JP4900776B2 - Glass melting furnace internal observation apparatus and glass melting furnace internal observation method - Google Patents

Description

  The present invention relates to a furnace interior observation apparatus and a furnace interior observation method used for observing the inside of a high-temperature atmosphere furnace such as a glass melting furnace, a firing furnace, and a waste incinerator.

  As is well known, a glass melting furnace, which is a high-temperature atmosphere furnace, supplies a flame into the furnace by a burner disposed in a predetermined part of the furnace wall, melts the glass raw material, and stores the molten glass in the furnace (For example, refer to Patent Document 1 below).

  Further, in a glass melting furnace, a viewing window is generally formed on the furnace wall in order to observe the state inside the furnace. For example, Patent Document 2 below discloses an in-furnace observation apparatus using this viewing window. Has been. More specifically, this in-furnace observation apparatus inserts and arranges an optical system member formed of quartz glass having a softening point higher than the in-furnace temperature in a viewing window, and the observation image in the furnace transmitted from the optical system member. Is imaged with a CCD camera installed outside the furnace.

Japanese Patent Laid-Open No. 11-100214 JP 2003-215470 A

  By the way, the molten glass stored in the glass melting furnace flows down from the melting furnace to the downstream side through a supply path (feeder) and is supplied to the forming apparatus, and is formed into a glass product having a predetermined shape by the forming apparatus. At this time, if the molten state of the glass raw material changes in the glass melting furnace, for example, a large number of undissolved spots and bubbles are generated in the molten glass, and the molten glass is not in the desired stable glass quality and is transferred to the molding apparatus Will be supplied. And in the glass product shape | molded from such a low grade molten glass, there exists a possibility that many defects resulting from the undissolved buttocks, bubbles, etc. which arose in the molten glass may arise.

  Therefore, in the observation inside this type of glass melting furnace, from the viewpoint of preventing the occurrence of defects in the above-mentioned molten glass, in addition to the molten state of the molten glass, for example, the combustion state of the flame of the burner and the melting furnace It is important to provide a plurality of observation objects inside the furnace, such as the deterioration state of the furnace wall, and to grasp the state throughout the furnace interior in detail by observing the state of these observation objects in detail.

  However, since the inside of the glass melting furnace is exposed to a high temperature atmosphere, light is radiated from various parts inside the furnace such as molten glass or a flame of a burner. Therefore, the light observed from the inside of the furnace through the viewing window (hereinafter referred to as observation light) is simultaneously observed as a unit of radiation emitted from various parts inside the furnace.

  Therefore, as disclosed in the above-mentioned Patent Document 2, when the observation light is simply dimmed as a whole, among a plurality of observation objects inside the furnace, a specific observation object such as molten glass is to be observed. Then, the light radiated from other observation objects inside the furnace and parts other than the observation objects is obstructed, which may cause a situation in which the state of the specific observation object cannot be observed in detail.

  In addition, the above problems may occur not only in a glass melting furnace but also in a high-temperature atmosphere furnace such as a firing furnace or a garbage incinerator.

  This invention is made | formed in view of the said situation, and makes it a technical subject to observe each of several observation object in the inside of a high temperature atmosphere furnace in detail.

