Exhaust treatment system

• US 7,762,060 B2
• Filed: 04/28/2006
• Issued: 07/27/2010
• Est. Priority Date: 04/28/2006
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Strauser, Aaron D., Easley, William L. Jr., Driscoll, James J., Verkiel, Maarten, Robel, Wade J.
• Primary Examiner(s): Tran; Binh Q
• Application Number:
  US11/412,883
• Publication Number:
  US 20070251216A1
• Time in Patent Office: 1,551 Days
• Field of Search: 602/74, 602/85, 602/86, 602/95, 602/97, 603/00, 603/11
• US Class Current: 60/285
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2250/02 filtering and catalytic conversion
• CPC Class Codes: F01N 2430/00 Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
• CPC Class Codes: F01N 3/025 using fuel burner or by adding fuel to exhaust
• CPC Class Codes: F01N 3/027 using electric or magnetic heating means
• CPC Class Codes: F01N 3/0821 combined with particulate filters catalysed diesel particulate filters F01N3/035

Abstract

An exhaust treatment system is provided. The system may include a particulate trap configured to remove one or more types of particulate matter from an exhaust flow of an engine. The system may also include a catalyst configured to chemically alter at least one component of the exhaust flow. Further, the system may include an exhaust conduit configured to direct the exhaust flow from the engine to the particulate trap and the catalyst. In addition, the exhaust treatment system may include a heating system configured to maintain the temperature of the catalyst above a first predetermined temperature. The heating system may also be configured to periodically raise the temperature of the particulate trap above a higher, second predetermined temperature to thereby effectuate a regeneration of the particulate trap by oxidizing particulate matter accumulated in the particulate trap.

Claims

1. An exhaust treatment system for an engine, comprising:

a particulate trap configured to remove one or more types of particulate matter from an exhaust flow of an engine;

a catalyst configured to chemically alter at least one component of the exhaust flow;

an exhaust conduit configured to direct the exhaust flow from the engine to the particulate trap and the catalyst; and

a heating system located downstream from the engine and upstream from the catalyst, the heating system being configured to;

maintain the temperature of the catalyst above a first predetermined temperature;

and periodically raise the temperature of the particulate trap above a higher, second predetermined temperature to thereby effectuate a regeneration of the particulate trap by oxidizing particulate matter accumulated in the particulate trap.

2. The system of claim 1, wherein the heating system includes a flame producing burner or an electrical heating element.

7. The system of claim 1, further including a controller configured to control the heating system, the controller being operatively coupled to an indicator configured to indicate a state of the exhaust treatment system.

8. The system of claim 1, wherein the catalyst is positioned downstream from the particulate trap.

9. The system of claim 1, wherein the catalyst is positioned upstream from the particulate trap.

10. The system of claim 1, wherein the catalyst includes a first catalyst positioned upstream from the particulate trap and a second catalyst positioned downstream from the particulate trap.

11. The system of claim 1, wherein the catalyst and the particulate trap are integrated together.

12. The system of claim 1, wherein the catalyst is one of a Selective Catalytic Reduction (SCR) or a Diesel Oxidation Catalyst (DOC).

13. The system of claim 1, wherein the heating system is configured to maintain the temperature of the catalyst within a predetermined range above the first predetermined temperature before and after periodically raising the temperature of the particulate trap.

3. A method for treating an exhaust flow produced by an engine, comprising:

directing the exhaust flow from the engine to a particulate trap configured to remove one or more types of particulate matter from the exhaust flow and to a catalyst configured to chemically alter at least one component of the exhaust flow;

applying heat to the exhaust flow using a heating system located downstream from the engine and upstream from the catalyst, the heating system,

maintaining the temperature of the catalyst above a first predetermined temperature, and

periodically raising the temperature of the particulate trap above a higher, second predetermined temperature to thereby effectuate a regeneration of the particulate trap by oxidizing particulate matter accumulated in the particulate trap.

4. The method of claim 3, wherein the heating system includes a flame producing burner or an electrical heating element.

14. The method of claim 3, wherein the catalyst is positioned upstream from the particulate trap.

15. The method of claim 3, wherein the catalyst is positioned downstream from the particulate trap.

16. The method of claim 3, wherein the catalyst and the particulate trap are integrated together.

17. The method of claim 3, wherein maintaining the temperature of the catalyst includes maintaining the temperature of the catalyst within a predetermined range above the first predetermined temperature before and after the periodic raising of the temperature.

5. A machine, comprising:

a frame;

an exhaust producing engine mounted to the frame;

an exhaust treatment system including;

a particulate trap configured to remove one or more types of particulate matter from an exhaust flow of the engine;

a catalyst configured to chemically alter at least one component of the exhaust flow;

an exhaust conduit configured to direct the exhaust flow from the engine to the particulate trap and the catalyst; and

a heating system located downstream from the engine and upstream from the catalyst, the heating system being configured to;

maintain the temperature of the catalyst above a first predetermined temperature; and

periodically raise the temperature of the particulate trap above a higher, second predetermined temperature to thereby effectuate a regeneration of the particulate trap by oxidizing particulate matter accumulated in the particulate trap.

6. The machine of claim 5, wherein the heating system includes a burner or an electrical heating element.

18. The machine of claim 5, wherein the catalyst is positioned downstream from the particulate trap.

19. The machine of claim 5, wherein the catalyst and the particulate trap are integrated together.

20. The machine of claim 5, wherein the heating system is configured to maintain the temperature of the catalyst within a predetermined range above a first predetermined temperature before and after periodically raising of the temperature of the particulate trap.