Abstract: A system for separating air by cryogenic rectification whereby liquid production is increased by employing two separate turboexpanders, one which exhausts at a pressure no higher than that sufficient to feed the lower pressure column, the other which exhausts at a pressure no lower than that sufficient to feed the higher pressure column, and wherein one of the turboexpanders is fed with ambient temperature or modestly cooled feed air and preferably operates intermittently depending upon whether greater or lesser amounts of liquid product are desired.

Abstract: A method for the cryogenic separation of air having defined temperatures for condensed feed air passed into a double column system relative to liquid oxygen and preferably to shelf vapor, and wherein kettle liquid is not subcooled from the higher pressure column to the lower pressure column.

Abstract: A process for carrying out cryogenic air separation wherein liquid oxygen is pressurized and vaporized against condensing feed air to produce oxygen gas product wherein excess plant refrigeration is generated such that the aggregate warm end temperature difference of the process exceeds the minimum internal temperature difference of the primary heat exchanger by at least 2K.

Abstract: A cryogenic rectification system employing a phase separator, which may include one or more trays, in conjunction with a double column air separation plant, wherein some shelf liquid is subcooled and phase separated to produce crude neon vapor, and the remaining liquid is used to reflux the lower pressure column of the double column plant.

Abstract: A cryogenic air separation system for producing elevated pressure nitrogen wherein a portion of the nitrogen product fed to the product compressor downstream of the primary heat exchanger is withdrawn as refrigerant nitrogen from the product compressor, preferably from an intermediate point of the product compressor, and turboexpanded to generate refrigeration for the system.