JP2003277815A - Observation device of high temperature furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and lightweight observation device of a high temperature furnace, and can use a cooling device whose size as comparatively small. <P>SOLUTION: In the observation device in the high temperature furnace provided with an image pickup unit, a reflection type filter at the front part of this image pickup unit and an infrared absorption filter at an interval between this reflection type filter and the image pickup unit, are provided. Further, this reflection type filter in the observation device in the high temperature furnace, is formed of a metallic film having the composition of 80-100 wt.% platinum on the one side surface or the both surfaces of a base board. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high temperature furnace observation apparatus, and more particularly to a high temperature furnace observation apparatus used for observing molten glass in a glass melting furnace.

[0002]

2. Description of the Related Art Glass is manufactured by melting raw materials such as silica sand, soda ash, and limestone at a high temperature of 1000 to 1800 ° C. in a glass melting furnace. In order to control the glass manufacturing process, continuous observation of molten glass in a high temperature glass melting furnace is required.

In the glass melting furnace in operation, the vapor phase temperature on the molten glass is as high as 1000 to 1800 ° C., and extremely strong heat rays are emitted from the high temperature molten glass. There is a CCD camera or the like as a general image pickup device, but the usable temperature of the CCD camera is limited to around room temperature, and in order to insert this into a glass melting furnace during operation and use it for observing molten glass, CC from hot air
Not only should the D-camera be protected, but it is also necessary to prevent the CCD camera from being hindered by heat rays.

For this reason, conventionally, as an observation device in the glass melting furnace, an image pickup device such as a CCD camera which is cooled strongly and which is provided with a diaphragm having a minimum diameter is used. However, this requires the installation of extensive air-cooling and water-cooling equipment. Moreover, the heat loss of the furnace due to strong cooling cannot be ignored, especially in a small melting furnace, and the temperature control may be affected. Further, it is difficult to adjust the amount of light by the diaphragm. If the diaphragm is insufficient, the inside of the image pickup device is overheated. On the other hand, if the diaphragm is too large, the field of view becomes dark and unclear, which hinders observation.

[0005]

As a method for dealing with such a problem, use of an infrared absorption filter which absorbs infrared rays and transmits visible light, and a reflection type filter which particularly reduces the light quantity regardless of wavelength are considered. However, there is no known infrared absorption filter or reflection type filter that can be used at a high temperature such as observation in a glass melting furnace.

The present invention solves this problem and can be used for observing the inside of a high temperature furnace such as a glass melting furnace in operation, and the cooling device can be made relatively small and compact. It is an object of the present invention to provide a lightweight high temperature furnace observation device.

[0007]

As a result of repeated studies for solving the above-mentioned problems, the present inventors have installed a reflection type filter having a metal thin film mainly containing platinum formed on a substrate on the front side of an image pickup device. It was found that this problem can be solved by doing so.

That is, the present invention is a high-temperature furnace observation apparatus equipped with an image pickup device, which has a reflection type filter in front of the image pickup device, and the reflection type filter is provided on one side or both sides of a substrate with platinum. Provided is a high temperature furnace observation device, which is a filter formed by forming a metal thin film having a composition of 80 to 100% by weight. By using the reflection type filter, it becomes easy to secure excellent visibility while sufficiently suppressing the heat dose reaching the imaging device.

The present invention further provides a high temperature furnace observation apparatus equipped with an image pickup device, wherein a reflective filter is provided in front of the image pickup device, and an infrared absorption filter is provided between the reflective filter and the image pickup device. And each of the reflection type filters has platinum of 80 to 100 on one surface or both surfaces of the substrate.
Provided is a high-temperature furnace observation device, which is a filter formed by forming a metal thin film having a composition of wt%. By using the reflection type filter and the infrared filter, it is possible to further improve the visibility of the image pickup device and more reliably protect the image pickup device from heat rays reaching the image pickup device.

The present invention further provides a high-temperature furnace observation apparatus equipped with an image pickup device, which has a reflection type filter in front of the image pickup device, and the reflection type filter uses an infrared absorption filter as a substrate. , Platinum 80 on one or both sides of the substrate
Provided is an apparatus for observing inside a high-temperature furnace, which is formed by forming a metal thin film having a composition of -100% by weight.
With such a configuration, it is possible to improve the visibility of the image pickup device and more reliably protect the image pickup device from heat rays with a very simplified structure.

