Studying and Proposing the Freeze Drying Model in Combination of High and Low Temperatures to Dry Medicinal Herbs

   The article represents a theoretical and experimental study on the model of drying equipment with heat pump. In this paper, we have analyzed weaknesses and advantages of drying process: hot-drying and freeze-drying methods. The paper has also studied and established the freeze drying model that combines high and low temperatures to dry medicinal herbs in order to restrict its weaknesses. It has also presented the process of operation, analyzed weaknesses and advantages of the drying model of combining heat and freeze regimes. The research findings will be used for students and engineers majoring in the study and research on heat-refrigeration technology. This is also a foundation for medicinal herbs processing and preserving enterprises to enhance quality and reduce expenditure