Experiment study on minimum fluidization velocity in fluidized bed with wide particle size distribution at elevated pressure and high temperature

An experimental study of the influence of pressure and temperature on minimum fluidization velocity was carried out in a fluidized bed with an inner diameter of 80mm in the range of operating absolute pressure 0.1~4.5 MPa and temperature 20~800 ℃ with four wide particle-size distributions of different mean diameters.The results show that at a given temperature,minimum fluidization velocity decreases with increasing pressure and that at a given pressure,the effect of temperature on minimum fluidization velocity is dependent on the particle type.Based on Ergun equation and bed stress analysis,an equation about minimum fluidization velocity is proposed,and then reasonable calculation steps about it at elevated pressure and temperature is given.The discrete degree between predicted minimum fluidization velocity and experimental results is in the range of 10 %.Moreover,the accuracy of it is higher than the correlations often employed in literature.It seems that the conclusion is useful for the design and operation of the pressured fluidized bed.