Method and system for heat recovery in an oxygen-fueled glass furnace.

Abstract

Processes and systems for glass manufacturing can utilize heat recovery to improve operational efficiency and flexibility in order to provide improved yield, higher quality, or more consistent quality glass, and / or other efficiencies. Some embodiments can utilize burner operation adjustments to account for different manufacturing conditions to provide improved quality of processed glass and improved glass yield by utilizing heat more efficiently, which can improve the operational efficiency and flexibility of the glass manufacturing process, as well as the environmental impact associated with the manufacturing process.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 524,752, filed on July 3, 2023.

[0002] This disclosure generally relates to processes and systems for producing glass. More specifically, this disclosure relates to processes and related systems for producing glass using heat recovery.

Background Art

[0003] Glass manufacturing is a process that consumes large amounts of energy. This process requires the use of a glass furnace to heat glass - making materials (e.g., sand, soda ash, limestone, dolomite, feldspar, rouge, cullet, or combinations thereof) to a high temperature sufficient to melt the glass - making materials and thereby form glass. To achieve these temperatures, in many cases, the combustion of hydrocarbon fuels (e.g., natural gas) in the glass furnace is used. However, the combustion process produces gaseous combustion products (known as flue gas) that exit the furnace at temperatures significantly above 1000°C. The temperature at which the flue gas exits the furnace represents a significant waste of energy unless the thermal energy of the flue gas is partially recovered from the flue gas.

Summary of the Invention

[0004] It has been determined that glass manufacturing can be configured to provide more efficient and flexible heat utilization, thereby enhancing operational efficiency and reducing the environmental impact associated with glass manufacturing. For example, improved flame and heat generation can be facilitated, which can result in improved starting operation and lower nitrous oxide formation and / or improved use of heat from the heat generated through the combustion of fuel, by more flexible manipulation of flue gas from the combustion of fuel through one or more burners in the furnace used to melt and form glass from glass raw materials. Embodiments can also be configured to provide enhanced flexibility during operation to provide enhanced flexibility for the use of preheated oxidizer, fuel, and raw material feed, and to allow the operation to be adapted to different conditions, thereby enabling the production of more consistent and higher quality glass.

[0005] Some embodiments can be configured and implemented to provide a glass manufacturing process that not only captures the thermal energy of flue gases exiting an oxygen-fueled furnace during glass manufacturing, but also reduces overall energy consumption and, optionally, the amount of nitrous oxide (NOx) produced during glass manufacturing, while simultaneously improving the overall quality of the resulting glass. Embodiments can also be provided so that the utilization of the captured flue gas heat can be adjusted to take into account glass manufacturing parameters, which may affect the quality of the glass being manufactured and other processing parameters (e.g., furnace temperature).

[0006] In a first embodiment, a method for producing glass can be provided. This method involves supplying fuel and oxidizer to a burner in a furnace, burning the fuel to produce glassmaking material for glassmaking, such that (i) at least one burner in at least one upstream zone of the furnace operates in a mode of operation in which the internal flow of fuel and the internal flow of oxidizer are output into the furnace between the upper oxidizer conduit and the lower oxidizer conduit, such that a flame is formed to protrude into the combustion chamber of the furnace without upper oxidizer staging via the upper oxidizer conduit and without lower oxidizer staging via the lower oxidizer conduit, while the oxidizer is below a pre-selected high-temperature oxidizer temperature threshold, and (ii) at least one upstream zone of the furnace Downstream of the furnace, at least one burner in at least one downstream zone of the furnace may be heated to operate in a foam-controlled operating mode, such that the combustion of fuel from at least one burner in at least one downstream zone of the furnace forms an upwardly extending flame, providing a reducing atmosphere adjacent to the glassmaking material in at least one downstream zone of the furnace, dissolving the foam and returning it to the glassmaking material, and the upper oxidizer flow is passed out of the upper oxidizer conduit of the burner along with the inner flow of fuel and the inner flow of oxidizer output into the furnace.

[0007] In some embodiments, all burners in at least one upstream zone can operate without upper and lower oxidizer staging while remaining below a pre-selected high-temperature oxidizer temperature threshold. Additionally, all burners in at least one downstream zone can operate in a foam-controlled operating mode. In some embodiments, the upstream zone may be a first zone, and the downstream zone may be a second zone. In other embodiments, at least one upstream zone may include a first zone, a second zone, and a third zone, and the downstream zone may include a fourth zone and a fifth zone. The second zone may be located between the first and third zones, and the fourth zone may be located between the third and fifth zones.

[0008] Embodiments of this method may include other steps or features. Furthermore, embodiments of a system may be configured to implement embodiments of this method.

[0009] In a second embodiment, the method for producing glass may also include passing the flue gas output from the furnace through an oxidizer preheater located downstream of the furnace between the stack and the furnace to preheat at least a portion of the oxidizer before the oxidizer is supplied to the burner of the furnace. Some embodiments may also include passing the flue gas through a fuel preheater located downstream of the furnace between the stack and the furnace to preheat at least a portion of the fuel before the fuel is supplied to the burner. The fuel preheater may be located upstream or downstream of the oxidizer preheater. The conduit arrangement may be provided such that the fuel can at least partially bypass the fuel preheater, the oxidizer can at least partially bypass the oxidizer preheater, and / or the flue gas can at least partially bypass the oxidizer preheater and / or the fuel preheater. Embodiments of this method may also include in-operation adjustments so that portions of fuel, oxidizer, and / or flue gas bypassing different preheaters can be adjusted to take into account desired operating conditions of the furnace system and / or burner.

[0010] For example, in some embodiments, a method for producing glass may include preheating at least a portion of the oxidizing agent through an oxidizing agent preheater positioned to heat the oxidizing agent before the oxidizing agent is supplied to the burner of the furnace via flue gas output from the furnace, passing through an oxidizing agent preheater, and / or preheating at least a portion of the fuel through a fuel preheater positioned to heat the fuel before the fuel is supplied to the burner of the furnace via flue gas output from the furnace, passing through a fuel preheater.

[0011] In a third embodiment, an embodiment of a method for producing glass may include adjusting the operation of at least one burner in at least one upstream zone of the furnace to a split staging operation mode in which, in response to detecting that the oxidizer is above a pre-selected high-temperature oxidizer temperature threshold, the oxidizer is passed out of the inner oxidizer conduit and the fuel is passed out of the inner fuel conduit, as well as the oxidizer is passed out of the lower oxidizer conduit and also out of the upper oxidizer conduit.

[0012] In a fourth embodiment, an embodiment of a method for producing glass may include adjusting the operation of at least one burner in at least one upstream zone of the furnace to a mode of operation in which the flame has a radiant underside that is facilitated via an oxidizer flow that is passed to the outside of a lower oxidizer conduit, without being provided through an upper oxidizer conduit, in response to detecting that a pre-selected high-temperature oxidizer temperature threshold has been reached. In some embodiments, the flame may have a radiant underside such that radiant heat is directed directly to the upper surface of the glassmaking material in at least one upstream zone of the furnace along an unobstructed radiant path.

[0013] In a fifth embodiment, the method for producing glass may include passing flue gas output from the furnace to a fluid heater to heat a heat transfer medium that can be supplied to a glass manufacturing material preheating device. The fluid heater may be positioned between the stack and the furnace. In some embodiments, the fluid heater may be positioned upstream of the oxidizer preheater and also upstream of the fuel preheater.

[0014] Embodiments of this method may also include feeding a portion of the glassmaking material to a glassmaking material preheating device for preheating the portion of the glassmaking material, and discharging the preheated portion of the glassmaking material from the glassmaking material preheating device and discharging it to a furnace. Preheating of the glassmaking material to be fed to the glassmaking material preheating device can be facilitated via a heated heat transfer medium discharged from a fluid heater.

[0015] In some embodiments, the glass manufacturing feed material preheating device may include a rotatable shaft having a rotatable flight that allows a portion of the glass manufacturing material fed to the glass manufacturing feed material preheating device to pass through the device. In some embodiments, the rotatable shaft may be hollow, and this method may also include passing heated air through the hollow shaft of the glass manufacturing feed material preheating device to enter a portion of the glass manufacturing material as it passes through the device. The heated air may help to facilitate the flow of glass manufacturing material through the glass manufacturing feed material preheating device. In some embodiments, this method may also include outputting heated air to feed through the hollow shaft of the glass manufacturing feed material preheating device, forming a slipstream of a heat transfer medium that is output from a fluid heater and passes through a heat exchanger for heating the air.

[0016] In a sixth embodiment, the method for producing glass may also include adjusting the operation of at least one burner in at least one downstream zone of the furnace to a split staging operation mode in which, in response to detecting that the oxidizer is above a pre-selected high-temperature oxidizer temperature threshold, the oxidizer is passed out of the inner oxidizer conduit and the fuel is passed out of the inner fuel conduit, as well as the oxidizer is passed out of the lower oxidizer conduit and also of the upper oxidizer conduit. This type of adjustment may occur for all burners in at least one downstream zone in some embodiments. This type of adjustment may occur in combination with adjustments in the operation of one or more (or all) of the burners in at least one upstream zone.

[0017] In the seventh embodiment, the method for producing glass may also include adjusting the flow of the oxidizer such that, after the oxidizer is above a pre-selected high-temperature oxidizer temperature threshold, at least a portion of the oxidizer bypasses an oxidizer preheater positioned between the furnace and the stack; and / or adjusting the flow of the fuel such that, after the oxidizer is above a pre-selected high-temperature oxidizer temperature threshold, at least a portion of the fuel bypasses a fuel preheater positioned between the furnace and the stack; and / or adjusting the flow of the flue gas such that, after the oxidizer is above a pre-selected high-temperature oxidizer temperature threshold, at least a portion of the flue gas bypasses the oxidizer preheater and / or the fuel preheater.

[0018] In the eight embodiments, an embodiment of the method of the first embodiment may include one or more features of the second, third, fourth, fifth, sixth, and / or seventh embodiments. Embodiments may also utilize other process steps or elements. Some embodiments may also utilize embodiments of a system for manufacturing glass, or the arrangement of burners in a furnace of such a system. Examples of additional embodiments of this method can be understood, for example, from the exemplary embodiments discussed herein.

[0019] In a ninth aspect, a system for manufacturing glass can be provided. Several embodiments of this system can be adapted to implement embodiments of a method for manufacturing glass. Embodiments of this system may include a furnace having a plurality of zones, including a first zone, a second zone, a third zone, a fourth zone, and a fifth zone. The first zone may be upstream of the fifth zone. The second zone may be between the first and third zones, the third zone may be between the second and fourth zones, and the fourth zone may be between the third and fifth zones.

[0020] This system may also include an oxidizer preheater positioned between the stack and the furnace. The oxidizer preheater can be positioned to facilitate the preheating of the oxidizer before it is supplied to the furnace burner via flue gas output from the furnace. A fuel preheater can be positioned between the stack and the furnace. The fuel preheater can be positioned to facilitate the preheating of the fuel before it is supplied to the furnace burner via flue gas output from the furnace.

[0021] A first zone of the furnace may have at least one burner, and a fifth zone of the furnace may have at least one burner. At least one burner in the first zone may be configured to operate in a mode of operation in which the internal flow of fuel and the internal flow of oxidizer are output into the first zone of the furnace between the upper oxidizer conduit and the lower oxidizer conduit, such that a flame is formed to protrude into the combustion chamber of the furnace without upper oxidizer staging via the upper oxidizer conduit and without lower oxidizer staging via the lower oxidizer conduit, while the oxidizer is below a pre-selected high-temperature oxidizer temperature threshold. At least one burner in the fifth zone can be configured to operate in a bubble-controlled operating mode, such that while the temperature is below a pre-selected high-temperature oxidizer temperature threshold, the combustion of fuel from at least one burner in the fifth zone of the furnace forms an upwardly extending flame, providing a reducing atmosphere adjacent to the glassmaking material in the fifth zone of the furnace, dissolving the bubbles and returning them to the glassmaking material, and the upper oxidizer flow is passed out of the upper oxidizer conduit of the burner, along with the inner flow of fuel and the inner flow of oxidizer output into the fifth zone of the furnace.

[0022] In this embodiment of the system, all burners in the first zone can be configured to operate in the same operating mode. All burners in the fifth zone can be configured to operate in the same foam control operating mode.

