Determination of Heat Transfer Coefficients in Air-Solid Fluidized Bed

Abstract

Abstract The heat transfer of gas-solid fluidized bed has been investigated using pre-heating system. A Perspex column of 7cm inner diameter and 1.5 m height is used as a fluidizing column filling with three different sizes of sand with a height of 21 cm as packing. The experimental work is carried out under superficial air velocities ranged of (0.029-0.365) m/s. The effect of opening area air distributors, particle diameter of sand packing, and different heat fluxes as powers have been investigated. The results show that the minimum fluidizing velocity increases with increasing the particle diameter and opening area of distributor. The gas-particle heat transfer coefficient is found to be increased by increasing superficial velocity, heat flux and opening area of distributor and decreased by particle diameter. A mathematical correlation of dimensionless groups based on experimental data has been suggested. A comparison between results of present correlation and the speculations of previous ones has been made.