A. Cockx et al., Use of computational fluid dynamics for simulating hydrodynamics and mass transfer in industrial ozonation towers, CHEM ENG SC, 54(21), 1999, pp. 5085-5090
Ozonation is often used for drinking water disinfection. Ozonation lower is
usually used to dissolve the ozonated gas in water by mass transfer betwee
n the two phases. In particular, bubbly flow is chosen due to its high inte
rfacial area. The main objective of the present paper is to upgrade industr
ial ozonation tower by using the computational fluid dynamics software ASTR
ID adapted to such flows. Hydrodynamics is simulated and numerical results
are compared to global measurements of residence time distribution (RTD). T
hen ozone mass transfer is simulated and results are compared to local meas
urements of ozone concentration in water. A more complete validation of the
methodology and the choice of closure relations has been done previously i
n an airlift reactor (Cockx, Chemical Engineering Science, 1997, 52(21/22)
3787-3793). Numerical results are in good agreement with experimental measu
rements. Accounting for the water quality and for the ozone consumption in
the gas phase, it is possible to simulate in the two-phase flow reactor the
zones with high ozone concentration and be able to predict the inactivatio
n level for the micro-organisms. After validation, the same method is used
to propose an upgraded tower allowing to double the efficiency of the disin
fection process. (C) 1999 Elsevier Science Ltd. All rights reserved.