Publications Details

The effect of oxygen enrichment on soot formation and thermal radiation in turbulent, non-premixed methane flames

Shaddix, Christopher R.; Williams, T.C.

A non-premixed coannular burner in which oxygen concentrations and oxidizer flow rates can be independently varied was developed to investigate the effects of turbulent mixing intensity from oxygen enrichment on soot formation and flame radiation. Local radiation intensities soot concentrations and soot temperatures were measured using a thin-film thermopile planar laser-induced incandescence and two-color imaging pyrometry respectively. The measurements showed that soot formation increased as the oxygen concentration decreases from 100% to 50% helping to moderate a decrease in overall flame radiation. An increase in turbulence intensity had a remarkable effect on flame height soot formation and thermal radiation resulting to decreases in all of these parameters. The soot temperature decreased with a decrease in the oxygen concentration and increased with an increase in turbulent mixing intensity. Thus properly designed oxygen-enriched burners that enhance soot formation for intermediate levels of oxygen purity may be able to achieve thermal radiation intensities as high as 85% of traditional oxy-fuel burners utilizing high-purity oxygen.