Characteristics of non-magnetic nanoparticles in magnetically fluidized bed by adding coarse magnets  

作　　者：周立 刁润丽 周涛 Hiroyuki Kage Yoshihide Mawatari 

机构地区：[1]School of Chemistry and Chemical Engineering,Central South University [2]Department of Mechanical Engineering,Hunan Institute of Technology [3]Department of Applied Chemistry,Kyushu Institute of Technology,Tobata,Kitakyushu,Japan

出　　处：《Journal of Central South University》2011年第5期1383-1388,共6页中南大学学报（英文版）

基　　金：Project(20776163) supported by the National Natural Science Foundation of China;Project(20070533121) supported by the PhD Programs Foundation of Ministry of Education of China;Project supported by the NSFC-JSPS Cooperation Program

摘　　要：The fluidization behavior of SiO2, ZnO and TiO2 non-magnetic nanoparticles was investigated in a magnetically fluidized bed （MFB） by adding coarse magnets. The effects of both the amount of coarse magnets and the magnetic field intensity on the fluidization quality of these nanoparticles were investigated. The results show that the coarse magnets added to the bed lead to a reduction in the size of the aggregates formed naturally by the primary nanopartieles. As the macroscopic performances of improved fluidization quality, the bed expansion ratio increases whilst the minimum fluidization velocity decreases with increasing the magnetic field intensity, but for TiO2 nanoparticles there exists a suitable magnetic field intensity of 0.059 6 T. The optimal amounts of coarse magnets for SiO2, ZnO and TiO2 non-magnetic nanoparticles are 40%, 50% and 60% （mass fraction）, respectively. The bed expansion results analyzed by the Richardson-Zaki scaling law show that the exponents depend on both the amount of coarse magnets and the magnetic field intensity.The fluidization behavior of SiO2,ZnO and TiO2 non-magnetic nanoparticles was investigated in a magnetically fluidized bed (MFB) by adding coarse magnets.The effects of both the amount of coarse magnets and the magnetic field intensity on the fluidization quality of these nanoparticles were investigated.The results show that the coarse magnets added to the bed lead to a reduction in the size of the aggregates formed naturally by the primary nanoparticles.As the macroscopic performances of improved fluidization quality,the bed expansion ratio increases whilst the minimum fluidization velocity decreases with increasing the magnetic field intensity,but for TiO2 nanoparticles there exists a suitable magnetic field intensity of 0.059 6 T.The optimal amounts of coarse magnets for SiO2,ZnO and TiO2 non-magnetic nanoparticles are 40%,50% and 60% (mass fraction),respectively.The bed expansion results analyzed by the Richardson-Zaki scaling law show that the exponents depend on both the amount of coarse magnets and the magnetic field intensity.

关 键 词：non-magnetic nanoparticles magnetic fluidization AGGLOMERATE coarse magnet 

分 类 号：TB383.1[一般工业技术—材料科学与工程]