基于分子蒸馏原理的金属铯提纯实验系统研制

Design and study of molecular distillation device for purify metal cesium

为了进一步提高铯原子钟用金属铯原料的纯度，研制了一套刮膜式分子蒸馏实验系统，进行99.5%金属铯的进一步提纯。本文介绍了系统的结构，对系统的真空性能、刮膜器性能进行了实测，最后进行了金属铯提纯实验。实验结果表明：系统的极限真空度达到4.3×10^-6Pa，工作真空度达到5.0×10^-4Pa，刮膜器转速实现0-300 r/min范围内可调，均符合设计要求。金属铯经过该设备蒸馏后纯度达到99.95%，可以满足铯原子钟的使用要求。

A film wiping molecular distillation system was developed to purify the 99.5% cesium using molecular distillation in order to satisfy the purity requirement of the Cesium Atomic Clock.The structure design was discussed, while the vacuum pumping capability and film wiping form were measured actually. The system was experimented to purify cesium. The results indicate that the ultimate pressure of the system can reach 4.3×10^-6Pa and the working pressure is about 5.0×10^-4 Pa. The rotate speed of the wiper blade can be adjusted from 0 to 300 rpm. The results show that the design and structure can meet the design demand. Af-ter the purification, the content of cesium is improved to 99.95%, which can be used for the Cesium Atomic Clock.