JPS645899B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called chemical heater that generates heat by using the oxidation reaction of iron powder. This invention relates to a time control method.

In recent years, heat insulators have been developed that utilize the oxidation reaction of iron powder to generate heat. This warmer is safe because it does not use a combustion mechanism like traditional warmers, and it is not subject to size or usage restrictions, so it can be used not only for its original purpose of being used in a pocket, but also for keeping warm. Hottie as Matsuto,
It has the characteristic that it can be widely used for various purposes as a heat-retaining device.

By the way, conventional chemical pots are made by enclosing water absorbents such as pure iron, coal powder, metal salts, moistened sawdust, silica gel, and fiber waste in a breathable, water-repellent bag. The material is sealed in an airtight packaging bag, and when used, the bag is removed from the packaging bag and the contents are thoroughly shaken to evenly contact the pure iron powder with the moisture in the water absorbent such as sawdust. This was to cause an exothermic reaction to take place.

Therefore, in conventional chemical hot pots, a certain amount of iron or more is required to obtain the necessary heat capacity of the hot pot, and the amount of water filled in the bag relative to the amount of iron powder is Due to the limited heat, the duration of heat generation was limited to 20 to 24 hours when using chemical gels that were applied to the body.

Moreover, even though a considerable amount of unreacted iron remains after use, these unreacted irons are discarded without being reused. Furthermore, since conventional chemical pots contain moisture during production, it is necessary to cut off contact with air and preferably perform production in a nitrogen atmosphere, but in reality this is difficult. Manufacturing was carried out in air, and the oxidation of iron powder progressed during manufacturing, resulting in wasted energy.

An improved product that compensates for these drawbacks is a method in which iron powder, other catalysts, charcoal powder, and hydrated water absorbent are separated in the same bag and mixed together at the time of use, iron powder, catalyst, charcoal powder, and water absorbent. There is a method in which a bag filled with water and a mixture of iron powder is sealed in advance in the same bag as the iron powder, and the water bag is crushed before use. In both cases, the loss of iron powder oxidation due to air intrusion is taken into consideration, but in this case, the water contained during manufacturing gradually radiates out of the bag as steam, leaving unused iron powder. There are still drawbacks, such as the manufacturing process being complicated and the failure rate high. In addition, in the method using a water absorbent, as the water in the water absorbent heats up, it is gradually lost as water vapor, and the space inside the bag is replaced by air, which causes the amount of air to become too large relative to the amount of iron powder, and the temperature rises. The temperature rises and often causes low-temperature burn injuries.

On the other hand, warmers are used during daytime activities and when going to bed, but they are rarely used continuously for more than 10 hours, and it is not necessarily advantageous to continuously generate heat for a long period of time due to the purpose of use. From this point of view, it must be said that conventional products that generate heat for a long time after being used only once are a huge loss of energy because they continue to generate heat even when not in use.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for controlling the duration of heat generation in a chemical heating element.

In order to achieve the above object, in the heat generation time control method of a chemical heater according to the present invention, on the surface of a bag body containing a mixture mainly composed of iron powder and metal as a heating element and having surface water absorption and air permeability, Add a water carrier of a predetermined size that has a water-containing property such as sponge, paper, rubber, synthetic resin foam, etc., and is saturated with an amount of water that is less than the amount necessary for the total amount of heat generated by the heating element. Water is supplied, the heat generation duration of the heating element is controlled by the water content specific to the water carrier, and the heat generation time is divided into two or more times.

Examples of the present invention will be described below.

A water carrier impregnated with a certain amount of water is superimposed on one side of the inner bag, which is made of a sheet-like material that has air permeability, water permeability, and surface moisture content, and contains a certain amount of iron powder and metal acid salts. Insert into a waterproof outer bag that has ventilation holes on a portion of the surface.

The water contained in the water carrier wets and penetrates the surface of the inner bag, while air is supplied into the inner bag through the vents opened in the outer bag, causing the iron contained in the mixture to penetrate into the inner bag. Heat is generated due to the oxidation reaction of the powder.

The iron powder used is not only the pure reduced iron conventionally used in this type of hotpot, but also thoroughly ground shavings of cast iron, pig iron, etc. that contain carbon in the iron. In the case of pure iron, it is necessary to add charcoal powder, but if the iron contains 3 to 4% carbon, there is no need to add charcoal powder. Moreover, pig iron powder is a solid solution system with carbon, which is advantageous in terms of the utilization of iron. When charcoal powder is added to iron powder, the oxidation reaction of the iron stops only at the surface, and the heat generation often ends while the inside remains unreacted.

Although the particle size of the powder is not particularly limited,
100 to 400 meshes is sufficient.

As the salts to be mixed with iron, mineral acid salts of alkali metals, alkaline earth metals, aluminum, and iron are suitable, and alkali metal hydrochlorides and nitrates are particularly preferred, and dilute mineral acids and organic acids are also effective. The proportion of these metal salts used alone or in combination with respect to the iron powder varies depending on the purpose of use, but is approximately in the range of 1 to 10%.

Specific examples of metal acid salts include potassium chloride, sodium chloride, potassium nitrate, sodium nitrate, calcium chloride, magnesium chloride, barium chloride, magnesium nitrate, magnesium sulfate, ferric sulfate, aluminum chloride, citric acid, malic acid, etc. can be mentioned.

It is necessary that the bag for the heating element has air permeability and water permeability, and in particular, the surface has water-retaining properties. It is also possible to use a material in which the surface of the breathable sheet is subjected to a water-retaining treatment. When the material is a laminate sheet of nonwoven fabric, paper, or woven fabric and a synthetic resin film with many small holes, such as polyethylene film, a fixed amount of the mixture is supplied onto the surface of the polyethylene sheet, and the sheet is bent. The open edges are sealed by heat sealing. The outer surface of the resulting bag is covered with a water-absorbing nonwoven, paper or woven fabric.

The water carrier controls the duration of heat generation, and uses water-containing materials such as sponge, paper (cellulose), rubber, and synthetic resin foam. The water content of a water carrier is determined by its water carrying capacity. The water holding capacity is determined by the size of the water carrier. Accordingly, the present invention uses a water carrier of a predetermined size that is saturated with a certain amount of water content. The size of the water carrier will define the amount of water to be supplied to the heating element.

The outer bag is a case that stores the inner bag containing the mixture and the water carrier.In order to prevent water contained in the water carrier from seeping out, a waterproof sheet made of synthetic resin, rubber, etc. is processed into a bag shape. , one or more ventilation holes for controlling the amount of air supplied are opened on one side thereof. Alternatively, a metal or plastic case that maintains a certain shape may be used, and ventilation holes may be opened on one or more surfaces thereof. In order to strictly control the heat generation temperature, the inner bag and the water carrier insertion opening provided in this outer bag should be airtightly sealed, and air should be supplied into the outer bag only through the ventilation holes, and all of the ventilation holes should be The opening area is determined according to the required heat generation temperature.

When the outer bag is not used, the heating element always generates heat at its maximum temperature and cools down to a low temperature in a relatively short period of time. When using it as a so-called "kairo" to put in your pocket, it is better to use an outer bag.

The use of water carriers is effective in controlling the amount of water supplied. A certain amount of water can be supplied by selecting the material and size. When the amount of air supplied is constant, the duration of heat generation is proportional to the amount of water supplied, and when the amount of air is not limited, the temperature of heat generation increases.

By adding the absorbed water carrier to the heating element, the surface of the heating element becomes hydrated, and the moisture permeates into the interior through the small pores of the synthetic resin film along with the air, and the oxidation reaction of the iron powder begins, generating heat. do. Even if a large amount of water is added at once, most of it will be absorbed by the surface, and the space between the particles of the mixture will not be blocked by water, thereby preventing heat generation.

As described above, the heating element of the present invention starts generating heat by supplying water during use.
The temperature and duration of heat generation can be freely controlled. Therefore, the heating element can be divided into two or more parts to generate heat. In addition, when a laminate sheet of water-containing, breathable nonwoven fabric, paper, or woven fabric and a perforated synthetic resin film with heat-sealing properties is used for the heating element bag, filling and sealing of the mixture becomes easier. During use, the supplied water is temporarily held on the surface and then gradually supplied through the small holes of the synthetic resin film, so the exothermic reaction is not hindered, especially when used in combination with an outer bag. For example, most of the water vapor generated by the exothermic reaction can be trapped in the outer bag, and this water vapor can be circulated inside and outside the heating element to effectively sustain heat generation.

According to the present invention, by setting the size of the water carrier, that is, setting the water content capacity, the water carrier can be impregnated with water in an amount that is a fraction of the amount of water required to generate heat in the mixture filled in the bag. This has the effect that the chemical heating element can be repeatedly used to generate heat whenever necessary.

Claims (1)

[Claims] 1. The surface of a bag body containing a mixture mainly composed of iron powder and metal as a heating element and having surface water absorption and air permeability is saturated by impregnating it with an amount of water that is less than the amount required for the entire amount of heat generated by the heating element. Water is supplied by adding a water-containing water carrier of a predetermined size such as sponge, paper, rubber, synthetic resin foam, etc., and the duration of heat generation of the heating element is determined depending on the water content specific to the water carrier. 1. A heat generation time control method for chemical heating, characterized by controlling the heat generation time and dividing the heat generation time into two or more times.