Figure 1. Experimental setups of
the fast (left) and turbulent (right) fluidized beds. The fast fluidized
riser had an inner diameter of 0.30 m and was 18.3 m tall, while the
turbulent riser had an inner an inner diameter of 0.184 m and was 4 m
tall. The fast fluidized bed schematic is reprinted from17, Copyright 2012, with permission from Elsevier. The
turbulent fluidized bed schematic is reprinted from21, Copyright 2012, with permission from Elsevier.
The Geldart Group B particles evaluated are listed in Table 1. The
particle types included glass, high-density polyethylene (HDPE),
polystyrene and sand, with the average diameters
(dave ) ranged between 165 – 650 μm and densities
(ρp ) between 900 – 2650 kg/m3.
The broad particle size distributions (PSDs), with larger standard
deviations (σ /dave ), were particles used
as received from the vendor. The other particles were pre-sieved to
obtain narrower PSDs between two available sieves, which were either
used as is (i.e., narrow PSDs) or mixed to form binary mixtures.
Also listed in Table 1 are the operating conditions. The superficial gas
velocities (Ug ) used in the fast fluidized bed
were in the range of 10 – 17 m/s, which are an order of magnitude
greater than that in the turbulent fluidized bed of 1.5 and 1.7 m/s.
While the overall solid fluxes (Gs ) were
controlled through a slide valve in the fast fluidized bed to range
between 50 – 300 kg/m2/s, that in the turbulent bed
depended on the superficial gas velocity (Ug ) and
ranged between 0.05 – 0.51 kg/m2/s.
Table 1. Geldart Group B materials
and operating conditions for the fast 14-19 and
turbulent 20,21 fluidized beds.