锥形流化床内碳纳米管的膨胀特性研究

Research on Expansion Characteristics of Carbon Nanotubes in a Conical Fluidized Bed

流化床是碳纳米管宏量制备的一个关键设备,本文对100 mm管径无分布器式锥形流化床内的碳纳米管进行了床层膨胀研究的实验。通过对两种碳纳米管流化特性的观测分析,结果发现:对于垂直阵列管,存在分部流化的特性,对于聚团管,存在小颗粒迁移流化的特性。对初始床层高度为150,170,190 mm的流化床内的碳纳米管进行研究,在不同初始床层高度的情况下,不同种类的碳纳米管的膨胀行为和压力信号存在明显的差异,实验表明,在相同流速下,随着初始床层的增加,床层压降增加、初始流化风量和完全流化风量增加,膨胀率降低。

The fluidized bed is a key equipment for the macro-preparation of carbon nanotubes.In this paper,an experiment on the bed expansion of the carbon nanotubes in a conical fluidized bed with a diameter of 100 mm without a distributor is carried out.Through the observation and analysis of the fluidization characteristics of the two types of carbon nanotubes,it was found that for the vertical array nanotubes,there is the characteristic of partial fluidization,and for the agglomerated nanotubes,there is the characteristic of the migration and fluidization of small particles.Research on carbon nanotubes in fluidized beds with initial bed heights of 150,170,and 190 mm.With different initial bed heights,the expansion behavior and pressure signals of different types of carbon nanotubes are significantly different,Experiments show that under the same flow rate,with the increase of the initial bed layer,the bed pressure drop increases,the initial fluidized air volume and the fully fluidized air volume increase,and the expansion rate decreases.