Porous surface solar energy receiver

Claim 1

A solar energy receiver system comprising: (A) a porous surface concentrating receiver or reflected solar radiation comprising: (1) a housing enclosing an air chamber, said housing being disposed elevated atop a tower in open air, (2) a porous air permeable wall composed of high temperature heat absorptive material comprising at least one wall of said housing, said wall being directed downwardly, (a) said air permeable wall being exposed to the atmosphere, (b) said porous wall thickness being between about 1 mm and 2 cm, (c) said porous wall having openings over about 10 to 90 percent of its surface, (d) the pore dimensions of said opening ranging between about 0.05 mm to 5 mm effective hydraulic diameter, and (e) said porous wall being composed of a substance selected from the group consisting of metallic alloys and refractory non-metallic material capable of withstanding temperatures in the range of about 500° to at least about 1500° C., (B) a plurality of concentrating reflectors disposed at a lower level relative to said housing arrayed around the base of the tower to reflect and concentrate sunlight upon said porous wall to produce high radiation fluxes at the wall surface, (C) heat exchanger means by which heat from heated atmospheric air is transferred to another medium, (D) air flow conduit means connecting said housing and heat exchanger means, and (E) means for drawing atmospheric air through said porous wall into said chamber to heat the air, and for withdrawing said heated air from the chamber through the conduit means to the heat exchanger.