Patent US4102393A successfully refreshed from Google Patents.
US4102393A
Expired / Lapsed
US
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Heat exchange apparatus
Assignee: Bank of Nova Scotia
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Filing: 1976-09-17
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Granted: 1978-07-25
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Expires: 1996-09-17
Abstract
Abstract An improvement in heat transfer and a reduction in fouling by liquid flowing inside of heat exchanger tubes is achieved by the apparatus and method of the present invention wherein the heat exchanger includes internally ridged or corrugated metal tubes rather than conventional plain tubes. Despite the formation of a normal appearing fouling layer on the downstream portion of a ridge, the ridged tubes remain relatively clear on the upstream portion of the ridge. Periodically, as the downstream portions of the tubing ridge surfaces build up a fouling coating, the flow direction of the tube side fluid is reversed to remove at least a substantial portion of the previously deposited coating.
Inventors
- 👤 James G. Withers, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:35
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/10; F28F1/42; F28F1/424; F28F1/426; F28F27/00; F28F27/02; F28G; F28G13/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
An improved heat exchange apparatus for use with a tubeside fluid which is capable of fouling the tube walls comprising at least one tube for circulating fluid through the apparatus, said at least one tube being characterized in that it has integral internal ridging in its inner wall which is generally transverse to the tube axis and has a lead angle of less than 60° as measured from a perpendicular to the tube axis, said ridging being adapted to turbulate said tubeside fluid to prevent fouling of the areas of the tube immediately upstream of the ridging, and valve means for reversing the direction of fluid flow of said tubeside fluid within said at least one tube.
Claim 2
Dependent Claim
117 words
An improved heat exchange apparatus for use with a tubeside fluid which is capable of fouling the tube walls comprising at least one tube for circulating fluid through the apparatus, said at least one tube being characterized in that it has integral internal ridging in its inner wall which is generally transverse to the tube axis and has a lead angle of less than 60° as measured from a perpendicular to the tube axis, said ridging being adapted to turbulate said tubeside fluid to prevent fouling of the areas of the tube immediately upstream of the ridging, and valve means for reversing the direction of fluid flow of said tubeside fluid within said at least one tube.
Claim 3
Dependent Claim
34 words
The apparatus of claim 1 wherein the inner wall of said at least one tube has an alternately concave and convex profile in a longitudinal section taken along the major portion of its length.
Claim 4
Dependent Claim
14 words
The apparatus of claim 1 wherein said internal ridging comprises a single start helix.
Claim 5
Dependent Claim
14 words
The apparatus of claim 1 wherein said internal ridging comprises a multiple start helix.
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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) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |