Solar heating and cooking apparatus

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Still another important object of the present inven

SOLAR HEATING AND COOKING APPARATUS tion is to provide a solar heating and cooking apparatus having a heating and cooking surface which is both

ORIGIN OF THE INVENTION readily accessible and convenient to use in cooking The invention described herein was made by employ 5 operations.

ees of the United States Government and may be man Still another important object of the present inven ufactured and used by or for the Government for gov tion is to provide an efficient solar heating and cooking ernmental purposes without the payment of any royal apparatus installed within a residential building struc ties thereon or therefor. ture wherein a radiation pipe may be installed through O an exterior wall of the building to deliver a concen

BACKGROUND OF THE INVENTION trated beam of solar radiation to the solar apparatus. Much attention has been given lately to the problems These and other objects and advantages of the pre and advantages in utilizing solar energy for various sent invention will become apparent upon reference to heating purposes. While the utilization of solar energy the following specification, attendant claims and draw for heating purposes appears to be attractive, providing 15 ings.

solar applicances which efficiently utilize solar energy BRIEF DESCRIPTION OF THE DRAWINGS is a problem to which considerable attention must be given. FIG. 1 is a top plan view of a building structure with a solar heating and cooking apparatus installed within

Heretofore, devices have been provided for utilizing 20 the solar energy to provide a source of heat for various interior thereof as constructed in accordance with solar applicances such as shown in U.S. Pat. No. the present invention, 1,081,098 and 3,391,688. However, these devices are FIG. 2 is a side elevational cut-way view illustrating a not very practical for ordinary cooking operations such solar heating and cooking apparatus constructed in as in the home. accordance with the present invention, 25 FIG. 3 is a side elevational cut-away view illustrating

SUMMARY OF THE INVENTION another embodiment of a solar heating and cooking A solar heating and cooking apparatus is provided apparatus invention, constructed in accordance with the present and comprising a housing and a heat transfer medium car FIG. 4 is a side elevational cut-away view illustrating ried within the housing for storing and transferring 30 another embodiment thermal energy. A cone member is carried by the hous apparatus constructedofin aaccordance solar heating and cooking with the present ing for receiving and absorbing solar thermal radiation. invention.

The cone member is tapered inwardly into the heat transfer medium and terminates in an apex portion DESCRIPTION OF A PREFERRED EMBODIMENT surrounded by the medium in heat exchange contact 35 The apparatus of the present invention relates to therewith. Lens means is provided for receiving and solar heating and cooking apparatus and, more particu focusing a concentrated beam of solar radiation rays larly, to a solar heating and cooking apparatus 10 upon the cone member. A heat conductive surface is which is installed stationarily within a residential build carried by the housing in heat exchange relationship with the heat transfer medium for heating and cooking. 40 ing structure 12. A light pipe 14 passes through an exterior wall 16 of the residential building 12. A solar

A control means is provided for regulating the heat energy collector 18 may be provided for collectig solar transferred to the heat conductive surface to control the temperature of the surface. Thus, solar energy re into a concentratedand rays from the sun for concentrating the solar rays ceived by the cone member is effectively transferred to is then delivered through ofbeam the solar radiation rays which radiation pipe 14 to the the heat conductive surface for heating and cooking. 45 solar heating and cooking apparatus Accordingly, an important object of the present in solar cooking and heating apparatus 1010.isAlthough the illustrated as vention is to provide apparatus for efficiently utilizing being installed in a residental dwelling, other applica solar energy in heating and cooking. tions are also contemplated.

