Investigation of a Piezoelectric Plasma Generator as a Charging Source for Aerosols

Schriefl, M. A. (Speaker), Bergmann, A. (Contributor), Alexander Melischnig (Contributor), Markus Puff (Speaker)

Activity: Talk or presentationTalk at conference or symposiumScience to science

Description

Recently, a new low-cost piezoelectric Plasma generator, called CeraPlas™, was developed by EPCOS OHG. This device allows for high efficient gas ionization at atmospheric pressure and temperature conditions at secure operating conditions. The dimensions, as well as the power consumption of the device enable its usage for mobile applications (PEMS). Depending on operating power, surrounding gas flow rate and position downstream of the device, an ion density of up to 2 x 10^13 m^-3 for both, positive and negative polarities, can be achieved.
In this study, we investigated the applicability of the device as a bipolar charging source for aerosols. For this purpose, the device was mounted in an apparatus which enables the measurement of the ion current using electrostatic precipitation. The CeraPlas™ was operated in an N2 atmosphere, ensuring reproducible working conditions and minimizing generation of ozone. With this setup, the device was characterized with respect to ion densities at different working conditions (operating power, gas flow rates and measurement positions).
Moreover, a mixing chamber for aerosols and ions for aerosol charging was designed. A multiphysical simulation of the mixing chamber was performed, including fluid dynamics, transport of the ion species and particle trajectories. Assuming an ion recombination coefficient of 1.6 x 10^12 m^3s-1, the Nit product was estimated to be ~10^12 m^-3s.
The bipolar charger was used as a neutralizer for a differential mobility analyser and tested against commercially available bipolar aerosol chargers (x-ray source and radioactive source). First promising results show comparable charging efficiencies. Nevertheless, enhancement of the charging chamber – in order to increase the Nit product – as well as the determination of charge distributions of the charged particles is ongoing.
Period2017
Held at2017 Cambridge Particle Meeting
Event typeConference
LocationCambridge, United Kingdom

Keywords

  • Aerosol Science