Two-and three-dimensional analysis on the bubble flow characteristics using CPFD simulation

Bubble flow characteristics in fluidized beds were analyzed by CPFD simulation. A fluidized bed, which had the size of 0.3 m-ID × 2.4 m-high, was modeled by commercial CPFD Barracuda®. Properties of bed material were dp = 150 μ m, p_p = 2,330 kg/m³, and U_mf = 0.02 m/s. Gas was uniformly distributed and the range of superficial gas velocity was 0.07 to 0.16 m/s. Two other geometries were modeled. The first was a three-dimensional model, and the other was a two-dimensional model of 0.01 m × 0.3 m × 2.4 m. Bubble size and rising velocity were simulated by axial and radial position according to superficial gas velocity. In the case of three-dimensional model, simulated bubble rising velocity was different from correlations, because there was zigzag motion in bubble flow, and bubble detection was duplicated. To exclude zigzag motion of bubble flow, bubble rising velocity was simulated in the two-dimensional model and compared to the result from three-dimensional model.