Glass article manufacturing device and manufacturing method

Abstract

This glass article manufacturing device is provided with: a tubular part (10) of a transfer tube made of platinum or a platinum alloy, said tubular part (10) transferring molten glass (Gm); and a housing (12) surrounding the periphery of the tubular portion (10), the tubular portion (10) having an end portion (10a) including a protruding portion (10ax) protruding to the outside of the housing (12). A sprayed film (19) is formed only on the outer peripheral surface of the end portion (10a) including the protruding portion (10ax) among the outer peripheral surfaces of the tubular portion (10).

Description

Technical Field

[0001] The present invention relates to a manufacturing device and a manufacturing method for glass products such as plate glass. Background Art

[0002] The manufacturing device of glass articles is provided with a transfer pipe made of platinum or platinum alloy so as to supply molten glass generated by a melting furnace to a forming device. The transfer pipe is surrounded by a metal shell. Inside the shell, a refractory is arranged between the inner surface of the shell and the outer peripheral surface of the transfer pipe, and the transfer pipe is held by the refractory. In this state, the end of the transfer pipe has a protrusion protruding to the outside of the shell, and the protrusion is connected to other components (other transfer pipes, etc.) on the outside of the shell (for example, refer to Patent Document 1).

[0003] Here, in a transfer pipe made of platinum or a platinum alloy, due to contact with oxygen, the platinum component may be oxidized and evaporated, and thus lost. Therefore, in order to prevent this, Patent Document 2 discloses forming a spray coating on the outer peripheral surface of the transfer pipe, at least the outer peripheral surface of the middle portion of the transfer pipe located inside the shell. It should be noted that, hereinafter, the phenomenon of oxidizing and evaporating the platinum component is referred to as "oxidative evaporation", but this phenomenon is also referred to as "oxidative volatilization".

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-108258

[0007] Patent Document 2: WO2019 / 045099 Summary of the invention

[0008] Problems to be solved by the invention

[0009] As a result of intensive studies, the inventors of the present application have found that the following problems occur when a thermal spray film is formed on the outer peripheral surface of the middle portion of the transfer pipe located inside the housing.

[0010] Sometimes cracks occur in the spray coating due to thermal expansion of the transfer pipe. In this case, the transfer pipe remains protected by the spray coating except for the cracked portion of the spray coating. Therefore, oxidation evaporation of the transfer pipe is concentrated in the cracked portion of the spray coating due to oxidation pitting corrosion. However, the housing becomes an obstacle and the state of the spray coating formed on the outer peripheral surface of the middle portion of the transfer pipe located in the housing cannot be visually confirmed from the outside. That is, even if cracks occur in the spray coating, the cracks cannot be found at an early stage. As a result, there is a problem that oxidation pitting corrosion progresses in the cracked portion of the spray coating, which easily causes local wear of the transfer pipe.

[0011] An object of the present invention is to reliably suppress the loss of the transfer pipe due to oxidation evaporation of the platinum component.

[0012] Solutions to Solve Problems

[0013] (1) The present invention made in order to solve the above-mentioned problems is a manufacturing device for glass articles, comprising: a transfer tube made of platinum or a platinum alloy, which transfers molten glass; and an outer shell, which surrounds the periphery of the transfer tube, the transfer tube having an end portion including a protrusion protruding to the outside of the outer shell, and the manufacturing device for glass articles is characterized in that a sprayed film is formed only on the outer peripheral surface of the transfer tube including the end portion of the protrusion.

[0014] The amount of oxygen outside the shell tends to be higher than that inside the shell. Therefore, the end of the transfer pipe including the protrusion has more opportunities to contact oxygen than the middle part of the transfer pipe located inside the shell, and is prone to loss caused by oxidation evaporation of the platinum component. In addition, when a spray coating is formed on the outer peripheral surface of the middle part of the transfer pipe located inside the shell, local loss of the middle part due to oxidation pitting corrosion is prone to occur as described above. Therefore, in the present invention, the range in which the spray coating is formed only on the outer peripheral surface of the end including the protrusion in the outer peripheral surface of the transfer pipe is limited. If the end includes the protrusion, it is not affected by the shell and can be easily visually confirmed from the outside, so even if cracks occur in the spray coating formed on the end, the cracks can be found at an early stage. That is, while the transfer pipe is protected by the spray coating, local loss of the transfer pipe due to oxidation pitting corrosion can also be suppressed.

[0015] (2) In the configuration of (1) above, it is preferable that the thermal spray film is formed over the entire circumference of the outer peripheral surface including the end portion of the protruding portion.

[0016] The loss of the transfer pipe due to oxidation evaporation of the platinum component can be more reliably suppressed.

[0017] (3) In the configuration of (1) or (2) above, the thermal sprayed film is preferably a zirconium oxide thermal sprayed film.

[0018] Zirconia thermal spraying film has higher gas barrier properties than alumina thermal spraying film etc. Therefore, if the zirconium oxide thermal spraying film is used, it is possible to more reliably suppress the loss of the transfer pipe due to oxidation evaporation of the platinum component.

[0019] (4) In any one of the above structures (1) to (3), the thermal spraying film preferably has a thickness of 50 to 500 μm.

[0020] In this way, the gas barrier property of the thermal sprayed film is sufficient, and the loss of the transfer pipe due to oxidation evaporation of the platinum component can be more reliably suppressed.

[0021] (5) In any one of the above structures (1) to (4), the protruding portion is preferably covered with a detachable heat insulating member.

[0022] In this way, the heat-insulating component can be used to suppress the local temperature drop in the protrusion. The local temperature drop in the protrusion may cause defects (such as foreign matter defects) in the manufactured glass products, but by providing the heat-insulating component, the occurrence of such defects can be suppressed. In addition, the proportion of the protrusion in contact with oxygen can be reduced by covering the protrusion with the heat-insulating component, so the oxidation evaporation of the platinum component in the protrusion can be more reliably suppressed by the superposition effect of the heat-insulating component and the sprayed film. Moreover, the heat-insulating component can be loaded and unloaded, so the state of the sprayed film can be easily observed in the state where the heat-insulating component is removed. Therefore, even if cracks occur in the sprayed film, the state of the cracks can be found at an early stage.

[0023] (6) The present invention made in order to solve the above-mentioned problems is a method for manufacturing a glass article, comprising: a preheating step of thermally expanding a transfer tube made of platinum or a platinum alloy surrounded by an outer shell; and a production step of manufacturing the glass article by transferring molten glass using the thermally expanded transfer tube after the preheating step, wherein the method for manufacturing the glass article further comprises a spray coating forming step of forming a spray coating only on the outer peripheral surface of the transfer tube at an end portion of the transfer tube before the preheating step, wherein in the preheating step, due to the thermal expansion of the transfer tube, at least a portion of the end portion of the transfer tube formed with the spray coating protrudes to the outside of the outer shell.

[0024] In this manner, by utilizing the thermal spray film forming step and the preheating step performed before the preheating step, it is possible to easily create a state in which the thermal spray film is formed only on the outer peripheral surface of the end portion of the transfer pipe including the protruding portion.

[0025] Effects of the Invention

[0026] According to the present invention, it is possible to reliably suppress the loss of the transfer pipe due to oxidation evaporation of the platinum component. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a side view showing a manufacturing apparatus for a glass article according to a first embodiment of the present invention.

[0028] Figure 2 It is shown Figure 1 A cross-sectional view of a clarification tank included in the manufacturing apparatus shown.

[0029] Figure 3 yes Figure 2 A-A section view.

[0030] Figure 4 yes Figure 2 B-B section view.

[0031] Figure 5 This is a flowchart showing the method for producing a glass article according to the first embodiment.

[0032] Figure 6 It is used to illustrate Figure 5 A diagram showing a thermal spray film forming step included in the manufacturing method shown.

[0033] Figure 7 It is used to illustrate Figure 5 A diagram showing a preheating step included in the manufacturing method shown.

[0034] Figure 8 It is used to illustrate Figure 5 A diagram showing a preheating step included in the manufacturing method shown.

[0035] Fig. 9 It is a cross-sectional view which shows the clarification tank included in the manufacturing apparatus of the glass article which concerns on 2nd Embodiment of this invention. DETAILED DESCRIPTION

[0036] Hereinafter, the manufacturing method of the glass article of the embodiment of the present invention is described with reference to the accompanying drawings. The same reference numerals are marked on the corresponding components in each embodiment, so that repeated descriptions are sometimes omitted. In the case where only a part of the structure is described in each embodiment, the structure of other embodiments previously described can be applied to the other parts of the structure. In addition, not only the combination of structures explicitly described in the description of each embodiment, but also the structures of multiple embodiments can be partially combined with each other even if not explicitly stated, as long as there is no particular obstacle in the combination.

[0037] (First embodiment)

[0038] like Figure 1 As shown, the manufacturing device of the glass article of the first embodiment includes a melting tank 1, a clarification tank 2, a homogenization tank (stirring tank) 3, a kettle 4, a forming body 5, and glass supply paths 6, 7, 8, and 9 connecting the above-mentioned components 1 to 5. In addition, the manufacturing device includes an annealing furnace (not shown) for annealing the glass ribbon Gr formed by the forming body 5 and a cutting device (not shown) for cutting the glass ribbon Gr after annealing.

[0039] Here, in this embodiment, the clarification tank 2, the homogenization tank 3, the kettle 4, and the glass supply paths 6, 7, 8, and 9 correspond to transfer pipes for transferring the molten glass Gm. These transfer pipes include a tubular portion made of platinum (including reinforced platinum) or a platinum alloy (including reinforced platinum alloy).

[0040] The melting tank 1 is a container for performing a melting step of melting charged glass raw materials to obtain molten glass Gm. The melting tank 1 is connected to the clarification tank 2 via a glass supply path 6 .

[0041] The clarification tank 2 is a container for performing a clarification step of degassing the molten glass Gm while transferring the molten glass Gm by the action of a clarifier, etc. The clarification tank 2 is connected to the homogenization tank 3 via a glass supply path 7 .

[0042] The homogenization tank 3 is a container for performing a homogenization step of stirring and homogenizing the clear molten glass Gm. The homogenization tank 3 includes a stirrer 3 a having a stirring blade. The homogenization tank 3 is connected to the kettle 4 via a glass supply path 8 .

[0043] The kettle 4 is a container for performing a state adjustment step of adjusting the molten glass Gm to a state suitable for forming. The kettle 4 is exemplified as a volumetric unit for adjusting the viscosity and flow rate of the molten glass Gm. The kettle 4 is connected to the forming body 5 via a glass supply path 9 .

[0044] The forming body 5 is a forming device for performing a forming process of forming the molten glass Gm into a desired shape (e.g., a plate shape). In this embodiment, the forming body 5 forms the molten glass Gm into a plate shape by an overflow down-draw method. Figure 1 The cross-sectional shape (orthogonal to the paper plane) is roughly wedge-shaped, and an overflow groove (not shown) is formed on the upper part of the formed body 5.

[0045] The forming body 5 allows the molten glass Gm to overflow from the overflow trough and flow down along the side wall surfaces on both sides of the forming body 5 (the side surfaces located on both sides of the front and back of the paper surface). The forming body 5 allows the molten glass Gm that has flowed down to merge at the lower end of the side wall surface. Thus, a glass ribbon Gr having a formed converging surface in the central part of the plate thickness direction where the molten glass Gm merges is formed. It should be noted that the forming body 5 may also be a forming body that implements other down-drawing methods such as a slit down-drawing method and a redrawing method, or a float method. However, from the viewpoint of achieving smoothness of the surface of the glass ribbon Gr, it is preferred to use an overflow down-drawing method.

[0046] By cutting the glass ribbon Gr thus obtained, a single sheet of plate glass (glass article) is cut out. The plate glass has a thickness of, for example, 0.01 to 2 mm and is used in substrates and protective covers of displays such as liquid crystal displays and organic EL displays, organic EL lighting, and solar cells. When the glass ribbon Gr is formed using the overflow down-draw method, the cut plate glass can be used while keeping the surface as an unpolished surface (forged surface).

[0047] As the material of the plate glass, for example, alkali aluminosilicate glass, alkali-free glass, etc. are used. If alkali-free glass is used, a plate glass that is preferred as a display substrate can be obtained. In addition, if alkali aluminosilicate glass is used, a glass plate that is preferred as chemically strengthened glass can be obtained. It should be noted that the molten glass Gm is made of the same material as the plate glass.

[0048] Next, the detailed structure of the transfer pipe will be described using the clarification tank 2 as an example.

[0049] like Figure 2 to Figure 4 As shown, the clarification tank 2 includes a long tubular portion 10 for transferring the molten glass Gm, and flange portions 11 provided at both ends of the tubular portion 10 in the longitudinal direction.

[0050] The tubular portion 10 is surrounded by a housing 12. The housing 12 is supported by a stand (not shown) in a building such as a factory where a glass manufacturing device is installed so that the position can be changed. A refractory material 13 is arranged inside the housing 12 between the inner surface of the housing 12 and the outer peripheral surface of the tubular portion 10. The tubular portion 10 is held by the refractory material 13. Figure 1 In the figure, the flange portion of the transfer pipe of the clarification tank 2 and the like, the refractory material arranged around the transfer pipe, the outer shell, and the like are omitted from illustration.

[0051] The tubular portion 10 is formed of platinum or a platinum alloy in a tubular shape (e.g., a round tube shape). The tubular portion 10 is formed longer than the refractory 13 and the outer shell 12. Therefore, both ends 10a of the tubular portion 10 have protrusions 10ax protruding in the length direction from the ends of the refractory 13 and the outer shell 12, respectively. The middle portion 10b of the tubular portion 10 other than the both ends 10a is located inside the outer shell 12.

[0052] The flange portion 11 is configured in a plate shape (e.g., an annular shape). An electrode portion (not shown) is integrally provided on each flange portion 11. Electrical heating is performed by passing an electric current to the tubular portion 10 via the above-mentioned electrode portions, thereby heating the molten glass Gm transferred in the tubular portion 10. It should be noted that each flange portion 11 and each electrode portion of the clarification tank 2 may also be provided with a cooling portion (not shown) such as water cooling, so as to suppress losses caused by oxidation, etc. In addition, any transfer pipe other than the clarification tank 2 may also be electrically heated in the same manner to heat the molten glass Gm transferred in the transfer pipe.

[0053] The flange portion 11 on the upstream side of the clarification tank 2 is connected to the flange portion 15 provided at the downstream end of the tubular portion 14 of the glass supply path 6. The flange portion 11 on the downstream side of the clarification tank 2 is connected to the flange portion 17 provided at the upstream end of the tubular portion 16 of the glass supply path 7.

[0054] Refractory 13 is configured in a manner that the entire surrounding of tubular portion 10 is surrounded. In the present embodiment, the cross-sectional shape of refractory 13 is that the inner surface is circular and the outer surface is rectangular. The cross-sectional shape of refractory 13 is, for example, divided into two, upper and lower, so that the assembly property relative to tubular portion 10 is good. The cross-sectional shape of the shell 12 that fixes refractory 13 is that the inner surface and the outer surface are rectangular. The shapes of refractory 13 and shell 12 are not limited thereto.

[0055] The refractory 13 is made of refractory bricks (eg, high zirconia refractory bricks) having heat insulation properties, but the material thereof is not particularly limited. The outer shell 12 is made of steel or other metals, but the material thereof is not particularly limited.

