BURNER PANELS, SUBMERGED COMBUSTION MELTERS, AND METHODS
Combustion burner panels, submerged combustion melters including one or more of the panels, and methods of making the same are disclosed. In certain embodiments, the burner panel includes a panel body having first and second major surfaces, at least one oxidant through-passage extending from the first to the second major surface, and at least one fuel through-passage extending from the first to the second major surface. Oxidant and fuel delivery conduits are positioned in the respective passages. The oxidant and fuel delivery conduits include proximal and distal ends, at least some of the distal ends positioned away from the first major surface of the panel body. In other embodiments the burner panels include a frame enclosing a porous material having through passages for fuel and oxidant. The burner panels may enable delaying combustion in a submerged combustion melter, and therefore promote burner life and melter campaign length.
This patent application is a division of pending U.S. patent application Ser. No. 14/838,148, filed Aug. 27, 2015.BACKGROUND INFORMATION Technical Field
The present disclosure relates generally to the field of combustion burners and methods of use, and more specifically to burners, submerged combustion melters, and methods of their use, particularly for melting glass-forming materials, mineral wool forming materials, and other non-metallic inorganic materials.Background Art
A submerged combustion melter (SCM) may be employed to melt glass batch and/or waste glass materials to produce molten glass, or may melt mineral wool feedstock to make mineral or rock wool, by passing oxygen, oxygen-enriched mixtures, or air along with a liquid, gaseous and/or particulate fuel (some of which may be in the glass-forming materials), directly into a molten pool of glass or other material, usually through burners submerged in a melt pool. The introduction of high flow rates of products of combustion of the oxidant and fuel into the molten material, and the expansion of the gases during submerged combustion (SC), cause rapid melting of the glass batch or other feedstock and much turbulence and foaming.
In the context of SCMs, SC burners are predominately water-cooled, nozzle mix designs and may avoid premixing of oxidant and fuel for safety reasons due to the increased reactivity of using oxygen as the oxidant versus air. Nevertheless, one currently used submerged combustion burner employs a smooth exterior surface, half-toroid metallic burner tip of the same or similar material as the remainder of the burner, where the fuel and oxidant begin mixing just after escaping the burner tip. When using such burners in an SCM for the manufacture of glass, the burner tip is placed in an extreme environment. The burner tip is exposed to corrosive combustion gases, high temperature glass contact, internal pressure from water or other coolant, vaporization of coolant within the burner tip, thermal cycling, and the like. As a result, it has been determined that thermal fatigue resistance, high melting point, high temperature corrosion/oxidation resistance, high temperature structural strength, and ability to join/fabricate are some of the key requirements for designing next generation SC burners.
Due to these requirements, noble metal alloys have become the focus. However, being expensive alloys, it is not presently economical to fabricate the entire burner using these materials. Because of this, up until now the burner designer was left with the challenge of determining how to best attach the non-noble metal portion of the burner to the noble metal tip without sacrificing other concerns, such as good mechanical strength, coolant leak proofing, and noble metal recovery. It would be an advanced in the submerged combustion burner art if new burner designs were able to avoid some or all of these issues, and prolong the run-length or campaign length of the submerged combustion melter.SUMMARY
In accordance with the present disclosure, submerged combustion (SC) burner panels are described that may reduce or eliminate problems with known SC burners, melters, and methods of using the melters to produce molten glass and other non-metallic inorganic materials, such as rock wool and mineral wool.
A combustion burner panel comprising:
- (a) a panel body having first and second major surfaces;
- (b) at least one oxidant through-passage in the panel body extending from the first to the second major surface;
- (c) at least one fuel through-passage in the panel body extending from the first to the second major surface;
- (d) at least one oxidant delivery conduit positioned in the at least one oxidant through-passage;
- (e) at least one fuel delivery conduit positioned in the at least one fuel through-passage;
wherein each of the oxidant delivery conduits and fuel deliver conduits comprise proximal and distal ends, at least some of the distal ends positioned away from the first major surface of the panel body.
Other burner panels, and submerged combustion melters (SCM) comprising at least one burner panel of this disclosure, and methods of producing molten non-metallic inorganic materials such as molten glass, in the SCMs, are considered aspects of this disclosure. Certain methods within the disclosure include methods wherein the fuel may be a substantially gaseous fuel selected from the group consisting of methane, natural gas, liquefied natural gas, propane, carbon monoxide, hydrogen, steam-reformed natural gas, atomized oil or mixtures thereof, and the oxidant may be an oxygen stream comprising at least 90 mole percent oxygen.
