High-frequency Torch Discharge Research Articles

Застосування факельного розряду і парогенератора для шоопування поверхонь матеріалів

Subject and Purpose. The present paper is concerned with the method of surface schooping of materials using high-frequency torch discharge (HFTD) and glycerol vapor as a base for dissolving activating additives to the working gas. To approach the problem, a steam generator is employed in an effort to improve the HFTD catalytic performance in the activation of surfaces and deposition of coatings on them. The purpose is to develop a design technique of a steam generator intended for making a proper gas environment in the HFTD burning area. The discussed design techniques seek to enhance efficiency of the self-contained steam generator with allowance for its small size compared to the wavelength. Methods and Methodology. The analysis of the glycerol vapor behavior in the HFTD plasma depends on the knowledge of glycerol molecule ionization potential in the electron impact case. To find out about the measure to which the glycerol vapor affects the HFTD current, a known calcium ionization potential is used as a defined point. The heating elements as part of the steam generator are designed in terms of thermal design methodology adopted in the electroheating machine making. The calculation formulas of the running time ratios of the steam generator with various heating elements and energy efficiencies have been obtained in terms of galvanic cell theory. Results. It has been shown that glycerol vapor itself cannot affect the HFTD current. For the HFTD excitation, the microwave region has been chosen. In cooperation with activating additives to the discharge plasma, this factor also adds to the HFTD current increase. Hence, the HFTD catalytic performance depends not only on the HFTD energy and its excitation field frequency but on the glycerol-dissolved additives as well. A special design has been developed for the heating element as part of a small-size steam generator. Reference tables have been composed, enabling one to pick up a prpoper diameter and number of parallel connected wires in the spiral coil. Conclusion. A good use of glycerol vapor as a base for vaporous fluxes and activating additives to the HFTD working gas has been shown. The developed design technique concerning the heating element of the steam generator optimizes its heating circuit. Specifically, it enhances the steam generation and reduces the power consumption of the steam generator running on the galvanic cell. Second, it makes it possible to use stainless-steel spiral heating coils in regime of automatic temperature control.

Effect of plasma suppression additives on electrodynamic characteristics of the torch discharge burning in the air

The paper shows the results of measurements of wave number of electromagnetic wave, which supports burning of high-frequency torch discharge in the mixture of air with water vapor and carbon dioxide. The nonmonotonic dependence of attenuation factor of electromagnetic waves is set on a concentration of water vapor. It is shown that the attenuation degree of electromagnetic field in the plasma with water vapor significantly exceeds the attenuation degree of electromagnetic field in the plasma with carbon dioxide.

Особенности электродинамики высокочастотного факельного разряда, горящего в аргоне

Особенности электродинамики высокочастотного факельного разряда, горящего в аргоне

Features of the Distribution Process of the Electromagnetic Field Frequency Components in the High-Frequency Torch Discharge Plasma

The measurements of axial harmonics distribution of the radial component of the electric field have been made for a torch discharge burning in argon and argon-air mixture. The resonant character of the electric field fourth harmonic attenuation has been found. Using the Saha formula for the two-temperature plasma the electrons concentration and the electrons Langmuir frequency of the investigated plasma discharge have been evaluated.

Nonlinear Electrodynamic Effects of the Torch Discharge Argon Plasma

The measurements of the amplitude-frequency characteristics were done for the high-frequency torch discharge burning in argon. The resonant character of the electric field fourth harmonic attenuation was found. The axial harmonics distribution measurements of the electric field were done for the torch discharge burning in argon-air mixture. The electron concentration in the investigated plasma discharge was evaluated. The selective influence of the change in the electron concentration on the propagation process of the fourth harmonic of the electric field was found.

The influence of the axial heterogeneity of the plasma of high-frequency torch discharge on its electrodynamic characteristics

Measuring results for axial distribution of gas temperature of high-frequency torch discharge burning in the air at atmospheric pressure are presented. The distribution of electric field over the discharge axis was calculated based on the model of discharge in the form of heterogeneous electric line of finite length. It is shown that the experimentally observed linear character of electric field change along the discharge axis is conditioned by its axial heterogeneity.

Amplitude—frequency characteristics of an electromagnetic field in the high-frequency torch discharge

Measured axial distributions of harmonic components of the electric field of the torch discharge in argon at different frequencies of the fundamental harmonic are presented. It is found that the fourth electromagnetic field harmonic decays in the resonance manner.

Determination of electric characteristics of a high-frequency torch discharge

Electric characteristics of a high-frequency torch discharge measured by the resonance method are presented. It is shown that discharge capacity determined by the modified Neumann scheme is close to the value of electrostatic capacity. Capacity of discharge channel was calculated with consideration of propagation of a surface electromagnetic wave along this channel.

The electromagnetic field characteristics of the high-frequency torch discharge

The axial distribution measurements of the electric field harmonic component amplitudes of the high-frequency torch discharge operating in air, argon and helium were carried out. The truth of the high frequency torch discharge model, considering reflection of the electromagnetic wave at the end of the discharge channel, was examined on basis of this experimental data. The absence of coefficient variation of electromagnetic field damping due to the frequency in case of flare discharge ignition in air or argon was found. The ion and electron plasma frequencies estimation of the high-frequency torch discharge operating in various gases was carried out. The suggestion about parametric interaction of the external electromagnetic field with the own oscillations of the discharge plasma was formed.

Distribution of the Electromagnetic Field of a High-Frequency Capacitive Filamentary Discharge Operating at Atmospheric Pressure

Results are presented from measurements of the electromagnetic field of a high-frequency capacitive discharge operating in air and argon at atmospheric pressure. The experimental results are compared to those obtained for a high-frequency torch discharge.

Excitation of Copper in a High-Frequency Torch Discharge

A 2449 MHz torch discharge was used at 300 to 500 W as an excitation source for spectrochemical analysis of copper.The spectra were measured photoelectrically.The sample was put on a graphite electrode.Nebulized pure water was supplied to the discharge with argon as the carrier gas.Feeding rates of argon gas and pure water were 5.3l/min and 0.22 g/min, respectively.The stability and the reproducibility of the intensity of the line CuIλ 3247.5Å were as good as 3 and 4%, respectively.The intensity of the line FeIλ 3719.9Å was so stable that the fluctuation in it was as low as 4%, while the intensity of the line PbI λ 4057.8Å decreased with time.The detection limits for iron and lead in copper were 1 ppm and less than 1 ppm, respectively.

High-Frequency Torch Discharge as Excitation Source for Spectrochemical Analysis

High-Frequency Torch Discharge as Excitation Source for Spectrochemical Analysis