Effect of middling coal on separation efficiency in air dense gas–solid fluidized bed

ABSTRACTDry coal separation using the air dense medium fluidized bed (ADMFB) is an effective method for the coal cleaning. The characteristic of feed coal would affect the fluidization behavior in the separation process. In this study, effect of middling coal1 1 Middling coal: coal with density closing to separation density in the continuous production. on the pressure drop fluctuation, settling time of jetsam, and separation efficiency was investigated. Separation experiments with different amount of middling coal content were conducted. The results indicated that middling particles could increase the pressure drop fluctuation and decrease the separation efficiency. The middling particles could impede the falling of jetsam, increasing the jetsam settling time. With the increasing content of middling coal, probable error (E) had a slight tendency to increase from 0.057 to 0.072 g/cm3. The study provides theoretical support for decreasing the content of middling coal from the gas–solid fluidized bed separa...