The present invention has been made to solve the above problems is a glass melting furnace internal observation device, for observing the molten glass within the glass melting furnace, formed from the internal furnace furnace wall of the furnace A multilayer film having a wavelength region in which a transmission wavelength region of visible light is selected on a translucent substrate is provided on an optical path from the observation window to the observation position (preferably on an optical path from the observation window to the observation position). One or a plurality of formed interference plates are arranged, and at least one interference plate can be rotated so that the inclination angle of the incident surface changes with respect to the incident light incident along the optical path. In other words, the multilayer film transmits only light having a wavelength λ ₁ or more in the visible light wavelength region and only light having a wavelength λ ₂ (> λ ₁ ) or less in the visible light wavelength region. and a short-wavelength transmission multilayer film, forming a lambda ₁ or lambda ₂ or less in the transmission wavelength region While, by rotating operation, characterized in Rukoto are adjustably configure the transmission wavelength region to selectively observable wavelength range radiation emitted from a specific observation target containing molten glass. Here, the “translucent substrate” means a substrate that transmits light in the wavelength region of visible light, and examples thereof include a glass substrate and a resin substrate. The above-mentioned “multilayer film in which the visible light transmission wavelength region is a selected wavelength region” means, for example, a multilayer film that selectively transmits visible light of a predetermined wavelength or more in the visible light wavelength region. Or, it is a multilayer film that selects or transmits only visible light in a predetermined wavelength region. Further, the above-described “interference plate” includes not only a state in which the “interference plate” is always disposed on the optical path but also a state in which the “interference plate” is temporarily disposed on the optical path when observing the inside of the melting furnace. Further, the “rotation operation” includes not only manual operation but also rotation by mechanical drive. In addition, the above “long wavelength transmission multilayer film” is not limited to a film that completely blocks light having a wavelength less than λ ₁ , but includes a film that attenuates light to an extent that does not affect observation. The same applies to the “short wavelength transmission multilayer film”.

According to the above configuration, since one or a plurality of multilayer films are arranged on the optical path, only the light transmitted through the multilayer film is observed at the observation position out of the light from the inside of the furnace. In this case, the light transmission wavelength region of these one or more multilayer films varies depending on the inclination angle of the incident surface with respect to the incident light incident along the optical path. Therefore, a visible light transmission wavelength region that transmits one or more multilayer films is required by inclining an interference plate formed by forming one or more multilayer films on a light-transmitting substrate at a predetermined angle with respect to the optical path. It becomes possible to change according to. As a result, the object to be observed from the inside of the furnace is selected, and interference is selectively transmitted so that light of a specific wavelength emitted due to the material of the object to be observed and the surface temperature inside the furnace is selectively transmitted. If the plate is held at a predetermined angle with respect to the optical path, light emitted from a specific observation target is selectively transmitted, so that the observation target can be observed in detail. Similarly, by measuring in detail a plurality of observation objects inside the furnace, it becomes possible to grasp the state inside the furnace in detail. Furthermore, in the wavelength region of visible light, the long wavelength transmission multilayer film transmits only light having a wavelength λ ₁ or more, and the short wavelength transmission multilayer film transmits only light having a wavelength λ ₂ or less. Therefore, by arranging these two types of multilayer films separately on the optical path, it is possible to select and observe light of λ ₁ or more and λ ₂ or less from visible light incident from the inside of the furnace . Since each value of λ ₁ and λ ₂ can be adjusted by the inclination angle of the interference plate on which the multilayer film is formed, the radiated light of a specific wavelength radiated from the observation target is accurately selected for observation. It becomes possible to do.

  Further, by rotating the interference plate so that the inclination angle of the incident surface changes with respect to the incident light incident along the optical path each time, depending on the state of the interior of the furnace from the above observation object, It is possible to find the most preferable inclination angle position of the interference plate for selectively transmitting the emitted light, and it is possible to perform more detailed observation inside the furnace.

  In the above-described configuration, it is preferable to use at least two interference plates in which a multilayer film is formed on one surface of the light-transmitting substrate.

  In this way, for example, when using a plurality of interference plates each formed with different types of multilayer films, the inclination angle of each interference plate can be set separately, so that the transmission wavelength region can be freely selected. It is possible to increase the degree, and this is advantageous in performing precise observation by increasing the types of observation objects.

  In the above structure, at least one interference plate in which a multilayer film is formed on both surfaces of a light-transmitting substrate may be used.

  In this way, the space for disposing the interference plate can be reduced, and the layout can be advantageous, and it is possible to meet demands for space saving or miniaturization.

