Improving the Operation of a Drum Grain Dryer With Justification of the Low-Temperature Mode Parameters

Abstract

The proposed engineering and technological solutions are aimed at improving the operation of a low-temperature drum grain dryer by using a combined mechanical vibration exciter, with the further justification of low-temperature regime parameters. Existing vibration technologies imply the high-temperature drying of food grains with further utilization of spent heat carrier for reheating it. In this case, the high-temperature drying of cereals and seed crops (grains, onions, etc.) does not make it possible to maintain high germination, emphasizing the need for low-temperature treatment, which, in this case, reduces the efficiency of spent heat carrier. Therefore, to improve the efficiency of the drying process and technology, it has been proposed to employ vibration low-frequency technologies that ensure seed quality. The trajectory and the kinetic energy of the drum container with a combined mechanical vibration exciter have been calculated for the improved vibratory drum grain dryer. The rational vibration intensity for seed drying providing the following kinetic characteristics has been established: vibration speed, to 0.03 m/s; vibration acceleration, 30 m/s 2 ; vibration intensity, 2.6 m 2 /s 2 ; at amplitude vibration not exceeding 2 mm. It has been also established that the intense warming of a barley layer occurs at a temperature of 50 °C and a humidity of 13.5 %, the final temperature is 42.4 °C, and, at 40 °C, is, accordingly, 35.4 °C. This has confirmed that the low-temperature drying of barley seeds of the variety "Stalker" (Ukraine) takes place during the periods of constant and falling drying speed characterized by a high level of germination (95...93 %)