中文摘要：

一种新型的双阳极等离子喷枪．通过改变阳极弧根的位置，可以有效地提高电弧电压和喷枪的热效率。双阳极喷枪的阳极由相互绝缘的两部分组成。距离阴极较近的阳极称为阳极Ⅰ，较远的称为阳极Ⅱ。阳极弧根可以在任意阳极表面形成，从而获得不同长度，不同特性的等离子电弧。本研究比较了阳极弧根在不同的阳极表面形成的情况下，电弧的伏安特性，喷枪的内部压力，以及喷枪的热效率。结果表明，当阳极弧根在阳极Ⅰ表面形成时，电弧具有下降的伏安特性，热等离子体对阳极的传热剧烈，喷枪的热效率比较低；当阳极弧根在阳极Ⅱ表面形成时，电弧可以获得上升的伏安特性，喷枪的热效率也显著升高。

英文摘要：

A novel plasma torch, named bi-anode plasma torch, has been developed in order to improves the are voltage and the torch efficiency. The torch consists of two well inter-insulated anodes： Anode Ⅰ is close to the cathode and anode Ⅱ is further away from the ehthode. The anode arc root can be controlled to attach either in anode Ⅰ surface to obtain a normal are or in anode Ⅱ surface to obtain a lengthened are. Experimental works were carried out to compare various characteristics of the ares in different anode are root positions, including torch efficiency, pressure inside the nozzle, and voltage-current characteristics. The results show that when anode are root attaches in anode Ⅰ surface, the are has a decreasing U-I characteristic and the torch efficiency is 37% -48% ;when anode are root attaches in anode Ⅱ surface,the are has an increasing U-I characteristic and the torch efficiency significantly increases to 60%.