[0056] A bonding layer 18 for bonding the tubular portion 10 and the refractory 13 is sandwiched between the tubular portion 10 and the refractory 13. As the bonding layer 18, for example, a diffusion bonded body containing aluminum oxide powder and silicon dioxide powder, glass powder, alumina cement, etc. can be used. In addition, the bonding layer 18 may also include a refractory fiber layer and a cement layer. Here, the diffusion bonded body refers to a bonded body formed by heating the powders that will become the raw materials after being filled between the tubular portion 10 and the refractory 13 to make the powders diffusely bonded. Diffusion bonding refers to a method of bonding the powders by contacting each other and utilizing the diffusion of atoms generated between the contact surfaces.

[0057] The sprayed film 19 is formed on the outer peripheral surface of each end portion 10a of the tubular portion 10 including the protruding portion 10ax. The sprayed film 19 is formed only on the outer peripheral surface of the end portion 10a including the protruding portion 10ax among the outer peripheral surfaces of the tubular portion 10. That is, the sprayed film 19 is not formed on the outer peripheral surface of the middle portion 10b of the tubular portion 10.

[0058] The clarification tank 2 is not limited to a clarification tank composed of a single tubular portion (transfer pipe) 10, and may be a clarification tank obtained by connecting a plurality of tubular portions (transfer pipes) 10 in the length direction. Specifically, when a plurality of tubular portions 10 are connected, each tubular portion 10 is connected by butting each flange portion 17 against each other. In this case, a refractory 13 and a shell 12 are separately provided on the outside of each tubular portion 10, and a protrusion 10ax protruding out of the shell 12 is provided at both ends 10a of each tubular portion 10. A sprayed film 19 is formed on the outer peripheral surface of the end portion 10a including each protrusion 10ax.

[0059] The inside of the housing 12 is a substantially closed space, so there is a tendency for the amount of oxygen to be less than that outside the housing 12. That is, the middle portion 10b located inside the housing 12 is less likely to produce oxidative evaporation of the platinum component than the protrusion 10ax located outside the housing 12. Therefore, as described above, the sprayed film 19 is formed only on the outer peripheral surface of the end portion 10a including the protrusion 10ax. As a result, the end portion 10a including the protrusion 10ax, which is easily in contact with oxygen, is protected by the sprayed film 19, so that the loss of the end portion 10a including the protrusion 10ax caused by oxidative evaporation of the platinum component can be suppressed. In addition, if the end portion 10a including the protrusion 10ax is not affected by the housing 12 and can be easily visually confirmed from the outside, even if cracks occur in the sprayed film 19, the cracks can be found at an early stage. That is, it is possible to reliably suppress the situation in which the end portion 10a including the protrusion 10ax is locally lost due to oxidative pitting corrosion generated in the cracked portion of the sprayed film 19.

[0060] The thermal sprayed film 19 is a ceramic thermal sprayed film, preferably an alumina thermal sprayed film or a zirconia thermal sprayed film. In particular, the zirconia thermal sprayed film is suitable for the thermal sprayed film 19 because it has higher gas barrier properties than the alumina thermal sprayed film.

[0061] The thermal spray film 19 is preferably formed over the entire circumference of the outer peripheral surface including the end portion 10a of the protrusion 10ax.

[0062] The thickness of the thermal sprayed film 19 is preferably 50 to 500 μm, more preferably 100 to 400 μm, and even more preferably 200 to 300 μm.

[0063] The end portion 10a including the protrusion 10ax may slightly include the portion of the tubular portion 10 located inside the housing 12 other than the protrusion 10ax. That is, the sprayed film 19 formed on the outer peripheral surface of the end portion 10a is allowed to slightly include the portion located inside the housing 12. However, it is preferred that the sprayed film 19 substantially does not include the portion located inside the housing 12. The intrusion dimension of the sprayed film 19 into the housing 12 is preferably 500 mm or less, more preferably 300 mm or less, and further preferably 0 mm to 100 mm from the end surface of the housing 12 along the length direction of the tubular portion 10.

[0064] Inert gas (e.g., nitrogen) and water vapor may be supplied into the housing 12 to fill the housing 12 with the inert gas and water vapor. The inert gas and water vapor penetrate the refractory 13 and act on the tubular portion 10 (mainly the middle portion 10b) located in the housing 12. Under the action of the inert gas and water vapor, the oxidative evaporation of the platinum component of the tubular portion 10 located in the housing 12 can be more reliably suppressed. It should be noted that the supply of inert gas and water vapor into the housing 12 is not essential and can be appropriately omitted.

[0065] Regarding other transfer pipes, when the end of the tubular portion of the transfer pipe has a protrusion protruding to the outside of the housing, a thermal spraying film may be formed on the outer peripheral surface of the end including the protrusion. In the present embodiment, thermal spraying films 20 and 21 are formed on the outer peripheral surface of the end of the tubular portion 14 of the glass supply path 6 connected to the upstream side of the clarification tank 2 and the outer peripheral surface of the end of the tubular portion 16 of the glass supply path 7 connected to the downstream side of the clarification tank 2, respectively. In addition, a thermal spraying film may be formed on the outer peripheral surface of the end including the protrusion in the glass supply path 8 connecting the homogenizing tank 3 and the kettle 4.

[0066] Next, a method for manufacturing a glass article (plate glass) using the manufacturing apparatus having the above-described configuration will be described.

[0067] like Figure 5 As shown, the method includes a spray coating forming step S1, a preheating step S2, an assembling step S3, a melting step S4, a molten glass supplying step S5, a forming step S6, an annealing step S7, and a cutting step S8. Among them, the melting step S4, the molten glass supplying step S5, the forming step S6, the annealing step S7, and the cutting step S8 are included in the production process of the glass article. That is, the spray coating forming step S1, the preheating step S2, and the assembling step S3 become the pre-process of the production process. In the following description, in the pre-process of the production process, the clarification tank 2 is sometimes used as an example to illustrate as a transfer pipe, but the same process can also be applied to other transfer pipes.

[0068] like Figure 6 As shown, in the thermal spray film forming step S1, the thermal spray film 19 is formed only on the outer peripheral surface of the end 10a including the protruding portion 10ax among the outer peripheral surface of the tubular portion 10 of the clarification tank 2. The thermal spray film 19 is formed, for example, by spraying the thermal spray material to the outer peripheral surface of the end 10a of the tubular portion 10. The thermal spray film forming step S1 is performed before the refractory 13 and the shell 12 are arranged outside the tubular portion 10 of the clarification tank 2. That is, the refractory 13 and the shell 12 will not become obstacles to the film forming operation such as blowing the thermal spray material, and the thermal spray film 19 can be easily formed. It should be noted that, when a part or all of the flange portion 11 is composed of platinum or a platinum alloy, the thermal spray film can be formed on the end surface of the flange portion 11 on the tubular portion 10 side, the butt surface of the flange portion 11, and the outer peripheral surface of the flange portion 11.

[0069] In the preheating step S2, the components 1 to 9 of the manufacturing apparatus are heated while being separated. It should be noted that some components (such as the kettle 4 and the glass supply path 9) may be heated while being connected. Figure 7 as well as Figure 8As shown, the refractory 13 and the outer shell 12 are arranged outside the tubular portion 10 of the clarification tank 2, and the powder P is filled between the tubular portion 10 and the refractory 13. The powder P forms a bonding layer 18 that fixes the tubular portion 10 to the refractory 13 by diffusion bonding.

[0070] In order to increase the temperature of the tubular portion 10 of the clarification tank 2, electric current is passed to the tubular portion 10 via the flange portion 11. By this electric heating, Figure 8 As shown, the tubular portion 10 of the clarification tank 2 thermally expands in the longitudinal direction from the state shown by the double-dashed line in the figure. In addition, the tubular portion 10 of the clarification tank 2 also thermally expands in the radial direction. At this time, the powder P filled between the tubular portion 10 and the refractory 13 maintains a powder state and can flow (move) in the space between the tubular portion 10 and the refractory 13. The powder P acts as a lubricant, so that the tubular portion 10 can be thermally expanded smoothly.

[0071] In the preheating step S2, before the tubular portion 10 is thermally expanded in the longitudinal direction, most of the end portion 10a of the tubular portion 10 formed with the sprayed film 19 is located inside the housing 12 (see Figure 7 On the other hand, in the preheating step S2, after the tubular portion 10 is thermally expanded in the longitudinal direction, the end portion 10a of the tubular portion 10 formed with the sprayed film 19 includes a protrusion 10ax that protrudes greatly outward from the housing 12 (see Figure 8 That is, along with the thermal expansion of the tubular portion 10 in the longitudinal direction in the preheating step S2, the sprayed film 19 located in the housing 12 also moves to the outside of the housing 12. Therefore, by using such a sprayed film forming step S1 and a preheating step S2, it is possible to easily create a state in which the sprayed film 19 is formed only on the outer peripheral surface of the end portion 10a of the tubular portion 10 including the protruding portion 10ax.

[0072] When the tubular portion 10 reaches a predetermined temperature (eg, 1200 to 1400° C.), the preheating step S2 is completed and the assembly step S3 is performed. In the assembly step S3, the manufacturing device is assembled by connecting the components 1 to 9 of the manufacturing device that have undergone thermal expansion.

[0073] In the melting step S4 , the glass-making raw material supplied into the melting tank 1 is heated to generate molten glass Gm.

[0074] In the molten glass supply process S5, the molten glass Gm of the melting tank 1 is sequentially transferred to the clarification tank 2, the homogenization tank 3, the kettle 4 and the forming body 5 via each glass supply path 6, 7, 8, 9. That is, the molten glass supply process S5 includes a clarification process, a homogenization process and a state adjustment process. In the clarification process, in the clarification tank 2, gas (bubbles) is generated from the molten glass Gm under the action of the clarifier mixed into the glass raw material. The gas is discharged from the clarification tank 2 to the outside. In the homogenization process, in the homogenization tank 3, the molten glass Gm is stirred and homogenized. In the state 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.

[0075] It should be noted that, in the molten glass supplying step S5, when the temperature of the powder P sandwiched between the refractory 13 and the tubular portion 10 becomes high temperature, the diffusion bonding of the powder P is activated, and finally a bonding layer 18 is formed that fixes the tubular portion 10 to the refractory 13. The heating temperature of the powder P can be above the temperature at which the diffusion bonding of the powder P is activated (for example, above 1400° C. and below 1650° C.).

[0076] In the forming step S6, the molten glass Gm that has passed the molten glass supplying step S5 is supplied to the forming body 5. The forming body 5 allows the molten glass Gm to overflow from the overflow channel and flow down along the side wall surface thereof. The forming body 5 allows the flowing molten glass Gm to merge at the lower end, thereby forming a glass ribbon Gr.

[0077] After that, the glass ribbon Gr is subjected to an annealing step S7 in an annealing furnace and a cutting step S8 in a cutting device, and is cut into plate glasses of a predetermined size. Through the above, plate glasses as glass articles are completed.

[0078] (Second embodiment)

[0079] like Fig. 9 As shown, in the second embodiment, a modified example of a clarification tank 2 as a transfer pipe is illustrated. In the clarification tank 2 of this embodiment, the outer peripheral surface of the protruding portion 10ax of the tubular portion 10 is covered with a detachable heat-insulating member 22. In detail, the heat-insulating member 22 is provided on the outer side of the sprayed film 19 formed on the outer peripheral surface of the protruding portion 10ax. The heat-insulating member 22 is preferably provided on the entire circumference of the outer peripheral surface of the sprayed film 19.

[0080] In this way, the protrusion 10ax is kept warm by the heat-insulating member 22, and the local temperature drop of the protrusion 10ax can be suppressed. The local temperature drop of the protrusion 10ax may cause defects (such as foreign matter defects) in the manufactured plate glass (glass article), but by providing the heat-insulating member 22, the occurrence of such defects can be suppressed.

[0081] Furthermore, since the proportion of the protrusion 10ax in contact with oxygen can be reduced by covering the protrusion 10ax with the heat insulating member 22, the oxidative evaporation of the platinum component in the protrusion 10ax can be more reliably suppressed by the synergistic effect of the heat insulating member 22 and the sprayed film 19.

