Suppression of Soot in Flames by Alkaline-Earth and Other Metal Additives

摘要

Experiments were performed to clarify the role of metallic fuel additives in relation to soot suppression in a well defined laboratory-scale diffusion flame. Principal emphasis was given to three alkaline-earth metals; namely, Ba, Sr and Ca. The experiments included Cu, Sn, Li, Na and K as well, but only to the extent that the latter contributed to under standing the details of alkaline-earth behavior. The additives were in the form of aqueous solutions of salts of the preceding metals. The solutions were aspirated into the oxidant flow of a nearly two-dimensional laminar C2H4/air flame emanating from a symmetric Wolfhard-Parker burner. Soot size, number density and volume fraction were determined from Mie scattering. Additive, Alkaline-earth, Flame, Soot, Barium, Strontium, Air pollution, Lithium, Sodium, Potassium. (jes)