Apparatus and method for manufacturing glass articles

Abstract

A glass article manufacturing apparatus provided with a fining tank (2) that transfers molten glass (GM) and a holding brick (11) that holds the fining tank (2), wherein the glass article manufacturing apparatus is provided with felt (15) that insulates an end portion (2z) of the fining tank (2) that protrudes from the holding brick (11).

Description

Technical Field

[0001] This invention relates to an apparatus and method for manufacturing glass articles such as sheet glass. Background Technology

[0002] A glass article manufacturing apparatus includes a transfer tube for conveying molten glass and a retaining brick for holding the transfer tube, in order to supply molten glass generated by a glass melting furnace to a forming device. Typically, a glass article manufacturing apparatus has multiple sets consisting of transfer tubes and retaining bricks, with the ends of the transfer tubes in adjacent sets connected to each other. Furthermore, in each set, the end of the transfer tube may protrude from the retaining brick for the purpose of releasing thermal expansion during preheating processes, assembly processes, etc. (see, for example, Patent Documents 1 and 2). In this case, in each set, the middle portion of the transfer tube is surrounded by the retaining brick, while the end of the transfer tube is exposed and not surrounded by the retaining brick.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-19629

[0006] Patent Document 2: Japanese Patent Application Publication No. 2019-108258 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, there are cases where foreign matter defects (such as tin oxide) can occur in the manufactured glass articles due to the protruding end of the transfer tube from the retaining brick.

[0009] Here, the cause of foreign matter defects is hypothesized as follows: At the end of the transfer tube, an air layer forms inside the tube, and some components (e.g., SnO2) evaporate from the molten glass into this air layer. However, the end of the transfer tube protrudes from the holding brick, making it easily cooled from the outside. Therefore, components such as SnO2 that have evaporated into the air layer solidify upon cooling and become mixed into the molten glass, resulting in what is believed to be foreign matter defects such as tin oxides in the glass article. It should be noted that SnO2 is added to the molten glass, for example, as a clarifying agent.

[0010] The objective of this invention is to suppress foreign matter defects in glass articles caused by the protruding end of the transfer tube from the retaining brick.

[0011] Solution for solving the problem

[0012] (1) The present invention, made in order to solve the above-mentioned problems, is a glass article manufacturing apparatus, comprising a transfer tube for transferring molten glass and a retaining brick for holding the transfer tube, wherein the glass article manufacturing apparatus is characterized in that the glass article manufacturing apparatus comprises a heat-insulating member for heat-insulating at least one end of the transfer tube protruding from the retaining brick.

[0013] In this way, by using thermal insulation components to suppress local temperature drops, it is possible to suppress the formation of foreign object defects in glass articles. This is believed to be because even if the volatilization of SnO2 and other substances that could cause foreign object defects occurs, the cooling and solidification of these volatilized substances are suppressed by the thermal insulation components.

[0014] (2) In the structure of (1) above, it is preferable that the heat insulation member is disposed on the outside of the end of the transfer tube and includes at least one member selected from the group consisting of felt, heater, refractory brick, unshaped refractory and metal member.

[0015] In this way, the end of the transfer tube can be easily and appropriately insulated, thus suppressing the generation of foreign matter defects caused by the end of the transfer tube. In particular, when the insulation member is felt, it can perform its insulation function even without an external power source, and it can be easily changed into a shape that corresponds to the installation space by bending or folding, thus offering the advantage of easy installation of the insulation member. Furthermore, when the insulation member is a heater, the end of the transfer tube can be heated and maintained at a high temperature, thus offering the advantage of more reliably suppressing the generation of foreign matter defects caused by the end of the transfer tube.

[0016] (3) In the structure of (1) or (2) above, it is preferable that the insulation member is configured to insulate at least the top of the end of the transfer tube in the circumferential direction.

[0017] It is speculated that an air layer tends to form at the top of the circumferential direction of the transfer tube end. Therefore, if the top of the transfer tube end is insulated with an insulating member as described above, the cooling of volatile components can be effectively prevented, and it is expected that foreign object defects in glass articles can be effectively suppressed.

[0018] (4) In any of the structures (1) to (3) above, it is preferred that the transfer tube is a clarification tank.

[0019] In the refining tank, the temperature of the molten glass is high, which makes it easier for SnO2 and other substances that cause foreign object defects to volatilize, thus making the effect of the present invention significant.

[0020] (5) In the structure of (4) above, it is preferable that the heat insulation member is configured to heat the end of the clarification tank on the outflow side.

[0021] The temperature of the molten glass at the outlet end of the clarifier is higher than the temperature of the molten glass at the inflow end of the clarifier. That is, at the outlet end of the clarifier, the volatilization of substances such as SnO2, which contribute to foreign matter defects, is particularly likely to occur. Therefore, the effect of the present invention becomes more significant if an insulating member is provided to keep the outlet end of the clarifier warm.

[0022] (6) In any of the structures (1) to (5) above, it is preferred that the transfer tube is made of platinum or a platinum alloy and the insulation component covers the outer peripheral surface of the end of the transfer tube.

[0023] In this way, the contact between the outer circumference of the transfer tube end, made of platinum or platinum alloy, and oxygen can be reduced through the insulation component. Therefore, the volatilization of the transfer tube end due to reaction with oxygen can be suppressed. That is, the loss at the transfer tube end caused by platinum volatilization can be suppressed.

[0024] (7) In the structure of (6) above, it is preferable that the insulation member covers the entire circumference of the outer peripheral surface of the end of the transfer pipe.

[0025] In this way, the contact between the outer circumference of the transfer tube end, made of platinum or platinum alloy, and oxygen can be reduced more effectively through the insulation components. Therefore, the loss at the end of the transfer tube caused by the volatilization of platinum can be suppressed more reliably.

[0026] (8) In the structure of (6) or (7) above, it is preferable that the thermal insulation member is kept so as to move with the thermal expansion of the transfer tube.

[0027] In this way, even if the transfer tube elongates due to thermal expansion during preheating processes before operation, the insulation component moves along with the transfer tube. Therefore, even if the transfer tube expands due to heat, the insulation component easily protects the ends of the transfer tube from oxygen.

[0028] (9) The present invention, made in order to solve the above-mentioned problems, is a method for manufacturing a glass article, characterized in that the method for manufacturing a glass article includes a step of transferring molten glass using a glass article manufacturing apparatus having any one of the structures in (1) to (8) above.

[0029] In this way, it can enjoy the same effect as the corresponding structure that has been described.

[0030] Invention Effects

[0031] According to the present invention, it is possible to suppress foreign object defects in glass articles caused by the end of the transfer tube protruding from the retaining brick. Attached Figure Description

[0032] Figure 1This is a side view showing a glass article manufacturing apparatus according to a first embodiment of the present invention.

[0033] Figure 2 It is shown Figure 1 A cross-sectional view of the periphery of the downstream end of the clarification tank.

[0034] Figure 3 yes Figure 2 AA sectional view.

[0035] Figure 4 yes Figure 2 A variation of the AA sectional view.

[0036] Figure 5 This is a flowchart illustrating a method for manufacturing a glass article according to the first embodiment.

[0037] Figure 6 This is a cross-sectional view showing the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the second embodiment of the present invention.

[0038] Figure 7 yes Figure 6 BB cross-sectional view.

[0039] Figure 8 yes Figure 6 A variation of the BB cross-sectional view.

[0040] Figure 9 This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the third embodiment of the present invention (state before the preheating process).

[0041] Figure 10 This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the third embodiment of the present invention (in the state during the preheating process).

[0042] Figure 11 This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the fourth embodiment of the present invention (state before the preheating process).

[0043] Figure 12 This is a cross-sectional view showing the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the fourth embodiment of the present invention (in the state during the preheating process).

[0044] Figure 13 This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the fifth embodiment of the present invention (state before the preheating process).

[0045] Figure 14This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the fifth embodiment of the present invention (first state of the final stage of the preheating process).

[0046] Figure 15 This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the fifth embodiment of the present invention (second state of the final stage of the preheating process).

[0047] Figure 16 This is a cross-sectional view showing the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the sixth embodiment of the present invention (state before the preheating process).

[0048] Figure 17 This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the sixth embodiment of the present invention (first state of the final stage of the preheating process).

[0049] Figure 18 This is a cross-sectional view of the periphery of the end of the transfer tube of the glass article manufacturing apparatus according to the sixth embodiment of the present invention (second state of the final stage of the preheating process). Detailed Implementation

[0050] Hereinafter, a method for manufacturing a glass article according to an embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that there are instances where corresponding constituent elements in different embodiments are labeled with the same reference numerals, thus omitting repeated descriptions. Even when only a part of the structure is described in each embodiment, structures from other previously described embodiments can be applied to the other parts of that structure. Furthermore, not only combinations of structures explicitly shown in the descriptions of each embodiment, but also structures from multiple embodiments can be partially combined with each other, provided that such combinations do not present particular obstacles.

[0051] (First Implementation)

[0052] like Figure 1 As shown, the glass article manufacturing apparatus of the first embodiment includes a melting tank 1, a refining tank 2, a homogenizing tank (stirring tank) 3, a kettle 4, a forming body 5, and glass supply lines 6, 7, 8, and 9 connecting the above elements 1 to 5. Furthermore, this manufacturing apparatus includes an annealing furnace (not shown) for annealing the sheet glass GR (glass article) formed by the forming body 5, and a cutting device (not shown) for cutting the sheet glass GR after annealing.

[0053] In this embodiment, the clarifying tank 2, the homogenizing tank 3, the kettle 4, and the glass supply lines 6, 7, 8, and 9 correspond to transfer tubes for conveying molten glass GM. These transfer tubes are made of platinum or platinum alloys.

[0054] Melting tank 1 is a container used for the melting process of input glass raw materials to obtain molten glass GM. Melting tank 1 is connected to refining tank 2 through glass supply line 6.

[0055] The refining tank 2 is a container used for a refining process in which molten glass GM is degassed under the action of a refining agent or the like while being transferred. The refining tank 2 is connected to the homogenizing tank 3 via the glass supply path 7.

[0056] The homogenization tank 3 is a vessel used for a homogenization process in which clarified molten glass GM is stirred and homogenized. The homogenization tank 3 is equipped with a stirrer 3a with stirring blades. The homogenization tank 3 is connected to the reactor 4 via a glass supply passage 8.

[0057] The vessel 4 is a container used for conditioning the molten glass GM to a suitable state for forming. The vessel 4 is exemplified as a volumetric unit for adjusting the viscosity and flow rate of the molten glass GM. The vessel 4 is connected to the forming body 5 via the glass supply passage 9.

[0058] The forming body 5 is a forming apparatus for performing a forming process of shaping molten glass GM into a desired shape (e.g., a plate). In this embodiment, the forming body 5 shapes the molten glass GM into a plate shape by an overflow pull-down method. Specifically, the cross-sectional shape of the forming body 5 (compared to...) Figure 1 The cross-sectional shape of the paper (orthogonal to the paper surface) is roughly wedge-shaped, and an overflow groove (not shown) is formed on the upper part of the molded body 5.

[0059] The forming body 5 causes molten glass GM to overflow from the overflow channel and flow down along the sidewalls of both sides of the forming body 5 (located on the sides of the paper's back side). The forming body 5 causes the flowing molten glass GM to converge at the lower end of the sidewalls. Thus, a strip-shaped sheet glass GR with a shaped confluence surface at its center in the thickness direction is formed by the convergence of the molten glass GM. It should be noted that the forming body 5 can also be a component that implements other draw methods such as slit drawing, redrawing, or float glass. However, from the viewpoint of achieving a smooth surface of the sheet glass GR, the overflow draw method is preferred.

[0060] The strip-shaped glass GR thus obtained is cut to produce single-sheet glass. The glass sheet has a thickness of, for example, 0.01 to 2 mm, and is used as a substrate and protective cover for displays such as liquid crystal displays and organic EL displays, organic EL lighting, and solar cells. When the glass sheet GR is formed using the overflow pull method, the cut glass sheet can be used with the surface as an unpolished (forged) surface.

[0061] As a material for sheet glass, it can be made of silicate glass, silica glass, borosilicate glass, soda-lime glass, aluminosilicate glass, alkali-free glass, aluminosilicate glass, etc. It should be noted that fused glass (GM) is made of the same material as sheet glass.

[0062] Alkali-free glass, preferably composed of, by mass percent, 50–70% SiO2, 12–25% Al2O3, 0–12% B2O3, 0 to less than 1% Li2O+Na2O+K2O (total amount of Li2O, Na2O, and K2O), 0–8% MgO, 0–15% CaO, 0–12% SrO, 0–15% BaO, and 0.01–1.5% SnO2. This glass composition is suitable for glass substrates used in displays.

[0063] Aluminosilicate glass, preferably composed of the following components by mass%, comprises 40%–70% SiO2, 10%–30% Al2O3, 0%–3% B2O3, 5%–25% Na2O, 0%–5.5% K2O, 0.1%–10% Li2O, 0%–5.5% MgO, 2%–10% P2O5, and 0.01%–1.5% SnO2. This glass composition readily balances high-level ion exchange performance and devitrification resistance, making it suitable for chemically strengthened glass applications.

[0064] Next, the detailed structure of the transfer pipe will be explained using the periphery of the end 2z on the downstream side (outflow side) of the clarification tank 2 as an example.

[0065] like Figure 2 as well as Figure 3 As shown, the clarifying tank 2 includes a tubular portion 2x and a flange portion 2za provided at the downstream end of the tubular portion 2x. In this embodiment, the downstream end 2z of the clarifying tank 2 also has a curved portion 2zb that smoothly bends from the flange portion 2za toward the tubular portion 2x between the flange portion 2za and the tubular portion 2x. It should be noted that a flange portion and a curved portion are also provided at the upstream end (inflow side) of the clarifying tank 2, which are not shown in the figure.

[0066] Electrode portions are integrally provided on each flange of the refining tank 2, including the flange portion 2za. Current is energized and heated by flowing current through each electrode portion into the tubular portion 2x, thereby heating the molten glass GM inside the tubular portion 2x. It should be noted that each flange and electrode portion of the refining tank 2 may also be equipped with cooling components such as water cooling (not shown) to suppress oxidation. Furthermore, any transfer tube other than the refining tank 2 can also be energized and heated in the same manner to heat the molten glass GM inside the transfer tube.

[0067] The glass supply path 7 on the downstream side of the clarification tank 2 has a tubular portion 7x and a flange portion 7ya provided at the upstream end of the tubular portion 7x. In this embodiment, the upstream end 7y of the glass supply path 7 also has a curved portion 7yb that smoothly bends from the flange portion 7ya toward the tubular portion 7x between the flange portion 7ya and the tubular portion 7x.

[0068] At the downstream end 2z of the clarifying tank 2, the flange portion 2za of the clarifying tank 2 and the flange portion 7ya of the glass supply path 7 are configured to be in a mating state.

[0069] The tubular portion 2x of the clarifying tank 2 and the tubular portion 7x of the glass supply path 7 are held by retaining bricks 11 and 12, respectively. Each retaining brick 11 and 12 is arranged to surround the entire circumference of each tubular portion 2x and 7x. The cross-sectional shape of the retaining bricks 11 and 12 is a circular inner surface and a rectangular outer surface. Each retaining brick 11 and 12 is housed inside a metal housing 16 and 17. On the other hand, the end portion 2z of the clarifying tank 2 and the end portion 7y of the glass supply path 7 protrude from the retaining bricks 11 and 12, respectively. That is, the flange portions 2za and 7ya and the bend portions 2zb and 7yb are exposed to the outside of each retaining brick 11 and 12. It should be noted that... Figure 1 The illustration of the retaining brick is omitted. Furthermore, for other transfer tubes, including the glass supply path 6, a structure can be adopted in which the middle portion of the transfer tube is held by the retaining brick while the end of the transfer tube protrudes from the retaining brick. In this case, the protruding end of each transfer tube from the retaining brick can also have a flange and a bend.

[0070] Bricks 11 and 12 are made of refractory bricks with heat-insulating properties. For example, high-zirconia refractory bricks can be used as refractory bricks.

[0071] A bonding layer 13 and 14 are sandwiched between the tubular portions 2x and 7x and the retaining bricks 11 and 12 to join the tubular portions 2x and 7x with the retaining bricks 11 and 12. For example, a diffusion bond containing alumina powder and silica powder or bauxite cement can be used as the bonding layer 13 and 14. Here, a diffusion bond refers to a bond formed by heating the tubular portions 2x and 7x after the powder to be used as raw material is filled between the retaining bricks 11 and 12 to allow diffusion bonding. Diffusion bonding is a method of bonding powders by contacting each other and utilizing the diffusion of atoms generated between the contact surfaces. The filling of the powder to become the raw material for the diffusion bond is performed, for example, in the assembly process before operation, and the heating of the powder to become the raw material for the diffusion bond is performed, for example, in the molten glass transfer process after operation.

[0072] A felt (insulating member) 15 is disposed at the downstream end 2z of the clarifying tank 2, which protrudes from the retaining brick 11, to insulate the end 2z. Specifically, the felt 15 fills the space outside the curved portion 2zb sandwiched between the retaining brick 11 and the flange 2za. In this state, the felt 15 is in contact with, for example, the retaining brick 11, the flange 2za, and the curved portion 2zb. It should be noted that the felt 15 may also not be in contact with at least one of the retaining brick 11, the flange 2za, and the curved portion 2zb. However, from the viewpoint of insulating the downstream end 2z of the clarifying tank 2, the felt 15 is preferably in contact with at least the outer peripheral surface of the curved portion 2zb.

[0073] By configuring the felt 15 in this way, the downstream end 2z of the refining tank 2, which protrudes from the holding brick 11, can be prevented from being locally cooled by external air, thus reliably suppressing the formation of tin oxides within the refining tank 2. Specifically, at the end 2z of the refining tank 2 (e.g., the bend 2zb of the refining tank 2), even if an air layer S is formed within the refining tank 2, components such as SnO2 that volatilize from the molten glass GM into the air layer S are difficult to cool and solidify. Furthermore, when the concentration of components volatilizing into the air layer S becomes high, it reaches a saturation state, making it difficult for volatilization itself to occur. Therefore, the generation of foreign matter defects is effectively suppressed.

