Claims
- 1. A method for removing sulfur dioxide from a sulfur dioxide-containing flue gas comprising:
- injecting small particles of an aqueous dispersion of material selected from the group consisting of pressure hydrated lime and pressure hydrated dolomitic lime into a confined zone within a flue gas stream flowing in a duct in an amount sufficiently large to reduce the sulfur dioxide content of said flue gas to a level equivalent to between 10% and 90% of the original sulfur dioxide content but sufficiently small so that the aqueous dispersion is completely dried within within the confined zone, in a stoichiometric ratio to said sulfur dioxide of not larger than 1.5, wherein said confined zone is spaced-apart from the inside walls of the duct and completely dry.
- 2. A method as set forth in claim 1, wherein said gas is contacted with the material dispersion in the boiler outlet ducting of a boiler.
- 3. A method as set forth in claim 1, wherein said gas is contacted with the material dispersion in the inlet of an electrostatic precipitator.
- 4. A method as set forth in claim 1, wherein said confined zone is defined by a surrounding slip zone of the flue gas in the flue duct.
- 5. A method as set forth in claim 1, wherein the aqueous dispersion has at least about five weight percent solids.
- 6. A method as set forth in claim 1, wherein said aqueous dispersion is atomized with a rotary atomizer.
- 7. A method as set forth in claim 1, wherein the aqueous dispersion is atomized with a piezo-electric driven nozzle.
- 8. A method as set forth in claim 1, wherein the aqueous dispersion is atomized in successive places in the flue gas stream.
- 9. A method as set forth in claim 1, wherein the aqueous dispersion is atomized with a pressurized gas.
- 10. A method as set forth in claim 9, wherein said gas is compressed air.
- 11. A method for removing sulfur dioxide from a sulfur dioxide-containing flue gas stream flowing within a duct, said method comprising axially spraying an aqueous slurry of a sulfur-dioxide scavenger selected from the group consisting of pressure hydrated lime and pressure hydrated dolomitic lime near the center of the duct so that absorption occurs and the aqueous slurry is completely dried within a confined dispersion zone spaced apart from the inside walls of the duct.
- 12. A method as in claim 11, wherein the stoichiometric ratio of scavenger to sulfur dioxide is in the range from 1.0 to 1.5.
- 13. A method as in claim 11, wherein the duct is an inlet to an electrostatic precipitator.
Parent Case Info
This is a continuation-in-part of application Ser. No. 474,226, filed Mar. 11, 1983, now abandoned, which was a continuation-in-part of application Ser. No. 349,728, filed Feb. 18, 1982, now U.S. Pat. No. 4,388,283, the latter application being a continuation-in-part of application Ser. No. 181,315, filed Aug. 25, 1980, now abandoned, the last-mentioned application being a continuation of application Ser. No. 000,406, filed Jan. 2, 1979, now U.S. Pat. No. 4,426,245, all of which disclosures are incorporated herein by reference.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
55-81722 |
Jun 1980 |
JPX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
406 |
Jan 1979 |
|
Continuation in Parts (3)
|
Number |
Date |
Country |
Parent |
474226 |
Mar 1983 |
|
Parent |
349728 |
Feb 1982 |
|
Parent |
181315 |
Aug 1980 |
|