Кількісна оцінка пошкоджень пшениці при вільному падінні в транспортно-технологічних лініях

The object of research is the process of gravitational fall of grain during its movement along a typical transport and technological line at the enterprise. The problem of the lack of a comprehensive analysis of operational deficiencies of transport equipment, which leads to mechanical damage to grain, was solved. The results of a comprehensive research of the impact of free fall of grain from different heights on surfaces with different physical and mechanical properties are presented. The relevance of the work is due to the need to minimize post-harvest losses of grain, which due to equipment imperfections can reach 55–65% of the total volume. The nonlinear nature of the change in the speed of grain fall under gravity was experimentally established: on a section of up to 10 m, the speed increases to 12.4 m/s, after which it stabilizes within 13.3 m/s under the influence of air resistance. It is proven that the type of material of the surface in contact with the grain is a determining factor in the intensity of damage. The highest injury rates (up to 0.6%) were recorded in contact with Hardox 450 steel, while the use of polyurethane lining reduces the level of damage by 12%. The most trauma-saving method was recognized as the “grain on grain” method, which provides a reduction in injury by 54–57%. A direct correlation was established between the angle of inclination of the surface and the degree of destruction of the kernel: a direct impact (90°) is critical, which increases the level of macrotrauma by 2–2.4 times. Using the method of staining with aniline dyes, a hierarchy of vulnerability of the grain structure was identified, where endosperm microtrauma occurs in any fall regime. This difference in injury can be explained by the ability of materials to absorb kinetic impact energy. The appearance of endosperm microtrauma in any regime indicates the fragile nature of the starch structure of the kernel. Scientifically based recommendations are provided on limiting the height of free fall to 4 meters and introducing grain gravity-braking devices to preserve grain quality.