Coal-fired fine particles were generated by a coal-fired boiler
burning anthracite. Fig. 3a shows the particle size distribution
measured by the ELPI, and displays a unimodal distribution in
the number concentration, which may be attributed to the combustion
condition, coal and boiler type employed. As can also be
seen from Fig. 3a, the fine particles were mostly in the submicron
size range with maximum number concentration at 0.07 lm, and
the median value of the size distribution at 0.045 lm.