JPH11214129A - Far infrared ceramic heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a far infrared ceramic heater provided with characteristics of generating minus ions effective in improving high far infrared radiation characteristics, air purification, deodorization, and indoor environment. SOLUTION: Concerning a self-conductive ceramic material containing electricity conductive powders made of Si or FeSi2 in an insulation material having alumino silicate as a main component and a ceramic material having a double structure having a heater layer containing mineral powders in the insulation material or electricity conductive powders made of Si or FeSi2 in an insulation material layer having alumino silicate as a main component and the insulation material having alumino silicate as a main component, tourmaline powders are contained in the insulation material of the insulation material layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a far-infrared ceramic heater having both the characteristic of high radiation of far-infrared rays and the property of generating negative ions effective for purifying and deodorizing air and improving the indoor environment. About.

[0002]

2. Description of the Related Art Far-infrared heaters emit radiant heat energy at a spectral emissivity (ε) of about 0.8 in the far-infrared region, which approximates a black body, and are used in industrial to consumer applications to provide efficient heating. It is widely used in a wide range of fields. As far-infrared heaters, silica, alumina,
Known are those having a structure using ceramics such as zirconia and titania as a far-infrared radiating material.For example, a structure in which a heating wire such as a nichrome wire is sealed in a tube formed of these ceramic materials, or the above-described ceramic is provided on the surface of a sheathed heater. Material-coated structures have been developed. However, the structure in which the heating wire is sealed in the ceramic tube causes inconveniences such as heat energy loss, uneven temperature distribution, and delay in response time in temperature control because the heating method is indirect heating. There is a disadvantage in that the material of the heat ray is deteriorated with time and is broken. Further, in the structure in which the ceramics material is coated on the surface of the sheathed heater, there is a problem that the metal tube constituting the sheathed heater and the coated ceramic coating layer are separated due to a difference in thermal expansion during use. Such problems far infrared heater which solves the, having a structure composed of an insulating heat resistant structural material resistive heating element Si or FeSi ₂ was contained 5 to 60 wt% of the conductive material in the present application Disclosed by a person. (Japanese Patent Laid-Open Publication No. 63-307682) The far-infrared heater is capable of directly heating a far-infrared radiator formed into an arbitrary shape itself with resistance, so that the heater can be easily designed and has a small heat capacity. Demonstrate fast heat and sufficient thermal efficiency. There are two types of indoor air purifiers: so-called air purifiers, a fan type that sucks dust with an electric fan and adsorbs and removes dust on the filter, and a fanless type that disperses electrons to give negative charges to dust and collects dust by Coulomb force. Exists. On the other hand, tourmaline ore, which is a crystal of tourmaline that is produced naturally, is known as a material having a deodorizing effect and a dust removing effect due to generation of negative ions. Tourmaline ore is a polar crystal and has been found to exhibit pyroelectric and piezoelectric properties. The tourmaline (electric stone)
Has several compositions depending on the difference in its formation process, but is basically a silicate mineral containing boron, and its representative chemical formula is shown as follows. 3 ｛NaX ₃ Al ₆ (BO ₃ ) ₃ Si ₆ O ₁₈ (OH ₉
F) ₄ ｝ (X = Mg, Fe, Li) Normally, a dielectric causes electric polarization in an electric field. However, in a so-called polar crystal, electric polarization is performed from the beginning even without an external electric field. I have. That is, the pyroelectric property affecting the deodorizing effect of tourmaline is a secondary pyroelectric effect due to thermal expansion and piezoelectricity, and charges are generated on the surface by heating and thermally expanding tourmaline ore. By utilizing this characteristic, negative ions generated by dissociating moisture in the air have a deodorizing effect, and are kneaded into fibers or the like as a deodorizing material and used as clothing or wallpaper material.

[0003]

The air purifiers of the fan type or the fanless type are both expensive devices. In the case of the fan type, the motor noise is loud and the filter must be replaced frequently. Not suitable for general household use. 800 for fanless type
Since a high voltage of about 0 V is applied to cause corona discharge to generate a negative charge, there are disadvantages in that problems such as radio wave interference and ozone generation occur, and that a high voltage transformer is expensive. On the other hand, the deodorizing action of tourmaline ore is a cheaper and safer method than a normal air purifier. However, the deodorizing effect due to the generation of negative ions,
It is very poor without external energy, and the fact is that even if it is simply kneaded into fiber or resin, the effect is small and cannot be expected much. The present inventor has conducted intensive research to solve these problems, and as a result, by adding tourmaline ore powder to a ceramic heater, external energy by heating is added to the tourmaline ore to efficiently extract pyroelectric properties. As a result, it has been found that it is possible to increase the amount of generated negative ions and enhance the deodorizing effect.

[0004]

According to the present invention, there is provided a far-infrared heater according to the present invention, which comprises an insulating material containing aluminosilicate as a main component, which is made of Si or FeS.
respect self energized ceramic material containing a conductive powder comprising i _2, characterized in construction that it contains the tourmaline powder in the insulating material. Another configuration of the far-infrared heater according to the present invention is that an insulating material layer mainly containing aluminosilicate and an insulating material mainly containing aluminosilicate are made of Si or Fe.
A double-layered ceramic material having a heater layer containing a conductive powder of Si ₂ is characterized in that the insulating material layer contains tourmaline ore powder in the insulating material.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A far-infrared ceramic heater according to the present invention comprises a self-heating type ceramic heater obtained by blending an insulating ceramic material containing tourmaline ore powder and a conductive material, molding and firing, or This ceramic heater has a double-layered structure having an insulating ceramic layer containing tourmaline ore on the surface, and is characterized by having both a high far-infrared radiation characteristic and a deodorizing effect by generating negative ions. The ceramic heater material of the present invention is made of a resistance heating material containing an aluminosilicate made of a clay raw material or a glass powder as a main component and containing a conductive material made of Si or FeSi ₂ . Since this heater material is a self-energizing ceramic heater, it has excellent features such as relatively quick temperature rise, easy to obtain uniform temperature distribution, and easy resistance adjustment for various shapes. . Further, when the spectral emissivity of the material is measured, a high emissivity of 0.9 or more is obtained in the far infrared region having a spectral wavelength of 10 μm or more. Tourmaline ore itself has a high far-infrared radiation characteristic, and even if it is combined with the ceramic heater, the radiation characteristic of the heater itself is not impaired. The production method is as follows: 30 to 80% by weight of a pulverized raw material of tourmaline ore powder, and 20 to 20% by weight of a binder mainly composed of aluminosilicate composed of clay raw material and glass powder.
It blended 70% by weight and mixed powder of an insulating material, a mixed powder of the mixed powder a conductive material composed of Si or FeSi ₂ against blended 5-60 wt% conductive material. For the ratio of tourmaline ore powder, 30 to 80
It is desirably in the range of weight%. This is because if the ratio of tourmaline ore is less than 30%, the deodorizing effect due to generation of negative ions is reduced, and if it is more than 80%, the ratio of the binder decreases, and sufficient sintering cannot be obtained by firing. It depends. The mixing ratio of Si or FeSi ₂ can be varied in order to adjust the resistance to a desired value, and a range of 5% to 60% can easily obtain a resistance value capable of resistance heating as a heater. The binder preferably contains borosilicate glass having a softening point of 900 ° C. or less. This is because the tourmaline crystal changes its crystal by heating at 900 ° C. or more and loses pyroelectricity.
This is because it is necessary to perform sintering at a temperature of 0 ° C. or less. For the molding method, it is possible to use the general ceramic molding methods such as extrusion molding, slip casting, and sheet molding method, and it can be manufactured from simple shapes such as pipes and plates to complex shapes such as honeycomb. Becomes As for the heater having a double structure, it is desirable to manufacture the sheet by a doctor blade method, by laminating green sheets and by integrally firing. That is, as the heater layer sheet, aluminosilicate made of clay raw material, glass powder, or the like is mixed with Si powder as conductive powder.
Alternatively, a mixed slurry obtained by mixing 5 to 60% by weight of FeSi ₂ powder is formed. As the tourmaline ore composite layer sheet, a mixed slurry obtained by mixing 30 to 80% by weight of tourmaline ore powder in an aluminosilicate composed of a clay raw material or a glass powder is formed, and the mixture is formed into a state of the heater layer sheet and the green sheet. And press and laminate.
Then, it is baked at 900 ° C. or lower and sintered to form a heater. Further, as a method of manufacturing a double-structure heater, there is a method of coating a material containing tourmaline ore powder on a heater sintered in advance. This method comprises adding 5% to 60% of Si or FeSi ₂ powder as a conductive powder in an aluminosilicate made of clay raw material, glass powder, or the like.
The mixed powder obtained by blending by weight% is formed into a desired shape, fired and sintered. On the other hand, the mixture contains 30 to 80% by weight of tourmaline, and as other materials, mixed with an aluminosilicate made of a clay raw material or glass powder, a binder such as an organic binder or water glass, and water as a solvent. To obtain a coating solution. The obtained coating liquid is sprayed on a heater that has been previously fired and sintered,
Paint the entire heater evenly. After that, it is heat-treated at a temperature at which the dried and used binder hardens, thereby obtaining a double-structured heater. In any of the manufacturing methods for the dual-structure heater, since the coefficient of thermal expansion between the heater layer and the tourmaline ore layer is very close, there is no problem of peeling during firing or heating of the heater element. In addition, the dual structure heater has an advantage that the distribution of the tourmaline ore composition can be concentrated on the heater surface. Regarding the pyroelectricity of tourmaline, it is said that secondary pyroelectricity derived from piezoelectricity accompanying thermal expansion is strong. 100 to 3 tourmaline particles
When heated to 00 ° C. and thermally expanded, polarization occurs in one direction due to a piezoelectric effect caused by the distortion. Due to the discharge phenomenon caused by the polarized electric charges, when water molecules floating in the atmosphere pass through an electric field generated from the polarization, they are dissociated into hydrogen ions and hydroxyl ions. In particular, most of the hydroxyl ions combine with surrounding water molecules to form hydroxyl ions having a negative charge and float in the air. Hydroxyl ions floating in the air combine with bad smell molecules such as the smell of tobacco and ammonia to eliminate the bad smell. In addition, the hydroxyl ions themselves are said to have a role of enhancing the feeling of exhilaration in the room, which improves the indoor environment. Therefore,
In order to efficiently bring out the pyroelectric effect of tourmaline ore, it is essential to cause thermal expansion and contraction by heating. Heating temperature of this far infrared heater is 100 ~
A temperature of about 300 ° C. is preferable, and a cycle load from room temperature to 300 ° C. is preferably performed because pyroelectric properties can be obtained during the thermal expansion process.

