Thin-layer Drying Process Of Corn With Vacuum

The yield of corn in China is only lower than America, which is the second in the world. While the moisture of the corn is higher, so drying is an important process after harvesting. At present most of the corn is dried by hot-air, but quality is loared, and a lot of nutrition lost in high temperature, which seriously affect the nutrition of corn. According to principle that the boiling point of the moisture on the surface of corn changes with the environmental pressure, the high moisture corn is continuously dried in vacuum condition. By this method high quality and nutrition corn is produced.In this experiment, the process of and vacuum drying was basically studied; the influence of temperature, vacuum, time and original moisture on the drying velocity and quality after drying was analyzed; the changing order of the drying velocity and moisture was studied; the corn thin layer drying model was set by orthogonal test; the regression model among moisture change, stress crack rate, starch yield, drying time, vacuum and temperature was set by method of the combination design of orthogonal rotating; After synthesizing every index, the optimum parameter of vacuum drying is found by nonlinear optimization theory and method; the compound process of hot-air drying and vacuum drying is studied after the comparison test.The conclusions are as followed:1) The influence of different parameters on drying velocity is studied, after single factor test the conclusion is drawn that drying velocity is increasing with temperature and vacuum increasing in the course of drying.2) The influence of every parameter on corn quality is studied. After single factor test, it is found that stress crack rate decreases with the vacuum and temperature increase; the starch yield increases with the vacuum increasing and decreases with the temperature; the germinating rate firstly increases and then...