Tubular membrane modules and a method for the manufacture thereof

Abstract

The present invention relates to a method for the manufacture of a tubular membrane module, the method comprising the steps of: providing a plurality of tubular membranes; surrounding an end portion of the plurality of tubular membranes with a first powdered material; forming a tubular membrane bundle by heating the first powdered material such that the first powdered material forms a solid mass encapsulating the end portion; locating the tubular membrane bundle in a housing; introducing a second powdered material to the housing; and forming the tubular membrane module by heating the second powdered material such that the second powdered material forms a bond between an inner surface of the housing and the tubular membrane bundle.

Description

TUBULAR MEMBRANE MODULES AND A METHOD FOR THE MANUFACTURE THEREOFTECHNICAL FIELD

[0001] The present invention relates to tubular membrane modules and a method for the manufacture thereof. In particular, the present invention relates to porous tubular membrane modules, such as those used for separation processes.BACKGROUND

[0002] Tubular membrane modules, and particularly porous tubular membrane modules, are commonly used in separation processes such as oily wastewater treatment, membrane bioreactors, hydrogen separation and the like.

[0003] Typically, a tubular membrane module comprises a plurality of porous tubular membranes located within a housing. The porous tubes are typically retained in the housing using compression fittings and conventional welding methods.

[0004] The retention of the tubular membranes in the housing with compression fittings and conventional welding methods incorporates points of mechanical weakness. Such points of mechanical weakness are especially notable in high-temperature and high-pressure reactions where the housing and the tubular membranes may become damaged by the compression fittings and / or welding during use which may in turn impair functionality.

[0005] In addition, the use of compression fittings and welding means to retain the tubular membranes in the housing requires the wall thickness of the tubular membranes to be relatively high. This relatively high wall thickness limits the number of tubular membranes that may be positioned in the housing which in turn limits the efficacy of the tubular membrane module.

[0006] In some applications, it is desirable to coat an inner surface of the tubular membranes with a catalyst so as to form a catalytic membrane. However, existing methods of retaining the tubular membranes in the housing often result in damage to the catalytic membrane which may lead to decreased operating efficiency and increase costs associated with re-coating the tubular membrane.

[0007] Thus, it would be advantageous to provide a tubular membrane module and method of manufacture having an improved efficiency without sacrificing structural integrity, or without impairing inner surface modifications made to the tubular membrane.

[0008] It will be clearly understood that, if a prior art publication is referred to herein, thisreference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.SUMMARY OF INVENTION

[0009] Embodiments of the present invention provide a method for the manufacture of a tubular membrane module, which may at least partially address one or more of the problems or deficiencies mentioned above or which may provide the public with a useful or commercial choice.

[0010] In a first aspect, the invention resides broadly in a method for the manufacture of a tubular membrane module, the method comprising the steps of: a) encapsulating an end portion of a plurality of tubular membranes within a metallic material to form a tubular membrane bundle; b) locating the tubular membrane bundle in a housing; and c) forming the tubular membrane module by introducing a bonding material into the housing such that the bonding material forms a bond between an inner surface of the housing and the tubular membrane bundle.

[0011] It will be understood that the term “metallic material” is used to indicate a material that is at least partially metallic in nature. The metallic material need not be predominantly metallic, but it will be understood that some metallic content is present.

[0012] In a second aspect, the invention resides broadly in a method for the manufacture of a tubular membrane module, the method comprising the steps of: a) providing a plurality of tubular membranes; b) surrounding an end portion of the plurality of tubular membranes with a first powdered material; c) forming a tubular membrane bundle by heating the first powdered material such that the first powdered material forms a solid mass encapsulating the end portion of the plurality of tubular membranes; d) locating the tubular membrane bundle in a housing; e) introducing a second powdered material to the housing; and f) forming the tubular membrane module by heating the second powdered material such that the second powdered material forms a bond between an inner surface of the housing and the tubular membrane bundle.

[0013] Advantageously, the method for the manufacture of a tubular membrane moduledoes not require the use of compression fittings or welding to secure the plurality of tubular membranes together, nor does it require the use of compression fittings or welding to secure the plurality of tubular membranes and / or the tubular membrane bundle within the housing. By excluding the need for compression fittings or welding, the present invention may enable a greater number of tubular membranes to be provided within the tubular membrane module and / or tubular membrane bundle, leading to an increased membrane surface area over which a reaction can occur. Furthermore, the wall thickness of the plurality of tubular membranes is not limited by the compressive forces applied during traditional compression fittings or welding, therefore, the plurality of tubular membranes may not have a minimum wall thickness. By making use of tubular membranes having a smaller wall thickness than conventional tubular membranes, a greater number of tubular membranes may be provided in a tubular membrane module and / or tubular membrane module.

[0014] The present invention may be used for any suitable purpose and in any suitable separation process. The material to be separated may be in the form of a gas, liquid, slurry or a combination thereof. For instance, the separation process may comprise water treatment to remove particulates, viruses and bacteria, gas separation to remove carbon dioxide, nitrogen oxides, sulphur oxides, hydrogen and the like, or haemodialysis to remove waste products and excess fluids from the blood. In other specific embodiments, the present invention may be used to separate particulate matter from beverages, including alcoholic beverages, in the manufacturing process. In these embodiments, it is envisaged that the present invention may be used in a filtration process during the brewing of beer, winemaking or vinification and / or the distillation of spirits.

[0015] As indicated, the method for the manufacture of a tubular membrane module comprises providing a plurality of tubular membranes.

[0016] Any number of tubular membranes may comprise the plurality of tubular membranes. The skilled addressee will appreciate that the number of tubular membranes forming the plurality of tubular membranes may influence the volume and velocity that a feed may be provided to the tubular membrane module.

[0017] The plurality of tubular membranes may be of any suitable size, shape, or configuration. Preferably, the tubular membranes are of a substantially uniform size, shape, and configuration.

[0018] In a preferred embodiment, the plurality of tubular membranes may be elongate and substantially linear. The plurality of tubular membranes may include opposed ends and at least one sidewall extending therebetween. A central axis may be defined between the opposed ends.

