Solar collector
First Claim
1. A solar energy collector element comprising a first glass tube into which a fluid to be heated can be directed, a second glass tube which has an internal diameter which is greater than the external diameter of the first tube and which is located about the first tube, an end-sealed evacuated space defined by the external and internal surfaces respectively of the first and second tubes, and a solar selective surface coating on the external surface of the first tube;
- the solar selective surface coating comprising a substrate and a composite metal film, the substrate having a thickness of at least 0.05×
10-6 m. and being composed of a metal which has a relatively low infra-red emittance, and the composite metal film comprising a metal-carbide which has a thickness between 0.04×
10-6 m. and 0.20×
10-6 m. and which is deposited on the substrate by a reactive sputtering process.
1 Assignment
0 Petitions
Accused Products
Abstract
A solar energy collector element which comprises a glass tube which is coated on its exterior surface with a solar selective coating, the coating comprising a metal substrate which has a relatively low infra-red emittance and a composite metal film. The composite metal film comprises a metal-carbide which is deposited on the substrate by a reactive sputtering process.
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Citations
11 Claims
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1. A solar energy collector element comprising a first glass tube into which a fluid to be heated can be directed, a second glass tube which has an internal diameter which is greater than the external diameter of the first tube and which is located about the first tube, an end-sealed evacuated space defined by the external and internal surfaces respectively of the first and second tubes, and a solar selective surface coating on the external surface of the first tube;
- the solar selective surface coating comprising a substrate and a composite metal film, the substrate having a thickness of at least 0.05×
10-6 m. and being composed of a metal which has a relatively low infra-red emittance, and the composite metal film comprising a metal-carbide which has a thickness between 0.04×
10-6 m. and 0.20×
10-6 m. and which is deposited on the substrate by a reactive sputtering process. - View Dependent Claims (2, 3, 4)
- the solar selective surface coating comprising a substrate and a composite metal film, the substrate having a thickness of at least 0.05×
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5. A solar energy collector element comprising a first glass tube into which a fluid to be heated can be directed, a second glass tube which has an internal diameter which is greater than the external diameter of the first tube and which is located about the first tube, and end-sealed evacuated space defined by the external and internal surfaces respectively of the first and second tubes, and a solar selective surface coating on the external surface of the first tube;
- the solar selective surface coating comprising a substrate and a composite metal film, the substrate having a thickness of at least 0.05×
10-6 m. and being composed of a metal which has a relatively low infra-red emittance, and the composite metal film comprising a metal-carbide which has a thickness of at least 0.04×
10-6 m. and which is deposited on the substrate by a reactive sputtering process. - View Dependent Claims (6)
- the solar selective surface coating comprising a substrate and a composite metal film, the substrate having a thickness of at least 0.05×
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7. A method of making a solar energy collector element and which comprises the steps of:
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depositing onto the external surface of a first glass tube to a thickness of not less than 0.05×
10-6 m. a substrate composed of a metal having a relatively low infra-red emittance,depositing onto the substrate by a reactive sputtering process a metal-carbide film, the metal-carbide film being deposited to a thickness falling within the range 0.04×
10-6 m. to 0.20×
10-6 m,locating about the first tube a second glass tube which has an internal diameter greater than the external diameter of the first tube, interconnecting the first and second tubes whereby a space is defined therebetween, and evacuating the space between the first and second tubes. - View Dependent Claims (8, 9)
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10. A method of making a solar energy collector element and which comprises the steps of:
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depositing onto the external surface of a first glass tube to a thickness of not less than 0.05×
1031 6 m. a substrate composed of a metal having a relatively low infra-red emittance,depositing onto the substrate by a reactive sputtering process a metal-carbide film, the metal-carbide film being deposited to a thickness of at least 0.04×
10-6 m,locating about the first tube a second glass tube which has an internal diameter greater than the external diameter of the first tube, interconnecting the first and second tubes whereby a space is defined therebetween, and evacuating the space between the first and second tubes. - View Dependent Claims (11)
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Specification