MIXING DEVICES FOR SELECTIVE CATALYTIC REDUCTION SYSTEMS

• US 20100132345A1
• Filed: 12/01/2008
• Published: 06/03/2010
• Est. Priority Date: 12/01/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Kasa, Venkata Subbareddy, Joshi, Chandrashekhar, Solbrig, Charles E., El Tahry, Sherif H.
• Granted Patent: US 9,429,058 B2
• Time in Patent Office: Days
• US Class Current: 60/301
• CPC Class Codes: B01F 23/2132 using nozzles
• CPC Class Codes: B01F 25/25 Mixing by jets impinging against collision plates
• CPC Class Codes: B01F 25/3141 with additional mixing means other than injector mixers
• CPC Class Codes: B01F 25/4315 the baffles being deformed flat pieces of material B01F25/4314 takes precedence
• CPC Class Codes: F01N 2240/20 a flow director or deflector
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• 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 selective catalytic reduction (SCR) system includes an exhaust pipe for receiving an exhaust gas from an engine. A selective catalytic reduction (SCR) unit is provided downstream of the exhaust pipe. A first mixing element including a meshed body defines a first surface, a second surface, and a plurality of openings extending from the first surface to the second surface. The first surface and second surface are parallel to each other and define an angle relative to a flow direction of the exhaust flow. The angle is less than 90 degrees.

Claims

1. A selective catalytic reduction (SCR) system comprising:

an exhaust pipe for receiving an exhaust gas from an engine;

a selective catalytic reduction (SCR) unit provided downstream of the exhaust pipe; and

a first mixing element including a meshed body that defines a first surface, a second surface, and a plurality of openings extending from the first surface to the second surface,

wherein the first surface and the second surface are parallel to each other and define an angle relative to a flow direction of the exhaust gas, the angle being less than 90 degrees.

2. The SCR system of claim 1 wherein the angle is between 0 and 60 degrees.

3. The SCR system of claim 1 wherein the first surface and the second surface are parallel to the flow direction of the exhaust gas.

4. The SCR system of claim 1 wherein the meshed body has a plate-like configuration.

5. The SCR system of claim 1 wherein the plurality of openings are perpendicular to the first surface and the second surface of the meshed body.

6. The SCR system of claim 1 wherein the first mixing element further comprises a plurality of tabs extending outwardly from one of the first surface and the second surface.

7. The SCR system of claim 6 wherein the plurality of tabs are spaced evenly on the one of the first surface and the second surface.

8. The SCR system of claim 6 wherein the plurality of tabs are arranged alternately along the plurality of openings.

9. The SCR system of claim 6 wherein the plurality of tabs include a plurality of upper tabs extending upwardly from the first surface and a plurality of lower tabs extending downwardly from the second surface, the upper tabs and the lower tabs extending in opposite directions.

10. The SCR system of claim 1 further comprising a second mixing element arranged in the exhaust pipe and spaced apart from the first mixing element, wherein the second mixing element has a meshed body, and wherein the meshed body defines a first surface, a second surface and a plurality of openings extending between the first surface and the second surface.

11. The SCR system of claim 10 wherein the plurality of openings of the second mixing element are parallel to the plurality openings of the first mixing element.

12. The SCR system of claim 11 wherein the second mixing element is spaced apart from the first mixing element along a thickness direction of the first mixing element.

13. The SCR system of claim 10 wherein the second mixing element is provided downstream of the first mixing element.

14. The SCR system of claim 13 wherein the plurality of openings of the second mixing element extend in a direction parallel to the flow direction.

15. The SCR system of claim 1 wherein a distance between the first meshed body and a wall of the exhaust pipe varies depending on a structure of the mixing device.

16. A mixing device provided in an exhaust pipe upstream of a selective catalyst reduction (SCR) system comprising:

a first meshed body defining a first surface, a second surface, and a plurality of openings extending from the first surface to the second surface, wherein the first surface and the second surface are parallel and define an angle relative to a flow direction of an exhaust gas, the angle being less than 90 degrees; and

a plurality of tabs extending outwardly from at least one of the first surface and the second surface.

17. The mixing device of claim 16 wherein the plurality of tabs are spaced evenly on the meshed body.

18. The mixing device of claim 17 further comprising a second meshed body spaced apart from the first meshed body, wherein the second meshed body defines a first surface, a second surface, and a plurality of openings extending between the first surface and the second surface.

19. The mixing device of claim 18 wherein the plurality of openings of the first meshed body and the plurality of openings of the second meshed body are parallel.

20. The mixing device of claim 18 wherein the second meshed body is provided downstream of the first meshed body and the plurality of the openings of the second meshed body extend along a direction parallel to the flow direction.