Thermodynamic Properties at High Temperatures and Particles Present After Arc Extinction in CO₂-CF₃I Mixture

Abstract

Fundamental investigations were carried out to find out the admixing influence of CF₃I to CO₂. Firstly, thermodynamic properties at 0.1MPa were derived in a temperature range of 300-30,000K for various CF₃I-concentrations X_CF3I. Secondly, from the thermodynamic properties, a temperature-reduction factor was determined as a function of the temperature for different X_CF3I. This determination led to the suggestion that admixture of CF₃I to CO₂ at X_CF3I above 0.9 can produce a rapid effect on decay in the temperature of an extinguishing arc. Finally, the principal particles present after an arc extinction were obtained in consideration of the phase transformation of iodine molecules at 0.1MPa. For instance, the principal particles proved to be CO₂, CF₄ and CO in the gaseous phase and I₂ in the solid phase for X_CF3I of 0.01-0.94.