KR20190045864A - Glass melting furnace and method for producing glass articles - Google Patents

Abstract

The present invention provides a glass melting furnace capable of suppressing mixing of foreign glass into glass goods, and a method for manufacturing glass goods. The glass melting furnace (10) includes a dissolver (20) and a throat (30). The dissolver (20) includes a dividing wall (40) and a discharge unit (50), and melts glass having temperature T_2 of 1,580°C or higher, wherein viscosity η becomes 10^2 poise. In addition, the dividing wall (40) is placed over the width direction of the dissolver (20) in order to block some of flow of molten glass G. The discharge unit (50) is placed in a bottom unit (21) of the dissolver (20) between the throat (30) and the dividing wall (40) in order to discharge molten glass G. Furthermore, height H_S from the bottom unit (21) to the bottom end of an inlet of the throat (30) is 20 mm or higher.

Description

TECHNICAL FIELD [0001] The present invention relates to a glass melting furnace,

The present invention relates to a glass melting furnace and a process for producing a glass article.

The refractory constituting the glass melting furnace is eroded in contact with the molten glass at a high temperature and eluted into the molten glass. Thus, a heterogeneous glass having a composition and specific gravity different from that of the molten glass is produced. On the other hand, as the refractory material in contact with the molten glass, it is often the case that a poling brick excellent in corrosion resistance to molten glass is used. Among them, zirconia-based electroconductive bricks have higher zirconia (ZrO ₂ ) content than other electroconductive bricks, and are superior in corrosion resistance to other electroconductive bricks. However, zirconia (ZrO ₂ ) is a component that is not included in the glass composition and has a specific gravity higher than that of the molten glass, so that when the molten glass is eluted into the molten glass, generation of the heterogeneous glass is promoted. When such a heterogeneous glass is mixed with a finally obtained glass article, there is a problem that the production yield is lowered because the desired quality is not satisfied.

In order to prevent such a heterogeneous glass from being mixed into a glass article, Patent Document 1 discloses a glass melting furnace having a glass discharge portion for discharging heterogeneous glass at the bottom.

Japanese Patent Application Laid-Open No. 2006-62903

However, merely providing the glass discharge portion at the bottom does not sufficiently prevent the heterogeneous glass from being mixed into the glass article. The molten glass in the glass melting furnace flows to the downstream side while forming a circulating flow in the glass melting furnace. When the circulating flow of the molten glass is large or when the traveling speed of the circulating flow is high, it is difficult for the heterogeneous glass stagnated at the bottom to flow to the glass discharging portion. For this reason, a heterogeneous glass is mixed in the throat for transferring the molten glass toward the blue sign or the molding furnace, and a heterogeneous glass is also mixed into the finally obtained glass article.

Particularly, the glass having the temperature T ₂ of 10 ² poise at a viscosity η of 10 ² poise or higher is 1580 ° C. or higher, because the temperature of the molten glass in the glass melting furnace is high, so that the refractory constituting the glass melting furnace is eroded and easily eluted into the molten glass. Therefore, a problem that heterogeneous glass is incorporated into a glass article is presently available.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a glass melting furnace capable of suppressing the incorporation of a heterogeneous glass into a glass article, and a method for producing a glass article.

A glass melting furnace of the present invention is a glass melting furnace having a melting vessel for flowing a molten glass obtained by melting a glass raw material to the downstream side and a throat provided for communicating with the melting vessel and for transferring the molten glass toward a blue- Wherein the melting tank has a partition wall and a discharge portion, the glass having a temperature T ₂ of 1580 ° C or more at which the viscosity η is 10 ² poise is dissolved, and the partition wall is provided over the width direction of the melting tank, And the discharge portion is provided at the bottom of the melting vessel between the throat and the partition wall to discharge the molten glass and the height from the bottom portion to the bottom of the inlet of the throat is 20 [Mm] or more.

