Experimental Study Of Unburned Carbon Distribution In Different Sizes Of Fly Ashes

A set of fly ashes from pulverized coal fired boilers were sampled from two power plants, and by the mean of standard dry-sieving techniques and loss on ignition technique, four parameters were measured and calculated, which are particle size distribution, total unburned carbon content, unburned carbon content of different size fractions and the contribution of each size fraction to the total carbon content of the fly ashes. By analyzing the results of experiments, the main factor that influence the unburned carbon content of fly ash can be founded, they are the inherent condition of the boiler, the kind of the coal that combusted and pulverizing condition of the coal. On the basis of selected particle diameters, the influence of particle size of coal char on its burnout time is analyzed by calculating burnout time of the char of some coals in our country, using simplified mathematical model.