分布器结构对环流反应器气含率分布的影响

Effect of gas distributor configuration on gas holdup distribution in loop reactor

采用κ ε二方程模型和欧拉多相流模型 ,对一种单筒单级气升式气液环流反应器内的湍流气液两相流进行了全尺寸的数值模拟研究 ,考察了采用 3种不同气体分布器时反应器内气含率和流速分布的细节 .模拟结果表明不同结构的分布器对总体气含率和内筒中的两相速度分布有很大影响 ,因而对气含率分布和气液两相接触效果有较大影响 ,从而对反应过程产生影响 .单环分布器产生的气液两相接触效果较差 ,对于反应过程很不利 .对于大直径的环流反应器推荐使用多环分布器 .计算所得的整体气含率与实测的整体气含率进行了对比 ,吻合较好 .

A full-size numerical simulation of an airlift loop reactor with three types of different gas distributors was carried out. The standard K-Ε model and Euler multiphase flow model were used for the simulation of gas-liquid two-phase turbulent flow. All details of gas holdup and flow velocity distribution in the reactor were obtained. It was found that different gas distributor affected greatly global gas holdup and two-phase velocity in the inner tube, and consequently affected greatly gas holdup distribution and gas-liquid contact, which influenced the progress of reaction. The results showed that the contact of gas and liquid was poor with gas distributor of one loop. Gas distributors with multi-loops were recommended in big-diameter loop reactors. The computing results were compared with experimental data on global gas holdup and the agreement was satisfactory.