JPH0594866A - Heat generating - Google Patents

Abstract

PURPOSE:To obtain comfortable heating environment by providing an adsorption layer composed of a hollow layer formed on the surface of a metallic pipe shaped body, zeolite or one kind of magnesium silicate formed on the surface of the hollow layer, and of inorganic binder, and an electric resistor. CONSTITUTION:Since an adsorption layer 3 is provided for the surface of a heat-generating element, when an electric resistor 4 is not energized, odor components around a place where the heat-generating element is placed, can be adsorbed and deodorized by zeolite or magnesium silicate contained in the adsorption layer 3. And when the resistor 4 is energized, the heat of the resistor 4 is transmitted to a metallic pipe shaped body 1 via an electrical insulator 5. A hollow layer 2 is heated by heat transmitted to the pipe shaped body 1, and the adsorption layer 3 formed on the surface of the layer 2 is also concurrently heated up quickly. Zeolite or magnesium silicate contained in the layer 3 which is heated up, separates absorbed odor components and harmful components, and the layer 3 restores its adsorption capacity so as to be regenerated. The layer 3 can absorb odor components after heating the resistor 4 through switching-on has been suspended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating element used for heating, hot water supply, drying, cooking equipment and refrigerators, air conditioners and the like.

[0002]

2. Description of the Related Art A conventional heating element is one in which a metal wire such as a nichrome wire or a kanthal wire is formed into a coil, a metal tube, a quartz tube, a ceramic tube, or the like, which is built into the tubular body. The structure is such that it is coated with far-infrared radiation material such as gillite, clay, glass or nickel oxide, iron oxide, or a ceramic heater in which an electric resistor is built in a ceramic sintered body. In heating, hot water supply and drying equipment, the heating element directly heats, or the fan is forced to send air from the heating element to generate hot air.
For example, by providing a reflector behind the heating element to perform radiant heating,
The object to be heated is heated by a heating element by heat conduction, convection, and radiation.

Such a conventional heating element has the following problems. For example, when heating with an electric stove, the heating element heats not only indoor air but also smoke of cigarettes floating in the room and indoor odor. Generally, the higher the temperature of an odor substance, the more strongly the human nose feels it, and the odor component once adsorbed in the room is also vaporized again and floats in the room atmosphere.

[0004]

Here, since the conventional heating element does not have the ability to purify odorous components, when the electric stove is used, the odor often becomes more intense than when the electric stove is not used. It was a problem.

The present invention has been made to solve the above-mentioned problems of the prior art, and provides a heating element for removing odors and harmful gases with a simple structure.

[0006]

DISCLOSURE OF THE INVENTION In the present invention, a heating element is a metal tubular body, a hollow layer formed on the surface of the metallic tubular body, and at least zeolite and / or magnesium silicate formed on the surface of the hollow layer. And an adsorption layer made of an inorganic binder, an electric resistor built in the metal tubular body, and an electric insulator installed to ensure electric insulation between the electric resistor and the metal tubular body. It is characterized by

[0007]

Since the adsorption layer is provided on the surface of the heating element, when the heating element is not energized, the odorous components around the heating element are mixed with the zeolite in the adsorption layer formed on the surface of the heating element. Alternatively, it can be adsorbed and deodorized with magnesium silicate. Further, the zeolite or magnesium silicate, before adsorbing the odorous component up to its adsorption capacity limit, the electric resistor in the heating element is energized to generate heat, and the adsorption layer is heated, whereby the zeolite in the adsorption layer or The odorous and harmful components adsorbed on magnesium silicate can be desorbed to restore the adsorption capacity of the coating film,
After stopping the heating by the heating means, the odorous components can be adsorbed again. While conventional activated carbon generally used as an adsorbent has variations in its adsorption performance due to odorant species, the zeolite or magnesium silicate of the present invention does not have variations in adsorption performance and adsorbs various odorous components in the room. Can be deodorized.

[0008]

FIG. 1 shows a concrete example of the present invention.

In FIG. 1, 1 is a metal tubular body, 2 is a hose.
B layer, 3 is an adsorption layer formed on the surface of the hollow layer, 4 is an electric resistor built in a metal tubular body, 5 is an electrical insulator, and the electrical resistor 4 is the metal tubular body 1 and the electrical insulator. It is electrically insulated by 5. Reference numeral 7 denotes a sealing portion for sealing the electric insulator 5 in the metal tubular body 1, and usually glass is used.

As the metal tubular body 1 of the present invention, stainless steel such as hollow steel, aluminized steel and SUS430 can be used. The shape thereof can also be used in various shapes such as a straight tube shape and a curved tube shape depending on the purpose.

As the material for forming the hollow layer 2 in the present invention, silicate glass, borosilicate glass, crystallized glass or the like can be used. The hollow layer 2 of the present invention is provided with the metal tubular body 1
The adhesion between the adsorption layer 3 and the adsorption layer 3 can be improved by forming it between the adsorption layer 3 and the adsorption layer 3.

As the electric resistor 4, there are stainless steel, nichrome, SiC, tungsten and the like, which can be used in a straight line or in a coil shape.

Since the adsorption layer 3 is provided on the surface of the heating element, when the electric resistor 4 is not energized, the odor component around the heating element is formed on the surface of the heating element. It can be adsorbed and deodorized by the zeolite or magnesium silicate in 3. Further, if the electric resistance 4 is energized before the zeolite or magnesium silicate adsorbs the odorous component up to its adsorption capacity limit, the electric resistance 4 generates heat and the heat of the electric resistance 4 changes to the electric insulator 5.
Is transmitted to the metal tubular body 1 via. The heat transferred to the metallic tubular body 1 heats the hollow layer 2 formed on the surface of the metallic tubular body 1, and at the same time, the adsorption layer 3 formed on the surface of the hollow layer 2
Also heat quickly. The zeolite or magnesium silicate in the heated adsorption layer 3 desorbs the adsorbed odorous components and harmful components, and the adsorption layer 3 recovers its adsorption ability and is regenerated. After stopping the heating by energizing the electric resistor 4,
The adsorption layer 3 can again adsorb odorous components.

Here, the magnesium silicate in the adsorption layer 3 is a composition in which magnesium oxide, silicon dioxide and water are bonded at various ratios such as magnesium orthosilicate, magnesium metasilicate, talc, magnesium tetrasilicate and magnesium trisilicate. is there.

Zeolites are A type, X type, Y type, ZS
Various zeolites such as M type can be used. Among them, copper ion-exchanged zeolite is particularly preferable because it has the best odor adsorption capacity.

As the inorganic binder, various materials such as aluminum hydroxide, glass powder, water glass, clay and silica can be used. Among them, silica is the most excellent and desirable in the comprehensive evaluation of odor adsorption capacity and coating film hardness. The content of the inorganic binder is 10 to 10 in the adsorption layer.
It is preferably 40 wt%. If the content of the inorganic binder exceeds 40 wt%, the adsorption layer is likely to be cracked and the adhesiveness tends to be deteriorated. On the other hand, if it is less than 10 wt%, sufficient adhesion characteristics of the inorganic binder cannot be obtained.

It is also desirable that the adsorption layer contains a noble metal salt. The noble metal salt is thermally decomposed by heating and becomes a noble metal catalyst substance. This noble metal catalyst substance is activated by applying electricity to an electric resistor and heating it to oxidize and decompose the odorous components adsorbed by zeolite or magnesium silicate in the adsorption layer and the odorous components in the vicinity of the adsorption layer by its catalytic action, resulting in no odor. As an ingredient. Since the adsorbed odorous components are removed from the zeolite or magnesium silicate heated by the heating means, the adsorption ability is restored again, and the odorous components can be adsorbed again after the heating by the heating means is stopped. In this way, the adsorption of odorous components by zeolite or magnesium silicate when not heated, and the heating regeneration of zeolite or magnesium silicate when heated and the catalytic decomposition of odorous components are alternately repeated to produce a bad odor over a long period of time. It can be removed continuously. Platinum group metals include platinum, palladium, rhodium, and the like, and a noble metal salt such as a chloride, nitrate, or ammine complex that decomposes by heating to become a noble metal is used.

(Example 1) Copper ion exchange type zeolite
800 g, 20 wt% silica as an inorganic binder
% Colloidal silica aqueous solution containing 1000%, water 500
g, and thoroughly mixed using a ball mill to prepare slurry-A. This slurry-A has an outer diameter of 10 mm,
The inner surface of the hollow portion of a stainless steel tube having an inner diameter of 9.6 mm, a length of 330 mm, and a hollow layer of 200 μm thick formed of borosilicate glass on the outer surface was coated with a central portion of 280 mm by a spray method. Then dried at room temperature, followed by 1 at 500 ° C.
A stainless tube having an adsorption layer A was fired for a period of time, a nichrome wire was used as an electric resistor, and magnesium oxide was used as an electric insulator to prepare a heating element A similar to that shown in FIG. Both ends of the stainless tube were sealed with low melting glass and heat resistant resin. The adsorbent coverage was 0.6 g.

Slurry B was prepared with the same composition as slurry A, using talc as the same amount of magnesium silicate instead of the copper ion exchange type zeolite. This slurry
Using B, in the same manner as the coating film A, a heating element B having an adsorption layer B formed on the surface of the stainless steel tube was prepared.

Further, for comparison, the same composition as Slurry A was used, but the same amount of activated carbon powder was used instead of the copper ion exchange type zeolite, and the same amount of iron-ascorbic acid powder was used as Comparative Slurry-1. Comparative Slurry-2 was prepared. These comparative slurries were used to prepare comparative heating elements 1 and 2 in which the comparative adsorption layers 1 and 2 were formed on the surface of the stainless steel tube in the same manner as the adsorption layer A.

Next, the odor substance adsorbing ability of each heating element was tested using methyl mercaptan, which is a typical odor substance. The test method was as follows. The various slurries described above were placed in a closed box having a volume of 0.3 m ³ whose inner wall surface was covered with a fluorine resin, and the air-diluted methyl mercaptan having a concentration of 10 ppm was adsorbed to the heating element (not The amount of residual methyl mercaptan was measured 30 minutes after the power was turned on and determined as the methyl mercaptan adsorption capacity. The air in the box was stirred by the fan during the experiment. The results are shown in (Table 1).

As is clear from Table 1, the heating element A containing the zeolite of the present invention and the silicic acid were compared with the comparative heating elements 1 and 2 formed by using the conventional adsorbent such as activated carbon and iron-ascorbic acid. The heating element B containing magnesium was excellent in the methyl mercaptan adsorption capacity. In addition, the adsorption capacity of methyl mercaptan of the adsorption layer formed by the slurry using magnesium silicate other than talc, magnesium orthosilicate, magnesium metasilicate, magnesium tetrasilicate, magnesium trisilicate is 28, 27, 29, 29%, respectively. A value was obtained.

In this embodiment, zeolite and magnesium silicate were individually added to the slurry, but they may be mixed and used.

[0024]

[Table 1]

(Example 2) The slurry prepared in Example 1
In A, a slurry was prepared in which the copper zeolite in the slurry was replaced with another ion-exchanged zeolite. With respect to the heating element formed on the stainless steel tube by using the same heating element forming method as the heating element A of Example 1 using these slurries, the odorous substance adsorption capacity test using methyl mercaptan shown in Example 1 I went. The results are shown in (Table 2).
As is clear from (Table 2), copper ion-exchanged zeolite is the most preferable in terms of its ability to adsorb odorous substances, which is desirable.

[0026]

[Table 2]

(Example 3) The slurry prepared in Example 1
In A, a slurry was prepared in which the aqueous colloidal silica solution in the slurry was replaced with various inorganic binders so that the amount of the inorganic binder contained in the final solid content was the same, and the slurry was prepared in the same manner as in Example 1. A heating element having an adsorption layer on a stainless steel tube was prepared. In order to examine the film hardness of these heating elements, a pencil hardness test of JIS G-3320 was conducted. Also, for each heating element,
A methyl mercaptan adsorption test was conducted in the same manner as in Example 1. The results are shown in (Table 3).

As shown in (Table 3), when alumina sol or bentonite is used, the hardness of the heating element is lowered, and when Li silicate or water glass is used, the coating hardness is improved, but the heating element does not become porous and odor is absorbed. The characteristics deteriorate. Therefore, it is most desirable to use colloidal silica as the inorganic binder.

[0029]

[Table 3]

(Example 4) The slurry prepared in Example 1
In A, with respect to all the solid components in slurry A, as an inorganic binder, the content of colloidal silica that becomes silica by firing is set to various contents between 0 wt% and 60 wt%, and the increment of colloidal silica is A slurry of the present invention having a reduced amount of copper zeolite was prepared. Using these slurries, a heat shock test was performed on a heating element in which an adsorption layer was formed on a stainless steel tube by the same heating element forming method as the heating element A of Example 1, and the adhesion was examined. In the thermal shock test, a quartz glass plate on which a heating element is formed is placed in an electric furnace set at a temperature of 25 ° C., held at that temperature for 10 minutes, and then dropped in room temperature water to check for the exfoliation of the heating element. The maximum temperature at which peeling did not occur was taken as the thermal shock resistance temperature. The results are shown in (Table 4).

As is clear from (Table 4), if the silica content of the inorganic binder exceeds 40 wt%, the adsorption layer of the heating element is likely to crack, leading to a decrease in adhesion. Cannot obtain sufficient adhesion characteristics. Therefore, the silica content is 10-40 wt% of the adsorption layer.
It is desirable to be%.

[0032]

[Table 4]

(Example 5) Copper ion exchange type zeolite
800 g, 20 wt% silica as an inorganic binder
Colloidal silica aqueous solution containing 1000 g, water 500
g, chloroplatinic acid as Pt and 6 g, palladium chloride as P
Slurry-C was prepared by adding 3 g as d and thoroughly mixing with a ball mill. This slurry-C was used in Example 1.
The same stainless steel tube surface was coated by a spray method, dried at 100 ° C. for 2 hours, and then baked at 500 ° C. for 1 hour to form a heating element C. The weight of the adsorption layer was the same as in Example 1.

The ammonia-catalyzed oxidative deodorization performance of the heating element C and the heating element A of Example 1 was examined. The catalytic oxidative deodorization performance test was conducted with a volume of 0.5 on which the inner wall surface was coated with fluorine resin
The heating element is placed in a closed box of m ³ and the temperature of the heating element is set to 400 ° C. by energizing the electric resistor of the heating element with a voltage of 100V. Next, the ammonia concentration in the box is 1
An amount of 0 ppm of ammonia was added, and the white metal catalyst in the activated heating element was used for oxidative decomposition, and after 30 minutes, the oxidative decomposition rate (%) of ammonia in the box was measured. The results are shown in (Table 5). As is clear from (Table 5), the heating element C containing a noble metal catalyst is more desirable than the heating element A because the catalytic oxidative deodorizing performance can be obtained.

[0035]

[Table 5]

(Embodiment 6) The slurry A of Embodiment 1 has an outer diameter of 10 mm, an inner diameter of 9.6 mm, a length of 330 mm, and a central portion of 280 mm on the surface of a stainless steel tube having no hollow layer on the outer surface. After painting by spray method, dry at room temperature,
Successively, a stainless tube having an adsorption layer A was fired at 500 ° C. for 1 hour, a nichrome wire was used as an electric resistor, and magnesium oxide was used as an electric insulator to prepare a comparative heating element 3 similar to the heating element A. did.

The same heat shock test as in Example 4 was conducted on the heating element A and the comparative heating element 3 to examine the adhesion.
The results are shown in (Table 6). As is clear from (Table 6), it is desirable to provide a hollow layer on the metal tube so that good adhesion (heat shock resistance) of the adsorption layer can be obtained.

[0038]

[Table 6]

[0039]

As described above, in the present invention, the odor of the atmosphere in which the heating element is placed and harmful gases such as cigarette smoke are adsorbed and removed by the adsorption layer formed on the surface of the heating element. Therefore, a comfortable heating environment can be provided when the heating element is used.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a heating element according to an embodiment of the present invention.

[Explanation of symbols]

 1 Metal Tubular Body 2 Hollow Layer 3 Adsorption Layer 4 Electrical Resistor 5 Electrical Insulator 6 Air Flow 7 Sealing Portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kyoe Yamade 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A metal tubular body, a hollow layer formed on the surface of the metallic tubular body, an adsorption layer made of at least one of zeolite or magnesium silicate formed on the surface of the hollow layer, and an inorganic binder. A heating element comprising an electric resistor incorporated in the metal tubular body. 2. The heating element according to claim 1, wherein the zeolite is a copper-containing zeolite. 3. The platinum group metal catalyst is contained in the adsorption layer.
Or the heating element described in 2.