One of the main tasks of agriculture is to achieve a stable growth of production. In this regard, a number of measures are necessary to help to create all the necessary conditions for the storage and processing of grain. This can be achieved through technical upgrading of grain drying industry.
The storage of grain and its processing is most closely linked with its moisture content. The usable quantity of the final product depends upon the moisture, as its quality and energy consumption in the processing of cereals. The drying is the most important way to treat the corn and to process it into flour, groats and other products. It is organized in consideration of the moisture content of grain and the difficulties that arise here.
The efficiency of the grain dryer is determined largely through the quality of control system. The control system must provide timely and reliable information about the properties of the grain, that is dried, about drying agent and the operating and other parameters. It shoud assure the timely reaction to any deviation from the specified values of moisture, temperature and quality of the grain during the drying and at the exit of the drying chamber.
The other side of the coin is that control system should be effective by improve the productivity of dryers, enhancement of the quality parameters of the grain and reduction of costs.
One of the ways of the intensification of the drying is the keeping of process at the maximum allowable heating temperature of the cereals depending on the further use.
The main operating characteristics, which need monitoring and provide the quality of the grain, are the moisture and the temperature of the heating.
The parameters that define the quality of the corn, are a large group of characteristics: colour, odour, glassiness, the number and quality of gluten, the protein content in the fractions, fat and starch content, baking quality, etc.
The state of the grain mass is characterised by moisture, contaminant and the temperature. In the drying process should be controlled the moisture and the temperature of the crop, germination capacity (for the seed grain), the number and quality of gluten (for the wheat) and other indicators, which are dependent on the heating temperature of cereals, the speed and duration of the grain drying. As was already stated, the duration of heating affects the grain quality only in the case of excess the permissible heating temperature of the corn.
The calculation algorithm of the drying can be defined in view of the effectiveness as follows: by supplying a determined quantity of the moisture extraction and at the same quality level of the corn due to keeping the maximum allowable heating temperature and with normalized or minimal costs for the drying at a certain power consumption of the drier.
The check of the temperature of the grain and moisture is enough by existence of the correlation of these parameters with the indicators of the quality. However, the correlation dependence should take into account not only technological, thermal and biochemical properties of the grain mass, but also constructive features of the dryer.
The used algorithm for the calculation of parameters of grain drying requires an existing data correction on the type and grain quality and begins with the input of the properties of the grain mass, of ambient air, as well as the assignment of the most important features of grain drying - dehumidification. After the calculation the productivity, energy consumption per 1 kg of the evaporated humidity and the total time of the drying are displayed. After that, the parameters of the flow of air, that becomes heated in order to intensify the drying process, are calculated. The calculation is performed for each step of dehumidification.
The analysis of the determined values indicates that we receive reduced energy costs per 1 kg of the evaporated moisture (1,5-2 times less) by high performance of grain drying for a limited dehumidification at the expense of the increased air stream.