The present invention further provides an apparatus for observing inside a high temperature furnace further characterized in that in each of the above-mentioned constitutions, a glass thin film is formed on the metal thin film of the reflection type filter. With such a structure, the durability of the metal thin film can be improved.

In each of the above structures, the substrate may be a glass substrate. The metal thin film may have a composition of 80% by weight or more of platinum and less than 100% by weight of platinum and 20% by weight or less of rhodium.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The substrate of the reflection type filter is not particularly limited as long as it has a high light transmittance in the visible region and is heat resistant. As the material of the substrate, for example, quartz glass, silica glass, soda lime glass,
In addition to glass such as aluminoborosilicate glass, borosilicate glass, and aluminosilicate glass, examples of crystals include sapphire, crystal, and magnesium oxide. Of these, quartz glass is particularly preferable from the viewpoint of heat resistance.

The thickness of the substrate is not particularly limited, and one having an appropriate thickness may be selected in consideration of strength and cooling efficiency.

The composition of the metal thin film formed on the substrate is preferably 80 to 100% by weight of platinum, and more preferably 90 to 100% by weight of platinum. The reason why the amount of platinum is 80% by weight or more is that if it is less than 80% by weight, the heat resistance of the metal thin film tends to be insufficient. When platinum is 80% by weight or more and less than 100% by weight, a metal such as gold, silver or rhodium, and 1% by weight or less of a metal oxide such as yttrium oxide or zirconia can be used as the rest of the composition. . Of these, rhodium is particularly preferable because it is used for crucibles and the like and has excellent heat resistance. Accordingly, for example, a combination of 80% or more and less than 100% by weight of platinum and 20% by weight or less of rhodium is used, and more preferably 90% by weight or more and less than 100% by weight of platinum and 10% by weight of rhodium.
It can be used in combination with the following.

The metal thin film has an average transmittance of 30% or less, preferably 20 for light in the wavelength range of 400 to 1500 nm.
% Or less, and more preferably 10% or less. The relationship between the thickness and the light transmittance differs depending on the method of forming the metal thin film, but in any method, the thickness can be set appropriately based on the average transmittance of light in the wavelength range of 400 to 1500 nm. Good.

The metal thin film can be formed on one side or both sides of the substrate. When the metal thin film is formed on one surface of the substrate, the side on which the metal thin film is formed may be used toward the high temperature furnace side or the opposite side. However, in the case of a reflection type filter in which the metal thin film is exposed on the surface, it is said that the durability of the metal thin film is maintained by using the side where the metal thin film is formed facing the opposite side of the high temperature furnace. In terms of points, it is somewhat preferable.

The method for forming the metal thin film is not particularly limited, and PV such as sputtering method (high frequency magnetron sputtering method, DC sputtering method), vapor deposition method, ion plating method, etc.
The D method (physical vapor deposition method), the electroless plating method, or the like can be used.

Further, by forming a glass thin film on the metal thin film formed on the substrate, a reflection filter in which the metal thin film is sealed in glass may be used. By doing so, the durability of the metal thin film can be increased. In the case of a reflection type filter in which the metal thin film is sealed in glass, the side on which the metal thin film and the glass thin film are formed can be used toward the high temperature furnace side or the opposite side. In particular, since the metal thin film is sealed by the glass thin film and the durability is increased, there is no disadvantage in using the side on which the metal thin film and the glass thin film are formed facing the high temperature furnace side.

Examples of the glass for forming the glass thin film include quartz glass, silica glass, soda lime glass, aluminoborosilicate glass, borosilicate glass, aluminosilicate glass and the like. Of these, quartz glass is particularly preferable from the viewpoint of heat resistance.

The method for forming the glass thin film is not particularly limited,
For example, an appropriate method such as a sputtering method can be used.

A plurality of reflective filters may be used in combination. By combining multiple sheets,
The heat ray shielding efficiency and the cooling efficiency can be improved as compared with the case of using it alone. When using a plurality of reflective filters, it is sufficient that all installed reflective filters fall within the range of the average transmittance as a whole, and therefore each reflective filter has a higher transmissivity. But it doesn't matter.

If a reflection type filter formed with a metal thin film and an infrared absorption filter are used in combination, a relatively large amount of visible light out of the light from the inside of the high temperature furnace can be transmitted, and the visible inside of the high temperature furnace can be visually recognized. It is possible to shield the heat ray better while improving the property. The infrared filter is preferably installed behind the reflective filter in order to prevent overheating due to infrared absorption.

In the present invention, the infrared absorption filter is
The average transmittance in the wavelength range of 700 to 1500 nm is 1 with respect to the average transmittance in the wavelength range of 400 to 700 nm.
/ 2 or less, more preferably 1/3 or less,
Particularly preferably, it means one-fourth or less. The thickness of the infrared filter is not particularly limited, and an appropriate thickness may be selected in consideration of strength and cooling efficiency. Further, a plurality of infrared absorption filters can be used in combination, and in terms of cooling efficiency, it is preferable to do so.

As the reflection type filter, an infrared absorption filter may be used as the substrate, and a metal thin film having a composition of 80 to 100% by weight of platinum may be formed on one surface or both surfaces of the infrared absorption filter. In that case, in a filter having a metal thin film formed on one surface, it is preferable to install the filter so that the metal thin film side faces the inside of the furnace in order to avoid overheating of the substrate which is also an infrared absorption filter.

As the image pickup device, for example, a CCD camera can be used.

The high temperature in-furnace observation apparatus of the present invention having a reflection type filter or an infrared absorption filter further, should be an apparatus including a cooling system by air cooling and / or water cooling depending on the positional relationship with the furnace. You can

[0028]

EXAMPLES The present invention will be described in more detail with reference to typical examples, but the present invention is not intended to be limited to these examples.

<Example 1> 22 mm x 22 mm, thickness 2
On a quartz glass substrate having a thickness of 15 mm, a platinum target is used by a high frequency magnetron sputtering method, a partial pressure of argon gas is 0.8 Pa, a substrate temperature is 300 ° C., a high frequency power is 50 W, and a film forming time is 30 seconds. A reflective filter was prepared by forming a platinum thin film. The transmission curve of this filter is shown in FIG. This filter had an average light transmittance of 7.5% in the wavelength range of 400 to 700 nm, and an average light transmittance of 4.5% in the wavelength range of 700 to 1500. Separately, the thickness is 2m
m infrared absorption filter (the transmission curve is shown in FIG. 2) was prepared. This infrared absorption filter has a wavelength of 4
The average light transmittance in the range of 00 to 700 nm is 3
The average transmittance of light in the range of 5% and wavelength 700 to 1500 nm was 8%. In the frame of the tubular cooling device 2 of the observation device 1 for high temperature furnace, using one reflection type filter prepared above and three commercially available infrared absorption filters,
It was installed as shown in the schematic cross-sectional view in FIG. That is, the C provided downward near the center of the high temperature furnace observation device 1
Below the CD camera 5, from below, the reflective filter 3,
The infrared absorption filters 4a, 4b, and 4c were attached in this order so as to be laminated with a gap therebetween. At this time, the reflection type filter 3 was arranged so that the surface of the platinum thin film 6 faced upward. FIG. 4 shows the light transmission curve of the thus-configured combination filter in the wavelength range of 400 to 1500 nm. Wavelength 4 of this combination filter
The average light transmittance in the range of 00 to 700 nm was 0.3%, and that in the wavelength range of 700 to 1500 nm was 0.002%.

The water jacket 7 of the cooling device is
It is provided with an inner flow path 8 and an outer flow path 9 that communicate with each other at the lower end, and industrial water for cooling is supplied to the inner flow path 8 from the inner flow path 8 to the outer flow path 9 by 10 L / Flowed at a flow rate of minutes. Further, cooling air is sent to the cooling air inflow passage 10 provided so as to pass through the water jacket 7 as shown by an arrow, and the cooling air is passed through the openings provided near the lower end of the cooling air inflow passage 10 to each filter. Flowing at a flow rate of about 10 L / min along the space between them, the cooling current was made to flow into the cooling air outflow passage 11 through an opening provided in the vicinity of the lower end of the cooling air outflow passage 11, and exhausted through this passage. . A part (about 10 L / min) of the cooling air is blown from the opening provided at the lower end of the cooling air inflow path 10 along the lower surface of the reflection type filter 3, whereby the evaporate in the glass melting furnace is blown out. Prevented from adhering to the reflective filter 3. Also, around the CCD camera 5,
Cooling air was likewise made to flow through the cooling air channels 12 and 13 communicating at the lower end. The high-temperature furnace observing device 1 thus configured is inserted and installed in the opening provided in the upper part of the glass melting furnace, and the inside of the glass melting furnace is continuously operated for 24 hours by the CCD camera 5 through the cable 14 (for power supply and image signal transmission). Observed with, but neither filter was damaged,
The CCD camera 5 also operated normally and continued to provide images of the inside of the furnace. At this time, the gas phase temperature in the vicinity of the apparatus 1 in the melting furnace was about 1400 ° C.

