Size distribution and emission characteristics of inhalable particulate from coal water slurry boiler

The fly ash before and after electrostatic precipitator(ESP) of coal water slurry(CWS) boiler was studied by using a seven-stage cascade impactor.Results indicated that the particle size distribution(PSD) before ESP accorded with logarithmic normal distribution and the correlation coefficient was higher than 0.999,while the PSD after ESP accorded with Rosin-Rammler distribution better and the correlation coefficient was 0.989.The mass fractions of PM1,PM2.5 and PM10 increased greatly after passing through ESP as the efficiency of ESP for coarse particles was higher than that for fine particles.The boiler load affected the fine particle fraction and the fine particle fraction increased as the boiler load decreasing.PM2.5 and PM10 mass fractions were lower than those of typical pulverized coal boiler because of the high water content of fuel and the atomization and coagulation during combustion.