Apparatus and method for reducing defects in a glass melting system

Abstract

Apparatus and methods for manufacturing glass articles include a conduit of precious metal or precious metal alloy encasing molten glass, and further include a flow channel within or adjacent to the conduit through which a defect-suppressing fluid flows, the flow channel having at least one opening adjacent to a free surface of the molten glass through which the defect-suppressing fluid flows.

Description

Priority

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 63 / 001,811, filed Mar. 30, 2020, the entire disclosure of which is hereby incorporated by reference and made a part hereof.

Technical Field

[0002] The present disclosure generally relates to glass melting systems, and more particularly to apparatus and methods for reducing defects in glass melting systems.

Background Art

[0003] In the manufacture of glass articles such as glass plates for displays of televisions and mobile devices (e.g., telephones and tablet terminals), molten glass is conveyed through a glass melting system. The glass melting system typically includes a tank or conduit containing a noble metal or noble metal alloy, through which the molten glass is conveyed while physically contacting the noble metal or noble metal alloy. When the molten glass contacts the noble metal or noble metal alloy, chemical reactions such as redox reactions may occur, and in such cases, noble metals or noble metal oxides may migrate into or onto the surface of the molten glass. The presence of noble metals or noble metal oxides in or on the molten glass may cause undesirable defects in the glass article. Further, such reactions may cause corrosion of the tanks or conduits of the glass melting system, resulting in the need to repair or replace these components and the risk of undesirable process interruption times.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, it is desirable to mitigate or suppress these effects. [Means for solving the problem]

[0005] Embodiments disclosed herein include apparatus for manufacturing glass articles. The apparatus comprises a conduit comprising a precious metal or a precious metal alloy, configured such that molten glass flows through it. The apparatus further comprises a channel located inside or adjacent to the conduit, configured such that a defect-suppressing fluid flows through it. The channel has at least one opening located adjacent to the free surface of the molten glass, configured to allow the defect-suppressing fluid to flow out of the channel.

[0006] Embodiments disclosed herein further include methods for manufacturing glass articles. The method includes the step of transporting molten glass through a conduit containing a precious metal or a precious metal alloy. The method further includes the step of flowing a defect-suppressing fluid through at least one opening of a flow channel located inside or adjacent to the conduit. The at least one opening is located adjacent to the free surface of the molten glass.

[0007] Further features and advantages of embodiments disclosed herein are described in the following detailed description. These further features and advantages will be immediately apparent to some extent from the description alone to those skilled in the art, or will be apparent from practicing embodiments of the disclosure described herein, including the following detailed description, claims, and accompanying drawings.

[0008] It should be understood that both the above general description and the following detailed description illustrate embodiments intended to provide an overview or framework for understanding the nature and features of the claimed embodiments. The accompanying drawings are provided for further understanding and are incorporated into and form part of this specification. The drawings illustrate various embodiments of this disclosure and, together with the following detailed description, illustrate the principles and operation of the various embodiments. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram showing an example of a fusion downdraw glass manufacturing apparatus and glass manufacturing process. [Figure 2] A schematic side view showing a portion of an exemplary mixing tank according to an embodiment disclosed herein. [Figure 3] Schematic upper cross-sectional view of an exemplary mixing tank shown in Figure 2. [Figure 4] A schematic side view showing a portion of an exemplary mixing tank according to an embodiment disclosed herein. [Figure 5] Schematic upper cross-sectional view of an exemplary mixing tank shown in Figure 4. [Figure 6] A schematic side section view showing a portion of an exemplary conduit according to an embodiment disclosed herein. [Figure 7] A schematic side section view showing a portion of an exemplary conduit according to an embodiment disclosed herein. [Modes for carrying out the invention]

[0010] Next, preferred embodiments of the present disclosure will be described in detail. The accompanying drawings illustrate examples of these preferred embodiments. Throughout the drawings, identical or similar parts are indicated by the same reference numerals whenever possible. This disclosure can be implemented in a wide variety of forms and should not be construed as being limited to the embodiments described herein.

[0011] In this specification, ranges may be expressed as "about" a certain value or greater, "about" a certain value to "about" another specific value, or "about" the other specific value or less. When ranges are expressed in this way, other embodiments exist that include "about" a certain value, "about" a certain value to "about" another specific value, or "about" the other specific value or less. Similarly, when a value is expressed as an approximation, for example by placing "about" before it, it will be understood that other embodiments also exist that consist of that specific value itself. Furthermore, it will be understood that the meanings of the two endpoints of each range are both correlated and independent of each other.

[0012] In this specification, directional terms (e.g., up, down, right, left, front, back, top, bottom, etc.) are merely references to the drawings and are not intended to imply absolute orientation.

[0013] Unless otherwise expressly stated, no method described herein is intended to be construed as requiring each step (process) to be performed in a specific order, nor is any apparatus intended to require a specific orientation. Therefore, unless the order of the steps is actually described in a method claim, or the arrangement or orientation of the individual components is actually described in an apparatus claim, or unless otherwise clearly stated in the claims or detailed description of the invention that each step is limited to a specific order, or the arrangement or orientation of the components of the apparatus is described, no order (arrangement) or orientation is intended to be inferred in any way. This applies to all implicit matters that could be used as a basis for interpretation, such as the order of the steps, the flow of operations, the arrangement of components, or the orientation of components, the common meaning derived from grammatical structure or punctuation, or the number or type of embodiments described herein.

[0014] In this specification, the singular forms "a," "an," and "the" (the / the aforementioned) also include references to their corresponding plural forms, unless the context clearly indicates that the plural form is not included. Therefore, for example, an expression introducing a component with the article "a" also includes forms having two or more of that component, unless the context clearly indicates otherwise.

[0015] In this specification, the term "proximate" refers to a distance of approximately 75 millimeters or less.

[0016] As used herein, the term "defect inhibiting fluid" refers to a fluid that inhibits the transfer of a noble metal or noble metal oxide from a conduit or tank of a glass manufacturing apparatus to molten glass.

[0017] As used herein, the term "molten glass" refers to a glass composition that is at or above its liquidus temperature (the temperature above which the crystalline phase cannot coexist with the glass in equilibrium).

[0018] As used herein, the term "free surface of the molten glass" refers to the region where the molten glass is in contact with the atmosphere above the molten glass.

[0019] As used herein, the term "conduit" refers to a conduit or tank of a glass manufacturing apparatus that is configured to have molten glass flow therethrough. Exemplary conduits include, but are not limited to, the mixing tank 36, the fining tank 34, the delivery tank 40, and each connecting conduit.

[0020] As used herein, the term "connecting conduit" refers to a conduit used to connect components of a glass manufacturing apparatus that is configured to have molten glass flow therethrough. Exemplary connecting conduits disclosed herein include, but are not limited to, the first connecting conduit 32, the second connecting conduit 38, and the third connecting conduit 46.

[0021] FIG. 1 shows an exemplary glass manufacturing apparatus 10. In some examples, the glass manufacturing apparatus 10 can include a glass melting furnace 12, and the glass melting furnace 12 can include a melting tank 14. In addition to the melting tank 14, the glass melting furnace 12 includes one or more additional components such as heating elements (described in more detail herein) that heat the raw materials and convert them into molten glass. In further examples, the glass melting furnace 12 can also include a thermal management device (e.g., a heat insulation element) that reduces heat loss from the vicinity of the melting tank. In still other examples, the glass melting furnace 12 can include an electronic device and / or an electromechanical device that assists in melting the raw materials into a glass melt. Additionally, the glass melting furnace 12 can also include components such as a support structure (e.g., a support housing, a support member, etc.).

[0022] The glass melting tank 14 is typically composed of a refractory material such as a refractory ceramic material (e.g., a refractory ceramic material containing alumina or zirconia). In some examples, the glass melting tank 14 can be composed of refractory ceramic bricks. Hereinafter, specific embodiments of the glass melting tank 14 will be described in more detail.

[0023] In some examples, the glass melting furnace can be incorporated as a component of a glass manufacturing apparatus for manufacturing a glass substrate (e.g., a long glass ribbon). In some examples, glass manufacturing apparatuses in which the glass melting furnace of the present disclosure can be incorporated as a component include slot draw apparatuses, float bath apparatuses, down draw apparatuses such as the fusion process, up draw apparatuses, press rolling apparatuses, or tube drawing apparatuses, etc., which will benefit from the aspects disclosed herein. As an example, FIG. 1 schematically shows a glass melting furnace 12 as a component of a fusion down draw type glass manufacturing apparatus 10. The fusion down draw type glass manufacturing apparatus 10 is an apparatus for stretching a glass ribbon by the fusion draw method, and this glass ribbon is processed into individual glass plates in subsequent processes.

[0024] The glassmaking apparatus 10 (e.g., fusion downdraw apparatus 10) may optionally include an upstream glassmaking apparatus 16 located upstream of the glass melting tank 14. In some examples, part or all of the upstream glassmaking apparatus 16 can be incorporated as part of the glass melting furnace 12. As shown in the illustrated example, the upstream glassmaking apparatus 16 may include a storage bin 18, a raw material delivery device 20, and a motor 22 connected to the raw material delivery device. The storage bin 18 may be configured to store a batch raw material 24 in an amount that can be delivered into the melting tank 14 of the glass melting furnace 12, as indicated by arrow 26. The batch raw material 24 typically includes one or more glass-forming metal oxides and one or more modifiers. In some examples, the motor 22 can be used to operate the raw material delivery device 20 so that the raw material delivery device 20 can deliver a predetermined amount of batch raw material 24 from the storage bin 18 to the melting tank 14. In a further example, the motor 22 can operate the material delivery device 20 to deliver batch material 24 at a controlled flow rate based on the molten glass level sensed downstream of the melting tank 14. The batch material 24 in the melting tank 14 can then be heated to form molten glass 28.

[0025] The glass manufacturing apparatus 10 may optionally also include a downstream glass manufacturing apparatus 30 located downstream of the glass melting furnace 12. In some examples, a portion of the downstream glass manufacturing apparatus 30 can be incorporated as part of the glass melting furnace 12. In some cases, the first connecting conduit 32, described later, or other parts of the downstream glass manufacturing apparatus 30 can be incorporated as part of the glass melting furnace 12. Each element of the downstream glass manufacturing apparatus, such as the first connecting conduit 32, can be made of a precious metal. Suitable precious metals include platinum group metals selected from the group consisting of platinum, iridium, rhodium, osmium, ruthenium, and palladium, or alloys thereof. For example, the downstream components of the glass manufacturing apparatus can be made of a platinum-rhodium alloy containing about 100% to about 60% by mass of platinum and about 0% to about 40% by mass of rhodium. However, other suitable metals may also be molybdenum, rhenium, tantalum, titanium, tungsten, and alloys thereof. Additionally, oxide dispersion-strengthened (ODS) precious metal alloys can also be used.

[0026] The downstream glass manufacturing apparatus 30 may include a first conditioning tank (i.e., a processing tank), such as a clarification tank 34. The first conditioning tank is located downstream of the melting tank 14 and is connected to the melting tank 14 by the first connecting conduit 32 described above. In some examples, the molten glass 28 can be gravity-fed from the melting tank 14 to the clarification tank 34 by the first connecting conduit 32. For example, gravity can cause the molten glass 28 to pass through the internal path of the first connecting conduit 32 from the melting tank 14 to the clarification tank 34. However, it should be understood that other conditioning tanks may also be located downstream of the melting tank 14 (for example, between the melting tank 14 and the clarification tank 34). In some embodiments, a conditioning tank may be employed between the melting tank and the clarification tank to further heat the molten glass that has left the primary melting tank to continue the melting process, or to cool the molten glass that has left the melting tank to a temperature lower than the temperature of the molten glass in the melting tank before it flows into the clarification tank.

[0027] Within the clarification tank 34, bubbles can be removed from the molten glass 28 by various techniques. For example, the batch raw material 24 may contain polyvalent compounds (i.e., clarifiers) such as tin oxide, which undergo a chemical reduction reaction and release oxygen when heated. Other suitable clarifiers include, but are not limited to, arsenic, antimony, iron, and cerium. The clarification tank 34 is heated to a temperature higher than that of the melting tank, thereby heating the molten glass and the clarifier. The chemical reduction of (one or more) clarifiers induced by the temperature generates oxygen bubbles that rise through the molten glass in the clarification tank, and gases in the molten glass produced in the melting furnace can diffuse (i.e., combine) into these oxygen bubbles generated by the clarifier. The enlarged bubbles then rise to the free surface of the molten glass in the clarification tank, after which the bubbles can be discharged outside the clarification tank. Furthermore, the oxygen bubbles may also induce mechanical mixing of the molten glass in the clarification tank.

[0028] Furthermore, the downstream glass manufacturing apparatus 30 may further include another conditioning tank, such as a mixing tank 36 for mixing molten glass. The mixing tank 36 can be located downstream of the clarification tank 34. By using the mixing tank 36, a homogeneous molten glass composition can be achieved, thereby reducing the chemical or thermally non-uniform cords that may be present in the clarified molten glass discharged from the clarification tank if the mixing tank 36 is not used. As shown in the figure, the clarification tank 34 can be connected to the mixing tank 36 by a second connecting conduit 38. In some examples, the molten glass 28 can be gravity-fed from the clarification tank 34 to the mixing tank 36 by the second connecting conduit 38. For example, gravity can cause the molten glass 28 to pass through the internal path of the second connecting conduit 38 from the clarification tank 34 to the mixing tank 36. Although the mixing tank 36 is shown downstream of the clarification tank 34, the mixing tank 36 can also be located upstream of the clarification tank 34. In some embodiments, the downstream glass manufacturing apparatus 30 may include multiple mixing tanks, for example, a mixing tank upstream of the clarification tank 34 and a mixing tank downstream of the clarification tank 34. These multiple mixing tanks may have the same design or different designs.

[0029] Furthermore, the downstream glass manufacturing apparatus 30 may further include another regulating tank, such as a delivery tank 40. The delivery tank 40 may be located downstream of the mixing tank 36. The delivery tank 40 can regulate the molten glass 28 being supplied to the downstream molding device. For example, the delivery tank 40 may function as an accumulator and / or flow control mechanism that adjusts and / or supplies the flow rate so that the molten glass 28 flows steadily through the outlet conduit 44 to the molding body 42. As shown in the figure, the mixing tank 36 may be connected to the delivery tank 40 by a third connecting conduit 46. In some examples, the molten glass 28 may be gravity-fed from the mixing tank 36 to the delivery tank 40 by the third connecting conduit 46. For example, gravity can cause the molten glass 28 to pass through the internal path of the third connecting conduit 46 from the mixing tank 36 to the delivery tank 40.

[0030] The downstream glass manufacturing apparatus 30 may further include a molding apparatus 48 comprising the molding body 42 and an inlet conduit 50. The outlet conduit 44 can be arranged to deliver molten glass 28 from the delivery tank 40 to the inlet conduit 50 of the molding apparatus 48. For example, the outlet conduit 44 can be arranged nested inside the inlet conduit 50 and spaced apart from the inner surface of the inlet conduit 50, thereby providing a free surface for molten glass between the outer surface of the outlet conduit 44 and the inner surface of the inlet conduit 50. The molding body 42 in the fusion down-draw glass manufacturing apparatus may include a trough 52 located on the upper surface of the molding body and converging molding surfaces 54 that approach each other in the drawing direction of the molding body and meet along the bottom edge 56. Molten glass delivered to the trough of the molding body via the delivery tank 40, outlet conduit 44, and inlet conduit 50 overflows the side walls of the trough, splits into separate molten glass flows, and flows down along each converging molding surface 54. These separate molten glass flows merge below the bottom edge 56, along the bottom edge 56, to form a single glass ribbon 58. As the glass cools and its viscosity increases, tension is applied to this glass ribbon by gravity, edge rolls 72, and tension rolls 82, stretching the glass ribbon from the bottom edge 56 in the draw direction (i.e., flow direction) 60, thereby controlling the dimensions of the glass ribbon. Consequently, the glass ribbon 58 undergoes a viscoelastic transition, through which it acquires mechanical properties that determine its own stable dimensional characteristics. In some embodiments, the glass ribbon 58 can be separated into individual glass plates 62 by a glass separation device 100 in the region where the elasticity of the glass ribbon is high. The individual glass plates 62 can then be transferred to a conveyor system by a robot 64 using a gripping tool 65, where they can undergo further processing.

[0031] Figure 2 is a schematic side cross-sectional view showing a portion of an exemplary mixing tank 36 according to an embodiment disclosed herein. The mixing tank 36 is configured to enclose molten glass 28. The mixing tank 36 includes walls 140 that circumferentially surround the molten glass 28. The mixing tank also further includes a removable cover 130 configured to be positioned above the molten glass 28. Furthermore, the mixing tank 36 includes a rotatable central shaft 132 from which stirring blades 142 extend. The removable cover 130 is configured so that the rotatable central shaft 132 can extend through the removable cover 130 and may include, for example, two substantially semicircular portions that extend like a bivalve surrounding the rotatable central shaft 132.

[0032] As shown in Figure 2, the flow path 134 extends into the interior of the mixing tank 36, and is positioned such that a portion of the flow path 134 is approximately parallel to the free surface S of the molten glass 28 (i.e., a portion of the flow path 134 extends horizontally). The flow path 134 can be fixed in the mixing tank 36 by a support structure 136 such as a wire and a fastening structure 138 such as a nut. The fastening structure 138 can be loosened or tightened, thereby adjusting the position of the flow path 134 in the mixing tank 36 (for example, by moving the flow path 134 to move its relative position up or down in the mixing tank 36). The flow path 134 is configured to allow a defect-suppressing fluid to flow through it and has an opening 144 that is close to the free surface S of the molten glass 28. The opening 144 is located in the portion of the flow path 134 that is approximately parallel to the free surface S of the molten glass 28.

[0033] The defect-suppressing fluid flows into the flow path 134 from a fluid source (not shown) as indicated by arrow F, and flows out of the flow path 134 from the opening 144 as indicated by arrow F'. As shown in Figure 2, the opening 144 is configured to allow the defect-suppressing fluid to flow toward the wall 140 of the mixing tank 36. As shown in Figure 2, the defect-suppressing fluid flows radially outward slightly downward toward the wall 140 of the mixing tank 36, but embodiments herein also include embodiments in which the defect-suppressing fluid flows radially outward slightly upward toward the wall 140 of the mixing tank 36, and / or flows radially outward straight toward the wall 140 of the mixing tank 36 (i.e., neither upward nor downward).

[0034] Figure 3 is a schematic upper cross-sectional view of an exemplary mixing tank 36 shown in Figure 2 along the line XX'. As shown in Figure 3, two channels 134 are located inside the mixing tank 36, and each channel 134 has a roughly semicircular portion surrounded circumferentially by the wall 140 of the mixing tank 36 (this roughly semicircular portion corresponds to the portion roughly parallel to the free surface S of the molten glass shown in Figure 2). Each channel 134 is configured to allow the defect-suppressing fluid to flow radially outward toward the wall 140 of the mixing tank 36 from a plurality of openings (not shown in Figure 3), as indicated by arrow F'.

[0035] Figure 4 is a schematic side cross-sectional view showing a portion of an exemplary mixing tank 36 according to an embodiment disclosed herein. Similar to the mixing tank 36 shown in Figure 2, the mixing tank 36 is configured to enclose the molten glass 28. The mixing tank 36 includes a wall 140 that circumferentially surrounds the molten glass 28. The mixing tank also further includes a removable cover 130 configured to be positioned above the molten glass 28. Furthermore, the mixing tank 36 includes a rotatable central shaft 132 from which stirring blades 142 extend. The removable cover 130 is configured so that the rotatable central shaft 132 can extend through the removable cover 130 and may include, for example, two substantially semicircular portions that extend like a bivalve surrounding the rotatable central shaft 132.

[0036] As shown in Figure 4, the flow path 134' is arranged such that a portion of it extends above the removable cover 130 and the other portion extends into the mixing tank 36, and the portion of the flow path 134' that extends into the mixing tank 36 is positioned to be approximately perpendicular to the free surface S of the molten glass 28 (i.e., some portions of the flow path 134' extend vertically). The flow path 134' can be fixed in the mixing tank 36 with a fastening structure 138 such as a nut. The fastening structure 138 can be loosened or tightened, thereby adjusting the position of the flow path 134' in the mixing tank 36 (for example, moving the flow path 134' to move its relative position up or down in the mixing tank 36). The flow path 134' is configured to carry a defect-suppressing fluid and has an opening 144 that is close to the free surface S of the molten glass 28. The opening 144 is located in the portion of the flow path 134' that is approximately perpendicular to the free surface S of the molten glass 28. The defect-suppressing fluid flows into the flow path 134' from a fluid source (not shown) as indicated by arrow F, and flows out of the flow path 134' from the opening 144 as indicated by arrow F'.

[0037] Figure 5 is a schematic upper cross-sectional view of the exemplary mixing tank 36 shown in Figure 4 along line XX'. As shown in Figure 5, the two channels 134' are arranged such that a roughly semicircular portion of each channel 134' extends above the removable cover 130, and the other portion of each channel 134' extends vertically into the mixing tank 36 (this vertically extending portion corresponds to the portion roughly perpendicular to the free surface S of the molten glass shown in Figure 4). Each channel 134' is configured to allow the defect-suppressing fluid to flow through a plurality of openings (not shown in Figure 5) in a direction roughly parallel to the wall 140 of the mixing tank 36, as indicated by arrow F'.

[0038] Figure 6 is a schematic side cross-sectional view showing a portion of an exemplary conduit according to an embodiment disclosed herein. Although Figure 6 shows a second connecting conduit 38 as the conduit, Figure 6 can also be applied to other conduits disclosed herein, such as a first connecting conduit 32 and a third connecting conduit 46. The second connecting conduit 38 is configured to enclose the molten glass 28. The second connecting conduit 38 includes an appendage 230 extending radially outward from the body of the second connecting conduit 38. The appendage 230 circumferentially surrounds a condition measuring device 232 (e.g., a level probe, a temperature probe, etc.), the tip of which extends into the interior of the molten glass 28. The condition measuring device 232 functions as a channel through which a defect suppression fluid flows. In detail, the defect suppression fluid flows into the condition measuring device 232 from a fluid source (not shown) as indicated by arrow F and flows out of the condition measuring device 232 from an opening 234 as indicated by arrow F'. As can be seen from Figure 6, the opening 234 is in close proximity to the free surface S of the molten glass 28.

[0039] Figure 7 is a schematic side cross-sectional view showing a portion of an exemplary conduit according to an embodiment disclosed herein. Similar to Figure 6, Figure 7 also shows a second connecting conduit 38 as the conduit, but this too can be applied to other conduits disclosed herein, such as the first connecting conduit 32 and the third connecting conduit 46. Similar to Figure 6, the second connecting conduit 38 is configured to enclose the molten glass 28. The second connecting conduit 38 includes an appendage 230 extending radially outward from the body of the second connecting conduit 38. The appendage 230 circumferentially surrounds a condition measuring device 232 (e.g., a level probe, a temperature probe, etc.), the tip of which extends into the interior of the molten glass 28. A sheath 236 also circumferentially surrounds the condition measuring device 232 and is circumferentially surrounded by the appendage 230. The sheath 236 functions as a channel through which a defect suppression fluid flows. In detail, the defect-suppressing fluid flows into the sheath 236 from a fluid source (not shown) as indicated by arrow F, and flows out of the sheath 236 through opening 234. As can be seen in Figure 7, opening 234 is close to the free surface S of the molten glass 28.

[0040] In certain exemplary embodiments, such as those shown in Figures 2 to 7, one or more openings are provided, positioned close to the free surface of the molten glass 28 and configured to allow defect-suppressing fluid to flow out of the flow channels (e.g., flow channels 134, 134', etc.). For example, one or more openings may be positioned about 5 mm to about 75 mm from the free surface of the molten glass 28, for example, about 10 mm to about 50 mm. Furthermore, in certain exemplary embodiments, one or more openings may be positioned about 5 mm to about 75 mm from the wall 140, for example, about 10 mm to about 50 mm.

[0041] In certain exemplary embodiments, such as those shown in Figures 2 to 7, each channel may be made of the same or similar material as the tank (e.g., mixing tank 36) or conduit (e.g., second connecting conduit 38). For example, in certain exemplary embodiments, the channel 134, channel 134', state measuring device 232, and / or sheath 236 may include noble metals or alloys of noble metals. Exemplary noble metals include platinum group metals selected from the group consisting of platinum, iridium, rhodium, osmium, ruthenium, and palladium, or alloys thereof. For example, the channel may include a platinum-rhodium alloy containing about 70% to about 90% by mass of platinum and about 10% to about 30% by mass of rhodium. However, other suitable metals may also be molybdenum, palladium, rhenium, tantalum, titanium, tungsten, and alloys thereof.

[0042] The defect-suppressing fluid inhibits the movement of noble metals or noble metal oxides from the tank (e.g., mixing tank 36) or conduit (e.g., second connecting conduit 38) to the molten glass 28. For example, if the tank or conduit contains a platinum-rhodium alloy, the following oxidation-reduction reactions may occur in an oxygen-rich atmosphere: Pt·Rh+O2→Pt·RhO2

[0043] Such a reaction may result in the presence of undesirable amounts of platinum and / or rhodium oxides in the molten glass 28. Furthermore, this reaction may generate a precious metal gas, which can then be used as a raw material for the following reverse reaction, potentially forming defects: Pt·RhO2 → Pt·Rh+O2

[0044] Furthermore, this reverse reaction may trigger other reactions, such as redox reactions of polyvalent elements (e.g., SnO / SnO2, FeO / Fe2O3). However, as disclosed herein, such reactions can be suppressed by flowing a defect-suppressing fluid in close proximity to the free surface of the molten glass 28.

[0045] Examples of defect-suppressing fluids include, but are not limited to, nitrogen, argon, helium, neon, krypton, xenon, radon, hydrogen, chlorine, or mixtures thereof.

[0046] In certain exemplary embodiments, the temperature of the defect-suppressing fluid can be at or near the temperature of the molten glass 28. For example, the temperature of the defect-suppressing fluid can be at least about 1200°C, for example, at least about 1300°C, for example, at least about 1400°C, for example, at least about 1500°C, and can be a temperature of about 1200°C to about 1700°C (for example, about 1300°C to about 1600°C).

[0047] In certain exemplary embodiments, the flow rate of the defect suppression fluid can be in the range of about 0.1 to about 100 standard liters per minute (SLPM), for example, in the range of about 5 SLPM to about 50 SLPM.

[0048] Although the above-described embodiments have been explained in relation to the fusion downdraw process, it should be understood that such embodiments can also be applied to other glass forming processes such as the float process, slot draw process, updraw process, tubing process, and press rolling process.

[0049] Those skilled in the art will see that various modifications and alterations can be made to the embodiments of this disclosure without departing from the spirit and scope of this disclosure. Accordingly, this disclosure is intended to include such modifications and alterations without departing from the scope of the appended claims and equivalents.

[0050] Preferred embodiments of the present invention are described below in separate sections.

[0051] Embodiment 1 A glass manufacturing apparatus, A conduit containing a precious metal or a precious metal alloy, configured such that molten glass flows through it, A channel is located inside or near the conduit, through which a defect-suppressing fluid flows, and the channel has at least one opening located near the free surface of the molten glass, configured to allow the defect-suppressing fluid to flow from the channel. A glass manufacturing apparatus equipped with the following features.

[0052] Embodiment 2 The apparatus according to Embodiment 1, wherein the at least one opening is configured to be located at a position of about 5 millimeters to about 75 millimeters from the free surface of the molten glass.

[0053] Embodiment 3 The apparatus according to Embodiment 1, wherein the conduit includes a tank that surrounds the flow path in the circumferential direction.

[0054] Embodiment 4 The apparatus according to Embodiment 3, wherein the aforementioned tank includes a mixing tank.

[0055] Embodiment 5 The apparatus according to Embodiment 1, wherein the conduit includes a connecting conduit.

[0056] Embodiment 6 The apparatus according to Embodiment 1, wherein the defect-suppressing fluid is selected from at least one of nitrogen, argon, helium, neon, krypton, xenon, radon, hydrogen, chlorine, or a mixture thereof.

[0057] Embodiment 7 The apparatus according to Embodiment 3, wherein the at least one opening is configured to allow the defect-suppressing fluid to flow toward the wall of the tank.

[0058] Embodiment 8 The apparatus according to Embodiment 3, wherein the at least one opening is configured to allow the defect-suppressing fluid to flow in a direction substantially parallel to the wall of the tank.

[0059] Embodiment 9 The apparatus according to Embodiment 7, wherein the opening is configured to be positioned along a portion of the flow path that is substantially parallel to the free surface of the molten glass.

[0060] Embodiment 10 The apparatus according to embodiment 8, wherein the opening is configured to be positioned along a portion of the flow path that is substantially perpendicular to the free surface of the molten glass.

[0061] Embodiment 11 A step of transporting molten glass through a conduit containing a precious metal or a precious metal alloy, The steps include flowing a defect-suppressing fluid inside the conduit or from at least one opening of a flow channel located adjacent to the conduit, A method for manufacturing glass articles, including A method wherein the at least one opening is located in close proximity to the free surface of the molten glass.

[0062] Embodiment 12 The method according to Embodiment 11, wherein the at least one opening is located about 5 millimeters to about 75 millimeters from the free surface of the molten glass.

[0063] Embodiment 13 The method according to embodiment 11, wherein the conduit includes a tank that surrounds the flow path in the circumferential direction.

[0064] Embodiment 14 The method according to embodiment 13, wherein the tank includes a mixing tank.

[0065] Embodiment 15 The method according to embodiment 11, wherein the conduit includes a connecting conduit.

[0066] Embodiment 16 The method according to Embodiment 11, wherein the defect-suppressing fluid is selected from at least one of nitrogen, argon, helium, neon, krypton, xenon, radon, hydrogen, chlorine, or a mixture thereof.

[0067] Embodiment 17 The method according to embodiment 13, wherein the at least one opening allows the defect-suppressing fluid to flow toward the wall of the tank.

[0068] Embodiment 18 The method according to Embodiment 13, wherein the at least one opening allows the defect-suppressing fluid to flow in a direction substantially parallel to the wall of the tank.

[0069] Embodiment 19 The method according to Embodiment 17, wherein the opening is arranged along a portion of the flow path that is substantially parallel to the free surface of the molten glass.

[0070] Embodiment 20 The method according to embodiment 18, wherein the opening is arranged along a portion of the flow path that is substantially perpendicular to the free surface of the molten glass.

[0071] Embodiment 21 A glass article manufactured by the method described in Embodiment 11.

[0072] Embodiment 22 An electronic device comprising a glass article as described in Embodiment 21. [Explanation of Symbols]

[0073] 10 Glass manufacturing equipment 12 Glass melting furnace 14. Glass melting tank 16 Upstream glass manufacturing equipment 18 Storage containers 20 Raw Material Delivery Devices 22 motors 24 batch raw materials 26 Arrows 28. Molten glass 30 Downstream glass manufacturing equipment 32 First connecting conduit 34 Clarification tank 36 Mixing tank 38 Second connecting conduit 40 Delivery tank 42 Molded body 44 Outlet conduit 46 Third connecting conduit 48 Molding equipment 50 Inlet conduit 52 Groove 54 Converging molding surface 56 Bottom edge 58 Glass Ribbon 60 Flow direction 62 Glass plate 64 Robots 65 Gripping Tools 72 Edge Roll 82 Tension Roll 100 Glass Separator 130 Cover 132 Central shaft 134, 134' channel 136 Support Structure 138 Clamping Structure 140 Wall 142 Agitator blade 144 (Opening of the flow path) 230 Addition part 232 Condition Measurement Devices 234 (Opening of a condition measuring device or sheath) 236 Sheath S free surface

Claims

1. A glass manufacturing apparatus, A conduit containing a precious metal or a precious metal alloy, configured such that molten glass flows through it, A channel disposed inside the conduit and configured such that a defect-suppressing fluid flows through it, the channel having at least one opening positioned above and close to the free surface of the molten glass, and configured to allow the defect-suppressing fluid to flow from the channel, Equipped with, A glass manufacturing apparatus in which the conduit includes a tank surrounding the flow path in the circumferential direction, and the at least one opening is configured to allow the defect-suppressing fluid to flow toward the wall of the tank.

2. The glass manufacturing apparatus according to claim 1, wherein the flow path is arranged so as to be able to adjust the distance perpendicular to the free surface of the molten glass.

3. The glass manufacturing apparatus according to claim 1 or 2, wherein the conduit is a mixing tank for mixing the molten glass.

4. The glass apparatus according to claim 1 or 2, wherein the tank surrounding the flow path in the circumferential direction extends radially outward from the main body of the conduit, and the flow path is equipped with a state measuring device.

5. A step of transporting molten glass through a conduit containing a precious metal or a precious metal alloy, The steps include flowing a defect-suppressing fluid through at least one opening of a flow path located inside the conduit, A method for manufacturing glass articles, including The at least one opening is located above the free surface of the molten glass and on the free surface It is positioned in close proximity to, The conduit includes a tank that surrounds the flow path in the circumferential direction, and the at least one opening is A method of flowing the defect-suppressing fluid toward the wall of the tank.

6. The method according to claim 5, wherein the flow path is arranged so as to be able to adjust its distance perpendicular to the surface of the molten glass.

7. The method according to claim 5 or 6, further comprising the step of mixing the molten glass in the conduit.

8. The method according to claim 5 or 6, wherein the tank surrounding the flow path in the circumferential direction extends radially outward from the main body of the conduit, and the flow path is equipped with a state measuring device.

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