振动流化床能够有效强化细粒煤的分选提质过程,通过利用二维振动分选流化床,以煤粉和磁铁矿粉混合作为二元复合加重质,采用压力传感器测量床层中的压力信号,结合高速动态摄像机同步捕捉气泡在床层中的演变行为,研究二维振动分选流化床中气泡的动态演变规律,探索气泡行为对细粒煤分选效果的影响。此外,利用塌落试验,研究不同操作条件下床层膨胀高度和气泡体积占比,进而揭示振动气流协同对气泡动态演变行为的抑制作用。研究结果表明,振动能量的引入能够促进颗粒床层均匀流化,在v=16cm/s,f=20Hz和A=2mm条件下,床层压降波动稳定,随振动频率的增大,床层完全流化膨胀高度He先增加后减小,气泡相体积分数Y先减小后增大。但随着振幅的增加,床层完全流化膨胀高度He先增加后减小,气泡相体积分数Y逐渐增大。振动与气流的协同作用对床层中的气泡行为具有明显的抑制作用,但随着床层高度的增加,气泡尺寸的瞬时值和平均值均逐渐增大,且在床层中上部,气泡尺寸分布范围较宽。在最佳操作条件下,气泡平均尺寸为1.12~2.45cm,气固接触效率高,床层介质颗粒呈准散式流化,此时,气泡对细粒煤分选效果的扰动作用弱,细粒煤分选效果最好,选后精煤灰分和产率分别为8.2%和56.1%,矸石的灰分和产率分别为44.5%和43.9%。

The vibrating fluidized bed can effectively strengthen the separation and quality improvement process offine coal. By using the pressure sensor to measure the pressure signal,combining with the high⁃speed dynamic camer⁃a to synchronously capture the evolution behavior of bubbles in the two⁃dimensional vibrating separation fluidized bedwith the mixture of pulverized coal and magnetite powder as the binary composite weight,the dynamic evolution ofbubbles and the influence of bubble behavior on the separation effect of fine coal were explored. In addition,the ex⁃pansion height of the bed and the volume proportion of bubbles under different operating conditions were studied,and the suppression effect of vibration airflow synergy on the dynamic evolution of bubbles was revealed. The resultsindicate that the introduction of vibration energy can promote the uniform fluidization of the particle bed.Under the conditions of v = 16 cm/ s,f = 20 Hz and A = 2 mm,the pressure drop fluctuation of the bed is stable.With the increase of vibration frequency,the fully fluidized expansion height He increases first and then decreases,but the change of the bubble phase volume fraction Y is opposite to that of the fully fluidized expansion height.With the increase of amplitude,the fully fluidized expansion height He increases first and then decreases,as well as thebubble phase volume fraction Y gradually increases. The results show that the synergistic effect of vibration and gasflow has an obvious inhibitory effect on the bubble behavior in the bed. Meanwhile,under the optimal operating condi⁃tions,the average bubble size is 1.12-2.45 cm. The disturbance of bubble on the separation effect of fine coal isweak,and the separation effect of fine coal is the best. The ash content and yield of bed clean coal products are 8.2%and 56.1% respectively,and the ash content and yield of discharged gangue are 44.5% and 43.9% respectively.

国家自然科学基金资助项目(51974306);国家自然科学基金杰出青年基金资助项目(52125403);高校基本科研业务费项目-青年科技基金资助项目(2022-11254)

陈增强,张亚东,赵光薪,等. 振动分选流化床气泡动态演变与细粒煤分选特性[ J].煤炭学报,2023,48(S1):296-304.

CHEN Zengqiang,ZHANG Yadong,ZHAO Guangxin,et al. Dynamic evolution of bubble and separation charac⁃teristics of fine coal in vibrating fluidized bed[J]. Journal of China Coal Society,2023,48(S1):296-304