Dosing and mixing arrangement for use in exhaust aftertreatment

Patent metadata

Field	Value
Publication number	US-10369533-B2
Application number	US-201415021567-A
Country	US
Kind code	B2
Filing date	Sep 12, 2014
Priority date	Sep 13, 2013
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

Dosing and mixing exhaust gas includes directing exhaust gas towards a periphery of a mixing tube that is configured to direct the exhaust gas to flow around and through the mixing tube to effectively mix and dose exhaust gas within a relatively small area. Some mixing tubes include a slotted region and a non-slotted region. Some mixing tubes include a louvered region and a non-louvered region. Some mixing tubes are offset within a mixing region of a housing.

First claim

What is claimed is:

1. A mixing tube arrangement for swirling exhaust gases, the mixing tube arrangement comprising:
a tube body having a longitudinal axis extending along an interior passage from a first end of the tube body to a second end of the tube body, the tube body defining a slotted region and a non-slotted region, the slotted region defining a plurality of slots, the slotted region extending over a first continuous circumferential distance of the tube body and the non-slotted region extending over a second continuous circumferential distance of the tube body, the second circumferential distance being less than the first circumferential distance, and the second continuous circumferential distance being larger than a circumferential distance of any portion of the tube body extending between two adjacent slots at the slotted region, and the width of each slot being less than half of the second continuous circumferential distance; and
a plurality of louvers disposed at the slots.

2. The mixing tube arrangement of claim 1 , further comprising a doser disposed at the first end of the tube body, the doser being configured to dispense a reactant into exhaust flowing through the interior passage of the tube body.

3. The mixing tube arrangement of claim 1 , wherein the slotted region extends along less than a full length of the tube body.

4. The mixing tube arrangement of claim 1 , wherein a ratio of an axial length of each slot to a diameter of the tube body is 1.5 to 2.

5. The mixing tube arrangement of claim 4 , wherein the ratio of the axial length of each slot to the diameter of the tube body is 1.75.

6. The mixing tube arrangement of claim 1 , wherein the louvers extend away from the tube body at an angle of 45°.

7. The mixing tube arrangement of claim 1 , wherein the slotted region extends along 210° to 330° of a circumference of the tube body.

8. The mixing tube arrangement of claim 7 , wherein the slotted region extends along 270° of the circumference of the tube body.

9. The mixing tube arrangement of claim 1 , wherein a ratio of a circumferential width of each slot to a diameter of the tube body is 0.05 to 0.15.

10. The mixing tube arrangement of claim 9 , wherein the ratio of the circumferential width of each slot to the diameter of the tube body is 0.1.

11. The mixing tube arrangement of claim 1 , wherein a diameter of the tube body is 5 inches, a circumferential width of each slot is 0.45 inches and a length of each slot is 8 inches.

12. The mixing tube arrangement of claim 11 , wherein the slots define 45% of an area of the slotted region.

13. A dosing and mixing arrangement comprising:
a housing defining an inlet having an inlet axis, a mixing region, and an outlet having an outlet axis, the outlet axis being generally orthogonal to the inlet axis;
a mixing tube arrangement disposed within the mixing region of the housing, the mixing tube arrangement including a tube body defining an interior passage that extends along the outlet axis, the tube body having a circumferential surface extending across the inlet axis, the circumferential surface having a continuous louvered region and a continuous non-louvered region, the louvered region defining a plurality of louvers extending outwardly from a circumferential surface of the tube body, the non-louvered region being free of louvers, the non-louvered region having a circumferential width that is larger than a circumferential width of a portion of the tube body extending between two adjacent louvers at the louvered region, the tube body also defining a plurality of slots that extend through the circumferential surface of the tube body, each louver being associated with at least one slot, each slot having a common width defined along a circumference of the tube body.

14. The dosing and mixing arrangement of claim 13 , wherein the mixing tube arrangement touches an interior portion of the housing.

15. The dosing and mixing arrangement of claim 14 , wherein a distal end of one of the louvers contacts the interior portion of the housing.

16. The dosing and mixing arrangement of claim 13 , wherein the mixing tube arrangement is offset within the housing to define a high pressure zone and a flow zone.

17. The dosing and mixing arrangement of claim 13 , wherein the mixing tube arrangement defines the outlet of the housing.

18. The dosing and mixing arrangement of claim 13 , wherein at least a portion of the louvered region faces towards the inlet.

19. The dosing and mixing arrangement of claim 13 , wherein at least a portion of the non-louvered region faces away from the inlet.

20. The dosing and mixing arrangement of claim 13 , wherein an area of the louvered region extends over 270° of the circumferential surface of the tube body.

21. The mixing tube arrangement of claim 1 , wherein the slotted region extends over a majority of an axial length of the mixing tube.

Assignees

• Donaldson Co Inc

Inventors

• Whitten Matthew S
• Hoppenstedt Bruce Bernard

Classifications

• F01N3/035

  with catalytic reactors · CPC title

• F01N1/088

  using vanes arranged on the flow path or flow tubes with tangentially directed apertures · CPC title

• F01N13/009

  having two or more separate purifying devices arranged in series · CPC title

• F01N2240/20

  a flow director or deflector · CPC title

• F01N2470/18

  the axis of inlet or outlet tubes being other than the longitudinal axis of apparatus · CPC title