  In the above configuration, the light-transmitting substrate can be an optical filter that can transmit visible light in a specific wavelength region.

  In this way, the light observed at the observation position becomes visible light in a region where the transmission wavelength region selected by the multilayer film matches the specific transmission wavelength region of the optical filter. In addition, as described above, in the multilayer film, the transmission wavelength region of visible light changes depending on the incident angle of light. Therefore, by tilting the interference plate by a predetermined angle with respect to the optical path, the region where the transmission wavelength regions of the multilayer film and the optical filter coincide with each other can be changed, and the transmission wavelength region of visible light transmitted through the interference plate can be changed. It is possible to easily set a narrow wavelength region as required. Therefore, it becomes possible to select and transmit the light emitted from the observation target more accurately, and it is possible to perform more detailed observation inside the furnace.

  In the above configuration, an optical filter capable of transmitting visible light in a specific wavelength region may be further disposed on the optical path.

  In this case, a colored resin plate or a colored glass plate can be used as the optical filter.

  In the above configuration, the interference plate or the optical filter may be disposed in a viewing window formed on the furnace wall of the furnace.

  In this way, it is not necessary to separately arrange an interference plate or an optical filter outside the melting furnace, which can contribute to simplification of observation work in the melting furnace.

In said structure, you may arrange | position a translucent heat-resistant glass plate in the side which faces the inside of the furnace of the observation window formed in the furnace wall of the furnace .

  In this way, even if heat resistance is required for the in-furnace observation device, for example, due to the fact that the in-furnace observation device is placed close to the inside of the melting furnace, the translucent heat-resistant glass Such a requirement can be appropriately met if the plate is preferably arranged on the higher temperature side in the furnace than all the interference plates or all the optical filters. Examples of the translucent heat resistant glass plate include transparent crystallized glass, borosilicate glass, quartz glass, and high silicate glass.

In the above configuration, it is preferable that a heat ray reflective film is formed on the interference plate, the optical filter, or the translucent heat-resistant glass plate. When a heat ray reflective film is formed on the translucent heat-resistant glass plate, a film of silicon oxide, silicon nitride, aluminum nitride, silicon aluminum nitride (SiAlN _x ), or titanium oxide is formed so as to cover the heat ray reflective film. It is preferable because the heat ray reflective film hardly deteriorates.

  If it does in this way, the heat ray which interferes with work can be intercepted appropriately. Specifically, the heat ray reflective film preferably has an infrared transmittance of 1000% to 2500 nm at a wavelength of 10% or less. Examples of the composition of the heat ray reflective film include tin-containing indium oxide and fluorine-containing materials. Oxides such as tin oxide, antimony-containing tin oxide, and aluminum-containing zinc oxide can be applied.

  In the above configuration, the multilayer film is formed by alternately laminating a high refractive index layer having a refractive index nd of 2.0 or more and a low refractive index layer having a refractive index nd of 1.7 or less in this order from the translucent substrate side. It may be a thing. Specifically, for example, the high refractive index layer is formed of a layer made of a material selected from niobium oxide, titanium oxide, tantalum oxide, silicon nitride, zirconium oxide, hafnium oxide, cerium oxide, and zinc oxide. The low refractive index layer can be formed of a layer made of a material selected from silicon oxide, magnesium fluoride, and aluminum oxide. Here, the above-mentioned “layer consisting of a selected substance” means a layer containing the selected substance as a main component.

  If it does in this way, the multilayer film which can ensure the various characteristics requested | required of said interference plate can be formed easily and appropriately.

