Numerical Investigation On Spheroidization Of Silica Powders In RF Induction Plasma

With the development of mobile Internet, The spherical silica powder as an indispensablepivotal materials in Integration circuits packaging field has rapid growth in demand. Itsnumerous applications in special type ceramics, aerospace, fine chemical have also attractedmore and more attention. Compared to other competing technologies, the induction plasmaprocess has proven to have many unique advantages in producing spherical silica powder andseems to be one of the most promising methods for the large-scale spheroidization of silicapowder.Therefore, the study on silica powder spheroidization in radio frequency inductionplasma (RF induction plasma)will be of great value in both theory and practice. The flowingand conducting heat of plasma and silica powder heating and trajectory in the plasma, Havebeen investigated.The theoretical of electromagnetic field theory of RF induction plasma is introduced.mathematical formulation of vector potential is obtained. A magnetohydrodynamic (MHD)model is used to simulate the RF palsma torch. By reprogramming the software FLUENT,add Lorentz force and Joule heating to the Navier-Stokes and energy equations via UserDefined Functions(UDF). the vector potential equation for the electromagnetic field wassolved by initializing a User Defined Scalar(UDS).The fluid field, temperature field andelectromagnetic field were obtained by coupling calculating. Meanwhile, the variation ofargon properties with temperature is considered in simulating process. For an extendedfield,vanishing boundary conditions is used for magnetic vector potential.Particles were introduced into the plasma torch on the basis of calculating inductionplasma flow field. The interaction between plasma and particles were considered by using theDiscrete Phase Module(DPM) of FLUENT. For the numerical investigation into the silicaparticle heating in induction plasmas. It is found that heat transfer to the particles dependsstrongly on the particles size.In this study, flow field structure and energy transport mechanism of RF inductionplasma torch, as well as silica particle heating and trajectories in induction plasmas wereexplored.The results has certain significance in practical engineering application forspheroidization of silica powder in induction plasma.