Melting section for glass molding apparatus

Abstract

The melting section for shaping molten glass includes an input wall, an output wall, and a pair of side walls. The input wall, the output wall, and the pair of side walls define the glass melting space of the melting section, which is enclosed by a floor section and a top section. The input wall includes a glass contact wall supported on the floor section and a jack arch positioned above at least a portion of the glass contact wall. The jack arch includes a jack arch electrical path. At least a portion of the jack arch contains a first high electrical resistivity material having a resistivity of 50% or more of the electrical resistivity of the molten glass when measured at the melting temperature.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 63 / 497782, filed on April 24, 2023, the content of which is relied upon herein and incorporated herein by reference in its entirety.

[0002] This specification generally relates to glass manufacturing apparatuses, and more particularly, to a melting section for forming molten glass and a glass manufacturing apparatus including the same.

Background Art

[0003] Optical quality glass sheets are commonly used in a variety of optical display devices, including LCD displays, LED displays, and the like. To provide optical quality glass sheets, various manufacturing processes can be used. These manufacturing processes generally involve melting a glass batch material in a ceramic refractory furnace (i.e., a melting section) and then producing a ribbon of glass from the molten glass by stretching the molten glass from a forming body. Individual glass sheets are then cut from the glass ribbon.

[0004] The refractory material forming a part of the melting section is susceptible to excessive fire - through at high temperatures when using electrodes to electrically heat the glass batch material to form molten glass within the melting section, which may cause damage to the melting section.

[0005] Therefore, there is a need for alternative glass manufacturing apparatuses that limit fire - through and / or components of glass manufacturing apparatuses such as melting sections.

Summary of the Invention

[0006] According to the first embodiment A1, the melting section for forming molten glass comprises an input wall, an output wall located on the opposite side of the input wall, and a pair of side walls extending from the input wall to the output wall, wherein the input wall, the output wall, and the pair of side walls define a glass melting space of the melting section enclosed by a floor and an uppermost portion, and the input wall comprises a glass contact wall supported on the floor, having a glass contact surface facing the glass melting space and extending perpendicularly away from the floor, and at least a portion of the glass contact wall and A jack arch positioned above at least a portion of the glass melting space, the jack arch comprising a jack arch electrical path, the jack arch further comprising a front surface facing the glass melting space and extending vertically away from the top toward the floor portion, a back surface positioned opposite the front surface, and a bottom surface extending horizontally from the front surface to the back surface, wherein at least a portion of the jack arch contains a high electrical resistivity material having a resistivity of 50% or more of the electrical resistivity of the molten glass when measured at the melting temperature.

[0007] A second embodiment A2 includes the melting section described in the first embodiment A1, the melting section further comprising a plurality of electrodes extending through at least one of the side wall portion and the floor portion, wherein the amount of power flowing through the jack arch electrical path is 1% or more and 25% or less of the power generated by the plurality of electrodes.

[0008] The third embodiment A3 includes the molten portion described in the first embodiment A1 or the second embodiment A2, wherein the high electrical resistivity material includes aluminum, zirconium, or a combination thereof.

[0009] A fourth embodiment A4 comprises a melting portion described in any one of the first to third embodiments A1 to A3, wherein another portion of the jack arch comprises a low electrical resistivity material having a resistivity of less than 50% of the electrical resistivity of the glass batch material when measured at the melting temperature.

[0010] The fifth embodiment A5 includes the molten portion described in the fourth embodiment A4, wherein the low electrical resistivity material includes aluminum, chromium, zirconium, or a combination thereof.

[0011] The sixth embodiment A6 includes a melting section according to any one of the first embodiments A1 to the fifth embodiment A5, wherein the jack arch comprises a bevel block and a wedge block, the bevel block being at least partially supported on the side wall, and the wedge block being positioned between the bevel blocks such that the jack arch extends over at least a portion of the width of the input wall.

[0012] The seventh embodiment A7 includes the melting portion described in the sixth embodiment A6, wherein at least one of the beveled blocks includes the high electrical resistivity material.

[0013] The eighth aspect A8 includes the melting portion described in the sixth aspect A6 or the seventh aspect A7, wherein at least one of the wedge blocks includes the high electrical resistivity material.

[0014] The ninth aspect A9 includes a melting section as described in any one of the sixth aspect A6 to the eighth aspect A8, wherein the jack arch further comprises support bricks, and the beveled block is supported on the support bricks.

[0015] The tenth embodiment A10 includes the molten portion described in the ninth embodiment A9, wherein at least one of the supporting bricks includes the high electrical resistivity material.

[0016] The eleventh embodiment A11 includes a melting section as described in any one of the sixth embodiment A6 to the tenth embodiment A10, wherein the jack arch further comprises a flat block, the flat block positioned adjacent to the beveled block and extending across the width direction of the input wall.

[0017] The twelfth embodiment A12 includes the melting portion described in the eleventh embodiment A11, wherein at least one of the wedge blocks and at least one of the flat blocks adjacent to the at least one of the wedge blocks include the high electrical resistivity material.

[0018] The 13th embodiment A13 includes a melting section as described in any one of the 6th embodiment A6 to the 12th embodiment A12, wherein the jack arch further comprises fireproof pins positioned between adjacent wedge blocks, or between one of the wedge blocks and one of the beveled blocks adjacent to that one wedge block.

[0019] The 14th embodiment A14 includes a melted portion described in any one of the 1st embodiment A1 to the 13th embodiment A13, and the glass contact wall portion includes the high electrical resistivity material.

[0020] The 15th embodiment A15 includes a melting section as described in any one of the 1st embodiments A1 to the 14th embodiment A14, wherein the input wall further comprises an input wall refractory supported on the jack arch.

[0021] The sixteenth embodiment A16 includes the melting portion described in the fifteenth embodiment A15, wherein the refractory material of the input wall includes the high electrical resistivity material.

[0022] The 17th embodiment A17 includes the melting portion described in the 16th embodiment A16, wherein at least one of the glass contact wall portion or the refractory material of the input wall portion is formed from the same high electrical resistivity material as the portion of the jack arch formed from the high electrical resistivity material.

[0023] The 18th embodiment A18 includes a melting section as described in any one of the 15th embodiment A15 to the 17th embodiment A19, wherein the jack arch further comprises mortar between the refractory material of the input wall and the jack arch.

[0024] Aspect A19 includes the melting part described in Aspect A18, and the mortar includes the high electrical resistivity material.

[0025] Aspect A20 includes the melting part described in Aspect A18 or Aspect A19, and the mortar includes mullite, alumina, or a combination thereof.

[0026] Additional features and advantages of the embodiments described herein are described in the following detailed description, and will be in part readily apparent to those skilled in the art from that description, or will be recognized by practicing the embodiments described herein, which include the following detailed description, the claims, and the accompanying drawings.

[0027] It should be understood that both the foregoing summary and the following modes for carrying out the invention are intended to describe various embodiments and provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, are incorporated herein, and constitute a part of this specification. The drawings illustrate the various embodiments described herein and, together with the description, serve to explain the principles and operations of the claimed subject matter.

Brief Description of the Drawings

[0028] [Figure 1] A glass manufacturing apparatus according to one or more embodiments shown and described herein is schematically depicted. [Figure 2] An isometric rear view of a melting part for a glass manufacturing apparatus according to one or more embodiments shown and described herein is schematically depicted. [Figure 3] An isometric front view of a melting part for a glass manufacturing apparatus according to one or more embodiments shown and described herein is schematically depicted. [Figure 4] A cross-section of the melting part is schematically depicted in the longitudinal direction of the melting part. [Figure 5]Figures 2 to 4 show a schematic representation of the input wall of the melting section without the outer frame. [Figure 6] Figure 5 schematically shows a cross-section of the input wall. [Modes for carrying out the invention]

[0029] Herein, various embodiments of a melting section for a glass forming apparatus that reduces fire penetration are referred to in detail. According to the embodiments, the melting section for forming molten glass comprises an input wall, an output wall located opposite the input wall, and a pair of side walls extending from the input wall to the output wall. The input wall, the output wall, and the pair of side walls define the glass melting space of the melting section enclosed by a floor section and an upper section. The input wall comprises a glass contact wall and a jack arch. The glass contact wall is supported on the floor section. The glass contact wall has a glass contact surface facing the glass melting space and extending perpendicularly away from the floor section. The jack arch is located above at least a portion of the glass contact wall and at least a portion of the glass melting space. The jack arch comprises a jack arch electrical path. The jack arch further comprises a front facing the glass melting space and extending vertically away from the top toward the floor, a rear positioned opposite the front, and a bottom extending horizontally from the front to the rear. At least a portion of the jack arch contains a high-resistivity material having a resistivity of 50% or more of the electrical resistivity of the molten glass in the melting section when measured at the melting temperature. Various embodiments of the melting section for the glass forming apparatus are described herein with specific reference to the accompanying drawings.

[0030] In this specification, a range may be expressed as "approximately" from a certain value and / or "approximately" to another specific value. Where such a range is expressed, another embodiment includes that certain value and / or to another specific value. Similarly, where a value is expressed as an approximation using the antecedent "approximately", it is understood that a certain value forms another embodiment. It will be further understood that each endpoint of a range is significant, whether related to the other endpoints or independent of the other endpoints.

[0031] The directional terms used herein, such as up, down, right, left, front, back, top, and bottom, are derived solely from the drawings and are not intended to imply absolute orientation.

[0032] Unless otherwise specified, no method described herein is intended to be construed as requiring its steps to be performed in a specific order, nor as requiring any particular orientation in any apparatus. Therefore, if a method claim does not actually list the order in which its steps should be followed, or if any apparatus claim does not actually list an order or orientation for its individual components, or if it is not otherwise specifically stated in the claim or specification that the steps should be limited to a specific order, or if no specific order or orientation for the components of the apparatus is listed, no order or orientation is intended to be inferred in any sense. This includes all possible implicit grounds for interpretation, including logical matters relating to the arrangement of steps, the flow of operation, the order of components, or the orientation of components, the plain meaning derived from grammatical organization or punctuation, and the number or type of embodiments described herein.

[0033] As used herein, the singular forms “a,” “an,” and “the” include multiple referents unless explicitly indicated otherwise by the context. Therefore, for example, a reference to a “a” component includes embodiments having two or more such components unless explicitly indicated otherwise by the context.

[0034] The term “flame penetration,” as used herein, refers to an electric current that travels through an undesirable electrical path (e.g., in parallel) separate from the intended electrical path. For example, the intended electrical path exists between one or more electrodes immersed in molten glass, and the intended electrical path is configured to extend further through the molten glass and heat the molten glass by Joule heating. On the other hand, an undesirable electrical path may also exist through the refractory material comprising the molten section itself, for example, the walls of the molten section, resulting in power that is not intended to heat the molten glass instead dissipating into the refractory walls of the molten section, thereby directly heating the walls of the molten glass. Thus, at least a portion of the current supplied to the electrodes “ignites” through the refractory walls.

[0035] As used herein, the term "power" refers to the rate at which electrical energy is transmitted through an electrical circuit or electrical path, measured from a power source, transformer, or any other power system. Power is measured in watts.

[0036] As used herein, the term "electrical path" refers to a path through which electrical energy can be transmitted.

[0037] The terms “resistivity” or “electrical resistivity,” as used herein, refer to the ability of a material to resist electric current, as measured according to ASTM D257.

[0038] As used herein, the term "high electrical resistivity material" refers to a material having an electrical resistivity of 50% or more of the electrical resistivity of the molten glass in the molten portion, as measured at the melting temperature.

[0039] As used herein, the term "low electrical resistivity material" refers to a material having a resistivity less than 50% of that of a high-resistivity material, for example, a resistivity of molten glass when measured at the melting temperature.

[0040] As used herein, the term "melting temperature" refers to the operating temperature of the melting section.

[0041] When used herein, the term "operating temperature" refers to the steady-state temperature at which the melting section operates during the melting process, unless otherwise specified.

[0042] As used herein, the term "jack arch" refers to a flat or low-curve arch used to support weight at and around an opening inside the input wall of the melting section.

[0043] Glass articles can generally be formed by melting a glass batch material to form molten glass, and then shaping the molten glass into a final glass article such as a glass ribbon or glass sheet. Exemplary processes for shaping glass ribbons include float glass processing, slot drawing, and fusion down drawing.

[0044] Referring to Figure 1, an exemplary glass manufacturing apparatus 100 for forming glass ribbons from molten glass using a fusion draw machine is schematically depicted. The glass manufacturing apparatus 100 includes a melting section 101, a clarification vessel 103, a mixing vessel 104, a delivery vessel 108, and a fusion draw machine (FDM) 120. Glass batch material is introduced into the melting section 101 through a batch material inlet 102. The batch material is melted in the melting section to form molten glass 106. The clarification vessel 103 has a high-temperature processing area that receives the molten glass 106 from the melting section 101, where molten gases and / or bubbles are removed from the molten glass 106. The clarification vessel 103 is fluidly connected to the mixing vessel 104 by a connecting pipe 105. That is, the molten glass flowing from the clarification vessel 103 to the mixing vessel 104 flows through the connecting pipe 105. The mixing container 104 is then fluidly connected to the discharge container 108 by a connecting pipe 107, so that the molten glass flowing from the mixing container to the discharge container 108 flows through the connecting pipe 107.

[0045] The delivery container 108 supplies molten glass 106 to the FDM 120 through the drop-off pipe 109. The FDM 120 comprises a housing 122 in which an input section 110 and a molding container 111 are positioned. As shown in Figure 1, the molten glass 106 from the drop-off pipe 109 flows into the input section 110, which leads to the molding container 111. The molding container 111 includes an opening 112 to receive the molten glass 106, which flows into a bucket section 113, then overflows and flows downward before the two converging surfaces 114a and 114b fuse together at the bottom edge (root) of the molding container where the two converging surfaces meet, that is, before the two converging surfaces come into contact and are stretched in the downstream direction 121 to form a glass ribbon 148.

[0046] Figure 1 schematically illustrates a glass manufacturing apparatus 100 for forming glass ribbons using FDM, but it should be understood that glass ribbons may be formed using other processes, including, but not limited to, float glass processing, slot drawing, or similar processes. Furthermore, although the glass manufacturing apparatus 100 is depicted as being used for forming glass ribbons, it should be understood that similar glass manufacturing apparatus may be used, but not limited to, to form glass articles other than glass sheets, including glass tubes and similar items.

[0047] The melting section 101 may be designed to include a jack arch supporting the weight of the refractory material located above an opening, for example, a feed opening, as described in U.S. Patent No. 11,492,281B2, which is incorporated herein by reference in whole. The refractory material forming the jack arch may be susceptible to excessive fire penetration at high temperatures when the glass batch material is electrically heated using electrodes (e.g., molybdenum electrodes) to form molten glass within the melting section 101. When the jack arch refractory material is heated to operating conditions (e.g., 1200°C or higher and 1800°C or lower), the electrical resistivity of the jack arch refractory material may decrease, approaching or falling below the electrical resistivity of the molten glass in the melting section. Thus, the electrodes may generate a current that “flames penetrate” the jack arch instead of, or in addition to, the molten glass, and the magnitude of that current may cause damage to the jack arch and the entire melting section 101.

[0048] Disclosed herein is a melting section for a glass forming apparatus that mitigates the aforementioned problems so as to limit flame penetration. Specifically, the melting section described herein includes a jack arch containing a high-resistivity material having a resistivity of 50% or more of the electrical resistivity of the molten glass when measured at the melting temperature. The high-resistivity material reduces the current passing through the electrical path of the jack arch, thereby reducing the magnitude of flame penetration and preventing damage to the melting section.

[0049] Returning to Figure 1, and now referring to Figures 2-4, a melting section 101 for use in a glass manufacturing apparatus is schematically depicted from the rear (Figure 2), from the front (Figure 3), and in an XY cross-section (Figure 4). The melting section 101 comprises an outer frame 130 and a base 170. The outer frame 130 generally defines an inner volume 132. The melting section 101 comprises a tank assembly 200 supported on the base 170 within the inner volume 132. In embodiments, the tank assembly may be supported on the base 170 and spaced apart from the outer frame 130. The tank assembly 200 of the melting section 101 includes an input wall 218 (Figure 2) with a plurality of batch material inlets 102, through which glass batch material can be introduced into the tank assembly 200 for melting. The tank assembly 200 also includes a discharge wall 220 on the opposite side of the input wall 218 in the longitudinal direction of the melting section 101 (i.e., the + / -Y direction of the coordinate axes shown in the drawings). The discharge wall 220 includes a discharge port 223 through which molten glass flows out of the tank assembly 200 of the melting section 101. The tank assembly 200 of the melting section 101 further includes a pair of side walls 241, 242 (side wall 241 is shown in Figures 2 and 3, respectively; side walls 241, 242 are shown in the cross-section of the tank assembly schematically shown in Figure 4) which face each other in the width direction of the melting section 101 (i.e., the + / -X direction of the coordinate axes shown in Figures 2 and 3). The pair of side walls 241, 242 connect the input wall 218 and the discharge wall 220. In embodiments, the melting section 101 may include a plurality of burners 402 (e.g., combustion burners) arranged along the length of the melting section 101. The burners 402 may be located within or on the side walls 241, 241 of the tank assembly 200. As described herein, the burners 402 facilitate the melting of batch material in the melting section 101 and help maintain the temperature of the molten glass in the melting section 101.

[0050] In addition to the input wall 218, discharge wall 220, and side walls 241, 242, the tank assembly 200 of the melting section 101 further includes a top section 206 (also referred to as the "crown") and a floor section 207 (Figure 4), which connect the input wall 218, discharge wall 220, and side walls 241, 242. The input wall 218, discharge wall 220, side walls 241, 242, and floor section 207 surround the glass melting space 250 of the tank assembly 200 of the melting section 101. In embodiments, each of the input wall 218, discharge wall 220, side walls 241, 242, and floor section 207 may be constructed from refractory materials such as bricks and blocks formed from ceramic refractories. As used herein, the term "refractory material" refers to a material capable of withstanding the high-temperature degradation of the glass manufacturing (i.e., melting) process with minimal degradation. The refractory material, specifically the refractory block used to construct the melting section 101, is generally a ceramic material such as alumina, zirconia, and similar materials, but should be understood to include, though not limited to, refractory metals and refractory alloys, as well as other refractory materials. The materials used to form portions of the inlet wall 218 are described in further detail herein.

[0051] Referring further to Figures 1 to 4, the outer frame portion 130 (Figure 1) of the melting section 101 is connected to the tank assembly 200, for example, by pressure bolts. In embodiments, the pressure bolts may be spring-loaded pressure bolts that allow expansion and contraction of the refractory block. In embodiments, the pressure bolts may be positioned within a support member, which is then firmly fixed to the outer frame portion 130. Alternatively, the pressure bolts may be fixed to a portion of the outer frame portion 130 (and extend through it).

[0052] Referring here to Figures 5 and 6, the input wall 218 of the tank assembly 200 in Figures 2 to 4 is schematically depicted without the outer frame. The input wall 218 generally comprises a glass contact section 204 and a superstructure section 202. The glass contact section 204 is the lower part of the tank assembly 200, where the glass batch material is heated to become molten glass. That is, the glass contact section 204 is the part of the tank assembly 200 that will come into contact with the molten glass located within the glass melting space 250 of the tank assembly 200 of the melting section 101. The superstructure section 202 is located above the glass contact section 204 (and the glass contact wall 260 of the glass contact section 204) and, in embodiments, may be supported at least partially on the glass contact wall 260. The superstructure section 202 then supports the uppermost part 206 of the tank assembly 200 of the melting section 101. In this embodiment, the batch material inlet 102 for receiving the glass batch material to be melted in the tank assembly 200 of the melting section 101 is located within the upper structure 202 of the inlet wall 218.

[0053] In the embodiment, the glass contact portion 204 of the input wall portion 218 includes a glass contact wall portion 260 supported on the floor portion 207. The glass contact wall portion 260 may be constructed from stacked fire-resistant blocks 213. The fire-resistant blocks 213 of the glass contact wall portion 260 are supported on the floor portion 207. In the embodiment, the fire-resistant blocks 213 of the glass contact wall portion 260 may be biased to contact each other by pressure bolts attached to the outer frame portion.

[0054] In embodiments, the glass contact wall 260 may include a glass contact surface 261 that faces the glass melting space 250 of the tank assembly 200 and extends perpendicularly away from the floor portion 207. In embodiments, at least a portion of the glass contact surface 261 of the glass contact wall 260 is inclined away from the glass melting space 250. For example, in embodiments, the glass contact wall 260 comprises a base portion 262 supported on the floor portion 207 and an upper portion 263 supported on the base portion 262, as depicted in Figure 6. In these embodiments, the glass contact surface 261 of the base portion 262 is substantially vertical, and the upper portion 263 tapers from the base portion 262 to the top of the glass contact wall 260, so that the glass contact surface 261 is inclined outward (relative to the vertical) away from the glass melting space 250. In other embodiments (not shown), the entire glass contact surface 261 may be oriented at an angle inclined with respect to the vertical. In some embodiments (not shown), the entire glass contact surface 261 may be substantially vertical. As shown in Figure 6, the base portion 262 may utilize a different block from the upper portion 263. In other embodiments, the base portion 262 and the upper portion 263 may be formed from a single block.

[0055] Referring again to Figures 5 and 6, the superstructure 202 of the input wall 218 includes at least one batch material inlet 102 extending through the refractory block 270, and in embodiments, may include a plurality of batch material inlets. As described above herein, at least one batch material inlet 102 provides a path for introducing batch material into the glass melting space 250 of the tank assembly 200 of the melting section 101. Optionally, the input wall 218 may include at least two batch inlets, for example, at least three or more batch material inlets 102 as depicted in Figure 5. These batch material inlets 102 may be spaced equidistant from each other in the width direction of the input wall 218.

[0056] Referring further to Figures 5 and 6, the upper structure 202 of the input wall 218 further comprises a jack arch 280 positioned above at least a portion of the glass contact wall 260 and at least a portion of the glass melting space 250. The jack arch 280 supports the weight of the input wall 218 at and above the batch material input opening 102 of the input wall, such as the refractory material 290, and can further support at least a portion of the uppermost part 206 of the melting section 101.

[0057] The jack arch 280 comprises a front surface 284 facing the glass melting space 250 and extending vertically away from the uppermost part 206 toward the floor portion 207, a rear surface 283 located opposite the front surface 284, and a lower surface 285 extending horizontally from the front surface 284 to the rear surface 283 (i.e., extending horizontally).

[0058] As shown in Figure 5, the jack arch 280 can be a flat arch such that the upper edge 280a and lower edge 280b of the flat arch are substantially flat and / or horizontal. In other embodiments, the jack arch can be a low-curve arch such that the upper edge is flat and the lower edge is curved. In such embodiments, the rise of the curve of the bottom edge can be more than 0 cm and less than or equal to 25 cm per meter span (for example, if the jack arch is 5 m wide, the bottom edge of the jack arch may vary from 0 cm to 62.5 cm, starting at a height of 0 cm, rising from a height of 0 cm to 62.5 cm at the center of the jack arch (i.e., at the 2.5 m position), and then returning to a height of 0 cm on the opposite side of the jack arch).

[0059] The jack arch 280 may be constructed of fire-resistant blocks. In an embodiment, the jack arch 280 may comprise a beveled block 281 and a wedge block 282. Both the beveled block 281 and the wedge block 282 are voussoirs, or wedge-shaped or tapered blocks, used to construct the jack arch 280.

[0060] The beveled block 281 is the lowest voussoir on either side of the springer, or jack arch 280. The beveled block 281 is the lowest element of the jack arch 280. The beveled block 281 is at least partially supported by the side walls 241, 242 (Figures 2-4) of the tank assembly 200 of the melting section 101, and is partially supported by the outer frame 130 of the melting section so that the lateral load of the jack arch is transmitted to the outer frame 130.

[0061] Multiple wedge blocks 282 are positioned between the beveled blocks 281 such that the jack arch 280 extends over at least a portion of the width of the input wall 218. The wedge blocks 282 are formed with beveled interlocking surfaces so as the wedge blocks 282 are assembled, the beveled interlocking surfaces of adjacent blocks are prevented from shifting vertically from each other. Multiple wedge blocks 282 include a keystone 282a, which locks the other wedge blocks 282 in place and prevents the jack arch 280 from collapsing. When the wedge blocks 282 are assembled with their interlocking surfaces in contact with each other, the weight of the wedge blocks 282 (and therefore the weight of the jack arch 280, and any other loads supported by the jack arch 280) is transferred laterally (i.e., in the width direction of the input wall 218) to the beveled blocks 281, and then to the outer frame 130 of the melting section 101.

[0062] In this embodiment, the jack arch 280 may further comprise support bricks 286, which are bases or blocks that function as the bases for the beveled blocks 281. The support bricks 286 can help transfer the lateral load of the jack arch 280 to the outer frame 130.

[0063] In some embodiments, the jack arch 280 may further comprise a flat block 287. Without the flat block 287, the jack arch 280 may interfere with the portion of the upper inlet wall 218 (e.g., the inlet wall refractory material 290) during expansion. The flat block 287 provides a surface over which the remainder of the inlet wall 218 can be constructed, minimizing the amount of damage to the remainder of the inlet wall 218 caused by the jack arch 280 during expansion. The flat block 287 may be positioned adjacent to the beveled block 281 and extend across the width of the inlet wall 218. The flat block 287 may be square or rectangular in shape, having four sides, four corners, and four approximately right angles. The lateral dimensions of the flat block 287 (e.g., the -x to +x dimensions) may be greater than the lateral dimensions of either the beveled block 281 or the wedge block 282.

[0064] In embodiments, the jack arch 280 may further include fire-resistant pins 288 positioned between adjacent wedge blocks 282, and between one of the wedge blocks 282 and one of the beveled blocks 281 adjacent to that wedge block 282. The fire-resistant pins 288 may have a circular or cylindrical structure and may lock the beveled blocks 281 and wedge blocks 282 together, helping to prevent slippage during thermal expansion of the blocks. For example, adjacent blocks may define passages configured to receive the fire-resistant pins 288 when assembled. The fire-resistant pins are inserted into the passages, preventing relative movement between the adjacent blocks. The fire-resistant pins 288 may be mortared in place.

[0065] Referring further to Figures 5 and 6, the superstructure 202 of the input wall 218 may further include an input wall refractory 290, which includes, for example, firebricks or blocks supported on a jack arch 280. The input wall refractory 290 helps support the uppermost part 206 of the tank assembly of the melting section 101.

[0066] As described above, the tank assembly 200 is used to heat the glass batch material and thereby form molten glass within the glass contact portion 204 of the tank assembly 200. In embodiments, the operating temperature of the melting portion 101 can be 1200°C or higher and 1800°C or lower, 1200°C or higher and 1700°C or lower, 1300°C or higher and 1800°C or lower, 1300°C or higher and 1700°C or lower, 1400°C or higher and 1800°C or lower, 1400°C or higher and 1700°C or lower, 1500°C or higher and 1800°C or lower, or 1500°C or higher and 1700°C or lower, or any sub-range formed from any of these endpoints. Various techniques can be used to heat the tank assembly 200. For example, in embodiments of the tank assembly 200 shown in Figures 2 to 4, the tank assembly 200 can be heated electrically. Referring again to Figures 5 and 6, the melting section 101 comprises a plurality of electrodes 292 extending through at least one of the side wall sections 241, 241 (not shown) and the floor section 207. The electrodes 292 supply electrical energy to the molten glass and / or the glass batch material contained within the melting section 101. Various configurations of the electrodes 214 can be used to heat the glass contact section 204 of the melting section 101. Furthermore, as described above, a plurality of burners 402 may be positioned within the side wall sections 241, 242 of the tank assembly 200 to supplement the heating provided by the electrodes.

[0067] In some embodiments, electrode 292 may contain molybdenum, while in other embodiments, the electrode may contain tin oxide (SnO2) or a platinum alloy. In some embodiments, the platinum alloy may include rhodium, iridium, oxide dispersion strengthened (ODS) alloy, graphite, or a combination thereof. In some embodiments, electrode 292 may extend from the floor portion 207. In some embodiments, electrode 292 may extend from the side wall portions 241, 242.

[0068] The power generated by electrode 292 can be transmitted along a jack arch electrical path (shown as dashed line 294) extending through at least a portion of the jack arch 280. As described above, conventional refractory materials forming a jack arch may be more susceptible to higher levels of fire penetration at high temperatures when the glass batch material is electrically heated using electrodes to form molten glass within the melting area. That is, at higher temperatures (e.g., operating temperature), the electrical resistance of the refractory material including the jack arch 280 may decrease significantly, allowing a considerable current to be generated within the jack arch 280, sufficient to cause the refractory material to break. Over time, this breakage may lead to the deterioration of the refractory material. Therefore, to mitigate this problem, at least a portion of the jack arch 280 described herein may include a high electrical resistivity material having a resistivity of 50% or more of the electrical resistivity of the molten glass contained in the glass melting space 250 when measured at the melting temperature. The high electrical resistivity material reduces the current passing through the jack arch 280, thereby diverting the current to a lower-resistance electrical path (for example, through the molten glass contained in the glass melting space 250). Consequently, the power flowing through the jack arch electrical path 294 is reduced.

[0069] For example, in one embodiment, the amount of power flowing through the jack arch electrical path 294 of the jack arch 280 containing a high electrical resistivity material may be 1% or more and 25% or less of the power generated by the multiple electrodes 292. In another embodiment, the amount of power flowing through the jack arch electrical path 294 of the jack arch 280 containing a high electrical resistivity material may be 1% or more, or even 2% or more, of the power generated by the multiple electrodes 292. In yet another embodiment, the amount of power flowing through the jack arch electrical path 294 of the jack arch 280 containing a high electrical resistivity material may be 25% or less, 20% or less, 15% or less, 10% or less, or even 5% or less of the power generated by the multiple electrodes 292. In the embodiment, the amount of power flowing through the jack arch electrical path 294 of the jack arch 280, which includes a high electrical resistivity material, may be 1% or more and 25% or less, 1% or more and 20% or less, 1% or more and 15% or less, 1% or more and 10% or less, 1% or more and 5% or less, 2% or more and 25% or less, 2% or more and 20% or less, 2% or more and 15% or less, 2% or more and 10% or less, or even 2% or more and less than 5%, or any subrange formed from any of these endpoints.

[0070] In the embodiment, the amount of power generated by the plurality of electrodes 292 may be 100kW or more and 10MW or less, 100kW or more and 5MW or less, 100kW or more and 1MW or less, 250kW or more and 10MW or less, 250kW or more and 5MW or less, 250kW or more and 1MW or less, 250kW or more and 1MW or less, 500kW or more and 10MW or less, 500kW or more and 5MW or less, or 500kW or more and 1MW or less, or any subrange formed from any of these endpoints.

[0071] In the embodiment, the high electrical resistivity material may have an electrical resistivity of 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more of the electrical resistivity of the molten glass contained in the glass melting space 250 when measured at the melting temperature.

[0072] In the embodiment, the high electrical resistivity material may have a resistivity of 20 ohms·cm or more, 30 ohms·cm or more, 40 ohms·cm or more, or even 50 ohms·cm or more when measured at 1600°C.

[0073] In embodiments, the high electrical resistivity material may be a refractory material containing aluminum, zirconium, or a combination thereof. For example, a high electrical resistivity material containing aluminum may include alumina, alumina-zirconia silica (AZS), mullite, or a combination thereof. A high electrical resistivity material containing zirconium may include zirconia.

[0074] As described above, at least a portion of the jack arch 280 includes a high resistivity material. In embodiments, the entire jack arch 280 may include a high resistivity material. In embodiments, it may be desirable to reduce costs, which can be achieved by limiting the amount of high resistivity material used. While low resistivity materials may not help minimize the level of flame penetration, using low resistivity materials together with high resistivity materials can be a cost-effective solution for reducing the level of flame penetration. Therefore, in embodiments, another portion of the jack arch 280 may include a low resistivity material having a resistivity less than that of the high-resistivity refractory material, for example, less than 50% of the resistivity of the molten glass in the glass melting space 250 when measured at the melting temperature. In embodiments, the low resistivity material may have a resistivity of less than 50%, 40%, 30%, or even 20% or less of the resistivity of the molten glass when measured at the melting temperature.

[0075] In the embodiment, the low electrical resistivity material may have a resistivity of less than 20 ohms·cm, 15 ohms·cm or less, 10 ohms·cm or less, or even 5 ohms·cm or less when measured at 1600°C.

[0076] In embodiments, the low electrical resistivity material may be a refractory material containing aluminum (e.g., alumina), chromium, zirconium (e.g., zirconia), or a combination thereof.

[0077] Referring back to Figures 5 and 6, any portion of the jack arch 280 may be formed from a high resistivity material, and any combination of high and low resistivity materials may be used, as long as the current (e.g., power) through the jack arch electrical path 294 is reduced. For example, in an embodiment, at least one of the beveled blocks 281 may include a high resistivity material. In an embodiment, both beveled blocks 281 may include a high resistivity material. In an embodiment, at least one of the wedge blocks 282 may include a high resistivity material. In an embodiment, at least two, at least three, at least four, or even at least five of the wedge blocks 282 may include a high resistivity material. In an embodiment, the wedge blocks 282 may be arranged alternately between high and low resistivity materials. In an embodiment, at least two adjacent wedge blocks 282 may include a high resistivity material. In an embodiment, at least one of the support bricks 286 may include a high resistivity material. In the embodiment, both of the supporting bricks 286 may include a high resistivity material. In the embodiment, at least one of the wedge blocks 282 and at least one of the flat blocks 287 adjacent to at least one of the wedge blocks 282 may include a high resistivity material. For example, the flat block 287a and the keystone 282a may include a high resistivity material.

[0078] Because the glass contact wall 260, the jack arch 280, and the refractory wall 290 are adjacent (e.g., in contact), the resistivity of one of these components may affect the overall electrical resistivity of the refractory wall 218. In embodiments, the glass contact wall 260 may include a high electrical resistivity material. In embodiments, the refractory wall 290 may include a high electrical resistivity material. In embodiments, at least one of the glass contact wall 260 and the refractory wall 290 may be formed from the same high electrical resistivity material as the portion of the jack arch 280 formed from the high electrical resistivity material.

[0079] In embodiments, the jack arch 280 may further comprise mortar 298 disposed between the refractory wall 290 and the jack arch 280 to lock the structural components together and prevent slippage during thermal expansion of the refractory material (e.g., during initial heating of the molten section). In embodiments, the jack arch 280 may further comprise mortar (not shown) disposed between the beveled blocks 281, wedge blocks 282, and / or flat blocks 287 of the jack arch 280. In embodiments, the mortar 298 may include a high electrical resistivity material. For example, in embodiments, the mortar may include mullite, alumina, or a combination thereof.

[0080] Referring again to Figures 2 to 4, the discharge wall 220 and the side walls 241, 242 may have a similar structure to the input wall 218, except for the jack arch. That is, each of the discharge wall 220 and the side walls 241, 242 may be constructed from blocks of fire-resistant material, and each may include a glass contact section and a superstructure above the glass contact section, as described above with respect to the input wall 218. In embodiments, the superstructures of each of the discharge wall 220 and the side walls 241, 242 include steps of fire-resistant blocks without a jack arch, as shown in Figure 4. For example, the side wall 242 in Figure 4 may include a glass contact section, including a glass contact wall, as described herein with respect to the input wall 218. The superstructure of the side wall 242 may include steps of several fire-resistant blocks. The fire-resistant blocks may be supported above or above the glass contact wall, as described herein with respect to Figures 4 and 5. Each of the discharge wall portion 220 and the side wall portion 241 can be configured similarly.

[0081] Referring to Figures 2 and 3, the uppermost part 206 of the tank assembly 200 may also be composed of refractory blocks. To form the uppermost part 206, refractory blocks are arranged to form a barrel vault above the glass melting space 250 (Figure 4) of the tank assembly 200 of the melting section 101, using conventional masonry techniques to form an arch and / or vault.

[0082] It should be understood here that the molten section for the glass forming apparatus described herein can limit fire penetration. The reduction in fire penetration is due to a jack arch containing a high electrical resistivity material having a resistivity of 50% or more of the electrical resistivity of the molten glass contained in the glass molten space 250 when measured at the melting temperature.

[0083] Those skilled in the art will see that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Therefore, this specification is intended to encompass modifications and variations of the various embodiments described herein, insofar as such modifications and variations fall within the scope of the appended claims and their equivalents.

Claims

1. A melting section for shaping molten glass, wherein the melting section is It comprises an input wall, a discharge wall located on the opposite side of the input wall, and a pair of side walls extending from the input wall to the discharge wall, wherein the input wall, the discharge wall, and the pair of side walls define the glass melting space of the melting section enclosed by the floor and the uppermost part, and the input wall is A glass contact wall portion supported on the floor portion, comprising a glass contact surface facing the glass melting space and extending perpendicularly away from the floor portion, A jack arch positioned above at least a portion of the glass contact wall and at least a portion of the glass melting space, wherein the jack arch comprises a jack arch electrical path, and further comprises a front surface facing the glass melting space and extending vertically away from the top toward the floor portion, a back surface positioned opposite the front surface, and a bottom surface extending horizontally from the front surface to the back surface, A molten portion of the jack arch comprises a high electrical resistivity material having a resistivity of 50% or more of the electrical resistivity of the molten glass when measured at its melting temperature.

2. The melting section according to claim 1, further comprising a plurality of electrodes extending through at least one of the side wall portion and the floor portion, wherein the amount of power flowing through the jack arch electrical path is 1% or more and 25% or less of the power generated by the plurality of electrodes.

3. The molten portion according to claim 1 or 2, wherein the high electrical resistivity material includes aluminum, zirconium, or a combination thereof.

4. The molten portion according to any one of claims 1 to 3, wherein another portion of the jack arch includes a low-resistivity material having a resistivity of less than 50% of the electrical resistivity of the glass batch material when measured at the melting temperature.

5. The molten portion according to claim 4, wherein the low electrical resistivity material includes aluminum, chromium, zirconium, or a combination thereof.

6. The jack arch comprises a beveled block and a wedge block, The angled cut block is at least partially supported on the side wall portion, The melting section according to any one of claims 1 to 5, wherein the wedge block is positioned between the bevel-cut blocks such that the jack arch extends over at least a portion of the widthwise direction of the input wall.

7. The melting portion according to claim 6, wherein at least one of the beveled blocks includes the high electrical resistivity material.

8. The melting portion according to claim 6 or 7, wherein at least one of the wedge blocks comprises the high electrical resistivity material.

9. The melting section according to any one of claims 6 to 8, wherein the jack arch further comprises support bricks, and the beveled block is supported on the support bricks.

10. The molten portion according to claim 9, wherein at least one of the supporting bricks includes the high electrical resistivity material.

11. The melting section according to any one of claims 6 to 10, wherein the jack arch further comprises a flat block, the flat block being positioned adjacent to the beveled block and extending across the width direction of the input wall.

12. The melting portion according to claim 11, wherein at least one of the wedge blocks and at least one of the flat blocks adjacent to the at least one of the wedge blocks include the high electrical resistivity material.

13. The melting section according to any one of claims 6 to 12, further comprising a fireproof pin positioned between adjacent wedge blocks, or between one of the wedge blocks and one of the beveled blocks adjacent to that wedge block.

14. The glass contact wall portion comprises the high electrical resistivity material, as described in any one of claims 1 to 13.

15. The melting section according to any one of claims 1 to 14, wherein the input wall further comprises a refractory material for the input wall supported on the jack arch.

16. The refractory material for the input wall portion includes the high electrical resistivity material, as described in claim 15.

17. The melting portion according to claim 16, wherein at least one of the glass contact wall portion or the refractory material of the input wall portion is formed from the same high electrical resistivity material as the portion of the jack arch formed from the high electrical resistivity material.

18. The jack arch further comprises mortar between the refractory material of the input wall and the jack arch, according to any one of claims 15 to 17.

19. The molten portion according to claim 18, wherein the mortar includes the high electrical resistivity material.

20. The molten portion according to claim 18 or 19, wherein the mortar comprises mullite, alumina, or a combination thereof.

Images