[0019] Preferably, the tubular membranes are substantially hollow. It is envisaged that a passageway may extend between the opposed ends of the tubular membranes. Preferably, the passageway may extend along a central axis of the tubular membranes.

[0020] Preferably, the opposed ends are substantially circular such that the plurality of tubular membranes are cylindrical tubes. However, the skilled addressee will appreciate that the plurality of tubular membranes may include opposed ends of any polygonal shape such as for example, square, hexagonal, or triangular.

[0021] The at least one side wall may include an inner surface configured, in use, to be in contact with the material to be separated. Preferably, the at least one side wall of the tubular membrane defines a lumen located at the interior thereof.

[0022] The plurality of tubular membranes may be fabricated from any suitable material. The skilled addressee will appreciate that the material of the plurality of tubular membranes may be selected depending on the application in which the tubular membranes will be used (i.e. , the nature of the material to be separated). It is envisaged that the considerations in selecting the material from which the tubular membranes may be fabricated may include the permeate and retentate preference of the material to be separated.

[0023] For example, the plurality of tubular membranes may be formed from ceramic, concrete, fibreglass, plastic and / or metals or metal alloys. In some embodiments, the tubular membranes may be fabricated from steel, polyvinyl chloride (PVC) or ceramic, preferably stainless steel, unplasticized PVC (uPVC) or chlorinated PVC (cPVC), or the like, or any suitable combination thereof.

[0024] Most preferably, the plurality of tubular membranes may be fabricated from an alloy of two or more of steel, vanadium, nickel and aluminium.

[0025] Preferably, the plurality of tubular membranes are at least semi porous or permeable such that when the feed enters the lumen of each of the plurality of tubular membranes, at least a portion of the material to be separated may permeate through the side wall of each of the plurality of tubular membranes. In these embodiments of the invention, it is envisaged that at least a portion of the material to be separated will be unable to permeate through the side wall of the tubular membranes, thereby resulting in the separation of one or more components of the material to be separated.

[0026] The plurality of tubular membranes may be fabricated using any suitable forming process. For instance, the plurality of tubular membranes may be formed by casting, powdercompaction, extrusion or the like.

[0027] In some embodiments, a portion of each of the plurality of tubular membranes may be coated with a catalyst. The coating may be applied using any suitable technique. For instance, the coating may be applied by spraying, hot dipping, painting, depositing (such as via vapour deposition), plating (such as via electroplating or electroless deposition) or otherwise applying a surface coating to the plurality of tubular membranes. Preferably, the coating is applied to the lumen of each of the plurality of tubular membranes.

[0028] Preferably, the catalytic coating is porous or permeable such that permeate is capable of permeating from the lumen of each of the plurality of tubular membranes for collection within the housing, or, in embodiments where no housing is provided, the permeate may disperse.

[0029] The plurality of tubular membranes may be positioned in a desired configuration. Most preferably, the plurality of tubular membrane is positioned prior to forming the tubular membrane bundle.

[0030] The skilled addressee will appreciate that the position of the plurality of tubular membranes may depend upon the material to be separated and the desired permeate and retentate.

[0031] The plurality of tubular membranes may be positioned in any suitable configuration. For example, the plurality of tubular membranes may be positioned in rows, in a circular configuration, or in an irregular configuration. In some embodiments, the plurality of tubular membranes may be positioned concentrically.

[0032] Preferably, the plurality of tubular membranes are configured in a non-tessellating manner such that the permeate may readily permeate from the lumen of the plurality of tubular membranes through the side wall thereof.

[0033] During the fabrication of the tubular membrane bundle, the plurality of tubular membranes may be releasably secured together in a desired configuration. For example, the plurality of tubular membranes may be secured together by a clamping device such as for example, a clamp, a hose clamp, support stand, retort stand, or other like device.

[0034] Any number of clamping devices may be utilised to releasably secure the plurality of tubular membranes together.

[0035] Any suitable portion of the plurality of tubular membranes may be secured together.However, preferably, the portion of the plurality of tubular membranes that are secured together does not include the end portion of the plurality of tubular membranes. Advantageously, this enables the solid mass encapsulating the end portion to be in direct contact with the plurality of tubular membranes.

[0036] In some embodiments, the plurality of tubular membranes may be secured together at more than one position. Advantageously, being secured together at more than one position may be useful where the plurality of tubular membranes is of a length that may require additional support in order to keep each of the plurality of tubular membranes in contact with each other along their length.

[0037] The plurality of tubular membranes may be releasably secured together such that the outer surfaces of each of the plurality of tubular membranes are in contact with each other.

[0038] Preferably, however, the plurality of tubular membranes is releasably secured together such that the outer surface of each of the plurality of tubular membranes are not in contact with each other. Advantageously, releasably securing together the plurality of tubular membranes in this manner may enable the permeate to readily flow from each of the plurality of tubular membranes without encountering a subsequent tubular membrane. Thus, the plurality of tubular membranes may be located in close proximity to one another.

[0039] In other embodiments, in particular where the configuration of the plurality of tubular membranes is of importance, the plurality of tubular membranes may be configured in a support cassette.

[0040] The support cassette may include a structure with a plurality of apertures. The structure may be any suitable shape such as a polyhedron or a sphere. However, most preferably, the structure of the support cassette is substantially plate-like or dish-like.

[0041] Each of the plurality of apertures may be of sufficient size to enable each of the plurality of tubular membranes to be fitted therethrough.

[0042] The plate may be positioned along a length of the plurality of tubular membranes. Most preferably, the plate is positioned away from the ends of the plurality of tubular membranes such that when the tubular membrane bundle is formed, the solid mass encapsulating an end portion of the plurality of tubular membranes is not impacted by the plate.

[0043] Most preferably, the length of the plurality of tubular membranes is uniform. In such instances, the plurality of tubular membranes may be positioned such that their ends align to form a substantially planar end surface. The skilled addressee will appreciate that where theplurality of tubular membranes is positioned such that their ends align to form a substantially planar end surface, it may be most appropriate to configure the plurality of tubular membranes to extend orthogonally from a planar surface without a support cassette i.e., to balance the plurality of tubular membranes orthogonally on a planar surface.

[0044] In some embodiments, the plurality of tubular membranes and the first powder material are positioned in a receptacle. Advantageously, placing the plurality of tubular membranes in a receptacle enables the first powdered material to be contained so as to minimise wastage. The first powdered material will be described in detail later.

[0045] Preferably, the receptacle is a mould. Most preferably, an end of the plurality of tubular membranes is positioned in the mould such that the end of the plurality of tubular membranes may contact a base of the receptacle and extend substantially orthogonally and upwardly.

[0046] The mould may be any shape, size and configuration suitable to receive the plurality of tubular membranes. Most preferably, the mould is suitable to receive an end portion of the plurality of tubular membranes.

[0047] The skilled addressee will appreciate that the size of the mould will influence the shape and size of the solid mass encapsulating an end portion of the plurality of tubular membranes.

[0048] The mould may be of any suitable height. For instance, the mould may be of a height between 10mm and 90mm. Preferably, the mould is of a height between 20mm and 80mm. More preferably, the mould is of a height between 30mm and 60mm. Most preferably, the mould is of a height of about 40mm.

[0049] The mould may be of any suitable depth. The mould may be of a depth between 1mm and 30mm. Preferably, the mould is of a depth between 2mm and 20mm. More preferably, the mould is of a depth between 3mm and 10mm. Most preferably, the mould is of a depth between 6mm and 8mm.

[0050] The skilled addressee will appreciate that the dimensions of the mould will depend on the number of tubular membranes and their relevant diameters forming the plurality of tubular membranes.

[0051] In some embodiments, the mould may include support members configured to support the plurality of tubular membranes in the desired configuration in the mould. For example, the support members may include brackets, struts or other like supports.

[0052] In alternate embodiments, a setting agent may be used. In some embodiments of the invention, the setting agent may be provided in the base of the mould, although it will be understood that the setting agent may be applied directly to the end portion of the tubular membranes. The setting agent may be configured to provide support to the plurality of tubular membranes such that they extend substantially orthogonally from the base of the mould and are stable in a desired configuration. In such embodiments, it is envisaged that the setting agent may at least partially block the ends of the plurality of tubular membranes such that the lumen cannot be accessed through the ends of the tubular membranes.

[0053] As stated in connection with the first aspect of the invention, an end portion of a plurality of tubular membranes is encapsulated within a metallic material to form a tubular membrane bundle. The metallic material may be of any suitable type. For instance, the tubular membranes may be suspended in a bath of molten metallic material which is allowed to cool and solidify to encapsulate the end portion. Alternatively, a coating process, such as a deposition process, hot dip process, or the like, may be used to deposit the metallic material on the end portion of the tubular membranes so that the end portion is encapsulated by the metallic material. Alternatively, a heat treatment process, such as sintering, may be used to encapsulate the end portion of the tubular membranes in the metallic material. In an alternative embodiment of the invention, one or more mechanical fasteners, such as screws, bolts, nails, rivets or the like, may be used may be used to assist in encapsulating the end portion of the plurality of tubular membranes. In this embodiment, it is envisaged that the one or more mechanical fasteners may be used to retain one or more cap members in place on the end portion of the plurality of tubular membranes.

[0054] Preferably, the method for forming the tubular membrane module includes surrounding an end portion of the plurality of tubular membranes with a first powdered material. It will be understood that the term “powdered” is intended to include any suitable granulated material, and the size of the particles within the powdered material is not critical to the invention.

[0055] The first powdered material may be provided around and / or between at least a portion of the plurality of tubular membranes. Preferably, the first powdered material is provided around and / or between an end portion of the plurality of tubular membranes.

[0056] The end portion of the plurality of tubular membranes may comprise any suitable length of the plurality of tubular membranes. In a preferred embodiment, however, the end portion may be positioned at or adjacent a first end of the plurality of tubular membranes and may extend towards an opposed second end of the plurality of tubular membranes. Preferably, the end portion may be positioned at or adjacent a first end of the plurality of tubular membranesand may extend towards an opposed second end of the plurality of tubular membranes along a portion of the length of the tubular membranes. Preferably, the end portion extends less than halfway along the length of the tubular membranes.

[0057] The skilled addressee will appreciate that the end portion of the plurality of tubular membranes may not include the opposed ends of the plurality of tubular membranes. For example, the end portion may comprise a portion of the plurality of tubular membranes from between the opposed ends of the plurality of tubular membranes, that is, a length of each of the plurality of tubular membranes. Preferably however, the end portion of the plurality of tubular membranes includes the opposed ends of the plurality of tubular membranes.

[0058] Preferably, each of the plurality of tubular membranes comprises a unified end portion length.

[0059] It will be understood that the length of the end portion of the plurality of tubular membranes provided with the first powdered material will correspond to the length of the solid mass encapsulating the end portion after heating of the first powdered material. The solid mass encapsulating the end portion may reduce permeability of the plurality of tubular membranes and therefore the skilled addressee may appreciate that the length of the end portion provided with the first powdered material may impact permeability.

[0060] In some embodiments, the first powdered material may be applied to opposed ends of the plurality of tubular membranes. In such embodiments, it is envisaged that the first powdered material and therefore the solid mass encapsulating the end portions of the plurality of tubular membranes may extend from the end of the plurality of tubular membranes to a point less than half way along the length of the plurality of tubular membranes. The skilled addressee will appreciate that the sold mass encapsulating the end portion must not extend the length of the plurality of tubular membranes as this would impair the permeability and therefore the separation ability of the plurality of tubular membranes.

