The application of polymers as a tool in the crystallization process is gaining more and more interest among the scientific community. According to Web of Science statistics the number of papers dealing with “Polymer induced crystallization” increased from 2 in 1990 to 436 in 2020, and for “Polymer controlled crystallization”—from 4 in 1990 to 344 in 2020. This is clear evidence that both topics are vivid, attractive and intensively investigated nowadays. Efficient control of crystallization and crystal properties still represents a bottleneck in the manufacturing of crystalline materials ranging from pigments, antiscalants, nanoporous materials and pharmaceuticals to semiconductor particles. However, a rapid development in precise and reliable measuring methods and techniques would enable one to better describe phenomena involved, to formulate theoretical models, and probably most importantly, to develop practical indications for how to appropriately lead many important processes in the industry. It is clearly visible at the first glance through a number of representative papers in the area, that many of them are preoccupied with the testing and production of pharmaceuticals, while the rest are addressed to new crystalline materials, renewable energy, water and wastewater technology and other branches of industry where the crystallization process takes place. In this work, authors gathered and briefly discuss over 100 papers, published in leading scientific periodicals, devoted to the influence of polymers on crystallizing solutions.

In this paper, the influence of hydrodynamic conditions in Kenics static mixer, which acts as a multifunctional reactor, on precipitation kinetics of barium sulfate is investigated. The investigated range of the Reynolds number varied between 500 and 5000, which covered both laminar and turbulent flow regimes. In all experiments, the relative supersaturation was maintained at the constant level (s = 205). The obtained precipitate was collected and used for crystal size distribution (CSD) determination. On that basis, the kinetic parameters of the process were calculated using the mixed suspension mixed product removal (MSMPR) mathematical model of the process. It was found that for the whole investigated range of Reynolds number, the mixing conditions were satisfactory. CSD analysis showed that in the laminar regime, a clear tendency in crystal behavior could not be noticed. However, during the analysis of the turbulent regime, the presence of a critical Reynolds number was noticed. Above this value, there is a change in the flow pattern, which results in a change of kinetic parameters (B, G), as well as manifests in a form of a decrease in the value of mean diameters of crystals. The flow pattern change is caused by the geometry of the reactor’s inserts.