US-12618351-B2 - Systems and methods for mixing exhaust gas

US12618351B2US 12618351 B2US12618351 B2US 12618351B2US-12618351-B2

Abstract

A mixer for an exhaust gas aftertreatment system includes an outer circumferential edge that extends in a first plane perpendicular to a longitudinal axis of the mixer, a hub including a flat portion that extends in a second plane perpendicular to the longitudinal axis, the second plane being offset from the first plane in a direction along the longitudinal axis; a plurality of openings, each extending in a region between the hub and the outer circumferential edge of the mixer; and a plurality of fins, each extending from at least one edge of the plurality of openings.

Inventors

Corey Verseman
Jacob D. Canik
Jose De Jesus Alvarez Duenas
Dustin Youngs
Rodrigo Macano Rodrigues
Jeffrey T. Sedlacek
Alex Kushner

Assignees

CUMMINS EMISSION SOLUTIONS INC.

Dates

Publication Date: 20260505
Application Date: 20240726

Claims (20)

1 . A mixer for an exhaust gas aftertreatment system, the mixer comprising: an outer circumferential edge that extends in a first plane perpendicular to a longitudinal axis of the mixer; a hub comprising a flat portion that extends in a second plane perpendicular to the longitudinal axis, the second plane being offset from the first plane in a direction along the longitudinal axis; a plurality of openings, each extending in a region between the hub and the outer circumferential edge of the mixer; and a plurality of fins, each extending from at least one edge of the plurality of openings; wherein: each opening of the plurality of openings comprises an inner circumferential edge and a radial edge, each fin of the plurality of fins is attached at least to an outermost edge of each opening and the radial edge of each opening, a radial edge of each fin on a side of the fin opposite the radial edge of each opening comprises, from the hub towards the outer circumferential edge of the mixer, a first portion, a second portion, and a third portion, an angle between the second portion of the radial edge of each fin and the first portion of the radial edge of each fin is greater than an angle between the second portion of the radial edge of each fin the third portion of the radial edge of each fin.
2 . The mixer of claim 1 , comprising: a plurality of tabs disposed along the outer circumferential edge of the mixer; wherein: each of the plurality of tabs extends in a respective third plane, a leading edge of each of the plurality of tabs is oriented towards the hub and away from the longitudinal axis of the mixer, and the longitudinal axis is oblique to the respective third plane.
3 . The mixer of claim 1 , wherein each of the plurality of fins is convex relative to the hub.
4 . The mixer of claim 1 , wherein each of the plurality of fins extends from the hub.
5 . The mixer of claim 1 , wherein the outer circumferential edge, the flat portion, and the plurality of openings define a frustoconical profile.
6 . The mixer of claim 1 , comprising: a notch disposed on the outer circumferential edge of the mixer, the notch configured to allow a liquid to flow from a first side of the mixer to a second side of the mixer.
7 . The mixer of claim 1 , wherein: each fin comprises: a convex portion that is convex relative to the hub, the convex portion coupled with the at least one edge of the plurality of openings, and a concave portion that is concave relative to the hub, the concave portion coupled with the first portion.
8 . The mixer of claim 1 , comprising: a plurality of spokes, each extending from the hub to the outer circumferential edge of the mixer and each positioned between two openings of the plurality of openings.
9 . An aftertreatment system, comprising: an exhaust conduit; a filter disposed in the exhaust conduit; a mixer disposed in the exhaust conduit at a location downstream of the filter, the mixer comprising: an outer circumferential edge that extends in a first plane perpendicular to a longitudinal axis of the mixer; a hub comprising a flat portion that extends in a second plane perpendicular to the longitudinal axis, the second plane being offset from the first plane in a direction along the longitudinal axis; a plurality of openings, each extending in a region between the hub and the outer circumferential edge of the mixer; and a plurality of fins, each extending from at least one edge of the plurality of openings; wherein: each opening of the plurality of openings comprises an inner circumferential edge and a radial edge, each fin of the plurality of fins is attached at least to an outermost edge of each opening the inner circumferential edge and the radial edge of each opening, and the plurality of fins are entirely upstream of the second plane; and a sensor disposed in the exhaust conduit at a location downstream of the mixer.
10 . The aftertreatment system of claim 9 , wherein the mixer comprises a notch disposed on the outer circumferential edge of the mixer, the notch configured to engage with an alignment element disposed in the exhaust conduit.
11 . The aftertreatment system of claim 9 , wherein exhaust gas is configured to contact the mixer downstream of the outer circumferential edge of the mixer.
12 . The aftertreatment system of claim 9 , wherein exhaust gas is configured to contact the mixer upstream of the outer circumferential edge of the mixer.
13 . The aftertreatment system of claim 9 , wherein the mixer comprises a plurality of tabs disposed along the outer circumferential edge of the mixer, the plurality of tabs configured to be welded to the exhaust conduit.
14 . The aftertreatment system of claim 9 , wherein: the mixer comprises a plurality of tabs disposed along the outer circumferential edge of the mixer, each tab of the plurality of tabs comprise a leading edge, prior to the mixer being positioned in the exhaust conduit, the plurality of leading edges are arranged around a first circle having a first diameter greater than an exhaust conduit diameter, and after the mixer is positioned in the exhaust conduit, the plurality of leading edges are arranged around a second circle having a second diameter equal to the exhaust conduit diameter.
15 . The aftertreatment system of claim 9 , comprising: a diesel particulate filter catalyst disposed in the exhaust conduit at a location downstream of the filter and upstream of the mixer; wherein the hub is positioned a distance from the diesel particulate filter catalyst.
16 . The aftertreatment system of claim 9 , wherein: the mixer comprises a plurality of tabs disposed along the outer circumferential edge of the mixer, and the plurality of tabs configured to elastically deform upon insertion into the exhaust conduit.
17 . The aftertreatment system of claim 9 , wherein the outer circumferential edge of the mixer has a diameter equal to an exhaust conduit diameter.
18 . An aftertreatment system, comprising: an exhaust conduit; a filter disposed in the exhaust conduit; a mixer disposed in the exhaust conduit at a location downstream of the filter; and a sensor disposed in the exhaust conduit at a location downstream of the mixer; wherein: the mixer comprises: an outer circumferential edge and a hub; a plurality of spokes each comprising a flat portion and extending from the hub to the outer circumferential edge; and a plurality of tabs disposed along the outer circumferential edge of the mixer and each extending from at least one flat portion, each tab of the plurality of tabs comprise a leading edge configured to contact the exhaust conduit, prior to the mixer being positioned in the exhaust conduit, the plurality of leading edges are arranged around a first circle having a first diameter greater than an exhaust conduit diameter, and after the mixer is positioned in the exhaust conduit, the plurality of leading edges are arranged around a second circle having a second diameter equal to the exhaust conduit diameter; wherein: the outer circumferential edge extends in a first plane perpendicular to a longitudinal axis of the mixer, the hub extends in a second plane perpendicular to the longitudinal axis of the mixer; each of the plurality of tabs and the respective leading edge extend in a respective third plane, the leading edge of each of the plurality of tabs is oriented towards the hub and away from the longitudinal axis of the mixer, and the longitudinal axis is oblique to the respective third plane.
19 . The aftertreatment system of claim 18 , wherein the second plane is offset from the first plane in a direction along the longitudinal axis.
20 . The aftertreatment system of claim 18 , the plurality of tabs are configured to be welded to the exhaust conduit.

