Fluidized particle flow is evaluated by the apparent buoyancy acting on a s
phere in the fluidized bed. The apparent buoyancy is simply obtained as fol
lows: the weight of the lead sphere is measured at various positions in the
fluidized glass beads and the difference between the weight in the fluidiz
ed bed and that in the atmosphere is regarded as the apparent buoyancy. The
particle flow coefficient ct is calculated using the distribution of the a
pparent buoyancy to show the strength of the particle flow. Measurements ar
e carried out varying the superficial air velocity, the height of the bed,
the particle size and the sphere size, and the distributions of the apparen
t buoyancy and the values of a are compared. It is found that the fluidized
particle flow can be simply evaluated by the distributions of the apparent
buoyancy and the values of a, and that the difference of the particle flow
under various experimental conditions is proved by them, e.g. the circulat
ing particle flow becomes strong as the superficial air velocity increases.