CHARACTERIZATION OF A FULL-SCALE, SINGLE-BURNER PULVERIZED COAL BOILER - TEMPERATURES, GAS CONCENTRATIONS AND NITROGEN-OXIDES

Local temperatures and gas concentrations were measured in a 17 MW top -fired pulverized coal furnace. A specially designed suction pyrometer was used for thermocouple temperature measurements as well as withdra wal of ps samples from the furnace. The gas sampling system was carefu lly tested to make sure that the sample gas was efficiently quenched. Gas samples were analysed for O2, CO, CO2, NO, NO2 and SO2. The effect s of furnace load, primary:secondary air ratio and total excess air le vel were investigated. NO emission increased with the total excess air level, but was less sensitive to variations in load and in distributi on of combustion air. These results are discussed in terms of NO forma tion mechanisms as well as burner and furnace characteristics. The exp erimental data provide good possibilities for scaling and modelling st udies, in that they characterize a full-scale, single-burner pulverize d coal system with a simple geometry.