COVERING WITH SOLAR ABSORPTION AGENT FOR HIGH TEMPERATURE SERVICE AND METHOD OF COATING THEREOF

摘要

A solar energy collecting apparatus contains a heat transmission component with a surface coating placed on it. This coating is a mineral oxide with a coefficient of solar absorption 0.90 for wavelengths of about 0.35-3.0 mu. The mineral oxide is a ferrite, a metallic oxide, or their mixts. The apparatus also contains (a) a device for the introduction of a fluid for heat exchange with the heat transmission component, and (b) a device for the introduction of fluid coming from the heat transmission component into an area where it can be used. The ferrite pref. contains 1-4 different metals in the crystalline network, the metals being Ni, Zn, Li, Mo, Mn, Mg, Co, Cu, Sr, Ba, Al, Gd or Y, it is e.g. a ferrite of Ni-Zn or of Li-Zn. The metallic oxide is pref. an oxide of Ni, Co, Fe, Mo or Sr. The coating is a more efficient absorber of solar energy than previous coatings used.