Mesure de l'energie d'inflammation de melanges gazeux par decharge capacitive inflammation par decharge d'une personne chargee d'electricite statique

Abstract

A method of measuring the ignition energy of mixtures of gases by a single electric spark from a capacitive discharge has been developed and a study has been made, at 23°C and at 1 bar, of the influence of several parameters which play an important role in the ignition energy, particularly: the electrode spacing, the value of the capacity, the profile shape of the electrodes, and the composition of the combustible gas mixture. In the case of mixtures of air and 28% hydrogen and of air and 8.5% of methane it is found that for the minimum energy of ignition by a single spark the values are even less than the smallest values found in the literature. The minimum energy always corresponds to a very low value of the capacity, a few picofarads, and depends rather little upon the form of electrode used; in the case of energies of ignition significantly greater than the minimum energy the role of the form of the electrode used is predominant. The ignition energy, through discharge of a person charged with static electricity, is never lower than the ignition energy through discharge of a capacitor having the same value as an operator relative to his surroundings. It is therefore clearly greater than the minimum ignition energy.