直流纯氩层流等离子体射流的长度变化

采用主要由阴极、阳极以及介于阴极和阳极之间的中间段组成的直流非转移式电弧等离子体发生器,在大气压条件下,比较系统地研究了纯氩层流等离子体射流的长度随着弧电流、气体流量以及发生器结构而变化的规律。结果表明:层流射流的长度随弧电流和工作气流量的增加而增长;层流向湍流流动转变的临界气流量值随弧电流增大而提高;在发生器的伏安特性呈大梯度变化的情况下,射流长度随弧电流的变化幅度增大。

LENGTH CHANGE OF DC LAMINAR-FLOW ARGON PLASMA-JET

Non-transferred DC plasma torch constituted mainly with a cathode, an inter-electrode insert and an anode was built to generate pure-argon laminar-flow plasma jet at atmospheric pressure. Length changes of the laminar plasma jet were systematically examined on the generating parameters such as arc current, gas flow rate and torch structure. Results show that the jet length of laminar plasma increases with the increase of arc current and gas flow rate; higher arc current allows higher gas flow rate which can keep the jet flow in the laminar regime; and the change scale of the jet length increased with the arc current regulation when a torch with high gradient of current-voltage characteristics is used.