WO2009148141A1 - Apparatus and method for producing plate glass - Google Patents

Apparatus and method for producing plate glass Download PDF

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Publication number
WO2009148141A1
WO2009148141A1 PCT/JP2009/060292 JP2009060292W WO2009148141A1 WO 2009148141 A1 WO2009148141 A1 WO 2009148141A1 JP 2009060292 W JP2009060292 W JP 2009060292W WO 2009148141 A1 WO2009148141 A1 WO 2009148141A1
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WO
WIPO (PCT)
Prior art keywords
glass ribbon
protective layer
glass
layer forming
sulfurous acid
Prior art date
Application number
PCT/JP2009/060292
Other languages
French (fr)
Japanese (ja)
Inventor
元一 伊賀
康一 花井
哲史 瀧口
信之 伴
Original Assignee
旭硝子株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 旭硝子株式会社 filed Critical 旭硝子株式会社
Priority to CN200980121196.7A priority Critical patent/CN102046542B/en
Priority to KR1020107021743A priority patent/KR101503964B1/en
Priority to JP2010515928A priority patent/JP5387920B2/en
Publication of WO2009148141A1 publication Critical patent/WO2009148141A1/en

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/001—General methods for coating; Devices therefor
    • C03C17/002—General methods for coating; Devices therefor for flat glass, e.g. float glass
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B25/00—Annealing glass products
    • C03B25/04—Annealing glass products in a continuous way
    • C03B25/06—Annealing glass products in a continuous way with horizontal displacement of the glass products
    • C03B25/08—Annealing glass products in a continuous way with horizontal displacement of the glass products of glass sheets
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/22—Surface treatment of glass, not in the form of fibres or filaments, by coating with other inorganic material
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C2217/00—Coatings on glass
    • C03C2217/20—Materials for coating a single layer on glass
    • C03C2217/28—Other inorganic materials
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C2218/00—Methods for coating glass
    • C03C2218/10—Deposition methods
    • C03C2218/15—Deposition methods from the vapour phase
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C2218/00—Methods for coating glass
    • C03C2218/30—Aspects of methods for coating glass not covered above
    • C03C2218/36—Underside coating of a glass sheet

Definitions

  • the present invention relates to a sheet glass manufacturing apparatus by a float method and a manufacturing method thereof, and in particular, a protective layer forming portion for forming a protective layer for preventing wrinkles made of sulfate on the lower surface of a high-temperature glass ribbon drawn from a float bath.
  • the present invention relates to a plate glass manufacturing apparatus and a plate glass manufacturing method.
  • the method for producing plate glass by the float process is to supply molten glass onto the molten tin surface of the float bath, and form the molten glass into a continuous sheet shape on the molten tin.
  • This is a manufacturing method in which a high-temperature glass ribbon formed into a glass plate is drawn out from the surface of the molten tin, and this is slowly cooled and cut into a glass plate of a predetermined size.
  • the glass ribbon is pulled out from the surface of the molten tin by lifting and conveying the glass ribbon at the exit of the float bath with a roll called “lift-out roll”.
  • the place where the lift-out roll exists is hereinafter referred to as a “dross box”.
  • the drawn glass ribbon is gradually cooled in a slow cooling furnace on the downstream side of the dross box.
  • the zone where the cooling is performed is hereinafter referred to as “slow cooling part”, and the roll that supports and conveys the glass ribbon in the slow cooling part is hereinafter referred to as “slow cooling roll”.
  • the atmosphere of the float bath is maintained at a positive pressure in a reducing atmosphere by a mixed gas of nitrogen gas and hydrogen gas.
  • the dross box communicating with the float bath is also maintained in a reducing atmosphere of positive pressure.
  • the area where these float baths and dross boxes are present is hereinafter referred to as “molded part”.
  • Patent Document 1 sulfurous acid gas (SO 2 ) is introduced into the slow cooling furnace, and this is reacted with alkali metal sodium, which is a constituent component of the glass ribbon, to prevent wrinkles such as sodium sulfate on the surface of the glass ribbon.
  • SO 2 sulfurous acid gas
  • alkali metal sodium which is a constituent component of the glass ribbon
  • the plate glass manufacturing apparatus of Patent Document 1 is an apparatus that partitions a predetermined section of a slow cooling section with a partition wall, and blows sulfurous acid gas onto a glass ribbon flowing through the section to form the protective layer for preventing wrinkles on the surface of the glass ribbon. It is.
  • the plate glass manufacturing apparatus of Patent Document 1 is provided with a partition wall in a section into which sulfurous acid gas is introduced, but the partition wall is provided apart from the glass ribbon. Therefore, in the technique of Patent Document 1, when the section is positioned on the uppermost stream side of the slow cooling furnace, the airflow in the section is disturbed by the intrusion of the airflow in the dross box adjacent to the upstream side, and sulfurous acid gas is removed from the glass ribbon. There is a drawback that it is difficult to stay on the surface and the protective layer for preventing wrinkles cannot be efficiently and uniformly formed on the glass ribbon. In addition, there is a problem that oxygen in the compartment enters a non-oxidizing atmosphere in the dross box or float bath.
  • the present invention has been made in view of such circumstances, and provides a plate glass manufacturing apparatus and a plate glass manufacturing method capable of efficiently and uniformly forming a sulfate-preventing protective layer on a glass ribbon. With the goal.
  • the invention of the sheet glass manufacturing apparatus of the present invention comprises a molding section for continuously supplying molten glass to a horizontal bath surface of a float bath containing molten metal to form a glass ribbon,
  • a plate glass manufacturing apparatus comprising a slow cooling part that transports the glass ribbon formed in the forming part to a slow cooling furnace and slowly cools the glass ribbon, the glass ribbon is located upstream of the slow cooling part in the glass ribbon transport direction. In a zone having a temperature of 500 ° C.
  • a protective layer forming part for forming a protective layer for preventing wrinkles made of sulfate is provided on the lower surface of the glass ribbon, and the protective layer forming part is provided in the direction of conveying the glass ribbon.
  • a nozzle that supplies a sulfurous acid gas to the protective layer forming portion is partitioned by a downstream shielding member that is spaced within m and is held in a substantially hermetically sealed state.
  • the wrinkle-preventing protective layer is formed on the lower surface, and there is no roll in contact with the glass ribbon in the protective layer forming portion, and the portion in contact with the glass ribbon of the upstream shielding member is a heat resistant fiber sheet.
  • the non-oxidizing gas is supplied to the heat-resistant fiber sheet from the non-oxidizing gas supply unit.
  • the glass ribbon reacts with sulfurous acid gas at a temperature of 500 ° C. or more to form a protective layer for preventing wrinkles.
  • the temperature of the glass ribbon drawn out from the forming portion is 750 ° C. or lower. Since the reaction rate between the sulfurous acid gas and the alkaline earth metal in the glass is higher as the temperature of the glass ribbon is higher, the preferable temperature of the glass ribbon is 650 ° C. or higher.
  • the roll present in the protective layer forming portion is retracted from the glass ribbon and does not come into contact with the glass ribbon when a normal glass ribbon is formed. This roll abuts against the glass ribbon that flows discontinuously at the start of glass ribbon molding or when trouble occurs, and efficiently carries out the glass ribbon. Therefore, when forming the protective layer for preventing wrinkles through which the glass ribbon is continuously flowing, there is no roll in contact with the glass ribbon, so the entire lower surface of the glass ribbon is exposed to sulfurous acid gas in the protective layer forming portion. A protective layer for preventing wrinkles is formed uniformly.
  • the protective layer forming part is in contact with the lower surface of the glass ribbon on the upstream side in the glass ribbon transport direction and in contact with the lower surface of the glass ribbon on the downstream side in the glass ribbon transport direction. And is held in a substantially sealed state by being separated by a downstream side shielding member separated within 50 mm from the center.
  • a protective layer formation part becomes the atmosphere filled with sulfurous acid gas, and can form the protective layer for wrinkle prevention uniformly.
  • the internal disturbance of the protective layer formation part by the non-oxidizing atmosphere upstream of the protective layer formation part permeating into the protective layer formation part can be prevented.
  • the protective layer for wrinkle prevention can be efficiently formed on the glass ribbon.
  • the downstream shielding member even if the oxidizing atmosphere of the protective layer forming portion leaks into the slow cooling furnace, there is no problem because the slow cooling furnace is an oxidizing atmosphere.
  • a nozzle for supplying sulfurous acid gas is disposed in the protective layer forming portion, and the protective layer for preventing wrinkles is formed on the lower surface of the glass ribbon by the sulfurous acid gas supplied from this nozzle.
  • an upstream shielding member is comprised from a heat resistant fiber sheet, can seal a protective layer formation part, and can remove the molten metal adhering to the lower surface of a glass ribbon. This prevents uneven formation of the protective layer due to adhesion of molten metal, and the protective layer is formed more uniformly.
  • the non-oxidizing gas is supplied to the upstream shielding member from the non-oxidizing gas supply unit, and the oxidation loss of the heat-resistant fiber sheet is prevented by the non-oxidizing gas.
  • the non-oxidizing gas is injected from the upstream side shielding member, the molded part and the protective layer forming part are shielded by the non-oxidizing gas, so that the non-oxidizing of the float bath and the dross box from the protective layer forming part. It is possible to completely block the oxidizing atmosphere that tries to enter the atmosphere.
  • the portion of the downstream shielding member that is in contact with the glass ribbon is composed of a heat resistant fiber sheet
  • the non-oxidizing gas is preferably supplied from the non-oxidizing gas supply unit.
  • the heat-resistant fiber sheet is preferably a felt-like fiber sheet made of carbon fiber.
  • a gas retaining member for retaining the sulfurous acid gas supplied from the nozzle at a position immediately below the glass ribbon is disposed in the protective layer forming portion. Since sulfurous acid gas is heavier than air, the sulfurous acid gas does not react well with the alkaline earth metal in the glass ribbon if it is simply blown from the nozzle to the glass ribbon. Therefore, the reaction between the sulfurous acid gas and the alkaline earth metal can be promoted by retaining the sulfurous acid gas at a position directly below the glass ribbon by the gas retaining member. Further, the supply amount of sulfurous acid gas can be saved.
  • a roll for conveying a glass ribbon is disposed in the protective layer forming section, and the roll is positioned at a position retracted relative to the glass ribbon when the protective layer for preventing wrinkles is formed, It is preferable that a roll is also used as the gas retention member. In addition, it is preferable that the upper surface of the roll is at the same level as or slightly below the sulfite gas injection position of the nozzle from the viewpoint of favorably retaining the sulfite gas on the roll.
  • the distance between the glass ribbon and the nozzle is preferably set to 10 mm to 150 mm. If the nozzle is too close to the glass ribbon, the sulfurous acid gas is sprayed on only a part of the glass ribbon, so that the protective layer for preventing wrinkles cannot be formed uniformly. If the nozzle is too far away from the glass ribbon, the sulfurous acid gas is heavier than air, so the sulfurous acid gas injected from the nozzle and the alkaline earth metal of the glass ribbon cannot react well.
  • the distance between the glass ribbon and the nozzle is more preferably 20 mm to 100 mm, still more preferably 40 to 75 mm.
  • the present invention is suitable for the production of alkali-free glass.
  • the temperature of the glass ribbon in the protective layer forming part is preferably 650 ° C. to 750 ° C.
  • the said glass ribbon is an alkali free glass which does not contain an alkali component.
  • the invention of the plate glass manufacturing method of the present invention is characterized in that plate glass is manufactured using the plate glass manufacturing apparatus of the present invention. Thereby, the protective layer for preventing wrinkles of sulfate can be efficiently formed on the glass ribbon.
  • the upstream side shielding member and the downstream side shielding member are supplied with the sulfurous acid gas to the protective layer forming portion held in a substantially sealed state, A protective layer for preventing wrinkles of sulfate can be formed efficiently and uniformly on the glass ribbon, and the supply amount of sulfurous acid gas can be saved. As a result, high-quality glass with less wrinkles can be obtained.
  • the present invention is effective for non-alkali glass for liquid crystal displays and the like that are difficult to form a protective layer for preventing wrinkles.
  • Sectional drawing which showed the structure of the glass plate manufacturing equipment of embodiment.
  • Explanatory drawing showing concentration distribution of sulfurous acid gas in a protective layer formation part when a saucer is installed.
  • FIG. 1 is a cross-sectional view of a glass plate manufacturing facility 10 by a float method to which a plate glass manufacturing apparatus according to the present invention is applied.
  • the downstream side refers to the same direction as the movement direction of the glass ribbon 12 in FIG. 1 (in the direction of arrow A in FIG. 1), and the opposite side is referred to as the upstream side.
  • a float bath 14 In the glass plate manufacturing facility 10 shown in FIG. 1, a float bath 14, a dross box 16, and a slow cooling furnace 18 are installed in this order from the upstream side to the downstream side, and the protective layer forming unit of the embodiment is located upstream of the slow cooling furnace 18. 20 is provided.
  • Hot float molten tin 22 is accommodated in the float bath 14, and glass ribbon 12 is formed toward the outlet 15 of the float bath 14 by continuously supplying molten glass to the horizontal bath surface of the molten tin 22.
  • the glass ribbon 12 is pulled up from the molten tin 22 by the lift-out roll 24 of the dross box 16 at the outlet 15 of the float bath 14 and conveyed in the dross box 16. Then, the glass ribbon 12, while passing through the protective layer forming unit 20 described below, sulfur dioxide (SO 2) scratch preventing protection layer made of sulfate on its lower surface by the like supplied is formed.
  • SO 2 sulfur dioxide
  • the glass ribbon 12 in which the wrinkle prevention protective layer was formed is conveyed in the slow cooling furnace 18, is gradually cooled during the conveyance by the slow cooling roll 30 of this slow cooling furnace 18, and is manufactured to plate glass.
  • the float bath 14 and the dross box 16 that are at or above the melting temperature of tin need to be maintained in a non-oxidizing atmosphere. Therefore, nitrogen (N 2 ) gas, or nitrogen (N 2 ) gas and hydrogen A mixed gas with the gas (H 2 ) is continuously supplied to prevent the molten tin 22 from being oxidized.
  • the protective layer forming part 20 is a zone upstream of the slow cooling furnace 18 and the temperature of the glass ribbon 12 is 500 ° C. to 750 ° C.
  • the glass ribbon 12 can react with sulfurous acid gas at a temperature of 500 ° C. or higher to form a protective layer for preventing sulfate wrinkles.
  • the temperature of the glass ribbon 12 drawn out from the float bath 14 is 750 ° C. or less.
  • the reaction rate between the sulfurous acid gas and the alkaline earth metal in the glass tends to increase as the temperature of the glass ribbon 12 increases, and the preferred temperature is 650 ° C. or higher.
  • the roll 32 installed in the protective layer forming unit 20 is a roll that is retracted from the glass ribbon 12 and does not come into contact with the glass ribbon 12 when the normal glass ribbon is formed, that is, when the glass ribbon 12 is continuously conveyed. is there.
  • the roll 32 abuts the glass ribbon 12 and efficiently carries the glass ribbon 12 to the slow cooling furnace 18 when the glass ribbon flows discontinuously at the start of glass ribbon molding or when trouble occurs. Therefore, since the roll 32 is not in contact with the glass ribbon 12 when the protective layer for preventing wrinkles is formed, the entire glass ribbon is exposed to the sulfurous acid gas in the protective layer forming portion 20, and the protective layer for preventing wrinkles is uniform. Will be formed.
  • the length of the protective layer forming portion 20 (the length in the transport direction of the glass ribbon 12) is a distance that does not hinder continuous transport of the glass ribbon 12, and is 300 to 600 mm, preferably 400 to 500 mm. .
  • the protective layer forming unit 20 contacts the lower surface of the glass ribbon 12 on the upstream side in the glass ribbon transport direction, and contacts the lower surface of the glass ribbon 12 on the downstream side in the glass ribbon transport direction. It is partitioned by a downstream shielding member 36 separated from the lower surface within 50 mm and held in a substantially sealed state.
  • the protective layer forming unit 20 becomes filled atmosphere of sulfurous acid gas (SO 2), can be uniformly and efficiently form a flaw preventing protection layer.
  • the side part of the protective layer formation part 20 may be shared by the side wall of a slow cooling furnace, and may provide a shielding wall.
  • the oxidizing atmosphere of the protective layer forming unit 20 is formed in the non-oxidizing atmosphere of the float bath 14 and the dross box 16 positioned on the upstream side of the protective layer forming unit 20. Does not leak. Further, since the atmosphere of the protective layer forming unit 20 can be prevented from being disturbed by the atmosphere of the dross box 16 entering the protective layer forming unit 20, the sulfurous acid gas and the alkaline earth metal in the glass react well. Therefore, the protective layer for preventing wrinkles can be efficiently formed on the glass ribbon 12.
  • the downstream shielding member 36 when a predetermined gap (within 50 mm) is provided between the glass ribbon 12 and the lower shielding member 36, the oxidizing atmosphere in the protective layer forming portion leaks into the slow cooling furnace 18. Even so, there is no problem because the slow cooling furnace 18 is in an oxidizing atmosphere.
  • the protective layer forming unit 20 is provided with a nozzle 38 for supplying sulfurous acid gas, and the protective layer for preventing wrinkles is uniformly formed on the lower surface of the glass ribbon 12 by the sulfurous acid gas supplied from the nozzle 38.
  • the upstream shielding member 34 consists of a heat-resistant fiber sheet, can endure the temperature of 750 degreeC, and can wipe off the foreign material adhering to the lower surface of the glass ribbon 12.
  • a non-oxidizing gas for example, nitrogen
  • a non-oxidizing gas supply unit not shown
  • the non-oxidizing gas is injected from the upstream shielding member 34, the dross box 16 and the protective layer forming unit 20 are shielded by the non-oxidizing gas. It is possible to completely block the oxidizing atmosphere that is going to enter the non-oxidizing atmosphere of the dross box 16.
  • downstream side shielding member 36 is in contact with the lower surface of the glass ribbon 12
  • the downstream side shielding member 36 is preferably made of a heat resistant fiber sheet in the same manner as the upstream side shielding member 34. In this case, even if foreign matter remains on the lower surface of the glass ribbon 12, it can be further wiped off. Further, a non-oxidizing gas (for example, nitrogen) is also supplied to the downstream shielding member 36 from a non-oxidizing gas supply unit (not shown), and the oxidation loss of the heat-resistant fiber sheet is prevented by this non-oxidizing gas.
  • a non-oxidizing gas for example, nitrogen
  • the heat-resistant fiber sheet fibers made of a material that can withstand a temperature of 750 ° C. or higher, particularly 1000 ° C. or higher are preferable.
  • inorganic fibers such as carbon fibers, silica fibers, alumina fibers, silicon carbide fibers, metal fibers, and the like, and carbon fibers that are particularly low in hardness and difficult to bend glass ribbons and that repel molten tin are preferable.
  • a felt-like sheet, a woven fabric, or a non-fibrous sheet is preferable.
  • a carbon fiber felt sheet carbon felt
  • carbon fiber woven fabric carbon cloth
  • the heat-resistant fiber sheet may be a fiber sheet composed of two or more kinds of inorganic fibers of different materials. Even if the carbon fiber remains on the lower surface of the glass ribbon, the carbon fiber does not burn out in the oxidizing atmosphere at a relatively high temperature, for example, in the latter half of the slow cooling furnace 18 parts, so that it does not cause defects such as dirt.
  • the thickness of the heat resistant fiber sheet is not particularly limited, but is preferably 5 mm or more in order to have flexibility.
  • the upper limit of the thickness is not particularly limited, but when the non-oxidizing gas is supplied to the heat-resistant fiber sheet from the non-oxidizing gas supply unit, the thickness is 30 mm or less, that is, 10 to 10 from the viewpoint of pressure loss with respect to the non-oxidizing gas. 20 mm, especially 15 mm is preferred.
  • the felt-like sheet or a plurality of woven or non-woven fabrics may be stacked, and further, the felt-like sheet may be combined with the woven or non-woven fabric.
  • a glass ribbon 12 of a non-alkali glass for a liquid crystal display which does not substantially contain an alkali component such as sodium, calcium sulfate, strontium sulfate, not a protective layer for preventing sodium sulfate wrinkles
  • a protective layer for preventing wrinkles of sulfate such as magnesium sulfate is formed on the lower surface of the glass ribbon 12.
