抄録
The elutriation of dust from a batch fluidized bed consisting of fine and coarse particles was investigated. The materials used were dust (JIS Z-8901 (1974), No. 11) for fine particles and sand and glass beads for coarse ones.
The elutriation rate coefficient k was defined as V=kw0exp(-kt), where V=elutriation rate of fine particles, w0=initial holdup of fines and t=time.
The experiment was to determine the effects of the experimental conditions and materials on the elutriation rate coefficient k.
The results were as follows;
(1) k was not affected by the initial holdup of dust and the column length.
(2) k was affected by the holdup of the coarse particles and the humidity in the air as the fluidizing medium.
(3) k was proportional to u2.5 (u=superficial air velocity).
(4) k was affected by the kinds of coarse particles with humid air and was not affected by them with dry air.
(5) The estimated value of k, which was calculated from the reported equation for fine particles above 100μm in diameter, coincided roughly with the one used in the experiment.
(6) The generated dusts were throughly deagglomerated, and their size distribution were independent of time.
