| Sonstiges: |
- Nachgewiesen in: USPTO Patent Grants
- Sprachen: English
- Patent Number: 11927,345
- Publication Date: March 12, 2024
- Appl. No: 16/806578
- Application Filed: March 02, 2020
- Claim: 1. A device for reducing emissions of nitrogen oxides and for increasing heat transfer in a fired process heater, said fired process heater comprising a radiant section having a plurality of process tubes and a burner, said device comprising: a fuel and flue gas entrainment unit positioned remote from the burner of the fired process heater, the entrainment unit comprising: a fluid outlet, a fluid inlet, and a fluid flow path intermediate of said fluid inlet and said fluid outlet; said entrainment unit fluid outlet configured to attach to said fired process heater upstream of one or more convection tubes such that said entrainment unit fluid flow path is in fluid communication with said radiant section of said fired process heater; an inlet section of reducing diameter, a mixing section of constant diameter, and an exit section of expanding diameter; a fuel injector configured to issue fuel at subsonic, sonic, or supersonic velocity into said entrainment unit fluid flow path, wherein the fuel is entrained with flue gas from said radiant section of said fired process heater in said entrainment unit fluid flow path to form an entrained flue gas and fuel mixture, which flows through said entrainment unit fluid flow path to said radiant section of said fired process heater; ductwork positioned remote from the burner of the fired process heater, the ductwork comprising a fluid outlet, a fluid inlet, and a fluid flow path intermediate of said fluid inlet and said fluid outlet; said ductwork fluid outlet connected to said entrainment unit fluid inlet such that said ductwork fluid flow path is in fluid communication with said entrainment unit flow path; said ductwork fluid inlet configured to attach to said fired process heater such that said ductwork fluid flow path is in fluid communication with the flue gas from said radiant section of said fired process heater; and wherein the entrainment unit and the ductwork form a closed circuit regarding fluid flow from the radiant section of the fired process heater, through the ductwork fluid flow path, the entrainment unit fluid flow path, and back to the radiant section of the fired process heater.
- Claim: 2. The device of claim 1 wherein said ductwork further comprises an internal lining of refractory material encased in steel, an internal high-temperature steel lining with external insulation, or both.
- Claim: 3. The device of claim 1 wherein said entrainment unit further comprises a fluid injector configured to issue a reagent fluid at subsonic, sonic, or supersonic velocity into said entrainment unit fluid flow path wherein the reagent fluid is mixed with the flue gas from said radiant section of said fired process heater and the fuel from the fuel injector.
- Claim: 4. The device of claim 3 wherein said reagent fluid is steam, ammonia, urea or a mixture thereof.
- Claim: 5. The device of claim 1 wherein said entrainment unit further comprises an interior core of heat resistant material and an exterior casing of steel, an interior of heat resistant steel encased with external insulation, or both.
- Claim: 6. The device of claim 1 wherein said entrainment unit further comprises a thermocouple downstream of said fuel injector, a zirconia oxygen sensor downstream of said fuel injector, a tunable diode laser downstream of said fuel injector, or a combination thereof.
- Claim: 7. The device of claim 1 wherein said entrainment unit, said ductwork or both further comprise a hot-wire anemometer.
- Claim: 8. The device of claim 1 further comprising a venturi eductor configured to attached to said entrainment unit fluid outlet and further configured to attach to said radiant section of said fired process heater.
- Claim: 9. The device of claim 8 wherein said venturi eductor further comprises a fluid outlet, a fluid inlet and a fluid flow path intermediate of said fluid inlet and said fluid outlet, said venturi eductor fluid inlet connected to said entrainment unit fluid outlet such that said venturi eductor fluid flow path is in fluid communication with said entrainment unit flow path.
- Claim: 10. The device of claim 9 wherein said venturi eductor is configured to use a secondary fluid to increase the fluid flow of the entrained flue gas and fuel mixture through said flue gas entrainment unit.
- Claim: 11. The device of claim 10 wherein said secondary fluid is steam.
- Claim: 12. The device of claim 8 wherein said venturi eductor has an inlet section of reducing diameter, a mixing section of constant diameter, and an exit section of expanding diameter.
- Claim: 13. The device of claim 8 wherein said venturi eductor further comprises a fluid injector configured to issue a reagent fluid at subsonic, sonic, or supersonic velocity into said fluid flow path of said venturi eductor.
- Claim: 14. The device of claim 13 wherein said reagent fluid is steam, ammonia, urea or a mixture thereof.
