Chemical kinetics modelling of a decaying SF₆arc plasma in the presence of a solid organic insulator, copper, oxygen and water

Abstract

The composition variations occurring in decaying SF6arc plasmas in the presence of atoms released from the vaporization of organic insulators (e.g. Teflon, polyethylene, polypropylene, megelit, nylon), copper, oxygen and water were studied between 12 000 K and 300 K by means of a chemical kinetics model. From the results obtained at 300 K and a pressure of 101.3 kPa: (i) the role of the impurities on the formation of the SF6decomposition products: SF4 , SOF2 , SO2 F2and S2 F10 , was determined; (ii) it was confirmed that the vaporization of an organic insulator leads to the appearance of CF4and an increase in the generation of the major byproduct (SF4 +SOF2 ) which is correlated to the production of CF4 ; (iii) it was seen that, for a given amount of vaporized insulator, insulators that contain fluorine atoms brought about less SF6decomposition than those that did not.