Ignition Delay of Coal Particles in Shock-Heated Air

Abstract

The objective of this study is to obtain the ignition delay for Pittsburgh seam coal particles shock heated in air to various temperatures and I atmosphere pressure. The ignition delay for coal particles of 19 μ and 41 μ was determined in a 7.62 cm shock tube. The gas temperature behind the reflected shock wave, T ₅, was calculated from the measured incident shock-wave speed. Plots or the ignition dealy vs. T ₅indicate the existence of a minimum gas temperature for ignition. The effect of particle size on the ignition delay is small for the particle size range used.