Glass article manufacturing apparatus and glass article manufacturing method

Abstract

To provide a manufacturing apparatus of a glass article capable of measuring, stably over a long period, a surface temperature of a transfer pipe for transferring molten glass.SOLUTION: A manufacturing apparatus of a glass article includes a transfer pipe 6 for transferring molten glass GM, and a temperature measurement device 5 for measuring a surface temperature outside the transfer pipe 6. The temperature measurement device 5 includes a measurement part 51 for measuring a temperature by receiving radiant light emitted from a measurement area on the outside surface, and a light guide part 52 for transferring radiant light to the measurement part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a glass article manufacturing apparatus equipped with a transfer pipe for transferring molten glass, and a glass article manufacturing method. [Background technology]

[0002] When manufacturing glass articles such as glass sheets and glass tubes, molten glass is transferred from a melting furnace to a forming device. A plurality of transfer pipes are disposed along the path along which the molten glass is transferred.

[0003] The main transfer pipes include, in order from the upstream side of the transfer route, those constituting a fining tank, a stirring tank, a cooling pipe, etc. There are also transfer pipes constituting an upstream connecting pipe connecting the melting furnace and the fining tank, a midstream connecting pipe connecting the fining tank and the stirring tank, etc.

[0004] In order to improve the quality of manufactured glass articles, the surface temperature of the transfer pipe is sometimes measured. Patent Document 1 describes a method for monitoring the surface temperature of the refining vat using a thermocouple embedded in a refractory insulating material covering the refining vat.

[0005] Furthermore, when measuring the temperature of a high-temperature object exceeding 1400°C, such as the surface of a transfer pipe, the B thermocouple (platinum-rhodium 6% alloy / platinum-rhodium 30% alloy, normal use limit 1500°C), R thermocouple (platinum / platinum-rhodium 13% alloy, normal use limit 1400°C), or S thermocouple (platinum / platinum-rhodium 10% alloy, normal use limit 1400°C) specified in JIS C 1602 can be used. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-163205 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when B, R, or S thermocouples are used in high-temperature environments, creep rupture along the platinum grain boundaries and temperature drift occurs due to changes in the composition of the platinum-rhodium alloy wire caused by volatilization and redeposition of rhodium, making it difficult to stably measure temperature over long periods of time, such as several months or even several years.

[0008] An object of the present invention is to stably measure the surface temperature of a transfer pipe over a long period of time. [Means for solving the problem]

[0009] The present invention, which was invented to solve the above-mentioned problems, provides a glass article manufacturing apparatus including a transfer pipe for transferring molten glass and a temperature measurement device for measuring the temperature of the outer surface of the transfer pipe, the temperature measurement device including a measurement unit that receives radiant light emitted from a measurement area on the outer surface and measures the temperature, and a light guide unit that transmits the radiant light to the measurement unit. With this configuration, the temperature of the outer surface of the transfer pipe can be accurately measured by measuring the temperature based on the intensity of the radiant light emitted from the measurement area. Furthermore, compared to using a thermocouple, creep rupture and temperature drift of the wire do not occur, so the temperature of the outer surface of the transfer pipe can be measured stably over a long period of time.

[0010] In the above configuration, the light guiding unit preferably includes a cylindrical protective tube having open ends. With this configuration, the protective tube prevents foreign matter from entering the light guiding unit, preventing the emitted light from being blocked by foreign matter, thereby enabling accurate temperature measurement.

[0011] In the above configuration, the transfer pipe preferably includes a cylindrical portion surrounding the measurement area. With this configuration, the cylindrical portion can effectively prevent airflow around the transfer pipe from flowing into the measurement area, allowing for more accurate temperature measurement.

[0012] In the above configuration, it is preferable that the protective tube includes a first flange, the cylindrical portion includes a second flange, and the first flange is abutted against the second flange. According to this configuration, by abutting the first flange of the protective tube and the second flange of the cylindrical portion, a gap between the protective tube and the cylindrical portion can be eliminated. This makes it possible to suppress the incidence of light other than synchrotron radiation into the measurement portion. Furthermore, it is possible to more effectively suppress the intrusion of foreign matter into the optical path of synchrotron radiation and the inflow of airflow around the transfer tube into the measurement region, thereby enabling more accurate temperature measurement.

[0013] In the above configuration, it is preferable that the gap between the first flange and the second flange is sealed with ceramic paste. With this configuration, the gap between the protective tube and the cylindrical portion is sealed, which more effectively prevents foreign matter from entering the optical path of the synchrotron radiation, prevents airflow around the transfer tube from entering the measurement area, and prevents light other than synchrotron radiation from entering the measurement portion, thereby enabling more accurate temperature measurement.

[0014] In the above configuration, the protective tube is preferably inserted inside the cylindrical portion. With this configuration, since the protective tube is disposed inside the cylindrical portion, it is possible to prevent the radiated light on the inner surface of the cylindrical portion from penetrating the light guide portion. Therefore, even if the cylindrical portion is made of a material with high thermal conductivity, such as platinum or a platinum alloy, and the cylindrical portion becomes hot due to heat conduction from the transfer tube, the radiated light on the inner surface of the cylindrical portion is prevented from penetrating the light guide portion, thereby enabling more accurate temperature measurement. Furthermore, for example, if the protective tube is made of a material with low thermal conductivity, such as ceramics, it is possible to prevent the temperature rise of the protective tube. This allows the intensity of the radiated light emitted from the protective tube to be kept low, enabling more accurate temperature measurement.

[0015] In the above configuration, the protective tube is preferably made of ceramic. With this configuration, since ceramics have high heat resistance, deterioration of the protective tube can be suppressed. Furthermore, by using a ceramic protective tube that is generally used as a protective tube for thermocouples, the manufacturing cost of the protective tube can be reduced. Furthermore, since the temperature rise of the protective tube can be suppressed, the intensity of the radiation emitted from the protective tube can be kept low, allowing for more accurate temperature measurement.

[0016] In the above configuration, the light guide unit preferably includes an optical element that transmits the emitted light to the measurement unit. With this configuration, the measurement unit can be separated from the high-temperature environment near the transfer pipe, and the thermal load on the measurement unit can be reduced, thereby suppressing deterioration of the measurement unit.

[0017] In the above configuration, the optical element preferably includes a condenser lens and an optical fiber. With this configuration, the emitted light can be efficiently transmitted to the measuring unit, thereby making it possible to more accurately measure the temperature of the outer surface of the transfer pipe.

[0018] In the above configuration, the transfer pipe is preferably made of platinum or a platinum alloy. According to this configuration, platinum or a platinum alloy has high corrosion resistance against molten glass, allowing the transfer pipe to be used for a long period of time. Furthermore, platinum or a platinum alloy has high thermal conductivity, so the temperature difference between the inside and outside of the transfer pipe is small. Therefore, by measuring the temperature of the outer surface of the transfer pipe, the temperature of the molten glass inside the transfer pipe can be accurately determined.

[0019] The method for manufacturing a glass article according to the present invention is characterized in that it includes a transfer step of transferring the molten glass using the transfer pipe provided in the glass article manufacturing apparatus having the above-described configuration, and a measurement step of measuring the temperature of the transfer pipe using the temperature measurement device. According to this configuration, the temperature of the outer surface of the transfer pipe can be accurately measured by measuring the temperature based on the intensity of the radiated light emitted from the measurement area. Furthermore, compared to using a thermocouple, creep rupture of the wire and temperature drift do not occur, so the temperature of the outer surface of the transfer pipe can be stably measured over a long period of time. [Effects of the Invention]

[0020] According to the present invention, the surface temperature of the transfer pipe can be measured stably over a long period of time. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a side view showing an apparatus for manufacturing a glass article according to one embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart showing a method for manufacturing a glass article according to one embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing the details of the transfer process shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line AA in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of a glass article manufacturing apparatus and a glass article manufacturing method according to the present invention will be described with reference to the accompanying drawings.

[0023] 1, the manufacturing apparatus for a glass article according to this embodiment includes, in order from the upstream side, a melting tank 1, a transfer device 2, and a forming device 3. The transfer device 2 includes a fining tank 21, a homogenizing tank (stirring tank) 22, a pot 23, glass supply paths 41-44 connecting these components 1-3, and a temperature measuring device 5 that measures the temperature of the glass supply path 42. In addition, the manufacturing apparatus includes an annealing furnace (not shown) that anneals the sheet glass GR (glass article) formed by the forming device 3, and a cutting device (not shown) that cuts the sheet glass GR after annealing.

[0024] As shown in Fig. 2, the method for manufacturing a glass article according to this embodiment includes a melting step S1, a transporting step S2, and a shaping step S3. As shown in Fig. 3, the transporting step S2 includes a fining step S21, a homogenizing step S22, and a conditioning step S23. The transporting step S2 includes transporting the glass between steps S1 to S3 via glass supply paths 41 to 44. The transporting step S2 also includes a measuring step S4 for measuring the temperature of the glass supply path 42.

