In order to increase the movement of the particles in the annular region of
a conical spouted bed, a mechanical stirrer was incorporated. This led to
a study of the fluid dynamics of the conical spouted bed of inert particles
under different operating conditions: mass of inert particles, ratio of in
ert particles to suspension volumes, type of stirrer (2 designs) and stirre
r speed.
The action of the stirrers resulted in increased movement of the particles,
especially at low rpm values (less than or equal to 90 rpm), with the loss
of the annular region, and thus approaching the beds behavior to that of a
fluidized bed. To characterize this novel type of Spouted beds, the "minim
um spouting flow" (Q(ms)) parameter which is used usually was replaced by t
he "minimum pseudo-fluidizing flow" (Q(mpf)) The value of Q(mpf) decreases
when the agitation in the bed increases. A correlation for Q(mpf) with the
different operating conditions was developed.
Drying suspensions in the stirred spouted bed shows a considerable increase
of drying capacity, over units without agitation.