JPH0334926B2 - - Google Patents

Description

Claim 1: A heating device for heating liquid products and solid products, comprising a container structure and a heating means disposed at the bottom of the container structure, wherein the heating means is a gas-free heat generating device. A heating device comprising a heating element comprising a combustible material and an inner wall defining at least one fire path, wherein the heating element includes a heat distribution layer made of a heat transfer material and a heat dissipating layer made of a heat transfer material; a flat element comprising an intermediate layer composed of a combustible material and comprising said inner wall, and a layer made of a non-combustible insulating material, the ignition means comprising at least one of the layers covering the combustible material; A heating device for heating liquid and solid products, characterized in that the heating device is connected to the combustible material through an opening in the material.

2. Heating according to claim 1, characterized in that the ignition means comprises a finger-shaped ignition element, which stands on its own in contact with the combustible material and whose free end is adapted to be ignited. Device.

3. The ignition means comprises an element made of a material that is easily ignited by friction, and a rubbing plate arranged to be drawn across the material that is easily ignited by friction. A heating device according to claim 1 or 2.

4. The element of claim 3, wherein the element made of a frictionally ignitable material is adapted to ignite the free end of the finger-like ignition element by radiant heat without contact. Heating device as described.

5. The heating device according to claim 2, wherein the finger-shaped ignition element includes a cup-shaped member, and the finger-shaped portion of the ignition element projects from approximately the center of the cup-shaped member. Device.

6. Heating device according to claim 1, characterized in that the wall defining the fire path is made of a highly heat conductive material and is in heat transfer contact with a heat distribution layer.

7. The heating device according to claim 1, wherein the pyrolysis layer is made of aluminum foil.

8. Heating device according to claim 1, characterized in that the heat distribution layer is made of finely ground metal or metalloid bonded with a heat-resistant binder.

9. The heating device according to claim 8, wherein the metalloid is carbon.

10. The heating device according to claim 8, wherein the heat dispersion layer includes non-combustible fibers.

11. Heating device according to claim 1, characterized in that a thin heat-insulating layer made of a heat-resistant material is inserted between the heat distribution layer and the gas-free exothermic combustion material. .

12. According to claim 1, wherein the wall defining the fire path is made of a non-combustible heat insulating material formed into a single plate together with the heat insulating layer by casting. heating device.

13 The length of the fire path is such that the heat generated by the exothermic reaction per square centimeter of the bottom is 25
2. Heating device according to claim 1, characterized in that the combustible material is chosen to be less than watts.

14. The container structure is a food storage body formed of a non-combustible thermally conductive foil formed as a disposable dish, the bottom of which is in contact with the heating element, and the food storage body and the heating element are connected to the container. 2. The heating device according to claim 1, wherein the heating device is located in a heating device.

15. Heating device according to claim 1, characterized in that the flat element forms the bottom of an open container.

16. Heating device according to claim 1, characterized in that the flat element is in contact with the outer surface of the bottom of the container.

17. The heating device of claim 1, wherein the gas-free exothermic combustion material includes at least 20% silicon and at least 10% red lead.

18. The heating device of claim 17, wherein the gas-free, exothermic combustion material comprises at least one metal oxide other than red lead and a suitable binder.

19. The heating device of claim 18, wherein the gas-free exothermic combustion material comprises at least 20% manganese dioxide.

20. The heating device according to claim 17, wherein the exothermic combustion material that does not emit gas includes a material that does not react even when heated.

21. The heating device according to claim 1, wherein the raw material components of the layer of gas-free exothermic combustible material are combined together with a non-combustible binder.

22. The heating device according to any one of claims 1 to 21, wherein the gas-free exothermic combustion material layer and the heat insulating layer are made of a castable mixture. .

Description The present invention relates to a heating device for heating liquid and solid products.

A number of different types of devices have been proposed in the past that include a container structure and a heating element, ie so-called self-heating containers, which devices contain substances that can give rise to exothermic reactions; Therefore, when the reaction occurs, the contents of the container are heated.

It is known from the literature that the burning time of a heating element depends not only on the components used, but also on the heat conduction properties of its container and the way in which the heat generated by the reaction is extracted from the mass. ing. In order to control and increase the duration of the reaction, an inner wall or partition of some refractory material reaching from the top to the bottom of the heating element and ensuring the path of the fire,
It has been proposed to embed it in exothermic combustible materials.

Some devices of this type are dangerous to operate because the heating element is not isolated from the surroundings or can be operated separately from the container. As a result, the heat flow generated is not absorbed by the container and its contents, but rather is directed towards the surroundings.

The heat generated in such heating devices, especially of the thermite type, can have extremely high temperature values of up to 1200 degrees, so such devices are dangerous to handle by hand and pose a fire hazard. May cause an explosion. Moreover, the previously proposed arrangements do not satisfactorily heat the contents of the container in a uniform manner and are not convenient or easy to use.

The object of the invention is to provide suitable heat dissipation to the contents of the container or to the stored food and to provide a uniform heating thereof, while ensuring complete insulation to the surroundings and great safety of use. An object of the present invention is to provide a heating device including a structural body.

Another object of the invention is to provide a heating device that is reliable in use and does not require special precision in manufacture, and includes a relatively simple and safe ignition arrangement for combustible materials.

Another object of the invention is to provide a heating device that is inexpensive to manufacture and whose manufacture can be automated.

Yet another object of the invention is to completely separate the conditioning of the food into the sterile package and the manufacture of the heating element, and to assemble both as a complete unit.

Another object of the invention is the improved production of gases in liquid or semi-liquid form by the use of liquid binders, since it is well known that liquids or pastes are much easier to handle than powders. The purpose of the present invention is to provide a composition that does not generate heat. The use of liquids or pastes makes it possible to obtain cakes of the composition with well-controlled porosity in any shape that can be cast, whereas powders, on the other hand, make it possible to obtain cakes of composition with well-controlled porosity in any shape that can be cast, whereas powders have very limited porosity, such as cylinders. It can only be compressed to a given porosity or density in its shape. It is well known from pyrotechnics technology that the porosity of a pyrotechnic reaction mass is critical to its burning rate.

A heating device for heating liquid and solid products, comprising a container structure and a heating means arranged at the bottom of the container structure, the heating means comprising at least a gas-free exothermic combustion material and a heating means disposed at the bottom of the container structure. a heating element comprising an inner wall defining a fire path, the heating element comprising a heat distribution layer made of a heat transfer material and the gas-free exothermic combustion material; a flat element comprising an intermediate layer and comprising said inner wall and a layer made of a non-combustible insulating material, the ignition means comprising an opening in at least one of the layers covering the combustible material; A heating device for heating liquid and solid products is provided, characterized in that the heating device is connected to the combustible material through a section.

The above and other objects, features and advantages of the present invention include:
It will become clear from the detailed description below and the accompanying drawings.

FIG. 1 shows a heating device, the bottom of which is shown in section.

FIG. 2 shows a cross section taken along the line - in FIG. 1 and a top view of the container.

Figure 3 shows the heating element separated from the container.

FIG. 4 shows another embodiment of the invention.

FIG. 5 is a perspective view of the starter used in the embodiment of FIG. 4.

FIG. 6 is a cross-sectional view through the heating element.

FIG. 7 is a cross-sectional view through a third embodiment of the invention.

8 is a cross-sectional view through the heating element of the embodiment shown in FIG. 7; FIG.

The heating device shown in FIGS. 1, 2 and 3 is
It consists of a container with a peripheral wall 102, preferably made of metal, and a flat and relatively thick bottom 103 made of a good thermally conductive material such as aluminum.
is fixed to the surrounding wall 102 in a watertight manner. A portion 104 of the peripheral wall 102 is connected to the bottom plate 1
03 and forms a recess in which a heating element 105 and its ignition system 106 can be accommodated.
A ring-shaped element 107 is inserted opposite the peripheral wall 102. This ring-shaped element includes a cover 108 that is frictionally engaged with a ring 107.
guide and support. This cover is lined with insulating material 109. This material may be comprised of glass fiber, rock wool, ceramics, etc. This cover connects the heating element 105 to the bottom 103
A recess 110 in the insulating material houses the ignition system. The heating element shown in FIG. 3 consists of a heat spreader plate 111 made of a good thermally conductive material such as aluminum. Vertical wall made from a thermally conductive material such as steel 1
12 is fixed to the thermal expansion plate 111 in a manner that allows heat to be transferred. These walls define a fire path for the exothermic material placed therein. An advantageous shape of the fire path is a helical arrangement of these walls. A heat-generating material consisting of a thermite composition such as manganese dioxide and silicon, and a material that does not react even when heated (hereinafter referred to as inert material) such as anhydrous silicic acid with the addition of a suitable binder such as a silicate. 113 is cast into the path of the fire.

Some inventors have proposed in the past to use thermite, a reaction between aluminum and iron oxide, as the exothermic material. Reaction temperatures in excess of 2000° C. are induced in plunger-type structures, which are unsuitable for transferring heat to the food to be heated. The idea of the invention is to provide a container in which the food in the container is heated from the bottom and the liquid is subject to natural convection or agitation. this is,
This is possible through the use of reactive compositions that burn at lower temperatures. Various oxides such as red lead, manganese dioxide, copper oxide, and silicon give a gas-free exothermic reaction whose propagation rate can be controlled by the addition of inert materials such as silica, Chinese clay, etc. It turned out that it is possible. The use of oxides containing little oxygen, such as red lead, gives lower reaction temperatures than oxides containing large amounts of oxygen, such as manganese dioxide, and the amount of heat released per unit weight is greater than 2. It has been found that this can be adjusted by using oxides of, for example, mixtures of manganese dioxide and red lead, as well as by varying the amount of inert material.

The heat generating material is covered with a layer of insulating material such as finely divided silicic acid mixed with a suitable binder such as silicate or gypsum. Prior to casting the heat generating material 113 and the insulation layer 114, a primer 115 is placed in the center of the spiral. This primer has approximately 400
It consists of a composition that reacts when heated to ℃. Typical composition of this kind is lead oxide ( _PbO2 )
finely ground silicone mixed with
This composition, mixed with a suitable binder such as a silicate, is molded in a separate mold to form a cup shape with free-standing fingers such as conical portion 116 projecting from the bottom. to be cast. The outer wall 117 of the primer is in contact with the heat generating material 113 and the primer can be inserted and removed through an opening in the layer 114 of insulating material.

The ignition means consists of a thin metal strip 118. The end of this metal strip is folded over the edge of the heating element, as shown at 117. This U-shaped element is positioned by a slight spring action of the legs 117. metal strip 11
8 has a hole bored in its center. A small amount of exothermic material 120 that burns with very high heat, such as a mixture of boron powder and potassium perchlorate (KClO ₄ ) bonded with glue, is placed in such a way that the pasty material protrudes through the holes 119. is cast over the hole. A frictionally ignitable material 121, such as a pine head composition, also bonded with glue, is cast on the other side of the metal strip. A scraping board or pull tab 122 consisting of a strip of strong paper or similar material covered on one side with a pine rubbing material is placed across the pine head composition 121 and at both ends 12.
It is held resiliently against the pine head composition 121 by a thin flexible metal strip 123 spot welded to strip 118 at 4,125. As shown in FIG. 3, this ignition means is placed on the heating element, with the exothermic material 120 facing the opening and the cone of the primer 115.

A cavity 110 made in the insulation layer 109 of the cover 108 accommodates the protruding parts of these ignition means 118. Slots 127 and 128 are provided between the insulation layer of the cover and the heating element and between the cover 108 and the body of the container 101. Pull tab 122 projects outwardly through slot 127.

The functions of the heating device are as follows. Container 101
After filling the tab 122 with the food to be heated, the tab 122
is pulled outward, frictionally igniting the pinehead composition 121 which transfers the fire to the exothermic composition 120. The heat radiated by this composition is strong enough to ignite the primer cone 116 and the reaction propagates by contact through the body of the primer to the exothermic material 113 filling the fire path. The heat generated by the slowly propagating reaction is transferred to the metal fin 11 to the heat diffusion plate 111 which is in contact with the bottom plate 103 of the container.
2, the heat is transferred to the container, which acts as another heat spreading element. bottom plate 10
The thickness of 3 is chosen in such a way as to ensure the correct spread of heat over the bottom wall, so as to avoid burning of the food to be heated. By varying the proportions of the components of the exothermic composition, the propagation rate of the reaction can be adjusted, and is maintained at less than 25 watts per square centimeter when considering the entire surface of the heat spreader plate 111. preferable.

After burning, the heating element 105 can be easily removed and replaced with a new one.

For safety, the heating element should not be operated unless properly secured to the bottom of the container 101. As mentioned above, the ignition system is placed on the heating element by two resilient legs 117 that press against the side walls of the heating element. When outside the container,
If the pull tab is actuated, the entire ignition system will be pulled apart without functioning. Within the container, the ignition system is maintained in place by mating recesses 110 formed in the insulation layer 109 of the cover 108.

In a second embodiment of the invention, shown in FIG.
01, the bottom part 202 of which is a heat-spreading surface. The peripheral wall 203 is obtained by a deep drawing process and can be made thin to save material. A vertical wall 204 made of a thermally conductive material, such as steel, is secured in thermally conductive contact to the heat spreader plate 202 in a contour to form a fire path. The ideal contour is a spiral as shown in FIG.
A thin insulation layer 205 made of a refractory material such as silicic acid combined with silicate is cast within the path of the fire. A cup-shaped primer 206 with a protruding cone in the center is placed in the center of the helix on the thin insulation layer 205 . The exothermically reactive material 207 is mixed with a suitable binder such as a silicate and cast into the path of the fire. The end of the last turn of helix 204 is bent in such a way as to leave an annular space 209 between wall 203 and the helix, closing the fire path. On top of the exothermic material 207, a thermal insulation layer 210, which may consist of silicic acid combined with silicate or calcined gypsum, is cast, also filling the annular recess 209. Corrugated aluminum foil or glass fiber mat21
A ring-shaped spacer made of an insulating material such as 1 is placed on the insulating layer 210. A ring-shaped paperboard 212 is placed on the spacer. A starter 213 is positioned in the center of the ring. The starter consists of a U-shaped metal disc 214 spot welded to a flat metal disc 215 by spot welds 216, 217 forming a groove therebetween;
A pull tab 218 made of a flexible material such as paper coated with a mating composition on the side facing the U-shaped disk at one end 219 is placed in the groove. The U-shaped disc has a hole drilled in its center, and a small amount of a heat-generating material 221, such as boron and potassium perchlorate bonded with glue, is inserted into the hole 220 made in the center of the U-shaped member. Cast on top.
A small amount of pine head composition 222 bound with glue
is cast inside the U-shape over the hole 220 so as to be in contact with the exothermic material 221 through said hole. Paperboard disc 223 maintains starter 213 in its position. End 22 of pull tab 218
4 passes through a hole 225 made in a paperboard disc 223 and this end of the tension tab is folded over this paperboard disc. A frangible seal membrane 22 made from a water-impermeable material such as polyethylene
6 is placed on the top of the disc 223 to maintain the pull tab in that position. The protruding end of the container 201 is connected to a spacer 211 and a paperboard disc 21.
2, 223 and sealing oil 226 are held firmly and pressurized at those positions while being rolled up. The heating element described above is a completely sealed unit that can be easily stored and handled until used in the container, making the container a self-heating container. In FIG. 4, section 227 is a tube-shaped member made from a water-impermeable material such as silicate-impregnated aluminum and plastic-backed paperboard. The heating element 201 is
A push-fit is used in this tube that is strong enough to prevent water from leaking. This tube 227 forms the peripheral wall of the self-heating container 231. Prior to filling, the container membrane 226 is broken and the pull tab is folded back to the outside of the container as shown by dotted line 232;
The container is then filled with the medium to be heated. By pulling pull tab 218 outward, its coated end 219 is rubbed against the pinehead composition, which ignites and activates the exothermic composition 221, causing this reaction. The heat radiated by the cup-shaped primer 206 is strong enough to heat the tip of the cone 233 protruding from the bottom of the cup-shaped primer 206 above its ignition temperature which initiates combustion of the primer, which causes a reaction of the exothermic composition 207. induce. This reaction propagates at a speed between 4 mm and 20 mm per second, and the released heat transfers this heat to the heat spreader plate 20.
The heat flows from the heat spreader plate 202 into the medium to be heated. Insulation 205 prevents direct contact between the exothermic material and heat spreader plate 202 . This insulating barrier is advantageous in spreading the heat into the heat spreader plate 202 by means of the fins, avoiding hot spots on this plate and avoiding scorching of the food to be heated. The insulation material 205, the spacer 215, and the two paperboard discs 213, 223 are
A multilayer insulating barrier is formed that prevents heat from flowing in the opposite direction to the heat spreader plate 202. Finn 204
acts as a heat sink that conducts heat into the diffuser plate and avoids large heat transfer to unreacted parts of the exothermic material that could cause uncontrolled progression of the reaction. According to the embodiment shown in FIG.
We have found that a quantity of 70 grams of heated mixture can raise 400 c.c. of water from normal room temperature, e.g. 20°C, to 70°C in 2 minutes. Calorie output is
It has 300 calories per gram.

