Abstract: A sheet of porous filter material folded into accordion pleats, the pleats having opposite edges folded over on diagonal fold lines to close the opposite edges of alternate pleats. The pleated and folded sheet is selectively disposed in flat panel form or formed into a tube with the pleats extending axially of the tube. When the filter is in its tubular form, the folded pleat ends are disposed at the exterior of the tube.

Abstract: A filter element for gas or liquid comprises a layer of glass, ceramic, metal, mineral wool or organic fibers containing, wholly within the layer, an apertured sheet, for example of steel or aluminum, the fibers being bound to one another throughout the layer and through the apertures, as well as to the sheet itself, by a synthetic resin such as silicone resin or polyurethane. The filter element is formed by mounting the apertured sheet a selected distance above a filter surface on which the fibers build up while a slurry containing the fibers is drained through the filter surface. When the fibers have built up to a predetermined distance above the sheet, the fibers containing the sheet are removed and the assembly impregnated with a synthetic resin and cured. Two or more grades of slurry mixture may be used in succession to produce a density grading through the thickness of the fibrous layer.

Abstract: An improved filter of the cartridge type having concentric inner and outer filter elements is disclosed. The elements are formed of non-woven polypropylene fibers. In a preferred embodiment the outer element is formed of a laminate including a supporting layer of a continuous filament and a filtering layer of randomly oriented polypropylene fibers. The outer element is pleated and the space between the elements is filled with particulate, activated charcoal. The axial ends of the filter components are encapsulated in plastisol end caps to secure them together, and to form a sealable working surface to be engaged by the filter housing.

Abstract: An improved inside-to-outside flow filter tube and method of manufacturing the tube, which filter tube comprises: a plurality of nonwoven fibers having interstices therebetween to define the porosity of the filter tube, the tube containing a binding agent at the junction of the fiber crossovers to provide a self-supporting structure of a defined wall thickness and filter porosity; and an open scrim reinforcing sheet material within the wall of the filter tube extending generally the length of the tube and at least one overlapping revolution about the tube diameter, the fibers of the filter tube bonded integrally through the open scrim material, thereby permitting the use of the filter tube in applications requiring inside-to-outside fluid flow without the necessity for an external peripheral support.

Abstract: A multi-layer filter material assembly. The assembly includes a filter medium which consists of a single sheet formed of fibers of a glass having a low coefficient of thermal expansion. The filter medium is supported on each side by at least one sheet of bonded synthetic fibers and a sheet of metallic wire mesh. The two sheets of metallic wire mesh form the two outermost layers and the entire assembly is formed into a pleated configuration.

Abstract: A filtering device comprises a cylindrical member bored with a large number of holes; a sheet-like filter element crosswise folded like bellows and rolled into a cylindrical form so as to concentrically surround the bored cylindrical member and a plurality of thin band-shaped liquid passage plates interposed between every adjacent folded portions of the inner wall of the filter element, and wherein each liquid passage plate has both surfaces made irregular and further its width chosen to be equal to or larger than the height of the projecting folded portion of the sheet-like filter element.At least one annular support band surrounds the outer periphery of the filter element defined by the apexes of the folded projections. An adhesive applied to the inner peripheral wall of said annular support band permits the support band to hold the folded projections in position and also permeates the apexes of the folded portions, thereby fixing the inner walls of the apexes to the outer edges of the passage plates.

Abstract: A method of making a liquid filter includes the steps of providing a spiral roll of filtering material on a central tubular member, providing a housing member into which the roll is to be placed and laying a bead of thermoplastic material having a given softening point on an outer surface of the roll at least around the circumference of the roll close to an end thereof. The bead is pressed with cooled forming jaws, while in a warm state, to suitable dimensions corresponding to inside dimensions of the housing member. The housing member is heated to a temperature above the softening point of the thermoplastic material, the roll is inserted into the housing member and thereafter, the housing member is cooled. The thermoplastic material cools, acts as a glue and constitutes a tight, rigid connection between the housing member and the roll of filtering material.

Abstract: A filter includes a rigid core through which the filtrate passes and about which there are wound a number of elongated porous tubular filter mediums that contain a resilient grid, there being a scrubber screen between successive turns of each filter medium, and resilient means yieldably enclosing the outermost surfaces of the helically wound parts. The filter mediums compress radially and expand radially in response to fluid pressure variations to produce relative movement between the filter mediums and the scrubber screen by which cleaning takes place, thereby extending filter life. The solids that have been filtered out are collected and built up on the screen and the helical assembly expands diametrically a corresponding amount.

Abstract: Filtration apparatus comprising at least one microporous member having at least a pair of opposed surfaces and a predetermined thickness, a tubular member positioned with respect to at least one of said opposed surfaces whereby fluid passing through said microporous member is filtered and the filtrate is received by said tubular member for distribution and/or collection.

Abstract: A membrane separation apparatus adapted for use in ultrafiltration is provided comprising a casing and a membrane unit enclosed therein, said membrane unit comprising a composite membrane folded flatly in zigzag relation to form a plurality of stacked layers defining a plurality of first flow channels in alternately interleaving relation thereto, said composite membrane being made of a flexible porous support and having a pair of selectively permeable membranes on opposite outer surfaces thereof and a second flow channel therebetween.

Abstract: A filter unit formed by spirally winding a multi-layer material around a core to form a generally cylindrical construction having two opposing spiral end surfaces. The multilayer material has at least two filter layers and at least two spacer layers formed from a material with a high void volume. The multi-layer material need not include a fluid-impermeable layer. The layers are arranged and adhered along the lengthwise and widthwise edges so that, in use, unfiltered fluid passing through one spiral surface of the filter unit into one spacer layer must pass through a filter layer prior to passing out of the construction through the opposing spiral end surface.

Abstract: A process and apparatus for catalytic treatment of a material containing solid contaminants (in particular residue from hydrodesulfurization), the catalytic reactor being provided upstream of the catalyst bed with filter units small enough to be replaced via the reactor inlet, said filter units containing parallel void chambers alternately closed at top and bottom, respectively, (possibly by means of rupture discs), so that material to be filtered flows into a void chamber, through its wall which has filtering (and possibly also catalytic, e.g., demetallizing) properties, and then out of the next void chamber and onto the catalyst bed.

Abstract: A disc filter is provided with undulating filter material formed by ridges and grooves extending radially and alternating circumferentially to increase the effective area of the filter.