A numerical analysis of plasma-particle heat exchange during in-flight treatment of granulated powders by argon-oxygen induction thermal plasmas

A plasma-particle interaction flow model has been developed to investigate the effects of plasma and particle parameters on the energy transfer to particles, and thermal treatment of soda-lime-silica glass powders. In this paper attention will be given to the effects of individual particle diameter, size distribution, and average diameter, which govern the plasma-particle energy transfer to a large extent. To investigate the size distributions, computations have been carried out for two size distributions: flat and Maxwellian. Computations have also been performed for Maxwellian size distribution with three different average diameter (51, 58 and 84 μm) powders. It is found that the energy transfer to particles is higher with flat diameter distribution than that of with Maxwellian distribution; however individual particle temperature becomes lower with flat distribution. On the other hand, smaller average diameter of powders leads much heat transfer to powders, but individual particle temperature becomes lower. Both the effects come from the intense cooling of plasma due to the large heat transfer to large number of particles with flat distribution as well as small average diameter powders.