Powder Technology, Vol.379, 223-230, 2021
Scale-up effects of the flow structure in bubbling and turbulent fluidized beds
In bubbling and turbulent fluidized beds, gas bubbles are dispersed in the emulsion phase with the bubble cloud as the transition, offering a vigorous interaction between gas and particles. Despite numerous studies in the literature, many difficulties were encountered for modeling and scale-up. Hence, it is imperative to further study the flow details and scale-up effects. In this work, instantaneous solids holdup was captured in bubbling and turbulent fluidized beds using an optical fiber probe. The degree of local segregation was quantified with the intermittency index. Then, according to the signal details, phases, namely bubble phase, bubble cloud and emulsion phase, can be easily identified and characterized in perspectives of solids holdup and time fraction. Finally, the influences of the column diameter and static bed height were systematically analyzed to study scale-up effects. (C) 2020 Elsevier B.V. All rights reserved.