| 摘要 |
PURPOSE:To make it possible to obtain the vacuum glass tube heat collector having a high degree of absorptivity by a method wherein a selective absorption film consisting of an oxidized film of cobalt is formed on the surface of the body of the titled heat collector made of iron or copper. CONSTITUTION:The body 4' of a heat collector plated with cobalt in advance is fitted into a glass tube 7 provided with a vacuum discharge hole 6 at one end thereof and after sealing the other end with a sealing metal 9, distilled water or oxidizing water 10 such as 2-3% of a hydrogen peroxide solution is poured into the glass tube through the vacuum discharge hole 6. Then the glass tube is put into a vacuum evacuation furnace and after keeping a heat collecting plate at 350-400 deg.C for 5-10min, the glass tube is evacuated. As a result, the selective absorption film in cobalt blue is formed on the surface of the glass tube due to the oxidation of cobalt. Thus, with the selective absorption film formed in the above process, it is possible to obtain 92-98% of alpha and 7-10% of epsilon. |
