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为了建立当归药材干燥过程的水分动力学模型,以期对当归药材干燥过程和干燥效果进行预测。该实验研究了当归药材采用控温鼓风干燥、控温红外干燥方法,分别在50,60,70℃干燥温度条件下的干燥曲线、水分有效扩散系数以及干燥活化能,利用Weibull分布函数对其干燥动力学曲线进行模拟与分析。研究结果表明,Weibull分布函数能够较好地模拟当归药材在实验条件下的干燥过程(R2=0.994~0.999),当归药材的干燥过程属于降速干燥;尺度参数α与干燥温度有关,并且随着干燥温度的升高而降低;干燥温度对形状参数β的影响较小;水分有效扩散系数在0.425~2.260×10-9m2·s-1随着干燥温度的升高而升高;控温鼓风干燥和控温红外干燥的干燥活化能分别为68.82,29.60 k J·mol-1。Weibull分布函数可较好地预测当归药材干燥过程中的水分脱除规律,对于药材干燥过程的预测、调控和工艺优化具有重要意义,该研究为使用现代干燥技术工业化干燥当归药材提供了技术依据。
In order to establish the moisture dynamic model of Angelica sinensis drying process, in order to predict the drying process and drying effect of Angelica sinensis. The experimental study Angelica herbs using temperature-controlled blast drying, temperature-controlled infrared drying method, respectively, at 50,60,70 ℃ drying temperature drying curve conditions, the effective diffusion coefficient of water and dry activation energy, the Weibull distribution function of its Drying kinetics curves were simulated and analyzed. The results showed that the Weibull distribution function can simulate the drying process of Angelica sinensis under the experimental conditions (R2 = 0.994-0.999). The drying process of Angelica sinensis belongs to the desiccation drying process. The scale parameter α is related to the drying temperature, Drying temperature increased and decreased; the drying temperature had little effect on the shape parameter β; the effective diffusion coefficient of water increased from 0.425 to 2.260 × 10-9m2 · s-1 with the increase of drying temperature; Drying and temperature-controlled infrared drying drying activation energy were 68.82,29.60 kJ · mol-1. Weibull distribution function can predict the law of moisture removal during the drying process of Angelica sinensis well, which is of great significance for the prediction, regulation and optimization of the process of medicinal herbs drying. This study provides a technical basis for the industrialization of the drying of Angelica sinensis using modern drying technology.