Wet scrubbing apparatus for controlling NOx emission

• US 7,534,400 B2
• Filed: 03/28/2007
• Issued: 05/19/2009
• Est. Priority Date: 07/09/2003
• Status: Active Grant

• Current Assignee: Belco Technologies Corporation (Corteva, Inc.)
• Original Assignee: Belco Technologies Corporation (Corteva, Inc.)
• Inventors: Morin, Andrew, Hsieh, Joseph, Philibert, Dominique, Gilman, Kevin R., Eagleson, Scott
• Primary Examiner(s): Johnson; Edward M
• Application Number:
  US11/729,545
• Publication Number:
  US 20070189949A1
• Time in Patent Office: 783 Days
• Field of Search: 422/168, 422/169, 422/182, 423/235, 423/239.1
• US Class Current: 422/182
• CPC Class Codes: B01D 2251/104 Ozone
• CPC Class Codes: B01D 2257/402 Dinitrogen oxide
• CPC Class Codes: B01D 2257/404 Nitrogen oxides other than dinitrogen oxide
• CPC Class Codes: B01D 53/56 Nitrogen oxides B01D53/60 takes precedence
• CPC Class Codes: B01D 53/79 Injecting reactants
• CPC Class Codes: Y02C 20/10 of nitrous oxide (N2O)

Abstract

An apparatus for controlling NOx emissions which includes a chamber having a wall surface and an interior, a flue gas entrance and a flue gas exit for a flue gas to enter and exit the interior of the chamber, a gas quenching zone in which the temperature of the gas can be lowered, an ozone injection and retention zone in the chamber, and a liquid spray zone including at least one spray nozzle for spraying a liquid towards the wall surface.

Claims

1. An apparatus for controlling NOx emissions comprising:

a chamber having a wall surface and an interior;

a flue gas entrance and a flue gas exit for a flue gas to enter and exit said interior of said chamber;

a gas quenching zone in which the temperature of the gas can be lowered;

an ozone injection and retention zone in said chamber; and

a liquid spray zone including at least one spray nozzle for spraying a liquid towards the wall surface so that a portion of said ozone injection and retention zone is substantially free of liquid droplets.

2. An apparatus according to claim 1, further including:

an ozone supply;

an ozone injection nozzle to inject a predetermined amount of ozone into said ozone injection and retention zone;

a liquid supply in said liquid spray zone;

a gas quenching liquid supply; and

at least one gas quenching nozzle.

3. An apparatus according to claim 2, wherein said liquid spray zone is located above said ozone injection and retention zone, and said flue gas entrance is below said liquid spray zone.

4. An apparatus according to claim 2, wherein said liquid spray zone of said apparatus is located below said ozone injection and retention zone, and said flue gas entrance and said gas quenching zone are above said liquid spray zone.

5. An apparatus according to claim 2, wherein said liquid comprises a calcium, magnesium, or sodium reagent.

6. An apparatus according to claim 2, wherein said flue gas is quenched to a temperature of below 200°

F. in said gas quenching zone.

7. An apparatus according to claim 2, wherein said gas quenching nozzle sprays a liquid towards the wall surface, so that a portion of said ozone injection and retention zone is substantially free of liquid droplets.

20. An apparatus according to claim 2, wherein said apparatus has a height ranging from 50-120 feet, and a diameter ranging from 1-50 feet.

21. An apparatus according to claim 1, wherein said apparatus includes three spray nozzles.

22. An apparatus according to claim 2, wherein said apparatus has a liquid to gas ratio ranging from 5-80 gallons per 1000 feet³ of gas flow.

23. An apparatus according to claim 2, wherein said flue gas travels through said apparatus at a rate ranging from 3-26 feet/second.

24. An apparatus according to claim 2, wherein said apparatus has a percentage of NOx removal greater than or equal to 50%.

25. An apparatus according to claim 2, wherein said liquid supply includes a liquid comprising a chemical and water solution, and said liquid has a pH ranging from 5.5-7.5 pH.

