Cantilevered flow distributing apparatus
An exhaust aftertreatment system may include a housing, an aftertreatment device, and a cantilevered flow distributing element. The housing receives exhaust gas output from an engine and has a main body and an exhaust gas inlet that is angled relative to the main body. The flow distributing element is disposed within the housing upstream of the exhaust aftertreatment device and includes a baffle plate and a collar. The baffle plate is attached to an inner wall of the main body. The collar may include a plurality of first apertures, a downstream axial edge and an upstream axial edge. A portion of the downstream axial edge may abut an upstream-facing surface of the baffle plate. The baffle plate may have a plurality of second apertures extending through the upstream-facing surface. The collar may extend across and partially block at least some of the second apertures.
1. An exhaust aftertreatment system comprising:
a housing receiving exhaust gas output from a combustion engine and having a main body and an exhaust gas inlet that is angled relative to the main body;
an exhaust aftertreatment device disposed within the main body; and
a cantilevered flow distributing element disposed within the housing upstream of the exhaust aftertreatment device, the flow distributing element including a baffle plate and a collar fixed to the baffle plate, the baffle plate including a radially outer periphery that is attached to an inner circumferential wall of the main body, the collar having a plurality of first apertures, a downstream axial edge and an upstream axial edge opposite the downstream axial edge, at least a portion of the downstream axial edge abuts an upstream-facing surface of the baffle plate, the baffle plate having a plurality of second apertures extending through the upstream-facing surface, the collar extending across and partially blocking at least some of the second apertures, wherein the upstream-facing surface of the baffle plate extends axially upstream such that a central portion of the upstream-facing surface is disposed upstream relative to the radially outer periphery of the baffle plate.
2. The exhaust aftertreatment system of claim 1 , wherein the downstream axial edge of the collar includes a plurality of attachment zones that are circumferentially spaced apart from each other, wherein the attachment zones are locations at which the downstream axial edge is welded to the baffle plate.
3. The exhaust aftertreatment system of claim 2 , wherein the downstream axial edge includes a plurality of buffer zones, each of the buffer zones including a circumferentially extending segment of the downstream axial edge that abuts the upstream-facing surface and is disposed between and directly adjacent to one of the attachment zones and one of a plurality of open zones, wherein the open zones are circumferentially extending segments of the downstream axial edge that extend across and partially block some of the second apertures.
4. The exhaust aftertreatment system of claim 3 , wherein each of the attachment zones includes a tab that projects into one of a plurality of slots in the baffle plate, and wherein the welds are applied along circumferential lengths of the tabs.
5. The exhaust aftertreatment system of claim 4 , wherein a sum of circumferential lengths of all of the attachment zones is 32%-36% of a total circumference of the downstream axial edge of the collar.
6. The exhaust aftertreatment system of claim 5 , wherein a sum of circumferential lengths of all of the attachment zones and all of the buffer zones is 64%-68% of the total circumference of the downstream axial edge of the collar.
7. The exhaust aftertreatment system of claim 6 , wherein a sum of circumferential lengths of all of the open zones is 32%-38% of the total circumference of the downstream axial edge of the collar.
8. The exhaust aftertreatment system of claim 1 , wherein the collar is a tubular member that extends entirely around a longitudinal axis of the baffle plate.
9. The exhaust aftertreatment system of claim 1 , wherein the collar extends circumferentially around only a portion of a longitudinal axis of the baffle plate.
10. The exhaust aftertreatment system of claim 1 , wherein the exhaust aftertreatment device is one of a particulate filter, an oxidation catalyst and a selective catalytic reduction catalyst.
11. An exhaust aftertreatment system comprising:
a housing receiving exhaust gas output from a combustion engine and having a main body and an exhaust gas inlet that is angled relative to the main body, the housing defining an end chamber at an intersection of longitudinal axes of the main body and the inlet;
an exhaust aftertreatment device disposed within the main body downstream of the end chamber; and
a cantilevered flow distributing element disposed within the housing upstream of the exhaust aftertreatment device, the flow distributing element including a baffle plate and a collar fixed to the baffle plate, the collar extending into the end chamber, the baffle plate including a radially outer periphery that is attached to an inner circumferential wall of the main body, the collar having a plurality of first apertures, a downstream axial edge and an upstream axial edge opposite the downstream axial edge, at least a portion of the downstream axial edge abuts an upstream-facing surface of the baffle plate, the baffle plate having a plurality of second apertures extending through the upstream-facing surface, the collar extending across and partially blocking at least some of the second apertures, wherein the upstream-facing surface of the baffle plate extends axially upstream such that a central portion of the upstream-facing surface is disposed upstream relative to the radially outer periphery of the baffle plate.
12. The exhaust aftertreatment system of claim 11 , wherein the downstream axial edge of the collar includes a plurality of attachment zones that are circumferentially spaced apart from each other, wherein the attachment zones are locations at which the downstream axial edge is welded to the baffle plate, wherein the downstream axial edge includes a plurality of buffer zones, each of the buffer zones including a circumferentially extending segment of the downstream axial edge that abuts the upstream-facing surface and is disposed between and directly adjacent to one of the attachment zones and one of a plurality of open zones, and wherein the open zones are circumferentially extending segments of the downstream axial edge that extend across and partially block some of the second apertures.
13. The exhaust aftertreatment system of claim 12 , wherein each of the attachment zones includes a tab that projects into one of a plurality of slots in the baffle plate, and wherein the welds are applied along circumferential lengths of the tabs.
14. The exhaust aftertreatment system of claim 13 , wherein a sum of circumferential lengths of all of the attachment zones is 32%-36% of a total circumference of the downstream axial edge of the collar.
15. The exhaust aftertreatment system of claim 14 , wherein a sum of circumferential lengths of all of the attachment zones and all of the buffer zones is 64%-68% of the total circumference of the downstream axial edge of the collar.
16. The exhaust aftertreatment system of claim 15 , wherein a sum of circumferential lengths of all of the open zones is 32%-38% of the total circumference of the downstream axial edge of the collar.
17. The exhaust aftertreatment system of claim 11 , wherein the collar is a tubular member that extends entirely around the longitudinal axis of the baffle plate.
18. The exhaust aftertreatment system of claim 11 , wherein the collar extends circumferentially around only a portion of the longitudinal axis of the baffle plate.