Ostroha R. Process of mineral fertilizer granules covering with organic suspension

Thesis work is devoted to theoretical and experimental researches of process of mineral fertilizer granules covering with organic suspension in the form of liquid poultry manure. Characteristic temperature regimes of application of poultry manure suspension on mineral fertilizer granules were experimentally indicated. Working temperature range was detected, when solid competent layer of dry poultry manure was formed on particle surface, that promoted complete organic encapsulation of mineral granules. Particles aggregation kinetics in fluidized bed was investigated. Thereby it was found that granules enlargement by organic substance with working conditions was characterized by proportional and surface (normal) growth - without formation of new granulation organic centers. It allowed to enlarge all granules to market size (4-5 mm). Empiric equation was obtained, which allowed to forecast changes of weighted average diameter of particles during encapsulation process. Equation in the form of dimensionless values for hydraulic resistance calculation of material disperse layer depending on air speed and suspension productivity was got on the basis of general experimental data. Criteria equations for determination of heat-conduction coefficient from heat agent to particles surface during organic suspension evaporation were got. Mathematic model of process of mineral fertilizer granules covering with organic suspension was developed, which took into account changes of granules division density by size. Theoretic calculations were confirmed by results of experimental researches (inaccuracy did not exceed 10%); it means that this mathematic model can be used for calculation of investigated process. Engineering analysis methods of encapsulation process were developed on the basis of received theoretical dependencies. Technological scheme of installation of mineral fertilizer granules covering with poultry manure suspension equipped with cavitator was proposed. As a result of cavitation process use it will be possible to get disinfected and homogenized raw material, completely prepared for work, which will not do harm to both human and soil. On the basis of conducted test investigations it was found, that organic cover, applied on mineral granules surface in amount of 50% wt increased their static durability practically threefold, and the most important fact was that received product could be used as fertilizer of prolonged effect with nutrient substances release period 3-4 months. Basic results of thesis work were transferred to manufacture for their use during development of initial data for projecting and technical and commercial propositions.