THE EFFECTIVENESS OF MULTI-STAGED SWIRLING FLUIDIZED BED

Fluidization is defined as an operation through which fine solids are transformed into a
fluid like state through contact with either a gas or a liquid. Circulating fluidized beds
are used mostly in the chemical process industry, mineral processing, pharmaceutical
production, energy related processes and catalysts process in the petroleum industry and
also for drying. Although it has been investigated by many researchers, a good
understanding in the effects of different design parameters on it is yet to be established.
In fluidized bed processes, the effectiveness of fluidization process is necessary as it
determines how much energy or power required by means of improvement in residence
time distribution and bed pressure drop. The aim of the project is to combine multistaging
with counter-flow operation in the novel Swirling Fluidized Bed. In this study,
the experiments were conducted utilizing one bed particle shape and size (spherical
plastic beads with a diameter, dp = 2.99mm), with four different bed weights (500 g,
1000 g, 1500 g and 2000 g) as well as with various distributor blade overlap angles (9°,
12° and 15°) at constant blade inclination of 10°. The experimental set up has two stages
and it has been tested and to work properly. A particular set of variables that include bed
weight and blade overlap angle were set to analyze the results of two-staged swirling
fluidized bed. During hydrodynamics study, it was found that the bed pressure drop ΔPb
for both stages increases with superficial velocity and bed weight. Moreover, a
distributor with 15° blade overlap angle showed the lowest pressure drop when
compared to 12° and 9°. The experimental results of solid residence time distribution
have shown that as the bed weight increases, the area under the tail of curve increases
and it shifts the peak of the distribution towards the higher value of (moving the curve
to the right) with the value of dimensionless age distribution E( ) reduce. Concurrently,
the blade overlap angle affects the value of E( ) with no significant change on the value
of . Thus, the experiment set up is shown to be highly versatile and capable of
representing widely different conditions depending on the variables from the parameters.