Hydrodynamics of a circulating fluidized bed

On the Cluster Structure of a Circulating Fluidized Bed

“…* ) This indicates that the influence of inertia forces can be neglected. The quantity 1 − ε fb is rather stable [6]:…”

“…In [5], we obtained simple relations for the descending velocities of clusters and their vertical dimensions:…”

“…Clearly, this is possible only because of the fact that the bottom fluidized bed is not an independent system but is a part of a more general straight-through one, such as the circulating fluidized bed is. The bottom fluidized bed may even be considered as a peculiar dynamic gas distributor, in which particles are accelerated and the thickness of which depends on the rate of filtration [6]:…”

Mixing of particles in apparatuses with a circulating fluidized bed

“…In the CFB core, we have the upward motion of particles with a velocity u 1 and the descending motion near the riser's walls with a velocity u 2 (Fig. 1); these velocities are calculated from the formulas It is noteworthy that (5) is written under the assumption that filtration of the gas is absent from the annular zone, whereas (6) is written from the data of [5]. The velocity of the gas in the bed's core is equal to u/A in this case.…”

“…Particles from the descending contour and the annular zone are accelerated in it. This region of a CFB acts as an unusual kind of dynamic gas distributor whose height depends on the CFB's operating parameters and is calculated from the formula [7] …”