Dehydration Characteristics of Viscous Fine Coal in Compound Force-Field with Vibration and Airflow

The paper utilizes the synergy of vibration and hot air flow to form a composite force field, and low-quality fine coal with viscous moisture is subjected to ash removal. The vibration signals of the bed surface at different positions are collected online using an accelerometer, and the dominant force affecting the vibration behavior of the bed is analyzed using signal time-domain analysis. By examining the impact of the synergy between vibration and airflow on the ash removal effect of low-quality, viscous moisture coal, the response of the drying and sorting behavior of low-quality fine coal to this synergy is elucidated. Based on the study of the experimental results of dehydration and ash removal of −6 + 1 mm fine coal, under the synergy of temperature and load force field, when the air flow temperature is 90 °C, v = 0.65 m/s, and f = 20 Hz, the collision force range between particles is 120 nN–370 N, which is different from that between particles. The liquid bridge force is large, which can achieve the fracture of liquid bridges between particles and strengthen the loose fluidization of particles. In addition, based on the study of the vibration characteristics of the bed surface at different positions, the vibration along the y-axis direction plays a dominant role in the density segregation behavior of the bed particles. With the increase in gas velocity and vibration frequency, the ash content of the selected clean coal exhibits a trend of first decreasing and then increasing. At the same time, the ash segregation degree initially increases and then decreases. Moreover, under the conditions of v = 0.65 m/s and f = 20 Hz, the separation effect of fine coal is the best. The separation accuracy E values of 1–6 mm without fine particles are 0.06 g/cm3, and the ash content of the clean coal is 12.55%.