[0061] In instances where the first powdered material is applied to opposed ends of the plurality of tubular membranes, the application of the first powdered material to each of the opposed ends may be performed sequentially such that the first powdered material is applied to a first end and is heated and a first powdered material is later applied to an opposite end and is heated. Alternatively, the application of the first powdered material to each of the opposed ends may be performed simultaneously and the first powdered material may be heated simultaneously at respective ends. Thus, in this embodiment of the invention, the tubular membrane bundle may include a first encapsulated end portion and an opposed second encapsulated end portion. Preferably, the first encapsulated end portion extends from at or adjacent a first end of the tubularmembranes towards the opposed second end along less than half the length of the tubular membranes. Similar, it is envisaged that the second encapsulated end portion may extend from at or adjacent a second end of the tubular membranes towards the opposed first end along less than half the length of the tubular membranes. In this way it is envisaged that a portion of the length of the tubular membranes will not be encapsulated.

[0062] The first powdered material may be any suitable material configured for heating and forming a solid mass encapsulating the end portion. The heating of the first powdered material and the formation of the solid mass encapsulating the end portion will be described in detail later.

[0063] The first powdered material may be any suitable type that may be heated so as to from a solid mass encapsulating the end portion.

[0064] For example, the first powdered material may comprise sand, metal, clay, glass, or a combination of these. Preferably, the first powdered material is a metallic powder.

[0065] Preferably, the first powdered material is placed in the mould with the plurality of tubular membranes. Preferably, the first powdered material and the plurality of tubular membranes are vibrated so as to prevent the formation of air pockets and / or other irregularities in the first powdered material and in turn, the solid mass encapsulating the end portion.

[0066] Preferably, the first powdered material is a metallic powder such as for example a metal or metallic compound including iron, zinc, aluminium, copper, or nickel. Preferably, the first powdered material includes a plurality of metallic powders. Advantageously, this may facilitate the formation of an alloy during heating.

[0067] Preferably, the plurality of metallic powders is mixed prior to heating to form a substantially homogenous powder mixture. The powder mixture may be dry, or water may be added to the powder mixture to form a slurry, suspension, or gel.

[0068] In some embodiments, the powder mixture may include one or more non-metallic substances. For instance, the powder mixture may include a quantity of phosphorus.

[0069] In some embodiments, the first powdered material may include any one of or a combination of a binding agent, a curing agent, or a catalyst. The skilled addressee will appreciate that the binding agent, a curing agent, or a catalyst utilised will depend on the type of first powdered material or combination of first powdered materials utilised.

[0070] In embodiments where the first powdered material includes a binding agent, the binding agent may include formaldehyde, a polymeric condensate, or a dissolved phenolcompound.

[0071] In embodiments where the first powdered material includes a curing agent, the curing agent may include a crosslinking or setting agent, such as for example, sodium silicate, methylene diphenyl diisocyanate, carbon dioxide, methyl formate, or liquid esters dissolved in any blend of suitable aliphatic or aromatic solvents.

[0072] In embodiments where the first powdered material includes a catalyst, the catalyst may include dimethylamine, trimethylamine, or a liquid tertiary amine. In embodiments where the first powdered material is provided in a mould, the catalyst may be provided to the first powdered material via am aperture in a base of the mould.

[0073] The skilled addressee will appreciate that additives such as sugar, calcium carbonate, phenol, zinc carbonate, carbohydrates, metal, clay, or glass may also be provided in the first powdered material so as to impart distinct properties on the solid mass encapsulating the end portion formed by heating of the first powdered material. The solid mass encapsulating the end portion will be described in detail later.

[0074] Most preferably, the first powdered material includes sodium silicate. Even more preferably, the first powdered material may comprise between 0.001 % w / w and 10% w / w sodium silicate. Preferably, the first powdered material comprises between 0.01 % w / w and 5% w / w sodium silicate. Most preferably, the first powdered material comprises between 1 % w / w and 2% w / w sodium silicate. Most preferably, the 1% w / w and 2% w / w sodium silicate is dispersed in 98% w / w to 99% w / w metallic powder.

[0075] It is envisaged that the first powdered material may comprise between 1% and 2% sodium silicate dispersed in a metallic powder. In such instances, it is envisaged that the first powdered material is exposed to carbon dioxide. The skilled addressee will appreciate that carbon dioxide may cure the mixture. Advantageously, the use of sodium silicate in combination with carbon dioxide the metallic powder avoids the use of corrosives or flammable liquids for curing which would otherwise pose safety risks.

[0076] While this specification refers to a first powdered material, the skilled addressee will appreciate that the plurality of tubular membranes may be positioned in a liquid such as a molten metal and the molten metal may be allowed to cool thereby forming the solid mass encapsulating the end portion of the plurality of tubular membranes.

[0077] Alternatively, the plurality of tubular membranes may be positioned in a polymeric material. The polymeric material may then be cured or allowed to harden thereby forming thesolid mass encapsulating the end portion of the plurality of tubular membranes.

[0078] Furthermore, the plurality of tubular membranes may be positioned in a gel or solution which may be allowed to harden and form a substantially solid mass encapsulating an end portion of the plurality of tubular membranes.

[0079] As indicated, the method for the manufacture of a tubular membrane module comprises forming a tubular membrane bundle by heating the first powdered material such that the first powdered material forms a solid mass encapsulating an end portion of the plurality of tubular membranes.

[0080] The first powdered material may be heated in any suitable manner to form a solid mass encapsulating the end portion. For example, the first powdered material may be heated using a furnace, a boiler, radiant heat, infrared heating, microwave heating, direct plate, or other like heating method.

[0081] Most preferably, the first powdered material is heated using a furnace. More preferably, the furnace includes different temperature zones. Most preferably, the first powdered material is heated using a controlled atmosphere furnace.

[0082] In a preferred embodiment, the first powdered material is sintered. The skilled addressee will appreciate that sintering may enhance the strength of a material while preserving porosity.

[0083] Sintering may be performed at any suitable temperature, and for any suitable period of time and in any suitable furnace, and it will be understood that the sintering process used (in terms of the temperature and the time period used) will depend at least in part on the composition of the first powdered material and the desired properties thereof.

[0084] In a preferred embodiment of the invention, the sintering process may be conducted in a vacuum or in the presence of an inert gas, such as nitrogen. Preferably, the sintering is conducted in the presence of argon.