[0006]

The present invention will be described in more detail with reference to examples.

[0007]

Example 1 Powder crushed from tourmaline ore (particle size 3 to
5 μm) 50% by weight and borosilicate glass (softening point 650)
° C, average particle size 1.0 μm) 30% by weight, ball clay 2
0% by weight, and 70% by weight of the mixed powder and 30% by weight of Si powder (average particle size: 10 μm) are mixed by a ball mill. A binder and a plasticizer are added to this mixed powder slurry and mixed again by a ball mill to obtain a sheet forming slurry. After defoaming the slurry, the slurry was molded with a doctor blade device to obtain a green sheet having a thickness of 1 mm.
Four green sheets are laminated and pressed by a press machine,
It was cut into a width of 110 mm and a length of 220 mm to obtain a heater shape. Thereafter, the degreasing treatment was performed by heating to 500 ° C. in a nitrogen atmosphere, and the degreased body was fed and baked at 900 ° C. in a tunnel furnace to obtain a fired body having a width of 100 mm, a length of 200 mm, and a thickness of 2.5 mm. . Both ends 10 of the obtained fired body
The aluminum was sprayed onto the mm to form an electrode. The electric resistance value was 150Ω. This heater was installed in a cubic room having a length of 1 m, and a deodorizing effect test was performed using ammonia gas. The heater was heated under the conditions of AC 100 V, power ON for 10 minutes, power OFF for 10 minutes, and a cycle load. The surface temperature of the heater changed from 300 ° C. to 70 ° C. The deodorization rate is about 50% of the initial concentration after about 1 hour.
%, And a higher deodorizing effect than that without the heater was observed.