[0023] In a tenth aspect, the system can also be provided such that the furnace adjusts its operation in response to the oxidizer being above a pre-selected high-temperature oxidizer temperature threshold, such that at least one burner in the first zone of the furnace adjusts to a split staging operating mode in which, in addition to the oxidizer being passed out of the inner oxidizer conduit and the fuel being passed out of the inner fuel conduit, the oxidizer is also passed out of the lower oxidizer conduit and also of the upper oxidizer conduit. Alternatively, at least one burner in the first zone can also be configured to adjust its operation in response to the oxidizer being above a pre-selected high-temperature oxidizer temperature threshold, such that at least one burner in the first zone of the furnace adjusts to a mode in which the flame has a radiating underside that is facilitated via an oxidizer flow that is passed out of the lower oxidizer conduit without being provided through the upper oxidizer conduit of at least one burner in the first zone of the furnace.

[0024] In an eleventh embodiment, the system may include a fluid heater positioned to receive flue gas output from the furnace in order to heat a heat transfer medium that can be fed to a glass manufacturing feed material preheating device. In some embodiments, the fluid heater may be positioned between the stack and the furnace, such that the fluid heater is downstream of an oxidizer preheater and / or a fuel preheater. The glass manufacturing feed material preheating device may be positioned to receive a portion of the glass manufacturing material, preheat a portion of the glass manufacturing material, and output the preheated portion of the glass manufacturing material for feeding to a first zone of the furnace.

[0025] In some embodiments, the glass manufacturing feed material preheating device can include a rotatable shaft having flights that are rotatable to pass a portion of the glass manufacturing material fed to the glass manufacturing feed material preheating device through the glass manufacturing feed material preheating device. The heat exchanger can receive a slip stream of the heat medium output from the fluid heater to heat air and position it to feed the heated air into the hollow shaft of the glass manufacturing feed material preheating device (for example, the rotatable shaft having flights may be hollow to receive the heated air). The hollow shaft can have holes such that the heated air can pass through a portion of the glass manufacturing material as it passes through the glass manufacturing feed material preheating device.

[0026] In a twelfth aspect, the system can be provided such that at least one burner in the fifth zone of the furnace is also configured to operate in a split staging mode of operation where the oxidant is passed outside the inner oxidant conduit, the fuel is passed outside the inner fuel conduit, the oxidant is passed outside the lower oxidant conduit, and also passed outside the upper oxidant conduit, and the furnace is configured to adjust its operation in response to being at or above a preselected high temperature oxidant temperature threshold.

[0027] In a thirteenth aspect, embodiments of the system of the ninth aspect can include other elements or features. For example, embodiments of the system of the ninth aspect can include one or more features of the tenth, eleventh, or twelfth aspects. Embodiments of this system can also include process control elements. Examples of additional embodiments of this system can be understood, for example, from the exemplary embodiments discussed herein.

[0028] In a 14th aspect, an apparatus for preheating glass manufacturing materials to be fed into a furnace for heating therein is provided. The apparatus can include a glass manufacturing feed material preheating device positioned to receive a portion of the glass manufacturing materials, preheat a portion of the glass manufacturing materials, and output the preheated portion of the glass manufacturing materials for feeding into the furnace. The glass manufacturing feed material preheating device can include a rotatable shaft having flights positioned within an inner conduit of the glass manufacturing feed material preheating device. The rotatable shaft can be connectable to a motor and drive rotation of the rotatable shaft to move a portion of the glass manufacturing materials through the glass manufacturing feed material preheating device. The glass manufacturing feed material preheating device can have an annular conduit surrounding at least a portion of the inner conduit such that a heat medium can pass through the annular conduit to heat a portion of the glass manufacturing materials passing through the inner conduit via rotation of the rotatable shaft.

[0029] Embodiments of the apparatus for preheating glass manufacturing materials can be utilized in embodiments of a system for manufacturing glass and / or a method for generating glass.

[0030] Embodiments of this apparatus can include a motor operably coupled to the rotatable shaft to drive rotation of the shaft. In some embodiments, for example, at least one coupling can be provided to facilitate the connection between the motor and the rotatable shaft to ease rotation of the shaft.

[0031] In a 15th aspect, an apparatus for preheating glass manufacturing materials can include a heat exchanger positioned to output heated air for heating air and feeding it to the rotatable shaft. The rotatable shaft can be a hollow shaft having holes. The hollow shaft can be configured to receive heated air from the heat exchanger to pass the heated air through the holes of the hollow shaft into the inner conduit.

[0032] In the sixteenth embodiment, the apparatus for preheating glassmaking materials may also include other features. For example, the apparatus of the fourteenth embodiment may include one or more features and / or other elements or features of the fifteenth embodiment. Examples of additional embodiments of the apparatus for preheating glassmaking materials can be understood, for example, from the exemplary embodiments discussed herein.

[0033] It should be understood that the embodiments can utilize a variety of different conduit arrangements and process control elements. Embodiments may utilize sensors (e.g., pressure sensors, temperature sensors, flow sensors, concentration sensors, etc.), controllers, valves, piping, and other process control elements. Some embodiments can utilize, for example, automatic process control systems and / or distributed control systems (DCS). By utilizing a variety of different conduit arrangements and process control systems, a specific set of design criteria can be met.

[0034] Further details, objectives, and advantages of the process for operating a burner for glassmaking, the process for glassmaking, the process apparatus for glassmaking, the devices for glassmaking, and the methods for manufacturing and using them will become apparent as the following description of their specific exemplary embodiments progresses. [Brief explanation of the drawing]

[0035] Exemplary embodiments of apparatus for glassmaking, processes for glassmaking, devices for glassmaking, processes and apparatus for controlling burners for glassmaking, and methods for manufacturing and using them are shown in the drawings included herein. It should be understood that the same reference numerals used in the drawings may identify the same components. [Figure 1] A schematic block diagram of a first exemplary embodiment of an apparatus for glass manufacturing. An exemplary embodiment of a glass manufacturing process that can be carried out by this embodiment is also illustrated in Figure 1. [Figure 2] A schematic block diagram of a second exemplary embodiment of an apparatus for glass manufacturing. An exemplary embodiment of a process for glass manufacturing that can be carried out by this embodiment is also illustrated in Figure 2. [Figure 3] A schematic block diagram of a third exemplary embodiment of an apparatus for glass manufacturing. An exemplary embodiment of a glass manufacturing process that can be carried out by this embodiment is also illustrated in Figure 3. [Figure 4] A schematic block diagram of a fourth exemplary embodiment of the apparatus for glass manufacturing. An exemplary embodiment of the process for glass manufacturing that can be carried out by this embodiment is also illustrated in Figure 4. [Figure 5] A schematic diagram of an exemplary embodiment of a furnace 6 having a burner 6, which can be used in the first, second, third, and fourth exemplary embodiments of the apparatus shown in Figures 1, 2, 3, and 4. [Figure 6] A schematic side cross-sectional view of an exemplary embodiment of the burner 6 in a first operating mode, which can be used in the first, second, third, and fourth exemplary embodiments of the apparatus shown in Figures 1, 2, 3, and 4. [Figure 7] A schematic side cross-sectional view of an exemplary embodiment of the burner 6 in a second operating mode, which can be used in the first, second, third, and fourth exemplary embodiments of the apparatus shown in Figures 1, 2, 3, and 4. [Figure 8] A schematic side cross-sectional view of an exemplary embodiment of the burner 6 in a third operating mode, which can be used in the first, second, third, and fourth exemplary embodiments of the apparatus shown in Figures 1, 2, 3, and 4. [Figure 9] A schematic side cross-sectional view of an exemplary embodiment of burner 6, which can be used in the first, second, third, and fourth exemplary embodiments of the apparatus shown in Figures 1, 2, 3, and 4, and can be configured for use in the exemplary operating modes shown in Figures 6, 7, and 8. [Figure 10]A schematic side cross-sectional view of an exemplary embodiment of burner 6, which can be used in the first, second, third, and fourth exemplary embodiments of the apparatus shown in Figures 1, 2, 3, and 4, and can be configured for use in the exemplary operating modes shown in Figures 6, 7, and 8. [Figure 11] Schematic side cross-sectional view of an embodiment of a glass manufacturing material feeding preheating device 26, which can be used in the first, second, third, and fourth exemplary embodiments of the apparatus shown in Figures 1, 2, 3, and 4. The outer conduit 26d through which the heated fluid can pass for heating the material is omitted from this figure. [Figure 12] Figure 11 shows a schematic cross-sectional view of an exemplary embodiment of a glass manufacturing material feeding preheating device 26. [Figure 13] A flowchart illustrating an exemplary embodiment of a process for glass manufacturing. [Modes for carrying out the invention]

[0036] Referring to Figures 1 to 4, an exemplary embodiment of the apparatus for glassmaking can be configured as System 2 for glassmaking. System 2 may include a glass furnace 4 comprising at least one burner 6, an oxidizer heater 8, a fuel heater 10, and a stack 12. A flue gas conduit arrangement 14 may be positioned between the furnace 4 and the stack 12 to deliver flue gas output from the furnace 4 to the stack 12 for release into the atmosphere. The apparatus may also include a glass material preheater device 26 positioned to preheat at least a portion of the feed of glassmaking material before the glassmaking material is fed into the furnace 4.

[0037] Embodiments may also include other elements. For example, System 2 may also include a contamination control device 36, a sulfur reagent source 40, a nitrous oxide (NOx) reagent source 42, and / or a cooling medium source 30. System 2 may also include a glass manufacturing feed material source (batch / cullet), a fuel source 20 for feeding to the burner 6 of the furnace, and an oxidizer source 20 for feeding to the burner 6 and / or furnace 4 for combustion of the fuel for heating the glass manufacturing feed material in the furnace 4.

[0038] The furnace 4 may be configured to receive glassmaking material to heat the glassmaking material within the furnace via one or more flames FL generated by burners 6 positioned on or adjacent to the side walls, end walls, and / or highest points of the furnace 4. The flames FL can be formed through the combustion of fuel supplied to the burners for output into the combustion chamber of the furnace 4. An oxidizer from an oxidizer supply source 20 may be supplied to the burners 6 to facilitate the combustion of the fuel and form the flames FL.

[0039] Burner 6 may be an oxygen fuel burner, a transient heating burner, or another suitable burner. The oxidizer may be air, oxygen-enriched air, or another suitable oxidizer. The fuel may be natural gas or another suitable fuel for combustion of the fuel to form the flame FL.

[0040] Glassmaking materials (batch / cullet) may include sand, soda ash, limestone, dolomite, feldspar, rouge, cullet, or combinations thereof. Glassmaking materials may also include other raw materials (e.g., additives). Furnace 4 may be configured to heat the glassmaking materials as they pass through the furnace so that glass (glass) is output as a finished product. The output glass may then be further cooled, polished, cut, and / or otherwise processed for storage and / or supply. The formed glass, which is incorporated into a finished product (e.g., windshield, window, etc.), may be suitable for use and / or manufacture.

[0041] The fuel source 20 can be positioned to supply fuel to the burner 6 of the reactor 4 via a fuel supply conduit arrangement. A compressor, fan, or other type of flow drive mechanism can be used to facilitate the flow of fuel to the burner 6.

[0042] The fuel supply conduit arrangement may include a valve 22 that controls the flow of fuel so that a portion of the fuel can be moved to the burner 6 without being preheated, and (or alternatively), a portion of the fuel heated upstream of the burner 6 between the fuel source 20 and the burner 6 may also pass through the fuel preheater 10 via heat from the flue gas passing through the fuel preheater 10. The heat from the flue gas can be at least partially captured through the fuel preheater and provide preheat to the fuel to be supplied to the burner 6 for combustion in the combustion chamber of the furnace 4 for the formation of the flame FL. Fuel preheating can be performed via valve 22 such that the valve is in a first position where the fuel is not preheated at all, a second position where all the fuel passes through the fuel preheater 10 for preheating, and at least one third position where the preheated portion of the fuel passes through the fuel preheater 10 for preheating, and the unpreheated portion of the fuel bypasses the fuel preheater 10 via a fuel preheater bypass conduit so that the fuel portion does not receive preheating before being supplied to the burner 6. The preheated and unpreheated portions can be mixed via an in-line mixer or other fuel mixing device connected to the fuel preheater bypass conduit and the outlet of the fuel preheater 10. The mixing device can be positioned between the outlet of the fuel preheater 10 and the burner 6 to merge the fuel flow for supplying the fuel to the burner 6.

[0043] In some embodiments, the valve 22 may include multiple valves (e.g., a first valve in the fuel preheater feed conduit and a second valve in the fuel preheater bypass conduit). These valves may be adjustable between open and closed positions to provide a preheated fuel portion and / or an unpreheated fuel portion, instead of using a single multi-position valve.

[0044] The oxidizer source 16 can supply an oxidizer (e.g., air, oxygen-enriched air, commercial pure oxygen, etc.) to the burner 6 of the furnace and / or other outlets for the oxidizer in the furnace 4 in order to supply an oxidizer to the furnace 4 in order to assist in the combustion of the fuel and / or the generation of flame FL in the combustion chamber of the furnace 4. A compressor, fan, or other type of flow drive mechanism can be used to facilitate the flow of the oxidizer to the burner 6 and / or the furnace 4.

[0045] The oxidant supply conduit arrangement can be positioned between the oxidant supply source 16 and the burner 6 and / or furnace 4 so that the oxidant can be supplied to an oxidant preheater 8 positioned between the oxidant supply source 16 and the burner 6, so that the oxidant can be preheated via the flue gas output from the furnace 4 before the flue gas is output through the stack 12. The flue gas can be used as a heat transfer medium to preheat the oxidant.

[0046] For example, the oxidizer supply conduit arrangement may include a valve 18 that controls the flow of the oxidizer so that a portion of the oxidizer can be moved to the burner 6 without being preheated, and (or alternatively), a portion of the oxidizer heated upstream of the burner 6 between the oxidizer source 16 and the burner 6 may also pass through the oxidizer preheater 8 via heat from the flue gas passing through the oxidizer preheater 8. The heat from the flue gas can be at least partially captured via the oxidizer preheater 8 to preheat the oxidizer to be supplied to the burner 6 in order to facilitate the combustion of the fuel in the combustion chamber of the furnace 4 for the formation of the flame FL. Preheating of the oxidizer can be facilitated via valve 18 such that valve 18 is in a first position where the oxidizer is not preheated at all, a second position where all of the oxidizer passes through the oxidizer preheater 8 for preheating, and at least one third position where the preheated portion of the oxidizer passes through the oxidizer preheater 8 for preheating, and the unpreheated portion of the oxidizer bypasses the oxidizer preheater 8 and is therefore not preheated before being supplied to the burner 6. The preheated and unpreheated portions can be mixed via an in-line mixer or other oxidizer mixer connected to the oxidizer bypass conduit and the outlet of the oxidizer preheater 8. The mixing device can be positioned between the outlet of the oxidizer preheater 8 and the burner 6 to merge the flow of oxidizer for supplying the oxidizer to the burner 6 and / or furnace 4.

[0047] In some embodiments, the valve 18 may include multiple valves (e.g., a first valve in the oxidizer preheater supply conduit and a second valve in the oxidizer preheater bypass conduit). These valves may be adjustable between open and closed positions to provide a preheated oxidizer portion and / or a non-preheated oxidizer portion, instead of using a single multi-position valve.

[0048] The glassmaking material source (batch / cullet) may include solid materials, which may be in granular form or other types of relatively dry bulk forms (e.g., pellets, lumps, finely ground, fine particle size, etc.). The glassmaking material source may be connected to the furnace 4 to supply glassmaking material to the furnace for melting inside to form glass to be output from the furnace 4, via a glassmaking material supply conduit arrangement positioned between the glassmaking material source and the furnace 4.

[0049] At least a portion of the glassmaking material can be fed to a glassmaking material preheating device 26, which is positioned between the furnace 4 and the glassmaking material supply source (batch / cullet). The glassmaking material preheating device 26 can be positioned so that it can be used optionally. No material should be fed to the glassmaking material preheating device 26 when the furnace is started at a low temperature. After the furnace is started and combustion has occurred, at least a portion of the glassmaking material can be fed to the glassmaking material preheating device 26 to preheat the material before it is fed into the furnace 4. A motor-driven conveyor or other glassmaking material feeding drive mechanism can be used to help feed the flow of glassmaking material to the furnace 4 and / or the glassmaking material preheating device 26.

[0050] The glass manufacturing feed material preheating device 26 can utilize a heat transfer medium that can be heated via heat from the flue gas, which can pass through a fluid heater 24 positioned between the furnace 4 and the stack 12, so that the heat transfer medium used to heat the glass manufacturing material in the glass manufacturing feed material preheating device 26 can be heated via heat from the flue gas, which can utilize heat from the flue gas. For example, the fluid heater 24 can receive a flow of heat transfer medium (for example, a heat transfer fluid suitable for receiving heat from the flue gas via the fluid heater 24 and providing that heat to heat the glass manufacturing material that has passed through the glass manufacturing feed material preheating device 26, and examples of such heat transfer fluids include kerosene, DOWTHERM A available from Dow Chemical Company, glycol-based heat transfer fluids, etc.). The heated heat transfer medium can be output from the fluid heater 24 and fed to the glass manufacturing feed material preheating device 26 to pass through the outer conduit 26d surrounding the inner conduit 26e through which the glass manufacturing material passes. The heat transfer medium can pass through the outer conduit 26d in a counterflow configuration compared to the glass manufacturing material passing through the inner conduit 26e of the glass manufacturing material preheating device 26, or the heat transfer medium can pass through the outer conduit 26d in a parallel flow configuration together with the glass manufacturing material passing through the inner conduit 26e of the glass manufacturing material preheating device 26.

[0051] The heat transfer fluid, cooled through heating of the glass manufacturing material, can be output from the glass manufacturing material preheating device 26 to be supplied to a fluid heater 24 for reheating for subsequent use in a closed-circuit configuration. A pump 28 of another heat transfer fluid drive mechanism can be connected to a heat transfer fluid conduit arrangement positioned between the fluid heater 24 and the glass manufacturing material preheating device 26 to facilitate the flow of heat transfer fluid for use in the glass manufacturing material preheating device 26.

[0052] As best seen in Figures 11 and 12, the glass manufacturing feed material preheating device 26 may have an inlet through which the glass manufacturing material can be fed into the inner conduit 26e of the glass manufacturing feed material preheating device 26 as a feed flow 26f. The glass manufacturing feed material preheating device 26 may include a rotatable shaft 26s having flights 26t extending from a shaft that can rotate via the rotation of the shaft 26s, which can help direct the flow of the glass manufacturing material through the inner conduit 26e to an outlet of the glass manufacturing feed material preheating device 26 through which a preheated flow 26o of the glass manufacturing material can be fed to the furnace 4.

[0053] The shaft 26s of the glass manufacturing material feeding preheating device 26 may be hollow to allow a heated airflow 11 to pass through the shaft 26s. The shaft 26s may have a hole 26h that communicates with a hollow cavity in the shaft 26s through which the heated airflow passes, allowing the heated airflow 11a passing through the shaft 26s (for example, as indicated by the arrow in Figure 12) to be passed out of the hole 26h of the shaft 26s and into the inner conduit 26e to mix with the glass manufacturing material passing through the inner conduit 26e via the rotation of the shaft 26s having a flight 26t. The heated air may help to heat the glass manufacturing material. The heated airflow can be provided at a speed sufficient to prevent the reverse movement of the solid glass manufacturing material in the inner conduit 26e. The velocity of the heated air 11 passing through shaft 26s and exiting hole 26h can also be made low enough so that no fluidization of the solid material occurs as it passes through the glass manufacturing material preheating device 26, and so that the glass manufacturing material, heated via the heat transfer medium passing through the outer conduit 26d surrounding the inner conduit 26e, has sufficient residence time in the glass manufacturing material preheating device 26 to preheat the glass manufacturing material to a pre-selected desired preheating temperature. The heated air passing through the glass manufacturing material preheating device 26 can be output from the outlet of the glass manufacturing material preheating device 26 as a cooled airflow 11o. This cooled airflow 11o may still be partially warm and can be sent to the flue gas conduit arrangement 14, as shown by the dashed lines in Figures 1, 2, 3, and 4, to pass through one or more preheaters and / or fluid heaters 24 before being sent to the stack 12.

[0054] The glass manufacturing material preheating device 26 may include a motor 26m that is coupled to a shaft 26s and can rotate the shaft 26s. A rotating coupling 26r can be positioned to connect the motor 26m to the shaft 26s so that the motor can drive the rotation of the shaft 26s at a desired rotational speed, while a heated airflow 11 can be introduced from a non-rotating conduit into the hollow cavity of the shaft 26s. The rotational speed of the shaft 26s may be a pre-selected speed to facilitate a desired level or residence time in the glass manufacturing material preheating device 26 for preheating glass manufacturing materials.

[0055] The heated airflow 11 can be supplied by a compressor, fan, or other air source that supplies an airflow AR through a heat exchanger HX that outputs the heated airflow 11, utilizing a slipstream SL of the heat transfer medium to supply the airflow AR to the shaft 26s of the glass manufacturing material preheating device 26, as a heat transfer medium for preheating the air. The heated airflow 11 output from the heat exchanger HX can be supplied to the glass manufacturing material preheating device 26 to be supplied into the hollow shaft 26s. The cooled heat transfer medium passing through the heat exchanger HX can be output from the heat exchanger HX as cooled heat transfer medium OC and then supplied to a heat transfer medium conduit arrangement at a location between the fluid heater 24 and the glass manufacturing material preheating device 26 to be mixed with the cooled heat transfer medium output from the glass manufacturing material preheating device 26 to be supplied to the fluid heater 24.

[0056] As shown by the dashed lines in Figures 1, 2, 3, and 4, a slipstream heat transfer conduit arrangement can be positioned between the heat exchanger HX and the fluid heater 24 to facilitate the slipstream flow SL of the heat transfer medium. The slipstream heat transfer conduit arrangement may include valves positioned to control the flow rate of the heat transfer medium passing through the slipstream conduit arrangement to pass through the heat exchanger HX for heating the airflow AR. An airflow conduit arrangement can be positioned between the glass manufacturing material preheating device 26 and the flue gas conduit arrangement 14 to supply air output from the glass manufacturing material preheating device 26 to the flue gas conduit 14. The air supply conduit of the glass manufacturing material preheating device 26 can be positioned between the heat exchanger HX and the glass manufacturing material preheating device 26 to supply a heated airflow to the glass manufacturing material preheating device 26, passing through the shaft 26s and entering the inner conduit 26e of the glass manufacturing material preheating device 26.

[0057] In some embodiments, the flue gas conduit arrangement 14 can be positioned so that the flue gas output from the furnace 4 passes through the oxidizer preheater 8, then the fuel preheater 10, and then the fluid heater 24. After the flue gas is output from the glass manufacturing feed material preheating device 26, the flue gas can be sent to the stack 12 or to a contamination control unit 36 ​​positioned between the stack 12 and the glass manufacturing feed material preheating device 26. Alternatively, the contamination control unit 36 ​​can be positioned at another location between the stack 12 and the furnace 4. For example, the contamination control unit 36 ​​can be positioned between the furnace 4 and the oxidizer preheater 8 to process the flue gas before it passes through the oxidizer preheater 8, the fuel preheater 10, and the fluid heater 24.

[0058] In some embodiments, a first contamination control unit 36 ​​may be located upstream of the oxidizer preheater 8, the fuel preheater 10, and the fluid heater 24, and a second contamination control unit 36 ​​may be located downstream of these heat exchangers, either between the stack 12 and the fluid heater 24 (e.g., the dashed second contamination control unit 36 ​​shown in Figure 1) or between the stack 12 and the fuel preheater 10 (e.g., the dashed second contamination control unit shown in Figures 1 and 2). In such embodiments, the first contamination control unit may be configured to limit or avoid fouling of the heat exchangers, and the second contamination control unit may be configured to remove sulfur and / or NOx from the flue gas by removing any particulate matter present via the injection of reagents (e.g., the second contamination control unit 36 ​​may include a particulate removal mechanism, and the first contamination control unit 36 ​​may be configured for sulfur removal and / or removal of other fouling elements from the flue gas output from the furnace 4).

[0059] In other embodiments, a first contamination control unit 36 ​​may be positioned upstream of the oxidizer preheater 8, the fuel preheater 10, and the fluid heater 24, as well as a second contamination control unit 36 ​​positioned between the fluid heater 24 and the fuel preheater 10, as shown by the dashed line in Figure 2. In such embodiments, the positioning of the second contamination control unit 36 ​​can allow flue gas to be at a temperature high enough to facilitate the removal of sulfur and NOx before being supplied to the fluid heater 24. This type of arrangement may be desired in situations where flue gas may be output from the fluid heater 24 at a temperature too low for sufficient operation of the contamination control unit 36, for example.

[0060] The pollution control unit 36 ​​can be connected to a sulfur reagent source 40, which can be configured to supply sulfur reagents to the pollution control unit 36 ​​in order to help reduce the level of sulfur in the flue gas. For example, the sulfur reagent source 40 may contain a calcium or sodium-containing compound, such as sodium sesquicarbonate dihydrate, for use in the pollution control unit to remove sulfur from the flue gas. The sulfur reagent from the sulfur reagent source can be supplied to the pollution control unit 36 ​​via a sulfur reagent supply conduit positioned between the sulfur reagent source 40 and the pollution control unit 36.

[0061] The NOx reagent source 42 can be connected to the flue gas conduit arrangement 14 to supply at least one type of NOx reagent to the flue gas moving from the furnace 4 to the stack 12 and to reduce the level of NOx in the flue gas. The NOx reagent may include, for example, urea and / or ammonia. The NOx reagent supply conduit can be positioned between the NOx reagent source 42 and the flue gas conduit arrangement 14 to supply the NOx reagent to the flue gas moving from the furnace 4 to the stack 12 in order to reduce the level of NOx in the flue gas. In some embodiments, the NOx reagent can be supplied to the flue gas conduit arrangement so that the NOx reagent is injected into the flue gas between the furnace 4 and the oxidizer preheater 8 and / or between the furnace 4 and the pollution control unit 36.

[0062] The system may also utilize a cooling medium source 30. In some embodiments, the cooling medium may include, for example, air, partially cooled and recirculated flue gas, or water. The cooling medium source 30 may be connected to the flue gas conduit arrangement 14 via a cooling medium supply conduit arrangement positioned between the cooling medium source 30 and the flue gas conduit arrangement 14 to supply the cooling medium to the flue gas at one or more locations between the furnace and the stack 12 in order to help cool the flue gas to a more desired temperature. The addition of water or other cooling medium to the flue gas may also be provided to facilitate NOx removal, sulfur removal, or other contamination control treatments.

[0063] The cooling medium supply conduit arrangement may include a first control valve 32 and a second control valve 38 for regulating the flow of the cooling medium to the flue gas at different locations. The first control valve 32 may be communicably connected to a first flue gas temperature sensor 34, which can be positioned to detect the temperature of the flue gas upstream of the contamination control unit 36 ​​and / or upstream of the oxidizer preheater 8. The first control valve 32 may be adjusted from a closed position to a fully open position (e.g., fully closed, at least one intermediate partially open position, fully open position, etc.) to control the flow of the cooling medium to the flue gas upstream of the contamination control unit 36 ​​and / or the oxidizer preheater 8 so that the flue gas passing downstream of the first cooling medium injection point is below a pre-selected temperature suitable for supplying to the downstream elements.

[0064] The second control valve 38 can be positioned to control the injection of the cooling medium upstream of the oxidizer preheater 8 and downstream of a first location which can be controlled via the first control valve 32. The second control valve 38 can be communicated to a second flue gas temperature sensor 35 which can be positioned to detect the temperature of the flue gas upstream of the oxidizer preheater 8. The second control valve 38 can be adjusted from a closed position to a fully open position (e.g., fully closed, at least one intermediate partially open position, fully open position, etc.) to control the flow of the cooling medium to the flue gas upstream of the oxidizer preheater 8 so that the flue gas passing downstream of the second cooling medium injection location is below a pre-selected temperature suitable for supplying to the downstream elements.

[0065] In some embodiments, only a control valve 38 located upstream of the oxidizer preheater 8 may be present. In such embodiments, this control valve may be considered a first control valve. In situations where the contamination control unit 36 ​​is further downstream and located closer to the stack 12, the coolant supply conduit may be configured to supply the coolant upstream of the contamination control unit 36 ​​and downstream of the fluid heater 24 and / or fuel preheater 10 and / or oxidizer preheater 8. In such embodiments, the control valve may be positioned to adjustably control the supply of the coolant injected into the flue gas upstream of the contamination control unit. A temperature sensor located upstream of the contamination control unit may be used to detect the temperature of the flue gas, providing data to the control unit to facilitate control of the flow of coolant injected at this location.

[0066] As can be best understood from Figures 3 and 4, the flue gas conduit arrangement 14 can include a preheater bypass conduit that can be positioned to extend from the bypass valve 39 of the flue gas conduit arrangement to a location downstream of the oxidizer preheater 8, the fuel preheater 10, and / or the fluid heater 24, thereby preventing hotter flue gas from passing through these heat exchangers. The bypass valve 39 can be adjusted between a fully open position and a fully closed position, so that when the valve is in the fully open position, all flue gas can bypass these heat exchangers, and when the valve is in the fully closed position, no flue gas bypasses these heat exchangers at all. The bypass valve 39 can also have one or more intermediate positions so that a bypass portion of the flue gas can bypass the heat exchangers, while another portion of the flue gas can pass through the oxidizer preheater 8, the fuel preheater 10, and the fluid heater 24.

[0067] In embodiments where the pollution control unit 36 ​​is located upstream of the heat exchanger, the bypass valve 39 can be positioned between the pollution control unit 36 ​​and the heat exchanger (e.g., the oxidizer preheater 8, the fuel preheater 10, and the fluid heater 24). In other embodiments, the preheater bypass conduit of the flue gas conduit arrangement 14 can be positioned so that flue gas bypassing the heat exchanger is supplied to the pollution control unit 36. An example of such an arrangement is shown in Figure 4.

[0068] The cooled airflow 11o output from the glass manufacturing material preheating device 26 can be supplied to the flue gas conduit arrangement 14 upstream of the bypass valve 39. Since the cooled airflow 11o may contain some trapped dust from contact with the glass manufacturing material in the glass manufacturing material preheater 26, the location where the cooled airflow 11o is supplied into the flue gas conduit arrangement 14 may be upstream of the contamination control unit 36, as well as one or more of the preheaters and / or fluid heaters 24.

[0069] Embodiments of System 2 may also utilize one or more purge block valves 48. The purge block valves 48 can be positioned at various points in System 2 to allow the flow of purge gas through various units (e.g., the oxidizer preheater 8 and the fuel preheater 10). In certain cases, the function of the purge gas is to remove all residual oxidizer in the oxidizer preheater 8 or fuel preheater 10 immediately after an emergency shutdown of System 2 to reduce the possibility of unwanted ignition. In addition, the purge may also function to remove any residual oxygen that may have diffused upstream during an emergency shutdown event. Nitrogen or other suitable gases may be used as the purge gas.

[0070] The purge block valve 48 may also be configured to connect to one or more other valves at the outlet of the heated oxidizer or fuel conduit so that if the oxidizer or fuel bypasses its respective preheater and one or more of the additional outlet valves are closed, the pressurized fluid can be supplied through the purge block valve 48 to pressurize the inner conduit of the preheater. The purge block valve 48 can then be closed, and the pressure can be measured over time (measuring device not shown) to determine whether there is a conduit leak in the preheater, preheater inlet, or preheater outlet.

[0071] In some embodiments, changes in the temperature, pressure, or composition of the flue gas can be detected via at least one sensor inside or downstream of the oxidizer preheater 8 to detect oxidizer leaks that may occur and require attention. Alternatively, changes in the temperature, pressure, or composition of the flue gas can be detected via at least one sensor inside or downstream of the fuel preheater 10 to detect fuel leaks that may occur and require attention.

[0072] One or more temperature sensors may be present, positioned to monitor the temperature of the flue gas as it passes through furnace 4 and the flue gas conduit arrangement. The flue gas temperature can be used to adjust the extent to which the oxidizer and fuel are preheated and to what extent the flue gas bypasses any heat exchangers.

[0073] As can be best understood from Figures 5 to 10, the burner 6 can be positioned within the furnace to emit a flame FL in the furnace's combustion chamber, melting the glassmaking material to form glass that can be output from the furnace. The burner 6 can be positioned in different zones, which may include a first zone Z1, a second zone Z2, a third zone Z3, a fourth zone Z4, and a fifth zone Z5. In different embodiments, there may be fewer than five zones or more than five zones. The first zone Z1 may be closest to the glassmaking material feed inlet GF, into which the glassmaking material from the glassmaking material preheating device 26 and / or the glassmaking material source (batch / cullet) is fed into the furnace. The fifth zone may be downstream of the first zone Z1 and may be positioned by an outlet into which the glass output stream GO of glass can be output from the furnace 4. In embodiments that may have only two zones (for example, a first zone and a second zone), a fifth zone Z5 may be the last downstream zone and may be considered the second zone, and the first zone Z1 may be considered the upstream zone extending from the furnace feed inlet to the second downstream zone. The glassmaking material can transition from a solid state to a molten state and then, as it moves from the first zone Z1 upstream of the furnace to the downstream zones, it can transition to a formed glass state so that it is output from the furnace as formed glass.

[0074] Burners 6 in different zones can be configured to operate in different modes to facilitate the melting of the glassmaking material and provide high-quality glass for output as formed glass. Figures 6, 7, and 8 illustrate different modes of burner operation that can be utilized to provide different types of flame FL to facilitate desired types of glass melting conditions for different zones of the furnace 4 for forming glass from the glassmaking material. The glassmaking material 100 is schematically shown in Figures 6, 7, and 8 and can be glass when near the furnace outlet, a solid material fed into the furnace when near the inlet of the furnace 4, and an intermediate state when in the intermediate zone of the furnace between the inlet and the outlet of the furnace 4.

[0075] Each burner 6 may have an upper oxidizer conduit 76 that can be positioned above the inner fuel conduit and inner oxidizer conduit of the burner 6. A lower oxidizer conduit 78 may also be present, which can be positioned below the inner fuel conduit and inner oxidizer conduit. The inner fuel conduit and inner oxidizer conduit can be positioned between the lower oxidizer conduit 78 and the upper oxidizer conduit 76.

[0076] The burner 6 can be configured such that the internal fuel flow R1 and the internal oxidizer flow R2 can pass through the internal oxidizer and fuel conduits between the upper oxidizer conduit 76 and the lower oxidizer conduit 78. The output of these fuel and oxidizer flows can form a flame 96. In the operating mode shown in Figure 8, the flame can project into the combustion chamber and avoid any type of lower or upper oxidizer staging (significant oxidizer flow cannot pass through the upper oxidizer conduit 76 and the lower oxidizer conduit 78). Such an operating mode may be desired in situations where a relatively short, high-velocity flame is desired, such as when the burner 6 may be located near a furnace vent or flue, and there may be a large, highly turbulent direct or counterflow of hot flue gas flowing toward a vent or flue within the combustion chamber of the furnace 4.

[0077] Burner 6 can also be configured to operate in another mode, which can provide bubble control by the flame output from burner 6. Figure 7 illustrates an example of such an operating mode. Bubbles 106 can form within the glassmaking material 100 as it is heated. Bubbles can be various elements that move outwards as the glassmaking material is heated to form glass. In this operating mode, the flame 102 formed from the burner can have a luminous upper 104, which can be provided via an upper oxidizer flow 92 that is passed outwards from the upper oxidizer conduit 76 of the burner. Such an increased presence of oxidizer near the top of the flame can help promote a flame that extends further upward to provide a reducing atmosphere adjacent to the heated glassmaking material 100 in order to break up the bubbles 106 and help dissolve the bubbles and return them to the glassmaking material, and can also help heat generated from below the flame to approach the glass. This type of function can help improve the quality of the glass produced by preventing different elements from escaping from the glassmaking material during the heating process. For example, a fuel-rich flame 102 can create a reducing atmosphere 108 below the flame directly above the glass 100, which can help destabilize and break bubbles on the glass surface so that the bubble components dissolve and return to the molten glass formed from the heating of the glassmaking material. In this mode of operation, there is no significant flow of oxidizer being passed to the outside of the lower oxidizer conduit 78.

[0078] Figure 6 illustrates yet another operating mode of the burner 6, wherein the flame 96 has a radiating underside 94 that is facilitated via an oxidizer flow 92 that is passed out to the outside of the lower oxidizer conduit 78. In this operating mode, the flame 96 output from the burner 6 may have a sooty, optically thick, fuel-rich primary upper flame 96 above the radiating underside 94. The radiating underside 94 of the flame 96, which can be facilitated via an oxidizer flow 92 that is passed out to the outside of the lower oxidizer conduit 78, can be effective in transferring radiant heat 98 to the glassmaking material 100 in the furnace 4. The radiant heat 98 can be directed directly to the upper surface of the glassmaking material 100 along an unobstructed radiating path, and the oxidizer flow from the lower oxidizer conduit 78 can help facilitate such heating.

[0079] Figures 9 and 10 illustrate different exemplary embodiments of the burner 6 that can be utilized to provide these different operating modes for generating different flames FL that can provide different heating effects. Each of the burners 6 may include an innermost conduit 66 surrounded by another inner conduit 72. A fuel source 20 can be operably connected to the innermost conduit 66, through which fuel output from the fuel source 20 can be supplied to the conduit so that it is passed to the outside of the burner outlet surface via the innermost conduit 66. The inner conduit 72 may be an innermost oxidizer conduit that can be operably connected to the burner's oxidizer plenum 70, which can receive oxidizer from an oxidizer source 16 for supplying through the inner oxidizer conduit 72 as oxidizer flow R2. To facilitate a desired flow rate of oxidizer through the inner oxidizer conduit 72 as oxidizer flow R2, a variable flow limiter 84 or a fixed flow limiter 84 may be present, positioned at the junction of the plenum 70 and the oxidizer conduit 72. The limiter 84 can be used, but it can also be omitted from the burner 6.

[0080] The plenum 70 may include an inlet 62 for receiving oxidizer to feed into one or more of the burner conduits (e.g., an inner oxidizer conduit 72, an upper oxidizer conduit 76, a lower oxidizer conduit 78, etc.). The burner 6 may have a combustion chamber output region 64 that can define the outlet plane of the burner 6. The first reactant inlet 60 can feed fuel into the central innermost conduit 66, which may terminate at the central nozzle 68 in the combustion chamber output region 64 of the burner 6, so that a stream of fuel can flow out of the central nozzle 68 and into the combustion chamber of the furnace 4, forming a flame FL through combustion of the fuel. The central nozzle 68 may be circular or non-circular. In some embodiments, the central nozzle may be configured to facilitate the formation of a wide or flat flame configuration having at least two aspect ratios (maximum dimension versus minimum dimension). In some embodiments, the burner 6 may also include a pre-combustion chamber that can be positioned to facilitate the mixing of fuel and oxidizer output from the inner oxidizer conduit 72 and the innermost fuel conduit 66, thereby facilitating fuel ignition and forming a flame FL. Ignition can be facilitated via an igniter positioned within or adjacent to the pre-combustion chamber, or via radiant heat from the furnace 4.

[0081] The annular inner oxidizer conduit 72 can terminate at the annular nozzle 80 in the combustion chamber output region 64 of the burner 6. The central innermost conduit 66 and central nozzle 68, together with the annular inner conduit 72 and annular nozzle 80, can form a central burner element 82.

[0082] The flow rate of oxidizer distributed between the inner oxidizer conduit 72 and the staging inlet 74 is controlled by gradually opening and closing one or more oxidizer valves V. A flow limiter 84 is positioned at the junction of the plenum 70 and can also assist in controlling the distribution of oxidizer flow to various burner oxidizer conduits. At least one valve may include a single valve V, as shown in the exemplary embodiment of Figure 10, or multiple valves V, including a first valve V1 and a second valve V2, as shown in the exemplary embodiment of Figure 9.

[0083] The plenum 70 can receive an oxidizer through the inlet 62 to facilitate the combustion of fuel for flame formation and flame generation, and can supply the oxidizer to one or more conduits. For example, the plenum 70 can distribute the oxidizer as a flow R2 passing through an annular inner conduit 72 that surrounds and is coaxial with the central innermost conduit 66.

[0084] In some embodiments, the plenum may include a staging inlet 74 which can be positioned to distribute oxidant to the upper oxidant conduit 76 and / or the lower oxidant conduit 78. The staging inlet 74 may include a valve V which can be adjusted from a closed position so that no oxidant moves to the upper oxidant conduit 76 and the lower oxidant conduit 78, or so that a minimum flow rate of oxidant passes through these conduits (for example, when the valve V is in the closed position, less than 5% of the oxidant supplied to the plenum is transferable to the upper oxidant conduit and less than 5% of the oxidant supplied to the plenum is sent to the lower oxidant conduit). The valve V may also be adjusted to other positions so that a larger flow of oxidant can be supplied to the lower oxidant conduit 78 or the upper oxidant conduit 76, in order to facilitate different operating modes of the burner 6 as described above.

[0085] The upper oxidizer conduit 76 can be parallel to and spaced apart from one side of the central burner element 82 and can terminate at a first staging nozzle 86 in the combustion chamber output region 64 of the burner 6. The upper oxidizer conduit 78 can be parallel to and spaced apart from the other side of the central burner element 82 and can terminate at a second staging nozzle 88 in the combustion chamber output region 64 of the burner 6. In some embodiments, the three-way valve V can be positioned downstream of or at the staging inlet 74 so that the valve V can be adjusted to distribute the staging flow of oxidizer between the upper oxidizer conduit 76 and the lower oxidizer conduit 78. Valve V can be positioned such that substantially all of the oxidizer flow directed to the upper oxidizer conduit 76 and / or the lower oxidizer conduit 78 is directed to the upper oxidizer conduit 76 (for example, the burner operates in the operating mode shown in Figure 7), or substantially all of the oxidizer flow directed to the upper oxidizer conduit 76 and / or the lower oxidizer conduit 78 is directed to the lower oxidizer conduit 78 (for example, the burner operates in the operating mode shown in Figure 6), or the oxidizer flow is distributed between a pre-selected minimum non-zero portion directed to the upper oxidizer conduit 76 and a pre-selected minimum non-zero portion directed to the lower oxidizer conduit 78 (for example, the burner operates in the operating mode shown in Figure 8).

[0086] The burner embodiment may utilize multiple valves instead of a single valve V. For example, the staging inlet 74 may include an inlet for passing oxidant into the upper oxidant conduit 76 and another inlet for passing oxidant into the lower oxidant conduit 78. The inlet for the upper oxidant conduit 76 may have a first valve V1, and the inlet for the lower oxidant conduit 78 may have a second valve V2. Each valve V may be adjustable between an open position and a closed position. In the closed position, each valve may prevent oxidant from flowing into the respective oxidant conduit to which the valve is connected, or may allow only a pre-selected minimum flow rate of oxidant to pass through the valve and enter the oxidant conduit to which the valve is connected. Each valve may also be adjusted to different open positions to facilitate operation in different modes of burner operation, as shown in Figures 6, 7, and 8.

[0087] For example, the first valve V for the upper oxidizer conduit 76 and the second valve V for the lower oxidizer conduit 78 can be in their closed position to facilitate burner operation in the operating mode shown in Figure 8. The first valve V1 for the upper oxidizer conduit 76 may be in the open position, and the second valve V2 for the lower oxidizer conduit 78 may be in the closed position to facilitate burner operation in the operating mode shown in Figure 7. The first valve V1 for the upper oxidizer conduit 76 may be in the closed position, and the second valve V2 for the lower oxidizer conduit 78 may be in the open position to facilitate burner operation in the operating mode shown in Figure 6.

[0088] When the burner 6 operates in an operating mode in which the oxidizer at the minimum purge flow rate passes through the upper oxidizer conduit 76 and the high flow rate passes through the lower oxidizer conduit 78, the oxidizer also passes through the inner oxidizer conduit 72, so that the burner operates in the mode shown in Figure 6, the oxidizer passing through the upper oxidizer conduit 76 can be 0% to 20%, 0% to 10%, or 0% to 5% of the oxidizer supplied to the plenum, the oxidizer passing through the lower oxidizer conduit 78 can be 40% to 90% of the oxidizer supplied to the plenum, and the inner oxidizer conduit 72 can receive the remaining portion of the oxidizer.

[0089] When the burner is operating in an operating mode in which the oxidizer at the minimum purge flow rate passes through the lower oxidizer conduit 78 and the oxidizer at the high flow rate passes through the upper oxidizer conduit 76, the oxidizer also passes through the inner oxidizer conduit 72, so that the burner operates in the mode shown in Figure 7, the oxidizer passing through the lower oxidizer conduit 78 can be 0% to 20%, 0% to 10%, or 0% to 5% of the oxidizer supplied to the plenum, the oxidizer passing through the upper oxidizer conduit 76 can be 40% to 90% of the oxidizer supplied to the plenum, and the inner oxidizer conduit 72 can receive the remaining portion of the oxidizer.

[0090] When the burner 6 operates in an operating mode in which the oxidizer in the minimum purge flow passes through the upper oxidizer conduit 76 and the oxidizer in the minimum purge flow passes through the lower oxidizer conduit 78, while the oxidizer also passes through the inner oxidizer conduit 72, so that the burner operates in a mode as shown in Figure 8, the oxidizer passing through the lower oxidizer conduit 78 can be 0% to 20%, 0% to 10%, or 0% to 5% of the oxidizer supplied to the plenum, the oxidizer passing through the upper oxidizer conduit 76 can be 0% to 20%, 0% to 10%, or 0% to 5% of the oxidizer supplied to the plenum, and the inner oxidizer conduit 72 can receive the remaining portion of the oxidizer (e.g., 100% to 60% of the oxidizer supplied to the plenum 70).

[0091] Burner 6 can also be configured to facilitate a split staging mode in which there is a high-flow oxidizer stream that has passed through both the upper oxidizer conduit 76 and the lower oxidizer conduit 78. In such a configuration, valve V for controlling the supply of oxidizer received by the plenum 70 via inlet 62 can be set so that a high-flow oxidizer stream passes through both the upper oxidizer conduit 76 and the lower oxidizer conduit 78. Such a staging stream of oxidizer can facilitate the formation of flame FL, with oxidizer output from both the lower oxidizer conduit 78 and the upper oxidizer conduit 76 and flowing along the underside and upper side of the flame, in order to facilitate flame propagation in the combustion chamber and to provide the flame FL with a desired flame length. In some embodiments, this splitting operation mode can be provided such that the oxidizer supplied to the plenum 70 is split so that 0% to 40% of the oxidizer supplied to the plenum 70 passes through the inner conduit 72, 30% to 60% of the oxidizer supplied to the plenum 70 passes through the upper oxidizer conduit 76, and 30% to 60% of the oxidizer supplied to the plenum 70 passes through the lower oxidizer conduit 78.

[0092] The split staging mode of burner 6 can be advantageous when a combination of high flame momentum and high flame brightness is desired. This is often the case when burner 6 is positioned, for example, near the exhaust flue in the melting region of furnace 4. The burner flame in this region may be adversely affected by the close-range flow of combustion gases exiting the furnace through the flue. The high-momentum flame that can be generated through the use of the split staging mode can help maintain flame stability in such an environment. However, achieving a high-momentum flame while simultaneously generating high flame brightness, which may be desirable for efficient glass melting, can be challenging. For example, high flame momentum may not provide sufficient residence time for the processes of soot initiation, growth, and aggregation, which may often be desirable to achieve a high-luminosity flame. When the burner 6 is operating in split staging mode, such challenges can be overcome by surrounding the generated flame FL with oxygen on both the upper and lower sides of the flame FL as it is released into the furnace. This allows the fuel jet output from the innermost conduit 66 to burn and heat much more rapidly compared to when oxidizer staging occurs on only one side. Furthermore, the staged oxygen on both sides of the flame can help suppress the vertical expansion of the flame in the furnace. In this case, the more rapid combustion and heating of the fuel jet can increase the forward axial acceleration, providing the flame with high (axial) momentum. The brightness of the flame in this split staging mode can be provided by operating with a low primary oxygen flow through the inner oxidizer conduit 72, to the extent that it can be tolerated according to the part-specific operating constraints. It has been unexpectedly found that the combination of simultaneous over- and under-oxygen staging, and a relatively low ratio of primary oxidizer passing through the inner oxidizer conduit 72 to the fuel flow rate passing through the central innermost conduit 66, advantageously provides sufficient residence time for soot initiation, growth, and aggregation while also achieving high flame momentum.

