US3840069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat pipe with a sintered capillary structure
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1972-04-20
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Granted: 1974-10-08
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Expires: 1992-04-20
Abstract
Abstract In a heat pipe, a sintered capillary structure is provided on both of its heat-receiving and heat-delivering surfaces with the sintered capillary structure including both coarse and fine pores. In a preferred arrangement the fine and coarse pores are each distributed in a range of sizes with a maximum range of fine pores of certain sizes in the range of the fine pores and a maximum range of coarse pores of certain sizes in the range of the coarse pores. The coarse pores are formed in the sintering operation while the fine pores can be formed in a number of different ways. In one method the fine pores are formed by using different sizes and shapes of grains in the metal powder which is sintered. In another method, a chemical treatment of the sintered structure provides the fine pores.
Inventors
- 👤 W Fischer
- 👤 G Gammel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:29
CPC Classifications
F; F28; F28D; F28D15/00; F28D15/02; F28D15/04; F28D15/046; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49353
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
255 words
A heat pipe comprising a closed tube having a heat-receiving surface and a heat-delivery surface, a layer of capillary structure sintered to the inside surface of said tube at least on the heat-receiving surface and the heat-delivery surface therein and another capillary structure interconnecting the heatreceiving and the heat-delivery surface for liquid transport therebetween, said tube and layer of capillary structure defining an enclosed space in the heat pipe for transporting vapor between the heat-receiving surface and the heat delivery surface, wherein the improvement comprises that the layer of capillary structure consists of pores of different sizes, and a vaporizable liquid filled into said tube in a quantity to fill only the smaller sized pores by capillary force, said pores are of a size in which capillary force takes effect and consists of a first group having a range of pores of relatively small sizes and a second group having a range of pores of relatively large sizes and within each of said first group and said second group there is a broad range of a maximum number of relatively small pore sizes and a broad range of a maximum number of relatively large pore sizes and the two maximum ranges are spaced apart by a range of pore sizes which fall between the pore sizes represented by the tWo ranges of maximum sizes, and the quantity of said working liquid being just sufficient to fill the relatively small sized pores in said first group because of the greater capillary force exerted by such pores.
Claim 2
Dependent Claim
255 words
A heat pipe comprising a closed tube having a heat-receiving surface and a heat-delivery surface, a layer of capillary structure sintered to the inside surface of said tube at least on the heat-receiving surface and the heat-delivery surface therein and another capillary structure interconnecting the heatreceiving and the heat-delivery surface for liquid transport therebetween, said tube and layer of capillary structure defining an enclosed space in the heat pipe for transporting vapor between the heat-receiving surface and the heat delivery surface, wherein the improvement comprises that the layer of capillary structure consists of pores of different sizes, and a vaporizable liquid filled into said tube in a quantity to fill only the smaller sized pores by capillary force, said pores are of a size in which capillary force takes effect and consists of a first group having a range of pores of relatively small sizes and a second group having a range of pores of relatively large sizes and within each of said first group and said second group there is a broad range of a maximum number of relatively small pore sizes and a broad range of a maximum number of relatively large pore sizes and the two maximum ranges are spaced apart by a range of pore sizes which fall between the pore sizes represented by the tWo ranges of maximum sizes, and the quantity of said working liquid being just sufficient to fill the relatively small sized pores in said first group because of the greater capillary force exerted by such pores.
Claim 3
Dependent Claim
29 words
A heat pipe, as set forth in claim 1, wherein said pores in said first group have approximately the same total volume as said pores in said second group.
Claim 4
Dependent Claim
189 words
A heat pipe comprising a closed tube having a heat-receiving surface and a heat-delivery surface, a layer of capillary structure sintered to the inside surface of said tube at least on the heat-receiving surface and the heat-delivery surface therein and another capillary structure interconnecting the heat-receiving and the heat-delivery surface for liquid transport therebetween, said tube and layer of capillary structure defining an enclosed space in the heat pipe for transporting vapor between the heat-receiving surface and the heat-delivery surface, wherein the improvement comprises that the layer of capillary structure consists of pores of different sizes, and a vaporizable liquid filled into said tube in a quantity to fill only the smaller sized pores by capillary force, said pores comprise a first group of pores and a second group of pores and the pores in said first group being distinctly smaller and of substantially the same size as compared to the pores in said second group which are of substantially the same size and both of said first and second groups having a maximum number of pores as compared to similarly sized other said pores in said capillary structure.
Claim 5
Dependent Claim
189 words
A heat pipe comprising a closed tube having a heat-receiving surface and a heat-delivery surface, a layer of capillary structure sintered to the inside surface of said tube at least on the heat-receiving surface and the heat-delivery surface therein and another capillary structure interconnecting the heat-receiving and the heat-delivery surface for liquid transport therebetween, said tube and layer of capillary structure defining an enclosed space in the heat pipe for transporting vapor between the heat-receiving surface and the heat-delivery surface, wherein the improvement comprises that the layer of capillary structure consists of pores of different sizes, and a vaporizable liquid filled into said tube in a quantity to fill only the smaller sized pores by capillary force, said pores comprise a first group of pores and a second group of pores and the pores in said first group being distinctly smaller and of substantially the same size as compared to the pores in said second group which are of substantially the same size and both of said first and second groups having a maximum number of pores as compared to similarly sized other said pores in said capillary structure.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |