A rotating liquid helium transfer system

This chapter demonstrates the successful operation of a stable transfer system suitable for fault worthy superconducting generators. A turbine type flowmeter for liquid helium has been developed and successfully operated. The transfer system was cooled to helium temperature and the transfer of liquid was initiated without any detectable pressure oscillations or surges. Transfer system losses were computed for subcooled, two-phase and superheated helium transfer and various mass flow rates up to 70 L/h. Transfer losses are shown to be a strong function of angular velocity, void fraction and mass flow rate. It is suggested that to minimize losses and oscillation a vapor separator should be used at the transfer system inlet to control void fraction in the transfer stream