Minimum fluidization velocity of particles with different size distributions at elevated pressures and temperatures

Abstract

This paper presents a detailed investigation into the effect of pressure, temperature and particle size distribution (PSD) on the minimum fluidization velocity (Umf). A series of measurement of Umf were carried out under the pressure from 0.1 MPa to 0.5 MPa and the temperature from 300 °C to 850 °C on a lab-scale pressurized fluidized bed reactor for three narrow PSD and three wide PSD (binary, uniform, and Gaussian-type) silica sand particles. The results showed that the Umf for narrow and wide PSDs both decreased with increasing temperature and decreased slightly with rising pressure. Besides, the Gaussian-type mixtures had almost the same Umf as the reference narrow PSD particle, while the Umf of binary and uniform PSD mixtures was larger than these two. Based on the experimental data, a new simple relationship for predicting Umf of the different PSD particles at elevated pressures and temperatures was developed.