Vacuum freeze drying technology, freeze drying in short, is freeze the materials that containing. Water first, and then sublimate them in vacuum After being dried by freeze drying, the materials chemical and biological characters are still the same and can keep for a long time, it can turn back to its initiative condition when was added water and the biological features are the same. Therefore, the vacuum freeze drying technology is widely applied in the fields of chemical industry and biological products. TH-2-80D-2 TIANHAN series driers are pint-size frozen dries, and are suitable for the laboratory use of drying samples, This series of dries have four models,TH-80D-2A,TH-80-2B,TH-80-2C and TH-80-2D.