[0085] The sintering process may be conducted in an induction furnace.

[0086] In one embodiment, the first powdered material may be sintered between 1000° C and 2000° C for a period between one and three hours. In a preferred embodiment, the first powdered material is sintered at approximately 1230° C for a period of approximately two hours.

[0087] While sintering is described, the skilled addressee will appreciate that the firstpowdered material may be subjected to a powder compaction process to encapsulate the end portion of the plurality of tubular membranes within the metallic material to form the tubular membrane bundle.

[0088] The solid mass encapsulating the end portion may be cooled. In some embodiments, the solid mass encapsulating the end portion is passively cooled. In alternate embodiments, the solid mass encapsulating the end portion may be actively cooled such as by liquid cooling, thermos electric cooling, or other like cooling.

[0089] It is envisaged that, by encapsulating an end portion of the plurality of tubular membranes in the solid mass, the plurality of tubular membranes may be substantially precluded from movement relative to one another.

[0090] Preferably, an end of the solid mass encapsulating the end portion is removed (such as by cutting), thereby exposing the lumens of the plurality of tubular membranes. It will be understood that only a portion of the solid mass encapsulating the end portion will be removed such that the plurality of tubular membranes will remain substantially precluded from movement relative to one another.

[0091] Any suitable means may be utilised to remove the end of the solid mass encapsulating the end portion. For example, a grinder, scoring and snapping, or saw, blade, laser cutter or similar cutting implement may be used.

[0092] In alternate embodiments, the end of the solid mass encapsulating the end portion may not be removed before the tubular membrane bundle is located in the housing. In such embodiments, it is envisaged that the end of the solid mass encapsulating the end portion may be removed at a later stage. Preferably the end of the solid mass encapsulating the end portion end portion is removed in conjunction with an end of the housing.

[0093] Once the end of the encapsulated portion is removed, the tubular membrane bundle and / or the tubular membrane module may be finished appropriately, such as for example, by grinding and / or polishing.

[0094] In embodiments of the invention in which both a first end portion and a second end portion of the tubular membrane bundle is encapsulated, it is envisaged that both the first end and the second end of the encapsulated end portions may be removed so as to provide the tubular membrane bundle with open ends.

[0095] As indicated the tubular membrane module includes locating the tubular membrane bundle in a housing.

[0096] The skilled addressee will appreciate that the housing is configured to receive the permeate from the tubular membrane bundle.

[0097] The housing may be any size, shape or configuration suitable to receive the tubular membrane bundle. Preferably, the housing is elongate and substantially linear.

[0098] Preferably, the housing is substantially hollow and comprises a substantially symmetrical cross section along its length.

[0099] Most preferably, the housing includes at least one side wall and a passageway (and preferably a substantially linear passageway) extending from a first end to an opposed second end such that the housing substantially resembles a tube. The at least one side wall of the housing includes an inner surface and an outer surface. The inner surface is configured to contact the tubular membrane bundle. Most preferably, the inner surface of the housing is configured to contact the solid end portion encapsulating the plurality of tubular membranes.

[0100] Preferably, the housing includes an inlet end and an outlet end. Preferably, the inlet end of the housing is the end at which the material to be separated will be introduced to the housing. Preferably, the outlet end of the housing is the end at which the retentate will exit the housing.

[0101] The inlet end of the housing may be provided at any suitable location along the length of the housing such that it may enable the feed to contact the lumen of the plurality of tubular membranes. Preferably, the inlet is positioned at an end substantially towards the solid mass encapsulating the end portion of the plurality of tubular membranes. Advantageously, the inlet is distal to the outlet end of the housing so as to maximise the permeation of the feed through the plurality of tubular membranes.

[0102] The tubular membrane bundle may be partially received in the housing such that a portion of the tubular membrane bundle may extend outwardly from the housing. Preferably, the tubular membrane bundle is entirely received in the housing.

[0103] In some embodiments, the housing may extend the length of the plurality of tubular membranes not encompassed by the solid mass encapsulating the end portion.

[0104] The at least one side wall of the housing may be continuous, or, in preferred embodiments, the at least one side wall may include at least one aperture. The at least one aperture may function as a permeate outlet through which the permeate leaves the tubular membrane module and is preferably collected. Preferably, the permeate outlet is positioned downstream of the inlet end of the housing. In other words, it is envisaged that the permeateoutlet may be located relatively close to the outlet of the housing.

[0105] The housing may be formed of any suitable material. The skilled addressee will appreciate that the material of the housing will depend on the desired permeability, insulation, resistivity, conductivity, and mechanical strength of the housing. Most preferably, the housing is substantially impermeable so as to capture the permeate from the plurality of tubular membranes.

[0106] In some embodiments, a plurality of tubular membrane bundles may be located within a single housing.

[0107] The tubular membrane module may form part of a larger system. In such instances, the inlet and outlet of the tubular membrane module may include a connecting mechanism for connecting the tubular membrane module to the larger system. The larger system may be of any suitable type, and may include one or more upstream and / or downstream processes. The upstream and / or downstream processes may be of any suitable form, and the nature of the upstream and / or downstream processes is not critical to the invention.

[0108] The connecting mechanism may include complementary male and female portions that couple together, such as, e.g., by a threaded connection, an interference (snap-fit) connection, a bayonet-type connection or a friction fit connection.

[0109] In some such embodiments, the first part of the connecting mechanism associated with the tubular membrane module may include a male formation configured to be inserted into, or coupled with, a female formation of the larger system.

[0110] Conversely, in other such embodiments, the first part of the connecting mechanism may include a female formation configured to at least partially receive, or be coupled with, a male formation of the second part of the connecting mechanism.

[0111] In some embodiments, each coupling or connection between the tubular membrane module and the larger system may include one or more sealing members for providing a fluid- tight coupling or connection.

[0112] Any suitable type of sealing member may be used. For example, in some embodiments, the sealing member may be formed from a resiliently deformable material or materials capable of at least partially deforming for forming a fluid-tight seal between the main conduit and a branch conduit. Preferably, the sealing member may be an O-ring.

