Calculation of Heat Transfer Characteristics of an Arc in a Gas Stream of Plasma-Arc Furnaces

Resumo

Within the framework of the heat exchange model of electric arc, the arc characteristics in the gas jet of a melting plasmotron are calculated in the approximation of the interaction of a semi-infinite isothermal jet with a wall. The temperature profile, structure, and values of the heat fluxes of a part of the arc column in the melting space of the plasma arc furnace are determined to a distance from the cathode. For the given power and composition of plasma-forming gas, the electric and thermal characteristics of the plasmotron and its geometry are established. Examples are given of calculation of arc characteristics in argon and argon–hydrogen mixture in the initial period of melting of solid charge with stable arc combustion taking into account the influence of electric circuit parameters. The results on the temperature profile of the arc in a gas jet are presented.