不同参数对振动流化床分选细粒褐煤的影响

Influence of vibrated fluidized bed parameters on fine lignite separation

阐述了振动流化床的结构及作用机理。对6～3,3～1 mm褐煤分别进行了浮沉实验,说明当分选密度为1.7 kg/L时,褐煤属中等可选煤。在振动强度大于1的情况下,利用振动流化床模型机对6～3 mm和3～1 mm褐煤分别进行分选实验,研究流化气速、振动强度、床层高度、煤炭水分等对褐煤分选效果的影响。结果表明:当流化数N为0.3,振动强度为1.5时,褐煤分选效果最好。从上至下将床层按体积分数7∶3的比例分为精煤和矸石时,可能偏差E值分别为0.202(6～3 mm)和0.225(3～1 mm)。随着外水含量的增加,褐煤分选效果逐渐变差,当外水含量分别小于4.5%(6～3 mm)和2.0%(3～1 mm)时对褐煤分选几乎没有影响。当床层高度低于70 mm时,床层高度对褐煤分选影响甚微,当床层高度高于70 mm时,褐煤分选效果急剧变差,床层高度的选择应考虑分选效果与处理量2个因素。

Introduce the structure and working principle of vibrated fluidized bed. The analysis of 6mm to 3 mm, 3 mm to 1 mm lignite separation experiments show that, when the separation density is 1.7 kg/L, the washability of lignite is medium. Adjusting the vibration intensity greater than 1, separate above two kinds of lignite in vibrated fluidized bed. Investigate the influence of gas velocity, vibration intensity, bed height,lignite moisture on separation. The results show that, when the fluidized number is 0. 3, the vibration intensity is 1.5, the separation effect is the best. From top to bottom, divide the bed according to the volume ratio of clean coal and gangue, which is 7 to 3, the ecart probable is 0. 202 and 0. 225. With the increase of surface moisture, the separation effect gradually become worse. For clean coal and gangue, when the surface moisture content is less than 4.5 percent and 2.0 percent respectively, its impact can be ignored. When the bed height is less than 70 mm, its influence on separation is little, while the height is more than 70 mm, the separation effect dramatically become worse. So the choice of bed height should take full account of separation effect and handing capacity.