US3733838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for reliquefying boil-off vapor from liquefied gas
Assignee: Chicago Bridge and Iron Co
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Filing: 1971-12-01
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Granted: 1973-05-22
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Expires: 1991-12-01
Abstract
Abstract Apparatus and processes for recondensing boil-off vapor from an insulated storage tank containing a liquefied gas, such as liquefied natural gas, so that it continues to comprise a part of the stored liquefied gas. Boil-off vapor is recondensed by refrigeration obtained from expansion of a liquefied gas stream withdrawn from the storage tank. The expanded stream, as a vapor, can be pressurized by feeding it to the suction side of an ejector to which a high pressure gas is fed to supply the motive force. Alternatively, a vapor stream derived from the stored liquefied gas can be fed to a venturi ejector as the motive force to pressurize boil-off vapor fed from the storage tank to the suction side of the ejector. The combined stream from the ejector, after being refrigerated by the withdrawn liquefied gas stream, is expanded to the tank vapor space to cool the tank contents. Under either system, liquefied gas stored at about atmospheric pressure can be vaporized and distributed at a pressure greater than atmospheric pressure.
Inventors
- 👤 T Delahunty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:41
CPC Classifications
F; F25; F25J; F25J1/00; F25J1/0002; F25J1/0022; F25J1/0025; F25J1/003; F25J1/0032; F25J1/0045; F25J1/02; F25J1/0201; F25J1/0221; F17; F17C; F17C2227/00; F17C2227/03; F17C2227/0337; F17C2227/0358; F17C2265/00; F17C2265/03; F17C2265/032; F17C2265/033; F25J2210/00; F25J2210/62; F25J2235/00; F25J2235/60; F25J2240/00; F25J2240/60; F25J2290/00; F25J2290/34; F25J2290/62
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
135 words
A process which comprises: removing a boil-off stream of vapor from an insulated storage tank and feeding it into inspiration communication with a venturi ejector; removing a stream of liquefied gas from the storage tank, pumping it to a high pressure and passing it through a heat exchanger to provide refrigeration therein; feeding at least part of the stream from the heat exchanger in the form of a high pressure vapor through the venturi ejector as the motive force to pressurize the inspirated boil-off vapor and form a combined warm vapor stream thereof; feeding the combined warm vapor stream through the heat exchanger to at least partially condense said stream; and expanding the at least partially condensed stream and feeding it to the vapor space of the tank to absorb heat from the tank contents.
Claim 2
Dependent Claim
135 words
A process which comprises: removing a boil-off stream of vapor from an insulated storage tank and feeding it into inspiration communication with a venturi ejector; removing a stream of liquefied gas from the storage tank, pumping it to a high pressure and passing it through a heat exchanger to provide refrigeration therein; feeding at least part of the stream from the heat exchanger in the form of a high pressure vapor through the venturi ejector as the motive force to pressurize the inspirated boil-off vapor and form a combined warm vapor stream thereof; feeding the combined warm vapor stream through the heat exchanger to at least partially condense said stream; and expanding the at least partially condensed stream and feeding it to the vapor space of the tank to absorb heat from the tank contents.
Claim 3
Dependent Claim
35 words
A process according to claim 1 in which that part of the refrigeration stream from the heat exchanger that is not fed to the venturi ejector is fed as a vapor to a distribution line.
Claim 4
Dependent Claim
39 words
A process according to claim 1 in which the stream from the heat exchanger which provides refrigeration therein, is warmed and vaporized by passage through a heater and is then fed, at least in part, to the venturi ejector.
Claim 5
Dependent Claim
127 words
A process which comprises: removing a boil-off stream of vapor from an insulated storage tank, compressing it and feeding it to a heat exchanger to be cooled; removing a first stream of liquefied gas from the storage tank and passing it through the heat exchanger to provide refrigeration therein; removing from the heat exchanger the at least partially condensed boil-off stream as a cold liquid stream; expanding the at least partially condensed boil-off stream and feeding the resulting cold liquid stream to the vapor space of the tank to absorb heat from the tank contents; removing from the heat exchanger the first stream of liquefied gas and further heating it; and feeding the now warmed first stream of liquefied gas as a vapor to a distribution line.
Claim 6
Dependent Claim
127 words
A process which comprises: removing a boil-off stream of vapor from an insulated storage tank, compressing it and feeding it to a heat exchanger to be cooled; removing a first stream of liquefied gas from the storage tank and passing it through the heat exchanger to provide refrigeration therein; removing from the heat exchanger the at least partially condensed boil-off stream as a cold liquid stream; expanding the at least partially condensed boil-off stream and feeding the resulting cold liquid stream to the vapor space of the tank to absorb heat from the tank contents; removing from the heat exchanger the first stream of liquefied gas and further heating it; and feeding the now warmed first stream of liquefied gas as a vapor to a distribution line.
Claim 7
Dependent Claim
177 words
In combination: an enclosed insulated storage tank for a liquefied gas; a first conduit communicating with the tank interior and a heat exchanger outside thereof for removing liquefied gas from the tank and sending it to the heat exchanger as a refrigeration stream; a second conduit communicating with the heat exchanger and a venturi ejector for removing the refrigeration stream therefrom and sending it as a high pressure vapor to the ejector; a third conduit communicating with the vapor space of the tank and the suction side of the ejector to remove boil-off vapor from the tank; a fourth conduit communicating with the exit side of the ejector and the heat exchanger for supplying a mixture of pressurized boil-off vapor and refrigeration vapor to the heat exchanger for cooling; a fifth conduit communicating with the heat exchanger and an expansion valve for delivering the condensed liquid mixture of boil-off vapor and refrigeration vapor to the expansion valve; and a sixth conduit communicating with the expansion valve and the tank vapor space for delivering the liquid mixture thereto.
Claim 8
Dependent Claim
177 words
In combination: an enclosed insulated storage tank for a liquefied gas; a first conduit communicating with the tank interior and a heat exchanger outside thereof for removing liquefied gas from the tank and sending it to the heat exchanger as a refrigeration stream; a second conduit communicating with the heat exchanger and a venturi ejector for removing the refrigeration stream therefrom and sending it as a high pressure vapor to the ejector; a third conduit communicating with the vapor space of the tank and the suction side of the ejector to remove boil-off vapor from the tank; a fourth conduit communicating with the exit side of the ejector and the heat exchanger for supplying a mixture of pressurized boil-off vapor and refrigeration vapor to the heat exchanger for cooling; a fifth conduit communicating with the heat exchanger and an expansion valve for delivering the condensed liquid mixture of boil-off vapor and refrigeration vapor to the expansion valve; and a sixth conduit communicating with the expansion valve and the tank vapor space for delivering the liquid mixture thereto.
Claim 9
Dependent Claim
22 words
The combination of claim 5 in which the second conduit has a heater therein to vaporize the stream as it passes therethrough.
Claim 10
Dependent Claim
26 words
The combination of claim 5 in which a seventh conduit communicates with the second conduit for diverting part of the vapor stream to a distribution line.
Claim 11
Dependent Claim
15 words
The combination of claim 5 in which a pump is located in the first conduit.
Claim 12
Dependent Claim
123 words
In combination: an enclosed insulated storage tank for a liquefied gas; means for removing liquefied gas from the storage tank, feeding it through a heat exchanger as a source of refrigeration, and delivering it as a high pressure vapor to the motive power inlet side of a venturi ejector; means for removing boil-off vapor from the storage tank and delivering it to the suction side of the ejector; means for receiving the pressurized vapor from the ejector, passing it through the heat exchanger to cool and at least partially condense it; and means for receiving the at least partially condensed liquid from the heat exchanger, expanding it and delivering the stream to the vapor space of the tank to cool the tank contents.
Claim 13
Dependent Claim
123 words
In combination: an enclosed insulated storage tank for a liquefied gas; means for removing liquefied gas from the storage tank, feeding it through a heat exchanger as a source of refrigeration, and delivering it as a high pressure vapor to the motive power inlet side of a venturi ejector; means for removing boil-off vapor from the storage tank and delivering it to the suction side of the ejector; means for receiving the pressurized vapor from the ejector, passing it through the heat exchanger to cool and at least partially condense it; and means for receiving the at least partially condensed liquid from the heat exchanger, expanding it and delivering the stream to the vapor space of the tank to cool the tank contents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |