Abstract
Objectives: In this study, a unipolar corona discharger was developed and experimentally evaluated for its intrinsic and extrinsic charging efficiencies, and electrostatic and diffusion losses of submicron aerosol particles in the size range of 20–300 nm at different corona and ion trap voltages. Method: The applied voltage of the discharger ranged between 2.4 and 3.2 kV, corresponding to a discharge current of 0.19 nA–2.0 mA, and an ion number concentration of 1.88X1011–1.97X1015 ions/m3. Findings: Increasing the corona voltage could lead to a higher discharge current and ion concentration inside the discharger. In the proposed discharger, intrinsic charging efficiencies of aerosol particles between 76.9% and 93.0% were obtained for particle sizes ranging between 20 and 100 nm for the given corona and ion trap voltages. The extrinsic charging efficiency decreased as the ion trap voltage increased at a given corona voltage. Novelty: The optimal extrinsic charging efficiency of the discharger was observed to be approximately 20.8–58.6% for particle sizes ranging from 20 to 300 nm at a corona voltage and ion trap voltage of approximately 2.8 kV and 200 V, respectively. In this discharger, the highest electrostatic losses (approximately 73.5%, 83.7%, and 54.0%) were observed corresponding to corona voltages of 2.8, 3.0, and 3.2 kV, respectively at a particle diameter of 20 nm and an ion trap voltage of 300 V. Finally, the highest diffusion loss (approximately 18.9%) was observed at a particle diameter of 20 nm. Keywords: Corona discharge; particle charging; aerosol discharger; particle loss
Highlights
Nanoparticles are defined as particulate substances of nano-scale dimensions
When the corona voltage increased from 2.4 to 3.2 kV, the discharge current increased from 0.19 nA to 2.0 μA, while the ion concentration increased from 1.32X1011 to 1.03X1015 ions/m3, respectively
As shown in Equation [2], the ion number concentration inside the charging zone of the developed discharger could be controlled by the discharge current or the corona voltage
Summary
Nanoparticles are defined as particulate substances of nano-scale dimensions (typically less than 100 nm). Intra et al / Indian Journal of Science and Technology 2021;14(4):335350 particles and most atmospheric nanoparticles are typically smaller than 50 nm. The diesel-exhaust particles are usually black carbonaceous soot with submicron particles of diameters typically ranging from 30 to 500 nm (0.03–0.5 μm). They are the major components of fine particles or PM2.5 [1]. As the epidemiological studies consider the relationship between mortality and morbidity, and ambient particle exposures use particulate data, the gravimetric analysis is selected. A number of methods have been incorporated in the instruments to achieve real-time airborne PM2.5 monitoring, including beta ray absorption, light scattering, quartz microbalances, and electrical aerosols
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call