JPH02236987A - Tubular heater and manufacture thereof - Google Patents

Abstract

PURPOSE:To maintain rapid effect of a heater, and to provide comfortable warmness continuously by partially coating a porous far infrared radiant material on the surface of a visible ray part translucent tubular body in which stored a heat source. CONSTITUTION:On the surface of a visible ray part translucent tubular body in which stored a heat source, a porous far infrared radiant material is partially coated. When the energy from the heat source in the visible ray part translucent tubular body is absorbed in the porous far infrared radiant material, which is then heated, it can be radiated as a far infrared ray. For the visible light part translucent tubular body, in consideration of heat resistance and heat resistant impact, a fused quartz 2 is used. For the far infrared radiant material, activated alumina, zirconia oxide or titanium dioxide is used. By heating the activated alumina, zirconia oxide or titanium dioxide held platinum group metal, discomfort small can be rapidly removed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a tube heater that utilizes electrical energy and is used in home heating appliances and the like.

Conventional technology Conventional tubular heaters have a coiled metal wire such as nichrome wire, Kanthal wire, or tungsten wire built into a tubular body as a heat source, and the tubular body is made of quartz glass or stainless steel. was. However, stainless steel heaters, generally called sheathed heaters, have a large heat capacity, making them unsuitable for applications such as home heating that require immediate action. Ceramic pipe heaters have also been used industrially, but they have a large heat capacity and are unsuitable for applications such as household heating that require immediate action.

Therefore, the tubular heaters currently commonly used for home heating etc. have a nichrome wire built into a quartz glass sheath in the form of a coil rod.

By applying electrical energy, this tubular heater
Since it was red hot, I could feel the warmth even by looking at it visually. This tubular heater can be used to directly heat the object (human being), to generate hot air by forcing air through the tubular heater from a fan, or to generate radiant heating by installing a reflector behind the tubular heater. They put that heat to good use by doing things like this.

Problems to be Solved by the Invention Problems with such conventional tubular heaters will be briefly explained.

The wavelength range that humans perceive as warm is determined by the depth of the cold-sensing nerves and warm-sensing nerves in the skin and muscles, the penetrating power of the infrared wavelength range, and the correlation with the wavelengths that are effective in stimulating the nerves. Ru. Generally, it is said that human cold-sensing nerves are located at a depth of about 100 μm, and warm-sensing nerves are located at a depth of 260 μm. Figure 6 shows the infrared absorption spectrum of the skin. When we consider these correlations, we find that in the infrared wavelength range, near-infrared rays are highly transmitted, while far-infrared rays are absorbed by the epidermis. Therefore, it is very difficult for humans to feel comfortable warmth, as there are individual differences, but near-infrared rays provide an immediate effect, and far-infrared rays provide a slow and moderate amount of warmth.

Currently, there are 1 type of tubular heater, which has a nichrome wire coiled inside a quartz glass sheath and is used for home heating.
It emits a large amount of near-infrared rays of ~4 μm, and only a small amount of far-infrared rays of 5 μm or more. Therefore, although it is possible to feel the warmth immediately, in order to continuously feel the warmth comfortably, the radiation of far-infrared rays is also essential.

Furthermore, when heating with an electric kotatsu or the like, the human body is heated, and the odor of the human body (feet) and other objects to be heated (futon) are also heated. Generally speaking, the higher the temperature, the stronger the smell is perceived by the human nose. For this reason, when you use an electric kotatsu and turn on the heat, the smell of the human body (feet) and other heated objects (futon) will naturally become stronger. If the inner part leaks into the room, it will cause discomfort to humans. Therefore, this odor problem is also an issue to be solved.

The present invention is based on the above-mentioned conventional problem and provides a tubular heater with a simple structure that allows the user to continuously feel comfortable warmth while maintaining the immediate effect of heating.

Means for Solving the Problems The present invention is a tubular heater characterized in that the surface of a visible light-transmitting tubular body containing a heat source is partially coated with a porous far-infrared radiating material.

Further, the present invention is a tubular heater having the above configuration, in which the visible portion transparent tubular body is made of quartz glass.

Further, the present invention provides a tubular heater having the above configuration, in which the porous far-infrared radiating material is made of at least one oxide selected from activated alumina, zirconia oxide, or titanium dioxide.

Further, the present invention provides a tubular heater having the above-mentioned configuration, in which a platinum group metal is supported on a porous far-infrared radiation material.

