HEATER

Abstract: A heater adapted to heat a material with the heat generated by a hydration reaction between a heating material and water. A container in which a material to be heated is placed is provided above a container in which a heating material is placed. The bottom wall of the container for a material to be heated is provided with a plurality of slits through which high-temperature steam generated by the heat occurring due to a hydration reaction between the heating material and water is ejected into the same container,whereby the high-temperature steam is applied to the object material from a position just thereunder in addition to the heat transmitted to the object material via the walls of the container therefor.

Description: The present invention relates to a heating device which heats material by the heat of a hydration reaction of an exothermic material and water. See for example WO-A-8700409. As a heating device for easily heating drinks such as coffee, tea and so forth or cooked foods, there have been provided heating devices which use the heat of the hydration reaction between an exothermic material and water. However, in these conventional heating devices, as seen in, for example, Japanese Patent Publication (Kokai) No. 62-16371 and 61-259974, and Japanese Utility Model Publication (Koukoku) No. 62-32500, European Patent Publication No. 3231513, Japanese Utility Model Publication (Koukai) No. 61-35, a portion for containing a material to be heated and a exothermic part are parted by a partition wall or walls of container and the material to be heated is heated only by conductive heat transferred therethrough. As a result, therefore, a part of the material to be heated contacting with the wall is heated to a high temperature, while other parts distant from the wall cannot be heated directly. In the case when a material to be heated is a solid, this tendency becomes remarkable; that is, the part in contact with the wall is scorched but the interior temperature is not raised sufficiently. The heating devices, described in Japanese Utility Model Publication (Koukai) Nos. 62-123742 and 61-137318, are provided with an aperture at a bottom wall so the vapour produced by the heat of the hydration reaction can heat the materials to be heated without causing unevenness of temperature, as described above. In this heating device, however, as described in Japanese Utility Publications (Koukai) Nos. 62-123742 and 61-137318, there is a problem in that small pieces of the exothermic material may be brought into the material to be heated by the passage of the high temperature vapour through the apertures to the portion for containing the material to be heated. The object of the present invention is to provide a heating device in which small pieces of the exothermic materials spattered by the reaction do not tend to get into the material to be heated. The heating device described above is one in which the exothermic material and water after hydration reaction are permanently mounted, as disclosed in Japanese Patent Publication (Koukai) No. 62-16371, and one in which exothermic materials or a bag containing the exothermic materials is directly included, as in Japanese Utility Model (Koukai) No. 61-137318; thus the device, after having completed the hydration reaction, the exothermic materials could not be re-used. The other object of the present invention is to provide a cartridge-type heating device comprising a portion for containing the exothermic materials, which is applied to different styles of heat devices, and also is re-used. The present invention is a heating device which consists of a bag comprising an upper container for materials to be heated; a lower container containing separately water and an exothermic material which generates heat when it contacts water; means for starting contact between the water and the exothermic material operable from the outside of the device; and a cover on an opening of the lower container; the cover of the lower container is a sheet-type filter means which allows high temperature vapour to pass but prevents the exothermic material from passing through, and the bottom wall of the upper container has apertures. In a preferred embodiment of the invention, the water and the exothermic material are contained in different bags. It is further preferable that the means for starting contact between water and exothermic materials is tape-shaped. In a preferred embodiment, it is further desirable that said heating device has a removable lid and that this lid is provided with slits through which the vapour entered into said portion can be vented to the outside of the heating device. As an exothermic material, calcium oxide, magnesium chloride, calcium chloride, iron oxide and so on can be used for example, which generate heat of hydration reaction by contacting with water. Calcium oxide is most preferred as it generates a high heat of reaction, and boils water in contact with it, thus producing a large quantity of vapour of a high temperature. In the drawings:- Figs. 1 to 5 are explanatory views of a heating apparatus according to a first embodiment of the present invention, in which Fig. 1 is a perspective view of the heating device; Fig. 2 is a longitudinal-section view of the heating device; Fig. 3 is a stacked perspective view of the heating device; Fig. 4 is a longitudinal-sectional view of a portion for containing an exothermic material; and Fig. 5 shows a container; Figs. 6 to 10 are explanatory views of a heating device according to a second embodiment of the present invention, in which Fig. 6 is a perspective view of the heating device; Fig. 7 is a sectional view of a cut; and Figs. 8 to 10 are plan views showing other shapes of a cut. The present invention is explained in more detail in accompaniment with the attached drawings. Fig. 1 through Fig. 5 show a heating device according to a first embodiment of the invention. The heating device shown in the figures is a lunch box for Japanese food, in which a container for contents of food 3 for containing food as a material to be heated is provided inside of a container 2 which can be opened and closed by a lid 1, while a portion for containing an exothermic material 4 to heat the food is provided below the container 3, presenting a shape of a flat box. As shown in Fig. 4, the portion for containing an exothermic material comprises an exothermic source 5 and an insulation container 6 for containing the source 5. The exothermic source 5 consists of materials which generate heat by the hydration reaction of calcium oxide (CaO) and water. Although calcium oxide can be used as it is, it is better to pack it in a bag for easier handling, namely, the exothermic source 5 includes a bag for containing the exothermic material 5a calcium oxide and a bag for containing water 5b provided below the bag 5a. The bag for the exothermic material 5a is contained in aluminium foil and a number of small holes is formed on the whole surface thereof, while the bag is filled with calcium oxide as an exothermic material. The bag for water 5b is made of a plastic film such as polyethylene and so on, which is filled with water, while a tear element 7 for the water bag 5b is provided on the upper surface thereof. The exothermic material bag may be made of a non-woven fabric, as well as aluminium foil. The tear element 7 has a tape-shape, having large tensile strength, and is deposited to the water bag 5b so that by pulling the tear element 7, the plastic film constituting the water bag 5b is torn in the direction of the extending of the plastic film, the width of which is relative to the width of the tear element. When the water bag 5b is broken, water enters inside of the bag 5a through the small holes of the bag for the exothermic material 5a, thus starting contact with the exothermic material. An opening is provided at a side wall of the insulation container 6 and further, an opening 20 is provided at a side wall 2b of the container 2. The tear element 7 passes through these openings and the tip thereof can be seen from an outer wall of the container 2, so that the tear element 7 can be pulled from the outside of the container 2. Moreover, a mark showing a limit of the length to be pulled is provided midway on the tear element 7. As described above, in this embodiment shown in the figures, the tape-shaped tear element 7 protrudes from the container 2 through the opening 20 at the side wall 2b of the container 2. Alternatively, it may be let out from an aperture between the container 2 and the container 3 without providing the opening 20. Further, instead of providing the opening at the side wall of the insulation container 6, a cut may be provided at the upper edge of the side wall of the insulation container 6 so that the tear element 7 can pass through the cut. Therefore in the state in which the container 2 is covered with the lid 1, as the surfaces 1b are in contact with the top of each isolating wall 14b, the portions for containing the materials to be heated 11 and 12 and the portion for containing the material not to be heated 13 forms sealed apertures completely isolated with each other. Especially, at the isolating wall 14 between the first container 11 and the second container 12, and at the isolating wall 14 between the second container 12 and the portion for containing the material not be heated 13, high sealing performance is ensured due to the respective attachment of the partition ribs 17a and 17b of the lid 1 to the concavities 18 of the container 3. Now, upon using the heating device constituted as described above, cooked rice A, and other articles of food B and C are placed in each container 11, 12 and 13, respectively, after the container 3 is placed in the container 2, then, the lid 1 is placed on the upper surface of the container 2. Upon eating the contained foods A, B and C, for example, a few hours later, the portion for containing the exothermic material 4 provided inside of the heating device is operated and among the foods described above, only the foods A and B contained in the portions for containing the materials to be heated 11 and 12, respectively, are heated. The heating process of the above-mentioned heating device is explained. The tear element 7 extending outside of the container 2 is pulled until the mark 9 showing the limit of the length to be pulled is seen from the outside. Then the water bag 5b in the portion for containing the exothermic material is torn and water having contained inside thereof touches calcium oxide contained in the exothermic material bag 5a, which causes calcium oxide to vigorously generate heat and high temperature vapour due to the hydration reaction. Moreover, at this time, as the water bag 5b is provided below the exothermic material bag 5a and a number of small holes are provided on the exothermic material bag 5a, water in the water bag 5b permeates upward through the small holes of the exothermic material bag 5a resulting in uniform and gradual contact of the water and the whole of the calcium oxide inside of the exothermic material bag 5a. Accordingly, the process of heat generation of calcium oxide is highly effective and its duration time is long. The high temperature vapour is sent to the portions for containing the materials to be heated 11 and 12 in the container 3 through the filter material 8 of the insulation container 6, and then through the apertures 15 and 16 in the container 3, thus heating the foods A and B in the containers 11 and 12 together with the conductive heat transferred through walls of the container 3. Thus, as the high temperature vapour spouts not only from below but also from above, the rice A contained in the first container 11 is heated both from above and below. Still, the food C in the container for the material not to be heated 13 is not heated, as the container for the material not to be heated 13 in the container 3 is positioned away from the heating device and further the partition rib 17b attaching to the concave 18 of the partition wall 14 of the container 3 is provided. The high temperature vapour is filtered by the filter material 8 so that it enters the containers for the materials to be heated 11 and 12 only after impurities such as calcium oxide and calcium hydroxide generated by the reaction of calcium oxide and water have been removed, whereby decrease in the tastes of the rice A and the articles of food B by the impurities is prevented. Further, the vapour in the first container 11 and that in the second container 12 are not mixed, which prevents the vapour reeking of the articles of food B from contacting with the rice A and vice versa, thus preserving the tastes from decreasing with the mixture of the smells. As only the rice A and the articles of food B which increase their tastes when they are hot are heated, and the articles of food C which increase their tastes when they are cold remain cold, a more tasty meal can be obtained. The present invention can also be utilized as a heating device for heating retort-packed food contained in a bag made of aluminium or instant food cooked only by heating and so on, other than as a lunch box as described in the first embodiment. Moreover, the heating device may be constituted in such a way in which while providing the apertures 15 and 16 spouting the vapour in the first container 11, such apertures are not provided in the second container 12, so that the articles of food B are heated without using the vapour. In this case, if the container 3 is made of aluminium, it is possible to appropriately bake the articles of food B in the second container 12. The tear element 7 is not limited to a tape-shape as described above, but it may be a sharp-pointed stick type. In this case, the water bag is broken by piercing it with the tear element from the opening. The tear tape 7 may be affixed to both the bag for the exothermic material 5a and the bag for water 5b so that both bags 5a and 5b can be broken at the same time. The insulation container 6 prevents the exothermic source 5 and the container 2 from directly contacting each other in order to prevent the container from melting or deforming due to the heat generated from the exothermic source 5. The insulation container 6 is a flat box which has an opening at the top, inside of which the exothermic source 5 is contained. A sheet-type filter material 8 which allows the vapour of high temperature to pass but prevents small pieces of the exothermic material from passing through is spread on the upper opening. A non-woven fabric may be used for the filter material 8. The portion for containing the exothermic material 4 is a cartridge, and is contained in the container in a removable way, that is, the container can be re-used by replacing a used container of the exothermic material 4 with an unused one. Moreover, the portion for containing the exothermic material 4 and the container 2 may be constituted in a body to be used in a disposable way. The container 2 is, as shown in Fig. 3, a flat cubic box having a releasable top and is made of styrene foam. At the bottom of the container 2, a partition 9 projecting inwards from a bottom wall 2a is formed, thus partitioning and forming a portion 10 for containing the portion for containing the exothermic material 4. The container 3 is made of plastic, formed in a body. The container 3 includes an engagement part 3a formed at the edge of the outside periphery of the container 3 to engage the container 3 to the outside periphery at the top of the opening of the container 2, and is partitioned by isolating walls 14 to form a first portion for containing a material to be heated 11, a second portion for containing a material to be heated 12, both located above the portion for containing the exothermic material 4, and a portion for containing a material not to be heated 13 located away from the materials to be heated 11 and 12. Moreover, at the top of the isolating wall 14 located between the first containing portion 11 and the second containing portion 12, a slit-shaped aperture 16 is formed to spout out the high temperature vapour into the first containing portion 11 from above. As shown in Fig. 2, when the container 3 is attached to the container 2, as the portion for containing the material not to be heated 13 is completely isolated from the portion 10 containing the insulation container 6 by the partition 9 of the container 2, it is insusceptible to the heat of the exothermic reaction from the portion for containing the exothermic material 4. The lid 1 to cover the container 2 is, similar to the container 3, made of plastic, formed in a body, having an engagement part 1a to engage the engagement part 3a of the container 3 at the edge of the outside periphery in a state in which the engagement part 1a covers with the engagement part 3a and inner surfaces 1b to be faced to the top of each isolating wall 14 of the container 3. At the inner surfaces corresponding to the isolating wall 14 between the first and second portions for containing the materials to be heated 11 and 12, and to the wall 14 between the second portion for containing the material to be heated and the portion for containing the material not to be heated 13, the above mentioned partition ribs 17a and 17b are provided. As shown in Fig. 2, the partition rib 17a facing to the concavity 18 of the isolating wall 14 between the first container portion 11 and the second container portion 12 is provided in such a manner as a facing part of the partition rib 17a is located at the outside (on the right side in Fig. 2) of an aperture 16 for allowing high temperature vapour to escape. Figs 6 to 10 show a heating device according to a second embodiment of the present invention. In the above-mentioned heating device according to the first embodiment, the lid 1 is a sealing lid and therefore, if the volume of vapour entering the containers 11 and 12 is more than that of the portions for containing the materials to be heated 11 and 12, heating of the materials to be heated may be done insufficiently, or the tastes of food may be decreased because of dew of the vapour attaching to or permeating into the material to be heated. Further, in the case in which the sealing between the container and the lid is not appropriate, the vapour of high temperature may spout from an aperture between the container and the lid, or the lid may be blown off. Accordingly, as shown in Fig. 6, a small cut 19 is provided on a lid 1 of the heating device according to the preferred embodiment 2, so that the vapour in excess of the volume of the portion for containing the material to be heated in the container is gradually discharged through the cut 19 to the outside, thus the inside of the container is always kept filled with newly generated high temperature vapour. Moreover, a state of heating inside of the portion for containing the material to be heated can be detected from the vapour being discharged from the cut 19. In the case in which the portion for containing the material to be heated is divided into some parts, such cut 19 is not required to be provided at the lid corresponding to the container on which any vapour remaining therein or any dew generated does not have any adverse effect. Such cut 19 may be provided at the lid corresponding to the container for the material not to be heated. By providing the cut 19 at such a location, even if the vapour enters the container for the material not to be heated as a result of deformation or a damage of the isolating wall between the portion for containing the material to be heated and the portion for containing the material not to be heated, the vapour can be discharged. A plurality of cuts 19 may be provided at every location corresponding to the partitioned portions for containing the material to be heated, so that the vapour having entered the portions for containing the material to be heated can be discharged in a short time. Fig. 7 shows a longitudinal sectional view of the cut 19. As shown with two-dot chain lines, the cut may be lifted upward. In this case, as an opening for discharge of the vapour is made bigger, the vapour in the portion for containing the material to be heated is discharged in a shorter time. In the case as shown in Fig. 6, the cut has a V-shape, but a variety of shapes can be considered as shown in Figs. 8 to 10. A cut shown in Fig. 8, for example, has a U-shape, a cut shown in Fig. 9 has an approximately trapezoid-shape, and a cut shown in Fig. 10 has an approximately rectangular shape.

Claims: A heating device comprising an upper container (11 or 12) for materials to be heated; a lower container (6) containing separately water and an exothermic material which generates heat when it contacts water; means (7) for starting contact between the water and the exothermic material operable from the outside of the device; and a cover (8) on an opening of the lower container (6); characterized in that the cover (8) of the lower container (6) is a sheet-type filter means which allows high temperature vapour to pass but prevents the exothermic material from passing through, and the bottom wall (11a,12a) of the upper container has apertures (15). The heating device of claim 1, wherein the water and the exothermic material are contained in separate bags (5). The heating device as claimed in claim 2, in which said starting means (7) is tape-shaped for tearing the water bag (5b). The heating device as claimed in any of claims 1 to 3, in which said exothermic material is calcium oxide. The heating device as claimed in any of the preceding claims, which has a removable lid (1). The heating device as claimed in claim 5, in which said lid is provided with slits (19) through which the vapour entered into said portion can be vented to the outside of the heating device.

Inventors: KANEKO GENTOKU, KANEKO, GENTOKU
Applicants: JAPAN WARMER INC, JAPAN WARMER INC.
Application year: 1988
Main classification: A47J36
IPC codes: A47J36, B65D81