US3779312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internally ridged heat transfer tube
Assignee: Bank of Nova Scotia
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Filing: 1972-03-07
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Granted: 1973-12-18
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Expires: 1992-03-07
Abstract
Abstract Metal heat transfer tube has a single start helical ridge on its inner surface which conforms to a range of values of a disclosed equation relating the height of the ridge to its pitch and to the inner diameter of the tube. A method of designing a tube for maximum performance is also disclosed. The improved tube provides especially good results in systems, such as steam condensation systems, wherein a single phase fluid is carried by the tube.
Inventors
- 👤 J Withers
- 👤 E Habdas
- 👤 M Jurmo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:40
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/10; F28F1/42; F28F1/424; F28F1/426; B; B21; B21D; B21D15/00; B21D15/04; B21D15/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
100 words
A metal heat transfer tube having single start internal helical ridging such that the inner boundary of the tube wall, when viewed in longitudinal sectional profile, is comprised of alternating convex and concave portions which join at common tangents, and wherein the internal tube surface can be described by the equation: phi e2/pdi where phi is a dimensionless severity parameter, e is the height of the helical ridge, p is the helical pitch and di is the inside diameter, and where phi is greater than 0.1 X 10 2 and equal to Or less than about 0.365 X 10 2.
Claim 2
Dependent Claim
100 words
A metal heat transfer tube having single start internal helical ridging such that the inner boundary of the tube wall, when viewed in longitudinal sectional profile, is comprised of alternating convex and concave portions which join at common tangents, and wherein the internal tube surface can be described by the equation: phi e2/pdi where phi is a dimensionless severity parameter, e is the height of the helical ridge, p is the helical pitch and di is the inside diameter, and where phi is greater than 0.1 X 10 2 and equal to Or less than about 0.365 X 10 2.
Claim 3
Dependent Claim
18 words
The metal heat transfer tube of claim 1 wherein phi is equal to about 0.365 X 10 2.
Claim 4
Dependent Claim
32 words
The metal heat transfer tube of claim 1 wherein the helical ridge has a convex ridge cap, the axial thickness t of said cap being equal to or greater than 0.085 inches.
Claim 5
Dependent Claim
32 words
The metal heat transfer tube of claim 2 wherein the helical ridge has a convex ridge cap, the axial thickness t of said cap being equal to or greater than 0.085 inches.
Claim 6
Dependent Claim
19 words
The metal heat transfer tube of claim 1 wherein said tube is corrugated and has a uniform wall thickness.
Claim 7
Dependent Claim
19 words
The metal heat transfer tube of claim 2 wherein said tube is corrugated and has a uniform wall thickness.
Claim 8
Dependent Claim
19 words
The metal heat transfer tube of claim 3 wherein said tube is corrugated and has a uniform wall thickness.
Claim 9
Dependent Claim
19 words
The metal heat transfer tube of claim 4 wherein said tube is corrugated and has a uniform wall thickness.
References Cited (Backward Citations)
US3612175A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |