Improvement of a high-volume aerosol particle sampler for collecting submicron particles through the combined use of a cyclone with a smoothened inner wall and a circular cone attachment

A cyclone is an effective tool to facilitate the collection of aerosol particles without using filters, and in cell exposure studies is able to collect a sufficient amount of aerosol particles to evaluate their adverse health effect. In this study, we examined two different methods to improve the aerosol particle collection efficiency of a cyclone. The individual and combined effects of reducing the surface roughness of the inner wall of the cyclone and of using a circular cone attachment were tested. The collection efficiency of particles of diameter 0.2 μm was improved by approximately 10% when using a cyclone with a smoothened inner wall (average roughness Ra=0.08 μm) compared with the original cyclone (Ra=5.1 μm). A circular cone attachment placed between the bottom section of the cyclone and the top section of a collection bottle, resulted in improved collection of smaller particles without the attachment. The 50% cutoffdiameter of the modified cyclone (combined use of smoothened inner wall and attachment) was 0.23 μm compared to 0.28 μm in the original model. The combined use of these two techniques resulted in improved collection efficiency of aerosol particles.