts is achieved using a locating and locking mechanism (restraint mechanism) similar to either of the parts being joined, according to industry standards ("The First Snap-Fit Handbook", 1st Edition, (P. Bonenberger) (2000)). To join, the (flexible) locking mechanism must be moved apart to engage the mating part, followed by the locking mechanism returning to its original position to achieve the interference required to latch the parts together. The second type of restraint mechanism, the locator mechanism, is inflexible and provides strength and stability to the attachment. Reinforcements complete the snap-fit ​​system, adding robustness and ease of use to the attachment. The most common forms of snaps are annular (circular connector), cantilever (hook and recess), and torsional (latch attached to a torsion bar or shaft). Snap fits are commonly used as an assembly method for injection molded parts. Because the snap is molded into the product, no additional parts are required to join the snap. Furthermore, snaps, if properly designed, can be disassembled and reassembled many times without issue. Snap fits can be designed as permanent snaps or multi-snaps. Permanent fits are used for disposable parts that are not intended to be disassembled. Multi-snaps are used in most designs where disassembly for service is anticipated.

[0034] As used herein, the term "distal end" in reference to an implanted unit refers to a molded element or molded connector, and should be understood to mean an element that gives the membrane bundle a particular shape (e.g., angled, cross, linear, square, rectangular, triangular, hexagonal, other polygonal or circular cross section, etc.) that provides a connector end that can be fixed in an air-tight manner to an upper or lower manifold (or header), and thus becomes known as an implanted membrane.

[0035] In this specification, the terms "upper manifold" and "lower manifold" should be understood to mean gas manifolds (or headers) with ports designed to receive implanted units, including bundles of hollow fiber membranes. In addition, multiple implanted units may be directly implanted into the upper and lower gas manifolds to form a continuous membrane bundle that spans from one end of the manifold to the other. When oriented vertically, the upper manifold is referred to as the upper manifold and the lower manifold is referred to as the lower manifold. The upper and lower manifolds are in fluid communication with the internal structure of all the hollow fibers such that air / gas can flow from the interior of the upper manifold through the hollow fibers to the lower manifold or vice versa.

[0036] In the present specification, the term "membrane module" or "membrane aeration biofilm reactor (MABR)" should be understood to mean a device in which several (2-1,000, 2-900, 2-800, 2-750, 2-700, 2-650, 2-600, 2-550, 2-500, 2-450, 2-400, 2-350, 2-300, 2-250, 2-200, 2-150, 2-100, 2-50) cassettes consisting of hollow fiber membranes can be fixed in parallel. The cassettes are generally fixed in a frame.

[0037] As used herein, the term "liquid" should be understood to mean any form of fluid or gas, such as water or wastewater, and any water whose quality has been adversely affected by human-caused influences. Wastewater can originate from a combination of domestic (e.g., sewage), industrial, commercial, or agricultural activities, surface runoff, or storm water, and from sewer inflow or seepage. [Brief description of the drawings]

[0038] The invention will be more clearly understood from the following description of embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:

[0039] [Figure 1] 1 shows a perspective view of one embodiment of an implant unit of the claimed invention. [Diagram 2] 2A and 2B show a first part (FIG. 2A) and a second part (FIG. 2B) of a two-part fastener of the claimed invention configured to engage and secure the implant unit of FIG. 1 to a header or manifold. [Diagram 3] 2A and 2B. [Figure 4] 1 is shown engaging the two-part fastener of FIGS. 2a, 2b and 3 and attached to the header of a processing tank to form the implantation system of the claimed invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] The invention described herein provides an implantation system for use in the manufacture of fluid treatment systems such as MABRs or MSBRs, membrane bioreactors (MBRs used for wastewater treatment), membrane contactors for gas supply or gas removal (typically found in the beverage or chemical industry) and membrane filtration units (which can be used in the chemical, pharmaceutical or food and beverage industries), which includes an implantation unit and optionally fasteners. The implantation unit is typically a single piece made of the same potting agent used to secure the bundle of hollow fiber membranes to the implantation unit. The implantation unit also includes an integrated compression seal that is resistant to attack from chemicals or other reagents that may be found in the liquid to be treated and also provides a mechanical seal within the treatment system to ensure that liquids on either side of the membrane do not mix.

