Improving Hygienic Characteristics of Coated Electrodes for Welding High-Alloy Steels

The article presents the results of experimental studies showing that the use of an inverter power supply instead of a diode rectifier provides:: fine-droplet electrode metal transfer which reduces generation time by 46% and transfer time by 28%; transfer of alloying elements from welding materials into the weld metal which reduces its loss from the welding line by 6% and the heat affected area by 3%; reducing the emission rate of welding fumes and their components by 23%; reducing specific emission of welding fumes and their components by 23%

High Power Argon, Nitrogen Plasma Torches

© Published under licence by IOP Publishing Ltd. The paper describes a high power supply for Argon and Nitrogen plasma torches. A high frequency was used in order to drive the pulse width modulation circuit. The average output current consumption (AOCC) was modified from 20A up to 80A by increasing the pulse width from 2μsec up to 3μsec for Argon gas plasma torches. The (AOCC) was reduced from 70A down to 25A by increasing the pulse width from 6μsec up to 8μsec in the case of Nitrogen gas plasma torches

The effect of electrically conductive additives on the plasma pyrolysis of heavy hydrocarbons

© Published under licence by IOP Publishing Ltd. It's shown that the electric discharge initiation of in-situ combustion can be executed by entering conductive additives to hydrocarbon raw materials. It is observed, that the most of all the soot is formed from aromatic hydrocarbons during the plasma pyrolysis. Cracking of hydrocarbons by electric discharge, with conducting additives and precursors of catalysts, leads to formation of carbon and metal nanoparticles

Evaluation method of influence of catalyst precursors on initiation of in-situ combustion and it's dynamics

Copyright 2017, Society of Petroleum Engineers. The growing demand for energy requires alternative technologies for the development of new deposits with tar sands and heavy oil, as well as the rehabilitation of depleted, abandoned deposits. Combining all the advantages of thermal methods, the method of in-situ combustion in the presence of catalyst precursors caused interest in petroleum industry due to the possibility of upgrading or primary refining of heavy oils directly in the reservoir. This article describes an experimental method for studying the effect of catalyst precursors on initiation of in-situ combustion of heavy oils. Thermograms in air atmosphere (combustion curves) for oil-saturated sandstones from Permian deposits in the presence of different precursors were obtained. As a precursor, resinates of copper, cobalt, iron and nickel were used. The possibility of evaluation the catalyst effect on the initiation of in-situ combustion was shown

Interaction of electric and acoustic vibrations in combustion

The results of experimental studies of the interaction of electrical discharges in the acoustic oscillations in the combustion of isobutane are presented in the article. Electric discharges were created using a pulsed high voltage source at specified intervals. The purpose of the study was to determine the feasibility of using electrical pulse action to control combustion. The study was conducted on the specifically designed pattern of the combustion chamber with a swirl burner in the frequency range from 100 Hz to 1400 Hz. The study found that the method of periodic pulsed electrical influences can be used to control the combustion in the combustion chamber model. There is a steady increase in the amplitude of the oscillations in the combustion chamber model. Effects due to the mechanism of interaction of acoustic waves and oscillations heat release from the combustion zone. Estimated physical mechanism is a periodic change in the concentration of ions in the interaction of the combustion zone with the electric field of high potential. The proposed control method is advantageous in terms of energy costs

Functional plasma sprayed coatings on magnesium ceramic substrates.

© Published under licence by IOP Publishing Ltd.The possibility of improving the quality of the titanium articles using ceramic molds with improved surface layer. The improvement is achieved by reducing a porosity of by plasma sprayed Al2O3

Step-Down dc-dc Converter for Low Temperature Plasma

© 2018 Institute of Physics Publishing. All rights reserved. This paper presents a step down converter with a high speed rectifier and filter for Argon plasma torches. Buck circuit with a high frequency pulse width modulation control and very fast MOSFET transistor were used for switching. For Argon (Ar) gas Plasma Torches, and by increasing the pulse width, the average output voltage has modified from 80 V up to 100 V. The frequency of the designed step down converter was steady at 20 KHz

Experimental setup for plasma treatment of disperse materials in the arc plasma jet

The experimental setup for the plasma treatment of particulate materials was created. Spend the processing of composite powder of chromium oxide with aluminium oxide

Development of the setup for study of the gas ionization in the pulsating mode of combustion

© 2018 Institute of Physics Publishing. All rights reserved. At present, known methods of direct conversion of the chemical energy of gaseous fuels to electrical energy are not so effective. This work is directed to developing the setup for experimental study of the gas ionization processes in the pulsating mode of combustion. This problem being solve for the first time. As result, schematic diagram and methodological recommendations will be developed which will be subsequently used for experimental studies

Plasma technologies application for building materials surface modification

© Published under licence by IOP Publishing Ltd.Low-temperature plasma modification of LiYF4 crystal surface in Helium atmosphere caused microhardness decreasing and increasing of roughness of crystal surface. The change of microhardness and morphology is a possible result of Fluorine outgoing from material structure due to heating of surface and plasma chemical reactions and ingoing of Oxygen. As a result of exchange and diffusion processes crystal surface structure become more crumbly, its morphology and mechanical properties change