TW201922633A - Glass melting furnace and method for manufacturing glass articles comprising a melting tank and a furnace throat - Google Patents

Abstract

The present invention provides a glass melting furnace capable of suppressing incorporation of foreign glass into a glass article, and a method of manufacturing glass articles. The glass melting furnace 10 of the present invention is characterized in that it comprises a melting tank 20 and a furnace throat 30. The melting tank 20 is provided with a partition wall 40 and a discharge part 50, wherein the temperature T2 at which the glass is melted to have a viscosity [eta] of 102 poise is 1580 DEG C or higher, the partition wall 40 is disposed across the width direction of the melting tank 20 to block a portion of the flow of the molten glass G, the discharge part 50 is disposed on the bottom part 21 of the melting tank 20 between the furnace throat 30 and the partition wall 40 to discharge the molten glass G, and the height HS from the bottom part 21 to the lower end of the inlet of the furnace throat 30 is 20[mm] or more.

Description

Glass melting furnace and glass article manufacturing method

The invention relates to a glass melting furnace and a method for manufacturing glass articles.

The refractory constituting the glass melting furnace is in contact with the molten glass at a high temperature, is eroded, and dissolves into the molten glass. Thereby, a heterogeneous glass having a composition and specific gravity different from that of the molten glass is generated. On the other hand, many refractory parts in contact with the molten glass use electroformed bricks that are superior in corrosion resistance to the molten glass. Among them, zirconia-based electroformed bricks have a higher content of zirconia (ZrO ₂ ) than other electroformed bricks, and have superior corrosion resistance compared to other electroformed bricks. However, zirconia (ZrO ₂ ) is a component not included in the glass composition, and its specific gravity is higher than that of the molten glass. Therefore, if dissolved into the molten glass, the growth of heterogeneous glass is promoted. If such a heterogeneous glass is mixed into the finally obtained glass article, the required quality cannot be satisfied, thus causing a problem that the production yield is reduced.

In order to prevent such a heterogeneous glass from being mixed into a glass article, Patent Document 1 discloses a glass melting furnace provided with a glass discharge section for discharging heterogeneous glass to the bottom.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2006-62903

[Problems to be solved by the invention]

However, the provision of the glass discharge portion only at the bottom cannot sufficiently suppress the incorporation of heterogeneous glass into the glass article. The molten glass in the glass melting furnace forms a circulating flow in the glass melting furnace and flows toward the downstream side. When the circulating flow of the molten glass is large, or when the circulating flow is moving at a high speed, it is difficult for the heterogeneous glass staying at the bottom to flow to the glass discharge portion. Therefore, the heterogeneous glass is mixed into the throat of the molten glass toward the clarification tank or the forming furnace, and the heterogeneous glass is also mixed into the finally obtained glass article.

Especially for the glass whose viscosity η is 10 ² poises and the temperature T ₂ is 1580 ° C or higher, the temperature of the molten glass in the glass melting furnace becomes higher, so the refractory constituting the glass melting furnace is corroded and easily dissolves into the molten glass . Therefore, the problem of mixing heterogeneous glass into glass articles is significant.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a glass melting furnace capable of suppressing the incorporation of heterogeneous glass into a glass article, and a method for producing a glass article.
[Technical means to solve the problem]

The glass melting furnace of the present invention is characterized by comprising: a melting tank that melts glass raw materials and causes the obtained molten glass to flow downstream; and a furnace throat that is provided in communication with the melting tank so that the molten glass is clarified. The melting tank is provided with a partition wall and a discharge part, and the glass having a viscosity η of 10 ² poise and a temperature T ₂ of 1580 ° C or higher is melted. The partition wall is provided across the width direction of the melting tank to block the above. As part of the flow of molten glass, the discharge part is disposed at the bottom of the melting tank between the furnace throat and the partition wall, and discharges the molten glass. The height from the bottom to the lower end of the entrance of the furnace throat is 20 [mm] or more.

