Determination of the temperature of mineral fertiliser granules after contact with the air in a granulation tower

The object of research is the process of cooling mineral fertilizer granules in a granulation tower. The main problem that was solved was the analysis of the temperature mode of cooling the granules to increase their strength and quality, as well as to reduce the probability of their destruction during storage and transportation. The design of a rotating vibrating granulator (RVG) and a mathematical model for calculating the temperature of granules and air at different stages of the granulation process are presented. Reynolds, Peclet and Prandtl criteria are used to describe hydrodynamic and thermodynamic processes. In the course of the work, a calculation model and the possibility of predicting the final temperature of mineral fertilizer granules were created, which allows to avoid negative consequences, such as a decrease in the strength of the granules and their destruction during shipment, transportation and introduction into the soil. Improving the technological performance of the granulation tower, in particular the temperature regimes of granule cooling, contributes to the improvement of product quality. The calculation model allows to adjust the process parameters to ensure the formation of granules with specified properties that meet modern requirements for the monodisperse composition of mineral fertilizer granules. Results were obtained that show the influence of hydrodynamic and thermodynamic factors on the process of cooling and crystallization of granules. This is due to the use of a rotating vibrating granulator, which ensures uniform distribution of liquid droplets across the cross section of the tower and their effective cooling due to contact with the air flow. The results can be used in practice to improve the operation of granulation towers in the production of mineral fertilizers, which allows to improve the quality of products and improve their storage and use. Compared to similar methods, the use of the proposed models provides increased strength and uniformity of granules, which are key advantages in conditions of large-scale production of fertilizers.