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One of the main requirements for grain dryers is the need for high-quality cooling of grain material after drying. Today, the most widespread are grain coolers built into grain dryers. As the practice of operation has shown, the most widespread in agriculture mine grain dryers with their cooling zones are ineffective: the temperature of the grain after cooling often exceeds the ambient air temperature by 15-30 0C, which is unacceptable. Devices with boxes have such disadvantages as uneven distribution air in the volume of grain mass and the corresponding uneven temperature field of the cooling air, limited opportunities for intensifying heat transfer during grain cooling. More promising for agricultural grain dryers are external coolers, which are installed separately from the dryer and can operate in an independent mode, which has a number of advantages: the quality of cooling improves, the productivity of existing grain dryers increases due to the use of the cooling part as a dryer. The main disadvantages of using the existing external column coolers: the need for an additional vehicle - a bucket elevator for reloading grain from the dryer to the column; vertical arrangement, it is necessary to use transporting means for grain for feeding to a considerable height. But if a pneumatic transport loader with a pulsating air flow is used as a vehicle, then the efficiency of the coolers can be increased due to the removal of a part of the heat accumulated by the grain by the transporting air flow. The paper proposes an analytical rationale for increasing the efficiency of coolers with pneumatic transport in a pulsating air flow.

This paper presents microbiological composition of lightbrown soil in the Lower Volga Region, which has been harvest on different nutriculture mediums. Diagnosed characteristics of microbian biocoenosis expansion on drip irrigation and unwatered soils. The Fusarium, Bacillus subtilis and Erwinia, which make more difficult to cultivate and preserve the agricultural produce, had located in irrigated plow horizon of light-brown soil of Volgograd Region. The forms of soil humidity on drip irrigation had not show any influence on microbiological composition.

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.

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.

The paper contains theoretical substantiation of the processes of radiation-convective heat and mass transfer between all the defining objects inside the vibration dryer with IR energy supply. The presented equations, developed on the basis of the heat and material balance, describe the basic dynamic characteristics of the drying mode for oil-bearing grain material in a continuously operating IR dryer. Since there is no exact analytic solution of the presented mathematical model shaped as a system of differential equations with partial derivatives, the authors propose an approximate solution. The latter allows identifying the dependences between the distribution of temperature and moisture content of grain and oil-containing materials along the length of the dryer for any moment of time. The numerical solution of the reduced mathematical model is possible only with the presence of certain interconnected kinetic coefficients. The kinetic coefficients can not be found experimentally by direct measurements; therefore, the article proposes a method to overcome these difficulties. The presented approximate analytical solution of the synthesized mathematical model, with the use of the method of inverse problems, has allowed determining sets of coefficients by the results of the experimental identification of dehydration. In the future, experimentally identified parametric complexes of the model can be used in the analysis of the drying process for approximate solutions or for further exact numerical solution. Experimental studies of dehydration of grain material have proved that when the power of an IR source is increased from 400 to 500 W, the time for drying from the initial moisture content of 11 % to 8.75 % decreases from 9 to 7 minutes. It is determined that the Rebinder effect characterizing the dampness and thermal properties of the material decreases with a decrease in the moisture content from 0.04 at 11 % to 0.01 at 9 %. This is interesting from the practical point of view as the obtained results and the developed mathematical model can be used for increasing the energy efficiency of the processes of thermal drying in typical facilities that prepare oil-bearing grain materials for their processing.