CFD Research on the Influence of 45° Disk Turbine Agitator Blade Diameter on the Solid-Liquid Mixing Characteristics of the Cone-Bottom Stirred Tank

摘要

Anumerical simulation of a solid-liquidmixture concentration field in a cone-bottom stirred tank (diameter D=150 mm) was conducted using computational fluid dynamics (CFD). The influence of the 45° disk turbine impeller diameter on the mixing time number of solid-liquid mixture, mixing energy per unit volume, concentration standard deviation, turbulence energy and turbulent dissipation rate as well as solid just-suspended impeller speed was analyzed. The Eulerian two-fluid model was employed along with the standard k-ε turbulence model to simulate the turbulent solid-liquid flow in the cone-bottom stirred tank. A multiple reference frame approach was used to simulate the impeller rotation in a fully baffled reactor. The Fluent® 14.5 commercial CFD software was employed for the transient simulation. The radial and tangential velocities at the outer edge of the impeller along the blade width were compared with the experimental data of Wu and Patterson (Chem Eng Sci 44:2207-2221, 1989),Mahouast et al. (Entropy 133:7-17, 1987) and Kemoun et al. (IChemE Symp Ser 136:399-406, 1994). The further extended computational model could well predict the influence of impeller diameter on the solid-liquid mixing characteristics.