To improve the separation efficiency of air dense medium fluidized beds for dry coal preparation, a gas-vibro fluidized bed has been proposed in which magnetic powder is used as the heavy medium. Pressure fluctuations in the gas-vibro fluidized bed were investigated using time- and frequency-domain analysis methods. The relationship between pressure fluctuations, bubble behavior, and separation efficiency was established. The low amplitude of the standard deviation, the power spectral density (PSD), the incoherent-output PSD, and the high amplitude of the coherent-output PSD, which corresponds to the bubble behavior in the bed, were improved for coal preparation. The coal ash content was reduced from 42.55% to 16.54% by using the gas-vibro fluidized bed.
Dong, L., Zhao, Y., Peng, L., Zhao, J., Luo, Z., Liu, Q., & Duan, C. (2015). Characteristics of pressure fluctuations and fine coal preparation in gas-vibro fluidized bed. Particuology, 21, 146–153. https://doi.org/10.1016/j.partic.2014.08.011