液固磁稳定床中固含率分布与液相返混特性  

Solid Holdup and Liquid Backmixing of Liquid-SRNA-4 Catalysts in Magnetically Stabilized Beds

作　　者：李韡[1] 张晓尘[1] 张金利[1] 李晓芳[1] 卢立祥[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《化学工业与工程》2006年第4期283-286,共4页Chemical Industry and Engineering

基　　金：国家自然科学基金资助项目(20206023);中石化股份公司科技基金资助项目(X502012)

摘　　要：固含率分布和液相返混系数是液固磁稳定反应器放大与优化所必需的基础数据。采用床层膨胀高度法、光电法及瞬态点源示踪技术,研究了以SRNA-4催化剂为固相的液固磁稳定床中固含率分布和液相返混特性。试验结果表明,固含率轴向分布基本均匀,径向为“扁-陡曲线”分布。固含率随磁场强度和颗粒尺寸的增大而增大,随液体粘度和空塔液速的增大而减小。轴向液相返混系数随磁场强度和液体粘度的增大而减小,随空塔液速和颗粒尺寸的增大而增大。回归得到了固含率和轴向普朗特准数的关联式。Solids holdup distribution and liquid backmixing coefficients are fundamental to the scale-up design and optimization of liquid-solid magnetically stabilized reactors. In this article, local solid holdup distribution and liquid backmixing coefficients were analyzed using the bed height-expanded method, the photoelectric method and the transient point source tracer pulse input technique for the liquid-solid magnetically stabilized bed taking the ferromagnetic amorphous alloy catalysts of SRNA-4 as the solid phase. The experimental results showed that the local solid holdup appeared a uniformly axial distribution and a ＂flat-steep curve＂ of radial distribution. The solid holdup increased at higher magnetic intensity as well as under larger particle sizes, but decreased at lower liquid viscosity and slower superficial liquid velocity. Axial liquid backmixing coefficients weakened at higher magnetic intensity and liquid viscosity, but enhanced at higher superficial liquid velocity and larger particle size. Based on the experimental data,the equation was established to estimate accurately the axial liquid backmixing Peclet number using physical properties and operating conditions in the magnetically stabilized bed. The experimental results showed they were in accordance with the prediction.

关 键 词：磁稳定床 返混 固含率 

分 类 号：TQ021[化学工程]