[0074] It should be noted that in this embodiment, an electrode for electric heating is provided in the flange portion 2za. However, electric heating by this electrode alone is insufficient to keep the end portion 2z of the clarifying tank 2 sufficiently warm, and tin oxide may be generated. In other words, even when an electrode for electric heating is provided in the flange portion 2za, a felt 15 is still needed as an insulation member from the viewpoint of suppressing the generation of tin oxide.

[0075] As the felt 15, for example, a felt made of refractory fiber material can be used. Specifically, a felt that has heat resistance capable of withstanding temperatures of 1000°C or higher (preferably 1300°C or higher) and has elasticity can be used. As an example, a felt made of alumina fiber, silica fiber, zirconium fiber, and blends thereof can be used. It should be noted that, in addition to the felt 15, as an insulation component, for example, heaters, refractory bricks, monolithic refractories (e.g., refractory cement), metal components, etc., can be used.

[0076] like Figure 2 as well as Figure 3 As shown, in this embodiment, the felt 15 is disposed around the entire circumference of the end 2z (bent portion 2zb in the example) of the clarifying tank 2. In this case, the thickness of the felt 15 can be constant throughout the entire circumference. However, from the viewpoint of suppressing foreign matter defects, as Figure 3As shown, preferably, the thickness T1 of the felt 15 at the top 2zc of the end 2z of the clarifying tank 2 is greater than the thickness T2 of the felt 15 at other parts of the end 2z in the circumferential direction. This is because an air layer S is easily formed at the top 2zc of the end 2z of the clarifying tank 2. That is, improving the heat preservation effect at the top 2zc of the end 2z of the clarifying tank 2 (the part where the air layer S forms) can be expected to more effectively suppress the generation of foreign matter defects. It should be noted that, as Figure 4 As shown, the felt 15 may also be disposed only at the top 2zc (the portion forming the air layer S) of the end 2z of the clarifying tank 2. That is, the felt 15 may be disposed at least at the top 2zc (the portion forming the air layer S) of the end 2z of the clarifying tank 2 in the circumferential direction.

[0077] Furthermore, in this embodiment, at least a portion of the outer peripheral surface 2zd of the end 2z of the clarifying tank 2 is covered by felt 15. Therefore, the contact between the outer peripheral surface 2zd of the end 2z of the clarifying tank 2 and oxygen can be reduced. As a result, the volatilization of platinum constituting the end 2z of the clarifying tank 2 due to reaction with oxygen can be suppressed. That is, the loss of the end 2z of the clarifying tank 2 due to platinum volatilization can be suppressed. From the viewpoint of suppressing the loss of the end 2z of the clarifying tank 2 due to platinum volatilization, felt 15 is preferably disposed around the entire circumference of the end 2z of the clarifying tank 2.

[0078] Next, the manufacturing method of glass articles using the manufacturing apparatus configured as described above will be explained.

[0079] like Figure 5 As shown, this manufacturing method mainly includes melting process S1, molten glass transfer process S2, forming process S3, annealing process S4, and cutting process S5.

[0080] In the melting process S1, the glass raw material supplied to the melting tank 1 is heated to generate molten glass GM.

[0081] The molten glass GM preferably contains 0.01 to 1.5% SnO2 by mass. This makes degassing of the molten glass GM easier in the clarification process included in the molten glass transfer process S2.

[0082] In the molten glass transfer process S2, the molten glass GM from the melting tank 1 is sequentially transferred via glass supply paths 6, 7, 8, and 9 to the refining tank 2, the homogenizing tank 3, the kettle 4, and finally the formed body 5. That is, the molten glass transfer process S2 includes a refining process, a homogenizing process, and a condition adjustment process. In the refining process, in the refining tank 2, gas (bubbles) is generated from the molten glass GM under the action of a refining agent added to the glass raw material. This gas is discharged from the refining tank 2 to the outside. In the homogenizing process, in the homogenizing tank 3, the molten glass GM is stirred and homogenized. In the condition adjustment process, in the kettle 4 and the glass supply path 9, the state (e.g., viscosity, flow rate) of the molten glass GM is adjusted.

[0083] Furthermore, in the molten glass transfer process S2, due to... Figure 2 as well as Figure 3 As shown, a felt 15 is provided to insulate the end 2z of the clarifying tank 2 protruding from the retaining brick 11 downstream side, thereby suppressing the local temperature drop at the end 2z of the clarifying tank 2 and suppressing the generation of foreign matter defects.

[0084] The temperature of the molten glass GM at the downstream end 2z of the refining tank 2 is higher than that at the upstream end of the refining tank 2, for example, exceeding 1300°C. That is, at the downstream end 2z of the refining tank 2, the high temperature of the molten glass GM makes it particularly prone to the volatilization of SnO2 and other substances that contribute to foreign object defects. Therefore, by arranging the felt 15 to insulate the downstream end 2z of the refining tank 2, the generation of foreign object defects can be effectively suppressed.

[0085] In forming step S3, the molten glass GM, which has passed through the molten glass transfer step S2, is supplied to forming body 5. Forming body 5 causes the molten glass GM to overflow from the overflow tank and flow down its sidewall. Forming body 5 causes the flowing molten glass GM to merge at the lower end, thereby forming a strip of sheet glass GR.

[0086] Next, the strip of sheet glass GR undergoes an annealing process S4 using an annealing furnace and a cutting process S5 using a cutting device to cut sheet glass to the specified dimensions. Through the above steps, high-quality sheet glass (glassware) with minimal defects caused by foreign matter is produced.

[0087] (Second Implementation)

[0088] like Figure 6 as well as Figure 7 As shown, in the glass article manufacturing apparatus and manufacturing method of the second embodiment of the present invention, an example is shown where the heat-insulating member for heat-insulating the end of the transfer tube includes a heater 21. Furthermore, as the end of the transfer tube, the downstream end 2z of the clarifying tank 2 is exemplified.

[0089] In this embodiment, the heater 21, serving as an insulation member, is configured to insulate the downstream end 2z of the clarifying tank 2 protruding from the retaining brick 11. The heater 21 is positioned in the space outside the curved portion 2zb, which is sandwiched between the retaining brick 11 and the flange 2za. In this state, the heater 21 is in contact with, for example, the retaining brick 11, the flange 2za, and the curved portion 2zb. It should be noted that when the heater 21 is in contact with the clarifying tank 2, it is preferable to provide an insulation mechanism (e.g., an insulating film) between the heater 21 and the clarifying tank 2 in a manner that does not obstruct the electrical heating performed by the electrode portion of the flange 2za of the clarifying tank 2. The heater 21 may not be in contact with at least one of the retaining brick 11, the flange 2za, and the curved portion 2zb.

[0090] The heater 21 can heat the downstream end 2z of the clarifier 2 and maintain it at a high temperature, thus its heat preservation effect is higher than that of the felt 15. Therefore, if the heater 21 is configured as a heat preservation component, the generation of foreign matter defects caused by the downstream end 2z of the clarifier 2 can be suppressed more reliably.

[0091] As the heater 21, for example, resistance heating or induction heating can be used.

[0092] In this embodiment, the heater 21 is disposed only at the top 2zc of the circumferential direction of the end 2z of the clarification tank 2. It should be noted that the heater 21, like the felt 15, can be disposed at least at the top 2zc (the portion forming the air layer S) of the circumferential direction of the end 2z of the clarification tank 2. Figure 8 As shown, when the heater 21 is arranged to surround the entire circumference of the end 2z of the clarification tank 2, it is preferable that the heating temperature of the heater 21a at the top 2zc is higher than the heating temperature of the heater 21b at the other parts.

[0093] In addition, in this embodiment, the heater 21 is configured to cover at least a portion of the outer peripheral surface 2zd of the end 2z of the clarification tank 2, thus suppressing the loss of the end 2z caused by the volatilization of platinum.

[0094] (Third Implementation)

[0095] like Figure 9 as well as Figure 10 As shown, in the glass article manufacturing apparatus and method of the third embodiment of the present invention, an example is given where the heat-insulating member for heat-insulating the end of the transfer tube includes a refractory brick 31. Furthermore, as the end of the transfer tube, the downstream end 2z of the settling tank 2 is exemplified. It should be noted that in... Figure 9 And in 10, the bending portion 2zb and the bonding layer 13 are omitted from the illustration.

[0096] In this embodiment, the refractory brick 31, serving as an insulating member, is configured to insulate the downstream end 2z of the settling tank 2 protruding from the retaining brick 11 (e.g., the end of the tubular portion 2x and / or the bent portion 2zb). The retaining brick 11 has a cross-sectional shape with a circular inner surface and a rectangular outer surface. The refractory brick 31 is disposed in the space outside the end 2z of the settling tank 2. A portion of the outer peripheral surface 31a of the refractory brick 31 and the outer peripheral surface 11a of the retaining brick 11 are held by a metal outer shell 16.

[0097] The refractory brick 31 is a cylindrical shape that covers the entire circumference of the outer peripheral surface 2zd of the end 2z of the settling tank 2 when in contact with it. It is divided into multiple sections circumferentially (e.g., upper and lower sections), which are not shown in the figure. The cross-sectional shape of the refractory brick 31 is, for example, a circular inner surface and a rectangular or circular outer surface. The refractory brick 31 is fixed relative to the flange 2za by engaging claws 32 provided on the flange 2za. Multiple engaging claws 32 are provided at intervals circumferentially on the flange 2za such that they engage with the refractory brick 31 at multiple locations.

[0098] The refractory brick 31 has an inner portion 31x and an outer portion 31y that protrudes towards the retaining brick 11 from the end on the retaining brick 11 side (upstream end). Similarly, the retaining brick 11 has an outer portion 11y and an inner portion 11x that protrudes towards the refractory brick 31 from the outer portion 11y. The inner portion 31x of the refractory brick 31, which is a non-protruding portion, is embedded in the inner portion 11x of the retaining brick 11, which is a protruding portion, and the outer portion 31y of the refractory brick 31, which is a non-protruding portion, is embedded in the outer portion 31y of the refractory brick 31, which is a protruding portion.

[0099] In this state, the inner surface 31ya of the outer side portion 31y of the refractory brick 31 and the outer surface 11xa of the inner side portion 11x of the retaining brick 11 are in contact with each other, and when viewed in the radial direction, the outer side portion 31y of the refractory brick 31 and the inner side portion 11x of the retaining brick 11 have overlapping portions 33.

[0100] In this way, even if the settling tank 2 elongates due to thermal expansion during preheating processes, the refractory brick 31 engaged with the locking claw 32 moves along the length of the settling tank 2 together with the end 2z of the settling tank 2. Therefore, the outer peripheral surface 2zd of the end 2z of the settling tank 2 remains covered by the refractory brick 31. It should be noted that the inner surface 31ya of the outer side 31y of the refractory brick 31 and the outer surface 11xa of the inner side 11x of the retaining brick 11 can have either a circular or a rectangular cross-sectional shape.

[0101] Specifically, in the clarification tank 2 before the preheating process, before thermal expansion, such as... Figure 9 As shown, the end face 31xb of the inner side portion 31x of the refractory brick 31 is in contact with the end face 11xb of the inner side portion 11x of the retaining brick 11, and the end face 31b of the outer side portion 31y of the refractory brick 31 is in contact with the end face 11yb of the outer side portion 11y of the retaining brick 11. Therefore, the dimension D1 of the overlapping portion 33 (the dimension in the length direction of the clarifying tank 2) of the refractory brick 31 and the retaining brick 11 becomes the largest.

[0102] When the clarification tank 2 thermally expands due to the preheating process from this state, as... Figure 10 As shown, under the action of the engaging claw 32, the refractory brick 31 moves along the length of the settling tank 2 together with the flange 2za in a manner that follows the thermal expansion of the settling tank 2. During this process, the size D1 of the overlapping portion 33 of the refractory brick 31 and the retaining brick 11 decreases, but the overlapping portion 33 is maintained. That is, the outer peripheral surface 2zd of the end 2z of the settling tank 2 protruding from the retaining brick 11 is not exposed to the outside, but is maintained to be covered by the refractory brick 31.

[0103] Therefore, in the process including the preheating process and the subsequent operation process, it is possible to suppress the generation of foreign object defects in glass articles, and it is also possible to suppress the loss of the end 2z of the clarifying tank 2 caused by the volatilization of platinum.

[0104] Here, the preheating process refers to the process of heating the food in a preheated state. Figure 1 The manufacturing apparatus shown is used in a process where components 2 to 9 are heated individually and their thermal expansion is achieved through methods such as electric heating. Following the preheating process, an assembly process is performed to connect components 2 to 9 together. Both the preheating and assembly processes are performed before the actual operation.

[0105] The shapes of the ends of the refractory brick 31 and the retaining brick 11 are not particularly limited as long as the protrusion of one component is embedded in the non-protrusion of the other component. For example, the inner side 31x of the refractory brick 31 and the outer side 11y of the retaining brick 11 can be designated as protrusions.

[0106] (Fourth Implementation)

[0107] like Figure 11 as well as Figure 12 As shown, in the glass article manufacturing apparatus and method of the fourth embodiment of the present invention, an example is given where the heat-insulating member for heat-insulating the end of the transfer tube includes a metal member 41. Furthermore, as the end of the transfer tube, the downstream end 2z of the clarifying tank 2 is exemplified. It should be noted that in... Figure 11 as well as Figure 12 The bending portion 2zb and the bonding layer 13 are omitted from the illustration.

[0108] In this embodiment, the metal member 41, which serves as an insulation member, is configured to insulate the downstream end 2z (e.g., the end of the tubular portion 2x and / or the bent portion 2zb) of the settling tank 2 that protrudes from the retaining brick 11. The metal member 41 is disposed in the space outside the end 2z of the settling tank 2.

[0109] The metal component 41 is a square tube that covers the entire circumference of the outer peripheral surface 2zd at a position separating from the end 2z of the settling tank 2 towards the outer diameter side. The metal component 41 is fixed to the flange portion 2za.

[0110] Metal member 41 is disposed on the outside of metal housing 16 that holds the outer peripheral surface of retaining brick 11. In this state, the inner peripheral surface 41a of metal member 41 is in contact with the outer peripheral surface 16a of housing 16, and when viewed in the radial direction, metal member 41 and housing 16 have overlapping portions 42.

[0111] In this way, even if the settling tank 2 elongates due to thermal expansion during preheating processes, the metal member 41 fixed to the flange 2za moves along the length of the settling tank 2 together with the end 2z of the settling tank 2. Therefore, the outer peripheral surface 2zd of the end 2z of the settling tank 2 remains covered by the metal member 41.

[0112] Specifically, in the clarification tank 2 before the preheating process, before thermal expansion, such as... Figure 11 As shown, the flange 2za is brought into contact with the retaining brick 11. As a result, the dimension D2 of the overlapping portion 42 (the dimension in the length direction of the clarifying tank 2) where the metal component 41 overlaps with the outer shell 16 becomes the largest.

[0113] When the clarification tank 2 thermally expands due to the preheating process from this state, as... Figure 12 As shown, the metal component 41 also moves along the length of the clarifying tank 2 together with the flange 2za in a manner that follows the thermal expansion of the clarifying tank 2. During this process, the size D2 of the overlapping portion 42 where the metal component 41 overlaps with the outer casing 16 decreases, but the overlapping portion 42 is maintained. That is, the outer peripheral surface 2zd of the end 2z protruding from the retaining brick 11 of the clarifying tank 2 is not exposed to the outside, but is maintained to be covered by the metal component 41.

[0114] Therefore, in processes including the preheating process and subsequent processing steps, it is possible to suppress the generation of foreign matter defects in glass articles and also to suppress the loss of the end 2z of the clarifying tank 2 due to platinum volatilization. Here, the metal component 41 is separated from the outer peripheral surface 2zd of the end 2z of the clarifying tank 2, but the external space of the outer peripheral surface 2zd becomes a closed space divided by the outer shell 16, the metal component 41, etc. The oxygen content in this closed space is very low compared to the oxygen content in the open external space, so as described above, the loss of the end 2z of the clarifying tank 2 due to platinum volatilization can also be suppressed.

[0115] (Fifth Implementation)

[0116] like Figures 13-15 As shown, in the glass article manufacturing apparatus and manufacturing method of the fifth embodiment of the present invention, the heat-insulating member for heat-insulating the end of the transfer tube includes a first refractory brick 51 (see reference). Figure 13 Or including the first and second refractory bricks 51 and 52 (refer to...) Figure 15 In the case of ), the downstream end 2z of the clarification tank 2 is shown as an example of the end of the transfer pipe. It should be noted that in Figures 13-15 The bending portion 2zb and the bonding layer 13 are omitted from the illustration.

[0117] In this embodiment, the first refractory brick 51, or the first and second refractory bricks 51 and 52, which serve as heat-insulating components, are arranged to heat the downstream end 2z (e.g., the end of the tubular portion 2x and / or the bent portion 2zb) of the settling tank 2 that protrudes from the retaining brick 11. The refractory bricks 51 and 52 are disposed in the space outside the end 2z of the settling tank 2.

[0118] Refractory bricks 51 and 52 are each cylindrical in shape, covering the entire circumference of the outer peripheral surface 2zd of the end 2z of the settling tank 2 while in contact with it. They are also divided circumferentially into multiple sections (e.g., upper and lower sections), which are not shown in the diagram. That is, the cross-sectional shape of refractory bricks 51 and 52 is a circular inner surface and a circular outer surface. It should be noted that the cross-sectional shape of the outer surface of refractory bricks 51 and 52 can be the same rectangular shape as the retaining brick 11.

[0119] In the clarification tank 2 before the preheating process, before thermal expansion, such as Figure 13 As shown, one end face 51a of the first refractory brick 51 is brought into contact with the flange portion 2za, and the other end face 51b of the first refractory brick 51 is brought into contact with the retaining brick 11.

[0120] When the clarification tank 2 thermally expands due to the preheating process from this state, as... Figure 14As shown, the first refractory brick 51 does not move in accordance with the thermal expansion of the settling tank 2. As a result, a gap G1 is formed between the flange 2za and the end face 51a of the first refractory brick 51. Therefore, as... Figure 15 As shown, a second refractory brick 52 is placed in the gap G1, and the outer peripheral surface 2zd of the end 2z of the clarifying tank 2 corresponding to the gap G1 is covered by the second refractory brick 52. In this state, one end face 52a of the second refractory brick 52 is in contact with the flange 2za, and the other end face 52b of the second refractory brick 52 is in contact with the end face 51b of the first refractory brick 51. That is, before the preheating process, the outer peripheral surface 2zd of the end 2z of the clarifying tank 2 protruding from the retaining brick 11 is covered by the first refractory brick 51, and after the preheating process (e.g., the working process), the outer peripheral surface 2zd of the end 2z of the clarifying tank 2 protruding from the retaining brick 11 is covered by the first and second refractory bricks 51 and 52.

[0121] Therefore, in processes including the preheating process and subsequent operating processes, it is possible to suppress the generation of foreign object defects in glass articles, and also to suppress the loss of the end 2z of the clarifying tank 2 caused by the volatilization of platinum.

[0122] It should be noted that the second refractory brick 52 can also be replaced with unshaped refractory materials such as refractory cement. Furthermore, the process of adding new refractory to gap G1 can be performed multiple times during the preheating process or after the preheating process has ended.

[0123] (Sixth Implementation Method)

[0124] like Figures 16-18 As shown, in the glass article manufacturing apparatus and manufacturing method of the sixth embodiment of the present invention, the heat-insulating member for heat-insulating the end of the transfer tube includes a first refractory brick 61 (see reference). Figure 16 Or the second refractory brick 62 (refer to) Figure 18 In the case of ), the downstream end 2z of the clarification tank 2 is shown as an example of the end of the transfer pipe. It should be noted that in Figures 16-18 The bending portion 2zb and the bonding layer 13 are omitted from the illustration.

[0125] In this embodiment, the first refractory brick 61 or the second refractory brick 62, serving as insulation components, is arranged to insulate the end 2z (e.g., the end of the tubular portion 2x and / or the bent portion 2zb) of the settling tank 2 protruding from the retaining brick 11. The refractory bricks 61 and 62 are disposed in the space outside the end 2z of the settling tank 2.

[0126] Refractory bricks 61 and 62 are each cylindrical in shape, covering the entire circumference of the outer peripheral surface 2zd of the end 2z of the settling tank 2 while in contact with it. They are also divided circumferentially into multiple sections (e.g., upper and lower sections), which are not shown in the diagram. That is, the cross-sectional shape of refractory bricks 61 and 62 is a circular inner surface and a circular outer surface. It should be noted that the cross-sectional shape of the outer surface of refractory bricks 61 and 62 can also be the same rectangular shape as the retaining brick 11.

[0127] In the clarification tank 2 before the preheating process, before thermal expansion, such as Figure 16 As shown, one end face 61a of the first refractory brick 61 is not in contact with the flange portion 2za, while the other end face 61b of the first refractory brick 61 is in contact with the retaining brick 11. A gap G2 is formed between one end face 61a of the first refractory brick 61 and the flange portion 2za.

[0128] When the clarification tank 2 thermally expands due to the preheating process from this state, as... Figure 17 As shown, the first refractory brick 61 does not move in accordance with the thermal expansion of the settling tank 2. As a result, the size of the gap G2 between the end face 61a of the first refractory brick 61 and the flange 2za increases along the length of the settling tank 2. Therefore, as... Figure 18 As shown, the first refractory brick 61 is removed from the end 2z of the settling tank 2 using the enlarged gap G2. A second refractory brick 62 is then placed between the flange 2za and the retaining brick 11, and the outer peripheral surface 2zd of the end 2z of the settling tank 2 is covered by the second refractory brick 62. In this state, one end face 62a of the second refractory brick 62 contacts the flange 2za, and the other end face 62b of the second refractory brick 62 contacts the retaining brick 11. That is, before the preheating process, the outer peripheral surface 2zd of the end 2z of the settling tank 2 protruding from the retaining brick 11 is covered by the first refractory brick 61; after the preheating process (e.g., during the working process), the outer peripheral surface 2zd of the end 2z of the settling tank 2 protruding from the retaining brick 11 is covered by the second refractory brick 62.

[0129] Therefore, in processes including the preheating process and subsequent processing steps, it is possible to suppress foreign object defects in glass articles and also to suppress end 2z loss caused by platinum volatilization.

[0130] It should be noted that the second refractory brick 62 can also be replaced by refractory cement or other monolithic refractories. Furthermore, the process of adding new refractory to the gap G2 can be performed multiple times during the preheating process or after the preheating process has ended.

[0131] The manufacturing method of glass articles according to the embodiments of the present invention has been described above. However, the embodiments of the present invention are not limited thereto, and various modifications can be made without departing from the spirit of the present invention.

[0132] In the above embodiments, the effects of the present invention were explained using the example of foreign matter defects caused by the cooling and solidification of components such as SnO2 volatilized from molten glass GM to air layer S. However, the generation of foreign matter defects caused by components of the transfer tube such as platinum can also be suppressed. Specifically, when the felt 15 and heater 21 are not provided, platinum sublimates from the end of the transfer tube to air layer S, and the platinum cools and solidifies, mixing into the molten glass GM, thus generating platinum. If the felt 15, heater 21, refractory bricks 31, 51, 52, 61, 62, metal component 41, or unshaped refractory are provided, the generation of platinum can be suppressed.

[0133] In the first and second embodiments described above, the case in which only one of the felt 15 and the heater 21 is used as the insulation component is illustrated, but the felt 15 and the heater 21 can be used simultaneously.