[0008]

[Example 2] Powder crushed from tourmaline ore (particle size 3 to
5 μm) 50% by weight and borosilicate glass (softening point 650)
° C, average particle size 1.0 μm) 30% by weight, ball clay 2
0% by weight was mixed with a ball mill, a binder and a plasticizer were added, and the mixture was mixed again with a ball mill to obtain a tourmaline layer sheet slurry. On the other hand, borosilicate glass (softening point 6
50 ° C., average particle size 1.0 μm) 40% by weight, ball clay 20% by weight, Si powder (average particle size 10 μm) 40% by weight are mixed in a ball mill, a binder and a plasticizer are added, and mixed again in a ball mill. Thus, a slurry for a heater layer sheet was obtained. After defoaming both slurries, they were molded with a doctor blade device to obtain green sheets each having a thickness of 1 mm. Two heater layers are laminated on the green sheet by a press device, and an insulating layer sheet is laminated one by one on the outside thereof, and a total of four laminated layers are pressure-bonded, and a width of 110 mm and a length of 220 mm
Into a heater shape. Thereafter, the sample was heated to 500 ° C. in a nitrogen atmosphere to perform a degreasing treatment.
A fired body having a length of 200 mm and a thickness of 2.5 mm without warpage or peeling was obtained. Aluminum was sprayed on both ends of 10 mm of the obtained fired body to form electrodes. The electric resistance value was 130Ω. When the heater was energized and heated at an alternating current of 100 V, the exothermic temperature reached about 300 ° C., in particular, no separation between the coating layer containing tourmaline powder and the heater layer was observed, and the deodorizing effect was confirmed.

[0009]

Example 3 40% by weight of borosilicate glass (softening point: 650 ° C., average particle size: 1.0 μm), 25% by weight of ball clay, 5% by weight of bentonite clay, and 30% by weight of Si powder were mixed to obtain a mixed raw material powder. Was. 5% by weight of water was added to 100% by weight of the mixed raw material powder, kneaded and extruded using a mold having an outer diameter of 21 mm and an inner diameter of 15 mm to obtain a pipe-shaped molded body. After drying, the molded article was cut into a piece having a length of 210 mm and fired in a tunnel furnace at 1300 ° C. in the atmosphere. Aluminum was sprayed on both ends of 15 mm of the obtained fired body to form electrodes. The electric resistance value was 200Ω. Separately, 80% by weight of tourmaline powder and 20% by weight of water glass powder were mixed, and 20% by weight of water was added to 100% by weight of the mixed powder and kneaded to obtain a coating slurry. After defoaming the slurry, the viscosity was adjusted and the surface of the pipe-shaped heater was coated with a spray gun. Then, it was air-dried and heat-treated at 300 ° C. for 1 hour to cure the coated surface to obtain a double-structured heater. Use this heater for AC 1
When heat was generated at 00V, the heat generation temperature was 300 ° C.
In particular, no separation between the coating film containing tourmaline powder and the ceramic heater was observed, and the deodorizing effect was confirmed.

[0010]

As described above, the far-infrared heater according to the present invention is a ceramic heater containing tourmaline ore powder or a double structure ceramic heater having a ceramic layer containing tourmaline ore powder on the surface. In addition, it has both the characteristic of high radiation of far-infrared rays and the characteristic of generating negative ions which are effective in purifying and deodorizing air and improving the indoor environment by generating heat by energizing.

Claims (2)

[Claims] 1. A self-energizing ceramic heater containing a conductive powder of Si or FeSi _{2 with} respect to an insulating material containing an aluminosilicate as a main component, wherein the tourmaline ore powder is contained in the insulating material. Features a far infrared ceramic heater. 2. A double-layer ceramic heater having an insulating material layer mainly composed of an aluminosilicate and a heater layer containing a conductive powder of Si or FeSi _{2 with} respect to an insulating material mainly composed of an aluminosilicate. 3. The far-infrared ceramic heater according to claim 1, wherein the insulating material layer contains tourmaline ore powder.