Temperature measurement of plasma jet by a water-cooled enthalpy probe under atmosphere pressure spraying

The enthalpy and temperature of the thermal plasma jet was determined using enthalpy probe under the atmosphere plasma spray, several parameters such as arc current intensity, gas flow rate and working distance were considered in order to check their effect on the characteristics of the plasma jet. An increase in input power considerably increased the enthalpy and temperature of the thermal plasma jet, while the increase of Ar gas flow rate decreased the enthalpy and temperature of the plasma jet. The enthalpy and temperature of the plasma jet decreased rapidly due to the increase of the spray distance. Changes in the flow rate of Ar almost have no impact on heat efficiency of the spray gun. An increase in input power considerably increased the heat efficiency a lot, and the highest heat efficiency of the spray gun can reach to 60%. (authors)