Glass manufacturing apparatus and glass manufacturing method

Abstract

This glass manufacturing apparatus comprises a melting device for melting a glass raw material to obtain molten glass, a molding device for molding the molten glass into a glass article, and a slow cooling device for slowly cooling the glass article. At least one among the melting device, the molding device, and the slow cooling device includes a heat insulating material containing an inorganic fiber. The inorganic fiber comprises Al2O3 and SiO2, wherein the Al2O3 content in the inorganic fiber is at least 60 mass%, and the SiO2 content in the inorganic fibers is at most 40 mass%.

Description

Technical Field

[0001] The present disclosure relates to a glass manufacturing apparatus and a glass manufacturing method.

Background Art

[0002] The manufacturing apparatus for float glass described in Patent Document 1 includes a melting apparatus that melts glass raw materials into molten glass, a forming apparatus that forms the molten glass supplied from the melting apparatus into a ribbon-like shape to obtain a glass ribbon, and a lehr that gradually cools the glass ribbon formed by the forming apparatus.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The melting apparatus, the forming apparatus, and the lehr include a heat insulating material. When the heat insulating material contains inorganic fibers, the quality of the glass may be deteriorated due to dust generated from the heat insulating material.

[0005] One aspect of the present disclosure provides a technique for suppressing dust generation from a heat insulating material containing inorganic fibers.

Means for Solving the Problems

[0006] The The glass manufacturing apparatus according to one aspect of the present disclosure includes a melting apparatus that obtains molten glass by melting glass raw materials, a forming apparatus that forms the molten glass into a glass article, and a lehr that gradually cools the glass article. At least one of the melting apparatus, the forming apparatus, and the lehr includes a heat insulating material containing inorganic fibers. The heat insulating material is the molten glass butIt is exposed to the atmosphere. The molten glass or the glass article has an upward-facing surface. The heat-insulating material is positioned above the molten glass or the glass article. The inorganic fibers contain Al2O3 and SiO2, with an Al2O3 content of 60% by mass or more and an SiO2 content of 40% by mass or less. Furthermore, a glass manufacturing apparatus according to a second aspect of this disclosure comprises a melting apparatus for obtaining molten glass by melting glass raw materials, a molding apparatus for forming the molten glass into a glass article, and an annealing apparatus for slowly cooling the glass article. At least one of the melting apparatus, the molding apparatus, and the annealing apparatus includes an insulating material containing inorganic fibers. The insulating material is exposed to the atmosphere to which the molten glass or the glass article is exposed. The molten glass has an upward-facing surface. The insulating material is positioned above the molten glass. The inorganic fibers are Al 2 O 3 and SiO 2 Includes the Al of the inorganic fiber 2 O 3 The content is 60% by mass or more, and the inorganic fiber is SiO 2 The content is 40% by mass or less. [Effects of the Invention]

[0007] According to one aspect of this disclosure, by having an Al2O3 content of 60% by mass or more in the inorganic fibers, changes in the crystal structure of the inorganic fibers caused by temperature changes can be suppressed, and dust generation from the inorganic fibers can be suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view showing a glass manufacturing apparatus according to one embodiment. [Figure 2] Figure 2 is a cross-sectional view showing a specific example of the glass manufacturing apparatus shown in Figure 1. [Figure 3] Figure 3 is a cross-sectional view showing an example of the upstream end of the molding apparatus shown in Figure 2. [Figure 4] Figure 4 is a cross-sectional view showing an example of one end in the width direction of the molding apparatus shown in Figure 2. [Figure 5] Figure 5 is a cross-sectional view showing an example of one end in the width direction of the slow cooling device shown in Figure 2. [Figure 6] Figure 6 is a cross-sectional view showing an example of the superstructure of the molding apparatus shown in Figure 2. [Figure 7] Figure 7 is a cross-sectional view showing an example of the buffer film forming section of the slow cooling device shown in Figure 2. [Figure 8] Figure 8 shows the X-ray diffraction spectrum of the heat-insulating material in Example 1. [Figure 9]FIG. 9 is a diagram showing the X-ray diffraction spectrum of the heat insulating material of Example 2. [Figure 10] FIG. 10 is a diagram showing the dust scattering rate of the heat insulating materials of Example 1 and Example 2.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and the description may be omitted. In each drawing, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other, the X-axis direction and the Y-axis direction are horizontal directions, and the Z-axis direction is a vertical direction. When the glass manufacturing apparatus 1 manufactures sheet glass by the float method, the X-axis direction is the conveyance direction of the glass ribbon, and the Y-axis direction is the width direction of the glass ribbon. In the specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value.

[0010] First, referring to FIG. 1, a glass manufacturing apparatus 1 according to an embodiment will be described. The glass manufacturing apparatus 1 includes a melting apparatus 2, a forming apparatus 3, a lehr 4, and a processing apparatus 5. Note that the glass manufacturing apparatus 1 only needs to include the melting apparatus 2, the forming apparatus 3, and the lehr 4, and does not necessarily need to include the processing apparatus 5.

[0011] The melting apparatus 2 melts glass raw materials to produce molten glass. The glass raw materials are prepared by mixing a plurality of types of materials. The glass raw materials may include glass cullets in order to recycle glass. The glass raw materials may be powder raw materials or granulated raw materials obtained by granulating the powder raw materials.

[0012] The forming apparatus 3 forms the molten glass obtained by the melting apparatus 2 into a glass article having a desired shape. As a forming method for obtaining a plate-shaped glass article, a float method, a fusion method, a roll-out method, or the like is used. The plate-shaped glass article is generally called a glass ribbon. As a forming method for obtaining a tubular glass article, a Vello method, a Danner method, or the like is used.

[0013] The annealing device 4 anneals the glass article formed by the forming device 3. The annealing device 4 has, for example, a heat treatment furnace and a conveying roller that conveys the glass article in a desired direction inside the heat treatment furnace. The conveying rollers are, for example, arranged in a plurality at intervals in the horizontal direction. The glass article is annealed while being conveyed from the inlet of the heat treatment furnace to the outlet of the heat treatment furnace. By annealing the glass article, a glass article with less residual strain can be obtained.

[0014] The processing device 5 processes the glass article annealed by the annealing device 4 into a desired shape. The processing device 5 includes, for example, one or more selected from a cutting device, a grinding device, a polishing device, and a coating device. The cutting device cuts the glass annealed by the annealing device 4. The cutting device, for example, forms a scribe line on the glass annealed by the annealing device 4 and cuts the glass along the scribe line. The scribe line is formed using a cutter or a laser beam. The grinding device grinds the glass annealed by the annealing device 4. The polishing device polishes the glass annealed by the annealing device 4. The coating device forms a desired film on the glass annealed by the annealing device 4.

[0015] Although not shown, the glass manufacturing apparatus 1 may further have a fining device. The fining device removes bubbles contained in the molten glass before the molten glass obtained by the melting device 2 is formed by the forming device 3. As a method for removing bubbles, for example, one or more selected from a method of reducing the ambient atmosphere of the molten glass and a method of heating the molten glass to a high temperature are used. The fining device may be a part of the melting device 2.

[0016] Next, a specific example of the glass manufacturing apparatus 1 will be described with reference to FIG. 2. The glass manufacturing apparatus 1 in FIG. 2 manufactures sheet glass by the float process. The sheet glass is, for example, non-alkali glass, aluminosilicate glass, borosilicate glass, or soda lime glass. Non-alkali glass means glass that substantially does not contain alkali metal oxides such as Na2O and K2O. Here, substantially not containing alkali metal oxides means that the total content of alkali metal oxides is 0.1 mass% or less.

[0017] The uses of flat glass are not particularly limited, but one example is its use as cover glass for displays (e.g., liquid crystal displays or organic EL displays). When flat glass is used as cover glass, it is chemically strengthened glass. Unlike alkali-free glass, chemically strengthened glass contains alkali metal oxides.

[0018] The thickness of the sheet glass is selected according to its intended use. If the sheet glass is used as cover glass for a display, the thickness is, for example, 0.1 mm to 5.0 mm. If the sheet glass is used as a glass substrate for a display, the thickness is, for example, 0.1 mm to 0.7 mm. If the sheet glass is used in automobiles, the thickness of sheet glass for laminated glass is, for example, 0.5 mm to 6.0 mm, and the thickness of sheet glass for tempered glass is, for example, 2.3 mm to 6.0 mm. When the use of sheet glass is architectural glass, the thickness of sheet glass for double glazing is, for example, 3mm to 12mm, the thickness of sheet glass for heat-reflective or heat-absorbing glass is, for example, 5mm to 12mm, the thickness of sheet glass for tempered glass is, for example, 4mm to 19mm, the thickness of sheet glass for disaster prevention and security glass is, for example, 3mm to 5mm, the thickness of sheet glass for fire-resistant glass is, for example, 5mm to 12mm, the thickness of sheet glass for soundproof glass is, for example, 3mm to 8mm, the thickness of sheet glass for renovation is, for example, 3mm to 10mm, the thickness of sheet glass for design glass is, for example, 2mm to 6mm, the thickness of sheet glass for patterned glass is, for example, 4mm to 6mm, and the thickness of sheet glass for frosted glass is, for example, 2mm to 5mm. Double glazing includes those with a Low-E coating. Disaster prevention and security glass is laminated glass made by sandwiching an interlayer between two sheets of sheet glass and pressing them together. Patterned glass is glass that has a patterned design on one side using the roll-out manufacturing method.

