种分槽内部流场分布的数值模拟及实验对比分析

Numerical Simulation and Experimental Contrastive Analysis of Flow Field Distribution Inside Seed Precipitation Tank

种子分解是生产氧化铝的关键工序之一,其中种分槽是该工序的核心设备,种分槽内部流场分布是影响种分槽是否沉积结疤、搅拌功率高低的关键因素,本文采用Fluent软件,基于雷诺时均方程(RANS)的Realizable的κ-ε模型、Eulerian多相流模型以及多重参考系(MRF),对种分槽内部流场进行数值模拟,研究了搅拌转速、桨叶离底距离、桨叶直径对氢氧化铝固体颗粒分布规律的影响。在功率一定的前提下,通过对浓度场和速度场的分析得到转速越大、桨叶直径越大,越有利于颗粒悬浮,过低和过高的桨叶离底距离都不利于颗粒悬浮。

As one of critical steps in alumina production, seed precipitation adopts the core equipment,seed precipitation tanks inside which flow field distribution is a key factor influencing sedimentation, scaling and stirring power. This paper has used Fluent, Realizable κ-ε model of RANS, Eulerian multi-phase model and multi-reference frame(MRF) method to conduct numerical simulation of flow field inside seed precipitation tanks and study the influence of stirring speed, distance between blade and the bottom as well as blade diameter on solid particle distribution pattern of aluminum hydroxide. The analysis of concentration field and velocity field shows that on the premise of a fixed stirring power, blades with higher speed and larger diameter are beneficial to suspension of particles, while blades with a too small or too large distance to the bottom can affect suspension of particles.