Numerical investigation into the characteristics of a vortex in an argon inductively coupled plasma

Abstract

A numerical simulation of a technical radio frequency inductively coupled plasma was made with three coils and coupled power in the range of 2-10 kW. The generator frequency varied from 1.76 to 13.56 MHz. The mechanisms of forming a vortex on the upstream side of the discharge and the influences of coupled power, generator frequency and flow rate of central gas on the vortex dimensions were studied. Special attention was paid to investigate two different kinds of vortex flow pattern-Benard and toroidal-as well as the vortex intensity under those two kinds of flow pattern. A critical flow rate of central gas, above which the flow pattern would transform from a Benard to a toroidal vortex, was found on the basis of force balance between the dynamic head of central cool gas and magneto-hydrodynamic and Stokes drag forces of plasma. The influences of coupled power, generator frequency, diameter of the injection probe and the compositions of central gas on the critical flow rate of the central gas were discussed. The dependences of the vortex intensity and maximum vorticity on the coupled power under different generator frequencies and flow rates of central gas were established.

Prediction of extinguish boundary of radio frequency thermal plasma torch within carrier gas injector

“…The injection probe is water-cooled and the temperature is T = 300 K. At the outlet (Z4 = 200 mm) the pressure of ICP torch is constant and set at 1atm. The boundary conditions for the vector potential formulation are given as in accordance with [4].…”

Dynamic heating and thermal destruction conditions of quartz particles in polydisperse plasma flow of RF-ICP torch system

“…The Maxwell's equations are written as in [22] under the assumption of quasi-stationary approximation. Taking into account of the electromagnetic forces, Joule heat, radiation loss and gas-particle interaction, the magneto-hydrodynamic equations for the subsonic multicomponent polydisperse flow could be written as follows [23]:…”

“…t are the turbulent viscosity and thermal conductivity, respectively. E, B and J are the electric and magnetic fields, as well as the induction current in plasma, which are determined by solving the system of Maxwell's equations [22].…”

Gas dynamic-thermal-concentration fields and evaporation process of quartz particles in Ar–H2inductively coupled plasma

“…The electric and magnetic field in the calculating domain could be established by solving the following equation expressed by the magnetic vector potential A [29]:…”

“…The discharge current in the coil is assumed uniformly distributed J coil = 4I coil /πd 2 coil . Since the calculation domain include the inductor coil and plasma regions, as well as the walls and free space regions around the plasma and inductor coil [29], the specific forms of equation ( 2) in those regions would be written as follows:…”