制备磷酸铁的氧化反应器数值模拟分析

Numerical simulation analysis of oxidation reactor for preparation of iron phosphate

对磷酸铁氧化工序鼓泡式反应器内气泡直径大、传质效果差的问题,文中结合射流技术设计了一种新型氧化反应器。根据欧拉-欧拉模型、RNG k-ε模型和群体平衡模型进行数值建模,探究射流器内气泡的破碎机理、反应器内的流场形态、流体入口流速对混合效果的影响。结果表明:射流器喉管处的气泡被高速液体剪切破碎;增大液体入口速度会使气泡直径减小,当液体入口速度从3.2 m/s增加到5.2 m/s时,反应器出口的气泡直径从9.0 mm下降到7.2 mm;增大空气入口速度会使气泡直径增加,当空气入口速度从1.0 m/s增加到2.5 m/s时,反应器出口的气泡直径从7.2 mm增加到9.2 mm。

Aiming at the problems of large bubble diameter and poor mass transfer effect in the bubbling reactor in the oxidation process of iron phosphate,a new oxidation reactor was designed based on jet technology.Based on the Euler-Euler model,RNG k-ε model and population equilibrium model,the numerical modeling was conducted to explore the bubble breaking mechanism in the jet,the flow field morphology in the reactor and the influence of fluid inlet velocity on the mixing effect.The results show that the bubbles in the throat of the jet are broken by high-speed liquid shear.The bubble diameter decreases with the increase of liquid inlet velocity.When the liquid inlet velocity increases from 3.2 m/s to 5.2 m/s,the bubble diameter decreases from 9.0 mm to 7.2 mm.Increasing the air inlet velocity can increase the bubble diameter.When the air inlet velocity increases from 1.0 m/s to 2.5 m/s,the bubble diameter at the reactor outlet increases from 7.2 mm to 9.2 mm.