KR101971755B1 - Apparatus for producing molten glass, method for producing molten glass, and method for producing plate glass using said apparatus and method - Google Patents

Apparatus for producing molten glass, method for producing molten glass, and method for producing plate glass using said apparatus and method Download PDF

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KR101971755B1
KR101971755B1 KR1020147015101A KR20147015101A KR101971755B1 KR 101971755 B1 KR101971755 B1 KR 101971755B1 KR 1020147015101 A KR1020147015101 A KR 1020147015101A KR 20147015101 A KR20147015101 A KR 20147015101A KR 101971755 B1 KR101971755 B1 KR 101971755B1
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molten glass
bubbler
glass
upstream
melting
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KR1020147015101A
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KR20140107233A (en
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가즈요시 와타나베
료스케 아카기
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에이지씨 가부시키가이샤
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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/16—Special features of the melting process; Auxiliary means specially adapted for glass-melting furnaces
    • C03B5/18—Stirring devices; Homogenisation
    • C03B5/193—Stirring devices; Homogenisation using gas, e.g. bubblers
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/16—Special features of the melting process; Auxiliary means specially adapted for glass-melting furnaces
    • C03B5/18—Stirring devices; Homogenisation
    • C03B5/183—Stirring devices; Homogenisation using thermal means, e.g. for creating convection currents
    • 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
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
    • C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
    • C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
    • 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
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
    • C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
    • C03C3/091—Glass compositions containing silica with 40% to 90% silica, by weight containing boron containing aluminium

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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)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Glass Compositions (AREA)

Abstract

An apparatus for producing a molten glass suitable for producing homogeneous high-quality alkali-free glass capable of promoting homogenization of the molten glass even when the operation of the molten bath is started or when the operating condition of the molten bath is changed. Wherein said melting tank has a burner for heating an upper space of said melting tank, and when a length of the molten glass channel of said melting tank is L F , said melting tank has a melting tank for melting glass raw materials, And the upstream region side bubbling unit is provided at a position where the distance from the upstream side is 0.4L F to 0.6L F and the upstream region bubble is provided at a position where the distance from the upstream side of the melting vessel is 0.05L F to 0.2L F , Wherein the middle region bubbling unit is constituted by a bubbler group provided with a plurality of bubblers in the vicinity of the bottom face of the melting bath in the width direction of the molten glass channel of the melting bath, The ring unit is constituted by a plurality of bubblers provided in parallel in the width direction of the molten glass flow path of the melting tank in the vicinity of the bottom surface of the melting tank, Region bubbling unit, the molten glass producing apparatus which comprises at least a pair of the bubbler is installed at a position that is symmetric with respect to the center in the width direction of the molten glass flow path.

Figure R1020147015101

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten glass production apparatus, a molten glass production method, and a method of manufacturing a molten glass using the molten glass production apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten glass production apparatus, a molten glass production method, and a manufacturing method of a glass plate using the same. More specifically, the present invention relates to a molten glass production apparatus, a molten glass manufacturing method, and a manufacturing method of a plate glass using the same, for producing high quality non-alkali glass having high homogeneity.

In the production of a glass substrate for a flat panel display (FPD), it is preferable to use alkali-free glass that does not substantially contain alkali metal ions because it improves the insulating property of the glass substrate. Further, the alkali-free glass is preferable for the production of a glass substrate for FPD even in view of a small thermal expansion coefficient.

In the production of a glass substrate for FPD, it is required to further improve the quality, that is, to manufacture a high-quality glass substrate having high homogeneity. In the melting furnace (melting furnace) where the glass raw material is melted to obtain the molten glass for this purpose, various studies have been conducted in order to increase the homogeneity of the molten glass.

In the melting furnace described in Patent Document 1, the melting furnace is divided into the upstream band and the downstream band by the transverse baffle, and the circulating flows of the molten glass (upstream circulation flow and downstream circulation flow) are formed in the respective bands, And melting and homogenization of the molten glass are performed. More specifically, the glass raw material is dissolved by forming the upstream-side circulation flow in the upstream band and the downstream-side circulation flow is formed in the downstream band to homogenize the molten glass. In the melting furnace described in Patent Document 1, in order to control the upstream-side circulation flow and the downstream-side circulation flow, a bubbler is provided on the upstream side of the transverse bottoms.

The melting furnace (melting tank) described in Patent Document 2 does not have a structure corresponding to the transverse bury in the melting furnace described in Patent Document 1. However, it is also possible to use at least one row of bubbler and at least two mutually opposing burners to melt the glass , And clarification.

However, the melting furnace described in Patent Documents 1 and 2 is not always suitable for producing high-quality alkali-free glass.

As the index of the melting temperature of the glass, a temperature at which T η , that is, a glass viscosity η of 10 2 [dPa · s] is used. The alkali free glass has a T η of 1,500 to 1,760 ° C., Containing glass of the present invention has a T eta of 100 DEG C or more, which makes homogenization difficult. As a result, it is difficult to sufficiently homogenize a glass furnace (such as a glass substrate for FPD) having a strict requirement for homogeneity in a melting furnace having a layout such as soda lime glass disclosed in Patent Documents 1 and 2 for general mass production. .

Further, as described above, since the non-alkali glass has a higher T η than alkali-containing glass such as soda lime glass, the temperature of the molten glass in the melting furnace is inevitably increased. When the temperature of the molten glass is high, the erosion action on the in-house structure by the molten glass is strengthened accordingly. Therefore, in the case of non-alkali glass, if there is a step that affects the molten glass at the bottom of the melting furnace, such as a cross section in the melting furnace described in Patent Document 1 or a refining band in the melting furnace described in Patent Document 2, Erosion of the step difference due to the molten glass and generation of impurities due to the erosion are problems.

Further, in the case of alkali-free glass, since the temperature of the molten glass in the melting furnace is inevitably increased, if the downstream zone is long as in Patent Document 1 or a large melting furnace as in Patent Document 2, The energy efficiency is disadvantageous. Incidentally, erosion due to the molten glass and generation of impurities therefrom, and a change in the flow velocity of the molten glass are also problematic.

In order to solve the above problems, the applicant of the present application proposes a molten glass producing apparatus described in Patent Document 3. (The first and second bubblers 13 and 14) provided near the bottom of the melting tank 10 for dissolving the glass raw material and the upper portion of the melting vessel 10 By setting the burner 15 that heats the space in a specific arrangement, a step structure that affects the molten glass flow described in Patent Documents 1 and 2 is not provided at the bottom of the molten glass flow path, The flow rate of the upstream-side circulation stream 100 and the flow rate of the downstream-side circulation flow 101 are set so as to be in a predetermined relationship with each other in order to promote the formation of the molten glass circulation flows (the upstream side circulation stream 100 and the downstream side circulation stream 101) Alkali-free glass having high homogeneity and high quality can be produced (all the symbols in the text are the same as those described in Patent Document 3).

Japanese Patent Laid-Open No. 9-124323 Japanese Patent Laid-Open No. 7-144923 International Publication No. 2011/036939

As described above, by using the glass manufacturing apparatus described in Patent Document 3, it is possible to produce high-quality, non-alkali glass having high homogeneity.

