Hydrodynamics of fluidization in a semicircular bed with a jet

Abstract

A hydrodynamic model of fluidization was developed that computes void fractions, pressure and solid and gas velocities in cylindrical fluidized beds. Cmputed time‐averaged gas velocity distributions of a jet compared well with Westinghouse experimental data without the use of any fitted parameters. The main empirical input was a drag correlation from the literature.

CFD and experimental studies of solids hold-up distribution and circulation patterns in gas–solid fluidized beds

“…Gidaspow and Ettehadieh [12], Ettehadieh et al [13] and Gidaspow [14] fitted the data to obtain an expression for the emulsion phase elastic modulus. However, numerical computations of Ettehadieh et al [13], Gidaspow [14], Kuipers et al [15] and Bouillard et al [16] have shown that the G(ε) fit obtained from the Rietema and Mutsers [11] data is inadequate in predictive ability. Unrealistically low voidages are predicted with this correlation.…”

Remarks on the modeling of fluidized systems

“…In some articles, Gidaspow and his coworkers make it clear that they use the data for glass beads. However, Ettehadieh et al (1984) used two values for G ( E ) that are orders of magnitude apart. Gidaspow (1986) also used a value for G ( E ) that corresponds t o a value for glass beads at a value of void fraction of 0.8.…”

Numerical evaluation of a one‐dimensional two‐fluid model applied to gas–solid cold‐flows in fluidised beds

“…In addition to the momentum and continuity equations, closure laws are needed to close the set of equations. The gas and solid friction factors are respectively given by: and where the Reynolds number is defined as: The modulus of elasticity function adopted for the bubbling bed and riser are respectively given by: and It is required that the sum of the area phase fractions fulfills the definition: The ideal gas law gives the relation between the gas density and gas pressure: …”