Abstract: A hollow fiber membrane is produced having an outer surface, and inner surface enclosing a lumen, and a continuous network of interconnecting pores extending from the outer surface to the inner surface, wherein substantially all of the pores have an elongated dimension and a shortened dimension, the elongated dimension being oriented substantially parallel to the axis of the hollow fiber, wherein the ratio of the elongated dimension to the shortened dimension is substantially constant from the outer surface to the inner surface, and wherein the pores change shape to increase the shortened dimension in response to a high pressure differential imposed across the membrane by increasing fluid pressure within the lumen.

Abstract: A process for maintaining a high rate of mass transfer of nutrients contained in a liquid feed stream to a biofilm of microorganisms supported on a bed of particulate matter. The microorganisms in the biofilm are subjected to a continuous, uniform flow of the liquid feed steam and a countercurrent flow of respiratory air so as to support biofilm growth. The bed is periodically pulsed with air at a pressure sufficient to shed microorganisms from the biofilm, and at intervals sufficient to avoid preferential channeling of the liquid feed steam through the bed and/or to disrupt and rearrange the bed of particulate matter.

Abstract: A method of making a porous polymeric material by heating a mixture comprising polyvinylidene fluoride and a solvent system initially comprising a first component that is a latent solvent for polyvinylidene fluoride and a second component that is a non-solvent for polyvinylidene fluoride wherein, at elevated temperature, polyvinylidene fluoride dissolves in the solvent system to provide an optically clear solution. The solution is then rapidly cooled so that non-equilibrium liquid-liquid phase separation takes place to form a continuous polymer rich phase and a continuous polymer lean phase with the two phases being intermingled in the form of bicontinuous matrix of large interfacial area, and cooling is continued until the polymer rich phase solidifies. The polymer lean phase is removed from the solid polymeric material.

Abstract: An improved microporous, modular filter structure assembled from replaceable filter cartridges (25) housed within a filter cartridge assemby (10) connected at opposed ends by means of symmetrical headers (41). The headers include a tube within a tube structure whereby they are adapted to conduct first and second fluids independently to both adjacent, like interconnected headers and into and out of filter cartridges (25) to which each header (41) is connected at both ends of each cartridge. Manifolds (100, 101) include a similar tube within a tube structure which allows them to be connected to the ends of rows of interconnected headers (41) whereby a modular filter bank can be constructed of indefinite dimension and capacity.

Abstract: Extrusion of hollow membranes is improved by coextruding a coating fluid layer about the extrudate of heated polymer solution with its interior lumen forming extrudate. The coating fluid is disposed between the forming hollow fiber and a cooling fluid, and controls the rate of heat transfer to afford superior control over the structure and form of the hollow fiber produced in the invention. The coating fluid is typically the same material as the cooling fluid, and often is the same material as the solvent for the polymer in the heated polymer solution.

Abstract: A manifold structure for connecting rows of cartridges (100) to adjacent like rows of cartridges (100). The manifold structure includes a first fluid passage (153, 183) adapted to pass either feed or filtrate through the body of the manifold structure, a second fluid passageway (169, 197) adapted to be coupled to a first passageway of a filter cartridge to provide fluid communication between the cartridge and the first passageway, a third fluid passageway (167, 199) adapted to be coupled to a second passageway of the filter cartridge to provide fluid communication between the cartridge and the first passageway; only one of the second fluid passageway or the third fluid passageway being enabled for fluid communication at any one time.

Abstract: Polyphenolic substances such as food dyes, tannins, fruit juices and wine colorings are removed from a solution by adsorption onto a regeneratable adsorbent polyamide of extended surface and controlled porosity. The surface chemistry of the polyamide may be modified by a glutaraldehyde/resorcinol treatment. The polyphenolic substances are recovered by elution with water or other protonic solvent.

