Abstract: The present invention relates to etched disc stack filters and particularly to such filters in which the etched discs include multiple arms in which are etched flow channels for the passage of a medium to be filtered and the removal or separation of a contaminant. In a particular embodiment of the invention, the etched discs may have an overall shape that is circular and may have filtering arms which radially extend from the center of each disc to the exterior border of the disc. The filtering arms may separate inlet and outlet openings. End caps may be attached at the ends of the disc stack and these end caps may have openings corresponding to the inlet and outlet openings in the discs in the disc stack.

Abstract: A thin metal foil disc etched on both sides in such a way as to form a crossover pattern of rectangular flow passages (or channels) spiraling out, in opposite directions, from the inner diameter to the outer diameter of the disc. In the preferred embodiment, these channels have a depth slightly greater than half of the disc thickness, creating an opening through the thickness of the disc at their points of intersection. This disc design, when stacked appropriately into a filter element, provides substantially lower flow losses than other existing designs. When used as a filter, it performs as an absolute surface filter featuring a tortuous flow path and high degree of porosity. When used as a surface tension device, it offers superior wetting and re-wetting characteristics.

Abstract: A thin and narrow sheet, having an inlet edge and an outlet edge, is formed on one surface, e.g., the top, with a continuous land that is parallel to the inlet edge. The inlet side of the land is coplanar with the inlet edge of the sheet or, alternatively, disposed slightly inwardly relative thereto. Inwardly behind the land the same surface of the sheet is formed with a plurality of channels defined between adjacent pairs of finger lands each of which extends between the outlet edge of the sheet and the inside of the continuous land. On its opposite side the sheet is formed with a like plurality of transverse lands that form fluid passages extending across the full width of the sheet from the inlet to the outlet edges thereof. The bottom surface lands register with the finger lands of the top surface of the sheet. A congruent stack of the sheets is compressively loaded through the lands to define a rigid filter column.