Degree of dispersion of metal combustion products in a laminar dust flame

This paper presents the results of experimental and theoretical studies of the effect of parameters of laminar dust flames of metal particles (Al, Fe, Ti, and Zr) on the degree of dispersion of the combustion products of these metals in oxygen-containing media. Extensive experiments with Al powders showed that with variation in the mass concentrations of fuel and oxidizer, fuel particle size, type of carrier gas, and conditions of dust flame production, the most probable particle diameter varied in the range of 50–70 nm. Similar results were also obtained for other metals. The results of the experiments agree with numerical calculations. The experiments showed that the particle size of metal combustion products in laminar dust flames can be substantially increasing. The proposed method for controlling the particle size is based on the ionization of the gas phase by adding impurities to the initial fuel to affect nucleation conditions in the flame.