[0093] In some embodiments, the entire amount of fuel supplied to the oxygen fuel burner 6 can pass through the innermost central conduit 66 to be output into the furnace via the central nozzle 68, while a very small proportion of the oxidizer supplied to the burner 6 can pass through the inner oxidizer conduit 72 of the annular nozzle 80. In some configurations, for operation in upper oxidizer conduit staging mode (e.g., the operating mode shown in Figure 7), operation in the split staging mode discussed above, or operation in lower oxidizer conduit staging mode (e.g., the operating mode shown in Figure 6), less than 20%, less than 10%, or less than 5% of the oxidizer can pass through the inner oxidizer conduit 72, depending on the balance of oxygen directed toward one or both of the upper oxidizer conduit 76 and the lower oxidizer conduit 78. This corresponds to preferred staging allocations of at least 80%, at least 90%, or at least 95% of the oxidizer supplied to the plenum 70 of the burner 6, respectively.

[0094] In some embodiments, when the burner 6 is operating in under-flame staging (e.g., a high flow rate of oxidizer passing through the lower oxidizer conduit 78, as discussed above and shown in Figure 6), at least 50% of the oxidizer can pass through the lower oxidizer conduit 78 while the balance flows through the inner oxidizer conduit 72. In some embodiments, at least 70% or at least 90% of the oxidizer can pass through the lower oxidizer conduit 78 while the balance flows through the inner oxidizer conduit 72 (and in some embodiments, any minimum purge amount passes through the upper oxidizer conduit 76).

[0095] When the burner 6 is operating in over-flame staging mode (e.g., a foam reduction mode similar to the operating mode shown in Figure 7, where a reducing atmosphere is created above the glassmaking material 100), at least 70% of the oxidizer supplied to the burner's plenum 70 can pass through the upper oxidizer conduit 76, where the balance flows through the inner oxidizer conduit 72 (and in some embodiments, any minimum purge amount passes through the lower oxidizer conduit 78). In some embodiments, at least 80% or at least 90% of the oxidizer supplied to the plenum 70 can pass through the upper oxidizer conduit 76 when the burner is in foam reduction mode (e.g., an operating mode similar to the one shown in Figure 7).

[0096] The operation of the furnace to control the heating provided via the flame FL generated by the burner 6 can also be adapted to take into account the temperature conditions of the oxidizer. For example, the burner 6 can be adjusted during operation depending on any possible low-temperature or high-temperature (e.g., heated) oxidizer conditions. Adjustment from a low-temperature oxidizer operating state to a high-temperature oxidizer operating state (e.g., a state where the oxidizer supplied to the burner 6 is above a pre-selected high-temperature oxidizer temperature threshold) can involve both the flue gas and the oxidizer passing through the oxidizer heater 8 and can occur at different times to take into account different operating cycles (e.g., after or following maintenance or repair of the equipment, the start-up and heating of the furnace 4). Conversely, adjustment from a high-temperature oxidizer operation to a low-temperature oxidizer operation (e.g., a state where the oxidizer supplied to the burner 6 of the furnace is below a pre-selected high-temperature oxidizer temperature threshold) can occur before starting maintenance or repair of the equipment, with the latter involving substantially bypassing the oxidizer preheater 8 for one or both of the oxidizer and flue gas. Temperature sensors and other sensors can provide data to one or more controllers to adjust the operating mode of the burner 6 according to a pre-selected process control scheme. Operator input can also be used to activate such adjustments during operation.

[0097] In some embodiments, the pre-selected high-temperature oxidizing agent temperature threshold can be 1000°F, or 540°C. Other embodiments may utilize different temperature thresholds relative to the pre-selected high-temperature oxidizing agent temperature threshold (e.g., 425°C, 450°C, 475°C, 500°C, 520°C, 538°C, etc.).

[0098] As can be best understood from Figures 5 to 8, during low-temperature oxidizer operation, when the oxidizer is below a pre-selected high-temperature oxidizer threshold, the burners 6 in different zones can be set to operate in different operating modes to facilitate accelerated glass melting, high fuel efficiency, and glass defect removal, which can be achieved through bubble breaking in the downstream zone of the furnace 4. For example, the first zone Z1 of the burner 6 can operate in a mode similar to the mode shown in Figure 8, in which there is no staging oxidizer flow passing through the upper oxidizer conduit 76 and the lower oxidizer conduit 78 (e.g., no oxidizer flow or only a minimal purge flow, as described above), and the oxidizer passes completely or almost completely through the inner conduit 72 in close proximity to the fuel to promote combustion in the low-temperature furnace. The downstream final zone may have a burner 6 operating in a different mode for bubble control. This operating mode can be similar to the mode shown in Figure 7, where, as described above, there is a balance of oxidizer passing through the inner oxidizer conduit 72 so as to be close to the fuel output from the central inner conduit 66 in order to form the desired flame FL for foam control, with a high flow rate of oxidizer passing through the upper oxidizer conduit 76 and either no oxidizer flow or only a minimum purge flow of oxidizer passing through the lower oxidizer conduit 78. The furnace may have other zones between the first upstream zone and the final downstream zone. For example, a second zone Z2 may be an intermediate zone, and the burner 6 in this zone may operate in the same operating mode as the burner in the first zone Z1. As another example, a third zone Z3 may be an intermediate zone between the second zone Z2 and the fifth zone Z5, and the burner 6 in this third zone Z3 may operate in the same operating mode as the burner in the first zone Z1 and the burner in the second zone Z2 which may be located between the first zone Z1 and the third zone Z3. Furthermore, there may be a fourth zone Z4 having a burner 6 that can operate in a mode similar to that of the burner in the fifth zone Z5. The intermediate fourth zone Z4 can be located between the third zone Z3 and the fifth zone Z5 and can operate in a foam control mode similar to the operating mode shown in Figure 7.

[0099] Under high-temperature oxidizer operating conditions, where the oxidizer temperature is above a pre-selected high-temperature oxidizer temperature threshold, the burner 6 can be adjusted during operation to provide a different flame to account for the heating conditions of the oxidizer. Such adjustments can be made based on the detected temperature of the oxidizer being supplied to the burner 6, or they can be inferred via the detected pressure of the oxidizer at or upstream of the burner inlet.

[0100] In some embodiments, changes in the temperature of the oxidizer supplied to the burner 6 may cause adjustments in the operating mode of the burner so that the furnace burner in the upstream zone operates in a different mode. The downstream zone (e.g., the fifth zone Z5, and optionally the fourth zone Z4) is shown in Figure 4 and can remain in an operating mode for foam control, similar to the operating modes discussed above. The upstream zone (e.g., the first zone Z1, and optionally the intermediate second zone Z2 and third zone Z3, etc.) can have different operating modes. For example, in some embodiments, the burner in the first zone Z1 can operate in a split staging operating mode, where a high flow rate of oxidizer passes through the upper oxidizer conduit 76 and the lower oxidizer conduit 78, as discussed above. Burners 6 in the second zone Z2 and / or the third zone Z3 may also operate in this operating mode, or in an operating mode similar to the operating mode shown in Figure 6, in which a significant oxidizing agent flow passes through the lower oxidizing agent conduit 78, while there is no oxidizing agent flow or only a minimal purging oxidizing agent flow passes through the upper oxidizing agent conduit 76.

[0101] As another example, in some embodiments, the burners in the first zone Z1, the second zone Z2, and the third zone Z3 can operate in a mode similar to the operating mode shown in Figure 6, which is a high-temperature oxidizer condition, with a significant oxidizer flow passing through the lower oxidizer conduit 78, while there is no oxidizer flow or only a minimal purge oxidizer flow passing through the upper oxidizer conduit 76, respectively.

[0102] As yet another example, the burners in the first zone Z1 and the second zone Z2 can operate in the split staging operation mode discussed above, in which a high flow rate of oxidizer passes through the upper oxidizer conduit 76 and the lower oxidizer conduit 78. The burner in the third zone Z3 can operate in an operation mode similar to the operation mode shown in Figure 6, which is a high-temperature oxidizer condition, in which a significant oxidizer flow passes through the lower oxidizer conduit 78, while there is no oxidizer flow or only a minimal purge oxidizer flow passes through the upper oxidizer conduit 76.

[0103] The high-temperature oxidizing conditions of the oxidizer may cause adjustments to the burner operating mode so that the furnace burners in the downstream zones can also operate in different modes. For example, one or more burners 6 in the downstream zones (e.g., the fifth zone Z5 and / or the fourth zone Z4) can be adjusted from an operating mode for foam control, similar to the operating modes discussed above and shown in Figure 4, to a split staging operating mode, as discussed above, in which a high flow rate of oxidizer passes through the upper oxidizing conduit 76 and the lower oxidizing conduit 78. In some embodiments, the burner in the fourth zone Z4 may be adjusted to such a split staging mode while the burner in the fifth zone Z5 is kept in foam control mode, or the burner in the fourth zone Z4 may be kept in foam control mode while the burner in the fifth zone Z5 is adjusted to split staging mode, or both burners in the fourth zone Z4 and the fifth zone Z5 may be adjusted to split staging mode.

[0104] When the furnace is sufficiently hot, the flue gas can have a suitable output temperature for use in preheating the oxidizer, fuel, and / or a portion of the glassmaking material through the fluid heater 24. After the flue gas temperature has reached sufficiently high temperatures, the flow of the oxidizer, fuel, and heat transfer medium through the fluid heater 24 can be adjusted to take into account the desired level of flue gas temperature and preheating in order to provide enhanced efficiency through heat recovery from the flue gas, as described above.

[0105] As mentioned above, each of the burners 6 of the furnace 4 can operate in various different modes (e.g., split mode, melting mode, foam control mode, etc.) depending on the operator's needs. The combustion profile of the burner 6 (e.g., the operating mode of the burner 6) can be adjusted based on the temperature of the oxidizer and / or fuel being supplied to the burner 6.

[0106] When the temperature of the oxidizer and / or fuel supplied to the burner 6 is at or slightly above ambient conditions (e.g., 1°C to 50°C or 1°C to 100°C above ambient temperature), the density of the oxidizer is relatively high compared to that when the glass manufacturing process is operating at "normal" operating temperatures and no bypass is used around the oxidizer preheater 8. Therefore, the volumetric flow rate (e.g., velocity) of the oxidizer at or slightly above ambient temperature (e.g., 1°C to 50°C or 1°C to 100°C) is relatively low. Given the relatively low velocity, at least 60% of the oxidizer supplied to the burner 6 can be directed to flow through the central nozzle 68 of the burner 6 (e.g., via the inner oxidizer conduit 72) to provide an optimal mixture of oxygen and fuel for a good effect on combustion efficiency. Directing the majority of the oxygen entering the burner 6 to the central nozzle 68 can be achieved through the closure or partial closure of one or more valves V of each burner 6, as described above.

[0107] In contrast, when a heated oxidizer stream enters the oxygen fuel burner 6 (e.g., via the oxidizer preheater 8), the oxidizer velocity can be considerably higher (e.g., 3 times or 2.5 times higher, respectively) at a given flow rate compared to the oxidizer velocity at or slightly above ambient temperature. Such conditions, without a change in oxidizer staging, can lead to a decrease in oxidizer density and an increase in volumetric flow rate, which can substantially adversely affect the combustion characteristics of the flame generated through the burner 6 by the mixing of fuel and oxidizer at the burner outlet, compared to those formulated for low-temperature oxidizer operation, as outlined previously. The configuration and operation of the burner 6 utilizing the burner 6 described herein, which can provide a number and arrangement of oxidizer staging conduits, can obtain a second optimal mixing state of fuel and oxidizer in the high-temperature oxidizer mode through the burner valve operation discussed above.

[0108] The operation of burner 6 can be adjusted to change the furnace's oxidizer operating mode from a low-temperature oxidizer operating mode to a high-temperature oxidizer operating mode and vice versa in different operating cycles. Adjustment of the supply of oxidizer to the oxidizer preheater 8 via the oxidizer preheater bypass conduit can facilitate such adjustments of operating conditions. Fuel can also be routed to bypass the fuel preheater 10, as may be desired to facilitate such operation as well. Along with changes in oxidizer temperature, the oxidizer rate profile can change significantly. Flue gas can also be routed to bypass the oxidizer preheater 8 and / or fuel preheater 10 to facilitate less or more preheating of the oxidizer and / or fuel, thereby facilitating such operation. Flue gas bypass can occur in combination with oxidizer bypass of oxidizer preheater 8 and / or fuel bypass of fuel preheater 10, or alternatively, instead of fuel bypass of fuel preheater 10 and / or oxidizer bypass of oxidizer preheater 8.