The method for manufacturing a glass article according to the present invention includes a melting step, a forming step, and a slow cooling step. The melting step is to melt glass raw materials in a melting tank, and to cause the obtained molten glass to flow downstream. To melt glass having a viscosity η of 10 ² poise and a temperature T ₂ of 1580 ° C. or more, the melting tank is provided with partition walls provided throughout the width direction of the melting tank, and further between the furnace throat and the partition wall. The bottom of the melting tank is provided with a discharge part, and the partition wall blocks a part of the flow of the molten glass. The molten glass is transferred to the clarification step or the forming step through a furnace throat connected to the melting tank, and the discharge part transfers the molten glass. The height from the bottom to the lower end of the inlet of the furnace throat is 20 [mm] or more.
[Effect of the invention]

According to the glass melting furnace and the glass article manufacturing method of the present invention, it is possible to suppress the incorporation of heterogeneous glass into the glass article.

Hereinafter, various embodiments of the present invention will be described using drawings. In this specification, "~" indicating a numerical range means a range including numerical values before and after the numerical range.

In addition, the reference directions of the drawings correspond to the directions of the symbols and numbers. In the figure, the XYZ coordinate system is represented as a three-dimensional orthogonal coordinate system, the Z-axis direction is set to the upper and lower directions in Figs. 1-4, and the X-axis direction is set to the glass melting furnace 10 shown in Figs. The length direction (left-right direction) of 110, and the Y-axis direction is the width direction (left-right direction) of the glass melting furnaces 10 and 110 shown in FIG. In this specification, the X-axis direction is the flow direction of the molten glass G in a plan view, and the Y-axis direction is orthogonal to the flow direction of the molten glass G.

In the present specification, the upstream and downstream sides are relative to the flow direction (X-axis direction) of the molten glass G in the glass melting furnaces 10 and 110, the + X side is the downstream side, and the -X side is Upstream side.

[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, taken along a vertical plane of the Y axis. FIG. 2 is a cross-sectional view of the glass melting furnace according to the first embodiment of the present invention, taken along the X-axis vertical plane, and is a cross-sectional view in the direction of arrow II in FIG. 1. 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 according to this embodiment includes a melting tank 20 that melts glass raw materials supplied from a raw material supply device (not shown) and flows the obtained molten glass G toward the downstream side (+ X side); and The furnace throat 30 is provided in communication with the melting tank 20 so that the molten glass G is transferred to a clarification tank (not shown) or a forming furnace (not shown).

The melting tank 20 includes a partition wall 40 and a discharge section 50, and melts a glass having a viscosity T of 10 ² poise and a temperature T ₂ of 1580 ° C or higher. The partition wall 40 is provided across the width direction (Y-axis direction) of the melting tank 20 and blocks a part of the flow of the molten glass G. The discharge part 50 is provided in the bottom part 21 of the melting tank 20 between the furnace 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 portion (+ Z side) above the molten glass G, and the glass raw material supplied to the inside of the melting tank 20 is melted by burning with a burner using fuel and gas. Thus, a molten glass G is obtained. Fuel uses natural gas or heavy oil, and gas uses oxygen or air. The melting tank 20 includes a bottom portion 21 and a side wall portion 22, and holds the molten glass G. Since the bottom portion 21 and the side wall portion 22 are in contact with the molten glass G on the inner side, they are formed of an electroformed brick having excellent corrosion resistance. Examples of electroformed 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 conducting electrode (not shown). The current-carrying electrode generates Joule heat by applying a voltage, and melts the glass raw material to obtain molten glass G.

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

The height from the bottom 21 to the lower end of the entrance of the furnace throat 30 is set to 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 even more preferably 60 to 100 [mm]. By setting the height H _S to 20 [mm] or more, the outflow of the heterogeneous glass G1 to the downstream side (+ X side) through the furnace throat 30 can be suppressed. Further, by setting the height H _S to 200 [mm] or less, the molten glass G other than the heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side) than the furnace throat 30.

As shown in FIG. 2, the furnace throat 30 and the center of the width direction (Y-axis direction) of the melting tank 20 are provided in communication. Therefore, the flow of the molten glass G is symmetrical in the width direction (Y-axis direction), so that it is easy to control the downstream-side circulating flow 102 shown in FIG. 1.

