CFD modeling to determine the minimum fluidization velocity of particles in gas-solid fluidized bed at different temperatures

Abstract

It is often important to know minimum fluidization velocity of particles in gas-solid fluidized bed at different temperatures and with different fluidizing gases. Generally, carrying out such experiments are often time consuming as well as very expensive. Computational fluid dynamic (CFD) modeling is presently an important tool that can be extended to solve these problems. The present work demonstrates the use and advantages of CFD modeling to study the effect of temperature on fluidization velocity for lithium titanate (Li2TiO3) particles which fall under Geldart B type and air as fluidizing media. 2D simulation of fluidized bed was performed using Eulerian-Eulerian approach. The inlet superficial air velocity was varied and pressure drop across the bed was predicted at different temperatures from 30 to 600°C for spherical particles of diameter from 231 to 780μm. Minimum fluidization velocity was also determined using experiments for validation for different temperatures and diameter of particles. CFD predicts the minimum fluidization velocity with 95% accuracy when compared to experimental observations. The minimum fluidization velocity decreases with increase in temperature which is confirmed with validated model. The data from simulations was also compared with correlations reported in literature.