US3846994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low temperature natural gas transmission
Assignee: Individual
•
Filing: 1973-11-05
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Granted: 1974-11-12
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Expires: 1993-11-05
Abstract
Abstract Natural gas is transmitted by pipeline at low temperature by maintaining pump stations which warm the pipeline gas, compress the warm gas, cool the compressed gas by rejecting heat to the atmosphere and expanding the cooled gas to pipeline pressure and the temperature below that which could cause damage to the surroundings of the pipeline. The described method is used to protect arctic permafrost from melting by virtue of temperature of a natural gas pipeline running through such permafrost.
Inventors
- 👤 W Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:43
CPC Classifications
F; F17; F17D; F17D1/00; F17D1/02; E; E21; E21B; E21B36/00; E21B36/001
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
A method for moving natural gas at low temperatures in a pipeline which comprises; a. conducting the natural gas through a heat exchanger wherein heat is transferred with the cooled gas from step (c); b. compressing the natural gas from step (a) to a pressure greater than the pressure of the pipeline at the point at which the gas is returned thereto; c. cooling the compressed gas by rejecting heat to the surroundings; d. conducting the cooled gas to the heat exchanger wherein heat is transferred with the gas entering from the pipeline; and e. returning the gas to the pipeline at pipeline pressure and a temperature below that which would damage the environment.
Claim 2
Independent Claim
114 words
A method for moving natural gas at low temperatures in a pipeline which comprises; a. conducting the natural gas through a heat exchanger wherein heat is transferred with the cooled gas from step (c); b. compressing the natural gas from step (a) to a pressure greater than the pressure of the pipeline at the point at which the gas is returned thereto; c. cooling the compressed gas by rejecting heat to the surroundings; d. conducting the cooled gas to the heat exchanger wherein heat is transferred with the gas entering from the pipeline; and e. returning the gas to the pipeline at pipeline pressure and a temperature below that which would damage the environment.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the gas from step (d) is conducted through an expander prior to returning it to the pipeline.
Claim 4
Dependent Claim
25 words
The process of claim 2 wherein the energy of expanding the gas is used to compress a portion of the natural gas in step (b).
Claim 5
Dependent Claim
36 words
The method of claim 3 wherein the temperature of the gas introduced to the pipeline is controlled by a closed loop controller responsive to said temperature and controlling the amount of gas expanded after step (d).
Claim 6
Dependent Claim
40 words
The method of claim 4 wherein the temperature of the gas entering the gas expander is controlled by a closed loop controller responsive to said temperature and limiting the amount of gas passing through the heat exchanger of step (d).
Claim 7
Dependent Claim
62 words
The method of claim 5 wherein the natural gas entering the system is at a pressure of from about 1,300 to 1,450 psig and a temperature of from about zero to about 20*F. and the natural gas returned to the pipeline at a pressure of from about 1,600 to about 1,800 psig and a temperature of from about 10* to about 20*F.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |