Investigation of elec­tric arc into twin plasma torch with forced convective heat transfer in arc column
The experimental investigation of electric arc was carried out for d.c. twin plasma torch with tube single chamber elec­trode assemblies at operation with air. Operating modes are varied as follows: arc current I = 105 - 550 A, arc voltage U = 400 -1320 V, plasma gas (air) flow rate summarized on electrodes G = (0.76 - 7.18)10<sup>-3</sup> kg/s, interelectrode (between anode and cathode assemblies) degree a = 45 - 62°, distance between axises of the electrode assemblies at outlet from their nozzles c = 0.07 -0.14 m, pressure at plasma torch outlet р ~ 0.1 MPa. Analytical model of electric arc was developed for twin torch which is oper­ated with forced convection mode of arc column. Comparison with experimental data is fulfilled. New theoretical expression to describe arc current-voltage characteristics in generalized form which corrected for experimental results was obtained.