JP2018095535A - Sheet glass manufacturing method, clear container, and sheet glass manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for performing excellently a defoaming treatment of molten glass, and producing a high-quality sheet glass.SOLUTION: A sheet glass manufacturing method includes a melting step, a clarifying step and a molding step. In the sheet glass manufacturing method, the clarifying step is executed, while bringing molten glass GM into contact with the whole inner surface of a body part 7 so that a vapor phase space is not formed in a clear container. In the sheet glass manufacturing method, vaporization of platinum from the inner surface of the body part 7 can be prevented, and contamination of platinum into the molten glass can be also prevented, to thereby perform excellently a defoaming treatment of the molten glass.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing plate glass, a clarification container used in the method, and a plate glass production apparatus including the clarification container.

  As is well known, plate glass is used for flat panel displays such as liquid crystal displays and organic EL displays. In recent years, with the advent of smartphones and tablet-type terminals, flat panel displays have become thinner and lighter, and high definition has progressed, and accordingly, thin plate glass has also been promoted. As the material of the glass substrate, alkali-free glass that is small in deformation and gravity deflection and excellent in dimensional stability in a high-temperature process is preferably used.

  The plate glass is formed into a thin plate through each step such as a melting step, a refining step, a homogenizing step, and a forming step. For example, Patent Document 1 discloses that a molten glass is heated from a molten glass while the molten glass is passed in a clarified container composed of platinum or a platinum alloy while the vapor phase space is formed. A method for producing plate glass is disclosed that includes a clarification step of performing a defoaming process for releasing bubbles into the phase space. In the upper part of the clarification container, a vent part (vent pipe) is provided for communicating with the gas phase space in the clarification container and for discharging the gas in the gas phase space to the outside.

JP 2014-028734 A

  In the conventional plate glass manufacturing method, there exists a problem that the gaseous-phase space in a clarification container becomes high temperature, and the volatilization wear in the inner surface of a clarification container becomes easy to occur. Further, when the gas in the clarification container is discharged from the vent portion, the volatile component of platinum contained in the gas is cooled, solidified and mixed into the molten glass, and the quality of the plate glass may be deteriorated.

  This invention is made | formed in view of said situation, and makes it a technical subject to manufacture a high quality plate glass while performing the defoaming process of a molten glass favorably.

  The present invention is for solving the above-mentioned problems, and a melting step of melting a glass raw material in a melting tank to produce a molten glass, and passing the molten glass through a clarification container composed of platinum or a platinum alloy. In a plate glass manufacturing method comprising: a clarification step for defoaming and a molding step for forming the molten glass after the clarification step as a plate glass in a molding tank, the clarification container is configured to move the molten glass from upstream to downstream. And a plurality of partition plates arranged at intervals in the main body portion, and the main body portion is provided at an upper portion thereof and generates gas generated in the molten glass. A vent portion for discharging, the partition plate being provided at an upper portion thereof, a first opening for allowing the gas bubbles to pass therethrough, and a lower position of the first opening; And the second opening for allowing the molten glass to pass therethrough, and performing the clarification step while contacting the molten glass with the entire inner surface of the main body so as not to form a gas phase space in the clarification container. It is characterized by that.

  According to such a method, when the clarification step is performed, the gas phase space is not formed between the inner surface of the main body portion and the molten glass by filling the entire internal space of the main body portion in the clarification container with the molten glass. . Moreover, the partition plate provided in a main-body part allows the bubble by the gas which generate | occur | produces in a molten glass to pass through a 1st opening part, and can guide it toward a vent part. Thereby, it can prevent that platinum volatilizes from the inner surface of a main-body part in high temperature gaseous-phase space like the past. Therefore, it is possible to prevent the platinum from being mixed into the molten glass and perform the defoaming treatment of the molten glass well, and to manufacture a high-quality plate glass.

  In the above case, it is desirable that the liquid level of the molten glass in the melting tank is set at a position higher than the top of the inner surface of the main body portion so that the molten glass is brought into contact with the entire inner surface of the main body portion. . Thereby, a clarification process can be performed, without making molten glass reach the top part of the inner surface in a main-body part, and forming a gaseous-phase space between the inner surface of a main-body part and molten glass.

