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US4097311A Expired / Lapsed US ⏱️ 0.0 years remaining

Absorption surface of solar collector

Assignee: Yazaki Corp
•
Filing: 1976-08-18
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Granted: 1978-06-27
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Expires: 1996-08-18
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Abstract

Abstract The present invention relates to a selective absorption surface of a solar collector in which a coating layer consisting of the predetermined composition of metal oxide is tightly adhered to a substrate having the mirror-like surface in the predetermined thickness. The composition of metal oxide consists of those comprising 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005-10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr, 0.005 - 22.00 wt % of Ni, optionally, 0.75 - 5.00 wt % of Mo and the balance being Fe or those comprising instead of Cr, 0.001 - 5.0 wt % of at least one of metals selected from the group of N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr, and Hf, the atom ratio of Metal/Carbon + additional element being more than 5.0. An acidic oxidation method and an alkaline oxidation method are applied to manufacture oxide of the metal compositions. It has been observed that the superior selective absorption surface showing high energy absorption factor at a wave length of 0.3 - 2.5 μm and low energy radiative factor at a wave length of 3 -50 μm is manufactured by coating said oxide of the metal composition at a thickness of 500 - 2000 A on the base plate having the mirror-like surface of arithmetical mean deviation (Ra) less than 0.07μ or ten point height (RZ) less than 0.2μ determined according to the method of ISO Recommendation R 468.

Inventors

  • 👤 Toshihiro Ishibashi
  • 👤 Kinya Horibe
  • 👤 Masaharu Ishida
  • 👤 Youzi Sano

