Patent Application
20210101817
This patent application discloses a device and methods of glass manufacturing, and more particularly, devices and methods to melt glassmaking materials into molten glass.
During glass manufacturing, bubblers are sacrificial components that extend through a floor of a furnace for melting glassmaking raw materials into molten glass. As their name implies, the bubblers introduce or bubble gases into the molten glass in order to assist in mixing of the molten glass. The bubblers are either cooled, periodically replaced, or clad with materials, such as platinum, that can withstand the harsh environment of the furnace in order to extend their useful lifetime.
However, even when clad with these materials, the bubblers can fail earlier than expected and/or require frequent adjustment and/or replacement. For example, if there is a significant amount of metal contamination in the molten glass, such metal can alloy with the platinum, leaving the platinum cladding less refractory and weakened. When a bubbler fails and is not adjusted or replaced, the agitation of the glass by bubbles from such broken bubbler may cause rapid corrosion of the furnace refractory brick floor near the location of the bubbler, thereby causing a glass leak in the adjacent floor that can cause a failure of the entire furnace, not simply the bubbler itself.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
In accordance with one aspect of the disclosure, there is a bubbler device that includes a bubbler tube including an internal bore that provides bubbles to a molten material in a furnace; a protective layer disposed on an outside surface of the bubbler tube; and a first wire that is electrically coupled to the protective layer, wherein the first wire extends through at least a portion of the bore, and wherein the protective layer and the first wire form a first electrical circuit for measuring integrity of the bubbler device based on at least one of conductivity or resistance in the electrical circuit or temperature of the molten material by a thermoelectric effect of the circuit. In some instances, an inner protective material may be disposed on an inside surface of the tube and coupled to the protective layer, and the first wire can be coupled to the inner protective material as part of the electric circuit. In some instances, the bubbler device may include a second wire and multiple thermocouples.
In accordance with another aspect of the disclosure, there is provided a method of operating a bubbler device with a bubbler tube as described herein. The method can comprise monitoring electrical conductivity or resistivity of at least one electrical circuit of the bubbler device, the bubbler device comprising: a bubbler tube including an internal bore that provides bubbles to a molten material in a furnace; a protective layer disposed on an outside surface of the bubbler tube; and at least one wire that is electrically coupled to the protective layer, wherein the at least one wire extends through at least a portion of the bore, and wherein the protective layer and the at least one wire partially form at least one electrical circuit for monitoring integrity of the bubbler device based on at least one of conductivity or resistivity in the electrical circuit, or temperature of the molten material.
The disclosure, together with additional objects, features, advantages and aspects thereof, will be best understood from the following description, the appended claims and the accompanying drawings, in which:
In accordance with at least one aspect of the disclosure, a bubbler is provided that can be monitored to verify integrity of the bubbler. For example, if the monitored integrity is good, the bubbler device will likely be functioning properly. If the monitored integrity of the bubbler device is poor, then the bubbler device is likely malfunctioning and should be maintained or replaced.
As briefly discussed in the Background, glass manufacturing furnaces melt glassmaking materials into molten glass. They can include bubblers that introduce various gases, typically air, into a furnace to facilitate mixing of the molten glass. While some bubblers can last up to eight years or more in the furnace, harsh environmental conditions (e.g., high temperatures and extreme temperature changes) in the furnace can lead to rapid bubbler failure, for example, within four years. Even before a total bubbler failure, the bubblers often may need maintenance and repositioning in order to continue functioning properly.
In addition to the unpredictability of when a bubbler will fail, it is often difficult to determine if a bubbler currently in use is already malfunctioning. The bubblers are generally positioned within the molten glass and may not be easy to access. If a bubbler is malfunctioning for a period of time, it can lead to a molten glass leak developing at a location of the bubbler, which, if left unattended, can cause a failure of the entire furnace. The leak can release the molten material through the floor of the furnace and below, potentially damaging various components in and around the furnace and leaking the molten material.
In order to solve the problems of early bubbler failure and the difficulty of determining when a bubbler is already malfunctioning, one solution is to provide a bubbler that can be readily, automatically or manually, verified to see if it is intact and functioning properly. Integrity of the bubbler device disclosed herein can be verified by monitoring voltage and/or resistivity in an electrical circuit within the bubbler device.
Like numerals (e.g., 10, 110, 210, and so forth) among the embodiments generally designate like or corresponding elements throughout the several views of the drawing figures. Accordingly, the descriptions of the embodiments are incorporated into one another, and description of subject matter common to the embodiments generally may not be repeated.
The bubbler device 10 can serve to introduce bubbles 18 into the molten material 20 in order to facilitate mixing of the molten material 20, for example, to obtain a uniform temperature and/or composition, before the molten material 20 is drawn from the furnace 12, used, and/or further processed. In implementations, the bubbler device 10 can extend along a longitudinal axis and may be configured to be inserted directly through the floor 16 and/or a side wall 14 of the furnace 12. In the embodiment illustrated in
In the embodiment illustrated in
The bubbler device 110 can include a bubbler tube 124, which can be a tubular and/or cylindrical shaped conduit configured to provide a gas to the molten material 20. The bubbler tube 124 may be formed from an insulating material, for example a refractory-based material, and may be resistant to high temperature and corrosion caused by the environment in the furnace 12. It will be appreciated that the bubbler tube 124 can include any known material for providing electrical insulation against the harsh environment of the furnace 12, for example ceramic, alumina, or zirconia tubes (e.g., ZrO2), ring segments, and/or powder (e.g., Al2O3).
The bubbler device 110 can include a bubbler aperture 128 in the bubbler tube 124 through which bubbles 18 can enter into the molten material 20. The bubbler aperture 128 can allow gases to pass from a bore 130 and exit proximate a first end 132 of the bubbler device 110.
The longitudinally extending internal bore 130 can be formed through the bubbler tube 124 and/or electrically conductive material 138 to allow a fluid or air flow A to flow from a remote fluid supply (not shown), through the bubbler tube 124 and bubbler aperture 128, and into the molten material 20. Although it is possible to provide different fluid or air flows with different pressures through the bubbler device 110, it is not necessary, and a constant fluid flow through the bubbler device 110 may be provided during its operation.
In an exemplary embodiment, the bubbler aperture 128 and/or the bore 130 may have a diameter of approximately 0.2 to 0.5 millimeters or more. The diameter may be maintained from the first end 132 to a second end 134 of the bubbler device 110. However, it is also contemplated that the diameter may change in size or remain at least partially constant throughout the length of the bubbler 110. It will be appreciated that the bubbler aperture 128 may include various other diameters and/or configurations known to one of skill in the art.
A protective layer 136 can be disposed on an outer surface of the bubbler tube 124. The protective layer 136 can include a layer, a coating, and/or a cladding formed of a protective and conductive material (e.g., platinum (Pt), platinum-rhodium alloy (Pt—Rh), and/or other high temperature alloys) that is glass contact resistant and that can cover and/or extend over at least part of the bubbler tube 124. The protective layer 136 can also function as part of an electrical circuit for monitoring the babbler device 110.
The bubbler device 110 may include an electrically conductive material 138 (e.g., an inner protective material, a layer, a concentric tube, at least one wire, and the like) disposed on at least a portion of and/or extending within the bubbler tube 124, for example from the first end 132 to the second end 134. For example, the electrically conductive material 138 can include a layer, a coating, a sheath, and/or a tube disposed on an inner surface of the bubbler tube 124 within the bore 130. For example, the electrically conductive material 138 can include a concentric tube or layer of conductive material disposed on the inner surface of the bubbler tube 124 at least partially the length of the bore 130. The electrically conductive material 138 can comprise a protective and conductive material (e.g., platinum, platinum-rhodium alloy, or other high temperature/conductive alloys) and can function as part of the electrical circuit.
The bubbler device 110 may include at least one wire 140, 142 electrically and/or mechanically coupled to the protective layer 136 and/or the electrically conductive material 138. The at least one wire 140, 142 can form part of the electrical circuit and can extend through the bubbler tube 124 and can be electrically and/or mechanically coupled to at least one line 44a, 44b and/or a meter 46. The at least one wire 140, 142 can be formed from materials that are corrosion and failure resistant within the environment of the bubbler device 110. For example, the at least one wire 140, 142 may comprise platinum and/or a platinum alloy. It will be appreciated that the bubbler device 110 may include a variety of configurations of mechanically and/or electrically coupling the at least one wire 140, 142 to the protective layer 136. For example, more than two wires may be utilized and may be mechanically and/or electrically coupled to the protective layer 136. When more than one wire is used, the wires may be coupled in parallel.
The protective layer 136 may be mechanically and/or electrically connected to an electrically conductive material 138 and/or the wire(s) 140, 142 at at least one connection point 148, which may include a weld, a pressure fitting, and/or another mechanical connection, for example. The connection point 148 may be located at or proximate to an end (e.g., the first end 132) of the bubbler tube 124 exposed to the molten material 20, although it will be appreciated that the connection point 148 may be disposed at other locations. For example, the connection point 148 may include an embodiment where the at least one wire 140, 142 can be coupled to the electrically conductive material 138 within the bubbler tube 124 at a predetermined distance from the first end 132. The protective layer 136 can also be mechanically and/or electrically coupled to a line 44a, 44b (e.g., by a weld and/or a wire) to form part of the electrical circuit.
The material compositions of the various components can further protect the bubbler device 110 from early corrosion and failure. For example, the electrically conductive material 138, the protective layer 136, and/or the at least one wire 140, 142 may include platinum and/or a platinum alloy, which is a highly unreactive precious metal that is an electrical conductor. Various other similar materials, for example, ruthenium, rhodium, palladium, osmium, iridium, and/or alloys of these may also be used for forming the electrically conductive material 138, the protective layer 136, and/or the at least one wire 140, 142.
In some implementations, the electrically conductive material 138, the protective layer 136, and/or the at least one wire 140, 142 can include the same or similar materials. In these implementations, an electrical current may be applied to the electrically conductive material 138, the at least one wire 140, 142, and/or the protective layer 136, and an output current can be measured to determine resistivity/conductivity of the bubbler device 110 and whether the bubbler device 110 has been damaged. For example, if the measured output current indicates a higher-than-normal resistance, then it can be determined that the bubbler device 110 is failing or has failed. However, if the measured output current indicates high or normal conductivity, it can be determined that the bubbler device 110 is in good operating condition.
In some implementations, the electrically conductive material 138, the protective layer 136, and/or the at least one wire 140, 142 can comprise dissimilar aterials. When dissimilar materials are used, the electrical junction(s) of the electrically conductive material 138, the protective layer 136, and/or the at least one wire 140, 142 can act as a thermocouple and may serve to measure temperature (of the molten glass 20) in addition to resistivity/conductivity of the electrical circuit in the bubbler device 110 by measuring a temperature-dependent voltage as a result of the thermoelectric effect of the dissimilar materials.
At least one line 44a, 44b (e.g., an electrical line or wire) can connect components (e.g., electrically conductive material 138, protective layer 136, and/or wires) 140, 142) of the bubbler device 110 to external components, such as various meters, monitors, readers, processors, various other electronics, or the like. For example, the at least one line 44a, 44b may electrically connect the bubbler device 110 to a meter 46 for measuring and/or recording various metrics (e.g., electrical conductivity, voltage, resistance, temperature, pressure, bubbling rate, air flow, or the like) of the furnace 12 and the molten material 20. It will be understood that electrical conductivity and resistivity are related properties of a given electrical circuit; therefore, measuring one makes it possible to determine the other and vice versa. In
At least one electrical circuit can be at least partially created by the electrically conductive material 138, the protective layer 136, the at least one wire 140, 142, at least one line (e.g., 44a, 44b), and/or the meter 46. The electrical circuit(s) can be utilized for detecting conductivity, resistivity, and/or temperature, in the case of a thermocouple configuration. It will be appreciated that the bubbler device 110 can include other configurations of electrical circuits for measuring resistivity, conductivity, and/or temperature, and/or other configurations of thermocouples.
Additionally, in
In the embodiment illustrated in
In the example illustrated in
When the bubbler device 110 is operating normally (e.g., the electrical circuit is closed, as illustrated in the bubbler devices 10, 110, 210, 310, 410, 510 in
Over time, various components of the bubbler device 610 can at least partially fail, for example, the molten material 20 may corrode the bubbler device 610 or components of the bubbler device 610, as illustrated by the broken bubbler device 610 in
In a specific example, the resistivity of platinum at 1200° C. can be about 42 μohms cm, where at the same temperature, the resistivity of glass can be about 0.89 ohms·cm. For a meter-long path using an approximately 1 mm diameter wire (e.g., wire 140), the resistivity of the wire can be about 0.4 ohms. However, if the wire is broken, corroded, or otherwise damaged, the resistivity of the wire 140 may increase above 1 ohm, which may indicate failure or potential failure of the bubbler device 110. When measurement of the electrical current within the bubbler device 110 indicates a low electrical conductivity/high electrical resistivity, the bubbler device 110 will likely need maintenance and/or replacement. In this way, the electrical circuit allows monitoring of the integrity and functionality of the bubbler device 110.
