STRUCTURE OF A NEAR-LAMINAR COAL JET FLAME

Flame data from a near-laminar coal jet have been compared with model predictions. Inclusion of gas turbulence with laminarization was neces sary for adequately predicting the upper-flame and postflame regions a nd for predicting particle dispersion. Dispersion of gas and particles was insensitive to inlet turbulence intensity. Gas buoyancy induced r adially inward flow that opposed particle dispersion. Gas temperature was predicted too high near the coal nozzle, perhaps due to neglecting finite-rate mixing of volatiles with the bulk gas and chemical kineti cs effects. Single-particle burning effects were important in the flam e zone, as evidenced by the sensitivity of particle temperature to dir ect enthalpy feedback from volatiles combustion. Particle burnout was insensitive to enthalpy feedback, heterogeneous CO2 formation, and che mistry/turbulence interaction.