Patent ID: 8607718
Filing Date: 2013-12-17
Classification: F23G,F23L

Abstract:
1. A combustion air system for a recovery boiler having four generally orthogonal walls and a floor, comprising: a primary air level formed by a plurality of primary air ports in all of the walls of the furnace proximate to the floor; a single secondary air level formed by opposed secondary air ports in front and rear walls of the furnace above the primary air ports; black liquor guns in the walls of the furnace above the single secondary air level of opposed secondary air ports; an elevation of liquor air ports only in the front and rear walls of the furnace and located a vertical distance in the range of about zero to four feet above the elevation of black liquor guns; and at least first, second and third tertiary air levels formed by tertiary air ports only in the front and rear walls of the furnace above the black liquor guns, wherein the tertiary air ports in all of the at least first, second and third tertiary air levels are arranged in substantially vertically aligned columns in opposing walls of the furnace and wherein the columns are vertically aligned with the liquor air ports, each tertiary air port located at one of the at least three tertiary air levels, the first tertiary air level located a vertical distance in the range of about four feet to twelve feet above the elevation of liquor air ports, and the second and any additional tertiary air levels are located and spaced from an adjacent tertiary air level at regular spaced vertical intervals in the range of about four feet to eight feet, and wherein at least a portion of each of the at least three or more tertiary air levels in only one of the front wall, or the back wall, of the furnace are substantially vertically aligned with a black liquor gun.