The article presents the data obtained as a result of an experiment on the distribution of the microwave field and the power dissipated in a dense grain layer at different material humidity and waveguide configurations. The development of processing modes with the use of electrical technologies and electromagnetic fields will reduce the energy intensity and cost of grain heat treatment processes. When developing them, it is necessary to take into account the technological requirements for the processed material, the types of electrical technologies used, the operating mode of the intensifying equipment (constant, pulse, and others). (Research purpose) The research purpose is in experimentally evaluating the uniformity of the distribution of the microwave field in the zone of ultrahigh-frequency convective grain processing of a laboratory installation containing six sources of microwave energy. (Materials and methods) The article presents the scheme of the zone of ultrahigh-frequency convective treatment for the study; the factors considered in the experiment and the levels of their variation. (Results and discussion) An experiment was conducted to determine the coefficient of uniformity of the propagation of the microwave field in a layer of grain material. The article presents obtained dependencies. (Conclusions) The results of the study of the microwave field strength in the grain mass can be used in the study of the dielectric properties of the processed grain, as well as in the construction of a control system for the design of ultrahigh-frequency convective processing plants. The values and patterns of changes in the uniformity coefficient of the electromagnetic field distribution in the grain layer indicate a difference between the reference data on the dielectric properties of grain materials and their values for the layer of the processed material. The values of the uniformity coefficient in the considered variants for a dense layer of wheat are in the range of 0.247713-0.426276.

Classical thermal methods of grain drying are characterized by high energy intensity. The study of grain processing modes using electrical technologies allows to reduce the cost of drying. When studying, it is necessary to take into account the technological requirements for the processed material, types of electrical technologies, and the operating mode of the intensifying equipment (constant, pulse, and others). (Research purpose) The research purpose is obtaining dependences of the energy efficiency of drying wheat grain using the energy of the microwave field for different states of the layer. (Materials and methods) A diagram of a laboratory installation has been used. Experimental studies were performed to determine the drying curves and the energy intensity of drying the layer of wheat grain. (Results and discussion) The two-factor experiment was conducted to determine the effect of the power of the field and the density of the grain mound on the energy intensity of the grain drying process. Article presents the required dependencies. (Conclusions) Data has been obtained as a result of an experiment on drying a grain layer located in a dense, fluidized and suspended layer under the influence of a microwave field at an initial grain humidity of 17 percent. It was found that the use of an ultra-high-frequency field in the process of drying grain crops is advisable when the humidity of the processed material is close to the standard one (17-18 percent for wheat). It was found that the use of an ultra-high-frequency field makes it possible to intensify the drying process when humidity is close to the standard by 3-4 times and reduce the overall energy consumption of the drying process in areas of humidity close to the standard by 20-40 percent. It was found that in order to increase the reliability of data, it is necessary to increase experiments on large-scale models that allow predicting the energy intensity of drying in industrial plants.

Currently, the development of effective control systems for technological equipment is still actual problem. This project aims to develop and manufacture a learning control system that can implement control according to specified drying criteria and operating on the basis of changes in the moisture content of the processed material. This article presents the results of the development of a control system for a laboratory setup of electrophysical effects on grain. During this work elements of experimental planning, elements of statistical processing, computer modeling by using applied software for electrodynamic modeling, development of SCADA systems and programming of control equipment were used. The experiments were carried out using certified measuring equipment. The value of the research results lies in determining energy-efficient operating modes of grain processing equipment using a microwave field. The scientific novelty of the research consists in determining the grain wetness by the relative decrease voltage of the electromagnetic field in the layer of processed grain. Main provisions: the application of the developed humidity level control system allows you to determine the wetness content of the grain layer during processing by a microwave field; the implementation of one setup of combined microwave-convective drying of grain with a capacity of 5 tons per hour, operating under the control of the developed system and designed for productivity, allows you to get an income of 5231.2 thousand rubles for eight years of project implementation, while the simple payback period of capital investments will be 3.6 years. Conclusions: the using of the developed system by the experimental installation of microwave effecting on grain makes it possible to implement control according to relevant control criteria, while the average energy consumption of wheat drying from 20 to 14% stands at 3.7 MJ per kg of evaporated moisture; the implementation of the control system for the technological process of electrophysical exposure with further improvement allows for the accumulation of statistical information and the developing of operating modes of equipment according to more complete data.

The article considers the microwave electromagnetic fields as one of the options for improving the thermal drying of grain. Their application is limited by the high unevenness of the field propagation in the layer of the processed material. (Research purpose) The research purpose is in justifying the uniformity of distribution of microwave field in the layer of the processed grain. (Materials and methods) The article presents the scheme of computer models of microwave processing zones and waveguides, properties of materials for conducting a numerical experiment. (Results and discussion) A numerical experiment was performed to determine the uniformity coefficient of propagation of the microwave field in a layer of grain material. The article presents the dependencies. (Conclusions) It was found that the results of modeling the distribution of the electromagnetic field in the zone of microwave convective influence of the installation containing two sources of microwave power for processing the grain layer indicate a high level of its unevenness in the volume of the product pipeline. To assess the uniformity of the distribution of the electromagnetic field in the working area of a laboratory installation, there used a coefficient that is the ratio of the average value of the intensity in the zone of microwave convective action to its average value of the wave strength passing through the output of the waveguide. The values of the uniformity coefficient in the considered implementation options are in the range of 0.1757-0.4946 for a dense layer of wheat. To ensure a sufficient level of uniformity of the electromagnetic wave distribution in the volume of the microwave convective zone, the uniformity coefficient must be higher than 0.37. The article presents the dependence of the uniformity coefficient of the electromagnetic field on the humidity of the processed material by a third-degree polynomial with a coefficient of determination higher than 0.98.