Experimental study on PM10 feature during caol combustion

Abstract

By using Low Pressure Impactor, fly ash is sampled at the ESP inlet and outlet of a 300MW utility boiler. The composition, mass and element size distribution of fly ash was measured by X-ray fluorescence and 0.001mg precision microbalance, respectively. Mass and element size distribution of Si, Al, Fe, Ca, Mg, S, Cu, Pb, Zn and Mn is of bimodal. Fly ash diameters of the fine and the coarse are about 0.1μm and 2.36-3.95μm, respectively. Efficiency of ESP for submicron ash is lower than that for normal variables ranging 62∼83%, while for ash bigger than 10μm it is almost 100%. Mg, S, Cu, Zn and Pb are obviously enriched in fine ash, especially Cu, Zn and Pb. They are found in PM2.5 accounting for 50∼60%. The relative enrichment coefficient of Cu, Zn and Pb is about 30∼40. The relative enrichment coefficient of Si, Al and Ca decreases with the ash size decreasing. No direct connection is found between the change of relative enrichment coefficient of Fe, Mn and their ash size.