著者

中川 洋 石島 三郎

出版者

日本真空協会

雑誌

真空 (ISSN:05598516)

巻号頁・発行日

vol.3, no.10, pp.381-388, 1960-10-20 (Released:2009-09-29)

参考文献数

8

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The conventional evacuating system : combination of oil diffusion pump, booster pump and mechanical rotary pump, has serious faults in the case of pumping the chemically unstable matter. For instance, in the degassing stage of the molecular distillation plant, the gas is composed of air, volatile matter, water vapor and mist of unstable compound. These components are decomposed or polymerized in a evacuating system, and damage the normal opperation of pumps, especially in oil rotary pump. This is caused by less circulation of oil, and moving parts would be damaged.To conquer this difficulty, we tried to select the new pump composion ; diffusion-booster, steam ejector and water jet. This system has not any moving parts, so we can avoid adove difficulty. The performances of these pumps are as follows : Diffusion booster : Pumping speed (800900 l/sec at 10-310-2 mmHg) Critial back pressure (57mmHg) Steam ejector : Pumping speed (20 l/sec at 1 mmHg), Back pressure (40 mmHg) Water jet : Pumping speed (0. 95 l/sec at 5 mmHg), Back pressure (atmosphere).The overall performance shows very satisfactory result, and this system is now under continious operation for over a year.