Computational Fluid Dynamics of Advanced Gas Dispersion: Deep Hollow Blade Turbine

摘要

Stirred tanks are widely used in the chemical and biochemical process industries. Mixing, fermentation, polymerization, crystallization and liquid-liquid extractions are significant examples of industrial operations usually carried out in tanks agitated by one or more impellers. The flow phenomena inside the tank are of great importance in the design, scale-up and optimization of tasks performed by stirred tanks. This work presents of a stirred tank agitated by an advanced gas dispersion impeller namely deep hollow blade turbine (HEDT) using Computational Fluid Dynamic (CFD) method. The standard k-ε, realizable k-ε and shear-stress transport k-ɷ were considered in this study for comparison purposes. Predictions of the impeller-angle-resolved and time-averaged turbulent flow have been evaluated and compared with data from Particle Image Velocimetry (PIV) measurements. Multiple Reference Frame (MRF) used to capture flow features in details and predicts flow for steady state for the impeller blades relative to the tank baffles. Unsteady solver indeed predicts periodic shedding, and leads to much better concurrence with available experimental data than has been achieve with steady computation.