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 08:36
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/24; C23C22/60; C23C22/62; 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; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 146 words
A selective absorption surface of a solar collector comprising a coating surface of metal oxide at a thickness of 500 - 2,000 A on the substrate having a mirror-like surface, said substrate surface having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO recommendation R 468, said metal oxide consisting of those of 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr, 0.005 - 22.00 wt % of Ni, optionally 0.75 - 5.00 wt % of Mo and the balance being Fe and possessing properties of high energy absorption factor at a wave length of 0.3 - 2.5 μm and low energy radiative factor at a wave length of 3 - 50 μm.
Claim 2
Dependent Claim 146 words
A selective absorption surface of a solar collector comprising a coating surface of metal oxide at a thickness of 500 - 2,000 A on the substrate having a mirror-like surface, said substrate surface having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO recommendation R 468, said metal oxide consisting of those of 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr, 0.005 - 22.00 wt % of Ni, optionally 0.75 - 5.00 wt % of Mo and the balance being Fe and possessing properties of high energy absorption factor at a wave length of 0.3 - 2.5 μm and low energy radiative factor at a wave length of 3 - 50 μm.
Claim 3
Dependent Claim 78 words
A selective absorption surface of a solar collector as claimed in claim 1 in which a metal composition constituting a coating surface of metal oxide is that of the stainless steel (683/XIII 11 (ISO), 304 (AISI)) consisting of 0.005 - 0.08 wt % of C, 0.005 - 1.00 wt % of Si, 0.005 - 2.00 wt % of Mn, 8.00 - 10.50 wt % of Ni, 18.00 - 20.00 wt % of Cr and the balance being Fe.
Claim 4
Dependent Claim 85 words
A selective absorption surface of a solar collector as claimed in claim 1 in which a metal composition constituting a coating surface of the metal oxide is that of the stainless steel (683/XIII 20 (ISO), 316(AISI)) consisting of 0.005 - 0.08 wt % of C, 0.005 - 1.00 wt % of Si, 0.005 - 2.00 wt % of Mn, 10.00 - 14.00 wt % of Ni, 16.00 - 18.00 wt % of Cr, 2.00 - 3.00 wt % of Mo and the balance being Fe.
Claim 5
Dependent Claim 77 words
A selective absorption surface of a solar collector as claimed in claim 1 in which a metal composition constituting a coating surface of metal oxide is that of the stainless steel (683/XIII 8 (ISO), 430(AISI)) consisting of 0.05 - 0.12 wt % of C, 0.005 - 0.75 wt % of Si, 0.005 - 1.000 wt. % of Mn, 0.005 - 0.60 wt % of Ni, 16.00 - 18.00 wt % of Cr and the balance being Fe.
Claim 6
Dependent Claim 82 words
A selective absorption surface of a solar collector as claimed in claim 1 in which a metal composition consisting a coating surface of metal oxide is that of the stainless steel (434 (AISI)) consisting of 0.05 - 0.12 wt % of C, 0.05 - 1.00 wt % of Si, 0.005 - 1.00 wt % of Mn, 0.005 - 0.60 wt % of Ni, 16.00 - 18.00 wt % of Cr, 0.75 - 1.25 wt % of Mo and the balance being Fe.
Claim 7
Dependent Claim 74 words
A selective absorption surface of a solar collector as claimed in claim 1 in which the optical thickness of the coating layer is determined on the basis that the wave length of the primary absorption represented by the following formula n 1 d = λ/4 (wherein n 1 represents the refractive index of the coating layer, d represents the thickness of the coating layer, μ represents the wave length μm) is about 0.8 μm.
Claim 8
Dependent Claim 170 words
A selective absorption surface of a solar collector comprising a coating surface of metal oxide at a thickness of 500 - 2,000 A on the substrate having a mirror-like surface, said substrate surface having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO recommendation R 468, said metal oxide consisting of those of 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr and 0.001 - 5.00 wt % of at least one additional element selected from the group comprising N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr, and Hf, optionally, 0.75 - 5.00 wt % of Mo and the balance being Fe and possessing properties of high energy absorption factor at a wave length of 0.3 - 2.5 μm and low energy radiative factor at a wave length of 3 - 50 μm.
Claim 9
Dependent Claim 170 words
A selective absorption surface of a solar collector comprising a coating surface of metal oxide at a thickness of 500 - 2,000 A on the substrate having a mirror-like surface, said substrate surface having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO recommendation R 468, said metal oxide consisting of those of 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr and 0.001 - 5.00 wt % of at least one additional element selected from the group comprising N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr, and Hf, optionally, 0.75 - 5.00 wt % of Mo and the balance being Fe and possessing properties of high energy absorption factor at a wave length of 0.3 - 2.5 μm and low energy radiative factor at a wave length of 3 - 50 μm.
Claim 10
Dependent Claim 73 words
A selective absorption surface of a solar collector as claimed in claim 7 in which a metal composition constituting a coating surface of metal oxide is that of the stainless steel consisting of 0.005 - 0.03 wt % of C, 0.005 - 0.75 wt % of Si, 0.005 - 1.00 wt % of Mn, 16.00 - 18.00 wt % of Cr, 0.1 - 1.0 wt % of Ti and the balance being Fe.
Claim 11
Dependent Claim 79 words
A selective absorption surface of a solar collector as claimed in claim 7 in which a metal composition consisting a coating surface of metal oxide is that of the stainless steel consisting of 0.005 - 0.03 wt % of C, 0.005 - 0.75 wt % of Si, 0.005 - 1.00 wt % of Mn, 16.00 - 18.00 wt % of Cr, 0.1 -1.0 wt % of Ti, 0.75 - 5.00 wt % of Mo and the balance being Fe.
Claim 12
Dependent Claim 43 words
A selective absorption surface of a solar collector as claimed in claim 7, in which Me/C + N ratio is more than 5.0, while said ratio is more than 8.0 in the stainles steel comprising Nb, Ta or Ti as the additional element.