  The present invention is for solving the above-described problems, and includes a hollow main body that transfers molten glass from upstream to downstream, and a plurality of partition plates that are arranged at intervals in the main body. And a clarification container made of platinum or a platinum alloy, wherein the main body portion includes a vent portion for discharging a gas generated in the molten glass at an upper portion thereof, and the partition plate is disposed at an upper portion thereof. It is provided with the 1st opening part which lets the bubble by the said gas pass through, and the 2nd opening part which lets the said molten glass pass through while being provided in the downward position of said 1st opening part, It is characterized by the above-mentioned.

  In performing the refining process, it is necessary to induce bubbles generated in the molten glass to the vent portion. In the present invention, the fining container allows the foam to be reliably guided to the vent portion by allowing the foam to pass through the first opening formed in the upper part of the partition plate, and performs the defoaming treatment of the molten glass satisfactorily. be able to.

  In the clarification container having the above-described configuration, it is desirable that the distance between the partition plate located upstream of the vent part and in the immediate vicinity of the vent part and the vent part is 10 mm or more and 300 mm or less. Moreover, it is preferable that the distance between the partition plate located downstream of the vent part and in the immediate vicinity of the vent part and the vent part is 10 mm or more and 300 mm or less. By separating the vent part and the partition plate at an appropriate distance as described above, the bubbles in the molten glass can be suitably guided to the vent part.

  In the fining container having the above-described configuration, it is preferable that the first opening of the partition plate is offset to one side in the width direction with respect to the center portion in the width direction of the partition plate. The plurality of partition plates include a first partition plate having a first opening offset from a center portion in the width direction to one side in the width direction, and the other in the width direction from the center portion in the width direction. And a second partition plate having a first opening offset to the side.

  It is desirable that the plurality of partition plates be positioned upstream from the vent portion. Further, it is desirable that the first opening is formed in all of the plurality of partition plates.

  In the clarification container according to the present invention, the first opening may be a recess formed in an upper portion of the plurality of partition plates.

  The clarification container according to the present invention may further include a partition plate that is disposed on the downstream side of the plurality of partition plates and in which the first opening is not formed. By arranging the partition plate in which the first opening is not formed on the most downstream side in this way, when the molten glass is transferred from the clarification container to the next process, bubbles generated in the molten glass are transferred to the next process together with the molten glass. It can be prevented from being transferred.

  The present invention is for solving the above-described problems, and includes a melting tank that melts a glass raw material to generate molten glass, the clarification container, and a molding tank that molds the molten glass into a plate glass. In the plate glass manufacturing apparatus, the liquid surface of the molten glass in the melting tank is set at a position above the top of the inner surface of the main body.

  According to this structure, when performing a clarification process, all the interior space of the main-body part of a clarification container can be filled with molten glass. For this reason, a gas phase space is not formed between the inner surface of the main body and the molten glass. Therefore, platinum does not volatilize on the inner surface of the main body due to the high-temperature gas phase space as in the prior art. Accordingly, it is possible to prevent the situation where the volatilized platinum is mixed into the molten glass and to perform the defoaming treatment of the molten glass well, and to manufacture a high-quality plate glass.

  ADVANTAGE OF THE INVENTION According to this invention, while performing the defoaming process of a molten glass favorably, it becomes possible to manufacture a high quality plate glass.

It is a side view which shows the whole structure of a plate glass manufacturing apparatus. It is a side view of a clarification container. It is a fragmentary sectional view of a clarification container. It is the IV-IV sectional view taken on the line of FIG. It is a front view of a 1st partition plate. It is a front view of a 2nd partition plate. It is a fragmentary sectional view which shows a clarification container and a dissolution tank side by side. It is a front view which shows the other example of a partition plate. It is a front view which shows the other example of a partition plate. It is a front view which shows the other example of a partition plate.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 thru | or FIG. 10 shows one Embodiment of the plate glass manufacturing apparatus and plate glass manufacturing method in this invention.

