Patent US4645119A successfully refreshed from Google Patents.
US4645119A
Expired / Lapsed
US
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Method of brazing an aluminum heat exchanger
Assignee: Hitachi Ltd
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Filing: 1984-07-05
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Granted: 1987-02-24
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Expires: 2004-07-05
Abstract
Abstract A heat exchanger and a method of manufacturing a heat exchanger by brazing metal members mainly made of Al or Al alloy is disclosed. The heat exchanger has a plurality of brazed metal members, at least one of the brazed metal members being made of brazing sheet clad with a brazing material. The brazed portions of the metal members or the whole surface of the heat exchanger are coated with a corrosion-resistant fluoride flux consisting essentially of 25-40% KF, 38-54% AlF3 and 3-30% ZnF2 by weight which forms a corrosion-inhibiting metallic film.
Inventors
- 👤 Takashi Haramaki
- 👤 Katsuhiko Shiota
- 👤 Satoshi Kokura
- 👤 Takao Funamoto
- 👤 Akira Tomita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:46
CPC Classifications
F; F28; F28F; F28F21/00; F28F21/08; F28F21/089; B; B23; B23K; B23K1/00; B23K1/0008; B23K1/0012; B23K35/00; B23K35/22; B23K35/34; B23K35/36; B23K35/3601; B23K35/3603; B23K35/3605; F28D; F28D1/00; F28D1/02; F28D1/04; F28D1/047; F28D1/0477; F28D1/0478; F28F1/00; F28F1/10; F28F1/12; F28F1/24; F28F1/32; F28F21/081; F28F21/084
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
169 words
A method of manufacturing a heat exchanger by brazing metal members mainly made of aluminum or aluminum alloy comprising the following steps: (a) making a heat exchanger combination by assembling a plurality of brazed metal members, at least one of said brazed metal members being made of a brazing sheet clad with a brazing material; (b) immersing said heat exchanger combination in an aqueous solution consisting essentially of 6 to 30% by weight of a fluoride flux containing Zn F 2 and drying said immersed heat exchanger combination to deposit the fluoride flux on brazed portions of said brazed metal members or said whole surface of said heat exchanger combination, said fluoride flux being a corrosion resistant fluoride flux which forms a corrosion inhibiting metallic film; and (c) heating said heat exchanger combination on which said fluoride flux is deposited and brazing said brazed members in a furnace in an atmosphere of a non-oxidizing gas of which the dew point of non-oxidizing gas is not more than -15° C.
Claim 2
Independent Claim
169 words
A method of manufacturing a heat exchanger by brazing metal members mainly made of aluminum or aluminum alloy comprising the following steps: (a) making a heat exchanger combination by assembling a plurality of brazed metal members, at least one of said brazed metal members being made of a brazing sheet clad with a brazing material; (b) immersing said heat exchanger combination in an aqueous solution consisting essentially of 6 to 30% by weight of a fluoride flux containing Zn F 2 and drying said immersed heat exchanger combination to deposit the fluoride flux on brazed portions of said brazed metal members or said whole surface of said heat exchanger combination, said fluoride flux being a corrosion resistant fluoride flux which forms a corrosion inhibiting metallic film; and (c) heating said heat exchanger combination on which said fluoride flux is deposited and brazing said brazed members in a furnace in an atmosphere of a non-oxidizing gas of which the dew point of non-oxidizing gas is not more than -15° C.
Claim 3
Independent Claim
157 words
A method of manufacturing a heat exchanger by brazing metal members mainly made of aluminum or aluminum alloy comprising the following steps: (a) making a heat exchanger combination by assembling a plurality of brazed metal members, at least one of said brazed metal members being made of a brazing sheet clad with a brazing material; (b) depositing a fluoride flux to brazed portions of said brazed metal members or said whole surface of said heat exchanger combination, said fluoride flux being a corrosion resistant fluoride flux which forms a corrosion-inhibiting metallic film and which consists essentially of 25-40% by weight KF, 38-54% by weight AlF 3 , and 3-30% by weight ZnF 2 ; and (c) heating said heat exchanger combination on which said fluoride flux is deposited and brazing said brazed members in a furnace in an atmosphere of a non-oxidizing gas of which the dew point of non-oxidizing gas is not more than -15° C.
