Received:
July 21, 2011
Revised:
October 11, 2011
Accepted:
October 11, 2011
Download Citation:
||https://doi.org/10.4209/aaqr.2011.07.0103
Cite this article:
Li, L. and Chen, D.R. (2011). Aerosol Charging Using Pen-Type UV Lamps.
Aerosol Air Qual. Res.
11: 791-801. https://doi.org/10.4209/aaqr.2011.07.0103
A portable aerosol charger utilizing pen-type Hg lamps was constructed to investigate the particle charging process under UV irradiation. The charger primarily consisted of a quartz tube surrounded by four pen-type low-pressure Hg lamps and an ion trap located downstream of the quartz tube to remove excessive ions. The performance of the prototype UV charger at 5 L/min flow rate and with four UV lamps turned on using monodisperse silver (Ag) particles with diameters ranging from 7 to 30 nm was evaluated. As expected, the prototype UV charger provided higher particle charging efficiencies than corona-based unipolar chargers for Ag particles. To evaluate the effect of irradiation intensity on particle photocharging, the charging efficiencies and charge distributions for Ag particles ranged from 7 to 30 nm when the prototype was operated at an aerosol flow rate of 5 L/min for the cases of one, two, and four lamps turned on. The UV charging model with the photoemission based on the Fowler-Nordheim law was further applied to predict the charging performance of the UV charger at different operational conditions.
ABSTRACT
Keywords:
Nanoparticle charging; UV charger; UV irradiation intensity
