CFD Based Determination of Mixing Power of Beet Sugar Molasses - Water Mixture

摘要

In the present paper, a computer-based determination of mixing power is shown for the case of mixing of sugar beet molasses - water mixture in a mixing vessel - homogenizer. The mixture behaves as a pseudoplastic non-Newtonian fluid, which can be described by the power law model. The investigation was limited to isothermal flow situation, therefore the governing set of equations representing fluid flow in the vessel consisted of mass and momentum conservation equations. For the solution of governing equations Computational Fluid Dynamics code CFX-Pro Mixus was used. With the aim of improving power demands of mixing in the homogenizer a computational analysis of influence of different stirrer types on power consumption was performed and it was experimentally verified for a chosen configuration. The difference in measured and computed power consumption was less than 6 % for a selected test case. As working stirrers disk turbine and pitched blade turbine were chosen. The influence of baffles in the homogenizer was also studied. The good agreement of computed and measured results presents a solid basis for the future research on temperature dependent non-Newtonian fluids.