RELIABLE CENTRIFUGAL MACHINES FOR HELIUM CIRCULATION IN CRYOGENIC REFRIGERATORS

THIS PHASE I PROJECT ADDRESSES THE NEED FOR ROBUST, CONTAMINATION-FREE CIRCULATORS TO DISTRIBUTE LIQUID OR SUERCRITICAL HELIUM THROUGH SUPERCONDUCTING MAGNETS. AN ADVANCED CENTRIFUGAL MACHINE SUITABLE FOR LIQUID OR GAS CIRCULATION AT CRYOGENIC TEMPERATURES WILL BE DEVELOPED. THE MACHINE INCORPORATES TWO INNOVATIVE FEATURES THAT PROVIDE FOR HIGH EFFICIENCY AND RELIABLE OPERATION IN THE PRESENCE OF SIGNIFICANT PRESSURE TRANSIENTS. THIS DEVELOPMENT WILL DEMONSTRATE ENABLING TECHNOLOGY THAT CAN BE SCALED TO A VARIETY OF MACHINES OVER A BROAD RANGE OF PUMPING AND COMPRESSING CAPACITIES. THE PLANNED CONCEPT COMBINES A UNIQUE, HIGHLY DAMPED PRESSURIZED GAS BEARING SYSTEM TO ACCOMMODATE SEVERE PRESSURE LOADS, AND A SOLID ROTOR MOTOR TO INCREASE THE RANGE OF ACCEPTABLE OPERATING SPEEDS, THEREBY ENHANCING PERFORMANCE. THIS MACHINE REPRESENTS A SIGNIFICANT IMPROVEMENT OVER SELF ACTING GAS BEARING SYSTEMS IN TERMS OF LOAD CAPACITY, AND IS SIGNIFICANTLY EASIER TO CONTROL THAN ELETROMAGNETIC SHAFT SUPPORT SYSTEMS.