Modeling of non-equilibrium argon–hydrogen induction plasmas under atmospheric pressure

Watanabe, Takayuki; Atsuchi, Nobuhiko; Shigeta, Masaya

doi:10.1016/j.tsf.2006.02.100

Cited by 10 publications

(8 citation statements)

References 32 publications

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“…Axis symmetry is assumed and physical constants are used from the literature. 22,23) There might be a deviation from local thermodynamic equilibrium for ionization at 30 kPa. 24) However, the two-temperature effect was not considered in this calculation since the objective of this work is not to understand the chemical interactions but to obtain the thermal influence of powder loading on particle heating.…”

Section: Particle Heatingmentioning

confidence: 99%

Effect of powder loading on plasma spheroidization of hydride-dehydride titanium powders

Kambara¹,

Fukuda²,

Ohta³

et al. 2021

Jpn. J. Appl. Phys.

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Spherical titanium particles have been produced from hydride-dehydride titanium raw powders using an inductively coupled plasma spray system. Taking into account the variously modified particle morphologies with different plasma conditions, the effect of powder loading on spheroidization was quantified and evaluated in terms of the altered particle heating capabilities. The averaged particle heat transfer coefficient was found to vary with powder feeding rate and associated strongly with Ar–H2 gas thermal conductivity. Furthermore, there observed a most efficient particle heating condition for each powder feeding rate, but the efficient heating condition tends to vaporize small raw powders and increase the overall oxygen content unintentionally as a result of the attachment of satellites nanoparticles on spherical particles. It is therefore important that the plasma input power is optimally controlled with particular attention to the altered degree of heat transfer especially for the case of small powder injection.

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Section: Particle Heatingmentioning

confidence: 99%

Effect of powder loading on plasma spheroidization of hydride-dehydride titanium powders

Kambara¹,

Fukuda²,

Ohta³

et al. 2021

Jpn. J. Appl. Phys.

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“…For a particle with radius r p and charge c, the electron collision frequency is determined from equation (8), and depends on the electron mass m e , the electron density N e and the electron temperature T e . The attraction or repulsion factor e is calculated from equation (9) or (10), depending on the sign of the particle charge, and c is the particle surface potential, calculated according to equation (11); e is the electron charge.…”

Section: Charging Of Particlesmentioning

confidence: 99%

“…For example, Watanabe et al investigated a series of processes, from evaporation of powder by a thermal plasma, to nucleation and condensation in the quench region, for production of nanoparticles in an inductively-coupled plasma (ICP). The model assumed that all the particles were spherical, so the shape of the nanoparticles could not be investigated [9]. Shigeta and Watanabe extended this work to take into account coagulation of the primary particles, but the assumption of spherical particles was retained [10].…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of the influence of particle charging on the fume formation process in arc welding

Tashiro¹,

Murphy²,

Matsui³

et al. 2013

J. Phys. D: Appl. Phys.

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In order to clarify the influence of electrostatic forces caused by charging of particles on the coagulation process in fume formation in arc welding, a previously-developed fume formation model has been modified to consider the influence of charging, for both local thermodynamic equilibrium (LTE) and non-LTE conditions. The model takes into account formation of the particles from metal vapour by nucleation, growth of the particles by condensation of metal vapour, and coagulation of the particles by collisions to form secondary particles. Results have been obtained for both ballistic and Brownian motion of the particles. It was found that the growth of secondary particles is suppressed when the average particle charge becomes significant, because charging of the particle hinders collisions among secondary particles through the strong repulsive electrostatic force. Furthermore, deviations from LTE strongly affect the coagulation process, because the increased electron density at a given gas temperature increases the charging of particles. Brownian motion leads to larger secondary particles, since the average particle speed is increased. The influence of Brownian motion and particle charging cancel each other to a large extent, particularly when deviations from LTE are considered.

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“…Thermal plasmas provide the advanced tool for waste treatment. For the environmental problems, thermal plasmas have received much attention due to their high chemical reactivity, easy and rapid generation of high temperature, high enthalpy to enhance the reaction kinetics, oxidation and reduction atmosphere in accordance with required chemical reaction, and rapid quenching capability (10 5 -10 6 K s −1 ) to produce chemical nonequilibrium compositions [1][2][3][4][5][6][7][8][9]. Thermal plasmas have been widely applied to many fields because of these advantages.…”

Section: Introductionmentioning

confidence: 99%

Water Plasmas for Environmental Application

Watanabe¹

2010

Industrial Plasma Technology

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Modeling of non-equilibrium argon–hydrogen induction plasmas under atmospheric pressure

Cited by 10 publications

References 32 publications

Effect of powder loading on plasma spheroidization of hydride-dehydride titanium powders

Effect of powder loading on plasma spheroidization of hydride-dehydride titanium powders

Numerical analysis of the influence of particle charging on the fume formation process in arc welding

Water Plasmas for Environmental Application

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