Patent US3675809A successfully refreshed from Google Patents.
US3675809A
Expired / Lapsed
US
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Capillary insulation
Assignee: Lockheed Martin Corp
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Filing: 1970-06-09
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Granted: 1972-07-11
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Expires: 1990-06-09
Abstract
Abstract The internal capillary insulation comprises cellular material secured to the internal wall of a vessel which is to contain liquid having a boiling temperature lower than the ambient temperature of the vessel. The cellular material disclosed provides a plurality of discrete cells. Each cell provides for establishing a column of gas therein between the tank wall and the liquid body. A capillary cover substantially closes the liquid side of the cells and has at least one capillary opening per cell designed to form a stable capillary gas-liquid interface or membrane at the capillary opening. The gas columns having a stable gas-liquid interface insulate the liquid from the vessel and in addition, support the liquid in the vessel thereby permitting fabrication of the insulation from materials which have low strength and weight and low thermal conductivity.
Inventors
- 👤 Jay L Mcgrew
- 👤 John P Gille
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:42
CPC Classifications
F; F16; F16L; F16L59/00; F16L59/06; F16L59/14; F16L59/147; F17; F17C; F17C3/00; F17C3/02; F17C3/04; F17C3/06; F17C2201/00; F17C2201/01; F17C2201/0128; F17C2203/00; F17C2203/01; F17C2203/011; F17C2203/013; F17C2203/03; F17C2223/00; F17C2223/01; F17C2223/0146; F17C2223/0153
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
91 words
Insulation for reducing heat transfer from the surface of a container for liquid to liquid being contained therein, comprising first means adapted to be attached to an internal surface of the container and providing a plurality of discrete cells adapted to contain insulating gas, means closing the ends of said cells adjacent the container surface, and second means for providing a stabilized capillary gas-liquid interface closing the opposite ends of said cells when in contact with the contained liquid with none of the liquid penetrating the cells during steady state conditions.
Claim 2
Dependent Claim
91 words
Insulation for reducing heat transfer from the surface of a container for liquid to liquid being contained therein, comprising first means adapted to be attached to an internal surface of the container and providing a plurality of discrete cells adapted to contain insulating gas, means closing the ends of said cells adjacent the container surface, and second means for providing a stabilized capillary gas-liquid interface closing the opposite ends of said cells when in contact with the contained liquid with none of the liquid penetrating the cells during steady state conditions.
Claim 3
Dependent Claim
29 words
Insulation as defined in claim 1, wherein said first means comprises structural material having thermal conductivity of 1 (Btu - ft)/(ft2 -*F-Hr) or less when measured at 70* F.
Claim 4
Dependent Claim
44 words
Insulation as defined in claim 1, wherein said first means comprises a structure such that the ratio of cross sectional area of the solid portion of the structure to the total area of the surface being insulated is equal to or less than 0.09.
Claim 5
Dependent Claim
20 words
Insulation as defined in claim 1, further including means associated with each cell for reducing free convection within each cell.
Claim 6
Dependent Claim
19 words
Insulation as defined in claim 1, further including means associated with each cell for reducing radiation in each cell.
Claim 7
Dependent Claim
26 words
Insulation as defined in claim 1 wherein the contained liquid has a boiling temperature corresponding to pressure imposed on the liquid below the container surface temperature.
Claim 8
Dependent Claim
76 words
Insulation as defined in claim 1 wherein the bulk of the contained liquid is at a temperature below the boiling temperature corresponding to the pressure imposed on the liquid and wherein the cell is partially filled with a gas other than the vapor of the contained liquid, so as to permit a stable liquid gas capillary interface to be maintained at a temperature lower than the boiling temperature corresponding to the pressure imposed on the liquid.
Claim 9
Dependent Claim
30 words
Insulation as defined in claim 1, wherein said second means includes a member capping said opposite ends of said cells and having a capillary opening in communication with each cell.
Claim 10
Dependent Claim
20 words
Insulation as defined in claim 8, wherein the projections of the edges of said member defining said openings includes angles.
Claim 11
Dependent Claim
35 words
Insulation as defined in claim 8, wherein said openings are located relative to the portion of said first means that define said cells, so that capillary ducting of the liquid into the cell is prevented.
Claim 12
Dependent Claim
19 words
Insulation as defined in claim 8, wherein each portion of said member Defining said openings has a continuous curvature.
