Principles of Innovative Technology for Presowing Seed Treatment

The results of studies on an innovative technology for complex presowing seed treatment, which includes the application of protective and nutrient substances with subsequent drying, are presented. Traditional apparatuses with mechanical agitators or rotating bottoms have substantial limitations, such as a high risk of mechanical damage to seeds, the formation of agglomerates, and a low intensity of heat and mass transfer. To solve these problems, the application of an inhomogeneous jet-pulsating fluidization in a self-oscillating mode is put forward as a viable solution. A physical model of the interaction of a gas coolant with granular material of non-spherical (ellipsoidal) shape is theoretically and experimentally validated using wheat grains as an example. It has been experimentally proven that in a gas flow, seeds orient themselves with minimal projection along the flow direction. This reduces hydrodynamic resistance and leads to a local increase in bed porosity to 0.5-0.9. It was established that the introduction of a coolant forms an intense asymmetric spouting motion. At the same time, cyclic entrainment of about 40 % of the bed mass into the freeboard space occurs with a frequency of more than 1.5 hertz. The ratio of the gas bubble volume to the initial bed volume increases to 37 %. This specific hydrodynamic condition provides active volumetric mixing with a significant increase in the interfacial contact area and intensification of heat and mass transfer processes at low temperatures (not exceeding 40 °C), which significantly mitigates the risk of thermal degradation and mechanical impact to the seeds compared to traditional methods.