EFFECT OF VOIDAGE VARIATION AND BUBBLE ASPECT RATIO ON THROUGHFLOW IN 2-D ELLIPTIC BUBBLES

The first principles hydrodynamic model of gas-fluidized beds has been employed to study the effects of voidage variation and bubble aspect ratio on the magnitude of throughflow velocity in an elliptical bubble. The equations for the throughflow are derived without the restrictive assumption of constant voidage along the surface of the bubble. Numerical calculations of voidage variations and throughflow in elliptical cap bubbles have been compared with the corresponding values in circular cap bubbles. It was observed that the throughflow velocity component at the nose of an elongated bubble is higher than that in a flattened bubble. Comparison with the sparse experimental data on throughflow in single isolated bubbles shows fairly good agreement.