However, even when the glass manufacturing apparatus described in Patent Document 3 is used, a long time is required for homogenization of the molten glass when the operation of the melting tank is started or the operation conditions of the melting tank are changed, for the reason described later.

To start the operation of the melting tank, the wave glass is introduced into the melting tank while heating the upper space of the melting tank with a burner in order to improve the efficiency of the melting operation, and the wave glass is melted to secure the depth of the molten glass in the melting tank. For example, the depth of the molten glass is secured by melting the molten glass until the molten glass reaches about 50% or more of the target depth of the molten glass in the molten bath.

The time required until about 50% or more of the target depth of the molten glass in the melting tank differs depending on the dimensions of the melting vessel. In the case of a melting vessel having a glass production amount of 20 to 100 tons / day, a long time is required until it reaches about 50% or more of the target depth of the molten glass in the melting vessel because the size thereof is considerably large.

In the case of an alkali-free glass composition, a component easily volatile (such as B 2 O 3 or Cl) (hereinafter referred to as a "volatile component" , The composition of the molten glass becomes different from the target composition due to the vaporization from the molten glass.

Therefore, at the start of feeding of the glass raw material, the raw material of the volatile acid component is supplied more than the target composition, thereby shortening the time until the molten glass becomes the target composition.

As described above, in the molten glass producing apparatus described in Patent Document 3, the gases 16 and 17 from the bubbler (first and second bubblers 13 and 14) provided near the bottom of the melting tank 10, (The upstream side circulation stream 100 and the downstream side circulation stream 101) in the melting tank 10 is promoted by the supply of the upstream circulation stream 100 and the downstream side circulation stream 100, The homogenization of the molten glass is promoted by controlling the flow velocity of the circulating flow 101 to be in a predetermined relationship (all the reference numerals in the text are the same as those described in Patent Document 3).

However, since the volatile component having a small molecular weight has a smaller specific gravity than other glass raw materials, the light raw material tends to migrate to the downstream side of the melting tank by floating the upstream circulating flow phase without dissolving in the upstream side circulating flow. Therefore, it takes a long time to homogenize the molten glass in the melting tank.

Further, when the operating condition of the melting tank is changed, the molten glass may be retained on the upstream side of the melting tank rather than the upstream-side circulating flow. Such retention of the molten glass causes the homogenization of the molten glass to be delayed. Such retention of the molten glass tends to occur when a glass raw material having a specific gravity smaller than that of the molten glass in the melting tank is added for the purpose of adjusting the specific gravity of the glass to be produced, for example, when the amount of the glass raw material is increased. Further, there is a tendency to occur when the depth of the molten glass in the melting tank is lowered for some reason, or when the temperature of the molten glass present on the upstream side of the melting tank is lowered.

The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a high-quality, non-alkali glass having high homogeneity and capable of promoting homogenization of molten glass even when the operation of the melting tank is started or the operation condition of the melting tank is changed A method for manufacturing a molten glass, and a method for manufacturing a glass plate using the same.

In order to achieve the above object, the present invention provides a molten glass producing apparatus having a melting tank for melting a glass raw material,

Wherein the melting tank has a burner for heating an upper space of the melting tank,

When the length of molten glass flow path of the melting vessel to L F, the distance from the upstream side of the melting vessel F 0.4L to 0.6L, and F is a middle zone in the bubbling unit where installed, the dissolving tank of the upstream The upstream region bubbling unit is disposed at a position where the distance from the upstream side bubbling unit is 0.05L F to 0.2L F ,

The middle stream region bubbling unit is constituted by a bubbler group provided with a plurality of bubblers in the vicinity of the bottom surface of the melting tank in the width direction of the molten glass channel of the melting tank,

The upstream region bubbling unit is constituted by a plurality of bubblers provided in parallel in the width direction of the molten glass channel of the melting vessel near the bottom of the melting vessel,

The upstream region bubbling unit includes at least a pair of bubblers provided at positions symmetrical with respect to the center in the width direction of the molten glass flow path.

The present invention also provides a molten glass production method for producing a molten glass by supplying a gas from each of the bubbling units constituting the bubbling unit and the upstream region bubbling unit using the apparatus for producing molten glass of the present invention .

The present invention also provides a method of manufacturing a glass plate for molding a molten glass obtained by the method for manufacturing a molten glass of the present invention into a glass plate.

According to the apparatus for producing a molten glass of the present invention and the method for producing a molten glass, since the homogenization of the molten glass can be promoted at the time of starting the operation of the molten bath or changing the operating condition of the molten bath, It is possible to shorten the time required for the production of the alkali-free glass.

The process for producing a plate glass of the present invention is suitable for the production of a substrate for FPD because it can produce a plate glass having high homogeneity and high transparency.

1 is a cross-sectional view of one embodiment of a melting tank in an apparatus for producing a molten glass of the present invention.
2 is a plan view of the dissolution tank 10 shown in Fig. However, the upper wall surface of the dissolution tank 10 is omitted.

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

Fig. 1 is a cross-sectional view of an embodiment of a melting vessel in the apparatus for producing a molten glass of the present invention, and Fig. 2 is a plan view of the melting vessel shown in Fig. However, in order to facilitate understanding, the upper wall surface of the dissolution tank 10 is omitted.

At the end on the upstream side of the melting tank 10, a glass raw material inlet port 11 is provided. The glass raw material introduced through the inlet 11 is melted by the heating by the burner 16 to become a molten glass G and is retained in the melting tank 10. [ At the downstream end of the melting tank 10, a discharge port 12 for discharging the molten glass G to the next process is provided. The outflow port (12) communicates with the conduit (20) on the downstream side.

An upstream region bubbling unit and a midstream region bubbling unit constituted by a plurality of bubblers 13, 14 and 15, respectively, are provided in the vicinity of the bottom surface of the dissolution tank 10 shown in Figs. The bubbler 13 constituting the upstream region bubbling unit is provided in the upstream region of the molten glass flow path of the melting vessel 10 and the bubblers 14, 15 are provided in the middle region of the molten glass flow path of the melting tank 10.

On both sides of the melting tank 10 shown in Figs. 1 and 2, a burner 16 is disposed above the molten glass G held in the melting tank 10. The burners 16 are provided at regular intervals throughout the lengthwise direction of the melting vessel 10, except for exceptional portions which will be described later.

The upstream region bubbling unit is constituted by a plurality of bubblers 13 provided in parallel in the width direction of the molten glass flow path of the melting tank 10 in the vicinity of the bottom surface of the melting tank 10.

2, the upstream region bubbling unit is constituted by a pair of bubblers 13 provided at positions symmetrical with respect to the center in the width direction of the molten glass channel of the melting vessel 10 .

As described later in detail, in the melting vessel 10 of the molten glass producing apparatus of the present invention, by supplying the gases 18 and 19 from the bubblers 14 and 15 constituting the bubbling unit in the midstream region, The circulation flow of the molten glass G in the melting tank 10 (the upstream circulation stream 100, the upstream circulation stream 100, and the upstream circulation stream 100) can be performed without providing a step structure that affects the molten glass as described in Patent Documents 1 and 2, The flow rate of the upstream-side circulation stream 100 and the flow rate of the downstream-side circulation flow 101 can be controlled to have a predetermined relationship. Hereinafter, in the present specification, the supply of the gases 18, 19 from the bubblers 14, 15 constituting the midstream bubbling unit is sometimes referred to as "bubbling from the midstream region bubbling unit" .

However, the bubbling alone from the bubbling unit in the midstream region requires a long time to homogenize the molten glass G in the melting tank 10 at the start of operation of the melting tank 10 or when changing the operating conditions of the melting tank.

In order to shorten the time until the molten glass G in the melting tank 10 becomes the target composition at the start of the operation of the melting tank 10, the raw material of the volatile acid component is supplied in an amount larger than the target composition Since the vaporized component having a small molecular weight has a smaller specific gravity than other glass raw materials, the light raw material floats on the upstream circulation stream 100 without dissolving in the upstream circulation stream 100, The molten glass G in the melting tank 10 needs to be homogenized for a long period of time.

Further, when the operating condition of the melting tank 10 is changed, the molten glass G may be retained on the upstream side of the melting tank 10 rather than the upstream-side circulating stream 100. Hereinafter, in the present specification, the stay of the molten glass G on the upstream side of the melting tank 10 rather than the upstream-side circulating stream 100 is referred to as " stay of the molten glass G on the upstream side of the molten bath 10 ".

The stay of the molten glass G on the upstream side of the molten bath 10 causes the homogenization of the molten glass G in the molten bath 10 to be delayed so that the molten glass G in the molten bath 10 after the change of the operating condition of the molten bath 10 It takes a long time to homogenize the material.

In the melting tank 10, the gas 17 is supplied from the bubbler 13 constituting the upstream-side bubbling unit to the melting tank 10 when the operation of the melting tank 10 is started or the operation conditions of the melting tank are changed. The homogenization of the molten glass G in the molten glass G can be promoted. Hereinafter, in this specification, the supply of the gas 17 from the bubbler 13 constituting the upstream region bubbling unit may be referred to as " bubbling from the upstream region bubbling unit ".

At the commencement of the operation of the dissolution tank 10, the bubbling from the upstream-side bubbling unit promotes dissolution of the raw material of the volatile component into the upstream-side circulation stream 100. Thus, the homogenization of the molten glass G in the melting tank 10 is promoted.

Further, even when the operating condition of the dissolution tank 10 is changed, it is possible to suppress the retention of the molten glass G on the upstream side of the dissolution tank 10 by performing bubbling from the upstream region bubbling unit, , The stay of the molten glass G can be eliminated.

The bubbler 13 constituting the upstream region bubbling unit needs to satisfy the following conditions in relation to the length of the molten glass flow path of the melting vessel 10 in order to achieve the above effect.

In the melting vessel 10 in the apparatus for producing a molten glass of the present invention, when the length of the molten glass channel of the melting vessel 10 is L F , the length of each molten glass channel from the upstream end of the molten glass channel to each bubble And the distance to the rotor 13 is 0.05L F to 0.2L F.

If the distance from the upstream end of the molten glass channel to each bubbler 13 is less than 0.05 L F , the distance between the upstream side wall surface of the dissolution tank 10 and each bubbler 13 is too close, Erosion of the upstream side wall surface of the dissolution tank 10 may be accelerated by the bubbling from the ring unit.

On the other hand, if the distance from the upstream end of the molten glass channel to the bubbler 13 is larger than 0.2 L F, even if bubbling is performed from the upstream region bubbling unit at the start of operation of the dissolution tank 10, The dissolution of the raw material of the volatile component into the circulating stream 100 can not be promoted and homogenization of the molten glass G in the dissolution tank 10 can not be promoted. Further, even when bubbling is performed from the upstream-side region bubbling unit when the operating condition of the dissolution tank 10 is changed, the retention of the molten glass G on the upstream side of the dissolution tank 10 can not be suppressed.

In the melting vessel 10 in the molten glass producing apparatus of the present invention, the distances to the respective bubblers 13 constituting the upstream bubbling unit area from the upstream end of the molten glass flow path F 0.1L to 0.2L F And more preferably 0.1 L F to 0.15 L F.

As described above, the melting tank 10 shown in Fig. 2 is provided with a pair of bubblers 13 at positions symmetrical with respect to the center in the width direction of the molten glass channel of the melting tank 10 . Hereinafter, in the present specification, the bubbler 13 is provided at a position symmetrical with respect to the center in the width direction of the molten glass channel of the melting tank 10, The bubbler 13 is provided so as to be symmetrical ". In the melting vessel 10 of the apparatus for producing a molten glass of the present invention, the bubbler 13 must be provided so as to be symmetrical in the width direction of the melting vessel 10. As an example in which the bubbler 13 is not provided so as to be symmetrical in the width direction of the melting tank 10, there is a case where one of the pair of bubblers 13 shown in Fig. 2 is not provided. In this case, when the bubbling is performed from the upstream-side bubbling unit, the flow of the molten glass G in the melting tank 10 is not symmetrical with respect to the width direction of the molten bath 10, The side wall of the dissolution tank 10 may be eroded. Further, confusion may occur in the upstream-side circulation stream 100, which may adversely affect the homogenization of the molten glass G.

An example in which the bubbler 13 is not provided so as to be symmetrical in the width direction of the bubbler melting vessel 10 is that one bubbler (not shown) is provided near the center in the width direction of the molten glass channel of the melting vessel 10 13) is installed. Also in this case, when the bubbling is performed from the upstream-side bubbling unit, the flow of the molten glass G toward the side wall of the dissolution tank 10 is promoted, so that the side wall of the dissolution vessel 10 may be eroded.

At least two bubblers 13 need to be provided since the bubbler 13 must be provided so as to be symmetrical in the width direction of the melting tank 10. When increasing the number of the bubblers 13 more than two, it is necessary to make the number of the bubblers 13 an even number. For example, when four bubblers 13 are provided, it is necessary to provide two bubblers 13 so as to be symmetrical in the width direction of the dissolving tank 10.

It is preferable that the bubbler 13 constituting the upstream region bubbling unit satisfies the following conditions also in relation to the width of the molten glass flow path of the melting vessel 10. [

In the melting vessel 10 in the apparatus for producing a molten glass of the present invention, when the width of the molten glass channel of the melting vessel 10 is W, each bubbler 13 constituting the upstream region bubbling unit, And the distance from the center in the width direction of the flow passage is 0.25 W or more.

When the distance from the center in the width direction of the molten glass channel is smaller than 0.25 W, the bubbler 13 is provided in the vicinity of the center in the width direction of the molten glass channel, The flow of the molten glass G toward the sidewall of the dissolution tank 10 is promoted when the bubbling is performed, so that the side wall of the dissolution tank 10 may be eroded.

In the melting vessel 10 in the apparatus for producing a molten glass of the present invention, the bubblers 13 constituting the upstream region bubbling unit are arranged so that the distance from the center in the width direction of the molten glass channel is 0.27 W or more More preferably 0.4 W or more, and more preferably 0.4 W or more.

However, it is preferable that the bubblers 13 constituting the upstream region bubbling unit are installed at a position where the distance from the sidewall of the melting vessel 10 is 400 mm or more. Since the distance between the sidewall of the dissolution tank 10 and the bubbler 13 is too close when the bubbler 13 is provided at a position smaller than 400 mm from the sidewall of the dissolution tank 10, There is a possibility that the side wall erosion of the melting tank 10 is promoted by the bubbling from the unit.

In the melting vessel 10 in the apparatus for producing a molten glass of the present invention, each bubbler 13 constituting the upstream region bubbling unit is located at a position where the distance from the side wall of the melting vessel 10 is 1000 mm or more And it is more preferable that it is installed.

The length L F of the molten glass flow path of the melting tank 10 of the present invention is different depending on the width W of the molten glass flow path, preferably 10 to 30 m, more preferably 10 to 25 m, Preferably 15 to 22 m.

On the other hand, the width W of the molten glass channel is preferably 5 to 10 m, more preferably 5.5 to 9 m, and still more preferably 6.5 to 8 m.

In the melting tank 10 shown in Figs. 1 and 2, the bubblers 13 constituting the upstream-side region bubbling unit are arranged so that the bubblers 13 in the upstream region bubbling unit And is disposed on the upstream side. As described above, in the melting vessel 10 of the molten glass production apparatus of the present invention, the bubblers 13 constituting the upstream-side region bubbling unit are installed on the upstream side of the burner 16 located at the most upstream side In order to exert the effect of promoting the homogenization of the molten glass by the bubbling from the upstream region bubbling unit.

Further, depending on the melting tank, the flue for discharging the combustion exhaust gas by the burner 16 may be provided on the more upstream side than the burner 16 located on the most upstream side. In this case, it is preferable that the bubblers 13 constituting the upstream-side region bubbling unit are provided on the upstream side of the flue.

However, in order to exert the effect of promoting the homogenization of the molten glass by the bubbling from the upstream-side bubbling unit, in the longitudinal direction of the molten glass channel, the bubbler 13 ) And the burner 16 located at the most upstream side is not too large. In the melting vessel 10 in the apparatus for producing a molten glass of the present invention, the bubbler 13 constituting the upstream region bubbling unit and the burner 16 located at the most upstream side are arranged in the longitudinal direction Is preferably within 2000 mm, more preferably within 1500 mm, and even more preferably within 1000 mm.

The middle stream region bubbling unit is composed of a bubbler group provided with a plurality of bubblers (14, 15) in the vicinity of the bottom surface of the melting tank (10) across the width direction of the molten glass channel of the melting tank (10).

In the melting vessel 10 in the apparatus for producing a molten glass of the present invention, by performing bubbling from the bubbling unit in the middle-range region, molten glass such as those described in Patent Documents 1 and 2 (The upstream side circulation stream 100 and the downstream side circulation stream 101) of the molten glass G in the melting tank 10 without providing a step structure that affects the upstream side circulation flow The flow rate of the downstream-side circulation flow 101 and the flow rate of the downstream-side circulation flow 101 can be controlled to be a predetermined relationship.

In the melting vessel 10 in the melting glass manufacturing apparatus of the present invention, it is not necessary to provide a step structure at the bottom of the molten glass channel at which erosion by the molten glass is a problem, so that T 侶 is 1500 to 1760 캜, Is suitable for the production of alkali-free glass having a temperature of 100 deg. C or higher as compared with an alkali-containing glass such as lime glass.

In the melting vessel 10 shown in Figs. 1 and 2, the middle-range bubbling unit is composed of two bubbler groups of different positions in the longitudinal direction of the molten glass channel of the melting vessel 10, that is, A first bubbler group provided with a plurality of bubblers 14 in the width direction of the flow path and a second bubbler group provided with a plurality of bubblers 15 in the width direction of the molten glass flow path.

However, in the melting tank 10 in the apparatus for producing a molten glass of the present invention, the midstream region bubbling unit may have a single bubbler group. Concretely, for example, only one of the first bubbler group and the second bubbler group described above may be used.

It should be noted that the middle-range bubbling unit is composed of a plurality of groups of bubblers different in position in the longitudinal direction of the molten glass channel of the melting tank 10 from the bubbling unit It is preferable for exerting the effect by the practice.

When the middle-range bubbling unit is composed of a plurality of bubbler groups, the molten glass channel of the melting tank 10 may be composed of three or more bubbler groups having different positions in the longitudinal direction. However, It is more preferable from the viewpoint of cost versus effect that two bubbler groups having different positions in the longitudinal direction of the molten glass channel of the melting tank 10 as in the melting tank 10 shown in Fig.

The bubblers 14 and 15 constituting the midstream bubbling unit need to satisfy the following conditions in relation to the length of the molten glass flow path of the melting tank 10 have.

In the melting vessel 10 in the apparatus for producing a molten glass of the present invention, when the length of the molten glass channel of the melting vessel 10 is L F , from the upstream end of the molten glass channel to each bubbler And the bubblers 14 and 15 constituting the first bubbler group (the first bubbler group and the second bubbler group) are 0.4L F to 0.6L F, respectively.

Therefore, the length of the melting tank 10 is shorter than that of the conventional melting tank (melting furnace) as described in Patent Documents 1 and 2, and the length of the portion forming the downstream-side circulating flow in the melting tank is also short.

Here, as in the case of the melting vessel 10 shown in Figs. 1 and 2, two bubbler groups (first bubbler group, second bubbler group) having different positions in the longitudinal direction of the molten glass channel of the melting vessel 10, Group), the distances from the upstream end of the molten glass channel to the bubblers 14, 15 constituting each bubbler group preferably satisfy the following conditions.

That the distance to each of the molten glass bubbler 14, which constitute the first bubbler group from the upstream end of the flow path F of 0.4L to 0.5L F are preferred, more preferably from 0.43L to 0.46L F F. On the other hand, the distance from the upstream end of the molten glass channel to each of the bubblers 15 constituting the second bubbler group is preferably 0.45L F to 0.55L F , more preferably 0.46L F to 0.53L F Do.

Two bubbler groups (first bubbler group and second bubbler group) having different positions in the longitudinal direction of the molten glass channel of the melting tank 10 as in the melting vessel 10 shown in Figs. 1 and 2, , When L P is a distance between each bubbler (14) constituting the first bubbler group and each bubbler (15) constituting the second bubbler group, L P is 500 to 1000 mm is preferable for exerting the effect of the bubbling from the above-mentioned midstream bubbling unit, and it is more preferable that L P is 600 to 800 mm.

The pitch p between each bubbler constituting each bubbler group of the bubbling unit in the middle stream region, that is, the distance between each bubbler in the width direction of the molten glass channel of the melting vessel 10 is 400 to 700 mm Is preferable in view of the effect of the bubbling from the above-described midstream bubbling unit while taking the cost-effectiveness into consideration.

Two bubbler groups (first bubbler group and second bubbler group) having different positions in the longitudinal direction of the molten glass channel of the melting tank 10 as in the melting vessel 10 shown in Figs. 1 and 2, The bubbler 14 constituting the first bubbler group and the bubbler 15 constituting the second bubbler group are arranged in the direction of the flow direction of the molten glass in the melting tank 10 as the axis, Are not disposed on the coaxial plane.