[0113] Typically, each sealing member may be formed from plastic and / or rubber materialor materials, such as, e.g., polyethylene, high density polyethylene, low density polyethylene, polyvinyl chloride, polyurethane, polypropylene, polystyrene, polycarbonate, silicone, or polyester, preferably polyurethane.

[0114] As indicated, the method for the manufacture of a tubular membrane module comprises introducing a second powdered material to the housing.

[0115] The second powdered material may be similar, or identical, to the first powdered material.

[0116] The second powdered material may be positioned at an end portion of the tubular membrane bundle. The end portion of the tubular membrane bundle may comprise any suitable length of the tubular membrane bundle. In a preferred embodiment, however, the end portion may be positioned at or adjacent a first end of the tubular membrane bundle and may extend towards an opposed second end of the tubular membrane bundle. Preferably, the end portion may be positioned at or adjacent a first end of the tubular membrane bundle and may extend towards an opposed second end of the tubular membrane bundle along a portion of the length of the tubular membrane bundle.

[0117] The second powdered material may be introduced to an end portion of the tubular membrane bundle so as to correspond with, or be of a smaller area than, the solid mass encapsulating the end portion of the plurality of tubular membranes.

[0118] Most preferably, the second powdered material is introduced to the housing and aligns with the solid mass encapsulating an end portion of the tubular membrane bundle.

[0119] Preferably, the second powdered material and the tubular membrane bundle are vibrated so as to prevent the formation of air pockets and / or other irregularities in the second powdered material.

[0120] The skilled addressee will appreciate that it is desirable for the outer surface of the length of the plurality of tubular membranes to be prevented from contacting the housing as this would preclude the permeate from permeating out of the plurality of tubular membranes.

[0121] It is envisaged that the inner surface of the housing is configured to contact the solid mass encapsulating the end portion of the plurality of tubular membranes. Advantageously, this may enable the tubular membrane bundle to be substantially precluded from movement relative to the housing.

[0122] As stated in connection with the first aspect of the invention, a bonding material maybe introduced to a housing such that the bonding material forms a bond between an inner surface of the housing and a tubular membrane bundle. The bonding material may be of any suitable type. For instance, the housing, including the tubular membrane bundle, may be suspended in a bath of molten bonding material which is allowed to cool and solidify to encapsulate the end portion. Alternatively, a coating process, such as a deposition process, hot dip process, or the like, may be used to deposit the bonding material on the end portion of the housing so that the end portion is encapsulated by the bonding material. Alternatively, a heat treatment process, such as sintering, may be used to encapsulate the end portion of the housing in the bonding material. In some embodiments, the bonding material is similar or the same as the metallic material. In some embodiments, the bonding material is a powdered material. In such embodiments, the bonding may be vibrated between a solid end and the tubular porous membrane bundle housing.

[0123] As indicated, the method for the manufacture of a tubular membrane module comprises forming the tubular membrane module by heating the second powdered material such that the second powdered material forms a bond between an inner surface of the housing and the tubular membrane bundle.

[0124] The heating of the second powdered material may be similar, or identical, to the heating of the first powdered material. Preferably, the second powdered material may be sintered.

[0125] Not only does the bonding material substantially preclude movement of the tubular membrane bundle relative to the housing, but it also ensures that the ends of the housing are sealed, thereby substantially precluding permeate that permeates through the walls of the tubular membranes from exiting the housing through the opposed ends thereof.

[0126] In a third aspect, the invention resides broadly in a method for the manufacture of a tubular membrane bundle, the method comprising the steps of: a) providing a plurality of tubular membranes; b) surrounding an end portion of the plurality of tubular membranes with a first powdered material; and c) forming a tubular membrane bundle by heating the first powdered material such that the first powdered material forms a solid mass encapsulating the end portion of the plurality of tubular membranes.

[0127] In a fourth aspect, the invention resides broadly in a tubular membrane modulefabricated according to the method of the first aspect.

[0128] In a fifth aspect, the invention resides broadly in a tubular membrane module fabricated according to the method of the second aspect.

[0129] In a fifth aspect, the invention resides broadly in a tubular membrane bundle fabricated according to the method of the third aspect.

[0130] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[0131] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.BRIEF DESCRIPTION OF DRAWINGS

[0132] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[0133] Figure 1 illustrates an overview of the method of manufacturing a tubular membrane module according to an embodiment of the present invention;

[0134] Figure 2 illustrates an overview of the method of manufacturing a tubular membrane module according to an alternate embodiment of the present invention;

[0135] Figure 3 illustrates a cross-sectional view of a tubular membrane module, according to an embodiment of the present invention; and

[0136] Figure 4 illustrates a plan view of a tubular membrane module, according to an embodiment of the present invention.DETAILED DESCRIPTION

[0137] The invention resides broadly in a method for the manufacture of a tubular membrane module, the method comprising the steps of: encapsulating an end portion of a plurality of tubular membranes within a metallic material to form a tubular membrane bundle; locating the tubular membrane bundle in a housing; and forming the tubular membrane moduleby introducing a bonding material into the housing such that the bonding material forms a bond between an inner surface of the housing and the tubular membrane bundle.

[0138] Figure 1 shows a method 100 for the manufacture of a tubular membrane module according to an embodiment of the present invention.

[0139] At step 105, an end portion (or opposed end portions) of a plurality of tubular membranes is encapsulated within a metallic material to form a tubular membrane bundle. In the embodiment of the invention illustrated in Figure 1 , the encapsulation of the tubular membranes is achieved by surrounding the end portion (or opposed end portions) of the plurality of tubular membranes with a granulated material in the form of a metallic powder including iron, zinc, aluminium, copper and / or nickel. The tubular membranes and the metallic powder are heated in a furnace to so that sintering of the metallic powder occurs, thereby forming a solid material encapsulating the end portion (or opposed end portions) of the tubular membranes. After step 105, the metallic material is allowed to cool around the end portion (or opposed end portions) of the plurality of tubular membranes to form a tubular membrane bundle.

[0140] At step 110, the tubular membrane bundle is located in a housing. The housing may be of any suitable form, although it is envisaged that the housing comprises a tubular housing with one or more side walls defining a cavity therewithin into which the tubular membrane bundle (or a plurality of tubular membrane bundles) is received. The housing includes an inlet end and an outlet end, with the inlet end of the housing including an inlet configured to provide a point of entry for a material to be separated to enter the housing (and therefore enter the tubular membrane bundle within the housing). The outlet end of the housing includes an outlet configured to provide an exit point for retentate material to be removed from the housing.

[0141] The housing also includes one or more permeate outlets configured to provide an exit point for permeate separated from the material separated by the tubular membrane bundle to be removed from the housing.

[0142] At step 115, the tubular membrane module is formed by introducing a bonding material into the housing such that the bonding material forms a bond between an inner surface of the housing and the tubular membrane bundle. The bonding material used in the embodiment of the invention illustrated in Figure 1 is a granulated material in the form of a metallic powder including iron, zinc, aluminium, copper and / or nickel. Thus, the bonding material is the same as the metallic material used to encapsulate an end portion (or opposed end portions) of the tubular membranes. The tubular membrane bundle, the housing and the bonding material are heated in a furnace to so that sintering of the bonding material occurs, thereby forming a solid material that bonds the tubular membrane bundle to an inner surface of the housing. After step 105, thebonding material is allowed to cool to form the tubular membrane module.

[0143] Figure 2 shows a method 200 of manufacture of a tubular membrane module according to an embodiment of the present invention.

[0144] At step 205, a plurality of tubular membranes are provided. At step 210, an end portion of the tubular membranes are surrounded with a first powdered material. At step 215, a tubular membrane bundle is formed by heating the first powdered material such that the first powdered material forms a solid mass encapsulating the end portion of the tubular membranes. At step 220, the tubular membrane bundle is located in a housing. At step 225, a second powdered material is introduced to the housing. At step 230, the tubular membrane module is formed by heating the second powdered material such that the second powdered material forms a bond between an inner surface of the housing and the tubular membrane bundle.

[0145] At step 210, the first powdered material comprises between 1% and 2% sodium silicate in metallic powder. The first powdered material is exposed to carbon dioxide to allow it to cure. The metallic powder includes iron, zinc, aluminium, copper and / or nickel.

[0146] At step 215, the first powdered material is heated by sintering. In this instance, the sintering is conducted in the presence of the inert gas argon. In the embodiment of the invention illustrated in Figure 2, the first powdered material is sintered at 1230° C for a period of two hours to from a solid mass encapsulating the end portion.

[0147] Once sintered, the solid mass encapsulating the end portion is actively cooled such as by liquid cooling, thermos electric cooling, or other like cooling. Once cooled, the encapsulation of the end portion (or opposed end portions) of the tubular membranes substantially precludes movement of the tubular membranes relative to one another.

[0148] Subsequently, an end of the solid mass encapsulating the end portion (or opposed end portions if both are encapsulated) is removed (along with, in some embodiments, an end of the tubular membranes), such as by cutting, exposing a lumen located at the interior of each of the plurality of tubular membranes. It will be understood that only a portion of the solid mass encapsulating the end portion will be removed. Once the end of the solid mass is removed, the tubular membrane bundle is finished by grinding and polishing.

[0149] The skilled addressee will appreciate that the method 200 may terminate after step 215 such that the resultant product is a tubular membrane bundle.

[0150] At step 220, the tubular membrane bundle is entirely received in the housing. It is envisaged that a plurality of tubular membrane bundles may be received in a single housing.

[0151] At step 225, the second powdered material is introduced to the housing and aligns with the solid mass encapsulating an end portion of the tubular membrane bundle. Advantageously, this enables the tubular membrane bundle to be substantially precluded from movement relative to the housing without impairing the permeability of the tubular membranes.

[0152] At step 230, the housing, the tubular membrane bundle, and second powdered material are heated in a furnace in the presence of argon at 1230° C for a period of two hours so that sintering of the second powdered material occurs. Sintering of the second powdered material results in the tubular membrane bundle being bonded to an inner surface of the housing by the sintered second powdered material, thereby substantially precluding movement of the tubular membrane bundle relative to the housing. Once sintered, the tubular membrane module is cooled.

[0153] Figure 3 illustrates a cross-sectional view of a tubular membrane module 300 manufactured according to the method described in Figure 1 or Figure 2. The tubular membrane module 300 includes a plurality of tubular membranes 305 located therewithin. Opposed end portions of the plurality of tubular membranes 305 are encased in a solid mass 310. The plurality of tubular membranes 305 encased in the solid mass 310 form the tubular membrane bundle 330.

[0154] The plurality of tubular membranes 305 provided at step 205 are tubular with a central passageway extending between opposed ends of the tubular membranes 305 such that that the plurality of tubular membranes 305 are substantially hollow.

[0155] As indicated in Figure 3, the two regions of solid mass 310 encapsulating the tubular membranes 305 are positioned on opposing ends of the plurality of tubular membranes 305. Notably, the two regions of solid mass 310 do not extend the entire length of the plurality of tubular membranes 305. The skilled addressee will appreciate that it is necessary for at least a portion of the length of the plurality of tubular membrane 305 to be exposed such that the permeate may permeate through the wall of the tubular membranes 305 from the lumen located within each of the plurality of tubular membranes 305.

[0156] Advantageously, the two regions of solid mass 310 at the opposing end portions of the plurality of tubular membranes 305 provide increased support to the tubular membrane bundle 330 such that that the plurality of tubular membranes 305 are substantially precluded from movement relative to one another.

[0157] The tubular membrane bundle 330 is provided in a housing 315 to define a tubular membrane module 300.

[0158] The housing 315 includes an inlet end 335 for receiving a feed material 320 in the form of a material to be separated. The material to be separated 320 may be in the form of a gas, liquid, slurry or a combination thereof.

[0159] The material to be separated 320 enters the housing 315 and enters the open ends of the tubular membranes 305 within the tubular membrane bundle 330. The material to be separated 320 enters the lumen of each of the plurality of tubular membranes 305. In use, it is envisaged that at least a portion of the material to be separated permeates through the side wall of each of the plurality of tubular membranes 305.

[0160] Permeate that has permeated through the walls of the plurality of tubular membranes 305 enters the housing 315 between opposed ends thereof. The solid mass 310 also serves to seal the opposed ends of the housing 315 so that permeate is unable to leave the housing through the opposed ends thereof.

[0161] In the embodiment of the invention illustrated in Figure 2, a permeate outlet 325 is positioned distal to the inlet end 335 of the housing 315 (i.e. , adjacent to the outlet end 340 of the housing 315. The permeate outlet 325 is configured to allow permeate from the tubular membranes 305 that is received in the housing 315 to exit the housing 315. The permeate may be collected for use, further processing or disposal, or may simply be dispersed to the atmosphere.

[0162] The retentate portion of the material to be separated 320 flows through the tubular membranes 305 and exits the housing 315 through the outlet end 340 of the housing 315. The retentate may be collected for use, further processing or disposal, or may simply be dispersed to the atmosphere.

[0163] While the embodiment illustrated in Figure 3 shows a single tubular membrane bundle 330 provided in a single housing 315, it will be understood that any number of tubular membrane bundles 330 may be positioned in a single housing 315. Advantageously, this may enable a greater volume of material to be separated 320 to be treated or processed in the tubular membrane module 300.

[0164] Figure 4 illustrates a plan view of a tubular membrane module 335 manufactured according to the method described in Figure 1 or Figure 2. As indicated, a plurality of tubular membranes 305 are positioned within the housing 315. The tubular membranes 305 are spaced apart from one another and from the inner surface of the housing 315, thereby enabling the permeate to pass through the lumen 350 of each of the plurality of tubular membranes 305 and be received in the housing 315.

[0165] Permeate received in the housing 315 may then be removed periodically or continuously from the housing 315 through the permeate outlet 325.

[0166] In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0167] Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0168] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims

CLAIMS1. A method for the manufacture of a tubular membrane module, the method comprising the steps of: a) encapsulating an end portion of a plurality of tubular membranes within a metallic material to form a tubular membrane bundle; b) locating the tubular membrane bundle in a housing; and c) forming the tubular membrane module by introducing a bonding material into the housing such that the bonding material forms a bond between an inner surface of the housing and the tubular membrane bundle.

2. A method for the manufacture of a tubular membrane module, the method comprising the steps of: a) providing a plurality of tubular membranes; b) surrounding an end portion of the plurality of tubular membranes with a first powdered material; c) forming a tubular membrane bundle by heating the first powdered material such that the first powdered material forms a solid mass encapsulating the end portion of the plurality of tubular membranes; d) locating the tubular membrane bundle in a housing; e) introducing a second powdered material to the housing; and f) forming the tubular membrane module by heating the second powdered material such that the second powdered material forms a bond between an inner surface of the housing and the tubular membrane bundle.

3. The method of claim 1 or claim 2 wherein each of the plurality of tubular membranes is elongate and substantially linear, and wherein each of the plurality of tubular membranes further comprises opposed ends and at least one sidewall extending between the opposed ends.

4. The method of claim 3 wherein the at least one sidewall includes an inner surface configured, in use, to be in contact with a material to be separated.

5. The method of claim 2 or claim 3 wherein the at least one sidewall defines a lumen located at an interior of each of the tubular membranes.

6. The method according to any one of the preceding claims wherein the plurality of tubular membranes is arranged in a non-tessellating manner prior to forming the tubularmembrane bundle.

7. The method according to any one of the preceding claims wherein the plurality of tubular membranes is releasably secured together in a desired configuration during fabrication of the tubular membrane bundle.

8. The method according to claim 2 wherein the first powdered material is provided around and / or between an end portion of the plurality of tubular membranes.

9. The method of claim 2 or claim 8 wherein the first powdered material is a metallic powder.

10. The method of claim 9 wherein the metallic powder comprises a plurality of metal powders that facilitate the formation of an alloy during heating.

11. The method of claim 9 or claim 10 wherein the metallic powder included one or more non-metallic substances.

12. The method of claim 11 wherein the one or more non-metallic substances includes sodium silicate.

13. The method of claim 2 wherein the first powdered material is sintered to form the solid mass.

14. The method of claim 2 or claim 13 wherein an end of the solid mass encapsulating the end portion is removed to exposing lumens in an interior of the plurality of tubular membranes.

15. The method of claim 1 or claim 2 wherein the housing includes at least one side wall and a passageway extending from a first end to an opposed second end thereof.

16. The method of claim 15 wherein the at least one side wall of the housing includes an inner surface configured to contact the tubular membrane bundle.

17. The method of claim 16 wherein the inner surface of the housing is configured to contact the solid end portion encapsulating the plurality of tubular membranes of the tubular membrane bundle.

18. The method of claim 1 or claim 2 wherein a plurality of tubular membrane bundles are located within a single housing.

19. The method of claim 2 wherein the first powdered material and the second powderedmaterial are identical to one another.

20. The method of claim 2 wherein the second powdered material is heated in a sintering process.

21. The method according to claim 1 or claim 2 wherein the bond substantially precludes permeate that permeates through the walls of the tubular membranes from exiting the housing through opposed ends thereof.

22. A method for the manufacture of a tubular membrane bundle, the method comprising the steps of: a) providing a plurality of tubular membranes; b) surrounding an end portion of the plurality of tubular membranes with a first powdered material; and c) forming a tubular membrane bundle by heating the first powdered material such that the first powdered material forms a solid mass encapsulating the end portion of the plurality of tubular membranes.

23. A tubular membrane module fabricated according to the method of claim 1 .

24. A tubular membrane module fabricated according to the method of claim 2.

25. A tubular membrane bundle fabricated according to the method of the claim 22.

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