Comparison of Coal Ash Particle Size Distributions from Berner and Dekati Low Pressure Impactors

摘要

This article presents the differential mass size distributions of coal combustion particulate matter(PM)determined with the Berner low-pressure impactor(BLPI,Hauke Model 25-4/0.015)and a newer generation of low pressure impactor,the Dekati low-pressure impactor(DLPI,Dekati Ltd Model 6281).The collection characteristics of the BLPI and DLPI are compared and cutoff diameters are calculated.Samples were collected in the post-combustion zone of a 19 kW vertical downflow combustor from two coal types.Both BLPI and DLPI represent a tri-modal distribution and give statistically similar characterizations of the coal ash particle size distribution.Distributions generated from DLPI data have higher fractions of submicron particles compared to those generated from BLPI data.The DLPI's two additional stages may provide greater resolution in the submicron region than the BLPI.