Further, the method for molten glass of the glass melting furnace, a glass melting furnace section view viewing through viewing window formed in the furnace wall of the furnace according to the present invention was invented in order to solve the above problems A transmission wavelength region of visible light is selected on the light transmitting substrate on the optical path from the inside of the furnace to the observation position through the observation window formed on the furnace wall of the furnace. One or more interference plates with a multilayer film are arranged, and at least one interference plate can be rotated so that the tilt angle of the incident surface changes with respect to incident light incident along the optical path. And the multilayer film transmits only light having a wavelength of λ ₁ or more in the visible light wavelength region and light having a wavelength of λ ₂ (> λ ₁ ) or less in the visible light wavelength region. And a transmission wavelength region of λ ₁ or more and λ ₂ or less. In other words, the transmission wavelength region is adjusted to a wavelength range in which radiated light emitted from a specific observation target including molten glass can be selectively observed by a rotating operation .

  According to said method, the light from the arbitrary observation objects in a furnace can selectively permeate | transmit, and the state of each observation object can be observed in detail. And about the structure corresponding to this, the effect similar to the matter already stated can be acquired.

  In addition, when selectively transmitting light from an arbitrary observation target inside the furnace, the interference plate can be appropriately rotated so that the inclination angle of the incident surface with respect to the incident light changes. And about the structure corresponding to this, the effect similar to the matter already stated can be acquired. In addition, when the inside of the furnace is dark, the inside of the furnace may be brightened and observed by irradiating light from a fluorescent lamp or a mercury lamp through a viewing window from the outside of the furnace.

According to the present invention as described above, it is possible to selectively observe light emitted from an arbitrary observation target inside the glass melting furnace by the interference plate arranged on the optical path. Therefore, it is possible to prevent troubles from occurring in the furnace by grasping the state of the whole furnace in detail by observing the state of each observation object in detail with multiple places inside the furnace as observation objects. it can. Even if a trouble occurs inside the furnace, it is possible to discover the trouble occurrence point at an early stage and take appropriate measures by observing the entire inside of the furnace in detail.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an essential part enlarged cross-sectional view schematically showing a state in which a furnace interior observation apparatus 1 according to the present embodiment is arranged in a glass melting furnace 2 which is a high-temperature atmosphere furnace. As shown in the figure, a flame 3 is supplied from a burner inside the glass melting furnace 2, and a molten glass 4 melted by the flame 3 is stored. The furnace interior observation device 1 is disposed on an optical path 7 that passes from the inside of the glass melting furnace 2 to the observation position 6 through the observation window 5 formed on the furnace wall. The furnace interior observation apparatus 1 includes an interference filter 8 disposed in a range from the observation window 5 to the observation position 6 on the optical path 7 and a transparent heat-resistant glass plate 9 attached to the observation window 5. Yes.

As shown in FIGS. 2A and 2B, the interference filter 8 is formed by arranging the first interference plate 10 and the second interference plate 11 on the optical path 7 so as to be separated from each other. . More specifically, the first interference plate 10 has a first multilayer film 13 formed only on one side of the light incident side of the glass substrate 12 that is a transparent substrate, and is incident on the incident light A incident along the optical path 7. rotation angle of inclination as theta ₁ (the incident light a, the angle between the normal line B ₂ with respect to the incident surface of the light interference plate 10) is changed, manually or mechanically driven about the pivot shaft 14 It is configured to be operable. Similarly, in the second interference plate 11, the second multilayer film 16 is formed only on one surface on the light incident side of the glass substrate 15, and an inclination angle (incident light A and light incident surface of the interference plate 10 is formed). rotating operation is configured to be able to about the rotation axis 17 so as to change the angle) theta ₂ between the normal line B ₂ against. In the illustrated example, the first and second multilayer films 13 and 16 are formed on the light incident side of the glass substrates 12 and 15, but may be formed on the light emitting side. Further, one of the first and second multilayer films 13 and 16 may be formed on the light incident side, and the other may be formed on the light emission side.