  • protective layers such as calcium sulfate, strontium sulfate, and magnesium sulfate cannot be formed as efficiently as protective layers of sodium sulfate.
  • the temperature of the glass ribbon 12 of the protective layer forming unit 20 is preferably 650 ° C. to 750 ° C.
  • the glass ribbon 12 made of alkali-free glass when the temperature of the glass ribbon 12 is 650 ° C. or higher, the alkaline earth metal component in the glass and the sulfurous acid gas easily react to form a protective layer for preventing sulfate wrinkles. Is done.
  • the distance between the glass ribbon 12 and the nozzle 38 is preferably set to 10 mm to 150 mm. If the nozzle 38 is too close to the glass ribbon 12, the sulfurous acid gas is sprayed on only a part of the glass ribbon 12, so that the protective layer for preventing wrinkles cannot be formed uniformly. On the other hand, if the nozzle 38 is too far away from the glass ribbon 12, the sulfurous acid gas is heavier than air, so the sulfurous acid gas injected from the nozzle 38 and the alkaline earth metal of the glass ribbon 12 cannot react well. Therefore, the distance between the glass ribbon 12 and the nozzle 38 is more preferably 20 mm to 150 mm, still more preferably 40 to 75 mm.
  • the protective layer forming unit 20 is provided with a tray (gas retaining member) 50 for retaining the sulfurous acid gas supplied from the nozzle 38 at a position directly below the glass ribbon 12. Since the sulfurous acid gas is heavier than air, the sulfurous acid gas does not react well with the alkaline earth metal if it is simply blown from the nozzle 38 to the glass ribbon 12. Thus, the reaction between the sulfurous acid gas and the alkaline earth metal can be promoted by retaining the sulfurous acid gas at a position directly below the glass ribbon 12 by the tray 50. Further, the supply amount of sulfurous acid gas can be further saved.
  • FIG. 2 is a diagram illustrating the concentration distribution of sulfurous acid gas in the protective layer forming unit 20 when the tray 50 is installed, expressed as a region (concentration: high), b region (concentration: medium), and c region (concentration: low).
  • FIG. As shown in the figure, the sulfurous acid gas stays around the roll 32 by the receiving tray 50, and the concentration of the sulfurous acid gas is maximized in the area between the roll 32 immediately below the glass ribbon 12 and the lower surface of the glass ribbon 12. Thereby, reaction with sulfurous acid gas and the alkaline-earth metal of the glass ribbon 12 is accelerated
  • FIG. 3 shows the concentration distribution of sulfurous acid gas in the protective layer forming unit 20 when the roll 32 is also used as a gas retention member, a region (concentration: high), b region (concentration: medium), c region (concentration: It is explanatory drawing represented by (low).
  • the sulfurous acid gas stays above the roll 32 by the roll 32, and the staying effect as much as the receiving tray 50 cannot be obtained, but the concentration thereof is between the roll 32 directly below the glass ribbon 12 and the lower surface of the glass ribbon 12. The area between is the maximum. Thereby, reaction with sulfurous acid gas and the alkaline-earth metal of the glass ribbon 12 is accelerated
  • the upper surface of the roll 32 is at the same level or lower than the sulfite gas injection position of the nozzle 38 in terms of favorably retaining the sulfite gas on the roll 32.
  • the sulfate anti-fogging protective layer can be efficiently and uniformly formed on the glass ribbon 12.
  • a protective layer made of sulfurous acid gas is continuously formed on the bottom surface of an alkali-free glass ribbon drawn continuously from a float bath in the protective layer forming portion for preventing wrinkles of the present invention.
  • a protective layer is uniformly formed on the lower surface of the glass ribbon, and the amount of sulfurous acid gas used is reduced as compared with the prior art.
  • This invention can be utilized for manufacture of the plate glass by the float method using a float bath, and is suitable for manufacturing glass plates, such as a plate glass for construction, a plate glass for motor vehicles, and a plate glass for displays, by a float method.
  • glass plates such as a plate glass for construction, a plate glass for motor vehicles, and a plate glass for displays, by a float method.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
  • Surface Treatment Of Glass (AREA)

Abstract

Provided are apparatus and a method for producing plate glass, wherein a sulfate protective layer for preventing defects can be formed efficiently on the glass ribbon. The protective layer forming part of the plate glass production apparatus is upstream of the slow-cooling furnace and the temperature of the glass ribbon is set in the 500°C to 750°C zone which is favorable for the reaction between sulfurous acid gas and alkaline earth metals.  The protective layer forming part is maintained in an essentially sealed state, being separated off by an upstream barrier member which makes contact with the lower surface of the glass ribbon on the upstream side in the direction of travel of the glass ribbon and a downstream barrier member which may or may not be in contact with the lower surface of the glass ribbon on the downstream side in the direction of travel of the glass ribbon.  The upstream barrier member is in contact with the glass ribbon and so there is no leakage of the oxidizing atmosphere in the protective layer forming part into the non-oxidizing atmosphere in the float bath and dross box located upstream of the protective layer forming part.  Furthermore, disturbance of the protective layer forming part due to the intrusion of the atmosphere on the upstream side into the protective layer forming part (20) can be prevented and so the sulfurous acid gas and alkaline earth metals react effectively.

Description

板ガラスの製造装置及び板ガラスの製造方法Sheet glass manufacturing apparatus and sheet glass manufacturing method
　本発明は、フロート法による板ガラスの製造装置及びその製造方法に関し、特にフロートバスから引き出された高温のガラスリボンの下面に硫酸塩からなる疵防止用保護層を形成するための保護層形成部が設けられた板ガラスの製造装置及び板ガラスの製造方法に関する。 The present invention relates to a sheet glass manufacturing apparatus by a float method and a manufacturing method thereof, and in particular, a protective layer forming portion for forming a protective layer for preventing wrinkles made of sulfate on the lower surface of a high-temperature glass ribbon drawn from a float bath. The present invention relates to a plate glass manufacturing apparatus and a plate glass manufacturing method.
　建築用板ガラス、自動車用板ガラス、及びディスプレイ用板ガラスなどのガラス板においては、フロートバスを使用したフロート法による板ガラスの製造装置、及び製造方法が従来から知られている。 For glass plates such as architectural glass plates, automotive glass plates, and display glass plates, a plate glass manufacturing apparatus and manufacturing method using a float bath using a float bath have been known.
　フロート法による板ガラスの製造方法は、溶融ガラスをフロートバスの溶融錫表面上に供給して、溶融ガラスを溶融錫上で連続したシート状に成形するものであり、フロートバスで所定の幅の連続したガラス板となった高温のガラスリボンを溶融錫表面から引き出し、これを徐冷して所定の大きさのガラス板に切断する製法である。 The method for producing plate glass by the float process is to supply molten glass onto the molten tin surface of the float bath, and form the molten glass into a continuous sheet shape on the molten tin. This is a manufacturing method in which a high-temperature glass ribbon formed into a glass plate is drawn out from the surface of the molten tin, and this is slowly cooled and cut into a glass plate of a predetermined size.
　溶融錫表面からのガラスリボンの引き出しは、「リフトアウトロール」と称されるロールによってガラスリボンをフロートバスの出口で持ち上げて搬送することにより行われる。このリフトアウトロールが存在する場所を以下「ドロスボックス」という。引き出されたガラスリボンは、ドロスボックスの下流側の徐冷炉で徐冷される。この徐冷する区域を以下「徐冷部」といい、この徐冷部でガラスリボンを支持搬送するロールを以下「徐冷ロール」という。フロートバスの溶融錫は酸化しやすいため、フロートバスの雰囲気は窒素ガスと水素ガスとの混合ガスにより還元雰囲気で正圧に保たれている。また、フロートバスと連通しているドロスボックスも正圧の還元雰囲気に保たれている。これらのフロートバス及びドロスボックスが存在する区域を以下「成形部」という。 The glass ribbon is pulled out from the surface of the molten tin by lifting and conveying the glass ribbon at the exit of the float bath with a roll called “lift-out roll”. The place where the lift-out roll exists is hereinafter referred to as a “dross box”. The drawn glass ribbon is gradually cooled in a slow cooling furnace on the downstream side of the dross box. The zone where the cooling is performed is hereinafter referred to as “slow cooling part”, and the roll that supports and conveys the glass ribbon in the slow cooling part is hereinafter referred to as “slow cooling roll”. Since the molten tin in the float bath is easily oxidized, the atmosphere of the float bath is maintained at a positive pressure in a reducing atmosphere by a mixed gas of nitrogen gas and hydrogen gas. The dross box communicating with the float bath is also maintained in a reducing atmosphere of positive pressure. The area where these float baths and dross boxes are present is hereinafter referred to as “molded part”.
　ところで特許文献１には、徐冷炉内部に亜硫酸ガス（ＳＯ２）を導入し、これとガラスリボンの構成成分であるアルカリ金属のナトリウムとを反応させてガラスリボンの表面に硫酸ナトリウム等の疵防止用保護層を形成する板ガラスの製造装置が開示されている。 By the way, in Patent Document 1, sulfurous acid gas (SO 2 ) is introduced into the slow cooling furnace, and this is reacted with alkali metal sodium, which is a constituent component of the glass ribbon, to prevent wrinkles such as sodium sulfate on the surface of the glass ribbon. An apparatus for producing plate glass for forming a protective layer is disclosed.
　特許文献１の板ガラスの製造装置は、徐冷部の所定の区画を仕切壁によって仕切り、その区画を流れるガラスリボンに亜硫酸ガスを吹き付けてガラスリボンの表面に前記疵防止用保護層を形成する装置である。 The plate glass manufacturing apparatus of Patent Document 1 is an apparatus that partitions a predetermined section of a slow cooling section with a partition wall, and blows sulfurous acid gas onto a glass ribbon flowing through the section to form the protective layer for preventing wrinkles on the surface of the glass ribbon. It is.
