Numerical Investigation of the Effects of Configuration Parameters on the Hydrodynamic and Turbulence Characteristics Inside a DTB Crystallizer

The increasing demand for highly pure crystalline materials with narrow Crystal Size Distribution (NCSD) leads related industries to utilize the Draft Tube Baffle (DTB) Crystallizers. The product Crystal Size Distribution (CSD) significantly alters by enhancing the mixing characteristics inside crystallizer, therefore acquiring a precise vision of hydrodynamics will help in designing and scaling up the DTB crystallizer. There are numerous studies on the flow field in the DTB crystallizers, but none of them investigates the interactions and effects of the internal arrangement of DTB crystallizers. In this study, the optimal configuration of three geometrical parameters (tube diameter, the ratio of tube diameter to baffle diameter, and the width of the annular settlement zone) was obtained by numerical simulation of the flow field in 18 DTB crystallizers. The interaction of parameters was studied by employing the general factorial method. Each crystallizer was divided into five compartments where various results such as the distribution of axial velocity, the turbulent kinetic energy, and streamlines were considered for data analysis. The results demonstrate that the hydrodynamics requirements in each compartment will be satisfied in crystallizer with 17.5 cm tube diameter, the ratio of tube diameter/baffle diameter=0.5, and the width of the annular settlement zone equal to the tube diameter.