Numerical and Experimental Investigation on the Effects of a Nozzle Attachment to Plasma Torches for Plasma Atomization

Plasma atomization technology is able to both melt and atomize a material which is fed into the converging plasma jets as a wire. Temperature and velocity distribution in a plasma jet obtained at the outer region of a plasma torch is very important to melt a solid wire and to disintegrate the liquid metal into fine spherical particles. In this study, a non-transferred arc plasma torch is designed and numerically solved for the determination of temperature and velocity distributions in the plasma jet. A high velocity nozzle attachment is assembled to plasma torches for increasing the jet velocity for atomization purposes. Results of numerical solutions with and without high velocity nozzle attachment are discussed and compared with experimental studies. It is found that high velocity nozzle attachment can be favourable in terms of the higher velocity and temperature distribution in the plasma jet at longer distances from the torch exit.