JPH09192026A - Exothermic body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exothermic body which is easy to handle and capable of maintaining a long reaction time. SOLUTION: An exothermic agent 3 is composed of a mixture consisting of 85-90% quicklime and 15-10% anhydrous magnesium chloride, to which approximately 1% aluminum oxide is added in weight ratio. The exothermic agent 3 is contained in a water-permeable bag 2. The quicklime has a purity of 96% or more and a particle size of 150-600μm, and the water-permeable bag 2 is composed of a material having 55-70 mesh pores for water permeation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating element for heating food and drink by adding heat to generate heat.

[0002]

2. Description of the Related Art There is a heating element for heating food and drink which contains a heating agent mainly composed of granular quicklime in a water-permeable bag such as nonwoven fabric. When soaked, quicklime generates heat due to a hydration reaction to heat food and drink.

When water is added only to quick lime, the quick lime reacts rapidly with water to generate heat, which may cause burns to the user and the quick lime may expand and break the bag. In order to suppress the rapid reaction of, the exothermic agent was a mixture of quicklime and magnesium chloride.

In order to safely and sufficiently heat food and drink, it is necessary to appropriately control the reaction rate and keep the reaction duration long. Regarding the reaction rate, the user adds water to the exothermic agent. It is desirable to control the heating time so that the heating element does not reach a high temperature and then quickly reaches the maximum temperature, and in order to keep the reaction duration long, all the heating agents in the heating element must react. I have to.

In the conventional heating element, magnesium chloride is mixed in to suppress the reaction, but even after 1 to 2 seconds, the maximum temperature is reached and steam rises, and the user does not pay sufficient attention when pouring water. There was a risk of getting burned.

[0006] When water is added to quicklime, the surface of quicklime is changed into paste-like calcium hydroxide which is a hydrated compound of quicklime. This paste-like calcium hydroxide covers the surface of quicklime and enters the interior of quicklime. Water was prevented from seeping in, and unreacted quicklime remained, so that a sufficient reaction duration could not be obtained. An object of the present invention is to provide a heating element that can be used safely and that can maintain a long reaction duration.

[0007]

In order to achieve the above object, the heating element according to the present invention contains quick lime of 85 to 85 in weight ratio.
About 1% of aluminum oxide was added to a mixture of 90% and anhydrous magnesium chloride of 15 to 10% to form an exothermic agent, and the exothermic agent was stored in a water-permeable bag, and the quicklime had a purity of 96% or more. And a particle size of 150 to 600 μm, and the water-permeable bag is made of a material having small holes for water transmission of 55 to 70 mesh.

[0008]

EXAMPLES Specific examples of the heating element according to the present invention will be described in detail below. As shown in FIG. 1, the heating element 1 of this embodiment has a water-permeable bag 2 containing a heating agent 3, and the water-permeable bag 2 has small holes (mesh) of 55 to 70 mesh.
For example, a non-woven fabric is used, and the exothermic agent 3 is a mixture of quicklime of 85 to 90% and anhydrous magnesium chloride of 15 to 10% in weight ratio, to which about 1% of aluminum oxide as a catalyst is added. The quicklime is used in the form of powder having a purity of 96% or more and a particle size of 150 to 600 μm.

The heating element 1 constructed as described above is placed in the inner bottom of a water-resistant box-shaped container 4 as shown in FIG. 2, the object to be heated 5 is placed on the box-shaped container 4, and the lid of the container is closed. From the water injection port 6 opened on the side surface of the container, approximately the same amount of water as the mass of the exothermic agent is injected and used.

The water inlet 6 is designed so that it can be closed after water injection, as shown by the phantom line in FIG.
The vapor from the exothermic reaction is prevented from escaping from the water inlet. The reference numeral 7 in the figure indicates a tray on which an object to be heated is placed.

The water injected into the container penetrates the bag 2 of the heating element 1 and enters the bag to react with the heating agent 3. Not all of the injected water is used for the hydration of the exothermic agent,
A part is heated to become water vapor, which fills the container 4 and heats the object to be heated 5 from all directions.

Next, how the surface temperature of the heating element changes with the lapse of time was measured, and the results of tests on the following items will be described. A: Correlation between particle size of quick lime and reaction duration B: Correlation between addition amount of aluminum oxide and reaction start-up time C: Correlation between bag mesh and reaction start time All were carried out at room temperature of 20 ° C., the mass of the exothermic agent was 270 g, the amount of water injection was 270 cc, the mixing ratio of quicklime and anhydrous calcium chloride was all the same as those in the above-mentioned examples, and the above A and B matters were bags. The temperature of the central portion of the upper surface of the heating element was measured using a non-woven fabric of 60 mesh.

