Patent ID: 8043572

Claim:
A product comprising: a regeneration particulate trap comprising a catalyzed foam filter and wall flow filter combination, wherein the wall flow filter has at least one through hole cell formed therein running the longitudinal length of the wall flow filter and wherein at least a portion of the wall flow filter circumferentially surrounds a portion of the catalyzed foam filter and wherein the catalyzed foam filter and wall flow filter are constructed and arranged so that exhaust first flows through the catalyzed foam filter and then flows through the wall flow filter and wherein the catalyzed foam filter includes a side edge and a rear face and wherein the wall flow filter circumferentially surrounds at least a portion of the side edge to trap particulate matter between the wall flow filter and the catalyzed foam filter, wherein a first space is located between the side edge and the rear face of the catalyzed foam filter and an inner surface of the wall flow filter, wherein a second space is located between an outer surface of the wall flow filter and an inner surface of an exhaust conduit which circumferentially surrounds the wall flow filter, wherein exhaust flows in a radial direction through the catalyzed foam filter, through the first space, through the wall flow filter, and then to the second space, and wherein exhaust flows in an axial direction through the catalyzed foam filter, through the first space, and then through the wall flow filter, and wherein the catalyzed foam filter comprises a catalyst constructed and arranged to convert NO in engine combustion exhaust flowing through the product to NO 2 and so that additional NO 2 is in the exhaust stream an amount sufficient to oxidize carbon particulates trapped by the catalyzed foam filter and wall filter combination.