[0025] The melting tank 1 is a vessel for carrying out the melting step S1 in which the charged glass raw materials are melted to obtain the molten glass GM. The melting tank 1 is connected to the fining tank 21 by a glass supply line 41. The molten glass GM obtained by the melting step S1 is transferred to the fining tank 21 by the glass supply line 41.

[0026] The fining tank 21 performs a fining step S21 in which the molten glass GM is degassed by the action of a fining agent or the like while being transported. The fining tank 21 is connected to the homogenizing tank 22 by a glass supply path 42. The molten glass GM degassed in the fining step S21 is transported to the homogenizing tank 22 by the glass supply path 42.

[0027] The homogenization vessel 22 is a platinum-bottomed vessel used in the homogenization step S22, which stirs and homogenizes the refined molten glass GM. The homogenization vessel 22 is equipped with a stirrer 221 having stirring blades. The homogenization vessel 22 is connected to the pot 23 via a glass supply path 43. The molten glass GM homogenized in the homogenization step S22 is transferred to the pot 23 via the glass supply path 43.

[0028] The pot 23 is a container for performing a condition adjusting step S23 in which the molten glass GM is adjusted to a state suitable for forming. The pot 23 is exemplified as a volume for adjusting the viscosity and flow rate of the molten glass GM. The pot 23 is connected to the forming device 3 by a glass supply path 44. The molten glass GM whose viscosity and flow rate have been adjusted by the condition adjusting step S23 is transferred to the forming device 3 by the glass supply path 44.

[0029] The forming device 3 is for performing a forming step of forming the molten glass GM into a desired shape (for example, a plate shape). In this embodiment, the forming device 3 is provided with a forming body 31 that forms the molten glass GM into a plate shape by the overflow downdraw method. In detail, the forming body 31 has a cross-sectional shape (cross-sectional shape perpendicular to the paper surface of FIG. 1) that is approximately wedge-shaped, and an overflow groove (not shown) is formed in the upper part of this forming body 31.

[0030] The forming body 31 causes the molten glass GM to overflow from the overflow groove and flow down along both side wall surfaces (side surfaces located on the front and back sides of the paper) of the forming body 31. The forming body 31 fuses the flowing molten glass GM at the lower apex of the side wall surfaces. This forms a belt-shaped sheet glass GR. Note that the forming body 31 may also be one that performs other downdraw methods, such as a slot downdraw method.

[0031] The belt-shaped sheet glass GR thus obtained is cut into sheet glass. The sheet glass has a thickness of, for example, 0.01 to 2 mm and is used as a substrate or protective cover for displays such as liquid crystal displays and organic EL displays, organic EL lighting, solar cells, etc. The glass article according to the present invention is not limited to sheet glass, but also includes glass tubes and other glass articles having various shapes. For example, when forming a glass tube, a forming apparatus using the Danner method is provided instead of the forming apparatus 3.

[0032] As the material for the plate glass, silicate glass or silica glass is used, preferably borosilicate glass, soda-lime glass, aluminosilicate glass, or chemically strengthened glass is used, and most preferably alkali-free glass is used. Here, alkali-free glass refers to glass that is substantially free of alkali components (alkali metal oxides), specifically glass with a weight ratio of alkali components of 3000 ppm or less. In the present invention, the weight ratio of alkali components is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 300 ppm or less.

[0033] FIG. 4 is a cross-sectional view of the glass supply path 42. As shown in FIG. 4, the transfer pipe 6 is held by a refractory material 7, which is fixed to a casing 8. The transfer pipe 6 is made of platinum or a platinum alloy and has a tubular (e.g., cylindrical) shape. The transfer pipe 6 has a measurement area 61 on its outer surface and a cylindrical tubular portion 62 surrounding the measurement area 61. The tubular portion 62 is made of platinum or a platinum alloy and is joined (e.g., welded) to the outer surface of the transfer pipe 6. The tubular portion 62 has a disk-shaped second flange 63 at its tip.

[0034] The temperature measuring device 5 includes a measuring unit 51 that receives radiant light emitted from a measurement area 61 and measures the temperature of the measurement area 61 based on the intensity of the radiant light, and a light guiding unit 52 that guides the radiant light to the measuring unit 51. The measuring unit 51 can be configured, for example, by a radiation temperature sensor.

[0035] The light guide unit 52 includes a cylindrical protective tube 521, a focusing lens 527 that focuses the radiation emitted from the measurement region 61, and an optical fiber 528 that guides the radiation focused by the focusing lens 527 to the measurement unit 51.

[0036] The protective tube 521 is a cylindrical member with both ends (front end 522 and rear end 523) open. The protective tube 521 has a disk-shaped first flange 524 between the front end 522 and the rear end 523 and on its outer circumferential surface. The outer diameter of the protective tube 521 is smaller than the inner diameter of the cylindrical portion 62, and the front end 522 of the protective tube 521 is inserted into the cylindrical portion 62 so as to be close to or abutting the measurement region 61. The gap between the front end 522 of the protective tube 521 and the measurement region 61 is preferably 0 mm or more and 50 mm or less, and more preferably 5 mm or more and 30 mm or less. By bringing the front end of the protective tube 521 close to or abutting the measurement region 61, it is possible to block radiation from the inner surface of the cylindrical portion 62. From the viewpoint of suppressing heat transfer from the measurement region 61 to the protective tube 521, it is preferable that the front end of the protective tube 521 be close to the measurement region 61. The outer diameter of the first flange 524 may be smaller or larger than the outer diameter of the second flange 63. Ceramics can be used as the material for the protective tube 521. In this embodiment, the protective tube 521 is made of alumina ceramics. Alumina ceramic protective tubes are widely available as protective tubes for thermocouples, and by using such a protective tube for the protective tube 521, the manufacturing cost of the temperature measuring device 5 can be reduced. Furthermore, alumina ceramics has low thermal conductivity and can suppress a temperature rise in the protective tube 521, so the intensity of the radiation light emitted from the protective tube 521 can be kept low and the temperature of the measurement region 61 can be measured more accurately.

[0037] The protective tube 521 is attached to the casing 8 with the first flange 524 and the second flange 63 butted together. Because the measurement area 61 is not covered with the refractory material 7, there is a risk that the temperature of the measurement area 61 may fluctuate due to the inflow of airflow around the transfer tube 6. Furthermore, there is a risk that foreign matter may enter the optical path 525 of the radiation light emitted from the measurement area 61, making it difficult to accurately measure the temperature of the measurement area 61. By butting the first flange 524 and the second flange 63, it is possible to prevent foreign matter from entering the optical path 525 due to the airflow around the transfer tube 6, thereby enabling more accurate measurement of the temperature of the measurement area 61. Furthermore, it is possible to prevent the airflow around the transfer tube 6 from flowing toward the measurement area 61, thereby further suppressing fluctuations in the temperature of the measurement area 61.

[0038] The gap between first flange 524 and second flange 63 is sealed with ceramic paste 526. As ceramic paste 526, for example, alumina paste can be used. This makes it possible to further suppress airflow into measurement region 61 and intrusion of foreign matter into optical path 525, thereby enabling more accurate measurement of the temperature of measurement region 61.

[0039] A condenser lens 527 and an optical fiber 528 are attached to the rear end 523 of the protective tube 521. The attachment positions of the condenser lens 527 and the optical fiber 528 are adjusted so that the light emitted from the measurement region 61 is condensed onto the end face of the optical fiber 528. This allows the installation position of the measurement unit 51 to be away from the high-temperature environment near the transfer tube 6, reducing the thermal load on the measurement unit 51 and preventing deterioration of the measurement unit 51.

[0040] Furthermore, the radiation light emitted from the measurement region 61 passes through the inside (light path) 525 of the protective tube 521, is collected by the collecting lens 527, and enters one end of the optical fiber 528. This prevents light other than the radiation light emitted from the measurement region 61 from entering the light detection unit 511, and allows the temperature of the measurement region 61 to be measured accurately.

[0041] The measurement unit 51 has a light detection unit 511 and a control unit 512. The emitted light guided by the light guide unit 52 enters the light detection unit 511 and is converted into an electrical signal. A photodiode or the like can be used as the light detection unit 511. The electrical signal is corrected by the control unit 512, converted into a temperature, and output. A microcomputer or a PC can be used as the control unit 512.

[0042] According to the manufacturing apparatus and manufacturing method described above, the surface temperature of the transfer tube 6 can be accurately measured by measuring the temperature based on the radiation emitted from the measurement region 61. Furthermore, the provision of the protective tube 521 in the light guide unit 52 can prevent foreign matter from entering the optical path 525, and the provision of the cylindrical portion 62 in the transfer tube 6 can prevent airflow toward the measurement region 61 and the incidence of light other than the radiation emitted from the measurement region 61 into the light detection unit 511. These features allow the temperature of the measurement region 61 to be accurately measured. Furthermore, the radiation emitted from the measurement region 61 is guided to the measurement unit 51 using the condenser lens 527 and the optical fiber 528, so that the measurement unit 51 can be located away from the high-temperature environment near the transfer tube 6, reducing the thermal load and thereby suppressing deterioration of the measurement unit 51.

