Segregation of binary particles in pulsed gas-solid fluidized bed

Abstract

Pulsating airflow-driven gas-solid fluidization is an effective method to segregate particles of different densities. The current article presents an elaborate computational study on the development of simulation methodology, and parametric trend identification of pulsating airflow-driven granular segregation for the first time using computational fluid dynamics (CFD), discrete element modeling (DEM) coupled analysis. The rigorous validation of the computational prediction has been produced against the experimental result reported by Li et al. (2021) and an excellent agreement has been observed. Segregation behavior for different density ratios of particles, different patterns of pulsation, and different particle shapes is presented in the current article. The segregation index improves with the density ratio of the binary mixture of particles, but the rate of increment of the segregation index is highly dependent on the airflow rate. Near the optimal value of airflow rate, the rate of increment of the segregation index reduces with the density ratio. Keeping the bed height and material property constant, different patterns of pulsation namely—sinusoidal, triangular, and exponential have been adopted. The segregation index is higher for sinusoidal patterns, whereas it reduces when the pattern is changed to triangular and exponential. Particles of constant volume with different shapes are also considered to understand the effect of particle shape on segregation. The segregation index deteriorates with the increasing surface area of the particle at constant volume.