Particle motion in fluidised beds
When a gas is passed upwards through a bed of granular material such as
sand, there comes a point as the gas flow is increased at which the bed
becomes supported by the resulting drag forces. At this point the bed is
considered to be “fluidised”, and the corresponding flow rate is termed the
“minimum fluidisation velocity”.
Fluidised beds are used for many industrial operations, including performing
chemical reactions. Most polyethylene is made this way, for example. In such
operations, the history of the particles, which are often reactants, products or
catalysts, is important, but modelling techniques are very approximate.
The proposed supervisor, Professor Jonathan Seville, has pioneered the use
of a single particle radioactive tracking technique called Positron Emission
Particle Tracking (PEPT), which enables the trajectory of a single particle to
be followed at a frequency of about 100Hz. The figure below is a 2D
representation of 3D tracking in a particular geometry of fluidised bed.
The objectives of the project are:
 To develop novel ways of obtaining distribution information on particle
behaviour in fluidised beds from single particle (PEPT) tracking data
 To apply the above to some practical design problems
Experimental data will be supplied and the work will be done in conjunction
with an Engineering PhD student, Chian Chan. Some knowledge of at least
one programming language is required. A PhD project could definitely result
from this work.
Jonathan Seville, Engineering
j.p.k.seville@warwick.ac.uk