Feasibility of suspension spraying of yttria-stabilized zirconia with water-stabilized plasma torch

Mušálek, Radek; Bertolissi, G.; Medřický, Jan; Kotlan, Jiří; Pala, Zdeněk; Curry, Nicholas

doi:10.1016/j.surfcoat.2014.07.069

Cited by 14 publications

(2 citation statements)

References 19 publications

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“…Some of the important studies of the physical and chemical processes in materials after their interaction with plasma can be found, e.g. in [36][37][38][39][40][41][42][43]. Approximately a decade ago, an experimental plasmachemical reactor PLASGAS was built, equipped with the spraying torch WSP ® H, and was utilized for the investigation of the pyrolysis and gasification of waste streams with the aim of obtaining a high content of a combustible mixture of hydrogen and carbon monoxide (the so-called syngas) [44,45].…”

Section: Introductionmentioning

confidence: 99%

Modeling of inhomogeneous mixing of plasma species in argon–steam arc discharge

Jenista

Takana

Uehara

et al. 2018

J. Phys. D: Appl. Phys.

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This paper presents numerical simulation of mixing of argon- and water-plasma species in an argon–steam arc discharge generated in a thermal plasma generator with the combined stabilization of arc by axial gas flow (argon) and water vortex. The diffusion of plasma species itself is described by the combined diffusion coefficients method in which the coefficients describe the diffusion of argon ‘gas,’ with respect to water vapor ‘gas.’ Diffusion processes due to the gradients of mass density, temperature, pressure, and an electric field have been considered in the model. Calculations for currents 150–400 A with 15–22.5 standard liters per minute (slm) of argon reveal inhomogeneous mixing of argon and oxygen–hydrogen species with the argon species prevailing near the arc axis. All the combined diffusion coefficients exhibit highly nonlinear distribution of their values within the discharge, depending on the temperature, pressure, and argon mass fraction of the plasma. The argon diffusion mass flux is driven mainly by the concentration and temperature space gradients. Diffusions due to pressure gradients and due to the electric field are of about 1 order lower. Comparison with our former calculations based on the homogeneous mixing assumption shows differences in temperature, enthalpy, radiation losses, arc efficiency, and velocity at 400 A. Comparison with available experiments exhibits very good qualitative and quantitative agreement for the radial temperature and velocity profiles 2 mm downstream of the exit nozzle.

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Section: Introductionmentioning

confidence: 99%

Modeling of inhomogeneous mixing of plasma species in argon–steam arc discharge

Jenista

Takana

Uehara

et al. 2018

J. Phys. D: Appl. Phys.

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“…(IPP) in Prague, a DC plasma torch stabilized by both gas (almost entirely argon) and water swirl, or water vortex (so called hybrid plasma torch), has been developed to generate steam plasmas of high mean temperature (⩾15 000 K) and enthalpy (270 MJ kg −1 ) with the input torch power up to 160 kW, approaching the industrial scale. This plasma torch combines the advantages of a gas and water swirl stabilized arc to generate reactive steam plasmas usable (and already successfully utilized) in a wide range of applications as follows: plasma spraying of metallic and ceramic powders (TiO 2 , Al 2 O 3 , ZrSiO 4 , W-based, Ni-based alloys, Al, steel) [16][17][18][19][20][21][22][23], methane reforming [24], pyrolysis and gasification of waste and biomass producing synthetic gas in plasma reactor [25][26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Modeling of argon–steam thermal plasma flow for abatement of fluorinated compounds

Jenista¹,

Chau²,

Chien³

et al. 2022

J. Phys. D: Appl. Phys.

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This study presents a numerical model of the hybrid–stabilized argon–steam thermal DC plasma torch of a new design for generating an argon–steam plasma suitable for efficient abatement of persistent perfluorinated compounds (PFCs). The model includes the discharge region and the plasma jet flowing to the surrounding steam atmosphere contained in a plasma-chemical chamber. Compared to previous studies, the torch had a smaller nozzle diameter (5.3 mm) and a reduced input power (20-40 kW) and arc current (120-220 A). The outlet region for the plasma jet extends to 20 cm downstream of the exit nozzle. Fluid dynamic and thermal characteristics together with diffusion of argon, hydrogen and oxygen species, and distribution of plasma species in the discharge and the plasma jet are obtained for currents from 120 to 220 A. The results of the calculations show that the plasma jet exhibits high spatiotemporal fluctuations in the shear layer between the plasma jet and colder steam atmosphere. The most abundant species in the plasma jet are hydrogen and oxygen atoms near the jet center, and molecules of H2, O2 and OH in colder surrounding regions. Satisfactory agreement is obtained with measurements of the radial temperature and electron number density profiles near the jet center close to the nozzle exit.

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