Solar Furnace

solar furnace [′sō·lər ′fər·nəs]

(engineering)

An image furnace in which high temperatures are produced by focusing solar radiation.

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Solar Furnace 

an apparatus that uses concentrated solar radiation to melt materials or to subject them to heat treatment. The principal components of a solar furnace are a short-focus concentrator of solar radiation, a receiver (the furnace proper), and an automatic tracking system, which follows the motion of the sun and continuously turns the concentrator so that its axis is always directed toward the sun.

The receiver is positioned in the focal region of the concentrator and consists of a chamber with a transparent window. In this chamber there may be created, for example, a vacuum or an atmosphere of an inert gas. Frequently the chamber is a crucible made from a material that is to be melted or subjected to heat treatment. The operating temperature can reach 3600°. In many cases, the solar furnace is equipped with an orientating device consisting of a plane mirror that directs the sun’s rays to the concentrator; the orientating device follows the sun, and the concentrator remains stationary. Owing to their high cost, solar furnaces are used only when it is necessary to create special (“sterile”) conditions for melting and heat treatment that prevent the introduction of impurities into the material being processed.

As of 1975, the largest solar furnace was located at Odeillo in France. The diameter of its concentrating mirror is 54 m, and its power output is ~1 megawatt.

R. R. APARISI