EXPERIMENTAL RESEARCH OF CYLINDER TO BED HEAT TRANSFER IN AGITATED FLUIDIZED BEDS

NOMENCLATUREAc　　 cylinder surface area,m2dc cylinder diameter,mdp mean diameter of solid particles,mD cylinder vessel diameter,mH static bed height,mh average surface-to-bed heattransfer coeffcient,Wm- 2 K- 1hmax maximum average surface-to-bed heattransfer coefficient,Wm- 2 K- 1n rotary speed of agitating mechanism,r/ minL cylinder length,mQ heattransfer rate,WTs heater surface temperature,KTb bed temperature,KU overall superficial gas velocity,ms- 1Umf superficial minimum fluidiza…

EXPERIMENTAL RESEARCH OF CYLINDER-TO-BED HEAT TRANSFER IN AGITATED FLUIDIZED BEDS

Cylinder to bed heat transfer in agitated fluidized beds was studied experimentally. In the experiments, the aluminum particles were used as bed material, the diameter of which ranges from 0.5mm to 2mm. The effects of gas velocity, particles size, and agitator rotary speed on heat transfer were studied. From the experimental results, we have come to the following conclusions: (1) There are optimal ranges for airflow velocity and rotary speed to get optimal heat transfer coefficient; (2) The cylinder to bed heat transfer is greatly affected by gas velocity, rotary speed and particles sizes and the effect of rotary speed on heat transfer is similar to that of gas velocity; (3) Higher heat transfer coefficient is obtained with smaller particles.