Claims
- 1. A Process for obtaining gaseous nitrogen by low-temperature separation from air in a distillation column system, having a single column (4), comprising the following stages:compressed air is cooled in a main heat exchanger, and fed to single column; a nitrogen-rich fraction is drawn off from the distillation column system and is compressed, at least in part, in a circulation compressor; a first part of compound nitrogen-rich fraction is fed downstream from the circulation compressor to a liquefaction chamber of a condenser-evaporator and is condensed therein under a pressure higher than the operating pressure of the single column, thereby forming a nitrogen-rich liquid; a liquid, oxygen-enriched fraction is withdrawn from the distillation column system and is at least partially evaporated in an evaporation chamber of the condenser-evaporator; a first oxygen-enriched gas is withdrawn from the evaporation chamber and introduced into the single column, as ascending vapor; and a second part of the compressed nitrogen-rich fraction is withdrawn at least at times as gaseous nitrogen product, and wherein a second oxygen-enriched gas is withdrawn from the evaporation chamber of the condenser-evaporator, is work expanded, and is heated in the main heat exchanger.
- 2. A process according to claim 1, wherein said nitrogen-rich liquid in the condenser-evaporator is passed to the single column, fulfilling entire reflux requirements for said single column.
- 3. A process for obtaining gaseous nitrogen by low-temperature separation from air in a distillation column system, having a single column (4), comprising the following stages:compressed air is cooled in a main heat exchanger, and fed to single column; a nitrogen-rich fraction is drawn off from the distillation column system and is compressed, at least in part, in a circulation compressor; a first part of compound nitrogen-rich fraction is fed downstream from the circulation compressor to a liquefaction chamber of a condenser-evaporator and is condensed therein under a pressure higher than the operating pressure of the single column, thereby forming a nitrogen-rich liquid; a liquid, oxygen-enriched fraction is withdrawn from the distillation column system and is at least partially evaporated in an evaporation chamber of the condenser-evaporator; a first oxygen-enriched gas is withdrawn from the evaporation chamber and introduced into the single column, as ascending vapor; and a second part of the compressed nitrogen-rich fraction is withdrawn at least at times as gaseous nitrogen product, and wherein a second oxygen-enriched gas is withdrawn from the evaporation chamber of the condenser-evaporator, is work expanded, and is heated in the main heat exchanger, and wherein air compressors and circulation compressors (9) are formed by a single machine.
- 4. A process according to claim 1, wherein at least a portion of mechanical energy produced in work expanding the second oxygen-enriched gas is applied for compression (1063) of the first portion or the second portion of nitrogen-rich fraction (5, 7, 8), or for compression (1063) of the first portion and the second portion of nitrogen-rich fraction (5, 7, 8).
- 5. Apparatus for obtaining gaseous nitrogen by low-temperature separation from air with a distillation column system comprising a single column (4), an air compressor, a main heat exchanger, passage means for feed air, between the single column (4) from the air compressor through the main heat exchanger (2),a circulation compressor (9, 1063) for compression of the first portion of a nitrogen-rich fraction (5, 7, 8) from the distillation column system, a circulation line (12, 13), from the outlet of circulation compressor (1063, 9) to a liquefaction chamber of a condenser-evaporator (14), means for feeding a liquid, oxygen-enriched fraction from the distillation column system to the evaporation chamber of condenser-evaporator (14), means for the production of a first oxygen-enriched gas (234, 533) from vapor (232) formed in the evaporation chamber of the condenser-evaporator (14) and for introduction into the single column (4) and a a gas production line for drawing off a second portion (19, 20, 1064) of nitrogen-rich fraction (5, 7, 8) as a gaseous nitrogen product, said apparatus further comprising a machine (23) for engine expanding a second oxygen-enriched gas (221, 521) from the evaporation chamber of condenser-evaporator (14), and conduits leading from said evaporation chamber to said machine.
- 6. A process according to claim 1, wherein oxygen enriched fractions have an oxygen content of 25% to 90%.
- 7. A process according to claim 1, wherein oxygen enriched fractions have an oxygen content of 30% to 80%.
- 8. A process according to claim 1, wherein the pressure at the bottom of the single column is 3.0 bar.
- 9. A process according to claim 1, wherein the compressed air that is cooled in the heat main heat exchanger and is fed to the single column is under a pressure of 3.5 bar.
- 10. A process according to claim 1, wherein the compressed air that is cooled in the heat main heat exchanger and is fed to the single column is purified.
- 11. A process for obtaining gaseous nitrogen by low-temperature separation from air in a distillation column system, having a single column (4), comprising the following stages:compressed air is cooled in a main heat exchanger, and fed to single column; a nitrogen-rich fraction is drawn off from the distillation column system and is compressed, at least in part, in a circulation compressor; a first part of compound nitrogen-rich fraction is fed downstream from the circulation compressor to a liquefaction chamber of a condenser-evaporator and is condensed therein under a pressure higher than the operating pressure of the single column, thereby forming a nitrogen-rich liquid; a liquid, oxygen-enriched fraction is withdrawn from the distillation column system and is at least partially evaporated in an evaporation chamber of the condenser-evaporator; a first oxygen-enriched gas is withdrawn from the evaporation chamber and introduced into the single column, as ascending vapor; and a second part of the compressed nitrogen-rich fraction is withdrawn at least at times as gaseous nitrogen product, and wherein a second oxygen-enriched gas is withdrawn from the evaporation chamber of the condenser-evaporator, is work expanded, and is heated in the main heat exchanger, and wherein the second oxygen-enriched gas is disposed of in the atmosphere or is used as regeneration gas in an air purification system or is used as gaseous by-product.
Priority Claims (1)
Number |
Date |
Country |
Kind |
100 13 074 |
Mar 2000 |
DE |
|
CROSS-REFERENCE OF RELATED APPLICATION
This application is related to our concurrently filed application entitled “Process for Obtaining Gaseous and Liquid Nitrogen with a Variable Proportion of Liquid Products.“ Application No. 09/810,340 based on German Priority Application No. 10013075.5, filed Mar. 17, 2001.
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