Patent Application
20240240787
This patent application discloses innovations related to industrial melters and, more particularly, to burners for use in industrial melters.
Machines for melting glass in an industrial setting typically include a melting chamber and a number of burners installed along and through a wall of the chamber. In one example, U.S. Pat. No. 11,319,235 (Wang, et al.) discloses a glass melting chamber configured to continuously receive solid glass batch materials that are melted in the chamber via heat provided by submerged combustion burners in the floor of the chamber. The burners melt and continuously heat the glass and to keep the melted glass in a molten state before the glass is fed to a treatment chamber to refine the glass before it is fed further downstream to undergo additional processing. Submerged burners of this type are exposed to an extreme environment that includes intense heat, molten glass, and combustion gases and must be routinely replaced due to corrosion, erosion, and/or thermal stresses along portions of the burner.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A burner in accordance with one aspect of the disclosure is configured for attachment along a wall of a melting chamber of a melter and includes a fuel conduit and a coolant shell. The fuel conduit extends from a supply end to a combustion end, and the coolant shell surrounds the combustion end of the fuel conduit. The burner is configured to receive a cooling fluid and circulate the cooling fluid within the coolant shell before the cooling fluid exits the burner. The coolant shell is removable and replaceable with another identical coolant shell.
In accordance with another aspect of the disclosure, there is provided a burner configured for attachment along a wall of a melting chamber of a melter includes a main body, a fuel conduit, a tubular body, and an elastomeric seal. The main body is configured for mounting the burner to the furnace. The fuel conduit extends from a supply end to a combustion end. The tubular body is removably attached to the main body and surrounds the combustion end of the fuel conduit. The elastomeric seal is at an interface between the main body and the tubular body and is releasable from at least one of the tubular body or the main body when the tubular body is removed from the main body.
In accordance with another aspect of the disclosure, there is provided a submerged combustion melting burner includes a rearward section and a forward section. The forward section is removably and replaceably coupled to the rearward section. The rearward section includes a mounting flange, a cooling shell partition extending in a forward direction with respect to the mounting flange, and a gas conduit. The forward section includes an attachment flange and a coolant shell. The attachment flange is sealingly and removably coupled to the mounting flange of the rearward section. The coolant shell is coupled to the attachment flange and includes an outer wall, an end wall, and an inner wall. The outer wall extends in the forward direction from the attachment flange and is spaced radially outwardly of the cooling shell partition of the rearward section to establish a coolant inlet path between the cooling shell partition and the outer wall, the end wall terminates the outer wall at an end of the burner and is spaced axially from the cooling shell partition to establish a coolant transition path between the cooling shell partition and the outer wall. The inner wall extends from the end wall in a rearward direction and is sealingly and removably coupled to the gas conduit of the rearward section. The inner wall is spaced radially inwardly of the cooling shell partition of the rearward section to establish a coolant outlet path between the cooling shell partition and the inner wall.
Described below is a burner for use in an industrial melter for melting glass, metal, waste, or any other material suitable for industrial melting. The burner is serviceable so that only a portion of the burner requires periodic replacement. The remainder of the burner can easily be placed back in service after replacement of the removable portion. Sealing surfaces that permit fluid-tight conveyance of fluids into and out of the replaceable portion during use can be located away from the hottest parts of the burner to preserve their integrity and facilitate removal and replacement of the removable portion. The disclosed burner construction offers significant cost advantages over conventional burners, the entirety of which are disposed of after a period of use in a glass melter. While disclosed in the context of submerged combustion melting, the burner may be suitable for use with other industrial melting processes.
In this example, the melter 10 is a submerged combustion melter and the burners 12 are submerged combustion burners installed along a bottom wall 16 of the furnace that provides a floor 22 of the melting chamber. The disclosed burner 12 and its easily serviceable construction may extend through other walls of the furnace 14 and/or be employed in other industrial melting processes. A portion of each burner 12 may extend beyond the floor 22 and into the molten material G as shown in
With additional reference to
The combustion side 26 of the burner 12 is configured to emit thermal energy into the melting chamber of the furnace 14 during operation by burning the supplied fuel with the supplied oxidant. The combustion side 26 includes a combustion gas outlet 38 at a distal end of the burner 12 from which thermal energy and combustion gases are discharged during operation. The combustion side 26 of the burner may also include a thermal barrier coating 35 along surfaces exposed to molten glass and/or burning fuel. The mounting flange 28 is configured for mounting the burner 12 to the furnace 14. In this example, the mounting flange 28 includes apertures 40 through which fasteners are received to engage corresponding features (e.g., threaded holes) along the furnace wall 16, such as those illustrated in the flange 19 of the receiver 15 of
As illustrated in the partially exploded view of
As used herein, the term “removable” and its variants are used to characterize a reversible or temporary attachment of one component to another. For a component to be “removable” from another component for purposes of this disclosure, the two components must be separable without destroying or materially damaging either component. Examples of removable attachments or couplings include mechanical fasteners, clamps, threads, magnets, latches, or couplings relying on a clamp load applied to the components when assembled to the furnace.
The tubular body 42 is removably attached to the main body 44 by threaded fasteners 52 (
In this case, the tubular body 42 is fully seated when a planar surface B of the main body 44 and a parallel planar surface B′ of the tubular body are as close together as they can be—i.e., leaving room for manufacturing tolerances, stand-off features, and/or a sealing element. The planar surface B of the main body 44 is provided by a recess 56 formed on the combustion side of the mounting flange 28.
The tubular body 42 includes a radially outer wall 58, a radially inner wall 60, an end wall 62, and the attachment flange 54, all of which are concentric about the central axis A. The outer wall 58 and the inner wall 60 are tubular and generally cylindrical in this example, and the end wall 62 is annular and interconnects the two axially extending walls 60, 62. The outer wall 58 extends axially in a forward direction from a first side of the attachment flange 54 to an outer perimeter of the end wall 62, and the inner wall 60 extends axially in a rearward direction from an inner perimeter of the end wall 62 to a distal supply end 64 on the supply side of the attachment flange 54.
Together, the three walls 58-62 form a shell 66 with an annular and axially extending hollow portion 68 defined between the outer and inner walls 58, 60. As discussed further below, the shell 66 may function as a coolant shell within which a cooling fluid is circulated during operation. The shell 66 may be constructed as a three-piece weldment, as shown, with a burner tip 70 providing the end wall 62 along with respective end portions of the radially outer and radially inner walls 58, 60. The combustion gas outlet 38 is provided by the burner tip 70 in this example. The burner tip 70 may be made from the same material as the radially inner and outer walls 58, 60.
The thermal barrier coating 35 is formed along surfaces of the shell 66 exposed to molten material and/or burning fuel. The thermal barrier coating 35 has a lower thermal conductivity and a higher heat resistance than the underlying material and may be formed from a ceramic material such as yttrium-stabilized zirconia (YSZ), for example. A metal bond coat (e.g., NiCrAlY) may be formed between the shell walls and the thermal barrier coating 35 to accommodate differences in thermal expansion between the ceramic and the underlying metallic material. The coating 35 fully covers the axially outer surface of the annular end wall 62 and extends along the exterior surface of both of the outer and inner walls 58, 60 of the shell 66. The coating 35 extends along the outer wall 58 to a distance at least as far as the combustion end 26 of the burner protrudes beyond the floor 22 of the melting chamber 18. The coating 35 extends along the inner wall 60 to a distance at least as far as the combustion end 50 of the fuel conduit 46. In one embodiment, the thermal barrier coating 35 has a thickness in a range from 0.008 inches to 0.015 inches (200 μm to 380 μm) and is applied over a bond coat having a thickness in a range from 0.003 inches to 0.005 inches (75 μm to 125 μm).
The tubular body 42 may include one or more seals 72 along the inner wall 60. The seals 72 enable fluid-tight conveyance of a fluid (e.g., a combustible fuel or an oxidant) from the main body 44 to the tubular body 42 along a radially inner surface 74 of the shell 66 during burner operation. In this example, the seals 72 are O-rings set in annular grooves along the inner surface 74 proximate the flared end 64 of the radially inner wall 60. O-rings 72 can provide an impermanent seal that is releasable from one or both of the tubular body 42 and the main body 44 when the tubular body is removed. The annular grooves in which the seals 72 are set open on a radially facing surface of the tubular body 42 such that the seal is in radial compression when the tubular body 42 is attached to the main body 44. The seals 72 may be elastomeric and made from a fluoroelastomer (e.g., Viton®), silicone, or other high-temperature elastomer.
The attachment flange 54 extends radially outward from the outer wall 58 and includes threaded holes 76 or other suitable attachment features aligned with apertures or other attachment features of the mounting flange 28 of the main body 44. The attachment flange 54 may be in the form of a ring welded or otherwise permanently attached to the shell 66. The joint between the shell 66 and the attachment flange 54 may be liquid or fluid-tight to permit conveyance of a fluid (e.g., a cooling fluid) from one side of the flange to the other.
