[关键词]
[摘要]
目的 以二至丸为研究对象,探索中药丸剂热风干燥过程温度变化规律,为提高丸剂干燥效率及干燥均匀性提供理论依据。方法 基于COMSOL Multiphysics建立传热传质模型模拟二至丸层在无孔底及筛孔底2种干燥盘不同温度干燥过程温度分布并进行求解;研究了二至丸层在60、80、100℃热风温度下干燥过程,并通过Fick第2定律平板模型计算二至丸水分有效扩散系数(Deff);采用探针温度传感器监测二至丸层干燥过程中间表面及内部温度变化进行干燥模型验证。结果 不同热风温度干燥过程中二至丸层表面及内部温度呈现先剧烈上升后缓慢上升的趋势,二至丸层无孔底干燥模型及筛孔底干燥模型内部温度分别为55.3~56.0℃、57.5~57.7℃,使用筛孔底干燥盘可提高干燥温度均匀性;2种模型实验得到水分Deff分别为0.76×10-7~2.82×10-7 m2/s、1.15×10-7~3.94×10-7 m2/s;实验结果验证模型在一定干燥温度范围内能够较好反映二至丸层干燥过程温度变化规律。结论 通过可靠的二至丸层热风干燥模型直观反映干燥过程温度变化情况,该研究为二至丸干燥工艺优化提供参考。
[Key word]
[Abstract]
Objective To explore the law of temperature change in hot air drying process, and provide a theoretical basis for improving the drying efficiency and uniformity of Erzhi Pills (EP). Methods Heat and mass transfer models were established to simulate the temperature distribution of the drying process of EP with no hole bottom and screen hole bottom based on COMSOL Multiphysics. The drying process of EP layer at 60, 80 and 100℃ was studied. The effective water diffusion coefficient (Deff) of EP layer was calculated by Fick's second law plate model. A probe temperature sensor was used to monitor the temperature changes of the intermediate surface and interior of EP layer during the drying process to verify the drying model. Results The surface and internal temperature of EP layer showed a trend of first sharp rise and then slow rise in the drying process of different hot air temperature. The inner temperature range of the drying model with no hole bottom and screen hole bottom was 55.3-56.0℃ and 57.5-57.7℃ respectively. The uniformity of drying temperature of EP can be improved by using drying plate with screen hole. The Deff range of the two model experiments were 0.76×10-7-2.82×10-7 m2/s and 1.15×10-7-3.94×10-7 m2/s, respectively. The experimental results showed that the model could well reflect the temperature variation of EP layer drying process within a certain drying temperature range. Conclusion The change of drying temperature was directly reflected through the reliable hot air drying model of EP layer. The study provides reference for the optimization of EP drying process.
[中图分类号]
R283.6
[基金项目]
国家自然科学基金资助项目(81760716);江西省自然科学基金资助项目(20171BAB215065)