Characteristics of corona and silent discharges as influenced by geometry of the discharge reactor

Abstract

This paper is aimed at investigating how the characteristics of corona and silent discharges including ozone generation are influenced by geometry of the discharge reactor. The corona discharges have been generated in coaxial wire-cylinder and wire-duct reactors stressed by dc and ac voltages. The silent discharges have been generated in the same reactors in addition to tubular reactors under ac voltage after pasting a dielectric barrier on the ground electrode of the reactors. The reactors were fed by dry air flowing at atmospheric pressure and temperature. The pulse characteristics of silent discharges are compared with those of ac corona discharges. The current-voltage and the ozone generation characteristics of silent and ac discharges are recorded. These characteristics depend significantly on the geometry of the reactor irrespective of the discharge type. NomenclatureC ozone concentration, ppm d width of the discharge gap, mm dV /dt time derivative of voltage V , kV s −1 P discharge power, W Q air flow-rate through the reactor, litre min −1 r radius of the discharge wire, mm STP standard temperature and pressure conditions V o onset voltage of the discharge (peak value), kV V p applied voltage (peak value), kV

Charge neutralization of submicron aerosols using surface-discharge microplasma

“…4. The microdischarges occur in every half period of applied voltage for the alternating voltage of 2.7 kV with 2 kHz (Massines et al, 1988;Abdel-Salam et al, 2003;Korzec et al, 2003). Thus, the occurrence of these microdischarges confirmed the typical performance of the SMAC used in this study.…”

“…A large fraction of the electron energy released by the microdischarge can be used to dissociate molecules and thereby produce ions. The wide range of discharge characteristics observed are known to depend on factors such as the DBD geometry, material, type of applied voltage, and so on (Müller & Zahn, 1996;Gibalov & Pietsch, 2000;Abdel-Salam et al, 2003). The typical voltage type used to induce surface discharge is an alternating voltage; however, the DC pulse can be utilized also (Reitz, Salge, & Schwarz, 1993;Liu & Neiger, 2001).…”

“…DBD is well known to produce highly non-equilibrium plasmas in a controllable way at atmospheric pressure, and this method has been established to effectively generate atoms, radicals, and excited species with energetic electrons at moderate gas temperature (Massines et al, 1988;Abdel-Salam et al, 2003;Wagner et al, 2003). Until recently, DBD has been mainly used as an effective ozone generator.…”

Characterization and mechanism studies of dielectric barrier discharges generated at atmospheric pressure

“…Here, the active current I act defined as P / V rms , where P is the discharge power and V rms is the root mean square voltage, is used to evaluate the average current provided by the generator to the discharge. 9 In the previous literature reports, [9][10][11][12] the discharge power or current of DBD increases all the way proportionally along with the applied voltage. However in our experiment, we observed that the discharge power and active current increase with voltage only in certain local ranges ͑zone I and III in the figure͒, and in the other range ͑zone II͒, they decrease with the voltage increase.…”

Collection of submicron particles by an electrostatic precipitator using a dielectric barrier discharge

“…Dielectric barrier discharge (DBD) is well known to produce highly non-equilibrium plasmas in a controllable way at atmospheric pressure, and this method can effectively generate atoms, radicals, and excited species with energetic electrons at moderate gas temperatures (Abdel-Salam et al, 2003;Massines et al, 1988). The DBD usually is comprised of two electrodes that are separated by a gas gap spacing and at least one of which should be covered with dielectric material.…”