Abstract: A filter medium (100) having an inflow side (110) and an outflow side (120) defining a flow direction (190). The filter medium comprises at least n consecutive layers Lx of fiber media, x varying from 1 to n, n being more than or equal to 2. L1 (101) is the layer of the n consecutive layers closest to the inflow side of the filter medium and Ln (103) is the layer of the n consecutive layers closest to the -outflow side of the filter medium. For all layers Lx of the at least n consecutive layers, the ratio Hx/(kx*Ax) is substantially identical, wherein Hx is the average thickness of the layer Lx in flow direction, Ax is the average surface area of cross sections according to planes perpendicular to the flow direction, and kx is the permeability coefficient of this layer Lx. The fiber media of at least part of the layers of the filter medium comprises metal fibers.

Abstract: A filter element (100) according to the invention comprises a filter volume (150) having an inflow side and an outflow side defining an average flow direction. The filter volume (150) has an axis substantially parallel to the average flow direction and further comprising a casing (140) delimiting the outer boundary of the filter volume in the direction of the average flow path. The casing (140) is gas impermeable in radial direction. The filter volume (150) is filled with a filter material (111) comprising fibers, a majority of the fibers (102) at least partially encircle the axis.

Abstract: A filter element according to the invention comprises a filter volume having an inflow side and an outflow side defining an average flow direction. The filter volume has an axis substantially parallel to the average flow direction and further comprising a casing delimiting the outer boundary of the filter volume in the direction of the average flow path. The casing is gas impermeable in radial direction. The filter volume is filled with a filter material comprising fibers, a majority of the fibers at least partially encircle the axis.

Abstract: A diesel soot particulate filter medium, as subject of the invention comprises fibers, preferably metal fibers. The diesel soot particulate filter medium has a thickness T between its inflow side and its outflow side being equal or more than 5 cm. The S/V at the inflow side is preferably more than 50 m2/m3 and the S/V at the outflow side is preferably less than 80000 m2/m3, whereas S/V increases stepwise or gradually from the inflow side to the outflow side. S is the sum of all mantle surface of the fibers present in a volume V.

Abstract: A filter medium (100) having an inflow side (110) and an outflow side (120) defining a flow direction (190). The filter medium comprises at least n consecutive layers Lx of fiber media, x varying from 1 to n, n being more than or equal to 2. Ll (101) is the layer of the n consecutive layers closest to the inflow side of the filter medium and Ln (103) is the layer of the n consecutive layers closest to the -outflow side of the filter medium. For all layers Lx of the at least n consecutive layers, the ratio Hx/(kx*Ax) is substantially identical, wherein Hx is the average thickness of the layer Lx in flow direction, Ax is the average surface area of cross sections according to planes perpendicular to the flow direction, and kx is the permeability coefficient of this layer Lx. The fiber media of at least part of the layers of the filter medium comprises metal fibers.

Abstract: A diesel soot particulate filter medium, as subject of the invention comprises fibers, preferably metal fibers. The diesel soot particulate filter medium has a thickness T between its inflow side and its outflow side being equal or more than 5 cm. The S/V at the inflow side is preferably more than 50 m2/m3and the S/V at the outflow side is preferably less than 80000 m2/m3, whereas S/V increases stepwise or gradually from the inflow side to the outflow side. S is the sum of all mantle surface of the fibers present in a volume V.

Abstract: The invention relates to a burner membrane comprising at least one layer consisting of a compressed, needled fibre web with a porosity of between 60% and 95%, and that is constructed of heat-resistant stainless steel fibres. Moreover, the invention relates to a method for its manufacture, comprising the steps of providing a fibre web composed of heat-resistant stainless steel fibres, needling the fibre web, and compressing the needled fibre web to the desired porosity.

Abstract: A burner membrane has at least one layer consisting of a compressed, needled fiber web with a porosity of between 60% and 95%, and that is constructed of heat-resistant stainless steel fibers. A method for its manufacture includes the steps of providing a fiber web composed of heat-resistant stainless steel fibers, needling the fiber web, and compressing the needled fiber web to the desired porosity.