<Example 2> Sputtering was performed under the same conditions and materials as in Example 1 except that the film formation time was 50 seconds, to produce a reflective filter having a platinum thin film with a film thickness of about 25 nm. This filter has a wavelength of 400-700
The average light transmittance in the range of nm was 1.6%, and the average light transmittance in the wavelength range of 700 to 1500 nm was 0.8%. Separately, the same two infrared absorption filters as in Example 1 were prepared. A high temperature furnace observation apparatus was assembled in the same manner as in Example 1 except that the prepared reflection type filter and two infrared absorption filters were used, and cooling water and cooling air were passed. The average transmittance of light in the wavelength range of 400 to 700 nm for the entire combination filter was 0.2%, and that in the wavelength range of 700 to 1500 nm was 0.005%. High temperature furnace observation device 1
Is inserted into the opening provided in the upper part of the glass melting furnace in operation, and the inside of the glass melting furnace is moved by the CCD camera 5
After continuous observation for a period of time, none of the filters were damaged, and the CCD camera 5 also operated normally and continued to provide images inside the furnace. At this time, the gas phase temperature in the vicinity of the apparatus 1 in the melting furnace was about 1200 to 1450 ° C.

<Embodiment 3> 22 mm × 22 mm, thickness 2
Using a platinum target on a quartz glass substrate of mm by DC sputtering, the partial pressure of nitrogen gas is 12 Pa, the partial pressure of oxygen gas is 3 Pa, the substrate is not heated, the discharge current is 15 mA, and the film formation time is 15 minutes. A reflective filter was prepared by forming a 65 nm platinum thin film. This filter had an average light transmittance of 4.5% in the wavelength range of 400 to 700 nm, and an average light transmittance of 6.4% in the wavelength range of 700 to 1500. Separately, the same two infrared absorption filters as in Example 1 were prepared. A high temperature furnace observation apparatus was assembled in the same manner as in Example 1 except that the prepared reflection type filter and two infrared absorption filters were used, and cooling water and cooling air were passed. The average transmittance of light in the wavelength range of 400 to 700 nm for the entire combination filter is 0.6%, and the wavelength of 700 to
It was 0.04% in the 1500 nm range. The high-temperature furnace observing device 1 was installed in the opening provided in the upper part of the glass melting furnace in operation, and the inside of the glass melting furnace was observed with the CCD camera 5 for 24 hours continuously, but any filter was damaged. No, and the CCD camera 5 also worked normally and continued to provide images of the inside of the furnace. At this time, the gas phase temperature in the vicinity of the apparatus 1 in the melting furnace was about 1200 ° C.

<Embodiment 4> By a high frequency magnetron sputtering method on the metal thin film of the reflection type filter of Embodiment 1,
Argon gas pressure 0.7 using quartz glass target
2 Pa, oxygen gas pressure 0.08 Pa, substrate temperature 300 ° C.,
Film thickness of about 5 at 50 W of high frequency power and 20 minutes of film formation time
A 0 nm quartz glass thin film was prepared and used as a platinum thin film protective film. In the same manner as in Example 1 except that this filter was used instead of the reflective filter in Example 1, the inside of the glass melting furnace in operation was observed continuously for 24 hours, but neither filter was damaged. The CCD camera 5 also operated normally and continued to provide images of the inside of the furnace. At this time, the gas phase temperature in the vicinity of the apparatus 1 in the melting furnace was about 1400 ° C.

<Comparative Example 1> An apparatus was assembled in the same manner as in Example 1 except that the reflective filter 3 was omitted, and an opening provided in the upper portion of the glass melting furnace in operation while passing cooling water and cooling air. When it was inserted and arranged above, the infrared absorption filter on the melting furnace side cracked almost instantaneously due to the absorption of heat rays, and the apparatus became unusable.

