The Effect of Oxygen Concentration on Sooting Diffusion Flames

Abstract

In a concentric diffusion flame arrangement, sooting heights were determined as a function of the oxygen concentration in the oxidizing stream. Changing the oxygen concentration has two different and competing effects on the tendency of a fuel jet to soot. Increasing the oxygen concentration increases the stoichiometric flame temperature which in turn increases the fuel pyrolysis and soot formation rates. However, increasing the oxygen concentration also increases the particle burn-up rate in the vicinity of the flame. The initial effect dominates at high oxygen concentrations and the latter at low concentrations. In most practical combustor systems, the temperature would appear to be the controlling parameter.