The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1992
Filed:
Nov. 22, 1991
Terry G Hunt, Aurora, CO (US);
George R Offen, Woodside, CA (US);
Public Service Company of Colorado, Denver, CO (US);
Abstract
A method and apparatus for reducing SO.sub.x and NO.sub.x levels in flue gases generated by the combustion of coal in a boiler in which low NO.sub.x burners and air staging ports are utilized to inhibit the amount of NO.sub.x initially produced in the combustion of the coal, a selected concentration of urea is introduced downstream of the combustion zone after the temperature has been reduced to the range of 1300.degree. F. to 2000.degree. F., and a sodium-based reagent is introduced into the flue gas stream after further reducing the temperature of the stream to the range of 200.degree. F. to 900.degree. F. Under certain conditions, calcium injection may be employed along with humidification of the flue gas stream for selective reduction of the pollutants.