[0082] Furthermore, since the heat-insulating member 22 is detachable, the heat-insulating member 22 can be removed (for example, by Fig. 9 The state of the thermal sprayed film 19 can be easily observed in the state shown by the single-dot chain line. Therefore, even if cracks occur in the thermal sprayed film 19, the state in which the cracks can be found at an early stage is maintained.

[0083] As the heat insulating member 22, for example, felt, refractory bricks, metal members, etc. can be used. As the felt, for example, a felt made of a refractory fiber material can be used. Specifically, a felt having heat resistance and elasticity that can withstand a temperature of 1000° C. or more (preferably 1300° C. or more) can be used. For example, a felt made of alumina fiber, silica fiber, zirconia fiber, and a blended fiber thereof can be used.

[0084] As mentioned above, although the manufacturing method of the glass article which concerns on embodiment of this invention was demonstrated, embodiment of this invention is not limited to this, Various changes can be implemented in the range which does not deviate from the summary of this invention.

[0085] In the above-mentioned embodiment, the glass article is described as a plate glass, but the present invention is not limited thereto. The glass article may be, for example, a glass roll. When manufacturing a glass roll, for example, after both ends of a glass ribbon in a width direction are removed by a cutting process, the glass ribbon is wound in a roll to obtain a glass roll (winding process).

[0086] Description of Reference Numerals

[0087] 1 Melting tank

[0088] 2 Clarification tank

[0089] 3 Homogenization tank

[0090] 3a. Agitator

[0091] 4 cauldron

[0092] 5 formed body

[0093] 6~9 Glass supply path

[0094] 10 Tubular part

[0095] 10a End

[0096] 10ax protrusion

[0097] 10b Middle

[0098] 11 Flange

[0099] 12. Housing

[0100] 13 Refractory (Retaining member)

[0101] 18 Bonding layer

[0102] 19 Spray coating

[0103] 22 Insulation components

[0104] Gm Molten glass

[0105] Gr Glass Ribbon

[0106] P powder

[0107] S1 Spray coating process

[0108] S2 Preheating process

[0109] S3 Assembly process

[0110] S4 Melting process

[0111] S5 Molten glass supply process

[0112] S6 Forming process

[0113] S7 Annealing process

[0114] S8 cutting process.

Claims

1. A manufacturing device for glass articles, comprising: a transfer tube made of platinum or a platinum alloy, which transfers molten glass; and a housing, which surrounds the periphery of the transfer tube, wherein the transfer tube has an end portion including a protruding portion protruding to the outside of the housing, The manufacturing device of the glass article is characterized in that: The thermal spray film is formed only on the outer peripheral surface of the transfer pipe including the end portion of the protruding portion.

2. The manufacturing device for glass articles according to claim 1, wherein: The thermal spray film is formed over the entire circumference of the outer peripheral surface including the end portion of the protrusion.

3. The manufacturing device for glass articles according to claim 1 or 2, wherein: The sprayed film is a zirconium oxide sprayed film.

4. The manufacturing device for glass articles according to claim 1 or 2, wherein: The film thickness of the sprayed film is 50 to 500 μm.

5. The manufacturing device for glass articles according to claim 1 or 2, wherein: The protruding portion is covered with a detachable heat insulating member.

6. A method for manufacturing a glass article, comprising: A preheating step to thermally expand the transfer tube made of platinum or platinum alloy surrounded by the outer shell; and a production process, after the preheating process, transferring molten glass using the heat-expanded transfer pipe to manufacture a glass article, The method for manufacturing the glass article is characterized in that: The method for manufacturing a glass article further includes a thermal spray film forming step of forming a thermal spray film only on an outer peripheral surface of an end portion of the transfer tube among the outer peripheral surfaces of the transfer tube before the preheating step. In the preheating step, due to thermal expansion of the transfer pipe, at least a portion of the end portion of the transfer pipe on which the thermal spray film is formed protrudes to the outside of the housing.

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