New approaches in thermal plasma technology

Abstract

Thermal plasmas offer unique advantages for materials processing, such as high fluxes of heat and of reactant species. Recent developments have concentrated on improving control of these fluxes across the boundaries surrounding the thermal plasma. Secondary discharges (hybrid plasma generators) and pulse modulation of the plasma have been some of the approaches for this end. The use of such methods is described for selected applications. Plasma characterization through advanced models and diagnostics are concentrating on description of plasma instabilities and various nonequilibrium conditions. Understanding of these effects will allow their use for enhanced processing methods.

Thermal Plasma Synthesis of Nano-Sized Powders

“…Thermal plasmas, normally generated by DC (direct current) arc or inductively coupled RF (Radio Frequency) discharge, can be described as a high enthalpy flame with extremely high temperature fields (1,000~20,000 K) and a wide range of velocity fields from several m/s [1][2][3][4][5] to supersonic values [6][7]. Since the resultant huge enthalpy can be realized for various kinds of plasma forming gases and easily controlled by electricity, thermal plasmas have been expected to facilitate not only fast chemical reactions but also rapid heat transfer in a variety of synthetic routes for nano-sized materials [8][9][10][11].…”

Energy Fluctuations in a Direct Current Plasma Torch with Inter-Electrode Inserts Operated at Reduced Pressure

“…Because of its high energy density, thermal plasma is widely accepted as a processing medium which facilitates high fluxes of radical species, high processing rates, a wide choice of reactants, and high quench rates [1]. A broad range of industrial processing methods have been developed based on thermal plasma technology, and have been intensively applied in the areas of novel material processing, advanced machining, high enthalpy flow ground simulation (e.g.…”

Time-resolved tomographic measurements of temperatures in a thermal plasma jet

“…Progress in these technologies is, among other things, closely connected with the development of new approaches aiming at describing realistic conditions in thermal plasmas [1]. One of the most important parameters needed for the plasma description is temperature.…”