Date of this Version
Aerosol Science and Technology, 42:505–512, 2008
We have developed a low-cost, miniaturized disk-type electrostatic aerosol precipitator for a personal nanoparticle sizer, often needed in applications requiring spatially distributed measurement or personal exposure monitoring. The performance of prototype mini-disk precipitator was evaluated in this study. Measurement of particle transmission through the precipitator for both neutral and singly charged particles shows that the compact size of the disk precipitator does not lead to serious particle loss resulting from particle diffusion and/or electrical image force. The transmission of singly charged particles of 10 nm is 64% at an aerosol flowrate of 0.3 lpm. The device consists of two precipitation chambers, separated by a metal disk. The design further allows the device to be configured to precipitate charged particles by establishing electrical fields in one or both precipitation chambers. Both operations work well to precipitate particles by electrical mobility. The operation of dual-chamber precipitation, with electrical field established on both sides of the middle disk, is preferred since it lowers the maximum requirement of applied voltage to precipitate particles with a specific electrical mobility for a given flowrate. Semi-empirical models were also developed to describe the dependence of the particle penetration curves on particle electrical mobility.