Burner for prevention of devitrified glass during glass manufacturing

Abstract

A glass forming system for controlling devitrification in glass is provided. The glass forming system comprises a glass forming body, an edge director, and a burner. The edge director is positioned proximate to the glass forming body, and the edge director is configured to contact molten glass flowing on the glass forming body to assist in controlling a shape of a glass ribbon formed by the molten glass. The burner is configured to generate a flame that produces heat. The burner is positioned proximate to the edge director so that the heat from the flame increases a temperature of the edge director.

Description

BURNER FOR PREVENTION OF DEVITRIFIED GLASS DURING GLASS MANUFACTURINGCROSS 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 / 581739 filed on September 11, 2023, the content of which is relied upon and incorporated herein by reference in its entirety.FIELD

[0002] Embodiments relate generally to the use of burners to prevent devitrification growth during glass manufacturing, such as to prevent devitrification growth on edge directors.BACKGROUND

[0003] Devit (devitrified glass) growth during glass manufacturing, such as on edge directors, impacts the stability of glass ribbons comprising molten glass and often leads to a reduction in the quality of any glass products that are eventually formed from the molten glass. Edge directors are positioned at opposing ends of a molten glass ribbon adjacent to a glass forming body. A portion of an edge director is located lower than a root of the glass forming body, and this portion of the edge director often experiences lower temperatures relative to other portions of the edge director. When the temperature falls, the molten glass may fall below the glass liquidus temperature and, accordingly, devitrify to form devit.

[0004] Current production tanks use radiation heater components to heat up the edge director area, but these radiation heater components heat up a relatively large area. In some cases, the heating capacity of the radiation heater components is insufficient to maintain the edge director area temperature above the liquidus temperature. The efficiency of the approaches using radiation heater components is low as heat is used to increase the temperature of the entire edge director area rather than specific locations on the edge director.

[0005] Improvements in the foregoing are desired.BRIEF SUMMARY

[0006] In various embodiments, a burner is utilized to heat an edge director in a glass forming system. This heat may assist in reducing the size of or eliminating cold areas on edge directors, with the cold areas having a temperature below the liquidus temperature for the molten glass. This heat may also help prevent cold areas from forming during operation of the glass forming system in some embodiments.

[0007] If devitrification does occur, then a burner may optionally be directed towards the molten glass itself to remove devit already developed. Where burners are directed towards molten glass, the heat from the burner may be directed to an elevation above the target location where cold areas have developed, and the heated molten glass may flow downwardly to the cold areas. Burner technology may provide a cost effective approach for local heating of molten glass.

[0008] The burner may heat air upstream of the edge director, and chimney air current may cause the heat to rise towards the edge director. By doing so, the chance of damage to the edge director may be reduced by avoiding direct exposure of the edge director to a flame, but heat may still be applied with the burner in a more targeted manner than radiation heaters so that heat is used efficiently.

[0009] The use of burners allows for the creation of cost-effective systems for prevention of devit growth. Burners may be gas-powered, and this may reduce the costs of operation as gas tends to be significantly cheaper than electricity. Burners may also be easily introduced and / or adjusted to fit in a wide variety of systems.

[0010] In an example embodiment, a glass forming system for controlling devitrification in glass is provided. The glass forming system comprises a glass forming body, an edge director, and a burner. The edge director is positioned proximate to the glass forming body, and the edge director is configured to contact molten glass flowing on the glass forming body to assist in controlling a shape of a glass ribbon formed by the molten glass. Additionally, the burner is configured to generate a flame that produces heat, and the burner is positioned proximate to the edge director so that the heat from the flame increases a temperature of the edge director.

[0011] In some embodiments, the heat from the flame may increase the temperature of the molten glass at one or more locations. In some embodiments, heating at least one of the edge director or the molten glass may reduce buildup of devitrified glass proximate to the edge director. In some embodiments, the burner may be configured to enable changes in at least one of a size of the flame or a direction of the flame.

[0012] In some embodiments, the glass forming body may comprise a root, the burner may be positioned at a height lower than the root and the edge director, and the heat from the burner may rise from the burner to heat the edge director. Additionally, in some embodiments, the root may comprise a linear shape and at least a portion of the burner may extend in a direction parallel to the root. Furthermore, in some embodiments, the root may comprise a linear shape and at least a portion of the burner may extend in a direction perpendicular to the root.

[0013] In some embodiments, the glass forming system may be arranged to create a chimney effect to cause an upward flow of air that assists in heating the edge director. In some embodiments, the burner may comprise an outlet where a flame is output from the burner. In some embodiments, the burner is positioned below the edge director, and the heat from the flame generated by the burner rises to increase the temperature of the edge director.

[0014] In some embodiments, the burner may be configured to enable steering of a direction of the flame. Additionally, in some embodiments, the burner may be configured to enable steering of the direction of the flame by mechanically moving an outlet on the burner where the flame is output from the burner. Furthermore, in some embodiments, the burner is configured to enable steering of the direction of the flame without mechanically moving an outlet on the burner where the flame is output from the burner. In some embodiments, the burner may also comprise an outlet surface. The burner may also comprise a first oxygen supply channel and a second oxygen supply channel, with the first oxygen supply channel and the second oxygen supply channel configured to output oxygen to assist in generation of the flame. The burner may be configured to apply a greater amount of oxygen at the first oxygen supply channel relative to the second oxygen supply channel to cause the flame to be emitted at an angle not normal to the outlet surface. In some embodiments, a gas supply channel may be positioned between the first oxygen supply channel and the second oxygen supply channel.

[0015] In some embodiments, the glass forming system may also comprise a temperature sensor, and the flame may be generated by the burner based on temperature data from the temperature sensor. Furthermore, in some embodiments, the temperature sensor may be configured to measure the temperature of the edge director. Additionally, in some embodiments, at least one of a size of the flame generated by the burner, a frequency at which the flame is generated by the burner, or a duration of time the flame is generated are dependent on the temperature at the edge director. In some embodiments, the flame may be generated by the burner when the temperature at the edge director falls below a threshold temperature. Furthermore, in some embodiments, the glass forming system may also comprise a processor and memory comprising computer readable code. The computer readable code is configured, when executed, to cause the processor to receive first temperature data from the temperature sensor and to determine that a temperature at the edge director or the molten glass is below or above a threshold value. After the determining, The computer readable code is configured, when executed, to cause at least one of the flame to be generated at the burner, a change in a size of the flame generated at the burner, a change in a direction of an outlet of the burner totarget a location having a temperature below the threshold value, or a change in a direction of the flame generated at the burner to target the location.

[0016] In another example embodiment, a burner for use in controlling devitrification in glass is provided. The burner comprises a body and a head comprising an outlet. The burner is configured to generate a flame that produces heat. The burner is also positioned proximate to an edge director so that the heat from the flame increases a temperature of the edge director, and the burner is capable of steering the flame.

[0017] In some embodiments, the burner may be capable of steering the flame by mechanically moving the outlet on the burner. In some embodiments, the burner may be capable of steering the flame without mechanically moving the outlet on the burner. Additionally, in some embodiments, the burner may comprise an outlet surface. The burner may comprise a first oxygen supply channel and a second oxygen supply channel, and the first oxygen supply channel and the second oxygen supply channel may be configured to output oxygen to assist in generating the flame. The burner may be configured to apply a greater amount of oxygen at the first oxygen supply channel relative to the second oxygen supply channel to cause the flame to be emitted at an angle not normal to the outlet surface. Furthermore, in some embodiments, a gas supply channel may be positioned between the first oxygen supply channel and the second oxygen supply channel.

[0018] In another example embodiment, a method for manufacturing a glass forming system for controlling devitrification in glass is provided. The method comprises positioning an edge director proximate to a glass forming body so that the edge director is configured to contact molten glass flowing on the glass forming body to assist in controlling a shape of a glass ribbon formed by the molten glass. The method also comprises positioning a burner relative to the edge director so that heat from a flame generated by the burner increases a temperature of the edge director. Generating a flame at the burner generates heat that increases the temperature of the edge director to reduce buildup of de vitrified glass proximate to the edge director.

[0019] In another example embodiment, a method for using a glass forming system is provided. The method comprises receiving first temperature data from a temperature sensor and determining that a temperature at an edge director or molten glass is below or above a threshold value. The edge director is positioned proximate to a glass forming body and is configured to contact the molten glass flowing on the glass forming body to assist in controlling a shape of a glass ribbon formed by the molten glass. A burner is configured to generate a flame that produces heat, and the burner positioned proximate to the edge director so that the heatfrom the flame increases a temperature of the edge director. After the determining, the method also comprises causing at least one of a flame to be generated at the burner, an increase or a decrease in a size of the flame generated at the burner, a change in a direction of the outlet of the burner to target a location having a temperature below the threshold value, or a change in a direction of the flame generated at the burner to target the location having a temperature below the threshold value.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Having thus described the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0021] FIG. 1 is a schematic view illustrating an example glass manufacturing apparatus, in accordance with some embodiments discussed herein;

[0022] FIG. 2 is a cross sectional, schematic view illustrating the glass manufacturing apparatus of FIG. 1 along line A-A of FIG. 1, in accordance with some embodiments discussed herein;

[0023] FIG. 3 is a schematic view illustrating example cold areas on an edge director having a decreased temperature relative to other portions of the edge director, in accordance with some embodiments discussed herein;

[0024] FIG. 4A is a schematic view illustrating an example glass forming system where a burner is positioned proximate to an edge director to heat the edge director, in accordance with some embodiments discussed herein;

[0025] FIG. 4B is an enhanced, schematic view illustrating the burner of the example glass forming system of FIG. 4A, in accordance with some embodiments discussed herein;

[0026] FIG. 5A is a schematic view illustrating another example glass forming system where a burner is positioned proximate to an edge director to heat the edge director, in accordance with some embodiments discussed herein;

[0027] FIG. 5B is an enhanced, schematic view illustrating the burner of the example glass forming system of FIG. 5A, in accordance with some embodiments discussed herein;

[0028] FIG. 6A is a schematic view illustrating another example glass forming system where a burner is positioned proximate to an edge director to heat the edge director, in accordance with some embodiments discussed herein;

[0029] FIG. 6B is an enhanced, schematic view illustrating the burner of the example glass forming system of FIG. 6A, in accordance with some embodiments discussed herein;

[0030] FIG. 7A is a schematic view illustrating another example glass forming system where a burner is positioned proximate to an edge director to heat the edge director, in accordance with some embodiments discussed herein;

[0031] FIG. 7B is a schematic view illustrating another example glass forming system where a burner is positioned proximate to an edge director to heat the edge director, in accordance with some embodiments discussed herein;

[0032] FIG. 8 is a schematic view illustrating an example burner capable of steering the direction of a flame relative to an outlet of the burner, in accordance with some embodiments discussed herein;

[0033] FIG. 9 is a perspective view illustrating an example burner head with a plurality of openings on the burner head, in accordance with some embodiments discussed herein;

[0034] FIG. 10 is a block diagram illustrating an example components of a glass forming system, in accordance with some embodiments discussed herein;

[0035] FIG. 11 is a flow chart illustrating an example method for manufacturing a glass forming system, in accordance with some embodiments discussed herein; and

[0036] FIG. 12 is a flow chart illustrating an example method for using a glass forming system, in accordance with some embodiments discussed herein.DETAILED DESCRIPTION

[0037] Example embodiments of the present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the disclosure are shown. Indeed, the disclosure may be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals generally refer to like elements throughout. For example, reference numbers 380A, 480A, 780A each refer to edge directors. Additionally, any connections or attachments may be direct or indirect connections or attachments unless specifically noted otherwise. As used herein the terms “the,” “a,” or “an,” mean “at least one,” and should not be limited to “only one” unless explicitly indicated to the contrary. Thus, for example, reference to “a component” includes embodiments comprising two or more such components unless the context clearly indicates otherwise.

[0038] 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. When the term “about” is used in describing a value or an endpoint of a range, the disclosure should be understood to include the specific value or endpoint referred to. If a numerical value or endpoint of a range in the specification recites “about,” the numerical value or endpoint of a range is intended to include two embodiments: one modified by “about,” and one not modified by “about.” 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.

[0039] FIG. 1 is a schematic view illustrating an example glass manufacturing apparatus. As schematically illustrated in FIG. 1, in some embodiments, a glass manufacturing apparatus 100 may include a glass forming apparatus 101 including a glass forming body 110 designed to produce a glass ribbon 103 from a quantity of molten glass 121. The glass forming body 110 extends between a first opposing edge 110A and a second opposing edge HOB. In some embodiments, the glass ribbon 103 may include a central portion 152 disposed between opposite, relatively thick edge beads formed along a first outer edge 153 and a second outer edge 155 of the glass ribbon 103. Additionally, in some embodiments, a glass sheet 104 may be separated from the glass ribbon 103 along a separation path 151 by a glass separator 149 (e.g., scribe, score wheel, diamond tip, laser). In some embodiments, before or after separation of the glass sheet 104 from the glass ribbon 103, the relatively thick edge beads formed along the first outer edge 153 and the second outer edge 155 may be removed to provide the central portion 152 as a glass sheet 104 comprising a more uniform thickness.

[0040] In some embodiments, the glass manufacturing apparatus 100 may include a melting vessel 105 oriented to receive batch material 107 from a storage bin 109. The batch material 107 may be introduced by a batch delivery device 111 powered by a motor 113. In some embodiments, a controller 115 may optionally be operated to activate the motor 113 to introduce a desired amount of batch material 107 into the melting vessel 105, as indicated by arrow 117. The melting vessel 105 may heat the batch material 107 to provide molten glass 121. In some embodiments, a glass melt probe 119 may be employed to measure a level of molten glass 121 within a standpipe 123 and communicate the measured information to the controller 115 by way of a communication line 125.

[0041] Additionally, in some embodiments, the glass manufacturing apparatus 100 may include a first conditioning station including a fining vessel 127 located downstream from the melting vessel 105 and coupled to the melting vessel 105 by way of a first connecting conduit 129. In some embodiments, molten glass 121 may be gravity fed from the melting vessel 105 to the fining vessel 127 by way of the first connecting conduit 129. For example, in someembodiments, gravity may drive the molten glass 121 through an interior pathway of the first connecting conduit 129 from the melting vessel 105 to the fining vessel 127. Additionally, in some embodiments, bubbles may be removed from the molten glass 121 within the fining vessel 127 by various techniques.

[0042] In some embodiments, the glass manufacturing apparatus 100 may further include a second conditioning station including a mixing chamber 131 that may be located downstream from the fining vessel 127. The mixing chamber 131 may be employed to provide a homogenous composition of molten glass 121, thereby reducing or eliminating inhomogeneity that may otherwise exist within the molten glass 121 exiting the fining vessel 127. As shown, the fining vessel 127 may be coupled to the mixing chamber 131 by way of a second connecting conduit 135. In some embodiments, molten glass 121 may be gravity fed from the fining vessel 127 to the mixing chamber 131 by way of the second connecting conduit 135. For example, in some embodiments, gravity may drive the molten glass 121 through an interior pathway of the second connecting conduit 135 from the fining vessel 127 to the mixing chamber 131.

[0043] Additionally, in some embodiments, the glass manufacturing apparatus 100 may include a third conditioning station including a delivery vessel 133 that may be located downstream from the mixing chamber 131. In some embodiments, the delivery vessel 133 may condition the molten glass 121 to be fed into an inlet conduit 141. For example, the delivery vessel 133 may function as an accumulator and / or flow controller to adjust and provide a consistent flow of molten glass 121 to the inlet conduit 141. As shown, the mixing chamber 131 may be coupled to the delivery vessel 133 by way of a third connecting conduit 137. In some embodiments, molten glass 121 may be gravity fed from the mixing chamber 131 to the delivery vessel 133 by way of the third connecting conduit 137. For example, in some embodiments, gravity may drive the molten glass 121 through an interior pathway of the third connecting conduit 137 from the mixing chamber 131 to the delivery vessel 133. As further illustrated, in some embodiments, a delivery pipe 139 may be positioned to deliver molten glass 121 to the inlet conduit 141 of the glass forming body 110.

[0044] Various embodiments of forming vessels may be provided in accordance with features of the disclosure including a forming vessel with a wedge for fusion drawing the glass ribbon, a forming vessel with a slot to slot draw the glass ribbon, or a forming vessel provided with press rolls to press roll the glass ribbon from the forming vessel. By way of illustration, the glass forming body 110 shown and disclosed below may be provided to fusion draw the molten glass 121 off a root 145 of a glass forming body 110 to produce the glass ribbon 103. For example, in some embodiments, the molten glass 121 may be delivered from the inletconduit 141 to the glass forming body 110. The molten glass 121 may then be formed into the glass ribbon 103 based at least in part on the structure of the glass forming body 110. For example, as shown, the molten glass 121 may be drawn off the bottom edge (e.g., root 145) of the glass forming body 110 along a draw path extending in a draw direction 154 of the glass manufacturing apparatus 100. In some embodiments, edge directors may direct the molten glass 121 off the glass forming body 110 and define, at least in part, a width W of the glass ribbon 103. In some embodiments, the width W of the glass ribbon 103 may extend between the first outer edge 153 of the glass ribbon 103 and the second outer edge 155 of the glass ribbon 103.

[0045] In some embodiments, the width W of the glass ribbon 103 may be about 20 millimeters or more, about 50 millimeters or more, about 100 millimeters or more, about 500 millimeters or more, about 1,000 millimeters or more, about 2,000 millimeters or more, about 3,000 millimeters or more, about 4000 millimeters or more, although other widths may be provided in further embodiments. In some embodiments, the width W of the glass ribbon 103 may be in a range from about 20 millimeters to about 4,000 millimeters, from about 50 millimeters to about 4,000 millimeters, from about 100 millimeters to about 4,000 millimeters, from about 500 millimeters to about 4,000 millimeters, from about 1,000 millimeters to about 4,000 millimeters, from about 2,000 millimeters to about 4,000 millimeters, from about 3,000 millimeters to about 4,000 millimeters, from about 20 millimeters to about 3,000 millimeters, from about 50 millimeters to about 3,000 millimeters, from about 100 millimeters to about 3,000 millimeters, from about 500 millimeters to about 3,000 millimeters, from about 1,000 millimeters to about 3,000 millimeters, from about 2,000 millimeters to about 3,000 millimeters, from about 2,000 millimeters to about 2,500 millimeters, and all ranges and subranges therebetween.

[0046] FIG. 2 is a cross sectional perspective view of the glass manufacturing apparatus 100 along line A-A of FIG. 1. As shown, the forming vessel 260 includes a glass forming body 210 comprising a pair of downwardly inclined forming surface portions 266A, 266B that extend from a first end 264A to another end of the glass forming body 210. The glass forming body 210 is configured to enable molten glass 218 to flow over the pair of downwardly inclined forming surface portions 266A, 266B. The downwardly inclined forming surface portions 266A, 266B converge along a downstream direction 268 to form a root 245 (e.g., a bottom edge of the forming body), which may be linear in shape. A draw plane 272 extends through the root 245. The glass ribbon 203 may be drawn in the downstream direction 268 along the draw plane 272. The draw plane 272 bisects the root 245 in a generally horizontal, lengthwisedirection of the forming vessel. However, it should be understood that the draw plane 272 may extend at other orientations with respect to the root 245. While FIGS. 1 and 2 generally depict one embodiment of a glass forming apparatus and a forming vessel, it should also be understood that aspects of the present disclosure may be used with various other forming vessel configurations.

[0047] Referring to FIGS. 1 and 2, in certain embodiments, the forming vessel 260 may comprise an edge director 280A intersecting with the pair of downwardly inclined forming surface portions 266A, 266B. While one edge director 280A is illustrated at a first end 264A of the glass forming body 210, another edge director may be positioned at the other end of the glass forming body 210. The edge director 280A may help achieve a desired glass ribbon width and edge bead characteristics by directing the molten glass proximate to the root 245 of the glass forming body 210. In further embodiments, the edge director may intersect with both downwardly inclined forming surface portions 266A, 266B. Additionally or alternatively, in certain embodiments, an edge director may be positioned at each of the opposed ends of the glass forming body 210. Where multiple edge directors are used, the edge directors may be substantially identical to one another. However, it should be understood that, in alternative embodiments, the edge directors may have different configurations and / or geometries depending on the specific characteristics of the glass forming apparatus. Further, it should be understood that various glass forming body and edge director configurations may be used in accordance with aspects of the present disclosure. For example, aspects of the present disclosure may be used with glass forming bodies and edge director configurations as disclosed in U.S. Pat. Nos. 3,451,798, 3,537,834, and / or 7,409,839, each of which are herein incorporated by reference.

[0048] Referring now to FIG. 2, an embodiment of an edge director that may be used with aspects of the present disclosure is schematically depicted. The edge director 280A will be described in more detail. However, it should be understood that the any additional edge directors may be identical to or of a similar construct as the edge director 280A. Use of identical edge directors may be beneficial for providing a uniform glass ribbon. However, it should be understood that the individual edge directors may also have different configurations and / or geometries to accommodate various glass forming apparatus and / or forming vessel configurations.

[0049] FIG. 2 illustrates a first side of one embodiment of a edge director 280A positioned with respect to the first downwardly inclined forming surface portion 266A of the glass forming body 210. Although not depicted, the edge director 280A further includes a second sidepositioned with respect to the second downwardly inclined forming surface portion 266B of the glass forming body 210. The second side of the edge director 280A is a mirror image of the first side about the draw plane 272 bisecting the root 245. As depicted, the first side of the edge director 280A includes a first surface 282 that intersects the first downwardly inclined forming surface portion 266A of the glass forming body 210.

[0050] In some embodiments, each opposed end of the glass forming body 210 is provided with a retaining block 284 designed to laterally position the edge director 280A. Optionally, as depicted, the edge director 280A may include an upper portion 286 and a lower portion 288. The lower portion 288 can, in some embodiments, join the edge director 280A on the first end 264A with a second edge director on the second opposed end. Joining edge directors together may be beneficial to simplify assembly of the edge directors to the glass forming body 210. In further embodiments, the upper portions 286 of the edge directors may be provided separately. For example, as depicted, the edge director 280A is separate from a second edge director and the separate edge directors are assembled independently to each of the pair of downwardly inclined forming surface portions 266A, 266B of the glass forming body 210. With certain embodiments, providing upper portions 286 that are not joined may simplify the manufacture of edge directors.

[0051] The glass manufacturing apparatus 100 also includes at least one edge roller assembly for drawing glass ribbon from the root 245 of the forming vessel 260. While only one edge roller assembly 230A is illustrated in FIG. 2, another roller assembly may be included on the opposite side of the glass ribbon 203. The edge roller assembly 230A includes a pair of edge rollers 232 configured to engage a corresponding edge of the glass ribbon 203 as the glass ribbon 203 is drawn from the root 245 of the glass forming body 210. The edge roller assembly 230 aids in drawing the glass ribbon 203 from the root 245 of the glass forming body 210 and also facilitates proper finishing of the edges of the glass ribbon 203. For example, the edge roller assembly 230A may provide the desired edge characteristics and proper fusion of the edge portions of the molten glass being drawn off opposed surfaces of the edge director 280A associated with the pair of downwardly inclined forming surface portions 266A, 266B. In certain embodiments, the edge roller assembly 230A may be located at various positions within the viscous region of the glass being drawn from the root 245. For instance, in some embodiments, the edge roller assembly 230A may be located at various positions below the root 245. Where multiple edge roller assemblies are used, the edge roller assemblies may be substantially identical to each other.

[0052] FIG. 2 depicts one embodiment of an edge roller assembly 230A. As depicted in FIG. 2, the first edge roller assembly 230A includes a first pair of edge rollers 232 including a first edge roller 232A and a second edge roller 232B. The edge rollers 232A, 232B are configured to simultaneously engage the first side and the second side of a glass ribbon 203 drawn from the root 245 of the glass forming body 210. The first edge roller assembly 230A includes a first shaft 234A attached to the first edge roller 232A and a second shaft (not shown) attached to the second edge roller 232B. The shafts extend through a housing seal plate 236 and are rotatably driven by a motor. The housing seal plate 236 provides a closure to an opening (not shown) leading to an area in which the motor is located. The housing seal plate 236 forms part of a housing which encloses the forming vessel 260, any edge directors, and any edge roller assemblies. The housing may comprise a refractory material, steel, and / or other thermal insulation to protect sensitive components of the motor and / or other mechanisms located within the housing as well as to thermally insulate the forming vessel 260, and the molten glass flowing in and around the forming vessel 260, from the surrounding environment.

[0053] In certain embodiments, the replaceable heating cartridge 208 may be positioned below a portion of the edge director 280A and may extend generally in a direction parallel to the root 245 of the glass forming body 210 and in close proximity to the shafts. As shown in FIG. 2, the replaceable heating cartridge 208 may be positioned below only a portion of the edge director 280A. Positioning the replaceable heating cartridge 208 in this manner may maximize the heat directed onto the edge director 280A while ensuring that the lower edge 222 of the center facet 262 of the heat directing surface 222A does not interfere with the glass ribbon 203 drawn from the glass forming body 210. The replaceable heating cartridge 208 is illustrated in one position relative to the other components in FIG. 2 for the purposes of illustration, but the replaceable heating cartridge 208 may be moved to other positions. For example, the replaceable heating cartridge 208 may be positioned closer to the edge director 280A in some embodiments, but the replaceable heating cartridge 208 may be positioned farther away from the edge director 280A in other embodiments.

[0054] One or more blocks of refractory material 228 may be located behind a face of the heat directing surface 222A and within the enclosure 220. The blocks of refractory material 228 may insulate the heat directing surface 222A from the balance of the replaceable heating cartridge 208. The refractory material 228 may be oriented in alternating vertical stacks and horizontal stacks to minimize heat transfer from the heat directing surface 222A. Specifically, it is believed that alternating vertical stacks and horizontal stacks of refractory material 228 may assist in reducing heat at seams between the blocks of refractory material 228. Inembodiments, the refractory material 228 may be oriented at an angle approximately equal to the angle of the heat directing surface 222A. In still other embodiments, such as where the heat directing surface 222A is formed from a refractory material such as SALI board or the like, the refractory material of the heat directing surface 222A may extend into the enclosure. In the embodiments described herein, the refractory material 228 may be formed from commercially available refractory materials including, without limitation, DuraBoard® 3000 and / or DuraBoard® 2600.

[0055] In one embodiment, the replaceable heating cartridge 208 includes an enclosure 220 comprising a heat directing surface 222A with at least one heating element 224 positioned on or adjacent to the face thereof. The enclosure 220 may be fabricated from a variety of materials that absorb or reflect heat energy or that provide a thermal shield while maintaining structural integrity under typical temperature conditions associated with the glass manufacturing apparatus 100. For instance, the enclosure 220 and other portions of the replaceable heating cartridge 208 may be formed from a refractory material, high temperature, nickel-based alloys, steel (e.g., stainless steel), or other alloys or other materials or combinations of materials to meet the structural and / or thermal requirements of the glass manufacturing apparatus. For example, in one embodiment, the enclosure 220 may be made of nickel-based alloys, such as Hanes 214. In one particular embodiment, the heat directing surface 222A of the replaceable heating cartridge 208 is formed from a ceramic refractory backer material with low emissivity. Suitable ceramic refractory materials include, without limitation, SALI board available from Zircar ceramics. Portions of the enclosure which are not directly exposed to the high temperatures of the glass manufacturing apparatus may be made from materials suitable for lower temperature applications. For example, a back face of the enclosure 220 may be made from stainless steel, such as, for example, 420 stainless steel.

[0056] The replaceable heating cartridge 208 may also include a heating element 224 positioned on or adjacent to the heat directing surface 222A of the enclosure 220. In certain embodiments, the heating element 224 positioned on or adjacent to the heat directing surface 222A is a resistance heating element. The material of the resistance heating element may be molybdenum disilicide, platinum, platinum-rhodium, iron-chromium-aluminum alloys such as Kanthal Al, Kanthal APM (a ferritic iron-chromium-aluminum alloy), or another appropriate winding material.

[0057] In some embodiments, the heating element 224 may be constructed from wire formed from one of the above referenced materials which is wound into a coil. For example and without limitation, in one embodiment, the heating element 224 may be constructed fromplatinum wire comprising a circular cross section which is wound around a mandrel comprising a circular cross section in order to form a coil with a circular cross section. However, it should be understood that other cross sectional shapes of the coil are possible and contemplated. For example, in one embodiment, wire of the heating element may be wound around a mandrel comprising an elongated cross section, such as an oval, ellipse, or the like, in order to produce a coil comprising the same elongated cross section as the mandrel. It has been determined that forming the heating element 224 from a coil with an elongated cross section may improve the heating efficiency of the coil by increasing the power-carrying capacity of the coil. For example, it has been determined that platinum wire comprising a circular cross section which is wound into an oval coil with a 3 / 8 inch (9.53 millimeter) internal major diameter and a 3 / 16 inch (4.78 millimeter) internal minor diameter has a 25 percent increase in power carrying capacity compared to a round coil comprising a 3 / 8 inch (9.53 millimeter) diameter formed from the same platinum wire. The increased power carrying capacity translates to improved heating efficiency and efficacy for the coil.

[0058] In certain embodiments, as shown in FIG. 2, the heat directing surface 222A comprises a plurality of facets oriented to at least partially surround the edge director(s). For example, in the embodiment of the replaceable heating cartridge 208 schematically depicted in FIG. 2, the heat directing surface 222A has a center facet 262 and two side facets 264 on opposite ends of the center facet 262. Typically, the largest angle between each of the two side facets 264 relative to the center facet 262 is from about 145 degrees to about 175 degrees. For example, the largest angle between each of the two side facets 264 relative to the center facet 262 may about 160 degrees, although it should be understood that other angles are possible and contemplated.

[0059] FIG. 3 is a schematic view illustrating example cold areas on an edge director having a decreased temperature relative to other portions of the edge director. The first area 382A and the second area 382B may be locations that have fallen below a specified temperature, and other portions of the edge director 380A may be above the specified temperature. The specified temperature may be the glass liquidus temperature for the molten glass. Where the temperature of the edge director 380A falls below the specified temperature, an increased risk may be present that molten glass will devitrify at locations proximate to the areas. For example, as molten glass contacts a surface of the edge director 380A proximate to the second area 382B, the molten glass may be subject to an increased risk of devitrification. A temperature sensor such as a thermocouple may be utilized to obtain the temperature at various points on the edge director 380A.

[0060] In FIG. 4A, an example glass forming system 450A is illustrated with a burner 484 being positioned proximate to an edge director 480A to heat the edge director 480A. The burner 484 may be used to allow the glass forming system 450A to control the amount of devitrification in glass. By heating the edge director 480A, the burner 484 may indirectly heat the molten glass to prevent devitrification of glass at locations proximate to the edge director 480A. However, in some embodiments, the heat from the flame may be directed directly to the molten glass itself rather than the edge director 480A.

[0061] The glass forming system 450A comprises a glass forming body 410, an edge director 480A, and a burner 484. The edge director 480A is positioned proximate to the glass forming body 410, and the edge director 480A is in contact with the glass forming body 410 in FIG. 4A. The edge director 480A is configured to contact molten glass flowing down the sides of the glass forming body 410 to assist in controlling the shape of a glass ribbon 403 formed by the molten glass. The burner 484 and other burners described herein may be positioned at a lower height than the root 445 of the glass forming body and at a lower height than the edge director 480A. The burner 484 and other burners described herein may also be positioned at a greater height than any edge rollers 232A, 232B (see FIG. 2). At this position, heat generated by flames from the burners may rise to heat the edge director 480A.

[0062] The glass ribbon 403 is illustrated with various regions having different temperatures falling in different temperature ranges. The shape of these regions is exemplary based on the temperatures that occur before the burner is ever used. The glass ribbon 403 comprises a first region 403 A, a second region 403B, a third region 403C, and a fourth region 403D. The first region 403A has temperatures within a first temperature range, the second region 403B has temperatures within a second temperature range below the first temperature range, the third region 403C has temperatures within a third temperature range below the second temperature range, and the fourth region 403D has temperatures within a fourth temperature range below the third temperature range. Additionally, the edge director 480A comprises a first area 482A and a second area 482B. The first area 482A and the second area 482B each have temperatures within the second temperature range so that the temperatures at the areas 482A, 482B generally match the temperatures of the second region 403B. Remaining areas of the edge director 480A have temperatures within the first temperature range so that the temperatures at these remaining areas generally match the temperatures of the first region 403A. At temperatures within the second temperature range, the third temperature range, and the fourth temperature range, the temperature may be below the glass liquidus temperature.

[0063] As illustrated by the shape of the regions 403A, 403B, 403C, 403D, the temperatures are not perfectly even horizontally across the molten glass. Arches are illustrated at locations 490A, 490B in the shape of the regions 403B, 403C, 403D, and this is indicative of a decreased temperature at these locations 490A, 490B. The burner 484 may be used to heat the edge director 480A to reduce the size of the area 482A, 482B or to completely eliminate these areas 482A, 482B, and doing so may indirectly heat the molten glass at locations proximate to the sides of the glass ribbon 403 to make the arch shapes less pronounced at the locations 490A, 490B. This heat applied by the burner 484 may assist in preventing devitrification of glass at locations proximate to the edge director 480A and at locations 490A, 490B.

[0064] The burner 484 comprises a body 484A and a head 484B. In FIG. 4A, the body 484A of the burner 484 extends in a direction parallel to the root 445, with the root 445 comprising a linear shape. As illustrated in FIG. 4B, the head 484B comprises one outlet 484C, but a greater number of outlets 484C may be included in the head 484B in other embodiments. The burner 484 may be configured to generate a flame that produces heat. In some embodiments, the burner 484 may be configured to increase and decrease the size of the flame. This may be done by increasing an amount of gas or oxygen and / or by increasing a power level for the burner. Furthermore, the burner 484 may be positioned proximate to the edge director 480A so that the heat from flames generated by the burner 484 increases the temperature of the edge director 480A. In some embodiments, the burner 484 may steer any flames generated by the burner 484 by mechanically moving outlets 484C on the burner 484. Additionally or alternatively, the burner 484 may be capable of steering flames without mechanically moving the outlets 484C, and this may be accomplished, for example, using an approach similar to the one described in reference to FIG. 8. In some embodiments, the burner 484 may be utilized to ensure that a temperature at the edge director 480A remains above a glass liquidus temperature for the molten glass.

[0065] The burner 484 and other burners described herein may be adjusted and / or positioned to easily fit within the framework of a glass forming system. For example, the burner 484 is positioned in the glass forming system 450 so that the burner 484 extends underneath the insulation 488 and the replaceable heating cartridge 408. A space 489 is positioned between the edge director 480A and the replaceable heating cartridge 480, and the head 484B of the burner 484 extends into the space 489. The space 489 may enable the head 484B to be adjusted in some embodiments. Other burners may be similarly positioned.

[0066] The glass forming system 450A creates a chimney effect to cause an upward flow of air. Chimney air current may flow substantially in the direction indicated by the arrow 492, and this upward flow of air may assist in heating the edge director 480A. In some embodiments, no exhaust system is included since the total amount of heat energy is relatively small, but an exhaust system may be included in other embodiments. Glass forming systems described herein may be positioned in a muffle or another contained environment in some embodiments.

[0067] As illustrated in FIG. 4B, the head 484B of the burner 484 extends in a first direction DI, with this first direction DI being offset at a first angle 01 relative to the horizontal plane. The first angle 01 may be about 10 degrees in the illustrated embodiment, but this angle may possess other values in other embodiments. The outlet 484C may be configured to cause any flames that are formed to extend substantially in a direction extending at this first angle. The burner 484 is configured to cause flames to be directed towards the glass ribbon 403. Aiming the burner 484 in this direction heats the surrounding air, and a chimney air current may cause the heat to rise towards the edge director 480A. However, in other embodiments, the angle of burners may be different.

[0068] Another example glass forming system is illustrated in FIG. 5 A, with a burner being positioned proximate to an edge director to heat the edge director. The glass forming system 450B is similar to the glass forming system 450A of FIG. 4A, but a different burner 485 is used in the glass forming system 450B of FIG. 5A. The burner 485 is provided in the form of a surface mix burner, with flames being emitted at multiple outlets and with these flames mixing proximate to an outlet surface of the burner 485. The burner 485 of FIG. 5 A may be configured to heat a relatively wide zone (e.g., as compared to the burner 484 shown in FIG. 4A). The burner 485 may be configured to generate multiple flames to control the heat at an edge director 480A.

[0069] The burner 485 comprises a body 485A and a head 485B. In FIG. 5A, the body 485 A of the burner 485 extends in a direction parallel to the root 445. As illustrated in FIG. 5B, the head 485B comprises four outlets 485C, but another number of outlets 485C may be included in the head 485B in other embodiments. The burner 485 may be configured to generate a flame that produces heat. In some embodiments, the burner 485 may be configured to increase and decrease the size of the flame. Furthermore, the burner 485 may be positioned proximate to the edge director 480A so that the heat from flames generated by the burner 485 increases the temperature of the edge director 480A. In some embodiments, the burner 485 may steer flames generated by the burner 485 by mechanically moving outlets 485C on the burner 485. Additionally or alternatively, the burner 485 may be capable of steering flames withoutmechanically moving the outlets 485C, and this may be accomplished, for example, using an approach similar to the one described in reference to FIG. 8. In some embodiments, the burner 485 may be utilized to ensure that a temperature at the edge director 480A remains above a glass liquidus temperature for the molten glass. The outlets 485C extend in a direction D2, with this second direction D2 being offset at a second angle 02 relative to the horizontal plane. This second angle 02 is about 40 degrees in the illustrated embodiment, but the second angle 02 may possess different values in other embodiments so that the burner may be directed to another target location. The glass forming system 450B may create a chimney effect to cause an upward flow of air. Chimney air current may flow substantially in the direction indicated by the arrow 492, and this upward flow of air may assist in heating the edge director 480A.

[0070] Looking now at FIG. 6A, another example glass forming system 450C is illustrated where a burner 487 is positioned proximate to an edge director 480A to heat the edge director 480A. The glass forming system 450C is similar to the glass forming system 450A of FIG. 4A, but a different burner 487 is used in the glass forming system 450C of FIG. 6A.

[0071] The burner 487 comprises a body 487A and a head 487B. In FIG. 6A, the body 487A of the burner 487 extends in a direction parallel to the root 445. As illustrated in FIG. 6B, the head 487B comprises four outlets 487C, but another number of outlets 487C may be included in the head 487B in other embodiments. The burner 487 is provided in the form of a surface mix burner, with flames being emitted at multiple outlets and with these flames mixing proximate to an outlet surface of the burner 487. The burner 487 of FIG. 6A may be configured to heat a relatively wide zone (e.g., as compared to the burner 484 in FIG. 4A), and the burner 487 may have a high spatial resolution relative to radiation heater components. The burner 487 may be configured to generate a flame that produces heat. In some embodiments, the burner 487 may be configured to increase and decrease the size of the flame. Additionally, the burner 487 may be positioned proximate to the edge director 480A so that the heat from flames generated by the burner 487 increases the temperature of the edge director 480A. In some embodiments, the burner 487 may steer flames generated by the burner 487 by mechanically moving outlets 487C on the burner 487. Additionally or alternatively, the burner 487 may be capable of steering flames without mechanically moving the outlets 487C, and this may be accomplished using an approach similar to the one described in reference to FIG. 8. In some embodiments, the burner 487 may be utilized to ensure that a temperature at the edge director 480A remains above a glass liquidus temperature for the molten glass. The glass forming system 450C creates a chimney effect to cause an upward flow of air. Chimney air current mayflow substantially in the direction indicated by the arrow 492, and this upward flow of air may assist in heating the edge director 480A.

[0072] In FIG. 6B, the head 487B ofthe burner 487 extends vertically, but the outlets 487C extend in a different direction than the head 487B. The outlets 487C extend in a third direction D3, with this third direction D3 being offset at a third angle 03 relative to the horizontal plane. This third angle 03 is about 15 degrees in the illustrated embodiment, but the third angle 03 may possess other values in other embodiments so that the burner 487 may be directed towards a different target location.

[0073] Another example glass forming system is illustrated in FIG. 7A where a burner 784 is positioned proximate to an edge director 780A to heat the edge director 780A. By heating the edge director 780A, the burner 784 may indirectly heat the molten glass to prevent devitrification of glass at locations proximate to the edge director 780A. However, in some embodiments, the heat from the flame may be directed towards the molten glass itself rather than the edge director 780A.

[0074] In FIG. 7A, portions of a glass forming system are illustrated, and a glass forming body may be positioned relative to the edge director 780A similar to how the glass forming body 410 is positioned relative to the edge director 480A in FIG. 4A to complete the glass forming system. The edge director 780A may be configured to contact molten glass flowing on the glass forming body to assist in controlling the shape of a glass ribbon formed by the molten glass. The burner 784 is positioned at a distance B below the edge director 780A in FIG. 7A. The burner 784 is configured to generate a flame 799 that produces heat, and the burner 784 is positioned proximate to the edge director 780A so that the heat from the flame 799 increases the temperature of the edge director 780A. The burner 784 may be attached directly or indirectly to a replaceable heating cartridge 708. Similar to other burners described herein, the burner 784 may comprise a body 784A, a head 784B, and an outlet 784C. A chimney effect may be created that causes an upward flow of air. Chimney air current may flow substantially in the direction indicated by the arrow 792, and this upward flow of air may assist in heating the edge director 780A.

[0075] Another example glass forming system is illustrated in FIG. 7B where a burner 784’ is positioned proximate to an edge director 780A to heat the edge director 780A. By heating the edge director 780A, the burner 784’ may indirectly heat the molten glass to prevent devitrification of glass at locations proximate to the edge director 780A. However, in some embodiments, the heat from the flame may be directed directly to the molten glass itself rather than the edge director 780A.

[0076] In FIG. 7B, portions of a glass forming system are illustrated, and a glass forming body may be positioned proximate to the edge director 780A similar to how the glass forming body 410 is positioned relative to the edge director 480A to complete the glass forming system. The edge director 780A may be configured to contact molten glass flowing on the glass forming body to assist in controlling the shape of a glass ribbon formed by the molten glass. The burner 784’ is positioned so that it abuts the edge director 780A in FIG. 7B. However, the burner 784’ may be positioned at a distance away from the edge director 780A in other embodiments. The burner 784’ is configured to generate a flame out of the burner outlet 784C’ that produces heat, and the burner 784’ is positioned proximate to the edge director 780A so that the heat from the flame increases the temperature of the edge director 780A.

[0077] In FIG. 7B, the burner 784’ extends in a direction perpendicular to the root 445 (see FIG. 4A) when the glass forming body 410 (see FIG. 4A) is positioned relative to the burner 784’ and the edge director 780A. A chimney effect may be created that causes an upward flow of air. Chimney air current may flow substantially in the direction indicated by the arrow 792, and this upward flow of air may assist in heating the edge director 780A. The burner 784’ is attached to the side heater 792A in FIG. 7B, but the burner 784’ may be attached to other components in other embodiments.

[0078] FIG. 8 is a schematic view illustrating an example burner 884 capable of steering the direction of a flame 899 relative to an outlet of the burner 884. The burner 884 may be configured to assist in controlling devitrification in glass. The burner 884 is provided in the form of a ribbon burner comprising multiple outlets, but other types of burners may be used. The burner 884 is also a surface mix burner as the burner 884 has a gas supply channel 897 with a corresponding outlet and two oxygen supply channels 895A, 895B with corresponding outlets, and the gas and oxygen from these supply channels 895 A, 895B, 897 mix at the outlet surface 845 of the burner 884. The burner 884 is capable of steering the flame 899 without mechanically moving any outlets on the burner 884. Additionally or alternatively, the burner 884 may steer the flame 899 by mechanically moving outlets on the burner 884.

[0079] The burner 884 comprises an outlet surface 845. The burner 884 comprises a first oxygen supply channel 895A connected to a first oxygen supply port 894A, and the burner 884 also comprises a second oxygen supply channel 895B connected to a second oxygen supply port 894B. The first oxygen supply channel 895A and the second oxygen supply channel 895B are configured to output oxygen to assist in generation of the flame 899. The burner 884 is configured to apply a greater amount of oxygen at the first oxygen supply channel 895A relative to the second oxygen supply channel 895B to cause the flame 899 to be emitted at anangle not normal to the outlet surface 845. For example, in FIG. 8, the flame 899 travels in a direction offset from a direction normal to the outlet surface 845 by an angle 04. Additionally, the gas supply channel 897 may be positioned between the first oxygen supply channel 895A and the second oxygen supply channel 895B, and the gas supply channel 897 may be connected to a gas supply port 896. The gas supply channel 897 may travel in a direction E, and this direction E may extend at an angle normal to the outlet surface 845. In some embodiments, the burner 884 may be configured to cause between about 0.5 liters per minute and about 50 liters per minute of gas to be emitted through the gas supply channel 897 when the burner 884 is turned on, but gas may travel through the gas supply channel 897 at different rates in other embodiments. While two oxygen supply ports 894A, 894B are illustrated, a single oxygen supply port may be used in other embodiments, and the amount of oxygen flow to the oxygen supply channels 895A, 895B may be controlled by valves or other similar mechanisms.

[0080] Where the amounts of oxygen flowing through the first oxygen supply channel 895A and the second oxygen supply channel 895B are equal, the burner 884 may be configured to generate a flame that extends in a direction normal to the outlet surface 845. For example, oxygen may flow through the first oxygen supply channel 895A at a rate of 8 liters per minute and oxygen may flow through the second oxygen supply channel 895B at a rate of 8 liters per minute so that the flame tends to travel in a direction normal to the outlet surface 845. When oxygen is supplied at about 8 liters per minute in both of the oxygen supply channels 895A, 895B and when gas is supplied at a rate of about 4 liters per minute, a flame may be formed that extends about 100 millimeters in a direction normal to the outlet surface 845. When oxygen is supplied at about 40 liters per minute in both of the oxygen supply channels 895A, 895B, when gas is supplied at a rate of about 40 liters per minute, and when the power level is about 26 kilowatts, a flame may be formed that extends more than about 300 millimeters in a direction normal to the outlet surface 845. When oxygen is supplied at about 40 liters per minute in both of the oxygen supply channels 895A, 895B, when gas is supplied at a rate of about 28 liters per minute, and when the power level is about 18.3 kilowatts, a flame may be formed that extends more than about 250 millimeters in a direction normal to the outlet surface 845. When oxygen is supplied at about 2 liters per minute in both of the oxygen supply channels 895A, 895B, when gas is supplied at a rate of about 2 liters per minute, and when the power level is about 1.3 kilowatts, a flame may be formed that extends more than about 100 millimeters in a direction normal to the outlet surface 845. When oxygen is supplied at about 2 liters per minute in both of the oxygen supply channels 895A, 895B, when gas is supplied at a rate of about 1 liter per minute, and when the power level is about 0.65 kilowatts, a flame may be formed thatextends more than about 50 millimeters but less than about 100 millimeters in a direction normal to the outlet surface 845. When oxygen is supplied at about 2 liters per minute in both of the oxygen supply channels 895A, 895B, when gas is supplied at a rate of about 0.6 liters per minute, and when the power level is about 0.4 kilowatts, a flame may be formed that extends less than about 25 millimeters in a direction normal to the outlet surface 845. The power level may be adjusted to change the amount of gas supplied, with the power level and the amount of gas supplied generally having a linear relationship. The output power range for a burner may be between about 5 watts to about 1000 watts range, and the power level for a burner may be easy to precisely control and easy to limit by applying flow limits. The power levels and rates at which gas and oxygen discussed above are merely provided as examples, and it may be appropriate to tailor the power level and the flow rates for gas and oxygen to a particular system.

[0081] Where the amount of oxygen flowing through the first oxygen supply channel 895A and amount of oxygen flowing through the second oxygen supply channel 895B are not equal, the burner 884 may be configured to generate a flame that extends in a direction not normal to the outlet surface 845. For example, in FIG. 8, the amount of oxygen flowing through the first oxygen supply channel 895A is greater than the amount of oxygen flowing through the second oxygen supply channel 895B, so the direction of the oxygen from the first oxygen supply channel 895A tends to be controlling so that the flame 899 extends in the direction offset at an angle 04 from the normal to the outlet surface 845. In the example illustrated in FIG. 8, the amount of oxygen flowing through the first oxygen supply channel 895A is about 20 liters per minute and the amount of oxygen flowing through the second oxygen supply channel 895B is about 2 liters per minute . However, the direction of the flame 899 may be altered in the opposite direction by causing an increased amount of oxygen to flow through the second oxygen supply channel 895B relative to the first oxygen supply channel 895A. When oxygen is supplied at about 2 liters per minute in one oxygen supply channel, when oxygen is supplied at about 20 liters per minute in another oxygen supply channel, and when gas is supplied at a rate of about 4 liters per minute, a flame may be formed that extends about 100 millimeters.

[0082] The first oxygen supply channel 895A extends in a direction C, and the second oxygen supply channel 895B extends in a direction D. These directions C, D extend at an angle of about 20 degrees relative to a direction normal to the outlet surface 845 in FIG. 8. However, the directions C, D of these oxygen supply channels 895 A, 895B may extend at different angles in other embodiments. Increasing these angles for the directions C, D may enable flames to be emitted at even greater angles relative to the outlet surface 845.

[0083] As illustrated in FIG. 8, the burner 884 may also have cooling channels 898A, 898B in some embodiments. The cooling channels 898A, 898B may contain gases or liquids at a relatively low temperature (e.g., as opposed to the temperature of the burner 884), and the cooling channels 898A, 898B may tend to cool the burner 884. In some embodiments, water may travel through the cooling channels 898A, 898B, but other gases or liquids may be utilized alternatively. In some embodiments, the cooling channels 898A, 898B may be omitted, and the flow of oxygen through the oxygen supply channels 895A, 895B may tend to cool the burner 884.

[0084] In some embodiments, the burner 884 of FIG. 8 and other burners described herein may be capable of self-ignition. The burners may optionally be surface mix burners, but other burner types may also be used. Burners, such as surface mix burners, may minimize the risk of backfire and are safe. Burners may be provided without a need to design a pilot burner system.

[0085] FIG. 9 is a perspective view illustrating an example head 994B of a burner with a plurality of openings on the head 994B. The head 994B comprises a first series of oxygen supply channels 956A aligned in a first line, a series of gas supply channels 996 aligned in a second line, and a second series of oxygen supply channels 956B aligned in a third line. Using this head 994B, the direction of a flame may be adjusted by providing a different amount of oxygen to the first series of oxygen supply channels 956A relative to the second series of oxygen supply channels 956B. In some embodiments, a head of a burner may be provided with a ribbon burner or single flame type, and the head may be adjustable so that the flame direction may be adjusted.

[0086] FIG. 10 is a block diagram illustrating example components of a glass forming system 1000. The glass forming system 1000 may comprise one or more processors 1004. Additionally, the glass forming system 1000 may comprise memory 1002. The memory 1002 may comprise computer readable code thereon, and the computer readable code may be configured to cause the processor to execute certain functions described herein when the computer readable code is executed by the processor. For example, the computer readable code may be configured to cause the processor to execute the operations illustrated in the method 1200 of FIG. 12.

[0087] The glass forming system 1000 may also comprise one or more temperature sensors 1006. The temperature sensor(s) 1006 may be provided in the form of a thermocouple or in some other form. The temperature sensor(s) 1006 may be configured to measure the temperature at a location on an edge director, at a location on a glass forming body, at a location on molten glass, at air proximate to the edge director, glass forming body, or molten glass, orat another location. Based on temperature data received from the temperature sensor(s) 1006, the processor(s) 1004 may be configured to cause the generation of flames by the burner 1008 on an as needed basis. By doing so, risks of equipment damage and unwanted process impacts may be minimized.

[0088] In some embodiments, the processor(s) 1004 may be configured to cause a change in the size of the flame generated by the burner 1008, a duration of time that the flame is generated by the burner 1008, a frequency at which flames are generated by the burner 1008, etc. Additionally or alternatively, the processor(s) 1004 may be configured to cause a flame to be generated by the burner 1008 when the temperature at the edge director or at another location falls below a threshold temperature.

[0089] A variety of components may form the burner 1008. The burner 1008 may comprise a position sensor 1008A, a gas supply 1008B, a coolant supply 1008C, and an oxygen supply 1008D. The position sensor 1008A may be configured to provide data regarding a position and / or an orientation of the burner 1008 or a portion of the burner (e.g., the head, an outlet, the body, etc.). The gas supply 1008B, coolant supply 1008C, and oxygen supply 1008D may each comprise valves to assist in controlling the flow of these materials. The processor(s) 1004 may be configured to send and receive signals or data from the position sensor 1008 A, the gas supply 1008B, the coolant supply 1008C, and the oxygen supply 1008D. The processor(s) 1004 may also be configured to control the operation of these components within the burner 1008 to adjust the operation of the burner 1008 as desired. For example, to increase the size of a flame, the processor(s) 1004 may cause an increase in the amount of gas provided from the gas supply 1008B and / or cause an increase in the amount of oxygen provided from the oxygen supply 1008D.

[0090] Methods of manufacturing glass forming systems comprising burners are also contemplated. An example method 1100 for manufacturing a glass forming system for controlling devitrification in glass is illustrated in FIG. 11. At operation 1102, an edge director is positioned proximate to the glass forming body. The edge director may be positioned so that the edge director is configured to contact molten glass flowing on the glass forming body to assist in controlling the shape of a glass ribbon formed by the molten glass.

[0091] At operation 1104, the burner is positioned relative to the edge director. This may be done so that heat from any flame generated by the burner increases the temperature of the edge director. Generation of a flame at the burner may generate heat that increases the temperature of the edge director to reduce buildup of devit proximate to the edge director.

[0092] Methods of using glass forming systems comprising burners are also contemplated. An example method 1200 for using a burner of a glass forming system is also illustrated in FIG. 12. At operation 1202, temperature data is received from a temperature sensor. This temperature data may be data for the temperature at an edge director, at molten glass, at a location proximate to the edge director or the molten glass, or at another location.

[0093] At operation 1204, a determination is made that the temperature is below a threshold value. At operation 1206, a change is caused at the burner after making the determination. The burner is configured to generate a flame that produces heat, and the burner may be positioned proximate to the edge director so that the heat from the flame increases a temperature of the edge director. The change made at operation 1206 may take a variety of forms. For example, the generation of a flame at the burner may be caused, an increase in a size of the flame generated at the burner may be caused, a change in a direction of the outlet of the burner may be caused to target a location having a reduced temperature, or a change in a direction of the flame generated at the burner may be caused to target a location having a reduced temperature.

[0094] Many modifications and other embodiments set forth herein will come to mind to one skilled in the art to which these embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, the disclosure is not limited to the specific embodiments disclosed and modifications and other embodiments are intended to be included within the scope of the disclosure. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and / or functions, different combinations of elements and / or functions may be provided by alternative embodiments without departing from the scope of the disclosure. In this regard, different combinations of elements and / or functions than those explicitly described above are also contemplated within the scope of the disclosure. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

WHAT IS CLAIMED IS:

1. A glass forming system for controlling devitrification in glass, the glass forming system comprising: a glass forming body; an edge director positioned proximate to the glass forming body, the edge director configured to contact molten glass flowing on the glass forming body to assist in controlling a shape of a glass ribbon formed by the molten glass; and a burner configured to generate a flame that produces heat, the burner positioned proximate to the edge director so that the heat from the flame increases a temperature of the edge director.

2. The glass forming system of claim 1, wherein the heat from the flame increases the temperature of the molten glass at one or more locations.

3. The glass forming system of claim 1 or 2, wherein heating at least one of the edge director or the molten glass reduces buildup of devitrified glass proximate to the edge director.

4. The glass forming system of claim 1, wherein the burner is configured to enable changes in at least one of a size of the flame or a direction of the flame.

5. The glass forming system of any of claims 1-4, wherein the glass forming body comprises a root, the burner positioned at a height lower than the root and the edge director, and the heat from the burner rising from the burner to heat the edge director.

6. The glass forming system of claim 5, wherein the root comprises a linear shape and at least a portion of the burner extends in a direction parallel to the root.

7. The glass forming system of claim 5, wherein the root comprises a linear shape and at least a portion of the burner extends in a direction perpendicular to the root.

8. The glass forming system of claim 1, wherein the glass forming system is arranged to create a chimney effect to cause an upward flow of air that assists in heating the edge director.

9. The glass forming system of claim 1, wherein the burner comprises an outlet where a flame is output from the burner.

10. The glass forming system of claim 1, wherein the burner is positioned below the edge director, and the heat from the flame generated by the burner rises to increase the temperature of the edge director.

11. The glass forming system of claim 1, wherein the burner is configured to enable steering of a direction of the flame.

12. The glass forming system of claim 11, wherein the burner is configured to enable steering of the direction of the flame by mechanically moving an outlet on the burner where the flame is output from the burner.

13. The glass forming system of claim 11, wherein the burner is configured to enable steering of the direction of the flame without mechanically moving an outlet on the burner where the flame is output from the burner.

14. The glass forming system of claim 13, wherein the burner comprises an outlet surface, the burner comprising a first oxygen supply channel and a second oxygen supply channel, the first oxygen supply channel and the second oxygen supply channel configured to output oxygen to assist in generation of the flame, the burner configured to apply a greater amount of oxygen at the first oxygen supply channel relative to the second oxygen supply channel to cause the flame to be emitted at an angle not normal to the outlet surface.

15. The glass forming system of claim 14, wherein a gas supply channel is positioned between the first oxygen supply channel and the second oxygen supply channel.

16. The glass forming system of any of claims 1-3, 5-10, or 15, further comprising: a temperature sensor,wherein the flame is generated by the burner based on temperature data from the temperature sensor.

17. The glass forming system of claim 16, wherein the temperature sensor is configured to measure the temperature of the edge director.

18. The glass forming system of any of claims 16 or 17, wherein at least one of a size of the flame generated by the burner, a frequency at which the flame is generated by the burner, or a duration of time the flame is generated are dependent on the temperature at the edge director.

19. The glass forming system of any of claims 16 or 17, wherein the flame is generated by the burner when the temperature at the edge director falls below a threshold temperature.

20. The glass forming system of claim 16 or 17, further comprising: a processor; and memory comprising computer readable code configured, when executed, to cause the processor to: receive first temperature data from the temperature sensor; determine that a temperature at the edge director or the molten glass is below or above a threshold value; after the determining, causing at least one of: the flame to be generated at the burner; an increase or decrease in a size of the flame generated at the burner; a change in a direction of an outlet of the burner to target a location having a temperature below the threshold value; or a change in a direction of the flame generated at the burner to target the location.

21. A burner for use in controlling devitrification in glass, the burner comprising a body; a head comprising an outlet,wherein the burner is configured to generate a flame that produces heat, the burner positioned proximate to an edge director so that the heat from the flame increases a temperature of the edge director, the burner capable of steering the flame.

22. The burner of claim 21, wherein the burner is capable of steering the flame by mechanically moving the outlet on the burner.

23. The burner of any of claims 21 or 22, wherein the burner is capable of steering the flame without mechanically moving the outlet on the burner.

24. The burner of claim 23, wherein the burner comprises an outlet surface, the burner comprising a first oxygen supply channel and a second oxygen supply channel, the first oxygen supply channel and the second oxygen supply channel configured to output oxygen to assist in generating the flame, the burner configured to apply a greater amount of oxygen at the first oxygen supply channel relative to the second oxygen supply channel to cause the flame to be emitted at an angle not normal to the outlet surface.

25. The burner of claim 24, wherein a gas supply channel is positioned between the first oxygen supply channel and the second oxygen supply channel.

26. A method for manufacturing a glass forming system for controlling devitrification in glass, the method comprising: positioning an edge director proximate to a glass forming body so that the edge director is configured to contact molten glass flowing on the glass forming body to assist in controlling a shape of a glass ribbon formed by the molten glass; and positioning a burner relative to the edge director so that heat from a flame generated by the burner increases a temperature of the edge director, wherein generating a flame at the burner generates heat that increases the temperature of the edge director to reduce buildup of devitrified glass proximate to the edge director.

27. A method for using a glass forming system, the method comprising: receiving first temperature data from a temperature sensor; determining that a temperature at an edge director or molten glass is below or above a threshold value, the edge director positioned proximate to a glass forming body andconfigured to contact the molten glass flowing on the glass forming body to assist in controlling a shape of a glass ribbon formed by the molten glass, a burner configured to generate a flame that produces heat, the burner positioned proximate to the edge director so that the heat from the flame increases a temperature of the edge director; and after the determining, causing at least one of: a flame to be generated at the burner; an increase or a decrease in a size of the flame generated at the burner; a change in a direction of the outlet of the burner to target a location having a temperature below the threshold value; or a change in a direction of the flame generated at the burner to target the location having a temperature below the threshold value.

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