Effects of fine particles and moisture on the minimum fluidization velocity for the gas-solid fluidized bed coal beneficiator

The gas-solid fluidized bed coal beneficiator (GSFBCB) represents a proficient method for the dry separation of raw coal. The minimum fluidization velocity (Umf)of GSFBCB is significantly affected by the presence of fine particles and moisture in the coarse bed materials. In this work the Umf is found to decrease with an increase in fine particles. The incipient fluidization velocity (Uif) and total fluidization velocity (Utf) first rise and then fall, maintaining a constant inflection point despite variations in particle moisture. With increasing moisture, Uif, Umf, and Utf show a consistent linear escalation. Identifying a critical moisture threshold of 1.5% has proven effective in mitigating the impact of fine particles on fluidization. A correlation based on the Cheung equation proposed in 1974 was extended to predict the minimum fluidization velocity under low moisture conditions, achieving a standard deviation of 12.4% against the experimental data.