PLASMA CHARACTERISTICS IN A CUTTING PLASMA TORCH

An experimental and theoretical study of a low current intensity cutting plasma torch is presented. The operating gas is oxygen discharging in an air environment. The plasma model is developed with the commercial code Fluent 4.5. Two configurations were used: One where the arc is transferred on a rotating anode 15 mm away and another one in a real cutting configuration (distance nozzle exit − workpiece around few mm). In the first configuration, spectroscopic measurements were made and compared with the model. In the second one, a power balance of the cutting process is presented above and in the thickness of the plate. The model shows that the power used for fusion comes mainly from the convective, conductive and radiation terms with a contribution between 50% and 70%. The electrical and oxidation contributions are also quantified.