Patent ID: 8640634
Filing Date: 2014-02-04
Classification: D21C,F23G,F23L

Abstract:
1. A furnace of a recovery boiler comprising: a front wall, a rear wall and side walls to the furnace, at least one black liquor spraying device disposed at or above a black liquor spray elevation on at least one of said walls; a plurality of primary air ports on at least one of said walls; a first elevation of secondary air ports arranged on opposite walls of said furnace and arranged to project a pattern of air jets into the furnace from said opposite walls; and a second elevation of secondary air ports on said opposite walls adjacent in a vertical direction to the first elevation, the secondary air ports at the second elevation including large air ports and small air ports, wherein the large air ports are arranged to project a pattern of large air jets into the furnace from said opposite walls, and the small air ports at the second elevation are each smaller than each of the secondary air ports at the first elevation, and for each of opposite walls, the large air ports are each vertically aligned with one of the secondary air ports at the first elevation on the same one of the opposite walls, wherein said first and second horizontal elevations of secondary air ports are vertically lower on said walls than the black liquor horizontal spray elevation and are vertically above the primary air ports.