WO2025029417A1

WO2025029417A1 - Inductively heated glass manufacturing apparatus

Info

Publication number: WO2025029417A1
Application number: PCT/US2024/035761
Authority: WO
Inventors: Pierre Rene Joseph Laronze; JR Eugene LEHMAN
Original assignee: Corning Incorporated
Priority date: 2023-08-01
Filing date: 2024-06-27
Publication date: 2025-02-06
Also published as: CN119430617A

Abstract

A molybdenum conduit forming a passage for conveying molten glass from a first vessel to a second vessel, the molybdenum conduit. The molybdenum conduit may include a flange coupled thereto. The molybdenum conduit may include more than one flange attached thereto. The one or more flanges may comprise molybdenum. An electromagnetic inductor is positioned exterior to the molybdenum conduit and is configured to inductively heat the molybdenum conduit. A refractory material may be positioned around the molybdenum conduit to control heat loss from the molybdenum conduit and to support the molybdenum conduit. The molybdenum conduit may be spaced apart from the refractory material, thereby forming a gap between the refractory material and the molybdenum conduit. The gap may be filled with an inert gas or a glass material.

Description

Attorney Docket No. SP23-090 INDUCTIVELY HEATED GLASS MANUFACTURING APPARATUS CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Serial No. 63/516903 filed on August 1, 2023, the content of which is relied upon and incorporated herein by reference in its entirety. FIELD [0002] The present disclosure relates to a glass manufacturing apparatus for forming a glass ribbon, and more particularly, inductively heated conduits configured to convey molten glass between vessels of the manufacturing apparatus. BACKGROUND [0003] It is known to manufacturing glass articles by heating a batch material in a melting furnace and conveying the molten glass between one or more molten glass conditioning vessels and delivering the molten glass to a forming body to be formed into the glass article. Typically, such conditioning vessels, and the conduits extending therebetween, are formed from platinum or a platinum alloy. Platinum, or platinum alloys have high melting temperatures, making them ideal for conveying high temperature molten glass. Additionally, platinum is resistant to corrosion, thereby providing the platinum vessels and conduits with an ability to withstand the corrosive nature of molten glass. Unfortunately, platinum, and other platinum group metals, are expensive, making the construction of glass making apparatus costly. SUMMARY [0004] In a first aspect, a glass manufacturing apparatus is disclosed comprising a molybdenum conduit configured to convey molten glass, the molybdenum conduit comprising a conduit wall extending between a first end of the molybdenum conduit and a second end of the molybdenum conduit opposite the first end, the conduit wall defining a passage through the molybdenum conduit between the first end and the second end, and a first flange comprising molybdenum attached to the molybdenum conduit. [0005] In a second aspect, the first flange of the first aspect may comprise a disc portion and a hub portion positioned on the disc portion such that a longitudinal axis of the hub portion is orthogonal to a plane of the disc portion, and the first flange defines a bore extending therethrough along the longitudinal axis. [0006] In a third aspect, the first flange of the second aspect may be attached to the first end of the molybdenum conduit by the hub portion. Attorney Docket No. SP23-090 [0007] In a fourth aspect, the first end of the molybdenum conduit of the third aspect may comprise a first thread, the hub portion may comprise a second thread complementary to the first thread, and the hub portion may be attached to the first end with the first and second threads. [0008] In a fifth aspect, the first thread of the fourth aspect may be disposed on an exterior surface of the conduit wall and the second thread may be disposed on an interior surface of the hub along the bore. [0009] In a sixth aspect, the molybdenum conduit of the first aspect may comprise a groove disposed in an outside surface of the molybdenum conduit wall around a circumference of the molybdenum conduit, and a first bolster plate may be disposed in the groove. [0010] In a seventh aspect, the first bolster plate of the sixth aspect may comprise a curved edge surface corresponding to a curvature of the groove. [0011] In an eighth aspect, a second bolster plate may be disposed in the groove of the sixth aspect. [0012] In a ninth aspect, the first flange of the eighth aspect may be attached to the first bolter plate and the second bolster plate. [0013] In a tenth aspect, the first flange of the first aspect may be welded to the molybdenum conduit. [0014] In an eleventh aspect, a first refractory material may be positioned around the molybdenum conduit of any one of the first to the tenth aspects. [0015] In a twelfth aspect, the molybdenum conduit wall of the eleventh aspect may be spaced apart from an interior surface of the first refractory material such that a gap is disposed between the molybdenum conduit wall and the first refractory material. [0016] In a thirteenth aspect, an inert gas may be disposed in the gap of the twelfth aspect. [0017] In a fourteenth aspect, a glass material may be disposed in the gap of the twelfth aspect. [0018] In a fifteenth aspect, a plurality of spacers separating the conduit wall from the first refractory material of the eleventh aspect. [0019] In a sixteenth aspect, a second refractory material may be positioned around the first refractory material of any one of the eleventh aspect to the fifteenth aspect. [0020] In a seventeenth aspect, a thermal conductivity of the second refractory material of the fourteenth aspect may be different from a thermal conductivity of the first refractory material. [0021] In an eighteenth aspect, the glass manufacturing apparatus of any one of the first aspect to the seventeenth aspect may further comprise an electromagnetic inductor disposed around Attorney Docket No. SP23-090 at least a portion of a circumference of the molybdenum conduit, the electromagnetic inductor configured to induce an electrical current in the conduit wall. [0022] In a nineteenth aspect, the electromagnetic inductor of the eighteenth aspect may be helically disposed around the molybdenum conduit. [0023] In a twentieth aspect, a pitch of the electromagnetic inductor of the nineteenth aspect may vary as a function of length along the molybdenum conduit. [0024] In a twenty first aspect, the glass manufacturing apparatus of any one of the eighteenth aspect to the twentieth aspect may further comprise a second electromagnetic inductor disposed around at least a portion of the circumference of the molybdenum conduit, the second electromagnetic inductor spaced apart from the first electromagnetic inductor in a direction parallel with a longitudinal axis of the molybdenum conduit. [0025] In a twenty second aspect, the electromagnetic inductor of any one of the eighteenth aspect to the twentieth aspect may comprise an internal channel extending along a length of the electromagnetic inductor, the channel configured to receive a flow of coolant therethrough. [0026] In a twenty third aspect, a glass manufacturing apparatus is disclosed comprising a first molybdenum conduit comprising a first conduit wall extending between a first end of the first molybdenum conduit and a second end of the first molybdenum conduit, the first molybdenum conduit comprising a first flange comprising molybdenum attached to the first end of the first molybdenum conduit, and a first electromagnetic inductor disposed around at least a portion of the first conduit wall, the first electromagnetic inductor configured to induce a first electrical current in the first conduit wall. [0027] In a twenty fourth aspect, the first molybdenum conduit of the twenty third aspect may comprise a second flange comprising molybdenum attached thereto intermediate the first end and the second end. [0028] In a twenty fifth aspect, the first electromagnetic inductor of the twenty fourth aspect may be positioned between the first flange and the second flange. [0029] In a twenty sixth aspect, the glass manufacturing apparatus of the twenty fifth aspect may further comprise a second electromagnetic inductor disposed around at least a portion of the first conduit wall between the second flange and the second end. [0030] In a twenty seventh aspect, the glass manufacturing apparatus of the twenty third aspect may further comprise a second molybdenum conduit comprising a second conduit wall extending between a third end of the second molybdenum conduit and a fourth end of the second molybdenum conduit opposite the third end, the second molybdenum conduit comprising a second flange comprising molybdenum attached to the third end of the second Attorney Docket No. SP23-090 molybdenum conduit, the second molybdenum conduit arranged adjacent the first molybdenum conduit such a first longitudinal axis of the first molybdenum conduit is coaxial with a second longitudinal axis of the second molybdenum conduit and the second flange is spaced apart from the first flange, the second molybdenum conduit further comprising a second electromagnetic inductor disposed around at least a portion of the second conduit wall and positioned between the third end and the fourth end, the second electromagnetic inductor configured to induce a second electrical current in the second conduit wall. [0031] In a twenty eighth aspect, a glass seal may be disposed between the first flange and the second flanges of the twenty seventh aspect. [0032] In a twenty ninth aspect, a pitch of the first electromagnetic inductor of the twenty third aspect may vary as a function of length along the first molybdenum conduit. [0033] Both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and character of the embodiments disclosed herein. The accompanying drawings are included to provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure, and together with the description explain the principles and operations thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0034] FIG.1 is a schematic view of an exemplary glass manufacturing apparatus; [0035] FIG.2 is a perspective view of a molybdenum conduit in accordance with the present disclosure; [0036] FIG.3 is a side view of the molybdenum conduit of FIG.2 including a flange attached to an end thereof; [0037] FIG.4 is a side view of the molybdenum conduit of FIG.2 including flanges attached to both ends thereof; [0038] FIG. 5 is a side view of the molybdenum conduit of FIG. 4 including another flange attached to the molybdenum conduit intermediate between the ends of the molybdenum conduit; [0039] FIG. 6 is a cross-sectional side view of a flange configured to attach to an end of the molybdenum conduit of FIG.2 using a slip joint (e.g., interference fit); [0040] FIG. 7 is a cross-sectional side view of a flange configured to attach to an end of the molybdenum conduit of FIG.2 using a threaded joint; Attorney Docket No. SP23-090 [0041] FIG. 8 is a perspective view of the molybdenum conduit of FIG. 2 including a circumferential groove in an outer surface of a conduit wall of the molybdenum conduit; [0042] FIG. 9 is a close-up view of the attachment of a flange configured to attached to an intermediate position along a length of the molybdenum conduit in or adjacent to the groove of FIG.8 via a bolster plate; [0043] FIG.10 is a perspective view of the flange of FIG.9; [0044] FIG.11 is a perspective view of a portion of a molybdenum conduit comprising a first flange attached to and end thereof (type A flange), and a second flange attached intermediate between the ends of the conduit by way of the bolster plates of FIG. 9; [0045] FIG. 12 is a side view of a molybdenum conduit comprising a flange (e.g., type C flange) welded to the molybdenum conduit; [0046] FIG. 13 is an axial cross-sectional view of a molybdenum conduit comprising a first refractory material disposed around the molybdenum conduit and a second refractory material disposed around the first refractory material; [0047] FIG. 14 is an axial cross-sectional view of a molybdenum conduit comprising a first refractory material disposed around the molybdenum conduit and a second refractory material disposed around the first refractory material, and an electromagnetic inductor disposed around the molybdenum conduit; [0048] FIG. 15 is a side view of the molybdenum conduit of FIG. 3 comprising an electromagnetic inductor in the shape of a coil disposed around the molybdenum conduit; [0049] FIG. 16 is a cross-sectional view of induction heating a molybdenum conduit using two independent circuits, on the top and the bottom of the conduit, instead of a continuous coil around the tube; [0050] FIG. 17 is a side view of a molybdenum conduit comprising a plurality of electromagnetic inductors disposed around or adjacent to the molybdenum conduit; [0051] FIG. 18 is a side view of two molybdenum conduits arranged end-to-end, each molybdenum conduit comprising a plurality of electromagnetic inductors; [0052] FIG.19 is a close-up side view of the end-to-end portions of FIG.18 including a glass seal between adjacent flanges of the two molybdenum conduits; and [0053] FIG. 20 is a side view of a molybdenum conduit in accordance with the present disclosure extending between a first molten glass conditioning vessel and a second molten glass conditioning vessel, the molybdenum conduit comprising a plurality of flanges and a plurality of electromagnetic inductors. Attorney Docket No. SP23-090 DETAILED DESCRIPTION [0054] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. However, this disclosure can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. [0055] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. [0056] Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value to the other particular value. Similarly, when values are expressed as approximations by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. [0057] Directional terms as used herein—for example, up, down, right, left, front, back, top, bottom—are made only with reference to the figures as drawn and are not intended to imply absolute orientation. [0058] Unless otherwise expressly stated, it is in no way intended that a specific order or orientation of components of an apparatus be inferred in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification. [0059] As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise. [0060] The word “exemplary,” “example,” or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” or as an “example” should not be construed as preferred or advantageous over Attorney Docket No. SP23-090 other aspects or designs. Furthermore, examples are provided solely for purposes of clarity and understanding and are not meant to limit or restrict the disclosed subject matter or relevant portions of this disclosure in any manner. It can be appreciated that a myriad of additional or alternate examples of varying scope could have been presented but have been omitted for purposes of brevity. [0061] As used herein, the terms “comprising” and “including,” and variations thereof, shall be construed as synonymous and open-ended, unless otherwise indicated. A list of elements following the transitional phrases comprising or including is a non-exclusive list, such that elements in addition to those specifically recited in the list may also be present. [0062] The terms “substantial,” “substantially,” and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, “substantially” is intended to denote that two values are equal or approximately equal. In some embodiments, “substantially” may denote values within about 10% of each other, such as within about 5% of each other, or within about 2% of each other. [0063] Shown in FIG. 1 is an exemplary glass manufacturing apparatus 10. Glass manufacturing apparatus 10 can comprise a glass melting furnace 12 including a melting vessel 14. In addition to melting vessel 14, glass melting furnace 12 can optionally include one or more additional components such as heating elements (e.g., combustion burners and/or electrodes) configured to heat raw material and convert the raw material into a molten material (hereinafter, molten glass). For example, melting vessel 14 may be an electrically boosted melting vessel, wherein energy is added to the raw material through both combustion burners and by direct heating, wherein an electrical current is passed through the raw material, the electrical current thereby adding energy via Joule heating of the raw material. [0064] In further embodiments, glass melting furnace 12 can include other thermal management devices (e.g., insulation components) that reduce heat loss from the melting vessel. In still further embodiments, glass melting furnace 12 can include electronic and/or electromechanical devices that facilitate melting of the raw material into a glass melt. Glass melting furnace 12 can include support structures (e.g., support chassis, support member, etc.) or other components. [0065] Melting vessel 14 can be formed from a refractory material, such as a refractory ceramic material, for example a refractory ceramic material comprising alumina or zirconia, although the refractory ceramic material can comprise other refractory materials, such as Attorney Docket No. SP23-090 yttrium (e.g., yttria, yttria-stabilized zirconia, yttrium phosphate), zircon (ZrSiO4) or alumina- zirconia-silica or even chrome oxide, used either alternatively or in any combination. In some examples, melting vessel 14 may be constructed from refractory ceramic bricks. [0066] In some embodiments, glass melting furnace 12 can be incorporated as a component of a glass manufacturing apparatus configured to fabricate a glass article, for example a glass ribbon, although in further embodiments, the glass manufacturing apparatus can be configured to form other glass articles without limitation, such as glass rods, glass tubes, glass envelopes (for example, glass envelopes for lighting devices, e.g., light bulbs) and glass lenses, although many other glass articles are contemplated. In some examples, the melting furnace may be included in a glass manufacturing apparatus comprising a float bath apparatus, a down-draw apparatus (e.g., a fusion down draw apparatus or a slot draw apparatus), an up-draw apparatus, a pressing apparatus, a rolling apparatus, a tube drawing apparatus, or any other glass manufacturing apparatus that would benefit from the present disclosure. By way of example, FIG. 1 schematically illustrates glass melting furnace 12 as a component of a fusion down- draw style glass manufacturing apparatus 10 for fusion drawing a glass ribbon for subsequent processing into individual glass sheets or rolling the glass ribbon onto a spool. [0067] Glass manufacturing apparatus 10 can optionally include an upstream glass manufacturing apparatus 16 positioned upstream of melting vessel 14. In some examples, a portion of, or the entire upstream glass manufacturing apparatus 16, can be incorporated as part of the glass melting furnace 12. [0068] As shown in the embodiment illustrated in FIG. 1, upstream glass manufacturing apparatus 16 can include a raw material storage bin 18, a raw material delivery device 20 and a motor 22 connected to a raw material delivery device 20. Raw material storage bin 18 can be configured to store a quantity of raw material 24 that can be fed into melting vessel 14 of glass melting furnace 12 through one or more feed ports, as indicated by arrow 26. Raw material 24 typically comprises one or more glass forming metal oxides and one or more modifying agents. In some examples, raw material delivery device 20 can be powered by motor 22 to deliver a predetermined amount of raw material 24 from raw material storage bin 18 to melting vessel 14. In further examples, motor 22 can power raw material delivery device 20 to introduce raw material 24 at a controlled rate based on a level of molten glass sensed downstream from melting vessel 14 relative to a flow direction of the molten glass. Raw material 24 within melting vessel 14 can thereafter be heated to form molten glass 28. Typically, in an initial melting step, raw material is added to the melting vessel as particulate, for example as various “sands” and/or powders. Raw material 24 can also include scrap glass Attorney Docket No. SP23-090 (e.g., cullet) from previous melting and/or forming operations. Combustion burners are typically used to begin the melting process. In an electrically boosted melting process, once the electrical resistance of the raw material is sufficiently reduced, electric boost can begin by developing an electrical potential between electrodes positioned in contact with the raw material, thereby establishing an electrical current through the raw material, the raw material typically entering, or in, a molten state. [0069] Glass manufacturing apparatus 10 can also optionally include a downstream glass manufacturing apparatus 30 positioned downstream of glass melting furnace 12 relative to a flow direction of molten glass 28. In some examples, a portion of downstream glass manufacturing apparatus 30 may be incorporated as part of glass melting furnace 12. For example, in some instances, first connecting conduit 32 discussed below, or other portions of the downstream glass manufacturing apparatus 30, can be incorporated as part of the glass melting furnace 12. [0070] Downstream glass manufacturing apparatus 30 may include a first conditioning (i.e., processing) chamber, such as fining vessel 34, located downstream from melting vessel 14 and coupled to melting vessel 14 by way of the above-referenced first connecting conduit 32. Molten glass 28 may be gravity fed from melting vessel 14 to fining vessel 34 by way of an interior pathway of first connecting conduit 32. Accordingly, first connecting conduit 32 provides a flow path for molten glass 28 from melting vessel 14 to fining vessel 34. However, other conditioning chambers may be positioned downstream of melting vessel 14, for example between melting vessel 14 and fining vessel 34. In some embodiments, a conditioning chamber can be employed between the melting vessel and the fining chamber. For example, molten glass from a primary melting vessel can be further heated in a secondary melting (conditioning) vessel positioned between melting vessel 14 and fining vessel 34 or cooled in the secondary melting vessel to a temperature lower than the temperature of the molten glass in the primary melting vessel before entering the fining vessel. [0071] Bubbles may be removed from molten glass 28 by various techniques. For example, raw material 24 may include multivalent compounds (i.e., fining agents) such as tin oxide that, when heated, undergo a chemical reduction reaction and release oxygen. Other suitable fining agents may include without limitation arsenic, antimony, iron, cerium, and various sulfates, although the use of arsenic and antimony may be discouraged for environmental reasons in some applications. Fining vessel 34 may be heated, for example to a temperature greater than the melting vessel temperature, thereby heating the fining agent. Oxygen produced by the temperature-induced chemical reduction of one or more fining agents included in the molten Attorney Docket No. SP23-090 glass diffuse into bubbles produced during the melting process. The enlarged gas bubbles with increased buoyancy can then rise to a free surface of the molten glass within the fining vessel and thereafter be vented from the fining vessel. [0072] The downstream glass manufacturing apparatus 30 may further include another conditioning chamber, such as mixing apparatus 36, for example a stirring vessel, for mixing the molten glass that flows downstream from fining vessel 34. Mixing apparatus 36 can be used to provide a homogenous glass melt composition, thereby reducing chemical or thermal inhomogeneities that may otherwise exist within the molten glass exiting the fining chamber. As shown, fining vessel 34 may be coupled to mixing apparatus 36 by way of a second connecting conduit 38. In some embodiments, molten glass 28 can be gravity fed from fining vessel 34 to mixing apparatus 36 by way of an interior pathway of second connecting conduit 38. Molten glass within mixing apparatus 36 may include a free surface, with a free volume extending between the free surface and a top of the mixing apparatus. As used herein, a free volume is a gaseous volume, generally free of liquid material. Similarly, a free surface refers to the surface of the molten glass within a vessel or conduit and represents an interface between the liquid (e.g., molten glass) and the gaseous atmosphere above the molten glass. While mixing apparatus 36 is shown downstream of fining vessel 34 relative to a flow direction of the molten glass, mixing apparatus 36 may be positioned upstream from fining vessel 34 in other embodiments. In some embodiments, downstream glass manufacturing apparatus 30 may include multiple mixing apparatus, for example a mixing apparatus upstream from fining vessel 34 and a mixing apparatus downstream from fining vessel 34. These mixing apparatus may be of the same design, or they may be of a different design from one another. One or more of the vessels and/or conduits may include static mixing vanes positioned therein to promote mixing and subsequent homogenization of the molten material. [0073] Downstream glass manufacturing apparatus 30 may further include another conditioning chamber such as delivery vessel 40 located downstream from mixing apparatus 36. Delivery vessel 40 can condition molten glass 28 to be fed into a downstream forming device. For instance, delivery vessel 40 can act as an accumulator and/or flow controller to adjust and provide a consistent flow of molten glass 28 to forming body 42 by way of exit conduit 44. The molten glass within delivery vessel 40 can, in some embodiments, include a free surface, wherein a free volume extends upward from the free surface to a top of the delivery chamber. As shown, mixing apparatus 36 may be coupled to delivery vessel 40 by way of third connecting conduit 46. In some examples, molten glass 28 may be gravity fed from mixing Attorney Docket No. SP23-090 apparatus 36 to delivery vessel 40 by way of an interior pathway of third connecting conduit 46. [0074] Downstream glass manufacturing apparatus 30 may further include forming apparatus 48 comprising the above-referenced forming body 42, including inlet conduit 50. Exit conduit 44 can be positioned to deliver molten glass 28 from delivery vessel 40 to inlet conduit 50 of forming apparatus 48. [0075] Components of downstream glass manufacturing apparatus 30, including any one or more of connecting conduits 32, 38, 46, fining vessel 34, mixing apparatus 36, delivery vessel 40, exit conduit 44, or inlet conduit 50 may be formed from 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, downstream components of the glass manufacturing apparatus may be formed from a platinum-rhodium alloy including from about 70% to about 90% by weight platinum and about 10% to about 30% by weight rhodium. In some embodiments, such components may be formed from greater than about 90% platinum by weight, such as greater than 92% platinum by weight, greater than 94% platinum by weight, greater than 96% platinum by weight, greater than 98% platinum by weight, and even up to 100% platinum by weight. However, other suitable metals for forming downstream components of the glass manufacturing apparatus can include molybdenum, rhenium, tantalum, titanium, tungsten, and alloys thereof. [0076] Forming body 42 in a fusion down-draw glass manufacturing apparatus can comprise a trough 52 positioned in an upper surface of the forming body, and converging forming surfaces 54 (only one surface shown) that converge in a draw direction along a bottom edge (root) 56 of the forming body. Molten glass delivered to forming body trough 52 via delivery vessel 40, exit conduit 44 and inlet conduit 50 overflows the walls of trough 52 and descends along converging forming surfaces 54 as separate flows of molten glass. The separate flows of molten glass join along and below root 56 to produce a single ribbon 58 of molten glass that is drawn along a draw plane in a draw direction 60 from root 56 by applying a downward tension to the glass ribbon, such as by gravity and/or pulling roll assemblies (not shown), to control dimensions of the glass ribbon as the molten glass cools and a viscosity of the molten glass increases. Accordingly, glass ribbon 58 goes through a visco-elastic transition to an elastic state and acquires mechanical properties that give glass ribbon 58 stable dimensional characteristics. Glass ribbon 58 comprises first outer edge 62a and second outer edge 62b opposite first outer edge 62a, the first and second outer edges extending lengthwise along glass ribbon 58. Glass ribbon 58 may further comprise first thickened edge portion 64a and second Attorney Docket No. SP23-090 thickened edge portion 64b (hereinafter first bead 64a and second bead 64b, respectively), beads 64a, 64b extending inward from respective first and second outer edges 62a, 62b. Glass ribbon 58 comprises a width W defined between first and second outer edges 62a and 62b. First and second beads 64a, 64b can comprise a thickness greater than a thickness of the glass ribbon along a longitudinal centerline of the glass ribbon. The glass ribbon extending between first bead 64a and second bead 64b can be referred to as the “quality” region 66 of the glass ribbon. Quality region 66 exhibits a substantially uniform thickness and pristine or substantially pristine surfaces and is the most commercially valuable portion of the ribbon, as the beads are typically removed and used as cullet or scrapped. Glass ribbon 58 may, in some embodiments, be separated into individual glass sheets 68 by a glass separation apparatus 100, although in further embodiments, glass ribbon 58 may be wound onto spools and stored for further processing. [0077] As described above, suitable metals for forming downstream components of the glass manufacturing apparatus can include molybdenum, rhenium, tantalum, titanium, tungsten, and alloys thereof. More specifically, in embodiments described herein, any one of first connecting conduit 32, second connecting conduit 38, or third connecting conduit 46 may be formed from a material comprising molybdenum. The conduit may include other material. For example, the molybdenum may be an alloy of molybdenum, such as titanium zirconium molybdenum (TZM) or molybdenum lanthanum (ML). In some embodiments, the conduit may comprise an oxidation protection coating disposed on at least a portion of a surface thereof, for example over at least a portion of an external surface, at least a portion of an internal surface, or at least a portion of both an internal surface and an external surface. In some embodiments, the oxidation protection coating may be deposited over an entire surface of the conduit, for example over the entire external surface of the conduit, the entire internal surface of the conduit, or both the entire external surface and the entire internal surface of the conduit. Suitable oxidation protection coatings may include a silicon-boron-carbon (Si-B-C) based material, such as SIBOR^® available from Plansee AG, Reutte, Austria. A conduit formed from a material comprising molybdenum, and heated inductively, is described in greater detail herein below. [0078] Shown in FIG.2 is a conduit 200 formed from or comprising molybdenum, including alloys thereof. Accordingly, a molybdenun conduit may comprise substantially all molybdenum (except for trace amounts of other materials, e.g., less than about 1% by weight), or less than substantially all molybdenum. As such, a conduit formed from or comprising molybdenum are hereinafter referred to as a “molybdenum conduit”. Molybdenum conduit Attorney Docket No. SP23-090 200 comprises a conduit wall 202 extending from a first end 204 of the molybdenum conduit to a second end 206 of the molybdenum conduit opposite the first end. Molybdenum conduit 200 may further comprise a flange 208, e.g., a first flange, attached thereto. Referring to FIG. 3, in some aspects flange 208 may be attached to first end 204 or second end 206 of molybdenum conduit 200. In some embodiments, molybdenum conduit 200 may comprise a plurality of flanges 208 attached thereto. For example, as shown in FIG. 4, molybdenum conduit 200 may comprise first flange 208a attached to first end 204 and a second flange 208b attached to second end 206. In some embodiments, molybdenum conduit 200 may comprise a flange 208 attached thereto intermediate first end 204 and second end 206. For example, FIG. 5 illustrates molybdenum conduit 200 comprising two end flanges 208 (e.g., 208a and 208b) and a third flange 208c intermediate first end 204 and second end 206. That is, flange 208c may be positioned at a location along a length of the conduit between first end 204 and second end 206. Accordingly, molybdenum conduit 200 may comprise a plurality of flanges attached thereto along a length of the conduit, at one or both ends of the molybdenum conduit and/or intermediate first end 204 and second end 206. Flanges 208 are mechanical flanges in that the flanges are not intended nor used for directing an electrical current to the molybdenum conduit. Rather, flanges 208 may be used for mating sections of molybdenum conduit, mating the molybdenum conduit to a vessel, or mechanical support of the molybdenum conduit. [0079] Referring to FIGS. 3-7, in embodiments, flanges 208 configured to attach to ends of molybdenum conduit 200, hereinafter type A flanges 208, may comprise a disc portion 210, wherein disc portion 210 is substantially planar and circular. Type A flanges 208 may further comprise a hub portion 212. Hub portion 212 may be centrally located on disc portion 210. That is, hub portion 212 may be positioned relative to disc portion 210 such that a longitudinal axis 214 of hub portion 212 is coaxial with an axis 216 extending through a center of disc portion 210. In embodiments, hub portion 212 may be cylindrical. Hub portion 212 comprises a bore 218 extending through the hub portion [0080] In some embodiments, type A flanges 208 may be slip-fit (e.g., interference fit) onto an end of molybdenum conduit 200. Thus, bore 218 may be a smooth-walled bore as shown in FIG. 6. In other embodiments, type A flanges 208 may be screwed onto an end of molybdenum conduit 200. For example, as shown in FIG. 7, in some embodiments, bore 218 may include threads formed on inside surface 220 of hub portion 212 (the inside surface defining bore 220). That is, bore 218 may be a threaded bore. The thread profile may be any suitable thread profile, such as, by way of example, a trapezoidal thread profile (e.g., Acme), a V-shaped thread profile, or a square thread profile. Similarly, one or both ends 204, 206 of Attorney Docket No. SP23-090 molybdenum conduit 200 may be threaded. In various embodiments, an outside surface of conduit wall 202 may be threaded at an end of molybdenum conduit 200, the threads of molybdenum conduit 200 may be complementary to the threads of bore 218. That is, the threads of molybdenum conduit 200 are configured to engage with the threads of bore 218. Thus, in some embodiments, hub portion 212 may be threaded onto an end of molybdenum conduit 200. While not shown, in other embodiments, an external surface of hub portion 212 may comprise threads and an interior surface of conduit wall 202 may comprise threads such that hub portion 212 may be screwed into and end of molybdenum conduit 200. [0081] In some embodiments, molybdenum conduit 200 may comprise a flange 208 configured to attach thereto intermediate first end 204 and second end 206, hereinafter a type B flange 208. For example, as shown in FIGS. 8 and 9, molybdenum conduit 200 may comprise a groove 222 formed into an exterior surface of conduit wall 202, for example about a circumference of conduit wall 202. A first bolster plate 230 may be fitted into groove 222. First bolster plate 230 may, for example, be annularly shaped, but as a minimum include a curved inner edge surface 232 shaped to be received into groove 222. For example, a radius of curvature of the inner edge surface 232 of first bolster plate 230 may be equal to or substantially equal to a radius of curvature of groove 222. First bolster plate 230 may further comprise a plurality of holes 234 extending through a thickness of the bolster plate. In embodiments, a second bolster plate 236 (see FIG. 11) may be fitted into groove 222, for example opposite first bolster plate 230. Second bolster plate 236 may be identical or substantially identical to first bolster plate 230. Second bolster plate 236 may be a mirror image of first bolster plate 230. A radius of curvature of the inner edge surface of the second bolster plate may be equal to the radius of curvature of the inner edge surface 232 of first bolster plate 230. In embodiments, first bolster plate 230 and second bolster plate 236 may entirely encircle molybdenum conduit 200. Like first bolster plate 230, second bolster plate 236 may include a plurality of holes 234 extending through the thickness of the second bolster plate. [0082] In this latter arrangement, and like type A flanges 208, a type B flange 208 comprises a disc portion 210 but may not, in embodiments, include a hub portion. Disc portion 210 comprises an aperture 240 sized to receive molybdenum conduit 200. That is, an inside diameter D1 of aperture 240 may be greater (e.g., slightly greater) than an outside diameter D2 (see FIG. 10) of molybdenum conduit 200 such that disc portion 210 may be fitted over molybdenum conduit 200 and positioned in an intermediate position on molybdenum conduit 200 abutting first and second bolster plates 230, 236. Accordingly, disc portion 210 of type B flanges may be configured to receive molybdenum conduit 200 through aperture 240. As Attorney Docket No. SP23-090 shown in FIGS. 10-11, disc portion 210 may include holes 242 extending through a thickness of disk portion 210 and arranged to align with holes 234 in first and second bolster plates 230, 236. Thus, disc portion 210 may be slipped over an end of molybdenum conduit 200 such that molybdenum conduit 200 extends through aperture 240, whereupon the disc portion 210 is positioned abutting first and second bolster plates 230, 236. With disc portion 210 positioned intermediate first end 204 and second end 206 and abutting first bolster plate 230 and second bolster plate 236, and with holes 234 aligned with holes 242, fasteners 244 (e.g., bolts, rivets, pins) may be inserted into the aligned holes and secured (see FIG. 9). If bolts are used, nuts 246, and optionally washers 248, may be engaged with the bolts and tightened, thereby securing disc portion 210 to bolster plates 230, 236. With disc portion 210 secured to bolster plates 230, 236 and bolster plates 230, 236 engaged in groove 222, type B flange 208 is secured to molybdenum conduit 200. [0083] In still other embodiments, flanges 208 may be attached to molybdenum conduit 200 by welding. For example, molybdenum conduit 200 may include another flange style, referred to hereinafter as a type C flange 208, comprising a disc portion 210 including an aperture 240 sized to fit a diameter of molybdenum conduit 200. Molybdenum conduit 200 may be inserted into aperture 240, the type C flange 208 positioned in a desired location on the molybdenum conduit, then welded to molybdenum conduit 200, for example at an end of the molybdenum conduit. FIG.12 is a side view of a molybdenum conduit 200 showing an end thereof including a type C flange 208 and weld beads 250. Accordingly, a type C flange 208 may be attached at any location along a length of molybdenum conduit 200, including at the ends thereof and/or intermediate the ends. [0084] Turning to FIG. 13, molybdenum conduit 200 may be positioned within a refractory material, e.g., a first refractory material, such as a ceramic refractory material. For example, a function of the refractory material can be to support the molybdenum conduit mechanically. Another function of the refractory material can be to reduce or control heat loss from molybdenum conduit 200. For example, in some instances the molybdenum conduit 200 be positioned within downstream glass manufacturing apparatus 30 to facilitate cooling of molten glass within the molybdenum conduit. Accordingly, a thermal conductivity of the refractory material may be selected to promote cooling (e.g., a high thermal conductivity. In other instances, the molybdenum conduit may be positioned within the downstream glass manufacturing apparatus such that the temperature (e.g., viscosity) of the molten glass therein is to be maintained. Thus, the thermal conductivity of the refractory material may be selected to be low to minimize heat loss from the molybdenum conduit (and the molten glass therein). Attorney Docket No. SP23-090 Accordingly, FIG. 13 illustrates molybdenum conduit 200 surrounded by a first refractory material 300. [0085] In embodiments, molybdenum conduit 200 may be separated from first refractory material 300 by a gap 302 that extends at least partially around the molybdenum conduit. For example, first refractory material 300 may comprise a bore 304 extending along a length of the first refractory material in which molybdenum conduit 200 is positioned. Accordingly, an inside diameter of bore 304 is greater than an outside diameter of molybdenum conduit 200. Molybdenum conduit 200 may be supported within bore 304 by a plurality of spacers 306 that maintain the outside surface of molybdenum conduit 200 spaced apart from first refractory material 300. Spacers 306 may be a metal (e.g., platinum, molybdenum), or spacers 306 may be formed from a refractory material, e.g., a ceramic material. In embodiments, glass manufacturing apparatus 10 may be configured to provide a cooling fluid to gap 302. That is, in some embodiments, a cooling fluid may be flowed through gap 302 between molybdenum conduit 200 and first refractory material 300. Molybdenum does not visibly react with oxygen or water at room temperature. However, weak oxidation of molybdenum may start above about 300°C, and bulk oxidation may begin at temperatures above about 600°C. Accordingly, the cooling fluid may comprise, for example, a low-oxygen gas, such as an inert gas (e.g., nitrogen, helium, argon, etc.). The cooling fluid may contain less than about 1% by volume oxygen, such as equal to or less than about 0.75% by volume, equal to or less than 0.50% by volume, equal to or less than about 0.25% by volume oxygen. [0086] In some embodiments, gap 302 may include a glass material disposed therein. For example, gap 302 may be filled with cullet and/or frit (i.e., powdered glass). The cullet and/or frit may be selected such that the cullet and/or frit melts during operation of the glass manufacturing apparatus and surrounds molybdenum conduit 200, thereby displacing the atmosphere surrounding the molybdenum conduit and reducing or preventing oxidation of the molybdenum conduit. [0087] In some embodiments, and as shown in FIG.13, a second refractory material 310 may be positioned around first refractory material 300. A thermal conductivity of second refractory material 310 may be different than a thermal conductivity of first refractory material 300. The thermal conductivity of second refractory material 310 may be selected to be equal to, less than, or greater than the thermal conductivity of first refractory material 300 depending on the position of molybdenum conduit 200 within the downstream glass manufacturing apparatus and the desired insulating properties of the refractory material. Attorney Docket No. SP23-090 [0088] In aspects disclosed herein, molybdenum conduit 200 may be heated by electromagnetic induction. Accordingly, an electrical conductor 312, hereinafter electromagnetic inductor 312, e.g., a copper electromagnetic inductor, may be positioned around at least a portion of a circumference of molybdenum conduit 200. For example, in some embodiments, as shown in FIGS.14-15, electromagnetic inductor 312 may be in the form of a coil, e.g., a helical wound electrically conductive coil, wherein molybdenum conduit 200 extends within the coil, e.g., along a longitudinal axis thereof. Electromagnetic inductor 312 is supplied with an alternating electrical current (AC) from a suitable power source 314. The expanding and contracting electromagnetic field produced by the alternating electrical current in electromagnetic inductor 312 induces an electrical eddy current in molybdenum conduit 200. The electrical eddy current in molybdenum conduit 200 heats molybdenum conduit 200 by Joule heating. The frequency of the alternating electrical current selected for the induction heating of the molybdenum conduit will depend on the conduit size, material type, electromagnetic coupling (between the electrical conductor and the molybdenum conduit), and the desired penetration depth, but may be in a range from about 1 kHz to about 100 kHz, for example in a range from about 1 kHz to about 90 kHz, from about 1 kHz to about 80 kHz, from about 1 kHz to about 70 kHz, from about 1 kHz to about 60 kHz, from about 1 kHz to about 50 kHz, from about 1 kHz to about 40 kHz, from about 1 kHz to about 30 kHz, from about 1 kHz to about 20 kHz, from about 1 kHz to about 10 kHz, from about 10 kHz to about 100 kHz, from about 20 kHz to about 100 kHz, from about 30 kHz to about 100 kHz, from about 40 kHz to about 100 kHz, from about 50 kHz to about 100 kHz, from about 60 kHz to about 100 kHz, from about 70 kHz to about 100 kHz, from about 80 kHz to about 100 kHz, or from about 90 kHz to about 100 kHz, including all ranges and subranges therebetween. [0089] Referring to FIG. 16, in some embodiments, electromagnetic inductor 312 may not extend around the entire circumference of molybdenum conduit 200 such that one portion of the molybdenum conduit may be inductively heated, whereas another portion of the molybdenum conduit is not inductively heated. For example, in some embodiments, a first portion of a circumference of the conduit wall 202 may be inductively heated, whereas a second portion of a circumference of the conduit wall 202, for example opposite the first portion, may not be inductively heated, or inductively heated differently (to a different amount, e.g., temperature) by supplying a different electrical current. For example, the top electromagnetic inductor may be an independent circuit from the bottom electromagnetic inductor. Accordingly, in some embodiments, an upper portion of the molybdenum conduit may be unheated, and a lower portion of the molybdenum conduit may be heated. In other Attorney Docket No. SP23-090 embodiments, an upper portion of the molybdenum conduit may be heated, and a lower portion of the molybdenum conduit may not be heated. In still other embodiments, a top portion of the molybdenum conduit may be heated to a temperature different from a bottom portion of the molybdenum conduit opposite the top portion. For example, the top portion of the molybdenum conduit may be heated to a temperature less than the bottom portion of the molybdenum conduit. Such a heating scheme may be used, for example, if a top portion of the molybdenum conduit interior does not contain molten glass, such as might occur if the molybdenum conduit is arranged as a fining vessel. [0090] In embodiments, electromagnetic inductor 312 may be positioned external to the first refractory material 300, for example positioned between the first refractory material and second refractory material 310. In some embodiments, electromagnetic inductor 312 may be positioned external to second refractory material 310. In still other embodiments, downstream glass manufacturing apparatus may comprise multiple layers of refractory material positioned around molybdenum conduit 200, and wherein electromagnetic inductor 312 may be positioned between any adjacent layers of refractory material. For example, electromagnetic inductor 312 may be embedded in one or both adjacent layers of refractory material, such as being cast therein. In further embodiments, a channel may be formed in one or both adjacent refractory layers to accommodate electromagnetic inductor 312. [0091] To prevent overheating of electromagnetic inductor 312, electromagnetic inductor 312 may be configured for fluid cooling. For example, in some embodiments, electromagnetic inductor 312 may comprise a hollow tube, for example a hollow copper tube, wherein the hollow tube is in fluid communication with a source of cooling fluid. The cooling fluid may then be flowed through the hollow tube, thereby cooling the hollow tube. The cooling fluid may be a gas, e.g., air or an inert gas, such as helium, or the cooling fluid may be a liquid, e.g., water. [0092] In some embodiments, more than one electromagnetic inductor 312 may be employed. For example, as shown in FIG. 17, in some embodiments, two or more electromagnetic inductors 312 may be used. Each electromagnetic inductor 312 of the plurality of electromagnetic inductors 312 may be arranged along a length of molybdenum conduit 200 to form a plurality of heating zones in the molybdenum conduit. Each electromagnetic inductor 312 of the plurality of electromagnetic inductors 312 may, in some embodiments, be individually and separately controlled. For example, each electromagnetic inductor 312 may be powered by a separate electrical circuit. Thus, a first portion 400 of molybdenum conduit 200 along the length of the molybdenum conduit may be inductively heated by a first Attorney Docket No. SP23-090 electromagnetic inductor 312, the first electrical inductor maintaining a temperature of the first portion of the molybdenum conduit at a first temperature, a second portion 402 of the molybdenum conduit may be inductively heated by a second electromagnetic inductor 312 to maintain the second portion of the molybdenum conduit at a second temperature different from the first temperature, and a third portion 404 of molybdenum conduit 200 may be inductive heated by a third electromagnetic inductor 312 to maintain the third portion of the molybdenum conduit at a third temperature. Multiple electromagnetic inductors 312 may be arranged along a length of molybdenum conduit 200 such that one electromagnetic inductor 312, for example one electromagnetic inductor coil, may be adjacent to or longitudinally spaced apart from another electrical conductor, for example a second electromagnetic inductor coil. The number of and spacing between electromagnetic inductors 312 will depend on a particular glass manufacturing apparatus design, type of glass being processed, and other individual processing parameters. [0093] In some embodiments, an electromagnetic inductor 312 may be configured to provide more inductive heating to one portion of the molybdenum conduit than to another portion of the molybdenum conduit. For example, a pitch of portions of an individual electromagnetic inductor 312, for example the pitch of partial or complete coils (wraps) of an electromagnetic inductor 312 may vary along a length of the electromagnetic inductor relative to molybdenum conduit 200. By way of explanation and not limitation, the electromagnetic inductor 312 may be configured as a coil comprising multiple wraps around the molybdenum conduit, with the molybdenum conduit extending through an open central region of the coil. Accordingly, the coil extends longitudinally along at least a portion of the length of the molybdenum conduit. The spacing between each wrap may be varied, thereby altering the amount of heating of the molybdenum conduit as a function of length of the coil relative to the molybdenum conduit. For example, as shown in FIG. 15, in some embodiments, the pitch P1 within an intermediate portion of the coil, e.g., in the middle of the coil, which is the distance from one wrap to another wrap, may be greater than the pitch P2 of the coil at the ends of the coil. However, the pitch may be varied in any manner desired to obtain the needed lengthwise temperature profile of the molybdenum conduit and is not limited by this example. Thus, in some embodiments, the pitch of the coil may be greater at one or both ends of the coil relative to the pitch at an intermediate location between the two ends of the coil. [0094] In some embodiments, molybdenum conduit 200 may comprise a plurality of molybdenum conduits 200, such that a first molybdenum conduit 200a is in fluid communication with a second molybdenum conduit 200b as seen in FIGS. 18 and 19. In such Attorney Docket No. SP23-090 instances, the first molybdenum conduit may not be in direct contact with the second molybdenum conduit. For example, in embodiments, the first molybdenum conduit may comprise a first end flange 208 (e.g., Type A flange 208) as previously described, while the second molybdenum conduit comprises a second Type A flange. First molybdenum conduit 200a and second molybdenum conduit 200b may be arranged such that the disc portion of each flange 208 is proximate the disc portion of the adjacent flange but spaced apart therefrom. The spacing allows for thermal expansion of the molybdenum conduits as the molybdenum conduits are heated. When molten glass is flowed through the heated molybdenum conduits, a quantity of the molten glass flows between the adjacent end flanges but is cooled when exposed to the outside (ambient) environment. The cooled glass forms a glass seal 410 between the first flange and the second flange, thereby bonding the first flange to the second flange and securing first molybdenum conduit 200a to second molybdenum conduit 200b. Glass seal 410 prevents further leakage of molten glass between the first flange and the second flange. [0095] Molybdenum conduit 200 may be positioned to extend between a first vessel and a second vessel. For example, as shown in FIG.20, in some embodiments, molybdenum conduit 200 may extend between a first conditioning vessel 500 and a second conditioning vessel 502. In some embodiments, first conditioning vessel 500 may comprise melting vessel 14 and second condition vessel 502 may comprise fining vessel 34. First conditioning vessel 500 may be a fining vessel, such as fining vessel 34. Second conditioning vessel 502 may comprise a mixing apparatus 36, such as a stirring vessel. In some embodiments, first molten glass conditioning vessel 500 may comprise mixing apparatus 36 and second conditioning vessel 502 may be delivery vessel 40. In still further embodiments, molybdenum conduit 200 may comprise fining vessel 34. For example, molybdenum conduit 200 may be arranged and configured as a fining vessel. Accordingly, in such configurations, molybdenum conduit 200 may be arranged with multiple electromagnetic inductors 312 and multiple heating zones associated with the multiple electromagnetic inductors. Conditioning vessels 500 and 502 may comprise stub conduits 504 extending therefrom that connect with molybdenum conduit 200 via flanges 506. Stub conduits 504 may be molybdenum conduits or may comprises a different material, such as platinum. A stub conduit 504 may comprise a short length of conduit extending from melting vessel 14, or from another vessel, e.g., a vessel comprising platinum, wherein the stub conduit is attached to the vessel, such as welded to the vessel to provide an attachment point to another conduit. Flanges 506 may comprise molybdenum or another metal, such as platinum. Accordingly, flanges 506 may be configured as mechanical flanges Attorney Docket No. SP23-090 208, or another flange, such as an electrical flange configured to supply an electrical current to stub conduit 504. [0096] In embodiments, molybdenum conduit 200 extending between first conditioning vessel 500 and second conditioning vessel 502 may comprise a plurality of molybdenum conduits 200, such as first molybdenum conduit 200a and second molybdenum conduit 200b. Molybdenum conduit 200 may include flanges 208 configured to attach to an end of the conduit (i.e., type A flanges) and/or one or more type B flanges 208 configured to attach intermediate the ends of molybdenum conduit 200. Molybdenum conduit 200 may be first connecting conduit 32, second connecting conduit 46, third connecting conduit 46, or any other conduit included in a glass manufacturing apparatus. In some embodiments, molybdenum conduit 200 may be a fining vessel, e.g., fining vessel 34. [0097] It will be apparent to those skilled in the art that various modifications and variations can be made to embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Thus, it is intended that the present disclosure cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.

Claims

Attorney Docket No. SP23-090 What is claimed is: 1. A glass manufacturing apparatus, comprising: a molybdenum conduit configured to convey molten glass, the molybdenum conduit comprising a conduit wall extending between a first end of the molybdenum conduit and a second end of the molybdenum conduit opposite the first end, the conduit wall defining a passage through the molybdenum conduit between the first end and the second end, and a first flange comprising molybdenum attached to the molybdenum conduit. 2. The glass manufacturing apparatus of claim 1, wherein the first flange comprises a disc portion and a hub portion positioned on the disc portion such that a longitudinal axis of the hub portion is orthogonal to a plane of the disc portion, and the first flange defines a bore extending therethrough along the longitudinal axis. 3. The glass manufacturing apparatus of claim 2, wherein the first flange is attached to the first end of the molybdenum conduit by the hub portion. 4. The glass manufacturing apparatus of claim 1, wherein the first end of the molybdenum conduit comprises a first thread, the hub portion comprises a second thread complementary to the first thread, and the hub portion is attached to the first end with the first and second threads. 5. The glass manufacturing apparatus of claim 4, wherein the first thread is disposed on an exterior surface of the conduit wall and the second thread is disposed on an interior surface of the hub along the bore. 6. The glass manufacturing apparatus of claim 1, wherein the molybdenum conduit comprises a groove disposed in an outside surface of the molybdenum conduit wall around a circumference of the molybdenum conduit, and a first bolster plate is disposed in the groove. 7. The glass manufacturing apparatus of claim 6, wherein the first bolster plate comprises a curved edge surface corresponding to a curvature of the groove. Attorney Docket No. SP23-090 8. The glass manufacturing apparatus of claim 6, further comprising a second bolster plate disposed in the groove. 9. The glass manufacturing apparatus of claim 8, wherein the first flange is attached to the first bolster plate and the second bolster plate. 10. The glass manufacturing apparatus of claim 1, wherein the first flange is welded to the molybdenum conduit. 11. The glass manufacturing apparatus of any one of claims 1 to 10, wherein a first refractory material is positioned around the molybdenum conduit. 12. The glass manufacturing apparatus of claim 11, wherein the molybdenum conduit wall is spaced apart from an interior surface of the first refractory material such that a gap is disposed between the molybdenum conduit wall and the first refractory material. 13. The glass manufacturing apparatus of claim 12, wherein an inert gas is disposed in the gap. 14. The glass manufacturing apparatus of claim 12, wherein a glass material is disposed in the gap. 15. The glass manufacturing apparatus of claim 11, further comprising a plurality of spacers separating the conduit wall from the first refractory material. 16. The glass manufacturing apparatus of any one of claims 11 to 15, further comprising a second refractory material positioned around the first refractory material. 17. The glass manufacturing apparatus of claim 14, wherein a thermal conductivity of the second refractory material is different from a thermal conductivity of the first refractory material. 18. The glass manufacturing apparatus of any one of claims 1 to 17, further comprising an electromagnetic inductor disposed around at least a portion of a circumference of the Attorney Docket No. SP23-090 molybdenum conduit, the electromagnetic inductor configured to induce an electrical current in the conduit wall. 19. The glass manufacturing apparatus of claim 18, wherein the electromagnetic inductor is helically disposed around the molybdenum conduit. 20. The glass manufacturing apparatus of claim 19, wherein a pitch of the electromagnetic inductor varies as a function of length along the molybdenum conduit. 21. The glass manufacturing apparatus of any one of claims 18 to 20, further comprising a second electromagnetic inductor disposed around at least a portion of the circumference of the molybdenum conduit, the second electromagnetic inductor spaced apart from the first electromagnetic inductor in a direction parallel with a longitudinal axis of the molybdenum conduit. 22. The glass manufacturing apparatus of any one of claims 18 to 20, wherein the electromagnetic inductor comprises an internal channel extending along a length of the electromagnetic inductor, the channel configured to receive a flow of coolant therethrough. 23. A glass manufacturing apparatus, comprising a first molybdenum conduit comprising a first conduit wall extending between a first end of the first molybdenum conduit and a second end of the first molybdenum conduit, the first molybdenum conduit comprising a first flange comprising molybdenum attached to the first end of the first molybdenum conduit, and a first electromagnetic inductor disposed around at least a portion of the first conduit wall, the first electromagnetic inductor configured to induce a first electrical current in the first conduit wall. 24. The glass manufacturing apparatus of claim 23, wherein the first molybdenum conduit comprises a second flange comprising molybdenum attached thereto intermediate the first end and the second end. 25. The glass manufacturing apparatus of claim 24, wherein the first electromagnetic inductor is positioned between the first flange and the second flange. Attorney Docket No. SP23-090 26. The glass manufacturing apparatus of claim 25, further comprising a second electromagnetic inductor disposed around at least a portion of the first conduit wall between the second flange and the second end. 27. The glass manufacturing apparatus of claim 23, further comprising a second molybdenum conduit comprising a second conduit wall extending between a third end of the second molybdenum conduit and a fourth end of the second molybdenum conduit opposite the third end, the second molybdenum conduit comprising a second flange comprising molybdenum attached to the third end of the second molybdenum conduit, the second molybdenum conduit arranged adjacent the first molybdenum conduit such a first longitudinal axis of the first molybdenum conduit is coaxial with a second longitudinal axis of the second molybdenum conduit and the second flange is spaced apart from the first flange, the second molybdenum conduit further comprising a second electromagnetic inductor disposed around at least a portion of the second conduit wall and positioned between the third end and the fourth end, the second electromagnetic inductor configured to induce a second electrical current in the second conduit wall. 28. The glass manufacturing apparatus of claim 27, wherein a glass seal is disposed between the first flange and the second flange. 29. The glass manufacturing apparatus of claim 23, wherein a pitch of the first electromagnetic inductor varies as a function of length along the first molybdenum conduit.