Perforated mixing pipe with swirler
View Patent ↗An aftertreatment system may include an exhaust pipe and a mixing pipe. The exhaust pipe may receive exhaust gas from an engine and may include a first portion defining a first longitudinal axis and a second portion defining a second longitudinal axis that is angled relative to the first axis. The mixing pipe may be disposed in the exhaust pipe and may include a tubular portion and a collar extending radially outward from the tubular portion. The tubular portion may include a plurality of openings and a plurality of deflectors. The plurality of openings may extend through inner and outer diametrical surfaces of the tubular portion. Each of the plurality of deflectors may be disposed adjacent a corresponding one of the plurality of openings.
1. An aftertreatment system comprising:
an exhaust pipe receiving exhaust gas from an engine and including a first portion defining a first longitudinal axis and a second portion defining a second longitudinal axis that is angled relative to the first axis; and
a mixing pipe disposed in the exhaust pipe and including a tubular portion and a collar extending radially outward from the tubular portion, the collar comprising a swirler having a plurality of blades extending radially outward from the tubular portion, the tubular portion including a plurality of openings and a plurality of deflectors, the plurality of openings extending through inner and outer diametrical surfaces of the tubular portion, each of the plurality of deflectors disposed adjacent a corresponding one of the plurality of openings, wherein each of the blades includes a radially inner end and a radially outer end, the radially outer ends being spaced apart from each other.
2. The aftertreatment system of claim 1 , wherein the deflectors extend inward from the inner diametrical surface.
3. The aftertreatment system of claim 1 , wherein the collar extends from a downstream end of the tubular portion.
4. The aftertreatment system of claim 1 , wherein each of the blades includes a tab extending radially inward from an edge of the blade between the radially inner and outer ends.
5. The aftertreatment system of claim 1 , wherein radially extending edges of the blades are angled so that the radially inner end of each blade and the outer end of the same blade are rotationally misaligned with each other.
6. The aftertreatment system of claim 1 , further comprising: a reductant injector disposed along the second longitudinal axis at an upstream end of the tubular portion; and a catalyst disposed downstream of the mixing pipe and the reductant injector.
7. An aftertreatment system comprising:
an exhaust pipe receiving exhaust gas from an engine and including a first portion defining a first longitudinal axis and a second portion defining a second longitudinal axis that is angled relative to the first axis; and
a mixing pipe disposed in the exhaust pipe and including a tubular portion and a swirler extending radially from the tubular portion, the tubular portion including a plurality of openings extending through inner and outer diametrical surfaces of the tubular portion, the swirler comprising a plurality of blades extending radially outward from the tubular portion, wherein each of the blades includes a radially inner end and a radially outer end, the radially outer ends being spaced apart from each other.
8. The aftertreatment system of claim 7 , wherein the tubular portion includes a plurality of deflectors, each of the deflectors is disposed adjacent a corresponding one of the plurality of openings.
9. The aftertreatment system of claim 8 , wherein the deflectors extend inward from the inner diametrical surface.
10. The aftertreatment system of claim 7 , wherein the swirler extends from a downstream end of the tubular portion.
11. The aftertreatment system of claim 7 , wherein each of the blades includes a tab extending radially inward from an edge of the blade between the radially inner and outer ends.
12. The aftertreatment system of claim 7 , wherein radially extending edges of the blades are angled so that the radially inner end of each blade and the outer end of the same blade are rotationally misaligned with each other.
13. The aftertreatment system of claim 7 , further comprising: a reductant injector disposed along the second longitudinal axis at an upstream end of the tubular portion; and a catalyst disposed downstream of the mixing pipe and the reductant injector.
14. An aftertreatment system comprising:
an exhaust pipe receiving exhaust gas from an engine and including a first portion defining a first longitudinal axis and a second portion defining a second longitudinal axis that is angled relative to the first axis; and
a mixing pipe disposed in the exhaust pipe and including a tubular portion and a collar extending radially outward from the tubular portion, the collar comprising a swirler having a plurality of blades extending radially outward from the tubular portion, the tubular portion including a plurality of openings and a plurality of deflectors, the plurality of openings extending through inner and outer diametrical surfaces of the tubular portion, each of the plurality of deflectors disposed adjacent a corresponding one of the plurality of openings, wherein the deflectors extend outward from the outer diametrical surface.
15. An aftertreatment system comprising:
an exhaust pipe receiving exhaust gas from an engine and including a first portion defining a first longitudinal axis and a second portion defining a second longitudinal axis that is angled relative to the first axis; and
a mixing pipe disposed in the exhaust pipe and including a tubular portion and a swirler extending radially from the tubular portion, the tubular portion including a plurality of openings extending through inner and outer diametrical surfaces of the tubular portion, the swirler comprising a plurality of blades extending radially outward from the tubular portion, wherein the deflectors extend outward from the outer diametrical surface.
16. A method of mixing exhaust gas and reductant in an aftertreatment system, the method comprising:
providing a mixing device in an exhaust pipe through which exhaust gas from an engine flows, the mixing device including a tubular portion;
receiving a first portion of the exhaust gas in the tubular portion through a plurality of openings in the tubular portion;
allowing a second portion of the exhaust gas to flow between the tubular portion and an inner diametrical surface of the exhaust pipe;
injecting reductant into the tubular portion;
generating a first swirling flow pattern within the tubular portion; and
generating a second swirling flow pattern with the second portion of the exhaust gas, the second swirling flow pattern surrounding the first swirling flow pattern downstream of the tubular portion of the mixing device, wherein the second swirling flow pattern is generated with a plurality of blades extending radially outward from the tubular portion, wherein the first swirling flow pattern is generated with a plurality of deflectors extending radially outward from the tubular portion.
17. The method of claim 16 , wherein the first swirling flow pattern is generated with a plurality of deflectors extending radially inward from the tubular portion.
18. The method of claim 16 , further comprising blending the first and second swirling flow patterns downstream of the mixing device.