Axial evolution of radial heat flux profiles transmitted by atmospheric pressure nitrogen and argon arcs

Axial evolutions of radial heat flux profiles in argon and nitrogen plasma jets from an atmospheric pressure dc non-transferred arc plasma torch are determined using a double calorimetric technique. Results are presented for power levels suitable for the processing of high temperature ceramic oxides, where the heat flux data reported in the literature is rare. Variations of the profile widths and profile maxima are presented as a function of axial distance as well as power. Relatively uniform profile width over prolonged axial distance for nitrogen plasma compared to argon is an important observation which has the potential to offer a much longer dwell time of the injected particles inside the plasma, avoiding the problem of unmelts, especially for ceramics. A comparative study of the heat flux profiles for argon and nitrogen plasma is presented. The obtained results are compared with the data reported in literature.