【作者】 卢立祥；

【导师】 张金利；

【作者基本信息】 天津大学 ， 化学工程， 2004， 硕士

【摘要】 根据非晶态合金催化剂SRNA-4在工业加氢反应过程中的需要，以不同粒度的SRNA-4工业催化剂为固相、水为液相、空气为气相，在Φ110mm的上流式磁稳定床中，对流体力学特性、液相扩散以及液固传质特性展开了研究。分别采用光电传感器和微型双针电阻探头测量了床层的固含率和气含率，研究结果表明床层的固含率随磁场强度的增大而增大，随表观液速和液体粘度的增大而减小，其在轴径向分布比较均匀；床层的气含率随表观气速、磁场强度和液体粘度增加而增加，随表面张力的增加而减小，其在径向上分布比较均匀。考察了床层的压降和相速度随操作条件和物性参数的变化规律，试验过程中最小流化速度和带出速度均随磁场强度的增加而增大。采用瞬态点源示踪法测定了床层液相扩散系数，研究结果表明液固磁稳定床的液相轴向扩散系数随表观液速和颗粒粒径的增大而增大；随液体粘度和磁场强度的增加而减小，液相轴向扩散系数在径向上分布比较均匀。气液固磁稳定床中液相扩散系数随表观液速和气速的增大而增大，随液体粘度和表面张力的增大而减小。采用电化学方法测定了床层的液固传质系数，研究结果表明在液固磁稳定床中液固传质系数较普通流化床要小，且随磁场强度和液体粘度的增加而减小；在磁链区操作，液速对传质系数没有影响；传质系数在轴径向上分布均匀。在气液固磁稳定床中，液固传质系数随磁场强度、液体粘度和表面张力的增加而略有减小，在轴径向上分布均匀。更多还原

【Abstract】 According to the need of amorphous alloy SRNA-4 as catalyst in the industry process of hydrogenating reaction, a new up-flow magnetically stabilized with diameter of 110mm has been proposed, in which different diameter particles of SRNA-4 were used as solid, water as liquid and compressed air as gas. The characteristic hydrodynamic, liquid dispersion and mass transfer have been studied.The photoelectric sensor and micro double probe have been used respectively to get the solid holdup and gas holdup, drawing the conclusion that the solid holdup increases with increase of the magnetic field intensity, and decreases with the increase of superficial liquid velocity and liquid viscosity, the axial of radial distribution of solid holdup is uniformity. The gas holdup increases with the increase of superficial gas velocity, magnetic field intensity and liquid viscosity and magnetic field intensity, decreasing with the increases of liquid surface tension, the axial distribution of gas holdup is uniformity. In the experiment, the pressure drop and phase velocity has also been also considered, the minimum fluidization velocity and carryover rate increase with the increase of magnetic field intensity. The electrolyte tracer method has been used to measure the liquid dispersion coefficients. Drawing the conclusion that in the LSMSB the liquid dispersion coefficients increase with the increase of superficial liquid velocity and diameter of particles, decreasing with the increase of liquid viscosity, the radial distribution of liquid dispersion coefficients are uniformity. In the GLSMSB, the liquid dispersion coefficients increase with the increase of superficial liquid velocity and gas velocity, while decreasing with the increase of liquid viscosity and liquid surface tension.With the electrochemical method, liquid solid mass transfer coefficients have been gained. Compared to conventional fluidized bed, the mass transfer coefficients in MSB are smaller. And they decrease with the increase of magnetic field intensity and liquid viscosity, in the magnetic stabilized regime, liquid velocity has nothing to do with the mass transfer coefficients. The axial or radial distribution of mass transfer coefficients is uniformity. In the GLSMSB, the mass transfer coefficients have slightly decreased with the increase of magnetic field intensity, liquid viscosity and liquid surface tension. The axial or radial distribution of mass transfer coefficients is uniformity. What is mentioned above is essential for the design, operation and control of magnetic stabilized bed.更多还原