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.