国際公開　ＷＯ　０２/０５１７６７号公報International Publication WO 02/051767
　しかしながら、特許文献１の板ガラスの製造装置は、亜硫酸ガスを導入する区画に仕切壁を設けているが、その仕切壁はガラスリボンから離れて設けられている。よって、特許文献１の技術では、前記区画が徐冷炉の最上流側に位置していると、区画内の気流が、上流側に隣接するドロスボックスの気流の浸入によって乱れ、亜硫酸ガスをガラスリボンの表面に滞留させることが困難になり、疵防止用保護層をガラスリボンに効率よく均一に形成することができないという欠点があった。また、その区画内の酸素が、ドロスボックスやフロートバス内の非酸化性雰囲気に浸入するという問題があった。 However, the plate glass manufacturing apparatus of Patent Document 1 is provided with a partition wall in a section into which sulfurous acid gas is introduced, but the partition wall is provided apart from the glass ribbon. Therefore, in the technique of Patent Document 1, when the section is positioned on the uppermost stream side of the slow cooling furnace, the airflow in the section is disturbed by the intrusion of the airflow in the dross box adjacent to the upstream side, and sulfurous acid gas is removed from the glass ribbon. There is a drawback that it is difficult to stay on the surface and the protective layer for preventing wrinkles cannot be efficiently and uniformly formed on the glass ribbon. In addition, there is a problem that oxygen in the compartment enters a non-oxidizing atmosphere in the dross box or float bath.
　特に、液晶ディスプレイ用の無アルカリガラスの場合、実質的にアルカリ成分を含有しないため、疵防止用保護層をガラスリボンに効率よく形成することが困難であった。 In particular, in the case of non-alkali glass for liquid crystal displays, it is difficult to efficiently form a protective layer for preventing wrinkles on a glass ribbon because it does not substantially contain an alkali component.
　本発明は、このような事情に鑑みてなされたもので、硫酸塩の疵防止用保護層をガラスリボンに効率よく均一に形成することができる板ガラスの製造装置及び板ガラスの製造方法を提供することを目的とする。 The present invention has been made in view of such circumstances, and provides a plate glass manufacturing apparatus and a plate glass manufacturing method capable of efficiently and uniformly forming a sulfate-preventing protective layer on a glass ribbon. With the goal.
　本発明の板ガラスの製造装置の発明は、前記目的を達成するために、溶融金属を収容したフロートバスの水平な浴面に溶融ガラスを連続的に供給してガラスリボンを形成する成形部と、該成形部で形成された前記ガラスリボンを徐冷炉に搬送して徐冷する徐冷部とを備えた板ガラスの製造装置において、前記徐冷部のガラスリボン搬送方向の上流位置であってガラスリボンの温度が５００℃～７５０℃のゾーンにおいて、前記ガラスリボンの下面に硫酸塩からなる疵防止用保護層を形成するための保護層形成部が設けられ、前記保護層形成部は、ガラスリボン搬送方向の上流側においてガラスリボンの下面に接触する上流側遮蔽部材と、ガラスリボン搬送方向の下流側においてガラスリボンの下面に接触、又はガラスリボンの下面から５０ｍｍ以内に離間した下流側遮蔽部材とによって仕切られて略密閉状態に保持され、前記保護層形成部に亜硫酸ガスを供給するノズルが配置され、該ノズルから供給される亜硫酸ガスによって前記ガラスリボンの下面に前記疵防止用保護層が形成されるとともに、該保護層形成部には、前記ガラスリボンと接するロールは存在せず、前記上流側遮蔽部材のガラスリボンと接触する部分は、耐熱繊維シートから構成されるとともに、該耐熱繊維シートには非酸化性ガス供給部から非酸化性ガスが供給されることを特徴としている。 In order to achieve the above-mentioned object, the invention of the sheet glass manufacturing apparatus of the present invention comprises a molding section for continuously supplying molten glass to a horizontal bath surface of a float bath containing molten metal to form a glass ribbon, In a plate glass manufacturing apparatus comprising a slow cooling part that transports the glass ribbon formed in the forming part to a slow cooling furnace and slowly cools the glass ribbon, the glass ribbon is located upstream of the slow cooling part in the glass ribbon transport direction. In a zone having a temperature of 500 ° C. to 750 ° C., a protective layer forming part for forming a protective layer for preventing wrinkles made of sulfate is provided on the lower surface of the glass ribbon, and the protective layer forming part is provided in the direction of conveying the glass ribbon. The upstream shielding member that contacts the lower surface of the glass ribbon on the upstream side of the glass ribbon, and the lower surface of the glass ribbon on the downstream side of the glass ribbon conveyance direction, or 50 from the lower surface of the glass ribbon. a nozzle that supplies a sulfurous acid gas to the protective layer forming portion is partitioned by a downstream shielding member that is spaced within m and is held in a substantially hermetically sealed state. The wrinkle-preventing protective layer is formed on the lower surface, and there is no roll in contact with the glass ribbon in the protective layer forming portion, and the portion in contact with the glass ribbon of the upstream shielding member is a heat resistant fiber sheet. The non-oxidizing gas is supplied to the heat-resistant fiber sheet from the non-oxidizing gas supply unit.
　ナトリウム等のアルカリ成分を含有するガラスリボンの場合、ガラスリボンの温度が５００℃以上で亜硫酸ガスと反応し、疵防止用保護層が形成される。一方、成形部から引き出されるガラスリボンの温度は７５０℃以下である。亜硫酸ガスとガラス中のアルカリ土類金属との反応速度は、ガラスリボンの温度が高いほど速いため、好ましいガラスリボンの温度は６５０℃以上である。 In the case of a glass ribbon containing an alkali component such as sodium, the glass ribbon reacts with sulfurous acid gas at a temperature of 500 ° C. or more to form a protective layer for preventing wrinkles. On the other hand, the temperature of the glass ribbon drawn out from the forming portion is 750 ° C. or lower. Since the reaction rate between the sulfurous acid gas and the alkaline earth metal in the glass is higher as the temperature of the glass ribbon is higher, the preferable temperature of the glass ribbon is 650 ° C. or higher.
　保護層形成部に存在するロールは、通常のガラスリボン形成時にはガラスリボンから退避してガラスリボンと接触しない。このロールは、ガラスリボン成形の立ち上げ時やトラブル発生時に不連続に流れてくるガラスリボンに当接してガラスリボンを効率的に搬出する。よって、ガラスリボンが連続的に流れている疵防止用保護層の形成時には、ガラスリボンと接するロールは存在しないため、保護層形成部においてガラスリボンの下面全体が亜硫酸ガスにさらされることになり、疵防止用保護層が均一に形成される。 The roll present in the protective layer forming portion is retracted from the glass ribbon and does not come into contact with the glass ribbon when a normal glass ribbon is formed. This roll abuts against the glass ribbon that flows discontinuously at the start of glass ribbon molding or when trouble occurs, and efficiently carries out the glass ribbon. Therefore, when forming the protective layer for preventing wrinkles through which the glass ribbon is continuously flowing, there is no roll in contact with the glass ribbon, so the entire lower surface of the glass ribbon is exposed to sulfurous acid gas in the protective layer forming portion. A protective layer for preventing wrinkles is formed uniformly.
　また、前記保護層形成部は、ガラスリボン搬送方向の上流側においてガラスリボンの下面に接触する上流側遮蔽部材と、ガラスリボン搬送方向の下流側においてガラスリボンの下面に接触、又はガラスリボンの下面から５０ｍｍ以内に離間した下流側遮蔽部材とによって仕切られて略密閉状態に保持されている。これにより、保護層形成部は、亜硫酸ガスの充満雰囲気となり、疵防止用保護層を均一に形成できる。また、保護層形成部の上流側に位置するフロートバスやドロスボックスの非酸化雰囲気に、保護層形成部の酸化雰囲気が漏出するのを防止できる。更に、保護層形成部の上流側の非酸化雰囲気が保護層形成部に浸入することによる保護層形成部の内乱を防止できる。これによって、疵防止用保護層をガラスリボンに効率よく形成することができる。下流側遮蔽部材については、保護層形成部の酸化雰囲気が徐冷炉に漏出しても、徐冷炉は酸化雰囲気であるので問題はない。 In addition, the protective layer forming part is in contact with the lower surface of the glass ribbon on the upstream side in the glass ribbon transport direction and in contact with the lower surface of the glass ribbon on the downstream side in the glass ribbon transport direction. And is held in a substantially sealed state by being separated by a downstream side shielding member separated within 50 mm from the center. Thereby, a protective layer formation part becomes the atmosphere filled with sulfurous acid gas, and can form the protective layer for wrinkle prevention uniformly. Moreover, it is possible to prevent the oxidizing atmosphere of the protective layer forming portion from leaking into the non-oxidizing atmosphere of the float bath or the dross box located on the upstream side of the protective layer forming portion. Furthermore, the internal disturbance of the protective layer formation part by the non-oxidizing atmosphere upstream of the protective layer formation part permeating into the protective layer formation part can be prevented. Thereby, the protective layer for wrinkle prevention can be efficiently formed on the glass ribbon. Regarding the downstream shielding member, even if the oxidizing atmosphere of the protective layer forming portion leaks into the slow cooling furnace, there is no problem because the slow cooling furnace is an oxidizing atmosphere.
　更にまた、本発明では、保護層形成部に亜硫酸ガスを供給するノズルが配置され、このノズルから供給される亜硫酸ガスによってガラスリボンの下面に疵防止用保護層を形成する。そして、上流側遮蔽部材は、耐熱繊維シートから構成され、保護層形成部を密閉できるとともに、ガラスリボンの下面に付着している溶融金属を除去することができる。これにより、溶融金属付着による保護層形成ムラが防止され、保護層がさらに均一に形成される。また、この上流側遮蔽部材には非酸化性ガス供給部から非酸化性ガスが供給され、非酸化性ガスによって耐熱繊維シートの酸化損失を防止している。更に、非酸化性ガスが上流側遮蔽部材から噴射されることにより、成形部と保護層形成部とが非酸化性ガスによってシールドされるため、保護層形成部からフロートバスやドロスボックスの非酸化雰囲気に浸入しようとする酸化雰囲気を完全に遮断することができる。 Furthermore, in the present invention, a nozzle for supplying sulfurous acid gas is disposed in the protective layer forming portion, and the protective layer for preventing wrinkles is formed on the lower surface of the glass ribbon by the sulfurous acid gas supplied from this nozzle. And an upstream shielding member is comprised from a heat resistant fiber sheet, can seal a protective layer formation part, and can remove the molten metal adhering to the lower surface of a glass ribbon. This prevents uneven formation of the protective layer due to adhesion of molten metal, and the protective layer is formed more uniformly. Further, the non-oxidizing gas is supplied to the upstream shielding member from the non-oxidizing gas supply unit, and the oxidation loss of the heat-resistant fiber sheet is prevented by the non-oxidizing gas. Further, since the non-oxidizing gas is injected from the upstream side shielding member, the molded part and the protective layer forming part are shielded by the non-oxidizing gas, so that the non-oxidizing of the float bath and the dross box from the protective layer forming part. It is possible to completely block the oxidizing atmosphere that tries to enter the atmosphere.
　本発明は、前記下流側遮蔽部材が前記ガラスリボンの下面に接触される場合には、前記下流側遮蔽部材のガラスリボンと接触する部分は耐熱繊維シートから構成されるとともに、該耐熱繊維シートには非酸化性ガス供給部から非酸化性ガスが供給されることが好ましい。これにより、保護層形成部を密閉できるとともに、ガラスリボンの下面に付着している溶融金属等をさらに除去することができ、溶融金属付着による保護層形成ムラが防止され、保護層がさらに均一に形成される。また、非酸化性ガスによって耐熱繊維シートの酸化損失を防止できる。 In the present invention, when the downstream shielding member is in contact with the lower surface of the glass ribbon, the portion of the downstream shielding member that is in contact with the glass ribbon is composed of a heat resistant fiber sheet, The non-oxidizing gas is preferably supplied from the non-oxidizing gas supply unit. Thereby, while being able to seal a protective layer formation part, the molten metal adhering to the lower surface of a glass ribbon can be removed further, the nonuniformity of protective layer formation by molten metal adhesion is prevented, and a protective layer is made more uniform. It is formed. Further, oxidation loss of the heat-resistant fiber sheet can be prevented by the non-oxidizing gas.
　本発明は、前記耐熱繊維シートがカーボン繊維からなるフェルト状の繊維シートであることが好ましい。これにより、カーボン繊維がガラスリボンの下面に接触してもガラスリボンの下面に疵が付くのを防止できる。 In the present invention, the heat-resistant fiber sheet is preferably a felt-like fiber sheet made of carbon fiber. Thereby, even if a carbon fiber contacts the lower surface of a glass ribbon, it can prevent that a wrinkle adheres to the lower surface of a glass ribbon.
　本発明は、前記保護層形成部には、前記ノズルから供給された亜硫酸ガスをガラスリボンの直下の位置で滞留させるためのガス滞留部材が配置されていることが好ましい。亜硫酸ガスは空気よりも重いため、ノズルからガラスリボンにただ単に吹き出しているのでは、亜硫酸ガスがガラスリボン中のアルカリ土類金属と良好に反応しない。そこで、ガス滞留部材によって亜硫酸ガスを、ガラスリボンの直下の位置で滞留させることにより、亜硫酸ガスとアルカリ土類金属との反応を促進させることができる。また、亜硫酸ガスの供給量も節約することができる。 In the present invention, it is preferable that a gas retaining member for retaining the sulfurous acid gas supplied from the nozzle at a position immediately below the glass ribbon is disposed in the protective layer forming portion. Since sulfurous acid gas is heavier than air, the sulfurous acid gas does not react well with the alkaline earth metal in the glass ribbon if it is simply blown from the nozzle to the glass ribbon. Therefore, the reaction between the sulfurous acid gas and the alkaline earth metal can be promoted by retaining the sulfurous acid gas at a position directly below the glass ribbon by the gas retaining member. Further, the supply amount of sulfurous acid gas can be saved.
　本発明は、前記保護層形成部には、ガラスリボン搬送用ロールが配置され、該ロールは、前記疵防止用保護層の形成時にはガラスリボンに対して相対的に退避した位置に位置され、該ロールが前記ガス滞留部材として兼用されていることが好ましい。また、ノズルの亜硫酸ガスの噴射位置に対してロールの上面は同レベルか、若干下方であることがロール上に亜硫酸ガスを好適に滞留させる点で好ましい。 In the present invention, a roll for conveying a glass ribbon is disposed in the protective layer forming section, and the roll is positioned at a position retracted relative to the glass ribbon when the protective layer for preventing wrinkles is formed, It is preferable that a roll is also used as the gas retention member. In addition, it is preferable that the upper surface of the roll is at the same level as or slightly below the sulfite gas injection position of the nozzle from the viewpoint of favorably retaining the sulfite gas on the roll.
　本発明は、前記ガラスリボンと前記ノズルとの距離が１０ｍｍ～１５０ｍｍに設定されていることが好ましい。ガラスリボンに対してノズルを近づけすぎると、ガラスリボンの一部分だけに亜硫酸ガスが吹き付けられるため、疵防止用保護層を均一に形成できない。
ガラスリボンに対してノズルを遠ざけすぎると、亜硫酸ガスは空気よりも重いためノズルから噴射した亜硫酸ガスとガラスリボンのアルカリ土類金属が良好に反応できない。ガラスリボンとノズルとの距離は２０ｍｍ～１００ｍｍがより好ましく、４０～７５ｍｍが更に好ましい。 In the present invention, the distance between the glass ribbon and the nozzle is preferably set to 10 mm to 150 mm. If the nozzle is too close to the glass ribbon, the sulfurous acid gas is sprayed on only a part of the glass ribbon, so that the protective layer for preventing wrinkles cannot be formed uniformly.
If the nozzle is too far away from the glass ribbon, the sulfurous acid gas is heavier than air, so the sulfurous acid gas injected from the nozzle and the alkaline earth metal of the glass ribbon cannot react well. The distance between the glass ribbon and the nozzle is more preferably 20 mm to 100 mm, still more preferably 40 to 75 mm.
　本発明は、無アルカリガラスの製造に好適であり、その場合、前記保護層形成部のガラスリボンの温度が６５０℃～７５０℃であることが好ましい。また、前記ガラスリボンは、アルカリ成分を含有しない無アルカリガラスであることが好ましい。 The present invention is suitable for the production of alkali-free glass. In this case, the temperature of the glass ribbon in the protective layer forming part is preferably 650 ° C. to 750 ° C. Moreover, it is preferable that the said glass ribbon is an alkali free glass which does not contain an alkali component.
　本発明の板ガラスの製造方法の発明は、本発明の板ガラスの製造装置を用いて板ガラスを製造することを特徴としている。これにより、硫酸塩の疵防止用保護層をガラスリボンに効率よく形成することができる。 The invention of the plate glass manufacturing method of the present invention is characterized in that plate glass is manufactured using the plate glass manufacturing apparatus of the present invention. Thereby, the protective layer for preventing wrinkles of sulfate can be efficiently formed on the glass ribbon.
　本発明に係る板ガラスの製造装置及び板ガラスの製造方法によれば、上流側遮蔽部材と下流側遮蔽部材とで略密閉状態に保持された保護層形成部に亜硫酸ガスを供給するようにしたので、硫酸塩の疵防止用保護層をガラスリボンに効率よく均一に形成することができるとともに、亜硫酸ガスの供給量も節約することができる。その結果、疵の少ない高品質なガラスを得ることができる。また、本発明は、疵防止用保護層を形成し難い液晶ディスプレイ用等の無アルカリガラスに有効である。 According to the plate glass manufacturing apparatus and the plate glass manufacturing method according to the present invention, since the upstream side shielding member and the downstream side shielding member are supplied with the sulfurous acid gas to the protective layer forming portion held in a substantially sealed state, A protective layer for preventing wrinkles of sulfate can be formed efficiently and uniformly on the glass ribbon, and the supply amount of sulfurous acid gas can be saved. As a result, high-quality glass with less wrinkles can be obtained. In addition, the present invention is effective for non-alkali glass for liquid crystal displays and the like that are difficult to form a protective layer for preventing wrinkles.
実施の形態のガラス板製造設備の構成を示した断面図。Sectional drawing which showed the structure of the glass plate manufacturing equipment of embodiment. 受皿を設置したときの保護層形成部における亜硫酸ガスの濃度分布を表した説明図。Explanatory drawing showing concentration distribution of sulfurous acid gas in a protective layer formation part when a saucer is installed. ロールをガス滞留部材として兼用したときの保護層形成部における亜硫酸ガスの濃度分布を表した説明図。Explanatory drawing showing concentration distribution of sulfurous acid gas in a protective layer formation part when a roll is also used as a gas retention member.
　以下、添付図面に従って本発明の板ガラスの製造装置及び板ガラスの製造方法の好ましい実施の形態について説明する。 Hereinafter, preferred embodiments of a plate glass manufacturing apparatus and a plate glass manufacturing method of the present invention will be described with reference to the accompanying drawings.
　図１は、本発明に係る板ガラスの製造装置が適用されたフロート法によるガラス板製造設備１０の断面図である。なお、以下の説明において、下流側とは図１のガラスリボン１２の移動方向を基準としてそれと同方向側をいい（図１の矢印Ａ方向）、その反対方向側を上流側という。 FIG. 1 is a cross-sectional view of a glass plate manufacturing facility 10 by a float method to which a plate glass manufacturing apparatus according to the present invention is applied. In the following description, the downstream side refers to the same direction as the movement direction of the glass ribbon 12 in FIG. 1 (in the direction of arrow A in FIG. 1), and the opposite side is referred to as the upstream side.
　図１に示すガラス板製造設備１０は、上流側から下流側に向けてフロートバス１４、ドロスボックス１６、徐冷炉１８が順に設置され、この徐冷炉１８の上流位置に、実施の形態の保護層形成部２０が設けられている。 In the glass plate manufacturing facility 10 shown in FIG. 1, a float bath 14, a dross box 16, and a slow cooling furnace 18 are installed in this order from the upstream side to the downstream side, and the protective layer forming unit of the embodiment is located upstream of the slow cooling furnace 18. 20 is provided.