  As shown in FIG. 1, the plate glass manufacturing apparatus which concerns on this embodiment is the dissolution tank 1, the clarification container 2, the homogenization tank (stirring tank) 3, the state adjustment tank 4, and the forming tank in order from the upstream side. 5 and glass supply paths 6a to 6d connecting the tanks 1 to 5 respectively. In addition, the sheet glass manufacturing apparatus may include a slow cooling furnace (not shown) for gradually cooling the sheet glass GR formed by the forming tank 5 and a cutting device (not shown) for cutting the sheet glass GR after the slow cooling.

  The melting tank 1 is a container for performing a melting step of melting molten glass raw material GM by melting the charged glass raw material. The dissolution tank 1 is connected to the clarification container 2 by a glass supply path 6a. The clarification container 2 is a container for performing a clarification step of defoaming the molten glass GM supplied from the dissolution tank 1 by the action of a clarifier or the like. The clarification container 2 is connected to the homogenization tank 3 by a glass supply path 6b.

  The homogenization tank 3 is a container for performing a homogenization process in which the clarified molten glass GM is stirred with a stirring blade or the like to make it uniform. The homogenization tank 3 is connected to the state adjustment tank 4 by a glass supply path 6c. The state adjustment tank 4 is a container for performing a state adjustment process for adjusting the molten glass GM to a state suitable for molding. The state adjustment tank 4 is connected to the forming tank 5 by a glass supply path 6d.

  The forming tank 5 is a container for forming the molten glass GM into a desired shape. In the present embodiment, the forming tank 5 forms the molten glass GM into a plate shape by the overflow down draw method. Specifically, the forming tank 5 has a substantially wedge-shaped cross section (a cross section perpendicular to the paper surface of FIG. 1), and an overflow groove (not shown) is formed in the upper part of the forming tank 5. Has been.

  After the molten glass GM is supplied to the overflow groove by the glass supply path 6d, the molding tank 5 overflows the molten glass GM from the overflow groove, and the side walls on both sides of the forming tank 5 (positioned on the front and back sides of the paper surface). Flow down along the side). The forming tank 5 fuses the molten glass GM that has flowed down at the lower top portion of the side wall surface, and forms it into a plate shape.

  The formed sheet glass GR has a thickness of 0.01 to 10 mm, for example, and is used for a flat panel display such as a liquid crystal display or an organic EL display, an organic EL illumination, a substrate such as a solar cell, or a protective cover. The forming tank 5 may execute another downdraw method such as a slot downdraw method.

  Hereinafter, a specific configuration of the clarification container 2 will be described with reference to FIGS. 2 to 10. The clarification container 2 includes a hollow main body 7 that transfers the molten glass GM from upstream to downstream, a plurality of partition plates 8 that are arranged in the main body 7 at intervals, and heating that heats the main body 7. Part 9. The main body part 7, the partition plate 8, and the heating part 9 are all formed in a predetermined shape from platinum or a platinum alloy.

  Although the main-body part 7 is comprised by the cylindrical shape which has predetermined | prescribed length, it is not limited to this shape, What is necessary is just to be provided with the space which flows the molten glass GM inside by hollow shape. A glass supply path 6 a that connects the melting tank 1 and the main body 7 is connected to one end (upstream end) of the main body 7 in the longitudinal direction. A glass supply path 6 b that connects the homogenization tank 3 and the main body 7 is connected to the other end (downstream end) in the longitudinal direction of the main body 7.

  The main body part 7 includes a vent part 7a (vent pipe) for discharging gas generated in the molten glass GM. The vent portion 7 a is provided so as to protrude upward from the upper portion of the main body portion 7. The vent portion 7 a is configured in a cylindrical shape (for example, a cylindrical shape), is fixed to the upper outer surface of the main body portion 7, and communicates with the inside of the main body portion 7. The vent part 7 a is made of platinum or a platinum alloy like the main body part 7.

