U.S. patent application number 14/521419 was filed with the patent office on 2015-02-12 for solar cooking apparatus and methods of use.
The applicant listed for this patent is Patrick Sherwin. Invention is credited to Patrick Sherwin.
Application Number | 20150044345 14/521419 |
Document ID | / |
Family ID | 47555949 |
Filed Date | 2015-02-12 |
United States Patent
Application |
20150044345 |
Kind Code |
A1 |
Sherwin; Patrick |
February 12, 2015 |
SOLAR COOKING APPARATUS AND METHODS OF USE
Abstract
The present invention relates to a solar cooking apparatus,
comprising: a first solar reflector; a second solar reflector; a
solar collection element; and a solar collection element holder,
wherein the first solar reflector and the second solar reflector
are concave and parabolic, and are in a substantially symmetrical
arrangement to a solar collection element axis, each reflector
focuses solar radiation at the solar collection element from a
reflective surface, which rapidly heat when the the solar
collection element. The solar cooking apparatus is adjustable and,
in some embodiments, portable.
Inventors: |
Sherwin; Patrick;
(Cincinnati, OH) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Sherwin; Patrick |
Cincinnati |
OH |
US |
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|
Family ID: |
47555949 |
Appl. No.: |
14/521419 |
Filed: |
October 22, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13555213 |
Jul 23, 2012 |
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14521419 |
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61510713 |
Jul 22, 2011 |
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Current U.S.
Class: |
426/523 ;
126/600; 126/681; 126/694 |
Current CPC
Class: |
Y02B 40/18 20130101;
F24S 70/00 20180501; Y02E 10/47 20130101; A23L 5/15 20160801; F24S
23/745 20180501; F24S 30/425 20180501; F24S 23/71 20180501; Y02E
10/40 20130101; F24S 20/30 20180501; F24S 50/20 20180501; F24S
80/00 20180501; A23V 2002/00 20130101 |
Class at
Publication: |
426/523 ;
126/600; 126/681; 126/694 |
International
Class: |
F24J 2/02 20060101
F24J002/02; F24J 2/46 20060101 F24J002/46; A23L 1/01 20060101
A23L001/01; F24J 2/12 20060101 F24J002/12 |
Claims
1. A solar cooking apparatus, comprising one or more solar ovens
arranged in a fixed and parallel manner within a solar cooking
apparatus frame, each oven having: a first solar reflector; a
second solar reflector; a solar collection element; and a solar
collection element holder, wherein the first solar reflector and
the second solar reflector are concave and parabolic, and are in a
substantially symmetrical arrangement to the solar collection
element axis.
2. The solar cooking apparatus of claim 1 having a stand, wherein
the a solar cooking apparatus frame can tilt from 0.degree. up to
90.degree. and rotate 360.degree. to place the one or more solar
ovens arranged in a fixed and parallel manner in a position to
optimally capture solar radiation.
3. The solar cooking apparatus of claim 1, comprising two or more
ovens arranged in a fixed and parallel manner within a solar
cooking apparatus frame.
4. The solar cooking apparatus of claim 1, comprising three or more
ovens arranged in a fixed and parallel manner within a solar
cooking apparatus frame.
5. The solar cooking apparatus of claim 1, comprising four or more
ovens arranged in a fixed and parallel manner within a solar
cooking apparatus frame.
6. The solar cooking apparatus of claim 1, wherein the solar
collection element is an evacuated tube-in-tube comprising: an
inner tube having an inner tube diameter, an inner tube length, an
inner tube open end, an inner tube closed end, an interior surface
enclosing an interior space, and an exterior surface, the interior
and exterior surfaces extending the inner tube length, wherein the
exterior surface comprises an anti-reflection layer, an absorbance
layer, and an infrared-reflection layer; and the outer tube having
an outer tube diameter, an outer tube length, an outer tube open
end, and an outer tube closed end, wherein the outer tube diameter
and the outer tube length are both greater than the inner tube
diameter and the inner tube length, wherein the inner tube is fixed
inside of the outer tube and sealed between the inner open end and
outer tube open end to form a hollow space extending the length of
the exterior tube under vacuum pressure between the exterior wall
of the inner tube and the outer tube.
7. The cooking apparatus of claim 6, wherein the solar collection
element is comprised of borosilicate glass or Vycor.RTM. glass.
8. The cooking apparatus of claim 6, wherein the solar collection
element is enclosable with a cap element that is attached at the
inner tube open end to withstand cooking pressure in the interior
space.
9. The solar cooking apparatus of claim 1, wherein the first solar
reflector and/or the second solar reflector are comprised of at
least one of anodized aluminum, stainless steel, chrome, mylar,
silver film, plastic film or metallic paint.
10. The solar cooking apparatus of claim 1, further comprising a
cooking implement that fits within the inner tube, having a length
less than_or equal to the inner tube length; and an attachable
cleaning implement to loosen or remove residual waste from a solar
cooking apparatus.
11. The solar cooking apparatus of claim 1, for use in a
substantially horizontal solar collection axis.
12. The solar cooking apparatus of claim 9, the cooking implement
comprising: a first implement end; a second implement end; an
implement length less than or equal in length to the inner tube
length; a trough having a length less than the cooking implement
length; and a diameter less than the inner tube diameter, wherein
the first implement end is closed and insertable into the inner
tube open end, the second implement end is fashioned with a
heat-resistant cooking implement handle.
13. The solar cooking apparatus of claim 12, wherein the cooking
implement is enclosable and watertight having a pressure
outlet.
14. The solar cooking apparatus of claim 12, wherein the cooking
implement has a concave cooking surface extending between the first
implement end and the second implement end, the concave cooking
surface being accessible when the cooking implement is outside of
the solar cooking apparatus.
15. The solar apparatus of claim 12, the concave cooking implement
having a concave cooking surface between 40% to 70% round.
16. A method of cooking with a solar cooking apparatus, comprising
the steps of: exposing one or more solar ovens to solar radiation
for heating the inner tube of the solar collection element to a
desirable temperature; placing/loading a cookable substance upon
the cooking surface a concave cooking implement; inserting the
cookable substance upon the cooking implement into the inner tube;
cooking the cookable substance for a predetermined amount of time;
and removing the cooking implement.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/555,213, which claims the benefit of U.S.
Provisional Patent Application No. 61/510,713, filed Jul. 22,
2011.
BACKGROUND
[0002] In the outdoors, many modern conveniences are left behind.
Backyard enthusiasts, tailgaters, and anybody in need of a portable
heating source must plan accordingly, bringing equipment as well as
a source of power or fuel. For example, conventional portable
cookers can be electric, gas, or charcoal powered. While each
variety is useful, electric grills require electric outlets, which
seriously hinder their portability. Portable gas grills typically
require compressed propane tanks, which come from a finite
resource, can pose a fire hazard and are usually disposable thereby
generating waste. Charcoal grills require charcoal briquettes,
which are dirty, bulky, and are difficult and dangerous to dispose
of after use. These grills are often bulky and take lengthy times
to preheat, as well as cool down after use. Some of these drawbacks
have been overcome by solar powered cookers.
[0003] Solar cookers are advantageous over conventional cookers
because they are fueled solely by sunlight, without the use of
traditional fuels. Moreover, solar cookers do not produce any
smoke. Therefore, they do not contribute health-damaging pollutants
or waste associated with cookers needing carbon-based fuels.
Nevertheless, known solar cookers fail to work as intended because
they need to be large, they are inefficient, and they are difficult
to operate. For these reasons, no solar cooker has succeeded in
achieving widespread use.
[0004] There are several recognizable solar cookers in the art.
While, under desirable conditions, they all are capable of
generating heat to cook, these cookers all have substantial
shortcomings. For example, concentrating cookers are
disadvantageous because they possess no means to minimize heat
loss; they are large and awkward to operate; they reflect light at
the operator and, therefore, require eye shielding to use; and they
are messy, as drippings fall freely onto the reflector.
[0005] Box cookers are insulated. However, they can only achieve
temperatures of about 300.degree. F. because most of the heat
escapes through a glass panel. These devices are typically bulky,
heavy, slow to cook, and fragile.
[0006] The solar panel cooker is another example of a large and
awkward apparatus. It is also disadvantageous because it takes a
long time to generate low heat levels. The panel cooker is a
variation of the above-mentioned concentrator. It follows that this
cooker is inefficient because, like the concentrating cooker, it
also lacks any means to store or trap heat energy.
[0007] There is a clear need to improve the concentration of solar
energy to increase the thermal energy available to cook. Also,
there is a need to retain that thermal energy by means of
insulation. A disadvantage of a conventional parabolic reflector,
such as the reflector described in U.S. Pat. No. 4,002,499, is that
the solar energy is concentrated in a very small area, too small to
be desirable for most cooking purposes. Moreover, the image area
moves too quickly across the cooking container, unless the parabola
is adjusted frequently. The present invention provides an
improvement over known solar cookers by utilizing a non-imaging
reflector that strikes a larger area relative to conventional
parabolic reflectors, thereby increasing solar energy capture, and
incorporating a non-tracking capability for ease of use. It remains
that there are no known solar cookers that have the portability of
conventional cookers and are able to generate sufficient heat to
accomplish heating tasks, such as cooking, roasting, searing,
baking, vaporizing, or frying, in a reasonable time. There is a
need for an improved efficient working portable solar cooker.
[0008] The present invention shows superior performance in a wide
range of heating applications such as: cooking, roasting, searing,
baking, sterilizing, boiling, dehydrating, steeping, vaporizing,
smoking, and frying.
SUMMARY
[0009] The following presents a simplified summary in order to
provide a basic understanding of some aspects described herein.
This summary is not an extensive overview of the claimed subject
matter. It is intended to neither identify key or critical elements
of the claimed subject matter nor delineate the scope thereof. Its
sole purpose is to present some concepts in a simplified form as a
prelude to the more detailed description that is presented
later.
[0010] The present invention is a practical and elegant design,
which may incorporate the qualities of durability, mobility, and
convenience into an apparatus that a consumer/user can easily
operate and understand. Using principles of radiant energy
reflection, absorption and insulation, the present invention
provides a platform for solid performance and incomparable results
within the solar cooking field.
[0011] The present invention is a solar cooking apparatus, one or
more solar ovens arranged in a fixed and parallel manner within a
solar cooking apparatus frame, each oven having at least a first
solar reflector; a second solar reflector; and a solar collection
element, wherein the first solar reflector and the second solar
reflector are concave, and symmetrically arranged for focusing
solar radiation at the solar collection element from a reflective
surface when the first and/or second solar reflectors. Some
arrangements of features described herein allow the solar cooking
apparatus to be adjustable relative to a horizontal plane (e.g. the
ground).
[0012] The present invention can work whenever the sun is shining.
Water can be heated and most foods can be prepared even on the
coldest winter day. The apparatus described herein permits quick
simple adjustment to maximize and focus solar collection. To this
end, the solar cooking apparatus may comprise a solar collection
element that can be a transparent evacuated vacuum tube, which has
a tube-in-tube design. The inner tube can have layers comprised of
aluminum-nitrile/stainless steel/copper coatings, which may be
applied by spraying, etc. The inner tube may then be connectably
sealed under vacuum inside a clear outer tube. The vacuum provides
insulation, which prevents heat from escaping or radiating from the
inner tube. Therefore, the trapped heat cannot travel from the
inner tube to the outer tube. Hence, even though the invention can
achieve an internal temperature of about 700.degree. F.
(371.degree. C.), under good lighting conditions, there is minimal
risk of being burned by touching the outer tube. Finally, the tube
can be shatter resistant. For example, the solar collection element
may be coated with a shatter resistant coating and/or fitted inside
a clear sheath for protection from external and internal forces
(e.g., from thermal expansion/contraction, dropping).
[0013] The present solar cooking apparatus invention may also be
used, comprising the steps exposing a solar oven to solar
radiation; positioning the apparatus on a tilt plane perpendicular
to direct sun rays; heating the inner tube of the solar collection
element to a desirable temperature; placing a cookable substance
upon the cooking surface of the cooking implement; inserting the
cookable substance upon the cooking implement into the inner tube;
cooking the cookable substance for a predetermined amount of time;
and removing the cooking implement. In one embodiment of the
present invention the user open a solar cooking apparatus for
heating, insert a cooking implement into the inner tube of an
opened and heating solar collection apparatus, which cradles the
food to be prepared by the solar cooking apparatus.
[0014] Other objects and advantages will become apparent from
reading the following detailed description of the invention in
which reference is made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 2 is a top view of a solar cooking apparatus in an
opened position;
[0016] FIG. 3A is a perspective view of a solar cooking apparatus
in a closed position, without a stand;
[0017] FIG. 3B is an end view of a solar cooking apparatus in an
opened position, without a stand;
[0018] FIG. 3C is an end view of a solar cooking apparatus in a
closed position, without a stand;
[0019] FIG. 4 is a side view of a solar cooking apparatus showing a
cooking implement, brackets, and legs;
[0020] FIG. 5A is a perspective view of a solar cooking apparatus
in an opened position showing it attached to a tripod stand;
[0021] FIG. 5B is a perspective view of a cooking implement along
with cleaning tool;
[0022] FIG. 6A is an end view of a solar cooking apparatus in an
opened position showing a horizontal stand with the sun's rays
coming from directly above
[0023] FIG. 6B is the solar cooking apparatus of 6A showing the
sun's rays at 45 degrees above the horizon, showing arrange of
motion relative to the vertical;
[0024] FIG. 7A is a side view of a solar cooking apparatus showing
a vertical stand showing the sun's rays from a more vertical
position
[0025] FIG. 7B is the solar cooking apparatus of 7A showing the
sun's rays from a lower angle showing a range of motion relative to
the horizontal;
[0026] FIG. 8A is a front end view of a solar cooking apparatus
showing a vertical stand and a base frame;
[0027] FIG. 8B is a bottom view of a solar cooking apparatus
showing a vertical stand and a base frame;
[0028] FIG. 9 is a perspective view of a solar cooking apparatus in
an open position on a horizontal plane, which also shows a stand
and partially loaded cooking implement;
[0029] FIG. 10A is a perspective view of a cooking implement;
[0030] FIG. 10B is an end view of a cooking implement;
[0031] FIG. 10C is a perspective view of a cleaning implement;
[0032] FIG. 10D is a perspective view of a mesh cooking
implement;
[0033] FIG. 11A is an end view of an opened solar cooking apparatus
on a stand in an open position;
[0034] FIG. 11B is an end view of a closed solar cooking apparatus
with the stand in a closed position;
[0035] FIG. 11C is a side view of a closed solar cooking apparatus
with the stand in a closed position;
[0036] FIG. 11D is a perspective view of a closed solar cooking
apparatus with the stand in a closed position;
[0037] FIG. 12A is a perspective view of a skewer cooking
implement;
[0038] FIG. 12B is a side view of a French Press plunger;
[0039] FIG. 12C is a perspective view of a wire mesh cooking
implement;
[0040] FIG. 12D is an end view of a vaporizer;
[0041] FIG. 12E is a side view of a vaporizer;
[0042] FIG. 12 F is a side view of a temperature gauge;
[0043] FIG. 12G is a side view of a closed cylinder implement;
[0044] FIG. 12H is a side view of a grease collection cup;
[0045] FIG. 12I is a side view of a liquid tight cap;
[0046] FIG. 12J is a side view of a bent rod cooking implement;
[0047] FIG. 13A is an end view of a solar cooking apparatus in a
multiplex arrangement in a closed position with a plurality of
solar collection elements;
[0048] FIG. 13B is an end view of a solar cooking apparatus in a
multiplex arrangement in a closed position;
[0049] FIG. 14A is an end view of a solar cooking apparatus in a
multiplex arrangement in an open position with two solar collection
elements stacked among a set of two reflectors;
[0050] FIG. 14B is an end view of a solar cooking apparatus in a
multiplex arrangement in an open position with two solar collection
elements;
[0051] FIG. 15B is an end view of a solar cooking apparatus in a
multiplex arrangement in an open position with three solar
collection elements;
[0052] FIG. 15B is an end view of a solar cooking apparatus in a
multiplex arrangement in an open position with three solar
collection elements;
[0053] FIG. 16 is a perspective view of a solar cooking apparatus
in a multiplex arrangement.
WRITTEN DESCRIPTION
[0054] For purposes of the description hereinafter, spatial
orientation terms, if used, shall relate to the referenced
embodiment as it is oriented in the accompanying figures, or as
otherwise described in the following detailed description. However,
it is to be understood that the embodiments described hereinafter
may assume many alternative variations and embodiments. It is also
to be understood that the specific devices illustrated in the
accompanying drawing figures and described herein are simply
exemplary and should not be considered as limiting.
[0055] The following terminology is used herein to describe the
relationship between the orientation of the solar cooking apparatus
relative to the sun's rays. The sun's height above the horizon is
called altitude. The solar cooking apparatus collect maximum solar
energy when the sun's rays shine perpendicular (90.degree.) to the
open reflector plane. In order to create this perpendicular
relationship, the user will adjust the tilt angle of the cooker.
For example, if the sun is directly overhead (90.degree. above the
horizon) the solar cooker would be placed parallel to the earth's
plane or horizontal plane and thus have a 0.degree. tilt angle.
[0056] As used herein, "cooking" is construed as any heat driven
application, which includes processes such as sterilization,
vaporization, warming, heating, boiling, baking, pressure cooking,
frying, steeping, dehydration, roasting, smoking, etc.
[0057] In addition to tilt angle (relating to the height of the sun
in the sky), the solar cooker will have to be optimally adjusted
for azimuth which relates to the sun's apparent location east and
west of true south (in the Northern Hemisphere). On the solar
equinox, this azimuth angle changes over a 12 hour period, from
90.degree. east of true south when the rises, to 90.degree. west of
true south when the sun sets.
[0058] Azimuth adjustments to the solar cooker can be performed via
rotational movements whereby the user may physically move or shift
the entire apparatus as it rotates towards the sun's hourly degree.
Tilt angle adjustments to the solar cooker can be done in one of
two ways presently available. These two methods are differentiated
along a horizontal solar collection element axis and a vertical
solar collection element axis. Each method will be described
further below along with a more specific description of the
mechanics.
[0059] Beginning with FIGS. 2 and 3A-C, the solar cooking apparatus
200 may comprise a first solar reflector 202, a second solar
reflector 204, each solar reflector having a reflective surface
203, and a solar collection element 206. The solar collection
element 206 may comprise an inner tube 208, and outer tube 210, an
open end 212, and closed end 214.
[0060] Each of the first solar reflector 202 and second solar
reflector 204 may have parabolic reflective surfaces 203, which are
capable of focusing solar radiation. It is preferred that the
reflective surfaces 203 be smooth, without irregularities and micro
hills and valleys that cause deviations in reflected light. The
concentration ratio of standard solar flux (defined at 1,000
W/m.sup.2 at Standard Test Conditions) reflected onto the absorber
(e.g., solar collection element 206) is best within a range of 2-6
times. Thus, the absorber is struck by 2-6 times more solar
radiation than it would receive without the reflectors.
[0061] The reflectors (e.g. 202 and 204) used in the solar cooking
apparatus have the advantage of not having to be adjusted so often
for following the sun. The target (or solar collection element 206)
may have a rounded surface to intercept the focused radiation from
the outer rim of the reflector as well as from the bottom.
[0062] The reflectors herein may be short-focus parabolic
reflectors. Since the parabolic reflector does not have a set
radius, it must be discussed in general sizing terms in
relationship to the diameter of an absorber (e.g. the absorptive
layer of an outer layer of an inner tube of a solar collection
element, as described below). For example, if a solar collection
element (e.g., solar collection element 206) has a diameter of two
inches and solar reflectors (e.g., first solar reflector 202 and
second solar reflector 204) that are six inches in width, then
there is solar concentration ratio of about three fold.
[0063] The collector area or focus point is best in a range of
15-50% of the reflector's area. The collector (or solar cooking
apparatus) is best with an absorptivity greater than 70%. The
current model has an absorptivity above 90%. The re-radiation area
is generally the same as the collector area and the emissivity is
very close to zero. This low emissivity is due largely to the
anti-reflective copper layer on the outside of the inner tube
208.
[0064] In one embodiment, first solar reflector 202 and second
solar reflector 204 are each parabolic reflectors that are
symmetrically arranged about the solar collection element 206. The
parabolic reflectors each have a reflective surface 203 formed by
any reflective material (e.g., anodized aluminum) or any other
material capable of being formed into a parabolic shape and coated
with a reflective layer. Representative reflective materials may
include polished aluminum, stainless steel, chrome, mylar, silvered
film, aluminized plastic film, metallic paint, etc.
[0065] Each of the first solar reflector 202 and second solar
reflector 204 may be a parabolic reflector that may each be open at
the axial ends. The parabolic reflectors may each have an elongated
source/sink that extends along the axis of the reflecting surface
203 and may each be adjustable through a geometric surface
generated by rotating a parabola axes, relative to the solar
collection element 206. The solar reflectors each can articulate
along 90.degree. of angular rotation. The first solar reflector 202
and second solar reflector 204 may be rotated about a solar
collection element axis S into an opened position, a closed
position or someplace between the opened and closed positions. For
instance, the solar reflector may be adjustable on a plane
perpendicular to the solar collection element axis, and focusing
radiation upon the solar collection element when the first and/or
second solar reflectors are in an opened position, the first and
second solar reflectors protectably encase the solar collector when
in a closed position. These combinations of features have certain
advantages over other solar cookers. For example, U.S. Pat. No.
5,676,128 shows dual reflectors and a solar collection element,
which teaches the need for additional protective features for the
solar collection element and concave solar reflectors, which are
incapable of focusing the amount of energy required to sufficiently
perform the applications of the present invention.
[0066] The solar collection element 206 may be an evacuated tube
having a predetermined diameter in accordance with the desired
cooking application (e.g. a small diameter solar collection element
may be desirable for sterilization of instruments or for cooking
small foods, while a large diameter solar collection element may be
desirable for baking/roasting a small whole chicken). For example,
the solar collection element may be a twin-glass tube, which
consists of two glass tubes made from strong borosilicate glass.
The outer tube 210 is transparent allowing light rays to pass
through with minimal reflection. The exterior of the inner tube 208
forms an absorptive layer coated with a special selective coating
(e.g., aluminum-nitrile/aluminum, aluminum-nitrile/stainless
steel/copper coatings, borosilicate/aluminum/stainless
steel/copper) which may comprise two or more layers, and features
excellent solar radiation absorption and minimal reflection
properties. The top of the two tubes are fused together and the air
contained in the space between the two layers of glass is pumped
out while exposing the tube to high temperatures. This "evacuation"
of the gases forms a vacuum, which is an important factor in the
performance of the evacuated tubes due to insulating properties.
This arrangement of features permits the internal temperature of
the inner tube 208 to achieve temperatures in excess of 400.degree.
F. (and in excess of about 700.degree. F. under optimal solar
conditions) while the outer tube 210 of the solar collection
element 206 remains safe and cool to the touch.
[0067] In order to maintain the vacuum between the two glass
layers, a barium getter is used. During manufacturing of the
evacuated tube this getter is exposed to high temperatures which
cause the bottom of the evacuated tube to be coated with a pure
layer of barium. This barium layer actively absorbs any CO,
CO.sub.2, N.sub.2, O.sub.2, H.sub.2O, and H.sub.2 out-gassed from
the evacuated tube during storage and operation, thus helping to
maintaining the vacuum. The barium layer also provides a clear
visual indicator of the vacuum status. The silver colored barium
layer will turn white if the vacuum is ever lost. This makes it
easy to determine whether or not a tube is in good condition.
[0068] The solar collection apparatus may also have a
shatter-resistant feature that essentially encases the outer tube
210. This feature not only protects the glass tube from exterior
shocks, it also protects the user in the unlikely event that the
evacuated tube is broken (from impact or thermal shock).
Representative embodiments of the shatter-resistant feature include
a polymeric spray-on coating, tempered glass, an adhesive film,
shrink coating, and/or a protective sleeve (plastic or glass),
which the solar collecting element can be fitted into.
[0069] The solar collection apparatus may also have thermal shock
resistance. For example, solar collection element 206 may comprise
Vycor.RTM. glass (Corning, Inc.).
[0070] In FIGS. 4 and 5A-B, a solar cooking apparatus may have any
of a hinge 402, a bracket 404, a cooking implement 406, a cooking
implement handle 408, a tripod stand 502, a solar cooking apparatus
handle 1106, and a tripod stand fastener 504.
[0071] A hinge 402 may be one or more of any type of bearing that
connects each of or both of the first solar reflector 202 and
second solar reflector 204 to the solar cooking apparatus 400 or
500 (e.g., at a bracket or base frame, discussed below). The hinge
402 has a range of motion that accommodates moving each of the
first solar reflector 202 and second solar reflector 204 between
closed and open positions. Hinges may be made of flexible material
or of rigid moving components. A hinge may first attach to each of
or both of the first solar reflector 202 and second solar reflector
204 in an optimal optic relationship to the solar collection device
206. The hinges permit movement of the solar reflectors for
portability, protection and adjustments in solar energy capture
intensity. In some cases, the reflectors may not be attached to a
hinge but instead place in a cradle or frame to create the
necessary optics for optimal performance.
[0072] In one embodiment, the hinge 402 may be at least one
continuous hinge (e.g., a piano hinge), wherein the hinge 402
attaches the solar reflectors to the solar cooking apparatus 400 at
at least one bracket 404. The bracket 404 provides attachable
support for each of a solar collection element 206 and hinge
402.
[0073] The cooking implement 406 can be a concave cooking implement
having a concave cooking surface between 40% to 70% round.
[0074] In another embodiment, the solar cooking apparatus 500 may
have a tripod stand 502, a cooking implement 406 and/or a cleaning
tool 508. The cleaning tool 508 may have any shape capable of
fitting within the inner tube 208 of the solar collection element
206, made from any material capable of cleaning baked on waste
(e.g. food, grease or carbon buildup) within the inner tube 208.
Suitable materials for cleaning tool 508 may include a knit copper
mesh, steel wool, or nylon bristle brush.
[0075] The tripod stand 502 may have telescopic legs, each of which
is adjustable to a length to achieve desired orientation of the
solar cooking apparatus 500 relative to position of the sun. The
legs can each be adjusted to varied lengths that accommodate said
orientation, even when the solar cooking apparatus 500 is set upon
an uneven surface. When the solar cooking apparatus is ready to be
stored, the tripod stand may be collapsed, detached from connection
point 504, and stowed independently.
[0076] The stands of the invention (e.g., aforementioned stand 502
and other described herein, 410) provide for both portability and
stability of a solar cooking apparatus. However, it should be
appreciated that the solar cooking apparatus may be alternatively
fixed to any number of holding devices (e.g., stands) that are not
required to be portable. In another embodiment of the invention,
the solar cooking apparatus may be fixed to a yard post or
pedestal. In yet another embodiment of the invention, the solar
cooking apparatus may be fixed to a swing arm attached to a boat or
recreational vehicle.
[0077] In FIG. 6A and FIG. 6B, a solar cooking apparatus may have a
formed stand 602 that is rotatable about an apparatus axis to
position the apparatus about perpendicular to the sun's rays at a
vertical angle .theta..sub.H. With a horizontal solar collection
axis H, the solar cooking apparatus is adjusted through minor
movements in the rotatable stand to achieve the proper horizontal
tilt angle (.theta..sub.H) for orientation to be roughly
perpendicular to the sun's rays. In this embodiment, the hinge 402
attaches the solar reflectors to the solar cooking apparatus via a
bracket 404.
[0078] Turning to FIGS. 7A-B and 8A-BB, a solar cooking apparatus
700 or 800, respectively, may have a tiltable stand. In one
embodiment, the tiltable stand comprises at least one leg 704, at
least one leg foot 705, and a base foot 706. The solar cooking
apparatus 700 and solar cooking apparatus 800 are each tiltable
relative to a vertical solar collection element axis V. The legs
704 can each be adjusted to varied lengths that accommodate a tilt
angle from 0 to 90.degree. (the horizon is 0.degree.). The legs can
stabilize the solar cooking apparatus even when set upon an uneven
surface. When the solar cooking apparatus is ready to be stored,
the stand may be collapsed and stowed.
[0079] The embodiment with a vertical solar collection element axis
allows for the application of heating liquids. When heating
liquids, it is more efficient to utilize a pressure seal or tight
fitting cap 804 made of a relatively heat resistant material such
as metal, PVC, bakelite, silicone, etc. The cap could be screwed in
place over the solar collection element opening 212 or applied with
a light force via slip seal. The cap 804 may have a pressure
release valve 806 that allows hot gas or expanding fluids to escape
as the temperature inside the solar collection element increases. A
low pressure relief range between about 3-15 psi allows proper heat
accumulation in the fuels while preventing potentially damaging
levels of pressure inside the solar collection element.
[0080] In another embodiment, the tiltable stand may be a sliding
stand, wherein the stand has at least one telescopic leg (e.g., leg
704) and/or is pivotably attached at the end opposing the at least
one leg foot (e.g., foot X) to a track upon a base frame (e.g, base
frame 802). The stand may be slid along the track and fixed to the
stand by a first locking mechanism, in a position on the track.
Subsequently, the stand may be pivoted to alter vertical tilt angle
.theta..sub.V (See, e.g., FIG. 7) and fixed by a second locking
mechanism, at a user defined angle, relative to a stand foot (e.g.,
stand foot 706). The user defined angle (e.g., .theta..sub.V) may
altered further by changing the telescopy of the at least one
telescopic leg.
[0081] As shown in FIG. 9, a solar cooking apparatus may be opened
and deployed on a horizontal surface 902 (e.g. table, ground,
pavement, etc.) by utilizing legs 410. In this example, the cooking
implement 406 has been loaded with sausage 901 and partially
inserted inside the solar collection element 206 via the open end
212.
[0082] In FIGS. 10A-D, a solar cooking apparatus may be used with a
trough cooking implement 1000. In one embodiment, the trough
cooking implement 1000 comprises: a first implement end 1002; a
second implement end 1004; a trough 1006; an implement length at
least equal in length to the inner tube length; and a diameter less
than the inner tube 208 diameter, wherein the first implement end
1002 is closed and insertable into the inner tube 208 open end 212
of solar collection element 206, the second implement end 1004 can
be fashioned with a heat-resistant cooking implement handle 1008.
In one embodiment the cleaning implement 508 is attached to the
first implement end 1002 by any means of suitable connection 1014
to create secure, retrievable bond between the cleaning implement
and the cooking implement 1000.
[0083] In FIGS. 11A-D, a solar cooking apparatus is shown to be
open FIG. 11A and then fixed into a closed position FIG. 11B for
protection of the solar collection element 206 and/or transport.
FIG. 11C shows the closed solar cooking apparatus along with
integrated handle 1106 for easy carrying of the closed unit. In
this embodiment bracket 404 serves as a hinge wherein the legs 410
are pivotable to become handle 1106 when in the closed
position.
[0084] The solar cooking apparatus may be used with a cooking
implement such as a skewer cooking implement 1202 or 1206 (as shown
in FIGS. 12A and 12J) or a trough cooking implement 1000 (As shown
in FIG. 10). The cooking implement is fashioned to fit within the
inner tube 208 of the solar collection element 206. The cooking
implement may also be enclosable with a cap 804 which may
additionally be fashioned with a pressure release outlet.
[0085] FIGS. 12A-J represent a number of cooking implements and/or
accessories that could be used with the solar collection element
described above.
[0086] The cooking implement can take on many forms in order to
achieve the desired application. In one embodiment the cooking
element receives a cleaning scrubber which may be inserted into the
solar cooking apparatus. The scrubber may or may not be abrasive
(e.g., cleaning tool 508) and may be used along with up to several
ounces of water and a detergent after use. In another embodiment,
the cooking implement (e.g., trough cooking implement 1000) may
have a grease collection feature. When used in a vertical solar
cooking apparatus 700 a grease collection feature 1214 can be at an
end terminal to gravity flow such as the closed end of the solar
collection element 214. In this embodiment, the grease collection
cup 1214 is equipped with a heat resistant tie that would extend
outside the solar collection element 206 so it is easily deployable
and retrievable from the bottom of the solar collection element.
When used in a horizontal solar cooking apparatus 400 the grease
collection feature 1010 can be formed to fit within the open trough
of the cooking implement 1000. The grease collection feature may
perform a sieve-like function to compartmentalize and thereby
eliminate grease spillage into the solar collection element (e.g.,
solar collection element 206). The grease collection feature
promotes low-fat cooking by allowing cooked-out grease to flow away
from a food while cooking in a cooking implement inserted into a
solar collection element of an open solar cooking apparatus.
[0087] The grease collection features 1214 and 1010 explained above
may have additional functions, such as holding a special material
or fluid for various cooking applications. For example, wood chips
can be cooked in grease collection features 1214 or 1010 to add a
smoked flavor to foods inside a cooking implement (e.g. cooking
implement 1000).
[0088] In other embodiments, some of which are exemplified in FIGS.
12A-H, a cooking implement may also include: a French Press plunger
1204 for sifting loose tea or coffee, a bent shaft for stirring
1206, a temperature gauge 1208 clipped to the outside of the solar
cooking apparatus with a probe 1210 within the inner tube 208, a
bottle brush for cleaning, a vaporizer for creating aromatic gases
1212 with an inlet 1216 for incoming air and an outlet 1214 to
release the vapor infused heated air, a distillation device for
making spirits, a liquid tight cap 804 with vent 806, parchment
paper for baking with easy cleanup, a wire mesh tray 1226 for
cradling larger foods (e.g. whole chicken, bread loaf) sauce trays,
a closed cylinder 1220 with liquid tight cap 1222 and vent 1224,
and skewer rod 1202.
[0089] FIGS. 13A-B show embodiments of multiplex units wherein
several solar collection elements are connected to form one
multiplex cooking apparatus, several cooking apparatuses (e.g. a
multiplex cooking apparatus) may be attached together in a parallel
arrangement to form an apparatus having greater than one solar
collection element (e.g., solar collection element 206) and both of
a first solar reflector 202 and second solar reflector 204 per
solar collection element. Such multiplex embodiments are attachable
to a stand in either a substantially vertical or horizontal
orientation to the horizon (not shown). In FIG. 13A, solar
collection elements are each protected by two reflectors 202 and
204 which are connected to another set of reflectors by a hinge or
latch 1302.
[0090] FIGS. 14A-B show embodiments of multiplex units wherein, two
cooking apparatuses are arranged in tandem and are attached
together (not showing features such as a stand). FIG. 14A shows
solar collection elements in closed positions where each solar
collection element 206 is protected by two reflectors 202 and 204
which are connected to another set of reflectors by a hinge or
latch 1302.
