US4300629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross-fin tube type heat exchanger
Assignee: Hitachi Ltd
•
Filing: 1979-06-20
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Granted: 1981-11-17
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Expires: 1999-06-20
Abstract
Abstract A cross-fin tube type heat exchanger having a large number of parallel fins and a plurality of heat transfer tubes extended through and fixed to the fins, so that heat may be exchanged between a first heat exchanging medium flowing through the heat transfer tubes and a second heat exchanging medium flowing along the surfaces of the fin, across the walls of the heat transfer tubes and through the fins. In the portions of each fin between adjacent heat transfer tubes of the same row, formed are a number of slits perpendicular to the direction of flow of the second heat exchanging medium. Each elongated section defined between each pair of adjacent slits is bent along its breadthwise bisector line and is raised in the form of a bridge to constitute an upwardly convexed louver element. The upwardly convexed louver element may have a cross section with an obtuse apex angle, or may have an arcuate cross section. The successive louver elements are arrayed in the direction of flow of the second heat exchanging medium in a manner of corrugation, or alternately staggered in the heightwise direction so that the edges of adjacent louver elements may be staggered in the heightwise direction. The fins having louver elements thus constructed cause a turbulency of the flow of the second heat exchanging medium to effectively prevent boundary layers of the latter from growing, thereby to ensure a higher efficiency of the heat exchange. Also increased stiffness or rigidity of the fin is obtained thanks to the provision of upwardly convexed louver elements.
Inventors
- 👤 Toshio Hatada
- 👤 Takao Senshu
- 👤 Akira Arai
- 👤 Fumio Harada
- 👤 Atsushi Matsuzaki
- 👤 Hajime Futawatari
- 👤 Yutaka Imaizumi
- 👤 Sumiyoshi Takeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:20
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/10; F28F1/12; F28F1/24; F28F1/32; F28F1/325; F28F2250/00; F28F2250/02; Y; Y10; Y10S; Y10S165/00; Y10S165/454; Y10S165/50; Y10S165/501; Y10S165/502; Y10S165/503
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
197 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to have an obtuse apex angle with the edge line extending on the breadthwise bisector line of the elongated section and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent obtuse type louver elements are staggered in the direction of their heights.
Claim 2
Dependent Claim
197 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to have an obtuse apex angle with the edge line extending on the breadthwise bisector line of the elongated section and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent obtuse type louver elements are staggered in the direction of their heights.
Claim 3
Dependent Claim
33 words
A heat exchanger as claimed in claim 1, wherein the successive upwardly convexed louver elements disposed in the direction in which said fin extends are staggered alternately in the direction of said louvers.
Claim 4
Dependent Claim
19 words
A heat exchanger as claimed in claim 1, wherein said heat transfer tubes are arranged in a single row.
Claim 5
Dependent Claim
38 words
A heat exchanger as claimed in claim 1, wherein each group of said upwardly convexed louver elements formed in each fin as a whole extends in a manner of corrugation in the direction in which said fin extends.
Claim 6
Dependent Claim
21 words
A heat exchanger as claimed in claim 4, wherein said upwardly convexed louver elements are formed on a corrugated fin plate.
Claim 7
Dependent Claim
195 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to have an arcuate cross-section with its apex extending on the breadthwise bisector line of the elongated section, and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent arcuate type louver elements are staggered in the direction of their heights.
Claim 8
Dependent Claim
195 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to have an arcuate cross-section with its apex extending on the breadthwise bisector line of the elongated section, and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent arcuate type louver elements are staggered in the direction of their heights.
Claim 9
Dependent Claim
33 words
A heat exchanger as claimed in claim 6, wherein the successive upwardly convexed louver elements disposed in the direction in which said fin extends are staggered alternately in the direction of said louvers.
Claim 10
Dependent Claim
19 words
A heat exchanger as claimed in claim 6, wherein said heat transfer tubes are arranged in a single row.
Claim 11
Dependent Claim
38 words
A heat exchanger as claimed in claim 6, wherein each group of said upwardly convexed louver elements formed in each fin as a whole extends in a manner of corrugation in the direction in which said fin extends.
Claim 12
Dependent Claim
21 words
A heat exchanger as claimed in claim 11, wherein said upwardly convexed louver elements are formed on a corrugated fin plate.
Claim 13
Dependent Claim
211 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to make said elongated section have an upwardly convexed cross-section and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent louver elements are staggered in the direction of their heights, and wherein each of said upwardly convexed louver elements is formed to have an obtuse apex angle diverging from the bisector line of said elongated section.
Claim 14
Dependent Claim
211 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to make said elongated section have an upwardly convexed cross-section and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent louver elements are staggered in the direction of their heights, and wherein each of said upwardly convexed louver elements is formed to have an obtuse apex angle diverging from the bisector line of said elongated section.
Claim 15
Dependent Claim
19 words
A heat exchanger as claimed in claim 11, wherein said heat transfer tubes are arranged in a single row.
Claim 16
Dependent Claim
24 words
A heat exchanger as claimed in claim 11, wherein said heat transfer tubes are arranged in more than two rows in a zigzag manner.
Claim 17
Dependent Claim
44 words
A heat exchanger as claimed in one of claims 11, 12, or 13 wherein the angle of inclination of each flank of said upwardly convexed louver elements to the direction in which said fin extends falls within the range of between 8° and 24°.
Claim 18
Dependent Claim
41 words
A heat exchanger as claimed in one of claims 11, 12, or 13 wherein the angle of inclination of each flank of said upwardly convexed louver elements to the direction in which said fin extends is preferably between 14° and 20°.
Claim 19
Dependent Claim
41 words
A heat exchanger as claimed in one of claims 11, 12, or 13 wherein the angle of inclination of each flank of said upwardly convexed louver elements to the direction in which said fin extends is preferably around 16° to 17°.
Claim 20
Dependent Claim
197 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to make said elongated section having an upwardly convexed cross-section and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent louver elements are staggered in the direction of their heights, wherein each of said upwardly convexed louver elements has an arcuate cross-section.
Claim 21
Dependent Claim
197 words
A cross-fin tube type heat exchanger comprising a large number of fins spaced in parallel with one another and each having a predetermined area, and a plurality of heat transfer tubes extended through and fixed to said fins, thereby to permit heat exchange, across the walls of said heat transfer tubes and through said fins, between a heat exchanging medium flowing through said heat transfer tubes and another heat exchanging medium flowing along the surfaces of said fins, said heat exchanger further comprising a large number of upwardly convexed louver elements formed in the portions of said fins between adjacent heat transfer tubes, said louver elements being formed by forming a number of slits in said portions of said fins in a direction perpendicular to that of flow of air flowing along the surfaces of said fins, bending each elongated section defined between respective adjacent slits to make said elongated section having an upwardly convexed cross-section and raising said elongated sections in selected positions in the form of bridges such that the edges of adjacent louver elements are staggered in the direction of their heights, wherein each of said upwardly convexed louver elements has an arcuate cross-section.
Claim 22
Dependent Claim
19 words
A heat exchanger as claimed in claim 17, wherein said heat transfer tubes are arranged in a single row.
Claim 23
Dependent Claim
24 words
A heat exchanger as claimed in claim 17, wherein said heat transfer tubes are arranged in more than two rows in a zigzag manner.
Claim 24
Dependent Claim
69 words
A heat exchanger as claimed in one of claims 17, 18, or 19 wherein when said arcuate cross section of said louver element is equally divided into two sections by a straight line passing through its vertex, the angle formed between the direction in which the fin extends and a line tangential to the mid point of each divided section falls within the range of between 8° and 24°.
Claim 25
Dependent Claim
70 words
A heat exchanger as claimed in one of claims 17, 18, or 19 wherein when said arcuate cross section of said louver element is equally divided into two sections by a straight line passing through its vertex, the angle formed between the direction in which the fin extends and a line tangential to the mid point of each divided section falls preferably within the range of between 14° and 20°.
Claim 26
Dependent Claim
71 words
A heat exchanger as claimed in one of claims 17, 18, or 19 wherein when said arcuate cross section of said louver element is equally divided into two sections by a straight line passing through its vertex, the angle formed between the direction in which the fin extends and a line tangential to the mid point of each divided section falls most preferably within the range of between 16° and 17°.
Claim 27
Dependent Claim
41 words
A heat exchanger as claimed in one of claims 11, 12, 13, 17, 18, or 19, wherein the successive upwardly convexed louver elements disposed in the direction in which said fin extends are staggered alternately in the direction of said louvers.
Claim 28
Dependent Claim
46 words
A heat exchanger as claimed in one of claims 11, 12, 13, 17, 18 or 19, wherein each group of said upwardly convexed louver elements formed in each fin as a whole extends in a manner of corrugation in the direction in which said fin extends.
Claim 29
Dependent Claim
21 words
A heat exchanger as claimed in claim 24, wherein said upwardly convexed louver elements are formed on a corrugated fin plate.
References Cited (Backward Citations)
US2079032A
Cited
US2703226A
Cited
US2789797A
Cited
US3003749A
Cited
FR1212901A
Cited
US3135320A
Cited
US3298432A
Cited
US3380518A
Cited
US3397741A
Cited
US3438433A
Cited
US3796258A
Cited
JPS5317867A
Cited
GB2023798A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-16 | 1985-05-18 | 1985-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-16 | 1989-05-18 | 1989-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-16 | 1993-05-18 | 1993-11-17 | $7700.00 | Window Closed / Lapsed |