Abstract
A particle injected into a thermal plasma will experience a number of effects which are not present in an ordinary gas. In this paper effects exerted on the motion of a particle will be reviewed and analyzed in the context of thermal plasma processing of materials. The primary purpose of this paper is an assessment of the relative importance of various effects on particle motion.
Computer experiments are described, simulating motion of a spherical particle in a laminar, confined plasma jet or in a turbulent, free plasma jet. Particle sizes range from 5 to 50 µm, and as sample materials alumina and tungsten are considered.
The results indicate that (i) the correction term required for the viscous drag coefficient due to strongly varying properties is the most important factor; (ii) non-continuum effects are important for particle sizes <10 µm at atmospheric pressure and these effects will be enhanced for smaller particles and/or reduced pressures; (iii) the Basset history term is negligible, unless relatively large and light particles are considered over long processing distances; (iv) thermophoresis is not crucial for the injection of particles into thermal plasmas; (v) turbulent dispersion becomes important for particle <10 µm in diameter.
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References
K. V. Beard and H. R. Pruppacher, “A Determination of the Terminal Velocity and Drag of Small Water Drops by Means of a Wind Tunnel,”J. Atmos. Sci. 26, 1066 (1969).
M. I. Boulos and W. H. Gauvin, “Powder Processing in a Plasma Jet, a Proposed Model,”Can. J. Chem. Eng. 52, 355 (1974).
D. Bhattacharyya and W. H. Gauvin, “Modelling of Heterogeneous Systems in a Plasma Jet Reactor.”AIChE J. 21, 879 (1975).
M. I. Boulos, “Heating of Powders in the Fire-Ball of an Inductive Plasma,”IEEE Trans. Plasma Sci. 4, 93 (1978).
F. J. Harvey and T. N. Meyer, “A Model of Liquid Metal Droplet Vaporization in Arc Heated Gas Streams,”Metall. Trans. B 9, 615 (1978).
T. Yoshida and K. Akashi, “Particle Heating in a Radio-Frequency Plasma Torch,”J. Appl. Phys. 48, 2252 (1977).
J. K. Fizsdon, “Melting of Powder Grains in a Plasma Flame,”Int. J. Heat Mass Transfer 22, 749 (1979).
Y. C. Lee, K. C. Hsu, and E. Pfender, “Modeling of Particles Injected into a d.c. Plasma Jet,” 5th Inter. Symp. on Plasma Chemistry, Edinburgh, Scotland, 1981.
Y. C. Lee, “Trajectories and Heating of Particles Injected into a Thermal Plasma,” Masters' Thesis, Department of Mechanical Engineering, University of Minnesota (1982).
M. Vardelle, A. Vardelle, P. Fauchais, and M. I. Boulos, “Plasma-Particle Momentum and Heat Transfer: Modeling and Measurement,”AIChE J. 29, 236 (1983).
N. El-Kaddah, J. McKelliget, and J. Szekely, “Heat Transfer and Fluid Flow in Plasma Spraying,”Metall. Trans. B 15, 59 (1984).
R. Clift, J. R. Grace, and M. E. Weber,Bubbles, Drops, and Particles, Academic Press, New York (1978).
B. Waldie, “Review of Recent Work on the Processing of Powders in High-Temperature Plasmas. Part II: Particle Dynamics, Heat Transfer and Mass Transfer,”The Chemical Engineer, May, p. 188 (1972).
J. A. Lewis, and W. H. Gauvin, “Motion of Particle Entrained in a Plasma Jet,”AIChE J. 19, 982 (1973).
C. T. Crowe, “Gas-Particle Flow,” inPulverized-Coal Combustion and Gasification, L. D. Smoot and D. T. Pratt, eds., Plenum Press, New York (1979), p. 107.
C. Sheer, S. Korman, D. J. Angier, and R. P. Cahn, “Arc Vaporization of Refractory Powders,” inFine Particles, William E. Kuhn, ed., 2nd International Conference of the Electrochemical Society, 1974.
F. M. White,Viscous Fluid Flow, McGraw-Hill, New York (1974).
X. Chen, and E. Pfender, “Effect of the Knudsen Number on Heat Transfer to a Particle Immersed into a Thermal Plasma,”Plasma Chem. Plasma Process. 3, 97 (1983).
X. Chen and E. Pfender, “Behavior of Small Particles in a Thermal Plasma Flow,”Plasma Chem. Plasma Process. 3, 351 (1983).
W. F. Phillips, “Drag on a Small Sphere Moving through a Gas,”Phys. Fluids 18, 1089 (1975).
F. Odar, “Verification of proposed equation for calculation of forces on a sphere accelerating in viscous fluid,”J. Fluid Mech. 25, 591 (1966).
L. Talbot, “Thermophoresis—A Review,” inRarefied Gas Dynamics, S. S. Fisher, ed., AIAA Book, Vol. 74 (1981), p. 467.
J. R. Brock, “On the Theory of Thermal Forces Acting on Aerosol Particles,”J. Colloid Sci.,17, 768 (1962).
J. R. Brock, “Force Associated with the Temperature Gradient on a Small Particle Suspended in a Plasma,”Nature (London)204, 69 (1964).
A. D. Gosman and E. Ioannides, “Aspects of Computer Simulation of Liquid-Fueled Combustors,” AIAA Paper No. 81-0323 (1981).
J-S. Shuen, L-D. Chen, and G. M. Faeth, “Evaluation of a Stochastic Model of Particle Dispersion in a Turbulent Round Jet,”AIChE J. 29, 167 (1983).
X. Chen, Y. C. Lee, and E. Pfender, “The Importance of Knudsen and Evaporation Effect,” 6th International Symp. on Plasma Chemistry, Montreal, Canada, 1983.
Y. C. Lee, “Modeling Work in Thermal Plasma Processing,” Ph.D. Thesis, Department of Mechanical Engineering, University of Minnesota (1984).
J. McKelliget, J. Szekely, M. Vardelle and P. Fauchais, “The Temperature and Velocity Fields in a Gas Stream Exiting a Plasma Torch,”Plasma Chem. Plasma Process. 2, 317 (1982).
S. V. Patankar, and D. B. Spalding,Heat and Mass Transfer in Boundary Layers, Intertext Books, London (1972).
G. E. Klinzing,Ga-Solid Transport, McGraw-Hill, New York (1981).
P. Eisenklam, S. A. Arunachalam, and J. A. Weston, “Evaporation Rates and Drag Resistance of Burning Drops”, 11th Symposium on Combustion, California, 1960, p. 715.
R. D. Ingebo, “Heat Transfer and Drag Coefficients for Enthanol Drops in a Rocket Chamber Burning Ethanol and Liquid Oxygen,” 8th Symposium on Combustion, 1962, p. 1104.
A. Williams, “Combustion of Droplets of Liquid Fuels: A Review,”Combust. Flame 21, 1 (1973).
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Pfender, E., Lee, Y.C. Particle dynamics and particle heat and mass transfer in thermal plasmas. Part I. The motion of a single particle without thermal effects. Plasma Chem Plasma Process 5, 211–237 (1985). https://doi.org/10.1007/BF00615122
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DOI: https://doi.org/10.1007/BF00615122