The first multilayer film 13 is a long-wavelength transmission multilayer film that transmits light having a wavelength λ ₁ or more in the wavelength region of visible light. As a first embodiment, the first multilayer film 13 is shown in FIG. 3 when the inclination angle θ ₁ is zero degrees. A film having transmittance characteristics indicated by a solid line X in (a) was produced. More specifically, the first multilayer film 13 transmits light having a wavelength of about 590 nm (= λ ₁ ) or more in the visible light wavelength region, and as shown in Table 1 below by sputtering. The high refractive index layer made of Nb ₂ O ₅ and the low refractive index layer made of SiO ₂ are alternately laminated in this order from the glass substrate 12 side. On the other hand, the second multilayer film 16 is a low-wavelength transmission multilayer film that transmits light having a wavelength λ ₂ (> λ ₁ ) or less in the visible light wavelength region. ₂ to prepare a film having transmittance characteristics indicated by the dotted line Y in FIGS. 3 (a) when the zero. Specifically, the second multilayer film 16 transmits light having a wavelength of about 610 nm (= λ ₂ ) or less, and is sputtered to form Nb on the glass substrate 15 as shown in Table 1 below. 40 layers of ₂ O ₅ and SiO ₂ are alternately laminated.

According to the first and second interference plates 10 and 11 according to the first embodiment, when the respective inclination angles θ ₁ and θ ₂ are held at, for example, zero degrees, as shown in FIG. Light in a wavelength region Z (region partitioned by hatching in the figure) of about 590 to 610 nm can be selectively observed from the light A. Further, for example, by holding the tilt angles θ ₁ and θ ₂ at 45 degrees by the rotation operation, as shown in FIG. 3B, light in the wavelength region Z ₁ of about 530 to 570 nm is selectively selected. For example, by maintaining the incident angle θ ₁ at 45 degrees and the incident angle θ ₂ at zero degrees, light in the wavelength region Z ₂ of about 530 to 610 nm is selected as shown in FIG. Can be observed. Further, for example, by maintaining the inclination angle θ ₁ at 0 degree and the inclination angle θ ₂ at 45 degrees, the light transmittance in the visible light region is reduced as a whole as shown in FIG. In this way, the transmission wavelength region can be continuously adjusted by rotating the first and second interference plates 10 and 11 about the respective rotation shafts 14 and 17, so that the respective inclinations can be adjusted. By fixing or temporarily holding the angles θ ₁ and θ ₂ at arbitrary tilt angle positions, light in an arbitrary wavelength range can be selectively observed from the incident light A.

Further, as a second embodiment of the first multilayer film 13, the inclination angle theta ₁ is to prepare a film having transmittance characteristics indicated by the solid line X 'in FIGS. 4 (a) when the zero. As shown in the figure, the first multilayer film 13 transmits light of about 570 nm (= λ ₁ ) or more in the visible light wavelength region when the tilt angle θ ₁ is zero degree. As shown in Table 2 below, by sputtering, 44 layers of high refractive index layers made of Nb ₂ O ₅ and low refractive index layers made of SiO ₂ are alternately laminated in this order from the glass substrate 12 side. . On the other hand, as a second example of the second multilayer film 16, a film having a transmittance characteristic indicated by a dotted line Y ′ in FIG. 4A when the inclination angle θ ₂ is zero is manufactured. More specifically, the second multilayer film 16 transmits light having a wavelength of about 590 nm (= λ ₂ ) or less, and Nb is formed on the glass substrate 15 by sputtering as shown in Table 2 below. 48 layers of ₂ O ₅ and SiO ₂ are alternately laminated.

According to the first and second interference plates 10 and 11 according to the second embodiment, when the respective inclination angles θ ₁ and θ ₂ are held at, for example, zero degrees, FIG. As shown in the enlarged FIG. 5A, light in the wavelength region Z ′ (region partitioned by hatching in the drawing) of about 570 to 590 nm can be selectively observed from the incident light A. Further, for example, by holding both the inclination angles θ ₁ and θ ₂ at 45 degrees by the turning operation, as shown in FIG. 4B and FIG. It is possible to selectively observe light in the wavelength region Z ₁ ′ of 560 nm. For example, by maintaining the tilt angle θ ₁ at 45 degrees and the tilt angle θ ₂ at zero degrees, FIG. As shown in enlarged FIG. 5C, light in the wavelength region Z ₂ ′ of about 500 to 600 nm can be selectively observed. Further, for example, by maintaining the inclination angle θ ₁ at 0 degree and the inclination angle θ ₂ at 45 degrees, as shown in FIG. 4D and FIG. The light transmittance is generally reduced. Accordingly, it is possible to obtain the same operational effects as those of the first embodiment described above.

