US3874185A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for a more efficient liquefaction of a low-boiling gaseous mixture by closely matching the refrigerant warming curve to the gaseous mixture cooling curve
Assignee: Linde GmbH
•
Filing: 1973-08-31
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Granted: 1975-04-01
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Expires: 1993-08-31
Abstract
Abstract Gases volatilizing from liquefied nitrogen-containing natural gas are condensed efficiently employing a closed nitrogen refrigeration cycle by first cooling the natural gas with nitrogen which has been at least partially condensed by isenthalpic expansion and further cooling the natural gas with gaseous nitrogen which has been isentropically expanded.
Inventors
- 👤 Volker Etzbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:26
CPC Classifications
F; F25; F25J; F25J1/00; F25J1/0002; F25J1/0022; F25J1/0025; F25J1/003; F25J1/0047; F25J1/005; F25J1/0052; F25J1/006; F25J1/007; F25J1/0072; F25J1/02; F25J1/0203; F25J1/0204; F25J1/0243; F25J1/0244; F25J1/0245; F25J1/0257; F25J1/0262; F25J1/0264; F25J1/0265; F25J1/0275; F25J1/0277; F25J1/0279; F25J1/0285; F25J1/0288; F25J2220/00; F25J2220/60; F25J2220/62; F25J2230/00; F25J2230/08; F25J2230/30; F25J2290/00; F25J2290/62
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
108 words
IN A PROCESS FOR THE LIQUEFACTION OF A LOW-BOILING GASEOUS MIXTURE EMPLOYING A CLOSED REFRIGERATION CYCLE WHEREIN A CYCLE GAS IS COMPRESSED, COOLED, EXPANDED, AND REWARMED BY INDIRECT HEAT EXCHANGE WITH THE GASEOUS MIXTURE TO BE LIQUEFIED, THE IMPROVEMENT WHICH COMPRISES PROVIDING THE LOWEST TEMPERATURE REQUIRED FOR THE LIQUEFACTION OF THE GASEOUS MIXTURE BY WARMING IN A HEAT EXCHANGE ZONE AN ISENTROPICALLY EXPANDED WHOLLY GASEOUS FIRST FRACTION OF THE COOLED CYCLE GAS AND PROVIDING THE REMAINING COLD AT A HIGHER TEMPERATURE LEVEL BY VAPORIZATION IN A HEAT EXCHANGE ZONE OF THE RESIDUAL SECOND FRACTION OF THE CYCLE GAS WHICH HAS BEEN AT LEAST PARTIALLY CONDENSED BY ISENTHALPIC EXPANSION.
Claim 2
Dependent Claim
108 words
IN A PROCESS FOR THE LIQUEFACTION OF A LOW-BOILING GASEOUS MIXTURE EMPLOYING A CLOSED REFRIGERATION CYCLE WHEREIN A CYCLE GAS IS COMPRESSED, COOLED, EXPANDED, AND REWARMED BY INDIRECT HEAT EXCHANGE WITH THE GASEOUS MIXTURE TO BE LIQUEFIED, THE IMPROVEMENT WHICH COMPRISES PROVIDING THE LOWEST TEMPERATURE REQUIRED FOR THE LIQUEFACTION OF THE GASEOUS MIXTURE BY WARMING IN A HEAT EXCHANGE ZONE AN ISENTROPICALLY EXPANDED WHOLLY GASEOUS FIRST FRACTION OF THE COOLED CYCLE GAS AND PROVIDING THE REMAINING COLD AT A HIGHER TEMPERATURE LEVEL BY VAPORIZATION IN A HEAT EXCHANGE ZONE OF THE RESIDUAL SECOND FRACTION OF THE CYCLE GAS WHICH HAS BEEN AT LEAST PARTIALLY CONDENSED BY ISENTHALPIC EXPANSION.
Claim 3
Dependent Claim
26 words
A process according to claim 1 wherein the gaseous mixture is nitrogen-containing natural gas volatilized from stored liquid natural gas, and the cycle gas is nitrogen.
Claim 4
Dependent Claim
56 words
A process according to claim 1, wherein the isentropic expansion of the first fraction of the cycle medium is carried out to a lower pressure level than the isenthalpic expansion of the residual second fraction and the first fraction is thereafter combined with the second fraction only after recompression to the pressure of the second fraction.
Claim 5
Dependent Claim
75 words
A process according to claim 1 wherein the residual second fraction, after its isenthalpic expansion, is subjected to a phase separation in a separation zone into a liquid fraction and a gaseous fraction and, during periods of lower refrigeration requirements, a portion of the liquid fraction obtained in the phase separation is stored, and, during periods of higher refrigeration requirements, at least a portion of the stored liquid fraction is recycled into the refrigeration cycle.
Claim 6
Dependent Claim
26 words
A process according to claim 4, wherein the gaseous mixture is nitrogen-containing natural gas volatilized from stored liquid natural gas, and the cycle gas is nitrogen.
Claim 7
Dependent Claim
31 words
A process according to claim 4, wherein a portion of the liquid fraction obtained during the phase separation is stored in the separation zone during the periods of lower refrigeration requirement.
Claim 8
Dependent Claim
31 words
A process according to claim 4, wherein at least a portion of the liquid fraction obtained during the phase separation is stored in a storage zone separate from the separation zone.
Claim 9
Dependent Claim
42 words
A process according to claim 4, wherein the gaseous fraction obtained during the phase separation is thereafter admixed with the liquid fraction obtained during the phase separation after the latter has completely vaporized by heat exchange with the gas to be liquefied.
Claim 10
Dependent Claim
26 words
A process according to claim 8, wherein the gaseous mixture is nitrogen-containing natural gas volatilized from stored liquid natural gas, and the cycle gas is nitrogen.
References Cited (Backward Citations)
US3180709A
Cited
US3271965A
Cited
US3364685A
Cited
US3511058A
Cited
US3616652A
Cited
US3541802A
Cited
US3657898A
Cited
US3677019A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |