Exhaust gas mixing system

• US 7,581,387 B2
• Filed: 02/28/2005
• Issued: 09/01/2009
• Est. Priority Date: 02/28/2005
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Thirunavukarasu, Balamurugesh, Biswas, Subodh Chandra, Bui, Yung T.
• Primary Examiner(s): NGUYEN, TU MINH
• Application Number:
  US11/066,474
• Publication Number:
  US 20060191254A1
• Time in Patent Office: 1,646 Days
• Field of Search: 602/74, 602/86, 602/95, 603/01, 603/03, 603/24, 422/182, 422/183, 423/212, 423/235, 423/239.1
• US Class Current: 60/286
• CPC Class Codes: B01F 23/2132 using nozzles
• CPC Class Codes: B01F 25/3131 with additional mixing means other than injector mixers, e.g. screens, baffles or rotating elements
• CPC Class Codes: B01F 25/31331 Perforated, multi-opening, with a plurality of holes
• CPC Class Codes: B01F 25/4316 the baffles being flat pieces of material, e.g. intermeshing, fixed to the wall or fixed on a central rod
• CPC Class Codes: B01F 25/43161 composed of consecutive sections of flat pieces of material
• CPC Class Codes: B01F 25/431971 Mounted on the wall
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2240/20 a flow director or deflector
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 3/101 Three-way catalysts
• CPC Class Codes: F01N 3/103 Oxidation catalysts for HC and CO only
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 3/2892 Exhaust flow directors or the like, e.g. upstream of catalytic device
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A system for mixing exhaust gas components is provided. The system may include an exhaust passage and a substantially enclosed distribution chamber disposed within the exhaust passage. The distribution chamber may include an outer wall defining a chamber volume and at least one opening disposed in the outer wall configured to provide fluid communication between the chamber volume and the exhaust passage. An additive supply device may be configured to supply at least one exhaust gas additive to the chamber volume.

Claims

1. A method for mixing exhaust gas components, comprising:

supplying exhaust gas to an exhaust passage;

mixing the exhaust gas with at least one additive by supplying the at least one additive to a substantially enclosed distribution chamber disposed within the exhaust passage; and

further mixing the exhaust gas by deflecting peripherally flowing exhaust gases using two or more sets of mixing vanes disposed downstream of the distribution chamber, wherein the vanes are disposed about a periphery of the exhaust passage and include a central opening, and wherein the vanes of each set of mixing vanes are approximately evenly spaced about the periphery of the exhaust passage, and a first set of mixing vanes is angularly-offset with respect to a second set of mixing vanes positioned downstream of the first set of mixing vanes.

2. The method of claim 1, wherein the distribution chamber includes:

an outer wall defining a chamber volume; and

at least one opening disposed in the outer wall and configured to provide fluid communication between the chamber volume and the exhaust passage.

3. The system of claim 1, wherein the two or more sets of mixing vanes each include the same number of vanes.

4. The method of claim 1, wherein the exhaust gas additive includes ammonia.

5. The method of claim 1, wherein the exhaust gas additive includes urea.

6. The method of claim 1, wherein the at least one opening includes a plurality of holes.

7. The method of claim 1, wherein the two or more sets vanes includes two sets of vanes and the first set of vanes is angularly offset with respect to the second set of vanes.

8. The method of claim 1, further including exposing at least a portion of the exhaust gas and at least one additive to a catalyst.

9. The method of claim 8, wherein the catalyst includes a selective catalytic reduction system catalyst.

11. The system of claim 1, wherein the exhaust gas additive includes ammonia.

10. A system for mixing exhaust gas components, comprising:

an exhaust passage;

a substantially enclosed distribution chamber disposed within the exhaust passage and including;

an outer wall defining a chamber volume;

at least one opening disposed in the outer wall configured to provide fluid communication between the chamber volume and the exhaust passage;

an additive supply device configured to supply at least one exhaust gas additive to the chamber volume; and

two or more sets of mixing vanes disposed downstream of the distribution chamber, wherein the vanes are disposed about a periphery of the exhaust passage and include a central opening, and wherein the vanes of each set of mixing vanes are approximately evenly spaced about the periphery of the exhaust passage, and a first set of mixing vanes is angularly offset with respect to a second set of mixing vanes positioned downstream of the first set of mixing vanes.

12. The system of claim 10, wherein the exhaust gas additive includes urea.

13. The system of claim 10, wherein the distribution chamber includes a substantially cylindrical shape.

14. The system of claim 10, wherein the exhaust gas pressure drop across the system is less than one inch of water.

15. The system of claim 10, wherein the at least one opening includes a plurality of holes.

16. The system of claim 10, wherein the two or more sets of vanes includes two sets of vanes and the first set of vanes is angularly offset with respect to the second set of vanes.

17. The method of claim 10, wherein the two or more sets of mixing vanes each include the same number of vanes.

18. The system of claim 17, wherein the two or more sets of vanes each include between three and five vanes.

19. The system of claim 10, further including at least one catalyst disposed downstream of the distribution chamber.

20. The system of claim 19, wherein the catalyst includes a selective catalytic reduction system catalyst.

21. A machine, comprising:

an engine;

an exhaust passage configured to receive an exhaust gas stream produced by the engine;

an exhaust gas mixing system, including;

a substantially enclosed distribution chamber disposed within the exhaust passage and including;

an outer wall defining a chamber volume;

at least one opening disposed in the outer wall configured to provide fluid communication between the chamber volume and the exhaust passage;

an additive supply device configured to supply at least one exhaust gas additive to the chamber volume; and

two or more sets of mixing vanes disposed downstream of the distribution chamber, wherein the vanes are disposed about a periphery of the exhaust passage and include a central opening, and wherein the vanes of each set of mixing vanes are approximately evenly spaced about the periphery of the exhaust passage, and a first set of mixing vanes is angularly offset with respect to a second set of mixing vanes positioned downstream of the first set of mixing vanes.

22. The machine of claim 21, wherein the additive supply device is configured to supply at least one of urea and ammonia to the chamber volume.

23. The machine of claim 21, wherein the machine includes a generator set.

24. The machine of claim 21, wherein the two or more sets vanes includes two sets of vanes and the first set of vanes is angularly offset with respect to the second set of vanes.

25. The machine of claim 21, further including at least one catalyst disposed downstream of the exhaust gas mixing system.

26. The machine of claim 25, wherein the at least one catalyst includes a selective catalytic reduction system catalyst.