THE EFFECT OF AGITATION ON THE CHAR COMBUSTION CHARACTERISTICS OF LARGE COAL PARTICLES

To simulate combustion behaviour in a pilot-scale combustor, a laborat ory-scale agitated combustor has been developed which allows burnout a nd combustion rates for large coal particles to be measured. Particle sizes up to 25 mm can be studied, typical of those used in fixed-bed r etorts. Char burnout data were obtained to supplement previously publi shed volatiles release data. A power law relationship between char bur nout time, t(b), and particle size, d(p), given by t(b) = k(d)d(p)(n) is proposed, with kd and n as correlation constants. The data were als o used to correlate char combustion rates, r(c), for single particles, in the form r(c) = k(r)/d(p)(n').