Abstract: A fluid filter has a bundle of hollow fibres (40) within a casing. At one end of the casing (40) there is a header (41) which has a feed passageway (55) therethrough and in communication with the interior of the casing (40) and the exterior of the fibres. The header (41) also has a filtrate passageway (64) therethrough and in communication with the open ends of the fibres.

Abstract: A method of concentrating solids in a liquid suspension using a filter having a plurality of hollow, microporous, elastic fibres with a shell or housing, comprising applying the suspension to an outer surface of the fibres whereby a portion of the suspension passes through the fibre walls and at least a portion of the solids is retained on or in the fibres; and discharging the retained solids by stretching the fibre pores and washing out solids retained in the pores by application of gas under pressure.

Abstract: A process for producing a support capable of reaction with antibodies or enzymes, said process comprising the steps of:(i) reacting an aliphatic polyamide with a solution consisting essentially of sulphuryl chloride and a paraffin or cycloparaffin to produce a sulphuryl chloride modified polyamide reactive intermediate product;(ii) reacting the product of step (i) with a compound that binds to said product to provide a covalent chemical link to which antibodies or enzymes may be bound.

Abstract: A filter (10) has a shell (11) within which there is a bundle of microporous fibres (12). Pressurized feed suspension is introduced through inlet (15) and passes over the external walls of the fibers (12) with the clarified liquid being drawn from the lumens of the fibres (12) through outlet port (16) and the concentrated ffee being discharged through outlet (17). The solids retained within the shell are removed by a gaseous backwash cycle in which pressurized gas is introduced through the lumens and passes through the wall of the fibres (12) to dislodge solids retained on or in the fibre walls. The gaseous cleaning step is enhanced by varying the pressure within the housing (11) of the filter (10) while the gas is being introduced into the filter.

Abstract: A method of concentrating solids in a liquid suspension using a filter having a plurality of hollow, microporous, elastic fibres with a shell or housing, comprising applying the suspension to an outer surface of the fibres whereby a portion of the suspension passes through the fibre walls and at least a portion of the solids is retained on or in the fibres; and discharging the retained solids by stretching the fibre pores and washing out solids retained in the pores by application of gas under pressure.

Abstract: In the cleaning and removal of solids from microporous hollow fibre filters by a series of chemical cleaning cycles, the optimum time and pattern of the cleaning cycles is calculated from the rate of diminution in filtrate flow rate and the time and filtrate lost in each cycle.

Abstract: A porous membrane characterized by a morphology that is the reversed phase analogue of another porous membrane. The material which forms the reversed phase porous membrane can be a thermosetting resin, zirconia or silica. The other membrane can be polypropylene or polyamide.

Abstract: A fluid filter has a bundle of porous hollow fibres (40) within a casing. At one end of the casing (40) there is a header (41) which has a feed passageway (55) therethrough and in communication with the interior of the casing (40) and the exterior of the fibres. The header (41) also has a filtrate passageway (64) therethrough and in communication with the open ends of the fibres. At the other end of the casing there is a second header (42) which has a treated feed passageway (72) therethrough and in communication with the interior of the casing (40) and the exterior of the fibres. The header (42) also has a filtrate passageway (74) therethrough and in communication with the open ends of the fibres. The feed, treated feed and filtrate passageways (55, 72, 64 & 74) area formed in the off set portions (56, 73, 65 & 75) of the headers (41, 42) that have planar parallel end faces whereby a plurality of filter units may be joined together without a manifold to form a bank of filters.

Abstract: A filtration system for treating an emulsion containing water, an oil or a fat, an emulsifying agent and insoluble solid material (such as a maritime oil emulsion containing an anionic detergent and the solid, greasy calcium salt of the detergent) has a first hydrophobic microfilter (126) and a second hydrophobic microfilter (147).Both microfilters (126, 147) have a plurality of hollow porous fibers as the separating medium with the feed to the first filter (126) being applied to the outside of the fibers and the feed to the second filter (which is the permeate from the first filter) being applied down the lumens of the fibers. The first filter (126) removes the solid material and the second filter separates the oil or fat from the solid-free emulsion.