In the melting vessel 10 shown in Fig. 2, the protruding port of the bubbler 14 constituting the first bubbler group and the protruding port of the bubbler 15 constituting the second bubbler group are arranged in a staggered configuration And the protrusion of the bubbler 14 constituting the first bubbler group and the protrusion of the bubbler 15 constituting the second bubbler group do not coaxially exist.

In this arrangement, even when any one of the projections of the bubbler 14 constituting the first bubbler group does not function, the bubbler 14 constituting the second bubbler group arranged in a zigzag shape on the downstream side, The effect of promoting the formation of the circulating flows of the molten glass G (the upstream circulation stream 100 and the downstream circulation stream 101) in the melting tank 10 is not impaired by the presence of the protrusion of the downstream side circulation flow path 15, Further, the flow rate of the upstream-side circulation flow 100 and the flow rate of the downstream-side circulation flow 101 can be controlled to have a predetermined relationship.

The constituent materials of the bubbler 13 constituting the upstream region bubbling unit and the constituents of the bubblers 14 and 15 constituting the downstream region bubbling unit in the melting tank 10 of the molten glass producing apparatus of the present invention are , Platinum or a platinum alloy is preferable in that it is required to have excellent flame resistance and excellent corrosion resistance to molten glass.

The gases 17 supplied from the bubbler 13 constituting the upstream region bubbling unit and the gases 18 and 19 supplied from the bubblers 14 and 15 constituting the downstream region bubbling unit are supplied with molten It is preferable to use those which do not adversely affect the components of the dissolution tank 10 such as glass G and bubbler 13, 14, Specific examples of such gases include air, nitrogen, oxygen, helium, argon and the like. When platinum or a platinum alloy is used as the constituent material of the bubblers 13, 14 and 15, the gases 17, 18 and 19 supplied from the bubblers 13, 14 and 15 contain nitrogen, helium and argon It is preferable to use a gas that does not contain oxygen. Of these, nitrogen is particularly preferable.

On both sides of the melting vessel 10 shown in Figs. 1 and 2, burners 16 are provided at regular intervals over the entire lengthwise direction of the melting vessel 10. However, the burner 16 is not provided above the bubbler 15 constituting the second bubbler group.

The reason why the burner 16 is not provided above the bubbler 15 constituting the second bubbler group is that in the method of manufacturing a molten glass of the present invention to be described later (control 2) It is necessary to make the upper atmosphere temperature T 2 of the bubbler 15 constituting the second bubbler group lower than the upper atmosphere temperature T 1 of the bubbler 14 constituting the first bubbler group It is because.

(Control 2), it is preferable to dispose the bubbler 15 constituting the second bubbler group and the burner 16 near the downstream side of the bubbler 15 to some extent Do. Specifically, the distance L B2 between the bubbler 15 constituting the second bubbler group and the burner 16 immediately adjacent to the bubbler 15 on the downstream side is preferably 800 mm or more.

However, if the bubbler 15 constituting the second bubbler group and the burner 16 located immediately in the vicinity of the downstream side of the bubbler 15 are too far apart, the bubbler constituting the second bubbler group The temperature of the upper atmosphere of the molten glass 15 becomes too low, which may cause a problem such that the homogenization of the molten glass becomes insufficient. Further, there is a concern that the temperature of the molten glass G discharged from the discharge port 12 provided at the downstream end of the melting tank 10 is lowered, which makes it difficult to degas when the vacuum degassing is performed in the subsequent process have. Therefore, L B2 is preferably 2500 mm or less. Further, L B2 is preferably 1000 to 2000 mm, and L B2 is more preferably 1000 to 1600 mm.

In addition, the (control 2) when performing the second upper ambient temperature of the bubble bubbler to the upper atmosphere, the temperature T 2 in the bubbler (15) constituting the multiple groups of the first bubbler group (14) T 1 The distance L B1 between the bubbler 14 constituting the first bubbler group and the burner 16 immediately adjacent to the bubbler 14 in the vicinity of the upstream side and the distance L B1 between the bubbler 14 constituting the first bubbler group and the distance L B1 B2 is preferably in a relationship of L B2 > L B1 . Therefore, as shown in Fig. 2, it is preferable that the burner 16 is provided above the bubbler 14 constituting the first bubbler group. With this arrangement, the upper atmosphere temperature T 2 of the bubbler 15 constituting the second bubbler group can be made lower than the upper atmosphere temperature T 1 of the bubbler 14 constituting the first bubbler group .

In the present invention, L B2 -L B1 ≥300 mm is preferable, L B2 -L B1 ≥500 mm is more preferable, and L B2 -L B1 ≥800 mm is more preferable.

On the other hand, in the melting tank 10 shown in Fig. 2, the burner 16 near the upper side of the bubbler 14 constituting the first bubbler group is provided, but the burner 16 satisfying the relationship of L B2 > L B1 The bubbler 14 constituting the first bubbler group and the burner 16 immediately adjacent to the upstream side of the bubbler 14 may be arranged at some distance from each other. However, if the bubbler 14 constituting the first bubbler group and the burner 16 immediately adjacent to the upstream side of the bubbler 14 are too far apart, the temperature of the upper atmosphere of the bubbler 14 becomes too low, There is a possibility that the side circulation flow 100 is weakened and the melting of the glass raw material becomes insufficient and the homogenization of the molten glass G in the region downstream of the melting tank 10 becomes insufficient. From this viewpoint, it is preferable that L B1 is 2000 mm or less. It is more preferable that L B1 is 500 to 1500 mm.

The pitch between the adjoining burners 16 is preferably 600 to 2600 mm, more preferably 800 to 2400 mm, though it depends on the type of the burner 16 and the layout of the melting tank 10. [

The combustion by the burner 16 may be performed by mixing the fuel with the oxygen gas and burning the fuel, or by mixing the fuel with the oxygen gas and the air. By using these methods, the molten glass can contain moisture. In the subsequent process of the molten glass sent from the melting tank 10 to the conduit 20 on the downstream side, when the bubbles in the molten glass are degassed by vacuum degassing, it is preferable that the molten glass contains moisture. Is preferable.

In order to prevent the deposits on the inner wall brick surface of the melting vessel 10 (for example, the glass material eluted from the bricks, the raw material, the molten glass product of the molten glass, etc.) from falling onto the burner portion, It is preferable that an upper surface of the burner 16 on the inner wall is provided with an awning (not shown).

The refractory bricks containing ZrO 2 are used because the constituent material of the portion of the melting vessel 10 in contact with the molten glass G is required to have excellent heat resistance and corrosion resistance to molten glass, ), ZrO 2 is contained in an amount of from 85% to 97% by weight in the portion of 0.1L F to 0.3L F on the upstream side from the bubbler 14 constituting the first bubbler group, to use a hot melt to the refractory material of the glass 2 as the main component is preferred. The temperature of the molten glass flowing through the melting tank 10 is higher on the upstream side than on the downstream side and when the control method (control 1), which is a suitable control mode in the molten glass production method of the present invention The flow rate of the gas 18 from the bubbler 14 constituting the first bubbler group becomes larger than the flow rate of the gas 19 from the bubbler 15 constituting the second bubbler group, This is because the bottom constituent material of the melting tank 10 constituting the molten glass channel is likely to be eroded.

