TWI622558B - Method of cooling glass ribbon in a fusion draw - Google Patents

Abstract

Provided herein is a controlled cooling of a glass ribbon in a traction of a melt-drawing machine comprising the steps of obtaining a target temperature profile of the glass ribbon and providing at least two turns in the traction. The temperature profile of the glass ribbon resulting from the fluid injection at each of the crucibles and the temperature profile of the glass ribbon resulting from the fluid extraction at each of the crucibles are measured. The temperature gain factor is calculated using the above measurements. The injection fluid flow rate or the extraction fluid flow rate for each crucible is calculated by iteratively solving the least squares problem using a temperature gain factor to achieve a target temperature profile of the glass ribbon.

Description

Method for cooling glass ribbon in molten traction [Cross-reference to related applications]

The present application claims priority to U.S. Provisional Application No. 61/770,362, filed on Feb. 28, 2013, which is incorporated herein by reference.

This specification is generally directed to controlled cooling of glass ribbons in ultra high flow rate melt-drawing methods. More specifically, the present specification is directed to injecting fluid into a molten traction machine and extracting fluid from the fusion traction machine at a plurality of points in the fusion traction machine to control the temperature profile of the glass ribbon being formed.

The demand for glass substrates for various commercial applications is growing. To meet this demand, the glass flow rate in the glass manufacturing process is correspondingly increased. The glass flow rate of the melt-drawing process is increased to reduce manufacturing costs. One obstacle to achieving high glass flow rates in the melt-drawing process is the lack of ability to cool the glass in a controlled manner. Traditionally, attempts have been made to increase traction height, improve traction insulation, and provide additional water-cooled surfaces for controlling cooling in high glass flow melt-drawing processes. However, these measures have proven to be inadequate.

Active air cooling is used in other glass manufacturing methods but not used In the melt drawing process. Attempting to draw fluid (such as air) from the top, middle or bottom of the traction is rarely successful. The use of extraction (i.e., in the absence of air injection) increases the flow of gas within the traction to increase the convective heat loss of the glass ribbon. However, air extraction results in maximum cooling of the lower portion of the drag, and the desired temperature profile of the glass ribbon is not always achievable, such as when the glass flow rate is high.

Therefore, an alternative method for cooling the glass ribbon is needed.

According to one embodiment, a method for controlled cooling of a glass ribbon in a traction of a melt-drawing machine is provided. The method can include the steps of obtaining a target temperature profile of the glass ribbon and providing at least two turns in the drag. A temperature profile of the glass ribbon caused by fluid injection at each of the crucibles and a temperature profile of the glass ribbon resulting from fluid extraction at each of the crucibles can be measured. The temperature gain profile can be evaluated using a temperature profile of the glass ribbon caused by fluid injection at each of the crucibles and a temperature profile of the glass ribbon resulting from fluid extraction at each of the crucibles. The injection fluid flow rate or the extraction fluid flow rate for each crucible can be calculated by solving the least squares problem using a temperature gain factor. The actual temperature profile of the glass ribbon similar to the target temperature profile can be obtained by applying the determined gas flow to each of the crucibles.

In another embodiment, an active fluid flow scheme for cooling a glass ribbon in a traction of a fusion traction machine is provided. The active fluid flow scheme can include the steps of obtaining a target temperature profile of the glass ribbon and providing at least two turns in the traction. A temperature profile of the glass ribbon caused by fluid injection at each of the crucibles and a temperature profile of the glass ribbon resulting from fluid extraction at each of the crucibles can be measured. Can be used by each of the 埠 The temperature gain profile is calculated from the temperature profile of the glass ribbon caused by fluid injection and the temperature profile of the glass ribbon resulting from fluid extraction at each of the crucibles. The injection fluid flow rate or the extraction fluid flow rate for each crucible can be calculated by solving the least squares problem using a temperature gain factor to obtain an actual temperature change profile of the glass ribbon similar to the target temperature change profile. The individual calculated injection fluid flow rate or extraction fluid flow rate for each crucible can be applied. The tolerance between the actual temperature change profile of the glass ribbon and the target temperature profile of the glass ribbon can be determined, and the difference between the actual temperature change profile of the glass ribbon and the target temperature profile of the glass ribbon can be evaluated. Poor. When the difference between the actual temperature change profile of the glass ribbon and the target temperature profile of the glass ribbon is not within the tolerance, the scheme returns to the step of recalculating the gain factor and moves again to the calculation step. When the difference between the actual temperature change profile of the glass ribbon and the target temperature profile of the glass ribbon is within tolerance, the protocol is stopped for a predetermined amount of time and then returned to the evaluation step.

Additional features and advantages of the embodiments will be set forth in the <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; The embodiments described in the patent scope and drawings are recognized.

It is to be understood that both the foregoing general descriptions A further understanding of the various embodiments is provided by the accompanying drawings, and is incorporated in the claims The drawings illustrate the various embodiments described herein and, together with the description,