Description

TECHNICAL FIELD The present disclosure relates generally to aftertreatment systems for internal combustion (IC) engines. More specifically, the present disclosure relates to mixing exhaust gas in exhaust gas aftertreatment systems. BACKGROUND The exhaust of internal combustion engines, such as diesel engines, includes nitrogen oxide (NOx) compounds. To reduce NOx emissions, a treatment fluid may be dosed into the exhaust by a doser assembly within an aftertreatment system. The treatment fluid facilitates conversion of a portion of the exhaust into non-NOx emissions, such as nitrogen (N2), carbon dioxide (CO2), and water (H2O), thereby reducing NOx emissions. SUMMARY At least one aspect of the present disclosure is directed to a mixer for an exhaust gas aftertreatment system. The mixer includes an outer circumferential edge that extends in a first plane perpendicular to a longitudinal axis of the mixer. The mixer includes a hub. The hub includes a flat portion that extends in a second plane perpendicular to the longitudinal axis. The second plane is offset from the first plane in a direction along the longitudinal axis. The mixer includes a plurality of openings, each extending in a region between the hub and the outer circumferential edge of the mixer. The mixer includes a plurality of fins, each extending from at least one edge of the plurality of openings. In some embodiments, the mixer includes a plurality of tabs disposed along the outer circumferential edge of the mixer. Each of the plurality of tabs can extend in a respective third plane. A leading edge of the each of the plurality of tabs can be oriented towards the hub and away from the longitudinal axis of the mixer. The longitudinal axis can be oblique to the respective third plane. In some embodiments, each of the plurality of fins is convex relative to the hub. In some embodiments, each of the plurality of fins extends from the hub. In some embodiments, the mixer has an inner circumferential edge. Each of the plurality of fins can extend from the inner circumferential edge. In some embodiments, the outer circumferential edge, the flat portion, and the plurality of openings define a frustoconical profile. In some embodiments, the mixer includes a notch disposed on the outer circumferential edge of the mixer. The notch can be configured to allow a liquid to flow from a first side of the mixer to a second side of the mixer. In some embodiments, each fin includes a first portion that is convex relative to the hub. The first portion can be coupled with the at least one edge of the plurality of openings. Each fin can include a second portion that is concave relative to the hub. The second portion can be coupled with the first portion. In some embodiments, the mixer includes a plurality of spokes, each extending from the hub to the outer circumferential edge of the mixer and each positioned between two openings of the plurality of openings. In some embodiments, an aftertreatment system includes an exhaust conduit, a filter disposed in the exhaust conduit, and a mixer disposed in the exhaust conduit at a location downstream of the filter. The mixer can include an outer circumferential edge that extends in a first plane perpendicular to a longitudinal axis of the mixer. The mixer can include a hub. The hub can include a flat portion that extends in a second plane perpendicular to the longitudinal axis. The second plane can be offset from the first plane in a direction along the longitudinal axis. The mixer can include a plurality of openings, each extending in a region between the hub and the outer circumferential edge of the mixer. The mixer can include a plurality of fins, each extending from at least one edge of the plurality of openings. The aftertreatment system can include a sensor disposed in the exhaust conduit at a location downstream of the mixer. In some embodiments, the mixer includes a notch disposed on the outer circumferential edge of the mixer. The notch can be configured to engage with an alignment element disposed in the exhaust conduit. In some embodiments, exhaust gas is configured to contact the mixer downstream of the outer circumferential edge of the mixer. In some embodiments, exhaust gas is configured to contact the mixer upstream of the outer circumferential edge of the mixer. In some embodiments, the mixer includes a plurality of tabs disposed along the outer circumferential edge of the mixer. The plurality of tabs can be welded to the exhaust conduit. In some embodiments, the mixer includes a plurality of tabs disposed along the outer circumferential edge of the mixer. Each tab of the plurality of tabs can include a leading edge. Prior to the mixer being positioned in the exhaust conduit, the plurality of leading edges can be arranged around a first circle having a first diameter greater than an exhaust conduit diameter. After the mixer is positioned in the exhaust conduit, the plurality of leading edges can be arranged around