TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING IEEJ Trans 2009; 4: 504–509 Published online in Wiley InterScience (www.interscience.wiley.com). DOI:10.1002/tee.20436 Paper A Numerical Study of Plasma-Particle Heat Transfer Dynamics in Induction Thermal Plasmas for Glassification M. Mofazzal Hossain ∗ , Non-member Yaochun Yao ∗∗ , Non-member Takayuki Watanabe a∗∗∗ , Non-member Dependence of energy exchange between plasma and soda-lime-silica glass particles on the particle size, powder feed- rate and nozzle insertion length during in-flight thermal treatment for glassification by induction thermal plasmas has been studied. For the numerical investigation into the plasma-particle energy exchange dynamics during melting and vaporization of particles, a thermofluid plasma-particle interaction model has been developed taking into account the strong plasma-particle interactions and particle loading effects. It is found that heat transfer to the particles depends strongly on the particles’ size, powder feed-rate, nozzle insertion length, and plasma discharge parameters. Thus, for the efficient thermal treatment of particles, the above parameters should be optimized.  2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. Keywords: plasma-particle interaction, energy transfer, soda-lime-silica glass, glassification degree Received 11 December 2008; Revised 18 March 2009 1. Introduction Thermal plasma processing has become indispensable in a wide variety of disciplines from nano-materials synthesis to surface treatment of ceramic micro-particles [1,2]. Besides the experimental diagnosis, numerical analysis is important in the research and development of the thermal plasma technologies. After in-flight thermal treatment of particles, the diagnoses of experimental products usually provide information on the final characteristics of the particles.Furthermore, numerical analysis provides an insight to the thermal histories of the particles during in-flight treatment. It is our aim to melt and modify the size, morphology, and composition of granulated soda-lime-silica glass particles by in-flight treatment in an induction thermal plasma reactor. The modeling of particle heating in induction plasmas has been pioneered by Yoshida et al. [3] and Boulos [4]. Later Proulx et al. [5] discussed the particle loading effects taking into account the plasma-particle interaction effects for alumina and copper particles in argon plasmas. a Correspondence to: Takayuki Watanabe. E-mail: watanabe@chemenv.titech.ac.jp ∗ Department of Electronics and Communications Engineering, East West University, 43 Mohakhali C/A, Dhaka-1212, Bangladesh ∗∗ National Engineering Lab of Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, Yunnan, China ∗∗∗ Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, G1-22, 4259 Nagatsuta, Yokohama 226- 8502, Japan In the present work, mathematical modeling of plasma- particle interaction and energy exchange during in-flight melt- ing and vaporization of soda-lime-silica glass particles in argon–oxygen induction thermal plasma has been performed. The objective of this study is to investigate the particle ther- mal treatment in induction thermal plasma, with emphasis on the impacts of feed particle size and powder feed-rate on the plasma–particle energy exchange. 2. Modeling 2.1. Plasma Model Figure 1 shows the schematic geometry of the torch used in the modeling of plasma- particle interaction and flow. Torch dimensions and plasma discharge conditions are tabulated in Table I. The torch consists of a water-cooled coaxial quartz tube, surrounded by 3-turn induction coil. Soda-lime-silica glass powders premixed with carrier gas are injected into the plasma torch through the nozzle tube inserted into the high-temperature region of the plasma torch. The working gases are argon and oxygen. In this model, it is assumed that plasma is in LTE (local thermodynamic equilibrium) condition, and optically thin; plasma flow is 2-dimensional, axi-symmetric, and laminar. Electromagnetic fields are assumed to be 2-dimensional. In this model, the conservation equations are as follows: Mass conservation: ∇· ρu = S C p (1) Momentum conservation: ρu ·∇u = −∇p +∇· μ∇u + J × B + S M p (2)  2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.