Development and Performance Evaluation of Air Sampler with Inertial Filter for Nanoparticle Sampling

Masami Furuuchi,Mitsuhiko Hata,Kensei Ehara,Kazunobu Eryu,Takaharu Kato,Kazuhiko Sekiguchi,Takafumi Seto,Yoshio Otani,Naoko Tajima,Mizuki Nagura

doi:10.4209/aaqr.2009.11.0070

Masami Furuuchi, Mitsuhiko Hata + Show 8 more

Open Access

https://doi.org/10.4209/aaqr.2009.11.0070

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Abstract

This paper describes the design and evaluation of an ambient air sampler consisting of a four-stage impactor and an inertial filter, for collecting various size fractions, including nano-particles, in a short sampling period. Impactor stages of PM10/PM2.5/PM1/PM0.5 were successfully devised with a reasonable accuracy in terms of cutoff size and slope of the collection efficiency curves. The designed inertial filter had an aerodynamic cutoff size of dp50 ~65 nm with a satisfactory sharpness in classification. The total pressure drop of the sampler (hereinafter referred to as a “Nanosampler”) was ~30 kPa at a flow rate of 40 L/min. The developed Nanosampler has advantages over currently available samplers such as LPI and nano-MOUDI, in terms of portability and loss of semi-volatile components in ultrafine particles by evaporation at a reduced pressure. Furthermore, the size distributions of the ambient particles measured with the Nanosampler compared favorably with those measured by the conventional instruments that are currently available on the market.

Highlights

To accurately evaluate the health effect of airborne particulates, it is necessary to determine the chemical composition of particles with respect to particle size
This paper describes the design and evaluation of an ambient air sampler consisting of a four-stage impactor and an inertial filter, for collecting various size fractions, including nano-particles, in a short sampling period
The inertial filters were designed using filtration theory based on a single fiber collection efficiency (Otani et al, 2007; Eryu et al, 2009) to achieve a nanometer cutoff size with a relatively low pressure drop (< 20–30 kPa), which is much lower than the pressure drop of currently available samplers for nanometer size particles, such as low pressure impactors (LPI) (70–80 kPa) and nano-MOUDI (~60 kPa) (Fang et al, 1991; Otani et al, 2007)

Summary

Introduction

To accurately evaluate the health effect of airborne particulates, it is necessary to determine the chemical composition of particles with respect to particle size. This paper describes the design and evaluation of an ambient air sampler consisting of a four-stage impactor and an inertial filter, for collecting various size fractions, including nano-particles, in a short sampling period.

Results

Conclusion