Ozone Emission and Electrical Characteristics of Ionizers With Different Electrode Materials, Numbers, and Diameters

We investigated the ozone emission characteristics of ionizers differing in terms of the materials, edge numbers, and diameters of their high-voltage electrodes. Our goal was to determine the low ozone emission performance of a carbon brush ionizer that we developed in our previous research on a two-stage electrostatic precipitator (ESP) for cleaning indoor air and exhaust gases from industry. We measured corona discharge current and ozone concentration from the ionizer with different high-voltage electrodes using a digital voltage and current meter and an ozone monitor, while varying applied voltages from 0 to -12 kV at a constant air flow rate of 100 L/min. The corona currents varied from zero to several hundreds of μA depending on electrode material and geometry, while ozone concentrations varied from zero to several hundreds of ppb. Materials did not significantly affect the relationship between voltage and corona current, or ozone emissions from the ionizers. At the same applied voltage, both corona currents and ozone emissions were lower with higher edge numbers, while corona currents increased but ozone decreased with lower high voltage electrode diameters. We conclude that the low-ozone performance of the carbon brush ionizer is due to the effect of thin and/or multiedged electrodes.