Patent US4947548A successfully refreshed from Google Patents.
US4947548A
Expired / Lapsed
US
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Method of making a heat exchanger for condensing furnace
Assignee: Carrier Corp
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Filing: 1989-07-03
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Granted: 1990-08-14
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Expires: 2009-07-03
Abstract
Abstract A corrosion resistant condensing heat exchanger is formed from a flat sheet of engineering metal with a layer of polypropylene sheet material laminated thereto. Each condensing heat exchanger has a condensing flow passage of serpentine shape formed in the laminated flat sheet of engineering metal such that the polypropylene layer will be exposed to the flue gas/condensate environment to provide corrosion resistance to the metal.
Inventors
- 👤 Richard M. Bentley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:25
CPC Classifications
F; F28; F28F; F28F19/00; F28F19/02; F28F19/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49366; Y10T29/49826; Y10T29/49885; Y10T29/49893
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
171 words
A method of fabricating a condensing heat exchanger for a gas-fired warm air condensing furnace, comprising the steps of: providing a single flat engineering metal sheet having a dividing line between opposite ends thereof for apportioning said single flat engineering metal sheet into two portions; laminating said flat engineering metal sheet with a layer of corrosion resistant sheet material so that said laminated engineering metal sheet is thermally conductive; forming a mirror image flow path pattern in each portion of said laminated engineering metal sheet apportioned by the dividing line; folding each portion of said laminated engineering metal sheet along the dividing line so that said mirror image flow path pattern in one half is in registration with the other mirror image flow path pattern in the other portion to form a condensing flow passage with the layer of corrosion resistant sheet material on the inner surface of the condensing heat exchanger; and sealing selected edge portions of the folded laminated engineering metal sheet to form a fluid-tight condensing heat exchanger.
Claim 2
Independent Claim
171 words
A method of fabricating a condensing heat exchanger for a gas-fired warm air condensing furnace, comprising the steps of: providing a single flat engineering metal sheet having a dividing line between opposite ends thereof for apportioning said single flat engineering metal sheet into two portions; laminating said flat engineering metal sheet with a layer of corrosion resistant sheet material so that said laminated engineering metal sheet is thermally conductive; forming a mirror image flow path pattern in each portion of said laminated engineering metal sheet apportioned by the dividing line; folding each portion of said laminated engineering metal sheet along the dividing line so that said mirror image flow path pattern in one half is in registration with the other mirror image flow path pattern in the other portion to form a condensing flow passage with the layer of corrosion resistant sheet material on the inner surface of the condensing heat exchanger; and sealing selected edge portions of the folded laminated engineering metal sheet to form a fluid-tight condensing heat exchanger.
Claim 3
Dependent Claim
36 words
A method for fabricating a condensing heat exchanger as set forth in claim 1 wherein the step of laminating includes laminating with a corrosion resistant sheet of polypropylene material having a thickness of about 10 mils.
Claim 4
Dependent Claim
43 words
A method of fabricating a condensing heat exchanger as set forth in claim 2 wherein the step of forming includes connecting an edge of the mirror image flow path pattern in each portion at the dividing line of said laminated engineering metal sheet.
Claim 5
Dependent Claim
30 words
A method of fabricating a condensing heat exchanger as set forth in claim 3 wherein the step of formingincludes forming the mirror image flow path pattern in a serpentine shape.
References Cited (Backward Citations)
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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) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |