Electric and thermal characteristics of the linear, sectional dc plasma generator

Abstract

The two- and three-chamber, linear, high voltage (200–300 V) and limited current (120–280 A) plasma generators (PGs) have been designed and manufactured by us for application in surface engineering. The operating and thermal characteristics (TC) of PGs, along with the distribution of enthalpies and velocities in the plasma jet were measured and analysed under atmospheric pressure conditions in air. The influence of arc current, gas flow rate and anode diameter on the current–voltage characteristics and thermal efficiency are investigated. The modified similarity theory has been used for the analysis of operating and TC and result generalization. The results obtained were compared with those for the vortex linear plasma torches published by Zhukov, Yas'ko and by the authors of this paper. It has been found that properly distributed gas injection increases the current strength and potential difference, allows control and regulation of the plasma torch parameters and ensures operational stability. It helps to control parameters of the dispersed particles introduced into the chamber and the properties of the coatings obtained.