USING THE OSCILLATING MODE OF CONTACT DRYING OF BULK MATERIALS

Post-harvest processing of grain affects the duration of its storage. The purpose of the study is to determine the effectiveness of the oscillating mode in a new device with a contact method of heat supply to the dried material. The existing devices used in the oscillating mode of contact drying are considered. A grain dryer developed in the Ulyanovsk State Agrarian University is proposed, in the design of which a cooling device is used. Theoretical and experimental studies of the grain dryer were carried out, during which the influence of air velocity on grain parameters such as humidity and temperature at the outlet of the device was determined. It was revealed as a result of the research that the use of an oscillating mode of contact drying makes it possible to obtain grain at the outlet, the temperature of which ensures the preservation of its positive qualities. The use of a cooling device in the proposed grain dryer makes it possible to reduce the temperature of the grain at the outlet of the device by an average of 9%, which ultimately prevents the grain from overheating above 39°C. At the same time, the air flow velocity generated by the cooling device, which varies in the range from 1 m/s to 3.5 m/s, has a minimal effect on the final humidity. It was revealed that at the optimal average temperature of the heating surface of the device tp = 129 °C, grain velocity vz = 0,29 m/s, as well as air velocity vvp = 3,5 m/s, grain moisture at the outlet of the device does not change, and its temperature after the end of heating, cooling and reheating operations by 3 degrees lower than in the technological process without an intermediate grain cooling operation.