Micro corona based particle steering air filter

• Published in: Sensors and actuators. A. Physical. 2013-07, Vol.196, p.8-15
• Main Authors: Chua, Beelee, Wexler, Anthony S., Tien, Norman C., Niemeier, Debbie A., Holmén, Britt. A.
• Format: Article
• Language: English
• Subjects: Corona; Coronas; Electric potential; Electrodes; Electrostatic steering; Exhaust; Filtering facepiece respirator; Filtration; Mathematical analysis; Outlets; Steering; Voltage
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2013.03.029

•Miniaturized air filtration via particle charging and electrostatic steering.•Air filter consists of micro corona ionizer, steering electrodes and flow divider.•Particles were electrostatically steered from filtered to exhaust outlet.•Addresses issues posed by existing mechanical and electret filters. We have successfully demonstrated a micro corona-based air filter that operates by charging air particles and electrostatically steering them to the exhaust outlet. The filter consists of a corona ionizer, a pair of steering electrodes and a flow divider. Analytical calculations indicated that as the steering voltage increases, the number of particles exiting the waste outlet will increase and those at the filtered outlet will decrease accordingly. In the experiment, ambient air was pumped into the filter element at a rate of 1.28 LPM and the corona ionizer was operated at 1.3kV. Custom Faraday Cups were connected at both the exhaust and filtered outlets. As the steering voltage increased from 0V to 5V, the electrical current measured at the exhaust outlet increased from 6.0pA to 9.1pA, while that at the filtered outlet decreased from 5.8pA to 1.4pA. Further increase in steering voltage resulted in particle contact with the steering electrode. The Faraday cup current at the exhaust outlet also increased with flow rate. Applications include a miniaturized high efficiency low power air filtration system for respirators.