JPH088043A - Soaking device - Google Patents

Abstract

(57) [Summary] [Objective] As a device for thawing frozen foods or a device for producing pressed flowers, it is possible to uniformly heat an object to a low temperature range of 100 ° C or lower at a constant temperature. A thermal device is provided. A far-infrared radiation plate is formed by forming an anodized film having a thickness of 5 to 50 μm that exhibits gray or black on at least a front surface of a substrate made of an aluminum alloy, and the far-infrared radiation plate has a rear surface side. In addition, a self-controlled temperature heater including a resistance heating element having a positive resistance temperature coefficient is provided. Further, in particular, the heating element of the self-controlling temperature heater is composed of a resistance heating element in which conductive carbon particles are dispersed in a crosslinked polymer. It can be used not only as a defrosting device for frozen foods but also as a pressed flower manufacturing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat equalizer for heating and warming various articles in a low temperature region of 100 ° C. or lower for thawing frozen foods and creating pressed flowers.

[0002]

2. Description of the Related Art Various methods have been conventionally known as a method for thawing frozen foods such as fish and meat. Among them, natural thawing has a relatively low risk of deteriorating the flavor of fish meat or the like, but it takes a considerably long time to complete the thawing. Therefore, in the fish market where a large number of large frozen fish are handled, water, warm water, or hot water is directly thawed to the frozen fish. It has the disadvantage of being time consuming and often impairing the flavor of fish meat.

On the other hand, recently, a thawing plate using an aluminum thick plate which has good thermal conductivity and has few problems in food hygiene has been put into practical use. This thawing plate removes heat from the frozen fish or the like only by placing the frozen fish or the like on the thawing plate and causes the thawing by this, and it is said that the thawing plate can be thawed in a relatively short time. However, in a thaw plate made of such an aluminum thick plate, it is necessary to make the plate thickness at least 5 cm or more in order to increase its heat capacity and remove heat from the frozen food for a long time. In addition to the problem that it causes troubles, there is a problem that the thawing time is not sufficiently shortened for large-sized frozen foods, and the thawing does not proceed sufficiently when the ambient temperature is low due to the influence of the ambient temperature.

On the other hand, a thawing plate using a far infrared ray radiating function of ceramics has been put into practical use by using a ceramic plate instead of an aluminum plate. However, a thawing plate using a ceramic plate is also heavy and is not always sufficient for shortening the thawing time, and there is a problem that thawing does not proceed easily when the ambient temperature is low.

Further, as a constitution for holding hot water so as to contact the surface opposite to the thawing surface of the aluminum plate or the ceramic plate as described above, the so-called "hot water bottle" for thawing by transmitting the heat retained by the hot water to frozen foods. "Thawing equipment of the type" has also been put to practical use, but such hot water bottle type thawing equipment requires labor for pouring and discharging hot water, is not only inconvenient to handle, but also has a small heat capacity, so the temperature of hot water is low. However, there is a problem that the decompression progresses slowly.

Therefore, recently, there has been proposed a thawing apparatus which combines a ceramic plate having a far infrared ray emitting function and an electric heater such as a nichrome wire heater. Specifically, an electric heater such as a nichrome wire is arranged on one plate surface of the ceramic plate, and the ceramic plate is configured to be heated by the electric heater. It is placed on the defrosted surface. According to such a thawing device, it is possible to thawing in a short time without impairing the flavor and texture of food by far infrared rays emitted from the ceramic plate maintained at an appropriate temperature by the electric heater. .

[0007]

As described above, in the conventional defroster in which a ceramic plate having a far infrared ray radiating function and an electric heater are combined, a temperature sensor such as a thermostat is provided and a current flowing through the electric heater is provided. A general configuration is to keep the temperature of the ceramic plate constant by controlling ON and OFF. However, in such a defrosting device that controls on / off of the electric heater by using the temperature sensor, the fluctuation range of the temperature of the ceramic plate is large, and usually fluctuates by about ± 5 ° C, and therefore, the optimum defrosting temperature can be maintained. However, there is a problem that the flavor of the food is impaired and the thawing time varies. In addition, the ceramic plate generally has low thermal conductivity, while a linear electric heater such as a nichrome wire is often heated locally, in which case the temperature distribution of the ceramic plate becomes uneven.
There is also a problem that thawing for that purpose cannot be performed uniformly. Further, since the ceramic plate is difficult to process, there is also a problem that the degree of freedom of the shape is small.

Among the drawbacks of the conventional defrosting apparatus that combines a ceramic plate having a far-infrared radiation function and an electric heater as described above, the on / off control is changed to a proportional control method in order to solve the problem of temperature fluctuation. Can be considered,
In this case, a new problem that causes a large increase in cost occurs, and the problems other than the above problems cannot be solved.

On the other hand, there are cases where it is desired to heat and heat various articles to a constant temperature in a low temperature region of 100 ° C. or lower for purposes other than thawing frozen foods.
For example, while pressing a fresh flower while heating it in a low temperature range to remove water in the fresh flower, a pressed flower may be produced, but there is no soaking device suitable for making such a pressed flower. It was That is, when creating pressed flowers, it is desirable to heat in a low temperature range of 40 ° C. or lower in order to prevent the occurrence of discoloration, but a device for stably and uniformly heating in such a low temperature range is available. It has not been put to practical use in the past.

The present invention has been made in view of the above circumstances, and various kinds of articles are uniformly heated to a constant temperature in a low temperature range of 100 ° C. or lower in order to thaw frozen foods or create pressed flowers. The object of the present invention is to provide a soaking device that can be heated and has a large degree of freedom in shape.

[0011]

In order to solve the above-mentioned problems, the soaking apparatus according to the invention of claim 1 has a thickness 5 which is gray or black on at least the surface of the base material made of an aluminum alloy. A far-infrared radiation plate is formed by forming an anodic oxide film having a thickness of up to 50 μm, and a self-controlled temperature heater having a resistance heating element having a positive resistance temperature coefficient is provided on the back side of the far-infrared radiation plate. It has a specific configuration.

[0012] According to a second aspect of the heat equalizer of the present invention, in the heat equalizer of the first aspect, the aluminum alloy of the substrate contains Mn in an amount of 0.3 to 4.3 wt% and the balance substantially. And is made of Al.

Further, the heat equalizer of the third aspect of the present invention is the heat equalizer of the first aspect, wherein the aluminum alloy of the substrate contains 1 to 25 wt% of Si, and the balance substantially consists of Al. It is configured.

Further, the soaking apparatus according to the invention of claim 4 is
The heat equalizer according to claim 1, wherein the heating element of the self-controlled temperature heater is composed of a resistance heating element in which conductive carbon particles are dispersed in a crosslinked polymer.

On the other hand, a heat equalizer according to a fifth aspect of the present invention is the heat equalizer according to the first aspect, wherein frozen food is placed on the front surface of the far-infrared radiation plate and the frozen food is thawed. It is a decompression device for.

A heat equalizer according to a sixth aspect of the present invention is the heat equalizer according to the first aspect, wherein a fresh flower is pressed against the front side surface of the far-infrared radiation plate and the fresh flower is used as a pressed flower. It is a manufacturing device.

[0017]

When the soaking apparatus of the present invention is used as, for example, a defrosting device for frozen food, the frozen food to be defrosted is the front surface of the far infrared radiation plate (the surface on which the anodized film is formed). The device is placed on the substrate and a current is passed through the resistance heating element of the self-controlled temperature heater. As a result, the resistance heating element generates heat, and the far infrared radiation plate is heated. The far-infrared radiation plate is formed by forming an anodic oxide film on at least the front surface of a base material made of an aluminum alloy, and the anodic oxide film is alumina (Al ₂ O ₂₎ which is a type of ceramic.
_Since it consists of ₃ ) and is gray to black, it emits far infrared rays. Then, the heat of the far-infrared radiation plate is directly transferred to the frozen food, and at the same time, the far-infrared radiation generated from the far-infrared radiation plate is absorbed by the frozen food, so that the frozen food is thawed.

Since the resistance heating element of the self-controlled temperature heater has a positive resistance temperature coefficient, the electric resistance of the resistance heating element increases as the temperature rises, so that the resistance heating element has both ends. If the voltage applied to the resistance heating element is constant, the current flowing through the resistance heating element decreases, and the amount of heat generated by the resistance heating element also decreases. Therefore, the balance is maintained at a certain temperature, the temperature of the resistance heating element is maintained at the certain temperature, and the far infrared radiation plate is also heated and maintained at the certain temperature. The resistance temperature coefficient of the resistance heating element is the coefficient of resistance with respect to the ambient temperature (the temperature given by frozen food in the case of a defroster) plus the temperature rise due to the heat generated by the resistance heating element itself. Therefore, the self-controlled temperature heater including a resistance heating element having a positive temperature coefficient of resistance is self-controlled to a constant temperature regardless of whether the ambient temperature is high or low. That is, for example, when the ambient temperature is low as in the initial stage of thawing, a large amount of heat is generated and the temperature rises rapidly, while when the ambient temperature is high as in the latter stage of thawing, the amount of heat is reduced.
A constant temperature can be maintained regardless of the ambient temperature (especially the temperature of the frozen food product in the case of a thawing device). The constant holding temperature can be changed depending on the type of constituent material of the resistance heating element, the composition ratio of the constituent material, and the like.

As described above, the self-controlling temperature heater generates heat at a constant temperature, which heats the far infrared radiation plate to a constant temperature and radiates a certain amount of far infrared rays. When used as a thawing device, the far infrared rays are absorbed by the frozen food as described above, and thawing proceeds. In the case of thawing such frozen food, it is appropriate that the heating temperature is room temperature (about 10 to 40 ° C). When thawing a frozen food by far infrared rays, first, the ice around the food is thawed, and then the inside of the food is thawed.When the inside of the food is thawed, the far infrared rays act on the components such as proteins of the food. , Can be thawed in a state close to natural thaw without degrading the food ingredients. When used as a pressed flower manufacturing device, a fresh flower is pressed onto the far infrared radiation plate, and an electric current is applied to the resistance heating element of the self-controlled temperature heater to generate heat, and heat of the far infrared radiation plate is applied to the fresh flower at the same time. By adding far-infrared rays from the far-infrared radiation plate to fresh flowers, pressed flowers can be obtained. The heating temperature in this case is appropriately 40 ° C. or lower in order to avoid discoloration, but as already mentioned, the soaking apparatus of the present invention ensures stable and uniform heating even in a low temperature region of 40 ° C. or lower. You can

Here, as the resistance heating element used for the self-controlled temperature heater, it is appropriate to use a mixture of conductive carbon powder particles in a crosslinked polymer such as polyolefin or fluororesin. In such a resistance heating element, the polymer repeats thermal expansion and contraction due to the temperature change of the heating element itself. And the center distance of each conductive carbon particle changes due to the expansion and contraction of the polymer,
As a result, the contact area between adjacent conductive carbon particles changes, and the electric resistance of the entire resistance heating element changes. Specifically, an electric current flows through the entire resistance heating element to generate Joule heat, and if the temperature of the resistance heating element rises and the polymer thermally expands, the center-to-center distance of the conductive carbon particles increases accordingly. As a result, the contact area between the adjacent conductive carbon particles is reduced, the electric resistance of the entire resistance heating element is increased, the current is reduced, and the amount of heat generation is reduced. The ambient temperature also affects the resistance value of the resistance heating element. Therefore, if such a self-controlled temperature heater is used, the temperature can be maintained at a constant temperature regardless of whether the ambient temperature is high or low, as described above. The temperature fluctuation in this case varies slightly depending on the constituent materials, but it is usually ±
It is in the range of 1 ° C., and therefore the temperature fluctuation is remarkably small as compared with the temperature difference of about ± 5 ° C. in the case of the conventional control method using a temperature sensor using a nichrome wire heater. Further, since the temperature is kept constant by the resistance change inside the resistance heating element, there is little variation in temperature depending on the location, and a uniform temperature distribution within ± 1 ° C. can be obtained.

On the other hand, the far-infrared radiation plate is formed by using an aluminum alloy as a substrate as described above and forming an anodized film exhibiting gray to black. The gray-black anodized film (Al
₂ O ₃ film) has a high far infrared radiation efficiency. Particularly, as an aluminum alloy as a base material, Mn as defined in claim 2
Al-Mn-based alloy containing 0.3 to 4.3 wt% and Al containing 1 to 25% of Si as defined in claim 3.
When using a -Si alloy, far-infrared radiation characteristics are remarkably excellent.

That is, in the case of the above Al-Mn-based alloy, the Al-Mn-based intermetallic compound is finely precipitated,
The fine intermetallic compound particles remain in a state of being dispersed in the anodized film after the anodizing treatment, and in the case of an Al-Si alloy containing 1 to 25 wt% of Si as defined in claim 3, Si is Depending on the content and heat treatment conditions, primary crystal Si,
Metallic Si particles are dispersed in the alloy as eutectic Si or precipitated Si, and such metallic Si particles also remain dispersed in the anodized film after the anodizing treatment. Incident light is scattered and absorbed by the dispersed particles such as intermetallic compound particles and metal Si particles in these anodized films to improve far-infrared radiation characteristics, and a porous anodized film is formed during anodizing treatment. During the growth process, the pores have a branched structure, and such branched pore structure promotes the scattering and absorption of incident light in the anodic oxide film, and further improves the far infrared radiation characteristics. Therefore, especially 1
It exhibits excellent far-infrared radiation characteristics even in a low temperature range of 00 ° C or lower. For example, A1 having an anodized film of 25 μm thickness formed
In the case of a conventional far-infrared radiation plate in which an ordinary anodized aluminum plate such as 050, A5052, etc. is used and the anodized film is dyed with an organic paint, the far-infrared radiation rate in a temperature range of about 20 to 30 ° C. is 70. ˜75%, while 2% in Al-2% Mn alloy in which Al ₆ Mn is dispersed.
In the case of a far-infrared radiation plate having an anodized film with a thickness of 5 μm, it exhibits a far-infrared emissivity of 90% in a temperature range of 20 to 30 ° C., and the wavelength dependence of the former is in the short wavelength range of 8 μm or less. While the emissivity is low and unstable, the latter shows a stable and high level emissivity even in the wavelength region of 8 μm or less. When the Al-Mn-based alloy or Al-Si-based alloy as described above is used as a base material, intermetallic compound particles or metal S existing dispersedly in the anodized film are present.
The i-particle also functions as a stress relaxation point, and the branching structure of the pores as described above has a high strain absorbing ability, so that cracks are less likely to occur and even if cracks occur, their propagation is blocked and heat resistance is improved. Good crackability.

Further, since the base portion of the far-infrared radiation plate is made of an aluminum alloy having a high thermal conductivity, the heat applied by the self-controlled temperature heater is uniformly transmitted throughout the plate, and therefore the far-infrared radiation is performed. The temperature inside the plate becomes uniform, and the far-infrared radiation amount radiated from the anodic oxide film for far-infrared radiation on the surface becomes uniform, so that an object to be heated such as frozen food can be uniformly heated.

Here, if the thickness of the anodic oxide film is less than 5 μm, sufficient far-infrared radiation characteristics cannot be obtained.
If it exceeds m, the anodic oxidation process requires a significantly long time, which is economically wasteful. Therefore, the thickness of the anodized film is set within the range of 5 to 50 μm. In the anodic oxidation treatment, Al-Mn as described above is used.
In the case of the Al-Si based alloy and the Al-Si based alloy, it is possible to form the above-mentioned anodic oxide film having excellent far infrared radiation characteristics by electrolysis using a normal sulfuric acid bath.

[0025]

1 to 3 show a soaking apparatus according to an embodiment of the present invention, and FIG. 4 shows an example of a self-controlled temperature heater used in the soaking apparatus of the present invention.

1 to 3, the storage case 1 is formed in the shape of a rectangular thin box having a bottom with an open top surface, and the storage case 1 has a rectangular flat plate shape as a whole on the upper open end side. The far infrared radiation plate 2 is horizontally fixed. The far-infrared radiation plate 2 has a base material 2A made of an aluminum alloy such as Al-Mn or Al-Si as described above.
An anodized film 2B is formed on the surface of the base material 2A as shown in FIG. A ridge portion 7 is formed on the back surface of the base material 2A to define a meandering concave groove 5 for positioning a self-controlled temperature heater 3 described later. The protruding portion 7 may be formed integrally with the base material 2A, or may be formed separately from the base material 2A and fixed to the base material 2A by an appropriate joining means.

A self-controlled temperature heater 3 as shown in FIG. 4 is arranged in the groove 5 along the meandering direction. The self-controlled temperature heater 3 is provided with a resistance heating element 3C having a positive resistance temperature coefficient across a pair of parallel conductive core wires 3A, 3B. The resistance heating element 3C and the conductive core wires 3A, 3B are provided. An insulating coating 3D made of fluororesin or the like is provided so as to cover the whole of the. And, in such a portion on one end side of the self-controlled temperature heater 3,
The conductive core wires 3A and 3B are connected to the connector 4 so that power is supplied from the outside. Further, the other end portion (terminal portion) 3E of the self-controlled temperature heater 3 is appropriately subjected to terminal treatment such as insulation. Here, as the resistance heating element 3C having a positive temperature coefficient of resistance, as described above, for example, a mixture of conductive carbon powder particles in a cross-linked polymer such as polyolefin or fluororesin is used. A braid made of tin-plated copper wire (not shown) may be provided on the insulating coating 3D, and in that case, another insulating coating (not shown) made of fluororesin or the like may be provided on the tin-plated copper wire braid.

Further, a heat insulating material 9 such as urethane foam resin is disposed between the portion where the self-controlled temperature heater 3 is located and the bottom surface of the storage case 1.

In the heat equalizer of the above embodiment, the conductive core wire 3A of the self-controlled temperature heater 3 is
When a voltage is applied between 3B, a current flows through the resistance heating element 3C between the conductive core wires 3A and 3B to generate heat due to the electric resistance, and the far infrared radiation plate 2 is heated. Here, as the resistance heating element 3C, a material obtained by kneading conductive carbon powder particles in a crosslinked polymer is used.
In C, as described above, the cross-linked polymer thermally expands and contracts due to the temperature change, which changes the center-to-center temperature of each conductive carbon particle and changes the contact area between adjacent conductive carbon particles. , The electrical resistance of the resistance heating element 3C between the conductive core wires changes. Therefore, as described above, the calorific value changes depending on the temperature and is maintained at a constant temperature regardless of whether the ambient temperature is high or low. In addition, the conductive core wire 3
Since the electric resistance of the resistance heating element 3C between A and 3B is the same in any portion of the self-controlling temperature heater 3 in the lengthwise direction, the temperature distribution in the lengthwise direction of the self-controlling temperature heater 3 becomes uniform. In addition, the self-controlling temperature heater 3 is provided in a meandering shape on the rear surface of the far-infrared radiation plate 2 in a substantially meandering manner, and the base portion of the far-infrared radiation plate 2 is made of an aluminum alloy to conduct heat. Since the property is good, the far-infrared radiation plate 2 itself is uniformly heated in its entire plate, the far-infrared radiation is uniformly radiated, and the object to be heated such as frozen food is uniformly heated.

Therefore, if the frozen food is placed on the far-infrared radiation plate 2, it can be thawed uniformly in a short time without deteriorating the quality of the food and impairing its flavor as described above. . If a fresh flower is placed on the far-infrared radiation plate 2 and pressed against it, a pressed flower can be manufactured.

In some cases, the far infrared radiation plate 2 is
Although an anodized film may be formed on both front and back surfaces of a base material made of an aluminum alloy, in order to improve heat transfer from the self-controlled temperature heater 3 to the base material 2A,
As shown in the embodiment, it is desirable to selectively form the anodic oxide coating 2B only on the front surface.

The surface of the far-infrared radiation plate 2 on which the anodic oxide film 2B is formed, that is, the surface on which the object to be heated such as frozen food is placed, transmits far-infrared rays such as Teflon and silicon, and does not pass through. The coating layer having excellent adhesiveness may be coated in a thickness of several μm to several tens of μm, and in this case, the peelability of the object to be heated such as frozen food can be improved.

[0033]

According to the heat equalizer of the present invention, far infrared rays are used as a heat equalizer for heating and heating various articles in a relatively low temperature range of 100 ° C. or lower for thawing frozen foods and the like. Since the aluminum alloy plate with a gray to black anodized film with high emissivity is used as the far-infrared radiation plate and a self-controlled temperature heater equipped with a resistance heating element having a positive resistance temperature coefficient is used, Regardless of whether the temperature is high or low, it is possible to stably heat to a preset low temperature range of 100 ° C. or less with a small temperature fluctuation range, and there is little risk of large temperature variations depending on the location. It can be heated to a constant temperature. Further, in this heat equalizer, since the aluminum alloy is used as the base material of the far-infrared radiation plate, there is a large degree of freedom in shape and its processing is easy.

Further, when the heat equalizer of the present invention is used as a thawing device, not only direct heat transfer but also thawing of frozen foods due to absorption of far-infrared rays, so that the flavor of foods is less likely to be impaired. Also, since the self-controlled temperature heater is used, the temperature rising rate at the beginning of thawing is fast,
Since the temperature required for thawing is reached early, thawing time is shortened, and even if thawing proceeds to some extent, it is self-controlled to the same temperature, so there is no danger due to overheating, and there is also a safety device especially for overheating prevention. It is unnecessary and can reduce cost. Further, since the heat equalizer of the present invention can stably overheat in a low temperature range of 40 ° C. or lower, even when it is used as a device for obtaining pressed flowers, there is no risk of discoloration of flowers.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a heat equalizing device according to an embodiment of the present invention.

FIG. 2 is a bottom view showing parts of a far-infrared radiation plate and a self-controlled temperature heater in the heat equalizer of the embodiment shown in FIG.

FIG. 3 is a partially enlarged vertical sectional view of the heat equalizer of the embodiment shown in FIG.

FIG. 4 is a sectional perspective view showing an example of a self-controlled temperature heater used in the heat equalizer of the present invention.

[Explanation of symbols]

 1 Far-infrared radiation plate 2A Base material 2B Anodized film 3 Self-controlling temperature heater 3A, 3B Conductive core wire 3C Resistance heating element

Front page continuation (72) Inventor Yukihiko Kurosawa 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Ltd. (72) Inventor Ken Saito 1-1-5, Kiba, Koto-ku, Tokyo In Fujikura Ltd. (72) Inventor Shuichi Matsumoto 1-5-1, Kiba, Koto-ku, Tokyo, Fujikura Ltd. (72) Inventor Noriyasu Baba 1-1-5, Kiba, Koto-ku, Tokyo In Fujikura Ltd.

Claims (6)

[Claims] 1. A thickness of 5 to 50 .mu.m, which is gray or black on at least the front surface of a base material made of an aluminum alloy.
The far-infrared radiation plate is formed by forming the anodic oxide film of m, and a self-controlled temperature heater having a resistance heating element having a positive temperature coefficient of resistance is provided on the back side of the far-infrared radiation plate. A soaking device characterized in that 2. The aluminum alloy has a Mn of 0.3.
The heat equalizer according to claim 1, wherein the heat equalizer contains ˜4.3 wt% and the balance substantially consists of Al. 3. The aluminum alloy contains 1 to 2 Si.
The soaking apparatus according to claim 1, wherein the soaking apparatus contains 5 wt% and the balance is substantially Al. 4. The heating element of the self-controlled temperature heater,
The soaking apparatus according to claim 1, which is composed of a resistance heating element in which conductive carbon particles are dispersed in a crosslinked polymer. 5. The heat equalizer according to claim 1, wherein a frozen food is placed on the front surface of the far-infrared radiation plate and used as a thawing device for thawing the frozen food. 6. The heat equalizer according to claim 1, which is a pressed flower manufacturing apparatus for pressing a fresh flower against the front side surface of the far-infrared radiation plate to make the fresh flower a pressed flower.