将振动能量引入气固分选流化床，形成振动分选流化床，将煤粉和磁铁矿粉混合作为二元复合加重质，利用微差压传感器在线采集床层压力信号，并采用信号时频分析方法将信号进行划尺度分解，从微观角度分析振动流化床分选过程中的流化行为特性，研究振动能量对分选流化床流化质量的作用，并利用床层压力信号能量量化研究压力波动与不同流化现象的响应;基于对6~1 mm细粒煤分选试验结果的研究，结合床层中气泡行为的演变规律，提出了细粒煤分选效果的颗粒混合熵评价方法，研究了6~1 mm细粒煤在振动流化床中的分选特性及气泡运动行为对细粒煤离析分层效果的影响。结果表明，气泡引起压降信号的能量随着气速的增加，呈先增加后降低的趋势，随着振幅和频率的增加，气泡引起的压降信号能量逐渐增大，但床层压降信号的总能量随着气速、振动频率和振幅的增大逐渐增加。此外，通过对精煤和矸石组分的颗粒混合熵判定2组分的离析程度发现，随气速的增大，颗粒混合熵的变化趋势先降低后升高，随着振动频率和振幅的增加，精煤和矸石的颗粒混合熵逐渐增大，且在振幅A=2 mm，频率f=20 Hz，流化气速v=12 cm/s条件下，床层压力波动的能量和颗粒混合熵最低，床层压降波动平稳，床层密度分布均匀，对6~1 mm 细粒煤具有最佳分选效果，其分选精度E值为0.095 g/cm3，精煤灰分为9.59%。

The paper presents a vibration separation fluidized bed through introducing the vibration energy into a gas-solid fluidized bed and the pulverized coal and magnetite powder were mixed as a binary composite heavy medium solids.The micro-differential pressure sensors were used to collect the bed pressure signal online,and the signal time-frequency analysis method was used to decompose the signal.The fluidization behavior characteristics in the separation process of the vibration fluidized bed and the effect of vibration energy on the fluidization quality of separation fluidized bed were analyzed from microcosmic viewpoint.In addition,the energy characteristics of bed pressure signal was utilized to study the response of pressure fluctuation and different fluidization phenomena.Based on the research of 6-1 mm fine coal separation experimental results,combined with the evolution characteristic of bubble behavior in the bed,the evaluation method of particle mixing entropy was put forward for the analysis of the separation efficiency of fine coal beneficiation,meanwhile,the separation characteristics of 6-1 mm fine coal in vibrated fluidized bed and the effect of bubble movement on the separation and stratification of fine coal were studied.The results show that the energy of pressure drop signal caused by bubbles increases firstly and then decreases with the increase of gas velocity,and increases gradually with the increase of the amplitude and frequency.However,the total energy of bed pressure drop signal increases with the increase of the gas velocity,vibration frequency and amplitude.In addition,the separation degree of two components is determined by the particle mixing entropy of clean coal and gangue.It is found that with the increase of the gas velocity,the change trend of particle mixing entropy decreases firstly and then increases.With the increase of the vibration frequency and amplitude,the particle mixing entropy of clean coal and gangue increases gradually.Moreover,under the optimal conditions which are vibration amplitude A=2 mm,vibration frequency f=20 Hz and gas velocity v=12 cm/s,the energy of bed pressure fluctuation and particle mixing entropy are the lowest with stable bed pressure drop fluctuation and uniform bed density distribution.Moreover,the separation performance of 6-1 mm fine coal is the best with the separation accuracy value,E=0.095 g/cm3 and the ash content of clean coal is 9.59%.

1 试验系统与材料

   1.1 试验系统

   1.2 试验材料

   1.3 评价指标

2 试验结果与分析

   2.1 流化质量与压力波动

   2.2 压力波动的能量分布

   2.3 细粒煤灰分离析特性

   2.4 细粒煤的分选效果

3 结论