Experimental Investigation of the Influence of Coal Powder Fineness on Combustion Characteristics

Thermogravimetric tests of pulverized Lengshuijiang and Doulishan coal have been carried out.Ignition and combustion characteristics,burnt-out performance and dynamic parameters of coal samples of different fineness have been analyzed.A comprehensive discrimination index H_j,which may reflect the coal powder's burnt-out performance,is being recommended with comparisons performed.Results show that,under the same heating-up rate,the amount of released volatile matter and the DTG peak value,both increase with reducing coal particle size,which also causes the maximal combustion rate to appear earlier.On the other hand,decreasing coal particle size causes a reduction of activation energy and ignition temperature with an earlier occurrence of ignition;thus effecting an improvement of combustion characteristics.