[0041] Turning now to the drawings, Figure 1 illustrates a general embodiment of an implant system of the present invention. Specifically, Figure 1 illustrates a perspective view of an implant unit of an implant system of the present invention, generally referred to by reference numeral 1, with a hollow fiber membrane in place. The implant system 1 includes an implant unit 2 having a body 3 with an integrated compression seal 4. The body 3 includes a distal end 5, a mid-section 6, a base 9, and a proximal end 7. The integrated compression seal 4 is contiguous with the mid-section 6 of the implant unit 2 and is positioned towards or at the base 9 of the implant unit 2.

[0042] The distal end 5 is adapted to receive a bundle of hollow fiber membranes 10, which are potted in the implantation unit 2 with a potting agent. The implantation unit 2 is typically a single continuous piece manufactured with the same potting agent used to secure the hollow fiber membranes 10 within the distal end 5 of the implantation unit 2. The potting agent also creates the shape of the integral compression seal 4. The distal end 5 around the membranes 10 can function as a connector (molded connector) that can be molded in a specific way to space the membranes 10 apart to form a unique shape or pattern, as described in EP3297749. Alternatively, the distal end 5 can be essentially cylindrical.

[0043] Additionally, the integrated compression seal 4 can be manufactured in any desired shape, such as circular, angled, cross, linear, square, rectangular, triangular, hexagonal, other polygonal or circular cross-sectional shapes, oval, three-pointed star, four-pointed star, five-pointed star, etc.

[0044] The proximal end 7 typically has a connector 8 configured to mate with a header 50 (see FIG. 4) of a manifold.

[0045] 2A illustrates a first portion 21 of the two-part mechanical fastener 20, and FIG. 2B illustrates a second portion 22 of the two-part mechanical fastener 20. The fastener 20 is adapted to encase the integrated compression seal 4 when the implant unit 2 is engaged with a header 50 (see FIG. 4) of a manifold. The first portion 21 includes a series of spaced recesses 24 adapted to receive the integrated seal 4 of the implant unit 2 and a series of male / female connectors 26 adapted to engage with a corresponding series of male / female connectors 27 of the second portion 22. The second portion 22 also includes a series of corresponding spaced recesses 25 adapted to receive the intermediate portion 6 of the body 3. The fastener 20, when used, is configured to be used with any fastening means to maintain a downward force on the integrated compression seal 4 of the implant unit 2. The male / female connectors 26, 27 are typically snap-fit ​​connectors, although other well-known and equally practical male / female fastening means may be used, such as nut and bolt arrangements, cable tie arrangements, connectors, hooks, latches, locks, lugs, rivets, screws, and the like. The first and second parts 21, 22 each have an additional fastening means 28 at either end 29 thereof, which is adapted to engage a securing means 30 (see FIG. 3). The securing means 30 is adapted to lock the two-part fastener 20 in place and maintain a downward force on the integrated compression seal 4 of the implantable unit 2. The fastener 20 provides an additional downward force on the end of the cassette of the modular reactor, and can ensure that there is a uniform downward force along the length of the fastener 20.

[0046] 4 is an image of the implantation system 1 when attached to a header 50 of a modular reactor during use. During use, the inside of the hollow fiber membrane 10 is in fluid communication with a central channel 52 of the header 50. The header 50 is used to convey fluids inside the hollow fiber membrane 10 to and from the membrane 10. The processing module will include upper and lower headers 50. The upper and lower headers 50 are connected via a manifold or piping system. The headers 50 maintain separation of the two fluids within the modular reactor.

[0047] The membranes used in MABR are most often dense membranes. These membranes lack pores, but instead allow the diffusion of gas molecules through the interpolymer lattice. The most common materials used are polydimethylsiloxane (silicone) or polymethylpentane. Silicones are often used in non-stick applications due to their low surface energy, and are also used for seals and gaskets because they are elastic and compressible, allowing them to stretch around a nozzle or nipple and compress between two surfaces.

