Cryogenic rectification regenerator system
AssigneePraxair Technology, Inc.
InventorsJohn Fredric Billingham, Thomas John Bergman, Jr.
Life of this patent
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Abstract
A cryogenic rectification system for producing nitrogen, especially at low production flowrates, wherein incoming feed air is cooled by a regenerator without need for cold end imbalance and wherein exogenous cryogenic liquid is added to the rectification column.
Claims8
A method for producing nitrogen by the cryogenic rectification of feed air using a regenerator having a shell side and a coil side, said method comprising:
- (A) cooling feed air by passing the feed air through the shell side of a regenerator during a cooling period, and introducing the cooled feed air into a column;
- (B) passing exogenous cryogenic liquid into the column and separating the feed air by cryogenic rectification within the column into nitrogen vapor and oxygen-enriched liquid;
- (C) condensing a first portion of the nitrogen vapor by indirect heat exchange with oxygen-enriched liquid to produce oxygen-enriched vapor;
- (D) warming a second portion of the nitrogen vapor by indirect heat exchange with said cooling feed air by passing said second portion of the nitrogen vapor through the coil side of the regenerator;
- (E) recovering the warmed second portion of the nitrogen vapor as product nitrogen;
- and
- (F) passing oxygen-enriched vapor through the shell side of the regenerator during a non-cooling period.
Apparatus for producing nitrogen by the cryogenic rectification of feed air comprising:
- (A) a regenerator having a shell side and a coil side;
- (B) a column having a top condenser;
- (C) means for passing feed air into the shell side of the regenerator, means for passing feed air from the shell side of the regenerator into the column, and means for passing exogenous cryogenic liquid into at least one of the column and the top condenser;
- (D) means for passing vapor from the column into the top condenser and means for passing liquid from the column into the top condenser;
- (E) means for passing vapor from the upper portion of the column into the coil side of the regenerator and means for recovering vapor from the coil side of the regenerator as product nitrogen;
- and
- (F) means for passing vapor from the top condenser into the shell side of the regenerator.
A method for producing nitrogen by the cryogenic rectification of feed air using a regenerator having a shell side and a coil side, said method comprising:
- (A) cooling feed air by passing the feed air through the shell side of a regenerator during a cooling period, and introducing the cooled feed air into a column having a top condenser;
- (B) separating the feed air by cryogenic rectification within the column into nitrogen vapor and oxygen-enriched liquid;
- (C) passing exogenous cryogenic liquid into the top condenser and condensing a first portion of the nitrogen vapor by indirect heat exchange with oxygen-enriched liquid to produce oxygen-enriched vapor;
- (D) warming a second portion of the nitrogen vapor by indirect heat exchange with said cooling feed air by passing said second portion of the nitrogen vapor through the coil side of the regenerator;
- (E) recovering the warmed second portion of the nitrogen vapor as product nitrogen;
- and
- (F) passing oxygen-enriched vapor through the shell side of the regenerator during a non-cooling period.
Dependencies are inferred from the claim text.