Apparatus for elimination of nitrogen oxides from combustion waste gases
Patent 4003711 Issued on January 18, 1977. Estimated Expiration Date: 
January 18, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 18, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2330174 2493218 2913404 2924504 2973326 3032387 3497328 3512925 InventorsAssigneeApplicationNo. 514130 filed on 10/11/1974US Classes:422/178, And contact regenerating means or means for cleaning an internal surface of the reaction chamber422/177, Including solid, extended surface, fluid contact reaction means; e.g., inert Raschig rings, particulate absorbent, particulate or monolithic catalyst, etc.422/216, Compact bed of particulate, fluid contact material and means providing gravity flow of material within bed423/239.1Utilizing solid sorbent, catalyst, or reactantExaminersPrimary: Scovronek, JosephAssistant: Turk, Arnold Attorney, Agent or FirmForeign Application Priority Data1973-10-12 JAAbstractNitrogen oxides (NOx) are removed from combustion waste gases by injecting gas (NH3) into the combustion waste gases in the presence of a metallic catalyst to deoxidize the nitrogen oxides to nitrogen and water, within a reaction tower having the catalysts moving through the reaction tower, so that thereafter the dust may be separated from the catalysts and the catalysts may be regenerated continuously, so that the regenerated catalysts may be returned to the reaction tower. The catalyst moves in a substantially closed path, and preferable downwardly through the reaction tower, with the ammonia gas and combustion waste gases moving in cross current through the reaction tower, with mixing being enhanced by a plurality of angled baffle plates. Regeneration is accomplished by washing the catalysts, particularly ferrous catalysts with water to remove ferric sulfates, thereafter providing ferrous sulfates on the surface of the ferrous catalysts, and thereafter heating the catalysts with combustion gases separate from the ammonia gases, to dry the catalysts prior to their moving into the portion of the reaction tower having therein the mixed ammonia gas and combustion waste gases. |
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