Progress in Plasma Processing of Materials, 2001

ISBN Print: 1-56700-165-3

HIGH CURRENT DIVERGENT CHANNEL PLASMATRONS: SIMULATION, EXPERIMENTAL STUDIES AND TECHNOLOGICAL APPLICATIONS

DOI: 10.1615/ITPPC-2000.220
pages 173-180

Abstract

High current atmospheric pressure plasmatrons with a divergent channel present the line along which an essential progress has recently been made in Associated Institute for High Temperatures of the Russian Academy of Sciences. A number of nun1erical codes have bee~ developed for calculating two-dimensional plasma flows in plasn1atron channels of different geometries. The performed numerical experiments allowed a more precise determination of the turbulization threshold. With a purpose-developed automated system for spectral analysis, spatial distributions of electron concentrations and temperatures have been performed throughout the whole length of argon and nitrogen plasma jets as a function of the plasmatron currents and gas flow rates. Using high-speed CCD-camera, the discharge structure in a divergent channel-anode with a vortex stabilized arc is investigated.
The most advanced technological application of the plasmatrons under consideration is hardening and nitriding treatment of railway wheels doubling their resource. Several plasma devices brought into service in Moscow Railways have delivered more than 18,000 plasma treated wheel sets. Plasma sprayed coating of old railway frogs proved to be successful too. The next up-and-coming technology is the plasma coating of copper with wear-resistant alloys for molds used in continuous casting.