[0134] In the above embodiment, the case where a heat-insulating member is arranged at the downstream end 2z of the refining tank 2 has been described, but the arrangement position of the heat-insulating member is not limited to this. That is, heat-insulating members can also be arranged at the ends of the transfer tubes other than the downstream end 2z of the refining tank 2 (including the upstream end of the refining tank 2). However, from the viewpoint of suppressing defects such as tin oxide generated in glass articles, the heat-insulating member is preferably arranged at a position in the end of each transfer tube protruding from the holding brick where the temperature of the molten glass GM transferred in the transfer tube is 1300°C or higher (preferably 1350°C or higher, more preferably 1400°C or higher). On the other hand, from the viewpoint of suppressing the loss of the transfer tube due to the volatilization of platinum, the heat-insulating member is preferably arranged at a position in the end of each transfer tube protruding from the holding brick where the temperature of the molten glass GM transferred in the transfer tube is 1000°C or higher (preferably 1100°C or higher, more preferably 1200°C or higher).

[0135] In the above embodiments, when insulation components are arranged at multiple locations along the conveying direction of the molten glass GM, the structure of the insulation components can be changed according to the location of arrangement. For example, a heater can be arranged at the location where a relatively high insulation effect is required (where the temperature of the molten glass GM is relatively high), and a felt or the like can be arranged at the location where a relatively low insulation effect is required (where the temperature of the molten glass GM is relatively low).

[0136] In the above embodiments, an example is shown where, at the joint where the upstream transfer tube (e.g., the clarifying tank 2) and the downstream transfer tube (e.g., the glass supply path 7) meet, the radius of curvature of the bend between the flange and tubular portion of the upstream transfer tube is the same as the radius of curvature of the bend between the flange and tubular portion of the downstream transfer tube. However, the radii of curvature of these two bends can also be different. Specifically, for example, the radius of curvature of the bend 2zb of the clarifying tank 2 can be larger than the radius of curvature of the bend 7yb of the glass supply path 7. In the case where the radii of curvature of the bends are different, it is preferable to provide a heat-insulating member at least on the outer side of the end of the transfer tube with the larger radius of curvature. This is presumably because, inside the end of the transfer tube with the larger radius of curvature, volatile components tend to cool and solidify easily, and the heat-insulating member can effectively prevent cooling and solidification. The radius of curvature of the bend with the larger radius of curvature is preferably 2 to 20 mm. Here, "the outer side of the end of the transfer tube with a large radius of curvature" and "the outer side of the end of the transfer tube with a small radius of curvature" are divided into two regions by the joint (the mating part of the flange).

[0137] In the above embodiments, the inner diameters of the tubular portions of the upstream transfer pipe (e.g., clarification tank 2) and the downstream transfer pipe (e.g., glass supply path 7) are different, but they can also be the same. Furthermore, in the above embodiments, the upstream and downstream transfer pipes are joined so that the tops of their tubular portions are aligned; however, they can also be joined so that the bottoms of their tubular portions are aligned, or so that the top and bottom positions of their tubular portions are different, or so that the top and bottom positions of their tubular portions are aligned. When the top positions of the tubular portions are different, it is preferable to place an insulation member at the end (especially the top) of the transfer pipe on the side where an air layer is more likely to form.

[0138] In the above embodiments, the case where the glass article is a sheet glass has been described, but it is not limited to this. The glass article may be, for example, a glass roll formed by winding a strip of sheet glass into a roll, an optical glass component, a glass tube, a glass block, glass fiber, etc. In the case of manufacturing a glass roll, for example, after removing both ends of the sheet glass GR in the width direction by the cutting process S5, the strip of sheet glass GR is wound into a roll to obtain a glass roll (winding process).

[0139] Explanation of reference numerals in the attached figures

[0140] 1: Melting tank; 2: Refining tank; 2x: Tubular section; 2z: End (downstream side); 2za: Flange (downstream side); 2zb: Bend (downstream side); 3: Homogenizing tank; 4: Kettle; 5: Formed body; 6: Glass supply path; 7: Glass supply path; 7x: Tubular section; 7ya: Flange (upstream side); 7yb: Bend (upstream side); 8: Glass supply path; 9: Glass supply path; 11: Holding brick. 12: Retaining brick, 15: Felt (insulation component), 16: Outer shell, 17: Outer shell, 21: Heater (insulation component), 31: Refractory brick, 31x: Inner side, 31y: Outer side, 32: Engaging claw, 33: Overlapping part, 41: Metal component, 42: Overlapping part, 51: First refractory brick, 52: Second refractory brick, 61: First refractory brick, 62: Second refractory brick, GM: Molten glass, GR: Plate glass.

Claims

1. A glass article manufacturing apparatus comprising a transfer tube for conveying molten glass and a holding brick for holding said transfer tube, The apparatus for manufacturing glass articles is characterized in that, The glass article manufacturing apparatus includes a heat-insulating member for heat-insulating at least one end of the transfer tube that protrudes from the retaining brick. The transfer tube includes a tubular portion, a flange portion located at one end of the tubular portion, and a curved portion connecting the tubular portion and the flange portion. At the end of the transfer tube, the flange and the bend protrude outwards from the retaining brick. The thermal insulation component is in contact with the outer peripheral surface of the curved portion.

2. The glass article manufacturing apparatus according to claim 1, wherein, The insulation component is disposed on the outside of the end of the transfer tube and includes at least one component selected from the group consisting of felt, heater, refractory brick, monolithic refractory and metal components.

3. The apparatus for manufacturing glass articles according to claim 1 or 2, wherein, The insulation component is configured to insulate at least the top of the end of the transfer tube in the circumferential direction.

4. The apparatus for manufacturing glass articles according to claim 1 or 2, wherein, The transfer tube is a clarification tank.

5. The glass article manufacturing apparatus according to claim 4, wherein, The insulation component is configured to insulate the end of the clarification tank on the outflow side.

6. The apparatus for manufacturing glass articles according to claim 1 or 2, wherein, The transfer tube is made of platinum or a platinum alloy. The insulation component covers the outer circumferential surface of the end of the transfer tube.

7. The glass article manufacturing apparatus according to claim 6, wherein, The insulation component covers the entire circumference of the outer periphery of the end of the transfer tube.

8. The glass article manufacturing apparatus according to claim 6, wherein, The insulation component is kept in a position to move in sync with the thermal expansion of the transfer tube.

9. A method for manufacturing a glass article, wherein, The method for manufacturing the glass article includes a step of transferring molten glass using the glass article manufacturing apparatus of claim 1 or 2.

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