Spark Chemistry: Can We Control The Energy of the Electrons?
Field T.A., Asimakoulas L., Harkin C., Janda M., Hensel K., Machala Z. 24th Symposium on Applications of Plasma Processes and 13th EU-Japan Joint Symposium on Plasma Processing SAPP XXIV, Štrbské Pleso (Slovakia), Jan 27- Feb 1, p. 51 (2023)
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Abstract: One of the advantages of gliding-arc plasma reactors is the ability to operate in a wide range of composition and flow rate of working gas. Due to the significant influence of gas-dynamic forces, the gas parameters directly affect the shape of the discharge and thus the efficiency of plasma treatment and the requirements for the system geometry. The study presents the results from imaging of discharges in a miniature, two-electrode gliding-arc reactor for applications in environmental engineering and food technology using the high-speed camera (Photron FASTCAM SAZ 2100K). On the basis of the obtained images, the position and speed of the arc were analyzed for two values of the working gas flow rate, which was air, nitrogen or oxygen.
A comparison of the results shows the significant influence of the gas-dynamic forces resulting
from the forced gas flow. At the higher flow rate, the discharges lasted for a shorter time, but the arc was much longer. In addition, it was possible to observe the appearance of a main, longest discharge followed by successive, shorter ones. Adding up the duration of all the discharges per period of the voltage signal, the discharges thus lasted as long as individual discharges at a lower flow rate. Combined with the significantly longer length of the arc itself, represented by the positions of the discharges, the obtained results allow to indicate one of the possible reasons for the higher generation of reactive oxygen and nitrogen species for the higher flow rate. Differences between the different working gas compositions were negligible, where slightly higher arc positions were observed for oxygen as the working gas.
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