Analysis of nanosecond pulsed and square AC dielectric barrier discharges in planar configuration: Application to electrostatic precipitation

In this experimental work, atmospheric pressure dielectric barrier discharge (DBD) is generated in plane-to-plane configuration under square alternative (AC) and nanosecond pulsed (NP) high voltage excitations. The aim is to investigate their efficiency for submicron particles electrostatic precipitation. The AC and NP high voltage signals have rise and fall times of about 30 μs and 50 ns, respectively. The typical characteristics of the discharge such as current waveforms and Q-V curves are investigated. The average power consumption is analyzed as a function of applied voltage and frequency and the images of both discharges are presented. Results show that the measured current has two peaks with a magnitude of some amperes in the case of NP DBD, whereas it is composed with a multitude of pulses of about hundreds of milliamperes in the case of square AC DBD. A filamentary discharge mode is obtained in both cases. However, filaments in NP DBD are self-organized and uniformly distributed in the whole discharge area. The planar DBD is used as an electrostatic precipitator (ESP) for submicron particles filtration (diameter ranging between 0.18 and 0.7 μm). Results indicate that the square AC DBD-ESP is more effective than the NP DBD-ESP; it can collect 99 % of particles with relatively low power consumption.