Theoretical justification of rational design parameters of effective threshing and separation devices for corncobs of various subspecies requires knowledge of the mechanical characteristics of the grain, of which the modulus of elasticity is the most significant. At the present stage of the threshing theory development the numerical values of the modulus of elasticity of grain of various subspecies of corn require experimental clarification. The complex geometrical shapes of the grains of dent, flint, sugar and pop corn do not allow determining their modulus of elasticity by the conventional method of tensile testing. To solve this problem, an experimental-theoretical method was proposed for determining the modulus of elasticity of corn grain and refining its Poisson's ratio during compression, based on the application of Hertz's theory. The essence of the method is to determine the micro deformations of corn grains with a complex geometric shape and located in the platform under the action of special cylindrical indenter, by continuous loading to the boundary value of the elastic deformation of the grain shell. Resistance to displacement of the cylindrical indenter in the protective fruit shell of grain is controlled by analytical weight equipment of II-high accuracy class, and deformation by a micrometric depth meter of the first accuracy class. The humidity content of the test grain is in the range of 12.8…13.4% and controlled in laboratory conditions by means of equipment for controlling the humidity content of cereals. As a result of the studies, numerical values of modulus of elasticity for protective fruit shell were established of grain of dent corn 78…127 MPa, flint corn 98…125 MPa, sugar corn 97…124 MPa and popcorn 127…169 MPa and the physical causes of their numerical difference were analyzed. The research results make it possible to carry out more accurate theoretical and engineering calculations when designing innovative threshing and separation devices for the cobs of seed, food and forage corn of various subspecies.

Currently, the technological process of grinding stalked feed in a multi-plane horizontal grinding machine has not been studied enough, and the physics of the process remains poorly understood. The purpose of theoretical research is to study the physics of the process of material movement in a vertical-type cutting grinding machine, and the tasks are to determine the absolute speed of particle movement and the vertical speed of material passing through the grinding chamber. The hypothesis of the physics of the process of stalked feed grinding was put forward, an analytical model of the functioning of the grinding machine was developed and the forces affecting the stems in the inlet chamber and the grinding chamber were revealed. Material in the inlet chamber in spiral air flow descends along the screw line onto rotating knives and presses against the inner surface of the grinding chamber, along the perimeter of which segment contradictions are installed. The knives of the grinding drum for each phase make the selection of the material and its subsequent grinding from the impact in flight and when interacting with contradictions. Based on the analysis of the trajectory of particles, the mathematical model and theoretical value of absolute speed of particle movement along the inner surface of the grinding chamber -23.25 m•s -1 , values of vertical speed of material passing through the grinding chamber -3.95 m•s -1 and the dropping angle of the helical line -10º are obtained. The obtained results confirm the hypothesis of the physical essence of the process of grinding stalked feed about the possibility of regulating the vertical speed of material passing through the grinding chamber, the degree of grinding, energy intensity and productivity of the grinding machine. Due to this, the investigated multi-plane horizontal grinder has significant advantages over special and universal hammer grinders of stalked feed.

Modern continuous drying equipment does not allow in one pass of the drying chamber to obtain seed grain of conditioned moisture from freshly released seeds of melon crops. To solve this problem, a high moisture melon crop seed dryer was designed, in which the principle of differential heat supply to forced mixed material was implemented. The design of the drying chamber provides for the supply of a heat carrier to the zone of predried seeds, which withstand a higher temperature, and then at a lower temperature to the zone with high moisture seeds that prevents them from cracking. Design and technological parameters and operating modes of the experimental dryer were experimentally investigated. Studies were carried out by means of a series of one-factor experiments in three stages: determining the productivity of the device for supplying seeds to the drying chamber, studying the transport ability of dryer elastic agitators, choosing a rational angle of inclination of the gas distribution sieve of the unloading device. The following parameters and consistent patterns are established: angle of inclination of gas distribution sieve of unloading device 14º; seed supply to drying chamber 24-18 kg•h -1 ; revolutions per minute of elastic agitators, when the seeds are supplied to the drying chamber 24 kg•h -1 -4 min -1 ; when the seeds are supplied 22 kg•h -1 -4.75 min -1 ; at 20 kg•h -1 -6 min -1 and at 18 kg•h -1 -7 min -1 ; drying agent speed 5 m•s -1 ; specific energy intensity of pumpkin seed drying process was 1.27 kWh•kg -1 with the dryer productivity 18 kg•h -1 . The given research results make it possible to determine the rational rotation interval of the transporting working element, within which elastic agitators provide the required productivity and high quality of seed drying to conditioned moisture in one pass of the drying chamber against the direction of the drying agent movement.