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2021 |
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Wednesday, May 05, 2010, Sophia Room 10:00 AM Process Diagnostics 2 |
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Influence of the vortex component on jet characteristics and particle velocity when operating a multi-cathode triplex pro plasma torch |
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Jose-Luis Marques / Institute for Plasma Technology and Mathematics,
University of the Federal Armed Forces Munich, Germany Stefan Kirner / Universität der Bundeswehr München, Germany Stephan Zimmermann/ Universität der Bundeswehr München, Germany Günter Forster/ Universität der Bundeswehr München, Germany Jochen Schein*/ Universität der Bundeswehr München, Germany |
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The multi-cathode TriplexPro plasma torch has become one of the favorite tools for spraying coatings with a controlled microstructure. The high stability of the Triplex plasma jet, lacking the otherwise characteristic fluctuations of a single-cathode single-anode torch, stems from the operation of three individual arcs inside a single torch. Nevertheless, in order to increase the energy transfer from these arcs to the jet gas, a vortex component has to be imposed onto the gas flow. This vortex, still visible outside the torch, has a pronounced influence on the temperature distribution in the hot gas jet and thus controls the optimum location for particle injection. Moreover, the resulting velocity distribution of those injected particles is also clearly influenced by this vortex. In this paper these effects on gas jet and particles are quantitatively characterized for typical torch operation parameters and ceramic Al2O3 powder. The applied diagnostics tools are emission Computer Tomography (CT) to investigate the plasma flow and Laser Doppler Anemometry for determining particle velocity and number density distribution. |