100‧‧‧Glass manufacturing system

105‧‧‧Stainless glass

110‧‧‧melting tank

112‧‧‧ arrow

115‧‧‧Clarification tank/clarifier tube

120‧‧‧Mixing tank/stirring chamber

122‧‧‧Agitating cavity connecting pipe

125‧‧‧Transfer trough/tank pool

126‧‧‧Solid glass

127‧‧‧Slot pool connection tube

130‧‧‧ downflow tube

132‧‧‧ entrance

135‧‧‧forming trough/isostatic tube

136‧‧‧ openings

137‧‧‧ Groove

138a‧‧‧ side

138b‧‧‧ side

139‧‧‧ root

140‧‧‧ Pull roller assembly

140a‧‧‧Melt Traction Machine

150‧‧‧Road anvil machine

155‧‧‧Stainless glass

210‧‧‧First area

220‧‧‧Second area

230‧‧‧ Third Area

410‧‧‧ Curve

420‧‧‧ Curve

430‧‧‧ Curve

710‧‧‧ profile

720‧‧‧ profile

730‧‧‧ profile

810‧‧‧ first

820‧‧‧Second

830‧‧‧ Third

840‧‧‧Fourth

850‧‧‧ fifth

860‧‧‧6th

870‧‧‧ seventh

910‧‧‧Change in temperature profile

920‧‧‧Change in temperature profile

930‧‧‧Change in temperature profile

940‧‧‧Change in temperature profile

950‧‧‧Change in temperature profile

960‧‧‧Change in temperature profile

970‧‧‧Change in temperature profile

1010‧‧‧Change in temperature profile

1020‧‧‧Change in temperature profile

1030‧‧‧Change in temperature profile

1040‧‧‧Change in temperature profile

1050‧‧‧Change in temperature profile

1060‧‧‧Change in temperature profile

1070‧‧‧Change in temperature profile

1210‧‧‧Baseline temperature profile

1220‧‧‧temperature profile

1230‧‧‧ Temperature profile

1240‧‧‧temperature profile

1310‧‧‧Baseline temperature profile

1320‧‧‧temperature profile

1330‧‧‧ Temperature profile

1410‧‧‧ Baseline temperature profile

1420‧‧‧temperature profile

1430‧‧‧ Temperature profile

1 is a schematic view showing an embodiment of a glass manufacturing process including a melt-drawing machine; FIG. 2 is a schematic view showing a drag of a molten-drawing machine; and FIG. 3 is a view showing a dribbling according to an embodiment. a graph of the temperature profile of the glass ribbon that is designed to optimize the temperature profile change of the glass ribbon at a glass flow rate of 1x; and FIG. 4 is a diagram illustrating the absence of any cooling at a glass flow rate of 2x according to an embodiment. A graph of the temperature profile of the glass ribbon; FIG. 5A is a graph illustrating a temperature profile change according to an embodiment, the graph generally illustrating the shape of the temperature profile change after extraction; FIG. 5B is a diagram illustrating the temperature profile according to the embodiment A graph of variation that generally illustrates the shape of the temperature profile change after injection; FIG. 6 is a flow diagram of an active fluid flow scheme according to an embodiment; and FIG. 7 is a diagram illustrating fluid flow only for a target temperature according to Example 1. a graph of temperature profile changes of the glass ribbon of the extraction scheme and the fluid injection/extraction scheme; FIG. 8 schematically illustrates the position of the flaw in the drag according to the embodiment; and FIG. 9 is a diagram illustrating each of the examples according to Example 1. By A graph of temperature profile changes caused by fluid extraction in a helium system; FIG. 10 is a graph illustrating temperature profile changes caused by fluid injection in a helium system at each turn of Example 1; 11 is a bar graph illustrating a calculated fluid only extraction scheme and a calculated fluid injection/extraction scheme according to the seventh embodiment of the example 1; FIG. 12A is a graph illustrating the example according to the example 2 Baseline temperature profile of a 1x glass flow glass ribbon, temperature profile of a glass ribbon at 2x glass flow rate without cooling, temperature profile of a glass ribbon at 2x flow rate with fluid injection/extraction cooling, and fluid only A comparison between the temperature profiles of the glass ribbons at a 2x flow rate with cooling is extracted; and FIG. 12B is a diagram illustrating only a calculated fluid extraction scheme and calculated fluid injections in a seven-inch system at 2x glass flow rate according to Example 2. Bar graph of the extraction scheme; Figure 13A is a graph illustrating the temperature profile of the glass ribbon at a 3x glass flow rate without cooling, based on the baseline temperature profile of the glass ribbon at 1 x glass flow rate according to Example 2. Comparison with the temperature profile of the glass ribbon at 3x flow rate in the case of fluid injection/extraction cooling; Figure 13B is a diagram illustrating the flow rate at 3x glass according to Example 2. A bar graph of the calculated fluid injection/extraction scheme in the helium system; Figure 14A is a graph illustrating the baseline temperature profile of the glass ribbon at 1x glass flow rate according to Example 2, at 4x without cooling A comparison of the temperature profile of the glass ribbon at the glass flow rate with the temperature profile of the glass ribbon at a 4x flow rate in the case of fluid injection/extraction cooling; and Figure 14B is a diagram illustrating seven of the 4x glass flow rates according to Example 2. A bar graph of the calculated fluid injection/extraction scheme in the helium system.

Reference will now be made in detail be made to the exemplary embodiments Wherever possible, the same reference numerals will in the One embodiment of a melt-drawing machine is illustrated in Figure 1 and is generally referred to by the component symbol 100 .

As used herein, the term "fluid" is understood to include any gas, gas mixture, gas/liquid mixture, vapor, or combination of the foregoing that can move through the gas in a gas-like manner. Fluids may include, but are not limited to, air, nitrogen, boron vapor, and other gases or vapors derived from the glass manufacturing process.

Referring to Figure 1, a schematic illustration of an exemplary glass manufacturing system 100, the glass manufacturing system 100 for manufacturing a glass sheet using a melt process 105. The glass manufacturing system 100 can include a melting tank 110 , a clarification tank 115 , a mixing tank 120 (eg, agitation chamber 120 ), a transfer tank 125 (eg, a tank 125 ), a fusion draw machine (FDM) 140a, and travel. Traveling anvil machine (TAM) 150 . The melting tank 110 can be a location where the glass batch is introduced as indicated by arrow 112 and the glass batch is melted to form the molten glass 126 . The clarification tank 115 (e.g., the clarifier tube 115 ) may have a high temperature processing zone that receives the molten glass 126 from the melting tank 110 (not shown) and in which bubbles may be removed from the molten glass 126 . The clarification tank 115 can be coupled to the mixing tank 120 (e.g., the agitation chamber 120 ) by a clarifier to the agitation chamber connection tube 122 . Also, the mixing tank 120 can be connected to the transfer tank 125 by the agitation chamber to the tank connection pipe 127 . Transfer groove 125 via the downcomer pipe 130 to deliver the molten glass 126 FDM 140a, the FDM 140a may include an inlet 132, forming grooves 135 (e.g., isopipe 135) and the pinch roll assembly 140.

As shown in FIG. 1, the molten glass 126 from the downcomer 130 can flow into the inlet 132 leading to the forming groove 135 . Shaped groove 135 may include an opening 136, the opening 136 may flow into the receiving recess 137 and may then overflows and flows down to the two side surfaces 138a and 138b (138a at the back side 138b side and is not visible) of the molten glass 126. The root portion 139 is such that the two side faces 138a and 138b are brought together and the two overflow walls of the molten glass 126 are re-aggregated (eg, re-fused) before the pull roll assembly 140 drags the molten glass downward to form the glass sheet 105 . position. The area between the root 139 and the pull roll assembly 140 is referred to herein as a drag. According to an embodiment, the temperature of the glass is controlled within the traction. The TAM 150 then cuts the traversed glass sheet 105 into different glass sheets 155 .

The glass from the root portion 139 can be divided into three different regions by dragging. Referring now to Figure 2, the glass ribbon is indicated by a dashed line and the wall of the traction is indicated by a solid line. The first region 210 is a transition region in which glass transitions from the upper portion of the FDM (not shown in FIG. 2) to the traction. The second region 220 of the drag is a region in which the glass has viscous properties and elastic properties, and therefore, the glass may be referred to as viscoelastic in this region of the drag. In the third region 230 towards the bottom of the drag, the glass may be elastic.

The source of the thermo-artificial effect may vary due to the melt-drawing machine. One potential source of the thermal effect of the glass ribbon is the design of the FDM, for example, when the wall of the traction housing is not made of a single continuous material throughout the width of the traction. Another potential source of thermal interaction of the glass ribbon can be a device embedded in the FDM, for example, a temperature measuring device that is embedded in the traction to measure the thermal radiation in the traction. Another potential source of thermal artificial effects may be a non-uniform separation distance between the glass ribbon and the wall of the traction machine housing, which may be related to the design of the FDM or due to, for example, poor temperature within the traction The thickness of the glass ribbon caused by the degree of control is related to the change. If the thermal artificial effect of the glass ribbon is present in the glass ribbon when the glass ribbon is in a viscous state or a viscoelastic state, the thermal artificial effect of the glass ribbon induces stress in the glass ribbon. At the glass shaped area, the induced stress can be fixed into the glass. This fixed induced stress can be present in the finished glass sheet as a poor vertical stress band.

The design of the FDM (including, for example, drag height and drag insulation) is designed to optimize the temperature profile of the glass ribbon at a specific glass flow rate (hereinafter referred to as 1 x glass flow rate). Referring to the non-limiting embodiment illustrated in Figure 3, the optimized temperature profile in the traction of the 1x glass flow rate can have a large temperature change from the root of the glass ribbon to about the midpoint of the drag. In this embodiment, the temperature change within the hoist is not as fast after the maximum temperature change is reached around the middle of the hoist. This temperature profile provides the desired stress profile for the glass ribbon. However, it should be understood that temperature profiles other than the temperature profiles shown in FIG. 3 are preferably applicable to other types of processes and other glass compositions.

As the glass flow rate increases, the heat capacity of the glass flowing through the FDM increases. As the heat trapped in the glass increases, the glass ribbon does not cool at its desired rate, which can result in high stress and cracking. As shown in Figure 4, the temperature profile of the traction at 2x glass flow rate (illustrated by curve surface 410 ) without any form of cooling from the baseline temperature profile of the glass ribbon at 1x glass flow rate (by curve) 420 shows) shifting up. This temperature profile shift can result in increased stress and cracking of the glass ribbon caused by improper cooling. Embodiments of the methods disclosed herein can provide precise control of the temperature profile of the glass ribbon within the traction at increased glass flow rates. In an embodiment, the glass ribbon temperature profile (illustrated by curve 430 ) within the drag of the increased glass flow rate can be modified to be the same or similar to the baseline temperature profile 420 in the 1x flow rate drag. In an embodiment, the method can include a glass flow rate of about 2x, or even a glass flow rate of about 3x. In other embodiments, the method can include a glass flow rate of about 4x, or even a glass flow rate of about 5x.

In addition to controlling the temperature profile within the traction, embodiments of the methods disclosed herein can be used to control fluid flow above and below the traction. The direction and amount of fluid flow through the traction can be controlled to reduce the introduction of impurities that can adversely affect the quality of the glass ribbon as it is pulled through the traction. For example, if fluid enters at the top of the drag and flows down through the transition portion 210 , the boron vapor present in the transition region 210 can be cooled as the fluid pulls the boron vapor down to the draw. This cooling of the boron vapor can cause the boron vapor to condense on the glass ribbon upon cooling, which is undesirable. Similarly, if a large amount of fluid flows from the bottom of the traction to the top of the traction, solid particles present near the bottom of the traction can be carried by the fluid along the traction and deposited on the viscous glass. The deposited solid particles are referred to as inclusions and are undesirable. In addition to controlling the temperature profile of the glass ribbon, various embodiments may use fluid extraction and/or fluid injection to control fluid flow above and below the fluid traction. It will be appreciated that the choice of fluid injection or fluid extraction to control fluid flow within the traction may be based not only on the desired temperature profile, but also on the fluid flow within the traction and the fluid flow within the traction. Change to decide.