In a third embodiment shown in FIGS. 7 and 8, the heating element is a refractory material support 30 made of castable material such as plaster, clay, etc.
Consists of 1. The support is cast in such a way as to create on one side a fire path 303 constituted by grooves separated by raised walls 302. These walls are arranged in such a way that they form two zigzags starting from the center, as shown in FIG. The support 301 of refractory material has a hole 305 in its center and a primer 306 inside the hole 305.
is placed. This primer consists of a reactive composition bound with a suitable binder and is cast in a separate mold to take the shape of a cup, with finger-like elements 307 rising from the bottom inside the cup. ing. After solidification, this primer fills the holes 305
placed inside. The reactants, mixed with a suitable binder, are cast within the fire path 303 and in contact with the primer 306. On top of the reactants,
a layer 30 of a finely divided thermally conductive material such as a metal-like powder or metal powder such as graphite mixed with a suitable heat-resistant binder such as a silicate;
8 is cast. To reinforce this layer, thin sheets of non-combustible fibers such as glass fibers can be embedded. This layer is not shown.

This heating element is secured to the bottom of the paperboard container 309 by gluing or other suitable means. The aforementioned starter 311 shown in FIG. 5 is placed in a recess in the paperboard layer 310. Pull tab 31
2 protrudes through a slot made in the wall 313 of the container 309 and is accessible from the outside. In such a way that the stored food 314 in a shallow dish 315 made of thin deep-drawn aluminum foil sealed with a thin film of aluminum 316 ensures contact between the heat distribution layer 308 and the bottom 317 of the stored food and placed on the heating element 301. This stored food is attached to the rim 31 of the paperboard box 309 using hot melt or the like.
The umbilical edge 318 of 9 is clamped onto the cardboard box 309, for example by wedging or gluing.

The entire assembly constitutes a self-heating food storage container. After removing cover 316, the heating reaction is initiated by pulling pull tab 312 outward.

It is self-evident that this heating device can be supplied with an empty container 315 and that this device constitutes a disposable self-heating container.

The primary 306 has a heat distribution layer 30 on the opposite side.
It can be placed in the path of the fire which can be accessed through the opening in the 8. In this case, the starter
It should be located between the bottom 317 of the container 315 and the heat distribution layer 308. The tips of the fingers 307 can be affixed with a frictionally ignitable material, and the pull tab can be resiliently maintained against the frictionally ignitable tips.

Similarly, the primer 306 is applied to the sidewall 3 of the heating element.
20 and the starter can be suitably positioned between the side wall 320 and the vertical wall of the paperboard 309.