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US 6,141,990 AGranted
Process and plant for separating air by cryogenic distillation
AssigneesAir Liquide America Corporation, L'Air Liquide Societe Anonyme pour L'Etude et L'Exploitation des Percedes Georges Claude
InventorsFrancois De Bussy, Lasad Jaouani
Life of this patent
Estimating the term…
Abstract
In order to allow more flexible operation of a column for separating air by cryogenic distillation, a first air stream (6) exchanges heat with a liquid (16) which vaporizes, while a second air stream (7, 7A) is drawn off from an intermediate level in the exchange line and sent to a column in order to be distilled therein.
Claims16
Process for separating air by cryogenic distillation in a plant comprising a column system in which:
- a) at least two air streams (6, 7, 7A) are cooled in an exchange line (1) and are sent to a column (3) of the system,
- b) the air is separated in the column into an oxygen-enriched fraction and a nitrogen-enriched fraction,
- c) a liquid stream (16) is drawn off from a column (4) of the system and vaporizes in the exchange line,
- d) a first air stream (6) exchanges heat in the heat-exchange line with the liquid which vaporizes,
- e) a second air stream (7, 7A) is drawn off from an intermediate level in the exchange line, characterized in that the second air stream is sent from the exchange line to the column system without being expanded.
2 more elements
Plant for separating air by air distillation, comprising:
- a column system (2),
- means for sending a first air stream (6) and a second air stream (7, 7A) to an exchange line (1) and from the exchange line to a column,
- means for sending at least one pressurized liquid (16) coming from the double column to the exchange line,
- means for drawing off the second air stream (7, 7A) from an intermediate level in the exchange line, characterized in that it comprises means for sending the second stream from the intermediate level in the exchange line to the medium-pressure column, these means not comprising means for expanding the stream.
1 more element
Dependencies are inferred from the claim text.