Figure 12.8 shows how the liquid-liquid-solid three-phase fluidised bed is divided in
stirred tanks to represent flow characteristics, see also Table 12.1. The total three-phase
fluidised bed is divided in a number of tanks. The medium is perfectly mixed in each
tank. The gel beads remain in each tank. The organic-solvent phase in each tank is
divided into 15 perfectly mixed tanks-in-series to mimic plug flow behaviour. Mass
balances are derived for single tanks. The total derivation of these balances is given in
appendix A. The resulting dimensionless mass balances with the initial and boundary
conditions are:
Figure 12.8 Schematic representation
of the three-phase fluidised bed
Particle Mass Balancessubstrate
product
Design of liquid-liquid-solid fluidised-bed bioreactors 365