In Situ Measurement of Grain Dust Particle Size Distribution and Concentration

Abstract

ABSTRACT light extinction method for determining the in situ particle size distribution and concentration of grain dust that is suspended in a grain bin is presented. The particle size distribution was determined by analyzing the change in light attenuated as particles settled out of the dust cloud. The steady state particle size distribution before the onset of settling was assumed to be equal to the values determined by settling. The steady state dust mass concentration before the onset of settling was then calculated from the value of light attenuation and the particle size distribution at several locations in a grain bin using the light extinction-settling method. A high volume air sampler was also used to measure the dust mass concentration. Dust that settled onto a horizontal surface was collected and its particle size was measured. These measurements were made as the bin was filled with corn and wheat at two grain flow rates.