复合喷动反应塔气固反应区内循环特性

Internal circulation characteristics in gas-particle main reaction zone of multi-spouted bed

对复合喷动烟气净化塔内气固二相流动特性进行了数值模拟,得到了塔内气固二相流动特性。通过与传统反应塔对比,分析了复合喷动反应塔内循环的形成机理和气固主反应区流场分布特性。在此基础上,针对该型反应塔的工艺参数进行了优化研究。由结果可知,复合喷动反应塔可在气固主反应区形成良好的内循环,合适的回流区可延长颗粒塔内停留时间,有效增强内循环。回流区大小随入口风速的提高先增大后减小,并在入口风速为25 m/s附近存在最大值。烟气净化塔内颗粒停留时间随入口风速和颗粒粒径的变化均呈先增大后减小趋势,分别在入口风速为25 m/s、颗粒粒径为500μm时达到最大值。

The circulation characteristics of gas-particle flow field in multi-spouted bed were studied with the computational fluid dynamics （CFD） software. Comparing with the regular design, the mechanics of internal circulation in multi-spouted bed and the gas-particle flow distribution in gas-particle main reaction zone were studied, and the process parameters were optimized. The result shows that the muhilevel spraying structure enhances the internal circulation in the gas-particle main reaction zone, and well-optimized back flow field prolongs the particle residence time and increases the internal circulation. Mong with the increase of the inlet velocity, the back flow field first increases and then decreases, and reaches the maximum when the inlet velocity is around 25 m/s. Mong with the changes of inlet velocity and particle diameter, the particle residence first increases, then decreases, and reaches the maximum when the inlet velocity is 25 m/s and the particle diameter is 500 μm.