Method and system for determining a specific temperature corresponding to the viscosity fixation point of a free fluid flow.

Abstract

A computer implementation method for determining a specific temperature Tlog corresponding to a fixed viscosity point of a fluid. The method takes one value of fluid viscosity and one value of temperature as input. The method provides a characteristic temperature Tlog3 as output. The characteristic temperature Tlog3 is calculated using a VFT-like model, the variable parameters of the VFT-like model include a chemical composition-dependent variable parameter T0 that depends on the chemical composition of the fluid, and the variable parameters of the VFT-like model are statistically adjusted based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated for the fluid within a chemical composition range.

Description

Technical Field

[0001] The present disclosure relates to a method and a system for determining a specific temperature corresponding to the viscosity fixed point of a free fluid flow in an industrial environment, and more particularly, in an industrial process of glass manufacturing, and more specifically still, in an industrial process of manufacturing inorganic wool such as inorganic glass fiber-based materials, for example, glass wool or stone wool, to a method and a system for determining a specific temperature corresponding to the viscosity fixed point of a free fluid flow.

Background Art

[0002] In an inorganic wool production line, molten glass or molten stone discharged from a melting furnace for glass or stone is conveyed through a forehearth and supplied to a fiberizing tool. Generally, two methods, namely the internal centrifugal method and the external centrifugal method, are used for fiberization.

[0003] The molten glass flows from the forehearth through a so-called bushing to the fiberizing tool. This bushing is generally designed such that its opening is extended by a nozzle or a drain pan and terminated by a hole from which the molten glass flows by gravity. The bushing controls the flow rate of the molten glass to the fiberizing tool according to its size and diameter.

[0004] In the internal centrifugal method, the fiberizing tool generally includes a high-speed rotating device. This high-speed rotating device is called a centrifuge, a spinner, or a spinning plate, and is composed of an annular wall provided with calibrated holes by perforation. When the molten glass discharged from the bushing is supplied, the high-speed rotating device injects the molten glass through the holes formed by the perforation, thereby forming glass threads. The cross-section of the hole of the bushing is generally perpendicular to the flow direction of the molten glass, that is, perpendicular to gravity.

[0005] The fiberization tool also includes a ring burner or annular burner, which ejects a high-temperature gaseous flow or jet substantially tangentially to the annular wall, thereby pulling the formed glass thread downwards. It is also possible to heat and stretch the glass thread with this tensile flow or jet to form glass fibers.

[0006] In the external centrifugal method, molten glass or molten stone flows over the peripheral surface of at least one of several rotating rotors. The molten material first adheres to this surface, and then some of the adhered material is ejected from this surface by the centrifugal force generated by the rotation of the rotor. In this method, the cross-section of the bushing hole may or may not be perpendicular to the flow direction of the molten glass, i.e., perpendicular to gravity.

[0007] For example, one requirement for obtaining high-quality products such as stone wool or glass wool is that the glass threads are properly stretched when released from the rotating device and pulled downwards. This pulling and stretching operation must not be too strong or too fast to prevent breakage, but at the same time, it must be done in a way that forms sufficiently long glass fibers. Otherwise, the final product, such as stone wool or glass wool, will no longer meet technical requirements, such as thickness and thermal insulation performance. Such products will have to be discarded, resulting in economic losses for the manufacturer.

[0008] Since the flow rate of molten glass depends on its temperature and chemical properties, current practice involves periodically taking samples of the molten glass before it reaches the bushing and performing chemical analysis. It is also common practice to periodically measure or continuously monitor the temperature of the molten glass near the bushing, for example, immediately before, after, or inside the bushing.

[0009] In the short term, the flow rate of molten glass during tension and stretching operations can be controlled by changing its temperature near the bushing. This temperature adjustment can be achieved through a properly controlled heating operation, such as Joule heating performed by passing an electric current through a metal bushing. In the long term, it is also possible to change the chemical properties of the molten glass by appropriately adjusting the chemical properties of the raw materials in the melting process.

[0010] Most fluids exhibit a specific temperature corresponding to a so-called "viscosity fixed point." The viscosity fixed point is a temperature-viscosity value pair that characterizes the viscosity-temperature behavior of a fluid, and it depends on the fluid's chemical composition. For a given fluid with a given chemical composition, the viscosity fixed point can be considered the temperature at which the fluid reaches a given viscosity value, and vice versa. Therefore, a given fluid with a given chemical composition exhibits a specific intrinsic temperature at its viscosity fixed point, and if the chemical composition of the fluid changes, the specific intrinsic temperature value at the same viscosity fixed point may change accordingly.

[0011] All other things being equal, the viscosity fixed point can be considered an indicator of the fluid's chemical composition. A change in the fluid's chemical composition can cause any of its viscosity fixed points to change. Therefore, by monitoring the values ​​of one or more viscosity fixed points for a given fluid with a given composition, it becomes possible to monitor the fluid's chemical composition.

[0012] For molten glass or molten stone, five viscosity fixing points are generally defined: the working point, softening point, annealing point, strain point, and transformation temperature. These are all detailed in ISO 7884-1:1987 and ISO 7884-2:1987 standards, which also describe general methods for their measurement or determination. These methods are laboratory-level and not suitable for industrial implementation, particularly in inorganic wool production lines.

[0013] Meanwhile, several field methods have also been developed to determine the viscosity of free-falling fluid flows in manufacturing lines.

[0014] U.S. Patent No. 4,877,436 [SHEINKOP ISAC[US]] dated October 31, 1989, discloses a method for controlling the flow rate and viscosity of molten glass during manufacturing. This method relies on the calculation of molten glass viscosity using the Hagen-Poiseuille law, but requires that the density of the molten glass be known.

[0015] PCT / EP2022 / 086258 [SAINT-GOBAIN ISOVER] describes a method for measuring the viscosity of a fluid flowing through an opening at a constant acceleration by modeling the geometric profile of the fluid flow and calculating the fluid viscosity from the modeled geometric profile using a mathematical or physical model, and the contents of that document are incorporated herein by reference. [Overview of the Initiative] [Problems that the invention aims to solve]

[0016] Even if current methods for measuring the viscosity of free-fall fluid flows are effective, one of their main drawbacks is that they are only suitable for measuring a single viscosity value of the fluid at a given point in time during the operation of a manufacturing line. Since viscosity depends on both temperature and chemical composition, when monitoring viscosity on a manufacturing line, operators may still be unable to determine whether a change in viscosity is due to a change in temperature or a change in the fluid's chemical composition unless the fluid's temperature or chemical composition is measured simultaneously.

[0017] Furthermore, current methods make it impossible to measure the viscosity fixation point of a fluid. Therefore, it is also impossible to use these viscosity fixation points as indicators for real-time monitoring of the fluid's chemical composition in the field. [Means for solving the problem]

[0018] In a first aspect of the present invention, a computer-implemented method is provided for determining a specific temperature corresponding to the viscosity fixed point of a free fluid flow as recited in claim 1, and dependent claims 2 to 7 are advantageous embodiments.

[0019] In a second aspect of the present disclosure, a data processing apparatus, a computer program, and a computer-readable medium for implementing the method of the first aspect are provided.

[0020] In a third aspect of the present disclosure, a process for measuring the viscosity of a fluid flow is provided.

[0021] In a fourth aspect of the present disclosure, a system for measuring the viscosity of a fluid flow is provided.

[0022] In a fifth aspect of the present disclosure, a measurement process is provided for determining a specific temperature corresponding to the viscosity fixed point of a free fluid flow flowing at a constant acceleration from the opening recited in claim 11.

[0023] The process of the fifth aspect of the present invention can include one or more of the following features, either alone or in any technically feasible combination: - The opening has a circular cross-section. - The composition-dependent variable parameter may be a non-linear or linear function of the chemical composition of the fluid flow. The following parameter formula:

Number

[0024] In a sixth aspect of the present disclosure, a system is provided for determining a specific temperature corresponding to the viscosity fixed point of a fluid flow flowing at a constant acceleration from the opening described in claim 13.

[0025] The system according to the sixth aspect of the present invention can include one or more of the features described in claims 14 and 15, either alone or in any technically feasible combination.

[0026] According to a seventh aspect of the present invention, there is provided the use of the process according to the fifth aspect or the system according to the sixth aspect.

[0027] According to some embodiments, the use according to the seventh aspect of the present invention includes the features described in claim 17. Advantages of the Invention

[0028] A first significant advantage of the present invention is that the specific temperature Tlog corresponding to the viscosity fixed point of the fluid can be measured quickly without relying on regular sampling of the fluid or off-site chemical analysis.

[0029] A second significant advantage of the present invention lies in the non-contact measurement of a specific temperature Tlog corresponding to the viscosity fixation point of the fluid flow. In this case, the viscosity fixation point of the fluid flow can be continuously monitored without disturbing or interrupting the fluid flow. This can reduce time and cost in the manufacturing process of products such as glass fiber products.

[0030] A third advantage of the present invention is that, if the manufacturing line configuration allows for the measurement of the viscosity and temperature of the free fluid flow within a target region of the free fluid flow, the present invention can be easily introduced into existing manufacturing lines. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic diagram of an example of a glass fiber manufacturing line.

[0032] [Figure 2] Part I of Figure 1 is a schematic cross-sectional view of an example of a bushing and fiberization tool.

[0033] [Figure 3] This is a schematic diagram of part II of Figure 2.

[0034] [Figure 4] This is a data flow diagram of a computer implementation method according to a first aspect of the present invention.

[0035] [Figure 5] This is a physical data flow diagram of a processing data system for carrying out a method according to the first aspect of the present invention.

[0036] [Figure 6] This is a schematic diagram of a system according to a fourth aspect of the present invention.

[0037] [Figure 7] This plot shows the viscosity-temperature relationship for multiple fluids within a given chemical composition range. [Modes for carrying out the invention]

[0038] Referring to Figure 1, the internal centrifugal production line 1000 for glass or stone fibers may generally comprise a silo 1001 for storing raw materials 1001a, such as inorganic compounds and / or cullet; a glass or stone melting furnace 1002 for melting the raw materials 1001a transported from the silo 1001 by a conveyor 1003; and one or more fiberization tools 1005a, 1005b, 1005c to which molten glass or molten stone 1006 is supplied through a pre-furnace 1004. The pre-furnace is typically designed as an open or closed channel with an opening directly above each fiberization tool 1005a, 1005b, 1005c to which molten glass or molten stone 1006 is supplied.

[0039] Referring to Figure 2, a bushing 2002 can be provided at the opening 2001 of the pre-furnace 1004. The bushing 2002 is exemplified here as having an opening 2002a extended by a nozzle or drain pan 2002b and terminating at another opening 2002c, through which molten glass or molten stone 1006 flows by gravity as a fluid flow 2003 to a fibrous tool 1005c located below. The fibrous tool 1005c may comprise a spinner 2004 consisting of a bucket 2003a having a lateral opening and an annular wall 2004b having a plurality of calibrated holes. During high-speed rotation, the molten glass or molten stone 1006 that has emerged from the bushing 2002 and fallen into the bucket 2004a is ejected from the lateral opening of the bucket 2003a toward the inner surface of the annular wall 2004b, and then ejected through the calibrated holes to form glass threads 2005.

[0040] The fiberization tool 1005c may also include a ring burner 2006. The ring burner 2006 ejects a hot gaseous flow or jet substantially tangentially to the annular wall, pulling the formed glass thread 2005 downward, which is heated and solidified to ultimately form glass fibers 2007. The fiberization tool 1005c may also include a gas injector 2008 positioned below the ring burner 2005 to prevent the glass fibers 2007 from moving too far away from the axis of rotation of the spinner 2004.

[0041] As illustrated in Figures 2 and 3, when the molten glass 1006 flows through the opening 2002c of the bushing 2002 due to gravity, the molten glass 1006 flows freely as a free fluid flow 2003 with a constant acceleration.

[0042] "Free fluid flow" should be understood as a fluid flow having an open boundary; that is, a fluid flow that is not in contact with, for example, the wall of a pipe acting as a boundary for the fluid flow. On the other hand, "closed fluid flow" should be understood as a fluid flow having at least one closed boundary; that is, a fluid flow that flows through a pipe, for example, with the wall of the pipe acting as a closed boundary for the fluid flow. The present invention is applicable to both free fluid flow and closed fluid flow, but is preferably applicable to free fluid flow.

[0043] Referring to Figures 3 and 4, in a first aspect of the present invention, a computer implementation method 4000 is provided for determining a specific temperature Tlog corresponding to a viscosity fixing point of a fluid 2003. The method 4000 receives, as input I4000, one value of the viscosity μ of the fluid 2003 and one value of the temperature T; The method 4000 provides the characteristic temperature Tlog value as output O4000; The method 4000 is, (a) Step 4001 of providing a VFT-like model, wherein the variable parameters of the VFT-like model include a chemical composition-dependent variable parameter T0 that depends on the chemical composition of the fluid, and the variable parameters of the VFT-like model are statistically adjusted based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated for the fluid within a chemical composition range. (b) Step 4002 for calculating the value of parameter T0 from the VFT-like model, wherein the value of the viscosity μ of the fluid 2003 and the value of the temperature T are provided to the VFT-like model as input data, (c) A step 4003 to calculate the characteristic temperature Tlog corresponding to the viscosity fixed point of the fluid 2003 from the VFT-like model, wherein the value of a single parameter T0 calculated in step (b) and the viscosity fixed point are provided as input data to the VFT-like model. Includes.

[0044] In the context of this disclosure, a VFT-like model is a model based on the well-known parametric Vogel-Fulcher-Tammann equation, also known as the VFT equation, which is commonly used to describe the viscosity of a fluid as a function of temperature. The VFT equation can be considered a type of Arrhenius equation in which the variable parameters are modified so as to better simulate the change in fluid viscosity as a function of temperature, particularly in supercooled states, as it approaches a temperature known as the glass transition.

[0045] The parameters in the VFT equation are empirical fitting parameters whose values ​​are adjusted through a fitting operation against experimental data for specific chemical compositions of the fluid. Since the variable parameters do not depend on the chemical composition of the fluid, their values ​​need to be adjusted for each chemical composition of the fluid.

[0046] The VFT expression can be expressed in its simplest form as follows:

number

[0047] Here, μ is the viscosity of the fluid, T is the temperature of the fluid, and A0, B0, and T0 are variable fitting parameters.

[0048] VFT formulas may be expressed in more complex forms with a greater number of variable fitting parameters, depending on the level of reproducibility and accuracy required for modeling experimental data. However, as a rule of thumb, the number of variable fitting parameters should not be too large to avoid overfitting.

[0049] In the present invention, as described in step (a), the VFT-like model differs from the prior art in that it is based on or derived from the VFT equation and includes a chemical composition-dependent variable parameter T0 that depends on the chemical composition of the fluid. Since the parameter T0 depends on the chemical composition of the fluid, the VFT-like model according to the present invention allows the variable parameter to be statistically adjusted based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated for the fluid within a chemical composition range.

[0050] In certain embodiments, the chemical composition-dependent variable parameter T0 may be a nonlinear or linear function of the chemical composition of the fluid 2003. In supplemental embodiments, the chemical composition-dependent variable parameter T0 may be further weighted by a variable weighting coefficient β. This variable weighting coefficient β may be a variable fitting parameter among the variable parameters of a VFT-like model that is statistically adjusted based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated for the aforementioned fluids within a chemical composition range.

[0051] In a preferred embodiment, the VFT-like model may have the following parameter expression.

number

[0052] One of the outstanding features of the VFT-like model according to the present invention is that, when its variable parameters are statistically adjusted based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated from fluids within a chemical composition range, a kind of master curve of the temperature-viscosity relationship of the fluid flow within that chemical composition range is provided. This master curve provides a superposition of temperature-chemical composition over changes in fluid viscosity. By utilizing this superposition in subsequent steps (b) and (c) of the method according to the present invention, a specific temperature Tlog corresponding to a viscosity-fixing point of the fluid flow is determined.

[0053] The viscosity and temperature values ​​of the fluid 2003, provided as input data to method 4000 according to the present invention, can be obtained by any means.

[0054] For example, as shown in Figure 3, the temperature can be measured either by a thermocouple placed within the target area (A3001) or by a non-contact pyrometric sensor.

[0055] Viscosity can be measured by methods and apparatus commonly used in the art. For example, it can be determined by methods based on the Hagen-Poiseuille law, such as the method described in U.S. Patent No. 4,877,436 dated October 31, 1989 [SHEINKOP ISAC[US]]. In a preferred embodiment, viscosity can be measured by a non-contact method that involves digital processing of at least one image of the area A3001 of the fluid flow 2003. Such a method is described in PCT / EP2022 / 086258 [SAINT-GOBAIN ISOVER], the contents of which are incorporated herein by reference.

[0056] As described above, the viscosity fixation point is a temperature-viscosity value pair that characterizes the viscosity-temperature behavior of a fluid having a given chemical composition. In the context of the present invention, the value of the viscosity fixation point can be arbitrarily determined considering the operation performed on the fluid. Furthermore, the value of the viscosity fixation point can be determined according to the use and / or standards in the relevant art relating to fluids. For example, the value of the viscosity fixation point may be the working point, which corresponds to the most practical viscosity value for forming the fluid into a particular shape.

