Abstract
The synergistic effect of ethylene/propane mixture on soot formation is studied experimentally using a concentric co-flow diffusion burner, which provides the stratified fuel mixture. The soot volume fraction, soot particle diameter, number density and PAH concentrations are measured with various fuel supply configurations and compared to the homogeneously mixed case. When propane is supplied through the inner nozzle, an increase of soot formation is observed. However, when propane is supplied through the outer nozzle, a decrease is observed. The reaction path of PAH's formed from the pyrolysis process of propane is likely to be responsible to the observed differences. When propane is supplied through the outer nozzle, PAH's are formed in the relatively near oxidation region and exposed to the oxidization environment; on the other hand, when propane is supplied through the inner nozzle, PAH's are not likely to be oxidized and thus get involved in soot formation process. The synergistic effect in ethylene/propane diffusion flames is found to be affected not only by the com position of the mixture but also by the way of mixing.