  The main body 7 has a plurality of cylindrical bodies 7b. The main body 7 is formed by alternately connecting the cylindrical bodies 7b and the partition plates 8. The cylindrical body 7b is configured in a cylindrical shape, but is not limited to this shape. The vent portion 7a is integrally formed with one of the plurality of cylindrical bodies 7b.

  The partition plate 8 is configured in a disc shape, but is not limited to this shape, and is configured in an appropriate shape according to the shape of the main body portion 7. A part of the surface of the partition plate 8 is fixed to the end surface of the cylindrical body 7 b in the main body 7. The diameter of the partition plate 8 is set to be the same as the outer diameter of the cylindrical body 7 b in the main body 7.

  Hereinafter, among the plurality of partition plates 8, a partition plate (hereinafter referred to as “first partition plate”) 8 a located on the upstream side of the vent portion 7 a and in the immediate vicinity of the vent portion 7 a and the downstream side of the vent portion 7 a. However, a partition plate (hereinafter referred to as “second partition plate”) 8b positioned in the immediate vicinity of the vent portion 7a will be described as an example with reference to FIGS.

  In the following description, a perpendicular line passing through the center portion O of each partition plate 8 is referred to as a “first center line” (indicated by reference numeral Y1), and a horizontal line passing through the center portion O of the partition plate 8 is referred to as “second center line”. "(Indicated by reference numeral X1). In addition, the direction along the first center line Y1 is referred to as “vertical direction” (indicated by the symbol Y), and the direction along the second center line X1 is referred to as “width direction” (indicated by the symbol X). In each partition plate 8, a portion above the first center line Y <b> 1 is referred to as an “upper portion” of the partition plate 8, and a portion below the first center line Y <b> 1 is a “lower portion” of the partition plate 8. That's it.

  In the longitudinal direction of the main body 7, it is desirable that the distance D1 between the first partition plate 8a and the vent 7a is set to 10 mm or more and 300 mm or less. The distance D2 between the second partition plate 8b and the vent portion 7a is preferably set to 10 mm or more and 300 mm or less.

  The first partition plate 8a and the second partition plate 8b are provided at an upper portion thereof and provided at a position below the first opening portion 10 through which bubbles B caused by gas generated in the molten glass GM pass. And a second opening 11 through which the molten glass GM passes. As shown in FIGS. 3 to 6, the first opening 10 is a through hole formed inside the peripheral edge of the partition plate 8. The first opening 10 is formed at a position above the second opening 11. The opening area of the second opening 11 is set larger than the opening area of the first opening 10.

  The 1st opening part 10 is mainly for distribute | circulating the bubble B by the gas which generate | occur | produces in the molten glass GM. On the other hand, the 2nd opening part 11 is mainly for distribute | circulating the molten glass GM.

  As shown in FIG. 4, the first openings 10 of the first partition plate 8a and the second partition plate 8b are configured in a fan shape with a central angle of about 90 degrees, but are not limited to this shape. Absent. The first opening 10 of the first partition plate 8a is offset to one side in the width direction X with respect to the center portion O of the first partition plate 8a, as shown in FIGS.

  That is, as shown in FIG. 5, the first opening 10 of the first partition plate 8a is shifted to one side in the width direction X with respect to the first center line Y1 (right side with respect to the paper surface of FIG. 5). It is formed. The first opening 10 of the second partition plate 8b is offset to the other side in the width direction X with respect to the central portion O of the second partition plate 8b. That is, as shown in FIG. 6, the first opening 10 of the second partition plate 8b is shifted to the other side in the width direction X with respect to the first center line Y1 (left side with respect to the paper surface of FIG. 6). It is formed. In other words, the first opening 10 of the second partition plate 8b is offset in the width direction X to the side opposite to the first opening 10 of the first partition plate 8a.