[0057] In preferred embodiments, the fluid may be molten glass or molten stone. The present invention is particularly advantageous in monitoring the values ​​of one or more viscosity fixed points in a single flow of molten glass or molten stone, so that these values ​​can then be used as an index for detecting variations in the chemical composition of the fluid through specific temperature Tlog values ​​corresponding to the viscosity fixed points. This is particularly important for monitoring variations in the chemical composition of molten glass or molten stone (1006) flowing by gravity through a bushing (2002) in a glass fiber or stone fiber manufacturing line.

[0058] In certain supplemental embodiments, the viscosity fixing point is selected from the working point, softening point, annealing point, strain point, and transformation point. For molten glass and molten stone, these five viscosity points are detailed in the ISO 7884-1:1987 standard.

[0059] In a particular embodiment, referring to Figure 3, the fluid is a free flow 2003 flowing at a constant acceleration from an opening 2002c, preferably an opening 2002c having a circular cross-section, and the viscosity and temperature values ​​of the free flow 2003 are values ​​within the free flow region A3001.

[0060] The circular opening 2002c is a geometric configuration that corresponds to most cases in current industrial lines. Therefore, the fluid flow 2003 can also have a circular cross-section.

[0061] In a second aspect of this disclosure, referring to Figure 5, a data processing system 5000 is provided, comprising means 5001 for carrying out a method 4000 according to any embodiment of the first aspect of the present invention. A computer program I 5001 including instructions is also provided, which, when executed by a computer, causes the computer to carry out a method 4000 according to any embodiment of the first aspect of the present invention.

[0062] The data processing system 5000 includes means 5001 for carrying out a method according to any embodiment of the first aspect of the present invention. An example of means 5001 is a device capable of being instructed to automatically perform a sequence of arithmetic or logical operations in order to perform a task or action. The device is also called a computer and may comprise one or more central processing units (CPUs) and at least one control unit configured to perform these operations.

[0063] The device may further include other electronic components such as an input / output interface 5003, a non-volatile or volatile storage device 5002, and a bus which is a communication system for data transfer between components within or between computers. One of the input / output devices may be a user interface for human-machine interaction, for example, a graphical user interface for displaying human-readable information.

[0064] Since calculations sometimes require high computing power to process large amounts of data, data processing systems, especially in image processing, can be advantageously equipped with one or more image processing units (GPUs) that are more efficient than CPUs due to their parallel architecture.

[0065] Computer program I5001 can be written in any type of programming language, whether compiled or interpreted, for carrying out the steps of the method according to any embodiment of the first aspect of the present invention. Computer program I5001 may be part of a software solution, i.e., part of a collection of executable instructions, code, scripts, etc., and / or databases.

[0066] In certain embodiments, a computer-readable storage device or medium 5002 can also be provided, which includes instructions, the instructions causing a computer to perform a method 4000 according to any embodiment of the first aspect of the present invention when executed by a computer.

[0067] The computer-readable storage device 5002 may preferably be a non-volatile, non-temporary storage device or memory, such as a hard disk drive or a solid-state drive. The computer-readable storage device may be a removable storage medium or a non-removable storage medium as part of a computer.

[0068] Alternatively, the computer-readable storage device may be volatile memory located inside a removable medium.

[0069] The computer-readable storage device 5002 may be part of a computer used as a server, and can download executable instructions from the server, which, when executed by the computer, cause the computer to carry out any of the methods described herein.

[0070] Alternatively, program I5001 can be implemented in a distributed computing environment, such as cloud computing. Instructions can be executed on a server, and client computers can be connected to this server, providing encoded data as input to the method. After data processing, the output can be downloaded to the client computer for decoding, or sent directly as instructions, for example. This type of implementation can be advantageous because it is feasible in distributed computing environments such as cloud computing solutions.

