JP2019077584A - Glass melting furnace, and production method of glass article - Google Patents

Abstract

To provide a glass melting furnace capable of suppressing contamination of a glass article with heterogeneous glass, and a production method of a glass article.SOLUTION: A glass melting furnace 10 includes a melting vessel 20 and a throat 30. The melting vessel 20 is equipped with a partition wall 40 and a discharge port 50 and melts glass at a temperature Tof 1,580°C or higher where the viscosity η is 10poise. The partition wall 40 is set in the width direction of the melting vessel 20 and blocks a part of a flow of molten glass G. The discharge port 50 is set in the bottom 21 of the melting vessel 20 between the throat 30 and the partition wall 40 and discharges the molten glass G. The height Hof the lower edge of the entrance of the throat 30 is 20 [mm] or more from the bottom 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a glass melting furnace and a method of manufacturing a glass article.

The refractory constituting the glass melting furnace is corroded in contact with the high temperature molten glass and is eluted into the molten glass. As a result, extraneous glass different in composition and specific gravity from molten glass is produced. On the other hand, the refractory in the portion in contact with the molten glass often uses an electroformed brick which is excellent in corrosion resistance with respect to the molten glass. Among these, zirconia-based electroformed bricks have a higher zirconia (ZrO ₂ ) content than other electroformed bricks, and are more excellent in corrosion resistance than other electroformed bricks. However, zirconia (ZrO ₂ ) is a component not included in the glass composition, and has a specific gravity higher than that of the molten glass, and therefore elution to the molten glass promotes the formation of foreign glass. When such foreign glass is mixed into the finally obtained glass article, the desired quality is not satisfied, which causes a problem that the production yield is lowered.

  Patent Document 1 discloses a glass melting furnace provided with a glass discharge part for discharging the foreign glass at the bottom so as not to mix such foreign glass into the glass article.

JP, 2006-62903, A

  However, simply providing the glass discharge portion at the bottom can not sufficiently suppress foreign glass from being mixed into the glass article. The molten glass in the glass melting furnace flows downstream while forming a circulating flow in the glass melting furnace. In the case where the circulating flow of the molten glass is large or the moving speed of the circulating flow is high, the foreign glass stagnating at the bottom becomes difficult to flow to the glass discharge part. Therefore, foreign glass mixes in the throat which transfers molten glass toward a clarification tank or a forming furnace, and foreign glass also mixes in the glass article finally obtained.

In particular, the temperature T ₂ is 1580 ° C. or more glass viscosity η is 10 ² poise, the temperature of the molten glass in the glass melting furnace is increased, refractory constituting the glass melting furnace is eroded, the molten glass It is easy to elute. Therefore, the problem that foreign glass mixes in a glass article becomes apparent.

  This invention is made in view of the said subject, Comprising: It aims at providing the manufacturing method of a glass melting furnace which can suppress that foreign glass mixes in a glass article, and a glass article.

The glass melting furnace of the present invention is provided in communication with the melting tank for melting the glass raw material and causing the obtained molten glass to flow downstream, and the melting tank, and directs the molten glass to the clarification tank or the forming furnace a glass melting furnace and a throat for transferring Te, the dissolver was dissolved and the partition wall, and a discharge portion, temperature T ₂ at which the viscosity η is 10 ² poise to 1580 ° C. or more glass, The partition wall is provided across the width direction of the dissolution tank and blocks a part of the flow of the molten glass, and the discharge part is provided at the bottom of the dissolution tank between the throat and the partition wall. The molten glass is discharged, and the height from the bottom to the lower end of the throat inlet is 20 mm or more.

The method for producing a glass article according to the present invention is a method for producing a glass article comprising a melting step, a forming step, and a slow cooling step, and the melting step dissolves the glass raw material in the melting tank, the resulting molten glass to flow to the downstream side, the viscosity η is dissolved temperature T ₂ is 1580 ° C. or more glass becomes 10 ² poises, the melting tank, a partition wall provided across the width of the melting tank The apparatus further comprises a discharge part at the bottom of the dissolution tank between the throat and the partition wall, the partition wall interrupting a part of the flow of the molten glass, and the molten glass is in communication with the dissolution tank Through the provided throat, it is transported towards the clarification step or the forming step, the discharge part discharges the molten glass, and the height from the bottom to the lower end of the inlet of the throat is 20 mm ] It is characterized by being above.

  According to the glass melting furnace of this invention, and the manufacturing method of a glass article, it can suppress that foreign glass mixes in a glass article.

It is sectional drawing in the Y-axis perpendicular | vertical surface of the glass melting furnace in 1st embodiment which concerns on this invention. It is sectional drawing in the X-axis perpendicular | vertical surface of the glass melting furnace in 1st embodiment which concerns on this invention, and is an II arrow directional cross-sectional view of FIG. It is sectional drawing in the Y-axis perpendicular | vertical surface of the glass melting furnace in 2nd embodiment which concerns on this invention. It is sectional drawing in the X-axis perpendicular | vertical surface of the glass melting furnace in 2nd embodiment which concerns on this invention, and is II-II arrow sectional drawing of FIG. It is a flowchart which shows the manufacturing method of the glass article in 1st embodiment which concerns on this invention.

  Hereinafter, various embodiments according to the present invention will be described using the drawings. In the present specification, “to” representing a numerical range means a range including the numerical values before and after that.

  The direction of the reference of each drawing corresponds to the direction of the symbol and the numeral. In the drawings, the XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system, the Z axis direction is the vertical direction in FIGS. 1 to 4, and the X axis direction is the length direction of the glass melting furnaces 10 and 110 shown in FIGS. The Y-axis direction is taken as the width direction (left-right direction) of the glass melting furnace 10, 110 shown in FIGS. In the present specification, the X-axis direction is the flow direction of the molten glass G in plan view, and the Y-axis direction is orthogonal to the flow direction of the molten glass G.

  Further, in the present specification, the upstream side and the downstream side refer to the flow direction (X axis direction) of the molten glass G in the glass melting furnace 10, 110, and the + X side is the downstream side and the -X side is the upstream side. is there.

[Glass melting furnace]
"First embodiment"
FIG. 1 is a cross-sectional view of a glass melting furnace according to a first embodiment of the present invention in a plane perpendicular to the Y-axis. FIG. 2 is a cross-sectional view taken along a plane perpendicular to the X-axis of the glass melting furnace according to the first embodiment of the present invention, and is a cross-sectional view taken along the line II in FIG. A first embodiment of a glass melting furnace according to the present invention will be described with reference to FIGS. 1 and 2.

  The glass melting furnace 10 of the present embodiment melts a glass raw material supplied by a raw material supply device (not shown), and causes the obtained molten glass G to flow downstream (+ X side), and a melting tank 20 and provided with a throat 30 for transferring the molten glass G toward a clarification tank (not shown) or a forming furnace (not shown).

Dissolution tank 20, the partition wall 40, and a discharge unit 50, temperature _{T 2} at which the viscosity η is 10 ² poise dissolving 1580 ° C. or more glass. The partition wall 40 is provided across the width direction (Y-axis direction) of the melting tank 20 and blocks part of the flow of the molten glass G. The discharge part 50 is provided in the bottom part 21 of the dissolution tank 20 between the throat 30 and the partition wall 40, and discharges the molten glass G.

  The melting tank 20 is provided with a burner (not shown) on the wall located on the upper side (+ Z side) of the molten glass G, and the glass raw material supplied to the inside of the melting tank 20 by burner combustion using fuel and gas. Are melted to obtain a molten glass G. The fuel is natural gas or heavy oil, and the gas is oxygen or air. The melting tank 20 includes a bottom 21 and a side wall 22 and holds the molten glass G. The bottom portion 21 and the side wall portion 22 are formed of an electroformed brick which is excellent in corrosion resistance since the inside is in contact with the molten glass G. Examples of electroformed bricks include zirconia-based bricks, alumina-zirconia-silica (AZS) -based bricks, and alumina-based bricks. The bottom 21 or the side wall 22 may be provided with a current-carrying electrode (not shown). The current-carrying electrode generates Joule heat by applying a voltage and melts the glass material to obtain a molten glass G.

Since the melting tank 20 is in contact with the molten glass G, a portion of the electroformed brick constituting the melting tank 20 is eluted into the molten glass G. When an electroformed brick containing zirconia (ZrO ₂ ) is used for the dissolution tank 20, the zirconia (ZrO ₂ ) component having a high specific gravity is eluted into the molten glass G. Therefore, in the vicinity of the bottom portion 21 of the melting tank 20, the foreign glass G1 having a high concentration of zirconia (ZrO ₂ ) and a high specific gravity is retained.

The height from the bottom 21 to the lower end of the throat 30 inlet is H _S. The height H _S is at least 20 mm. The height H _S is preferably 200 mm or less, more preferably 40 to 150 mm, and still more preferably 60 to 100 mm. By setting the height H _S to 20 [mm] or more, it is possible to suppress the foreign glass G1 from flowing out to the downstream side (+ X side) through the throat 30. Further, by setting the height H _S to 200 [mm] or less, the molten glass G excluding the foreign glass G1 can be efficiently transferred to the downstream side (+ X side) from the throat 30.

  As shown in FIG. 2, the throat 30 is provided in communication with the central portion in the width direction (Y-axis direction) of the dissolution tank 20. Therefore, the flow of the molten glass G becomes symmetrical in the width direction (Y-axis direction), and it becomes easy to control the downstream circulation flow 102 shown in FIG.

  The partition wall 40 is provided to extend above the bottom portion 21 (+ Z side) and has a dam structure that blocks the flow of the lower layer of the molten glass G. The partition wall 40 is the forward flow 100, the upstream circulation flow 101, and the downstream side with respect to the molten glass G on the upper side (+ Z side), the upstream side (−X side), and the downstream side (+ X side) of the partition wall 40, respectively. A circulating flow 102 is formed. The forward flow 100 flows from the upstream side (−X side) in the dissolution tank 20 to the downstream side (+ X side). The upstream circulation flow 101 flows toward the upstream side (−X side) in the melting tank 20 in the upper part of the molten glass G, and on the downstream side (+ X side) in the melting tank 20 in the lower part of the molten glass G It is a circulating flow that flows toward. The downstream circulation flow 102 flows toward the downstream side (+ X side) in the melting tank 20 in the upper part of the molten glass G, and on the upstream side (-X side) in the melting tank 20 in the lower part of the molten glass G It is a circulating flow that flows toward. The partition wall 40 is made of a material having excellent corrosion resistance to the molten glass G, such as electroformed brick, platinum, platinum alloy, iridium, or molybdenum.

  The discharge part 50 is provided in the bottom part 21 between the throat 30 and the partition wall 40, and is provided with a discharge pipe 51 for discharging the foreign glass G1 on the lower side (−Z side) of the bottom part 21. Thereby, the foreign glass G1 remaining on the downstream side (+ X side) of the partition wall 40 can be prevented from flowing out to the throat 30. The discharge pipe 51 extends cylindrically below the bottom portion 21 (−Z side), and the cross section of the Z-axis vertical plane is circular, but may be polygonal or the like. The discharge pipe 51 may be provided with a heating facility (not shown) for controlling the amount of flow of the molten glass G mixed with the foreign glass G1. In this case, the discharge pipe 51 is made of platinum or a platinum alloy, and by providing direct current heating equipment, the amount of flow of the molten glass G can be precisely controlled.

  As shown in FIG. 2, the discharge unit 50 is provided at the center of the dissolution tank 20 in the width direction (Y-axis direction). In the discharge unit 50, the discharge pipe 51 is provided on the inner side in the width direction (Y-axis direction) of the throat 30. Thereby, the foreign glass G1 can be effectively suppressed from flowing out to the throat 30.

  The weight of the molten glass G held by the melting tank 20 between the inlet of the throat 30 and the partition wall 40 is W [ton], and the weight of the molten glass G transferred from the throat 30 one day P [ton / day] I assume. At this time, it is preferable that the glass melting furnace 10 of this embodiment satisfy | fills 0.2 <= W / P <= 2.0. W / P is more preferably 0.4 ≦ W / P ≦ 1.2, still more preferably 0.5 ≦ W / P ≦ 1.0. When W / P is 2.0 or less, the downstream circulation flow 102 is suppressed, and the foreign glass G1 is less likely to be rolled up, so that the foreign glass G1 can be prevented from flowing out to the throat 30. In addition, when W / P is 0.2 or more, the molten glass G excluding the foreign glass G1 can be efficiently transferred to the downstream side (+ X side) from the throat 30. Also, the weight P is preferably 20 to 200 [tons / day].

