US4883116A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic heat pipe wick
Assignee: National Aeronautics and Space Administration
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Filing: 1989-01-31
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Granted: 1989-11-28
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Expires: 2009-01-31
Abstract
Abstract A wick for use in a capillary loop pump heat pipe. The wick material is an essentially uniformly porous, permeable, open-cell, silicon dioxide/aluminum oxide inorganic ceramic foam having a silica fiber to alumina fiber ratio, by weight, of about 78 to 22, respectively, a density of 6 lbs/ft 3 , and an average pore size of less than 5 microns. A representative material having these characteristics is Lockheed Missiles and Space Company, Inc. HTP 6-22. This material is fully compatible with the FREONs and anhydrous ammonia and allows for the use of these very efficient working fluids, and others, in capillary loops.
Inventors
- 👤 Benjamin Seidenberg
- 👤 Theodore D. Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:02
CPC Classifications
F; F28; F28D; F28D15/00; F28D15/02; F28D15/04; F28D15/043; F28D15/046; Y; Y10; Y10S; Y10S165/00; Y10S165/905
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
53 words
A wick for inclusion in a capillary loop or heat pipe including a first surface means for contacting a working fluid in a liquid state in said loop, and a second surface means for evaporation of said liquid in said loop, said wick being comprised of a permeable, open-cell, fibrous ceramic foam material.
Claim 2
Dependent Claim
53 words
A wick for inclusion in a capillary loop or heat pipe including a first surface means for contacting a working fluid in a liquid state in said loop, and a second surface means for evaporation of said liquid in said loop, said wick being comprised of a permeable, open-cell, fibrous ceramic foam material.
Claim 3
Dependent Claim
56 words
The wick of claim 1 wherein said wick generally has the shape of a hollowed cylinder with an open end for liquid entrance and a closed end to block liquid flow, said first surface means being the interior surface area of said cylinder and said second surface means being the exterior surface area of said cylinder.
Claim 4
Dependent Claim
12 words
The wick of claim 1 includes silicon dioxide and aluminum oxide fibers.
Claim 5
Dependent Claim
12 words
The wick of claim 1 wherein said ceramic material is substantially inorganic.
Claim 6
Dependent Claim
13 words
The wick of claim 4 wherein said ceramic material includes an inorganic binder.
Claim 7
Dependent Claim
22 words
The wick of claim 1 wherein said ceramic material is essentially uniformly porous with a pore size of less than 5 microns.
Claim 8
Dependent Claim
33 words
The wick of claim 1 wherein said ceramic material is a silicon dioxide/aluminum oxide inorganic ceramic foam having a silica fiber to alumina fiber ratio, by weight, of about 78 to 22, respectively.
Claim 9
Dependent Claim
18 words
The wick of claim 1 wherein said ceramic material has a density of about 6 lbs/ft 3 .
Claim 10
Dependent Claim
18 words
The wick of claim 1 wherein said first surface has a plurality of spaced axial grooves formed therein.
Claim 11
Dependent Claim
74 words
A capillary loop, including an evaporator, in the form of a continuous loop, with a wick positioned within less than the entire portion of said capillary pump, which wick is comprised of a permeable, open-cell, fibrous ceramic foam material, said loop further including a working fluid, said working fluid being selected from the group consisting of anhydrous ammonia and the fluorinated hydrocarbons, said wick material being chemically and physically compatible with said working fluid.
Claim 12
Dependent Claim
74 words
A capillary loop, including an evaporator, in the form of a continuous loop, with a wick positioned within less than the entire portion of said capillary pump, which wick is comprised of a permeable, open-cell, fibrous ceramic foam material, said loop further including a working fluid, said working fluid being selected from the group consisting of anhydrous ammonia and the fluorinated hydrocarbons, said wick material being chemically and physically compatible with said working fluid.
Claim 13
Dependent Claim
12 words
The capillary loop of claim 10 wherein said fluorinated hydrocarbon is trichlorofluoromethane.
Claim 14
Dependent Claim
12 words
The capillary loop of claim 10 wherein said fluorinated hydrocarbon is tricholorotrifluoroethane.
Claim 15
Dependent Claim
12 words
The capillary loop of claim 10 wherein said fluorinated hydrocarbon is dichlorotetrafluoroethane.
Claim 16
Dependent Claim
12 words
The capillary loop of claim 10 wherein said wick material is inorganic.
Claim 17
Dependent Claim
23 words
The capillary loop of claim 10 wherein said wick material is essentially uniformly porous with a pore size of less than 5 microns.
Claim 18
Dependent Claim
19 words
The capillary loop of claim 10 wherein said wick material has a density of about 6 lbs/ft 3 .
Claim 19
Dependent Claim
34 words
The capillary loop of claim 10 wherein said wick material is a silicon dioxide/aluminum oxide inorganic ceramic foam having a silica fiber to alumina fiber ratio, by weight, of about 78 to 22, respectively.
Claim 20
Dependent Claim
17 words
The capillary loop of claim 10 wherein said wick material includes silicon dioxide and aluminum oxide fibers.
References Cited (Backward Citations)
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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) | 1992-11-27 | 1993-05-29 | 1993-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-27 | 1997-05-29 | 1997-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-27 | 2001-05-29 | 2001-11-28 | $7700.00 | Window Closed / Lapsed |