Mixer assembly for exhaust aftertreatment system
View Patent ↗An exhaust aftertreatment system may include an injector, an aftertreatment device and a mixer assembly. The injector may be configured to inject a fluid into an exhaust passageway that receives exhaust gas from a combustion engine. The aftertreatment device may be disposed in the exhaust passageway downstream of the injector. The mixer assembly may be disposed in the exhaust passageway upstream of the aftertreatment device and may include a first stage having a plurality of parallel plates and a second stage connected to the first stage and disposed downstream of the first stage. The second stage may include an auger blade. The mixer assembly may divide an exhaust stream into at least two flow paths.
1. An exhaust aftertreatment system comprising:
an injector configured to inject a fluid into an exhaust passageway that receives exhaust gas from a combustion engine;
an aftertreatment device disposed in the exhaust passageway downstream of the injector; and
a mixer assembly disposed in the exhaust passageway upstream of the aftertreatment device and including a first stage having a plurality of parallel plates and a second stage connected to the first stage and disposed downstream of the first stage, the second stage including an auger blade extending from one of the plurality of parallel plates, the mixer assembly dividing an exhaust stream into at least two flow paths.
2. The exhaust aftertreatment system of claim 1 , wherein the one of the plurality of parallel plates and the auger blade cooperate to form a monolithic body.
3. The exhaust aftertreatment system of claim 1 , wherein the second stage includes another auger blade.
4. The exhaust aftertreatment system of claim 3 , wherein the auger blades extend in different rotational directions.
5. The exhaust aftertreatment system of claim 4 , wherein an axis of rotation of at least one of the auger blades is offset from a longitudinal axis of a pipe in which the first stage is disposed.
6. The exhaust aftertreatment system of claim 5 , wherein the auger blades have different pitches.
7. The exhaust aftertreatment system of claim 1 , wherein the plurality of parallel plates is at least partially disposed within an annular housing.
8. The exhaust aftertreatment system of claim 7 , wherein the auger blade has a larger outer diameter than an outer diameter of the annular housing.
9. The exhaust aftertreatment system of claim 7 , wherein the auger blade has an outer diameter that is equal to an outer diameter of the annular housing.
10. The exhaust aftertreatment system of claim 7 , wherein first and second axial ends of the annular housing are angled at a non-perpendicular angle relative to a longitudinal axis of the annular housing.
11. The exhaust aftertreatment system of claim 1 , wherein the second stage includes a deflector plate that is angled away from the auger blade.
12. The exhaust aftertreatment system of claim 11 , wherein the second stage defines at least three flow paths, the deflector plate defining first and second ones of the at least three flow paths, and the auger blade defining a third one of the at least three flow paths.
13. The exhaust aftertreatment system of claim 1 , wherein the second stage includes a ridge formed in a plate between the first stage and the auger blade.
14. The exhaust aftertreatment system of claim 13 , wherein the ridge is formed on a stem plate that connects the auger blade with the one of the plurality of parallel plates of the first stage.
15. The exhaust aftertreatment system of claim 1 , wherein the plurality of parallel plates of the first stage includes main bodies that are parallel to each other and parallel to a longitudinal axis of an annular housing in which the plurality of parallel plates is disposed, and wherein the plurality of parallel plates of the first stage includes tabs disposed at distal ends of the main bodies, the tabs are angled relative to the main bodies and the longitudinal axis of the annular housing.
16. The exhaust aftertreatment system of claim 1 , wherein the first stage is disposed in a cylindrical portion of the exhaust passageway and the second stage is at least partially in a conical portion of the exhaust passageway, the conical portion having a longitudinal axis that is angled relative to a longitudinal axis of the cylindrical portion.
17. The exhaust aftertreatment system of claim 1 , wherein the first and second stages are disposed in a cylindrical portion of the exhaust passageway.
18. The exhaust aftertreatment system of claim 1 , wherein the aftertreatment device is a selective catalytic reduction catalyst, and wherein the fluid injected by the injector is a reductant.
19. The exhaust aftertreatment system of claim 18 , further comprising an oxidation catalyst and a particulate filter, the particulate filter disposed upstream of the injector, the oxidation catalyst disposed upstream of the particulate filter.
20. The exhaust aftertreatment system of claim 1 , wherein the at least two flow paths are equal divisions of a total flow through the mixer assembly.
21. The exhaust aftertreatment system of claim 1 , wherein the at least two flow paths are unequal divisions of a total flow through the mixer assembly.
22. The exhaust aftertreatment system of claim 1 , wherein the exhaust passageway includes a cylindrical portion in which the first stage is disposed and a curved portion directly adjacent the cylindrical portion, the curved portion disposed upstream of the cylindrical portion and intersecting the cylindrical portion at an angle relative to a longitudinal axis of the cylindrical portion.
23. The exhaust aftertreatment system of claim 22 , wherein upstream ends of at least two of the plurality of parallel plates of the first stage are offset from each other in an axial direction.
24. The exhaust aftertreatment system of claim 23 , wherein an upstream end of one of the plurality of parallel plates that is furthest away from an intersection of the curved portion and the cylindrical portion is further axially upstream than remaining upstream ends of the plurality of parallel plates.
25. The exhaust aftertreatment system of claim 24 , wherein the plurality of parallel plates is at least partially disposed within an annular housing, and wherein first and second axial ends of the annular housing are angled at a non-perpendicular angle relative to a longitudinal axis of the exhaust passageway.
26. An exhaust aftertreatment system comprising:
an injector configured to inject a fluid into an exhaust passageway that receives exhaust gas from a combustion engine;
an aftertreatment device disposed in the exhaust passageway downstream of the injector; and
a mixer assembly disposed in the exhaust passageway upstream of the aftertreatment device and downstream of the injector, the mixer assembly including an annular housing, a plurality of parallel plates disposed in the annular housing and an auger blade disposed downstream of the annular housing, the auger blade fixedly connected to and extending from one of the plurality of parallel plates, the mixer assembly dividing an exhaust stream into at least two flow paths.
27. The exhaust aftertreatment system of claim 26 , wherein the auger blade is disposed in a conical portion of the exhaust passageway.
28. The exhaust aftertreatment system of claim 26 , wherein the auger blade is disposed in a cylindrical portion of the exhaust passageway.
29. The exhaust aftertreatment system of claim 26 , wherein the one of the plurality of parallel plates and the auger blade cooperate to form a monolithic body.
30. The exhaust aftertreatment system of claim 26 , wherein the mixer assembly includes a plurality of auger blades.
31. The exhaust aftertreatment system of claim 30 , wherein two of the plurality of auger blades extend in different rotational directions.
32. The exhaust aftertreatment system of claim 31 , wherein an axis of rotation of at least one of the plurality of auger blades is offset from a longitudinal axis of a cylindrical portion of the exhaust passageway.
33. The exhaust aftertreatment system of claim 32 , wherein each of the plurality of auger blades has a different pitch.
34. The exhaust aftertreatment system of claim 26 , wherein the auger blade has a larger outer diameter than an outer diameter of the annular housing.
35. The exhaust aftertreatment system of claim 26 , wherein the auger blade has an outer diameter that is equal to an outer diameter of the annular housing.
36. The exhaust aftertreatment system of claim 26 , wherein the mixer assembly includes a deflector plate extending from another one of the plurality of parallel plates, the deflector plate is angled away from the auger blade.
37. The exhaust aftertreatment system of claim 36 , wherein the mixer assembly defines at least three flow paths, the deflector plate defining first and second ones of the at least three flow paths, and the auger blade defining a third one of the at least three flow paths.
38. The exhaust aftertreatment system of claim 26 , wherein the mixer assembly includes a ridge formed on a stem plate that connects the auger blade with the one of the plurality of parallel plates.
39. The exhaust aftertreatment system of claim 26 , wherein the plurality of parallel plates includes main bodies that are parallel to each other and parallel to a longitudinal axis of the annular housing, and wherein the plurality of parallel plates includes tabs disposed at distal ends of the main bodies, the tabs are angled relative to the main bodies and the longitudinal axis of the annular housing.
40. The exhaust aftertreatment system of claim 26 , wherein the aftertreatment device is a selective catalytic reduction catalyst, and wherein the fluid injected by the injector is a reductant.
41. The exhaust aftertreatment system of claim 40 , further comprising an oxidation catalyst and a particulate filter, the particulate filter disposed upstream of the injector, the oxidation catalyst disposed upstream of the particulate filter.
42. The exhaust aftertreatment system of claim 26 , wherein the at least two flow paths are equal divisions of a total flow through the mixer assembly.
43. The exhaust aftertreatment system of claim 26 , wherein the at least two flow paths are unequal divisions of a total flow through the mixer assembly.
44. The exhaust aftertreatment system of claim 26 , wherein the exhaust gas passageway includes a curved portion, a cylindrical portion downstream of the curved portion, and a conical portion downstream of the cylindrical portion, the cylindrical portion is directly adjacent the curved portion and the conical portion, wherein at least a portion of the mixer assembly is disposed within the cylindrical portion, and wherein the conical portion has a longitudinal axis that is angled relative to a longitudinal axis of the cylindrical portion.
45. The exhaust aftertreatment system of claim 44 , wherein the curved portion intersects the cylindrical portion at an angle relative to the longitudinal axis of the cylindrical portion.
46. The exhaust aftertreatment system of claim 45 , wherein upstream ends of at least two of the plurality of parallel plates are offset from each other in an axial direction.
47. The exhaust aftertreatment system of claim 46 , wherein an upstream end of one of the plurality of parallel plates that is furthest away from an intersection of the curved portion and the cylindrical portion is further axially upstream than remaining upstream ends of the plurality of parallel plates.
48. The exhaust aftertreatment system of claim 26 , wherein first and second axial ends of the annular housing are angled at a non-perpendicular angle relative to a longitudinal axis of the exhaust passageway.