Another important object of the present invention is The solar collector and concentrating apparatus 18 is to provide an efficient solar heating and cooking appa 50 preferably of the type disclosed in applicants' co-pend ratus for stationary installation within a residential ing U.S. Pat. application Ser. No. 653,872 filed on Jan. building structure for heating and cooking operations. 30, 1976 entitled APPARATUS FOR CONCEN Still another important object of the present inven TRATING SOLAR ENERGY. Such apparatus pro tion is to provide a solar heating and cooking apparatus vides a concentrated beam of solar radiation having a having a highly efficient solar radiation receiver for 55 fixed orientation while the collector apparatus adjusts absorbing solar radiation and for transferring the ab in position to compensate for changes in the sun's posi sorbed thermal energy to a heat transfer medium car tion.

ried within the apparatus. Referring now to FIG. 2 of the drawings, a solar Another important object of the present invention is heating and cooking apparatus, designated generally at to provide solar heating and cooking apparatus having 60 20, is shown in more detail. The apparatus includes a a lens system for accurately focusing a concentrated housing 22 constructed of a low heat conductive metal beam of solar energy to conform substantially to a such as steel and an inner metallic shell 24. This inner surface of a radiation receiver for efficient absorption shell 24 is formed from a suitable metal such as copper of solar radiation. or aluminum having a relatively high heat conductance. Another important object of the present invention is 65 A heat transfer medium 26 is carried within the inner to provide a solar heating and cooking apparatus shell 24 for storing and transferring thermal energy wherein the temperature of the heating and cooking therein. The heat transfer medium 26 may be liquids surfaces may be regulated to a desired temperature. having high boiling points, a eutectic material, or a

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fusible salt having a high melting point. A suitable high carried in focusing alignment with the concentrated boiling point liquid would be fish oil. It is to be under beam 50 and the cone member 38. stood, of course, that other suitable heat transfer media An optical iris 58 is carried adjacent the focusing lens may also be utilized. Insulating material 28 is placed in 48. The iris 58 is preferably manually adjustable so as the space between the outer housing shell 22 and the to adjust the amount of solar light rays impinging upon inner shell 24 to reduce the loss of heat from within the the focusing lens 48. The optical iris 58 is preferably a metallic shell 24 to outside of the housing. conventional type such as in a photographic apparatus An opening 30 is formed in an upper surface 32 of that may be manually adjusted.

the housing 22. A heating and cooking surface 34 An etched glass or metal plate 60 is provided at the formed integral with the inner metallic shell 24 and 10 junction of the radiation pipe 14 and the exterior wall having high heat conductivity extends through the 16 of the building structure in which the solar appara opening and is coextensive therewith. The heat con tus is installed. The plate 60 has an opening 62 formed ductive surface 34 provides a heating and cooking therein through which the concentrated beam 50 is surface having convenient access for cooking opera 5 allowed to pass for supplying thermal energy to the tions. An insulating ring 36 is fitted between the edge of solar apparatus 20.

the opening 30 and the side wall of the raised heating andIn order to regulate the temperature of the heating and cooking surface 34. The surface 34 is spaced above formed withinsurface cooking the 34, a cylinder chamber 64 is inner shell 24. A threadable stem the level of the heat transfer medium 26 in heat ex change relationship therewith. member 66 extends through the housing 22 and inner A radiation receiver is provided by a cone member 20 shellthe 24 and has an enlarged piston head 68 carried on end thereof. The stem 66 is threadably received in 38 carried integrally at one end of the inner shell 24. a threaded flange member 70 carried by inner shell 24. The cone member receives and absorbs thermal solar radiation coming from the outside solar collector 18. The piston head 68 is slideably received in the cylinder The cone member 38 is tapered inwardly into the inter 25 chamber 64 for varying the volume of the chamber 64. As the volume of the cylindrical chamber 64 is varied ior of the metal shell 24 and into the heat transfer the level 72 of the heat transfer medium within the medium 26 in heat exchage contact therewith. The inner cone member 38 terminates in an apex portion 40 of theshell 24 will change accordingly. As the level 72 which is surrounded by the heat transfer medium, as is ing surface 34,istheraised medium closer to the heating and cook temperature of the surface 34 will substantially the entire length of the cone member. A 30 be increased. Conversely, as the level 72 is lowered, the plurality of heat conductive fins 41 are carried in heat temperature of the heating and cooking surface 34 will exchange contact with the cone 38 and the heat trans be reduced. Thus, by varying the volume of the cylin fer medium 26. The fins 41 extend upwardly to adja drical chamber 64 the level of the heat transfer medium cent the bottom surface of the heated surface 34 aiding in the shell 24 will be varied relative to the heat con in the transfer of heat thereto.

The cone member 38, the heating and cooking sur ductive surface 34 to control the temperature thereof.

An expansion means is provided by bellows member face 34 and the inner metallic shell 24 may be con 74 carried by an interior surface of the inner shell 24. structed as a one-piece unit or the individual compo The bellows 74 extends into the interior of the shell 24 nents may be fastened together in an integral manner to accommodate the expansion and contraction of heat such as by welding and like. The structure so formed is 40 transfer medium 26 due to changes in the amount of preferably constructed of a high heat conductive metal heat being absorbed by the medium.

such as copper or aluminum. The inner shell 24 may be Referring now to FIG. 3, an alternate embodiment of mounted and secured within the housing 22 by any a solar heating and cooking apparatus is illustrated suitable means such as by L-shaped bracket members generally at 78. The apparatus is contained within a 42 and 44. The bracket members 42 and 44 may be 45 housing 80. A radiation receiver is provided by a plate fastened between the inner shell 24 and the outer hous member 82 which may be a smooth coated plate or a ing 22 in any suitable manner such as by welding. plate with irregular surface carried by the housing 80 to A plate of heat-proof glass 46 is carried by the increase the radiated area and absorption. The radia bracket members 42 and 44 adjacent the open end of tion receiver 82 may be mounted or secured to the the cone member 38 to prevent the heat absorbed 50 housing 80 in any suitable manner or may be made as within the cone member 38 from being lost from the one piece. A heating and cooking surface 84 is carried housing 22. Adjacent the glass plate 46 is a final focus by the housing member 80 extending across the plate ing lens 48 providing a lens means for receiving a con member 82 and the housing 80.

centrated beam 50 of solar radiation rays and focusing A heat transfer medium 86 is contained within an the beam upon the cone member 38. 55 inner shell defined by the housing 80, the plate member The lens 48 is preferably a condenser lens which 82, and the heating and cooking surface 84. A plurality condenses the light beam 50 into a cone-shaped beam of heat transfer rods 88 formed integral with the radia 52 for direct focusing upon the interior 54 of the cone tion receiving plate 82 extend into the heat transfer member 38. The shape of beam 52 conforms substan medium 86. As solar thermal radiation is received by tially to the interior receiving surface of the cone 38. 60 the plate member 82, the thermal energy is transferred Thus, the cone member will be heated to the highest to the heat transfer medium 86 by way of the heat temperature at the apex portion 40 extended into the transfer rods 88. Heat conductive fins 90 are provided heat transfer medium 26. The interior surface 54 may for aiding in the transfer of heat to the heating and be coated with a highly absorptive coating having a low cooking surface 84.

emissitivity factor. A suitable condenser lens means 48 65 A pair of insulating spacing members 92 and 94 con is a convex lens or a bi-convex lens. The lens 48 is nect the plate member 82 to upper and lower bracket carried by a pair of support members 56 which are members 96 and 98, respectively. The bracket mem carried integral with the housing 22. The lens 48 is bers 96 and 98 are provided by the housing 80 and may

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be secured thereto such as by welding. The upper and surfaces 84 and 120, respectively. It is to be under lower brackets 96 and 98 further provide support for a stood, however, that temperature control is to be pro plate 100 of heat-proof glass which prevents heat loss vided for the cooking surfaces in the same manner as outwardly from the corrugated plate member 82. disclosed and illustrated in the embodiment of FIG. 2. The brackets 96 and 98 also carry and support an Expansion means such as bellow member 74 shown in optical lens 102 for focusing the concentrated beam 50 FIG. 2 may also be provided in the heat transfer me of Solar radiation rays upon the radiation receiving dium reservoirs of FIGS. 3 and 4 to accommodate the plate 82. The optical lens 102 may be a conventional expansion and contraction of the heat transfer media. condenser lens such as shown at 48 of FIG. 2. The lens It is also noted in FIG. 2, that a window plate 142 102 condenses the concentrated beam 50 into a beam 10 may be provided between the solar apparatus 20 and of converging rays 104 which impinge on the plate 82. the building structure wall 16. The window allows ob The plate 82 reduces the need for accurate focusing servation of the correct location of the beam 50 passing of the beam 50 by the focusing lens 102 as is needed for through the plate 60 so that corrections can be made to the cone radiation receiving member 38 of FIG. 2. This tracking errors, tracking malfunctions, or other errors is so because in the embodiment of FIG. 2 the beam 50 5 in the concentrating of the beam 50 through the open must be focused and condensed in the form of a cone ing 62.

shaped beam 52 to hit upon the radiation receiver. Thus, an advantageous construction of a solar heat However, the use of a receiving member such as at 82 ing and cooking apparatus can be had in accordance provides a larger surface area over which the beam may with the present invention for utilization in a stationary be focused. The irregularities in the plate 82 increase 20 installation within residential building structures and the surface area and compensate if any of the rays of the like. A solar heating and cooking apparatus pro beam 104 do not come in at a right angle to the surface vides efficient use of solar energy to provide a conve 82. nient heating and cooking surface in the home such as The plate member 82, the heat transfer rods 88, and in the kitchen. The particular cone-shaped radiation the heat and conducting surface 84 may be made from 25 receiver 38 and the focusing of the concentrated solar any suitable metal having a high conductance such as radiation beam 50 upon the cone member provide aluminum or copper. maximum heat transfer to the heat transfer medium FIG. 4 illustrates another embodiment of a solar contained within the inner shell. heating and cooking apparatus, shown generally at 108, While a preferred embodiment of the invention has having a housing 110. A radiation receiver is provided 30 been described using specific terms, such description is by a plate member 112. Integral with the plate 112 are for illustrative purposes only, and it is to be understood a plurality of heat transfer concentric ribs 114 which extend upwardly into a space 115 in which a heat trans that changes and variations may be made without de parting from the spirit or scope of the following claims.

fermedium 116 is contained. The housing 110 further What is claimed is:

includes an inner shell 118 which provides an enclosure 35 1. A solar heating and cooking apparatus comprising: for containing the heat transfer medium 116 in con a. a housing;

junction with the boundary of the heat transfer concen b. a heat transfer medium carried within said housing tric ribs 114. The housing further includes a recessed for storing and transferring thermal energy; cooking surface defined by a bottom surface 120 and a pair of opposed side walls 122 and 124 extending up 40 ing andmember c. a cone carried by said housing for receiv absorbing solar thermal radiation; said wardly and integral with bottom surface 120. A cook cone member being tapered inwardly into said heat ing vessel 126 may be received in the recessed surface transfer medium and terminating in an apex por for cooking. The heat transfer concentric ribs 114 and tion surrounded by said medium in heat exchange the plate 112 may be made integral such as by welding contact therewith;

d. lens means for receiving and focusing a concen

A pair of lower bracket members 128 and 130 are trated beam of solar radiation rays upon said cone provided by the housing 10 for supporting a plate 32 of heat-proof glass which prevents loss of heat from the member;

radiation receiving plate 112. The lower brackets 128 e. a heat conductive surface carried by said housing and 130 further provide support for a focusing lens 134 50 fer in heat exchange relationship with said heat trans which focuses a concentrated beam 36 of solar radia medium for heating and cooking; tion rays onto the radiation receiving plate 112. The f. Control means for regulating said heat transferred lens 134 may be a conventional convex or fresnel lens. to said heat conductive surface to control the tem Since the surface of the radiation receiving plate 112 perature of said surface:

is at right angles to the concentrated beam 50 coming whereby solar energy received by said cone member from the solar collecting and concentrating apparatus is effectively transferred to said heat conductive 18, it is necessary to provide a re-directing mirror surface for heating and cooking. member 138. The mirror 138 reflects the beam SO 2. The apparatus set forth in claim 1 wherein said through approximately ninety degrees to provide the heat transfer medium is a liquid having a high boiling redirected beam 136 for striking the plate 112. 60 point.

As in the other embodiments, insulating material 140 heat 3. The apparatus set forth in claim wherein said may be provided in the space between the outer walls transfer medium is a fusible salt. of the housing 110 and the inner shell wall 118 for 4. The apparatus set forth in claim 1 wherein said reducing heat loss. As an alternative to conventional housing includes an inner metallic shell containing said heat transfer medium and wherein said cone member insulation, the space between the walls may be evacu 65 extends into said inner shell. ated and filled with reflective foil.

FIGS. 3 and 4 do not illustrate a control means for 5. The apparatus of claim 4 wherein said housing regulating the temperature of the heating and cooking includes an opening formed in an upper surface

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thereof, said heat conductive surface being carried by 11. The apparatus set forth in claim 10 wherein said said housing co-extensive with said opening. radiation receiver includes a cone member tapered 6. The apparatus set forth in claim 1 wherein said inwardly into said heat transfer medium terminating in lens means includes a condenser lens which condenses an apex portion surrounded by said medium. the concentrated beam into a cone-shaped beam of 5 12. The apparatus set forth in claim 10 wherein said solar rays for impingement upon said cone member. radiation receiver includes a plate member to compen 7. The apparatus set forth in claim 1 wherein said sate for radiation losses due to inaccuracies in focusing control means for regulating the temperature of said said2Sconcentrated beam upon said radiation receiving heat conductive surface comprises: 13. The apparatus set forth in claim 12 wherein said a. a cylinder chamber formed within said housing; 10 radiation receiver further includes a plurality of heat b. an adjustable piston member slideably received in transfer rods integral with said plate member extending said cylinder chamber for varying the volume of into and surrounded by said heat transfer medium. said chamber;

whereby varying the volume of said cylindrical cham 15 control means comprises:forth in claim 10 wherein said 14. The apparatus set ber changes the level of the heat transfer medium a. cylindrical chamber formed within said housing; in the housing to raise and lower the level of the b. an adjustable piston member slideably carried medium relative to the heat conductive surface to within said cylindrical chamber; and thereby control the temperature thereof. c. said adjustable piston member being slideably ad 8. The apparatus as set forth in claim 4 wherein said 20 justed in said cylindrical chamber so as to vary the inner shell includes a bellows member extending into volume thereof;

the interior thereof for accommodating the expansion whereby varying the volume of said cylindrical cham of said heat transfer medium due to the increase of heat ber adjusts the level of said heat transfer medium to being absorbed thereby. vary the distance between the level of the heat 9. The apparatus set forth in claim 1 wherein said 25 transfer medium and said heat conductive surface apparatus further comprises an adjustable optical iris so as to control the temperature of said heat con carried adjacent said lens means to adjust the amount ductive surface.

of solar rays received by said lens means. 15. The apparatus set forth in claim 11 wherein said 10. A solar heating and cooking apparatus compris cone member is heated to a higher temperature at said ing: apex portion.

a. a housing; 16. The apparatus set forth in claim 10 wherein said b. a heat transfer medium carried within said hous heat conductive surface is defined by a bottom surface 1ng, and a pair of spaced opposed sidewalls extending up c. a radiation receiver carried by said housing in heat 35 ceiving therefrom wardly a cooking providing a recessed surface for re vessel therein.

exchange contact with said heat transfer medium; 17. The apparatus set forth in claim 10 wherein said d. lens means for receiving and focusing a concen radiation receiver includes a plurality of integral heat trated beam of solar radiation rays upon said radia transfer concentric ribs extending into said heat trans tion receiver; fer medium.

e. a heat conductive surface carried by said housing 40 18. The apparatus set forth in claim 10 further com in heat exchange relationship with said heat trans prising an adjustable optical iris carried adjacent said fer medium for heating and cooking; and f. control means for regulating the temperature of lens means to adjust the amount of solar rays received by said lens means.

said heat conductive surface by regulating the dis 19. The apparatus set forth in claim 10 further com tance between the level of said heat transfer me 45 prising expansion means carried by said housing to dium and said heat conductive surface; accommodate the expansion of said heat transfer me whereby solar energy impinging on said radiation dium as it absorbs thermal energy from said radiation receiver is effectively utilized to heat said heating receiver.

and cooking surface. k k k