The Effect of Fluid Viscosity on Gas Dispersion in Stirred Tanks

• Main Authors: Yu-Chia Hsu, 許育嘉
• Other Authors: Wei-Ming Lu
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/55159157869512277462

碩士 === 國立臺灣大學 === 化學工程學研究所 === 89 === To investigate the effect of viscosity on gas dispersion mechanisms around the disc turbine, both the photoelectric capillary method and the numerical simulation techniques were adopted to analyze large cavity behind the blade. With the increase of the viscosity of the fluid, we can handle more gas under the same rotation speed. For high viscous fluid, the cavity structure will be very stable if the rotation speed is large enough. The power consumption curves are gathering very close. However, if the rotation speed is not large enough, the curves will separate into groups. The interface between cavity and fluid is depicted by the pressure contours. Turbulent kinetic energy and shear stress around the cavity are increasing with the increase of viscosity. Turbulent kinetic energy and shear stress of the boundary of the cavity are smaller than those at the vortex at the end of the cavity. From the bubble size measured by the photoelectric capillary method, the computation results are proved reliable.