Authors:
A. A. ZAVALIY, doctor of engineering, associate professor, head of the department,
L. A. LAGO, assistant,
Academy of bioresources and environmental management of KFU of V. I. Vernadsky (4 Vernadksy Ave, 295007, Simferopol)
A. S. RYBALKO, junior researcher,
Institute of agriculture of the Republic of Crimea (150 Kievskaya Str., 295493, Simferopol)
Abstract. Drying is one of the main technologies for processing agricultural raw materials, which can provide conditions for the long-term preservation of the nutritional or energy value stored in it and biologically active or functional substances. To better the product quality and the efficiency of drying this is a process proposed to place the device of infrared drying with controlled reflected thermal radiation into a sealed chamber with reduced pressure. This will increase efficiency of the drying process and the quality of the product by increasing the uniformity of moisture removal from the raw material in the volume of the device, eliminating the contact of the raw material surface with atmospheric air and significantly reducing the drying process time. In this paper we have completed analysis of the heat and mass balance and experimental studies of uniformity and intensity of infrared drying under reduced pressure. It revealed that pressure drop to 900 mm wg below atmospheric allows 16 % reduction in time and a 13 % reduction in power consumption of the device with the radiation sources capacity intake of 12 kW. Double shift work mode of such device allows to dry up to 200 kg of raw product per day. Therefore, increasing the vacuum degree will increase both the efficiency of the drying process and the evaporation intensity of useful product substances. Optimum modes of infrared drying under reduced pressure, providing maximum preservation of useful components of the product are subject to experimental determination for different types of agricultural raw materials. The main primary products for infrared drying under vacuum should be plant material of Crimea, rich in vitamins, essential oils, substances with antioxidant, immune stimulant effect, used as drugs and food additives.
Keywords: agricultural raw materials, infrared drying, low pressure.
