scholarly journals SURFACE-RENEWAL MODELS FOR HEAT TRANSFER BETWEEN WALLS AND FLUIDIZED BEDS.

1967 ◽  
Author(s):  
R.D. Patel
Keyword(s):  
Heat Transfer ◽  
Fluidized Beds ◽  
Surface Renewal ◽  
Renewal Models

scholarly journals Wall-to-Suspension Heat Transfer in a CFB Downcomer

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Huili Zhang ◽  
Jan Degrève ◽  
Raf Dewil ◽  
Jan Baeyens
Keyword(s):  
Heat Transfer ◽  
Fluidized Beds ◽  
Waste Heat ◽  
Circulation Rate ◽  
Circulating Fluidized Beds ◽  
Surface Renewal ◽  
Model Predictions ◽  
Heat Transfer System ◽  
And Storage ◽  
Model Expression

With the development of circulating fluidized beds (CFB) and dense upflow bubbling fluidized beds (UBFB) as chemical reactors, or in the capture and storage of solar or waste heat, the associated downcomer has been proposed as an additional heat transfer system. Whereas fundamental and applied research towards hydrodynamics has been carried out, few results have been reported on heat transfer in downcomers, even though it is an important element in their design and application. The wall-to-suspension heat transfer coefficient (HTC) was measured in the downcomer. The HTC increases linearly with the solids flux, till values of about 150 kg/m2 s. The increasing HTC with increasing solid circulation rate is reflected through a faster surface renewal by the downflow of the particle-gas suspension at the wall. The model predictions and experimental data are in very fair agreement, and the model expression can predict the influence of the dominant parameters of heat transfer geometry, solids circulation flow, and particle characteristics.

A Model of Heat Transfer in Fluidized Beds

1972 ◽  
Vol 94 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Benjamin T. F. Chung ◽  
L. T. Fan ◽  
C. L. Hwang
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
Nusselt Number ◽  
Fluidized Beds ◽  
Transfer Coefficients ◽  
Surface Renewal ◽  
Heat Transfer Coefficients ◽  
Fluidized System ◽  
The Heat Transfer Coefficient

An expression for estimating the heat transfer coefficient in a fluidized bed has been developed based on the surface renewal and penetration concept. The predicted heat transfer coefficients between walls and beds agree well with experimental results. The result of this analysis shows that, in general, the effect of thermal conductivity of particle on heat transfer is insignificant. The maximum possible Nusselt number for the gas fluidized system is determined theoretically as 13.5. This value appears to be reasonable in light of the majority of available experimental data.

Wall-to-bed heat transfer in gas-solid bubbling fluidized beds

AIChE Journal ◽  
2005 ◽  
Vol 52 (1) ◽  
pp. 58-74 ◽  
Author(s):  
D. J. Patil ◽  
J. Smit ◽  
M. van Sint Annaland ◽  
J. A. M. Kuipers
Keyword(s):  
Heat Transfer ◽  
Fluidized Beds
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