Experiments and simulations were conducted for bubble columns with diameter of 0.2 m (180 mm i.d.)

0.5 m (476 mm i.d.) and 0.8 m (760 mm i.d.) at high superficial gas velocities (0.12-0.62 m·s

-1

) and high solid concentrations (0-30 vol%). Radial profiles of time-averaged gas holdup

axial liquid velocity

and turbulent kinetic energy were measured by using in-house developed conductivity probes and Pavlov tubes. Effects of column diameter

superficial gas velocity

and solid concentration were investigated in a wide range of operating conditions. Experimental results indicated that the average gas holdup remarkably increases with superficial gas velocity

and the radial profiles of investigated flow properties become steeper at high superficial gas velocities. The axial liquid velocities significantly increase with the growth of the column size

whereas the gas holdup was slightly affected. The presence of solid in bubble columns would inhibit the breakage of bubbles

which results in an increase in bubble rise velocity and a decrease in gas holdup

but time-averaged axial liquid velocities remain almost the same as that of the hollow column. Furthermore

a 2-D

axisymmetric

k

-

ε

model was used to simulate heterogeneous bubbly flow using commercial code FLUENT 6.2. The lateral lift force and the turbulent diffusion force were introduced for the determination of gas holdup profiles and the effects of solid concentration were considered as the variation of average bubble diameter in the model. Results predicted by the CFD simulation showed good agreement with experimental data.