Background of the Invention
The invention relates to optical instruments, specifically to multiple-stage conical-lens concentrators which reduce the size and increase the intensity of solar beams.
Prior art includes the spherical magnifying lens which can be used to concentrate solar rays, and to the Conical Split-Image Microscopic Lens, U.S. Pat. No. 4,277,148, dated July 7, 1981, by the inventor. The effectiveness of the former is limited by the fact that it cannot produce parallel rays. The latter is similar to the disclosure in that it too consists of conical lenses and can be used as a concentrator by passing light rays through it in the opposite direction. It has three component lenses, however, and six sections (planar and concave conical, concave conical and convex conical, convex conical and concave conical) as opposed to two component lenses and four sections (planar and convex conical, convex conical and concave conical) of the disclosure.
Summary of the Invention
The conical beam concentrator is unique in that it can produce high-intensity solar beams of coherent light without the use of electricity. It is also unique in that it can produce high-intensity beams of considerable diameters, such as nine centimeters and larger, for example. High-intensity beams of such widths can be used to smelt ores, melt rock and other opaque substances.
Description of the Drawings
FIG. 1 is a longitudinal section of a one-stage beam concentrator.
FIG. 2 is a cross section taken on line 2--2 of FIG. 1.
FIG. 3 is a cross section taken on line 3--3 of FIG. 1.
Description of the Preferred Embodiment
FIG. 1 shows upper component lens 1 and lower component lens 2 mounted inside casing 3. Incipient beam 4 passes through planar section 5 and convex conical section 6 of upper component lens 1, and then through convex conical section 7 and concave conical section 8 of lower component lens 2, being refracted by the three conical sections 6-8 and emitted as concentrated beam 9.
The cross section of incipient beam 4 is shown in FIG. 2, and the cross section of concentrated beam 9 is shown in FIG. 3. All surfaces of component lens 1 and 2 not used for the refraction or transmission of light rays are opaque.
The angles of incidence and refraction of the beam are as follows:
Each stage of the beam concentrator reduces the beam by 0.23 1/X. Symbol 1/X denotes reduction of size as opposed to X which denotes enlargement or magnification of size. Enlargement of size of beams passing through the concentrator in the opposite direction is 4.33X; (0.23=1/4.33).
The inventor does not have access to data of the temperature of solar beams (BTUs per cm.sup.2), but it is possible to give a rough indication of the temperature of concentrated beams by calculating their intensities, which are herein defined as the quotient of the area of the incipient beam divided by the area of the concentrated beam. The following table shows the diameters, areas and intensities of concentrated beams produced by a three-stage reduction of an incipient beam with a diameter of 180 cm.
The concentrated beam produced by the 3rd stage would have an intensity of 6592.5. Obviously a beam of this intensity cannot be produced, even for a fraction of a second, without melting the lower lens of the 3rd stage.
The 2nd stage beam of intensity 351.6 can be produced, however. It can be used to smelt ores and melt rock, metals and other opaque substances. It can be used also to burn fuels which are noncombustible when exposed to ordinary heat. The 1st stage of the concentrator would be about six feet in diameter, the 2nd stage about sixteen inches, and the diameter of the emitted concentrated beam would be about four inches (9.6 cm).
The above calculations refer to incipient beams of full sunlight. It is possible to use hoods of darkened glass to reduce the intensities of the beams. Hoods will permit the use of the 3rd stage and also provide a means of controlling the intensities of emitted beams by allowing varying amounts of light to pass.