[0019] The melting apparatus 2 comprises a melting tank 21 for containing molten glass G, and a burner 22 that forms a flame above the molten glass G contained in the melting tank 21. The glass raw material introduced into the melting tank 21 gradually melts into the molten glass G by radiant heat from the flame formed by the burner 22. The molten glass G is continuously transported from the melting apparatus 2 to the molding apparatus 3. The heat source is not limited to the burner 22, but may also be an electric heater or electrodes. The electrodes generate heat by passing an electric current through the molten glass G.

[0020] The molding apparatus 3 includes a molding furnace 31, which is a heat treatment furnace. The molding furnace 31 has a bathtub 311. The bathtub 311 contains molten metal M. For example, molten tin is used as the molten metal M. In addition to molten tin, molten tin alloys can also be used, and the molten metal M only needs to have a higher density than the molten glass G. The molten glass G is continuously supplied onto the molten metal M and is formed into a strip-shaped glass ribbon GR using the smooth liquid surface of the molten metal M.

[0021] The molding furnace 31 has a ceiling 312 above the bathtub 311. The inside of the molding furnace 31 is filled with a reducing gas and maintained at a pressure higher than atmospheric pressure to prevent oxidation of the molten metal M. The reducing gas is, for example, a mixture of nitrogen gas and hydrogen gas, containing 85% to 98.5% by volume of nitrogen gas and 1.5% to 15% by volume of hydrogen gas. The reducing gas is supplied through the joints between the bricks of the ceiling 312 and through holes in the ceiling 312.

[0022] The molding apparatus 3 includes a heater 32 for heating the glass ribbon GR. The heater 32 is suspended, for example, from the ceiling 312 of the molding furnace 31 and heats the glass ribbon GR as it passes below. The heater 32 is, for example, an electric heater and is heated by energization. Multiple heaters 32 are arranged in a matrix in the transport direction and width direction of the glass ribbon GR. By controlling the output of the multiple heaters 32, the temperature distribution of the glass ribbon GR can be controlled, and the thickness distribution of the glass ribbon GR can be controlled.

[0023] The slow cooling device 4 comprises a dross box 41, which is a heat treatment furnace, and a lift-out roll 42. The lift-out roll 42 is positioned inside the dross box 41 and lifts the glass ribbon GR from the molten metal M. Multiple lift-out rolls 42 are arranged at intervals in the direction of transport of the glass ribbon GR (X-axis direction). The number of lift-out rolls 42 is not particularly limited. The lift-out rolls 42 are rotationally driven by a drive device such as a motor (not shown), and the driving force conveys the glass ribbon GR diagonally upward. The axial direction of the lift-out roll 42 is the same as the width direction (Y-axis direction) of the glass ribbon GR.

[0024] The slow cooling device 4 may be equipped with a heater (not shown) on the ceiling of the dross box 41 to adjust the temperature of the glass ribbon GR. The heater may be provided not only above the glass ribbon GR but also below it. Inside the dross box 41, the temperature of the glass ribbon GR is preferably (Tg-50)°C to (Tg+30)°C, with respect to the glass transition point Tg of the glass ribbon GR.

[0025] The annealing device 4 comprises an annealing furnace 45, which is a heat treatment furnace, and layer rolls 46. The annealing furnace 45 is located downstream of the dross box 41. The layer rolls 46 are located inside the annealing furnace 45 and transport the glass ribbon GR in the longitudinal direction (X-axis direction) of the glass ribbon GR. Multiple layer rolls 46 are provided at intervals in the transport direction of the glass ribbon GR. The number of layer rolls 46 is not particularly limited. The layer rolls 46 are rotationally driven by a drive device such as a motor (not shown), and the driving force transports the glass ribbon GR in the horizontal direction (X-axis direction). The axial direction of the layer rolls 46 is the same as the width direction (Y-axis direction) of the glass ribbon GR.

[0026] The annealing device 4 slowly cools the glass ribbon GR to a temperature below the strain point of the glass while conveying it with a layer roll 46. The annealing device 4 may be equipped with a heater (not shown) inside the annealing furnace 45 to adjust the temperature of the glass ribbon GR.

[0027] Next, with reference to Figure 3, an example of the upstream end of the molding apparatus 3 in Figure 2 will be described. The molding apparatus 3 comprises a spout lip 33 and a twill 34. The spout lip 33 continuously supplies molten glass G onto the molten metal M in the bath 311. The twill 34 is movable up and down relative to the spout lip 33 and adjusts the flow rate of molten glass G flowing over the spout lip 33. The narrower the distance between the twill 34 and the spout lip 33, the less the flow rate of molten glass G flowing over the spout lip 33. The twill 34 is made of refractory material. The twill 34 may have a protective film formed on it to prevent contact between the twill 34 and the molten glass G. The protective film may be made of, for example, platinum or a platinum alloy.

[0028] The molding furnace 31 has a ceiling 312 above the spout trip 33. The ceiling 312 includes a plurality of horizontally arranged bricks 313 and an insulating material 314 placed on top of the bricks 313. Gaps are formed between the bricks 313 and the twill 34, and also between adjacent bricks 313. Through these gaps, the insulating material 314 is exposed to the atmosphere to which the molten glass G is exposed. The insulating material 314 is positioned above the molten glass G.

[0029] The heat-insulating material 314 suppresses heat transfer from the inside to the outside of the molding furnace 31, maintaining a high temperature inside the molding furnace 31. The thermal conductivity of the heat-insulating material 314 is, for example, 1 W / m·K or less, preferably 0.5 W / m·K or less, more preferably 0.3 W / m·K or less, even more preferably 0.1 W / m·K or less, and particularly preferably 0.05 W / m·K or less. The thermal conductivity of the heat-insulating material 314 is 0 W / m·K or more.

[0030] The heat-insulating material 314 contains inorganic fibers. The heat-insulating material 314 may be a board-like material made by binding multiple inorganic fibers together with a binder, or a blanket made by forming layers of intertwined, cotton-like wool. The heat-insulating material 314 may remain in a cotton-like state or be processed into a string-like form. The air bubble content of the heat-insulating material 314 is, for example, 20% to 95% by volume, preferably 35% to 95% by volume, and more preferably 40% to 95% by volume. The upper limit of the numerical range for the air bubble content may be 90% by volume.

[0031] The inorganic fibers contained in the heat-insulating material 314 may be either artificial or natural fibers, and may be crystalline or amorphous. The inorganic fibers contain Al2O3 and SiO2. For example, the inorganic fibers contain Al2O3 and SiO2 as a solid solution. The inorganic fibers may also contain components other than Al2O3 and SiO2. These components other than Al2O3 and SiO2 are, for example, one or more selected from TiO2 and Fe2O3. The total content of components other than Al2O3 and SiO2 is, for example, 3% by mass or less. The chemical composition of the inorganic fibers is measured, for example, by X-ray fluorescence analysis (XRF).

[0032] The inorganic fibers contained in the heat-insulating material 314 have an Al2O3 content of 60% by mass or more and an SiO2 content of 40% by mass or less. As will be explained in detail in the Examples section, if the Al2O3 content is 60% by mass or more, changes in the crystal structure of the inorganic fibers due to temperature changes can be suppressed, and dust generation can be suppressed. Preferably, the inorganic fibers contained in the heat-insulating material 314 have an Al2O3 content of 90% by mass or less and an SiO2 content of 10% by mass or more.

[0033] As described above, the heat-insulating material 314 may be exposed to the atmosphere to which the molten glass G is exposed. In other words, the heat-insulating material 314 may be exposed to the molten glass G, and a path from the heat-insulating material 314 to the molten glass G (a space that is continuously connected from the heat-insulating material 314 to the molten glass G) may exist. According to this embodiment, since the generation of dust can be suppressed, even if a path from the heat-insulating material 314 to the molten glass G exists, there is little dust passing through that path, and the amount of dust adhering is small.

[0034] The molten glass G has an upward-facing surface (including an upward-facing surface), and the heat-insulating material 314 may be positioned above this upward-facing surface. Dust tends to fall due to gravity, and the upward-facing surface of the molten glass G easily catches dust. Therefore, a significant effect is obtained in suppressing the generation of dust from the heat-insulating material 314. The heat-insulating material 314 is preferably positioned directly above the molten glass G, but it may also be positioned diagonally above it.

[0035] Furthermore, the technology disclosed herein is applicable to applications other than the thermal insulation material 314 of the ceiling 312. The thermal insulation material only needs to be used in at least one of the melting apparatus 2, the molding apparatus 3, and the annealing apparatus 4. The thermal insulation material may be exposed to the atmosphere to which the glass ribbon GR is exposed. The glass ribbon GR may have an upward-facing surface, and the thermal insulation material may be positioned above that surface. The thermal insulation material is preferably positioned directly above the glass ribbon GR, but may also be positioned diagonally above it.

[0036] Next, with reference to Figure 4, an example of one end in the width direction of the molding apparatus 3 in Figure 2 will be described. The molding furnace 31 has a side wall 315 between the bathtub 311 and the ceiling 312. The side wall 315 includes a plurality of bricks 316 arranged vertically and a sealing member 317 that seals the gap between the lower brick 316 and the bathtub 311.

[0037] The sealing member 317 includes, for example, a metal box 318 and an insulating material 319 filled inside the box 318. The box 318 is composed of a plurality of metal plates (not shown). There may be gaps between the plurality of metal plates, and the insulating material 319 may be exposed to the atmosphere to which the glass ribbon GR is exposed through these gaps.

[0038] The thermal insulation material 319, like the thermal insulation material 314 (see Figure 3), contains inorganic fibers. The inorganic fibers contained in the thermal insulation material 319 have an Al2O3 content of 60% by mass or more and an SiO2 content of 40% by mass or less. If the Al2O3 content is 60% by mass or more, changes in the crystal structure of the inorganic fibers due to temperature changes can be suppressed, and the generation of dust can be suppressed.

[0039] The heat-insulating material 319 may be exposed to the atmosphere to which the glass ribbon GR is exposed. In other words, the heat-insulating material 319 may be exposed to the glass ribbon GR, and a path from the heat-insulating material 319 to the glass ribbon GR (a space that is continuously connected from the heat-insulating material 319 to the molten glass G) may exist. According to this embodiment, since the generation of dust can be suppressed, even if a path from the heat-insulating material 319 to the glass ribbon GR exists, there is little dust passing through that path, and the amount of dust adhering is small.

[0040] The glass ribbon GR has an upward-facing surface (including an upward-facing surface), and the heat-insulating material 319 may be positioned above that surface. Dust tends to fall due to gravity, and the upward-facing surface of the glass ribbon GR is good at capturing dust. Therefore, a significant effect is obtained in suppressing the generation of dust from the heat-insulating material 319. The heat-insulating material 319 is preferably positioned directly above the glass ribbon GR, but it may also be positioned diagonally above it.

[0041] Although not shown in the diagram, there may be gaps between the multiple bricks 316 that make up the side wall 315, and the insulation material 319 may be exposed to the atmosphere in which the glass ribbon GR is exposed through these gaps. Also, there may be gaps between the multiple bricks that make up the ceiling 312, and the insulation material 319 may be exposed to the atmosphere in which the glass ribbon GR is exposed through these gaps.

[0042] Next, with reference to Figure 5, an example of one end in the width direction of the annealing apparatus 4 of Figure 2 will be described. The annealing furnace 45 has a ceiling 451, a lower wall 452, and a side wall 453. At least one of the ceiling 451, the lower wall 452, and the side wall 453 may include, for example, a metal box 454 and an insulating material 455 filled inside the box 454. The box 454 is composed of a plurality of metal plates, which are not shown. There may be gaps between the plurality of metal plates, and through these gaps the insulating material 455 may be exposed to the atmosphere to which the glass ribbon GR is exposed.

[0043] The side wall 453 has an opening 456 through which the rotating shaft 47 of the layer roll 46 is inserted, and the opening 456 may have a heat insulating material 457 to suppress heat outflow. A drive device for rotating the rotating shaft 47 is located outside the annealing furnace 45. By locating the drive device outside the annealing furnace 45, thermal degradation of the drive device can be suppressed. The heat insulating material 457 may be exposed to the atmosphere to which the glass ribbon GR is exposed at the opening 456.

[0044] The thermal insulation materials 455 and 457 contain inorganic fibers, similar to thermal insulation material 314 (see Figure 3). The inorganic fibers contained in thermal insulation materials 455 and 457 have an Al2O3 content of 60% by mass or more and an SiO2 content of 40% by mass or less. As will be explained in detail in the Examples section, if the Al2O3 content is 60% by mass or more, changes in the crystal structure of the inorganic fibers due to temperature changes can be suppressed, and dust generation can be suppressed.

[0045] The insulating materials 455 and 457 may be exposed to the atmosphere to which the glass ribbon GR is exposed. In other words, the insulating materials 455 and 457 may be exposed to the glass ribbon GR, and a path from the insulating materials 455 and 457 to the glass ribbon GR (a space that is continuously connected from the insulating materials 455 and 457 to the glass ribbon GR) may exist. According to this embodiment, since the generation of dust can be suppressed, even if a path from the insulating materials 455 and 457 to the glass ribbon GR exists, there is little dust passing through that path, and the amount of dust adhering is small.

[0046] The glass ribbon GR has an upward-facing surface (including an upward-facing surface), and the heat-insulating materials 455 and 457 may be positioned above this upward-facing surface. Dust tends to fall due to gravity, and the upward-facing surface of the glass ribbon GR easily catches dust. Therefore, a significant effect is obtained in suppressing the generation of dust from the heat-insulating materials 455 and 457. The heat-insulating materials 455 and 457 are preferably positioned directly above the glass ribbon GR, but they may also be positioned diagonally above it.

[0047] Although not shown in the figures, the dross box 41 may have a structure similar to that of the annealing furnace 45. For example, the dross box 41 may have a ceiling, a bottom wall, and side walls, and at least one of the ceiling, bottom wall, and side walls may include a metal box and insulating material filled inside that box. Alternatively, the side wall of the dross box 41 may have an opening through which the rotating shaft of the lift-out roll 42 is inserted, and insulating material may be provided in that opening to suppress heat leakage.

[0048] Next, with reference to Figure 6, an example of the superstructure of the molding apparatus 3 in Figure 2 will be described. The molding apparatus 3 has a ceiling 312 of a molding furnace 31 and heaters 32 suspended from the ceiling 312. Multiple heaters 32 are arranged in a matrix in the direction of transport of the glass ribbon GR (X-axis direction) and in the width direction (Y-axis direction). The molding apparatus 3 may have heat insulating material 35 between adjacent heaters 32. The heat insulating material 35 may be placed between adjacent heaters 32 in the Y-axis direction, or between adjacent heaters 32 in the X-axis direction. The heat insulating material 35 restricts heat transfer between adjacent heaters 32.

[0049] The thermal insulation material 35, like the thermal insulation material 314 (see Figure 3), contains inorganic fibers. The inorganic fibers contained in the thermal insulation material 35 have an Al2O3 content of 60% by mass or more and an SiO2 content of 40% by mass or less. As will be explained in detail in the Examples section, if the Al2O3 content is 60% by mass or more, changes in the crystal structure of the inorganic fibers due to temperature changes can be suppressed, and dust generation can be suppressed.

[0050] The heat-insulating material 35 is exposed to the same atmosphere that the glass ribbon GR is exposed to. In other words, the heat-insulating material 35 is exposed to the glass ribbon GR, and a path exists from the heat-insulating material 35 to the glass ribbon GR (a continuous space from the heat-insulating material 35 to the glass ribbon GR). According to this embodiment, since dust generation can be suppressed, even if a path exists from the heat-insulating material 35 to the glass ribbon GR, there is less dust passing through that path, and the amount of dust adhering is small.

[0051] The glass ribbon GR has an upward-facing surface (including an upward-facing surface), and the heat-insulating material 35 is positioned above this upward-facing surface. Dust tends to fall due to gravity, and the upward-facing surface of the glass ribbon GR easily catches dust. Therefore, a significant effect is obtained in suppressing the generation of dust from the heat-insulating material 35. The heat-insulating material 35 is preferably positioned directly above the glass ribbon GR, but it may also be positioned diagonally above it.

[0052] Next, with reference to Figure 7, an example of the buffer film forming section 48 of the slow cooling device 4 in Figure 2 will be described. The buffer film forming section 48 has a supply pipe 481 that sprays a buffering agent onto the lower surface of the glass ribbon GR. The buffering agent reacts with the lower surface of the glass ribbon GR to form a buffer film on the lower surface of the glass ribbon GR. The buffer film mitigates the collision between the glass ribbon GR and the layer roll 46 and suppresses the occurrence of scratches on the lower surface of the glass ribbon GR. For example, sulfur oxide gas can be used as the buffering agent. The sulfur oxide gas may be either SO2 gas or SO3 gas. The sulfur oxide gas reacts with the lower surface of the glass ribbon GR to form a buffer film on the lower surface of the glass ribbon GR. The buffer film contains sulfate crystals, etc.

[0053] The buffer film forming section 48 includes a buffer material supply chamber 482 in which a supply pipe 481 is located, an upstream insulating material 483 provided on the upstream side (negative X-axis direction side) of the buffer material supply chamber 482, and a downstream insulating material 484 provided on the downstream side (positive X-axis direction side) of the buffer material supply chamber 482. The upstream insulating material 483 and the downstream insulating material 484 efficiently and uniformly form a buffer film by filling the buffer material supply chamber 482 with buffer material. The upstream insulating material 483 and the downstream insulating material 484 are not in contact with the lower surface of the glass ribbon GR, but may be in contact.

[0054] An upper insulation material 485 may be placed directly above the downstream insulation material 484. The upper insulation material 485 is placed above the glass ribbon GR. The upper insulation material 485 obstructs the gas flow above the glass ribbon GR.

[0055] The upstream insulation material 483, the downstream insulation material 484, and the upper insulation material 485 contain inorganic fibers, similar to the insulation material 314 (see Figure 3). The inorganic fibers have an Al2O3 content of 60% by mass or more and an SiO2 content of 40% by mass or less. As will be explained in detail in the Examples section, if the Al2O3 content is 60% by mass or more, changes in the crystal structure of the inorganic fibers due to temperature changes can be suppressed, and dust generation can be suppressed.

[0056] The upstream insulation material 483, the downstream insulation material 484, and the upper insulation material 485 are exposed to the atmosphere to which the glass ribbon GR is exposed. In other words, the upstream insulation material 483, the downstream insulation material 484, and the upper insulation material 485 are exposed to the glass ribbon GR, and a path exists from these insulation materials to the glass ribbon GR (a space that is continuously connected from these insulation materials to the glass ribbon GR). According to this embodiment, since the generation of dust can be suppressed, even if a path exists from the insulation material to the glass ribbon GR, there is little dust passing through that path, and the amount of dust adhering is small.

[0057] The glass ribbon GR has an upward-facing surface (including an upward-facing surface), and the upper insulation material 485 is positioned above this upward-facing surface. Dust tends to fall due to gravity, and the upward-facing surface of the glass ribbon GR easily catches dust. Therefore, a significant effect is obtained in suppressing the generation of dust from the upper insulation material 485. The upstream insulation material 483 is preferably positioned directly above the glass ribbon GR, but may also be positioned diagonally above it. [Examples]

[0058] The experimental data is described below. Example 1 below is a comparative example, and Example 2 is an example. In Example 1, IsoWool® 1260 manufactured by Isolite Industries Co., Ltd. was prepared as the heat insulating material. The chemical composition of the heat insulating material in Example 1 was Al2O3: 43.8 mass%, SiO2: 55.3 mass%, Fe2O3: 0.2 mass%, Na2O: 0.1 mass%, TiO2: 0.5 mass%, and CaO: 0.1 mass%. On the other hand, in Example 2, MAFTEC® manufactured by Mitsubishi Chemical Corporation was prepared as the heat insulating material. The chemical composition of the heat insulating material in Example 2 was Al2O3: 72.0 mass%, and SiO2: 28.0 mass%.

[0059] Figure 8 shows the X-ray diffraction spectrum of the thermal insulation material of Example 1. X-ray diffraction spectra were measured for samples stored at room temperature before heat treatment, heated at 800°C in air for 24 hours, heated at 1000°C in air for 24 hours, and heated at 1200°C in air for 24 hours. In Figure 8, the horizontal axis represents the diffraction angle (2θ), and the vertical axis represents the diffracted X-ray intensity. The X-rays were CuKα rays. The thermal insulation material of Example 1 had an Al2O3 content lower than 60 mass%, and as shown in Figure 8, the crystal structure changed when the heating temperature exceeded 1000°C. The change in crystal structure was particularly pronounced at 1200°C.

[0060] Figure 9 shows the X-ray diffraction spectrum of the thermal insulation material of Example 2. The X-ray diffraction spectrum was measured for samples stored at room temperature before heat treatment, heated at 800°C in air for 24 hours, heated at 1000°C in air for 24 hours, and heated at 1200°C in air for 24 hours. In Figure 9, the horizontal axis represents the diffraction angle (2θ), and the vertical axis represents the diffracted X-ray intensity. The X-rays were CuKα rays. The thermal insulation material of Example 2 had an Al2O3 content of 60 mass% or more, and as shown in Figure 9, the crystal structure hardly changed even when the heating temperature was 1000°C or higher.

[0061] Figure 10 shows the dust dispersion rates of the insulation materials in Example 1 and Example 2. The dust dispersion rate was determined by heating the insulation material in the atmosphere at 1000°C, then vibrating it with a vibration generator while it was housed in a case, and measuring the amount of dust that fell into the case. The vibration conditions were a frequency of 60Hz, a current of 2.0A, and a duration of 30 minutes. In both Example 1-1 and Example 1-2, IsoWool® 1260 manufactured by Isolite Industries Co., Ltd. was used as the insulation material. In both Example 2-1 and Example 2-2, MAFTEC® manufactured by Mitsubishi Chemical Corporation was used as the insulation material. From Figure 10, it can be seen that the insulation material in Example 2 has a lower dust dispersion rate than the insulation material in Example 1. This is thought to be because, as mentioned above, unlike the insulation material in Example 1, the crystalline structure of the insulation material in Example 2 hardly changes and does not deteriorate even when heat-treated at temperatures above 1000°C.

[0062] The following additional information is disclosed regarding the above embodiment. [Note 1] A glass manufacturing apparatus comprising: a melting apparatus for obtaining molten glass by melting glass raw materials; a molding apparatus for shaping the molten glass into a glass article of a desired shape; and a slow cooling apparatus for slowly cooling the glass article, At least one of the melting apparatus, the molding apparatus, and the slow cooling apparatus includes an insulating material containing inorganic fibers, A glass manufacturing apparatus in which the inorganic fibers contain Al2O3 and SiO2, wherein the Al2O3 content of the inorganic fibers is 60% by mass or more, and the SiO2 content of the inorganic fibers is 40% by mass or less. [Note 2] The glass manufacturing apparatus according to Appendix 1, wherein the Al2O3 content of the inorganic fiber is 90% by mass or less, and the SiO2 content of the inorganic fiber is 10% by mass or more. [Note 3] The glass manufacturing apparatus according to Appendix 1 or 2, wherein the heat-insulating material is exposed to the atmosphere to which the molten glass or glass article is exposed. [Note 4] The molten glass or glass article has an upward-facing surface, The glass manufacturing apparatus according to any one of the appendices 1 to 3, wherein the heat-insulating material is positioned above the molten glass or the glass article. [Note 5] A glass manufacturing method comprising manufacturing the glass article using a glass manufacturing apparatus described in any one of the appendices 1 to 4.

[0063] The glass manufacturing apparatus and glass manufacturing method described above are not limited to the embodiments described herein. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These also naturally fall within the technical scope of this disclosure.

[0064] This application claims priority based on Japanese Patent Application No. 2022-014214, filed with the Japan Patent Office on February 1, 2022, and the entire contents of Japanese Patent Application No. 2022-014214 are incorporated herein by reference. [Explanation of symbols]

[0065] 1. Glass manufacturing equipment 2 Melting equipment 3 Molding equipment 4. Slow Cooling Device

Claims

1. A glass manufacturing apparatus comprising: a melting apparatus for obtaining molten glass by melting glass raw materials; a molding apparatus for shaping the molten glass into a glass article of a desired shape; and a slow cooling apparatus for slowly cooling the glass article, At least one of the melting apparatus, the molding apparatus, and the slow cooling apparatus includes an insulating material containing inorganic fibers, The aforementioned heat-insulating material is exposed to the atmosphere to which the molten glass is exposed, The molten glass or glass article has an upward-facing surface, The heat-insulating material is positioned above the molten glass or the glass article. The aforementioned inorganic fiber is Al ２ O ３ and SiO ２ Includes the Al of the inorganic fiber ２ O ３ The content is 60% by mass or more, and the inorganic fiber contains SiO ２ Glass manufacturing apparatus with a content of 40% by mass or less.

2. A glass manufacturing apparatus comprising: a melting apparatus for obtaining molten glass by melting glass raw materials; a molding apparatus for shaping the molten glass into a glass article of a desired shape; and a slow cooling apparatus for slowly cooling the glass article, At least one of the melting apparatus, the molding apparatus, and the slow cooling apparatus includes an insulating material containing inorganic fibers, The heat-insulating material is exposed to the atmosphere to which the molten glass or glass article is exposed. The molten glass has an upward-facing surface, The aforementioned heat-insulating material is positioned above the molten glass. A glass manufacturing apparatus in which the inorganic fibers contain Al₂O₃ and SiO₂, wherein the Al₂O₃ content of the inorganic fibers is 60% by mass or more, and the SiO₂ content of the inorganic fibers is 40% by mass or less.

3. The Al content of the inorganic fiber ２ O ３ is 90% by mass or less, and the SiO content of the inorganic fiber ２ is 10% by mass or more. The glass manufacturing apparatus according to claim 1.

4. The slow cooling device has a buffer film forming section, The buffer film forming section comprises a buffer supply chamber, an upstream insulating material provided on the upstream side of the buffer supply chamber, and a downstream insulating material provided on the downstream side of the buffer supply chamber. An upper insulation material is placed directly above the aforementioned downstream insulation material. The upper insulating material is positioned above the glass article. The glass manufacturing apparatus according to claim 1, wherein the upstream insulating material, the downstream insulating material, and the upper insulating material include the inorganic fibers.

5. A method for manufacturing glass, comprising manufacturing a glass article using a glass manufacturing apparatus described in any one of claims 1 to 4.

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