GAS-FLOW DISPERSION IN JET-SPOUTED BEDS - EFFECT OF GEOMETRIC FACTORS AND OPERATING-CONDITIONS

The validity of using a dispersed plug-flow model to represent the gas flow in jet-spouted beds has been proven using a large number of experimental systems. The application of the model for calculation of the dispersion coefficient in the flow direction requires the knowledge of velocity profile in the contactor. The model allows for a simplified solution (one-dimensional model) for certain angle-inlet diameter combinations: gamma < 33 degrees and D-0/D-i > 2/3. Under these conditions the gas-flow rate is maintained constant along each and every one of the stream tubes established in the model. The effect of both the geometric factors of the contactor (angle and gas inlet diameter/base diameter ratio) and the operating conditions (particle diameter and gas velocity at the inlet) on the dispersion coefficient has been studied.