The present invention also provides a method for manufacturing a tubular heater, which comprises subjecting the surface of the tubular body that is transparent to visible light to a specific surface area enlargement treatment, and then partially covering the surface with a porous far-infrared ray emitting material.

Function The transparent tubular body in the visible light section transmits light emitted from the internal heat source to the outside, thereby providing an alarm information function of notifying whether the tubular heater is being used, and at the same time producing red-hot light. By transmitting the emitted light to the outside world, it plays an important role in appealing to humans about its heating effect.

As mentioned earlier, current tubular heaters emit a large amount of near-infrared rays, and emit only a small amount of far-infrared rays of 5 μm or more. This is essential, and it is important to maintain this effect while continuously providing a comfortable heating effect.

Therefore, in the present invention, the surface of the tubular body is partially coated with a porous far-infrared emitting material. Thereby, the porous far-infrared ray emitting material can absorb energy from the heat source inside the visible light-transparent tubular body, heat it, and then radiate it as far-infrared rays.

At this time, if the catalyst metal is supported on the porous far-infrared emitting material, the catalyst metal can be heated. Therefore, the catalytic metal can purify and deodorize the human body (feet) and other objects to be heated (futon) by being humidified to an activation temperature at which it can exert its catalytic action.

In consideration of heat resistance and thermal shock resistance, it is preferable to use quartz glass for the visible light-transmitting tubular body of the present invention.

Further, as the far-infrared emitting material used in the present invention, activated alumina, zirconia oxide, or titanium dioxide is preferable. These have excellent far-infrared radiation properties and are excellent as catalyst supports. In addition, in order to exhibit excellent far-infrared radiation properties and catalytic properties, the specific surface area of activated alumina, zirconia oxide, or titanium dioxide with a small particle size (approximately 1 to 5 μm) must be kept large and porous. is important.

By supporting platinum group metal on activated alumina, zirconia oxide, or titanium dioxide, unpleasant odors can be quickly removed.

In addition, before partially coating the surface of the visible light-transparent tubular body with the porous far-infrared emitting material, the surface of the visible light-transparent tubular soft body is subjected to a specific surface area expansion treatment, thereby forming a tubular body. Adhesion with the porous far-infrared emitting material can be improved.

Example Examples of the present invention will be described below.

(Example 1) As shown in Fig. 1, the outer diameter is 10 mm, the thickness is 0.5 mm, and the length is 150 m.
m, the surface of the quartz glass tubular heater 2 has a specific surface area of 15
0m”/H activated alumina 100 gs20wt
% boehmite sol 30 gs 10 wt% Silica sol 15 g paste of about 10,000 cps was printed in a lath-like pattern as shown in Fig. 2 by the screen printing method.
It was coated with a thickness of μm. At this time, the covered area was 50% of the surface of the tubular heater. In addition, in FIG. 1, 3 is a terminal of the tungsten wire 1.

Fig. 3 shows the infrared emissivity of the tubular heater of this example (Example 1), and the infrared emissivity of the tubular heater of this example not coated with activated alumina (Comparative example 1). . From this result, the tubular heater of this example is an excellent tubular heater that can simultaneously emit near-infrared rays and far-infrared rays.

In this embodiment, a lath-like pattern was printed, but the pattern can be freely selected, such as dot-like. Furthermore, when the tubular heater was coated with zirconia oxide or titanium dioxide as a far-infrared emitting material, or a mixture thereof with activated alumina, the infrared emissivity was almost the same as that of the tubular heater of Example 1, and there was no significant difference. This is thought to be because these are white ceramics, so they exhibited a similar tendency.

(Example 2) Pt and Pd were added to the activated alumina-coated tubular heater of Example 1 in an amount of 3 g of Pt per 100 g of activated alumina. Pdl. It was supported at a ratio of 5 g.

Using two of the tubular heaters of this example, an electric kotatsu having a configuration as shown in FIG. 4 was made, and the deodorizing effect was tested.

The tubular heater 4 is arranged parallel to the lower surface of the top plate of the skeleton structure 6 of the electric kotatsu, and a fan 5 is installed in the center. While applying 300W of electricity to this electric kotatsu,
Trimethylamine was injected into a sealed container measuring 0 mm x 900 mm x 350 mm to a concentration of 5 oppm. Subsequent changes in concentration were measured by gas chromatography analysis.