Burner panels, melters, and methods of the disclosure will become more apparent upon review of the brief description of the drawings, the detailed description of the disclosure, and the claims that follow.
The manner in which the objectives of the disclosure and other desirable characteristics can be obtained is explained in the following description and attached drawings in which:
It is to be noted, however, that the appended drawings are schematic in nature, may not be to scale, and illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the disclosed SC burner panels, SC burners, SCMs, and methods. However, it will be understood by those skilled in the art that the apparatus and methods covered by the claims may be practiced without these details and that numerous variations or modifications from the specifically described embodiments may be possible and are deemed within the claims. For example, wherever the term “comprising” is used, embodiments where “consisting essentially of” and “consisting of” are explicitly disclosed herein and are part of this disclosure. All published patent applications and patents referenced herein are hereby explicitly incorporated herein by reference. In the event definitions of terms in the referenced patents and applications conflict with how those terms are defined in the present application, the definitions for those terms that are provided in the present application shall be deemed controlling. All percentages herein are based on weight unless otherwise specified.
As explained briefly in the Background, one drawback to present SC burners employing a metallic burner tip of the same or similar material as the remainder of the burner is that, when using such burners in an SCM for the manufacture of glass, the burner tip is placed in an extreme environment. One problem is that the tip of the burner is exposed to the extreme high temperatures of an oxy-gas flame when oxygen-enriched oxidants are used. Such flames, when deflected, can melt the burner tip. Using noble metals and alloys for burner tips presents the additional challenge of attaching the burner tip to the base metal of the remainder of the burner. The present application is devoted to resolving this challenge with a new approach to burner design for submerged combustion.
Various terms are used throughout this disclosure. “Submerged” as used herein means that combustion gases emanate from combustion burners or combustion burner panels under the level of the molten glass; the burners may be floor-mounted, wall-mounted, or in melter embodiments comprising more than one submerged combustion burner, any combination thereof (for example, two floor mounted burners and one wall mounted burner). Burner panels described herein may form part of an SCM floor and/or wall structure. In certain embodiments one or more burner panels described herein may form the entire floor. A “burner panel” is simply a panel equipped to emit fuel and oxidant, or in some embodiments only one of these (for example a burner panel may only emit fuel, while another burner emits oxidant, and vice versa). “SC” as used herein means “submerged combustion” unless otherwise specifically noted, and “SCM” means submerged combustion melter unless otherwise specifically noted.
As used herein the phrase “combustion gases” as used herein means substantially gaseous mixtures comprised primarily of combustion products, such as oxides of carbon (such as carbon monoxide, carbon dioxide), oxides of nitrogen, oxides of sulfur, and water, as well as partially combusted fuel, non-combusted fuel, and any excess oxidant. Combustion products may include liquids and solids, for example soot and unburned liquid fuels.
“Oxidant” as used herein includes air and gases having the same molar concentration of oxygen as air, oxygen-enriched air (air having oxygen concentration greater than 21 mole percent), and “pure” oxygen, such as industrial grade oxygen, food grade oxygen, and cryogenic oxygen. Oxygen-enriched air may have 50 mole percent or more oxygen, and in certain embodiments may be 90 mole percent or more oxygen.
The term “fuel”, according to this disclosure, means a combustible composition comprising a major portion of, for example, methane, natural gas, liquefied natural gas, propane, hydrogen, steam-reformed natural gas, atomized hydrocarbon oil, combustible powders and other flowable solids (for example coal powders, carbon black, soot, and the like), and the like. Fuels useful in the disclosure may comprise minor amounts of non-fuels therein, including oxidants, for purposes such as premixing the fuel with the oxidant, or atomizing liquid or particulate fuels. As used herein the term “fuel” includes gaseous fuels, liquid fuels, flowable solids, such as powdered carbon or particulate material, waste materials, slurries, and mixtures or other combinations thereof.
The sources of oxidant and fuel may be one or more conduits, pipelines, storage facility, cylinders, or, in embodiments where the oxidant is air, ambient air. Oxygen-enriched oxidants may be supplied from a pipeline, cylinder, storage facility, cryogenic air separation unit, membrane permeation separator, or adsorption unit such as a vacuum swing adsorption unit.
