JPS59177887A - 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] Industrial Application Field The present invention relates to a far-infrared heater that efficiently emits far-infrared rays, and is intended to provide a heat source for space heaters, cookers, drying equipment, etc. be.

Conventional configurations and their problems Conventionally, far-infrared heaters that emit far-infrared rays include: ■ Infrared rays, ■ Heat-generating wires embedded in ceramics and fired, ■ Sheathed heaters with a far-infrared radiation layer on the front surface (i+). However, many types of sheathed heaters are manufactured with a far-infrared radiation layer formed on the surface of the sheathed heater from the viewpoint of radiation characteristics 9 mechanical strength and lifespan.In general, sheathed heaters are made of metal tubes. It is made by inserting an electric heating coil inside, filling it with an insulator such as Mq○, swaging it to increase the filling density of the insulator, and sealing the end.

The far-infrared heater is a sheathed heater with a far-infrared radiation layer formed on the surface. The far-infrared emissive layer is made of zircon with a content of 60% or more, and Fe 203. Co
O + old ○v Cr 20s, a mixture made of a saponified substance such as Mn01 and a viscosity added,
Alternatively, it is known to contain a composite oxide of an element of Group 2 and an element of Group 3 of the Periodic Table of Elements, and a composite oxide selected from the group of zirconium silicate in an amount of 30 or more. .

However, since zircon-based materials are a type of porcelain, they are mechanically weak, and cracks occur during cooling and heating cycles of 50oC or higher, resulting in poor longevity and low emissivity in the wavelength range of 8 μm or less. There were drawbacks. The latter had a large difference in coefficient of thermal expansion with metal, and peeling and cracking occurred during cooling and heating cycles, making it unsuitable for fish with limited lifespans.

Purpose of the Invention The present invention has been made in consideration of the above-mentioned drawbacks, and has a high emissivity in the far infrared region, excellent rapid heating properties, thermal stability, excellent adhesion to metals, and is sufficient for cooling and heating cycles. The aim is to provide a far-infrared heater that can be used to reduce energy consumption.

Structure of the Invention In the present invention, a far-infrared emitting layer made of nickel oxide with a coefficient of 30 or more is formed on the bottom surface of a metal or non-metallic tube.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which F e , S
An electric heating coil 2 having an electrode 6 is inserted into a filler material 1 made of uS, Ni-Cr, etc., and is filled with a heat-resistant insulating powder 3 such as MqO. It has a high packing density and its terminals are treated with a sealant 4, and is generally called a sheathed heater. A radiation layer 5 is formed on the surface of the retaining tube 1 of this sheathed heater by means of plasma spraying or the like with N i O powder.

The emissive layer of the present invention contains 30% or more of nickel oxide, and contains ferrite, zrO2,
Y2O3+Zr○2・CaO, Z r O211M90
Stabilized zirconia such as ゜ or Z r O2.S;
02゜3Aβ0 ・2 S z OAQ OT 10
It is also possible to add at least one type of 232923. The method for forming the radiation layer is to make the surface of the metal trench or pipe to be metallized into a river surface by using flasting, and then apply the purpose on that surface.

An infrared emitting material prepared according to the application is thermally sprayed using a plasma spraying device.

(Specific Example 1) A sheathed heater (diameter 10
Blasting the surface of 1ooV, 500W with corundum (#eo) abrasive! Then, N i O containing impurities within 5 lines was directly deposited by plasma spraying to form a far-infrared emitting layer of 50 μm.

EXAMPLE An infrared radiation material having the following composition was directly applied to the same 7-Z heater as in Example 1 by plasma spraying after pretreatment.
A far infrared region of 5011 m was formed.

N' i 0...6wt%A
Q ○ ・TiO2...40 wt% 3 A 50 μm emissive layer was formed in the same manner as in Example 1 using an infrared emitting material having the following compounding ratio.

NiO...30 wt% AQ OTiO2...70 wt% 3 As described above, experiments were conducted on three specific cases while comparing them with comparative examples.

In addition, in the comparative example, a radiation layer (50μ
m) was formed.

FIG. 2 shows the emissivity at each wavelength when the surface temperature is set at 500C.

As is clear from the figure, the far-infrared heater of the present invention has a higher emissivity in the wavelength region of 8 μm or less than the comparative example.

Next, a water heating experiment was conducted to clarify the absorption characteristics of heated objects.

Figure 3 shows the results of a water temperature rise test using the far infrared heater of the present invention and a comparative example.The electric power was kept constant and the same volume of water was heated, and the temperature rise over time during fr was measured. This is a graph.

As is clear from this figure, the far-infrared heater of the present invention can heat water more efficiently than the conventional example.

Next, in order to check the mechanical strength and life characteristics, the heater surface degree was set to 800C, and a heat cycle test (
20 minutes ON, 5 minutes ○FF) was performed once. As a result, in the comparative example, cracks and peeling occurred in the radiation layer after 10 cycles, but in the far infrared heater of the present invention, no abnormality occurred even after 1000 cycles, and the radiation layer was 75λ.

The reason why the content of nickel oxide is set at 30% or more is that if the content is less than 30%, no improvement in radiation characteristics can be expected. This is because there was a problem.

Effects of the Invention As described above, the far-infrared heater of the present invention is excellent in far-infrared radiation characteristics, particularly in the wavelength region of 3 to 1 Q μm. Therefore, it is a drying device that can efficiently heat the object to be heated, is resistant to cold and hot cycles, and has high industrial value.

Ideal as a heat source for heating equipment, cooking equipment, etc.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a far-infrared heater showing an embodiment of the present invention, Fig. 2 is a characteristic diagram showing the radiation characteristics of the far-infrared heater, and Fig. 3 shows the temperature rise of water by the far-infrared heater. It is a characteristic diagram. 1...Storage tube, 5...Radiation layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2: Liquid length <) to Figure 3: ○;

Claims (1)

[Claims] A far-infrared heater in which a far-infrared radiation layer made of 3Q% or more of nickel oxide is formed on the surface of a metal or non-metallic tube.