Measurements were conducted in both 0.10 and 0.14m
diameter columns for the perforated plate and bubble cap
distributors, with glass beads of 0.001 and 0.003m diameters,
and acetate beads of 0.003m diameters. The results are
shown in Table 1. In the operating range of Ul/Umf (the
ratio of superficial liquid velocity to minimum fluidizing velocity)
from 1.7 to 3.1, the overall averaged solids holdup
measured by bed expansion and pressure drop decreases
with increasing superficial liquid velocity. It was also found
that 0.001m particles yield higher solids holdup than the
0.003m particles at the same Ul/Umf .