The vertical axis solar furnace was designed to perform tests that require high radiant flux, strong gradients and very high test temperatures.
This system, called SF5 -Solar Furnace 5-, reaches concentrations over 6000 suns, and is mainly devoted to heat treatment of materials at high temperature, under vacuum and controlled atmosphere conditions. The new furnace differs substantially from that existing PSA Solar Furnace SF60 and most operating solar furnaces, as it operates in a vertical axis, ie parabolic concentrator and heliostat are vertically aligned on the optical axis of the paraboloid, while that in most existing solar furnaces, are horizontally aligned. The main advantage of vertical axis solar furnaces is that the focus is arranged in a horizontal plane, so that the samples may be treated on a horizontal surface, just placing them directly in the focus, without a holder, avoiding problems of loss of material by gravity in those tests in which the treatment requires surface melting of the specimens.
Basically consists of a concentrator mirror, placed upside-down with the reflecting surface facing the floor, on a 18 m height metallic tower; in the center of the base of the tower there is a flat heliostat, whose center of rotation is aligned with the optical axis of the concentrator. At the top of the tower, in the test room, and 2 m below the vertex of the concentrator, there is a test table. Finally, under the test table and at floor level of the test room, a louver attenuator is placed, located between heliostat and concentrator.
The main technical characteristics of the concentrator are:
- Surface: 8,77 m2
- Diámeter: 3,5 m
- Focal distance: 2 m
- f/d ratio: 0,57
- Rim angle: 54,4º
- Focus diameter -90% power-: 12 cm
- Total power: 5 kW
- Peak concentration: 6000