In some instances, the electrical circuit and voltage output of the bubbler device 110 may serve to monitor and/or measure a material temperature MT of the molten material 20. When the protective layer 136 and the electrically conductive material 138 and/or the wire(s) 140, 142 comprise different materials, the bubbler device 110 can function as a thermocouple for determining the material temperature MT. For example, an S-type thermocouple may be used herein, where the electrically conductive material 138 and/or wire(s) 140, 142 may comprise 90% platinum (Pt) and 10% rhodium (Rh) by weight, and the protective layer 136 may comprise 100% Pt. The connection point 148 (electrical junction) can include the measurement point of the material temperature MT and may be disposed at the inserted tip (e.g., first end 132) of the bubbler tube 124 or at other suitable locations.
Correspondingly, a first connection (e.g., a first electrical junction) within the thermocouple may have a different and/or higher temperature than a second connection (e.g., a second electrical junction) within the thermocouple, for example, because the first connection may be farther away from a wall (e.g., side wall 14, floor 16) of the furnace 12 than the second connection. For example, the first connection may be disposed proximate to the first end 132 of the bubbler tube 124, and the second connection may be disposed proximate to the floor 16 and/or the second end 134. Thus, there may be a temperature differential ΔT between the first and second connections. By placing the connections at locations having different temperatures, a thermocouple can be created to measure the temperature differential ΔT between the first and second connections. The temperature differential ΔT may be sent as data to the remote electronics (e.g., meter 46).
Not only can the thermocouple monitor the temperature differential ΔT, but it may also indicate a bubbling rate of the bubbler device 110. For example and as shown in
The determined bubbling rate may also indicate the integrity of the bubbler device 110. When the bubbler device 110 begins to fail, the temperature differential ΔT between the second end 134 and the first end 132 may be indicated as lower (e.g., the two temperatures T1 and T2 are closer than normal) and/or more sporadic than normal because of a lack of molten material flow due to a low bubbling rate and/or lack of bubbles produced by the bubbler device 110. By measuring the temperature differential ΔT and/or determining the bubbling rate, the integrity of the bubbler device 110 can be monitored.
A method of operating the bubbler device 110 can include a step of monitoring the electrical conductivity and/or resistivity of the electrical circuit of the bubbler device 110 using at least the electrically conductive material 138, wires 140, 142, and/or the protective layer 136 having any or all of the features described herein. Monitoring the electrical circuit can be performed by, for example, meter 46 and/or a controller or processor (not shown). Once the electrical conductivity or resistivity of the electrical circuit is monitored/determined, the method can further include sending a first signal S1, for example with the assistance of the meter 46 to a display and/or a controller, when a change in the electrical conductivity or resistivity from normal levels of the electrical circuit is detected. Sending the first signal S1 can include a first signal S1 that causes an alarm or alert in the remote electronics (e.g., a controller, a display, and the like) to provide an alert of change in the electrical conductivity or resistivity of the electrical circuit.
The method may also include monitoring the material temperature MT of the molten material 20 around the bubbler device 110 with the thermocouple of the bubbler device 110 and/or monitoring the bubbling rate of the bubbler device 110. These monitoring steps can both include monitoring the first temperature T1 of the molten material 20 proximate the first end 132 of the bubbler device 110, monitoring the second temperature T2 of the molten material 20 proximate the second end 134 of the bubbler device 110, and determining the temperature differential ΔT between the first and second temperatures T1, T2 to determine the bubbling rate. Once the bubbling rate is determined, the method can include sending a second signal S2, for example to a controller and/or a display, when there is a change in the bubbling rate of the bubbler 110, which second signal S2 can include an indication of the bubbling rate and can cause an alarm or alert as described with the first signal S1.
The disclosure has been presented in conjunction with several illustrative embodiments, and additional modifications and variations have been discussed. Other modifications and variations readily will suggest themselves to persons of ordinary skill in the art in view of the foregoing discussion. For example, the subject matter of each of the embodiments is hereby incorporated by reference into each of the other embodiments, for expedience. The disclosure is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.
