关键词: 搅拌槽, 气-液两相流, 计算流体力学, 数值模拟, 多层桨

Abstract: The fluid flow in a gas-liquid stirred tank of 0.476 m diameter with triple impellers was experimentally investigated and numerically simulated. The Eulerian-Eulerian formulation, standard k-e turbulent model and multiple frames of reference (MFR) method were used in the simulation. The newly developed four-half-elliptical-hollow-blade disk turbine (HEDT) was used as the bottom impeller to disperse the incoming gas, and two upward-pumping four-wide-blade hydrofoil (WHU) impellers were used as middle and top impellers to insure the homogenous mixing from the top to bottom in the tank. The power number, gassed power demand and overall gas holdup predicted by CFD are in good agreement with the experimental data. The local gas holdup distribution is mainly controlled by the flow field. There is a region with very high local gas holdup just above the top impeller and near the tank wall, which is in agreement with the literature. The results are of importance to the optimization of industrial stirred tank reactors.

Key words: stirred tank, gas-liquid flow, CFD, numerical simulation, multiple impeller agitator