Design and characterization of a sequential cyclone system for the collection of bulk particulate matter

Abstract

In this paper, we describe the design, development and characterization of a high-volume sequential cyclone system for the collection of size-segregated PM in dry bulk form from the ambient environment in sufficient quantity for physical, chemical and toxicological characterization. The first stage of the system consists of a commercially available high volume PM₁₀ inlet. The second stage cyclone was designed by us to collect inhalable coarse particles (<10 µm and >2.5 µm). When tested individually with a challenge aerosol, a D₅₀ cut-size of this stage was found to be 2.3 µm at a flow rate of 1 m³ min⁻¹. The third stage, a commercially available cyclone designed for surface dust sampling, had a D₅₀ cut-size of 0.3 µm when tested at the same flow rate. The purpose of the third stage is to collect the fine particle portion of PM_2.5 or accumulation mode (PM <2.5 µm and >0.1 µm). Thus, the sequential cyclone system will collect bulk samples of both the inhalable coarse particles and the fine particle portion of PM_2.5. The operation and maintenance of the new system are straightforward and allow for reliable collection of dry bulk ambient PM at relatively low cost.