Rh. Hurt et al., HEAT-TRANSFER FROM A MOLTEN PHASE TO AN IMMERSED COAL PARTICLE DURINGDEVOLATILIZATION, Journal of heat transfer, 115(3), 1993, pp. 717-723
In seuerul developmental and commercial processes, coal purticles come
into direct contuct with a high-temperature molten phase. These proce
sses include molten carbonate coal gasification and bath smelting for
the production of iron. Recently, real-time X-ray fluoroscopic images
have been published that show volatile matter evolving rapidly from co
al particles immersed in molten phases, displacing the surrounding mel
t andproducing a periodic cycle offormation, rise, and detachment of g
as cavities. Thepresent work makes use of these obseruations to develo
p a model of heat transferfrom the melt to particles undergoing gas ev
olution. The model is developed for the general case and applied to pr
edict melt-particle heat transfer coefficients under conditions releua
nt to bath smelting processes. The model shows that the presence of th
e gas film can actually increase the overall heat transfer rate under
certain conditions.