Segregation and intermixing in polydisperse liquid-solid fluidized beds:
A multi-fluid model validation study
Abstract
Multifluid model (MFM) simulations have been carried out on liquid-solid
fluidized beds (LSFB) consisting of binary and higher-order polydisperse
particle mixtures. The role of particle-particle interactions was found
to be as crucial as the drag force under laminar and homogenous LSFB
flow regimes. The commonly used particle-particle closure models are
designed for turbulent and heterogeneous gas-solid flow regimes and thus
exhibit limited to no success when implemented for LSFB operating under
laminar and homogenous conditions. A need is perceived to carry out
Direct Numerical Simulations of liquid-solid flows and extract data from
them to develop rational closure terms to account for the physics of
LSFB. Finally, a recommendation flow regime map signifying the
performance of the MFM has been proposed. This map will act as a
potential guideline to identify whether or not the bed expansion
characteristics of a given polydisperse LSFB can be correctly simulated
using MFM closures tested.