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 (9o, 12o, 15o, and 18o), blade inclinations (10o and 15o), 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.