【作者】 李明；

【导师】 李国兵；

【作者基本信息】 天津大学 ， 化学工程， 2013， 硕士

【摘要】 为寻找新型的冷氢化流化床反应器，以冶金级硅粉为原料，在内径为182mm的导向管喷动流化床中进行了流体力学实验。通过改变喷动气速和流化气速，测定喷动区压降和压降标准方差，结合近距离观察，对导向管喷动流化床的喷动区和环形区分别划分了不同的流动形态。结果表明喷动区具有喷动床性质，环形区则趋近于流化床。实验中系统研究了导向管安装高度、导向管内径、静止床高和流化气速对最小喷动速度和气体旁路分率的影响，结果表明降低导向管安装高度、引入流化气速、增加静止床高和增大导向管内径能有效的降低最小喷动气速与喷动气体旁路分率。此外，结合前人研究得到了最小喷动速度的关联式。实验中还考察了导向管安装高度、导向管内径、静止床高、流化气速和喷动气速对颗粒循环量的影响，结合颗粒循环量的夹带与卷席控制理论分析了以上参数引起颗粒循环量变化的原因。采用Fluent软件并运用基于颗粒动力学理论的双欧拉气固多相流模型，建立了与实验条件一致的导向管喷动流化床内气固多相流动的数学模型，结果表明软件模拟与实验结果整体趋势一致，可以成为预测实验结果的有效途径。更多还原

【Abstract】 In order to find a new hydrogenation reactor, hydrodynamic experiment was carried out in cylindrical spout-fluid bed (182mm inner diameter) with a draft tube(SFBDT). The metallurgical silicon particles were used as the raw materials. By changing the spouting gas velocity and fluidizing gas velocity, pressure drop and standard deviation of pressure drop in the spout zone were measured. Combining with the visual observation, SFBDT was divided into several different flow patterns. The results show that the spout zone has the properties of the spouted bed, and the annular region is similar with the fluidized bed.The effects of entrainment height, diameter of draft tube, bed height and fluidizing gas velocity on minimum spouting velocity and gas bypassing fraction of spouting gas were investigated. The results show that the minimum spouting velocity and gas bypassing fraction of spouting gas decrease with bed height, fluidizing gas velocity and diameter of draft tube, but increase with entrainment height.An experimental correlation was proposed for predicting the minimum spouting velocity.The effects of entrainment height, diameter of draft tube, bed height, fluidizing gas velocity and spouting gas velocity on solids circulation rates were also investigated. The parameters as mentioned above which caused the changes of solids circulation rates were analyzed with the vertical injection and lateral entrainment theory.Commercial software Fluent6.3was applied to simulate the experiment. Flow behavior of metallurgical silicon particles was studied using the Eulerian–Eulerian model and kinetic theory of granular flow. The overall trend of simulated results and experiment results was consistent. Simulation can be an effective way to predict the experimental results.更多还原