Claim 4
Independent Claim
157 words
A method of manufacturing a heat exchanger by brazing metal members mainly made of aluminum or aluminum alloy comprising the following steps: (a) making a heat exchanger combination by assembling a plurality of brazed metal members, at least one of said brazed metal members being made of a brazing sheet clad with a brazing material; (b) depositing a fluoride flux to brazed portions of said brazed metal members or said whole surface of said heat exchanger combination, said fluoride flux being a corrosion resistant fluoride flux which forms a corrosion-inhibiting metallic film and which consists essentially of 25-40% by weight KF, 38-54% by weight AlF 3 , and 3-30% by weight ZnF 2 ; and (c) heating said heat exchanger combination on which said fluoride flux is deposited and brazing said brazed members in a furnace in an atmosphere of a non-oxidizing gas of which the dew point of non-oxidizing gas is not more than -15° C.
Claim 5
Independent Claim
176 words
A method of manufacturing a heat exchanger by brazing metal members mainly made of aluminum or aluminum alloy comprising the following steps: (a) making a heat exchanger combination by assembling a plurality of brazed metal members, at least one of said brazed metal members being made of a brazing sheet clad with a brazing material; (b) depositing a fluoride flux to brazed portions of said brazed metal members or said whole surface of said heat exchanger combination, said fluoride flux being a corrosion resistant fluoride flux which forms a corrosion-inhibiting metallic film and which consists essentially of 25-40% by weight KF, 38-54% by weight AlF 3 , 3-30% by weight ZnF 2 , and 0.5-9% by weight of at least one material selected from the group consisting of Lif, NaF, MgF and CaF; and (c) heating said heat exchanger combination on which said fluoride flux is deposited and brazing said brazed members in a furnace in an atmosphere of a non-oxidizing gas of which the dew point of non-oxidizing gas is not more than -15° C.
Claim 6
Independent Claim
176 words
A method of manufacturing a heat exchanger by brazing metal members mainly made of aluminum or aluminum alloy comprising the following steps: (a) making a heat exchanger combination by assembling a plurality of brazed metal members, at least one of said brazed metal members being made of a brazing sheet clad with a brazing material; (b) depositing a fluoride flux to brazed portions of said brazed metal members or said whole surface of said heat exchanger combination, said fluoride flux being a corrosion resistant fluoride flux which forms a corrosion-inhibiting metallic film and which consists essentially of 25-40% by weight KF, 38-54% by weight AlF 3 , 3-30% by weight ZnF 2 , and 0.5-9% by weight of at least one material selected from the group consisting of Lif, NaF, MgF and CaF; and (c) heating said heat exchanger combination on which said fluoride flux is deposited and brazing said brazed members in a furnace in an atmosphere of a non-oxidizing gas of which the dew point of non-oxidizing gas is not more than -15° C.
Claim 7
Dependent Claim
14 words
The method according to claim 1, wherein said non-oxidizing gas in N 2 .
Claim 8
Dependent Claim
19 words
The method according to claim 1 wherein the ZnF 2 is contained in an amount of 3-30% by weight.
Claim 9
Dependent Claim
20 words
The method according to claim 5 wherein the ZnF 2 is contained in an amount of from 7-15% by weight.
Claim 10
Dependent Claim
53 words
The method according to claim 3, wherein said fluoride flux consists essentially of 32-36% by weight KF, 44-50% by weight AlF 3 , 7-15% by weight ZnF 2 and 3-6% by weight of Lif or 1-2% by weight of at least one material selected from the group consisting of NaF, MgF and CaF.
Claim 11
Dependent Claim
32 words
The method according to claim 3 wherein the at least one material is selected from NaF, MgF and CaF and is present in an amount within the range of 1-2% by weight.
References Cited (Backward Citations)
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US3855682A
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US3951328A
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JPS56160869A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |