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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a self-heating container capable of
heating liquid food such as Japanese sake, liquor, coffee or milk, water,
oil or the like contained therein.
2. Description of the Prior Art
There has been well known in the art a method for heating or warming liquid
contained in a container by using a heating element or exothermic
material. In general, food or the like is heated by utilizing hydration of
calcium oxide (burnt lime), oxidation or burning or combustion of metal
powder.
For instance, Japanese Utility Model Application Laid-Open Nos. 60-70235
and 60-94130 disclose a method in which a chamber for receiving therein
exothermic material is defined within a container. Calcium oxide and a
water bag are provided in the chamber. When the water bag is broken, an
exothermic reaction is started to heat the content in the container. In
this method, however, a ratio of a volume of the exothermic material
storage chamber to a volume of a content storage space of the container is
high, so that its thermal efficiency is not satisfactory. When it is
desired to heat the content in the container sufficiently, there arise
problems that a large-sized container is required and that a space not
filled with the content is likely to be heated. More particularly, when
liquid food or the like is charged into the container and then the
container is sealed, a space not filled with liquid is generally left.
Therefore, depending upon an attitude of the container, such a space is
heated by the activated exothermic material, so that the pressure in the
container rises to result in explosion thereof.
The same problems arise also in the case of a self-heating container of the
type disclosed in European Patent Application Laid-open No. 0180375. In
this container, a portion for storing calcium oxide and a water bag is
defined around the outer wall of a container to be heated, so that its
thermal efficiency is further degraded. Furthermore, there is a danger of
burn when the outer wall of the exothermic material storage portion is not
sufficiently thermally insulated.
In the above-described inventions, calcium oxide (burnt lime) is used as
exothermic material, so that there arise problems that it takes a long
time to heat the content to a desired temperature and that after heating
the content, calcium oxide expands, resulting in deformation of the
container.
U.S. Pat. No. 4,506,654 for Zellweger et al. discloses a heating device in
which a container is heated by a combustible exothermic material flatly
mounted on the bottom of the container. Japanese Utility Model Application
Laid-Open No. 57-55772 discloses a self-heating container of the type in
which exothermic material which undergoes an exothermic reaction in the
case of its oxidation with oxygen in the air is stored in a concave recess
at the bottom.
The self-heating containers of the types described above, however, have a
common defect that a space in the container not filled with liquid is
overheated when the container is turned upside-down or inclined
horizontally or diagonally. In addition, the thermal efficiency is also
low, because a part of high temperature heat is dissipated in the
direction opposite to the content.
Furthermore, Japanese Patent Application Laid-Open No. 56-64971 discloses a
container which is heated when water is added to exothermic material
consisting of ammonium persulfate and manganese powder. Such a container,
however, requires a large volume of an exothermic material storage
portion, and accordingly the same problems as those in case of calcium
oxide (burnt lime) are encountered.
Moreover, Japanese Patent Application Publication No. 27-582 or Japanese
Utility Model Application Publication No. 58-24119 discloses a heating
device in which exothermic material mainly consisting of trilead
tetraoxide and ferrosilicon is filled in a metal cylinder. However, a heat
output per unit of weight of such exothermic material is relatively low
and furthermore there is the possibility that toxic compounds such as lead
monoxide result after the combustible reaction, so that from a view point
of safety, such exothermic material is not preferably used when heating
food.
As described above, in a heating device utilizing exothermic material, the
selection of a suitable exothermic material and a design of a container to
be heated by the exothermic material are very closely related to each
other and therefore most of the conventional heating devices have some
defects.
SUMMARY OF THE INVENTION
In view of the above, it is a primary object of the present invention to
provide a self-heating container in which heat generated by exothermic
material when ignited can be efficiently transferred to a content in the
container and which can prevent undesired temperature rise of the outside
wall of the container so that the container can be used without a fear of
burn.
It is another object of the present invention to provide a self-heating
container which can substantially avoid the heating of a space not filled
with a content in the container regardless of an attitude thereof so that
there is no danger of explosion of the container and therefore the
container can be handled safely.
It is a further object of the present invention to provide a self-heating
container in which an exothermic material storage space is made small in
volume in relation to the container containing liquid or the like to be
heated, so that the content storage space efficiency is improved and
therefore the self-heating container can be made compact in size.
It is a still further object of the present invention to provide an
improved exothermic composition whose aging can be substantially avoided;
which can heat a content in a container within a short time; and which
will not produce toxic compounds after the combustible reaction, so that
the exothermic composition is very satisfactory for heating food and drink
from the standpoint of sanitation.
To the above and other ends, the present invention provides a self-heating
container comprising a container containing a content to be heated; a
chamber projecting inwardly in the container for storing therein an
exothermic material; the exothermic material placed at the innermost
portion of the exothermic material storage chamber; a heat insulating
layer disposed adjacent to the exothermic material; and ignition means
having a leading end extended through the heat insulating layer and
connected to the exothermic material for igniting the exothermic material.
An exothermic material used in the present invention consists of a
self-combustible exothermic composition and can produce an exothermal
reaction even in a closed space without using oxygen contained in the air
when ignited by suitable ignition means. More particularly, a
self-combustible exothermic material in the present invention consists
essentially of an oxidant or oxidizing agent and a combustible compound in
the form of a mixture, so that the heat output per unit volume of the
exothermic material is high and the exothermic material storage space is
made small in volume in relation to the container containing a content to
be heated.
The exothermic material storage chamber in the present invention is
constructed or arranged in such a way that the outer surface of the
exothermic material storage portion is substantially in contact with the
content to be heated regardless of the attitude or inclination of the
container. Especially, even when the container is inclined, the outer
surface of the exothermic material storage portion is not substantially
exposed to the space not filled with the content to such an extent that
the heat is efficiently transferred to the content. For instance, the
outer surface of the exothermic material storage portion can be slightly
exposed to the space when the container is inclined, as far as the heat
generated is substantially completely transferred to the content. In this
specification, the relationship of the outer surface with the space is
construed in this manner. It is the most preferable, however, that the
outer surface of the exothermic material storage portion is completely in
contact with the content even when the container is inclined diagonally.
Therefore, even when the container is turned upside-down or inclined
diagonally or horizontally, it is ensured that the outer surface of the
exothermic material storage portion is wrapped by the content in the
container, so that the heat transfer efficiency can be enhanced and the
heating of a space not filled with the content in the container can be
avoided.
The above and other objects, effects, features and advantages of the
present invention will become more apparent from the following description
of preferred embodiments thereof taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view showing a first embodiment of a
self-heating container in accordance with the present invention which is
in an upright position;
FIG. 2 is a plan view thereof;
FIG. 3 is a vertical sectional view thereof when it is horizontally
positioned;
FIG. 4 is a vertical sectional view showing a second embodiment of the
present invention;
FIG. 5 is a vertical sectional view showing a third embodiment of the
present invention; and
FIG. 6 is a vertical sectional view showing a fourth embodiment of the
present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A first embodiment of the present invention shown in FIGS. 1, 2 and 3
comprises a steel, stainless steel, aluminum or copper cylindrical
container 1 containing a content to be heated such as Japanese sake,
liquor, coffee or soup and a cylindrical exothermic material storage
chamber 2 projecting from the bottom of the container 1 thereinto by a
predetermined depth in coaxial relationship with the container 1. The
chamber 2 is formed integrally with the container 1.
The depth or height of the exothermic material storage chamber 2 is
selected to be higher than one half of the height of the cylindrical
container 1, so that exothermic material to be described in detail
hereinafter can be disposed substantially in the core of the cylindrical
container 1.
The diameter of the exothermic material storage chamber 2 is of the order
of from 1/5 to 2/3 of the diameter of the cylindrical container 1.
The upper end of the cylindrical container 1 is closed with a lid 4 after a
content 3 to be heated is filled into it. The lid 4 is provided with a
pull tab 5 which opens a drinking or discharging opening in the lid 4 when
the tab 5 is pulled out of the lid 4.
A self-combustible exothermic material 6 is disposed in an innermost
portion in the exothermic material storage chamber 2 and a heat insulating
layer 7 is disposed in contact with and outwardly of the exothermic
material 6. A metal plate 9 is forcibly inserted into the exothermic
material storage chamber 2 and pressed against the heat insulating layer 7
through a sponge layer 8.
A fuse 10 is extended along the inner cylindrical surface of the exothermic
material storage chamber 2 through the metal plate 9, the sponge layer 8
and the heat insulating layer 7 in such a way that the inner end of the
fuse 10 is connected to the self-combustible exothermic material 6 while
the outer end thereof is extended outwardly beyond the metal plate 9.
An opening of the storage chamber 2 is preferably covered with a sheet 11
so that the exothermic material 6 is prevented from absorbing moisture in
the air. Alternatively, a plastic cap may be fitted into the opening
thereof.
In the first embodiment with the above-described construction, a space 12
is left between an upper surface of the content 3 to be heated and the lid
4 when the cylindrical container 1 is in an upright attitude as shown in
FIG. 1. When the cylindrical container 1 is positioned horizontally as
shown in FIG. 3, a space 12 exists between the upper surface of the
content 3 to be heated and the cylindrical wall of the container 1.
However, when the fuse 10 is fired by a match or a lighter regardless of
the upright, horizontal or upside-down position (not shown), the
self-combustible exothermic material 6 is ignited to produce an exothermal
reaction. In this case, the outer surface or heat transfer surface of the
innermost portion of the storage chamber 2 in which the exothermic
material 6 is stored is surrounded or wrapped by the content 3 to be
heated due to the provision of the heat insulating layer 7 so that the
heating of the empty space 12 can be positively prevented.
More preferably, regardless of the attitude of the cylindrical container 1,
the upper end of the heat transfer surface of the exothermic material
storage chamber 2 which is made in contact with the content 3 to be heated
is spaced apart from the liquid level, that is, the surface of the content
3 by a distance longer than one centimeter.
A second embodiment of the present invention shown in FIG. 4 is
substantially similar in construction to the first embodiment described
above with reference to FIGS. 1, 2 and 3 so that same reference numerals
are used to designate similar parts in FIGS. 1, 2, 3 and 4 and only the
construction of the second embodiment different form that of the first
embodiment will be described below.
That is, according to the second embodiment, an aluminum disc 9A and a ring
washer 9B are forcibly fitted into the storage chamber 2 so as to press
the heat insulating layer 7A adjacent to the self-combustible exothermic
material 6. Furthermore, the upper lid 4A is tightly pressed into the
cylindrical container 1. A fuse 10A is extended through the heat
insulating layer 7A coaxially thereof in such a way that one end of the
fuse 10A is connected to the exothermic material 6 while the other (lower
end in FIG. 4) is extended through a cap 11A which closes the opening of
the storage chamber 2 in order to prevent the exothermic material 6 from
absorbing moisture in the air.
Referring next to FIG. 5, a third embodiment of the present invention will
be described. As in the case of the first embodiment, the third embodiment
uses a cylindrical container 21, but the cylindrical wall 21A is made of a
steel while the bottom 21B is made of a aluminum independently of the
cylindrical steel side wall 21A. An exothermic material storage chamber 22
is in the form of a cylinder projecting from the bottom 21B into the
container 21 coaxially thereof.
A top lid 24 is of a pull top type having a pull tab 25 so that the lid 24
can be easily opened when the tab 25 is pulled by hand.
An inorganic inert material layer 31 is interposed between the
self-combustible exothermic material 26 and the bottom of the storage
chamber 22, so that the area of the contacting surface between the portion
where the exothermic material 26 is charged and the content 23 to be
heated is decreased, whereby the boiling noise can be lowered.
Furthermore, a metal disc or a metal film 32 having a hole which allows to
pass a fuse 30 is interposed between the exothermic material 26 and the
heat insulating layer 27 so that the mixing of the exothermic material 26
and the heat insulating layer 27 can be prevented.
A fuse 30 is extended through the heat insulating layer 27 coaxially
thereof in such a way that one end of the fuse 30 is connected to the
exothermic material 26 while the other end thereof is extended through a
sponge layer 28 and a metal plate 29 to the exterior of the container 21.
In the third embodiment, the fuse 30 is fired also by a match or a lighter
so that the exothermal reaction of the exothermic material 26 proceeds,
but there is no danger that an empty space left in the container 21 is
heated because the exothermic material 26 is disposed substantially in the
core of the content 23 to be heated.
Referring next to FIG. 6, a fourth embodiment of the present invention will
be described. In this embodiment, the present invention is applied to a
glass or plastic bottle 42 containing a content to be heated.
An aluminum or steel cylindrical exothermic material storage chamber 42 is
projected into the bottle 41 from a cap 41B threadably engaged with a
threaded portion 41A of the bottle 41 coaxially thereof.
A self-combustible exothermic material 46, a metal disc 52 formed with a
hole, a heat insulating layer 47, a sponge layer 48 and a metal plate 49
are disposed in order in the storage chamber 42 from the bottom thereof.
A fuse 50 for igniting the exothermic material 46 is extended through the
metal disc 52, the heat insulating layer 47, the sponge layer 48 and the
metal plate 49 coaxially thereof into the exterior of the bottle 41. A
match head composition 51 is bonded on the exterior end of the fuse 50. It
is insured that one easily catches fire using match striking material.
The self-combustible exothermic materials 6, 26 and 46 used in the
self-heating containers in the present invention can be ignited and burned
in an enclosed space without oxygen in the air, causing the exothermic
reaction. That is, each exothermic material consists essentially of a
mixture of oxidant and combustible compound.
In order to attain the objects of the present invention, it is important
that the space filled with an exothermic material is small and it is
preferable that Caloric output per unit volume is at least higher than 300
cal/cc. Furthermore, it is not preferable to use an exothermic material
which melts and flows out of the storage chamber and produces toxic gases
when ignited and burned.
As described above, the exothermic material used in the present invention
is a mixture of oxidant and combustible compound. Potassium permanganate,
manganese dioxide, trilead tetraoxide, barium peroxide, bromates and
chlorates and so on can be used in the present invention as oxidant. While
the combustible compounds which can be used in the present invention are
metal powder of iron, silicon, ferrosilicon, aluminum, magnesium, copper
and so on. In addition, in order to control the exothermic reaction of the
self-combustible exothermic material, one or more inorganic inert material
such as alumina, ferrite, silica sand, diatom earth and so on which will
not discharge water and gases at high temperature can be added.
When a substance to be heated is food and drink, the most preferable
self-combustible exothermic material is a mixture of potassium
permanganate and one or more metal powder with or without an addition of
one or more inorganic inert materials. Such exothermic materials have an
extremely small degree of toxicity before and after the exothermic
reaction, have a relatively high heat output per volume as compared with
other materials and will not produce toxic gases.
Potassium permanganate used in the present invention may be an industrial
grade available in the commercial market and it is preferable that the
particle size is less than 20 mesh and more preferably from 100 to 350
mesh from the standpoint of its reactivity and handling properties.
The metal powder which is used as combustible compound in the present
invention, is easily oxidized by oxygen and will not react explosively
when mixed with potassium permanganate. As an example of the preferable
metal powder is one selected from the group consisting of iron powder,
silicon powder, ferrosilicon powder, aluminium powder, magnesium powder
and copper powder. Especially iron powder chemically reacts at a
relatively low rate and it is easy to control its heat output. It is
preferable that the particle size of metal powder is smaller than at least
60 mesh and it is more preferable that it is between 100 and 350 mesh from
the standpoint of its reactivity and handling properties.
The mixing ratio is such that 10 to 90% by weight of potassium permanganate
may be mixed with iron powder. When potassium permanganate and iron powder
are used to produce an exothermic reaction, it is preferable that the
ratio of potassium permanganate be between 30 and 50% by weight to iron
powder. However, when an inorganic inert material to be described
hereinafter are added, it is preferable that the ratio of potassium
permanganate be between 50-70% by weight.
An exothermic material can be prepared by mixing potassium permanganate as
oxidant or oxidizing agent with iron powder and silicon powder or
ferrosilicon powder as metal powder.
In this case, it is preferable that the exothermic material consists of
25-85% by weight of potassium permanganate and 15-75% by weight of iron
powder to which silicon powder or ferrosilicon powder is added so that
0.05-5% by weight of silicon per se is included as outer percentage. In
this case, the heat output is increased, so that the content can be heated
at a high temperature.
Even in this case, the content of potassium permanganate is most preferably
between 25 and 40% by weight in relation to iron powder because in the
case of burning, it will not melt and flow out of the exothermic material
storage chamber.
The particle size of silicon or ferrosilicon powder used in the present
invention suffices to be less than 100 mesh or more preferably between 200
and 350 mesh from the standpoint of its reactivity. The content of silicon
per se of silicon powder or ferrosilicon powder is higher than 0.05 but
less than 5 by outer weight percentage from the standpoint of safety
because the effects obtained by the addition of silicon or ferrosilicon
powder is less when the content is less than 0.05% by weight while the
reaction is too strong when the content is higher than 5% by weight. It is
more preferable that 0.05-2.5 outer wt.% of silicon per se of silicon
powder or ferrosilicon powder be added because the exothermic material
will not melt during burning, so that there is no danger that the melted
exothermic material flows out of the storage chamber.
The method for preparing the exothermic materials in the present invention
is only to uniformly mix potassium permanganate and iron powder and/or
silicon powder or ferrosilicon powder. According to the present invention,
any mixers can be used unless they receive strong impacts and encounter a
high degree of friction.
The exothermic materials in the present invention can remarkably increase
their heat output when a small quantity of silicon powder or ferrosilicon
powder is added to a mixture of potassium permanganate and iron powder. As
a result, the content in a container can be heated at various temperatures
by changing the amount of addition of silicon powder or ferrosilicon
powder without changing size of the container.
In addition to potassium permanganate and metal powder, one or more
inorganic inert materials may be added to the exothermic material in the
present invention used for heating food and drink. Preferably, inorganic
inert materials are rock powder, glass powder, aluminum oxide, silicic
acid and so on which will not discharge water and/or gases when heated at
high temperature.
Up to 50 outer wt.% of inorganic inert material can be added to a mixture
of potassium permanganate and metal powder.
The method for preparing the exothermic material in the present invention
for heating food and drink consists of only one step for uniformly mixing
potassium permanganate and metal powder or potassium permanganate, metal
powder and one or more inorganic inert materials. The present invention
can use any suitable mixers which will not receive strong impacts and
encounter a high degree of friction.
The heat insulating layer 7, 27 or 47 which is disposed outwardly of the
exothermic material 6, 26 or 46 which in turn is inserted into the
innermost portion of the exothermic material storage chamber 2, 22 or 42
is made of a material which is non-combustible and has a high heat
insulation capability. Preferably it has not only a function of plugging
the exothermic material but also a function of a filter for gases and the
like discharged during the burning of the exothermic material.
When the exothermic material is burned, its temperature rises as high or
higher than 1000.degree. C. so that in order to attain a desired degree of
heat insulation, it is preferable to use perforated or porous inorganic
materials. Furthermore, in order to further ensure a sufficient degree of
heat insulation from the exothermic material burning at a temperature
higher than 1000.degree. C., the thickness of the heat insulating layer
must be thicker than at least 1-1.5 cm. The inorganic perforated or porous
materials have in general a high degree of air permeability so that it
also functions as a filter which can filter the steam of water absorbed in
and evaporated from the exothermic material or metal vapor.
Perforated or porous inorganic materials which can be used as the heat
insulating layer 7, 27 or 47 are, for instance, rock powder, volcanic ash,
glass powder and their foamed materials. The most preferable material is
vermiculite obtained by foaming rock powder. Vermiculite has not only a
high degree of heat insulation capability and a high permeability but also
a satisfactory degree of resiliency and formability, so that it has a high
degree of workability.
The fuse 10, 30 or 50 for igniting the self-combustible exothermic material
6, 26 or 46 may be one used to ignite the gun powder. However, it is more
preferable to use a fuse consisting of a bundle of filaments or fibers
impregnated with a self-combustible agent because the smoke produced
during the burning of the fuse can be reduced in minimum in quantity.
Carbon fibers and metal fibers, such as stainless steel, copper, aluminum
fiber and the like, can be used as fibers of the fuse. A preferable
self-combustible agent consists of trilead peroxide and metal powder
impregnated with nitrocellulose which serves as a binder. In order to
ensure the successive burning of the fuse even when the latter is made in
contact with the wall of the exothermic material storage chamber, the
cross sectional area of each single filament is less than
1.times.10.sup.-2 mm.sup.2 and at least 50 filaments must be bundled as a
fuse. The upper limit of the number of such fibers is of the order of
10000. A bundle of 1000 stainless steel fibers 10 micron across is
preferred.
In order to ensure the impregnation of a self-combustible agent
sufficiently to the core of the bundle of fibers, it is preferable that
the particle size of the self-combustible agent is of the order of 200
mesh.
Instead of the fuse 10, 30 or 50, an electrical ignition device can be used
to ignite the self-combustible exothermic material. That is, a heater
attached at the leading end of an electric wire is embedded into the
exothermic material layer 6, 26 or 46 and a pair of electric wires are
extended out of the exothermic material storage chamber to the exterior so
that when the electric energy is supplied to the heater through the
electric wires from, for instance, a battery, the exothermic material is
ignited.
However, according to the present invention, the exothermic material
contains metal powder, so that there exists a fear that the supplied
electric current flows through the metal powder surrounding the heater and
consequently the heater is not energized. It follows therefore that it is
preferable that the heater embedded in the exothermic material layer is
electrically insulated. More preferably, in order to ensure the positive
ignition, the heater is coated with an ignition material such as a match
head composition.
The main body of the self-heating container containing a substance to be
heated may be fabricated from a material such as metal, paper, plastic or
composite material thereof which will not be softened, deformed or damaged
when the content is heated to 80.degree.-90.degree. C. Therefore, the
materials of the main body of the self-heating container in the present
invention are not especially limited.
The exothermic material storage chamber is made of metal having a high
degree of heat conductivity and a high degree of workability. For
instance, it is made of aluminum, copper, stainless steel or the like.
The portion of the exothermic material storage chamber in which is disposed
the exothermic material is positioned in such a way that it is
substantially in contact with the content to be heated regardless of the
attitude of the container. Therefore, the exothermic material storage
chamber must be projected into the self-heating container by a suitable
length, but since the heat output per unit volume of the self-combustible
exothermic material is high and the thermal efficiency is also high, the
volume of the exothermic material storage chamber can be made small. More
specifically, the ratio of the volume of the exothermic material storage
chamber to the volume of the container may be less than 25%.
Next, some of the examples of the present invention will be described.
EXAMPLE 1
An aluminum exothermic material storage chamber 35 mm in inner diameter and
50 mm in length was projected into an aluminum container as shown in FIG.
1 which was 65 mm in outer diameter and 85 mm in length. A
self-combustible exothermic material 6 consisting of a mixture of 10 grams
of potassium permanganate less than 200 mesh and 15 grams of iron powder
less than 200 mesh was disposed at the innermost portion of the storage
chamber 2. A heat insulating layer 7 seven grams by weight made of
vermiculite was placed outwardly of the exothermic material 6 in the
storage chamber 2 and urethan sponge layer 8 is disposed outwardly of the
heat insulating layer 7. Thereafter, the metal plate 9 whose peripheral
portion was partially cut out was fitted into the storage chamber 2. The
fuse 10 comprising carbon filaments and a mixture of ferrosilicon and red
lead, the mixture was bonded to the carbon filaments with nitrocellulose,
was extended from the opening through the cut-out portion of the metal
plate 9 to the self-combustible exothermic material layer 6. More
specifically, the fuse 10 was prepared by dipping a boudle of 3000 carbon
filaments (each filament is 8 .mu.m in diameter into 5 grams of acetone
solution of 4% nitrocellulose having H1/2 second grate (JIS K-6703-1975),
the acetone solution being mixed with 7 grams of red lead less than 200
mesh and 3 grams of ferrosilicon less than 200 mesh, and then by
evaporating the acetone. The fuse thus obtained was 22 milligrams by
weight per one centimeter. 200 cc of Japanese sake was filled in the
container with the above-described construction. The exothermic material
layer was about 10 mm in thickness; the heat insulating layer, 30 mm in
thickness; and the empty space 12 left after Japanese sake was filled into
the container 1 was about 10 mm in thickness when the container 1 was
maintained in an upright attitude as shown in FIG. 1. Next, the container
1 was turned upside-down and then a match was used to fire one exposed end
of the fuse 10. After 3 minutes, Japanase sake which was filled at a
temperature of 10.degree. C. was heated to 40.degree. C. The heat output
of the self-combustible exothermic material was 320 cal/g. The thermal
efficiency was 75%.
EXAMPLE 2
The self-heating container 1 which was the same as that described above in
EXAMPLE 1 was inclined horizontally as shown in FIG. 3 and then one
exposed end of the fuse 10 was fired by a match. In 3 minutes after
ignition, Japanase sake which was filled in the container 1 at 10.degree.
C. was heated to 40.degree. C. Even though the container 1 was heated in
an abnormal attitude, but it was not deformed or damaged.
EXAMPLE 3
The container 1 which was substantially similar to that as described above
with reference to FIG. 1 was used, however, the exothermic material 6 was
varied in quantity in order to evaluate the effect of the variation in
exothermic material 6. That is, 15 grams of KMnO.sub.4 less than 200 mesh
and 22.5 grams of iron powder less than 200 mesh were mixed and inserted
into the innermost portion of the exothermic material storage chamber 2.
Thereafter, 7 grams of vermiculite was forcibly packed as heat insulating
layer 7. The exothermic material layer was 15 mm in thickness, and the
heat insulating layer was 30 mm in thickness. The content in the container
1 was 200 cc of coffee. Except the above-described conditions, other
experimental conditions were substantially similar to those of EXAMPLE 1.
The container 1 was maintained in an upright attitude as shown in FIG. 1
and then one exposed end of the fuse 10 was fired by a match. In 3 minutes
after that ignition, coffee which was filled at 10.degree. C. in the
container was heated to 56.degree. C.
EXAMPLE 4
The container 1 which was substantially similar in construction to that
described above with reference to FIG. 1 was used and a self-combustible
exothermic material mixture 6 consisting of 15 grams of KMnO.sub.4 less
than 200 mesh, 22.5 grams of iron powder less than 200 mesh and 0.75 grams
of ferrosilicon powder less than 200 mesh was charged into the storage
chamber 2. Thereafter 200 cc of consomme soup was filled into the
container 1 as a content 3 to be heated. The exothermic material layer 6
was 15 mm in thickness and the heat insulating layer was 30 mm in
thickness. The remaining conditions were similar to those of EXAMPLE 1.
The container 1 with the above-described construction and containing
consomme soup was maintained in an upside-down attitude, so that the
opening of the storage chamber 2 is directed upwardly. Next one exposed
end of the fuse 10 was fired by using a match. In 3 minutes after the
ignition, consomme soup which was filled in the container at 10.degree. C.
was heated to 65.degree. C. The heat output of the self-combustible
exothermic material 6 was 350 cal/g. The thermal efficiency was 82.5%.
EXAMPLE 5
200 ml of Japanese sake was filled in a steel cylindrical container 1(65 mm
in diameter and 85 mm in height) having an exothermic material storage
chamber 2 (35 mm in diameter and 50 mm in length) which was substantially
similar in construction to the container 1 as shown in FIG. 1. The
exothermic material 6 was a mixture of 10 grams of potassium permanganate
less than 200 mesh, 15 grams of iron powder less than 200 mesh and 3 grams
of silica sand less than 200 mesh. The fuse 10 consists of a mixture of
trilead tetraoxide and ferrosilicon which was wrapped with glass fibers.
The heat insulating layer 7 consisted of foamed or calcined volcanic ash
(Shirasuballoon) and the metal plate 9 was made of aluminum. The remaining
experimental conditions were substantially similar to those described
above with reference to EXAMPLE 1. The fuse 10 was fired by using a match.
In 3 minutes after the ignition, Japanese sake which was filled at
10.degree. C. in the container 1 was heated to 43.degree. C. No abnormal
phenomenon of the container 1 was observed.
EXAMPLE 6
The aluminum can or container 1 having the construction as shown in FIG. 4
was used. The can 1 was 65 mm in diameter and 120 mm in height. The
exothermic material storage chamber 2 was 30 mm in diameter and 75 mm in
length. 300 ml of Japanese sake was filled in the can 1. The exothermic
material 6 was a mixture of 15 grams of potassium permanganate less than
200 mesh and 23 grams of iron powder less than 200 mesh. The heat
insulating layer 7A consisted of inorganic sponge and the bottom of the
storage chamber 2 was sealed with an aluminum plate 9A and a spring washer
9B. The fuse 10A consisted of a hemp cord impregnated with trilead
teraoxide and ferrosilicon with nitrocellulose as a binder. In 3 minutes
after the ignition of the exothermic material 6, Japanese sake which was
filled into the can 1 at 10.degree. C. was heated to 42.degree. C. No
abnormal phenomenon of the can 1 was observed.
EXAMPLE 7
The aluminum can 1 which was substantially similar in construction to that
shown in FIG. 4 and has a reduced volume of 200 cc (53 mm in diameter and
95 mm in height) was used and an aluminum storage chamber 20 mm in
diameter and 70 mm in length was projected inside the can 1 from the
bottom thereof. A mixture consisting of 20 grams of potassium permanganate
(250 mesh), 12 grams of iron powder (350 mesh), one gram of ferrosilicon
(200 mesh) and 5 grams of rock powder (250 mesh) was charged into the
innermost portion of the storage chamber 2. 160 cc of consomme soup was
filled in the aluminum can 1. The exothermic material 6 was fired by using
a time-delayed fuse 10A. The remaining experimental conditions were
substantially similar to those of EXAMPLE 6. Consomme soup which was at
20.degree. C. before ignition was heated to 85.degree. C. in 3 minutes
after the ignition.
EXAMPLE 8
The aluminum can 1 whose construction was substantially similar to that
shown in FIG. 4 and which has a volume of 200 cc (53 mm in diameter and 95
mm in height) was used and the exothermic material storage chamber 2 30 mm
in diameter and 65 mm in length was projected into the aluminum can 1 from
the bottom thereof. A mixture consisting of 18 grams of potassium
permanganate (250 mesh) and 26 grams of iron powder (350 mesh), 6 grams of
rock powder (100 mesh) was charged as an exothermic material at the
innermost portion of the storage chamber 2. 160 cc of consomme soup was
filled in the aluminum can 1 and the exothermic material 6 was ignited by
using time-delayed fuse 10A. The remaining experimental conditions were
substantially similar to those of EXAMPLE 6. Consomme soup which was at
20.degree. C. before ignition was heated to 80.degree. C. after the
burning of the exothermic material 6 in 3 minutes.
EXAMPLE 9
The container whose volume was increased as shown in FIG. 5 was used. The
can 21 was 65 mm in diameter and 110 mm in height while the exothermic
material storage chamber 22 was 25 mm in diameter and 75 mm in height. The
cylindrical wall of the can 21 is made of steel while the top and the
bottom of the can 21 from which the storage chamber 22 was extended
therein was made of aluminum. 0.7 grams of vermiculite was charged as an
inert material layer 31 in the innermost portion of the storage chamber
22. Then, the exothermic material consisting of 15 grams of KMnO.sub.4
less than 200 mesh and 23 grams of iron powder less than 200 mesh was
charged. Thereafter a steel disc 32 with a center hole was forcibly fitted
into the sto | | |
