On feasibility of decreasing metal fuel content in chemical oxygen generators

Sodium chlorate based mixtures for oxygen generators include metal fuels, which may produce instabilities and increase risk of fire. Eliminating or at least decreasing the metal content would improve the process stability and fire safety of the generators. In the present paper, thermal decomposition of sodium chlorate based mixtures with different concentrations of cobalt oxide catalyst and metals (iron and tin) is studied using thermogravimetric analysis. The effect of decreasing the catalyst particle size to nano scale is investigated. The possibility of decreasing the decomposition temperature of sodium chlorate by high-energy mechanical milling of its binary mixtures with cobalt oxide is explored. Thermodynamic calculations of the adiabatic combustion temperatures are conducted for the tested binary and triple compositions. The comparison of the characteristic decomposition temperatures, obtained in the experiments, with the predicted adiabatic combustion temperatures indicates that it is possible to achieve self-sustained propagation of the decomposition wave with no metal fuel or at least with a lower metal content.