The hydrodynamic characteristics of gas and solid flows in circulating fluidized
beds (CFB) can also influence other processes. To investigate various features of flows and
mass circulation in CFB, a computational study was performed with the support of
experiments measured in the riser section of a lab-scale apparatus of CFB. The fluidization
velocity was slightly below the terminal velocity to avoid a major solid entrainment. The
Gidaspow’s model was used to calculate the gas-solid drag term in computational cells,
which led to a good agreement with the experimental data of pressure profile. The gas inlet
conditions were shown to be uninfluential in the hydrodynamics of major part of the upper
riser, and the solid inlet (return) imposed non-uniformity in radial and tangential directions.
The time-averaged profiles presented a good indication of the wall layer formation. The rate
of circulating mass in the riser from simulations was obtained 25 percent lower than the
experiments. The coefficient of restitution was a parameter with notable influence on the
hydrodynamics and the present study suggests that a variable coefficient of restitution in
Eulerian models can describe the behavior of CFB system more accurately.