JPH09190872A - Soaking heater and furnace using the same - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To uniformize heat distribution by a soaking heater, to make heat transfer highly efficient, and to utilize it in a furnace for more efficient heat treatment. And SOLUTION: A graphite thermally conductive sheet 2 having high thermal conductivity is arranged at least between a heating portion and a surface portion between the heating portion and the insulating portion and / or between the insulating portion and the surface portion. The heat transfer efficiency from the heating part 4 to the surface part 1 or the object to be heated is enhanced and the heat is made uniform, and this is used in the heating chamber of the furnace body to achieve the above object.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a consumer heater product,
It is applied to commercial heater products and industrial heater products, and in particular, it uses hot air or a film material placed on the surface to be bonded.
The present invention relates to a soaking heater that heats or dries with radiant heat, and a furnace using the soaking heater.

[0002]

2. Description of the Related Art When manufacturing various electronic devices (for example, CRT tubes, liquid crystal display devices, etc.) and precision devices, a film is formed on a surface of a member for decoration or for exerting various functions. Sometimes. As a means for forming such a film, there is a method in which a liquid film material is applied and heated and dried to solidify the film material.

As a method for drying the film, there is a method using warm air or radiant heat. Far-infrared heaters that emit radiant heat energy with a spectral emissivity of about 0.8, which is close to that of a black body in the far-infrared region, are used in a wide range from industrial to consumer in order to provide efficient heating. .

With respect to the drying of the membrane material, it is difficult to uniformly dry the surface condition with warm air, and it is extremely difficult to keep the temperature at ± 5 ° C. Further, although the far-infrared heater can be dried from the inside of the film, there is a limit to uniformizing the surface temperature of the far-infrared heater, and there is a similar problem.

The reason for this is as follows. A conventional far infrared heater is shown in FIG. An insulating material 33 is inserted between the metal 31 whose surface is coated with far-infrared paint and the heating wire 32 to insulate them. This insulating material is
Since the heat conductivity is poor, the heat transfer is poor, and the flexibility is poor, so that a void 35 is formed as shown in FIG. As a result, the surface temperature of the metal 31 and the distribution thereof are as shown in FIG. 16, and the surface temperature varies from part to part, and the maximum temperature difference is as large as about 20 ° C. Moreover, the surface temperature rises only up to about 190 ° C., and the heat of the heat source cannot be fully utilized. A heat insulating portion 34 is provided below the heating wire 32.

As described above, in the case of the conventional far-infrared heater, since the heating temperature differs depending on the location, the heater cannot be brought close to the object to be heated for uniform heating, and the heating efficiency is correspondingly low. If the heater is brought close to the object to be heated, the surface will be unevenly dried, resulting in unevenness or uneven thickness, or in the case of a material that changes at high temperatures, only part of it will change to another compound. It becomes a defective product.

The object of the present invention is to uniformly heat the entire film material even on the surface of the film material even when the film material is placed on adhesive surfaces of various shapes with a uniform surface temperature and dried. It is an object of the present invention to provide a soaking heater capable of heating the whole film material in a single step with high thermal efficiency and uniformly drying in a short time while preventing unevenness such as unevenness and unevenness in thickness which occur and a furnace using the same.

[0008]

All of the soaking heaters according to the inventions of claims 1 to 12 are ones in which at least a heating part, an insulating part, and a surface part are sequentially laminated, and the heat in the heating part is conventional. , While preventing the direct influence of leakage current if it is an electric source of this heating source, while transmitting to the surface portion, to heat the object to be heated, it is possible to perform the necessary treatment such as drying, The heat conductive sheet made of graphite is provided between the heating part and the surface part at least between the heating part and the insulating part and / or between the insulating part and the surface part.

This graphite heat conductive sheet is flexible and has good adhesiveness to others, and also has good heat conductivity. Even if the heat source of the heating portion is sparsely located by heating wire or the like, each portion The heat generated from the heat source from the lower layer side is absorbed highly efficiently by the portion close to the heating part, and the heat conductivity allows it to quickly spread to the whole area of itself, while the upper layer portion facing from the whole area of itself. Also, since the heat is efficiently and uniformly transferred to the entire required area of the surface portion, soaking and heat efficiency are achieved in proportion to the number of portions provided with the heat conductive sheet. Therefore, there is no problem even if the film material is dried in a short time evenly from the adjacent position.

