Combustion Characteristics of Carbon: Influence of the Zone I-Zone II Transition on Burn-Out in Pulverized Coal Flames

摘要

Transition of reaction fromZone II to Zone I during char combustion in a pulverized coal (pc) flame is shown to result in significant and discontinuous drop, jointly, in temeprature and in reaction rate, with a correspondingly signficant increase in burn-out time. In the particular case studied, as example, the estimated increase in burn-out time is by a factor of a least 3. The reduction in reaction rate is partly ude to a (300 deg C) drop in temeprature, but it is jointly due to the doubling of the (operational) activation energy associated with the Zone transition.