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›› 2010, Vol. 10 ›› Issue (2): 221-225.

• 流动与传递 • 上一篇    下一篇

纳米二氧化硅的流态化行为及卧式流化床多釜串联模型

罗美芳 胡彦杰 赵映红 李春忠   

  1. 华东理工大学超细材料制备与应用教育部重点实验室 华东理工大学材料科学与工程学院 华东理工大学材料科学与工程学院 华东理工大学超细材料制备与应用教育部重点实验室
  • 收稿日期:2009-10-27 修回日期:2010-03-02 出版日期:2010-04-20 发布日期:2010-04-20
  • 通讯作者: 李春忠

Fluidization Properties and Tanks-in-series Model of Silica Nanoparticles in a Horizontal Rectangular Fluidized Bed

LUO Mei-fang HU Yan-jie ZHAO Ying-hong LI Chun-zhong   

  1. Key Lab. Ultrafine Mat. Min. Edu., East China Univ. Sci. & Technol. School of Materials Science and Engineering,East China University of Science and Technology School of Materials Science and Engineering,East China University of Science and Technology Key Laboratory For Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology
  • Received:2009-10-27 Revised:2010-03-02 Online:2010-04-20 Published:2010-04-20
  • Contact: LI Chun-zhong

摘要: 采用大型立式流化床,考察了气相法制备的纳米SiO2颗粒的流态化行为,研究了不同进料量下床层压降与气速的关系,得到了纳米SiO2体系的膨胀和塌落曲线. 利用多釜串联模型,研究了卧式流化床内挡板数目、物料流量等因素对纳米SiO2的停留时间分布密度和分布方差的影响. 结果表明,等间距设置2块挡板时,物料流动已明显偏向平推流,多釜串联模型参数N接近4. 在实验研究的基础上,设计了大型卧式流化床结构参数,脱酸后产品SiO2颗粒的pH值可达4.0以上,能满足工业生产需要.

关键词: 停留时间分布, 返混, 纳米二氧化硅, 卧式流化床, 多釜串联模型

Abstract: The fluidization characteristics of silica nanoparticles were investigated in a large-scale fluidized bed. The experimental results indicated that silica nanoparticles could be smoothly and uniformly fluidized, the incipient fluidization velocity was about 2 cm/s and the expansion ratio of bed could reach above 3. The backmixing characteristics and residence time distributions of silica nanoparticles in the horizontal rectangular fluidized bed were affected by the number of baffles, flow rate of SiO2 particles, etc. The results also showed that when two equidistant baffles were located in the horizontal rectangular fluidized bed, the solids flow pattern was apparently close to plug flow and the model parameter of tanks-in-series approached 4. On the basis of experimental results, a large horizontal rectangular fluidized bed was designed.

Key words: residence time distribution, backmixing, silica nanoparticles, horizontal rectangular fluidized bed, tanks-in-series model

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