US 8,459,017 B2 · Low pressure drop mixer for radial mixing of internal combustion engine exhaust flows, combustor incorporating same, and methods of mixing

Abstract

An exhaust aftertreatment system is provided. The exhaust aftertreatment system includes a mixing arrangement for mixing flows of exhaust along a flow path. The mixing arrangement radially and angularly rearranges segments of two different portions of flow to mix the different portions of flow. The mixing arrangement initially converts a generally radially stratified temperature profile into an angularly stratified temperature profile to increase surface area between cool segments of exhaust gas and hot segments of exhaust gas. The aftertreatment system may also include a combustion chamber, a combustor housing and a combustor liner. The mixing arrangement is downstream from the combustion chamber to direct radially outward hot gas passing through the combustor liner and to direct radially outer cool gas passing between the liner and the combustor housing radially inward in an interleaving fashion.

Claims28

Dependent claims

A method of mixing a flow of exhaust flowing along a flow axis including the step(s) of:

rearranging the flow of exhaust along the flow axis via a mixer arrangement coaxial to the flow axis, the exhaust made up entirely of combusted gases, wherein rearranging the flow of exhaust includes the steps of:
directing a first portion of the flow radially outward away from the flow axis by passing the first portion of the flow only over a plurality of first flow directing tabs, of the mixer arrangement, that are convex to the flow axis, and
directing a second portion of the flow radially inward toward the flow axis by passing the second portion of the flow only over a plurality of second flow directing tabs, of the mixer arrangement, that are concave to the flow axis;
and
wherein the steps of directing the first and second portions includes separating the first portion into a plurality of first segments and directing the first segments radially outward and separating the second portion into a plurality of second segments and directing the second segments radially inward, wherein the step of rearranging includes increasing the surface area between the first and second portions.

2 more elements

An exhaust gas mixer for interleaving portions of a flow of exhaust gas from an internal combustion engine comprising:

a plurality of first flow directing tabs;
a plurality of second flow directing tabs;
the first and second flow directing tabs arranged to circumscribe a flow axis;
and
the first flow directing tabs arranged to direct radially inward exhaust flow radially outward;
and
the second flow directing tabs arranged to direct radially outer exhaust flow radially inward;
and
wherein:
the first flow directing tabs have an upstream inlet end and a downstream outlet end;
the second flow directing tabs have an upstream inlet end and a downstream outlet end;
the inlet ends of the first flow directing tabs are radially inward of the outlet ends of the first flow directing tabs;
the inlet ends of the second flow directing tabs are radially outward of the outlet ends of the first flow directing tabs;
the inlet ends of the first flow directing tabs are radially inward of the inlet ends of the second flow directing tabs;
and
the outlet ends of the first flow directing tabs are radially outward of the outlet tends of the second flow directing tabs and the inlet ends of the first flow directing tabs.

13 more elements

A diesel fuel exhaust aftertreatment system for treating diesel fuel exhaust from an internal combustion engine comprising:

a heat generating device for heating the exhaust generating a radially stratified temperature profile;
a mixer arrangement downstream from the heat generating device, the mixer arrangement including:
a plurality of first flow directing tabs configured to direct a radially inward portion of the exhaust flow radially outward by passing the radially inward portion of the exhaust flow only over the plurality of first flow directing tabs;
and
a plurality of second flow directing tabs, each having an inlet attached to an interior surface of the combustor can, configured to direct a radially outer portion of the exhaust flow radially inward by passing the radially outer portion of the exhaust flow only over the plurality of second flow directing tabs.

2 more elements

A diesel fuel exhaust aftertreatment for treating diesel fuel exhaust from an internal combustion engine comprising:

a heat generating device for heating the exhaust generating a radially stratified temperature profile;
a mixer arrangement downstream from the heat generating device, the mixer arrangement including:
a plurality of first flow directing tabs configured to direct a radially inward portion of the exhaust flow radials outward;
and
a plurality of second flow directing tabs, each having an inlet attached to an interior surface of the a combustor can, configured to direct a radially outer portion of the exhaust flow radially inward;
a combustor housing;
a combustor liner disposed within the combustor housing with the radially inward portion of the exhaust flow passes through the combustor liner;
an annulus located between an inner surface of the combustor housing and an outer surface of the combustor liner, the radially outward portion of the exhaust flow passing through the annulus;
wherein the first flow directing tabs draw the radially inward portion of the exhaust passing through the combustor liner radially outward toward the inner surface of the combustor housing and the second flow directing tabs direct the radially outward portion of the exhaust passing through the annulus radially inward, such that the mixer arrangement is configured to form a plurality of angularly stratified segments formed from alternating segments of the inward portion of the exhaust and the outward portion of the exhaust;
and
wherein the second flow directing tabs have an inlet end that is radially outward of the inner liner and an outlet end that is radially inward of the inner liner.

8 more elements

Dependencies are inferred from the claim text.

Low pressure drop mixer for radial mixing of internal combustion engine exhaust flows, combustor incorporating same, and methods of mixing

Life of this patent

Low pressure drop mixer for radial mixing of internal combustion engine exhaust flows, combustor incorporating same, and methods of mixing

Life of this patent

Abstract

Claims28