Tadahisa Masai

A study of gas composition profiles for low NOx pulverized coal combustion and burner scale-up

A turbulent diffusion flame of pulverized coal was investigated to clarify the relationship between flame structure and NOx emissions. NO was formed in the initial flame zone and was reduced in the fuel-rich, post-flame regions, where HCN and NH 3 were produced probably by the oxidation of coal by H 2 O and CO 2 . Burner scale-up also was examined by conducting parallel experiments in a small-scale combustor and a facility with a 25-fold larger coal feedrate. The performance and the profiles of gas species in the flame of the large-scale furnace were well simulated by the data obtained in a laboratory-scale burner where combustion air inlets were remotely located from the central fuel jet to surpress the transverse mixing of air and coal.