When the heat conductive sheet is further provided on the upper surface of the surface portion in the invention of claim 1 as in the invention of claim 2, the same action is exerted also in that portion,
The specific heating material can be heated more efficiently and uniformly. The required thickness of each part of the heat conductive sheet can be obtained by stacking a plurality of sheets.

According to the third aspect of the present invention, since the far-infrared paint is applied to the outermost surface, the far-infrared paint is uniformly applied to the outermost surface of the far-infrared paint layer by heating the surface portion uniformly and efficiently. Moreover, it can be generated strongly, and the time required for heating, drying, etc. of the object to be heated can be further shortened.

The invention according to claim 4 is, in any one of the inventions according to claims 1 to 3, further comprising a heat insulating portion in a lower layer of the heating portion, and heat from a heat source of the heating portion is provided on one surface. Since it is directed to the part, it is possible to improve the thermal efficiency in the soaking heater having the surface part on only one side.

According to a fifth aspect of the present invention, in the graphite according to any one of the first to fourth aspects, the graphite of the heat conductive sheet has a mosaic spread showing its crystallinity.
0.5 to 20, and the invention of claim 6 is
In any one invention of claim 5, the graphite of the heat conductive sheet has a specific gravity of 0.3 to 2.6, and the invention of claim 7 is the same as that of any one of claims 1 to 5. Graphite in the conductive sheet has a thermal conductivity of 2
It is a sheet of 00 to 1000 kcal / m · hr · ° C, and the invention of claim 8 is the sheet according to any one of claims 1 to 7, wherein the insulating portion is made of an inorganic material or an organic material. According to the invention of claim 9, in the invention of claim 8, the inorganic material is at least one of ceramics, mica, and a graphite-containing inorganic composition, and the invention of claim 10 further comprises the invention of claim 8. The organic material is at least one of polyimide, a fluorine compound, a silicone rubber compounding composition, and a graphite compounding organic compound, and the invention of claim 11 further includes a heating unit in any one of claims 1 to 10. The heat source of is any one of electricity, gas, and heat medium, and is suitable in any case.

According to a twelfth aspect of the present invention, in any one of the first to third aspects of the present invention, the insulating portion and the surface portion are symmetrically arranged on both sides of the heating portion as a boundary.
The effects of the inventions Nos. 3 to 3 can be exhibited on both front and back sides, and it is effective for heating and drying a plurality of objects to be heated.
Further, the heat insulating part for directing the heat of the heat source of the heating part to the surface part can be omitted.

In the soaking heater of the thirteenth aspect of the present invention, the surface portion and the heating portion are formed of ceramics, the heat source is embedded in the heating portion, and the insulating portion is provided between the heating portion and the surface portion. Since ceramics efficiently generate far infrared rays, the heating part, the insulator, and the surface part can be solidified as a unit to form a soaking heater, and the heat from the heating part to the object to be heated can be configured. There is no need to apply a thermal conductive sheet made of graphite or far-infrared paint for conduction, which simplifies the structure and allows far-infrared rays to be generated uniformly and strongly from the surface, Efficiency is also high.

The furnace of the invention of claim 14 is the furnace of claims 1-13.
The uniform heating heater according to any one of the inventions is arranged in the heating chamber of the furnace body, and the excellent uniform heating property and efficiency of the uniform heating heater are effectively utilized in a state where heat is not released to the outside. Good heating is possible.

According to a fifteenth aspect of the present invention, in addition to the fourteenth aspect of the present invention, a plurality of soaking heaters are arranged so as to alternate with the object to be heated, and both surfaces of the object to be heated are the surface portions of the soaking heater. The heat treatment is performed uniformly and quickly from both the front and back sides with high efficiency while facing each other in the heating chamber of the furnace body, and the time required for heating can be shortened.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIGS. 1 to 3 show a first embodiment of a soaking heater according to the present invention. The present embodiment is a far infrared soaking heater. As shown in FIGS. 1 and 2, the heat insulating part 5, the heating part 4, the insulating part 3, and the surface part 1 are sequentially laminated, and the heat conductive sheet is provided between the surface part 1 and the insulating part 3. Two are provided. The surface portion 1 is formed of a metal sheet material such as SS steel plate or SUS steel plate. The upper surface of the surface portion 1 is coated with highly efficient far-infrared paint. This coating contains ceramics such as zirconia, alumina, titania, manganese oxide, cobalt oxide, etc., and is coated on the upper surface of the surface portion 1 by being baked at a high temperature with a dense structure using a vitreous binder. There is. Such a configuration is suitable for use in drying the above film material. However, it may be used for any purpose. Depending on the application, such surface treatment can be omitted. Further, the surface portion 1 and the far-infrared paint can be changed to other materials suitable for heating for the purpose.

The heat source of the heating section 4 employs the heating wire 4a and is made of, for example, a nichrome wire. However, it may be something else. Is the heating wire 4a wound on a mica plate,
As shown in FIG. 1 and FIG. 2, embedded in the surface of the heat insulating part 5,
Alternatively, it is housed in a groove provided on the surface of the heat insulating portion 5. In any case, the insulating part 3 is provided between the heating part 4 and the metallic surface part 1 to maintain the insulating property. Heat insulation part 5
Is made of, for example, a calcium phosphate-based material. The insulating part 3 is a mica plate. The heat conductive sheet 2 between the insulating portion 3 and the surface portion 1 is formed of a highly crystalline graphite sheet. This heat conductive sheet 2 is flexible and has good adhesiveness to others, and also has good heat conductivity, and the heat source of the heating unit 4 is the heating wire 4
In a, even if the heat insulating portion 5 is sparsely located, most of the heat generated from the heating wire 4a of each part is directed to the surface portion 1 side by the lower heat insulating portion 5 at a position close to the heating portion 4. Heat is efficiently absorbed and efficiently spreads over the entire area of itself by thermal conductivity, while efficiently and uniformly transmitted from the entire area of itself to the necessary area on the side of the facing surface portion 1, so that the temperature is uniformized. The thermal efficiency is improved, and the generation of far infrared rays from the entire area of the far infrared coating material on the outermost surface is made uniform and enhanced.

As an example of the present embodiment, the surface portion 1 has a thickness of about 1 mm, and the heat conductive sheet 2 has a thickness of 1 mm.
The heat insulating part 5 has a thickness of about 3 cm, and the insulating part 3 has a thickness of about 0.
The surface temperature distribution as shown in FIG. 3 was obtained at about 5 mm. In the conventional example which is different from the present example only in that the heat conductive sheet 2 is not present, the surface temperature distribution as shown in FIG. 16 is exhibited, the temperature unevenness is large, the maximum temperature difference is about 20 ° C., and the maximum temperature is about 19.
On the other hand, the temperature is 0 ° C., but in this embodiment, there is almost no temperature unevenness and the surface temperature is smooth, and the maximum temperature difference is about 2.5 ° C., which is about 1/8. Rises to near 200 ° C and is almost stable over the entire surface. Therefore, the film material can be efficiently and uniformly heated from a close position and dried in a short time without a problem due to uneven heating.

In the sense that the heat conductive sheet 2 achieves heat conduction efficiency from the heating part 4 to the surface part 1 and uniformization of heat at a position closer to the heating part 4, the insulating part 3 and the insulating part 3 in the present embodiment are provided. The one provided between the surface portion 1 and the heating portion 4 and the insulating portion 3 can be changed to one provided between the heating portion 4 and the insulating portion 3, and it is more preferable to provide both of them. However, these can be freely selected as needed. Further, in some cases, the heat conductive sheet 2 may be provided on the upper surface of the surface portion 1, and the surface of the heat conductive sheet 2 facing the object to be heated such as a film material is coated with far-infrared paint. Good. This can improve the drying efficiency of the film material and the like.

The heat conductive sheet 2 has good heat conductivity, and by adopting a highly flexible graphite sheet, the close contact with both the upper and lower surface portions 1 and the insulating portion 3 is improved, and The thermal efficiency is also improved in that there is no gap between them.

It is preferable that the insulating portion 3 is made of an inorganic material or an organic material. The inorganic material is preferably at least one of ceramics, mica, and a graphite-containing inorganic composition. The organic material is preferably at least one of polyimide, a fluorine compound, a silicone rubber compounding composition and a graphite compounding organic compound. Furthermore, it is preferable that the graphite-made thermally conductive sheet 2 has a mosaic spread of 0.5 to 20 showing crystallinity. Mosaic spread is one of the X-ray diffraction parameters and is one index for evaluating the graphite structure. The half value width of the peak in the diffraction intensity curve obtained by rotating the graphite sheet when a monochromatic X-ray is incident on the graphite sheet is called mosaic spread. For details, see JP-A-61-275114 and JP-A-61-2751.
No. 15 and Japanese Patent Application Laid-Open No. 61-275117.

The heat conductive sheet 2 made of graphite has a heat conductivity of 200 to 1000 kcal / m · h.
A graphite sheet of r · ° C. is preferable, and a specific gravity of 2.6 to 0.3 is also preferable. Further, as the thermally conductive sheet 2 made of graphite and having a thickness of 5 to 1000 μm, it is preferable to use a commercially available Panasonic graphite sheet (trade name). Such a sheet is light, has a small heat capacity, and has a good temperature response. Furthermore, since it is in a foamed state, it has good compressibility and restoration properties, and has particularly good adhesiveness to others, which helps improve thermal efficiency. Depending on the thickness of the graphite sheet used, it is possible to obtain a required thickness in the same portion by stacking a plurality of sheets.

The heat source of the heating section 4 is the heating wire 4a.
Other than electricity, gas, heat medium may be used. It is also possible to use solar heat or geothermal heat.

The corrosion resistance and thermal stability of graphite increase the freedom of heat source selection.

<Second Embodiment> FIG. 4 shows a second embodiment of the present invention. In this embodiment, a double-sided heater is constructed by arranging the insulating portion 3, the heat conductive sheet 2, and the surface portion 1 as in the first embodiment in a plane-symmetrical state with the heating portion 4 as a boundary. doing. In this way, the heat of the heating unit 4 can be effectively used on both sides. Further, the heat insulating portion 5 may be provided only around the region where the heating wire 4a is arranged to prevent heat from escaping to the side circumference, and the heat insulating portion 5 may be small. Also, in some cases,
The insulating portion 3, the heat conductive sheet 2, and the surface portion 1 may be provided so as to wrap around to a necessary position on the side circumference of the heating portion 4, and the heat insulating portion 5 may be omitted in that portion as well.

<Third Embodiment> FIGS. 5 and 6 show a third embodiment of the present invention in which the surface of a member such as a CRT tube, a liquid crystal display device, or a precision instrument is decorated and various functions are exhibited. A soaking heater suitable for drying the film member for heating is constituted.

Although the soaking heater has the same laminated structure as that of the first embodiment, the laminated portion of the heating portion 4, the insulating portion 3, the heat conductive sheet 2 and the metal surface portion 1 is connected to the side periphery of the heat insulating portion 5. It is provided along with. As a result, the heat from the heating section 4 becomes uniform and heat-efficient as in the first embodiment, and the surface section 1 has a three-dimensional shape.
It is possible to dry even a wide film material by a soaking heater having a plane space smaller than that by hanging it down along the side circumference.

The lower opening of the box-shaped surface portion 1 is closed by a cover plate 11 so as to cover the entire lower portion of the soaking heater. If the lid plate 11 is made of metal, it is attached to the surface portion 1 by welding, but it is useless if the heat of the surface portion 1 is conducted. Therefore, a non-heat conductive material is preferable, and the lid plate 11 is screwed to the surface portion 1 or is impossible. It may be fitted or adhered and attached appropriately. Legs 12 are provided on the lower surface of the cover plate 11 so that the heat of the soaking heater does not reach the mounting surface thereof.

<Fourth Embodiment> FIGS. 7 and 8 show a fourth embodiment of the present invention. In this embodiment, a heat conductive sheet 6 made of highly crystalline graphite coated with highly efficient far-infrared paint is directly bonded onto the surface portion 1. The heat conductive sheet 6 is the same as the heat conductive sheet 2 provided between the surface portion 1 and the insulating portion 3,
The coating material is the same as in the case of each of the first to third embodiments. Since the other structure is the same as that of the third embodiment, the same members are designated by the same reference numerals, and the duplicated description will be omitted.

In the present embodiment, the heat conductive sheet 6 makes the heat reaching the surface portion 1 uniform and heat-efficient, and further uniformizes it and transfers it to the paint layer heat-efficiently to further uniformize the far infrared radiation. Strengthening can be achieved, and drying etc. can be accelerated.

<Fifth Embodiment> FIGS. 9 and 10 show a fifth embodiment of the present invention. The present embodiment is suitable for the case where the object to be heated is a curved one such as a CRT.

In this embodiment, as shown in FIGS. 9 and 10, in the soaking heater having the same structure as that of the third embodiment, the heating part 4, the insulating part 3, the heat conductive sheet 2, and The laminated portion of the surface portion 1 is curved together with the surface shape of the heat insulating portion 4 into a convex convex shape to match the shape of the CRT.

By thus matching the surface shape of the soaking heater on the surface 1 side with the object to be heated, the distance between the soaking heater and the object to be heated can be kept constant, and uniform far infrared rays can be obtained. The object to be heated can be uniformly irradiated with radiation.

Therefore, if the object to be heated is spherical, it is preferable that the surface shape of the surface portion 1 is also spherical to match this.

In the present embodiment as well, the surface portion 1
The heat conductive sheet 6 as in the fourth embodiment may be attached to the upper surface of the.

<Sixth Embodiment> FIGS. 11 and 12 show a sixth embodiment of the present invention. In this embodiment, the surface portion 1 and the heating portion 4 are made of ceramics 8, a heating wire 4a made of nichrome wire as a heat source is embedded in the heating portion 4, and the heating portion 4 and the surface portion 1 are provided between the heating portion 4 and the surface portion 1. A mica plate is inserted to form the insulating portion 3.

The ceramic 8 efficiently generates far infrared rays, and the soaking heater can be constructed by solidifying the whole of the heating portion 4 to the surface portion 1 into an integrated body. The need to apply a graphite thermal conductive sheet or far infrared paint for heat conduction between the two becomes unnecessary, and the structure is simplified, and far infrared rays are uniformly and strongly generated from the surface portion 1. The heating efficiency is high.

The buried portion of the heating wire 4a has a ridge so that the distance difference from each heating wire 4a in each part of the surface portion 1 formed by the ceramics 8 does not become too large, and the heat capacity becomes smaller in the farther part, 11 and 12 with valleys between them
The surface shape is wavy as shown in FIG. Thereby, the temperature distribution of the surface portion 1 can be further homogenized.

<Seventh Embodiment> FIG. 13 shows a seventh embodiment of the present invention. In this embodiment, the first and second
It is a furnace suitable for heating using a panel-shaped soaking heater as in each of the above embodiments.

As shown in FIG. 13, this furnace has a rectangular furnace body 22 having a heating chamber 21 inside.
The insertion port 24 for inserting a planar soaking heater 23, which is a so-called panel as shown in the first and second embodiments, and the insertion port 26 for inserting the object to be heated 25 are provided on one surface of 2. They are arranged alternately in the vertical direction. The object to be heated 25 is in the form of a sheet, and in this embodiment, a glass substrate for heat treatment of liquid crystal is used.

However, the present invention is not limited to this, and depending on the form of the article to be heated 25, it may be put in and taken out through an entrance / exit with a door provided on one surface of the furnace body 22, and the like along the wall surface in the furnace body 22. The heat treatment may be performed by various types of soaking heaters provided in advance, or by various types of soaking heaters that are juxtaposed so as to face the object to be heated 25.

Therefore, in some cases, various three-dimensional soaking heaters as shown in the third to sixth embodiments may be used in the furnace body 22.

In any case, the excellent soaking property and thermal efficiency of the soaking heater are fully utilized in a state where heat does not escape to the outside,
More efficient heating can be performed.

In particular, in this embodiment, the uppermost soaking heater 23 is a soaking heater having a surface portion on one side as in the first embodiment, with the surface portion 1 facing downward,
It is preferable to use the same soaker heater 23 at the bottom so that the surface portion 1 faces upward, and the soaker heater 23 between them is the same on both surfaces as shown in the second embodiment. It is preferable to use a soaking heater capable of heating both surfaces having a portion. However, as the soaking heater 23 in the middle, those having a surface portion on one side may be used back to back.

By doing so, the sheet-shaped object to be heated 2
Both surfaces of No. 5 face the surface of the soaking heater 23 in the heating chamber 21 of the furnace body 22, and heat treatment is uniformly and quickly performed from both front and back surfaces with high efficiency in a state where heat does not escape to the outside.

Although not shown, in order to cool or lower the temperature of the object to be heated 25 as necessary, a cooling water pipe for cooling or a moving means for separating the object to be heated 25 and the soaking heater 23 by a predetermined amount are provided. It is also possible to work appropriately.

By providing the above-mentioned moving means, it is possible to bring the distances closer to each other during the rapid temperature rise and to separate the distances during the rapid temperature drop, which is particularly effective in the case of a liquid crystal or a large CRT.

Further, by designing and arranging a conveyor, a dust filter for cleaning, etc., it is possible to manufacture a furnace partially using the soaking heater 23 and apply it as a soaking and drying oven.

Since the surface of the heater is soaked, it can be achieved by bringing the object to be heated close to the heater during a rapid temperature rise, and moving the object to be heated away from the heater during a rapid temperature drop. This also allows for the drying of materials that require patterning.

Generally, the radiant amount of far infrared rays is 4
It is proportional to the power. By making the temperature of the radiator uniform with the heat conductive sheet, the radiation amount of far infrared rays can be made uniform very easily. Also, by inserting a heat conductive sheet,
Since the space density is increased and the heat transfer efficiency is increased, the radiation amount is almost double when compared with the same power. Moreover, since the heat distribution becomes uniform, it becomes possible to approach the object to be heated, and if the distance is halved, the thermal efficiency is increased four times, and the amount of electricity is ¼, or , The drying speed becomes 4 times.

[0054]

According to the soaking heater of the present invention, the thermally conductive sheet made of graphite is provided at least between the heating part and the insulating part and / or between the insulating part and the surface part. The heat from the lower layer is absorbed by the portion close to the heating portion with high efficiency, and the heat is quickly spread to the entire area of itself. Since the heat is efficiently and uniformly transmitted to the entire required area, uniform heat distribution and thermal efficiency can be achieved in proportion to the number of portions provided with the heat conductive sheet. Therefore, it is suitable for the purpose of drying the film material in a short time evenly from the adjacent position.

According to a second aspect of the present invention, in addition to the first aspect of the invention, the heat conductive sheet made of graphite has the same function as that of the first aspect of the invention even on the upper surface of the surface portion, and the specific heating The object can be heated more efficiently and uniformly.

According to a third aspect of the present invention, in addition to any one of the first and second aspects of the present invention, the far-infrared coating layer on the outermost surface is far infrared rays from the entire surface by heating the surface portion uniformly and with good thermal efficiency. Can be generated uniformly and strongly, and the time required for heating and drying the object to be heated can be further shortened.

According to the invention of claim 4, in particular, in any one of the inventions of claims 1 to 3, the heat from the heat source of the heating section is directed to the surface portion on one side, so that the surface portion has only one side. The thermal efficiency of the thermal heater can be improved.

According to a twelfth aspect of the present invention, in addition to any one of the first to third aspects of the present invention, the effects of the first to third aspects of the present invention can be exerted on both front and back sides, and a plurality of objects to be heated are provided. It is effective for heating and drying. Further, the heat insulating part for directing the heat of the heat source of the heating part to the surface part can be omitted.

According to the soaking heater of the thirteenth aspect of the invention,
Ceramics efficiently generate far-infrared rays, and can form a soaking heater by solidifying the entire heating part, insulator, and surface part into a unitary body, and also conduct heat transfer from the heating part to the object to be heated. It is not necessary to apply a graphite thermal conductive sheet or far-infrared paint for this, the structure is simplified, and far-infrared rays can be uniformly and strongly generated from the surface part, and heating efficiency is also improved. high.