[0091] FIG. 16 shows an embodiment of a multiplex unit wherein a
cooking apparatus 1600 is comprised of one or more solar ovens,
wherein each oven requires at least two reflectors 202 and 204 and
a solar collection element 206. The ovens are arranged as repeating
units in a fixed and parallel manner within a solar cooking
apparatus frame 1602, each oven having: a first solar reflector
202; a second solar reflector 204; a solar collection element 206;
and a solar collection element holder, wherein the first solar
reflector 202 and the second solar reflector 204 are concave and
parabolic, and are in a substantially symmetrical arrangement to
the solar collection element axis. The solar cooking apparatus 1600
is intended for use on a substantially horizontal solar collection
axis, as described in previous embodiments. The solar cooking
apparatus frame 1602 can be optimally adjusted on a stand 1604 to
rotate 360.degree. and tilt from 0.degree. to 90.degree. (the
horizon is 0.degree.) to capture solar radiation. In some
embodiments, the tilt angle will be 85.degree., and in other
embodiments the tilt angle will be 80.degree., 75.degree.,
70.degree., 65.degree., 60.degree., 55.degree., 50.degree.,
45.degree., or less. The solar cooking apparatus 1600 can be used
with a cooking implement (e.g., cooking implement 406), which
cradles the food to be prepared by the solar cooking apparatus,
into the open end 212 of a solar collection element 206.
[0092] While several embodiments of a solar cooking apparatus were
described in the foregoing detailed description, those skilled in
the art may make modifications and alterations to these embodiments
without departing from the scope and spirit of the invention.
Accordingly, the foregoing description is intended to be
illustrative rather than restrictive. The invention described
hereinabove is defined by the appended claims and all changes to
the invention that fall within the meaning and the range of
equivalency of the claim are embraced within their scope.
EXAMPLES
Example 1
[0093] The solar cooking apparatus in this example is tubular with
24'' in length (61 cm), 13/4'' (45 mm) inside diameter, 21/4'' (57
mm) outer diameter surrounded by an anodized aluminum reflecting
surface running the length of the tube which folds out to 8'' in
width. The 13/4'' internal diameter is large enough to accommodate
various meats, vegetables, and frozen finger-style foods while
remaining highly portable. The entire apparatus has a dry weight of
about three pounds (1.4 kg). It is capable of heating as much as 30
ounces (@ one liter) of fluid. Most fluids reach near boiling
temperatures. About 4-8 ounces of fluids can be elevated to about
170.degree. F. (77.degree. C.) in a short time, depending on
irradiance conditions (described in greater detail below).
Example 2
[0094] The example described below was conducted at GPS coordinates
35.degree. 34'48''N 82.degree. 33'21''W. The weather conditions
were as follows: Relative Humidity 63%, Winds 1.2 MPH from
variable, scattered clouds 4600 ft, Heat index 91.degree. F., dew
point 71.degree. F., UV 9 out of 16, Rainfall 0.00 in, visibility
10.0 miles.
[0095] A Flux 62 MINI IR Thermometer--Infrared, point-and-shoot
style thermometer was used to measure the internal temperature of a
solar collection element.
[0096] A DayStar Solar Irradiance Meter was used to measure
sunlight intensity/quality by using a solar PV cell and algorithm,
output given in Watts per Square Meter only, Standard Test
Conditions for Solar PV is set at full sun of 1,000 w/m.sup.2. The
irradiance meter was pointed in the direction of the sunlight.
[0097] At 9:37 AM the outside air temperature and temperature
within the solar collection element were measured at 77.degree. F.
The solar cooking apparatus was removed from its carrying case, and
unfolded into an open position. Subsequently, the solar cooking
apparatus was oriented by tilting the solar cooking apparatus
toward the rising sun in the east. The solar cooking apparatus was
locked into position at a horizontal tilt angle of about 45.degree.
from vertical.
[0098] At 9:43 AM the internal temperature of the solar collection
element was measured to be 194.degree. F. As the solar cooking
apparatus heated, the internal temperature of the solar collection
element was measured to be continued to increase as shown in Table
1 below:
TABLE-US-00001 TABLE 1 Time Temperature Irradiance 9:37 AM
77.degree. F. 850 w/m.sup.2 9:43 AM 194.degree. F. 9:45 AM
225.degree. F. 900 w/m.sup.2 9:47 AM 268.degree. F. 9:49 AM
304.degree. F. 9:52 AM 363.degree. F. 950 w/m.sup.2
[0099] Once the internal temperature of the solar collection
element achieved an internal temperature of about 400.degree. F.,
food (e.g., hot dogs) was placed into a trough style cooking
implement. In this example, four scrambled eggs, chopped onions and
some shredded cheese were placed in the cooking trough. The
combination of ingredients were fully cooked at 30 minutes, having
delicious taste and firm texture.
[0100] After use, the cooking implement was placed into a sink and
rinsed with water. A copper scrubber, which was formed for cleaning
the trough, was used to scrub the trough clean in less than about
one minute.
[0101] The cooker was permitted to cool down for about 5 minutes
before applying the cooking implement, with a copper scrubber
attached to the insertable end, into the solar collection element
for cleaning (The cooking element combined with the scrubber may be
used as a cleaning tool). A few drops of dish soap were applied to
the copper scrubber and a plunge/twist motion was conducted between
implement and cooker for about one minute. Next some lukewarm water
was added into the solar collection element. After about 30 seconds
more the tube was tipped out into the sink while about five ounces
of dirty, brown fluid poured out. The user then rinsed the tube
with clean luke warm water and began a slight shake to tip the
water back and forth in the tube. This water was poured into the
sink and found to be clear. One last rinse and then the cooking
device and implement were independently placed on a table outside,
in a closed position, to dry for repacking into the carrying
case.
* * * * *