Burner panels of the present disclosure aim to solve the problem of short life of SC burners. In certain embodiments this is accomplished by employing separate injection of oxidant and fuel into the material being melted, or molten material, so that the combustion reaction occurs further away from the tip of the burner, thus reducing the exposure of the burner tip to extreme high temperatures ad well as reducing the severity of thermal cycling. There are several embodiments in which this concept could be implemented within the SCM to achieve the final goal of moving combustion away from the tip of the burner. The current design is a design where the fuel is injected with the oxidant such that the fuel is surrounded by oxidant and they immediately begin mixing. By injecting oxidant and fuel separately, the intent of this disclosure is to inject the fuel and oxidant separately to delay mixing and the associated combustion until both fuel and oxidant are further from the burner tip.
Referring again to
Burner body panel 2 may have a thickness “t”, as indicated in
Other options are to use one or more slot nozzles for the introduction of the oxidant or fuel with small radial nozzles inside the oxidant or fuel slot for the introduction of the fuel or oxidant. This would change the glass and burner flows relationship relative to thermal stress and these designs are also easily scaled in size by increasing the length of the slot. Another version of this is replacing the radial nozzles with a small slot inside a larger slot. Again, changing the process dynamics and failure issues with the current shaped burners and allowing the burners to be scaled. These slot designs could also be beneficial to the glass quality and melting process by creating an improved burner for the glass to pass through as it moves through the melter toward the SCM exit.
In embodiment 1000, a plurality of slot nozzles 76, 78, 82, 84, and 86 may be employed for fuel or oxidant, with the other of the two combustion materials injected through surrounding internal spaces 74, 80, and 81 defined by frame pieces 52, 54, 56, and 58, as well as walls 70, 72. The magnitude of width “w” of slot nozzles 76, 78, 82, 84, and 86 is limited by the distance between frame pieces and walls, but may generally range from about 2 to about 10 cm.
Another option to approach separation of the fuel and oxidant is to generate separate permeable, or diffused zones in the melter that emit fuel and oxidant separately. This concept can include arrays of small holes, permeable membranes, porous materials and so forth. These systems may take on many forms. In one such embodiment, discrete zones or panels where each supplies only oxidant or fuel. Another embodiment may be a single panel with primarily oxidant on one side and primarily fuel on the other side with a gradual transition from one end to the other and fuel to oxidant with the center portion of the panel having a mixture of both. This embodiment may also include discrete and variably shaped zones within a given panel where oxidant and fuel may be added separately involving patterns such as checkerboards, waves, and countless others.
Embodiment 1430 illustrated schematically in plan view in
Embodiment 1440 illustrated schematically, in plan view in
Embodiment 1450 illustrated schematically, in plan view in
Referring now to
One or more or all of walls 454A, 454B, 454C, floor 2, and roof 452 may be comprised of a metal shell 472 and a fluid-cooled refractory panel 474.
System embodiment 450 further includes an exhaust stack 456, and submerged combustion fuel and oxidant conduits 4, 6, in burner panel 2 which create during operation a highly turbulent melt indicated at 468. In certain embodiments, fuel and oxidant conduits 4, 6 are positioned to emit fuel and oxidant into molten glass in the melting zone 464 in a fashion so that the gases combust and penetrate the melt generally perpendicularly to floor panel 2. In other embodiments, one or more fuel or oxidant conduits 4, 6 may emit fuel or oxidant into the melt at an angle to floor 2, where the angle may be more or less than 45 degrees, but in certain embodiments may be 30 degrees, or 40 degrees, or 50 degrees, or 60 degrees, or 70 degrees, or 80 degrees.
The initial raw material can be introduced into the melter of system 450 on a batch, semi-continuous or continuous basis. In some embodiments, a port 460 is arranged at end 454A of the melter through which the initial raw material is introduced by a feeder 458. In some embodiments a “batch blanket” 462 may form along wall 454A, as illustrated. Feed port 460 may be positioned above the average glass melt level, indicated by dashed line 466. The amount of the initial raw material introduced into the melter is generally a function of, for example, the capacity and operating conditions of the melter as well as the rate at which the molten material is removed from the melter.
The initial raw material feedstock may include any material suitable for forming molten inorganic materials, such as glass, such as, for example, limestone, glass, sand, soda ash, feldspar and mixtures thereof. In one embodiment, a glass composition for producing glass fibers is “E-glass,” which typically includes 52-56% SiO2, 12-16% Al2O3, 0-0.8% Fe2O3, 16-25% CaO, 0-6% MgO, 0-10% B2O3, 0-2% Na2O+K2O, 0-1.5% TiO2 and 0-1% F2. Other glass compositions may be used, such as those described in Applicant's published U.S. application 2008/0276652. The initial raw material can be provided in any form such as, for example, relatively small particles, or in the case of rock wool or mineral wool manufacture, in large pieces 5 cm or more in diameter.