The height from the bottom 21 to the upper surface of the molten glass G is H ₀ , the height from the bottom 21 to the upper end of the dividing wall 40 is H ₁ , and the height between the bottom of the throat 30 and the top is H ₂ I assume. Glass melting furnace 10 of the present embodiment is _preferably H 1 / _{H 0} meets 0.3 to 0.95, and more preferably meets 0.5 to 0.95. When H ₁ / H ₀ is 0.3 or more, the downstream side circulation flow 102 can be prevented from becoming large, and the foreign glass G1 becomes difficult to be wound up, so that the foreign glass G1 is prevented from flowing out to the throat 30 it can. In addition, when H ₁ / H ₀ is 0.95 or less, the forward flow 100 and the downstream circulation flow 102 become stable, and the foreign glass G1 becomes difficult to be wound up, so that the foreign glass G1 is prevented from flowing out to the throat 30 it can.

The glass melting furnace 10 of the present _embodiment, it is preferable that H 2 / _{H 0} meets 0.1-0.5. By setting H ₂ / H ₀ to 0.1 to 0.5, the molten glass G excluding the foreign glass G 1 is efficiently downstream of the throat 30 while suppressing the foreign glass G 1 from flowing out to the throat 30 ( Can be transported to the + X side).

In plan view, the distance from the upstream end to the downstream end in the dissolution tank 20 is L ₀ , and the distance from the downstream end of the partition wall 40 to the downstream end in the dissolution tank 20 is L ₁ . Dissolving tank 20 of the present _embodiment, it is preferable that L 1 / _{L 0} meets 0.1-0.5. By setting L ₁ / L ₀ to 0.1 to 0.5, the molten glass G excluding the foreign glass G 1 can be efficiently transferred to the downstream side (+ X side).

As shown in FIG. 2, the distance in the width direction (Y-axis direction) in the dissolution tank 20 is W ₀ , and the distance in the width direction (Y-axis direction) of the throat 30 is W ₁ . Glass melting furnace 10 of the present _embodiment, it is preferable that W 1 / _{W 0} meets 0.03-0.3. By setting W ₁ / W ₀ to 0.03 to 0.3, the molten glass G excluding the foreign glass G1 can be efficiently transferred to the downstream side (+ X side).

In the glass melting furnace 10 of the present embodiment, the average flow velocity V in the flow direction (X-axis direction) of the molten glass G is preferably 5 to 15 [m / h] at the inlet of the throat 30. The average flow velocity V [m / h] is V = P ÷ (S) where S [m ² ] is the cross-sectional area of the inlet 30 at the inlet of the throat 30 and d [t / m ³ ] is the density of the molten glass G. It is calculated by 24 × S × d). When the average flow velocity V is 5 [m / h] or more, the molten glass G excluding the foreign glass G1 can be efficiently transferred to the downstream side (+ X side) from the throat 30. Moreover, when the average flow velocity V is 15 [m / h] or less, the foreign glass G1 can be effectively suppressed from flowing out to the throat 30.

The glass used in the present embodiment, in order to effectively suppress the contamination of foreign glass G1, the temperature T ₂ at which the viscosity η is 10 ² poise preferably 1610 ° C. or higher, more preferably at 1640 ° C. or higher . Further, the glass used in the present embodiment preferably has a temperature T _{2 at} which the viscosity η is 10 ² poise to be 1670 ° C. or less, in order to facilitate melting.

"2nd embodiment"
FIG. 3 is a cross-sectional view of a glass melting furnace according to a second embodiment of the present invention taken along a plane perpendicular to the Y-axis. FIG. 4 is a cross-sectional view taken along a plane perpendicular to the X-axis of the glass melting furnace according to the second embodiment of the present invention, and is a cross-sectional view taken along the line II-II in FIG.

  A second embodiment of a glass melting furnace according to the present invention will be described with reference to FIGS. 3 and 4. Hereinafter, only differences from the first embodiment will be described. The glass melting furnace 110 according to the second embodiment is different in structure from the glass melting furnace 10 according to the first embodiment in that the housing 60 is provided in the melting tank.

  As shown in FIG. 3, the dissolution tank 120 according to the present embodiment includes a concave accommodating portion 60 provided in the bottom portion 21 between the inlet of the throat 30 and the partition wall 40. The housing portion 60 has a box shape, and stores the molten glass G. The storage unit 60 is provided at the bottom with a discharge unit 150 for discharging the molten glass G. The concave housing portion 60 has a rectangular cross section in the X-axis vertical plane or the Y-axis vertical plane, but may have a square, semi-circular, semi-elliptical or rounded rectangular shape. In addition, although the cross section of the Z-axis vertical plane is circular, the housing portion 60 may be square or rectangular.

