The effects of residence time and gas temperature on LOI were
addressed in the pilot study of Ikeda et al. [3]. They reported that
he reduction of carbon in ash was about 20% with the in-furnace
blending method supplying bituminous coal to the lower burners,
compared to the out-furnace method. This blending method corre-
sponds with the present case, Case S-1. In the case of supplying
bituminous coal to the upper burners (Case S-3 in the present
study), carbon in ash increased. This coincides with the present
simulation results. Ikeda et al. interpreted these results to be due
o the longer residence time and higher temperature when burning
bituminous coal at the lower burners. The study with drop tube