Experimental studies on group ignition of a cloud of coal particles

Technical Report · Mon Jan 01 04:00:00 EST 1990

DOI:https://doi.org/10.2172/6500144· OSTI ID:6500144

Annamalai, K

While the combustion characteristics of a single coal particle are well known, most practical applications of coal combustion involve a large number of particles burning collectively as a group. A group combustion model has been developed which models the transient combustion of a spherical coal cloud. This model predicts ignition of a homogeneous mixture of volatiles and oxygen outside the cloud. The flame then moves to the cloud surface, where it anchors itself until all of the oxygen at the cloud surface is consumed. Two concentric flames are then formed, an outward propagating diffusion flame and an inward propagating premixed/diffusion flame which supplies heat to the particles for pyrolysis. Once the inner flame has consumed all the oxygen in the cloud, pyrolysis is complete and the outer flame consumes the released volatiles. As the volatiles are consumed, the flame approaches the cloud surface. Once all the volatiles have been consumed, the remaining char in the cloud burns at rate controlled by the rate of oxygen diffusion to the cloud. 5 refs., 14 figs.

• Research Organization: Texas A and M Univ., College Station, TX (USA). Dept. of Mechanical Engineering
• Sponsoring Organization: DOE/FE
• DOE Contract Number: FG22-88PC88937
• OSTI ID: 6500144
• Report Number(s): DOE/PC/88937-T8; ON: DE91002676
• Country of Publication: United States
• Language: English

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CHEMICAL REACTIONS
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COMBUSTION
DOCUMENT TYPES
DROPLETS
ELEMENTS
ENERGY SOURCES
FLAMES
FOSSIL FUELS
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