US3768290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of modifying a finned tube for boiling enhancement
Assignee: Bank of Nova Scotia
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Filing: 1971-06-18
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Granted: 1973-10-30
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Expires: 1991-06-18
Abstract
Abstract Tubing having circumferentially extending fins, either annular or helical, is modified by forming or bending the fins transversely so that the tip of each fin convolution is closely adjacent to a portion of the next adjacent fin convolution providing small continuous or discrete gaps of predetermined and controlled average size into substantially confined spaces between adjacent fin convolutions.
Inventors
- 👤 V Zatell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:40
CPC Classifications
F; F28; F28F; F28F13/00; F28F13/18; F28F13/185; F28F13/187; B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/20; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378; Y10T29/49382; Y10T29/49385
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
121 words
The method of making tubing modified for the enhancement of boiling of liquid in contact with the exterior surface thereof which comprises rolling up fin convolutions out of the material at the exterior of the tubing with each convolution extending generally radially outwardly of the tubing parallel to and spaced substantially from adjacent convolutions, and thereafter drawing the finned tube through a die having a throat with a minimum transverse dimension smaller than the outside diameter of the original fin convolutions to form the outer portions of fin convolutions completely around the finned tube into proximity to a side of adjacent fin convolutions to define therewith a substantially enclosed space extending around the tubing and a restricted opening into such space.
Claim 2
Independent Claim
121 words
The method of making tubing modified for the enhancement of boiling of liquid in contact with the exterior surface thereof which comprises rolling up fin convolutions out of the material at the exterior of the tubing with each convolution extending generally radially outwardly of the tubing parallel to and spaced substantially from adjacent convolutions, and thereafter drawing the finned tube through a die having a throat with a minimum transverse dimension smaller than the outside diameter of the original fin convolutions to form the outer portions of fin convolutions completely around the finned tube into proximity to a side of adjacent fin convolutions to define therewith a substantially enclosed space extending around the tubing and a restricted opening into such space.
Claim 3
Dependent Claim
52 words
The method as defined in claim 1 which comprises using a die dimensioned to deform the outer portion of each fin convolution into solid contact with the surface of the adjacent convolution, and to provide predetermined width of the restricted opening into the space by spring-back of the outer fin convolution portion.
Claim 4
Dependent Claim
40 words
The method as defined in claim 2 which comprises using a die dimensioned to cause the outer portion of each fin convolution to deform the portion of the next adjacent fin contacted thereby as the tubing passes through the die.
Claim 5
Dependent Claim
23 words
The method as defined in claim 1 which comprises the initial step of forming the fin convolutions to extend helically around the tubing.
Claim 6
Dependent Claim
25 words
The method as defined in claim 1 in which the height of each fin prior to bending is at least twice the average thickness thereof.
Claim 7
Dependent Claim
24 words
The method as defined in claim 1 in which the average spacing between adjacent fin convolutions substantially exceeds the average thickness of each fin.
Claim 8
Dependent Claim
24 words
The method as defined in claim 5 in which the average spacing between adjacent fin convolutions substantially exceeds the average thickness of each fin.
Claim 9
Dependent Claim
49 words
The method as defined in claim 1 in which the throat of the die is dimensioned to form the outer portions of the fin convolutions into such proximity to the side of adjacent fins as to produce a gap having an average width of not more than 0.007 inch.
Claim 10
Dependent Claim
21 words
The method as defined in claim 8 in which the average width of the gap is not more than 0.005 inch.
Claim 11
Dependent Claim
21 words
The method as defined in claim 8 in which the average width of the gap is between 0.0035 - 0.0050 inch.
Claim 12
Dependent Claim
20 words
The method as defined in claim 5 in which the average width of gap is not more than 0.007 inch.
Claim 13
Dependent Claim
20 words
The method as defined in claim 5 in which the average width of gap is not more than 0.005 inch.
Claim 14
Dependent Claim
20 words
The method as defined in claim 5 in which the average width of gap is between 0.0035 - 0.0050 inch.
Claim 15
Dependent Claim
20 words
The method as defined in claim 6 in which the average width of gap is not more than 0.007 inch.
Claim 16
Dependent Claim
20 words
The method as defined in claim 6 in which the average width of gap is not more than 0.005 inch.
Claim 17
Dependent Claim
20 words
The method as defined in claim 6 in which the average width of gap is between 0.0035 - 0.0050 inch.
References Cited (Backward Citations)
GB595680A
Cited
US3326283A
Cited
FR1533025A
Cited
US3454081A
Cited
US3602027A
Cited
US3696863A
Cited
US3696861A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |