Regeneration device having external check valve

• US 20080209895A1
• Filed: 02/27/2008
• Published: 09/04/2008
• Est. Priority Date: 03/02/2007
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Miller, Robert L., Wiley, Stephen M., Cox, Glenn B., McClure, Thomas Randall
• Granted Patent: US 8,215,100 B2
• Time in Patent Office: Days
• US Class Current: 60/295
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/03 the substance being hydrocarbons, e.g. engine fuel
• CPC Class Codes: F01N 2610/14 Arrangements for the supply of substances, e.g. conduits
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 2610/1473 Overflow or return means for the substances, e.g. conduits or valves for the return path
• CPC Class Codes: F01N 3/0253 adding fuel to exhaust gases
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An exhaust treatment device for a combustion system is disclosed. The exhaust treatment device may have a housing, and an injector disposed within the housing to deliver an injection fluid into a flow of exhaust. The exhaust treatment device may also have at least one fluid supply passage that is disposed within the housing and being in fluid communication with the injector to supply the injector with injection fluid. The exhaust treatment device may further have at least one purge passage disposed within the housing and in fluid communication with the injector to supply the injector with a purge fluid. The exhaust treatment device may additionally have a first valve element that is mounted to the housing and disposed at an entrance of the at least one purge passage The first valve element may be configured to provide a unidirectional flow of purge fluid to the at least one purge passage.

Claims

1. An exhaust treatment device, comprising:

a housing;

an injector disposed within the housing to deliver an injection fluid into a flow of exhaust;

at least one fluid supply passage disposed within the housing and being in fluid communication with the injector to supply the injector with injection fluid;

at least one purge passage disposed within the housing and being in fluid communication with the injector to supply the injector with a purge fluid; and

a first valve element mounted to the housing and being disposed at an entrance of the at least one purge passage, the first valve element being configured to provide a unidirectional flow of purge fluid to the at least one purge passage.

2. The exhaust treatment device of claim 1, wherein an upstream side of the first valve element is only exposed to purge fluid, and a downstream side of the first valve element is periodically exposed to injection fluid and purge fluid.

3. The exhaust treatment device of claim 1, wherein the at least one purge passage is in fluid communication with the injector via the at least one fluid supply passage.

4. The exhaust treatment device of claim 3, wherein the at least one fluid supply passage includes a pilot supply passage and a main supply passage.

5. The exhaust treatment device of claim 4, wherein a pressure of the injection fluid in the pilot supply passage is almost always greater than a pressure of the injection fluid in the main supply passage.

6. The exhaust treatment device of claim 4, wherein the at least one purge passage branches to a pilot purge passage in fluid communication with the pilot supply passage, and to a main purge passage in fluid communication with the main supply passage, and the first valve element is disposed upstream of the pilot and main purge passages.

7. The exhaust treatment device of claim 6, further including a second valve element disposed within the pilot purge passage to allow a flow of purge fluid into the pilot supply passage, to prevent a flow of injection fluid from the pilot supply passage into the pilot purge passage, and to prevent a flow of injection fluid from the pilot purge passage into the pilot supply passage.

8. The exhaust treatment device of claim 7, wherein the second valve element is fixedly connected to the housing.

9. The exhaust treatment device of claim 6, wherein the pilot purge passage is oriented substantially orthogonal to the main purge passage.

10. The exhaust treatment device of claim 6, wherein the pilot and main purge passages are each periodically filled with injection fluid and purge fluid.

11. The exhaust treatment device of claim 1, wherein the first valve element is removably connected to an entrance port of the housing.

12. The exhaust treatment device of claim 11, further including an adapter fixedly receiving the first valve element and being removably connected to the entrance port.

13. The exhaust treatment device of claim 11, wherein the adapter is corrosion resistant.

14. A method of operating an exhaust treatment device, comprising:

supplying injection fluid to the exhaust treatment device;

separately supplying purge fluid to the exhaust treatment device in parallel relation to the supply of injection fluid; and

ensuring a unidirectional flow of purge fluid into the exhaust treatment device to purge the exhaust treatment device of injection fluid.

15. The method of claim 14, wherein all purge fluid within the exhaust treatment device is periodically replaced with injection fluid.

16. The method of claim 14, wherein supplying injection fluid includes directing a pilot flow of injection fluid and a main flow of injection fluid into the exhaust treatment device in parallel relation.

17. The method of claim 16, wherein a pressure of the pilot flow of injection fluid is almost always greater than a pressure of the main flow of injection fluid.

18. The method of claim 17, further including allowing the unidirectional flow of purge fluid to branch to a pilot flow of purge fluid directed to force the pilot flow of injection fluid from the exhaust treatment device, and to a main flow of pilot fluid directed to force the main flow of injection fluid from the exhaust treatment device.

19. The method of claim 18, further including allowing a portion of the pilot flow of injection fluid to join the main flow of injection fluid, and preventing any of the main flow of injection fluid from joining the pilot flow of injection fluid.

20. An exhaust treatment system configured to receive a flow of exhaust, comprising:

a particulate trap configured to remove particulates from the flow of exhaust; and

a regeneration device configured to periodically initiate regeneration of the particulate trap, the regeneration device including;

a supply of fuel;

a supply of purge air;

an injector configured to selectively inject fuel into the flow of exhaust; and

a housing disposed to receive in parallel, fluid fuel and air from the supplies of fuel and purge air and being configured to house the injector, the housing including;

a pilot supply passage fluidly communicating the supply of fuel with the injector;

a main supply passage fluidly communicating the supply of fuel with the injector at a pressure lower than the pressure of fuel within the pilot supply passage;

a purge passage fluidly communicating the supply of purge air with the pilot and main supply passages; and

a first check valve mounted to the housing at an inlet purge port between the supply of purge air and the purge passage, the first check valve being configured to provide a unidirectional flow of purge air into the housing.

21. The exhaust treatment system of claim 20, wherein an upstream side of the first check valve is only exposed to purge air, and a downstream side of the first check valve is periodically exposed to fuel and purge air.

22. The exhaust treatment system of claim 20, wherein the purge passage branches to a pilot purge passage in fluid communication with the pilot supply passage, and to a main purge passage in fluid communication with the main supply passage, wherein the first check valve is disposed upstream of the pilot and main purge passages.

23. The exhaust treatment system of claim 22, further including a second check valve disposed within the pilot purge passage to allow a flow of purge air into the pilot supply passage and to prevent a flow of fuel from the pilot purge passage into the pilot supply passage.

24. The exhaust treatment system of claim 23, wherein the second check valve also prevents a flow of fuel from the pilot supply passage into the main supply passage via the pilot and main purge passages.

25. The exhaust treatment system of claim 23, wherein the second check valve is fixedly connected to the housing.

26. The exhaust treatment system of claim 22, wherein the pilot and main purge passages are each periodically filled with fuel.

27. The exhaust treatment system of claim 20, further including an adapter fixedly receiving the first check valve and being removably connected to the to the inlet purge port.

28. The exhaust treatment system of claim 27, wherein the adapter is corrosion resistant.