<A: Correlation between particle size of quick lime and reaction duration> A heating element according to the present invention using powdered lime having a particle size of 150 to 600 μm and a particle size of 1
The measurement results for the conventional heating element using flakes of ~ 5 mm are as shown in Fig. 3. From these results, the heating element of the present invention having a smaller particle size has a longer reaction duration than the conventional one. It can be seen that the time is long and the maximum temperature is kept high at about 5 to 10 ° C.

The results are examined. It is considered that the heating element of the present invention in which the particle size of quick lime is small has a large contact area between quick lime and water, and almost all quick lime can react with water.

<B: Correlation between Addition Amount of Aluminum Oxide and Reaction Start-up Time> The heating element according to the present invention in which 1% of aluminum oxide is added to the heating agent, and no addition of aluminum oxide, 0.5% The measurement results for the addition of 2% and the addition of 2% are shown in FIG. 4, and it can be seen that the heating element of the present invention to which 1% of aluminum oxide is added has the fastest reaction rise time.

<C: Correlation between bag mesh and reaction start time> A heating element according to the present invention which uses a 55 mesh, 60 mesh or 70 mesh non-woven fabric as a bag material, 45
The measurement results for the one using the non-woven fabric of mesh are as shown in FIG. 5, and all the heating elements according to the present invention reached the maximum temperature about 10 seconds after the addition of water. It can be seen that the 45 mesh has a sharply increased temperature and a low maximum temperature.

Considering this result, in the heating element according to the present invention, the maximum temperature is reached after a lapse of time (about 10 seconds) related to the addition of water, so that the user may be burned. However, in the case of a heating element that uses a 45-mesh non-woven fabric, on the other hand, water immediately flows into the bag and reaches the maximum temperature immediately, while water does not reach the entire heating element. It is probable that the reaction time could not be maintained due to the remaining quick lime that could not react.

The same test was carried out for a heating element using a non-woven fabric of 80 mesh or more, but since the non-woven fabric was too fine, almost no water could flow into the bag and the temperature change could be measured. There wasn't.

[0019]

Since the heating element according to the present invention has the above-mentioned structure, the following operational effects can be obtained. When water is added to the heating element, the water passes through the small holes of the water-permeable bag and reacts with the heating agent in the bag to generate heat.

At this time, since the bag having the small holes of 55 to 70 mesh is used, the water does not collect at the local part of the heating element and spreads throughout the whole, and moreover, it is the main composition of the heating agent. Since quicklime has a particle size of 150 to 600 μm, it has a large contact area with water and is covered with pasty calcium hydroxide, which is a hydrated compound of quicklime, like a conventional heating element. Almost all exothermic agents can react with water to keep the reaction duration long, and the maximum temperature can be kept high without leaving unreacted quicklime.

The exothermic agent is a mixture of quick lime and anhydrous calcium chloride, and since the rapid hydration reaction of quick lime is suppressed by the anhydrous calcium chloride, 1% of aluminum oxide is added. After the required time, the reaction is promptly carried out and it can be used safely.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view showing an embodiment of a heating element of the present invention.

FIG. 2 is a vertical cross-sectional view showing an example of use of the heating element of this embodiment.

FIG. 3 is a graph showing the results of tests conducted on the correlation between the particle size of quicklime and the reaction duration.

FIG. 4 is a graph showing the results of tests conducted on the correlation between the amount of aluminum oxide added and the reaction rise time.

FIG. 5 is a graph showing the results of tests conducted on the correlation between the bag mesh and the reaction start time.

[Explanation of symbols]

 1 heating element 2 bag 3 exothermic agent 4 container 5 heated object 6 water inlet 7 tray

Claims (1)

[Claims] 1. A heat generating agent is prepared by adding about 1% of aluminum oxide to a mixture of 85 to 90% by weight of quick lime and 15 to 10% by weight of anhydrous magnesium chloride. The quicklime is made of a material having a purity of 96% or more and a particle size of 150 to 600 μm, and the water permeable bag is made of a material having small holes for water transmission of 55 to 70 mesh. A heating element made up of components.