[0035]

According to the apparatus for observing the inside of a high temperature furnace of the present invention, continuous observation inside the high temperature furnace such as a glass melting furnace is possible. In addition, since platinum, which is a material resistant to high temperatures, is used as the basic material of the metal thin film, the reflective filter located inside the high temperature furnace has the highest heat resistance, and therefore does not require a high capacity for the cooling system of the observation device. . Therefore, the influence of the cooling system of the observation device on the temperature distribution in the furnace is reduced particularly in a small furnace. In addition, according to the present invention, the cooling system of the high-temperature furnace observation device can be made smaller and lighter, so that it has excellent portability and can be inserted into a required place of the furnace at a necessary time to easily observe the inside of the high-temperature furnace. Is possible. Also, since no reflector is used in the filter system, there is no problem of image inversion and the structure of the device is simple.

[Brief description of drawings]

FIG. 1 is a light transmittance curve of the reflective filter of Example 1.

[Figure 2] Light transmittance curve of the infrared absorption filter used

[Fig. 3] Schematic cross-sectional view of high-temperature furnace observation device

FIG. 4 is a light transmittance curve of the combination filter of Example 1.

[Explanation of symbols]

1 = High temperature furnace observation device, 2 = Cooling device, 3 = Reflective filter, 4a, 4b and 4c = Infrared absorption filter, 5
= CCD camera, 6 = Platinum thin film, 7 = Water jacket, 8 = Inner channel, 9 = Outer channel, 10 = Cooling air inflow channel, 11 = Cooling air outflow channel, 12 = Cooling air channel, 1
3 = cooling air flow path, 14 = cable

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C22C 5/04 C22C 5/04 C23C 30/00 C23C 30/00 A F27D 21/02 F27D 21/02 (72 ) Inventor Umihiko Mori 2-21 Hamamatsubara-cho, Nishinomiya-shi, Hyogo Japan Yamamura Glass Co., Ltd. (72) Inventor Akio Konishi 2-21 Hamamatsubara-cho Nishinomiya-shi, Hyogo Japan Yamamura Glass Co., Ltd. (72) Inventor Wakabayashi Hajime 2-21 Hamamatsubara-cho, Nishinomiya-shi, Hyogo Prefecture Japan Yamamura Glass Co., Ltd. (72) Inventor Toshihiko Hiejima No. 1 Gakuencho, Sakai City, Osaka Prefecture (72) Hisao Higashi, Sakai City, Osaka Prefecture Gakuencho No. 1-1 Osaka Prefectural University (72) Inventor Akira Iwasaki 1-1-1 Higashi, Tsukuba, Ibaraki Prefecture Independent Administrative Law, National Institute of Advanced Industrial Science and Technology Tsukuba Center (72) Inventor Masashi Makihara 1-1-1 Higashi Tsukuba, Ibaraki Independent Administrative Law F-term in the Tsukuba Center, National Institute of Advanced Industrial Science and Technology (reference) 4G059 AA08 AA11 AB01 AC06 AC08 AC19 DA03 DB02 DB04 GA01 GA04 GA14 4K015 KA01 4K044 AA11 AA12 AA13 AB10 BA08 BA12 BB01 BC11 BC14 CA13 CA15 4K056 AA05 CA10 FA23

Claims (6)

[Claims] 1. A high temperature furnace observation apparatus equipped with an imaging device, comprising a reflective filter in front of the imaging device, the reflective filter comprising platinum 80-100 on one or both sides of a substrate. An apparatus for observing inside a high-temperature furnace, which is a filter formed by forming a metal thin film having a composition of wt%. 2. A high temperature in-furnace observation apparatus equipped with an imaging device, wherein a reflection filter is provided in front of the imaging device, and an infrared absorption filter is provided between the reflection filter and the imaging device. And the reflective filter
An apparatus for observing inside a high-temperature furnace, which is a filter formed by forming a metal thin film having a composition of 80 to 100% by weight of platinum on one or both sides of a substrate. 3. A high temperature in-furnace observation apparatus equipped with an imaging device, comprising a reflective filter in front of the imaging device, the reflective filter using an infrared absorption filter as a substrate. 80-100% by weight of platinum on one or both sides of
An apparatus for observing in-high-temperature furnaces, characterized in that it is formed by forming a metal thin film having the composition of. 4. The substrate according to claim 1, which is a glass substrate.
The high-temperature furnace observation device according to item 1. 5. The high temperature furnace observation apparatus according to claim 1, wherein a glass thin film is formed on the metal thin film. 6. The metal thin film comprises 80% by weight or more of platinum and 100% by weight.
The high temperature furnace observation device according to any one of claims 1 to 5, which has a composition of less than 20% by weight and 20% by weight or less of rhodium.