  As shown in FIG. 4, the housing portion 60 is provided at the central portion in the width direction (Y-axis direction) of the dissolution tank 120. Since the housing portion 60 is larger in width than the throat 30, the outflow of the foreign glass G1 to the throat 30 can be effectively suppressed.

  The discharge part 150 is provided with the discharge pipe 151 for discharging | emitting the foreign glass G1 in the lower side (-Z side) of the bottom part of the accommodating part 60. As shown in FIG. The discharge unit 150 is different from the discharge unit 50 of the first embodiment in that the length in the vertical direction (Z-axis direction) of the discharge pipe is shortened by the depth of the storage unit 60.

According to the melting tank 120 of the present embodiment, the foreign glass G1 can be effectively suppressed from flowing out to the throat 30. The distance between the bottom of the housing portion 60 and the bottom 21 of the dissolution tank 20 is taken as a height _HS1 . The height H _S1 is preferably 50 to 300 [mm]. When the height H _S1 is 50 [mm] or more, the foreign glass G1 is collected in the housing portion 60. In addition, when the height H _S1 is equal to or less than 300 [mm], circulation of the molten glass G can occur in the housing portion 60, and the foreign glass G1 can be prevented from flowing out to the upper part.

In the present embodiment, the distance in the flow direction (X-axis direction) between the downstream end of the housing portion 60 and the inlet of the throat 30 is L _S in a plan view. The distance L _S is preferably 0 to 1000 [mm]. The distance L _S is more preferably 0 to 500 [mm], still more preferably 0 to 100 [mm]. When the distance L _S is 1000 [mm] or less, the foreign glass G1 can be effectively suppressed from flowing out to the throat 30.

In plan view, the flow direction of the accommodating portion 60 (X-axis direction) distance and L _2. Dissolving tank 120 of the present _embodiment, it is preferable that L 2 / _{L 1} satisfies 0.05 to 0.5. By setting L ₂ / L ₁ to 0.05 to 0.5, outflow of the foreign glass G 1 to the throat 30 can be effectively suppressed.

As shown in FIG. 4, the width direction (Y axis direction) distance of the accommodating portion 51 and W _2. Dissolving tank 120 of the present _embodiment, it is preferable that W 2 / _{W 1} meets from 1.1 to 5.0. The outflow of the foreign glass G1 to the throat 30 can be effectively suppressed by setting W ₂ / W ₁ to 1.1 to 5.0.

  The weight of the molten glass G in the storage unit 60 is w [ton], and the weight of the molten glass G discharged from the discharge unit 150 one day is D [ton / day]. It is preferable that the glass melting furnace 110 of this embodiment satisfy | fills 0.02 <= w / D <= 0.4. When w / D is 0.02 or more, since the foreign glass G1 can be stored in the housing portion 60, the outflow of the foreign glass G1 to the throat 30 can be effectively suppressed. When w / D is 0.4 or less, the occurrence of circulation of the molten glass G in the housing portion 60 can be suppressed, and thus the outflow of the foreign glass G1 to the throat 30 can be effectively suppressed. Also, the weight D is preferably 0.5 to 30 [tons / day].

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the above embodiments, and design changes within the scope of the present invention are also included.

  Although the glass melting furnace 10, 110 of this embodiment performs melting of the glass material by burner heating and electric heating, the glass material may be melted by burner heating alone or electric heating alone.

  Although the dissolution tank 20, 120 of this embodiment is a rectangular shape extended long in the uniaxial direction (X-axis direction) in planar view, it is not limited to this as long as it can melt glass materials.

  In this embodiment, although the discharge part 50,150 is installed in one place, even if it is installed in two or more places in the length direction (X-axis direction) or the width direction (Y-axis direction) of the glass melting furnace 10,110. Good.

  Although the form of the partition wall 40 extended and provided in the upper side (+ Z side) from the bottom part 21 was demonstrated in this embodiment, a partition wall will not be limited to this, if it divides the molten glass G.

[Method of producing glass article]
Next, the manufacturing method of the glass article using the glass melting furnace 110 among the glass melting furnaces 10 and 110 of this embodiment is demonstrated. FIG. 5 is a flowchart showing a method of manufacturing a glass article according to the first embodiment of the present invention.

