@ARTICLE{Story_Anna_Experimental_2021, author={Story, Anna and Story, Grzegorz and Jaworski, Zdzisław}, volume={vol. 42}, number={No 2}, pages={173-190}, journal={Chemical and Process Engineering}, howpublished={online}, year={2021}, publisher={Polish Academy of Sciences Committee of Chemical and Process Engineering}, abstract={Complex rheological properties of yield-stress materials may lead to the generation of an intensive mixing zone near a rotating impeller. From the practical point of view, the zone should cover most of the stirred liquid. According to the literature review, several parameters may affect the size of the mixing zone, in particular forces exerted on the liquid. This paper presents both experimental and numerical investigation of axial and tangential forces generated during mechanical mixing of yield-stress fluids in a stirred tank. The tested fluids were aqueous solutions of Carbopol Ultrez 30 of concentration either 0.2 or 0.6 wt% and pH = 5:0. The study was performed for three types of impeller, pitched blade turbine, Prochem Maxflo T and Rushton turbine, in a broad range of their rotational speed, N = 60 - 900 rpm. The axial and tangential forces were calculated from the apparent mass of the stirred tank and torque, respectively. The experimental results were compared with CFD predictions, revealing their good agreement. Analysis of the generated forces showed that they are dependent on the rheological characteristic of liquid and the impeller type. It was also found that although axial force was smaller than tangential force, it significantly increased the resultant force.}, type={Article}, title={Experimental and numerical investigation of axial and tangential forces in a stirred tank with yield-stress fluids}, URL={http://sd.czasopisma.pan.pl/Content/121779/PDF-MASTER/a09_int.pdf}, doi={10.24425/cpe.2021.138923}, keywords={mixing, yield-stress fluid, axial force, tangential force, CFD}, }