Effect of the shaft eccentricity and rotational direction on the mixing characteristics in cylindrical tank reactors  

作　　者：Houari Ameur 

机构地区：[1]Institute of Sdence and Technology, University Center Ahmed Salhi, Ctr Univ Naama, 45000, Algeria

出　　处：《Chinese Journal of Chemical Engineering》2016年第12期1647-1654,共8页中国化学工程学报（英文版）

摘　　要：Strategy of the shaft eccentricity is introduced to enhance the mixing characteristics in a flat bottomed cylindrical vessel without baffles. The mixing is ensured by a six-curved blade impeller. Three solutions which are models of food emulsions are used as working fluids. These solutions have a shear thinning behavior modeled by the power-law. The effects of fluid properties, stirring rates, impeller rotational direction and impeller eccentricity on the 3D flow fields and power consumption are investigated. Three values of impeller eccentricity are considered, namely 0%, 24% and 48% of the vessel diameter. It is found that the opposite clockwise rotational direction reduces the power consumption, compared with the clockwise rotational direction. Also, the obtained results show that an impeller placed at an eccentric position between 24% and 48% of the vessel diameter and at the third of the vessel height may ensure the best mixing characteristics.Strategy of the shaft eccentricity is introduced to enhance the mixing characteristics in a flat bottomed cylindrical vessel without baffles. The mixing is ensured by a six-curved blade impeller. Three solutions which are models of food emulsions are used as working fluids. These solutions have a shear thinning behavior modeled by the power-law. The effects of fluid properties, stirring rates, impeller rotational direction and impeller eccentricity on the 3D flow fields and power consumption are investigated. Three values of impeller eccentricity are considered, namely 0%, 24% and 48% of the vessel diameter. It is found that the opposite clockwise rotational direction reduces the power consumption, compared with the clockwise rotational direction. Also, the obtained results show that an impeller placed at an eccentric position between 24% and 48% of the vessel diameter and at the third of the vessel height may ensure the best mixing characteristics.

关 键 词：Numerical simulation Hydrodynamics Mixing Impeller eccentricity Non-Newtonian fluids 

分 类 号：TS205[轻工技术与工程—食品科学]