As noted herein, submerged combustion burners and burner panels may produce violent turbulence of the molten inorganic material in the SCM and may result in sloshing of molten material, pulsing of combustion burners, popping of large bubbles above submerged burners, ejection of molten material from the melt against the walls and ceiling of melter, and the like. Frequently, one or more of these phenomena may result in undesirably short life of temperature sensors and other components used to monitor a submerged combustion melter's operation, making monitoring difficult, and use of signals from these sensors for melter control all but impossible for more than a limited time period. Processes and systems of the present disclosure may include indirect measurement of melt temperature in the melter itself, as disclosed in Applicant's U.S. Pat. No. 9,096,453, using one or more thermocouples for monitoring and/or control of the melter, for example using a controller. A signal may be transmitted by wire or wirelessly from a thermocouple to a controller, which may control the melter by adjusting any number of parameters, for example feed rate of feeder 458 may be adjusted through a signal, and one or more of fuel and/or oxidant conduits 4,6 may be adjusted via a signal, it being understood that suitable transmitters and actuators, such as valves and the like, are not illustrated for clarity.
Referring again to
A fluid-cooled skimmer 480 may be provided, extending downward from the ceiling of the melter vessel and positioned upstream of fluid-cooled transition channel 478. Fluid-cooled skimmer 480 has a lower distal end 482 extending a distance Ls ranging from about 1 inch to about 12 inches (from about 2.5 cm to about 30 cm) below the average melt level 466. Fluid-cooled skimmer 480 may be configured to form a frozen glass layer or highly viscous glass layer, or combination thereof, on its outer surfaces. Skimmer lower distal end 482 defines, in conjunction with a lower wall of melter exit structure 476, a throat 484 of the melter vessel, throat 484 configured to control flow of molten glass from the melter vessel into melter exit structure 476. Preferably, the throat 484 is arranged below average melt level 466. Molten material can be removed from melter exit structure 476 on a batch, semi-continuous basis or continuous basis. In an exemplary embodiment, the molten material continuously flows through throat 484 and generally horizontally through melter exit structure 476 and is removed continuously from melter exit structure 476 to a conditioning channel (not illustrated). Thereafter, the molten material can be processed by any suitable known technique, for example, a process for forming glass fibers.
Certain embodiments may include an overlapping refractory material layer 486 on at least the inner surface of fluid-cooled transition channel 478 that are exposed to molten material. In certain embodiments the overlapping refractory material may comprise a seamless insert of dense chrome, molybdenum, or other dense ceramic or metallic material. The dense chrome or other refractory material may be inserted into the melter exit structure and may provide a seamless transition form the melter vessel to a conditioning channel (not illustrated).
Another optional feature of system embodiment 450 is the provision of a fluid-cooled dam opening 488 in the upper wall or ceiling of melt exit structure 476. Dam opening 488 accommodates a movable, fluid-cooled dam 490, which is illustrated schematically in
Melter apparatus in accordance with the present disclosure may also comprise one or more wall-mounted submerged combustion burners, and/or one or more roof-mounted burners (not illustrated). Roof-mounted burners may be useful to pre-heat the melter apparatus melting zones and serve as ignition sources for one or more submerged combustion burners and/or burner panels. Melter apparatus having only wall-mounted, submerged-combustion burners or burner panels are also considered within the present disclosure. Roof-mounted burners may be oxy-fuel burners, but as they are only used in certain situations, are more likely to be air/fuel burners. Most often they would be shut-off after pre-heating the melter and/or after starting one or more submerged combustion burners. In certain embodiments, if there is a possibility of carryover of batch particles to the exhaust, one or more roof-mounted burners could be used to form a curtain to prevent particulate carryover. In certain embodiments, all submerged combustion burners and burner panels are oxy/fuel burners or oxy-fuel burner panels (where “oxy” means oxygen, or oxygen-enriched air, as described earlier), but this is not necessarily so in all embodiments; some or all of the submerged combustion burners or burner panels may be air/fuel burners. Furthermore, heating may be supplemented by electrical heating in certain embodiments, in certain melter zones.
Suitable materials for glass-contact refractory, which may be present in SC melters and downstream flow channels, and refractory panel bodies of burner panels, include fused zirconia (ZrO2), fused cast AZS (alumina-zirconia-silica), rebonded AZS, or fused cast alumina (Al2O3). The melter geometry and operating temperature, burner body panel geometry, and type of glass or other product to be produced, may dictate the choice of a particular material, among other parameters.
The term “fluid-cooled” means use of a coolant fluid (heat transfer fluid) to transfer heat away from the burner panel or other component (such as structural walls of an SCM), either by the fluid traveling through the refractory of the panel, through conduits positioned in or adjacent the refractory of the panel, and the like, and does not include natural heat transfer that may occur by ambient air flowing past the panel, or ambient air merely existing adjacent a panel. Heat transfer fluids may be any gaseous, liquid, slurry, or some combination of gaseous, liquid, and slurry compositions that functions or is capable of being modified to function as a heat transfer fluid. Gaseous heat transfer fluids may be selected from air, including ambient air and treated air (for example, air treated to remove moisture), inorganic gases, such as nitrogen, argon, and helium, organic gases such as fluoro-, chloro- and chlorofluorocarbons, including perfluorinated versions, such as tetrafluoromethane, and hexafluoroethane, and tetrafluoroethylene, and the like, and mixtures of inert gases with small portions of non-inert gases, such as hydrogen. Heat transfer liquids and slurries may be selected from liquids and slurries that may be organic, inorganic, or some combination thereof, for example, salt solutions, glycol solutions, oils and the like. Other possible heat transfer fluids include steam (if cooler than the expected glass melt temperature), carbon dioxide, or mixtures thereof with nitrogen. Heat transfer fluids may be compositions comprising both gas and liquid phases, such as the higher chlorofluorocarbons.
Certain SCMs of this disclosure may comprise one or more non-submerged burners. Suitable non-submerged combustion burners may comprise a fuel inlet conduit having an exit nozzle, the conduit and nozzle inserted into a cavity of a ceramic burner block, the ceramic burner block in turn inserted into either the SCM roof or the SCM wall structure, or both the SCM roof and SCM wall structure. Downstream flow channels may also comprise one or more non-submerged burners.
In certain SCMs, one or more fuel and/or oxidant conduits in the SCM and/or flow channel(s) downstream thereof may be adjustable with respect to direction of flow of the fuel or oxidant or both. Adjustment may be via automatic, semi-automatic, or manual control. Certain system embodiments may comprise a mount that mounts the fuel or oxidant conduit in a burner panel of the SCM and/or flow channel comprising a refractory, or refractory-lined ball joint. Other mounts may comprise rails mounted in slots in the wall or roof. In yet other embodiments the fuel and/or oxidant conduits may be mounted outside of the melter or channel, on supports that allow adjustment of the fuel or oxidant flow direction. Useable supports include those comprising ball joints, cradles, rails, and the like.
Certain SCMs and method embodiments of this disclosure may include fluid-cooled panels such as disclosed in Applicant's U.S. Pat. No. 8,769,992. Certain systems and processes of the present disclosure may utilize measurement and control schemes such as described in Applicant's U.S. Pat. No. 9,086,453, and/or feed batch densification systems and methods as described in Applicant's U.S. Pat. No. 9,643,869. Certain SCMs and processes of the present disclosure may utilize devices for delivery of treating compositions such as disclosed in Applicant's U.S. Pat. No. 8,973,405.
Certain SCMs and process embodiments of this disclosure may be controlled by one or more controllers. For example, combustion (flame) temperature may be controlled by monitoring one or more parameters selected from velocity of the fuel, velocity of the primary oxidant, mass and/or volume flow rate of the fuel, mass and/or volume flow rate of the primary oxidant, energy content of the fuel, temperature of the fuel as it enters the burner panel, temperature of the primary oxidant as it enters the burner panel, temperature of the effluent, pressure of the primary oxidant entering the burner panel, humidity of the oxidant, burner panel geometry, combustion ratio, and combinations thereof. Certain SCMs and processes of this disclosure may also measure and/or monitor feed rate of batch or other feedstock materials, such as glass batch, cullet, mat or wound roving and treatment compositions, mass of feed, and use these measurements for control purposes.
