Heat transfer in circulating fluidized bed

It is noted that most of the models and correlations that are developed are based on bubbling fluidization. However, most of them can be extended to the turbulent regime with reasonable error margins. The overall heat transfer coefficient in the turbulent regime is a result of two counteracting effects, the vigorous gas-solid movement, which enhances the heat transfer and the low particle concentration, which reduces the heat transfer. 

The mechanism of heat transfer in circulating fluidized beds is described in this section. Effects of the operating variables on the local and overall heat transfer coefficients are discussed. 

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Noymer, P. D., Hyre, M. R., and Glicksman, L. R., The Influence of Bed Diameter on Hydrodynamics and Heat Transfer in Circulating Fluidized Beds, Fluidization and Fluid-Particle Systems, AIChE, pp. 86-90 (1995)... 

Burki, V., Hirschberg, B., Tuzla, K., and Chen, J. C., Thermal Development for Heat Transfer in Circulating Fluidized Beds, ALChE Annual Meeting, (1993)... 

Grace, J., Heat Transfer in Circulating Fluidized Beds, Cir. Fluid. Bed Tech., 63-81 (1986)... 

Measurements of heat transfer in circulating fluidized beds require use of very small heat transfer probes, in order to reduce the interference to the flow field. The dimensions of the heat transfer surface may significantly affect the heat transfer coefficient at any radial position in the riser. All the treatment of circulating fluidized bed heat transfer described is based on a small dimension for the heat transfer surface. The heat transfer coefficient decreases asymptotically with an increase in the vertical dimension of the heat transfer surface [Bi et al., 1990]. It can be stated that the large dimensions of the heat transfer surface... 

Basu, P. and Nag, P. K. (1987). An Investigation into Heat Transfer in Circulating Fluidized Beds. Int. J. Heat Mass Transfer, 30,2399. 

Wirth, K. E. Prediction of Heat Transfer in Circulating Fluidized Beds, in Circulating Fluidized Bed Technology IV (Amos A. Avidan, ed), pp. 344-349. Somerset, Pennsylvania (1993). 

Zheng, Q Wang, X, and Li, X. Heat transfer in circulating fluidized beds, in Circulating Fluidized Bed Technology III (P. Basu, M. Horio and M. Hasatani, eds.), pp. 263-268. Pergamon Press, 1991. 

Andersson B.-A. Leckner B. (1992) Experimental methods of estimating heat transfer in circulating fluidized beds. Int. J. Heat/Mass Transfer, 35, 3353-3362. 

TABLE 13.4 Heat Transfer in Circulating Fluidized Beds... 

L. Glicksman, Circulating Fluidized Bed Heat Transfer, in Circulating Fluidized Bed Technology II, R Basu and J. F. Large eds., Pergamon Press, Oxford, 1988. 

Burki V, Hirschberg B, Tuzla K, Chen JC. Thermal development for heat transfer in circulating fluidized beds. AIChE Annual Meeting, St. Louis, MO, 1993. 

Chen JC, Cimini RJ, Dou SH. A theoretical model for simultaneous convective and radiative heat transfer in circulating fluidized beds. In Basu P, Large JF, eds. Circulating Fluidized Bed Technology II. Oxford Pergamon Press, 1988, pp 255-262. 

Glicksman LR. Heat transfer in circulating fluidized beds. In Grace JR, Avidan AA, Knowlton TM, eds. Circulating Fluidized Beds. London Chapman and Hall, 1997, pp 261-311. 

Lints M. Particle to wall heat transfer in circulating fluidized beds. PhD dissertation. Mass Inst Tech Cambridge, MA, 1992. 

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