[0043] The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. The present invention can be modified in various ways without departing from the spirit of the present invention.

[0044] In the above embodiment, the condenser lens 527 and the optical fiber 528 are used to guide the radiation emitted from the measurement region 61 to the measurement unit 51, but this is not limiting. The radiation may also be guided to the measurement unit 51 using a reflecting mirror.

[0045] In the above embodiment, the temperature measuring device 5 is attached horizontally to the transfer pipe 6, but this is not limiting. It may also be attached vertically or obliquely. With this configuration, the temperature measuring device 5 can be attached in an optimal position depending on the overall configuration of the glass article manufacturing apparatus.

[0046] In the above embodiment, the protective tube 521 and the tubular portion 62 are cylindrical, but are not limited to this and may be polygonal, such as rectangular, or elliptical.

[0047] In the above embodiment, the first flange 524 and the second flange 63 are disk-shaped, but are not limited to this, and may be polygonal, such as rectangular, or elliptical.

[0048] In the above embodiment, the rear end 523 of the protective tube 521 protrudes from the casing 8, and the condenser lens 527 and the optical fiber 528 are installed outside the casing, but the present invention is not limited to this.

[0049] In the above embodiment, the gap between the first flange 524 and the second flange 63 is filled with ceramic paste 526, but this is not limiting. The first flange 524 and the second flange 63 may be in direct contact with each other. With this configuration, the number of steps required to install the temperature measuring device 5 can be reduced.

[0050] In the above embodiment, the front end 522 of the protective tube 521 is inserted inside the cylindrical portion 62, but this is not limited to this. The front end 522 of the protective tube 521 may be flush with the first flange 524. This configuration can reduce the manufacturing cost of the protective tube 521. In this case, the outer diameter of the protective tube 521 may be the same as or larger than the inner diameter of the cylindrical portion 62.

[0051] In the above embodiment, the protective tube 521 includes the first flange 524, and the cylindrical portion 62 includes the second flange 63, but this is not limiting. With such a configuration, the manufacturing costs of the transfer tube 6 and the temperature measuring device 5 can be reduced.

[0052] In the above embodiment, the temperature measuring device 5 is provided in the transfer pipe 6 that constitutes the glass supply path 42, but this is not limiting. The temperature measuring device 5 may be provided in, for example, any of the fining tank 21, the homogenizing tank 22, the pot 23, and the glass supply paths 41 to 44, or may be provided in multiple devices. Furthermore, multiple temperature measuring devices 5 may be provided in one device. [Explanation of symbols]

[0053] 5 Temperature measuring device 51 Measuring part 52 Light guide section 521 Protection tube 524 First flange 526 Ceramic Paste 527 Condenser Lens 528 Optical Fiber 6 Transfer pipe 61 Measurement area 62 Cylindrical part 63 Second flange GM Molten Glass S2 Transfer process S4 Measurement process

Claims

1. a transfer pipe for transferring molten glass; a temperature measuring device for measuring the temperature of the outer surface of the transfer pipe, the temperature measuring device includes a measurement unit that receives radiant light emitted from a measurement area on the outer surface and measures a temperature, and a light guiding unit that transmits the radiant light to the measurement unit; the light guide portion includes a cylindrical protective tube having open ends, the transfer tube has a cylindrical portion joined to the outer surface and surrounding the measurement region; The glass article manufacturing apparatus is characterized in that the protective tube is inserted inside the cylindrical portion.

2. the protective tube includes a first flange; the tubular portion includes a second flange; 2. The apparatus for manufacturing a glass article according to claim 1, wherein the first flange is abutted against the second flange.

3. 3. The apparatus for manufacturing a glass article according to claim 2, wherein a gap between the first flange and the second flange is sealed with a ceramic paste.

4. 4. The apparatus for manufacturing a glass article according to claim 1, wherein the protective tube is made of ceramics.

5. 5. The glass article manufacturing apparatus according to claim 1, wherein the light guide unit includes an optical element that transmits the emitted light to the measurement unit.

6. 6. The apparatus for manufacturing a glass article according to claim 5, wherein the optical element comprises a condenser lens and an optical fiber.

7. 7. The glass article manufacturing apparatus according to claim 1, wherein the transfer pipe is made of platinum or a platinum alloy.

8. 8. A method for manufacturing a glass article, comprising: a transfer step of transferring the molten glass using the transfer pipe provided in the glass article manufacturing apparatus according to claim 1; and a measurement step of measuring the temperature of the transfer pipe using the temperature measuring device.

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