[0109] In the low-temperature operating mode of the oxidizer, the oxidizer may be much denser due to its lower temperature, and the lower velocity of the oxidizer output from the burner may result from a higher mass passing through those conduits. However, in the high-temperature operating mode of the oxidizer, the density of the oxidizer is much lower, and the velocity of the same mass of oxidizer may need to be substantially higher. Utilizing staging through the upper oxidizer conduit 76 and / or lower oxidizer conduit 78 in response to the oxidizer being above a pre-selected high-temperature oxidizer temperature threshold can provide an additional volume to accommodate the additional oxidizer needed to provide the same mass flow rate of oxidizer to the combustion chamber, taking into account the change in oxidizer density. The flexibility in adjusting the burner operation to take oxidizer temperature into account allows for a more precisely controlled flame that takes into account the momentum of the composite flame by diverting some oxidizer to other oxidizer conduits, thereby better managing the flame length in the combustion chamber and providing a more consistent flame length for the flame profile as the furnace operating mode changes. Considering the momentum of the combined flame allows for the adjustment of oxidant density changes from the use of lower-temperature oxidants to higher-temperature oxidants, and vice versa, in conjunction with changes in oxidant staging, thus enabling better control of the flame length and / or flame profile when the operating mode of the furnace 4 changes.

[0110] In many embodiments, the oxidizer supply pressure to the furnace 4 can be 4 psig to 15 psig (i.e., 28.2 kPa(g) to 103.4 kPa(g)), and the operator may want to minimize and / or avoid the pressure drop of the oxidizer from the oxidizer source to the furnace 4. In some embodiments, the oxidizer supply can be provided via a low pressure of 6 psig or less (e.g., less than 41.4 kPa and greater than 0 kPa). Operating the burner 6 with a larger oxidizer flow area is one way to prevent excessive pressure drops in the burner 6, which can be achieved by directing at least 50% of the oxidizer flowing through the burner 6 through the upper oxidizer conduit 76 and the lower oxidizer conduit 78. In other words, less than 50% of the oxygen can be directed through the central nozzle 68 (e.g., the inner oxidizer conduit 72). This method of operation can (i) reduce the pressure drop of the oxidizer and (ii) cool the central nozzle 68. This approach also avoids (a) introducing convective heating to the central nozzle 68 and (b) promoting combustion reactions near the central nozzle 68, which could further exacerbate the potential nozzle overheating problem, given the extremely high temperatures of the heated oxidizer available through the high-temperature furnace, preheating the oxidizer and fuel via the oxidizer preheater 8 and fuel preheater 10.

[0111] And, surprisingly, embodiments have found that low pressures of 6 psig or less can be utilized, even though the oxidizer can be routed from the oxidizer source to the burner via the oxidizer preheater 8 and / or bypass conduit. In some embodiments, an oxidizer compressor is not required to help facilitate the flow of the oxidizer due to the low pressure, which may be used to drive the flow of the oxidizer to the burner 6. Typically, in such cases, the oxidizer pressure is generated solely by an inlet blower, associated with oxygen produced via air separation in the adsorption system.

[0112] In some modes of operation of System 2 (and as discussed above), one or both of the oxidizer preheater bypass conduit and the fuel preheater bypass conduit can be used to gradually reduce the temperature of the heated oxidizer coming out of the oxidizer preheater 8 and the heated fuel coming out of the fuel preheater 10. The use of these bypass mechanisms can be done manually or via automatic process control and may be the detection of such pressure drop via at least one pressure sensor positioned to detect the pressure drop in the burner 6 in response to the temperature of the heated oxidizer and / or the temperature of the heated fuel, and / or the detection of such temperature via a temperature sensor positioned to detect the temperature of the central nozzle 68 of the burner 6.

[0113] Figure 13 illustrates an exemplary process that may be available in an embodiment of System 2. For example, in a first step S1, the furnace 4 can be cooled and receive unheated fuel and oxidizer for combustion. In this first step, the burners in at least one upstream zone (e.g., a first zone Z1, a second zone Z2, and / or a third zone Z3) can operate in an operating mode that allows the internal fuel flow R1 and internal oxidizer flow R2 to pass through the internal oxidizer and fuel conduits of the burner in one or more upstream zones between the upper oxidizer conduit 76 and the lower oxidizer conduit 78 of the burner 6. The output of these fuel and oxidizer flows can project into the combustion chamber and form a flame 96, which can avoid any type of lower or upper oxidizer staging (significant oxidizer flow cannot pass through the upper oxidizer conduit 76 and the lower oxidizer conduit 78).

[0114] Furthermore, one or more burners 6 in one or more downstream zones (e.g., a fourth zone Z4 and / or a fifth zone Z5) can operate in a bubble-controlled operating mode in which the flame 102 formed from the burner 6 in this operating mode can have a reducing lower 106, which can be supplied via an upper oxidizer flow 92 that is passed out to the outside of the upper oxidizer conduit 76 of the burner and a minimal oxidizer flow that is passed out to the outside of the lower oxidizer conduit 78. By thus deflecting the oxidizer away from the bottom of the flame, a reducing atmosphere can be created adjacent to the glassmaking material 100 that is being heated to help break the bubbles 106 and dissolve the bubbles and return them to the molten glass. This type of functionality can help improve the quality of the glass produced by preventing different elements from escaping from the glassmaking material during the heating process.

[0115] After the oxidizer is detected to be sufficiently hot (for example, after the oxidizer temperature is detected to be above a pre-selected high-temperature oxidizer threshold), the burner operation can be adjusted in a second step S2. In such a second step, at least the upstream burners of one or more upstream zones (e.g., a first zone Z1, a second zone Z2, and / or a third zone Z3) can be adjusted to a split staging operation mode as discussed above, or a melting operation mode having a radiating underside 94 through which the flame is propelled via an oxidizer flow 92 that is passed to the outside of the lower oxidizer conduit 78 (for example, as discussed above with reference to Figure 6). In this operation mode, the flame 96 output from the burner 6 may have a sooty, optically thick, fuel-rich primary upper flame 96 above the radiating underside 94. The luminous lower surface 94 of the flame 96, which can be facilitated via the oxidizer flow 92 passed to the outside of the lower oxidizer conduit 78, can be effective in transferring radiant heat 98 to the glassmaking material 100 in the furnace 4. Due to the optically thick upper flame 96, the radiant heat 98 can be preferentially directed directly to the upper surface of the glassmaking material 100 along an unobstructed radiation path, and the oxidizer flow from the lower oxidizer conduit 78 can help facilitate such heating.

[0116] In some situations, one or more burners in at least one downstream zone (e.g., the fourth zone Z4 and / or the fifth zone Z5) may also be adjusted in operation in this second step S2 in response to the detection that the oxidizer is above a pre-selected high-temperature oxidizer threshold. Such adjustments may, for example, adjust at least some of these burners from foam control mode to split staging mode, as discussed above.

[0117] In the third step S3, the oxidizer and / or fuel can be preheated via the oxidizer preheater 8 and / or fuel preheater 10. This preheating may also occur during the first step S1 and the second step S3. The preheating in the third step S3 may include adjustments to the preheating of the oxidizer and / or fuel. For example, the preheating of the oxidizer and / or fuel can be controlled to be adjustable to take into account the furnace temperature, the desired temperature of the oxidizer, and / or other operating parameters. For example, the entire oxidizer can be preheated via the oxidizer preheater and / or the entire fuel can be preheated via the fuel preheater 10. The preheating may also be adjusted via the oxidizer preheater bypass conduit and / or fuel preheater bypass conduit to adjust the degree to which the fuel and / or oxidizer can be preheated.

[0118] For example, the third step S3 may include adjusting the preheaters so that there is no more preheating of the oxidizer and fuel (for example, so that the temperature of the oxidizer being supplied to the burner is reduced to below a pre-selected high-temperature oxidizer temperature threshold) in order to transition the furnace 4 back to low-temperature operation. This type of adjustment during the process can be performed gradually or rapidly. In such a process, all fuel and oxidizer may utilize the oxidizer preheater bypass conduit and the fuel preheater bypass conduit so that they bypass the oxidizer preheater 8 and the fuel preheater 10 and return the furnace 4 to low-temperature operation mode. Such a process may also be performed in conjunction with adjusting the burners 6 to adjust their operating modes (for example, adjusting the burners 6 so that the first step S1 is performed and the burners 6 operate as described above in conjunction with the first step S1 (as shown via the dashed lines in Figure 13)). As described above, the adjustment of the burner operation can be performed to take into account the momentum of the composite flame, which may be affected through the changed temperature and density of the oxidizer being supplied to the burner, in order to better control the flame length of other flame profiles of the flame generated by the burner 6.

[0119] The glass manufacturing material feeding can also be preheated in the second step S2 or the third step S3 via the fluid heater 24 and the glass manufacturing material preheating device 26, as described above. This preheating can occur in response to a furnace that is determined to be sufficiently hot, or it can be provided at another preferred operating time. The heat transfer medium used in the glass manufacturing material preheating device 26 can be heated via flue gas passing through the fluid heater 24 for supply to the glass manufacturing material preheating device 26, for heating the glass manufacturing material fed to the glass manufacturing material preheating device 26. The heated air 11 can also be supplied to the glass manufacturing material preheating device 26, as described above, to facilitate the preheating of the glass manufacturing material and help avoid backward movement of the glass manufacturing material.

[0120] A flue gas bypass can be provided to bypass the fluid heater 24 in situations where the temperature of the flue gas may be, exceed, or approach the maximum operating temperature of the heat transfer medium used for preheating the glass manufacturing material. The bypass may be provided by a preheater bypass conduit or another fluid heater bypass conduit, which is positioned to provide flue gas to bypass the fluid heater 24 when passed toward the stack 12.

[0121] The preheating of the heat transfer medium used in the glass manufacturing material feeding preheating device 26 and the heating of the fluid heater can be adjusted during the third step S3 to take into account different operating conditions detected (e.g., temperature, pressure, flow rate, etc.) according to a predefined process control scheme.

[0122] If the operation of the furnace is substantially interrupted in such a way that the furnace must be returned to its low-temperature state, the process may return to the first step S1 in order to restart the furnace 4.

[0123] The embodiment can provide a process for manufacturing higher quality and / or more consistent quality glass in a more energy-efficient manner. The embodiment can also provide enhanced operational flexibility to provide such improvements.

[0124] It should be understood that different embodiments may utilize other elements or features. For example, embodiments may utilize different types of conduit arrangements, different sizes of structures, different fuel sources, or different arrangements of glassmaking material sources. The oxidizer may be oxygen gas, air, oxygen-enriched air, or other suitable oxidizers. The fuel may be natural gas, oil, or other suitable fuels. The heat transfer medium used to preheat the glassmaking material supplied to the furnace may similarly be any suitable heat transfer medium. Different embodiments may utilize different types of automated process control schemes for controlling the operation of the furnace 4 and / or burner 6, and / or the bypass of the oxidizer preheater 8, and / or the bypass of the fuel preheater 10. Flue gas bypassing one or more of these heat exchangers between the furnace 4 and the stack 12 may also be adjusted to take into account a pre-selected process control scheme via a heat exchanger bypass valve 39 or other suitable bypass conduit arrangement.

[0125] As used herein, the articles “a” and “an” mean one or more when applied to any feature in the embodiments of this disclosure described herein and in the claims. The use of “a” and “an” does not limit its meaning to a single feature unless such limitation is specifically stated. The article “the” preceding a singular or plural noun or noun phrase indicates a specific designated feature or a specific designated feature, and may have singular or plural implications depending on the context in which it is used.

[0126] As used herein, "plural" means two or more.

[0127] As used herein, “first,” “second,” “third,” etc., are used to distinguish between multiple steps and / or features and, unless expressly stated otherwise, do not indicate a total number or relative position in time and / or space.

[0128] As used herein, “includes” and similar terms mean “includes, but not limited to.”

