Numerical investigation of the minimum fluidization velocity in a gas–solid fluidized bed using discrete phase model

The main purpose of this work is to find a new numerical model that is capable of investigating the minimum fluidization velocity in a gas–solid bed over a broad range of particle diameters and particle densities. In the present work, CFD simulation of a cylindrical gas–solid fluidized bed has been carried out using discrete phase model. Different drag correlations were examined to simulate the momentum between phases. Comparing the numerical values with the experimental values of the minimum fluidization velocity indicates that the drag models of Cheremisinoff and Gupta and Holzer and Sommerfeld have the least deviation, so they are suitable for modeling the drag forces of spherical and non-spherical particles, respectively. Experimental studies were carried out using a 10.5 cm cylindrical bed. The ranges of particles diameter and density vary from 10 μm to 10 mm and 6–6500 kg/m 3 , respectively. Results showed that by 25% enhancement in diameter, density, crosswise sphericity coefficient, and sphericity of particles, the minimum fluidization velocity increases 94, 27, 12.5, and 3.5%, respectively. The numerical results of both spherical and non-spherical particles are in a very good agreement with experimental data within an average error of 6 and 9%, respectively.