Claim 13
Dependent Claim 176 words
A selective absorption surface of a solar collector comprising a coating surface of metal oxide at a thickness of 500 - 2,000 A on the substrate having a mirror-like surface, said substrate having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO recommendation R 468, said metal oxide consisting of those of 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr, 0.005 - 22.00 wt % of Ni, and 0.001 - 5.00 wt % of at least one additional element selected from the group comprising N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr and Hf, optionally, 0.75 - 5.00 wt % of Mo and the balance being Fe and possessing properties of high energy absorption factor at a wave length of 0.3 - 2.5 μm and low energy radiative factor at a wave length of 3 - 50 μm.
Claim 14
Dependent Claim 176 words
A selective absorption surface of a solar collector comprising a coating surface of metal oxide at a thickness of 500 - 2,000 A on the substrate having a mirror-like surface, said substrate having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO recommendation R 468, said metal oxide consisting of those of 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr, 0.005 - 22.00 wt % of Ni, and 0.001 - 5.00 wt % of at least one additional element selected from the group comprising N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr and Hf, optionally, 0.75 - 5.00 wt % of Mo and the balance being Fe and possessing properties of high energy absorption factor at a wave length of 0.3 - 2.5 μm and low energy radiative factor at a wave length of 3 - 50 μm.
Claim 15
Dependent Claim 178 words
A process for manufacturing the selective absorption surface of the solar collector, in which the stainless steel having a mirror-like surface having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO Recommendation R 468, and the metal composition comprising; 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr, 0.005 - 22.00 wt % of Ni, optionally 0.75 - 5.00 wt % of Mo, and the balance being Fe, is chemically oxidized in an acidic bath consisting of 150 - 800 g/l of sulfuric acid and a compound selected from the class consisting of 100 - 400 g/l of sodium, 100 - 400 g/l of potassium bichromate or 40 - 700 g/l of chromium trioxide, at the temperature of 50° C to the boiling point, a dipping time of 3 - 40 minutes to form the oxide film at a thickness of 500 to 2,000 A.
Claim 16
Dependent Claim 178 words
A process for manufacturing the selective absorption surface of the solar collector, in which the stainless steel having a mirror-like surface having a roughness of Ra of less than 0.07 μ or Rz of less than 0.2 μ determined according to the method of ISO Recommendation R 468, and the metal composition comprising; 0.001 - 0.15 wt % of C, 0.005 - 3.00 wt % of Si, 0.005 - 10.00 wt % of Mn, 11.00 - 30.00 wt % of Cr, 0.005 - 22.00 wt % of Ni, optionally 0.75 - 5.00 wt % of Mo, and the balance being Fe, is chemically oxidized in an acidic bath consisting of 150 - 800 g/l of sulfuric acid and a compound selected from the class consisting of 100 - 400 g/l of sodium, 100 - 400 g/l of potassium bichromate or 40 - 700 g/l of chromium trioxide, at the temperature of 50° C to the boiling point, a dipping time of 3 - 40 minutes to form the oxide film at a thickness of 500 to 2,000 A.
Claim 17
Dependent Claim 53 words
A process for manufacturing the selective absorption surface of the solar collector as claimed in claim 12, wherein 0.001 - 5.00 wt % of at least one additional element selected from the class comprising N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr and Hf is present in the composition.
Claim 18
Dependent Claim 188 words
A process for manufacturing the selective absorption surface of the solar collector, in which the stainless steel having a mirror-like surface having a roughness of Ra of less than 0.07μ or Rz of less than 0.2μ determined according to the method of ISO Recommendation R 468; and the metal composition comprising; at least one element selected from the class comprising N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr and Hf; 0.001 - 0.15 wt % of C; 0.005 - 3.00 wt % of Si; 0.005 - 10.00 wt % of Mn; 11.00 - 30.00 wt % of Cr; optionally 0.75 - 5.00 wt % of Mo; and the balance being Fe; is chemically oxidized in an acidic bath consisting of 150 - 800 g/l of sulfuric acid and a compound selected from the class consisting of sodium, 100 - 400 g/l of potassium bichromate or 40 - 700 g/l of chromium trioxide, at the temperature of 50° C to the boiling point; and, a dipping time of 3 - 40 minutes to form the oxide film at a thickness of 500 to 2,000 A.
Claim 19
Dependent Claim 188 words
A process for manufacturing the selective absorption surface of the solar collector, in which the stainless steel having a mirror-like surface having a roughness of Ra of less than 0.07μ or Rz of less than 0.2μ determined according to the method of ISO Recommendation R 468; and the metal composition comprising; at least one element selected from the class comprising N, Cu, Al, V, Y, Ti, Nb, Ta, U, Th, W, Zr and Hf; 0.001 - 0.15 wt % of C; 0.005 - 3.00 wt % of Si; 0.005 - 10.00 wt % of Mn; 11.00 - 30.00 wt % of Cr; optionally 0.75 - 5.00 wt % of Mo; and the balance being Fe; is chemically oxidized in an acidic bath consisting of 150 - 800 g/l of sulfuric acid and a compound selected from the class consisting of sodium, 100 - 400 g/l of potassium bichromate or 40 - 700 g/l of chromium trioxide, at the temperature of 50° C to the boiling point; and, a dipping time of 3 - 40 minutes to form the oxide film at a thickness of 500 to 2,000 A.

References Cited (Backward Citations)

US3125471A Cited
US2394899A Cited
US2528717A Cited
US3210220A Cited
US3915759A Cited
US3963530A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-06-26 1981-12-26 1982-06-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-06-26 1985-12-26 1986-06-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-06-26 1989-12-26 1990-06-27 $7700.00 Window Closed / Lapsed

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