The present invention also provides a method for producing a glass article, which comprises a melting step, a molding step and a quenching step, wherein the melting step is a step of causing the molten glass obtained by melting the glass raw material to flow downstream And the glass having a temperature T ₂ of 1580 ° C or more at which the viscosity η is 10 ² poise is melted. The melting tank has a partition wall provided over the width direction of the melting tank, and the throat and the partition wall Wherein the partition wall blocks a part of the flow of the molten glass and the molten glass is introduced into the molten glass through a throat provided in communication with the molten glass, And the discharge portion discharges the molten glass, and the height from the bottom portion to the lower end of the inlet of the throat is 20 [mm] or more.

According to the glass melting furnace of the present invention and the production method of the glass article, mixing of the heterogeneous glass into the glass article can be suppressed.

1 is a cross-sectional view of a glass melting furnace according to a first embodiment of the present invention in a Y-axis vertical plane.
Fig. 2 is a sectional view of the glass melting furnace in the X-axis vertical plane according to the first embodiment of the present invention, and is a sectional view taken along the line I-I in Fig.
Fig. 3 is a cross-sectional view of the glass melting furnace according to the second embodiment of the present invention on a Y-axis vertical plane. Fig.
Fig. 4 is a cross-sectional view of the glass melting furnace according to the second embodiment of the present invention taken along the X-axis vertical plane, and is a sectional view taken along the line II-II in Fig. 3;
5 is a flowchart showing a method of manufacturing a glass article according to the first embodiment of the present invention.

Hereinafter, various embodiments according to the present invention will be described with reference to the drawings. In the present specification, " to " representing the numerical range means a range including numerical values before and after the numerical range.

In addition, the direction of the reference in each drawing corresponds to the direction of the symbol or number. In the drawing, the XYZ coordinate system as a three-dimensional orthogonal coordinate system is appropriately represented, the Z-axis direction is the vertical direction in FIGS. 1 to 4, and the X-axis direction is the direction of the glass melting furnace 10, 110 And the Y axis direction is set to the width direction (left and right direction) of the glass melting furnaces 10 and 110 shown in Figs. In the present specification, the X-axis direction is a plane direction of the molten glass G, and the Y-axis direction is orthogonal to the flow direction of the molten glass G.

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 furnaces 10 and 110, and the + X side is the downstream side and the -X side is the upstream side to be.

[Glass melting furnace]

≪ First Embodiment >

1 is a cross-sectional view of a glass melting furnace according to a first embodiment of the present invention in a Y-axis vertical plane. Fig. 2 is a cross-sectional view taken along the X-axis vertical plane of the glass melting furnace according to the first embodiment of the present invention, and is a sectional view taken along the line I-I 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. Fig.

The glass melting furnace 10 of the present embodiment includes a melting vessel 20 for flowing a molten glass G obtained by melting a glass raw material supplied by a raw material supply device (not shown) to the downstream side (+ X side) And a throat 30 provided in communication with the molten glass 20 for transferring the molten glass G toward a blue sign (not shown) or a molding furnace (not shown).

The melting vessel 20 has a partition wall 40 and a discharge portion 50 and dissolves glass having a temperature T ₂ of 1580 ° C or higher at a viscosity η of 10 ² poise. The partition wall 40 is provided over the width direction (Y-axis direction) of the melting tank 20 to block a part of the flow of the molten glass G. The discharge portion 50 is provided on the bottom portion 21 of the melting tank 20 between the throat 30 and the partition wall 40 to discharge the molten glass G. [

The melting vessel 20 is provided with a burner (not shown) in a wall portion located on the upper side (+ Z side) of the molten glass G and is heated by burner burning using fuel and gas, The molten glass G is obtained by dissolving the supplied glass raw material. The fuel is natural gas or heavy oil, and the gas is oxygen or air. The melting vessel 20 has a bottom portion 21 and a side wall portion 22, and holds the molten glass G therein. Since the bottom portion 21 and the side wall portion 22 are in contact with the molten glass G on the inside, they are formed of electroconductive bricks having excellent corrosion resistance. Examples of the electropolishing bricks include zirconia-based bricks, alumina-zirconia-silica (AZS) -based bricks, and alumina-based bricks. The bottom portion 21 or the side wall portion 22 may be provided with a current-carrying electrode (not shown). The energizing electrode generates a joule heat by applying a voltage to dissolve the glass raw material to obtain a molten glass G.

Since the melting vessel 20 is in contact with the molten glass G, a part of the copper bricks constituting the melting vessel 20 is eluted into the molten glass G. In the case of using the electrolytic bath 20 with the electrolytic brick containing zirconia (ZrO ₂ ), the zirconia (ZrO ₂ ) component having a high specific gravity is eluted into the molten glass G. For this reason, in the vicinity of the bottom 21 of the melting vessel (20), and zirconia (ZrO ₂₎ a concentration of high specific gravity is high heterogeneity glass G1 are staying.

And the height from the bottom portion 21 to the lower end of the inlet of the throat 30 is H _S. The height H _S is 20 [mm] or more. 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 making the height H _S equal to or larger than 20 [mm], it is possible to prevent the heterogeneous 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 heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side) than the throat 30.

As shown in Fig. 2, the throat 30 is provided communicating with a central portion in the width direction (Y-axis direction) of the melting tank 20. As shown in Fig. Therefore, the flow of the molten glass G is symmetrical in the width direction (Y-axis direction), and the downstream-side circulation flow 102 shown in FIG. 1 can be easily controlled.

The partition wall 40 is a dam structure provided to extend above the bottom portion 21 (on the + Z side) to block the flow of the lower layer of the molten glass G. The partition wall 40 is divided into a forward flow 100 and a downstream flow region 50 on the upper side (+ Z side), the upstream side (-X side) and the downstream side (+ X side) of the partition wall 40, The circulation flow 101 and the downstream circulation flow 102 are formed. The forward flow 100 flows from the upstream side (-X side) in the melting tank 20 toward the downstream side (+ X side). The upstream side circulation flow 101 flows toward the upstream side (-X side) in the melting vessel 20 at the upper portion of the molten glass G and flows toward the downstream side (+ X side) in the melting vessel 20 below the molten glass G, As shown in Fig. The downstream side circulation flow 102 flows toward the downstream side (+ X side) in the melting vessel 20 on the upper side of the molten glass G and flows toward the upstream side (-X side) in the melting vessel 20 below the molten glass G, As shown in Fig. The partition wall 40 is made of a material excellent in corrosion resistance to the molten glass G, such as electric pole brick, platinum, platinum alloy, iridium, molybdenum and the like.

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

2, the discharge portion 50 is provided at a central portion in the width direction (Y-axis direction) of the melting tank 20. As shown in Fig. The discharge portion 50 is provided inside the width direction (Y axis direction) of the throat 30. As a result, it is possible to effectively prevent the heterogeneous glass G1 from flowing out into the throat 30. [

The weight of the molten glass G retained by the melting tank 20 between the inlet of the throat 30 and the partition wall 40 is W [ton], the weight of the molten glass G conveyed from the throat 30 Is referred to as P [ton / day]. At this time, the glass melting furnace 10 of the present embodiment preferably satisfies 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-side circulation stream 102 is suppressed and the heterogeneous glass G1 is hard to be rolled up, so that the heterogeneous glass G1 can be prevented from flowing out into the throttle 30. [ Further, when the W / P is 0.2 or more, the molten glass G excluding the heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side) than the throat 30. The weight P is preferably 20 to 200 [ton / day].

The height from the bottom part 21 to the upper surface of the molten glass G is H ₀ and the height from the bottom part 21 to the upper end of the partition wall 40 is H ₁ , the height between the bottom part of the inlet of the throat 30 and the ceiling part Is referred to as H ₂ . In the glass melting furnace 10 of the present embodiment, it is preferable that H ₁ / H ₀ satisfies 0.3 to 0.95, more preferably 0.5 to 0.95. If H ₁ / H ₀ is 0.3 or more, it is possible to prevent the downstream-side circulation flow 102 from becoming large, and it is difficult for the heterogeneous glass G 1 to be rolled up, so that the heterogeneous glass G 1 can be prevented from flowing out to the throttle 30 have. Further, when H ₁ / H ₀ is 0.95 or less, the forward flow 100 and the downstream side circulation flow 102 are stabilized and the heterogeneous glass G 1 becomes hard to be rolled up, so that the heterogeneous glass G 1 flows out into the throttle 30 .

In the glass melting furnace 10 of the present embodiment, it is preferable that H ₂ / H ₀ satisfies 0.1 to 0.5. By the H ₂ / H ₀ of 0.1 to 0.5, a dissimilar glass G1 is, while suppressing the leakage to the throat (30), except for dissimilar glass G1 molten glass G the effective throat (30) than the downstream side (+ X Side.

The distance from the upstream end to the downstream end in the melting tank 20 is referred to as L ₀ and the distance from the downstream end of the partition wall 40 to the downstream end in the dissolving tank 20 is referred to as L ₁ . The melting tank 20 of the present embodiment preferably has L ₁ / L ₀ of 0.1 to 0.5. By setting L ₁ / L ₀ to 0.1 to 0.5, molten glass G excluding the heterogeneous glass G 1 can be efficiently transferred to the downstream side (+ X side).

2, is referred to as the width direction (Y axis direction) to W _0, Width direction of Lot 30, the distance (Y axis direction) distance in the melting vessel (20) W _1. In the glass melting furnace 10 of the present embodiment, W ₁ / W ₀ preferably satisfies 0.03 to 0.3. By setting W ₁ / W ₀ to 0.03 to 0.3, the molten glass G excluding the heterogeneous glass G 1 can be efficiently transferred to the downstream side (+ X side).

It is preferable that the glass melt passage 10 of the present embodiment has an average flow velocity V of 5 to 15 [m / h] in the flow direction (X-axis direction) of the molten glass G at the inlet of the throat 30. [ The average flow velocity V [m / h] is expressed by V = P (m / h), where S [m2] denotes the cross- (24 x S x d). If the average flow velocity V is not less than 5 [m / h], the molten glass G excluding the heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side) than the throat 30. [ Further, when the average flow velocity V is 15 [m / h] or less, it is possible to effectively inhibit the heterogeneous glass G1 from flowing out into the throat 30.

The glass used in the present embodiment has a temperature T ₂ at which viscosity η is 10 ² poise is preferably at least 1610 ° C., more preferably at least 1640 ° C., in order to effectively suppress the incorporation of heterogeneous glass G ₁ . In order to facilitate dissolution, the glass used in the present embodiment has a temperature T ₂ at which the viscosity eta becomes 10 ² poise, preferably not more than 1670 ° C.

&Quot; Second Embodiment "

Fig. 3 is a cross-sectional view of the glass melting furnace according to the second embodiment of the present invention on a Y-axis vertical plane. Fig. Fig. 4 is a cross-sectional view of the glass melting furnace according to the second embodiment of the present invention taken along the X-axis vertical plane, and is a sectional view taken along the line II-II in Fig.

A second embodiment of the glass melting furnace according to the present invention will be described with reference to Figs. 3 and 4. Fig. Only the points different from the first embodiment will be described below. The glass melting furnace 110 of the second embodiment has a structure different from that of the glass melting furnace 10 of the first embodiment in that the melting vessel is provided with the receiving portion 60.

3, the melting tank 120 of the present embodiment is provided with a recessed receiving portion 60 provided at the bottom portion 21 between the inlet of the throat 30 and the partition wall 40 do. The receiving portion 60 is box-shaped and holds the molten glass G therein. The accommodating portion 60 is provided with a discharge portion 150 for discharging the molten glass G to the bottom portion thereof. The concave receiving portion 60 may be rectangular, semicircular, semi-elliptical, or a rectangle with rounded corners although the cross section of the X axis vertical plane or the Y axis vertical plane is rectangular. Further, although the receiving portion 60 has a circular cross-section on the Z-axis vertical plane, it may be square or rectangular.

As shown in Fig. 4, the accommodating portion 60 is provided at a central portion in the width direction (Y-axis direction) of the melting tank 120. As shown in Fig. Since the accommodating portion 60 is larger in width than the throat 30, it is possible to effectively suppress the outflow of the heterogeneous glass G1 into the throat 30. [

The discharging portion 150 has a discharge pipe 151 for discharging the foreign glass G1 on the lower side (-Z side) of the bottom portion of the accommodating portion 60. The discharge portion 150 is different from the discharge portion 50 of the first embodiment in that the length of the discharge pipe in the vertical direction (Z-axis direction) is shortened by the depth of the receiving portion 60.

According to the melting tank 120 of the present embodiment, it is possible to effectively prevent the heterogeneous glass G1 from flowing out into the throat 30. [ The distance between the bottom of the receiving portion 60 and the bottom portion 21 of the dissolving tank 20 is denoted by H _S1 . The height H _S1 is preferably 50 to 300 [mm]. When the height H _S1 is equal to or larger than 50 mm, the heterogeneous glass G1 is stored in the accommodating portion 60. When the height H _S1 is 300 mm or less, the circulation of the molten glass G in the accommodating portion 60 It is possible to prevent the heterogeneous glass G1 from flowing upward.

In the present embodiment, the distance in the flow direction (X-axis direction) between the downstream end of the accommodating portion 60 and the inlet of the throat 30 in plan view is referred to as L _S. Distance L _S is preferably 0 to 1000 [㎜]. The distance L _S is more preferably 0 to 500 [mm], and still more preferably 0 to 100 [mm]. When the distance L _S is 1000 [mm] or less, it is possible to effectively prevent the heterogeneous glass G1 from flowing out into the throat 30.

The distance in the flow direction (X-axis direction) of the accommodating portion 60 as viewed in plan is L ₂ . In the melting vessel 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, it is possible to effectively inhibit the heterogeneous glass G ₁ from flowing out into the throat 30.

It is referred to Fig. 4 a, the width direction (Y-axis) distance of the receiving part (51), W _2, as shown in. In the melting vessel 120 of the present embodiment, W ₂ / W ₁ preferably satisfies 1.1 to 5.0. By setting W ₂ / W ₁ to be 1.1 to 5.0, it is possible to effectively inhibit the heterogeneous glass G ₁ from flowing out into the throat 30.

The weight of the molten glass G in the accommodating portion 60 is denoted by w [ton], and the weight of the molten glass G discharged from the discharging portion 150 on a day is denoted by D [ton / day]. It is preferable that the glass melting furnace 110 of the present embodiment satisfies 0.02? W / D? 0.4. If w / D is 0.02 or more, the heterogeneous glass G1 can be stored in the accommodating portion 60, so that the heterogeneous glass G1 can be effectively prevented from flowing out into the throttle 30. If w / D is 0.4 or less, the circulation of the molten glass G in the accommodating portion 60 can be suppressed, so that the dissimilar glass G1 can be effectively prevented from flowing out into the throat 30. The weight D is preferably 0.5 to 30 [ton / day].

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific structure is not limited to the above embodiment but includes a design change within a range not departing from the gist of the present invention.

In the glass melting furnaces 10 and 110 of the present embodiment, the glass raw materials are melted by burner heating and electric heating, but the glass raw materials may be dissolved by burner heating alone or electric heating alone.

Although the melting vessels 20 and 120 of the present embodiment have a rectangular shape elongated in the uniaxial direction (X-axis direction) seen in plan view, they are not limited to the above as long as they can dissolve the glass raw material.

In this embodiment, the discharge units 50 and 150 are provided at one location, but two or more discharge units 50 and 150 may be provided in the longitudinal direction (X axis direction) or the width direction (Y axis direction) of the glass melting furnaces 10 and 110.

In the present embodiment, the shape of the partition wall 40 extended above the bottom portion 21 (+ Z side) has been described. However, the partition wall is not limited to this as long as it divides the molten glass G.

[Production method of glass article]

Next, a method for producing a glass article using the glass melting furnace 110 among the glass melting furnaces 10 and 110 of the present embodiment will be described. Fig. 5 is a flowchart showing a method for manufacturing a glass article in the first embodiment according to the present invention.

The manufacturing method of the glass article of the present embodiment includes a melting step S1 for melting a glass raw material to obtain a molten glass G, a refining step S2 for removing bubbles of the molten glass G, a molding step S3 for molding the molten glass G, And a quenching step S4 for quenching the formed glass.

In the dissolving step S1, a glass raw material is supplied into a dissolver and the glass raw material is heated to be dissolved. The glass raw material is heated from above by spinning the flame of the burner provided in the glass melting furnace toward the glass raw material. The glass raw material is heated by the flame of the burner and energized by applying a voltage to a plurality of energizing electrodes to generate joule heat to heat the glass raw material.

In the dissolving step S1, the molten glass is caused to flow downstream in the melting tank to dissolve the glass having a temperature T ₂ of 1580 ° C or higher at which the viscosity η becomes 10 ² poise. The dissolving tank has a partition wall provided over the width direction of the dissolving tank, and has a discharge portion at the bottom of the dissolving tank. The partition wall blocks a part of the flow of the molten glass. The molten glass is conveyed toward the fining step S2 through a throat provided in communication with the melting tank. The discharge portion discharges the molten glass.

The weight of the molten glass held by the melting vessel between the inlet of the throat and the partition wall is W [ton], and the weight of the molten glass conveyed from the throat per day is P [ton / day]. The melting 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 when the weight of the molten glass G discharged from the discharging portion on one day is D [ton / . If the D / P is 0.01 or more, the heterogeneous glass G1 can be sufficiently discharged from the discharge portion 50, so that the heterogeneous glass G1 can be prevented from flowing out to the throat 30. [ If the D / P is 0.2 or less, the production loss due to the discharge of the molten glass G from the discharge portion 50 can be suppressed.

The firing step S2 is a step of supplying the molten glass obtained in the melting step S1 to the blue sign and floating the bubbles in the molten glass. As a method for promoting the floating of the bubble, for example, there is a method of degassing the inside of the blue bubble by depressurization.

In the molding step S3, a molten glass is formed in a molding furnace located on the downstream side of the melting bath. In the quenching step S4, the glass molded in the thirst furnace provided on the downstream side of the forming furnace is thawed 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 flowed in a predetermined direction to form a strip-shaped glass ribbon (molding step S3). The glass ribbon is cooled in the process of flowing in the horizontal direction, then is drawn up from the molten metal and is conveyed in the throat furnace to be thawed to become a plate glass (quenching step S4). The plate glass is taken out from the throat furnace, and then cut into a predetermined shape by a cutter to obtain a glass plate as a product.

Further, a fusion method may be used as another molding method for obtaining a glass plate. The fusion method is a method in which molten glass overflowing from the upper edge on both right and left sides of the gutter-shaped member is lowered along both left and right side surfaces of the gutter-shaped member and joined at the lower edge where the right and left sides intersect, (Molding step S3). The molten glass ribbon moves downward in the vertical direction (Z-axis direction) to be frosted to become a plate glass (quenching step S4). The plate glass is cut into a predetermined dimension by a cutter to form a glass plate as a product.

Further, the method of manufacturing a glass article of the present embodiment includes a fining step S2, but the method of manufacturing a glass article of the present invention does not need to include a fining step. In this case, the molten glass is formed into a glass ribbon in a molding process through a dissolving process.

The composition of the glass raw material to be used in the present embodiment is not particularly limited and may be any of alkali-free glass, aluminosilicate glass, mixed alkali glass, borosilicate glass, and other glass.

The glass used in the present embodiment is preferably a temperature T ₂ at which the viscosity η is 10 ² poise is preferably at least 1610 ° C. and more preferably at least 1640 ° C. in order to effectively suppress the incorporation of the aliphatic glass G ¹ . Further, the glass used in the present embodiment has a temperature T ₂ at which the viscosity η is 10 ² poise, preferably not more than 1670 ° C., in order to facilitate dissolution.

While the invention has been described in detail and with reference to specific embodiments thereof, it is evident to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

This application is based on Japanese Patent Application No. 2017-205301 filed on October 24, 2017, the content of which is incorporated herein by reference.

The glass articles to be manufactured can be used for various purposes such as building use, automotive use, flat panel display use, cover glass use, and various other uses.

10, 110: glass melting furnace
20, 120: Melting bath
21:
22:
30: throat
40: compartment wall
50, 150:
51, 151:
60:
100: forward flow
101: upstream-side circulation flow
102: downstream side circulation flow
G: molten glass
G1: heterogeneous glass

Claims (13)

A glass melting furnace comprising a melting furnace for flowing a molten glass obtained by melting a glass raw material to a downstream side and a throat provided for communicating with the melting furnace and for transferring the molten glass toward a blue sign or a forming furnace,
Wherein the melting tank has a partition wall and a discharge portion, the glass having a temperature T ₂ of 1580 캜 or more at which the viscosity η is 10 ² poise is dissolved,
Wherein the partition wall is provided across the width direction of the melting vessel to block a part of the flow of the molten glass,
Wherein the discharge portion is provided at a bottom portion of the melting vessel between the throat and the partition wall to discharge the molten glass,
And a height from the bottom portion to a lower end of an inlet of the throat is 20 mm or more. The method according to claim 1,
The weight of the molten glass held by the melting vessel between the inlet of the throat and the partition wall is W [ton], the weight of the molten glass conveyed from the throat is P [ Ton / day], the glass melting furnace satisfies 0.2? W / P? 2.0. 3. The method according to claim 1 or 2,
Wherein the glass melting furnace has a height from the bottom portion to a lower end of an inlet of the throat is 200 mm or less. 3. The method according to claim 1 or 2,
Wherein the melting tank has a concave receiving portion provided in the bottom portion,
Wherein the accommodating portion has a depth of 50 to 300 [mm], and a discharge portion for discharging the molten glass is provided at the bottom portion. 5. The method of claim 4,
Wherein a flow direction distance between a downstream end of the accommodating portion and an inlet of the throat is 0 to 1000 [mm] in plan view. A method for producing a glass article, comprising a melting step, a forming step and a quenching step,
In the dissolution step, the molten glass obtained by dissolving the glass raw material in the melting tank flows downward, and the glass having a temperature T ₂ of 1580 ° C or higher at which the viscosity η is 10 ² poise is dissolved,
Wherein the melting tank has a partition wall provided over the width direction of the melting tank and has a discharge portion at a bottom portion of the melting tank between the throat and the partition wall, ,
Wherein the molten glass is conveyed toward the refining step or the forming step through a throat provided in communication with the melting tank, the discharging part discharging the molten glass,
And the height from the bottom portion to the lower end of the inlet of the throat is 20 mm or more. The method according to claim 6,
The weight of the molten glass held by the melting vessel between the inlet of the throat and the partition wall is W [ton], the weight of the molten glass conveyed from the throat per day is P [ton / day] , And satisfies 0.2? W / P? 2.0 when the glass article is produced. 8. The method according to claim 6 or 7,
Wherein a height from the bottom portion to a lower end of an entrance of the throat is 200 mm or less. 8. The method according to claim 6 or 7,
Wherein the dissolving step comprises:
The molten glass is stored in a recessed receiving portion provided at the bottom of the melting tank,
The molten glass is discharged by a discharge portion provided at a bottom portion of the accommodating portion,
Wherein the receiving portion has a depth of 50 to 300 [mm]. 10. The method of claim 9,
Wherein the dissolving step is such that a flow direction distance between a downstream end of the accommodating portion and an inlet of the throat is 0 to 1000 mm in plan view. 10. The method of claim 9,
W / D? 0.4 when the weight of the molten glass in the receiving portion is w [ton] and the weight of the molten glass discharged from the discharging portion on the day is D [ton / day] Of the glass product. 8. The method according to claim 6 or 7,
Wherein the dissolving step has an average flow rate of 5 to 15 [m / h] in the flow direction of the molten glass at the entrance of the throat. 8. The method of claim 7,
In the dissolving step, the weight P satisfies 0.01? D / P? 0.2 when the weight of the molten glass discharged from the discharge portion on a day is D [ton / day] .

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