  The 2nd opening part 11 of the 1st partition plate 8a is comprised by the ellipse shape in front view. The central part of the second opening 11 coincides with the central part O of the first partition plate 8a. The second opening 11 of the second partition plate is formed in the lower part of the second partition plate 8b. This 2nd opening part 11 is comprised by the semicircle in front view. Specifically, the second opening 11 of the second partition plate 8b is formed in the second partition plate 8b so that the straight line portion is located above and the arc portion is located below the straight line portion. The center of the second opening 11 is located at a position shifted downward from the center O of the second partition plate 8b. Therefore, the second opening portion 11 of the first partition plate 8a and the second opening portion 11 of the second partition plate 8b are in a state in which the position in the vertical direction Y is shifted in a front view. Thus, by making the formation position of the 2nd opening part 11 different in each partition plate 8 (8a, 8b), the molten glass GM which flows through the main-body part 7 can be made to meander, and a favorable defoaming process can be performed. It becomes possible.

  As shown in FIG. 2, the heating unit 9 includes a flange portion 12 formed so as to surround the periphery of the end portion of the main body portion 7, and an electrode portion 13 formed on the upper portion of the flange portion 12. The flange portion 12 and the electrode portion 13 are made of platinum or a platinum alloy like the main body portion 7. The heating unit 9 directly heats the main body unit 7 by applying a predetermined voltage to the electrode unit 13. Thereby, the clarification container 2 maintains the molten glass GM which flows in the main-body part 7 in a clarification process at predetermined temperature.

  As shown in FIG. 7, the liquid level GS of the molten glass GM in the melting tank 1 is set at a position higher than the top (vertex) 7 c of the inner surface of the main body 7 or the same position as the top 7 c. The height difference H is 0 mm or more and 200 mm or less, but is not limited to this range. With this setting, the entire internal space of the main body 7 is filled with the molten glass GM that has flowed from the melting tank 1. That is, inside the main body 7, the upper glass inner surface of the main body 7 and the molten glass GM are not separated from each other, and the molten glass GM comes into contact with the entire inner surface (see FIG. 3). As described above, the molten glass GM comes into contact with the entire inner surface of the main body portion 7, so that no gas phase space is formed in the main body portion 7.

  Of the partition plates 8 disposed in the main body 7, the first opening portion 10 is not formed in the partition plate 8 c (see FIG. 2) disposed on the most downstream side. The partition plate 8 can prevent the foam B generated in the molten glass GM from being transferred to the downstream side of the clarification container 2.

  8 to 10 show other examples of the partition plate 8. In these examples, the configuration of the first opening 10 is different from the examples shown in FIGS. 5 and 6. In the example shown in FIG. 8, a recess formed by cutting out the upper end of the partition plate 8 is formed as the first opening 10 of the partition plate 8. The recess is formed so as to be recessed from the upper edge of the partition plate 8 toward the center portion O of the partition plate 8. In this example, it is desirable to configure the main body portion 7 by bringing the peripheral edge portion of the partition plate 8 into contact with the inner surface of the cylindrical body 7 b in the main body portion 7. That is, the outer diameter of the partition plate 8 is set to be the same as the inner diameter of the cylindrical body 7b.

  In the example shown in FIG. 9, a plurality (two) of first openings 10 are formed in the partition plate 8. Specifically, a pair of first openings 10 are formed across the first center line Y1 of the partition plate 8. Each first opening 10 is offset in the width direction X with respect to the first center line Y <b> 1 of the partition plate 8. The pair of first openings 10 are provided so as to be line symmetric with respect to the first center line Y1.

  In the example illustrated in FIG. 10, the first opening 10 is configured in a semicircular shape. Specifically, the first opening 10 is formed on the partition plate 8 so that the linear portion is at the lower position and the arc portion is at the upper position. The central portion of the first opening 10 is offset in the width direction X with respect to the central portion O of the partition plate 8. That is, the first opening 10 is positioned such that a perpendicular (center line) Y2 passing through the center of the first opening 10 is shifted to one side (right side) in the width direction X with respect to the first center line Y1 of the partition plate 8. For this reason, the first opening 10 is asymmetric with respect to the first center line Y1 of the partition plate 8 (it is not configured symmetrically with respect to the first center line Y1).