　フロートバス１４には高温の溶融錫２２が収容され、この溶融錫２２の水平な浴面に溶融ガラスが連続的に供給されることによりフロートバス１４の出口１５に向けてガラスリボン１２が形成される。ガラスリボン１２はフロートバス１４の出口１５において、ドロスボックス１６のリフトアウトロール２４によって溶融錫２２から引き上げられてドロスボックス１６内を搬送される。そして、このガラスリボン１２は、後述する保護層形成部２０を通過中に、供給される亜硫酸ガス（ＳＯ２）等によってその下面に硫酸塩からなる疵防止用保護層が形成される。そして、疵防止用保護層が形成されたガラスリボン１２は、徐冷炉１８を搬送され、この徐冷炉１８の徐冷ロール３０による搬送中に徐々に冷却されて板ガラスに製造される。 Hot float molten tin 22 is accommodated in the float bath 14, and glass ribbon 12 is formed toward the outlet 15 of the float bath 14 by continuously supplying molten glass to the horizontal bath surface of the molten tin 22. The The glass ribbon 12 is pulled up from the molten tin 22 by the lift-out roll 24 of the dross box 16 at the outlet 15 of the float bath 14 and conveyed in the dross box 16. Then, the glass ribbon 12, while passing through the protective layer forming unit 20 described below, sulfur dioxide (SO 2) scratch preventing protection layer made of sulfate on its lower surface by the like supplied is formed. And the glass ribbon 12 in which the wrinkle prevention protective layer was formed is conveyed in the slow cooling furnace 18, is gradually cooled during the conveyance by the slow cooling roll 30 of this slow cooling furnace 18, and is manufactured to plate glass.
　錫の溶融温度以上の雰囲気であるフロートバス１４、及びドロスボックス１６は周知の如く非酸化性雰囲気に保持する必要があるため、窒素（Ｎ２）ガス、または、窒素（Ｎ２）ガスと水素ガス（Ｈ２）との混合ガスが絶えず供給され、溶融錫２２の酸化が防止されている。 As is well known, the float bath 14 and the dross box 16 that are at or above the melting temperature of tin need to be maintained in a non-oxidizing atmosphere. Therefore, nitrogen (N 2 ) gas, or nitrogen (N 2 ) gas and hydrogen A mixed gas with the gas (H 2 ) is continuously supplied to prevent the molten tin 22 from being oxidized.
　次に、保護層形成部２０について説明する。 Next, the protective layer forming unit 20 will be described.
　この保護層形成部２０は、徐冷炉１８の上流位置であって、ガラスリボン１２の温度が５００℃～７５０℃のゾーンである。ナトリウム含有のガラスリボン１２の場合には、ガラスリボン１２の温度が５００℃以上で亜硫酸ガスと反応し、硫酸塩の疵防止用保護層を形成することができる。フロートバス１４から引き出されたガラスリボン１２の温度は７５０℃以下である。亜硫酸ガスとガラス中のアルカリ土類金属との反応速度は、ガラスリボン１２の温度が高ければ速くなる傾向にあり、その好ましい温度は６５０℃以上である。 The protective layer forming part 20 is a zone upstream of the slow cooling furnace 18 and the temperature of the glass ribbon 12 is 500 ° C. to 750 ° C. In the case of the glass ribbon 12 containing sodium, the glass ribbon 12 can react with sulfurous acid gas at a temperature of 500 ° C. or higher to form a protective layer for preventing sulfate wrinkles. The temperature of the glass ribbon 12 drawn out from the float bath 14 is 750 ° C. or less. The reaction rate between the sulfurous acid gas and the alkaline earth metal in the glass tends to increase as the temperature of the glass ribbon 12 increases, and the preferred temperature is 650 ° C. or higher.
　保護層形成部２０に設置されているロール３２は、通常のガラスリボン形成時、すなわち、ガラスリボン１２が連続的に搬送されている時にはガラスリボン１２から退避してガラスリボン１２と接触しないロールである。このロール３２は、ガラスリボン成形の立ち上げ時やトラブル発生時にガラスリボンが不連続で流れてくる時には、ガラスリボン１２に当接してガラスリボン１２を効率的に徐冷炉１８に搬出する。よって、ロール３２は、疵防止用保護層の形成時にはガラスリボン１２と接触されていないため、保護層形成部２０においてガラスリボン全体が亜硫酸ガスにさらされることになり、疵防止用保護層が均一に形成されることになる。なお、保護層形成部２０の長さ（ガラスリボン１２の搬送方向の長さ）は、連続的なガラスリボン１２の搬送に支障のない距離であり、３００～６００ｍｍ、好ましくは４００～５００ｍｍである。 The roll 32 installed in the protective layer forming unit 20 is a roll that is retracted from the glass ribbon 12 and does not come into contact with the glass ribbon 12 when the normal glass ribbon is formed, that is, when the glass ribbon 12 is continuously conveyed. is there. The roll 32 abuts the glass ribbon 12 and efficiently carries the glass ribbon 12 to the slow cooling furnace 18 when the glass ribbon flows discontinuously at the start of glass ribbon molding or when trouble occurs. Therefore, since the roll 32 is not in contact with the glass ribbon 12 when the protective layer for preventing wrinkles is formed, the entire glass ribbon is exposed to the sulfurous acid gas in the protective layer forming portion 20, and the protective layer for preventing wrinkles is uniform. Will be formed. The length of the protective layer forming portion 20 (the length in the transport direction of the glass ribbon 12) is a distance that does not hinder continuous transport of the glass ribbon 12, and is 300 to 600 mm, preferably 400 to 500 mm. .
　また、保護層形成部２０は、ガラスリボン搬送方向の上流側においてガラスリボン１２の下面に接触する上流側遮蔽部材３４と、ガラスリボン搬送方向の下流側においてガラスリボン１２の下面に接触、又は該下面から５０ｍｍ以内で離間した下流側遮蔽部材３６とによって仕切られて略密閉状態に保持されている。これにより、保護層形成部２０は、亜硫酸ガス（ＳＯ２）の充満雰囲気となり、疵防止用保護層を均一に効率的に形成できる。なお、保護層形成部２０の側部は、徐冷炉の側壁で兼用させてもよいし、遮蔽壁を設けてもよい。
　また、上流側遮蔽部材３４がガラスリボン１２と接触しているため、保護層形成部２０の上流側に位置するフロートバス１４やドロスボックス１６の非酸化雰囲気に保護層形成部２０の酸化雰囲気が漏出しない。更に、ドロスボックス１６の雰囲気が保護層形成部２０に浸入することによる保護層形成部２０の雰囲気の乱れを防止できるので、亜硫酸ガスとガラス中のアルカリ土類金属とが良好に反応する。したがって、疵防止用保護層をガラスリボン１２に効率よく形成することができる。なお、下流側遮蔽部材３６については、ガラスリボン１２と下側遮蔽部材３６との間に所定の隙間（５０ｍｍ以内）が設けられている場合に、保護層形成部の酸化雰囲気が徐冷炉１８に漏出しても、徐冷炉１８は酸化雰囲気であるので問題はない。 Further, the protective layer forming unit 20 contacts the lower surface of the glass ribbon 12 on the upstream side in the glass ribbon transport direction, and contacts the lower surface of the glass ribbon 12 on the downstream side in the glass ribbon transport direction. It is partitioned by a downstream shielding member 36 separated from the lower surface within 50 mm and held in a substantially sealed state. Thus, the protective layer forming unit 20, becomes filled atmosphere of sulfurous acid gas (SO 2), can be uniformly and efficiently form a flaw preventing protection layer. In addition, the side part of the protective layer formation part 20 may be shared by the side wall of a slow cooling furnace, and may provide a shielding wall.
Further, since the upstream shielding member 34 is in contact with the glass ribbon 12, the oxidizing atmosphere of the protective layer forming unit 20 is formed in the non-oxidizing atmosphere of the float bath 14 and the dross box 16 positioned on the upstream side of the protective layer forming unit 20. Does not leak. Further, since the atmosphere of the protective layer forming unit 20 can be prevented from being disturbed by the atmosphere of the dross box 16 entering the protective layer forming unit 20, the sulfurous acid gas and the alkaline earth metal in the glass react well. Therefore, the protective layer for preventing wrinkles can be efficiently formed on the glass ribbon 12. As for the downstream shielding member 36, when a predetermined gap (within 50 mm) is provided between the glass ribbon 12 and the lower shielding member 36, the oxidizing atmosphere in the protective layer forming portion leaks into the slow cooling furnace 18. Even so, there is no problem because the slow cooling furnace 18 is in an oxidizing atmosphere.
　保護層形成部２０には亜硫酸ガスを供給するノズル３８が配置され、このノズル３８から供給される亜硫酸ガスによってガラスリボン１２の下面に疵防止用保護層が均一に形成される。 The protective layer forming unit 20 is provided with a nozzle 38 for supplying sulfurous acid gas, and the protective layer for preventing wrinkles is uniformly formed on the lower surface of the glass ribbon 12 by the sulfurous acid gas supplied from the nozzle 38.
　そして、上流側遮蔽部材３４は、耐熱繊維シートからなり、７５０℃の温度に耐えることができ、かつ、ガラスリボン１２の下面に付着している異物を拭き取ることができる。
また、この上流側遮蔽部材３４には非酸化性ガス供給部（不図示）から非酸化性ガス（例えば窒素）が供給され、この非酸化性ガスによって耐熱繊維シートの酸化損失が防止されている。更に、非酸化性ガスが上流側遮蔽部材３４から噴射されることにより、ドロスボックス１６と保護層形成部２０とが非酸化性ガスによってシールドされるため、保護層形成部２０からフロートバス１４やドロスボックス１６の非酸化雰囲気に浸入しようとする酸化雰囲気を完全に遮断することができる。 And the upstream shielding member 34 consists of a heat-resistant fiber sheet, can endure the temperature of 750 degreeC, and can wipe off the foreign material adhering to the lower surface of the glass ribbon 12. FIG.
Further, a non-oxidizing gas (for example, nitrogen) is supplied to the upstream shielding member 34 from a non-oxidizing gas supply unit (not shown), and the oxidation loss of the heat-resistant fiber sheet is prevented by this non-oxidizing gas. . Furthermore, since the non-oxidizing gas is injected from the upstream shielding member 34, the dross box 16 and the protective layer forming unit 20 are shielded by the non-oxidizing gas. It is possible to completely block the oxidizing atmosphere that is going to enter the non-oxidizing atmosphere of the dross box 16.
