scholarly journals Diagnostics of Plasma Jet Generated in Water/Argon DC Arc Torch

2016 ◽  
Vol 3 (1) ◽  
pp. 5-8
Author(s):  
O. Hurba ◽  
M. Hlína ◽  
M. Hrabovský

Thermal plasma jet generated by the torch with water/argon stabilized arc was investigated. Plasma torches of this type have been used for plasma spraying, waste treatment and gasification of organic materials. Electric probes, enthalpy probe, and schlieren photography were used for diagnostics of the jet in the region downstream of the torch exit. Information about structure and shape of plasma jet was evaluated from the measured data. Large extent of radial plasma spread and high level of turbulence were found from both the schlieren and the probe diagnostics. Plasma temperature corresponding to measured ion saturation currents was determined using calculated composition of plasma assuming ex-istence of local thermodynamic equilibrium.

Author(s):  
Milan Hrabovsky ◽  
M. Konrad ◽  
Vladimir Kopecky ◽  
J. Hlina ◽  
J. Benes ◽  
...  

Author(s):  
R. Bolot ◽  
M. Imbert ◽  
C. Coddet

Abstract Plasma spraying process modeling is useful to understand physical phenomena and to decrease the number of experiments. In this paper, a study of the external plasma jet is proposed: the PHOENICS™ CFD code was used with a 2D axisymmetrical geometry and a standard K-ε turbulence model. In a first step, thermodynamic and transport properties were calculated from chemical equilibrium composition, thermodynamic derivatives and kinetic theory of gases. Local Thermodynamic Equilibrium (LTE) was assumed for both plasma and surrounding gases. The proposed numerical results were computed for comparison with temperature measurements realized by Brossa and Pfender in the case of an argon plasma jet discharging into air, using enthalpy probes. The predictions were found reasonably accurate. The influence of the surrounding gas nature was also verified as the validity of the parabolic assumption.


Author(s):  
G. Barbezat ◽  
K. Landes

Abstract As a new plasma gun technology the TRIPLEX system has been introduced in the industrial field two years ago. The core of the TRIPLEX technology is a plasma gun with three cathodes and a long cascaded nozzle consisting of several insulated rings. Only the last ring with a relatively long distance to the cathode is operated as anode. Because of the equal and constant lengths of the three independent arcs, stretching from the three cathodes to the common anode, a stationary plasma jet is generated. Compared to conventional torches, the improved stability of the plasma jet allows a more uniform powder treatment and a higher deposition efficiency as well as the powder feed rate can be increased using a triple injection system. A significantly longer life time of the electrodes reduces the cost for quality control in the coating process. The characteristic properties of oxide ceramic coatings are improved in comparison with the coatings produced by conventional plasma torches. The results of two years industrial application of the innovative torch system TRIPLEX are presented in the paper.


2013 ◽  
Vol 46 (3) ◽  
pp. 201-208 ◽  
Author(s):  
Sooseok Choi ◽  
TianMing Li ◽  
Takayuki Watanabe ◽  
Takashi Nakayama ◽  
Koji Otsuki

2019 ◽  
Vol 85 (1II)) ◽  
pp. 145-150
Author(s):  
A. S. Cherevko ◽  
A. A. Morozova

The degree and nature of the violation of local thermodynamic equilibrium (LTE) in the analytical zone of a plasma jet generated by an argon arc two-jet plasmatron (TJP) was estimated using an unconventional method based on determination of the nonequilibrium parameterbiequal to the ratio of the experimentally determined actual population of the energy level (ni) of the element to the population of the same level calculated from the Saha equation (nis). Partial ionizing deviation of plasma under study from the equilibrium state takes place only when low-lying atomic levels are overpopulated. The distinct dependence ofbion the ionization potential of the considered element (e.g., Ca, Mg, and Be) is shown. The results were interpreted in the light of the increasing role of radiation processes upon excitation of spectra in the argon arc two-jet plasmatron.


2000 ◽  
Vol 9 (9-10) ◽  
pp. 1673-1677 ◽  
Author(s):  
H. Guo ◽  
Z.L. Sun ◽  
Q.Y. He ◽  
S.M. Du ◽  
X.B. Wu ◽  
...  

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