ABSTRACT
This work presented hydrodynamic performance of pilot-scale pulsed sieve-plate column (PSPC) and pulsed disc-and-doughnut column (PDDC) in different operation modes for the uranyl nitrate/30% (v/v) tributyl phosphate in kerosene system. It was found that the hydrodynamic performance of PSPC and PDDC was similar in the aqueous continuous mode, in which the stainless-steel internal plates were not wettable to the dispersed phase. In the organic-continuous mode, more energy inputting was required to attain a similar dispersion efficiency than that in the aqueous continuous mode. Moreover, the liquid–liquid flow in PSPC exhibited poorer dispersion efficiency than that in PDDC and was easier to run into the flooding regime as the throughput was increased. Wettability of the stainless-steel internal plates and geometrical structure differences between the sieve plates and disc/doughnut plates were the main reasons for these phenomena. Correlations for the prediction of holdup in both PDDC and PSPC were proposed based on experimental results.
Nomenclature
A | = | = pulsation amplitude, m |
Af | = | = pulsation intensity, m s−1 |
Da | = | = aperture diameter of doughnut plates, m |
Dc | = | = column diameter, m |
Di | = | = diameter of inner core, m |
Dd | = | = diameter of disc plates, m |
d | = | = droplet diameter |
F | = | = throughput, m/s |
f | = | = pulsation frequency, s−1 |
Hc | = | = column height, m |
h | = | = plate spacing, m |
p | = | = pressure, Pa |
Q | = | = flowrate, L/h |
R | = | = flow ratio |
Greek letters
α | = | = free area fraction of internal plates |
γ | = | = interfacial tension, N m−1 |
μ | = | = viscosity, Pa·s |
ρ | = | = density, kg m−3 |
ϕ | = | = holdup |
Abbreviations
PDDC = pulsed disc-and-doughnut column
PSPC = pulsed sieve-plate column
TBP = Tri-butyl Phosphate
Acknowledgments
We gratefully acknowledge the support of the National Natural Science Foundation of China (21776151 and 21576147) for this investigation.