Methods for Evaluating the Effectiveness of Gas Vortex Stabilization in Plasma Torches for Metal Cutting

Abstract

The well-known recommendations for the design of gas-vortex stabilization systems in metal-cutting plasma torches are considered. Various designs of such systems used in the series PMVR plasma torches developed by the authors are presented. It is noted that the method of efficiency assessment developed by the authors should be based on the calculation of the uniformity distribution of the gas flow velocity. The velocities are calculated in the control sections of the gas-air path in the plasma torch. Various simplified and precise estimation methods are proposed. The velocity distribution in control sections for various modifications of plasma torches are presented. Calculations are made based on the "cold"model of gas flow and its heating by a plasma arc. Recommendations are made on the choice of parameters for evaluating the effectiveness of gas-vortex stabilization in plasma torches. The advantages of the new modernized plasma torches, including those using narrow-jet plasma technology, in terms of the gas-vortex stabilization efficiency are demonstrated. The necessity of using several criteria for evaluating the effectiveness of plasma torches design is noted. © Published under licence by IOP Publishing Ltd.