Bunko V. Heat and mass transfer processes of production and use of fertilizers capsulated with film-forming aqueous suspension

The dissertation is dedicated to theoretical and experimental study of hydrodynamics, heat and mass transfer process of granular fertilizer encapsulation with film-forming aqueous suspension and kinetics of fertilizer components release from encapsulated particles. Film-forming encapsulation composition, which comprise of palygorskite - molasses mixture in the ratio 5:4, was developed. The obtained results led to development of (1) the equation for calculating the hydraulic resistance of material layer depending on the rate of irrigation with film-forming composition and the speed of fluidization air in the system fertilizer - palygorskite - molasses; (2) criterion dependences for determining the heat and mass transfer coefficient; and (3) the equation for calculating the mass transfer coefficient having the known value of heat transfer coefficient. The mathematical model of encapsulation of layer of granular material with different particle sizes was developed. The main technological parameters of encapsulating NPK fertilizer with an aqueous suspension of palygorskite - molasses mixture were calculated taking into account specific interactions in the system of solid particulate material - liquid - air in a fluidized bed reactor. A fundamental technological scheme of NPK fertilizer encapsulation with film-forming composition was developed. The performance of fluidized bed reactor was improved. The diffusion coefficients of NPK fertilizer internal components in the material of the shell were determined. The main results were passed for implementation in production of capsulated fertilizers and the teaching process.