The significance of the statistical character of wall-cooled packed-be
d reactors was studied by measuring angular temperature variations whi
ch result from the random nature of the packing. These are neglected i
n present-day mathematical models designed to describe the reactor beh
avior The amplitude of these variations was determined experimentally
as a function of the mass flux and the position in the tube, under con
ditions of heat transfer as well as of reaction. Angular variations ar
e significant whenever radial temperature gradients are large. Differe
nt methods used to average observed variations were surveyed. For the
system presented, the angular variations have only a limited influence
on the reaction rates if the angular averaged temperature is used. Th
us, a two-dimensional deterministic continuum model can be used, notwi
thstanding the statistical character of the packed bed.