Patent ID: 8431186
Filing Date: 2013-04-30
Classification: B01J,F01N

Abstract:
1. A method for coating a diesel particle filter with a catalytically active coating, wherein a zeolite-containing layer is introduced uniformly over the entire length of the particle filter, and a further, zeolite-free coating suspension of a noble metal catalyst is introduced into the pores of the filter material solely in an entry zone in order to increase a noble metal concentration in this zone, and the diesel particle filter being in the form of a cylindrical wall flow filter with a cylinder axis, which has an inlet end face, an outlet end face and a length L of the filter body, characterized in that the method comprises steps of, a) vertically orienting the axis of the filter body, with the inlet end face downward, b) pumping a first, zeolite-free coating suspension of a noble metal catalyst in through the inlet end face up to a predetermined height H, and suction extracting the coating suspension downward, c) rotating the filter body about an axis perpendicular to the cylinder axis through 180° , d) pumping a second, zeolite-containing coating suspension in through the then lower outlet end face into the filter substrate as far as the upper inlet end face, and suction extracting or pumping out the coating suspension downward, and e) drying and calcining the coating, wherein both coating suspensions are ground, before coating, so finely that the particles of the solids have a diameter d