  In the method of manufacturing a glass article according to the present embodiment, a melting step S1 for melting a glass raw material to obtain a molten glass G, a clarification step S2 for removing bubbles of the molten glass G, and a forming step S3 for forming the molten glass G And annealing step S4 of annealing the formed glass.

  In the melting step S1, the glass material is supplied into the melting tank, and the glass material is heated and melted. The glass material is heated from above by radiating a flame of a burner provided in the glass melting furnace toward the glass material. While heating with the flame of a burner, it supplies with electricity by applying a voltage to several electricity supply electrodes, Joule heat is generated, and a glass raw material is heated.

Dissolving step S1 is in the dissolution tank, in flowing molten glass downstream, temperature T ₂ at which the viscosity η is 10 ² poise dissolving 1580 ° C. or more glass. A dissolution tank is provided with the partition wall provided over the width direction of a dissolution tank, and also is equipped with the discharge part in the bottom part of a dissolution tank. The partition wall blocks part of the flow of molten glass. The molten glass is transferred toward the clarification step S2 via a throat provided in communication with the melting tank. The discharge unit discharges the molten glass.

  The weight of the molten glass held by the melting tank between the throat inlet and the partition wall is W [ton], and the weight of the molten glass transferred from the throat on one day is P [ton / day]. The dissolution step S1 of the present embodiment preferably satisfies 0.2 ≦ W / P ≦ 2.0.

  In the melting step S1 of the present embodiment, the weight P [ton / day] is 0.01 ≦ D / P ≦ 0.2, where D [ton / day] is the weight of the molten glass G discharged from the discharge part. It is preferable to satisfy. When D / P is 0.01 or more, the foreign glass G1 can be sufficiently discharged from the discharge part 50, and therefore, the foreign glass G1 can be prevented from flowing out to the throat 30. Moreover, if D / P is 0.2 or less, the production loss by discharge of the molten glass G from the discharge part 50 can be suppressed.

  The fining step S2 is a step of supplying the molten glass obtained in the melting step S1 to a fining tank and floating bubbles in the molten glass for removal. As a method of promoting floating of bubbles, there is, for example, a method of decompressing the inside of the clarification tank to degas.

  In the forming step S3, the molten glass is formed in a forming furnace provided downstream of the melting tank. In the slow cooling step S4, the glass formed in the slow cooling furnace provided downstream of the molding furnace is gradually cooled to finally obtain a glass article.

  In order to obtain a glass plate as a glass article, for example, a float method is used. The float method is a method in which molten glass introduced on a molten metal (for example, molten tin) accommodated in a float bath is made to flow in a predetermined direction to form a ribbon ribbon (a forming step S3). The glass ribbon is cooled in the process of flowing in the horizontal direction, and is then pulled up from the molten metal and gradually cooled while being transported in the annealing furnace to form a sheet glass (annealing step S4). The sheet glass is taken out of the annealing furnace and then cut into a predetermined size and shape by a cutting machine to become a glass sheet which is a product.

  Moreover, you may use the fusion method as another shaping | molding method to obtain a glass plate. In the fusion method, the molten glass overflowing from the left and right upper edges of the bowl-like member is allowed to flow down along the left and right sides of the bowl-like member, and joined together at the lower edge where the left and right sides meet. This is a method of forming a glass ribbon (forming step S3). The molten glass ribbon is gradually cooled while moving downward in the vertical direction (Z-axis direction) to be a sheet glass (necessary cooling step S4). The sheet glass is cut into a predetermined size and shape by a cutting machine to become a glass sheet which is a product.

  In addition, although the manufacturing method of the glass article of this embodiment contains fining process S2, the manufacturing method of the glass article of this invention does not need to include the fining process. In this case, the molten glass is formed into a glass ribbon in a forming process through a melting process.

  There is no restriction | limiting in particular in a composition of the glass-making feedstock used by this embodiment, Alkali-free glass, aluminosilicate glass, mixed alkali type glass, borosilicate glass, or any other glass may be sufficient.

The glass used in the present embodiment, it is possible to effectively suppress the contamination of foreign glass G1, the temperature T ₂ at which the viscosity η is 10 ² poise preferably 1610 ° C. or higher, more preferably at 1640 ° C. or higher . The glass used in the present embodiment, since the dissolution is facilitated, is preferably temperature T ₂ at which the viscosity η is 10 ² poise is 1670 ° C. or less.

  While the invention has been described in detail and 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 invention.

  Applications of the manufactured glass articles include for construction, for vehicles, for flat panel displays, for cover glass, or various other applications.