Claim 13
Dependent Claim
129 words
Insulation as defined in claim 11, wherein the maximum dimension of said openings is determined by the smaller dimension (d) provided by the following relationships: dft (K1 S/RG)1/2 (a) where K1 3.36 (a dimensionless, empirical constant for circular holes) S surface tension of the liquid gas interface under operating conditions (1bforce / ft) R difference between density of the liquid and the density of the gas (lbmass / ft3) G magnitude of the gravitational vector imposed by gravitational attraction and/or acceleration of the container wall (no. of std. earth gravity units with dimensions of lbforce/lbmass ) and dft K2 S/RGH (b) where K2 4 (a dimensionless constant for circular holes) H maximum distance between any two openings in the same cell in the direction of the gravitational vector (ft)
Claim 14
Dependent Claim
80 words
Insulation for reducing heat transfer from the surface of a container to liquid contained therein, comprising means for providing a plurality of discrete columns of gas between the liquid and the container surface and second means for providing a stable capillary interface between said gas columns and the liquid when said gas columns are in contact with the liquid to support the liquid away from the container while preventing the liquid from penetrating the gas columns during steady state conditions.
Claim 15
Dependent Claim
80 words
Insulation for reducing heat transfer from the surface of a container to liquid contained therein, comprising means for providing a plurality of discrete columns of gas between the liquid and the container surface and second means for providing a stable capillary interface between said gas columns and the liquid when said gas columns are in contact with the liquid to support the liquid away from the container while preventing the liquid from penetrating the gas columns during steady state conditions.
Claim 16
Dependent Claim
20 words
Insulation as defined in claim 13, further including means associated with each cell for reducing free convection within each cell.
Claim 17
Dependent Claim
19 words
Insulation as defined in claim 13, further including means associated with each cell for reducing radiation in each cell.
Claim 18
Dependent Claim
37 words
Insulation as defined in claim 13, wherein said means for providing a plurality of discrete columns of gas includes cellular material having a plurality of discrete cells or voids therein within which the gas columns are provided.
Claim 19
Dependent Claim
27 words
Insulation as defined in claim 16, wherein said cellular material has thermal conductivity of 1 (Btu - ft)/(ft2 - *F-Hr) or less when measured at 70* F.
Claim 20
Dependent Claim
37 words
Insulation as defined in claim 16, wherein said cellular material has a ratio of cross sectional area of the solid portion thereof to the total area of the surface being insulated equal to or less than 0.09.
Claim 21
Dependent Claim
49 words
Insulation as defined in claim 13, wherein second means comprises a capillary cover which substantially closes the liquid side of each cell, and capillary openings in said cover above each cell to provide communication between the gas columns and liquid to permit the stable capillary interface to be established.
Claim 22
Dependent Claim
15 words
Insulation as defined in claim 19, wherein said openings are configured of a continuous curvature.
Claim 23
Dependent Claim
125 words
Insulation as defined in claim 20, wherein the maximum dimension of said openings is determined by the smaller dimension (d) provided by the following relationships: dft (K1 S/RG)1/2 (a) where K1 3.36 (a dimensionless, empirical constant for circular holes) S surface tension of the liquid gas interface under operating conditions (obforce/ ft) R difference between density of the liquid and the density of the gas (lbmass/ft3) G magnitude of the gravitional vector imposed by gravitational attraction and/or acceleration of the container wall (no. of std. earth gravity units with dimensions of lbforce/lbmass) and dft K2 S/RGH (b) where K2 4 (a dimensionless constant for circular holes) H maximum distance between any two openings in the same cell in the direction of the gravitational vector (ft)
Claim 24
Independent Claim
78 words
A method for thermally insulating contained liquid to reduce heat transfer from the container to the liquid comprising the steps of providing a plurality of discrete columns of gas interposed between the liquid and the container and providing the ends of the gas columns in contact with the liquid with a stable capillary interface with the liquid to support the liquid away from the container while preventing the liquid from penetrating the gas columns during steady state conditions.
Claim 25
Independent Claim
78 words
A method for thermally insulating contained liquid to reduce heat transfer from the container to the liquid comprising the steps of providing a plurality of discrete columns of gas interposed between the liquid and the container and providing the ends of the gas columns in contact with the liquid with a stable capillary interface with the liquid to support the liquid away from the container while preventing the liquid from penetrating the gas columns during steady state conditions.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |