Motion characteristics of binary solids in a liquid fluidised bed with inclined plates
Yanfeng Lia,*, Xiangqian Qia, Ningbo Lia, Ai Wangb, Wenjun Zhangc, Rongtao Zhua, Zhengbiao Pengb,*
Rectangular inclined channels prove promising for solid classification based on the principle of particle differential sedimentation. In the present work, we investigated the motion characteristics of binary solids in a modified fluidised bed (mFB) with inclined plates. We developed a theoretical model for the particle motion behaviour that accounts for the average solid volume fraction in the inclined channel and interactions between binary solids. The experimental system was designed to be consistent with the idealised theoretical arrangements to maximise the measurement accuracy. The experimental particles were mixtures of silica sand particles of sizes 425–710 μm and 710–880 μm, respectively. Specifically, we investigated the flow hydrodynamics of the binary suspension in terms of the settling length of both particle species and the bed expansion behaviour. We also analysed the utilisation factor and the separation efficiency of the mFB. The results showed that the average solid volume fraction in the inclined channel fluctuated slightly for a given total solid inventory. The utilisation factor and separation efficiency of the system decreased when increasing either the fluidisation velocity or the solid inventory. The prediction results were in good agreement with the experimental data with an absolute deviation of less than 15%.
Inclined channel; Liquid–solid flow; Fluidised bed; Sedimentation; Fluidisation; Theoretical model