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 by heat of 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 (kaukoku) 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 partion 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 tile wall can not be heated until they reach a sufficient temperature. Especially, 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 an inner temperature is not raised sufficiently.
The heating devices, described in Japanese utility model publication (koukai) Nos. 62-123742 and 61-137318, have an aperture at a bottom wall. The vapor produced by heat of hydration reaction can heat the materials to be heated without causing uneveness of temperature, as described above.
In the heating devices described in Japanese utility publication (koukai) Nos. 62-123742 and 61-137318, it is a problem that small pieces of the exothermic material may be attached to the material to be heated together with the vapor of high temperature through apertures of the portion for containing the material to be heated.
The object of the present invention is to provide heating device in which small pieces of the exothermic materials spattered by reaction of the exothermic material and water does not tend to attach to the material to be heated.
Then, the heating device described above is one in which the exothermic material and water after hydration reaction are mounted with unremoved off, 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 Japanese utility model (koukai) No. 61-137318, the device, after having made hydration reaction of the exothermic materials could not be re-used.
The other object of the present invention is to provide a cartridge-type heating device comprising portion a for containing the exothermic materials, which is applied to different styles of the heat devices, and also the heating devices are reusable.