Hereinafter, a method of manufacturing the plate glass GR using the plate glass manufacturing apparatus having the above configuration will be described. In this method, the raw glass is melted in the melting tank 1 (melting step) to obtain a molten glass GM. A fining agent is blended in the glass raw material, and gas (bubbles) is generated in the molten glass GM by the action of the fining agent. As the clarifier, As ₂ O ₃ , Sb ₂ O ₃ , SnO ₂ , Fe ₂ O ₃ , SO ₃ , F, Cl, or the like can be used. However, since As ₂ O ₃ and Sb ₂ O ₃ are environmentally hazardous substances, their use should be avoided as much as possible, and SnO ₂ is most preferably used as a refining agent.

  In the clarification step, the molten glass GM supplied from the melting tank 1 via the glass supply path 6a is moved from one end (upstream) of the main body 7 in the clarification container 2 to the other end (downstream). The main body 7 is heated by the heating unit 9 to maintain the temperature of the flowing molten glass GM at 1300 to 1500 ° C. In this clarification process, the bubbles B caused by the gas generated by the redox action of the clarifier are floated (see FIG. 3). This bubble B passes through the first opening 10 of each partition plate 8 together with the molten glass GM, and is discharged as a gas from the liquid surface of the molten glass GM facing the vent portion 7a. The gas is finally discharged out of the main body portion 7 from the vent portion 7a. The bubble B that has passed through the vent portion 7a flows backward through the first opening 10 of the partition plate 8 (second partition plate 8b) located downstream of the vent portion 7a, and is discharged as a gas from the vent portion 7a. obtain.

  Thereafter, the molten glass GM subjected to clarification (defoaming treatment) is transferred to the molding tank 5 through a homogenization process by the homogenization tank 3 and a state adjustment process by the state adjustment tank 4. In the forming step, the molten glass GM is formed as a plate glass GR in the forming tank 5 (see FIG. 1). Thereafter, the plate glass GR is formed to have a predetermined size through a slow cooling process using a slow cooling furnace and a cutting process using a cutting device. Alternatively, the plate glass GR is wound into a roll shape without being cut after the slow cooling step.

  According to the plate glass manufacturing method which concerns on this embodiment demonstrated above, when performing a clarification process, molten glass GM is satisfy | filled in all the interior spaces of the main-body part 7 of the clarification container 2. FIG. That is, the molten glass GM flows from the upstream side to the downstream side while contacting the entire inner surface (entire surface) of the main body portion 7. Therefore, a gas phase space is not formed between the inner surface of the main body 7 and the molten glass GM.

  For this reason, platinum does not volatilize on the inner surface of the main body portion 7 due to a high-temperature gas phase space as in the prior art. Thereby, the situation which platinum volatilized like the past can mix in molten glass GM can be prevented. Moreover, since the partition plate 8 provided in the main-body part 7 has the 1st opening part 10 which allows the bubble B which generate | occur | produces in molten glass GM to pass through, the gas (bubble B) in molten glass GM is this 1st. The vent 10a can be reliably discharged through the opening 10.

  In addition, this invention is not limited to the structure of the said embodiment, It is not limited to an above-described effect. The present invention can be variously modified without departing from the gist of the present invention.

  In said embodiment, although the example which offset the 1st opening part 10 of the partition plate 8 in the width direction rather than the center part O of the partition plate 8 was shown, it is not limited to this. The first opening 10 may be configured such that the central portion thereof coincides with the central portion O of the partition plate 8 in the width direction X.

  In said embodiment, although the example which has arrange | positioned the several partition plate 8 to the upstream and downstream of the vent part 7a was shown, it is not limited to this. In the present invention, for example, a configuration in which a plurality of partition plates 8 are arranged only upstream from the vent portion 7a can be employed. In this case, it is good also as a structure which has arrange | positioned only the partition plate 8 which does not have the 1st opening part 10 in the downstream of the vent part 7a.