8. An apparatus for controlling NOx emissions comprising:

a chamber having a wall surface and an interior;

a flue gas entrance and a flue gas exit for a flue gas to enter and exit said interior of said chamber;

a gas quenching zone in which the temperature of the gas can be lowered;

an ozone injection and retention zone in said chamber; and

a liquid spray zone in said chamber,

said gas quenching zone including at least one spray nozzle for spraying a liquid towards the wall surface, so that a portion of said ozone injection and retention zone is substantially free of liquid droplets.

9. An apparatus according to claim 8, further including:

an ozone supply;

an ozone injection nozzle to inject a predetermined amount of ozone into said ozone injection and retention zone;

a liquid supply in said liquid spray zone;

a gas quenching liquid supply; and

at least one gas quenching nozzle.

10. An apparatus according to claim 9, wherein said liquid spray zone is located above said ozone injection and retention zone, and said flue gas entrance is below said liquid spray zone.

11. An apparatus according to claim 9, wherein said liquid spray zone of said apparatus is located below said ozone injection and retention zone, and said flue gas entrance and said gas quenching zone are above said liquid spray zone.

12. An apparatus according to claim 9, wherein said flue gas is quenched to a temperature of below 200°

F. in said gas quenching zone.

13. An apparatus according to claim 9, wherein said gas quenching nozzle sprays a liquid towards the wall surface, so that said ozone and injection and retention zone is substantially free of liquid droplets.

14. A combustion system comprising:

a boiler; and

an apparatus for controlling NOx emissions comprising;

a chamber having a wall surface and an interior;

a flue gas entrance and a flue gas exit for a flue gas to enter and exit said interior of said chamber;

a gas quenching zone in which the temperature of the gas can be lowered;

an ozone injection and retention zone in said chamber; and

a liquid spray zone including at least one spray nozzle for spraying a liquid towards the wall surface so that a portion of said ozone injection and retention zone is substantially free of liquid droplets.

15. An apparatus according to claim 14, further including:

an ozone supply;

an ozone injection nozzle to inject a predetermined amount of ozone into said ozone injection and retention zone;

a liquid supply in said liquid spray zone;

a gas quenching liquid supply; and

at least one gas quenching nozzle.

16. An apparatus according to claim 15, wherein said liquid spray zone is located above said ozone injection and retention zone, and said flue gas entrance is below said liquid spray zone.

17. An apparatus according to claim 15, wherein said liquid spray zone of said apparatus is located below said ozone injection and retention zone, and said flue gas entrance and said gas quenching zone are above said liquid spray zone.

18. An apparatus according to claim 15, wherein said gas quenching nozzle sprays a liquid towards the wall surface, so that a portion of said ozone injection and retention zone is substantially free of liquid droplets.

26. An apparatus according to claim 14, wherein said liquid comprises a calcium, magnesium, or sodium reagent.

27. An apparatus according to claim 14, wherein said apparatus has a height ranging from 50-120 feet tall and a diameter ranging from 1-50 feet.

28. An apparatus according to claim 15, wherein said apparatus has a liquid to gas ratio ranging from 5-80 gallons per 1000 feet³ of gas flow, and said liquid supply includes a liquid comprising a chemical and water solution and having a pH ranging from 5.5-7.5 pH.

29. An apparatus according to claim 14, wherein said flue gas travels through said apparatus at a rate ranging from 3-26 feet/second and said apparatus has a percentage of NOx removal greater than or equal to 60%.

30. A combustion system according to claim 14, further comprising a stack.

19. A combustion system comprising:

a boiler; and

an apparatus for controlling NOx emissions comprising;

a chamber having a wall surface and an interior;

a flue gas entrance and a flue gas exit for a flue gas to enter and exit said interior of said chamber;

a gas quenching zone in which the temperature of the gas can be lowered;

an ozone injection and retention zone in said chamber; and

a liquid spray zone in said chamber,

said gas quenching zone including at least one spray nozzle for spraying a liquid towards the wall surface so that a portion of said ozone injection and retention zone is substantially free of liquid droplets.