10, 110: Glass melting furnace 20, 120: Dissolution tank 21: Bottom 22: Side wall 30: Throat 40: Partition wall 50, 150: Discharge part 51, 151: Discharge pipe 60: Storage part 100: Forward flow 101: Upstream Side circulation flow 102: downstream circulation flow G: molten glass G1: foreign glass

Claims (13)

A glass comprising: a melting tank for melting a glass raw material and causing the obtained molten glass to flow downstream, and a throat provided in communication with the melting tank for transferring the molten glass toward a clarification tank or a forming furnace A melting furnace,
The dissolving tank is provided with a partition wall, and a discharge portion, temperature T ₂ at which the viscosity η is 10 ² poise by dissolving 1580 ° C. or more glass,
The partition wall is provided across the width direction of the melting tank, and blocks part of the flow of the molten glass,
The discharge unit is provided at the bottom of the melting tank between the throat and the partition wall, and discharges the molten glass.
The height from the said bottom part to the lower end of the inlet of the said throat is 20 [mm] or more, The glass melting furnace characterized by the above-mentioned.   The glass melting furnace uses the weight of molten glass held by the melting tank between the inlet of the throat and the partition wall as W [ton], and the weight of molten glass transferred from the throat daily as P [ The glass melting furnace according to claim 1, wherein 0.2 ≦ W / P ≦ 2.0 is satisfied as ton / day.   The glass melting furnace according to claim 1 or 2, wherein the height of the glass melting furnace from the bottom to the lower end of the throat inlet is 200 mm or less. The dissolution tank includes a concave receiving portion provided at the bottom,
The glass melting furnace according to any one of claims 1 to 3, wherein the storage portion has a depth of 50 to 300 mm, and a discharge portion for discharging the molten glass is provided at a bottom portion.   5. The glass melting furnace according to claim 4, wherein the flow direction distance between the downstream end of the accommodating portion and the inlet of the throat is 0 to 1000 [mm] in a plan view. A method for producing a glass article comprising a melting step, a forming step, and a slow cooling step,
The dissolution process, in the dissolution vessel to dissolve the glass raw material, in flowing molten glass obtained downstream, temperature T ₂ at which the viscosity η is 10 ² poise by dissolving 1580 ° C. or more glass,
The dissolution tank includes a partition wall provided across the width direction of the dissolution tank, and further includes a discharge portion at the bottom of the dissolution tank between the throat and the partition wall, and the partition wall is formed of the molten glass Interrupt part of the flow,
The molten glass is transferred to a fining process or the forming process through a throat provided in communication with the melting tank, and the discharge unit discharges the molten glass.
The height from the said bottom part to the lower end of the entrance of the said throat is 20 [mm] or more, The manufacturing method of the glass article characterized by the above-mentioned.   The weight of molten glass held by the melting tank between the inlet of the throat and the partition wall is W [ton], and the weight of molten glass transferred from the throat per day is P [ton / day], The manufacturing method of the glass article of Claim 6 which satisfy | fills 0.2 <= W / P <= 2.0.   The manufacturing method of the glass article of Claim 6 or 7 whose height from the said bottom part to the lower end of the entrance of the said throat is 200 [mm] or less. The dissolution step is
The molten glass is stored in a concave housing portion provided at the bottom of the melting tank,
The molten glass is discharged by a discharge portion provided at the bottom of the housing portion,
The manufacturing method of the glass article of any one of Claims 6-8 whose said accommodating part is 50-300 [mm] in depth.   The method for producing a glass article according to claim 9, wherein, in the melting step, the distance in the flow direction between the downstream end of the storage portion and the inlet of the throat is 0 to 1000 [mm] in plan view.   In the melting step, the weight of the molten glass in the storage unit is w [ton], and the weight of the molten glass discharged from the discharge unit in one day is D [ton / day], 0.02 ≦ w / D ≦ The manufacturing method of the glass article of Claim 9 or 10 which satisfy | fills 0.4.   The said melt | dissolution process manufactures the glass article of any one of Claims 6-11 whose average flow velocity of the flow direction of the said molten glass is 5-15 [m / h] in the entrance of the said throat. Method.   In the melting step, the weight P satisfies 0.01 ≦ D / P ≦ 0.2, where D [ton / day] is the weight of the molten glass discharged from the discharge part on one day. The manufacturing method of the glass article of any one of -12.