A concentric receiver tube for passing water to be disinfected twice before the aperture path of a concentric solar reflector. The novel receiver tube uses the water that is heated by the reflector to additionally pre-heat fresh incoming water to maximize the heat transfer exchange rate. The novel concentric tube receiver to preheat and disinfect water when the source of heat are combustion gases or catalyst beds. The maximum disinfecting temperature needs only be 90 C in order to create an instantaneous disinfection condition.
In order to provide a trough-shaped collector for radiation, in particular for solar radiation, comprising a trough-shaped mirror extending in longitudinal direction and reflecting the radiation into a focus region, and an absorber line extending in longitudinal direction through the focus region of the trough-shaped mirror and having a guide tube for the heat transport medium and an absorber pipe surrounding the guide tube such that an annular chamber is formed between guide tube and absorber line, with which the problems existing as a result of the uneven irradiation of the absorber line are also reduced or eliminated, it is suggested that an annular passage medium flow in the annular chamber and that the annular passage medium couple the guide tube thermally to the absorber pipe.
