New Particle Size Measuring Probe—Application to Aerosol Collector and Emissions Evaluations

Abstract

A basic parameter needed for judicious design, selection, and regulation of industrial gas cleanup equipment is particle size distribution of gas-borne emissions. Despite the importance of this parameter, a cloud of uncertainty about the validity of present methods used for particle size distribution measurements has produced a technological gap. This paper describes an apparatus and method which is capable of bridging this gap. Particle size distribution data obtained, particularly in the near micron and submicron range, can provide means for determining grade efficiencies of dust collectors, expected opacity of stack emissions, and dispersion characteristics of plumes. The apparatus described was developed for manual sampling and size distribution determination of aerosols within industrial flues and stacks. The entire apparatus is contained within a sampling probe. The principal component is a cylindrical cascade impactor. Design of the probe eliminates most of the technical difficulties associated with previous attempts at implementing cascade impactors to this task. This probe has been used successfully for sampling gases up to 450 F.