  In said embodiment, although the clarification container 2 provided with the one vent part 7a in the main-body part 7 was illustrated, it is not limited to this structure. The main body portion 7 may be provided with a plurality of vent portions 7a at intervals in the longitudinal direction. In this case, the some partition plate 8 can be arrange | positioned upstream from the vent part 7a located in the most downstream side. Moreover, you may arrange | position the partition plate 8 provided with the 1st opening part 10 and the 2nd opening part 11 in the further downstream of the vent part 7a located in the most downstream side, and it does not have the 1st opening part 10. Only the partition plate 8 (having only the second opening 11) may be disposed.

  In said embodiment, although the plate glass manufacturing apparatus which has one dissolution tank 1 was illustrated, this invention is not limited to this structure. The plate glass manufacturing apparatus may include a plurality of dissolution tanks 1.

DESCRIPTION OF SYMBOLS 1 Dissolution tank 2 Clarification container 5 Molding tank 8 Partition plate 8a 1st partition plate 8b 2nd partition plate 10 1st opening part 11 2nd opening part GM Molten glass GR Plate glass

Claims (12)

A melting step of melting a glass raw material in a melting tank to produce a molten glass, a clarification step of defoaming the molten glass by passing it through a clarification container composed of platinum or a platinum alloy, and a step after the clarification step In a sheet glass manufacturing method comprising: a forming step of forming the molten glass as a sheet glass by a forming tank;
The clarification container comprises a hollow main body for transferring the molten glass from upstream to downstream, and a plurality of partition plates arranged at intervals in the main body,
The main body portion is provided with an upper portion thereof and a vent portion for discharging gas generated in the molten glass.
The partition plate includes a first opening that is provided at an upper portion of the partition plate and allows bubbles from the gas to pass therethrough, and a second opening that is provided at a position below the first opening and allows the molten glass to pass through. ,
The plate glass manufacturing method, wherein the clarification step is performed while bringing the molten glass into contact with the entire inner surface of the main body so that a gas phase space is not formed in the clarification container.   The plate glass according to claim 1, wherein a liquid surface of the molten glass in the melting tank is set at a position higher than a top portion of the inner surface of the main body portion so that the molten glass is brought into contact with all inner surfaces of the main body portion. Production method. A clarification container comprising a hollow main body for transferring molten glass from upstream to downstream, and a plurality of partition plates arranged at intervals in the main body, and made of platinum or a platinum alloy. There,
The main body portion includes a vent portion for discharging gas generated in the molten glass at an upper portion thereof,
The partition plate includes a first opening that is provided at an upper portion thereof and allows the gas bubbles to pass therethrough, and a second opening that is provided at a position below the first opening and allows the molten glass to pass therethrough. A clarification container characterized by   The clarification container according to claim 3, wherein a distance between the partition plate located upstream of the vent part and in the immediate vicinity of the vent part and the vent part is 10 mm or more and 300 mm or less.   The clarification container according to claim 3 or 4, wherein a distance between the partition plate located on the downstream side of the vent part and in the immediate vicinity of the vent part and the vent part is 10 mm or more and 300 mm or less.   The clarification container according to any one of claims 3 to 5, wherein the first opening of the partition plate is offset to one side in the width direction with respect to a center portion in the width direction of the partition plate.   The plurality of partition plates include a first partition plate having a first opening offset from a center portion in the width direction to one side in the width direction, and from the center portion in the width direction to the other side in the width direction. The clarification container as described in any one of Claim 3 to 5 containing the 2nd partition plate which has the offset 1st opening part.   The clarification container according to any one of claims 3, 4, 6, and 7, wherein the plurality of partition plates are positioned upstream of the vent portion.   The clarification container according to any one of claims 3 to 8, wherein the first opening is formed in all of the plurality of partition plates.   The clarification container according to any one of claims 3 to 9, wherein the first opening is a recess formed in an upper portion of the partition plate.   The clarification container according to claim 3, further comprising a partition plate that is disposed downstream of the plurality of partition plates and in which the first opening is not formed. In a plate glass manufacturing apparatus comprising: a melting tank that melts a glass raw material to produce molten glass; a clarification container according to any one of claims 3 to 11; and a molding tank that molds the molten glass into a sheet glass.
The liquid glass surface of the molten glass in the melting tank is set at a position above the top of the inner surface of the main body.

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