Abstract: Fluid treatment elements and methods for treating fluids may be used to treat fluids, including gases, liquids, or mixtures of gases, and/or solids, in a crossflow mode of operation. For example, some fluid treatment elements and methods may be used to remove one or more substances from the fluid and may then function as concentrators or filters or separators. Other fluid treatment elements or methods may be used to transfer substances between two fluid streams and may then function as mass transfer devices.

Abstract: A filter assembly has a housing accommodating a filter element. One end cap of the filter element has a generally annular body with support fins projecting from one surface. A peripheral flange extends from the edge of the body and is spaced from the outer ends of the fins to allow differential expansion of the flange without undue stress. The flange carries two opposed sets of pegs for supporting respective sealing rings to allow the flange to seal between parts of the housing.

Abstract: A porous filter medium is formed by a pleated cylinder of a depth filter medium. An absolute rated inner filtration layer is arranged between upstream and downstream drainage layers. The depth filter medium is formed from a continuous sleeve. Additionally or alternatively at least the downstream drainage layer may be formed integrally with at least a part of an inner filtration layer. The material of the medium may be a fibrous mass of non-woven synthetic polymeric micro-fibres which are free of fibre-to-fibre bonding and are secured to each other by mechanical entanglement or intertwining, with the diameter of the fibrous structure varying across the medium.

Abstract: A filter unit comprises a plastics frame into which a sheet of filter medium is insert moulded. Portions of the frame form apertures and other portions allow fluid access to and from the opposed surfaces of the filter medium when the frame is covered by a flat surface. The frames also form portions of an integral capsule enclosing the medium. A number of such filter units can be stacked together in various configurations so that the apertures form inlets and outlets for fluid so that, in some configurations, fluid can be passed through the filter units in parallel while, in other configurations, fluid can be passed through filter units in succession. Filters of any convenient size can be produced by increasing the number of filter units in a stack. The filters are bi-directional. The frames can be of polypropylene connected to hydrophilic microporous nylon membrane by injection moulding, which has been found to give a filter unit that can be integrity tested.

Abstract: A porous filter medium is formed by a pleated cylinder of a depth filter medium. An absolute rated inner filtration layer is arranged between upstream and downstream drainage layers. The depth filter medium is formed from a continuous sleeve. Additionally or alternatively at least the downstream drainage layer may be formed integrally with at least a part of an inner filtration layer. The material of the medium may be a fibrous mass of non-woven synthetic polymeric micro-fibers which are free of fiber-to-fiber bonding and are secured to each other by mechanical entanglement or intertwining, with the diameter of the fibrous structure varying across the medium.

Abstract: A liquid treatment apparatus suitable for dewatering a radioactive sludge includes a cylindrical housing (14) open at one end and defining two ports (24, 26) for the sludge, one near the open end and the other at the closed end. A plug (30) locates in the open end of the housing and supports a module (44) comprising a sealed permeate-collecting chamber (46) through which extend a number of permeable-walled tubes (54), open at each end. The plug defines a header chamber (40) for the tubes (54) which communicates with the one sludge port (24); and defines an outlet duct (62, 38) for the permeate liquid. The apparatus can be installed remotely within a shielded enclosure (12), and the plug and module can be withdrawn without risking contamination of the permeate liquid.

Abstract: A method of treating a liquid, for example dewatering a sludge by ultrafiltration, in which the liquid is caused to flow repeatedly along a permeable walled tube (22) so that a filtrate passes through the wall of the tube, the progress of the treatment being monitored by monitoring the pressure difference between the ends of the tube (22). The method has enabled sludges of widely varying compositions to be dewatered to produce products of uniform viscosity, suitable for subsequent immobilization by cementation.