[0048] Silicone, due to its characteristics, is not always easy to bond with other materials. Therefore, silicone is often used as a potting agent for silicone membranes because it can adhere to itself and chemically bond to each membrane. Most other potting agents are not suitable for forming a mechanical seal as shown by the claimed invention because they are not compressible once solidified. By forming the potting silicone around the membrane to have an integrated seal, mechanical fasteners can be used to keep the potted membrane attached to the header. The potting material can have a compression seal by forming the potting in such a shape that it avoids the need to bond the potted membrane to the header to ensure complete separation of the fluids on either side of the membrane. The compressive force used for the mechanical seal must be sufficient to hold the potted membrane in place, but not excessive enough to damage and cause tears in the potting silicone. The elastomers used to pot the membrane should have similar bond lengths and use a catalytic crosslinking procedure similar to that used to form the hollow fiber membrane to ensure chemical compatibility. The elastomer used to form the implant should have the same Shore hardness as the polymer used to manufacture the membrane.

[0049] In this specification, the terms "comprise", "comprises", "comprised" and "comprising" or any variation thereof, and the terms "include", "includes", "included" and "including" or any variation thereof, are considered to be fully interchangeable and are all to be given the broadest possible interpretation and vice versa.

[0050] The invention is not limited to the embodiments described above, which may differ both in structure and details.

Claims

1. An implantation system (1) comprising an implantation unit (2) having a body (3) including a distal end (5), an intermediate portion (6) and a proximal end (7), the distal end (5) adapted to receive a hollow fiber membrane (10) and the proximal end (7) adapted to engage a header (50) of a fluid treatment system, the body (3) being continuous and perpendicular to the body (3), further comprising an integral compression seal (4) constructed from the same material as the implantation unit (2), the material being an elastomer; the fastener (20) includes a first portion (21) and a second portion (22) configured to engage and maintain a downward force on the integrated compression seal (4) of the implantation unit (2); the first portion (21) includes a series of spaced apart recesses (24) adapted to receive the integral compression seal (4) of the implantation unit (2), and the second portion (22) includes a series of corresponding spaced apart recesses (25) adapted to receive and engage the intermediate portion (6) of the body (3); Implantation system.

2. 2. An implant system (1) according to claim 1, wherein the elastomer is selected from polysiloxane, polyurethane, natural rubber, nitrile rubber, polyisoprene, fluoroelastomer.

3. 3. An implantation system (1) according to claim 2, wherein the elastomer is a polysiloxane selected from silicone, silicone rubber, silicone resin, silicone foam, silicone caulk.

4. An implantation system (1) according to any one of the preceding claims, wherein the integrated compression seal (4) is arranged at the base (9) of the body (3).

5. An implantation system (1) according to any one of the preceding claims, wherein the membrane (10) is potted at the distal end (5) with a potting agent of the same material as the implantation unit (2).

6. 6. An implantation system (1) according to claim 5, wherein the distal end (5) can be any shape selected from a circular, polygonal or circular cross-sectional shape, an ellipse, a three-pointed star, a four-pointed star, a five-pointed star.

7. An implantation system (1) according to any one of the preceding claims, wherein the implantation unit (2) is a single part.

8. 2. The implantation system (1) of claim 1, wherein the first part (21) includes a series of male / female connectors (26) adapted to engage with a corresponding series of male / female connectors (27) included in the second part (22).

9. An implantation system (1) according to claim 1, wherein the first and second parts (21, 22) each have additional fastening means (28) at their ends (29).

10. 2. The implantation system (1) of claim 1, further comprising a fixing means (30) adapted to engage the fastener (20) and maintain a downward force on the integrated compression seal (4) of the implantation unit (2).

11. An implantation system (1) according to any one of the preceding claims, wherein the body (2) tapers from the distal end (5) towards the proximal end (7).

12. 10. An implantation system (1) according to claim 9, wherein the fixing means (30) engages with the fastening means (28) at the end (29) of the first part (21) or the second part (22).

13. 2. The implantation system (1) of claim 1, wherein the fastener (20) includes a first portion adapted to engage with the body of the implantation unit and a second portion adapted to engage with the integrated compression seal of the implantation unit.

14. 14. The implantation system (1) according to claim 13, wherein the material of the fastener is selected from polypropylene, polyethylene (PE), polyethylene terephthalate copolymer (PETG) and amorphous polyethylene terephthalate (APET).

15. A fluid treatment system comprising an implantation system (1) according to any one of the preceding claims.

16. A membrane aerated biofilm reactor (MABR), a membrane supported biofilm reactor (MSBR), a membrane bioreactor (MBR), a membrane contactor or a membrane filtration unit comprising an implantation system (1) according to any one of claims 1 to 14.

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