[0071] The method according to the present invention can be carried out as part of a process. Accordingly, a third aspect of the present invention provides a measurement process for determining a specific temperature Tlog corresponding to a viscosity fixing point of a free fluid flow 2003 flowing from an opening 2002c at a constant acceleration, the process being: (a) A step of measuring one value of viscosity and one value of temperature of the free fluid flow 2003 within the target region A3001 of the free fluid flow 2003, (b) A step of providing a VFT-like model using a data processing device 5000, wherein the variable parameters of the VFT-like model include a chemical composition-dependent variable parameter T0 that depends on the chemical composition of the fluid, and the variable parameters of the VFT-like model are statistically adjusted based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated for the fluid within a chemical composition range. (b) A step of using a data processing device 5000 to calculate the value of a single parameter T0 from the VFT-like model, wherein the viscosity value and temperature value of the free fluid flow 2003 in the target region A3001 are provided to the VFT-like model as input data, (c) A step of using a data processing device 5000 to calculate a characteristic temperature Tlog corresponding to the viscosity fixed point of the free fluid flow 2003 from the VFT-like model, wherein the value of a single parameter T0 calculated in step (b) and the viscosity fixed point are provided to the VFT-like model as input data. Includes.

[0072] Any feature described in detail in the embodiment of the method according to the first aspect of the present invention can be applied to the method according to the third aspect.

[0073] In a fourth aspect of the present invention, referring to Figure 6, a system 6000 is provided for determining a specific temperature Tlog corresponding to a viscosity fixing point of a fluid flow (2003) flowing from an opening 2002c at a constant acceleration, wherein the system - A first apparatus 6001 configured to measure one value of viscosity and one value of temperature of the free fluid flow 2003 within a target region A3001 of the free fluid flow 2003, - A second device 6002 configured to measure one value of the temperature of the free fluid flow 2003 within a target region A3001 of the free fluid flow 2003, - A data processing device 5000 according to a second aspect of the present invention, configured to receive measurement values ​​from the first and second devices, and It is equipped with.

[0074] In exemplary embodiments, the first apparatus 6001 may perform measurements using a thermocouple in contact with the fluid flow within the area of ​​interest (A3001) or using a non-contact pyrometric sensor. The second apparatus (6002) may be an apparatus for carrying out a method based on the Hagen-Poiseuille law, such as the method described in U.S. Patent No. 4,877,436 dated October 31, 1989 [SHEINKOP ISAC[US]].

[0075] In certain advantageous embodiments, the first apparatus (6001) and the second apparatus (6002) may be part of the same apparatus.

[0076] In a preferred embodiment, the first apparatus is adapted for non-contact measurement of fluid viscosity by digital processing of at least one image of the target region A3001 of the fluid flow 2003. In particular, the first apparatus may be one that carries out the method described in PCT / EP2022 / 086258 [SAINT-GOBAIN ISOVER], the contents of which are incorporated herein by reference.

[0077] The processes and systems according to the third and fourth embodiments can each be advantageously used in a glass fiber or stone fiber manufacturing line to monitor variations in the chemical composition of molten glass or molten stone (1006) flowing by gravity through a bushing (2002).

[0078] In an advantageous embodiment, the observed fluctuations in chemical composition can be used to input feedback to adjust the temperature of the stone or glass near the bushing (2002) and / or the chemical composition of the molten glass or molten stone (1006). Examples

[0079] Forty-one types of inorganic glass were prepared within the chemical composition ranges shown in Table 1. Table 1 shows the type of oxide and the minimum and maximum limits of the relative content of each oxide, expressed as weight percentages.

[0080] [Table 1]

[0081] The viscosity of each inorganic glass was experimentally measured at temperatures ranging from 900°C to 1400°C. The relationship between viscosity and temperature is shown in Figure 7. For readability, only the data (dots) for four types of glass are plotted, with the lines used as a guide. The data for all 41 types of glass are distributed between the lower solid line (2) and the upper solid line (4).

[0082] According to the first step (a) embodiment of the method of the present invention, the following parameter formula (1):

number

[0083] The parameter equation (1) was statistically adjusted for viscosity-temperature datasets of 41 types of inorganic glass using the following method. (a) Initialize the variable parameters A0, B0, and β with the values ​​reported in the first row of Table 2, “Initial”. (b) With A0, B0, and β fixed, T0 is adjusted based on the entire dataset using gradient descent with the sum of squared errors as the loss function. (c) With T0 fixed, A0, B0, and β are adjusted based on the entire dataset using gradient descent with the sum of squared errors as the loss function. (d) Repeat steps (b) and (c) until the sum of squared errors is minimized.

