Abstract
The effects of solid concentration and liquid viscosity on bubble properties such as bubble size and bubble rising velocity were measured with a dual-electroresistivity probe in a slurry bubble column of 0.15m diameter. The behavior of volume-surface mean bubble diameter, dvs, was analyzed.
By addition of solid particles at small gas velocity, the bubble size distribution shifted to a large-size region and the bubble velocity distribution shifted to a large-velocity region. At the same time, the flow pattern changed from homogeneous flow to heterogeneous flow. The effect of solid particles on bubble size, however, became small as the particle diameter decreased or the liquid viscosity increased.
The following equation was derived to estimate dvs.
dvs=0.59(VD/εg)2/g
where VD is the drift flux of gas, εg is the cross-sectionally averaged gas holdup and g is the gravitational acceleration.
