US4255213A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing solar collector plates
Assignee: Cyprus Amax Minerals Co
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Filing: 1978-04-24
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Granted: 1981-03-10
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Expires: 1998-04-24
Abstract
Abstract A solar collector plate made of stainless steel or a metal having a nickel-flash coating is immersed in a molten dichromate salt bath at a temperature between about 375° C. and about 500° C. sufficiently long to provide a selective oxide coating which has a Figure of Merit of at least about 4. The oxide coating is continuous, has a microscopically nodular texture with the average nodule size being at least about 5000 A and displays a Figure of Merit of at least about 4.
Inventors
- 👤 James D. Redmond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:45
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/70; C23C22/72; F; F24; F24S; F24S70/00; F24S70/20; F24S70/225; F24S70/25; Y; Y02; Y02E; Y02E10/00; Y02E10/40; Y10; Y10S; Y10S126/00; Y10S126/907; Y10S126/908; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12583; Y10T428/1259
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
In a method for producing a solar collector which comprises a collector box; a collector plate through which a heat exchange fluid circulates for transferring heat from said heat plate to a remote location, said plate being placed in said collector box and having a collector surface of stainless steel or another metal flash coated with nickel or chromium which surface is provided with an oxide layer to provide a selective coating and a glass cover for enclosing said plate, the improvement which comprises immersing the collector plate in a molten bath of a dichromate salt of at least one metal selected from the group consisting of sodium and potassium for a time sufficient to provide the collector surface with an oxide coating having a Figure of Merit of between about 4 and about 13.
Claim 2
Dependent Claim
135 words
In a method for producing a solar collector which comprises a collector box; a collector plate through which a heat exchange fluid circulates for transferring heat from said heat plate to a remote location, said plate being placed in said collector box and having a collector surface of stainless steel or another metal flash coated with nickel or chromium which surface is provided with an oxide layer to provide a selective coating and a glass cover for enclosing said plate, the improvement which comprises immersing the collector plate in a molten bath of a dichromate salt of at least one metal selected from the group consisting of sodium and potassium for a time sufficient to provide the collector surface with an oxide coating having a Figure of Merit of between about 4 and about 13.
Claim 3
Dependent Claim
14 words
The method as described in claim 1 wherein said molten bath is sodium dichromate.
Claim 4
Dependent Claim
24 words
The method as described in claim 2 wherein the molten bath is maintained at a temperature between about 375° C. and about 500° C.
Claim 5
Dependent Claim
24 words
The method as described in claim 3 wherein the molten bath is maintained at a temperature between about 415° C. and about 435° C.
Claim 6
Dependent Claim
26 words
The method as described in claim 3 wherein the collector plate is immersed in the molten bath for between about 1 minute and about 15 minutes.
Claim 7
Dependent Claim
26 words
The method as described in claim 5 wherein the collector plate is immersed in the molten bath for between about 1 minute and about 5 minutes.
Claim 8
Dependent Claim
24 words
The method as described in claim 6 wherein the collector plate has a surface finish at least equivilent to a standard 2B mill finish.
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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) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |