Abstract: A system for treating diesel exhaust is disclosed. The system includes a first filter including layers of filtration material positioned between layers of corrugated metallic foil. The metallic foil defines a honeycomb arrangement of longitudinal passageways from an upstream end to a downstream end and also openings for allowing exhaust to pass between adjacent longitudinal passageways of the metallic foil. The filtration material is positioned such that exhaust between the adjacent longitudinal passageways passes through the filtration material. The metallic foil also includes flow diverting structures to divert flow within the longitudinal passageways through the openings. A second filter is positioned downstream from the first filter. The second filter defines a honeycomb arrangement of longitudinal passageways. The longitudinal passages are selectively plugged adjacent upstream and downstream ends to force flow radially through walls between the longitudinal passages of the second filter.

Abstract: A diesel exhaust treatment system is disclosed that includes first and second diesel particulate reduction devices. The first diesel particulate reduction device is located upstream in the exhaust flow and contains an oxidation catalyst coating. The second particulate reduction device is located downstream from the first particulate reduction device and is generally non-catalyzed or lightly catalyzed. Each particulate reduction device comprises a flow-through fabric-type filtration media with substantial internal turbulence. As exhaust gas passes through the catalyzed upstream particulate reduction device, nitric oxide (NO) is oxidized to form nitrogen dioxide (NO2), a portion of which interacts with the particulate trapped within the upstream diesel particulate reduction device to regenerate the upstream device.