Exhaust treatment method and apparatus having particulate filters and SCR
AssigneeCorning Incorporated
InventorsDouglas Munroe Beall, Sam George, Mahesh Govindareddy, Achim Karl-Erich Heibel
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Abstract
An exhaust treatment method and apparatus for treating an exhaust stream flowing through an exhaust line housing in a downstream direction, the apparatus comprising a first particulate filter, an SCR unit, and a second particulate filter downstream of the SCR unit, all serially positioned in the exhaust line.
Claims19
An exhaust treatment apparatus for treating an exhaust stream flowing through an exhaust line housing in a downstream direction from an upstream location of the exhaust line housing to a downstream location, the exhaust treatment apparatus comprising:
- a first particulate filter;
- an SCR unit disposed downstream of the first particulate filter;
- and
- a second particulate filter disposed downstream of the SCR unit;
- wherein the first particulate filter, the SCR unit, and the second particulate filter are disposed serially in the exhaust line housing and are configured to allow the exhaust stream to flow serially through the first particulate filter, subsequently through the SCR unit, and subsequently through the second particulate filter wherein the first particulate filter is comprised of a first honeycomb body comprised of intersecting porous ceramic walls comprising a first bulk average porosity of 40-65% as measured by mercury porosimetry, and the second particulate filter is comprised of a second honeycomb body comprised of intersecting porous ceramic walls comprising a second bulk average porosity of 35-55% as measured by mercury porosimetry.
An exhaust treatment apparatus for treating an exhaust stream flowing through an exhaust line housing in a downstream direction from an upstream location of the exhaust line housing to a downstream location, the exhaust treatment apparatus comprising:
- a first particulate filter;
- an SCR unit disposed downstream of the first particulate filter;
- and
- a second particulate filter disposed downstream of the SCR unit;
- wherein the first particulate filter, the SCR unit, and the second particulate filter are disposed serially in the exhaust line housing and are configured to allow the exhaust stream to flow serially through the first particulate filter, subsequently through the SCR unit, and subsequently through the second particulate filter wherein the first particulate filter is comprised of a first honeycomb body comprised of intersecting porous ceramic walls comprising a first bulk median pore size of 12-30 micrometers as measured by mercury porosimetry, and the second particulate filter is comprised of a second honeycomb body comprised of intersecting porous ceramic walls comprising a second bulk median pore size of 2-22 micrometers as measured by mercury porosimetry, and wherein the second bulk median pore size is less than the first bulk median pore size.
An exhaust treatment apparatus for treating an exhaust stream flowing through an exhaust line housing in a downstream direction from an upstream location of the exhaust line housing to a downstream location, the exhaust treatment apparatus comprising:
- a first particulate filter;
- an SCR unit disposed downstream of the first particulate filter;
- and
- a second particulate filter disposed downstream of the SCR unit;
- wherein the first particulate filter, the SCR unit, and the second particulate filter are disposed serially in the exhaust line housing and are configured to allow the exhaust stream to flow serially through the first particulate filter, subsequently through the SCR unit, and subsequently through the second particulate filter wherein the first particulate filter is comprised of a first honeycomb body comprised of intersecting porous ceramic walls comprising a first bulk average porosity as measured by mercury porosimetry, and the second particulate filter is comprised of a second honeycomb body comprised of intersecting porous ceramic walls comprising a second bulk average porosity as measured by mercury porosimetry, and the second bulk average porosity is greater than the first bulk average porosity.
Dependencies are inferred from the claim text.