Albin Czernichowski

Electrically assisted partial oxidation of methane

Abstract CO + H 2 synthesis gas is easily obtained from CH 4 + CO 2 mixtures in a new plasma reactor based on gliding discharges (GlidArc) at atmospheric pressure with a high efficiency. Preliminary trials performed in a laboratory reactor at 1.8–4.7 m 3 h −1 gas flow, CO 2 /CH 4 molar ratio of 0.55, 1.13 and 2.17, and up to 3 kW electric power are described. Results are compared with previous results obtained in a controlled arc.

INVESTIGATION OF THE CHEMICAL ACTION OF THE GLIDING AND POINT ARCS BETWEEN THE METALLIC ELECTRODE AND AQUEOUS SOLUTION

The plasma–solution interaction processes for gliding and “point” arcs between the aqueous solution surface and the metal electrode in the gas phase are studied. The plasma, liquid, and surface zones are taken into consideration. The electric field strength is measured, and the gas and electron temperatures and ion composition are estimated for the plasma zone. The cathode fall, water vaporization rate, and active species current yield due to the radiation chemistry mechanism are determined for the surface zone. The efficiency of oxidation of iodine ions and organic dyes by different types of discharge in the liquid zone are investigated. The difference in action of the various discharge types may be connected with various influences of the plasma and surface zone on the oxidation processes.

Wool treatment in the gas flow from gliding discharge plasma at atmospheric pressure

A new method of wool plasma surface treatment at atmospheric pressure employing the stable gas flow excited in gliding electrical discharge (called GlidArc) has been developed. The plasma from a small space between electrodes is drifted by the gas flow into a conic space, towards the base of which, the treated combed top moves. The subjective handle of the treated combed top is unchanged and the whiteness and the dye sorption are increased.

Use of the 447 nm He I line to determine electron concentrations

Abstract The helium 447 nm complex line has been excited in a wall-stabilized arc fed at atmospheric pressure by pure He, He-H 2 , He-Ne-H 2 or He-Ar-H 2 mixtures. Photoelectric endon observations of the central part of the arc channel were made with high spatial (1/600) and spectral (53,000) resolution. A collection of 88 helium 447 nm line profiles, of which 75 were recorded simultaneously with H β and Ne I or Ar II line profiles, yielded information about the electron concentration (2 X 10 20 -2 X 10 22 m -3 ), temperature and relative ion composition of the plasma. Plots have been made of the forbidden to allowed peak separations ( S ), forbidden to allowed relative intensities of the peaks ( F/A ) and dips (i.e. the minimum intensities between lines) to allowed peak intensities ( D/A ) as functions of electron concentration, temperature and ionic composition in different plasmas. The peak separations depend only on the electron concentration. Other characteristic line-profile parameters ( F/A and D/A ) show weak ion motion with a strong electron-concentration influence. We propose simple formulae, which may be useful for practical determinations of the electron concentrations in helium-containing plasmas with an accuracy of ±15% and without taking into account either the chemical composition of the plasma or the temperature.

Injection of Hot Particles in the Plasma Flame

This study deals with experimental and theoretical investigations of preheating of the particles injected into a flame during the process of atmospheric plasma spraying (APS). Prior to the injection in the flame, the particles, delivered from the powder feeder, were heated in a carrier gas. The experimental devices to preheat the carrier gas, based on a principle oflinear, superficial, andvolume heating are discussed. The particle velocity and temperature in the pipeline connected to a preheating device were estimated theoretically using a simple analytical model. Two types of preheating devices were submitted to preliminary tests. The temperature of the carrier gas was measured using a thermocouple for avolumetric device working with a gliding arc discharge. The microstructure and properties of chromium oxide coatings plasma sprayed with the aid of a superficial preheating device are also presented and discussed.

Anomalous Ar I 430.01 nm line profile distortion in an arc plasma

Abstract A strong asymmetry of the Ar I 430.01 nm line profile is investigated for high electron densities (Ne > 1017 cm-3) in an arc plasma operating in pure argon. This asymmetry may be explained by considering the presence of the forbidden 429.9 nm line of Ar I.

An interferometric and spectroscopic argon arc plasma diagnostic

In the spectral diagnostics of an arc plasma, when the halfwidth of the Balmer Hbeta line is measured, there is a certain amount of free choice in the selection of equations giving Ne=F( delta lambda 12/(Hbeta )) and Delta E1=G(Ne, T), the lowering of the ionisation energy. In order to clear up this problem, the argon arc plasma refraction, calculated on the grounds of end-on spectroscopic diagnostics, is compared with results of interferometric measurements. The influence of atoms in excited states on plasma refraction is taken into account. Results show that, for plasma temperature T)11000 K, interferometrically measured refraction is smaller than calculated values. The experiment was performed at four laser wavelengths 457.5, 580.3, 581.9 and 632.8 nm. The arc current was varied over a range from 10 to 100 A.