Extremely high-power-density atmospheric-pressure thermal plasma jet generated by the nitrogen-boosted effect

摘要

In this study, the effect of N-2 addition to an atmospheric-pressure Ar thermal plasma jet (TPJ) on ultrarapid heating was investigated. With increasing N-2 flow rate, a boost of arc voltage to similar to 36 V was observed, which significantly improved heating characteristics. As a result, a drastic power density increase from 10 to 12SkW/cm(2) was achieved with the addition of 2.0L/min N-2 to 3.0L/min Ar. The results of optical emission analysis and heating characteristics evaluation implied that dissociation and recombination of N-2 molecules and the high thermal transport property of nitrogen gas play important roles in the increase in TPJ power density. Furthermore, we obtained TPJ extension with N-2 addition that reached 300 mm, and it showed spatial enhancement of heat transport characteristics. (C) 2018 The Japan Society of Applied Physics.