From the viewpoint of preventing erosion of the bottom constituent material of the melting vessel 10 constituting the molten glass channel, it is preferable to use the above-mentioned hot-melt refractory material in the peripheral portion of the bubbler 13 constituting the upstream region bubbling unit .

When the length L F of the molten glass channel of the melting tank 10 is a dimension of 10 to 30 m (preferably 10 to 25 m, more preferably 15 to 22 m) as described above, The above-mentioned hot-melt refractory material is used in a portion in the range of 100 to 600 mm, preferably 150 to 400 mm, in the longitudinal direction of the molten glass channel around the bubbler 13 constituting the bubbling unit .

When the width W of the molten glass channel of the melting tank 10 is in the range of 5 to 10 m (preferably 5.5 to 9 m, more preferably 6.5 to 8 m) as described above, The bubbler 13 constituting the ring unit is disposed in the width direction of the molten glass flow passage in the range of 100 to 600 mm, preferably in the range of 150 to 400 mm, more preferably in the range of 150 to 300 mm It is preferable to use the above-mentioned hot-melt refractory material.

In these cases, the thickness of each of the hot-melt refractories is preferably 50 to 400 mm, and it is preferable that two or three hot-melt refractories are laminated. In addition, two to five layers of refractory bricks containing ZrO 2 can be stacked on the outside of the thus formed heat-fusible refractory layer. In addition, it is preferable that all of the portion of the melting vessel (10) which is in contact with the molten glass (G) is composed of the thermally molten refractory of the above composition. Further, each refractory brick can be laminated via a tamping material such as alumina, zircon or the like.

In order to prevent the molten glass from entering the joint of refractory bricks at the bottom of the melting tank 10 to prevent the refractory bricks from being eroded, it is preferable that the refractory bricks are stacked under the joint so as to cover the joints.

It is preferable that cooling means for cooling the refractory bricks by air cooling or water cooling is provided outside the refractory bricks at the bottom of the melting tank 10 because the life of the refractory bricks is improved.

If a ring or horseshoe-shaped water pipe for cooling the pipe is provided around the pipes of the bubblers 13, 14 and 15 in the refractory bricks at the bottom of the melting tank 10 or outside the refractory bricks desirable.

Next, the method for producing a molten glass of the present invention will be described.

In the method for producing a molten glass of the present invention, the molten glass production apparatus described above is used to perform bubbling from the middle-range region bubbling unit in the melting tank 10 of the molten glass production apparatus, A molten glass is produced while performing bubbling from the unit.

As described above, by performing bubbling from the bubbling unit in the midstream region, a step structure that affects the molten glass as described in Patent Documents 1 and 2 is not provided at the bottom of the molten glass flow path, (The upstream side circulation flow 100 and the downstream side circulation flow 101) of the molten glass G in the melting vessel 10 and the flow rate of the upstream circulation flow 100 and the flow rate of the downstream circulation flow 101, Can be controlled to have a predetermined relationship so that it is suitable for the production of highly homogeneous alkali-free glass at T ? Of 1500 to 1760 占 폚.

The homogenization of the molten glass G in the molten bath 10 can be promoted when the operation of the molten bath 10 is started or when the operation conditions of the molten bath are changed by performing bubbling from the brewing unit in the midstream region, The time required for the production of the alkali-free glass can be shortened.

Specific examples of the alkali-free glass having a T 侶 of 1,500 to 1,760 캜 include the alkali-free glass compositions 1 to 4 in which the mass percentage based on oxide is expressed by the following composition.

Alkali-free glass composition 1

SiO 2 : 50 to 73%, preferably 50 to 66%

Al 2 O 3 : 10.5 to 24%

B 2 O 3 : 0 to 12%

MgO: 0 to 10%, preferably 0 to 8%

CaO: 0 to 14.5%

SrO: 0 to 24%

BaO: 0 to 13.5%

MgO + CaO + SrO + BaO: 8 to 29.5%, preferably 9 to 29.5%

ZrO 2 : 0 to 5%

When the strain point is high and solubility is taken into consideration, it is preferable that the alkali-free glass composition 2

SiO 2 : 58 to 66%

Al 2 O 3 : 15 to 22%

B 2 O 3 : 5 to 12%

MgO: 0 to 8%

CaO: 0 to 9%

SrO: 3 to 12.5%

BaO: 0 to 2%

MgO + CaO + SrO + BaO: 9 to 18%

Particularly when solubility is taken into consideration, it is preferable that the alkali-free glass composition 3

SiO 2 : 50 to 61.5%

Al 2 O 3 : 10.5 to 18%

B 2 O 3 : 7 to 10%

MgO: 2 to 5%

CaO: 0 to 14.5%

SrO: 0 to 24%

BaO: 0 to 13.5%

MgO + CaO + SrO + BaO: 16 to 29.5%

Particularly in the case of considering a high strain point, the alkali-free glass composition 4

SiO 2 : 54 to 73%

Al 2 O 3 : 10.5 to 22.5%

B 2 O 3 : 0 to 5.5%

MgO: 0 to 10%

CaO: 0 to 9%

SrO: 0 to 16%

BaO: 0 to 2.5%

MgO + CaO + SrO + BaO: 8 to 26%

In the method for producing a molten glass of the present invention, it is preferable that the average flow rate of the gases (18, 19) supplied from the bubblers (14, 15) constituting the midstream bubbling unit is 0.5 to 5.0 liters / (The upstream side circulation flow 100 and the downstream side circulation flow 101) of the molten glass G in the upstream side circulation flow 10 and the flow rate of the upstream circulation flow 100 and the flow rate of the downstream side circulation flow 101 It is preferable to control the flow velocity so as to have a predetermined relationship.

Here, when the middle-range bubbling unit is constituted by the first and second bubbler groups like the melting tank 10 shown in Figs. 1 and 2, the (control 1) and the (control 2) (The upstream side circulation stream 100 and the downstream side circulation stream 101) of the molten glass G in the melting tank 10 is promoted and the flow rate of the upstream side circulation stream 100 and the downstream side It is preferable to control the flow velocity of the circulation flow 101 to be in a predetermined relationship. Thus, homogenization of the molten glass can be promoted when a molten glass having a T ? Of 1,500 to 1,760 deg. C is produced, and a high-quality molten glass having high homogeneity can be obtained.

(Control 1)

The average flow rate V 2 of the gas 19 from the bubbler 15 constituting the second bubbler group is higher than the average flow rate V 1 of the gas 18 from the bubbler 14 constituting the first bubbler group Small.

(Control 2)

The upper atmosphere temperature T 2 of the second bubbler 15 is made lower than the upper atmosphere temperature T 1 of the first bubbler 14.

When doing a (control 1), wherein V 1 is 0.5 to 20 l / min is preferable, and 0.7 to 5 l / min and more preferably, 0.9 to 3 liter / min, and more preferably, 1.8 to 2.6 l / Min. The V 2 is preferably 0.3 to 19.8 liters / minute, more preferably 0.4 to 4.8 liters / minute, still more preferably 0.5 to 2 liters / minute, and particularly preferably 0.9 to 2.0 liters / minute.

