Abstract: The invention relates to a filter arrangement comprising a filter cartridge, having an opening and a wall which is formed by a filter medium and has an inner side delimiting a clean side of the filter and an outer side delimiting a raw side of the filter, a fan for conveying air to be purified first through the wall and subsequently through the opening of the filter cartridge, and a purification device, which is configured to convey a jet of compressed air through the opening into the filter cartridge and through the out of the filter cartridge, for conveying dirt away from an outer wall of the wall. The invention also relates to a method for detecting a leak of a filter cartridge, wherein the filter cartridge has an opening and a wall which is formed by a filter medium and has an inner side delimiting a clean side of the filter and an outer side delimiting a raw side of the filter.

Abstract: A filter material for a filter insert of a fuel filter for separating solid particles and water droplets from fuel. The filter material comprises a particle filter medium layer through which the fuel flows first during use and at least one coalescer medium layer which lies on the particle filter medium layer on the outflow side. At least one coalescer medium layer is gradient-free in the flow direction with respect to the geometrical structure and/or physical properties and/or chemical properties of the layers. The at least one coalescer medium layer has a thickness measured in the flow direction which is maximally as large as the thickness of the particle filter medium layer measured in the flow direction.

Abstract: A filter material for a filter insert of a fuel filter for separating solid particles and water droplets from fuel. The filter material comprises a particle filter medium layer through which the fuel flows first during use and at least one coalescer medium layer which lies on the particle filter medium layer on the outflow side. At least one coalescer medium layer is gradient-free in the flow direction with respect to the geometrical structure and/or physical properties and/or chemical properties of the layers. The at least one coalescer medium layer has a thickness measured in the flow direction which is maximally as large as the thickness of the particle filter medium layer measured in the flow direction.