Felix Belin

WASTE WOOD COMBUSTION IN CIRCULATING FLUIDIZED BED BOILERS

Abstract Babcock & Wilcox circulating fluidized bed (CFB) boilers with steam capacity 27.6 kg/s/219,000 lb/hr and 20.7 kg/s/164,000 lb/hr utilize waste-wood fuel to produce 86.2 bar/1250 psig, 513°C/955°F steam for electric power generation. The boiler design and fuel/bed material data are provided. Problems encountered during the initial boiler operation and the boiler start-up regime are described. The influence of fuel properties (moisture content, size consist and reactivity) on the combustion process is analyzed. Test data provided on the furnace temperature and gas concentration patterns as a function of fuel properties, combustion air distribution and solids circulation. The vertical fuel heat release profile is determined from experimental data using a zonal furnace performance model. Carbon conversion and CO/NOx emissions data are presented. Major factors involved in design of waste wood-fired CFB furnaces are discussed.