土样真空冷冻升华干燥仪研制中的一些问题

Discussing on Some Issues in the Manufacture of Vacuum Freeze-drying Apparatus for Soil Samples

土的微观结构测试需要干燥后的样品,而常规的干燥方法,如风干法、烘干法、置换法都存在使样品体积收缩、改变土微结构状态的缺陷。真空冷冻升华干燥仪首先利用液氮使土样中的液态水变成非结晶态冰,不产生体积膨胀,然后在低温真空条件下让水分升华排出真空管路系统,使得样品干燥。本文介绍了真空冷冻升华干燥仪开发研制的设计构思以及安装过程中涉及的几个问题和试验操作中的注意事项。

It is necessary that soil samples should be dried for the microstructure inspection. The common methods for drying soil samples such as the air drying, heat drying and displacement drying have the defects which result in the shrinkage in volume and the deformation in microstructure. The water in soil could change into the non-crystallized ice with the help of liquid nitrogen, and the vacuum-freezing-drying apparatus make the water dry through the vacuum system of glass tube in the conditions of lower temperature and the higher vacuum degree. The concept design and installation about the apparatus are discussed and some key operations are mentioned.