The main body 44 includes a radially outer wall 78, a radially inner wall 80, a fluid jacket 82, a supply fitting 84, the mounting flange 28, the coolant inlet 30, and the coolant outlet 36. The outer wall 78, inner wall 80, fluid jacket 82, and supply fitting 84 are concentric about the central axis A, tubular, and generally cylindrical in this example.
The fluid jacket 82 surrounds a portion of the radially outer wall 78 on the supply side of the mounting flange 28 to define an axially extending annular hollow portion therebetween. The coolant inlet 30 is in fluidic communication with the hollow portion between the outer wall 78 and fluid jacket 82 through an opening formed through a wall of the fluid jacket. Dowels 86 or other centering features may be included between the tubular wall of the fluid jacket 82 and the radially outer wall 78 of the main body 44 as shown to help align the respective components along the central axis A during fabrication.
The mounting flange 28 extends radially outward from the outer wall 78 and fluid jacket 82 and includes the apertures 40 (
The outer wall 78 extends axially between the supply fitting 84 on the supply side of the mounting flange 28 to an opposite end 88 on the combustion side of the mounting flange. The outer wall 78 includes a central conduit 90 and an end piece 92. The central conduit 90 extends axially from the supply fitting 84 to the end piece 92 and through the mounting flange 28 and fluid jacket 82. The coolant outlet 36 is in fluidic communication with the inside of the central conduit 90 via an opening formed therethrough.
The end piece 92 has an inner diameter equal to that of the central conduit 90 and an outer diameter and wall thickness greater than that of the central conduit. Dowels 94 or other centering features may be included along the radially outer surface of the end piece 92 as shown to help guide the tubular body 42 on the main body 44 during burner assembly. Together, the central conduit 90 and the end piece 92 form a tubular partition 96 that is housed in the shell 66 of the tubular body 42 when the burner is assembled to define at least a portion of a coolant passage as described further below. A cooling fluid may flow into the shell 66 along one side of the partition 96 and exit the shell along the opposite side of the partition. The thicker wall of the end piece 92 may act as a flow restrictor for the cooling fluid that locally increases the velocity of the cooling fluid at the combustion end of the burner 12.
The supply fitting 84 is tubular and generally cylindrical with an end flange 98 at one end and the radially inner wall 80 at an opposite end. The inner and outer diameters of the supply fitting 84 are larger at the end flange 98 than at the radially inner wall 80. A radially outer surface 100 of the inner wall 80 provides a sealing surface along which the seals 72 of the tubular body 42 are located when the burner 12 is assembled. The end flange 98 includes one or more apertures 102 or other attachment features for attaching the fuel conduit 46 to the main body 44. The oxidant inlet 34 (extending from the back side of the main body 44 in
The main body 44 may include one or more seals that enable fluid-tight conveyance of a fluid along or between mating components of the burner 12. In the illustrated embodiment, the main body includes a first seal 104 set in an annular groove formed in the recess 56 of the mounting flange 28 and one or more second seals 106 each set in an annular groove formed in the supply fitting 84 at the supply end of the main body 44. The first seal 104 enables fluid-tight conveyance of a fluid (e.g., a cooling fluid) from the main body 44 to the tubular body 42 along a radially outer surface of the radially outer wall 78 of the main body. In this example, the first seal 104 is an O-ring that can provide an impermanent seal that is releasable from one or both of the tubular body 42 and the main body 44 when the tubular body is removed. The annular groove in which the seal 104 is set opens on an axially facing surface of the main body 44 so that the seal is in axial compression when the tubular body 42 is attached. The seal 104 may be elastomeric and made from a fluoroelastomer (e.g., Viton®), silicone, or other high-temperature elastomer. In other embodiments the seal 104 may include or be formed from a non-structural adhesive (e.g., silicone) that is easily removed from the tubular body 42 and/or main body 44 when the two components are separated for replacement of the tubular body.
The second seals 106 enable fluid-tight conveyance of a fluid (e.g., a combustible fuel or an oxidant) from the main body 44 to the tubular body 42 along a radially outer surface of the radially outer wall 78 of the main body. In this example, the second seals 106 are O-rings that can provide an impermanent seal that is releasable from one or both of the tubular body 42 and the main body 44 when the tubular body is removed. The annular groove in which the seals 106 are set opens on an axially facing surface of the main body 44 so that the seals are in axial compression when the tubular body 42 is attached.
The fuel conduit 46 extends from a supply end 48 to a combustion end 50 and includes a main tube 108, a combustion end piece 110, a collar 112, and a flange 114. The main tube 108 is the longest axially extending portion of the fuel conduit 46 and is cylindrical in this example. The end piece 110 provides the combustion end 50 of the fuel conduit 46 and may include dowels 116 or other suitable centering features to help align the fuel conduit with the main body 44 along the central axis A. One end of the end piece 110 is joined to the main tube 108 and has an inner and outer diameter equal to those of the main tube 108. The opposite end of the end piece 110 had an outer diameter larger than that of the main tube 108 and a frustoconical inner surface shaped to converge the flow of fuel where it exits the fuel conduit 46. The larger diameter of the combustion end of the end piece 110 may serve to locally increase the velocity of an oxidant along the outer surface of the fuel conduit just before it is mixed with the fuel to be burned. This will become more apparent in subsequent figures.
The collar 112 surrounds and is attached to the main tube 108 along its length between the end piece 110 and the flange 114. An outer surface of the collar provides a sealing surface along which the seals 106 at the supply end of the main body 44 are located when the burner is assembled. The interface between the collar 112 and the seals 106 prevents oxidant entering the main body through the oxidant inlet 34 from flowing out of the main body 44 in the wrong direction. The flange 114 is configured to attach the fuel conduit 46 to the main body 44. In this example, the flange 114 is ring-shaped with a radial extension 118 having a through-hole to accommodate a fastener or other attachment feature aligned with a complimentary attachment feature 102 of the main body (see also
All of the components of
In some embodiments, the tubular body 42, or at least the burner tip 70 of the tubular body, is made from a Ni-based metal alloy in which nickel (Ni) is the primary constituent, meaning there is more nickel in the alloy than any other metallic element by weight. The alloy many be a nickel-chromium (Ni—Cr) alloy in which over half of the alloy is a combination of Ni and Cr. The alloy may include from 46.5 wt % to 76.5 wt % Ni and from 16 wt % to 22 wt % Cr. The Ni—Cr alloy may include a third metallic element present in an amount less than the combined amount of Ni and Cr and greater than any other metallic element by weight. The third element may be up to 19 wt % cobalt (Co), up to 14 wt % tungsten (W), up to 4.5 wt % aluminum (Al), or up to 18 wt % iron (Fe). The Ni—Cr alloy may additionally include up to 9 wt % or from 2 wt % to 9 wt % molybdenum (Mo). The Ni—Cr alloy may be a Ni—Cr—Al—Fe alloy, a Ni—Cr—Co—Mo—Al alloy, a Ni—Cr—W—Mo alloy, or a Ni—Cr—Fe—Mo alloy. Suitable Ni-based alloys are available as HAYNES® 200-series high-temperature alloys or HASTELLOY® alloys from Haynes International (Kokomo, IN, USA).
It is also possible for one or more of the seals of
The radially outer wall 58 of the tubular body 42 forms the radially outermost axially extending wall of the burner 12. The radially inner wall 60 of the tubular body 42 extends axially from the annular end wall 62 and forms a sealed interface with the main body 44 at the radially inner wall 80 of the main body. The radially inner wall 60 of the tubular body 42 is located radially between the fuel conduit 46 and the partition 96 of the main body 44 to partly define separate fluid passages along opposite surfaces of the wall 60. In particular, an oxidant passage 120 is defined between the inner wall 60 of the tubular body 42 and the fuel conduit 46, and a portion of a coolant passage 122 is defined between the inner wall 60 of the tubular body and the partition 96 of the main body 44.
The oxidant passage 120 conveys an oxidant O (e.g., air or oxygen) from supply side 24 to the combustion side of the burner 12 and, in particular, from the supply fitting 84 of the main body 44 to a discharge end 124 of the oxidant passage at the combustion end 50 of the fuel conduit 46. In some embodiments, the fuel tube 108 and oxidant passage 120 are reversed with the fuel passage surrounding the oxidant passage.
The coolant passage 122 conveys a cooling fluid C (e.g., water) from the supply side 24 to the combustion side 26 of the burner and back again. In the illustrated embodiment, the partition 96 is housed in the coolant shell 66 and divides the coolant passage 122 into a radially outer portion 122a defined between the partition and the radially outer wall 58 of the coolant shell 66 and a radially inner portion 122b defined between the partition and the radially inner wall 60 of the coolant shell. As illustrated in
The hollow portion of the fluid jacket 82 may be considered a coolant passage of the main body 44, and the hollow portion 68 of the coolant shell 66 may be considered a coolant passage of the tubular body 42 such that the axially compressed seal 104 at the interface between the main body and the tubular body provides fluid-tight conveyance of the cooling fluid C between the coolant passage of the main body and the coolant passage within the coolant shell.
As noted above, the tubular body 42 and, thereby, the coolant shell 66 is removably coupled with the main body 44 at the mounting flange 28 with an axially compressed seal 104 at the mounting flange interface. The coolant shell 66 is also removably coupled with the main body 44 at the supply end of the radially inner wall 60 of the coolant shell via the radially compressed seals 106. Locating these releasable seals 104, 106 away from the hottest portions of the burner 12 and furnace permits the use of organic (i.e., polymeric) seal materials, which is unconventional in burners of glass melters due to the extreme temperatures. The axially compressed seal 104 in the illustrated examples is located outside the furnace wall 16, and the radially compressed seals 106 are located even further from the furnace axially beyond the coolant inlet and outlet 30, 36.
When the coolant shell 66 is removed, the cooling passage partition 96 stays with the main body to be used again in a replacement coolant shell. The fuel conduit 46 also remains with the main body 44 when the coolant shell 66 is removed, but at least a portion of the oxidant passage 120—i.e., the radially inner wall 60 of the coolant shell—is removed when the coolant shell is removed. The oxidant passage 120 is restored when a replacement tubular body 42 is installed on the main body 44.
The radial gap between the radially outer wall 78 of the main body 44 and the radially inner wall 80 provided by the supply fitting 84 is smaller than in the example of
The joint between the central conduit 90 and the supply fitting 84 may include one or more additional seals 105 to prevent cooling fluid from escaping from the conduit 90. In this example, the seals 105 are O-rings that can provide an impermanent seal that is releasable from one or both of the supply fitting 84 and the central conduit 90 when separated. The seals 105 may be elastomeric and made from a fluoroelastomer (e.g., Viton®), silicone, or other high-temperature elastomer. The annular groove in which the seals 105 are set opens on a radially facing surface of the supply fitting 84 so that the seals are in radial compression.
With this construction, the supply fitting 84 carries three seals or sets of seals, including the seal 72 at the interface between the radially inner wall 60 of the tubular body 42 and the radially inner wall 80 of the main body 44 (provided by the supply fitting 84), the seal 105 between the supply fitting 84 and the central conduit 90 of the main body 44, and the seal 106 between the main body 44 and the fuel conduit 46. As illustrated in
The tubular body 42 of
The disclosed burner 12 may be notable for the omission of certain features. For example, in the illustrated embodiments: none of the tubular components of the burner are joined by threads along their interior or exterior surfaces, the position of the distal end of the combustion side of the burner is not axially adjustable relative to the mounting flange or furnace wall, and no portion of the fuel or oxidant passages are radially extending passages or inclined between the radial direction and the axial direction. These features are of course not excluded from incorporation in other embodiments of the burner.
As used in herein, the terminology “for example,” “e.g.,” for instance,” “like,” “such as,” “comprising,” “having,” “including,” and the like, when used with a listing of one or more elements, is to be construed as open-ended, meaning that the listing does not exclude additional elements. Also, as used herein, the term “may” is an expedient merely to indicate optionality, for instance, of a disclosed embodiment, element, feature, or the like, and should not be construed as rendering indefinite any disclosure herein. Moreover, directional words such as front, rear, top, bottom, upper, lower, radial, circumferential, axial, lateral, longitudinal, vertical, horizontal, transverse, and/or the like are employed by way of example and not necessarily limitation.
Finally, the subject matter of this application is presently disclosed in conjunction with several explicit illustrative embodiments and modifications to those embodiments, using various terms. All terms used herein are intended to be merely descriptive, rather than necessarily limiting, and are to be interpreted and construed in accordance with their ordinary and customary meaning in the art, unless used in a context that requires a different interpretation. And for the sake of expedience, each explicit illustrative embodiment and modification is hereby incorporated by reference into one or more of the other explicit illustrative embodiments and modifications. As such, many other embodiments, modifications, and equivalents thereto, either exist now or are yet to be discovered and, thus, it is neither intended nor possible to presently describe all such subject matter, which will readily be suggested to persons of ordinary skill in the art in view of the present disclosure. Rather, the present disclosure is intended to embrace all such embodiments and modifications of the subject matter of this application, and equivalents thereto, as fall within the broad scope of the accompanying claims.