[0084] The values ​​of the variable parameters A0, B0, and β obtained through this optimization are reported in the second row of Table 2 under "Optimization". [Table 2]

[0085] Equation (1) with the optimized value can be written as follows:

number

[0086] By rewriting equation (1) as equation (2), we can express T0 as a function of T and μ:

number

[0087] Four exemplary glasses, G1 to G4, were prepared. Their compositions are shown in Table 3. A single measurement of viscosity μ at a given temperature T is reported in Table 4. Viscosity was measured by the Couette method. Alternatively, viscosity can be measured by any suitable method, for example, using either the method described in U.S. Patent No. 4,877,436 dated October 31, 1989 [SHEINKOP ISAC[US]] or PCT / EP2022 / 086258 [SAINT-GOBAIN ISOVER].

[0088] [Table 3]

[0089] [Table 4]

[0090] According to step (b) of the method of the present invention, for each of the four exemplary glasses G1 to G4 having the compositions shown in Table 3, the value of T0 was calculated from the corresponding measured viscosity-temperature T based on formula (2).

[0091] The results are reported in Table 5.

[0092] [Table 5]

[0093] The following equation is obtained by rewriting equation (1) according to step (c) of the method of the present invention:

number

[0094] Here, the variable μ is the viscosity fixed point μ for which the value of Tlog is to be calculated. fThe value has been replaced with the value previously calculated for the exemplary glass, and the variable T0 has been replaced with the value previously calculated for the exemplary glass. The results are reported in Table 6. The experimentally measured Tlog value for the same viscosity fixed point of the same exemplary glass is denoted as Tlog(experimental) and is also reported for comparison. [Table 6]

[0095] The results in Table 6 clearly and unambiguously demonstrate that the method according to the present invention enables the measurement of a specific temperature Tlog corresponding to a viscosity fixed point without relying on periodic fluid sampling or off-site chemical analysis.

[0096] A single variable parameter T0 differs for each chemical composition of the fluid.

[0097] Of all the variable parameters of the VFT-like model, except for the single variable parameter T0, they are constant with respect to the chemical composition of fluids within the aforementioned chemical composition range. In other words, of all the variable parameters of the VFT-like model, except for the single variable parameter T0, they do not change with respect to each chemical composition of fluids within that chemical composition range.

[0098] In this example, A0, B0, and β are constant with respect to the chemical composition range. In other words, A0 is identical in terms of the chemical composition of the fluids included within the chemical composition range, B0 is identical in terms of the chemical composition of the fluids included within the chemical composition range, and β is identical in terms of the chemical composition of the fluids included within the chemical composition range.

[0099] List of References Patent Documents

[0100] U.S. Patent No. 4,877,436 dated October 31, 1989 [SHEINKOP ISAC[US]]

[0101] PCT / EP2022 / 086258[SAINT-GOBAIN ISOVER] Non-patent literature

[0102] ISO 7884-1:1987, Glass - Viscosity and viscosity fixed point - Part 1: Principles for determining viscosity and viscosity fixed point

[0103] ISO 7884-2:1987, Glass - Viscosity and Viscosity at Fixed Points - Part 2: Measurement of Viscosity by Rotational Viscometer

Claims

1. A computer implementation method (4000) for determining a specific temperature Tlog corresponding to a fixed viscosity point of a fluid, The method (4000) takes as input (I4000) a value of the viscosity μ of the fluid (2003) and a value of the temperature T; The method (4000) provides the value of the characteristic temperature Tolog as the output (O4000); The above method (4000) is, (a) A step (4001) of providing a VFT-like model, wherein the variable parameters of the VFT-like model are chemical composition-dependent variable parameters T that depend on the chemical composition of the fluid. ０ (4001) includes the step of statistically adjusting the variable parameters of the VFT-like model based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated from the fluid within the chemical composition range, (b) The parameter T from the VFT-like model ０ A step (4002) for calculating the value of the fluid (2003), wherein the value of the viscosity μ and the value of the temperature T of the fluid (2003) are provided as input data to the VFT-like model. (c) A step (4003) of calculating a characteristic temperature Tlog corresponding to the viscosity fixed point of the fluid (2003) from the VFT-like model, wherein the single parameter T calculated in step (b) ０ Step (4003) of providing the value and the viscosity fixed point as input data to the VFT-like model. Computer implementation method (4000), including.

2. The aforementioned chemical composition-dependent variable parameter T ０ The computer implementation method (4000) according to claim 1, wherein the chemical composition of the fluid (2003) may be a nonlinear or linear function.

3. The aforementioned VFT-like model has the following parameter formula: [Math 1] It has, and here, A ０ , B ０ , and β are variable parameters, μ is viscosity, T is temperature, T ０ The computer implementation method (4000) according to claim 2, wherein is a single composition-dependent adjustment parameter.

