Effects of Vertical Baffle on the Hydrodynamic Behavior of Stirred Tanks

Stirred tanks have a wide range of uses in food, chemical, and mineral industries. As a result, accurate knowledge of the hydrodynamic behavior of the fluid in these tanks is essential. One of the issues that arises in stirred tanks when working at high speeds is the vortex inside the tank, which inhibits appropriate mixing. In the current numerical study, by attaching vertical baffles to the inner wall of the tank, the flow field and vortex phenomena were evaluated. Computational Fluid Dynamics (CFD) was employed to explore the influence of wall baffles on variations in radial velocity and turbulent kinetic energy. Based on the numerical results, it was discovered that adding baffles to the tank wall enables the radial flow to be extended, which provides for better mixing inside the stirred tank. Moreover, by adding the baffles, vertical flow is improved, enhancing the agitation inside the tank. According to the results, the turbulent kinetic energy for tanks with and without baffles is 0.00957 m2 / m3 and 0.0112 m2 / s3, respectively, while the energy dissipation rates were 0.955 m2 / m3 and 0.805 m2 / s3, respectively. Increasing velocity in the vicinity of the baffle, results in enhanced agitation, providing the energy demand for better mixing. This prevents continuous swirling motion which can reduce agitation quality.