　なお、下流側遮蔽部材３６がガラスリボン１２の下面に接触される形態の場合には、下流側遮蔽部材３６も上流側遮蔽部材３４と同様に耐熱繊維シートからなることが好ましい。この場合、ガラスリボン１２の下面に異物が残っていてもさらに拭き取ることができる。また、下流側遮蔽部材３６にも非酸化性ガス供給部（不図示）から非酸化性ガス（例えば窒素）が供給され、この非酸化性ガスによって耐熱繊維シートの酸化損失が防止されている。 In the case where the downstream side shielding member 36 is in contact with the lower surface of the glass ribbon 12, the downstream side shielding member 36 is preferably made of a heat resistant fiber sheet in the same manner as the upstream side shielding member 34. In this case, even if foreign matter remains on the lower surface of the glass ribbon 12, it can be further wiped off. Further, a non-oxidizing gas (for example, nitrogen) is also supplied to the downstream shielding member 36 from a non-oxidizing gas supply unit (not shown), and the oxidation loss of the heat-resistant fiber sheet is prevented by this non-oxidizing gas.
　耐熱繊維シートとしては、７５０℃以上、特に１０００℃以上の温度に耐えられる材質の繊維が好ましい。具体的にはカーボン繊維、シリカ繊維、アルミナ繊維、炭化ケイ素繊維、金属繊維等の無機繊維があり、特に硬度が低くガラスリボンを疵付けにくく、さらに溶融錫をはじくカーボン繊維が好ましい。繊維シートとしてはフェルト状のシートや織布ないし不繊維状のシートが好ましい。具体的には例えばカーボン繊維のフェルト状シート（カーボンフェルト）やカーボン繊維の織布（カーボンクロス）等を使用できる。耐熱繊維シートは異なる材質の無機繊維２種以上からなる繊維シートであってもよい。なお、カーボン繊維は仮にガラスリボン下面に残存したとしても比較的高温の酸化雰囲気中、例えば徐冷炉１８部の後半部等で燃え尽きて無くなることにより、汚れ等の欠点にならない。 As the heat-resistant fiber sheet, fibers made of a material that can withstand a temperature of 750 ° C. or higher, particularly 1000 ° C. or higher are preferable. Specifically, there are inorganic fibers such as carbon fibers, silica fibers, alumina fibers, silicon carbide fibers, metal fibers, and the like, and carbon fibers that are particularly low in hardness and difficult to bend glass ribbons and that repel molten tin are preferable. As the fiber sheet, a felt-like sheet, a woven fabric, or a non-fibrous sheet is preferable. Specifically, for example, a carbon fiber felt sheet (carbon felt), a carbon fiber woven fabric (carbon cloth), or the like can be used. The heat-resistant fiber sheet may be a fiber sheet composed of two or more kinds of inorganic fibers of different materials. Even if the carbon fiber remains on the lower surface of the glass ribbon, the carbon fiber does not burn out in the oxidizing atmosphere at a relatively high temperature, for example, in the latter half of the slow cooling furnace 18 parts, so that it does not cause defects such as dirt.
　耐熱繊維シートの厚さは特に限定されないが、柔軟性を持たせるためには５ｍｍ以上であることが好ましい。厚さの上限は特にないが、前述した非酸化性ガス供給部から非酸化性ガスが耐熱繊維シートに供給される場合に、非酸化性ガスに対する圧力損失の観点から３０ｍｍ以下、すなわち、１０～２０ｍｍ、特に１５ｍｍが好ましい。耐熱繊維シートの形成にあたっては、フェルト状シートのみ、又は複数の織布や不織布を重ねてもよく、さらにはフェルト状シートと織布や不織布とを組み合わせてもよい。 The thickness of the heat resistant fiber sheet is not particularly limited, but is preferably 5 mm or more in order to have flexibility. The upper limit of the thickness is not particularly limited, but when the non-oxidizing gas is supplied to the heat-resistant fiber sheet from the non-oxidizing gas supply unit, the thickness is 30 mm or less, that is, 10 to 10 from the viewpoint of pressure loss with respect to the non-oxidizing gas. 20 mm, especially 15 mm is preferred. In forming the heat-resistant fiber sheet, only the felt-like sheet or a plurality of woven or non-woven fabrics may be stacked, and further, the felt-like sheet may be combined with the woven or non-woven fabric.
　ナトリウム等のアルカリ成分を実質的に含有していない液晶ディスプレイ用の無アルカリガラスのガラスリボン１２に亜硫酸ガスを吹き付けた場合には、硫酸ナトリウムの疵防止用保護層ではなく、硫酸カルシウム、硫酸ストロンチウム、硫酸マグネシウム等の硫酸塩の疵防止用保護層がガラスリボン１２の下面に形成される。 When sulfite gas is sprayed on a glass ribbon 12 of a non-alkali glass for a liquid crystal display which does not substantially contain an alkali component such as sodium, calcium sulfate, strontium sulfate, not a protective layer for preventing sodium sulfate wrinkles A protective layer for preventing wrinkles of sulfate such as magnesium sulfate is formed on the lower surface of the glass ribbon 12.
　しかしながら、硫酸カルシム、硫酸ストロンチウム、硫酸マグネシウム等の保護層は、硫酸ナトリウムの保護層ほど効率よく形成することができない。 However, protective layers such as calcium sulfate, strontium sulfate, and magnesium sulfate cannot be formed as efficiently as protective layers of sodium sulfate.
　そこで、本発明は、保護層形成部２０のガラスリボン１２の温度が６５０℃～７５０℃であることが好ましい。無アルカリガラスのガラスリボン１２の場合には、ガラスリボン１２の温度が６５０℃以上でガラス中のアルカリ土類金属成分と亜硫酸ガスとが反応し易くなり、硫酸塩の疵防止用保護層が形成される。 Therefore, in the present invention, the temperature of the glass ribbon 12 of the protective layer forming unit 20 is preferably 650 ° C. to 750 ° C. In the case of the glass ribbon 12 made of alkali-free glass, when the temperature of the glass ribbon 12 is 650 ° C. or higher, the alkaline earth metal component in the glass and the sulfurous acid gas easily react to form a protective layer for preventing sulfate wrinkles. Is done.
　更に、ガラスリボン１２とノズル３８との距離が１０ｍｍ～１５０ｍｍに設定されていることが好ましい。ガラスリボン１２に対してノズル３８を近づけすぎると、ガラスリボン１２の一部分だけに亜硫酸ガスが吹き付けられるため、疵防止用保護層を均一に形成できない。これとは逆にガラスリボン１２に対してノズル３８を遠ざけすぎると、亜硫酸ガスは空気よりも重いためノズル３８から噴射した亜硫酸ガスとガラスリボン１２のアルカリ土類金属が良好に反応できない。よって、ガラスリボン１２とノズル３８との距離は２０ｍｍ～１５０ｍｍがより好ましく、４０～７５ｍｍが更に好ましい。 Further, the distance between the glass ribbon 12 and the nozzle 38 is preferably set to 10 mm to 150 mm. If the nozzle 38 is too close to the glass ribbon 12, the sulfurous acid gas is sprayed on only a part of the glass ribbon 12, so that the protective layer for preventing wrinkles cannot be formed uniformly. On the other hand, if the nozzle 38 is too far away from the glass ribbon 12, the sulfurous acid gas is heavier than air, so the sulfurous acid gas injected from the nozzle 38 and the alkaline earth metal of the glass ribbon 12 cannot react well. Therefore, the distance between the glass ribbon 12 and the nozzle 38 is more preferably 20 mm to 150 mm, still more preferably 40 to 75 mm.
　更にまた、保護層形成部２０には、ノズル３８から供給された亜硫酸ガスをガラスリボン１２の直下の位置で滞留させるための受皿（ガス滞留部材）５０が配置されていることが好ましい。亜硫酸ガスは空気よりも重いため、ノズル３８からガラスリボン１２にただ単に吹き出しているのでは、亜硫酸ガスがアルカリ土類金属と良好に反応しない。そこで、受皿５０によって亜硫酸ガスを、ガラスリボン１２の直下の位置で滞留させることにより、亜硫酸ガスとアルカリ土類金属との反応を促進させることができる。また、亜硫酸ガスの供給量も更に節約することができる。 Furthermore, it is preferable that the protective layer forming unit 20 is provided with a tray (gas retaining member) 50 for retaining the sulfurous acid gas supplied from the nozzle 38 at a position directly below the glass ribbon 12. Since the sulfurous acid gas is heavier than air, the sulfurous acid gas does not react well with the alkaline earth metal if it is simply blown from the nozzle 38 to the glass ribbon 12. Thus, the reaction between the sulfurous acid gas and the alkaline earth metal can be promoted by retaining the sulfurous acid gas at a position directly below the glass ribbon 12 by the tray 50. Further, the supply amount of sulfurous acid gas can be further saved.
　図２は、受皿５０を設置したときの保護層形成部２０における亜硫酸ガスの濃度分布をａ領域（濃度：高）、ｂ領域（濃度：中）、ｃ領域（濃度：低）で表した説明図である。同図の如く、亜硫酸ガスは受皿５０によってロール３２の周辺に滞留し、また、その濃度はガラスリボン１２直下のロール３２とガラスリボン１２下面との間のエリアが最大値となることが分かる。これにより、亜硫酸ガスとガラスリボン１２のアルカリ土類金属との反応が促進される。 FIG. 2 is a diagram illustrating the concentration distribution of sulfurous acid gas in the protective layer forming unit 20 when the tray 50 is installed, expressed as a region (concentration: high), b region (concentration: medium), and c region (concentration: low). FIG. As shown in the figure, the sulfurous acid gas stays around the roll 32 by the receiving tray 50, and the concentration of the sulfurous acid gas is maximized in the area between the roll 32 immediately below the glass ribbon 12 and the lower surface of the glass ribbon 12. Thereby, reaction with sulfurous acid gas and the alkaline-earth metal of the glass ribbon 12 is accelerated | stimulated.
