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The aim of the research is to determine ways to improve the efficiency of grain materials pneumatic separation based on the study of the interaction mechanism of grains with the air flow in the channel elements, which are inclined sections of the air duct. The paper considers a modified separation method that separates the grain material according to the aerodynamic properties of the components in a vertical zigzag air channel in an aerodynamic and gravitational field. The studies were carried out by means of mathematical modeling followed by experimental confirmation of the modeling results. A computer mathematical model was created in the MathCad 13 application package to determine the parameters of the zigzag aspiration channel. This model describes the influx of parameters in the channel (width, height, cut of the zigzag ledge to the horizon, edge of the zigzag ledge) on the nature of the grain trajectory. As a result of the numerical simulation process using the mathematical package Mathematica, dependence was obtained to determine the trajectory of motion depending on the angular velocity. An increase in the pneumatic separation effect during the grain mixtures division due to the influence of the Magnus effect was established as a result of experimental studies. The design of a zigzag separator with an annular channel section has been improved based of the research carried out.

The article considers the issue of increasing the efficiency of coolers of the material heated during drying by using a heat pump unit to produce artificial cold. The scheme of use of a thermal pump in a complex with the drying installation and the portable cooler of material is offered. A mathematical description of the stationary modes of operation of the drying unit, material cooler and heat pump elements on the basis of a steam compressor refrigeration unit is formulated. At creation of physical and mathematical models of heat and mass transfer in the course of drying and cooling of material (grain) the following conditions are accepted simplifying the mathematical description, but without changing real process: moisture from the material is removed according to Dalton's evaporation law, while the moisture in the material evaporates and is removed simultaneously; moisture content and temperature in the volume of the material are evenly distributed, heat and mass transfer occurs only between the surface of the material and the drying agent; the effects of radiation and contact heat transfer are taken into account by heat transfer coefficients; stationary fields of temperature and moisture content are assumed to be one-dimensional, which vary according to the coordinate calculated in the direction of movement of the material; when cooling the moisture removal material is not taken into account for low residual moisture; the size of the surface of the material in the process of drying and cooling does not change; the heat exchange equipment of the heat pump is an object with concentrated parameters. Using the obtained mathematical dependences, graphical dependences of changes in grain and air temperature are constructed, which allow to evaluate the expediency of using a heat pump. The formulated mathematical model of stationary modes of the heat pump drying unit with artificial cooling of the dried material can be used to evaluate the feasibility and energy efficiency of the used refrigeration machines for grain cooling, especially after high-temperature processing. The obtained analytical dependences in the form of a closed system of equations can be used to optimize the parameters of the heat pump drying unit by the criterion of minimizing energy consumption.

On the basis of the analysis of heat transfer processes in the moving layer of a dispersed material with immersed heat-generating elements placed in a cylindrical inductor, a mathematical model of the non-stationary process of heating of a grain material is formulated. Analytical dependences of grain temperature distribution in the direction of motion are obtained, unevenly distributed thermal power in steady state were taken into account. The static and transient characteristics of the induction heater, the distribution of the temperature of the core loading and the change of its temperature in time are analytically determined and verified according to the experiments. The dynamic characteristics of the installation as a control object are defined as transmission functions via control and perturbation channels.