- Claim: 15. A device for reducing emissions of nitrogen oxides and for increasing heat transfer in a fired process heater, said fired process heater comprising a radiant section having a plurality of process tubes and a burner, said device comprising: a fuel and flue gas entrainment unit positioned remote from the burner of the fired process heater, the entrainment unit comprising a fluid outlet, a fluid inlet and a fluid flow path intermediate of said fluid inlet and said fluid outlet; said entrainment unit further comprising an inlet section of reducing diameter, a mixing section of constant diameter, and an exit section of expanding diameter; wherein fuel is entrained with flue gas from the radiant section of the fired process heater in the fluid flow path of the entrainment unit to form an entrained flue gas and fuel mixture, which flows from the fluid outlet of the entrainment unit to a fluid inlet of a venturi eductor; ductwork positioned remote from the burner of the fired process heater, the ductwork comprising a fluid outlet, a fluid inlet and a fluid flow path intermediate of said fluid inlet and said fluid outlet; said ductwork fluid outlet connected to said entrainment unit fluid inlet such that said ductwork fluid flow path is in fluid communication with said entrainment unit flow path; said ductwork fluid inlet configured to attach to said fired process heater such that said ductwork fluid flow path is in fluid communication with the flue gas from said radiant section of said fired process heater; the venturi eductor comprising a fluid outlet, the fluid inlet and a fluid flow path intermediate of said fluid inlet and said fluid outlet; said venturi eductor fluid inlet connected to said entrainment unit fluid outlet such that said venturi eductor fluid flow path is in fluid communication with said entrainment unit fluid flow path; said venturi eductor fluid outlet attached to said fired process heater upstream of a plurality of convection tubes such that said venturi eductor fluid flow path is in fluid communication with said radiant section of said fired process heater; said venturi eductor comprising an inlet section of reducing diameter, a mixing section of constant diameter, and an exit section of expanding diameter; said venturi eductor configured to use a secondary fluid to increase the fluid flow through said flue gas entrainment unit; wherein the entrained flue gas and fuel mixture and the secondary fluid flow from the fluid outlet of the venturi eductor to the radiant section of the fired process heater; and wherein the entrainment unit, the ductwork, and the venturi eductor form a closed circuit regarding fluid flow from the radiant section of the fired process heater, through the ductwork fluid flow path, the entrainment unit fluid flow path, and the venturi eductor fluid flow path, and back to the radiant section of the fired process heater.
- Claim: 16. The device of claim 15 wherein said ductwork further comprises an internal lining of refractory material encased in steel, an internal high-temperature steel lining with external insulation, or both.
- Claim: 17. The device of claim 15 wherein said secondary fluid is steam, ammonia, urea or a mixture thereof.
- Claim: 18. The device of claim 15 wherein said entrainment unit, said venturi eductor or both further comprise an interior core of heat resistant material and an exterior casing of steel, an interior of heat resistant steel encased with external insulation, or both.
- Claim: 19. The device of claim 15 wherein said entrainment unit further comprises a thermocouple downstream of said fuel injector, a zirconia oxygen sensor downstream of said fuel injector, a tunable diode laser downstream of said fuel injector, or a combination thereof.
- Claim: 20. The device of claim 15 wherein said entrainment unit, said ductwork or both further comprise a hot-wire anemometer.
- Claim: 21. The device of claim 15 wherein said entrainment unit, said venturi eductor or both further comprise a fluid injector configured to issue a reagent fluid at subsonic, sonic, or supersonic velocity into said entrainment unit fluid flow path or said venturi eductor fluid flow path, respectively.
- Claim: 22. The device of claim 21 wherein said reagent fluid is ammonia, urea or a mixture thereof.
- Claim: 23. A fired process heater comprising a radiant section having a plurality of process tubes and a burner, said fired process heater further comprising the device of claim 1 .
- Claim: 24. A fired process heater comprising a radiant section having a plurality of process tubes and a burner, said fired process heater further comprising the device of claim 15 .
- Patent References Cited: 2270637 January 1942 Komar ; 3807321 April 1974 Stockman ; 4296921 October 1981 Hayashi ; 4475472 October 1984 Adrian ; 4995807 February 1991 Rampley ; 5135387 August 1992 Martin et al. ; 5165884 November 1992 Martin et al. ; 5316469 May 1994 Martin et al. ; 6015540 January 2000 McAdams et al. ; 6383461 May 2002 Lang ; 6383462 May 2002 Lang ; 6609907 August 2003 Wood ; 6796789 September 2004 Gibson et al. ; 7153129 December 2006 Bussman et al. ; 7172412 February 2007 Platvoet et al. ; 20030175640 September 2003 Stephens ; 20030234009 December 2003 Kennedy ; 20050061378 March 2005 Foret ; 20140080072 March 2014 Smirnov ; 20170336123 November 2017 Dodson ; 786962 November 1957 ; 1259351 January 1972 ; 2000065316 March 2000 ; 2005231984 September 2005 ; 0169132 September 2001 ; 2010036372 April 2010
- Other References: He, Yu , “Flameless Combustion of Natural Gas in the SJ/WJ Furnace”, Apr. 2008, pp. 1-213 Publisher: Queens University, Kingston, Ontario, Canada. cited by applicant ; Wunning, J , “Flameless Oxidation”, Oct. 17-19, 2005, Publisher: 6th HITACG Symposium—2005, pp. 1-13, Essen, Germany. cited by applicant ; International Search Report and Written Opinion PCT/US2023/061912 dated Jul. 14, 2023. cited by applicant
- Primary Examiner: Lau, Jason
- Attorney, Agent or Firm: Crowe & Dunlevy, P.C.
|
