Apparatus and method for extracting heat during forming of glass ribbon

Abstract

A glass forming apparatus is disclosed that includes a glass feed device and a heat extraction assembly. The glass feed device includes a slot block through which molten glass flows and is formed into a glass ribbon. The slot block includes a plurality of channels formed therein. The heat extraction assembly includes an outer tube, an inner tube, a cooling fluid source, and an exhaust manifold. The outer tube has proximal and distal ends connected to one of the plurality of channels. The inner tube extends within the outer lumen of the outer tube. The cooling fluid source is fluidly coupled to the inner tube, thereby supplying cooling fluid to the inner lumen of the inner tube. The exhaust manifold is fluidly coupled to an exhaust channel defined between the inner and outer tubes for exhausting the cooling fluid.

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 / 428,174, filed November 28, 2022, the contents of which are relied upon and incorporated by reference in their entirety herein.

[0002] FIELD OF THE INVENTION The present disclosure relates to glass manufacturing apparatus, and more particularly to glass manufacturing apparatus having a glass forming apparatus with a heat extraction assembly. [Background technology]

[0003] Glass manufacturing equipment can include a variety of separate components for melting, processing, and forming glass. For example, a typical glass manufacturing equipment can include, among other components, a melter for melting a batch of glass components to form a molten material (e.g., molten glass), a fining system for removing liquefied gases from the molten glass, a mixing vessel for homogenizing the molten glass, and a forming device for forming the molten glass into a desired shape (e.g., a ribbon, cylinder, tube, etc.).

[0004] In producing glass ribbons that can be divided into individual glass sheets for use in display applications, including televisions, computer monitors, and handheld devices, molten glass can be formed into a glass ribbon by flowing the molten glass into a glass forming apparatus and drawing the glass ribbon from the glass forming apparatus. However, challenges can exist in producing glass ribbons with acceptable dimensional properties. For example, glass ribbons can exhibit ribbon stability issues during forming, such as ribbon sagging (side-to-side ribbon movement) and sheet width variations.

[0005] Therefore, a need exists for alternative designs for glass forming apparatus that alleviate ribbon stability problems, thereby improving the quality of the resulting glass ribbon and glass sheets separated therefrom. Summary of the Invention

[0006] A first aspect is a glass forming apparatus comprising: a glass feed device including a slot block, wherein molten glass flows through the slot block and is formed into a glass ribbon as it exits slot orifices in the slot block, the slot block having a vertical dimension corresponding to the direction of flow of the molten glass, a width dimension orthogonal to the vertical dimension, a thickness dimension orthogonal to the vertical dimension and the width dimension, and a plurality of channels formed in the slot block proximate to the slot orifices; and a heat extraction assembly, wherein the heat extraction assembly comprises an outer tube having a distal end and a proximal end, the distal end of the outer tube having a plurality of channels extending therethrough. the glass forming apparatus includes an outer tube connected to one of the channels; an inner tube extending within the outer lumen of the outer tube, the inner tube having a distal end and a proximal end and positioned within the outer lumen of the outer tube such that the distal end of the inner tube is positioned proximate to the distal end of the outer tube; a cooling fluid source fluidly coupled to the inner tube thereby supplying cooling fluid to the inner lumen of the inner tube; and an exhaust manifold fluidly coupled to the outer lumen of the outer tube for exhausting the cooling fluid from an exhaust channel defined between the inner surface of the outer tube and the outer surface of the inner tube.

[0007] A second aspect includes the glass forming apparatus of the first aspect, further comprising a housing defining an internal channel, the outer tube being connected to the housing such that an outer lumen of the outer tube is in fluid communication with the internal channel of the housing, the exhaust manifold being fluidly coupled to the internal channel of the housing such that an exhaust lumen of the exhaust manifold is in fluid communication with the internal channel of the housing, and the inner tube extending at least partially through the internal channel of the housing.

[0008] A third aspect includes the glass forming apparatus of any preceding aspect, wherein the housing includes a connector slidably positioned within the housing, the connector including an internal passageway, and an inner tube extending through the internal passageway of the connector and coupled to the connector, whereby translating the connector relative to the housing adjusts the spacing between the distal end of the inner tube and the distal end of the outer tube.

[0009] A fourth aspect includes the glass forming apparatus of any preceding aspect, further comprising a set screw threadably inserted into the housing, the set screw for locking the connector to the housing and preventing sliding of the connector when the set screw is rotated in a first direction.

[0010] A fifth aspect includes the glass forming apparatus of any preceding aspect, wherein the inner tube is threadably coupled to the connector, whereby rotation of the inner tube within the connector adjusts the spacing between the distal end of the inner tube and the distal end of the outer tube.

[0011] A sixth aspect includes the glass forming apparatus of any preceding aspect, further including an insulating insert provided within one or more of the plurality of channels, the insulating insert having at least one opening, wherein material of the slot block proximate the slot orifice is exposed through the opening to enhance heat extraction from the material.

[0012] A seventh embodiment includes the glass forming apparatus of any preceding embodiment, wherein at least one opening in the insulating insert faces a bottom side of the slot block, and the glass ribbon exits the slot orifice through the bottom side.

[0013] An eighth aspect includes the glass forming apparatus of any preceding aspect, further comprising an exhaust temperature sensor operably coupled to the exhaust manifold to measure an outlet temperature of the cooling fluid in the exhaust manifold, and a cooling fluid temperature sensor operably coupled to the cooling fluid source to measure an inlet temperature of the cooling fluid supplied to the inner tube.

[0014] A ninth aspect includes the glass forming apparatus of any preceding aspect, further comprising a controller operably connected to the cooling fluid temperature sensor and the discharge temperature sensor, the controller being programmed to calculate heat extraction at the slot block based on an outlet temperature of the cooling fluid in the discharge manifold and an inlet temperature of the cooling fluid provided by the cooling fluid source.

[0015] A tenth aspect includes the glass forming apparatus of any preceding aspect, wherein the controller is operable to adjust the flow rate of cooling fluid provided by the cooling fluid source based on the calculated heat extraction.

[0016] An eleventh aspect includes the glass forming apparatus of any preceding aspect, further comprising a glass ribbon sensor for measuring a width of the glass ribbon exiting the slot orifice, the controller being operatively connected to the glass ribbon sensor and operable to adjust a flow rate of cooling fluid supplied by the cooling fluid source based on the width of the glass ribbon measured by the glass ribbon sensor.

[0017] A twelfth aspect includes the glass forming apparatus of any preceding aspect, wherein an insulating sleeve is disposed over at least a portion of the outer tube.

[0018] A thirteenth aspect includes the glass forming apparatus of any preceding aspect, further comprising a glass ribbon sensor for measuring a width of the glass ribbon exiting the slot block.

[0019] A fourteenth aspect includes the glass forming apparatus of any preceding aspect, further comprising a controller operably connected to the cooling fluid source and the glass ribbon sensor, the controller operable to adjust the flow rate of cooling fluid supplied by the cooling fluid source based on the width of the glass ribbon measured by the glass ribbon sensor.

[0020] A fifteenth aspect includes the glass forming apparatus of any preceding aspect, wherein at least one of the plurality of channels extends in a plane defined by the vertical dimension and the width dimension, and wherein the length of at least one of the plurality of channels is parallel to the vertical dimension.

[0021] A sixteenth aspect includes the glass forming apparatus of any preceding aspect, wherein at least one of the plurality of channels extends in a plane defined by the vertical dimension and the width dimension, and wherein a length of at least one of the plurality of channels is non-parallel to the vertical dimension.

[0022] A seventeenth aspect includes the glass forming apparatus of any preceding aspect, wherein at least one of the plurality of channels extends in a plane defined by the width dimension and the thickness dimension, and wherein the length of at least one of the plurality of channels is parallel to the thickness dimension.

[0023] An eighteenth aspect includes the glass forming apparatus of any preceding aspect, wherein at least one of the plurality of channels extends in a plane defined by the width dimension and the thickness dimension, and wherein the length of at least one of the plurality of channels is non-parallel to the thickness dimension.

[0024] A nineteenth embodiment comprises the glass forming apparatus of any preceding embodiment, wherein the cooling fluid is an inert gas.

[0025] A twentieth aspect includes the glass forming apparatus of any preceding aspect, wherein the distal end of the outer tube is fixedly attached to the slot block.

[0026] A twenty-first aspect is a glass forming apparatus, a glass feeding device comprising a slot block, wherein molten glass flows through the slot block and is formed into a glass ribbon as it exits an orifice in the slot block, the slot block having a vertical dimension corresponding to the direction of flow of the molten glass, a width dimension orthogonal to the vertical dimension, and a thickness dimension orthogonal to the vertical and width dimensions, the slot block comprising an internal cavity positioned proximate the orifice in the slot block, at least one inlet port in fluid communication with the internal cavity, and at least one outlet port in fluid communication with the internal cavity. and a heat extraction assembly, the heat extraction assembly comprising: a cooling fluid inlet tube connected to at least one inlet port such that an inner lumen of the cooling fluid inlet tube is in fluid communication with the internal cavity; a cooling fluid source fluidly coupled to the cooling fluid inlet tube to thereby supply cooling fluid to the inner lumen of the cooling fluid inlet tube and the internal cavity; and a cooling fluid outlet tube connected to at least one outlet port such that an inner lumen of the cooling fluid outlet tube is in fluid communication with the internal cavity.

[0027] A twenty-second aspect comprises the glass forming apparatus of the twenty-first aspect, wherein the at least one inlet port comprises a single inlet port.

[0028] A twenty-third aspect comprises the glass forming apparatus of the twenty-first or twenty-second aspect, wherein the at least one exit port comprises a single exit port.

[0029] A 24th aspect includes the glass forming apparatus of any one of the 21st to 23rd aspects, wherein the at least one outlet port comprises a plurality of outlet ports, and the cooling fluid outlet tube comprises a plurality of cooling fluid outlet tubes, each corresponding to one of the plurality of outlet ports.

[0030] A twenty-fifth aspect comprises the glass forming apparatus according to any one of the twenty-first to twenty-fourth aspects, wherein at least one of the plurality of cooling fluid outlet tubes is closed.

[0031] A 26th aspect includes the glass forming apparatus of any one of the 21st to 25th aspects, wherein each of the plurality of cooling fluid outlet tubes is provided with a valve that controls the flow of cooling fluid from each of the plurality of cooling fluid outlet tubes.

[0032] Additional features and advantages of the glass forming apparatus disclosed herein are set forth in the detailed description that follows, and in part will be readily apparent to those skilled in the art from the description, or will be learned by practicing the embodiments described herein, including the detailed description that follows, the claims, and the accompanying drawings.

[0033] It is to be understood that both the foregoing general description and the following detailed description are intended to describe various embodiments and provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter.

[0034] The embodiments illustrated in the drawings are exemplary in nature and are not intended to limit the subject matter defined by the claims. The following detailed description of exemplary embodiments can be understood when read in conjunction with the following drawings, in which like structure is indicated with like reference numerals and in which: [Brief explanation of the drawings]

[0035] [Figure 1] 1 illustrates a schematic diagram of a glass manufacturing apparatus for forming a glass ribbon. [Figure 2A] 1 schematically depicts a glass forming apparatus for forming a glass ribbon from molten glass according to one or more embodiments shown and described herein. [Figure 2B]2B schematically depicts a bottom view of the glass forming apparatus of FIG. 2A through line 2B-2B of FIG. 2A, according to one or more embodiments shown and described herein. [Figure 2C] 2C-2C in FIG. 2A is a schematic diagram illustrating a vertical cross section of the glass delivery device of FIGS. 2A and 2B taken through line 2C-2C in FIG. 2A, according to one or more embodiments shown and described herein. [Figure 3A] 2A-2C according to one or more embodiments shown and described herein. [Figure 3B] FIG. 3B is a detailed view of an exhaust channel of the heat extraction assembly of FIG. 3A according to one or more embodiments shown and described herein. [Figure 3C] FIG. 3B is a detailed view of a portion of the heat extraction assembly of FIG. 3A according to one or more embodiments shown and described herein. [Figure 4A] 3B schematically depicts the heat extraction assembly of FIG. 3A engaging with a slot block according to one or more embodiments shown and described herein. [Figure 4B] 4B schematically depicts an insulating insert for use with the heat extraction assembly of FIG. 3A and the cooling channel of FIG. 4A according to one or more embodiments shown and described herein. [Figure 4C] FIG. 4C is a detailed view of an insulating insert positioned within the cooling channel of FIG. 4B according to one or more embodiments shown and described herein. [Figure 5] 10A and 10B schematically depict a slot block of a glass feeding device with an internal cavity for use with an alternative heat extraction assembly according to an embodiment shown and described herein. [Figure 6] 1 graphically depicts the relationship between cooling fluid flow rate (X-axis) and glass ribbon width (Y-axis) according to one or more embodiments shown and described herein. [Figure 7] The standard deviation of the left and right bead positions when subjected to different flow rates of cooling fluid is plotted. [Figure 8]10 graphically depicts the relationship between variations in sheet width and the rate at which cooling fluid is introduced into the channels. [Figure 9] 10 graphically depicts thermal modeling calculation results of channel position versus slot orifice corner radius. DETAILED DESCRIPTION OF THE INVENTION

[0036] Reference will now be made in detail to embodiments of a heat extraction assembly for a glass forming apparatus, and a glass forming apparatus comprising the same, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. One embodiment of a heat extraction assembly is depicted schematically in FIG. 3A . The heat extraction assembly may include an outer tube and an inner tube extending within the outer lumen of the outer tube. A distal end of the outer tube is connected to a channel formed in a slot block of the glass forming apparatus, and the inner tube is positioned within the outer tube to deliver a cooling fluid to the channel, thereby extracting heat from the slot block. Various embodiments of the heat extraction assembly, a glass forming apparatus comprising the same, and a method for using the heat extraction assembly to produce a glass ribbon are described herein with specific reference to the accompanying drawings.

[0037] Ranges can be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0038] Directional terms used herein, e.g., up, down, right, left, front, back, top, bottom, are for reference only as depicted in the figures and are not intended to imply absolute orientation. The terms "proximal" and "distal" are defined herein with respect to the slot orifice in the slot block of the glass forming apparatus. The term "distal" refers to the location of an element closer to the slot orifice, and the term "proximal" refers to the location of an element further from the slot orifice.

[0039] Unless otherwise expressly stated, it is in no way intended that any method described herein be construed as requiring its steps to be performed in a particular order, or that any apparatus require a particular orientation. Thus, where a method claim does not actually recite an order to be followed, or where any apparatus claim does not actually recite an order or orientation for individual components, or where a claim or description otherwise specifically states that the steps are to be limited to a particular order or that no particular order or orientation for the apparatus components is recited, no order or orientation is intended to be inferred in any respect. This applies to any possible implicit basis for interpretation, including logical considerations relative to the arrangement of steps, operational flow, component order, or component orientation, any apparent meaning derived from grammatical construction or punctuation, and the number or type of embodiments described in the specification.

[0040] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component" includes aspects having two or more such components unless the context clearly dictates otherwise.

[0041] 1 , by way of example, an embodiment of a glass manufacturing apparatus 100 for forming a glass ribbon from molten glass is schematically depicted. The glass manufacturing apparatus 100 may include a melter 111, a fining system 113, a mixing vessel 114, a feed vessel 118, and a glass forming apparatus 120. Glass batch materials are introduced into the melter 111 through a batch inlet port 112. The batch materials are melted in the melter 111 to form molten glass 116. The melter 111 is fluidly coupled to the fining system 113 using a connecting tube 115. The molten glass 116 flows from the melter 111, through the connecting tube 115, and into the fining system 113.

[0042] The fining system 113 may include a high temperature processing area that receives the molten glass 116 from the melter 111. Liquefied gas and / or air bubbles are removed from the molten glass 116 while it exits the fining system 113. The fining system 113 may be fluidly coupled to the mixing vessel 114 by a connecting tube 140. That is, the molten glass 116 flowing from the fining system 113 to the mixing vessel 114 may flow through the connecting tube 140. As the molten glass 116 passes through the mixing vessel 114, the molten glass 116 may be agitated to homogenize the molten glass 116. The mixing vessel 114 may in turn be fluidly coupled to a feed vessel 118 by a connecting tube 117, such that the molten glass 116 flowing from the mixing vessel 114 to the feed vessel 118 flows through the connecting tube 117.

[0043] The feed vessel 118 supplies the molten glass 116 to the glass forming apparatus 120 through a downcomer 119. In the embodiments described herein, the glass forming apparatus 120 is a slot draw machine for forming the molten glass 116 into a glass ribbon 123. The glass forming apparatus 120 typically includes a glass feed device 121 having a slot block 122 through which the molten glass 116 flows and is formed into the glass ribbon 123. The glass feed device 121 may include an inlet conduit 124 in fluid communication with an inlet orifice of the slot block 122, and the downcomer 119 may be positioned to deliver the molten glass 116 from the feed vessel 118 to the inlet conduit 124 of the glass feed device 121. In embodiments, the downcomer 119 may fit within an inner surface of the inlet conduit 124 and is spaced apart from the inner surface of the inlet conduit 124.

[0044] The slot block 122 of the glass feed device 121 includes a slot orifice 125 from which the glass ribbon 123 flows in a continuous ribbon in a flow direction 126 and proceeds into an annealing region 127. The slot block 122 includes a lip 128 at a lower end of the slot block 122, and the slot orifice 125 is provided within the lip 128. The slot orifice 125 may be elongated and generally rectangular in cross section with semicircular or rounded edges corresponding to the edges 123 a, 123 b of the glass ribbon 123 formed therewith. The glass feed device 121 defines a passage 129 through which the molten glass 116 can accumulate and then be discharged from the slot orifice 125 in the form of a glass ribbon 123 having a width W measured between the edges 123 a, 123 b of the glass ribbon 123. The glass feeding device 121, including the lip 128, and the slot block 122 may be fabricated from a refractory metal such as platinum or a platinum alloy. Also, although not illustrated in FIG. 1 , the glass manufacturing apparatus 100 may include additional components positioned downstream of the glass feeding device 121. For example, an annealing device and a glass separating device may be provided downstream of the glass forming apparatus 120 in the flow direction 126 to separate the glass ribbon 123 into individual glass sheets.

[0045] In a conventional glass feeding device 121 including a slot block 122, the glass ribbon 123 exiting the slot block 122 may exhibit stability issues, such as ribbon sagging (side-to-side ribbon movement) and variations in the width W of the glass ribbon 123 (hereinafter, "sheet width variation"). These stability issues may result from non-uniform thermal properties of the glass ribbon 123 as it exits the slot block 122. These non-uniform thermal properties may adversely affect the dimensional properties of the glass ribbon 123, which in turn adversely affect the quality of the glass ribbon 123. Heat extraction may be utilized to control the stability of the glass ribbon 123, thereby minimizing ribbon sagging and sheet width variation, so that the glass ribbon 123 dispensed from the slot block 122 exhibits suitable dimensional properties (or quality).

[0046] For example, in a conventional glass feed device 121, such as that depicted schematically in FIG. 1 , water-cooled fingers 150, 152 may be utilized to extract heat from the glass ribbon 123 as it passes through the slot block 122 of the glass feed device 121. The water-cooled fingers 150, 152 may be made from the same material as the slot block 122 and may be positioned in contact with (e.g., abut) the exterior surface of the lip 128 so that heat is extracted through the material of the lip 128 and into the water-cooled fingers 150, 152, which then exchange heat with water flowing through the water-cooled fingers 150, 152. However, it has proven difficult to establish a good thermal bond between the water-cooled fingers 150, 152 and the lip 128 to efficiently extract heat from the glass ribbon 123. For example, the water-cooled fingers may not be sufficiently thermally coupled with the exterior surface of the lip 128, affecting the ability of the water-cooled fingers 150, 152 to extract a desired amount of heat from the slot block 122. Furthermore, the surfaces of the water-cooled fingers 150, 152 and / or the exterior surface of the lip 128 may be subject to oxidation. The buildup of an oxide layer between the water-cooled fingers 150, 152 and the lip 128 may act as a thermal barrier that prevents heat extraction by the water-cooled fingers 150, 152. Not only does oxidation prevent heat extraction, but oxidation may eventually require replacement of the slot block 122, which can be expensive and time-consuming and may reduce production yields because the glass manufacturing apparatus 100 may be shut down for extended periods of time to facilitate repair and / or replacement.

[0047] Disclosed herein is a glass forming apparatus including a heat extraction assembly that can alleviate the aforementioned problems. In the described embodiment, the slot block of the glass forming apparatus includes a channel molded therein adjacent to the slot orifice. The heat extraction assembly can be thermally coupled to the channel for introducing a cooling fluid into the channel. The glass forming apparatus including the heat extraction assembly described herein can improve sheet width variation and ribbon deflection by providing localized heat extraction within the channel molded in proximity to the slot orifice.

[0048] 2A-2C, FIG. 2A schematically depicts a glass forming apparatus 200 for forming a glass ribbon 123 from molten glass 116. In the embodiments described herein, the glass forming apparatus 200 is a slot drawing machine generally including a slot block 204 and a glass feed device 221 comprising a heat extraction assembly 400. FIG. 2B is a bottom view of the slot block 204 taken along line 2B-2B in FIG. 2A, and FIG. 2C is a cross-sectional view of a portion of the slot block 204 and the glass feed device 221 taken along line 2C-2C in FIG. 2A. The slot block 204 includes a vertical dimension in the direction of the Z-axis of the coordinate axes depicted in the figures, a width dimension in the direction of the X-axis of the coordinate axes depicted in the figures, and a thickness dimension in the direction of the Y-axis of the coordinate axes depicted in the figures. The vertical dimension generally corresponds to the flow direction 126. The width dimension is perpendicular to the vertical dimension, and the width W of the glass ribbon 123 can be measured in terms of the width dimension. The thickness dimension is orthogonal to the vertical and width dimensions, and the thickness of the glass ribbon 123 (ie, the measurement between opposing surfaces of the glass ribbon 123) may be evaluated in the thickness dimension.

[0049] The glass forming apparatus 200 generally includes a glass feed device 221 having a slot block 204 through which molten glass flows and is formed into the glass ribbon 123. The glass feed device 221 may include an inlet conduit 203 in fluid communication with an inlet orifice (not shown) of the slot block 204 such that molten glass flowing through the inlet conduit 203 flows through the glass feed device 221 and into the slot block 204. The inlet conduit 203 is thus fluidly coupled to the downcomer 119 ( FIG. 1 ), as described herein, such that the inlet conduit 203 receives molten glass from the feed vessel 118.

[0050] The slot block 204 of the glass feed device 221 includes a slot orifice 206 from which the glass ribbon 123 discharges as a continuous glass ribbon in the flow direction 126. The slot block 204 includes a lip 228 at a lower end of the slot block 204, and the slot orifice 206 is provided within the lip 128. The slot orifice 206 may be an elongated shape that is generally rectangular in cross section with semicircular or rounded edges corresponding to the edges 123 a, 123 b of the glass ribbon 123. The glass feed device 221 defines a passageway 208 within which the molten glass 116 from the inlet conduit 203 accumulates and can then be discharged from the slot orifice 206 as a glass ribbon 123 having a width W measured between the edges 123 a, 123 b of the glass ribbon 123. The glass delivery device 221, including the lip 228, and the slot block 204 may be fabricated from a refractory metal such as platinum or a platinum alloy.

[0051] In the embodiment of the glass forming apparatus 200 described herein, the slot block 204 of the glass feeding device 221 includes at least one channel 201 (e.g., multiple channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, 201j, etc.) into which a cooling fluid is introduced to facilitate heat extraction from the slot block 204 and the molten glass flowing through the slot block 204. As used herein, a reference to "channel 201" refers to any of the channels molded in slot block 204 (e.g., channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, 201j), and a reference to a "channel 201" having a particular alphabetical designation (i.e., channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, 201j) refers to the channel having the particular alphabetical designation. At least one channel 201 is molded in slot block 204 and includes a length L, where the length L of at least one channel 201 defines the distance the corresponding channel extends into the material of slot block 204. The at least one channel 201 can be fabricated internally within the slot block 204 at a desired location, for example, to reduce the distance between the heat extraction point and the interface between the slot orifice 206 and the glass ribbon 123 ejected therefrom. In this arrangement, heat transfer occurs between the cooling fluid and the surface within the at least one channel 201 through which the cooling fluid flows, which provides a better heat transfer interface compared to the water-cooled fingers 150, 152, which exchange heat at a solid-to-solid interface. That is, contact between the cooling fluid and the surface of the at least one channel 201 is more consistent and repeatable compared to the solid-to-solid interface of the water-cooled fingers 150, 152 depicted in FIG. 1 . Furthermore, fabricating the at least one channel 201 within the slot block 204 ensures that the point of heat extraction is consistent over time. Furthermore, the heat extraction assembly 400 described herein allows for adjustment of the flow of the cooling fluid to achieve the desired heat extraction.Additionally, the type of cooling fluid utilized may be selected to prevent or mitigate oxidation within the at least one channel 201, thereby maintaining heat transfer (i.e., an expected amount unaffected by oxidation) at the surface of the at least one channel 201 throughout the life of the slot block 204 and / or lip 228.

[0052] 2A , a heat extraction assembly 400 is shown coupled to channel 201f. While FIG. 2A depicts heat extraction assembly 400 coupled to channel 201f, an individual heat extraction assembly may be coupled to each of the channels formed in slot block 204. Heat extraction assembly 400 injects cooling fluid into channel 201f, and the cooling fluid interacts with the material of slot block 204 (including lip 228) at the forming temperature of glass ribbon 123. Such interaction results in heat exchange from the glass ribbon 123, through the material of slot block 204, to the cooling fluid, thereby increasing the temperature of the cooling fluid and decreasing the temperature of slot block 204, lip 228, and glass ribbon 123. That is, heat from the glass ribbon 123 exiting the slot orifice 206 is extracted via thermal conduction with the slot block 204 and the cooling fluid, thereby increasing the viscosity of the glass ribbon 123, and localizing the heat extraction to the edges of the slot orifice 206 adjacent the edges 123 a, 123 b of the glass ribbon 123. Such increased viscosity provides edge flow stability, reducing the occurrence of ribbon deflection and sheet width variations.

[0053] 2A, the heat extraction assemblies 400 are shown extending at an angle relative to the vertical dimension. In this manner, the heat extraction assemblies 400 are coupled to the corresponding channels 201f while avoiding interference with other components of the glass manufacturing apparatus 100 and / or glass forming apparatus 200, such as the annealing region 127. However, the heat extraction assemblies 400 may extend at other angles, such as parallel or perpendicular to the flow direction 126, and the corresponding channels may extend in the same direction within the slot block 204. Also, if multiple heat extraction assemblies 400 are utilized, they may each extend at the same angle.

[0054] The heat extraction assemblies 400 may be provided in pairs. In embodiments, a second heat extraction assembly similar to heat extraction assembly 400 may also be coupled to channel 201i, such that a first pair of heat extraction assemblies (each similar to heat extraction assembly 400) is provided in channels 201f, 201i. In addition to or instead of providing a first pair of heat extraction assemblies in channels 201f, 201i, a second pair of heat extraction assemblies (each similar to heat extraction assembly 400) may be provided in channels 201e, 201h, a third pair of heat extraction assemblies (each similar to heat extraction assembly 400) may be provided in channels 201g, 201j, a fourth pair of heat extraction assemblies (each similar to heat extraction assembly 400) may be provided in channels 201a, 201c, and / or a fifth pair of heat extraction assemblies (each similar to heat extraction assembly 400) may be provided in channels 201b, 201d. When a single pair of heat extraction assemblies 400 is utilized, they may each extend at the same angle. For example, the heat extraction assembly 400 coupled to channel 201f and the heat extraction assembly 400 coupled to channel 201i may extend at the same angle. When two or more pairs of heat extraction assemblies 400 are utilized, all of the heat extraction assemblies 400 may extend at the same angle, or at least one pair of heat extraction assemblies 400 may extend at a different angle. For example, the heat extraction assemblies 400 coupled to channels 201a, 201c may extend at a first angle, and the heat extraction assemblies 400 coupled to channels 201b, 201d may be oriented differently such that they extend at a second angle different from the first angle. Thus, as described further herein, a heat extraction assembly 400 may be coupled to any one or more of at least one channel 201 and may extend in various orientations.

[0055] 2B, a plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j are molded into a bottom surface 202 of a slot block 204. The plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j are positioned at various locations relative to a slot orifice 206. The slot orifice 206 includes a width axis 212′ parallel to the width dimension of the slot block 204, and the width of the slot orifice 206 is measured along the width axis 212′. The slot orifice 206 also includes a thickness axis 214′ parallel to the thickness dimension, and the thickness of the slot orifice 206 is measured along the thickness axis 214′. The width axis 212' and the thickness axis 214' bisect the width and thickness, respectively, of the slot orifice 206. Additionally, a vertical axis 210', which extends parallel to the vertical dimension, is at the intersection of the width axis 212' and the thickness axis 214'.

[0056] The location and orientation of the plurality of channels 201 a, 201 b, 201 c, 201 d, 201 e, 201 f, 201 g, 201 h, 201 i, 201 j, as well as the number and distribution of the channels, may be selected based on the desired heat extraction and / or temperature profile desired to be achieved in the slot block 204 for a particular application. Additionally, the orientation, number, and distribution of the channels 201 may be selected to control the thickness and / or width W of the glass ribbon 123 exiting the slot orifice 206. Thermal modeling and testing may be performed to determine how many channels 201 will be utilized in a particular application, where the channels 201 are located relative to the slot orifice 206, and the orientation or channels 201 relative to the slot orifice 206. Thus, the channels 201 may be shaped as desired to achieve the desired heat extraction and / or temperature profile within the slot block 204 during operation.

[0057] 2B , the plurality of channels 201 a, 201 b, 201 c, 201 d, 201 e, 201 f, 201 g, 201 h, 201 i, and 201 j are each positioned relative to a slotted orifice 206 such that localized heat extraction occurs adjacent to or at edges 240, 242 of the slotted orifice 206. Here, the edges 240, 242 of the slotted orifice 206 are each semicircular in shape and defined by a corner radius, with a corner radius axis 244 extending through the corner radius of the edge 240 and a corner radius axis 246 extending through the corner radius of the edge 242. The corner radius axes 244, 246 bisect a circle formed by rotating the radii of the edges 240, 242 360 degrees. The corner radius axes 244, 246 are parallel to the thickness axis 214′. Additionally, each of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j is positioned on either the first side 230 or the second side 232 of the slot block 204 along an axis parallel to the width axis 212′ and is offset from the corner radius axes 244, 246 toward the thickness axis 214′ of the slot orifice 206.

[0058] In the illustrated embodiment, each of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j is provided at a midpoint between the slot orifice 206 and the peripheral sidewall 216 of the slot block 204. Specifically, each of the channels 201e, 201f, 201g, 201h, 201i, and 201j is formed at a midpoint between the first inner wall 270 of the slot orifice 206 and the first side 230 of the peripheral sidewall 216, such that the glass ribbon 123 contacts the first inner wall 270 during forming. Similarly, channels 201 a, 201 b, 201 c, 201 d are each formed at a midpoint between second interior wall 272 of slot orifice 206 and second side 232 of peripheral sidewall 216, with glass ribbon 123 also contacting second interior wall 272 during forming. However, any one or more of at least one channel 201 may be closer or farther from slot orifice 206 depending on the desired heat extraction at the particular location.

[0059] In the illustrated embodiment, channel 201e may be offset from its associated corner radius axis 244 toward the thickness axis 214' by approximately 5 millimeters (mm), channel 201f may be offset from its associated corner radius axis 244 toward the thickness axis 214' by approximately 17.5 mm, and channel 201g may be offset from its associated corner radius axis 244 toward the thickness axis 214' by approximately 30 mm. In this embodiment, channels 201h, 201i, and 201j are symmetrical about the thickness axis 214' with channels 201e, 201f, and 201g, respectively. Thus, channel 201h may be offset from the corner radius axis 246 toward the thickness axis 214' by approximately 5 mm, channel 201i may be offset from the corner radius axis 246 toward the thickness axis 214' by approximately 17.5 mm, and channel 201j may be offset from the corner radius axis 246 toward the thickness axis 214' by approximately 30 mm. Also, in the illustrated embodiment, channel 201a may be offset from corner radius axis 244 toward thickness axis 214' by approximately 10 mm, and channel 201b may be offset from corner radius axis 244 toward thickness axis 214' by approximately 25 mm. In this embodiment, channels 201c and 201d are symmetrical about thickness axis 214' with respect to channels 201a and 201b, respectively. Thus, channel 201c may be offset from corner radius axis 246 toward thickness axis 214' by approximately 10 mm, and channel 201d may be offset from corner radius axis 246 toward thickness axis 214' by approximately 25 mm. However, while FIG. 2B illustrates an example number and relative positions of channels 201, other numbers and relative positions of channels 201 are contemplated and possible based on the heat extraction and temperature profile desired for a particular application.

[0060] In the illustrated embodiment, each of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j can extend in a plane defined by a vertical dimension and a width dimension (i.e., the XZ plane of the coordinate axes depicted in the figures). As described herein, the length L of each of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j corresponds to the distance the channel extends into the material of the slot block 204 in a direction corresponding to the long axis of the channel. In the depicted embodiment, the length L of each of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j is non-parallel to the vertical dimension. Specifically, in the illustrated embodiment, each of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j is oriented with respect to the bottom surface 202 of the slot block 204 such that each channel extends at a non-zero angle with respect to a vertical dimension in the XZ plane. In the illustrated embodiment, each of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j is oriented at a 45 degree angle with respect to a vertical dimension in the XZ plane. However, any one or more of the channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, 201j may extend into the bottom surface 202 of the slot block 204 at a different angle.

[0061] However, any one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may be oriented at an angle different from the angle of the channels illustrated in Figure 2B. For example, in embodiments, any one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may be parallel to the vertical dimension (i.e., parallel to the Z-axis of the coordinate system depicted in the figure). In other embodiments, one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j can extend in a plane defined by the vertical dimension and the thickness dimension (i.e., in the YZ plane of the coordinate system depicted in the figures), and the length L of the channel is non-parallel to the vertical dimension of the slot block 204 (i.e., non-parallel to the Z axis of the coordinate system depicted in the figures). In other embodiments, one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j can be oriented in a plane defined in part by the vertical dimension such that the channel is non-parallel to both the XZ and YZ planes of the coordinate system depicted in the figures.

[0062] In embodiments, at least one channel 201 may be provided on the first peripheral side 234 and / or the second peripheral side 236 of the slot block 204. For example, at least one channel 201 may be molded into the bottom surface 202 on the first peripheral side 234 and / or the second peripheral side 236, and such channel may extend in a plane defined by the vertical dimension (i.e., the Z axis of the coordinate system depicted in the drawings) and the thickness dimension (i.e., the Y axis of the coordinate system depicted in the drawings), and / or in a plane defined by the vertical dimension (i.e., the Z axis of the coordinate system depicted in the drawings) and the width dimension (i.e., the X axis of the coordinate system depicted in the drawings), and in such examples, any or all of the channels may be parallel or non-parallel to the vertical dimension (i.e., the Z axis of the coordinate system depicted in the drawings). In some examples, the channels may extend into the bottom surface 202 in the XZ plane along the width axis 212′ and / or may be laterally offset from the width axis 212′ (i.e., toward the first side 230 and / or the second side 232). In some examples, the channels may extend into the bottom surface 202 at locations proximate the first peripheral side 234 and / or the second peripheral side 236 and may extend toward the edges 240, 242 of the slot orifice 206 in various orientations non-parallel to the width axis 212′.

[0063] Additionally or alternatively to the above-described embodiments, any one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may be molded into the peripheral sidewall 216 of the slot block 204. For example, one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may extend in the XY plane of the coordinate axes depicted in the figures, such that one or more channels are oriented horizontally. In these embodiments, the length L of at least one channel 201 may be oriented parallel to the thickness axis 214′, as indicated by arrows 218a and 218b, such that the channel extends through the peripheral sidewall 216 toward the slot orifice 206. Any of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may be oriented as shown by arrows 218a and 218b, although it will be understood that they may be offset from the thickness axis 214′ by various distances, as may be determined by thermal modeling and testing. In an embodiment, one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may extend horizontally in the XY plane of the coordinate axes depicted in the figure, and the length L of at least one channel 201 is non-parallel to the thickness axis 214′. In these embodiments, the channels may extend within the peripheral sidewall 216 in a horizontal orientation, as indicated by, for example, any one or more of arrows 219a, 219b, 219c, 219d. It will be understood that arrows 219a, 219b are exemplary and that one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, 201j may be oriented at different angles and / or offset at various other distances from the thickness axis 214′, as may be determined by thermal modeling and testing.As indicated by arrows 219c and 219d, in embodiments, one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may extend horizontally within the XY plane of the coordinate axes depicted in the figure, and the length L of at least one channel 201 is parallel to the width axis 212′ such that the channel extends horizontally as indicated by arrows 219c and 219d. However, arrows 219c and 219d are exemplary, and one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may be offset from (and on either side of) the width axis 212′ by various other distances, as may be determined by thermal modeling and testing. In still other embodiments, any one or more of the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, 201j may be molded into the peripheral sidewall 216 but extend either downwardly toward the bottom surface 202 or upwardly away from the bottom surface 202 (i.e., extend in a direction outside the XY plane of the coordinate axes depicted in the drawings).

[0064] In an embodiment, the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may be arranged into channel sets. In the illustrated embodiment, the plurality of channels 201a, 201b, 201c, 201d, 201e, 201f, 201g, 201h, 201i, and 201j may include a first channel set 220, a second channel set 222, a third channel set 224, and a fourth channel set 226. Here, a first set of channels 220 includes channels 201e, 201f, and 201g positioned gradually away from the corner radius axis 244, a second set of channels 222 includes channels 201h, 201i, and 201j positioned gradually away from the corner radius axis 246, a third set of channels 224 includes channels 201a and 201b positioned gradually away from the corner radius axis 244, and a fourth set of channels 226 includes channels 201c and 201d positioned gradually away from the corner radius axis 244. The first set of channels 220 and the second set of channels 220 are positioned on a first side 230 of the slot block 204, and the third set of channels 224 and the fourth set of channels 226 are positioned on a second side 232 of the slot block 204, such that the first set of channels 220 and the second set of channels 220 are positioned on opposite sides of the width axis 212′ from the third set of channels 224 and the fourth set of channels 226. The first set of channels 220 and the third set of channels 224 are also positioned on opposite sides of the thickness axis 214′ from the second set of channels 222 and the fourth set of channels 226. The first set of channels 220 and the third set of channels 224 are also positioned symmetrically on opposite sides of the thickness axis 214′, and the second set of channels 222 and the fourth set of channels 226 are also positioned symmetrically on opposite sides of the thickness axis 214′. In an embodiment, individual channels within each set of channels may be utilized in conjunction with other channels within the set to achieve a desired heat extraction in a portion of slot block 204 .For example, the flow of cooling fluid in each channel in a set of channels may be controlled in the same manner as the other channels in the set to achieve a desired heat extraction profile along a portion of the slot block 204. Alternatively, the flow of cooling fluid in individual channels in each set of channels may be controlled independently to achieve a desired heat extraction profile along a portion of the slot block 204. However, it will be understood that Figure 2B illustrates only a few example groupings of channels, and that other groupings of channels may be utilized to achieve a particular heat extraction or temperature profile.

[0065] 2C, which schematically depicts a heat extraction assembly 400 coupled to a channel 201f. As described further herein, a cooling fluid is discharged from the heat extraction assembly 400 and introduced into the channel 201f for the purpose of extracting heat from the material of the slot block 204 and, in turn, from the glass ribbon 123 discharged from the slot block 204. In the embodiment illustrated in FIG. 2C, the channel 201f includes an open end 320 molded into the bottom surface 202 of the slot block 204, a closed end 322 opposite the open end 320, and a sidewall 330 extending between the open end 320 and the closed end 322. The channel 201f is molded with sufficient length such that, when measured in the vertical dimension, the closed end 322 of the channel 201f is spaced a distance 312 from the bottom surface 202 of the slot block 204.

[0066] The closed end 322 of the channel 201f defines a surface that provides an interface for heat transfer between the slot block 204 and the cooling fluid delivered by the heat extraction assembly 400. The sidewall 330 also defines a surface, and in some embodiments, at least a portion of the sidewall 330 is also contacted by the cooling fluid and also serves as an interface for heat transfer. The heat extraction assembly 400 includes an outer tube 402 coupled to the channel 102f and an inner tube 410 extending within the outer tube 402 and discharging the cooling fluid into the channel 102f. In some embodiments, the distal end 404 of the outer tube 402 may extend into the channel 201f such that the outer tube 402 is attached to the sidewall 330 of the channel 201f. In some of these embodiments, the distal end 404 of the outer tube 402 is fully inserted into the channel 201f, such that only the closed end 322 of the channel 201f is exposed to the cooling fluid injected by the inner tube 410 (e.g., the sidewall 330 is covered by the distal end 404 of the outer tube 402), while in other embodiments, the distal end 404 of the outer tube 402 is only partially inserted into the channel 201f, such that the closed end 322 of the channel 201f and a portion of the sidewall 330 are exposed to the cooling fluid, thereby facilitating greater heat extraction from the material of the slot block 204. In yet other embodiments, the distal end 404 of the outer tube 402 can be attached to the channel 201f at the open end 320 of the channel 201f in the bottom surface 202 of the slot block 204, such that the entire sidewall 330 and the closed end 322 of the channel 201f are exposed to the cooling fluid, thereby facilitating even greater heat extraction from the material of the slot block 204. Also, as described in more detail herein, the inner tube 410 of the heat extraction assembly 400 is positionable relative to the outer tube 402 and the closed end 322 of the channel 201f to further control how the cooling fluid is distributed over the surface area of ​​the channel 201f.For example, a portion of the inner tube 410 of the heat extraction assembly 400 may be at least partially inserted into the channel 201f so that cooling fluid discharged therefrom is focused onto a particular surface within the channel 201f (e.g., the closed end 322 of the channel 201f). Alternatively, the inner tube 410 may be retracted therefrom to diffuse the cooling fluid injection so that the cooling fluid is distributed over a relatively large surface within the channel 201f (e.g., over the closed end 322 and at least a portion of the sidewall 330 of the channel 201f). Thus, heat extraction is generally increased by positioning the inner tube 410 closer to the closed end 322 of the channel 201f. However, positioning the inner tube 410 too close to the closed end 322 of the channel 201f increases backpressure within the channel 201f, and positioning the inner tube 410 too close to the closed end 322 of the channel 201f may make it difficult to achieve desired heat extraction. Regardless of how much surface area within channel 201f is exposed to the cooling fluid, the contact between the cooling fluid and the surface area of ​​channel 201f is improved (e.g., more consistent and reproducible) compared to the solid-to-solid interface of the water-cooled fingers described herein.

[0067] In the illustrated embodiment, closed end 322 defines a cone-shaped surface. However, it should be understood that the surface defined by closed end 322 may have other geometries. For example, closed end 322 may define a flat surface, a semicircular surface, etc.

[0068] 3A-3C, FIG. 3A schematically depicts a heat extraction assembly 400 according to one or more embodiments described herein. In the illustrated embodiment, the heat extraction assembly 400 includes an outer tube 402 having a distal end 404 and a proximal end 406. During use, the distal end 404 of the outer tube 402 is secured to a corresponding channel molded in the slot block 204, for example, as depicted in FIG. 2C. Various means may be utilized to secure the outer tube 402 to the at least one channel 201, including, but not limited to, welding (including diffusion welding and soldering), utilizing a glass frit material that seals the outer tube 402 to the corresponding channel when heated to the operating temperature of the glass manufacturing apparatus 100, threaded fittings, compression fittings, and the like. In an embodiment, the distal end 404 is secured to the corresponding channel at a separation point that allows an operator to detach and remove the heat extraction assembly 400 from the slot block 204.

[0069] The outer tube 402 defines an outer lumen 408 extending between a distal end 404 and a proximal end 406 of the outer tube 402. The heat extraction assembly 400 also includes an inner tube 410 extending within the outer lumen 408 of the outer tube 402. The inner tube 410 includes a distal end 412 and a proximal end 414. The inner tube 410 is positioned within the outer lumen 408 of the outer tube 402 such that the distal end 412 of the inner tube 410 is positioned adjacent the distal end 404 of the outer tube 402. As shown in FIGS. 3B and 3C, which are detailed views of the inner tube 410 positioned within the outer lumen 408 of the outer tube 402, the outer surface 410' of the inner tube 410 is spaced apart from the inner surface 402' of the outer tube 402 to form an exhaust channel 411 between the inner tube 410 and the outer tube 402. 3C , the inner tube 410 includes an inner lumen 413 extending therethrough between the proximal end 414 and the distal end 412 of the inner tube 410. In the illustrated embodiment, the distal end 412 of the inner tube 410 is open to facilitate the release of cooling fluid from the inner lumen 413 of the inner tube 410. In embodiments, the opening at the distal end 412 of the inner tube 410 may have a contour that facilitates directing the cooling fluid released therefrom. In embodiments, a chamfer may be formed between the opening at the distal end 412 and the sidewall of the inner tube 410 (e.g., by grinding away a distal corner of the inner tube 410), with the inner lumen 413 of the inner tube 410 exposed through the chamfer such that cooling fluid may be directed from the chamfer of the inner tube 410. In an embodiment, a chamfer may be molded into the inner tube 410 such that it is oriented toward or facing the bottom surface 202 of the slot block 204 .

[0070] Referring again to FIG. 3A , in the illustrated embodiment, a cooling fluid source 420 is fluidly coupled to the inner tube 410, thereby supplying cooling fluid to the inner lumen 413 ( FIG. 3C ) of the inner tube 410. The cooling fluid may be circulated from the cooling fluid source 420 through the inner lumen 413 of the inner tube 410 to the channels 201 of the slot block 204 ( FIGS. 2A-2C ) and exhausted from the channels 201 of the slot block 204 through an exhaust channel 411 molded between the inner tube 410 and the outer tube 402 within the outer lumen 408 of the outer tube 402. As depicted in FIG. 3A , a fitting 422 may be provided at the proximal end 414 of the inner tube 410, and the cooling fluid source 420 may be coupled to the fitting 422 via a conduit 424, such as a hose. In an embodiment, the cooling fluid supplied by the cooling fluid source 420 is a gas or a liquid. In an embodiment, the cooling fluid may be an inert gas that helps prevent oxidation within the at least one channel 201. In an embodiment, the inert gas is nitrogen or argon. In an embodiment, the cooling fluid may be liquid water or another liquid coolant. A pressure sensor 425 may also be provided to measure the pressure of the cooling fluid supplied to the inner lumen 413 of the inner tube 410. In an embodiment, the pressure sensor 425 is a pressure transducer.

[0071] In embodiments, the rate at which cooling fluid is supplied by cooling fluid source 420 is controllable. For example, cooling fluid source 420 may include a variable speed pump and / or valve operable to control the rate at which cooling fluid is supplied to inner tube 410. In embodiments, the rate at which cooling fluid is supplied may be between 0 standard liters per minute ("slpm") and 100 slpm. In embodiments, the rate at which cooling fluid is supplied is up to 80 slpm, or even up to 60 slpm. In embodiments, the rate at which cooling fluid is supplied is selected to achieve a desired temperature profile within slot block 204.

[0072] In embodiments, the heat extraction assembly 400 may include a cooling fluid temperature sensor 426 operable to measure the temperature at which the cooling fluid is supplied to the inner tube 410 (i.e., the inlet temperature of the cooling fluid). In embodiments, the cooling fluid temperature sensor 426 may be positioned at the cooling fluid source 420, although it should be understood that the cooling fluid temperature sensor 426 may be located elsewhere. For example, in embodiments, the cooling fluid temperature sensor 426 may be integrated within a portion of the conduit 424 or positioned adjacent the proximal end 414 of the inner tube 410. In embodiments, the cooling fluid temperature sensor 426 is a thermocouple.

[0073] In embodiments, the inner tube 410 and the outer tube 402 may be designed to control the pressure and / or velocity of the cooling fluid when introduced into the channels 201 in the slot block 204. For example, the inner diameter of the inner tube 410 and the inner diameter of the outer tube 402 may be selected to have a particular ratio, with the ratio of the inner diameters controlling the pressure and / or velocity of the cooling fluid introduced into the corresponding channels. For example, in embodiments, the cooling fluid may have a pressure of up to approximately 586 kilopascals (“kPa”). Because the flow rate of the cooling fluid into the channels 201 depends on the inner diameter of the inner tube 410, increasing the cross-sectional area of ​​the inner lumen 413 of the inner tube 410 allows a greater flow rate of the cooling fluid to be delivered through the inner tube 410. However, the diameter of the outer tube 402 may be selected so that the cross-sectional area of ​​the exhaust channel 411 is large enough to exhaust the cooling fluid and minimize (or maintain) the backpressure created in the channels 201 to a level that does not adversely affect heat extraction. In an embodiment, the cross-sectional area of ​​the exhaust channel 411 is larger than the cross-sectional area of ​​the inner lumen 413 of the inner tube 410 .

[0074] In embodiments, the heat extraction assembly 400 may also include a housing 430 that defines an internal channel 432. In the illustrated embodiment, the outer tube 402 is connected to the housing 430 such that the outer lumen 408 of the outer tube 402 is in fluid communication with the internal channel 432 of the housing 430. In this embodiment, the proximal end 406 of the outer tube 402 may extend into a corresponding bore 431 molded in the distal end 433 of the housing 430 such that the outer lumen 408 of the outer tube 402 is in fluid communication with the internal channel 432. In this embodiment, the inner tube 410 passes through the internal channel 432 of the housing 430.

[0075] The heat extraction assembly 400 may further include an exhaust manifold 434 including an exhaust lumen 436. The exhaust manifold 434 is fluidly coupled to the interior channel 432 of the housing 430 such that the exhaust lumen 436 of the exhaust manifold 434 is in fluid communication with the interior channel 432 of the housing 430. During operation, the cooling fluid source 420 supplies cooling fluid to the interior lumen 413 of the inner tube 410, which then directs the cooling fluid into contact with the surfaces of corresponding channels molded in the slot block 204, as described herein. The cooling fluid is then exhausted from the heat extraction assembly 400 via the outer tube 402, specifically through the exhaust channel 411 molded between the inner tube 410 and the outer tube 402, into the interior channel 432 of the housing 430, through the exhaust inner lumen 436 of the exhaust manifold 434, and out of the interior channel 432 of the housing. That is, the exhaust manifold 434 is fluidly coupled to the outer lumen 408 of the outer tube 402 for exhausting cooling fluid from the outer lumen 408, and specifically through exhaust channels 411 molded between the inner surface 402' of the outer tube 402 and the outer surface 410' of the inner tube 410.

[0076] The heat extraction assembly 400 may include an exhaust temperature sensor 460 for measuring the temperature of the cooling fluid exhausted by the heat extraction assembly 400 (i.e., the outlet temperature of the cooling fluid). In embodiments, the exhaust temperature sensor 460 may be operably coupled to the exhaust manifold 434, for example, to measure the temperature of the cooling fluid as it is exhausted through the exhaust lumen 436. In embodiments, an exhaust apparatus 462 is provided in fluid communication with the exhaust lumen 436, such that the exhaust apparatus 462 receives the exhausted cooling fluid. The exhaust apparatus 462 may be coupled to the exhaust manifold 434 via a conduit 464, such as a hose. In embodiments, the exhaust temperature sensor 460 is positioned within the exhaust lumen 436 of the exhaust manifold 434, such that the exhaust temperature sensor 460 measures the temperature of the cooling fluid within the exhaust lumen 436. In other embodiments, the exhaust temperature sensor 460 may be positioned within the exhaust apparatus 462, or the exhaust temperature sensor 460 may be positioned on the conduit 464 to measure the temperature of the cooling fluid within that lumen. In other embodiments, an exhaust temperature sensor 460 may be positioned on the housing 430 to measure the temperature of the cooling fluid within the interior channel 432 of the housing 430. In an embodiment, the exhaust temperature sensor 460 is a thermocouple.

[0077] In an embodiment, at least a portion of the exterior surface of the outer tube 402 is insulated to minimize or eliminate the effect of the ambient temperature outside the outer tube 402 on the cooling fluid as it is discharged. In an embodiment, a portion of the outer tube 402 may be covered with an insulating sleeve. Similarly, depending on where the discharge temperature sensor 460 is provided, at least a portion of the housing 430, the discharge manifold 434, and / or the conduit 464 may be insulated to minimize or eliminate the effect of the ambient temperature.

[0078] In the illustrated embodiment of the heat extraction assembly 400, the connector 440 may be slidably positioned within the housing 430. The connector 440 may include an internal passageway through which the inner tube 410 extends. Specifically, the connector 440 may be slidably positioned within a connector channel 442 of the housing 430. As described herein, the inner tube 410 extends through the internal channel 432 of the housing 430 and into the internal passageway of the connector 440. In these embodiments, the inner tube 410 is fixedly coupled to the connector 440, thereby slidably adjusting the spacing 446 between the distal end 412 of the inner tube 410 and the distal end 404 of the outer tube 402 by translating the connector 440 along an axis 444 relative to the housing 430. This arrangement allows for coarse adjustment of the distal end 412 of the inner tube 410 relative to the distal end 404 of the outer tube 402, as well as coarse adjustment of the distal end 412 of the inner tube 410 within the corresponding channel of the slot block 204. For example, in embodiments, the connector 440 can be translated within the housing 430 to adjust the relative spacing 446 between the distal end 412 of the inner tube 410 and the distal end 404 of the outer tube 402. In these embodiments, the connector 440 can be translated within the housing 430 such that the distal end 412 of the inner tube 410 protrudes from the distal end 404 of the outer tube 402. Conversely, the connector 440 can also be translated out of the housing 430 to adjust the spacing 446 between the distal end 412 of the inner tube 410 and the distal end 404 of the outer tube 402.

[0079] In embodiments, the inner tube 410 may extend through an internal passageway of the connector 440 such that a proximal end 414 of the inner tube 410 is located proximally from the connector 440 and a distal end 412 of the inner tube 410 is located distally from the connector 440. In other embodiments, the inner tube 410 may be formed from two or more separate tubes, for example, the distal end 412 may be provided on a first tube and the proximal end 414 may be provided on a second tube separate from the first tube, with the proximal end of the first tube and the distal end of the second tube each sealed within the internal passageway of the connector 440, such that the internal passageway fluidly couples the first tube and the second tube.

[0080] In embodiments, connector channel 442 may limit distal movement of connector 440. For example, connector channel 442 may have a larger diameter (or size) than inner channel 432, such that an interface 448 is defined between connector channel 442 and inner channel 432. In this embodiment, connector 440 has a diameter that generally corresponds to the size of connector channel 442 to allow translation of connector 440 within connector channel 442. As connector 440 slides into housing 430 within connector channel 442, connector 440 eventually contacts interface 448, which prevents further movement of connector 440 into housing 430. In embodiments, connector channel 442 is sized such that when distal end 443 of connector 440 contacts interface 448, distal end 412 of inner tube 410 extends from outer lumen 408 of outer tube 402, such that distal end 412 of inner tube 410 protrudes from distal end 404 of outer tube 402. In this manner, distal end 412 of inner tube 410 may extend into channel 201. In embodiments, when distal end 443 of connector 440 contacts interface 448, distal end 412 of inner tube 410 contacts closed end 322 of channel 201f.

[0081] 3A , the housing 430 may include a set screw 450 for locking the connector 440 in place within the housing 430. In the illustrated embodiment, the set screw 450 is threadably inserted into the housing 430 and is operable to lock the connector 440 to the housing 430, thereby preventing further translational movement of the connector 440 when the set screw 450 is rotated in a first rotational direction. Here, rotation of the set screw 450 in an opposite, second rotational direction loosens the set screw 450, thereby allowing translational movement of the connector 440 within the housing 430.

[0082] In the illustrated embodiment, the inner tube 410 is threadably coupled to the connector 440, whereby rotation of the inner tube 410 within and relative to the connector 440 adjusts the spacing 446 between the distal end 412 of the inner tube 410 and the distal end 404 of the outer tube 402. Specifically, the outer surface 454 of the inner tube 410 may include threads 452 that engage with corresponding threads in the internal passageway of the connector 440. The threads 452 and the corresponding threads of the connector 440 may be of a known pitch so that the distance the inner tube 410 translates along the axis 444 can be determined based on the degree to which the inner tube 410 is rotated relative to the connector 440. The threaded interface between the inner tube 410 and the connector 440 allows for fine adjustment of the distal end 412 of the inner tube 410 relative to the distal end 404 of the outer tube 402.

[0083] Based on the above, the heat extraction assembly 400 may include a coarse adjustment mechanism and a fine adjustment mechanism, both of which may be utilized to adjust the relative spacing 446 between the distal end 412 of the inner tube 410 and the distal end 404 of the outer tube 402. Adjusting the relative spacing 446 between the distal end 412 of the inner tube 410 and the distal end 404 of the outer tube 402 may be utilized to adjust how much of the inner surface of the corresponding channel in the slot block 204 is contacted by the cooling fluid emitted from the inner tube 410, and therefore may be used to control the amount of heat extracted from the material of the slot block 204 and the amount of heat extracted from the glass ribbon ejected from the slot block 204. The course adjustment mechanism allows the set screw 450 to be loosened, after which the connector 440 may be translated along the axis 444, thereby moving the inner tube 410 toward the closed end 322 of the at least one channel 201. Once the distal end 412 of the inner tube 410 contacts the closed end 322 of the at least one channel 201 (or some other feature within the at least one channel 201 that prevents further translation), the set screw 450 may be tightened, thereby locking the connector 440 in place, which will later serve as a reference point. The fine adjustment mechanism may then be utilized to precisely position the distal end 412 of the inner tube 410 relative to the closed end 322 of the corresponding channel 201. For example, the inner tube 410 may be rotated a certain number of times relative to the connector 440 to translate the distal end 412 of the inner tube 410, thereby creating the desired spacing 446 for a certain amount of heat extraction. In embodiments, the inner tube 410 can be rotated within the connector 440 by an amount that translates the distal end 412 of the inner tube 410 to a position where the distal end 412 of the inner tube 410 is located 0 mm to 10 mm from the distal end 404 of the outer tube 402, with the distal end 404 of the outer tube 402 located a predetermined distance from the closed end 322 of the at least one channel 201. Thus, the coarse adjustment mechanism allows a user to set a reference point during installation, and the fine adjustment mechanism allows a user to position the distal end 412 of the inner tube 410 at a target position relative to the closed end 322 of the at least one channel 201.The coarse and fine adjustment mechanisms, along with the fixed dimensions of the corresponding channels 201 molded into the slot blocks 204, allow a user to precisely position the heat extraction assembly 400 to achieve a specific amount of heat extraction and then replicate that heat extraction during subsequent use. For example, the coarse adjustment mechanism may be utilized to insert the inner tube 410 further into the channel 201, closer to its closed end 322, thereby increasing heat extraction, and then the fine adjustment mechanism may be utilized to appropriately reposition the inner tube 410 to achieve an acceptable amount of backpressure while maximizing heat extraction.

[0084] In the embodiments described herein, heat extraction may be achieved by injecting cooling fluid into the channel 201 to which the heat extraction assembly 400 is coupled. In embodiments, the amount of heat extraction may be quantified using data captured by the cooling fluid temperature sensor 426 and the discharge temperature sensor 460, where the cooling fluid temperature sensor 426 measures the temperature of the cooling fluid supplied to the inner tube 410 and the discharge temperature sensor 460 measures the temperature of the cooling fluid in the discharge manifold 434. In the illustrated embodiment, a controller 470 may be operably connected to the cooling fluid temperature sensor 426 and the discharge temperature sensor 460. The controller 470 may be programmed to calculate the amount of heat extracted from the slot block 204 based on the temperature of the cooling fluid in the discharge manifold 434 and the temperature of the cooling fluid supplied by the cooling fluid source 420. In embodiments, the controller 470 may be communicatively coupled to the cooling fluid source 420 and may be operable to adjust the flow rate of the cooling fluid supplied by the cooling fluid source 420 based on the calculated heat extraction. For example, controller 470 may be operable to communicate with and control the operation of cooling fluid source 420, such that if controller 470 determines that the calculated heat extraction in at least one channel 201 deviates from the target heat extraction for the corresponding channel 201, controller 470 causes cooling fluid source 420 to adjust the flow rate of cooling fluid, thereby increasing or decreasing heat extraction from the corresponding channel 201 until the calculated heat extraction reaches the target heat extraction. In an embodiment, controller 470 includes a mass flow controller for controlling the flow rate of cooling fluid source 420. In other embodiments, the controller of cooling fluid source 420 may be a mass flow controller.

[0085] In embodiments, controller 470 is communicatively coupled to pressure sensor 425 and is operable to calculate the backpressure in channel 201. The backpressure of the cooling fluid in channel 201 may be calculated based on various operating parameters monitored in real time, such as the flow rate of cooling fluid measured by cooling fluid source 420, the inlet pressure of cooling fluid supplied to inner tube 410 measured by pressure sensor 425, the temperature of cooling fluid entering channel 201 measured by cooling fluid temperature sensor 426, and the temperature of cooling fluid exhausted from channel 201 measured by exhaust temperature sensor 460. Based on the calculated backpressure, an operator may then adjust the position of inner tube 410 within outer tube 402, and in some embodiments, controller 470 is operable to adjust the flow rate of cooling fluid supplied by cooling fluid source 420 based on the calculated backpressure.

[0086] In embodiments, the glass forming apparatus 200 may include a glass ribbon sensor 472 for measuring the width W of the glass ribbon 123. If utilized, the glass ribbon sensor 472 may be positioned to measure the width W of the glass ribbon 123 after the glass ribbon 123 is discharged from the slot block 204. For example, with reference to FIGS. 2A and 3A , the glass ribbon sensor 472 may be positioned downstream of the slot block 204, proximate the annealing region 127, such that the glass ribbon sensor 472 can accurately measure the width W of the glass ribbon 123 as it is discharged from the slot orifice 206. In other embodiments, the glass ribbon sensor 472 may be located downstream of the slot orifice 206 and upstream of the annealing region 127. In embodiments, the glass ribbon sensor 472 may be a thermal camera.

[0087] In an embodiment, controller 470 may be operatively coupled to glass ribbon sensor 472 and operable to adjust the flow rate of cooling fluid supplied by cooling fluid source 420 based on the width W of glass ribbon 123 measured by glass ribbon sensor 472. As previously mentioned, the amount of heat exchange occurring within the plurality of channels 201 depends on the flow rate of cooling fluid supplied by cooling fluid source 420, and controller 470 controls cooling fluid source 420 to achieve the target heat extraction based on feedback from cooling fluid temperature sensor 426 and exhaust temperature sensor 460.

[0088] If the controller 470 determines that the glass ribbon 123 exhibits sheet width variation based on the feedback signal from the glass ribbon sensor 472, the controller 470 may be operable to adjust the heat extraction occurring within the plurality of channels 201 formed within the slot block 204 to control the width W of the glass ribbon 123 in real time. For example, increased heat extraction from the slot block 204 (and therefore the glass ribbon 123 ejected therefrom) corresponds to an increased viscosity of the glass ribbon 123, and the increased viscosity at the edges 123a, 123b of the glass ribbon 123 reduces the amount of attenuation (narrowing) in the width W of the glass ribbon 123. However, too much heat extraction at the edges 123a, 123b of the glass ribbon 123 may narrow the width W of the glass ribbon 123. For example, excessive heat extraction at the edges 240, 242 of the slot orifice 206 may increase the viscosity of the edges 123a, 123b of the glass ribbon 123, causing the molten glass 116 in the slot orifice 206 to effectively freeze proximate the edges 240, 242, which in turn increases flow through the center of the slot orifice 206, making that path the path of least resistance, thereby narrowing the glass ribbon 123. In this manner, the amount of heat extracted from the glass ribbon 123 may be controlled to maintain the width W of the glass ribbon 123 within a desired tolerance. In an embodiment, the controller 470 may be operable to stabilize the glass ribbon 123 by controlling the cooling fluid source 420 based on feedback from the cooling fluid temperature sensor 426, the exhaust temperature sensor 460, and the glass ribbon sensor 472.

[0089] 4A, which schematically depicts a bottom view of an embodiment of a slot block 204 having channels molded therein, according to one or more embodiments. Specifically, FIG. 4A is a partial view of the slot block 204 and slot orifice 206. In the illustrated embodiment, a channel 488 is molded into the material of the slot block 204. The channel 488 is shown extending toward the slot orifice 206. During use, the heat extraction assembly 400 injects a cooling fluid into the channel 488, thereby extracting heat from the slot block 204.

[0090] In the illustrated embodiment, the channel 488 includes a proximal portion 540 closest to the heat extraction assembly 400 (e.g., furthest from the slotted orifice 206) and a distal portion 542 furthest from the heat extraction assembly 400 (e.g., closest to the slotted orifice 206), the distal portion 542 including a closed end 550. In this embodiment, the distal portion 542 of the channel 488 may have a smaller diameter than the proximal portion 540 such that the channel 488 also includes a proximally-facing annular wall 544 defined between the proximal portion 540 and the distal portion 542 of the channel 488.

[0091] The heat extraction assembly 400 may be connected to the channel 488 to facilitate the injection of cooling fluid into the channel 488. Specifically, the outer tube 402 of the heat extraction assembly may be positioned within and secured to the proximal portion 540 of the channel 488, with the distal end 404 of the outer tube 402 abutting a proximally-facing annular wall 544 defined between the proximal and distal portions 540, 542 of the channel 488. The distal end 404 of the outer tube 402 may be secured in a variety of manners, for example, via welding, fittings, threads, or the use of a glass frit material that (when heated) forms a seal between the channel 488 and the outer tube 402.

[0092] In embodiments, the proximal portion 540 of the channel 488 may be of a known length (e.g., the distance between the proximally-facing annular wall 544 and the closed end 550 is known) such that when the distal end 404 of the outer tube 402 abuts the proximally-facing annular wall 544, the distal end 404 of the outer tube 402 is likewise positioned a known distance from the closed end 550 of the channel 488. After the outer tube 402 is secured to the slot block 204, the coarse and fine adjustment mechanisms may be utilized to translate the inner tube 410, thereby adjusting the position of the distal end 412 of the inner tube 410. In the depicted embodiment, the inner tube 410 is adjusted such that the distal end 412 of the inner tube 410 is spaced apart from the closed end 550 of at least one channel 488. Once the distal end 412 of the inner tube 410 is properly positioned, cooling fluid can be injected from the inner lumen 413 of the inner tube 410 into the at least one channel 488 such that heat extraction can occur via forced convection. Embodiments of the channel 488 having a proximally-facing annular wall 544 (defined between a proximal portion 540 of the channel and a distal portion 542 of the channel 488) can be used in conjunction with any of the embodiments of the glass delivery device described herein.

[0093] 4B and 4C, FIG. 4B illustrates an embodiment in which an insulating insert 560 may be utilized to control heat extraction from within the channel 488 of the slot block 204. FIG. 4C illustrates a detailed view of the insulating insert 560 positioned within the channel 488 of FIG. 4B. As shown, the insulating insert 560 may be partially disposed within the channel 488 and partially disposed within the outer tube 402 of the heat extraction assembly 400. In the illustrated embodiment, the insulating insert 560 may include a proximal portion 562 closest to the heat extraction assembly 400 and a distal portion 564 furthest from the heat extraction assembly 400. The distal portion 564 of the insulating insert 560 may be positioned within the distal portion 542 of the channel 488, and the proximal portion 562 of the insulating insert 560 may be positioned within the proximal portion 540 of the channel 488.

[0094] In this embodiment, insulating insert 560 may be generally cylindrical such that proximal portion 562 and distal portion 564 have the same outer diameter. The outer diameter of insulating insert 560 corresponds to the inner diameter of distal portion 542 of channel 488 such that the outer surface of distal portion 564 of insulating insert 560 contacts the inner surface of distal portion 542 of channel 488. However, because proximal portion 540 of channel 488 has a larger diameter than distal portion 542 of channel 488, an annular space is defined between the outer surface of proximal portion 562 of insulating insert 560 and the inner surface of proximal portion 540 of channel 488.

[0095] When the heat extraction assembly 400 is secured to the slot block 204, the distal end 404 of the outer tube 402 is positioned within the proximal portion 540 of the channel 488, with the outer surface of the distal end 404 of the outer tube 402 contacting the inner surface of the proximal portion 540 of the channel 488. Specifically, the distal end 404 of the outer tube 402 is positioned within the annular space defined between the outer surface of the proximal portion 562 of the insulating insert 560 and the inner surface of the proximal portion 540 of the channel 488. The distal end 404 of the outer tube 402 may be permanently or removably connected within the proximal portion 540 of the channel 488 via, for example, welding, a frit material, threads, etc.

[0096] In this embodiment, the proximal portion 562 of the insulating insert 560 extends into the outer tube 402 of the heat extraction assembly 400 such that the proximal portion 562 of the insulating insert 560 can be positioned within the exhaust channel 411 defined between the inner surface 402′ of the outer tube 402 and the outer surface 410′ of the inner tube 410, where the outer surface of the proximal portion 562 of the insulating insert 560 contacts the inner surface 402′ of the outer tube 402. Furthermore, the inner surface of the insulating insert 560 can be spaced apart from the outer surface 410′ of the inner tube 410 such that the insulating insert 560 does not completely occupy the exhaust channel 411, providing clearance for the cooling fluid to drain, as described herein.

[0097] In embodiments, the proximal portion 562 (of the insulating insert 560) is press-fit into the outer lumen 408 of the outer tube 402. In some embodiments, an adhesive is utilized to secure the insulating insert 560 within the outer tube 402. In some embodiments, the outer surface of the proximal portion 562 of the insulating insert 560 may include threads that correspond to threads molded into the outer lumen 408 of the outer tube 402, such that the insulating insert 560 threadably engages the heat extraction assembly 400.

[0098] The insulating insert 560 may be configured to control the direction of heat extraction from the channel 488. In an embodiment, the insulating insert 560 may be at least partially open. For example, one or more openings 561 may be molded into the insulating insert 560, such that when the insulating insert 560 is installed in the channel 488, material of the slot block 204 in the channel 488 is exposed through the one or more openings 561, and cooling fluid may contact the exposed material of the slot block 204. Compared to areas of the channel 488 covered by the insulating insert 560, greater heat extraction may occur in areas of the channel 488 exposed to the cooling fluid. Thus, one or more openings 561 may be molded into the insulating insert 560 to direct or enhance heat extraction in certain areas of the slot block 204 while minimizing heat extraction in other areas of the slot block 204, such as areas where cooling may induce denitration. For example, the one or more openings 561 can be oriented toward the slot orifice 206 and / or the bottom surface 202 of the slot block 204. Orienting the one or more openings 561 toward the bottom surface 202 of the slot block 204 can also reduce the heat of the glass ribbon 123 exiting the slot orifice 206 and can also cool the area below the slot block 204 where a muffle assembly (not shown) may be provided.

[0099] In the illustrated embodiment, the one or more openings 561 of the insulating insert 560 include an open end 566 and an opening 568, where the open end 566 and the opening 568 are molded into the distal portion 564 of the insulating insert 560. In other embodiments, the opening 568 may extend at least partially through the proximal portion 562 of the insulating insert 560, where the open end 566 faces the slot orifice 206 and the opening 568 faces the bottom surface 202 of the slot block 204. Alternatively, the opening 568 may be in the form of a proximally extending gap in the insulating insert 560. Thus, the insulating insert 560 illustrated in Figures 4B and 4C may be configured to provide increased heat extraction and cooling toward a portion of the slot orifice 206 proximate the bottom surface 202 of the slot block 204 and toward the bottom surface 202 of the slot block 204, while relatively reducing heat extraction and cooling toward the top of the slot block 204 (i.e., opposite the bottom surface 202).

[0100] 4B and 4C. For example, insulating insert 560 may include a closed end or a partially closed end, opening 568 may be larger or smaller, proximal portion 562 and / or distal portion 564 may include one or more other openings, proximal portion 562 and / or distal portion 564 may include one or more gaps (e.g., in addition to opening 568), etc. In yet other embodiments, insulating insert 560 may not include any such openings and may completely insulate the entirety of the surfaces within channel 488.

[0101] In embodiments, the insulating insert 560 may be made from a thermal insulating material that, when placed between the cooling fluid and the material of the slot block 204, reduces heat exchange therebetween. Specifically, the insulating insert 560 may be made from a material that has a low thermal conductivity relative to the material of the slot block 204. In embodiments, the insulating insert 560 may be made from a ceramic material, pure silica, quartz, or alumina. The embodiment of the insulating insert 560 depicted in Figures 4B and 4C may be used in conjunction with any of the embodiments of the glass feeding device described herein.

[0102] 5 schematically depicts a bottom view of an embodiment of slot block 204 having an internal cavity 572 molded therein, according to one or more embodiments. Specifically, FIG. 5 illustrates a partial view of slot block 204 and slot orifice 206. In the illustrated embodiment, internal cavity 572 is molded into the material of slot block 204 and extends in its width dimension along slot orifice 206 (e.g., along the X-axis of the coordinate axes depicted in the drawings). During use, heat extraction assembly 570 can inject cooling fluid into internal cavity 572, thereby extracting heat from slot block 204, as described below.

[0103] In the illustrated example, a plurality of ports 574 may be molded into the slot block 204. As shown, the plurality of ports 574 may extend from the interior cavity 572 to an exterior of the slot block 204, such as to the peripheral sidewall 216 of the slot block 204. As will be further described, at least one of the plurality of ports 574 may be an inlet port in fluid communication with the interior cavity 572, and at least one of the plurality of ports 574 may be an outlet port in fluid communication with the interior cavity 572. The plurality of ports 574 in the illustrated embodiment include a first port 574a, a second port 574b, a third port 574c, and a fourth port 574d, although more or less than three of the plurality of ports 574 may be utilized in other embodiments.

[0104] The heat extraction assembly 570 may include a plurality of tubes 578, each extending through a respective one of the plurality of ports 574. In the illustrated embodiment, the plurality of tubes 578 may include a first tube 584a, a second tube 584b, a third tube 584c, and a fourth tube 584d. However, in embodiments utilizing a greater or lesser number of ports 574, a greater or lesser number of tubes 578 may likewise be utilized, such that the number of tubes 578 corresponds to the number of ports 574.

[0105] Here, first tube 584a extends through first port 574a, second tube 584b extends through second port 574b, third tube 584c extends through third port 574c, and fourth tube 584d extends through fourth port 574d. Also, the lumen of first tube 584a may be in fluid communication with internal cavity 572, the lumen of second tube 584b may be in fluid communication with internal cavity 572, the lumen of third tube 584c may be in fluid communication with internal cavity 572, and the lumen of fourth tube 584d may be in fluid communication with internal cavity 572.

[0106] At least one tube of the plurality of tubes 578 may be a cooling fluid inlet tube operable to inject cooling fluid into the internal cavity 572 of the slot block 204, and at least one tube of the plurality of tubes 578 may be a cooling fluid outlet tube operable to exhaust cooling fluid from the internal cavity 572 of the slot block 204. Further, a cooling fluid source 580 may be fluidly coupled to the cooling fluid inlet tube, thereby supplying cooling fluid to the inner lumen of the cooling fluid inlet tube and to the internal cavity 572. The cooling fluid source 580 may include a mass flow controller. An exhaust device 582 may be fluidly coupled to the cooling fluid outlet tube to exhaust cooling fluid through the lumen of the cooling fluid outlet tube and out of the internal cavity 572. The thermal profile formed within the slot block 204 during operation, as well as the amount of heat extracted from the slot block 204 and the length of time the cooling fluid remains in the internal cavity 572 (i.e., residence time), can be controlled by selecting which of the multiple tubes 578 function as cooling fluid inlet tubes, which function as cooling fluid outlet tubes, and which tubes are closed or blocked so as to serve neither function.

[0107] In the illustrated embodiment, the first tube 584a may be fluidly coupled to the cooling fluid source 580, while the second tube 584b, the third tube 584c, and the fourth tube 584d may each be fluidly coupled to the exhaust device 582. Thus, in this embodiment, the first tube 584a supplies cooling fluid to the internal cavity 572, while the second tube 584b, the third tube 584c, and the fourth tube 584d exhaust cooling fluid from the internal cavity 572. In other embodiments, one or more of the second tube 584b, the third tube 584c, and the fourth tube 584d may be fluidly coupled to the cooling fluid source 580 instead of the exhaust device 582, such that more than one of the plurality of tubes 578 may function as cooling fluid inlet tubes. In yet other embodiments, the first tube 584a may be fluidly coupled to the exhaust device 582 instead of the cooling fluid source 580 so as to function as a cooling fluid outlet tube, and one or more of the second tube 584b, the third tube 584c, and the fourth tube 584d may be fluidly coupled to the cooling fluid source 580 instead of the exhaust device 582 so as to function as a cooling fluid inlet tube.

[0108] In embodiments, only one of the plurality of tubes 578 may be fluidly coupled to the cooling fluid source 580, such that there is only one cooling fluid inlet tube and at least one of the remaining tubes of the plurality of tubes 578 is closed. In some of these embodiments, the remaining ones of the plurality of tubes 578 that are not closed may be fluidly coupled to the exhaust device 582. However, in other embodiments, all of the plurality of tubes 578 that are not connected to the cooling fluid source 580 may be fluidly connected to the exhaust device 582 and each may include a valve for selectively opening or closing its lumen.

[0109] In the illustrated embodiment, second tube 584b, third tube 584c, and fourth tube 584d may each include a valve 586b, 586c, 586d operable to open or close an associated lumen, thereby regulating access to drainage device 582. Each of valves 586b, 586c, 586d may be connected to a controller, such as controller 470 described above, such that the opening and closing of valves 586b, 586c, 586d may be controlled. Additionally, in embodiments in which any one or more of second tube 584b, third tube 584c, and fourth tube 584d are fluidly connected to cooling fluid source 580, associated valves 586b, 586c, 586d similarly operate to regulate the flow of cooling fluid from cooling fluid source 580 into internal cavity 572.

[0110] Also in the illustrated embodiment, first tube 584a includes a valve 586a operable to open or close a lumen associated therewith, thereby regulating access to cooling fluid source 580 such that the inflow of cooling fluid into internal cavity 572 can be regulated. Valve 586a can similarly be connected to a controller, such as controller 470 described above, such that the opening and closing of valve 586a can be controlled. In embodiments in which first tube 584a is in communication with drainage device 582, valve 586a can be operable to open or close a lumen of first tube 584a, thereby regulating access to drainage device 582.

[0111] One or more of valves 586a, 586b, 586c, 586d may be configured to open or close their associated lumens, but any one of them may also each be configured to partially close their associated lumens, thereby throttling the inflow or outflow of cooling fluid into or from internal cavity 572, thereby further controlling the thermal profile shaped within slot block 204 during operation. In some embodiments, one of plurality of tubes 578 (e.g., first tube 584a) may be fluidly connected to cooling fluid source 580, and the remaining tubes of plurality of tubes 578 (e.g., second tube 584b, third tube 584c, and fourth tube 584d) may be fluidly connected to exhaust device 582, but with their associated valves (e.g., valves 586b, 586c, 586d) partially open or partially closed. In one of these embodiments, valve 586d of fourth tube 584d can be opened to a greater extent than valve 586b of second tube 584b, and valve 586c of third tube 584c can be opened to a degree between valves 586b, 586d, such that the flow pattern of cooling fluid within internal cavity 572 and the residence time remaining in various regions of internal cavity 572 can be controlled. Thus, the amount of cooling fluid exiting internal cavity 572 through second tube 584b, third tube 584c, and fourth tube 584d can be controlled, and as a result, heat extraction from within internal cavity 572 can be regulated. For example, when valves 586c, 586d are closed, cooling fluid flowing in through the first tube 584a is forced out only through the second tube 584b, and heat extraction within the internal cavity 572 is focused to a region therein between the first tube 584a and the second tube 584b. However, when valves 586b, 586c are closed, cooling fluid is forced out only through the fourth tube 584d, and cooling fluid circulates around the internal cavity 572 between the first tube 584a and the fourth tube 584d, so that heat extraction within the internal cavity 572 is focused to a relatively large region therein.

[0112] 2A, 2C, 3A, and 3C, during operation, molten glass 116 flows into glass feed device 221 of glass forming apparatus 200 through inlet conduit 203. The molten glass 116 flows through passageway 208 of glass feed device 221 and into slot block 204. The molten glass 116 is shaped by slot block 204 as molten glass 116 passes through slot orifice 206 and exits slot block 204 as glass ribbon 123 in flow direction 126. In an embodiment, heat extraction assembly 400 (depicted in FIG. 2A) may be coupled to corresponding channels 201 formed in slot block 204 of glass feed device 221. Cooling fluid from a cooling fluid source 420 can be directed into the inner lumen 413 of the inner tube 410 (FIG. 3C) of each heat extraction assembly 400 (FIG. 3A) so that the cooling fluid flows into the corresponding channels 201 in the slot block 204 (FIG. 2C). As the molten glass 116 flows through the slot orifices 206, heat is transferred from the molten glass 116 to the material of the slot block 204. The cooling fluid from the cooling fluid source 420 introduced into the channels 201 extracts heat from the material of the slot block 204 around the channels 201, and therefore from the molten glass 116 in the glass ribbon 123 formed within the slot orifices 206. The cooling fluid introduced into the channels 201 of the slot block 204 (after being heated by interaction with the material of the slot block 204) is exhausted through an exhaust channel 411 between the inner tube 410 and the outer tube 402 of the heat extraction assembly 400. The heated cooling fluid is discharged from the discharge channel 411 into the internal channel 432 of the housing 430 of the heat extraction assembly 400 and discharged from the internal channel 432 through the discharge manifold 434, thereby extracting heat from the slot block 204 of the glass forming apparatus 200 and from the glass ribbon 123 formed by the slot block 204 of the glass forming apparatus 200.

[0113] As described herein, the amount of heat extracted from the slot block 204 and the glass ribbon 123 material formed thereby can be controlled by the position at which the outer tube 402 of the heat extraction assembly 400 is secured relative to its corresponding channel 201. When the outer tube 402 is coupled to the channel 201, the distal end 404 of the outer tube 402 can be secured to the bottom surface 202 of the slot block 204 above the open end 320 of the channel 201, thereby allowing the cooling fluid to directly contact and interact with substantially all of the surface area within the channel 201, or the distal end 404 of the outer tube 402 can be at least partially inserted into and secured to the channel 201, such that the outer tube 402 covers at least a portion of the surface area within the channel 201, thereby preventing the cooling fluid from directly contacting and interacting with the covered surface area of ​​the channel 201. Additionally, the amount of heat extracted from the slot block 204 and the material of the glass ribbon 123 may be controlled by adjusting the position of the inner tube 410 of the heat extraction assembly 400 within the corresponding channel of the slot block 204. For example, as described herein, coarse and fine adjustment of the heat extraction assembly 400 may facilitate inserting the inner tube 410 further into the corresponding channel 201 or withdrawing the inner tube 410 from the corresponding channel 201. Inserting the inner tube 410 further into the corresponding channel 201 may focus the injection of cooling fluid at the closed end 322 of the channel 201 such that heat extraction is greatest at the closed end 322 of the channel 201, which may help to create a temperature gradient within the material surrounding the channel 201. Conversely, withdrawing the inner tube 410 from the corresponding channel 201 may spread the injection of cooling fluid over a relatively larger surface area of ​​the channel 201, causing the cooling fluid to contact the surface area of ​​the channel 201 more uniformly, which may help create a more uniform temperature distribution in the material surrounding the channel 201.Additionally, because the distance between the distal end 412 of the inner tube 410 and the closed end 322 of the channel 201 affects backpressure within the heat extraction assembly 400, which in turn can change the flow rate and distribution of the cooling fluid, coarse and fine adjustments of the heat extraction assembly 400 can be utilized to position the inner tube 410 as needed to mitigate the effects of backpressure, thus controlling the amount of heat extracted from the material of the slot block 204 (and the glass ribbon 123 formed using the slot block 204) and reducing instability in the glass ribbon 123 through localized heat extraction.

[0114] In an embodiment, the position of the distal end 404 of the outer tube 402 within the channel 201 is set, then the position of the distal end 412 of the inner tube 410 may be adjusted relative to the closed end 322 of the channel 201, and then the molten glass 116 passes through the glass forming apparatus 200 to form the glass ribbon 123. During this forming, the cooling fluid temperature sensor 426 measures the temperature of the cooling fluid supplied to the inner tube 410, the discharge temperature sensor 460 measures the temperature of the cooling fluid in the discharge manifold 434, and the controller 470 calculates the heat extraction in the slot block 204 based on the temperature data received from the cooling fluid temperature sensor 426 and the discharge temperature sensor 460. If the calculated heat extraction does not equal the target heat extraction, forming may be stopped and the position of the inner tube 410 relative to the channel 201 may be fine-tuned, thereby changing the heat extraction in the channel 201. Alternatively, if controller 470 determines that the calculated heat extraction in a channel 201 deviates from the target heat extraction, controller 470 may cause cooling fluid source 420 to adjust the flow rate of cooling fluid, thereby increasing or decreasing heat extraction from the corresponding channel 201, until the calculated heat extraction reaches the target heat extraction. In an embodiment, if controller 470 determines, based on feedback from glass ribbon sensor 472, that glass ribbon 123 exhibits sheet width variation, controller 470 causes cooling fluid source 420 to adjust the flow of cooling fluid, based on feedback from cooling fluid temperature sensor 426 and exhaust temperature sensor 460, thereby controlling heat extraction and stabilizing glass ribbon 123. [Example]

[0115] The embodiments described herein are further clarified by the following examples.

[0116] Example 1 2A and 2B, tests were performed on the slot block 204 to determine whether injecting a cooling fluid into at least one channel 201 using a heat extraction assembly 400 improved heat extraction. The tests demonstrated that embodiments of the present disclosure improved thermal bonding at the interface where heat transfer from the slot block 204 occurs, inhibited oxidation of the slot block 204, and reduced stability issues and sheet width variation in the glass ribbon 123, resulting in the glass ribbon 123 exhibiting improved dimensional properties.

[0117] As shown in FIG. 2B , locations where multiple channels were molded within the slot block 204 were initially identified as possible channel locations based on the best performance of the conventional water-cooled fingers 150, 152, thermal modeling, and the selected offset locations. Channels 201a and 201c were selected for testing (hereinafter, the “selected channels”). Channel 201a was offset 25 mm from the corner radius axis 244 toward the thickness axis 214′. Similarly, channel 201c was offset 25 mm from the corner radius axis 246 toward the thickness axis 214′. For testing, each of the selected channels was molded with an inner diameter of approximately 6 mm and a length L of approximately 8 mm. Each of the selected channels was oriented at an angle of approximately 45 degrees with respect to the vertical dimension in the XZ plane, and the distance 312 between the closed end 322 of each of the selected channels and the bottom surface 202 was approximately equal to 5 mm. Each of the selected channels was molded into the bottom surface 202 of the slot block 204 at a midpoint between the second side 232 of the peripheral sidewall 216 and the second interior wall 272 of the slot orifice 206. Additionally, a first heat extraction assembly 400 was coupled to channel 201a, and a second heat extraction assembly 400 was coupled to channel 201c. Also, during testing, the viscosity of the glass ribbon 123 during glass formation was approximately 100 kpoise, the mass flow rate of the molten glass 116 was approximately 10 kg / hr, and cooling fluid was introduced into the channels at various rates as described below.

[0118] FIG. 6 is a diagram illustrating the relationship between cooling fluid flow rate and the width of the glass ribbon 123. Tests were conducted at increasing cooling fluid flow rates from 0 slpm. As can be seen in FIG. 6, the width W of the glass ribbon 123 increased as the cooling fluid flow rate into the channels 201 a, 201 c increased. The tests further demonstrated that, under similar forming conditions, the width W of the glass ribbon 123 increased beyond what was possible using the water-cooled fingers 150, 152, as shown by line 600.

[0119] FIG. 7 illustrates the standard deviation between the position of the left edge of the glass ribbon and the position of the right edge of the glass ribbon under different cooling fluid flow rates. As can be seen in FIG. 7, the deflection of the glass ribbon 123 was significantly reduced by increasing the flow rate of the cooling fluid in the channels 201a, 201c in the slot block 204. A "baseline" case was performed without any edge cooling (i.e., without the water-cooled fingers 150, 152 and without introducing cooling fluid into any of the channels 201 formed in the slot block 204). Cases 1, 2, 3, and 4 were then performed, each with cooling fluid introduced into the channels 201 at increasing flow rates. Specifically, the flow rate of the cooling fluid was increased from Case 1 to Case 4, with Case 1 being the lowest flow rate and Case 4 being the highest flow rate. Case 4 was then performed, followed by another repeat of Case 2. Increasing the flow rate of cooling fluid in channels 201a, 201c significantly reduced ribbon deflection, representing an improvement over the best standard deviation achieved using water-cooled fingers 150, 152, as shown by line 700.

[0120] FIG. 8 illustrates the relationship between sheet width variation of the glass ribbon 123 and the rate at which cooling fluid was directed into the channels 201 a, 201 c in the slot block 204. Initially, no cooling fluid (air in this case) was provided to the channels 201 a, 201 c of the slot block 204 (see “No Air Flow” in FIG. 8 ). The rate at which the glass ribbon was discharged from the slot block 204 remained constant, and after one hour of operation, a flow of air was introduced into the channels 201 a, 201 c (see “Air Flow #1” in FIG. 8 ) to extract heat from the slot block 204. Then, after another hour of operation, the flow rate at which air was introduced into the channels 201 a, 201 c was doubled (see “Air Flow #2” in FIG. 8 ) to increase heat extraction from the slot block 204. As shown in Figure 8, increasing the flow rate of cooling fluid in channels 201a, 201c reduced the standard deviation of the width W of glass ribbon 123 from 1.4% ("No Air Flow") to 0.5% ("Air Flow #2"). Figure 8 therefore demonstrates that increasing heat extraction by increasing the flow rate of cooling fluid improves sheet width variation.

[0121] Example 2 Because the overall width W of the glass ribbon 123 is affected by the amount of heat extraction from the glass ribbon 123 through the slot block 204, as well as the position of the channel 201 relative to the slot angular radius of the slot orifice 206, as represented by the angular radius axes 244 and 246, an increase in glass viscosity at the edges 123 a and 123 b due to heat extraction reduces the attenuation of the width W of the glass ribbon 123. However, if the channel 201 is too close to the slot angular radius, the width of the slot orifice 206 is substantially reduced. In this example, thermal modeling was utilized to identify the optimal location of the channel with respect to the width W of the glass ribbon 123. FIG. 9 illustrates thermal modeling calculations of channel position relative to the angular radius of the slot orifice 206. Specifically, FIG. 9 shows thermal modeling results for six different channel positions (i.e., curve 1, curve 2, curve 3, curve 4, curve 5, and curve 6), with each successive curve based on a channel position increased by 10 mm from the channel position of the previous curve. As depicted in FIG. 9, varying the position of the channel 201 affects the width W of the glass ribbon 123.

[0122] The heat extraction assemblies for glass forming apparatuses described herein can be used to control or mitigate sheet width variations and ribbon deflection by providing localized heat extraction within channels molded in the slot block at locations proximate the slot orifices, thereby improving the performance of slotted ribbons. The heat extraction assemblies inject cooling fluid into the channels, improving thermal coupling between the heat extraction assembly and the slot block and improving performance. Furthermore, the channels can be molded into the slot block at fixed locations, allowing the heat extraction assembly to be consistently positioned in a fixed location within the slot block so that the heat extraction point remains constant over time. Also, after being secured to the slot block, the heat extraction assembly can be precisely adjusted to a desired position within the channel, and such adjustments can be precisely repeated during subsequent operations. Furthermore, the use of cooling fluid within the channels prevents or mitigates the formation of oxidation within the channels, thereby maintaining heat transfer at the channel surfaces throughout the life of the slot block. Still further, the heat extraction assemblies can be controlled to stabilize the glass ribbon and / or maintain or adjust heat extraction in real time.

[0123] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the present specification cover modifications and variations of the various embodiments described herein, provided such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. A glass forming apparatus comprising: a glass feeding device comprising a slot block, wherein molten glass flows through the slot block and is formed into a glass ribbon upon exiting a slot orifice of the slot block, the slot block having a vertical dimension corresponding to a direction of flow of the molten glass, a width dimension orthogonal to the vertical dimension, a thickness dimension orthogonal to the vertical dimension and the width dimension, and a plurality of channels formed in the slot block proximate to the slot orifice; a heat extraction assembly, the heat extraction assembly comprising: an outer tube having a distal end and a proximal end, the distal end of the outer tube connected to one of the plurality of channels; an inner tube extending within an outer lumen of the outer tube, the inner tube having a distal end and a proximal end, the inner tube being positioned within the outer lumen of the outer tube such that the distal end of the inner tube is positioned adjacent to the distal end of the outer tube; a cooling fluid source fluidly coupled to the inner tube and configured to supply a cooling fluid to an inner lumen of the inner tube; an exhaust manifold fluidly coupled to the outer lumen of the outer tube and configured to exhaust the cooling fluid from an exhaust channel defined between an inner surface of the outer tube and an outer surface of the inner tube.

2. a housing defining an interior channel; the outer tube is connected to the housing such that the outer lumen of the outer tube is in fluid communication with the interior channel of the housing; the exhaust manifold is fluidly coupled to the interior channel of the housing such that an exhaust lumen of the exhaust manifold is in fluid communication with the interior channel of the housing; The glass forming apparatus of claim 1 , wherein the inner tube extends at least partially through the interior channel of the housing.

3. the housing includes a connector slidably positioned within the housing and including an internal passageway; 3. The glass forming apparatus of claim 2, wherein the inner tube extends through the inner passage of the connector and is coupled to the connector, whereby translating the connector relative to the housing adjusts the spacing between the distal end of the inner tube and the distal end of the outer tube.

4. 4. The glass forming apparatus of claim 3, further comprising a set screw threadably inserted into the housing, the set screw configured to lock the connector to the housing and prevent the connector from sliding when the set screw is rotated in a first direction.

5. 4. The glass forming apparatus of claim 3, wherein the inner tube is threadably coupled to the connector, whereby rotation of the inner tube within the connector adjusts the spacing between the distal end of the inner tube and the distal end of the outer tube.

6. 10. The glass forming apparatus of claim 1, wherein one or more of the plurality of channels comprises an insulating insert disposed therein, the insulating insert comprising at least one opening through which material of the slot block proximate the slot orifice is exposed to enhance heat extraction from the material.

7. 7. The glass forming apparatus of claim 6, wherein the at least one opening in the insulating insert faces a bottom side of the slot block, and the glass ribbon exits the slot orifice through the bottom side.

8. an exhaust temperature sensor operably coupled to the exhaust manifold configured to measure an outlet temperature of cooling fluid in the exhaust manifold; 10. The glass forming apparatus of claim 1, further comprising: a cooling fluid temperature sensor operably coupled to the cooling fluid source configured to measure an inlet temperature of the cooling fluid supplied to the inner tube.

9. 9. The glass forming apparatus of claim 8, further comprising a controller operably connected to the cooling fluid temperature sensor and the discharge temperature sensor, the controller being programmed to calculate heat extraction at the slot block based on the outlet temperature of the cooling fluid in the discharge manifold and the inlet temperature of the cooling fluid supplied by the cooling fluid source.

10. 10. The glass forming apparatus of claim 9, wherein the controller is operable to adjust the flow rate of cooling fluid provided by the cooling fluid source based on the calculated heat extraction.

11. 11. The glass forming apparatus of claim 10, further comprising a glass ribbon sensor configured to measure a width of the glass ribbon exiting the slot orifice, the controller being operably connected to the glass ribbon sensor and operable to adjust a flow rate of the cooling fluid supplied by the cooling fluid source based on the width of the glass ribbon measured by the glass ribbon sensor.

12. The glass forming apparatus of claim 1 , wherein an insulating sleeve is disposed over at least a portion of the outer tube.

13. The glass forming apparatus of claim 1 , further comprising a glass ribbon sensor configured to measure a width of the glass ribbon exiting the slot block.

14. 14. The glass forming apparatus of claim 13, further comprising a controller operably connected to the cooling fluid source and the glass ribbon sensor, the controller operable to adjust a flow rate of cooling fluid supplied by the cooling fluid source based on the width of the glass ribbon measured by the glass ribbon sensor.

15. 10. The glass forming apparatus of claim 1, wherein at least one of the plurality of channels extends in a plane defined by the vertical dimension and the width dimension, and wherein a length of the at least one of the plurality of channels is parallel to the vertical dimension.

16. 10. The glass forming apparatus of claim 1, wherein at least one of the plurality of channels extends in a plane defined by the vertical dimension and the width dimension, and wherein a length of the at least one of the plurality of channels is non-parallel to the vertical dimension.

17. 10. The glass forming apparatus of claim 1, wherein at least one of the plurality of channels extends in a plane defined by the width dimension and the thickness dimension, and a length of the at least one of the plurality of channels is parallel to the thickness dimension.

18. 10. The glass forming apparatus of claim 1, wherein at least one of the plurality of channels extends in a plane defined by the width dimension and the thickness dimension, and wherein a length of the at least one of the plurality of channels is non-parallel to the thickness dimension.

19. The glass forming apparatus of claim 1 , wherein the cooling fluid comprises an inert gas.

20. 10. The glass forming apparatus of claim 1, wherein the distal end of the outer tube is fixedly attached to the slot block.

21. A glass forming apparatus comprising: a glass delivery device comprising a slot block, wherein molten glass flows through the slot block and is formed into a glass ribbon upon exiting an orifice in the slot block, the slot block having a vertical dimension corresponding to a direction of flow of the molten glass, a width dimension orthogonal to the vertical dimension, a thickness dimension orthogonal to the vertical dimension and the width dimension, and an internal cavity positioned proximate the orifice in the slot block, wherein at least one inlet port is in fluid communication with the internal cavity and at least one outlet port is in fluid communication with the internal cavity; a heat extraction assembly, the heat extraction assembly comprising: a cooling fluid inlet tube connected to the at least one inlet port such that an inner lumen of the cooling fluid inlet tube is in fluid communication with the internal cavity; a cooling fluid source fluidly coupled to the cooling fluid inlet tube and configured to supply cooling fluid to the inner lumen and the internal cavity of the cooling fluid inlet tube; a cooling fluid outlet tube connected to the at least one outlet port such that an inner lumen of the cooling fluid outlet tube is in fluid communication with the internal cavity.

22. 22. The glass forming apparatus of claim 21, wherein the at least one inlet port comprises a single inlet port.

23. 23. The glass forming apparatus of claim 22, wherein the at least one exit port comprises a single exit port.

24. 23. The glass forming apparatus of claim 22, wherein the at least one outlet port comprises a plurality of outlet ports, and the cooling fluid outlet tube comprises a plurality of cooling fluid outlet tubes each corresponding to one of the plurality of outlet ports.

25. 25. The glass forming apparatus of claim 24, wherein at least one of the plurality of cooling fluid outlet tubes is closed.

26. 25. The glass forming apparatus of claim 24, wherein each of the plurality of cooling fluid outlet tubes comprises a valve configured to control the flow of cooling fluid from each of the plurality of cooling fluid outlet tubes.

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