V 1 -V 2 ≥0.2 liter / min is preferable, and V 1 -V 2 ≥0.4 liter / min is more preferable, and V 1 -V 2 ≥0.6 liter / min is more preferable, and V 1 -V 2 ≥1.0 Liter / minute is particularly preferable.

(Control 2), the above T 1 is preferably 1590 to 1710 ° C, and more preferably 1600 to 1695 ° C. The T 2 is preferably 1570 to 1690 ° C, and more preferably 1580 to 1675 ° C.

Further, T 1 -T 2 is preferably 10 to 35 ° C, T 1 -T 2 is more preferably 15 to 30 ° C, and further preferably 19 to 26 ° C.

Further, T 1 and T 2 can be measured by the following methods.

(Measurement position)

T 1 is a middle position between the burner 16 immediately upstream of the bubbler 14 constituting the first bubbler group and the burner 16 located immediately upstream of the burner 16, .

T 2 : a middle position between the burner 16 immediately downstream of the bubbler 15 constituting the second bubbler group and the burner 16 immediately downstream of the bubbler.

(How to measure)

From the observation window provided on the side of the dissolution tank, the temperature of the wall surface in the dissolution tank on the side of the opposite side is measured with a radiation thermometer (for example, CHINO IR-AH3SU (measurement wavelength: 0.65 mu m, epsilon = 1.0)).

In the molten glass production method of the present invention, it is preferable that the average flow rate of the gas 17 supplied from each bubbler 13 constituting the upstream-side region bubbling unit is 0.1 to 5.0 liters / Is preferable in that the homogenization of the molten glass G in the melting tank 10 can be promoted at all times including at the start of operation and at the time of changing the operating condition of the molten bath 10.

The average flow rate of the gas 17 supplied from each of the bubblers 13 constituting the upstream bubbling unit is set such that the flow rate of the gas 17 supplied from the bubbler 13 , It is possible to change the state in which the promotion of homogenization of the molten glass G in the dissolving bath 10 by the bubbling from the upstream region bubbling unit is more required and during the normal operation of the dissolving bath 10. The average flow rate of the gas 17 supplied from each bubbler 13 constituting the upstream-side bubbling unit is set to be the same as the average flow rate of the gas 17 supplied from the bubbler 13 constituting the upstream- (Bubbling) of the gas 17 supplied from each bubbler 13 constituting the upstream-side bubbling unit during normal operation of the dissolving tank 10 is set to 0.5 to 3.0 liters / minute, preferably 1.0 to 2.0 liters / The average flow rate is preferably 0.1 to 1.0 liter / min, and more preferably 0.2 to 0.5 liter / min. Wherein during normal operation of the melting vessel 10 is, for example glass in the case of a composition including B 2 O 3, in weight percent shown in oxide-based B 2 O 3 is is the ± 1%, preferably with respect to the target composition ± 0.5%, more preferably ± 0.3%.

In the molten glass production method of the present invention, when the average flow rate of the upstream-side circulation stream 100 is F 1 [m / hour] and the average flow rate of the downstream-side circulation flow 101 is F 2 [m / It is preferable to control F 1 = 5 to 20 m / hr and F 2 = 0.5 to 7 m / hr. Thus, homogenization of the molten glass can be promoted when a molten glass having a T ? Of 1,500 to 1,760 deg. C is produced, and a high-quality molten glass having high homogeneity can be obtained.

It is more preferable that F 1 = 8 to 15 m / hour and F 2 = 1 to 4 m / hour.

Further, F 1 and F 2 can be measured by the following methods.

(Measurement position)

F 1 : the distance from the upstream end of the molten glass passage is 0.30L F to 0.34L F , and the vicinity of the center in the width direction of the molten glass passage.

F 2 : the distance from the downstream end of the molten glass flow path is 0.22 L F to 0.30 L F , and the vicinity of the center in the width direction of the molten glass flow path.

(How to measure)

The flow of the bubbles in the surface layer of the molten glass is photographed by video, and the moving time with respect to the moving distance of the bubbles is measured to be the flow rate. This procedure is repeated 2-3 times to obtain an average flow rate.

Next, the method of manufacturing the plate glass of the present invention will be described.

In the method of manufacturing a glass plate according to the present invention, the molten glass obtained by the method for producing a molten glass of the present invention is molded into a glass plate. As means for forming the molten glass into a sheet glass, various molding methods such as a float method and a down-draw method can be used. In the case of glass having a T ? Of 1500 to 1760 占 폚, the float process is particularly preferable.

In the method of manufacturing a glass plate according to the present invention, the bubbles in the molten glass may be defoamed by vacuum degassing before molding the molten glass obtained by the molten glass production method of the present invention described above into a plate glass.

In the method for manufacturing a glass plate according to the present invention, a glass melt having high homogeneity obtained by the method for producing a molten glass of the present invention is molded into a plate glass, whereby a plate glass having high homogeneity and high transparency can be obtained.

In the apparatus for manufacturing a plate glass of the present invention, it is applicable to the production of plate glasses for various purposes. In view of obtaining a plate glass having a high homogeneity and a high transparency, It is particularly preferable to apply the present invention.

Example

Alkali glass having T η of 1,500 to 1,760 ° C., specifically, the above-mentioned alkali-free glass composition 1 to 4, is added to the inlet of the melting tank 10 shown in FIGS. 1 and 2, . The dimensions of the respective portions of the dissolution tank 10 shown in Figs. 1 and 2 are as follows.

Length of molten glass flow path L F : 16 to 25 m

Width of the molten glass channel W: 5.5 to 9 m

Distance from the upstream end of the molten glass channel to each bubbler 13 constituting the upstream bubbling unit: 0.1 L F

Distance from the center in the width direction of the molten glass channel to each bubbler 13 constituting the upstream bubbling unit: 0.5 W

Distance from the upstream end of the molten glass channel to each of the bubblers 14 constituting the first bubbler group: 0.43L F to 0.46L F

Distance from the downstream end of the molten glass channel to each of the bubblers 15 constituting the second bubbler group: 0.47 L F to 0.54 L F

The distance L P between each bubbler 14 constituting the first bubbler group and each bubbler 15 constituting the second bubbler group is 600 to 800 mm

A pitch p between each bubbler 14 constituting the first bubbler group is 400 to 700 mm

The pitch p between the bubblers 15 constituting the second bubbler group is 400 to 700 mm

The distance from the upstream end of the molten glass flow path to the burner 16 located at the most upstream side in the flow direction of the molten glass in the melting tank is 0.15 L F

The distance L B1 between the bubbler 14 constituting the first bubbler group and the burner 16 immediately in the vicinity of the upstream side of the bubbler 14 in the direction of the flow path of the molten glass in the melting tank is 500 to 1500 mm

The distance L B2 between the bubbler 15 constituting the second bubbler group and the burner 16 immediately in the vicinity of the downstream side of the bubbler 15 in the direction of the flow path of the molten glass in the melting tank is 1000 to 2000 mm

L B2 -L B1? 500 mm

The distance between the individual burners 16 in the direction of the flow path of the molten glass in the melting tank: 800 to 2400 mm

The average flow rate of the gas 17 from the bubbler 13 constituting the upstream-side bubbling unit is adjusted to 0.25 to 0.5 liter / min.

