Effect of coal particle swarm properties on the fluidization characteristics and coal beneficiation in a dense-phase gas-solid fluidized bed

• Published in: Particuology 2017-12, Vol.35 (6), p.108-118
• Main Authors: Zhang, Bo, Zhou, Chenyang, Chen, Zengqiang, Zhao, Yuemin
• Format: Article
• Language: English
• Subjects: Coal separation; Fluidized bed; Particle size distribution; Separation performance
• ISSN: 1674-2001; 2210-4291
• DOI: 10.1016/j.partic.2017.06.001

This paper analyzes the influence of different coal mass fraction in an air dense medium fluidized bed （ADMFB）. The effect of the low density particles layer on heavy sedimentation increased with increasing material layer thickness. The thickness of the low density particles layer also affected the final settling time of the high densiW particles. Increasing the thickness of the low density particles layer by △h provoked an increase in the settling of high density particles that was related to their diameter （△h/D）. The pressure gradient across the bed was lower than that observed for the control experiment, which had only the dense material, owing to a decrease in the pressure gradient in Zones 1 and 5 （at the top and bottom of the bed, respectively）. Introducing different coal sizes resulted in different fluidization environments, particle accumulation layers, and changes to the surrounding zone. However, the influence of the coal particles on the local bed characteristics was related to its concentration. The feeding mass fraction of 6-13mm size and 13-25mm size coal should be limited to10% and 13%, respectively. The ranges of possible deviation were found to be 0.08-0.15 and 0.07-0.10 for the respective samples.