As the high refractive index layer described above, in place of the _Nb 2 _{O 5,} for example _{TiO 2, Ta 2 O 5,} SiN, ZrO 2, HfO 2, CeO 2, the refractive index nd, such as ZnO is 2.0 or more In addition, the low refractive index layer may be made of a material having a refractive index nd of 1.7 or less, such as MgF ₂ and Al ₂ O ₃ , instead of SiO _2. Can be used.

Furthermore, the transparent heat-resistant glass plate 9 attached to the furnace wall, for example, superimposes one or a plurality of glasses selected from transparent crystallized glass, borosilicate glass, quartz glass, and high silicate glass. It is formed by. On the surface of the transparent heat-resistant glass plate 9, although not shown, a heat ray reflective film and a SiO _{2 −} film for preventing deterioration of the heat ray reflective film are sequentially formed from the surface, and the average transmittance of infrared rays having a wavelength of 1000 to 2500 nm is formed. It is now regulated to 10% or less. As the composition of the heat ray reflective film, for example, oxides such as tin-containing indium oxide, fluorine-containing tin oxide, antimony-containing tin oxide, and aluminum-containing zinc oxide can be applied.

  Hereinafter, the method of observing the inside of the glass melting furnace 2 through the furnace interior observation apparatus 1 is applied to the first multilayer film 13 and the second multilayer film 16 described in the first embodiment as multilayer films. The case where it is used will be described as an example.

As shown in FIG. 1, when an attempt is made to observe, for example, molten glass 4 in the glass melting furnace 2 as an observation object, the flame of the burner that obstructs the observation together with the radiation A ₁ emitted from the molten glass 4. The reflected light A ₂ emitted from 3 and reflected by the liquid surface of the molten glass 4 is also observed at the same time. Therefore, the first and second interference plates 10 and 11 are rotated to adjust the transmission wavelength region as shown in FIGS. 3 (a) to 3 (d), and the emitted light emitted from the molten glass 4. The state of the molten glass 4 can be observed in detail by holding only A _{1 at} the tilt angle position where it passes through the interference filter 8. The first interference plate 10 and the second interference plate 11 are not limited to be configured to be independently rotatable, and a link mechanism or the like is provided between the first and second interference plates 10 and 11. It may be configured to be capable of rotating operation in cooperation with each other. Further, in the case where a unique furnace interior observation apparatus 1 is provided for each observation object inside the furnace, the first interference plate 10 and the second interference plate 11 do not necessarily need to be able to be rotated at all times. As described above, once the optimum tilt angle position is determined by rotating, it may be fixed at that angle position.

  As described above, according to the furnace interior observation apparatus 1 according to the present embodiment, the predetermined observation inside the glass melting furnace 2 is performed by the first and second interference plates 10 and 11 disposed on the optical path 7. Light having a specific wavelength emitted by the object can be selectively observed. Therefore, it is possible to prevent troubles from occurring in the furnace by grasping the state of the whole furnace in detail by observing the state of each observation object in detail with multiple places inside the furnace as observation objects. it can. Even if a trouble occurs inside the furnace, it is possible to discover the trouble occurrence point at an early stage and take appropriate measures by observing the entire inside of the furnace in detail.

  In addition, this invention is not limited to the said embodiment, Various deformation | transformation as shown below are possible.

