solenergiabsorbator in the form of an aluminium permanent skivformigt elements with a eftertetat aluminiumoxidytskikt and still for framstellning of solenergiabsorbatorn

摘要

A solar energy absorber comprises an aluminium plate covered on one side thereof with a surface layer having a high absorbency and low emissivity and comprising a sealed aluminium oxide layer produced by anodising and subsequent metal electrodeposition under conditions such that the layer has a thickness less than approximately 1.5 mu m and has small pores containing metal elements which are fully enclosed within the pores of the sealed aluminium oxide layer and insulated from each other. The metal elements e.g. Ni, Co, Cu, Fe, Sn, Ag and/or Zn have a mean diameter of less than 0.08 mu m, are located at a mean distance between centres of less than 0.1 mu m and have a total volume per unit of surface area of 0.03-0.12 cm3/m2.