The partition wall 40 extends toward the upper side (+ Z side) from the bottom portion 21 and is a barrier structure that blocks the flow of the lower layer of the molten glass G. The partition wall 40 forms a forward flow 100, an upstream circulation flow 101, and a downstream 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.侧 circulation flow 102. The forward flow 100 flows from the upstream side (-X side) to the downstream side (+ X side) in the melting tank 20. The upstream-side circulation flow 101 is a circulation flowing above the molten glass G toward the upstream side (-X side) in the melting tank 20 and flowing below the molten glass G toward the downstream side (+ X side) in the melting tank 20 flow. The downstream-side circulation flow 102 is a circulation flowing above the molten glass G toward the downstream side (+ X side) in the melting tank 20 and flowing below the molten glass G toward the upstream side (-X side) in the melting tank 20 flow. 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, and molybdenum.

The discharge portion 50 is provided at the bottom portion 21 between the furnace throat 30 and the partition wall 40, and is provided below the bottom portion 21 (-Z side), and includes a discharge tube 51 for discharging the hetero glass G1. Accordingly, it is possible to suppress the outflow of the heterogeneous glass G1 remaining on the downstream side (+ X side) from the partition wall 40 toward the throat 30. The discharge tube 51 extends in a cylindrical shape toward the lower side (−Z side) than the bottom portion 21, and the cross section of the Z-axis vertical plane is circular, but may be a polygon or the like. The discharge pipe 51 may also be provided with a heating device (not shown) for controlling the flow-down amount of the molten glass G mixed with the hetero glass G1. In this case, the discharge pipe 51 is made of platinum or a platinum alloy, and the flow-through amount of the molten glass G can be precisely controlled by providing a direct current heating device.

As shown in FIG. 2, the discharge portion 50 is provided at the center in the width direction (Y-axis direction) of the melting tank 20. In the discharge section 50, the discharge pipe 51 is provided inside the width direction (Y-axis direction) of the furnace throat 30. Thereby, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be effectively suppressed.

Let the weight of the molten glass G held by the melting tank 20 between the entrance of the throat 30 and the partition wall 40 be W [ton], and let the weight of the molten glass G transferred from the throat 30 in one day be P [Tons / day]. At this time, the glass melting furnace 10 of this embodiment preferably satisfies 0.2 ≦ W / P ≦ 2.0. W / P is more preferably 0.4 ≦ W / P ≦ 1.2, and still more preferably 0.5 ≦ W / P ≦ 1.0. When W / P is 2.0 or less, the downstream-side circulating flow 102 can be suppressed, and the heterogeneous glass G1 is not easily rolled up, so that the heterogeneous glass G1 can be prevented from flowing toward the furnace throat 30. Moreover, if W / P is 0.2 or more, the molten glass G other than the heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side) compared to the furnace throat 30. 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 partition wall 40 is H ₁ , and between the bottom and the top of the entrance of the furnace throat 30 The height is set to H ₂ . In the glass melting furnace 10 of this embodiment, H ₁ / H ₀ preferably satisfies 0.3 to 0.95, and more preferably satisfies 0.5 to 0.95. When H ₁ / H ₀ is 0.3 or more, the downstream circulating flow 102 can be prevented from increasing, and the heterogeneous glass G1 cannot be easily rolled up. Therefore, the heterogeneous glass G1 can be prevented from flowing toward the furnace throat 30. When H ₁ / H ₀ is 0.95 or less, the forward flow 100 and the downstream circulating flow 102 are stable, and the heterogeneous glass G1 is not easily rolled up, so that the heterogeneous glass G1 can be prevented from flowing toward the furnace throat 30.

In the glass melting furnace 10 according to this embodiment, it is preferable that H ₂ / H ₀ satisfy 0.1 to 0.5. By setting H ₂ / H ₀ to 0.1 to 0.5, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be suppressed, and the molten glass G other than the heterogeneous glass G1 can be efficiently moved to the downstream side than the furnace throat 30 ( + X side) transfer.

In a plan view, the distance from the upstream end to the downstream end in the melting tank 20 is set to L ₀ , and the distance from the downstream end of the partition wall 40 to the downstream end in the melting tank 20 is set to L ₁ . In the melting tank 20 of this embodiment, L ₁ / L ₀ preferably satisfies 0.1 to 0.5. By setting L ₁ / L ₀ to 0.1 to 0.5, the molten glass G other than the heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side).

As shown in FIG. 2, the width direction (Y-axis direction) distance in the melting tank 20 is set to W ₀ , and the width direction (Y-axis direction) distance of the furnace throat 30 is set to W ₁ . In the glass melting furnace 10 of this 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 other than the heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side).

In the glass melting furnace 10 of this embodiment at the entrance of the furnace throat 30, the average flow velocity V in the flow direction (X-axis direction) of the molten glass G is preferably 5 to 15 [m / h]. The average flow velocity V [m / h] is when the cross-sectional area of the X-axis vertical plane at the entrance of the furnace throat 30 is set to S [m ² ] and the density of the molten glass G is set to d [ton / m ³ ]. It is calculated from V = P¸ (24 × S × d). If the average flow velocity V is 5 [m / h] or more, the molten glass G other than the heterogeneous glass G1 can be efficiently transferred to the downstream side (+ X side) compared to the furnace throat 30. When the average flow velocity V is 15 [m / h] or less, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be effectively suppressed.

In addition, regarding the glass used in this embodiment, in order to effectively suppress the mixing of the heterogeneous glass G1, the temperature T _{2 at} which the viscosity η becomes 10 ² poise is preferably 1610 ° C. or more, and more preferably 1640 ° C. or more. In addition, since the glass used in this embodiment is easy to melt, the temperature T _{2 at which the} viscosity η becomes 10 ² poise is preferably 1670 ° C. or lower.

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

A second embodiment of the glass melting furnace according to the present invention will be described with reference to Figs. 3 and 4. Hereinafter, only points different from the first embodiment will be described. The glass melting furnace 110 according to the second embodiment includes a storage portion 60 in a melting tank, which is different from the structure of the glass melting furnace 10 according to the first embodiment.

As shown in FIG. 3, the melting tank 120 according to the present embodiment includes a concave receiving portion 60 provided at a bottom portion 21 between the entrance of the furnace throat 30 and the partition wall 40. The accommodating portion 60 has a box shape and stores molten glass G. The storage portion 60 is provided at the bottom with a discharge portion 150 that discharges the molten glass G. The cross section of the X-axis vertical surface or the Y-axis vertical surface of the concave receiving portion 60 is rectangular, but may also be square, semi-circular, semi-oval, or rounded rectangle. The cross section of the Z-axis vertical plane of the receiving portion 60 is circular, but may be square or rectangular.

As shown in FIG. 4, the accommodating portion 60 is provided at the center in the width direction (Y-axis direction) of the melting tank 120. The width of the accommodating portion 60 is larger than that of the furnace throat 30, so that the outflow of the heterogeneous glass G1 toward the furnace throat 30 can be effectively suppressed.

The discharge section 150 includes a discharge pipe 151 for discharging the hetero glass G1 on the lower side (-Z side) of the bottom of the storage section 60. The discharge portion 150 differs from the discharge portion 50 of the first embodiment in that the length in the vertical direction (Z-axis direction) of the discharge tube is shorter by the depth of the receiving portion 60.

According to the melting tank 120 of this embodiment, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be effectively suppressed. The distance between the bottom of the receiving portion 60 and the bottom 21 of the melting tank 20 is set to a height H _S1 . The height H _{S1 is} preferably 50 to 300 [mm]. When the height H _S1 is 50 [mm] or more, the heterogeneous glass G1 stays in the storage portion 60. In addition, when the height H _S1 is 300 [mm] or less, circulation of the molten glass G in the storage portion 60 can be suppressed, and the heterogeneous glass G1 can flow out to the upper portion.

In the present embodiment, the distance in the flow direction (X-axis direction) between the downstream end of the accommodation portion 60 and the entrance of the furnace throat 30 is set to 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], and even more preferably 0 to 100 [mm]. When the distance L _S is 1000 [mm] or less, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be effectively suppressed.

In a plan view, the distance in the flow direction (X-axis direction) of the containing portion 60 is set to L ₂ . In the melting tank 120 of this embodiment, L ₂ / L ₁ preferably satisfies 0.05 to 0.5. By setting L ₂ / L ₁ to 0.05 to 0.5, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be effectively suppressed.

As shown in FIG. 4, the width direction (Y-axis direction) distance of the accommodation portion 51 is W ₂ . In the melting tank 120 according to this embodiment, W ₂ / W ₁ preferably satisfies 1.1 to 5.0. By setting W ₂ / W ₁ to 1.1 to 5.0, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be effectively suppressed.

The weight of the molten glass G in the containing portion 60 is set to w [ton], and the weight of the molten glass G discharged from the discharge portion 150 in one day is set to D [ton / day]. In the glass melting furnace 110 of this embodiment, it is preferable to satisfy 0.02 ≦ w / D ≦ 0.4. If w / D is 0.02 or more, the heterogeneous glass G1 can be retained in the accommodating portion 60, so that the heterogeneous glass G1 can be effectively prevented from flowing out of the furnace throat 30. When w / D is 0.4 or less, the circulation of the molten glass G in the containing portion 60 can be suppressed, and therefore, the outflow of the heterogeneous glass G1 to the furnace throat 30 can be effectively suppressed. The weight D is preferably 0.5 to 30 [tons / day].

As mentioned above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to the above embodiment, and also includes design changes that do not depart from the scope of the present invention.

The glass melting furnaces 10 and 110 of this embodiment perform melting of glass raw materials by burner heating and electric heating, but glass melting can also be performed by heating by a separate burner or electric heating alone.

The melting tanks 20 and 120 of this embodiment are rectangular shapes extending long in one axial direction (X-axis direction) in a plan view, but the glass raw materials are not limited to this as long as they can be melted.

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

In this embodiment, the form of the partition wall 40 extended above (+ Z side) from the bottom part 21 was demonstrated, However, if a partition wall is used to isolate molten glass G, it is not limited to this.

[Manufacturing method of glass articles]
Next, the manufacturing method of manufacturing glass articles 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 for manufacturing a glass article according to the first embodiment of the present invention.

The manufacturing method of the glass article in this embodiment includes: a melting step S1 of melting glass raw material to obtain molten glass G; a clarifying step S2 of removing bubbles of the molten glass G; a forming step S3 of forming the molten glass G; and Step S4 of slow cooling of glass.

In the melting step S1, the glass raw material is supplied into a melting tank, and the glass raw material is heated to melt it. The flame of the burner installed in the glass melting furnace is radiated toward the glass material, thereby heating the glass material from above. It is heated by the flame of the burner, and is energized by applying a voltage to a plurality of current-carrying electrodes, generating Joule heat, and heating the glass raw material.

The melting step S1 is performed in a melting tank so that the molten glass flows downstream, and the glass having a viscosity η of 10 ² poise and a temperature T ₂ of 1580 ° C. or more is melted. The melting tank includes a partition wall provided throughout the width direction of the melting tank, and further includes a discharge portion at the bottom of the melting tank. The partition wall blocks a part of the flow of the molten glass. The molten glass is transferred to the clarification step S2 through a furnace 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 entrance of the furnace throat and the partition wall is W [ton], and the weight of the molten glass transferred from the furnace throat in one day is P [ton / day]. . It is preferable that the melting step S1 in this embodiment satisfies 0.2 ≦ W / P ≦ 2.0.

In the melting step S1 of this embodiment, the weight of the molten glass G discharged from the discharge part in one day is set to D [ton / day], and the weight P [ton / day] preferably satisfies 0.01 ≦ D / P ≦ 0.2. When D / P is 0.01 or more, the heterogeneous glass G1 can be sufficiently discharged from the discharge section 50, so that the heterogeneous glass G1 can be suppressed from flowing out to the furnace throat 30. In addition, when D / P is 0.2 or less, production loss due to discharge of the molten glass G from the discharge section 50 can be suppressed.

The clarification step S2 is a step of supplying the molten glass obtained in the melting step S1 to a clarification tank, so as to float and remove bubbles in the molten glass. As a method for promoting the floating of the bubbles, for example, there is a method of decompressing the inside of the clarification tank to defoam.

The forming step S3 is to form the molten glass by using a forming furnace provided on the downstream side of the melting tank. The slow-cooling step S4 uses a slow-cooling furnace provided on the downstream side of the forming furnace to slowly cool the formed glass, and finally obtains a glass article.

In order to obtain a glass plate as a glass article, a float method is used, for example. The float method is a method in which a molten glass introduced into a molten metal (for example, molten tin) contained in a floating kiln flows in a specific direction to form a plate-shaped glass ribbon (forming step S3). After the glass ribbon is cooled in the process of flowing in the horizontal direction, it is pulled from the molten metal, and is slowly cooled while being transported in the slow cooling furnace to become sheet glass (slow cooling step S4). After the plate glass is carried out from the slow cooling furnace, it is cut into a specific size and shape by a cutting machine to become a glass plate, which is a product.

Moreover, as another shaping | molding method of obtaining a glass plate, the melting method can also be used. The melting method is to make molten glass overflowing from the upper edges of the left and right sides of the trough-like member flow down along the left and right sides of the trough-like member, and merge under the intersection of the left and right sides to form a plate-shaped glass ribbon Method (forming step S3). The molten glass ribbon is slowly cooled while moving downward in the vertical direction (Z-axis direction), and becomes a sheet glass (slow cooling step S4). The plate glass is cut into a specific size and shape by a cutter, and becomes a product, namely, a glass plate.

In addition, the manufacturing method of the glass article of this embodiment includes the clarification step S2, but the manufacturing method of the glass article of the present invention may not include the clarification step. In this case, the molten glass undergoes a melting step and is formed into a glass ribbon in a forming step.

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

In addition, in order that the glass used in this embodiment can effectively suppress the mixing of the heterogeneous glass G1, the temperature T _{2 at} which the viscosity η becomes 10 ² poise is preferably 1610 ° C. or more, and more preferably 1640 ° C. or more. In addition, since the glass used in this embodiment is easy to melt, the temperature T _{2 at which the} viscosity η becomes 10 ² poise is preferably 1670 ° C. or lower.

Although the present invention has been described in detail and with reference to specific implementation aspects, it is understood that various changes or modifications can be made without departing from the spirit and scope of the present invention.

This application is based on Japanese Patent Application No. 2017-205301 filed on October 24, 2017, the contents of which are incorporated herein by reference.
[Industrial availability]

The applications of the manufactured glass articles include construction, vehicles, flat panel displays, protective glass covers, and various other uses.

10‧‧‧Glass melting furnace

20‧‧‧ melting tank

21‧‧‧ bottom

22‧‧‧ sidewall

30‧‧‧furnace

40‧‧‧ partition

50‧‧‧Exhaust

51‧‧‧Exhaust pipe

60‧‧‧ Containment Department

100‧‧‧ Forward

101‧‧‧ upstream side circulation

102‧‧‧ downstream side circulation

110‧‧‧Glass melting furnace

120‧‧‧ melting tank

150‧‧‧Exhaust

151‧‧‧Exhaust pipe

G‧‧‧ molten glass

G1‧‧‧heterogeneous glass

H ₀ ‧‧‧ height

H ₁ ‧‧‧ height

H ₂ ‧‧‧ height

H _S ‧‧‧ height

L ₀ ‧‧‧ distance

L ₁ ‧‧‧ distance

L ₂ ‧‧‧ distance

S1‧‧‧ Melting step

S2‧‧‧ Clarification steps

S3‧‧‧forming steps

S4‧‧‧ Slow cooling step

W ₀ ‧‧‧Distance

W ₁ ‧‧‧Distance

W ₂ ‧‧‧Distance

FIG. 1 is a cross-sectional view of a glass melting furnace according to a first embodiment of the present invention, taken along a vertical plane of the Y axis.

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

3 is a cross-sectional view of a glass melting furnace according to a second embodiment of the present invention, taken along a vertical plane of the Y axis.

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

Fig. 5 is a flowchart showing a method for manufacturing a glass article according to the first embodiment of the present invention.