The first average flow rate of the gas 19 from the bubble average flow rate of the gas 18 from the bubbler 14 constituting the multiple groups V 1 and the second bubble bubbler constituting the multiple groups (15) V 2 is Adjust to the following conditions.

V 1 : 1.8 to 2.6 liters / minute

V 2 : 0.9 to 2.0 liters / minute

V 1 -V 2? 0.6 l / min

By the combustion of the burner 16, the first bubbler above the ambient temperature of the bubbler (14) constituting the groups T 1 and the second bubble above the ambient temperature of the bubbler (15) constituting the multiple groups T 2 is The following conditions are maintained. Further, T 1 and T 2 are measured by the above-described method.

T 1 : 1590 to 1710 ° C

T 2 : 1580 to 1675 ° C

T 1 -T 2 : 10 to 35 ° C

The bubbling from the bubbler 13 constituting the upstream bubbling unit at the start of the operation of the melting vessel 10 shortens the time required for homogenizing the molten glass in the melting vessel 10 .

Is measured by the average flow rate F 1 and the downstream above the average flow rate of the circulating flow F 2 method (101) of the upstream circulation flow 100 in the melting vessel within 10. The results are as follows.

F 1 = 8 to 15 m / hour

F 2 = 1 to 4 m / hour

By carrying out under the above-described conditions, a high-quality non-alkali glass having high homogeneity is produced at a temperature of T 侶 of 1500 to 1760 ° C, and the time required for the production of the alkali-free glass can be shortened.

Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

The present application is based on Japanese Patent Application No. 2011-277287 filed on December 19, 2011, the contents of which are incorporated herein by reference.

According to the apparatus for producing a molten glass and the method for producing a molten glass of the present invention, since the homogenization of the molten glass can be promoted at the time of starting the operation of the melting tank or changing the operating conditions of the melting tank, It is possible to shorten the time required for production of the alkali-free glass.

The process for producing a plate glass of the present invention is suitable for the production of a substrate for FPD because it can produce a plate glass having high homogeneity and high transparency.

10: Melting bath
11:
12: Non-outlet
13: Bubbler (upstream region bubbling unit)
14: Bubbler (middle region bubbling unit, first bubbler group)
15: Bubbler (middle-range bubbling unit, second bubbler group)
16: Burner
17: Gas from the bubbler (upstream region bubbling unit)
18: Gas from a bubbler (middle-range bubbling unit, first bubbler group)
19: Gas from a bubbler (middle region bubbling unit, second bubbler group)
20: downstream conduit
100: upstream side circulation flow
101: downstream side circulation flow

Claims (12)

An apparatus for producing a molten glass having a melting vessel for melting a glass raw material,
The melting tank has a burner for heating an upper space of the melting tank,
When the length of molten glass flow path of the melting vessel to L F, the distance from the upstream side of the melting vessel F 0.4L to 0.6L, and F is a middle zone in the bubbling unit where installed, the dissolving tank of the upstream The upstream region bubbling unit is disposed at a position where the distance from the upstream side bubbling unit is 0.05L F to 0.2L F ,
The middle stream region bubbling unit is constituted by a bubbler group provided with a plurality of bubblers in the vicinity of the bottom surface of the melting tank in the width direction of the molten glass channel of the melting tank,
The upstream region bubbling unit is constituted by a plurality of bubblers provided in parallel in the width direction of the molten glass channel of the melting vessel near the bottom of the melting vessel,
The upstream region bubbling unit is constituted by a pair or a plurality of pairs of bubblers provided at positions symmetrical with respect to the center in the width direction of the molten glass channel,
Each of the bubblers constituting the upstream region bubbling unit has a distance from the center in the width direction of the molten glass flow passage of 0.25 W or more, And a distance from the side wall of the molten glass is 400 mm or more. delete 2. The molten glass producing apparatus according to claim 1, wherein each of the bubblers constituting the upstream-side region bubbling unit is provided on a more upstream side than a burner located on the most upstream side in the longitudinal direction of the molten glass channel. The apparatus for manufacturing a molten glass according to claim 1, wherein the middle-range bubbling unit includes a plurality of groups of bubblers different in position in the longitudinal direction of the molten glass channel. The bubbling device according to claim 1, wherein each of the bubblers constituting the midstream bubbling unit and the upstream bubbling unit is made of platinum or platinum alloy, and the gas supplied from each bubbler is a gas not containing oxygen , A molten glass production apparatus. A method for producing a molten glass, wherein the molten glass is produced while supplying gas from each of the bubbling units constituting the bubbling unit and the bubbling unit. The method for producing a molten glass according to claim 6, wherein a molten glass having a temperature T ? At which the glass viscosity? Is 10 2 [dPa 占 퐏] is 1500 to 1760 占 폚 is produced. The bubble generator according to claim 6, wherein an average flow rate of the gas supplied from each bubbler constituting the midstream bubbling unit is 0.5 to 5.0 liters / minute, and supplied from each bubbler constituting the upstream region bubbling unit And the average flow rate of the gas is 0.1 to 5.0 liters / minute. A method for manufacturing a glass plate for molding a molten glass obtained by the method for manufacturing a molten glass according to claim 6 into a glass plate. The method according to claim 1, wherein the molten glass comprises, as an oxide-based mass percentage indication,
SiO 2 : 50 to 73%
Al 2 O 3 : 10.5 to 24%
B 2 O 3 : 0 to 12%
MgO: 0 to 10%
CaO: 0 to 14.5%
SrO: 0 to 24%
BaO: 0 to 13.5%
MgO + CaO + SrO + BaO: 8 to 29.5%
ZrO 2 : 0 to 5%
Wherein the molten glass is an alkali-free glass. 7. A process according to claim 6, wherein the molten glass comprises, by mass percentage indication on an oxide basis,
SiO 2 : 50 to 73%
Al 2 O 3 : 10.5 to 24%
B 2 O 3 : 0 to 12%
MgO: 0 to 10%
CaO: 0 to 14.5%
SrO: 0 to 24%
BaO: 0 to 13.5%
MgO + CaO + SrO + BaO: 8 to 29.5%
ZrO 2 : 0 to 5%
Wherein the glass is an alkali-free glass. 10. The process according to claim 9, wherein the molten glass comprises, by mass percent,
SiO 2 : 50 to 73%
Al 2 O 3 : 10.5 to 24%
B 2 O 3 : 0 to 12%
MgO: 0 to 10%
CaO: 0 to 14.5%
SrO: 0 to 24%
BaO: 0 to 13.5%
MgO + CaO + SrO + BaO: 8 to 29.5%
ZrO 2 : 0 to 5%
Wherein the alkali-free glass is a non-alkali glass.
KR1020147015101A 2011-12-19 2012-10-29 Apparatus for producing molten glass, method for producing molten glass, and method for producing plate glass using said apparatus and method KR101971755B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JPJP-P-2011-277287 2011-12-19
JP2011277287 2011-12-19
PCT/JP2012/077898 WO2013094313A1 (en) 2011-12-19 2012-10-29 Apparatus for producing molten glass, method for producing molten glass, and method for producing plate glass using said apparatus and method

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KR20140107233A KR20140107233A (en) 2014-09-04
KR101971755B1 true KR101971755B1 (en) 2019-04-23

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