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US 7,114,352 B2Granted
Cryogenic air separation system for producing elevated pressure nitrogen
AssigneePraxair Technology, Inc.
InventorsNeil Mark Prosser, Peter James Rankin
Life of this patent
Estimating the term…
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wherein a portion of the nitrogen product fed to the product compressor downstream of the primary heat exchanger is withdrawn as refrigerant nitrogen from the product compressor, preferably from an intermediate point of the product compressor, and turboexpanded to generate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.
Claims19
Cryogenic air separation apparatus for producing elevated pressure nitrogen comprising:
- (A) a primary heat exchanger, a cryogenic air separation plant, and means for passing feed air to the primary heat exchanger and from the primary heat exchanger to the cryogenic air separation plant;
- (B) a product compressor having a plurality of stages, a turboexpander, means for passing nitrogen from the cryogenic air separation plant to the primary heat exchanger and from the primary heat exchanger to the product compressor, and means for passing nitrogen from the product compressor to the primary heat exchanger and from the primary heat exchanger to the turboexpander;
- (C) a booster compressor, means for passing nitrogen from the turboexpander to the primary heat exchanger and from the primary heat exchanger to the booster compressor, and means for passing nitrogen from the booster compressor to the product compressor;
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- (D) means for recovering elevated pressure nitrogen from the product compressor.
2 more elements
A method for producing elevated pressure nitrogen comprising:
- (A) cooling feed air in a primary heat exchanger, passing the cooled feed air into a cryogenic air separation plant, and producing nitrogen by cryogenic rectification within the cryogenic air separation plant;
- (B) warming nitrogen withdrawn from the cryogenic air separation plant in the primary heat exchanger, compressing the warmed nitrogen in a product compressor, passing a portion of the compressed nitrogen as refrigerant nitrogen to the primary heat exchanger, cooling the refrigerant nitrogen, and turboexpanding the refrigerant nitrogen to generate refrigeration;
- (C) warming the turboexpanded refrigerant nitrogen in the primary heat exchanger, compressing the turboexpanded refrigerant nitrogen in a booster compressor, and passing the resulting refrigerant nitrogen to the product compressor;
- and
- (D) recovering elevated pressure nitrogen from the product compressor.
2 more elements
Dependencies are inferred from the claim text.