Electrode Heat Transfer in the Rotated Arc

摘要

The report discusses the problem of electrode cooling in plasma arcs. An approximation to the actual case of an electrode heated by a rotating arc column is obtained from the solution of the one-dimensional, periodic heating and cooling of a flat plate. The heating period of this plate is equal to the arc spot width divided by the linear arc velocity, and its cooling period is equal to the remaining electrode perimeter divided by the linear arc velocity. This approach allows an estimation of the practical limit of the arc current density as fixed by arc rotation rate and electrode perimeter. (Author)