High-Speed Visualization of Temperature Fluctuation of Diode-Rectified Multiphase Ac Arc near the Electrodes

 Diode-rectified multiphase AC Arc (DRMPA) has been developed to solve the electrode erosion of conventional multiphase AC Arc (MPA) in recent years. Arc temperature, as one of the most important parameters in the application of MPA, has been investigated in previous works. High-speed camera system with band-pass filters (BPF) was successfully developed to measure the fluctuated temperature of MPA. However, its measurement range of the arc temperature was limited and the highest limitation was lower than 15,000 K. This originated from the fact that the line emissions from atomic argon were only considered. In the present study, a new method to measure the arc temperature considering line emissions as well as continuum emissions is established to elucidate near-electrode temperature fluctuation in the DRMPA. The BPF of 440 ± 5 nm and 480 ± 5 nm, which involve the line emissions from singly ionized argon and strong continuum emissions, have been used in this work. The arc temperature near the electrodes fluctuated in the range from 15,000 K to 20,000 K. This result can serve as a reference for the mechanism of electrode erosion and the industrial application of DRMPA.