振动流化床超细介质床层流化及分选特性研究  

Study on the fluidization and separation characteristics of ultrafine medium bed in vibration fluidized bed

作　　者：黄金龙 马鹏耀 马军 吴庆运 HUANG Jinlong;MA Pengyao;MA Jun;WU Qingyun(China Energy Xinjiang Tuokexun Energy Co.,Ltd,Turpan,Xinjiang 838000,China)

机构地区：[1]国能新疆托克逊能源有限责任公司,新疆维吾尔自治区吐鲁番市838000

出　　处：《中国煤炭》2025年第2期173-184,共12页China Coal

摘　　要：选用Geldart A类超细磁铁矿粉和煤粉混合作为二元加重质,对比研究了振动超细介质流化床和普通介质振动流化床床层的流化特性及对细粒煤分选提质的效果,探究了2种加重质颗粒床层的膨胀特性、气泡行为及密度时空分布规律,分析了振动超细加重质颗粒床层对细粒煤分选的强化作用。结果表明,随着气速的增大,Geldart A类超细磁铁矿粉和Geldart B类磁铁矿粉这2种密相介质床层的空隙率均呈现出先增大后保持稳定的趋势,且Geldart A类超细磁铁矿粉介质床层的膨胀度较大。随着振动频率的增大,床层空隙率呈先增大后减小趋势,且Geldart B类磁铁矿粉床层膨胀率低于Geldart A类超细磁铁矿粉床层。随着气速的增大,床层中气泡尺寸逐渐增大,对比普通振动流化床中气泡的尺寸,超细介质床层中气泡的尺寸相对较小。对比2种床层的分选效果,超细磁铁矿粉床层对细粒煤的分选空间更大,选后精煤产品的灰分和产率较大,在频率f为20 Hz、振幅A为2 mm、流化数u/u-(mf)为1.3的最佳分选条件下,选后精煤灰分为9.1%,精煤产率63.5%,矸石灰分80.72%,可能偏差E为0.090 g/cm^(3)。The paper selects a mixture of Geldart A-type ultrafine magnetite powder and coal powder as binary dense media,and compares the fluidization characteristics of the vibrating ultrafine medium fluidized bed and the conventional vibrating medium fluidized bed,as well as the effect on the beneficiation and upgrading of fine coal.The expansion characteristics,bubble behavior,and density spatiotemporal distribution of the two types of heavy particle beds are explored,and the strengthening effect of the vibrating ultra-fine and heavy particle bed on the separation of fine coal is analyzed.The results indicate that,as the gas velocity increases,the porosity of the two dense phase media layers,Geldart A ultrafine magnetite powder and Geldart B ultrafine magnetite powder,both show a trend of first increasing and then maintaining stability,and the expansion degree of the medium layer of Geldart A ultrafine magnetite powder is relatively large.As the vibration frequency increases,the porosity of the bed layer shows a trend of first increasing and then decreasing,and the expansion rate of Geldart B-type magnetite powder bed is lower than that of Geldart A-type ultrafine magnetite powder bed.As the gas velocity increases,the size of bubbles in the bed gradually increases.Compared with the size of bubbles in a regular vibrating fluidized bed,the size of bubbles in the ultra-fine medium bed is relatively small.Comparing the separation performance of two types of bed layers,the ultra-fine magnetite powder bed layer has a larger sorting space for fine-grained coal,and the ash content and yield of the selected clean coal products are larger.Under the optimal separation conditions of a vibration frequency(f)of 20 Hz,an amplitude(A)of 2 mm,and a fluidized number(u/u_(mf))of 1.3,the ash content of the clean coal is 9.1%,with a clean coal yield of 63.5%,a gangue ash content of 80.72%,and a probable error(E)value of 0.090 g/cm^(3).

关 键 词：振动气流复合力场 细粒煤分选 微细颗粒 密度分布 

分 类 号：TD[矿业工程]