Bgm. Van Wachem et al., Validation of the Eulerian simulated dynamic behaviour of gas-solid fluidised beds, CHEM ENG SC, 54(13-14), 1999, pp. 2141-2149
In this paper, a Eulerian-Eulerian CFD model for a freely bubbling gas-soli
d fluidised bed containing Geldart-B particles is developed for studying it
s dynamic characteristics. This CFD model is based on the kinetic theory of
granular flow. Van Wachem et al. (1998a) Comput. Chem. Engng 22 (Suppl.),
S299-S307 have shown that this model is capable of providing reasonable pre
dictions of the time-averaged properties. In this paper, the dynamic charac
teristics of the gas-solids behaviour at different superficial gas velociti
es, at different column diameters, and at different pressures are evaluated
, namely (A) the velocity of pressure and voidage waves through the bed, (B
) the power of the low and high frequencies of the pressure and voidage flu
ctuations, (C) the reorientation of the gas-solids flow just above minimum
fluidisation and the effect of elevated pressure upon this reorientation, a
nd (D) the Kolmogorov entropy. The CFD simulation results for items (A)-(D)
are compared with published experimental data and with appropriate correla
tions from the literature. A good agreement is found between the Eulerian-E
ulerian CFD simulations of bubbling fluidised-bed dynamics, and the data fr
om experiments in the literature. This is a strong incentive for the furthe
r development of this type of simulation models in fluidised-bed reactor de
sign and scale-up. (C) 1999 Elsevier Science Ltd. All rights reserved.