Abstract: The invention provides a method for forming a fibrous layer within a tubular support, which comprises the steps of: (a) providing the tubular support; (b) providing forming mesh over the curved surface of the support and closing its ends against escape of fluid; and (c) introducing fibrous slurry (e.g. an aqueous slurry of borosilicate glass microfibers and water dispersible heat curable acrylic resin at a pH of about 3) from a pressurized source into an annular molding space between a rotary molding torpedo and an inner surface of the support, the torpedo having at least one channel for slurry opening along a curved surface thereof, fibers in the slurry collecting within the forming mesh to form the layer.

Abstract: The invention provides a method for forming a fibrous layer within a tubular support, which comprises the steps of: (a) providing the tubular support; (b) providing forming mesh over the curved surface of the support and closing its ends against escape of fluid; and (c) introducing fibrous slurry (e.g. an aqueous slurry of borosilicate glass microfibers and water dispersible heat curable acrylic resin at a pH of about 3) from a pressurized source into an annular molding space between a rotary molding torpedo and an inner surface of the support, the torpedo having at least one channel for slurry opening along a curved surface thereof, fibers in the slurry collecting within the forming mesh to form the layer.

Abstract: A method of molding a micro-fibrous filter including the steps of: (a) forming an aqueous slurry of micro-fibers; (b) introducing the slurry under pressure into the top of an annular molding space so that a mass of fibers becomes compacted on a vertical cylindrical screen and liquid is discharged from the molding space through the screen; (c) increasing the effective open area of the screen by moving upwardly a sleeve in sliding contact with the screen at a rate substantially equal to the rate at which the height of the mass of fibers increases above the support; then (d) removing, drying, and curing the resulting tubular mass of fibers. Acrylate binder resin compatible with the e.g. acidic conditions needed to stabilize the resin, can form part of the fiber slurry used for molding the filter, and after filter formation and drainage can be cured by heat to form the filter.

Abstract: The invention provides a moulded micro-fibrous filter in which micro-fibres are held together by a binder, wherein the binder is a cured thermosetting acrylate resin.

Abstract: Apparatus is provided for separating oil from compressor condensate. It comprises a separator having an upper chamber provided with a condensate inlet and a filter housing containing a hydrophobic oleophilic substance so that in use condensate flows from the upper chamber through the filter housing under the action of gravity. The upper chamber contains a coalescing filter connected with the condensate inlet. In an alternative structure, a holding tank is series connected with a separator, and means is provided for supplying a de-emulsifying agent to condensate in the holding tank before the condensate is supplied to the separator. The above apparatus can carry out a method which comprises mixing the condensate with de-emulsifying agent, holding the mixture while emulsion cracking at least partly proceeds, and supplying the at least partly cracked emulsion to a separator containing a hydrophobic oleophilic substance.

Abstract: Apparatus for forming fibrous filter elements such as tubular elements molded from borosilicate microfibers. Molding rigs are supplied with a slurry from a system including a holding tank and a reservoir. The reservoir is coupled to a water intake and also receives recycled aqueous liquid. The holding tank receives a mixture of fibers and aqueous liquid. A controller monitors volume levels in the holding tank and reservoir and allows for incremental pH changes.

Abstract: Apparatus is for forming fibrous filter elements, e.g tubular elements molded from borosilicate microfibers.

Abstract: An intake filter (1) or a coalescing filter (4) of a compressor or vacuum pump, or an in-line filter has its identity recorded in a transponder (50, 54), memory chip or other device such as a magnetic or magnetostrictive strip. Interrogation e.g. by means of antennae (52, 56) enables a control unit (55) to verify the identity of the filter and to store the result in memory (57). A record can therefore be maintained of whether approved filters are being used and whether they are exchanged at approved intervals.

Abstract: A filter is provided for coalescing droplets of oil in a stream of gas, comprising an oil coalescing layer of a microfibrous material and a second layer of an oil drainage material located downstream of and in face to face contact with the first layer. The drainage layer is for receiving oil from the coalescing layer and providing a path for oil to flow by gravity from the filter. Oil carry-over is reduced by providing a drainage layer which is a non-woven felt or wadding thermally bonded by bi-component polyester fibers.