Minimum Fluidization Velocity of Binary Particles with Different Geldart Classification

Abstract

The minimum fluidization behavior of four different binary particle systems with different Geldart classification is experimentally investigated by carrying out slow defluidization of an experimental cold device of I.D. 300 mm and height 3 m. The solid particles are four kinds of quartz sand particles with equal density, corresponding to Group A, B, C and D particles of Geldart classification, respectively. The fluidization processes can be divided into packing state, partial fluidization state and complete fluidization state. The difference in physical properties and mass fraction of the two constituent solid phases is found to strongly influence the fluidization behavior and the minimum fluidization velocity during the slow defluidization process. For binary particle systems, the minimum fluidization velocity decreases with increasing mass fraction of the component whose fluidization quality is better. Finally, the models of Noda et al. (1986), Cheung et al. (1974) and Chiba et al. (1979) are used to predict the minimum fluidization velocity of above binary particle systems.

Significance of the particle physical properties and the Geldart group in the use of correlations for the prediction of minimum fluidization velocity of biomass–sand binary mixtures

“…Although the classification is based on basic properties (density and size), it incorporates the extent of interparticle interactions in the bed and is the most widespread classification in the field of fluidized beds. This classification has already been considered for the study of biomass fluidization (not in a mixture) by several authors [9,10] and has also been highlighted as an important aspect to be considered in binary beds [11].…”