OPTIMIZATION OF COMBUSTION AIR DELIVERY

The load on a 1970 vintage recovery boiler caused accelerated fouling in the upper furnace, unstable combustion in the lower furnace, and TR S emissions that were difficult to control. A contractor worked with t he mill to determine the best way to increase combustion air delivered at or above the liquor guns. Evaluation of several configurations by computer modeling led to the use of air nozzles on both the front and rear walls at the liquor gen level. The primary benefits of the modifi cations were reduced carryover, less plugging of flue gas passages, re duced TRS emissions, and more stable combustion in the lower furnace.