Black-Body Evaporator Unit for a Point-Focus Solar Collector

The figure illustrates a solar thermal energy system for boiling water or another liquid. The system can be used for a variety of purposes that can include drying aqueous hazardous waste, distilling pure solvent from spent solvent, purifying water by distillation, or generating steam. The principal innovative feature of this system is an absorber/evaporator unit, which is designed to absorb radiant solar energy with an effectiveness close to that of an ideal (in the black-body sense) absorber. The design is such that unlike in some other systems, it is not necessary to coat the solar-irradiated surface with a high-solar-absorptivity ("solar black") material to obtain the desired black-body characteristic. The design is also simpler than that of other absorber/evaporator units.