All-Metal Scroll Vacuum Pumps for Tritium Processing Systems

Abstract

Over the past decade, Air Squared has been actively developing and improving the highly anticipated 15 m3/h tritium vacuum pump to replace the obsolete industry standard Normetex scroll pump. The all-metal pump features a metal bellows that hermetically seals all tritium gas from any material other than metal. Air Squared has listened to the tritium market’s needs and is currently developing the latest addition to the Air Squared tritium vacuum pump line: the 150 m3/h liquid cooled all-metal (LCAM) scroll vacuum pump. Through numerous hours of testing, Air Squared has demonstrated the advantages of LCAM scroll vacuum pumps. The effect that thermal expansion has on highly toleranced all-metal pumps has been observed and characterized to predict pump performance as well as provide safe operational temperature limits. Performance characteristics of the 15 m3/h pump have been analyzed with different process gases to understand the effects of pumping light gases. Vacuum pumping speed curves have been generated at various interstage pressures to understand the advantages that roughing pump systems have when used in series with all-metal scroll vacuum pumps. This paper presents Air Squared’s 15 m3/h designs and highlights the performance characteristics. The effects that pump temperature, process gas, and fore-vacuum have on all-metal scroll vacuum pumps are explained with empirical data collected over a decade of research. With the knowledge and data collected, Air Squared has a pathway for a new industry standard 15 m3/h and 150 m3/h positive displacement scroll pump for tritium service to support international nuclear fusion and tritium research.