Some characteristics of transferred-Arc plasmas

Abstract

Although the theoretical foundations of the characteristics of transferred arcs were established more than three decades ago, the design of reator systems based on this method of plasma are generation is still in an early stage of development. Although deceptively simple in concept, attempts to use transferred arcs im practical applications at scales of arc length and power somewhat larger than those previously studied in the laboratory soon revealed that considerably more information was required on the arc's unique properties before a sound reactor design could be carried out. This was principally due to the much higher temperature levels (up to 20,000 K) with consequent much higher radiative power achieved in this type of arc, as well as the fluid mechanical effects of the high-velocity plasma gas flowing in the latter. These, in turn, had profound effects on the various modes of heat transfer occurring in the system, on the stability of the arc, on the injection of the material to be treated, and on the overall efficiency of energy utilization in the whole system. The objective of this paper is to summarize the experimental evidence concerning transforred arc characteristics which have been obtained by the author and his colleageus during recent years.