CFD SIMULATIONS OF ANNULAR DISTRIBUTOR OF SWIRLING FLUIDIZED BED (SFB) REACTOR

This work reports the findings of CFD simulations on a swirling fluidized bed which
operates with an annular distributor. The simulations were carried out to predict the pressure
and velocity distribution when the fluidizing gas/ air flows through the passage between the
trapezoidal blades of the annular distributor. It is normally assumed that the air flow
characteristic through the distributor is affected by various aspects of the distributor like
blade overlaps, blade inclinations etc. Flow characteristics in the distributor provide us with
the fundamental understanding of the bed behaviour along with ideas for further
improvement in the fluidization quality hence needed to be studied in detail. Thus, the current
study was carried out to investigate the flow characteristics and predict non-uniformity in
flow through the annular distributor of a swirling fluidized bed. Inappropriate blade
configurations will lead to an unsatisfactory fluidization and mixing of the air and bed
particles.
In this project, a commercial CFD package, FLUENT 6.3, was used to simulate the flow
through the annular distributor. The velocity and pressure profiles for various blade designs
were investigated in order to lead to an understanding of the flow and the particle mixing
behaviour inside the reactor. The objective of this project is to obtain the pressure and
velocity profiles at the distributor outlet based on various operating variables including air
inlet velocities, blade overlap angles (9°, 12°, 15°, and 18"), blade inclinations (10° and 15"),
along with variations in the opening between the distributor blades. The most significance
finding of this work is that the fluid tend to flow through a path with least resistance which is
having a largest cross section area and shortest path length. The dynamic characteristic
obtained from CFD simulations have been validated with experimental results and a good
agreement has been observed.