4. The computer mounting method (4000) according to any one of claims 1 to 3, wherein the fluid is molten glass or molten stone.

5. The computer implementation method (4000) according to claim 4, wherein the viscosity fixing point is selected from the working point, softening point, slow cooling point, strain point, and transformation point.

6. The fluid for which the specific temperature (Tlog) is to be determined has a specific chemical composition, and the composition-dependent variable parameter (T ０ ) is the single variable parameter of the VFT-like model that depends on the specific chemical composition of the fluid for which the specific temperature (Tlog) is to be determined, among the variable parameters of the VFT-like model, and other variable parameters of the VFT-like model different from the composition-dependent variable parameter (T ０ ) are adjusted to fit the chemical composition range of the fluid, the computer-implemented method (4000) according to any one of claims 1 to 5.

7. The aforementioned chemical composition-dependent variable parameter (T ０ The computer implementation method (4000) according to any one of claims 1 to 6, wherein the variable parameters of the VFT-like model other than the one described above are adjusted based on a dataset of temperature-viscosity values ​​obtained from experiments and / or simulations of the fluid within the chemical composition range, and the values ​​obtained are constant for the specific chemical composition included in the chemical composition range.

8. A data processing device (5000) comprising means for carrying out the method (4000) according to any one of claims 1 to 7.

9. A computer program (I5001) including instructions, wherein the instructions cause the computer to perform the method (4000) according to any one of claims 1 to 7 when the program is executed by the computer.

10. A computer-readable medium (5002) containing instructions, wherein the instructions cause the computer to perform the method (4000) according to any one of claims 1 to 7 when the program is executed by the computer.

11. A measurement process for determining a specific temperature Tlog corresponding to the viscosity fixing point of a free fluid flow (2003) flowing from an opening (2002c) at a constant acceleration, wherein the process is: (a) A step of measuring one value of viscosity and one value of temperature of the free fluid flow (2003) within the target region (A3001) of the free fluid flow (2003), (b) A step of providing a VFT-like model using a data processing device (5000), wherein the variable parameters of the VFT-like model are chemical composition-dependent variable parameters T that depend on the chemical composition of the fluid. ０ The step of statistically adjusting the variable parameters of the VFT-like model based on a dataset of temperature-viscosity values ​​obtained experimentally and / or simulated from the fluid within the chemical composition range, (b) Using the data processing device (5000), a single parameter T is obtained from the VFT-like model. ０ A step of calculating the value of the viscosity and temperature of the free fluid flow (2003) in the target region (A3001) is provided to the VFT-like model as input data, (c) A step of using a data processing device (5000) to calculate a characteristic temperature Tlog corresponding to the viscosity fixed point of the free fluid flow (2003) from the VFT-like model, wherein the single parameter T calculated in step (b) ０ The steps include providing the value and the viscosity fixed point as input data to the VFT-like model. A process that includes this.

12. The measurement process for determining according to claim 11, wherein the opening (2002c) has a circular cross-section.

13. A system (6000) for determining a specific temperature Tlog corresponding to the viscosity fixing point of a fluid flow (2003) flowing from an opening (2002c) at a constant acceleration, wherein the system is - A first apparatus (6001) configured to measure one value of viscosity and one value of temperature of the free fluid flow (2003) within a target region (A3001) of the free fluid flow (2003), - A second device (6002) configured to measure one value of the temperature of the free fluid flow (2003) within the target region (A3001) of the free fluid flow (2003), - A data processing device (5000) according to claim 8, configured to receive measurement values ​​from the first and second devices, and A system (6000) equipped with [this feature].

14. The system (6000) according to claim 13, wherein the first device (6001) and the second device (6002) are part of the same device.

15. The system (6000) according to claim 13, wherein the first apparatus is an apparatus adapted for non-contact measurement of the viscosity of the fluid by digital processing of at least one image of the target region (A3001) of the fluid flow (2003).

16. Use of the process according to claim 11 or the system according to claim 13 for monitoring the variation in the chemical composition of molten glass or molten stone (1006) flowing through a bushing (2002) by gravity in a glass fiber manufacturing line, or in a glass fiber or stone fiber manufacturing line.

17. The use according to claim 16, wherein the monitored chemical composition is reflected in a feedback operation for adjusting the temperature of the stone or glass near the bushing (2002) and / or the chemical composition of the molten glass or molten stone (1006).

Images