Aim. Investigation of the influence of natural factors on the quality of grain drying in a grain modular dryer. Methods. Experimental studies in operational conditions and graphical modeling of dried grain moisture depending on natural factors. The results. The change in the environmental conditions causes a certain influence on the return of the spent waste dryer to the environment and the processes of drying the grain in it. This causes the production of undried grain and reduced drying efficiency. The influence of natural factors - temperature and humidity, atmospheric pressure and wind speed on the humidity of corn grain during its drying with a single-module grain dryer has been studied. The output of the refrigerant with moisture vapor is carried out through the perforated panels of the dryer circuit and at the same time experiences some resistance from atmospheric pressure. The results show that the reduction of atmospheric pressure helps to reduce the resistance for the exit of the coolant through the surface of the dryer housing. As a result, the coolant in the chamber is more efficiently spent on the grain drying process. This is evidenced by the simultaneous decrease in pressure and humidity of the dried grain The dryer is also affected by the wind: its body experiences cooling, and the drying temperature and drying conditions of the grain deteriorate. Thus, during the research period, the wind speed decreased from 5,3 m / s to 4,4 m / s, and the humidity of the dried grain decreased from 15,2 % to 13,9 %. That is, the reduction of the effect of wind on the surface of the dryer has a positive effect on the drying process of grain. The ambient air is characterized by the moisture present in it. Its reduction in atmospheric air promotes better moisture yield from corn grain and the "filling" of this air moisture: the humidity of the dried grain decreases. The positive temperature of the atmospheric air causes additional thermal action on the dryer and the drying process in it. In this case, the heat supplied to the working chamber of the dryer is more productively used for the drying process: in accordance with the increase in atmospheric air temperature, the humidity of the dried grain decreased from 15,2 % to 13,9 %. Based on the results of experimental studies, graphical dependences of the humidity of dried corn grain on humidity, pressure, temperature and velocity of atmospheric air are constructed. The grain harvester is a system adapter for Conclusions. Conclusions. The process of grain drying and the moisture content of the resulting dried grain of modular grain dryers depends on the influence of objective natural factors. These include, in particular, the weather conditions during the operation of dryers. With an increase in humidity, pressure and air velocity, the quality of drying deteriorates: when the moisture content of the grain decreases from 18,5 ° C to the regulated 14 %, with a single pass through the dryer, the moisture content of the dried grain exceeds the regulated one and vice versa. Drying grain in conditions of positive ambient air temperatures, especially at an air temperature of more than 21 °C, is most favorable for obtaining grain with a moisture content that is significantly less than 14 % and vice versa. Low wind speed, dry and warm atmospheric air with low pressure contribute to the production of dried grain with regulated humidity. For the maximum elimination of the unfavorable influence of natural factors on the quality of operation of modular dryers according to the criterion of the moisture content of dried grain in the conditions of the forest-steppe zone of Ukraine, it is advisable to carry out the drying process in the period from late September to early October.
