Patent ID: 7491373
Filing Date: 2009-02-17
Classification: F01N,Y10S,Y10T

Abstract:
1. An exhaust after treatment system, comprising: a wall-flow particulate filter, and a flow-through honeycomb substrate positioned upstream of the wall-flow particulate filter, the flow-through honeycomb substrate having an inlet face and an outlet face and a plurality of longitudinal walls extending between the inlet face and the outlet face, said walls defining a plurality of parallel channels extending between the inlet face and the outlet face, said flow-through honeycomb substrate having a flow-through region including a first portion of the parallel channels and a flow-control region including a second portion of the parallel channels, wherein the first portion of the parallel channels includes unplugged channels and the second portion of the parallel channels includes plugged channels wherein a radial plug density of the plugged channels is non-uniform.