Solids motion and holdup profiles in liquid fluidized beds

Granular temperature in a liquid fluidized bed as revealed by diffusing wave spectroscopy

“…Similarly, previous experimental studies in a cylindrical geometry (Kiared et al, 1997;Limtrakul, 1996) show no apparent radial variation especially for denser particles such as glass beads. This is in contrast to the experimental finding of Limtrakul et al (2005), who found a higher value of velocity fluctuations close to the wall. One possible reason for this is a larger influence of the outer walls in the cylindrical column used in their study than that of the (quasi-2D) rectangular geometry used here as pointed out by Cornelissen et al (2007), whose CFD simulations show little variation of velocity fluctuations across the bed width except very close to the wall (2x/W 0.7-0.8).…”

“…Limtrakul (1996), Kiared et al (1997) and Limtrakul et al (2005) used non-invasive radioactive particle tracking techniques to measure velocity fluctuations. Their work was, however, focused on the radial distribution of the granular temperature (amongst other quantities).…”

Kinetic theory based CFD simulation of turbulent fluidization of FCC particles in a riser

“…In bubble columns and slurry bubble columns, the turbulent dispersion coefficients are calculated from Lagrangian fluctuating velocity. (Limtrakul et al, 2005;Degaleesan et al, 1997Degaleesan et al, , 2001Chen et al, 1999) In this study we used a similar method to estimate the dispersion coefficients.…”

Emulsion phase expansion of Geldart a particles in bubbling fluidized bed methanation reactors: A CFD–DEM study

“…According to Chavarie and Grace [40], larger bubble size will reduce mass transfer between the bubble and emulsion phase, which thereby inhibits the gas from bubbles to compensate for the reduced gas volumetric flow in the emulsion phase, and lowers the fluidization quality in the fluidized bed reactor. In addition, the rising velocities of fast bubbles will increase at a higher inlet superficial gas velocity, resulting in a shorter gas residence time and a considerable gas bypass [41][42][43]. Higher reactant gas partial pressure can be found even at the top of the bed (see in Fig.…”