Multijet and multistage aerosol concentrator: Design and performance analysis

A multijet and multistage aerosol concentrator was designed and fabricated with two virtual impactors in a series. Collection efficiency, internal los s, and concentration factors were calculated at ambient conditions for each stage. The total inlet flow rate of the aerosol concentrator was set at 10 00 L/min(-1), while the minor flow rate for the first stage was at 6.0% of the total inlet flow and the minor flow rate of the second stage was at 6.7 % of the first stage minor flow. The aerosol concentrator was calibrated us ing polystyrene latex particles in aerodynamic sizes ranging from 0.5 to 10 mum. Several configurations of the multijet acceleration nozzles and multi tube receptors were designed in this study. The effects of the different de signs were subsequently evaluated through experimentation. It was found tha t a properly designed multijet and multistage aerosol concentrator can sign ificantly improve aerosol concentration performance. Results showed that th e concentration factor increases from 1 to 240 over the particle size range studied. Applications of the multijet and multistage aerosol concentrator with high-volume flow rate can vary widely, from detection of biological ae rosols at low concentration, laboratory aerosol sampling, clean room monito ring, and ambient aerosol measurements.