Study on low temperature moisture regain drying characteristics of different grades of Angelicae Sinensis Radix based on Weibull distribution function / 中国中药杂志

ABSTRACT

The drying process of different grades of Angelicae Sinensis Radix under low temperature and resurgence conditions was simulated based on the Weibull distribution function,in order to clarify the low-temperature moisture regain drying characteristics of different grades of Angelicae Sinensis Radix,and explore the effect of grade and drying conditions on the drying process of Angelicae Sinensis Radix. Research results indicated that the Weibull function can be used to simulate different grades of Angelicae Sinensis Radix low-temperature moisture regain drying process,and the lower the drying temperature,the smaller the grade,and the better the simulation effect. The grade and drying temperature showed a significant effect on the low-temperature moisture regain drying process of Angelicae Sinensis Radix,and the effect of temperature on the relative moisture regain rate of Angelicae Sinensis Radix was greater than the grade. The relative moisture regain rate of different grades of Angelicae Sinensis Radix at 40 ℃ was higher than 55 ℃,and the relative moisture regain rate at 40 ℃ was first class > second class > third class. After drying,the moisture ratio at 40 ℃ was lower than that at 55 ℃; the effect of the grade on the effective diffusion coefficient of dry water was greater than the temperature. Under different conditions of 40 ℃ and 55 ℃ moisture regain,the effective diffusion coefficient of water was between 2. 941 6×10-6-7. 991 5×10-6 and3. 093 8×10-6-8. 483 8×10-6 for different grades. Under the same temperature conditions,the effective diffusion coefficient of water was first class > second class > third class. Therefore,Weibull function can be used to study and simulate the drying characteristics of different grades of Angelicae Sinensis Radix under low-temperature moisture regain conditions,providing experimental basis for the improvement of traditional drying technology of Angelicae Sinensis Radix and the optimization of drying process of different specifications or grades of Angelicae Sinensis Radix.