Patent ID: 6146436
Filing Date: 2000-11-14
Classification: B01D,D04H

Abstract:
A cartridge filter containing non-woven fabric converted into a cylindrical shape for use as the filter element, the filter element being permeable in the radial direction and comprising:layered staple fibers of a titer of 0.1 to 50 decitex, said fibers being bonded together by a thermally softenable binding agent;a top layer bordering on the upstream side of the filter and having a thickness of between 10%-60% of the overall thickness of the non-woven fabric;a bottom layer bordering on the downstream side of the filter having a thickness of between 10% to 60% of the overall thickness of the non-woven fabric, said bottom layer being compressed between two to ten times the top layer, the non-woven fabric having an overall mass per unit area of 100 to 500 g/m.sup.2, and an overall thickness, as measured according to DIN 53 855, of 1.5-7.0 mm; andone or more transition zones intermediate the top and bottom layers, the transition zone(s) being formed integral with the top and the bottom layers so that the layers need not be separately joined together, wherein the top layer, the bottom layer, and the transition zone comprise 100% of the thickness of the filter element,wherein the non-woven fabric is cylindrical in shape and is pleated parallel to the cylindrical axis of its shape, and wherein the filter element is useable in air-supply filtration with initial pressure losses of less than 300 Pa at air flow rates through the filter medium of less than 250 m.sup.3 /m.sup.2 h.