Partic. vol. 21 pp. 146-153 (August 2015)
doi: 10.1016/j.partic.2014.08.011

Characteristics of pressure fluctuations and fine coal preparation in gas-vibro fluidized bed

Liang Dong^a, Yuemin Zhao^a,*, Liping Peng^b, Jie Zhao^a, Zhenfu Luo^a, Qingxia Liu^c, Chenlong Duan^a

ymzhao_paper@126.com

Abstract

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.

Graphical abstract

Keywords

Pressure fluctuation; Gas-vibro fluidized bed; Power spectral; Coherence; Coal preparation