Experimental study of an oxygen plasma cutting torch: I. Spectroscopic analysis of the plasma jet

An experimental study of the oxygen plasma jet of an OCP 150 cutting torch marketed by Air Liquide is presented. A fast CCD camera is used to visualize the shock wave geometry at the nozzle exit. Optical emission spectroscopy techniques are used to determine the temperature, the electron number density, the pressure and the fraction of nitrogen in the plasma jet between the nozzle exit and the anode. Measurements are performed in a real cutting configuration and compared with the results of a rotating anode device. The influence of several cutting parameters (voltage, torch velocity and plasma producing gas injection pressure) on the macroscopic properties of the arc is dealt with