Claims (13)

A glass melting furnace, comprising: a melting tank that melts glass raw materials and causes the obtained molten glass to flow downstream; and a furnace throat that is provided in communication with the melting tank so that the molten glass faces a clarification tank. Or the melting furnace transfers; and the melting tank is provided with a partition wall and a discharge part, and the glass having a viscosity η of 10 ² poises and a temperature T ₂ of 1580 ° C. or higher is fused, and the partition wall is provided across the width direction of the melting tank to block the melting As part of the flow of glass, the discharge part is disposed at the bottom of the melting tank between the furnace throat and the partition wall, and discharges the molten glass. The height from the bottom to the lower end of the entrance of the furnace throat is 20 [ mm] or more. For example, the glass melting furnace of claim 1, wherein the weight of the molten glass held in the melting tank between the entrance of the furnace throat and the partition wall is set to W [ton], and the weight is transferred from the furnace throat in one day. If the weight of the molten glass is set to P [ton / day], then the above glass melting furnace satisfies 0.2 ≦ W / P ≦ 2.0. For example, the glass melting furnace of claim 1 or 2, wherein the height of the glass melting furnace from the bottom to the lower end of the entrance of the throat is 200 [mm] or less. For example, the glass melting furnace according to claim 1 or 2, wherein the melting tank is provided with a concave-shaped receiving part provided at the bottom, The containing portion has a depth of 50 to 300 [mm], and a discharging portion for discharging the molten glass is provided at the bottom. For example, the glass melting furnace according to claim 4, wherein in a plan view, the distance between the downstream end of the containing portion and the inlet of the furnace throat is 0 to 1000 [mm]. A method for manufacturing a glass article, which comprises a melting step, a forming step, and a slow cooling step, and the melting step is to melt a glass raw material in a melting tank and cause the obtained molten glass to flow to the downstream side. The glass having a viscosity η of 10 ² poises and a temperature T ₂ of 1580 ° C. or more, the melting tank is provided with partition walls provided throughout the width direction of the melting tank, and further the melting tank between the furnace throat and the partition wall The bottom part is provided with a discharge part, the partition wall blocks a part of the flow of the molten glass, the molten glass is transferred to the clarification step or the forming step through a furnace throat connected to the melting tank, the discharge part discharges the molten glass, The height from the bottom to the lower end of the entrance of the furnace throat is 20 [mm] or more. For example, the method for manufacturing a glass article according to claim 6, wherein the weight of the molten glass held by the melting tank between the entrance of the furnace throat and the partition wall is W [ton], and the furnace is removed from the furnace in one day. The weight of the molten glass transferred by the throat is set to P [ton / day], and then 0.2 ≦ W / P ≦ 2.0 is satisfied. For example, the method for manufacturing a glass article according to claim 6 or 7, wherein the height from the bottom to the lower end of the entrance of the furnace throat is 200 [mm] or less. If the method of manufacturing a glass article according to claim 6 or 7, wherein in the above melting step, The molten glass is stored in a concave receiving part provided at the bottom of the melting tank, The molten glass is discharged by a discharge portion provided at the bottom of the containing portion, The depth of the containing portion is 50 to 300 [mm]. For example, the method for manufacturing a glass article according to claim 9, wherein in the above melting step, a distance in a flow direction between a downstream end of the containing portion and an inlet of the furnace throat in a plan view is 0 to 1000 [mm]. For example, the method for manufacturing a glass article according to claim 9, wherein in the above melting step, the weight of the molten glass in the containing part is set to w [ton], and the weight of the molten glass discharged from the discharging part in one day is set to D [Ton / day], then satisfy 0.02 ≦ w / D ≦ 0.4. For example, the method for manufacturing a glass article according to claim 6 or 7, wherein in the melting step, the average flow velocity of the molten glass in the direction of the inlet of the furnace throat is 5 to 15 [m / h]. For example, in the method for manufacturing a glass article according to claim 7, wherein in the above-mentioned melting step, the weight of the molten glass discharged from the above-mentioned discharge section in one day is set to D [ton / day], then the above-mentioned weight P satisfies 0.01 ≦ D / P ≦ 0.2.