[0129] As used herein, the phrase "and / or" placed between a first entity and a second entity includes any of the following meanings: (1) the first entity only, (2) the second entity only, and (3) the first entity and the second entity. The term "and / or" placed between the last two entities in a list of three or more entities means at least one of the entities in the list, including any particular combination of entities in the list. For example, "A, B, and / or C" has the same meaning as "A and / or B and / or C," and includes the following combinations of A, B, and C: (1) A only, (2) B only, (3) C only, (4) A and B but not C, (5) A and C but not B, (6) B and C but not A, (7) A, B and C.

[0130] When referring to any numerical range of a value, such a range is understood to include each and all numbers and / or fractions between the minimum and maximum values ​​of the stated range. For example, the range "1 to 10" is intended to include (and include) all subranges between the listed minimum value of 1 and the listed maximum value of 10, i.e., all subranges having a minimum value of 1 or greater and a maximum value of 10 or less.

[0131] While specific embodiments of this disclosure are described in detail, it will be understood by those skilled in the art that various modifications and alternatives to those details can be developed in light of the overall teachings of this disclosure. Accordingly, the specific configurations disclosed herein are illustrative only and not limit the scope of this disclosure, which would give the entirety of the claims and any and all equivalents thereof.

Claims

1. A method for producing glass, Fuel and oxidizer are supplied to the burner of the furnace, and the fuel is burned to produce glass manufacturing materials for glass production. (i) At least one burner in at least one upstream zone of the furnace operates in a mode of operation in which the internal flow of fuel and the internal flow of oxidizer are output into the furnace between the upper oxidizer conduit and the lower oxidizer conduit, such that a flame is formed to project into the combustion chamber of the furnace without upper oxidizer staging via the upper oxidizer conduit and without lower oxidizer staging via the lower oxidizer conduit, while the oxidizer is below a pre-selected high-temperature oxidizer temperature threshold. (ii) A method comprising heating at least one burner in at least one downstream zone of the furnace, located downstream of the at least one upstream zone of the furnace, to operate in a foam-controlled operating mode such that the combustion of the fuel from the at least one burner in the at least one downstream zone of the furnace forms an upwardly extending flame and provides a reducing atmosphere adjacent to the glassmaking material in the at least one downstream zone of the furnace, dissolving the foam and returning it to the glassmaking material, so that the upper oxidizer flow is passed out of the upper oxidizer conduit of the burner together with the inner flow of fuel and the inner flow of oxidizer output into the furnace.

2. The method according to claim 1, further comprising passing the flue gas output from the furnace through an oxidizer preheater positioned downstream of the furnace between the stack and the furnace, in order to preheat at least a portion of the oxidizer before the oxidizer is supplied to the burner of the furnace.

3. The method according to claim 2, comprising adjusting the operation of the at least one burner in the at least one upstream zone of the furnace to a split staging operation mode in which, in response to detecting that the oxidizer is above the pre-selected high-temperature oxidizer temperature threshold, the oxidizer is passed out of the inner oxidizer conduit and the fuel is passed out of the inner fuel conduit, in addition to the oxidizer being passed out of the lower oxidizer conduit and also to the upper oxidizer conduit.

4. The method according to claim 2, comprising adjusting the operation of the at least one burner in the at least one upstream zone of the furnace to a mode of operation in which the flame has a radiating underside that is facilitated by an oxidizing flow that is passed to the outside of the lower oxidizing conduit, rather than being provided through the upper oxidizing conduit of the at least one burner in the at least one upstream zone of the furnace, in response to detecting that the oxidizing agent is at a pre-selected high-temperature oxidizing agent temperature threshold, the at least one burner in the at least one upstream zone of the furnace.

5. The method according to claim 4, wherein the flame has a radiating underside such that the radiant heat is directed directly to the upper surface of the glassmaking material in the at least one upstream zone of the furnace along an unobstructed radiation path.

6. Adjusting the operation of the at least one burner in the at least one upstream zone of the furnace to adjust the operation of the at least one burner in the at least one upstream zone of the furnace to a split staging operation mode in which, in response to detecting that the oxidizer is above the pre-selected high-temperature oxidizer temperature threshold, the oxidizer is passed out of the inner oxidizer conduit and the fuel is passed out of the inner fuel conduit, in addition to the oxidizer being passed out of the lower oxidizer conduit and also to the upper oxidizer conduit, or In response to detecting that the furnace is at a pre-selected high furnace temperature, the operation of the at least one burner in the at least one upstream zone of the furnace is adjusted so that the flame has a radiating underside that is facilitated by an oxidizer flow that is passed to the outside of the lower oxidizer conduit, rather than being provided through the upper oxidizer conduit of the at least one burner in the at least one upstream zone of the furnace, and Before the oxidizing agent is supplied to the burner of the furnace via flue gas output from the furnace, passing through the oxidizing agent preheater, at least a portion of the oxidizing agent is preheated through the oxidizing agent preheater, which is positioned to heat the oxidizing agent. The method according to claim 1, comprising preheating at least a portion of the fuel via the fuel preheater, which is positioned to heat the fuel, before the fuel is supplied to the burner of the furnace via flue gas output from the furnace, which passes through the fuel preheater.

7. The flue gas output from the furnace is passed to a fluid heater to heat a heat transfer medium that can be supplied to a glass manufacturing material preheating device. A portion of the glass manufacturing material is supplied to a glass manufacturing material preheating device for preheating the portion of the glass manufacturing material. The method according to claim 6, comprising outputting the preheated portion of the glass manufacturing material from the glass manufacturing material preheating device and feeding it to the furnace.

8. The method according to claim 7, wherein the glass manufacturing material feeding preheating device includes a rotatable shaft having a flight that is rotatable to allow a portion of the glass manufacturing material fed to the glass manufacturing material feeding preheating device to pass through the glass manufacturing material feeding preheating device.

9. The method according to claim 7, comprising passing heated air through a hollow shaft of the glass manufacturing material preheating device so that it enters the portion of the glass manufacturing material as it passes through the glass manufacturing material preheating device.

10. The method according to claim 9, comprising outputting heated air from the fluid heater to form a slipstream of the heat transfer medium, which passes through a heat exchanger for heating the air, and to supply the heated air to the hollow shaft of the glass manufacturing material preheating device.

11. The method according to claim 1, comprising adjusting the operation of the at least one burner in the at least one downstream zone of the furnace to a split staging operation mode in which, in response to detecting that the oxidizer is above the pre-selected high-temperature oxidizer temperature threshold, the oxidizer is passed out of the inner oxidizer conduit and the fuel is passed out of the inner fuel conduit, in addition to the oxidizer being passed out of the lower oxidizer conduit and also to the upper oxidizer conduit.

12. After the oxidizing agent is above the pre-selected high-temperature oxidizing agent temperature threshold, the flow of the oxidizing agent is adjusted so that at least a portion of the oxidizing agent bypasses the oxidizing agent preheater positioned between the furnace and the stack, and / or After the oxidizer is above the pre-selected high-temperature oxidizer temperature threshold, the fuel flow is adjusted so that at least a portion of the fuel bypasses the fuel preheater positioned between the furnace and the stack, and / or The method according to claim 1, further comprising adjusting the flow of the flue gas such that, after the oxidizer is above the pre-selected high-temperature oxidizer temperature threshold, at least a portion of the flue gas bypasses the oxidizer preheater and / or the fuel preheater.

13. A system for manufacturing glass, A furnace having a plurality of zones, including a first zone, a second zone, a third zone, a fourth zone, and a fifth zone, wherein the first zone is upstream of the fifth zone, the second zone is between the first zone and the third zone, the third zone is between the second zone and the fourth zone, and the fourth zone is between the third zone and the fifth zone. An oxidizer preheater positioned between the stack and the furnace, the oxidizer preheater being positioned to facilitate the preheating of the oxidizer before it is supplied to the burner of the furnace via flue gas output from the furnace, A fuel preheater positioned between the stack and the furnace, the fuel preheater being positioned to facilitate the preheating of the fuel before it is supplied to the burner of the furnace via flue gas output from the furnace, The first zone has at least one burner, and the fifth zone has at least one burner. The at least one burner in the first zone, The fuel and oxidizer internal flows are configured to operate in a mode of operation in which they are output into the first zone of the furnace between the upper and lower oxidizer conduits, such that a flame is formed to protrude into the combustion chamber of the furnace, without upper oxidizer staging via the upper oxidizer conduit and without lower oxidizer staging via the lower oxidizer conduit, while the oxidizer is below a pre-selected high-temperature oxidizer temperature threshold. The at least one burner in the fifth zone, A system configured to operate in a bubble-controlled operating mode, wherein, while the oxidizer is below a pre-selected high-temperature oxidizer temperature threshold, the combustion of the fuel from at least one burner in the fifth zone of the furnace forms an upwardly extending flame, providing a reducing atmosphere adjacent to the glassmaking material in the fifth zone of the furnace, dissolving the bubbles and returning them to the glassmaking material, and the upper oxidizer flow is passed out of the upper oxidizer conduit of the burner together with the inner flow of fuel and the inner flow of oxidizer output into the fifth zone of the furnace.

14. The furnace is also configured to adjust its operation in response to the temperature being above a pre-selected high-temperature oxidizer temperature threshold, such that the at least one burner in the first zone of the furnace is adjusted to a split staging operation mode in which, in addition to the oxidizer being passed out of the inner oxidizer conduit and the fuel being passed out of the inner fuel conduit, the oxidizer is also passed out of the lower oxidizer conduit and also of the upper oxidizer conduit, or The system according to claim 13, wherein the at least one burner in the first zone is also configured to adjust its operation in response to the oxidizer being above a pre-selected high-temperature oxidizer temperature threshold, such that the at least one burner in the first zone of the furnace is adjusted to a mode of operation in which the flame has a radiating underside that is facilitated by an oxidizer flow that is passed to the outside of the lower oxidizer conduit, without being provided through the upper oxidizer conduit of the at least one burner in the first zone.

15. A fluid heater positioned to receive flue gas output from the furnace is used to heat a heat transfer medium that can be supplied to a glass manufacturing material preheating device. The system according to claim 13, further comprising: a glass manufacturing feed material preheating device positioned to receive a portion of the glass manufacturing material, preheat the portion of the glass manufacturing material, and output to feed the preheated portion of the glass manufacturing material to the first zone of the furnace.

16. The system according to claim 15, wherein the glass manufacturing material preheating device includes a rotatable shaft having a flight that is rotatable to allow a portion of the glass manufacturing material fed to the glass manufacturing material preheating device to pass through the glass manufacturing material preheating device.

17. The system according to claim 16, comprising: a heat exchanger positioned to receive a slipstream of the heat transfer medium that can be output from the fluid heater, heat air, and supply the heated air to a hollow shaft of the glass manufacturing material preheating device, wherein the hollow shaft has holes so that the heated air can pass through the portion of the glass manufacturing material as it passes through the glass manufacturing material preheating device.

18. The system according to claim 13, wherein the furnace is also configured to adjust its operation in response to the temperature being above a pre-selected high-temperature oxidizer temperature threshold, such that the at least one burner in the fifth zone of the furnace is adjusted to a split staging operation mode in which, in addition to the oxidizer being passed out of the inner oxidizer conduit and the fuel being passed out of the inner fuel conduit, the oxidizer is also passed out of the lower oxidizer conduit and also of the upper oxidizer conduit.

19. A device for preheating glassmaking material to be fed into a furnace to be heated in order to manufacture glass, wherein the device is The glass manufacturing feed material preheating device is positioned to receive a portion of the glass manufacturing material, preheat the portion of the glass manufacturing material, and output the preheated portion of the glass manufacturing material to feed to the furnace, wherein the glass manufacturing feed material preheating device is A rotatable shaft having flights positioned within an internal conduit of the glass manufacturing material feeding preheating device, comprising a rotatable shaft connectable to a motor to drive the rotation of the rotatable shaft for moving the portion of the glass manufacturing material through the glass manufacturing material feeding preheating device, The glass manufacturing material preheating device comprises an annular conduit surrounding at least a portion of the inner conduit, and having an annular conduit such that a heat transfer medium can pass through the annular conduit to heat the portion of the glass manufacturing material passing through the inner conduit via the rotation of the rotatable shaft.

20. A heat exchanger positioned to output heated air is provided to heat air and supply it to the rotatable shaft. The apparatus according to claim 19, wherein the rotatable shaft is a hollow shaft having a hole, and the hollow shaft is configured to receive heated air from the heat exchanger in order to introduce heated air into the inner conduit through the hole in the hollow shaft.

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