JPS60208079A - Far infrared ray heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a far-infrared heater that is used as a heat source for drying, heating, cooking, heating, etc., and that efficiently radiates far-infrared rays.

Conventional configuration and its problems Recently, far-infrared heaters have been attracting attention in terms of energy saving and speed.

This tendency is particularly strong in the fields of drying, heating, cooking, and space heating, and various types of far-infrared heaters have been devised and used.

Among these, sauna baths have been in the spotlight for maintaining and improving health, and their use is expanding from commercial to general household use.

Currently, far-infrared heaters for sauna baths are
The type that is mainly used is a type in which a ceramic tube is filled with magnesia powder and the surface K of the ceramic tube is coated with a far-infrared emitting material whose main component is zirconium oxide.

However, although the above-mentioned type of far-infrared heater has excellent radiation characteristics, it has the drawbacks of weak mechanical strength and high manufacturing cost.

On the other hand, some sheathed heater types are also used, in which a metal pipe is filled with magnesia powder and the surface of the metal pipe is coated with a far-infrared radiation material. This sheathed heater type uses 5US304 as a metal pipe, and a material containing titanium oxide or alumina as a main component as a far-infrared radiation emitting material.

However, when such a sheathed heater type far infrared heater is used in a humid atmosphere, the metal pipe S
The occurrence of rust in US 304 causes various problems as described below.

■ When using a far-infrared emitting material whose main component is titanium oxide, the far-infrared emitting layer may peel off due to a change in color due to crystal transformation or rust on the metal pipe.

■ When using a far-infrared emitting material whose main component is alumina, since it is white in color, the rust from the metal pipe becomes a stain and builds up on the far-infrared emitting layer, spoiling the aesthetics and damaging the far-infrared emitting layer. A peeling phenomenon occurs.

In addition to the above-mentioned problems, in order to prevent the magnesia powder from absorbing moisture, both ends of the metal pipe are sealed with low-melting glass or heat-resistant resin, which greatly increases costs.

As described above, both the ceramic tube type and the sheathed heater type currently used for sauna baths have problems in terms of cost, quality, and performance.

Purpose of the Invention The present invention provides a far-infrared heater that overcomes all of the conventional drawbacks, has excellent electrical insulation, does not cause discoloration or peeling of the far-infrared radiation layer, and is inexpensive to manufacture. .

Structure of the Invention The present invention uses SUS 304 as a metal pipe, uses fused magnesia powder added with silicone resin powder as an electrical insulating powder, and coats the surface of the metal pipe with:
A black far-infrared radiation layer containing 10% by weight or more of nickel oxide is provided, and as a result, it is possible to prevent a decrease in electrical insulation properties, and to prevent discoloration and peeling of the far-infrared radiation layer. This makes it possible to create a far-infrared heater with excellent electrical insulation and no discoloration or peeling of the far-infrared emitting layer.Description of Examples Below, see FIG. 1 for examples of the present invention. This will be explained in comparison with a conventional example.

As the metal pipe 3, SUS304 was used.

On the other hand, a coiled nichrome wire (
A heating wire 2 having a wire diameter of 0.55 m) was prepared, inserted into the center of a metal pipe 3, filled with electrical insulation powder 4 made of fused magnesia powder to which 2% by weight of silicone resin was added, and rolled to reduce its diameter. .

Thereafter, it was heat-treated at 250° C. for 1 hour and water-repellent treated with silicone resin.

Next, the surface of the metal pipe 3 is blasted with molten alumina, and then a far-infrared emitting material having the composition shown in Table 1 is treated by plasma spraying to coat the surface of the metal pipe 3 with far-infrared rays. A radiation layer 6 was formed.

Finally, both ends of the metal pipe 3 are sealed with heat-resistant resin 5,
Far-infrared heaters shown in FIG. 1 with a diameter of 1151M and a length of 50MM were completed and designated as sample numbers 1 to 14.

(Margin below) Table 1 In order to evaluate each of the far-infrared heaters mentioned above, the applied voltage was adjusted so that the surface temperature of the far-infrared emitting layer 6 was 50°C, and the temperature was 40°C and the relative humidity was 95°C. An intermittent energization test was conducted in an atmosphere with a cycle of 20 minutes of energization and 10 minutes of rest, and after 1,000 cycles, the far-infrared emitting layer was checked for color changes, stains, and peeling. The results are shown in Table 1.

In addition, before the above test, the state after completion was confirmed and similarly shown in Table 1.

Furthermore, the electrical insulation between the metal pipe 3 and the terminal bar 1 after 1,000 cycles was measured and is also shown in Table 1.

As is clear from Table 1, the conventional far-infrared heater of sample number 1.6.10 using conventional far-infrared radiating materials such as ZrO2, TiO2, and Al2O as main components and the conventional far-infrared heater described above In the far-infrared heater of sample number 2, 7.11, in which NiO was added to the radiation material in an amount of 10% by weight or less, changes in color, staining, or peeling of the far-infrared radiation layer were observed after 1,000 cycles.

However, sample numbers 3, 4° 5.8, 9, and 12 were obtained by adding 10% by weight or more of NiO to the conventional far-infrared emitting material and forming a far-infrared emitting layer exhibiting a blackish color.
．． Sample No. 14 containing 13 and 95 parts by weight of NiO
In the far-infrared heater of the present invention, no change in color, staining, or peeling of the far-infrared radiation layer, which was observed in conventional far-infrared heaters, was observed.

On the other hand, the electrical insulation after 1,000 cycles showed a value of 2,000 MΩ or more for each sample because of the water repellent treatment with silicone resin, indicating excellent electrical insulation.

As described above, in the far-infrared heater according to the embodiment of the present invention, since the color is black, discoloration caused by rust on the metal pipe, crystal transformation of titanium oxide, etc. becomes unclear and cannot be seen. This can be achieved by adding 10% by weight or more of nickel oxide.

Furthermore, since the addition of nickel oxide acts to improve the adhesion of the metal pattern, it has the effect of preventing peeling.

On the other hand, electrical insulation can be ensured by adding silicone 4it resin.

As a result, it is possible to obtain a far-infrared heater that has excellent electrical insulation and does not cause discoloration or peeling of the far-infrared emitting layer.

Effects of the Invention As is clear from the above explanation, according to the far infrared heater of the present invention, 5US304 is used as the metal pipe,
Electrofused magnesia powder added with silicone resin powder is used as the electrical insulating powder, and a black far-infrared radiation layer containing 10% by weight or more of nickel oxide is provided on the surface of the metal pipe. It is possible to provide a far-infrared heater that has excellent electrical insulation properties and does not cause discoloration or peeling of the far-infrared emitting layer even when used in a humid atmosphere, and has great practical value.

[Brief explanation of the drawing]

The figure is a sectional view of a far-infrared heater according to an embodiment of the present invention. 3...Metal pipe, 4...Electric insulating powder, 6...Far infrared radiation layer.

Claims (1)

[Claims] 5U83o4 is used as the metal pipe, fused magnesia powder added with silicone resin powder is used as the electrical insulating powder, and a black far-infrared radiation layer containing 10% by weight or more of nickel oxide is provided on the surface of the metal pipe. Far infrared heater.