Experimental and Numerical Studies of the Flow Field in a Stirred Tank Equipped with Multiple Side-Entering Agitators

The flow field and the macro-mixing process in a stirred tank equipped with four side-entering agitators were investigated experimentally and numerically. Experiments were conducted using two-dimensional particle image velocimetry (PIV) measurements to characterize the flow field at different positions in the vessel. The computational fluid dynamics (CFD) simulation was performed by the software Fluent 6.3, using the standard k-ε{lunate} turbulent model and the multiple reference frame together with the sliding mesh technique. The macro-mixing process was also discussed using CFD and decolorization experiments. The effects of the tracer detection positions and some mounting parameters in the mixing system were discussed. The results show that the mixing process was dominated by the flow field pattern in the stirred tank. According to the mixing times under different conditions using CFD simulation, the mounting parameters including inclination angle, plunging length and mounting height of the shaft were optimized. The flow field and macro-mixing process in a stirred tank equipped with four side-entering agitators were investigated experimentally and numerically, by combining two-dimensional PIV measurements and CFD simulations. The PIV measurements and CFD results showed good agreement for both the global flow pattern and the velocity component magnitude.