  For example, the interference plate is not limited to one in which a multilayer film is formed only on one side of a glass substrate, and as shown in FIG. 6, multilayer films 19 and 20 having different transmission wavelength regions are formed on both sides of a glass substrate 18. Also good. As the multilayer films 19 and 20, for example, the first and second multilayer films 13 and 16 can be applied without any problem. If it does in this way, it will become possible to form multilayer films 19 and 20 on the common glass substrate 18, and since the rotation axis of an interference plate is made common, rotation operation is simplified.

  Further, the glass substrate of the interference plate may be replaced with an optical filter 21 that can transmit visible light in a specific wavelength region, as shown in FIG. As the optical filter 21, for example, a colored resin plate or a colored glass plate can be used. Further, as the multilayer film 22 formed in the optical filter 21, the first multilayer film 13 or the second multilayer film 14 can be applied without any problem. In this way, since the wavelength region that can be transmitted does not change even when the optical filter 21 is rotated, two types of multilayer films are formed on separate glass substrates, and one of them is fixed and the other is fixed. It is possible to obtain the same operation and effect as when the is capable of rotating. As shown in FIG. 8, the optical filter 23 may be disposed on the optical path 7 separately from the interference plate in which the multilayer film 25 is formed on the glass substrate 24.

  Further, both the interference plate having a multilayer film formed on only one surface and the interference plate having a multilayer film formed on both surfaces may be disposed on the optical path 7. The number of interference plates in which each multilayer film is formed can be changed as appropriate. Further, the optical filters 21 and 23 may be used in combination with this configuration.

  The method for forming the multilayer film is not limited to the sputtering method, and a vapor deposition method or an ion plating method can be applied without any problem.

  Furthermore, the furnace interior observation apparatus 1 may be incorporated in a protective tool such as glasses, a face, or goggles worn by an operator. Further, the internal observation of the glass melting furnace 2 is not limited to the one performed by the operator directly from the observation position 6 via the furnace internal observation apparatus 1, and an electronic device such as a CCD camera is arranged at the observation position 6 to melt the glass. It may be performed indirectly from a place away from the furnace 2.

  Furthermore, the furnace interior observation apparatus 1 according to the present invention can be applied not only to the glass melting furnace 2 but also to various high-temperature atmosphere furnaces such as a metal melting furnace, a waste incinerator, and a firing furnace.

It is a principal part longitudinal cross-sectional view of the glass melting furnace to which the furnace inside observation apparatus which concerns on embodiment of this invention was applied. (A) is a principal part expansion perspective view which shows the furnace inside observation apparatus which concerns on embodiment of this invention, (b) is the longitudinal cross-sectional view. (A)-(c) is a figure which shows an example of the transmittance | permeability characteristic of the furnace inside observation apparatus which concerns on this embodiment. (A)-(c) is a figure which shows another example of the transmittance | permeability characteristic of the furnace inside observation apparatus which concerns on this embodiment. It is a principal part expanded vertical sectional view which shows the 1st modification of the furnace interior observation apparatus which concerns on embodiment of this invention. It is a principal part expanded longitudinal cross-sectional view which shows the 2nd modification of the furnace interior observation apparatus concerning embodiment of this invention. It is a principal part expanded vertical sectional view which shows the 3rd modification of the furnace inside observation apparatus which concerns on embodiment of this invention. It is a principal part expanded longitudinal cross-sectional view which shows the 4th modification of the furnace inside observation apparatus concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace observation apparatus 2 Glass melting furnace 3 Flame 4 Molten glass 5 Viewing window 6 Observation position 7 Optical path 8 Interference filter 9 Transparent heat-resistant glass plate 10 1st interference plate 11 2nd interference plate 13 1st multilayer film 16 1st 2 multilayer film

Claims (12)