At high level, the burner panels of the present disclosure include a burner body 3 and three internal chambers inside of the burner panel or melter floor panel, each chamber immediately below the next in elevation, with multiple ports from each of the fuel and oxidant chambers being fitted to eject the fuel and oxidant into the melter interior, and the “topmost” chamber being actively fluid-cooled to both ensure safety and long term survivability of the burner. The general configuration of the three chambers is as illustrated schematically in the simplified vertical cross-sectional view of
Embodiments to provide oxidant supply, fuel supply, cooling supply, and cooling return into and through the various chambers may vary in geometry such that various arrangements of alternating oxidant and fuel ports may be created. Two example configurations are illustrated in schematic plan views, partially in phantom, in
The fluid flow behaviors within each chamber and through the various oxidant and fuel conduits may be altered through a combination of conduit placement, supply placement, chamber height, and placement of any flow diverters, diffusing baffles or screens, or other components within the areas of flow such that all conduits carry purposeful amounts of the total flow, both equal or unequal. Such flow diverters thereby allow the flows out the top surface of the burner to be tailored. For example, diverters may be sized and positioned to ensure all conduits are flowing equally, or may be sized and positioned to give preference to fuel flow more centrally in plan view and oxidant flow more peripherally in plan view, or profiled from lowest to highest flows out the top surface of the burner laterally. Such tailoring, enabled by the design of the burner incorporating chambers, and judiciously positioning such burners within the overall melter floor plan, allows the SCM to have flames that encourage glass flow in specific patterns within the melter, those molten product flow patterns having operational benefit to the glass or other material produced, the melter walls or structure, energy utilization, or other performance attributes.
In the illustrations of
To enable this improved fabrication, the 4 complex parts illustrated in burner embodiment 580 may be formed by one or more methods selected from CNC machining each shape from a billet, EDM cutting each shape from a billet, direct laser metal sintering (such as rapid prototyping, metal 3D printing, SLA printing), near-net or net-shape casting, and other technologies which produce such specially formed shapes from uniform materials.
Further, a heat treatment process may be applied to improve the microstructural attributes and stored stresses of the specially formed shapes, and/or of the completed assembly. The heat treatments are material specific, and include classical time-temperature heat treatments, or time-pressure-temperature treatments (for example, hot isostatic pressing). The treatments enable the desired microstructure in the material within the specially formed shapes, the seams and seam heat-affected zones, and in the full assembly. While there is a specific design illustrated in
A method of fabricating such a burner and burner panel is an aspect of the present disclosure. One method embodiment 750 is illustrated in the logic diagram of
- (i) the planar cap and external wall as a single component;
- (ii) a tube table comprising the fluid conduits, the oxidant conduits, and a first horizontal wall, with two vertical walls positioned about the horizontal wall, wherein the fuel and oxidant conduits are of different lengths;
- (iii) a second horizontal wall having through-passages for oxidant and fuel conduits, and a third vertical wall; and
- (iv) a third horizontal wall having a single vertical wall pendant therefrom;
- (b) fitting components (i)-(iv) together to form a burner sub-assembly (box 754);
- (c) fitting coolant supply and return conduits to the burner sub-assembly (box 756);
- (d) fitting fuel and oxidant supply conduits to the burner sub-assembly (box 758); steps (a)-(d) forming the burner body; and
- (e) fitting or attaching the burner body to the panel body (box 760).
Referring again to
Typically, the improved burner design begins as a circular cylinder of appropriate diameter and length, as illustrated schematically in
At the base 606, the drilled passages 608 are threaded and fittings (not illustrated) may be installed such that the cooling passages 608 are interconnected and have a single coolant supply “CS” and coolant return “CR” as illustrated in
Oxidant and fuel conduits of burner panels of the present disclosure may be comprised of metal, ceramic, ceramic-lined metal, or combination thereof. Suitable metals include carbon steels, stainless steels, for example, but not limited to, 306 and 316 steel, as well as titanium alloys, aluminum alloys, and the like. High-strength materials like C-110 and C-125 metallurgies that are NACE qualified may be employed for burner body components. (As used herein, “NACE” refers to the corrosion prevention organization formerly known as the National Association of Corrosion Engineers, now operating under the name NACE International, Houston, Tex.) Use of high strength steel and other high strength materials may significantly reduce the conduit wall thickness required, reducing weight of the burners and/or space required for burners.
Oxidant and fuel conduits of burner panels of the present disclosure, or tips thereof, may comprise noble metals and/or other exotic corrosion and/or fatigue-resistant materials, such as platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), and gold (Au); alloys of two or more noble metals; and alloys of one or more noble metals with a base metal. In certain embodiments the conduit tip may comprise an 80 wt. percent platinum/20 wt. percent rhodium alloy attached to a base metal conduit using lap joints and brazing, welding or soldering of certain regions of the lap joints, as further explained in Applicant's Patent Cooperation Treaty application No. PCT/US13/42182, published as WO2014189504A1.
The choice of a particular material is dictated among other parameters by the chemistry, pressure, and temperature of fuel and oxidant used and type of melt to be produced. The skilled artisan, having knowledge of the particular application, pressures, temperatures, and available materials, will be able design the most cost effective, safe, and operable burner panels for each particular application without undue experimentation.
