Particle Growth in Flames. II: Experimental Results for Silica Particles

Abstract

—Silica particles were extracted at varying distances from the reaction zone of a flat-flame burner. Average particle size was determined by gas adsorption and correlated with growth times ranging from 10 to 130 milliseconds. Growth is consistent with a simple Brownian collision—coalescence model for residence times between 30 to 100 milliseconds where the experimental sticking coefficient is 0.004. Excessive growth at longer residence times and retarded growth at shorter residence times may stem from a variable sticking coefficient, electrical effects or a finite coalescence rate.