A glass melting furnace internal observation device used for observing the inside of the glass melting furnace,
On the light path from the inside of the furnace through the viewing window formed on the furnace wall of the furnace to the observation position, a multilayer film having a wavelength range in which the transmission wavelength range of visible light is selected is formed on the translucent substrate. One or a plurality of interference plates are arranged, and at least one of the interference plates can be rotated so that the inclination angle of the incident surface changes with respect to the incident light incident along the optical path. Oh it is,
The multilayer film has a long wavelength transmission multilayer film that transmits only light having a wavelength λ ₁ or more in the visible light wavelength region, and a short light that transmits only light having a wavelength λ ₂ (> λ ₁ ) or less in the visible light wavelength region. and a wavelength transmission multilayer film, to form a lambda ₁ or lambda ₂ or less in the transmission wavelength region, by the rotational operation, the radiation emitted from a specific observation target containing molten glass selectively observable glass melting furnace interior observing apparatus, characterized that you have been adjustably forming the transmission wavelength region to a wavelength range. 2. The glass melting furnace internal observation apparatus according to claim 1, wherein at least two interference plates each having a multilayer film formed on one side of the translucent substrate are used. The glass melting furnace internal observation apparatus according to claim 1 or 2, wherein at least one interference plate in which a multilayer film is formed on both surfaces of the translucent substrate is used. The glass melting furnace internal observation apparatus according to any one of claims 1 to 3 , wherein the translucent substrate is an optical filter capable of transmitting visible light in a specific wavelength region. The glass melting furnace internal observation device according to any one of claims 1 to 4 , further comprising an optical filter capable of transmitting visible light in a specific wavelength region on the optical path. The glass melting furnace internal observation apparatus according to claim 4 or 5 , wherein the optical filter is a colored resin plate or a colored glass plate. The optical filter is disposed in the viewing window in the furnace interior observation apparatus according to any one of the interference plate or claim 4-6, in the furnace interior observation apparatus according to any one of claims 1 to 3 A glass melting furnace internal observation device characterized by the above. Wherein the furnace interior-facing side of the viewing window, the glass melting furnace interior observation apparatus to claim 1, characterized in that a light-transmitting heat-resistant glass plate. The glass melting furnace internal observation device according to claim 8, wherein a heat ray reflective film is formed on the translucent heat-resistant glass plate. The multilayer film is formed by alternately laminating a high refractive index layer having a refractive index nd of 2.0 or more and a low refractive index layer having a refractive index nd of 1.7 or less in order from the translucent substrate side. The glass melting furnace inside observation apparatus according to any one of claims 1 to 9 , wherein The high refractive index layer is a layer made of a material selected from niobium oxide, titanium oxide, tantalum oxide, silicon nitride, zirconium oxide, hafnium oxide, cerium oxide, and zinc oxide, and the low refractive index layer. rate layer, silicon oxide, magnesium fluoride, and a glass melting furnace interior observation apparatus according to claim 1 0, characterized in that a layer made of a material selected from aluminum oxide. The molten glass within the glass melting furnace, a glass melting furnace section observation method of observing through a sight glass formed in the furnace wall of the furnace,
On the light path from the inside of the furnace through the viewing window formed on the furnace wall of the furnace to the observation position, a multilayer film having a wavelength range in which the transmission wavelength range of visible light is selected is formed on the translucent substrate. One or a plurality of interference plates are arranged, and at least one of the interference plates can be rotated so that the inclination angle of the incident surface changes with respect to incident light incident along the optical path,
The multilayer film has a long wavelength transmission multilayer film that transmits only light having a wavelength λ ₁ or more in the visible light wavelength region, and a short light that transmits only light having a wavelength λ ₂ (> λ ₁ ) or less in the visible light wavelength region. A wavelength transmission multilayer film, which forms a transmission wavelength region of λ ₁ or more and λ ₂ or less, and selectively emits radiated light from a specific observation object including molten glass by the rotation operation. A method for observing the inside of a glass melting furnace , wherein the transmission wavelength region is adjusted to an observable wavelength range .

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