This research presents a computer simulation investigation to develop a theoretical model to envision and understand the mixing phenomena in a stirred vessel. Mixing is required for phase homogeneity and effective heat and mass transfer within the stirred vessel. In many cases, it is challenging to obtain experimental information in a specific part of reactor and therefore the obtained results represent only average values. Also, data acquisition and interpretation can take a long time. If there is a necessity to change the geometry of a stirred vessel for scale-up purposes, then one should ensure the same reaction or process outcome is achieved as in experimental setup. Such problems can be solved at least approximately using computational fluid dynamics (CFD) model, which is less time consuming, less expensive than physical arrangement and has the capability to visualize the real system in three dimensions. Reactor construction and impeller configurations were chosen combining best available techniques used in industry with addition of magnetic coupling for impellers. Using advanced modelling of a system the critical parameters such as impeller revolutions per minute (rpm) and operation limits can be examined. The simulation results to a certain degree are comparable with experimental results ensuring the model is fit for the purpose. For the simulation process COMSOL Multiphysics® 5.2a with CFD module was used.