Patent US449336A successfully refreshed from Google Patents.
US4469167A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchanger fin
Assignee: Hitachi Ltd
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Filing: 1981-12-02
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Granted: 1984-09-04
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Expires: 2001-12-02
Abstract
Abstract A heat exchanger fin according to the invention has a multiplicity of fins arranged substantially in parallel with the direction of air flow and at least one heat transfer tube to which said fins are connected in a heat conducting relation. A multiplicity of louvers inclined by a small angle to the direction of air flow are formed in said fins. According to this construction, it is possible that the air as a whole can flow substantially straight across the heat exchanger and can strongly collide with all louvers, thereby to ensure a reduced flow resistance encountered by the air flow, as well as improved heat transfer performance of the heat exchanger.
Inventors
- 👤 Masaaki Itoh
- 👤 Takeo Tanaka
- 👤 Masakatsu Hayashi
- 👤 Mituo Kudo
- 👤 Akira Tomita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:06
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/10; F28F1/12; F28F1/126; F28F1/128; F24; F24F; F24F13/00; F24F13/30; F28D; F28D1/00; F28D1/02; F28D1/04; F28D1/047; F28D1/0477; F28D1/0478; F28F1/24; F28F1/32; F28F1/325
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
274 words
A heat exchanger fin for use in a heat exchanger of the type having a plurality of fins arranged substantially in parallel with a direction of air flow, the air flowing through a space between adjacent fins, said fins comprising a plurality of louvers cut and raised in a bridge-like form therefrom substantially perpendicular to the direction of said air flow, said louvers dividing said space between adjacent fins in a heightwise direction into n sections wherein n≧3, said louvers being inclined to a direction of air flow at a small attack angle, at least one of the louvers of each of said fins being cut and raised in such a manner that one end of the louver is positioned above an upper surface of the fin and a second end is positioned below a lower surface of the fin to divide the air flow into a flow above and below the louver, at least another one of the louvers of each said fins being cut and raised in such a manner that both ends are positioned above the upper surface of the fin, and at least one other of the louvers being cut and raised in such a manner that both ends of said louver are positioned below the lower surface of the fin, and wherein said attack angle γ (degrees) is determined to satisfy the following condition: ##STR1## wherein, t represents a thickness (m) of a fin, b represents the breadth (m) of a fin, P represents the pitch (m) of the fins, u represents the flow velocity (m/sec) of air and ν represents the kinematic viscosity (m 2 /S) of air.
Claim 2
Dependent Claim
274 words
A heat exchanger fin for use in a heat exchanger of the type having a plurality of fins arranged substantially in parallel with a direction of air flow, the air flowing through a space between adjacent fins, said fins comprising a plurality of louvers cut and raised in a bridge-like form therefrom substantially perpendicular to the direction of said air flow, said louvers dividing said space between adjacent fins in a heightwise direction into n sections wherein n≧3, said louvers being inclined to a direction of air flow at a small attack angle, at least one of the louvers of each of said fins being cut and raised in such a manner that one end of the louver is positioned above an upper surface of the fin and a second end is positioned below a lower surface of the fin to divide the air flow into a flow above and below the louver, at least another one of the louvers of each said fins being cut and raised in such a manner that both ends are positioned above the upper surface of the fin, and at least one other of the louvers being cut and raised in such a manner that both ends of said louver are positioned below the lower surface of the fin, and wherein said attack angle γ (degrees) is determined to satisfy the following condition: ##STR1## wherein, t represents a thickness (m) of a fin, b represents the breadth (m) of a fin, P represents the pitch (m) of the fins, u represents the flow velocity (m/sec) of air and ν represents the kinematic viscosity (m 2 /S) of air.
Claim 3
Dependent Claim
17 words
A heat exchanger fin as claimed in claim 1, wherein the attack angle is determined within ±3°.
Claim 4
Dependent Claim
267 words
A heat exchanger for use in heat exchanger of the type having a plurality of fins arranged substantially in parallel with a direction of air flow, the air flowing through a space between adjacent fins, said fins comprising a plurality of louvers cut and raised in a bridgelike form therefrom substantially perpendicular to the direction of said air flow, said louvers dividing said space between adjacent fins in a heightwise direction into n sections wherein n≧3, said louvers being inclined to the direction of air flow at a small attack angle, at least one of the louvers of each of said fins being cut and raised in such a manner that one end of the louver is positioned above an upper surface of the fin and a second end is positioned below a lower surface of the fin to divide the air flow into a flow above and below the louver, at least another one of the louvers of each of said fins being cut and raised in such a manner that both ends are positioned above the upper surface of the fin, and at least one other of the louvers being cut and raised in such a manner that both ends of said louver are positioned below the lower surface of the fin, and wherein said attack angle γ (degrees) is determined to satisfy the following condition: ##EQU7## wherein, t represents the thickness (m) of fin, b represents the breadth (m) of fin, P represents the pitch (m) of fins, u represents the flow velocity (m/s) of air, and ν represents the kinematic viscosity of air.
Claim 5
Dependent Claim
267 words
A heat exchanger for use in heat exchanger of the type having a plurality of fins arranged substantially in parallel with a direction of air flow, the air flowing through a space between adjacent fins, said fins comprising a plurality of louvers cut and raised in a bridgelike form therefrom substantially perpendicular to the direction of said air flow, said louvers dividing said space between adjacent fins in a heightwise direction into n sections wherein n≧3, said louvers being inclined to the direction of air flow at a small attack angle, at least one of the louvers of each of said fins being cut and raised in such a manner that one end of the louver is positioned above an upper surface of the fin and a second end is positioned below a lower surface of the fin to divide the air flow into a flow above and below the louver, at least another one of the louvers of each of said fins being cut and raised in such a manner that both ends are positioned above the upper surface of the fin, and at least one other of the louvers being cut and raised in such a manner that both ends of said louver are positioned below the lower surface of the fin, and wherein said attack angle γ (degrees) is determined to satisfy the following condition: ##EQU7## wherein, t represents the thickness (m) of fin, b represents the breadth (m) of fin, P represents the pitch (m) of fins, u represents the flow velocity (m/s) of air, and ν represents the kinematic viscosity of air.
Claim 6
Dependent Claim
17 words
A heat exchanger fin as claimed in claim 3, wherein the attack angle is determined with ±3°.
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) | 1987-09-04 | 1988-03-05 | 1988-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-04 | 1992-03-05 | 1992-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-04 | 1996-03-05 | 1996-09-04 | $7700.00 | Window Closed / Lapsed |