FACTORS INFLUENCING THE IGNITION OF COAL PARTICLES - STUDIES WITH A PRESSURIZED HEATED-GRID APPARATUS

The influence of coal rank, maceral composition, particle size, pressu re, temperature and heating rate on the ignition of single coal partic les was studied with a heated-grid apparatus (1400 K, 10 MPa) working in connection with a high-speed camera. Experimental conditions were c hosen to simulate the conditions of p.f. combustion and to provide dat a for a kinetic description. The temperatures of the homogeneous and h eterogeneous ignition are strongly influenced by oxygen partial pressu re and heating rate as well as rank and maceral composition. The oxyge n partial pressure is an important parameter during combustion, and al so influences the interplay of pyrolysis and combustion.