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Development of a Computational Code for the Design of Multi-Phase Processes at High Phase Fraction

Objective



Objectives and content
In a broad range of industrial sectors such as in
chemical, pharmaceutical, food, oil, paint and
biotechnology industries multi-phase processes are
abundantly in use. These operations comprise gas-liquid,
liquid-liquid or solid-liquid processes and often
combinations of these classes are encountered. In the
design and operation of these processes one often
utilises scaling rules or correlations as the relevant
physics is complicated and not well developed. This can
be understood if one e.g. realises that lengthscales are
involved of the order of metres (the impeller in a
stirred tank) and also of one micrometer (e.g. the
diameter of a droplet). Modelling of these processes
requires capturing of this large lengthscale regime. In
the last couple of years considerable progress has been
made in the development of the physics related to the
behaviour of the particles and its coupling to the flow
of the fluid in process equipment. The methodology used
is: Computational Fluid Dynamics, where the simulation of
the flow and the consequence of the flow on the particle
size distribution (and vice versa) has now become
possible. This so-called two-phase CFD methodology has
been applied successfully to processes such as
emulsification and aeration provided the number of
particles is relatively small.
It is the objective of this project to extend this
methodology to high phase fraction. This is extremely
relevant as most industrial operations are executed in
that regime for process-efficiency reasons. In order to
be able to develop a robust and flexible simulation code
for that regime, a number of fundamental problems have to
be unravelled: droplet/bubble break-up and coalescence
have to be modelled at high phase fraction, the CFD
methodology has to be extended into that regime which
requires the extension of the physics of turbulent flows
in close relationship with appropriate advanced algorithm
development. In addition to that models need to be
developed on phase-inversion that often takes place in
liquid-liquid dispersions at high phase fraction. In
this project universities will cover these topics and
will build the physical models. Those partners will also
support model-development by dedicated, well-defined
experiments to validate the models. These models will be
amalgamated into a commercial CFD code, STAR-CD, which
will be used in the evaluation of a number of test-cases
as designed and worked out by the industrial partners in
the project. They comprise emulsification in a stirred
tank, liquid-liquid extraction and settling a gas-liquid
fluidised bed and gas-liquid flow in a stirred tank. If
the simulations are successful, they prove the
versatility, reliability and flexibility of the
methodology for dispersions at high phase fractions.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE
Address
Exhibition Road
SW7 2BX London
United Kingdom

Participants (6)

COMPUTATIONAL DYNAMICS LTD
United Kingdom
Address
Prospect Place, Great North Road 85
AL9 5BS Welham Green,hatfieid
Imperial Chemical Industries Plc
United Kingdom
Address
The Heath
WA7 4QD Runcorn
Institut National Polytechnique de Toulouse
France
Address
Chemin De La Loge
31078 Toulouse
Total Raffinage Distribution S.A.
France
Address

76700 Harfleur
UNILEVER NEDERLAND BV
Netherlands
Address
120,Olivier Van Noortlaan 120
3133 AT Vlaardingen
Universiteit Twente
Netherlands
Address

7500 AE Enschede