Exhaust system for a diesel engine

Abstract

An exhaust gas system for a diesel engine comprises a filter 9 that includes channels extending in the direction of flow and having porous walls 13 which are clad with an SCR catalyst coating 25. Neighbouring channels are alternately shut off by end plugs 15, 17 at the inlet end and the outlet end, as a result of which the exhaust gas is forced to flow through the walls. The walls 13 are coated with an AMOX catalyst coating 29 from the end 21 over a distance 27. The end plugs 17 in the outlet ends have a length that at least equals said distance 27. As a result, one side of the wall sections coated with the AMOX catalyst coating is covered and the exhaust gas cannot but flow first through the wall sections coated with SCR catalyst coating 25 and only then can the exhaust gas flow past the wall sections coated with the AMOX catalyst coating 29.

1 . An exhaust gas system for a diesel engine comprising an inlet and an outlet and a filter located in between comprising a plurality of channels arranged next to one another and having porous walls, where neighbouring channels are alternately shut off by an end plug at the inlet end and the outlet end, as a result of which the exhaust gas is forced to flow through the walls which are at least partially coated with a first coating, characterized in that from the outlet end to a distance from this outlet end, the walls are coated with a second coating, where the end plugs in the outlet ends have a length that is at least equal to said distance over which the walls are coated with the second coating. 
     
     
         2 . An exhaust gas system as claimed in  claim 1 , characterized in that the filter is a diesel particle filter, in that the first coating is a selective catalytic reduction coating and in that the second coating is an ammonia oxidation catalyst coating.