As Comparative Example 2, the same deodorizing effect test as in Example 2 was conducted using two tubular Heags that were not coated with activated alumina used in Example 1. The measurement results of Example 2 and Comparative Example 2 are shown in FIG. As a result, it was revealed that the tubular heater of this example exhibited excellent catalytic action and was effective in deodorizing.

Furthermore, when coating a tubular body with a far-infrared emitting material (activated alumina), the preferred coating area and film thickness are approximately inversely proportional. The reason for this is that when the coating area is increased, the red heat of the tubular heater inevitably decreases, so to avoid this it is necessary to reduce the film thickness, and when the coating area is made small, it is necessary to maintain catalytic performance It is necessary to increase the film thickness.

As a result of experiments, the preferred coating area and film thickness when coating a far-infrared emitting material on a tubular body are approximately θO% of the coating area.
When the coating area was 20%, the film thickness was found to be approximately 50 μm.

(Example 3) Outside diameter 10mm1 with tungsten wire installed inside
The surface of a tubular heater made of quartz glass with a wall thickness of 0.5 mm and a length of 150 mm was roughened by etching. The surface has a surface roughness of Ral. 6μm1 Rmaxl2.3μm
Met. After that, a specific surface area of 150 m similar to Example 1 was applied.
Approximately 10,000 cps of a paste of 100 g of activated alumina/g, 120 wt% boehmite sol, 30 g, 10 wt% silica sol, 15 g was coated in a lath pattern to a thickness of approximately 20 μm by screen printing.At this time, the coated area was tubular. It was 50% of the heater surface.

In order to examine the adhesion of the tubular heaters of Examples 1 and 3, the following severe adhesion test was conducted. First, a current of 500W is applied to the tubular heater for 5 minutes to bring the surface temperature of the tubular heater to approximately 500°C, then the electricity is turned off, the air blower is used to cool it down to room temperature, and the electricity is turned on again for rapid heating and cooling. After repeating 1000 times, a tubular heater was further installed in the vibrator, and a vibration test was conducted for 1 hour in which the vibrator was moved back and forth over a distance of 20 mm at a speed of 15 m/s. The results were evaluated by the peeling rate of the following formula.

Table 1 From the results, it was found that by roughening the surface of the tubular body, adhesion that could withstand quite severe adhesion tests could be obtained. Moreover, the preferable surface roughness of the surface of this tubular body was Rat~3 μm1Rmax10~30 μm.

Effects of the Invention As described above, in the present invention, while emitting conventional near-infrared rays as a tubular heater for household heating equipment, etc., by partially covering the porous far-infrared radiating material, continuous chi It will provide a comfortable heating effect.

At this time, if a catalyst metal is supported on the porous far-infrared emitting material, unpleasant odors are purified and deodorized by the catalytic action.

Therefore, a comfortable heating environment can be created by the heating appliance using the tubular heater of the present invention.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the tubular heater in Example 1 of the present invention, FIG. 2 is an external view of the same tubular heater, and FIG. 3 is a diagram showing the infrared emissivity of the tubular beater of Example 1 and Comparative Example 1. FIG. 4 is a configuration diagram of an electric kotatsu in Embodiment 2 of the present invention,
Figure 5 is a diagram showing the deodorizing effect test results of Example 2 and Comparative Example 2, and Figure 6 is the infrared absorption spectrum of the skin. It is. 1... Yusuke Gusten wire, 2... Quartz glass, 4...
・Tubular heater. Name of agent: Patent attorney Shigetaka Awano and 1 other person Fig. fig. taO

Claims (5)

[Claims] (1) A tubular heater characterized in that the surface of a visible light-transparent tubular body containing a built-in heat source is partially coated with a porous far-infrared radiation material. (2) The tubular heater according to claim 1, wherein the visible light-transmitting tubular body is made of quartz glass. (3) at least one porous far-infrared emitting material selected from activated alumina, zirconia oxide, or titanium dioxide;
3. The tubular heater according to claim 1 or 2, comprising a single oxide. (4) The tubular heater according to claim 1, 2 or 3, wherein a platinum group metal is supported on the porous far-infrared emitting material. (5) A method for producing a tubular heater, which comprises subjecting the surface of the tubular body that is transparent to visible light to a specific surface area enlargement treatment, and then partially covering the surface with a porous far-infrared radiation material.