The terms “corrosion resistant” and “fatigue resistant” as used herein refer to two different failure mechanisms that may occur simultaneously, and it is theorized that these failure mechanisms may actually influence each other in profound ways. Preferably, burner panels will have a satisfactory service life of at least 12 months under conditions existing in a continuously operating SCM. As used herein the SCM may comprise a floor, a roof, and a sidewall structure connecting the floor and roof defining an internal space, at least a portion of the internal space comprising a melting zone, and one or more combustion burner panels of this disclosure in either the floor, the roof, the sidewall structure, or any two or more of these, producing combustion gases and configured to emit the combustion gases from a position under a level of, and positioned to transfer heat to and produce, a turbulent molten mass of glass containing bubbles in the melting zone.
The total quantities of fuel and oxidant used by burner panels of the present disclosure may be such that the flow of oxygen may range from about 0.9 to about 1.2 of the theoretical stoichiometric flow of oxygen necessary to obtain the complete combustion of the fuel flow. Another expression of this statement is that the combustion ratio may range from about 0.9 to about 1.2.
The velocity of the fuel in the various burner panel embodiments of the present disclosure depends on the burner panel geometry used, but generally is at least about 15 meters/second (m/s). The upper limit of fuel velocity depends primarily on the desired penetration of flame and/or combustion products into the glass melt and the geometry of the burner panel; if the fuel velocity is too low, the flame temperature may be too low, providing inadequate temperature in the melter, which is not desired, and if the fuel flow is too high, flame and/or combustion products might impinge on a melter wall or roof, or cause carryover of melt into the exhaust, or be wasted, which is also not desired. Similarly, oxidant velocity should be monitored so that flame and/or combustion products do not impinge on an SCM wall or roof, or cause carryover of melt into the exhaust, or be wasted. Oxidant velocities depend on fuel flow rate and fuel velocity, but in general should not exceed about 200 fft/sec at 400 scfh flow rate.
A combustion process control scheme may be employed. A master controller may be employed, but the disclosure is not so limited, as any combination of controllers could be used. The controller may be selected from PI controllers, PID controllers (including any known or reasonably foreseeable variations of these) and may compute a residual equal to a difference between a measured value and a set point to produce an output to one or more control elements. The controller may compute the residual continuously or non-continuously. Other possible implementations of the disclosure are those wherein the controller comprises more specialized control strategies, such as strategies selected from feed forward, cascade control, internal feedback loops, model predictive control, neural networks, and Kalman filtering techniques.
The term “control”, used as a transitive verb, means to verify or regulate by comparing with a standard or desired value. Control may be closed loop, feedback, feed-forward, cascade, model predictive, adaptive, heuristic and combinations thereof. The term “controller” means a device at least capable of accepting input from sensors and meters in real time or near-real time, and sending commands directly to burner panel control elements, and/or to local devices associated with burner panel control elements able to accept commands. A controller may also be capable of accepting input from human operators; accessing databases, such as relational databases; sending data to and accessing data in databases, data warehouses or data marts; and sending information to and accepting input from a display device readable by a human. A controller may also interface with or have integrated therewith one or more software application modules and may supervise interaction between databases and one or more software application modules.
The phrase “PID controller” means a controller using proportional, integral, and derivative features. In some cases the derivative mode may not be used or its influence reduced significantly so that the controller may be deemed a PI controller. It will also be recognized by those of skill in the control art that there are existing variations of PI and PID controllers, depending on how the discretization is performed. These known and foreseeable variations of PI, PID and other controllers are considered within the disclosure.
The controller may utilize Model Predictive Control (MPC). MPC is an advanced multivariable control method for use in multiple input/multiple output (MIMO) systems. MPC computes a sequence of manipulated variable adjustments in order to optimise the future behavior of the process in question. It may be difficult to explicitly state stability of an MPC control scheme, and in certain embodiments of the present disclosure it may be necessary to use nonlinear MPC. In so-called advanced control of various systems, PID control may be used on strong mono-variable loops with few or nonproblematic interactions, while one or more networks of MPC might be used, or other multivaiable control structures, for strong interconnected loops. Furthermore, computing time considerations may be a limiting factor. Some embodiments may employ nonlinear MPC.
A feed forward algorithm, if used, will in the most general sense be task specific, meaning that it will be specially designed to the task it is designed to solve. This specific design might be difficult to design, but a lot is gained by using a more general algorithm, such as a first or second order filter with a given gain and time constants.