According to an embodiment, extracting fluid from the traction can provide, for example, a temperature profile change of the glass ribbon as shown in Figure 5A. The temperature profile change for the fluid-extracted glass ribbon provides the maximum temperature change of the glass ribbon near the bottom of the drag, which is not related to the desired temperature profile of the glass ribbon shown in FIG. Closely matched.

In an embodiment, injecting fluid into the traction provides a temperature profile change of the glass ribbon as shown in Figure 5B. The temperature profile change for the fluid injected glass ribbon has a maximum at or near the location where the fluid is injected. For example, in Figure 5B, the fluid is injected about 125 ft below the root 139 of the glass ribbon along the drag, and therefore, the maximum change in the temperature profile of the glass ribbon is also located along the dragged glass ribbon. The root 139 is about 125 miles away. Embodiments disclosed herein incorporate fluid extraction and fluid injection to control the traction within a temperature profile of the glass ribbon as it deviates from the target temperature profile of the glass ribbon shown in FIG. 3 (such as when the glass flow rate increases above 1 x) The temperature profile of the glass ribbon is as follows. Although the following description is directed to temperature profile changes of the glass ribbon caused by an increase in glass flow rate, the methods disclosed herein can be used to adjust the deviation of the actual temperature profile of the glass ribbon from the target temperature profile caused by any temperature artifacts.

The temperature profile change of the glass ribbon within the traction during the 1x glass flow rate can be measured by any conventional technique. According to an embodiment, the temperature profile change of the glass ribbon may be similar to the profile shown in FIG. After measuring the glass profile of the glass ribbon for the traction at the 1x glass flow rate, the number of turns for injecting the fluid to the traction or self-draw extraction fluid may be determined. The number and location of the crucibles are not specifically limited and may be determined based on the cost and the desired control of the temperature profile within the traction. In an embodiment, a higher number of turns can be used to provide better control of the temperature profile of the glass ribbon within the traction. In other embodiments, a smaller number of turns may be included to reduce cost.

In an embodiment, for injecting a fluid or extracting a fluid from a traction Two fewer ticks may be included at one or more of the tracts. In an embodiment, the traction may include three or more turns, such as four or more turns, for injecting or extracting fluid from the draw. In other embodiments, the traction may include five or more turns, or even six or more turns, for injecting or extracting fluid from the traction. In some other embodiments, the traction may include seven or more turns, or even eight or more turns, for injecting or extracting fluid from the draw. The fluid can be injected into the traction using any known mechanism. In an embodiment, a pump or pressurized fluid can be used to inject fluid into the traction. The fluid can be drawn from the traction using any known mechanism. In an embodiment, a pump or vacuum source can be used to draw fluid from the traction.

The flow rate of the fluid drawn by the traction or self-draw is not particularly limited and will vary depending on the cooling and other thermal characteristics required for the traction. In an embodiment, the flow rate of the fluid being drawn into or drawn from the traction is measured relative to the baseline flow rate of the fluid flowing through the traction without injection or extraction. For example, where fluid is not drawn into or drawn from the traction, this fluid flow rate can be considered a baseline flow rate as the fluid moves through the traction (eg, from top to bottom or from bottom to top). In an embodiment, the baseline fluid flow rate can be from about 0.010 m ³ /s to about 0.040 m ³ /s, or even from about 0.015 m ³ /s to about 0.035 m ³ /s. In other embodiments, the baseline fluid flow rate can be from about 0.020 m ³ /s to about 0.030 m ³ /s, or even from about 0.022 m ³ /s to about 0.025 m ³ /s. However, it should be understood that the baseline fluid flow rate may vary widely depending on the drag and, therefore, other baseline flow rates are not within the scope of this disclosure.

According to some embodiments, it is not necessary to inject fluid into the traction or draw fluid from each of the weirs, and thus, injecting or extracting from the traction. The flow rate of the fluid can be zero. According to other embodiments, the flow rate of the fluid drawn by the traction or self-draw may be the same as the baseline fluid flow rate. In an embodiment, the flow rate of the fluid drawn by the draw or self-draw may be about twice the baseline fluid flow rate, about three times the baseline fluid flow rate, or even about four times the baseline fluid flow rate. In some embodiments, the flow rate of the fluid drawn or drawn from the traction can be about five times the baseline fluid flow rate, about six times the baseline fluid flow rate, or even about seven times the baseline fluid flow rate. In other embodiments, the flow rate of the fluid drawn by the traction or self-draw may be about eight times the baseline fluid flow rate, about nine times the baseline fluid flow rate, or even about ten times the baseline fluid flow rate. In yet another embodiment, the flow rate of the fluid drawn or drawn from the traction can be about eleven times the baseline fluid flow rate, about twelve times the baseline fluid flow rate, or even about threeteen times the baseline fluid flow rate. In other embodiments, the flow rate of the fluid drawn by the traction or self-draw may be about fourteen times the baseline fluid flow rate, about fifteen times the baseline fluid flow rate, or even about sixteen times the baseline fluid flow rate. In some embodiments, the flow rate of the fluid drawn by the draw or self-draw may be about seventeen times the baseline fluid flow rate or even about eighteen times the baseline fluid flow rate.

Once the number and position of the fluid for drawing the fluid or for injecting the fluid is determined, the actual temperature profile change of the glass as a result of fluid injection and fluid extraction at each turn can be measured. For example, in embodiments where the traction has three turns, the fluid may be just high enough to inject a first flow rate to measure the flow rate of the effect of the injection flow rate on the change in temperature profile. Similarly, the fluid will be injected separately into the second weir and injected into the third weir (i.e., the fluid will be injected only one helium at a time) at an injection flow rate just high enough to measure the effect of the injection flow rate on the temperature profile change. Figure 10 shows the injection from the seven-inch embodiment. An example of a change in temperature profile of a glass ribbon is discussed in more detail in the examples below. In an embodiment, the fluid may be just high enough to measure the extracted flow rate of the effect of the extracted flow rate on the temperature profile change of the glass ribbon from the first enthalpy. Also, in an embodiment, the fluid will be drawn separately from the second and third volumes at a pumping flow rate that is just high enough to measure the effect of the extracted flow rate on the temperature profile change of the glass ribbon (i.e., the fluid will only be used once Extracted from a )). An example of the resulting change in temperature profile resulting from the extraction of the seven embodiment is illustrated in Figure 9, which is discussed in more detail in the examples below. In an embodiment, such temperature profile changes caused by the injection fluid and by the extraction fluid may be experimentally obtained by injecting or withdrawing a fluid in the test trace. In other embodiments, such temperature profile changes due to fluid injection and resulting from fluid extraction may use computer modeling programs known in the art including, but not limited to, Fluent produced by ANSYS. Obtained theoretically or digitally.

After obtaining a change in the temperature profile of the glass ribbon caused by the extraction of the fluid at various helium and the injection of the fluid, the optimal fluid convection scheme can be determined by linearizing the effects of fluid extraction and fluid injection using the following equations. First, the temperature profile change can be used to calculate the temperature gain A gain at each turn using equation (1): Where i is the port, T (y) along the vertical direction of the hoisting function of temperature, and the mass m _i to i by the port of the injection or withdrawal of fluids. In an embodiment, T (y), and m _i can be determined experimentally by injecting or extracting air in the traction test. In other embodiments, m _i and T(y) may be theoretically determined by using computer modeling software. Once the decision has been made for each 埠A gain _i , the least squares can be performed using equation (2) to calculate each Δ m _i : F (Δ m )= w 1.∥Δ T ( y )- A gain _i ( y Δ m _i ∥+ w 2∥Δ m _i ∥ (2) where w1 and w2 are weighting factors, and ΔT(y) is the desired temperature change. The weights w1 and w2 can be any positive real number and can be selected according to the glass composition and process used. In all instances, the weights w1 and w2 are set to 0.5. After minimizing the least square equation for (2) △ m _i, the new value of m _i m _i will be added to by △ m _i is calculated. The newly obtained m _i value can be used to calculate the subsequent A gain _i value using equation (1). A combination of equations (1) and Equation (2), m _i may be used for each iteration to improve the port until the change in cross-sectional view of the glass ribbon between the actual temperature of the fluid injection and extraction of a matching fluid or in close proximity to the measurement of glass flow 1x The target temperature profile of the belt changes. Thus, using this method, the actual temperature profile of the glass ribbon can be modified to match the target temperature profile of the glass ribbon when the glass flow rate is increased from 1x using the same traction for 1x flow.

According to an embodiment, an active fluid flow scheme for cooling the FDM can be provided. An embodiment of an active fluid flow scheme is illustrated in FIG. In step 1, a model or drag is selected that is designed to optimize the temperature profile of the glass ribbon in the traction of the 1x glass flow rate. In step 2, the temperature profile in the selected model or traction is determined to produce a target temperature profile change in the traction glass ribbon. In an embodiment, the target temperature profile change of the glass ribbon can be experimentally determined, and in other embodiments, the target temperature change of the glass ribbon can be obtained via modeling. In step 3, numerical experiments (such as experiments using computer modeling programs) or physical experiments are performed to evaluate the A gain _i factor for each injection/extraction, as described above. In step 4, the least squares problem of equation (2) is solved for each m _i using the A gain _i value of equation (1) to obtain the optimum fluid mass flow rate m _{i for each turn} . In step 5, the fluid mass flow rate for each of the turns calculated in step 4 is applied to the model or traction. In step 6, it is determined whether the difference between the obtained temperature change profile of the glass ribbon in the test trajectory or the model and the target temperature change profile of the glass ribbon is at or below a predetermined tolerance value, and the predetermined tolerance value is in the step 2 decided. If the evaluation answer in step 6 is "YES", the active fluid flow scheme is stopped for a predetermined time and then returned to step 6. The predetermined amount of time is not particularly limited and may be, for example, 5 seconds or more. If the answer in step 6 is "NO", the active fluid flow control scheme returns to step 3 where the new gain factor is re-evaluated and used to solve the least squares problem to improve flow.

The active fluid control scheme can be implemented by a device including a processor, an input/output hardware, a network interface hardware, a data storage component (the component stores a temperature change profile), and a memory. The memory can be configured as volatile memory and/or non-volatile memory, and thus can include random access memory (eg, SRAM, DRAM, and/or other types of random access memory), flash memory Body, scratchpad, compact disc (CD), digital versatile disc (DVD) and/or other types of non-transitory storage components. Additionally, the memory can be configured to store a program that calculates a fluid injection flow rate or fluid extraction flow rate (each of the fluid injection flow rate or fluid extraction flow rate can be embodied as, for example, a computer program, firmware, or hardware).

The processor can include any processing component that is configured Instructions for receiving and executing (such as from a data storage component and/or memory). Input/output hardware can include monitors, keyboards, mice, printers, cameras, microphones, speakers, and/or other devices for receiving, transmitting, and/or presenting data. The network interface hardware can include any wired or wireless network hardware, such as a data modem, LAN port, Wi-Fi card, WiMax card, mobile communication hardware, and/or with other networks and/or Or other hardware for device communication.

If the difference between the temperature change profile achieved by the glass ribbon and the target temperature profile of the glass ribbon becomes too large, then the active fluid control scheme of the embodiment can be used to monitor and modify the fluid mass flow rate at each turn. Thus, the temperature profile using the fluid injection/extraction process according to an embodiment can always correspond to the target of the glass ribbon at any given time in the melt-drawing process by using an air injection/extraction scheme to compensate for the process offset. Temperature profile.

Instance

The examples will be further elucidated by the following examples.

Example 1

Example 1 illustrates how to modify the actual temperature profile change of the glass ribbon to approximate the target temperature profile change of the glass ribbon. The temperature profile change of the glass ribbon is experimentally or theoretically determined using a modeled soft body for drawing, which is designed to optimize the temperature profile of the glass ribbon without cooling at a glass flow rate of 1x. In Figure 7, the target temperature profile change for the glass ribbon is shown as 710 . The seven ridges are included in the hoist in various positions, as shown in Figure 8. In Fig. 8, the drag wall is illustrated by a solid line, and the glass ribbon is illustrated by a broken line. Referring to Fig. 8, the first 埠810 is positioned about 40 距 from the root, the second 埠820 is positioned according to about 60 ,, the third 埠830 is positioned according to about 65 ,, and the fourth 埠840 is positioned about 80 距 from the root. The five 埠850 is positioned about 105 距 from the root, the sixth 埠860 is positioned about 125 距 from the root, and the seventh 埠870 is positioned about 140 距 from the root.

The effect of fluid extraction on the temperature profile of the glass ribbon is measured. The fluid is withdrawn from the first crucible 810 at a rate of about 280 lb/hr and the temperature profile of the glass ribbon is measured along the vertical direction of the traction. The resulting temperature profile change for the glass ribbon in Figure 9 is shown as 910 . Similarly, fluid is withdrawn from the second crucible 820 at a rate of 280 lb/hr and the temperature profile of the glass ribbon is measured along the vertical direction of the traction. The resulting temperature profile change for the glass ribbon in Figure 9 is shown as 920 . Similarly, in / hr of 280lb rate from the third port 830, a fourth port 840 and fifth port 850, a sixth port and the seventh port 860 draws fluid 870, and the vertical direction of the hoisting of the glass ribbon measured temperature change. The resulting temperature profile changes are shown in Figures 9 as 930 , 940 , 950 , 960, and 970, respectively . As can be seen from Figure 9, the air extraction results in overall cooling of the glass, with more cooling in the lower portion of the traction than in the upper region of the traction. No reflux was observed at the exit.

After the extraction measurement, the effect of injecting room temperature air on the glass temperature was measured. Room temperature air is injected into the first crucible 810 at a rate of about 280 lb/hr and the temperature profile of the glass ribbon is measured in the vertical direction of the traction. The resulting temperature profile change for the glass ribbon in Figure 10 is shown as 1010 . Similarly, room temperature air is injected into the second crucible 820 at a rate of 280 lb/hr and the temperature profile of the glass ribbon is measured along the vertical direction of the drag. The resulting temperature profile change for the glass ribbon in Figure 10 is shown as 1020 . Similarly, at room temperature air / hr rate of 280lb third injection port 830, respectively, the fourth port 840 and fifth port 850, a sixth port 860 and a seventh port 870, and the vertical direction of the hoisting measured with a glass The temperature changes. The resulting temperature profile changes are shown in Figures 10 as 1030 , 1040 , 1050 , 1060, and 1070, respectively . As can be seen from Fig. 10, room temperature air is injected into the glass near and above the injection injection site, but room temperature air is injected into the glass in the lower portion of the cooling heating traction zone (i.e., the portion furthest from the root). There is no backflow at the exit.

Using the temperature profile changes taken from the above extraction and injection measurements, calculate the A gain _i for each 使用 using equation (1): A gain once for each port _i is calculated, using equation (2) performing least squares to calculate a value for each port _i m: F (△ m) = w 1.∥ △ T (y) - A _i gain (Y Δ m _i ∥ + w 2 ∥ Δ m _i ∥ (2) Each m _i obtained from the least squares calculation is then introduced into a physical experiment trajectory or a software model. Using the calculated value m _i, the cross-sectional temperature is measured again for each port. These new temperature change profiles can then be used as a new baseline to calculate additional A gain _i values, and additional A gain _i values can be used in equation (2) to further improve the temperature change profile. The process can be repeated until the temperature profile obtained is closely matched to the temperature profile from the traction for 1x flow optimization. Using this method, the combined fluid injection/extraction scheme shown in Figure 11 was developed. In Fig. 11, the forward airflow indicates that the fluid is drawn from the traction, and the reverse airflow indicates that the room temperature air is injected into the traction. Figure 11 also compares the air injection/extraction method with the extraction only method in which fluid is drawn from the first crucible 810 at a maximum of 40 lb/hr. As shown in Figure 7, the temperature profile change (illustrated by curve 720 ) of the glass ribbon using the implantation/extraction method can be closer to the temperature profile change (illustrated by section 730 ) of the glass ribbon achieved only by extraction. The shape of the temperature profile of the glass ribbon obtained from the 1x glass flow rate (illustrated by section 710 ) without cooling.

Thus, this example demonstrates that the combined injection/extraction cooling can be closer to the target temperature profile change than just extracting the cooling. Specifically, as shown, for example, in Figure 10, the temperature profile changes of the glass ribbon by implantation are achieved with a higher degree of freedom that allows for a change in the temperature profile achieved by the custom glass ribbon.

Example 2

Using the method disclosed herein and illustrated in Example 1, fluid injection/extraction cooling can be used to control the temperature profile of the glass ribbon as the glass flow rate increases within the traction.

2x glass flow rate

A baseline temperature profile of the glass ribbon is obtained by measuring the temperature profile within the traction, which is designed to optimize the temperature profile of the glass ribbon at a 1x glass flow rate. The fluid flow in the baseline traction is a natural fluid flow along the traction and is not caused by injection or extraction. The baseline airflow is about 0.0022 m ³ /s. The baseline temperature profile of the glass ribbon is shown as 1210 in Figure 12A.

