Abstract: A filter apparatus for removing contaminant particles from an air or gas stream, the apparatus including a filter medium, disposed therein in pleated form, across the air or gas stream to be treated. A rectangular frame has inner side walls defining therebetween a path for the air or gas stream to be treated. A filter medium is disposed in longitudinally-extending pleat form across an air or gas stream to be treated. A pleat spacer and supporting fiber is longitudinally co-extensive with the pleat filter medium. The fiber member consists integrally of a plurality of portions disposed along the pleat filter medium and of connecting portions extending at an acute angle from one end of the portion outside of the filter medium towards the other end, thereby providing a support inside the bend of each of the pleats and the connection portions extend crosswise to the pleats.

Abstract: An electrostatic air cleaning apparatus having a source of relatively large magnitude electrical voltage. The cell comprises a charged ionizing section and a collecting section comprising a charged grid and a grounded grid sandwiching therebetween a sheet of foraminous filter media. One of the grids is movable relative to the other grid. A single bus bar electrically connects the ionizing section and the charged grid to the source of voltage. The movable grip is positioned with respect to the stationary grid via support surfaces. Retainers maintain the movable grid in its desired position.

Abstract: A filter cartridge for suspended particles comprising a frame and a filter web supported by the frame, the filter web being embedded in the frame which is formed of plastic material. The outside of the filter web is provided with a support grid or wire network which is likewise embedded in the frame. The filter web and the support grid network are folded into the shape of a bellows.