Investigation of the Effect of Feeding Gas Flowrate on the Titanium Particle Temperature in Radiofrequency Plasma Torch

In this study, a computational fluid dynamics (CFD) model is developed for a radio frequency (RF) plasma system designed for powder spheroidization. The electric field is generated analytically by solving the RF coil system, and then the resulting equations are implemented as user-defined functions (UDF) to the CFD model. UDF codes were created and defined in the Fluent program to generate RF plasma. Electromagnetic fields and fluid flow have been modelled in numerical analysis studies, and temperature and velocity distributions were obtained. The effect of this plasma environment on titanium particle temperature is investigated using various particle-feeding gas flow rates. As a result, it is observed that an optimal powder-feeding rate could be determined. It is seen that high particle velocities prevent the attainment of the necessary temperature for melting, while low velocities may cause the temperature to exceed the boiling point. These results conclude that the feeding gas flow rate could be determined for a specific powder size range to obtain the powder temperatures within the melting and boiling temperatures.