Thermodynamic and Electrical Properties of Combustion Gas and Its Plasma : (2nd Report, Study of Combustion Inhibition Effect of Potassium Salt Measured by Opposed Jet Diffusion Flame)

Abstract

This study describes the combustion inhibition effect of a potassium salt on propane-air flames by the change of the activation energy of the overall chemical reaction. The extinction limit of an opposed jet diffusion flame and the laminar burning velocity of a premixed burner flame of propane-air were measured to obtain the activation energies. From a theoretical analysis of the opposed jet diffusion flame, the overall activation energy of the chemical reaction against the seeded quantities of potassium salt was calculated using the extinction limit data. Through increasing the potassium salt percentages, the increase of the activation energy, i.e. the decrease of the chemical reaction rate, was shown both analytically and experimentally. The ratio of the activation energies with potassium salt to the ones without obtained from the burning velocity of the premixed flame closely agreed with that from the opposed jet diffusion flame. The relation between the seeded quantities of potassium salt and the activation energies of the overall chemical reaction of propane-air was quantitatively obtained.