Oxygen vaporization method and system

摘要

A method and system for producing an oxygen product stream in which sensible heat from a compressed air stream is indirectly exchanged with a vaporized pumped liquid oxygen stream in a main heat exchanger and latent heat is exchanged in an auxiliary heat exchanger connected to the main heat exchanger. The latent heat exchange produces subcooled liquid air that is fed into a low pressure column of the air separation plant and vaporization of the pumped liquid. Part of the subcooled liquid air can be withdrawn from the auxiliary heat exchanger at a higher temperature than the remainder of the subcooled liquid air. All or part of the subcooled liquid air can be further cooled within the main heat exchanger. As a result, low temperature, subcooled liquid air is produced that allows for an increased oxygen recovery and also, argon recovery if an argon column is present.

主权项

1. A method of vaporizing a pumped oxygen stream in a cryogenic air separation plant to form an oxygen-rich vapor product stream, said method comprising:
indirectly exchanging sensible heat from a compressed air stream to the pumped oxygen stream, after having been vaporized such that the compressed air stream is partially cooled and the pumped oxygen stream is warmed to form the oxygen-rich vapor product stream; indirectly exchanging latent heat from the compressed air stream, after having been partially cooled, to the pumped oxygen stream such that the pumped oxygen stream is vaporized and the compressed air stream is liquefied to produce a liquid air stream; at least part of the sensible heat being exchanged within a main heat exchanger so that the warmed, oxygen-rich vapor product stream is discharged from a warm end thereof; the main heat exchanger employed in the cryogenic air separation plant to cool air to a temperature suitable for its distillation within the distillation column system that produces an oxygen-rich liquid that is in turn pumped to form the pumped oxygen stream; at least part of the latent heat being exchanged in an auxiliary heat exchanger connected to the main heat exchanger; directing a portion of the compressed air stream from the main heat exchanger after having been partially cooled to the auxiliary heat exchanger and after having been liquefied within the auxiliary heat exchanger, dividing the portion of the liquefied air stream while within the auxiliary heat exchanger and into a first subsidiary stream and a second subsidiary stream; discharging the first subsidiary stream from the auxiliary heat exchanger such that the first subsidiary stream is subcooled in the auxiliary heat exchanger and withdrawn from the auxiliary heat exchanger to form a first subcooled liquid air stream and the second subsidiary stream is subcooled in the auxiliary heat exchanger and discharged from the auxiliary heat exchanger as a second subcooled liquid air stream, wherein the first subcooled liquid air stream is withdrawn from the auxiliary heat exchanger at a higher temperature than the second subcooled liquid air stream; and introducing the first subcooled liquid air stream and the second subcooled liquid air stream into a distillation column system of the cryogenic air separation plant.