Design and Operation of the Oil-Turbine Ultracentrifuge

Abstract

The development of the oil-turbine ultracentrifuge, from the first model built in 1925 to the latest, is traced, with special attention being given to the principles of design for maximum resolving power in the analysis of mixtures as the lowest expenditure of energy. The efficiency of various types of rotors combined with centrifugal or screw-type oil pumps is reported. By proper attention to design, it has been possible to attain an efficiency at 60,000 r.p.m. of 40 percent in the oil turbines and an over-all efficiency of electric motor, oil pump, and oil turbines of 28 percent. The actual power consumption under these conditions is slightly over 1 kw, which appears to be somewhat better than has so far been attained with the air-turbine ultracentrifuge of comparable design. The frictional resistance of the rotor rotating in hydrogen at 20 mm pressure is 300 watts, 32 watts representing gas friction. The cost of electricity, cooling water and hydrogen for operating the latest rotor and assembly at 60,000 r.p.m. exclusive of the vacuum system and recording instruments, is 9¢ per hour, with electric power at 1.54¢ kw-hr., water at 6.4¢/cu.m, and hydrogen at 64¢/cu.m. The corresponding cost for an early model rotor and assembly was 28.7¢ per hour.