Hydrodynamic Characterization of Three Axial Impellers under Gassed and Ungassed Conditions

抄録

We investigate the hydrodynamic performance of a baffled stirred tank for an air–water system in the turbulent regime. Comparisons among three different axial impellers were conducted: Maxblend impeller, two coaxial Pitched Blade Turbine (down-pumping mode) and two coaxial Intermig impellers. Measurements of the mean velocity field and the power consumption for gassed and ungassed conditions were obtained. The gas phase was introduced in a controlled manner using a capillary bank mounted at the bottom of the tank. The measured distributions of turbulent intensities for each impeller system for both gassed and ungassed configurations showed significantly different distributions. The flow patterns were also drastically modified for gassed conditions for the conventional agitators. The Maxblend impeller was observed to maintain a certain degree of homogeneity in the turbulent distribution for both gassed and ungassed conditions.