OPTIMIZATION DRYING PROCESS OF CRUSHED SOYBEAN FOR OIL PRODUCTION

Abstract

Obtaining oil from soybeans by the extrusion-pressing method involves drying it to a moisture content of 8.0–8.5%. Energy consumption for drying can be 300–400% or more than the estimated energy consumption for moisture evaporation. Crushing accelerates thermo-moisture exchange processes in a separate product particle, but it causes some negative phenomena: it reduces the volume of hot air and increases aspiration mass loss during drying. The purpose of the research is to determine the speed of hot air movement in the outlet channels of the grain dryer during drying of crushed soybeans. The simulation of the speed of hot air movement carried out in the SOLIDWORKS software environment. Drying of crushed soybeans carried out in batch mode. A whole soybean taken as a control. Weighing soybeans before and after drying carried out on automobile scales. According to the simulation results, a diagram of hot air pressure indicators in the central plane of air ducts and gas distribution chambers was constructed. A significant pressure drop (200 Pa) observed in the middle of the gas distribution chambers: the zone of increased pressure – opposite the entrances of the ducts, the lowest – in the central part. The combination of high speed and hot air pressure in the upper part of the gas distribution chamber caused a sharp increase in speed in the upper row of the outlet channels of the first section. In fact, the average hot air speed determined by the anemometer is 4.2 m/s, which confirms the results of the SOLIDWORKS Flow simulation. Computer simulation made it possible to identify separate rows of outlet channels, the speed of hot air in which is much higher than the average indicators. A significant difference in hot air speed indicators within one zone of the grain dryer revealed, which is a consequence of the asymmetric connection of air ducts. Reducing the cross-section of the inlet channels in areas with a high speed of exhaust hot air will allow reduce it and reduce the mass loss of soybean crushing products.