Study on the Freeze-drying Dual-evaporator Refrigeration System

摘要

In the freeze-dryer, the dual-evaporator refrigeration system is used to meet the demands of the freeze-drying technology. One evaporator is used as "cold trap", and the other one, shelf evaporator, is used to control materials' temperature. In this paper, experimental study on the dual-evaporator refrigeration system in the process of freeze-drying is carried out. First, the influence of valve opening on the dual-evaporator refrigeration system is analyzed. Secondly, the influence of vacuum on the surface temperature of the heat exchanger is analyzed. Finally, the influence of the varied evaporation temperature on the first drying rate is analyzed.