Abstract: The present invention provides a method and apparatus for generating refrigeration in a process operating at sub-ambient temperatures in which the refrigeration is generated by a turboexpander. The turboexpander is coupled to a generator controlled so that its speed is maintained at a setpoint through electromagnetic braking and its power output is maintained at line matching voltage and frequency. The speed control of the generator therefore, also controls the speed of the turboexpander. The setpoint is calculated to be equal to a product of an operational efficiency parameter, U/Co, and a square root of twice the enthalpy drop in the flow passing through the turboexpander divided by a product of pi and a diameter of an impeller employed within the turboexpander.

Abstract: The present invention provides a method and apparatus for generating refrigeration in a process operating at sub-ambient temperatures in which the refrigeration is generated by a turboexpander. The turboexpander is coupled to a generator controlled so that its speed is maintained at a setpoint through electromagnetic braking and its power output is maintained at line matching voltage and frequency. The speed control of the generator therefore, also controls the speed of the turboexpander. The setpoint is calculated to be equal to a product of an operational efficiency parameter, U/Co, and a square root of twice the enthalpy drop in the flow passing through the turboexpander divided by a product of pi and a diameter of an impeller employed within the turboexpander.

Abstract: Systems and processes are provided for gas separation using high-speed permanent magnet variable-speed motors to accelerate and decelerate centrifugal compressors suitable for use in pressure swing adsorption (PSA) or vacuum pressure swing adsorption (VPSA) processes.

Abstract: Systems and processes are provided for gas separation using high-speed permanent magnet variable-speed motors to accelerate and decelerate centrifugal compressors suitable for use in pressure swing adsorption (PSA) or vacuum pressure swing adsorption (VPSA) processes.

Abstract: A distillation method and apparatus having application to the distillation of air in which liquid production make is varied by varying the pressure ratio across a turboexpander used in generating refrigeration. The pressure ratio is varied by varying the pressure of a compressed stream fed to the turboexpander. This is done by solely compressing such compressed stream by a first booster compressor during a low rate of production of liquid products. During a high rate of production of liquid products, the compressed stream is also compressed within a second booster compressor. The second booster compressor is driven by a variable speed drive to allow a variety of liquid production rates between the low level of liquid production and the high level of liquid production.

Abstract: A compliant foil fluid thrust bearing has a single sided or two sided thrust disk rotor, an integrally formed compliant foil member, and an underspring member. The non-rotating but compliant foils are located adjacent to the thrust face or faces or the rotatable disk and are formed as arcuate segments on washer-shaped disk members. The underspring member consists of three washer-shaped disk elements that together provide variable spring stiffness in both the circumferential and radial directions.