Although only a few exemplary embodiments of this disclosure have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this disclosure. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, no clauses are intended to be in the means-plus-function format allowed by 35 U.S.C. § 112, Section F, unless “means for” is explicitly recited together with an associated function. “Means for” clauses are intended to cover the structures, materials, and/or acts described herein as performing the recited function and not only structural equivalents, but also equivalent structures.
1. A combustion burner and frame combination, comprising:
- (a) a frame;
- (b) at least one slot nozzle held by the frame, each slot nozzle comprising at least one fuel slot, each fuel slot positioned within a single oxidant slot.
2. The burner and frame combination of claim 1 wherein the frame comprises an outer wall and at least one inner wall, the inner and outer walls forming at least one compartment for the at least one slot nozzle.
3. A combustion burner panel comprising:
- (a) a panel body having first and second major surfaces;
- (b) at least one through-passage in the panel body extending from the first to the second major surface;
- (c) at least one delivery conduit positioned in the at least one oxidant through-passage;
- wherein each of the delivery conduits comprise proximal and distal ends, at least some of the distal ends positioned away from the first major surface of the panel body, and wherein the proximal ends are fluidly connected to a source of fuel and a source of oxidant through valves allowing alternating flow of fuel and oxidant through the delivery conduits.
4. A combustion burner panel comprising:
- (a) a wall structure defining an internal space having a length, a width, and a thickness;
- (b) the internal space completely filled with a material comprising a random or non-random array of pathways therethrough, at least a first portion of the pathways being oxidant pathways, and at least a second portion of the pathways being fuel pathways.
5. The burner panel of claim 4 wherein at least a majority of the pathways extend from a first to a second major surface of the material.
6. The burner panel of claim 4 wherein the wall structure forms a shape selected from the group consisting of rectangular, triangular, and irregular shapes fitting together without gaps.
7. A submerged combustion melter comprising at least one submerged combustion burner panel of claim 1.
8. A submerged combustion melter comprising at least one submerged combustion burner panel of claim 3.
9. A submerged combustion melter comprising at least one submerged combustion burner panel of claim 4.
10. A combustion burner panel comprising:
- (a) a panel body;
- (b) one or more combustion burners randomly or nonrandomly positioned in the panel, each burner comprising: (i) a burner body comprising a substantially planar cap and an external wall and at least two inner walls, the external wall, planar cap, and inner walls arranged to form a fuel chamber, an oxidant chamber, and a coolant chamber, the planar cap having a plurality of fuel and oxidant exits; (ii) at least one fuel conduit fluidly connecting the fuel chamber with a first major exterior surface of the planar cap; (iii) at least one oxidant conduit oxidant conduit fluidly connecting the oxidant chamber with the first major external surface of the planar cap, and (iv) wherein the coolant chamber is positioned closer to the planar cap than both the fuel and oxidant chambers.
11. A method of making the combustion burner panel of claim 9 comprising:
- (a) forming components, in no particular order: (i) the planar cap and external wall as a single component; (ii) a tube table comprising the fluid conduits, the oxidant conduits, and a first horizontal wall, with two vertical walls positioned about the horizontal wall, wherein the fuel and oxidant conduits are of different lengths; (iii) a second horizontal wall having through-passages for oxidant and fuel conduits, and a third vertical wall; and (iv) a third horizontal wall having a single vertical wall pendant therefrom;
- (b) fitting components (i)-(iv) together to form a burner sub-assembly;
- (c) fitting coolant supply and return conduits to the burner sub-assembly;
- (d) fitting fuel and oxidant supply conduits to the burner sub-assembly;
- steps (a)-(d) forming the burner body; and
- (e) fitting or attaching the burner body to the panel body.
12. The method of claim 11 wherein components (i)-(iv) are formed using one or more methods selected from the group consisting of CNC machining each shape from a billet, EDM cutting each shape from a billet, direct laser metal sintering (aka rapid prototyping, metal 3D printing, SLA printing), near-net or net-shape casting, and heat treatment process selected from time-temperature heat treatment and time-pressure-temperature treatments.
Filed: Apr 24, 2020
Publication Date: Aug 20, 2020
Inventors: John Wayne Baker (Golden, CO), Michael William Luka (Littleton, CO), Jonathan McCann (Castle Rock, CO), Aaron Morgan Huber (Castle Rock, CO), Mark William Charbonneau (Highlands Ranch, CO), Paul Oscar Segar (Tucson, AZ), James E Graf (Littleton, CO)
Application Number: 16/857,302