US3875997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tubular heat transfer members
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1973-08-08
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Granted: 1975-04-08
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Expires: 1993-08-08
Abstract
Abstract A vertical heat transfer tube for condensation of vapor in a condenser is of substantially uniform wall thickness and grooved so as to impart turbulence to coolant passing through the tube and to assist in runoff of condensate on the tube surface. The hand of the part-helical lands and grooves changes at intervals along the tube before the helix has completed a complete turn. The pitch of the grooves (determined by half a wave length of the helix) is more than 0.5 but less than 5 times the inside minimum diameter of the tube.
Inventors
- 👤 Ivan Henry Newson
- 👤 Thomas David Hodgson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:49
CPC Classifications
F; F28; F28F; F28F13/00; F28F13/06; F28F1/00; F28F1/02; F28F1/06; F28F1/10; F28F1/42; F28F1/424; F28F1/426; F28F13/04; Y; Y10; Y10S; Y10S165/00; Y10S165/184; Y10S165/198
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
115 words
A condenser having at least one vertical tube for condensing vapor on its outer surface, the improvement comprising the tube wall being of substantially uniform thickness and shaped so as to exhibit a number of parallel part-helical continuous lands and grooves in the tube bore to impart turbulence to the coolant, and grooves and lands on the tube surface to assist in run off of condensate, the hand of the helix changing at intervals along the tube before the helix has completed a complete turn, the pitch of the grooves (determined by half a wavelength of the helix) being more than 0.5 but less than 5 times the inside, i.e. minimum, diameter of the tube.
Claim 2
Dependent Claim
115 words
A condenser having at least one vertical tube for condensing vapor on its outer surface, the improvement comprising the tube wall being of substantially uniform thickness and shaped so as to exhibit a number of parallel part-helical continuous lands and grooves in the tube bore to impart turbulence to the coolant, and grooves and lands on the tube surface to assist in run off of condensate, the hand of the helix changing at intervals along the tube before the helix has completed a complete turn, the pitch of the grooves (determined by half a wavelength of the helix) being more than 0.5 but less than 5 times the inside, i.e. minimum, diameter of the tube.
Claim 3
Dependent Claim
18 words
A condenser as claimed in claim 1 in which the pitch is about twice the tube internal diameter.
Claim 4
Dependent Claim
27 words
A condenser as claimed in claim 1 in which the ratio of groove depth to the minimum inside diameter of the tube lies between 0.02 and 0.2.
Claim 5
Dependent Claim
25 words
A condenser as claimed in claim 1 in which the ratio of groove depth to the inside diameter of the tube is equal to 0.15.
References Cited (Backward Citations)
US2252045A
Cited
US2864591A
Cited
US2896426A
Cited
US3212992A
Cited
US3358749A
Cited
US3612175A
Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |