A MATHEMATICAL-MODEL FOR COAL COMBUSTION IN A FLUIDIZED-BED COMBUSTOR- PARTICLE-SIZE DISTRIBUTION EFFECTS

A three phase multistage mathematical model for combustion of coal in fluidised bed has been derived. The model is based on three phase theo ry of fluidisation and material balance for shrinking coal particles. The burning of coal is assumed to take place according to single film theory. The model has been used to predict the effect of particle size distribution on combustion efficiency, exit gas composition, carbon c arry over rate, carbon load and combustion rate. The variation in gas composition along with the height of bed has also been predicted.