Force-based analysis of vortexes in atmospheric pressure ICPs

Abstract

The nature of vortices in the gas flow in atmospheric pressure ICPs is analyzed based on comparison of a Lorentz force exerted on the plasma and a gas inertia force. The theoretical analysis is supplemented by numerical modeling and experimental data. The theory is applied to explain a fundamental difference between spectroanalytical ICPs (SICPs), which are used as atomic and ionic sources for elemental analysis, and technological ICPs (TICPs) used for plasma processing of powders. It is shown that in the SICPs the pattern of the gas flow is predominantly determined by gas-dynamic effects. In the TICPs the vortices and the flow pattern are in contrast produced by the Lorentz force. The theory is also applied to find practical ways to reduce the effect of vortices in TICPs.

An experimentally verified three-dimensional non-stationary fluid model of unloaded atmospheric pressure inductively coupled plasmas

“…This complication in the flow pattern is caused by the Lorentz force pinching the plasma in the radial direction. The effect was analyzed in detail in our previous work [24] based on a simplified 2D description of the TICP.…”

“…Then developed models have been applied to optimize operating conditions of 2D axi-symmetric ICP torch equipped with vacuum mass-spectrometer interface [21,22] and to perform coupled thermal simulation and optimization of ICP torch with injected metallic powders [23][24][25][26]. Further development of FLUENT-based models led to full 3D simulations of ICP-based powder processing systems connected to cooling chamber [27,28].…”