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The relevance of research is conditioned upon the need to improve the efficiency of plot combines for harvesting sunflower seed crops. Experimental studies were carried out by planning and staging multifactorial experiments. The dependence of the force factors influence on the seed shedding from a sunflower basket was obtained based on the laboratory studies results. This dependence makes it possible to evaluate the influence of the parameters of the harvester header on the value of seed losses from shedding. The study made it possible to substantiate the design of the header attachment of the plot combine, consisting of a three-blade reel, box-type dividers and side shields. An experimental sample of the header attachment to the “Sampo-500” grain harvester has been developed and manufactured. Experimental studies of the influence of the speed of the combine movement and the coefficient of the operation kinematic mode of the reel to the developed device on the quality indicators of the harvesting of sunflower crops seeds were carried out.

The article considers the increase of efficiency of grain materials separation in pneumatic vertical channels by determining the rational shape and parameters of material supply, as well as the geometric shape of the pneumatic channel and options for separation into fractions. Regularities of change of trajectory and speed of movement of material in pneumatic vertical channels of round section with the lower unloading of material are received. The regularities of particle motion in the form of a material point were determined taking into account air resistance forces, friction forces, Magnus and Zhukovsky forces, material moisture and density based on a theoretical study of grain fractionation in pneumatic vertical channels. Using the proposed dependences for the design of air separators, it is possible to determine the initial rate of introduction and the direction of entry of grains into the air stream, which are the initial conditions for determining the trajectory of material in air channels with lower material discharge.

In the article, a drying scheme in a tower grain dryer has been developed, equations for the conservation of energy and material balance for grain, equations for mass transfer and heat transfer between the drying agent and grain have been drawn up. On their basis, analytical dependences of changes in the temperature and moisture content of grain, moisture content and temperature of the drying agent along and in the width of the drying channel were obtained, depending on the operating parameters (the value of rarefaction in the drying channel, the speed of grain movement along the drying channel, the speed of movement of the drying agent, the initial temperatures of the grain and drying agent, initial moisture content of grain, as well as initial moisture content of drying agent). Their analysis facilitates the work in choosing the optimal mode. The developed analytical dependences of changes in the main drying parameters (moisture and temperature of grain, moisture content and temperature of the drying agent) along the length and width of the drying channel in tower dryers with suction air flow make it possible to link the main operating parameters, which facilitate the choice of rational drying modes.

The article compiled and solved a system of differential equations of motion of a material point along a porous (air-permeable) surface, which is inclined at an angle to the horizon. Based on the analysis of solutions to this system of differential equations, it is proposed to change the speed of grain movement by the frequency of oscillations of the support surface, the angle of inclination of the support surface to the horizon and the coefficient of friction. Also, the graphical dependences of the speed of grain movement on the angle of inclination of the support surface to the horizon, the coefficient of friction and the frequency of oscillations were obtained. The possibility of decelerating the vibration movement of grain by an air flow, which is fed from the bottom of the porous support surface against (at an angle) the direction of grain movement, as well as using an asymmetrically corrugated support surface with vertical perforations, is theoretically substantiated. A linear regression dependence of the change in the vibration displacement speed has been experimentally determined, which makes it possible to form the required speed mode of vibration displacement of grain by changing the parameters: the inclination of the vibrating plane is 50 ÷ 90, the vibration frequency is 45 ÷ 55 s-1, the air flow speed is 0.1 ÷ 2 m/s in optimal operating modes. installations for high-intensity heat treatment of grain with a vibratory conveyor.

The possibilities of the action of uneven air flows on the grain material in the separating channels are still not used enough. The reason for this is the insufficient knowledge of the processes of interaction of the components of the grain material with an uneven air flow. The purpose of the research is to increase the efficiency of grain material separation according to aerodynamic properties by purposefully changing the diagram of air velocities in the channel sections using the actions of lateral and aerodynamic forces. The separation efficiency of grain material components was determined by trajectory analysis. The different geometry of the pneumatic separation channel was studied. The study of the distribution of air velocity and air pressure vectors in a vertical annular channel was carried out using the FlowVision software. It has been established that a change in the air velocity diagram can be implemented both by changing the geometric parameters of the channel and by additional distributed air supply through the perforation in the side walls of the pneumatic channel. Based on the analysis of the velocity field, an improved scheme of a pneumatic gravitational separator is proposed for separating grain material into three fractions according to aerodynamic characteristics.