Mechanism of Local Fluidization in Converging Packed Beds

The velocity profile on the bed surface of two-dimensional linear-converging beds with 15(degree) and 30(degree) wall angles was measured at different superficial velocities using hot-wire anemometry. The results of the velocity measurements indicate that local fluidization in the corners is caused by the geometry-induced maldistribution of fluid flow, and it occurs when the velocity in the corners exceeds the minimum fluidization velocity of particles. The results of pressure measurements within the bed show the same trend as the velocity profile, providing a qualitative verification of the velocity profile measurement. It is shown that the variation of measured pressure drop over the bed with velocity does not agree with the Ergun equation at high superficial velocities due to the severe maldistribution of fluid flow.