Manabu Tanaka1,Takafumi Okuma1,Takayuki Watanabe1,Tsugio Matsuura2,Juan Trelles3,Masaya Shigeta4
Kyushu University1,Taso Arc Corp.2,University of Massachusetts Lowell3,Tohoku University4
Manabu Tanaka1,Takafumi Okuma1,Takayuki Watanabe1,Tsugio Matsuura2,Juan Trelles3,Masaya Shigeta4
Kyushu University1,Taso Arc Corp.2,University of Massachusetts Lowell3,Tohoku University4
An innovative planar thermal plasma jet induced by diode-rectified AC arc was successfully generated under atmospheric pressure. The purpose of the present work is to investigate the feasibility of this plasma source in rapid surface treatment.<br/>Arc discharge was generated among 10 electrodes, which were placed in a line. These 10 electrodes were configurated by 2 AC electrodes, 2 diode-rectified electrodes, a cathode, and an anode. The order of these electrode are as follows; No. 1: cathode, No. 2 and 6: AC electrode, No. 3 and 7: diode-rectified anode, No. 4 and 8: AC electrode, No. 5 and 9: diode-rectified cathode, and No. 10: anode. When AC electrode (No. 2) is in the cathodic period, arc is generated between AC electrode (No. 2) and diode-rectified anode (No. 3). On the other hand, the arcing occurs between AC electrode (No. 2) and cathode (No. 1), when AC electrode (No. 2) is in anodic period.<br/>This electrode configuration enables to sustain the periodic AC arc in discharge chamber. In particular, 4 electrodes from No. 2 to No. 5 can be considered as one section. This electrode configuration can be easily extended with increasing the number of the sections.<br/>This setup also possesses the slit nozzle with 10 mm in width at 200 mm length. Planar thermal plasma jet was ejected from this slit nozzle. Arc current for each electrode was changed from 100 to 150 A. Argon gas was used as shield gas and plasma forming gas in discharge region.<br/>The experimental results indicated that the planar thermal plasma jet was successfully sustained. High-speed camera observation synchronized with arc voltage and current measurement revealed the plasma jet fluctuation. Spatial characteristics of the plasma jet was well corelated to the non-dimensional numbers such as Reynolds number and Enthalpy number.<br/>Obtained results suggest that the planar thermal plasma jet by diode-rectified AC arc expand the possibility of thermal plasma utilization in industrial field.