The scaling relationships proposed by Glicksman (Chem. Engng Sci. 39,
1373-1379, 1984) for fluidized-bed scale-up have been modified to prov
ide a full set of scaling parameters for spouted bed scale-up. A force
balance for particles in the annulus region of a spouted bed leads to
addition of two non-dimensional parameters, the internal friction ang
le (phi) and the loose packed voidage (epsilon(o)) to the original Gli
cksman scaling relationships. Experimental verification of the full se
t of modified scaling parameters was conducted, first in a series of s
mall spouted beds, then in larger columns up to 0.914m in diameter, an
d finally in a pair of high-temperature (500 degrees C) columns. Both
viscous and inertial forces were important for the conditions investig
ated so that the full set of scaling parameters is tested initially. I
t is demonstrated that the full set of modified scaling parameters is
valid for spouted beds when all dimensionless parameters are matched b
etween the prototype bed and model beds. For example, a corresponding
dead zone was observed at the bottom of the annulus not only in the 0.
914 m diameter column, but also in a properly scaled 0.152 m diameter
column. Reasonably, close similarity could also be achieved by substit
uting U/U-ms for the Reynolds number as a dimensionless group. Success
ful scaling could not be achieved by varying only the bed and particle
dimensions. Internal angles of particle friction and sphericities sig
nificantly influence the maximum spoutable depth, fountain height and
longitudinal pressure profiles, showing that particle-particle interac
tion forces cannot be ignored in spouted bed scale-up. Copyright (C) 1
996 Elsevier Science Ltd.