According to the furnace of the fourteenth aspect of the present invention, the excellent soaking property and efficiency of the soaking heater can be fully utilized without the heat being released to the outside, and more efficient heating can be performed.

According to a fifteenth aspect of the present invention, in addition to the fourteenth aspect, both sides of the object to be heated face the surface portion of the soaking heater in the heating chamber of the furnace body, and heat does not escape to the outside. The heat treatment is performed uniformly and quickly from both sides with high efficiency, and the time required for heating can be shortened.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a far-infrared type soaking heater showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of the soaking heater of FIG.

FIG. 3 is a graph showing a surface temperature distribution of the soaking heater of FIG.

FIG. 4 is a sectional view of a soaking heater showing a second embodiment of the present invention.

FIG. 5 is a perspective view of a soaking heater showing a third embodiment of the present invention.

6 is a sectional view of the soaking heater of FIG.

FIG. 7 is a perspective view of a soaking heater showing a fourth embodiment of the present invention.

FIG. 8 is a sectional view of the soaking heater of FIG.

FIG. 9 is a perspective view of a soaking heater showing a fifth embodiment of the present invention.

10 is a sectional view of the soaking heater of FIG.

FIG. 11 is a perspective view of a soaking heater showing a sixth embodiment of the present invention.

12 is a sectional view of the soaking heater of FIG.

FIG. 13 is a perspective view of a furnace showing a seventh embodiment of the present invention.

FIG. 14 is a sectional view showing a conventional far infrared panel heater.

FIG. 15 is a partially enlarged view of FIG.

16 is a graph showing a surface temperature distribution of the panel heater of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface part 2 Thermally conductive sheet 3 Insulating part 4 Heating part 4a Electric heating wire 5 Insulating part 6 Thermal conductive sheet coated with far-infrared paint 8 Ceramics 21 Heating chamber 22 Furnace body 23 Soaking heater 25 Heated object

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Inoue 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inujita Ikeda, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (15)

[Claims] 1. A soaking heater in which at least a heating part, an insulating part and a surface part are sequentially laminated, and at least between the heating part and the surface part and between the heating part and the insulating part and / or between the insulating part and the surface part. A soaking heater characterized in that a thermally conductive sheet made of graphite is arranged in the. 2. The soaking heater according to claim 1, wherein a heat conductive sheet made of graphite is arranged on the upper surface of the surface portion. 3. The soaking heater according to claim 1, wherein the far-infrared paint is applied to the outermost surface. 4. The heat insulating section is provided below the heating section.
4. The soaking heater according to any one of 4 to 4. 5. The soaking heater according to claim 1, wherein the graphite of the heat conductive sheet has a mosaic spread showing crystallinity of 0.5 to 20. 6. The soaking heater according to claim 1, wherein the graphite of the heat conductive sheet has a specific gravity of 0.3 to 2.6. 7. The soaking heater according to claim 1, wherein the graphite of the thermally conductive sheet is a sheet having a thermal conductivity of 200 to 1000 kcal / m · hr · ° C. 8. The soaking heater according to claim 1, wherein the insulating portion is made of an inorganic material or an organic material. 9. The soaking heater according to claim 8, wherein the inorganic material is at least one of ceramics, mica, and a graphite-containing inorganic composition. 10. The soaking heater according to claim 8, wherein the organic material is at least one of polyimide, a fluorine compound, a silicone rubber compounding composition, and a graphite compounding organic compound. 11. The soaking heater according to claim 1, wherein the heat source of the heating section is any one of electricity, gas, and a heat medium. 12. The soaking heater according to claim 1, wherein the insulating portion and the surface portion are symmetrically arranged on both sides of the heating portion as a boundary. 13. A soaking heater, wherein the surface portion and the heating portion are formed of ceramics, a heat source is embedded in the heating portion, and an insulating portion is provided between the heating portion and the surface portion. 14. A furnace comprising the soaking heater according to claim 1 arranged in a heating chamber of a furnace body. 15. The furnace according to claim 14, wherein a plurality of soaking heaters are arranged so as to alternate with the object to be heated.