The glass flow rate in the draw was then increased to 2x and the fluid flow rate was determined for each of the seven crucibles using the method described above and in Example 1. When calculating the fluid flow rate for each crucible, an injection/extraction scheme as shown in Fig. 12B is obtained. In Figure 12B, the air flow rate is measured as a function of the baseline airflow in the hoist, where the glass flow rate is 1x (e.g., 2 on the y-axis in Figure 12B is twice the baseline airflow). The forward flow shown in Figure 12B represents fluid extraction from the traction and the negative flow represents fluid injection into the traction. In Fig. 12B, the extraction only scheme is calculated by extracting the fluid at a rate of about 3.5 only at the first turn. Figure 12A shows the baseline temperature profile (measured at 1x glass flow rate) as 1210 , and the temperature profile at 2x glass flow rate without any fluid cooling is shown as 1220 , which will be used as shown in Figure 12B. The temperature profile at the 2x glass flow rate for fluid injection/extraction cooling is shown as 1230 and the temperature profile at 2x glass flow rate for fluid extraction only is shown as 1240 . As shown in Figure 12A, the temperature profile at 2x glass flow rate without fluid cooling has a slope that is not close to the baseline temperature profile, which indicates that less cooling occurs in the traction when the glass flow rate is set to 2x. However, both the injection/extraction scheme and the extraction-only scheme are closely related to the baseline temperature profile. Thus, for a 2x glass flow rate, the injection/extraction scheme and the extraction only scheme can provide adequate cooling in the traction. However, as shown in Fig. 12A, the temperature profile obtained using fluid injection/extraction cooling is almost the same as the baseline temperature profile. This situation shows the improved temperature control possible by using an injection/extraction scheme.

3x glass flow rate

A baseline temperature profile of the glass ribbon is obtained by measuring the temperature profile within the traction, which is designed to optimize the temperature profile of the glass ribbon at a 1x glass flow rate. The fluid flow in the baseline traction is a natural fluid flow along the traction and is not caused by injection or extraction. The baseline airflow is about 0.0022 m ³ /s. The baseline temperature profile of the glass ribbon is shown in Figure 13A as 1310 .

The glass flow rate was then increased to 3x and the fluid flow rate was determined for each of the seven crucibles using the method described in Example 1. When calculating the fluid flow rate for each crucible, an injection/extraction scheme as shown in Fig. 13B is obtained. In Figure 13B, the air flow rate is measured as a function of the baseline airflow in the hoist, where the glass flow rate is 1x (e.g., 2 on the y-axis in Figure 13B is twice the baseline airflow). The forward flow shown in Figure 13B represents fluid extraction from the traction and the negative flow represents fluid injection into the traction. Figure 13A shows the baseline temperature profile (measured at 1x glass flow rate) as 1310 , and the temperature profile at 3x glass flow rate without any fluid cooling is shown as 1320 and will be used as shown in Figure 13B. The temperature profile of the solution at 3x glass flow rate for fluid injection/extraction cooling is shown as 1330 . As shown in Figure 13B, the temperature profile at 3x glass flow rate without fluid cooling has a slope that is not close to the baseline temperature profile, which indicates that less cooling occurs in the traction when the glass flow rate is set to 3x. At a glass flow rate of 3x, the extraction cannot individually cool the glass sufficiently without backflow in the transition zone. This backflow will heat the glass, not the cooling glass, and can cause condensation problems. As shown in Figure 13A, a fluid injection/extraction scheme can be used to provide a temperature profile that is nearly identical to the baseline temperature profile. Thus, using an injection/extraction scheme, the flow rate of the glass can be increased to 3x without changing the physical size or insulation of the traction.

4x glass flow rate

A baseline temperature profile of the glass ribbon is obtained by measuring the temperature profile within the traction, which is designed to optimize the temperature profile of the glass ribbon at a 1x glass flow rate. The fluid flow in the baseline traction is a natural fluid flow along the traction and is not caused by injection or extraction. The baseline airflow is about 0.0022 m ³ /s. The baseline temperature profile of the glass ribbon is shown in Figure 14A as 1410 .

The glass flow rate was then increased to 4x and the fluid flow rate was determined for each of the seven crucibles using the method described in Example 1. When calculating the fluid flow rate for each crucible, an injection/extraction scheme as shown in Fig. 14B is obtained. In Figure 14B, the air flow rate is measured as a function of the baseline airflow in the traction, where the glass flow rate is 1x (e.g., 2 on the y-axis in Figure 14B is twice the baseline airflow). The forward flow shown in Figure 14B represents fluid extraction from the traction and the negative flow represents fluid injection into the traction. Figure 14A shows the baseline temperature profile (measured at 1x glass flow rate) as 1410 , and the temperature profile at 4x glass flow rate without any fluid cooling is shown as 1420 and will be used as shown in Figure 14B. The temperature profile of the solution at 4x glass flow rate for fluid injection/extraction cooling is shown as 1430 . As shown in Figure 14A, the temperature profile at 4x glass flow rate without fluid cooling has a slope that is not close to the baseline temperature profile, which indicates that less cooling occurs in the traction when the glass flow rate is set to 4x. At a glass flow rate of 4x, the extraction cannot individually cool the glass sufficiently without backflow in the transition zone. This backflow will heat the glass, not the cooling glass, and can cause condensation problems. As shown in Figure 14A, a fluid injection/extraction scheme can be used to provide a temperature profile that is nearly identical to the baseline temperature profile. Thus, using an injection/extraction scheme, the flow rate of the glass can be increased to 4x without changing the physical size or insulation of the traction.

It will be apparent to those skilled in the art that various modifications and changes can be made to the embodiments described herein without departing from the spirit and scope of the invention. Therefore, the modifications and variations of the various embodiments described herein are the equivalent of the scope of the appended claims and the scope of the appended claims. The scope of this specification is intended to cover such modifications and variations.