　一方、図３は、ロール３２をガス滞留部材として兼用したときの保護層形成部２０における亜硫酸ガスの濃度分布をａ領域（濃度：高）、ｂ領域（濃度：中）、ｃ領域（濃度：低）で表した説明図である。同図の如く、亜硫酸ガスはロール３２によってロール３２の上方に滞留し、また、受皿５０ほどの滞留効果は得ることができないものの、その濃度はガラスリボン１２直下のロール３２とガラスリボン１２下面との間のエリアが最大値となる。これにより、亜硫酸ガスとガラスリボン１２のアルカリ土類金属との反応が促進される。なお、ノズル３８の亜硫酸ガスの噴射位置に対してロール３２の上面は同レベルか、下方であることがロール３２上に亜硫酸ガスを好適に滞留させる点で好ましい。 On the other hand, FIG. 3 shows the concentration distribution of sulfurous acid gas in the protective layer forming unit 20 when the roll 32 is also used as a gas retention member, a region (concentration: high), b region (concentration: medium), c region (concentration: It is explanatory drawing represented by (low). As shown in the figure, the sulfurous acid gas stays above the roll 32 by the roll 32, and the staying effect as much as the receiving tray 50 cannot be obtained, but the concentration thereof is between the roll 32 directly below the glass ribbon 12 and the lower surface of the glass ribbon 12. The area between is the maximum. Thereby, reaction with sulfurous acid gas and the alkaline-earth metal of the glass ribbon 12 is accelerated | stimulated. In addition, it is preferable that the upper surface of the roll 32 is at the same level or lower than the sulfite gas injection position of the nozzle 38 in terms of favorably retaining the sulfite gas on the roll 32.
　以上の如く、実施の形態のガラス板製造設備１０によるガラス板製造方法によれば、硫酸塩の疵防止用保護層をガラスリボン１２に効率よく均一に形成することができる。 As described above, according to the glass plate manufacturing method using the glass plate manufacturing facility 10 of the embodiment, the sulfate anti-fogging protective layer can be efficiently and uniformly formed on the glass ribbon 12.
　実施例として、フロートバスから連続的に引き出される無アルカリガラスのガラスリボンの下面に、本発明の疵防止用保護層形成部において、亜硫酸ガスによる保護層を連続的に形成させる。ガラスリボンの下面に保護層が均一に形成され、また亜硫酸ガスの使用量が、従来に比較して低減する。 As an example, a protective layer made of sulfurous acid gas is continuously formed on the bottom surface of an alkali-free glass ribbon drawn continuously from a float bath in the protective layer forming portion for preventing wrinkles of the present invention. A protective layer is uniformly formed on the lower surface of the glass ribbon, and the amount of sulfurous acid gas used is reduced as compared with the prior art.
　本発明は、フロートバスを使用したフロート法による板ガラスの製造に利用でき、建築用板ガラス、自動車用板ガラス、及びディスプレイ用板ガラスなどのガラス板をフロート法で製造するのに好適する。
　なお、２００８年６月６日に出願された日本特許出願２００８－１４９６１５号の明細書、特許請求の範囲、図面及び要約書の全内容をここに引用し、本発明の明細書の開示として、取り入れるものである。 INDUSTRIAL APPLICATION This invention can be utilized for manufacture of the plate glass by the float method using a float bath, and is suitable for manufacturing glass plates, such as a plate glass for construction, a plate glass for motor vehicles, and a plate glass for displays, by a float method.
The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2008-149615 filed on June 6, 2008 are cited here as disclosure of the specification of the present invention. Incorporated.
　１０…ガラス板製造設備、１２…ガラスリボン、１４…フロートバス、１５…出口、１６…ドロスボックス、１８…徐冷炉、２０…保護層形成部、２２…溶融錫、２４…リフトアウトロール、３０…徐冷ロール、３２…ロール（ガス滞留部材）、３４…上流側遮蔽部材、３６…下流側遮蔽部材、３８…ノズル、５０…受皿（ガス滞留部材） DESCRIPTION OF SYMBOLS 10 ... Glass plate manufacturing equipment, 12 ... Glass ribbon, 14 ... Float bath, 15 ... Outlet, 16 ... Dross box, 18 ... Slow cooling furnace, 20 ... Protection layer formation part, 22 ... Molten tin, 24 ... Lift-out roll, 30 ... Slow cooling roll, 32 ... roll (gas retention member), 34 ... upstream shielding member, 36 ... downstream shielding member, 38 ... nozzle, 50 ... saucer (gas retention member)

Claims (9)

  1. 　溶融金属を収容したフロートバスの水平な浴面に溶融ガラスを連続的に供給してガラスリボンを形成する成形部と、該成形部で形成された前記ガラスリボンを徐冷炉に搬送して徐冷する徐冷部とを備えた板ガラスの製造装置において、
    　前記徐冷部のガラスリボン搬送方向の上流位置であってガラスリボンの温度が５００℃～７５０℃のゾーンにおいて、前記ガラスリボンの下面に硫酸塩からなる疵防止用保護層を形成するための保護層形成部が設けられ、
    　前記保護層形成部は、ガラスリボン搬送方向の上流側においてガラスリボンの下面に接触する上流側遮蔽部材と、ガラスリボン搬送方向の下流側においてガラスリボンの下面に接触、又はガラスリボンの下面から５０ｍｍ以内に離間した下流側遮蔽部材とによって仕切られて略密閉状態に保持され、
    　前記保護層形成部に亜硫酸ガスを供給するノズルが配置され、該ノズルから供給される亜硫酸ガスによって前記ガラスリボンの下面に前記疵防止用保護層が形成されるとともに、該保護層形成部には、前記ガラスリボンと接するロールは存在せず、
    　前記上流側遮蔽部材のガラスリボンと接触する部分は、耐熱繊維シートから構成されるとともに、該耐熱繊維シートには非酸化性ガス供給部から非酸化性ガスが供給されることを特徴とする板ガラスの製造装置。     A molding part that continuously supplies molten glass to a horizontal bath surface of a float bath containing molten metal to form a glass ribbon, and the glass ribbon formed in the molding part is conveyed to a slow cooling furnace and gradually cooled. In the manufacturing apparatus of the plate glass provided with the slow cooling part,
    Protection for forming a flaw-preventing protective layer made of sulfate on the lower surface of the glass ribbon in a zone where the temperature of the glass ribbon is 500 ° C. to 750 ° C. A layer forming part is provided;
    The protective layer forming part is in contact with the lower surface of the glass ribbon on the upstream side in the glass ribbon transport direction and in contact with the lower surface of the glass ribbon on the downstream side in the glass ribbon transport direction, or 50 mm from the lower surface of the glass ribbon. Partitioned by a downstream shielding member spaced apart within and held in a substantially sealed state,
    A nozzle for supplying sulfurous acid gas to the protective layer forming portion is disposed, and the protective layer for preventing wrinkles is formed on the lower surface of the glass ribbon by the sulfurous acid gas supplied from the nozzle, and the protective layer forming portion includes , There is no roll in contact with the glass ribbon,
    A portion of the upstream shielding member that contacts the glass ribbon is made of a heat-resistant fiber sheet, and the heat-resistant fiber sheet is supplied with a non-oxidizing gas from a non-oxidizing gas supply unit. Manufacturing equipment.
  2. 　前記下流側遮蔽部材が前記ガラスリボンの下面に接触される場合には、前記下流側遮蔽部材のガラスリボンと接触する部分は耐熱繊維シートから構成されるとともに、該耐熱繊維シートには非酸化性ガス供給部から非酸化性ガスが供給される請求項１に記載の板ガラスの製造装置。 When the downstream shielding member is in contact with the lower surface of the glass ribbon, the portion of the downstream shielding member that is in contact with the glass ribbon is composed of a heat resistant fiber sheet, and the heat resistant fiber sheet is non-oxidizing. The plate glass manufacturing apparatus according to claim 1, wherein the non-oxidizing gas is supplied from the gas supply unit.
  3. 　前記耐熱繊維シートがカーボン繊維からなるフェルト状の繊維シートである請求項１、又は２に記載の板ガラスの製造装置。 The apparatus for producing sheet glass according to claim 1 or 2, wherein the heat-resistant fiber sheet is a felt-like fiber sheet made of carbon fiber.
  4. 　前記保護層形成部には、前記ノズルから供給された亜硫酸ガスをガラスリボンの直下の位置で滞留させるためのガス滞留部材が配置されている請求項１～３のうちいずれかに記載の板ガラスの製造装置。 The plate glass according to any one of claims 1 to 3, wherein a gas retaining member for retaining the sulfurous acid gas supplied from the nozzle at a position immediately below the glass ribbon is disposed in the protective layer forming portion. Manufacturing equipment.
  5. 　前記ガス滞留部材が、前記保護層形成部に配置されたガラスリボン搬送用ロールであり、該ロールは、前記疵防止用保護層の形成時にはガラスリボンに対して相対的に退避した位置に位置されている請求項４に記載の板ガラスの製造装置。 The gas retention member is a roll for transporting a glass ribbon disposed in the protective layer forming portion, and the roll is positioned at a position retracted relative to the glass ribbon when the protective layer for preventing wrinkles is formed. The plate glass manufacturing apparatus according to claim 4.
  6. 　前記ガラスリボンと前記ノズルとの距離が１０ｍｍ～１５０ｍｍに設定されている請求項１～５のうちいずれかに記載の板ガラスの製造装置。 The plate glass manufacturing apparatus according to any one of claims 1 to 5, wherein a distance between the glass ribbon and the nozzle is set to 10 mm to 150 mm.
  7. 　前記ガラスリボンの温度が６５０℃～７５０℃のゾーンにおいて前記保護層形成部が設けられている請求項１～６のうちいずれかに記載の板ガラスの製造装置。 The apparatus for producing plate glass according to any one of claims 1 to 6, wherein the protective layer forming portion is provided in a zone where the temperature of the glass ribbon is 650 ° C to 750 ° C.
  8. 　前記ガラスリボンが、無アルカリガラスである請求項７に記載の板ガラスの製造装置。 The apparatus for producing plate glass according to claim 7, wherein the glass ribbon is alkali-free glass.
  9. 　請求項１～８のうちいずれかに記載の板ガラスの製造装置を用いて板ガラスを製造することを特徴とする板ガラスの製造方法。 A method for producing a plate glass, comprising producing a plate glass using the plate glass production apparatus according to any one of claims 1 to 8.
PCT/JP2009/060292 2008-06-06 2009-06-04 Apparatus and method for producing plate glass WO2009148141A1 (en)

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JPWO2009148141A1 (en) 2011-11-04
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CN102046542B (en) 2013-07-24
KR101503964B1 (en) 2015-03-18
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JP5387920B2 (en) 2014-01-15
TWI391336B (en) 2013-04-01

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