Figure 11.3 Residence Time
Distribution (RTD) curves obtained at
Rep=95, in a packed bed reactor with
particles of 6 mm diameter and water
as fluid.
Figure 11.4 shows the dependency of the axial dispersion coefficient (DA) on the feed
flowrate, when operating at different pulsation frequencies with two fluids of different
viscosities. The results are compared with those from the equipment without pulsation.
As is predictable, the fluid flowrate increases DA independently of the pulsation
frequency, a phenomenon which also occurs in the experiments without pulsation. When
pulsation is applied at low frequencies and high flowrates (higher amplitudes) the effect
of pulsation on DA is more significant.
20% sucrose-water solutions (2 cP), with viscosity characteristics similar to those of
many fermentation broths, were used to quantify the effects of viscosity on the dispersion
Multiphase bioreactor design 336