Claims (22)

A method for controlled cooling of a glass ribbon in one of a melting traction machine, the method comprising the steps of: obtaining a target temperature change profile of the glass ribbon; measuring at least two of the traction a temperature profile of the glass ribbon caused by fluid injection at each of the crucibles; measuring a temperature profile of the glass ribbon caused by fluid extraction at each of the crucibles; using each of the crucibles The temperature gain profile of the glass ribbon caused by the fluid injection at the location and the temperature variation profile of the glass ribbon caused by the fluid extraction at each of the crucibles; The equal temperature gain factor solves a least squares problem to calculate an injection fluid flow rate or an extraction fluid flow rate for each of the crucibles to obtain an actual temperature change profile of the glass ribbon, the actual temperature change profile substantially corresponding to the target The temperature change profile is matched; and the current flow rate is adjusted to the calculated injection fluid flow rate or the extracted fluid flow rate for each turn. The method of claim 1, wherein the fluid is withdrawn from the traction at a first imperfection and the fluid is injected into the traction at a second imperfection. The method of claim 2, wherein a flow rate of the fluid drawn from the traction via the first enthalpy is different from a flow rate of the fluid injected into the traverse via the second enthalpy. The method of claim 1 wherein the fluid is drawn from the drag at a point closest to one of the roots of the glass ribbon. The method of claim 1, wherein five or more defects are provided in the drag. The method of claim 1, wherein a flow rate of the fluid injected into the traction and a flow rate of the fluid drawn from the traction are from about zero to about eighteen times a baseline fluid flow rate. The method of claim 6, wherein the flow rate of the fluid injected into the traction and the flow rate of the fluid drawn from the traction is about twice the baseline fluid flow rate to about fifteen times the baseline fluid flow rate. . The method of claim 6, wherein the baseline fluid flow rate is from about 0.010 m ³ /s to about 0.040 m ³ /s. The method of claim 1, wherein the temperature gain factors are calculated by the following formula: Wherein for port i, T (y) along the vertical direction of the hoisting of a function of temperature; and m _i is the injection or extraction of fluid through the port i of the quality. The method of claim 9, wherein the injection fluid flow rate or an extraction fluid flow rate is calculated by solving a least squares problem using equation (2): F (Δ m ) = w 1. ∥ Δ T ( y ) - A gain _i ( y ) Δ m _i ∥ + w 2 ∥ Δ m _i ∥ (2) where w1 and w2 are weighting factors, and ΔT(y) is the desired temperature change. The method of claim 1, wherein the step of measuring the temperature change profiles of the glass ribbon caused by fluid injection at each of the crucibles and the measuring are performed by each of the crucibles The step of the temperature profile of the glass ribbon caused by fluid extraction at one of the steps is performed by a physical experiment. The method of claim 1, wherein the step of measuring the temperature change profiles of the glass ribbon caused by fluid injection at each of the crucibles and the measuring are performed by each of the crucibles The steps of the temperature profile of the glass ribbon resulting from fluid extraction at one of the locations are performed using data modeling. The method of claim 1 wherein the target temperature profile of the glass ribbon is measured at a particular glass flow rate. The method of claim 13 wherein the actual temperature profile of the glass ribbon is measured at three times the particular glass flow rate. The method of claim 13, wherein the actual temperature of the glass ribbon is changed The profile is measured at four times the specific glass flow rate. An active fluid flow method for controlling a glass ribbon in one of a traction traction machine, the active fluid flow method comprising the steps of: obtaining a target temperature change profile of the glass ribbon; measuring by the a temperature profile of the glass ribbon caused by fluid injection at each of the electrodes; measuring a temperature profile of the glass ribbon caused by fluid extraction at each of the weirs; The temperature variation profile of the glass ribbon caused by fluid injection at each of the water zones and the temperature variation profile of the temperature change of the glass ribbon caused by fluid extraction at each of the crucibles; Calculating a least squares problem using the temperature gain factors to calculate an injection fluid flow rate or an extraction fluid flow rate for each of the crucibles to obtain an actual temperature change profile of the glass ribbon, the actual temperature change profile substantially The target temperature change profile is matched; the fluid flow rate is adjusted to the calculated injection fluid flow rate or the extracted fluid flow rate for each enthalpy; the glass ribbon is determined a tolerance of the difference between the actual temperature change profile and the target temperature profile of the glass ribbon; and assessing the difference between the actual temperature profile of the ribbon and the target temperature profile of the ribbon Whether it is within this tolerance. The method of claim 16, wherein the method returns to the glass ribbon The step of evaluating the gain factor when the difference between the actual temperature change profile and the target temperature profile of the glass ribbon is not within the tolerance. The method of claim 16, wherein the method is stopped for a predetermined amount of time and then returned to the difference between the actual temperature change profile of the glass ribbon and the target temperature change profile of the glass ribbon. In the meantime, the step of evaluating the difference between the actual temperature change profile of the glass ribbon and the target temperature profile of the glass ribbon is evaluated. The method of claim 16, wherein the temperature gain factors are calculated using equation (1): Wherein for port i, T (y) along the vertical direction of the hoisting of a function of temperature; and m _i is the injection or extraction of fluid through the port i of the quality. The method of claim 19, wherein the calculating step comprises the step of solving a least squares problem using equation (2): F (Δ m ) = w 1. ∥ Δ T ( y ) - A gain _i ( y ) Δ m _i ∥+ w 2∥Δ m _i ∥ (2) where w1 and w2 are weighting factors, and ΔT(y) is the desired temperature change. The method of claim 16 wherein the target temperature profile of the glass ribbon is measured at a particular glass flow rate. The method of claim 16, wherein the actual temperature profile of the glass ribbon is measured at three times the particular glass flow rate.