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JP-2026514479-A - Method and system for measuring parameters related to the stability of a batch of floating material

JP2026514479AJP 2026514479 AJP2026514479 AJP 2026514479AJP-2026514479-A

Abstract

[Problem] To provide an efficient and reliable method for estimating the thickness of the portion of a batch of material floating in a pool of molten material that has reached a steady temperature. [Solution] A computer-implemented method (3000) for measuring the thickness e of a batch (2005) of material floating in a pool (2006) of molten material in an electric melting furnace (1002) for glass or stone. The method receives as input data a set of time-scale temperature maps M[T] of the batch (2005) (I3000), a range R[ Ts ] of predicted values for the steady-state temperature Ts of the batch (2005), and a threshold σ of the temperature variation ΔT over time Δt. The method provides as output data a spatial distribution (O3000) of the thickness of the batch (2005) across its surface. [Selection Diagram] Figure 3

Inventors

  • ダビド ブスケ
  • ジュスティーヌ ボロンコフ

Assignees

  • サン－ゴバン イゾベール

Dates

Publication Date
20260511
Application Date
20240411
Priority Date
20230421

Claims (15)

  1. A computer implementation method (3000) for measuring the thickness e of a batch (2005) of material floating in a pool (2006) of molten material in an electric melting furnace (1002) for glass or stone, The method takes as input data a set (I3000) of time-scale temperature maps M[T] of a batch (2005) of the material, a range R[ Ts ] of predicted values for the steady-state temperature Ts of the batch (2005), and a threshold σ for the temperature variation ΔT over time Δt; The method provides, as output data, the spatial distribution (O3000) of the thickness of the batch (2005) across its surface; The above method (3000) is, (a) step (3001) select a region within each temperature map M[T] of the provided set I3000 in which the temperature lies within the range R[ Ts ] of the predicted steady-state temperature Ts of the batch (2005); (b) A step (3002) of calculating the temperature variation ΔT between a plurality of temperature maps that are continuous over a given time range Δt within the same detection area; (c) step (3003) of selecting from the regions of step (b) in which the temperature variation ΔT at time Δt is below the threshold σ provided as input; (d) A step (3004) of calculating the thickness E of the batch 2005 for each point of the plurality of temperature maps within each of the regions selected in step (c), wherein the thickness E is calculated by applying a function E( Ts ) to each point, the function E( Ts ) defines a relationship between the thickness and the steady temperature Ts , and the function E( Ts ) is based on heat flow transfer obtained by simulation or experiment or an empirical model; Methods that include...
  2. The method further receives, as input data, the temperature T f in the internal region of the furnace 1002 located above the batch (2005), and the temperature T melt of the molten pool (2006); Here, the function E(T s ) is the heat flow transfer function provided by the following equation: The method according to claim 1 (3000), wherein λ is the thermal conductivity of the batch 2005, σ is the Stefan-Boltzmann constant, h is the convective heat transfer coefficient of the batch 2005, ε is the thermal emissivity of the batch 2005, Tf is the temperature in the internal region of the furnace located above the batch 2005, Tmelt is the temperature of the molten pool 2006, and Ts is the steady-state temperature of the batch 2005 from which the thickness E is calculated.
  3. The function E(T s ) is an empirical model provided by the following equation: The method according to claim 1 (3000), wherein T1 and T2 are two steady temperatures measured by the experiment of batch 2005, e1 and e2 are two thicknesses measured by the experiment of batch 2005 corresponding to temperatures T1 and T2 , respectively, and Ts is the steady temperature of batch 2005 from which the thickness E is calculated.
  4. The method according to claim 1 or 2 (3000), wherein the threshold value σ of the temperature fluctuation ΔT at the aforementioned time Δt is 5°C/min, preferably 2°C/min, and more preferably 1°C/min.
  5. The method (3000) according to any one of claims 1 to 4, wherein the range of predicted values R[ Ts ] for the steady-state temperature Ts of batch 2005 is a range of values experimentally determined for batches of similar materials under similar melting conditions, or a range of defined values between two modes of a bimodal distribution calculated from one or more of the temperature maps of the provided set (I3000).
  6. The method further includes step (e) detecting regions within each of the provided set I3000 temperature maps by applying an object detection function to the temperature map, wherein the object detection function is configured to process regions having a temperature equal to or greater than a threshold θ; The method according to any one of claims 1 to 5 (3000), wherein the method further provides the spatial distribution of the detected region over time as output data.
  7. The method according to claim 6 (3000), further comprising step (f) calculating the velocity of the region detected in step (e) by calculating the displacement of the region over time on the time scale of the set of time-scale temperature maps.
  8. The method according to claim 6 or 7 (3000), wherein the object detection function is selected from Otsu's thresholding function, the Laplacian of a Gaussian function, the Hessian determinant, the Gaussian difference, and a watershed-based gray-level blob detection function.
  9. A data processing device (4000) comprising means for carrying out the method described in any one of claims 1 to 8.
  10. A computer program (I4001) including instructions, wherein the instructions cause the computer to perform the method described in any one of claims 1 to 8 when the program is executed by the computer.
  11. A computer-readable medium (4002) containing instructions, wherein the instructions cause the computer to perform the method described in any one of claims 1 to 8 when the program is executed by the computer.
  12. A process for measuring the thickness of a batch (2005) of material (1001a) floating in a pool (2006) of molten material in an electric melting furnace (1002) for glass or stone, wherein the process is: - A step of obtaining a set (I3000) of time-scale temperature maps M[T] of the surface of a batch (2005) of the material (1001a) within the internal region (2009) of the melting furnace (1002); - A step of carrying out the method (3000) according to any one of claims 1 to 8 using a data processing device (4000), wherein the acquired set of time-scale temperature maps M[T] (I3000) is provided to the method (3000) as input data; A process that includes this.
  13. A system for measuring the thickness of a batch (2005) of material (1001a) floating in a pool (2006) of molten material in an electric melting furnace (1002) for glass or stone, wherein the system is - An acquisition device (2010) configured to acquire a set (I3000) of time-scale temperature maps M[T] of the surface of a batch 2005 of the material (1001a) within the internal region (2009) of the furnace (1002); - A data processing device (4000) according to any one of claims 1 to 8, wherein the data processing device (4000) and the acquisition device (2010) are connected to each other by wire or wireless for data transfer; A system that includes these features.
  14. The system according to claim 13, wherein the acquisition device (2010) comprises an infrared camera configured to acquire a set of time-scale infrared maps M[T], and the infrared camera or the data processing device (4000) comprises means for converting the set of time-scale infrared maps into a set of time-scale temperature maps I3000.
  15. The system according to claim 13 or 14, wherein the data processing device (4000) further comprises means for correcting the perspective view of the acquisition device by applying a perspective or homography transformation function to each temperature map of the set of time-scale temperature maps M[T] (I3000).

Description

This invention relates to a computer-based method and system for monitoring the stability of batches of material floating in a pool of molten material within an electric melting tank for glass. In conventional electric glass melting furnaces, multiple electrodes are immersed in a pool of molten glass in a predetermined pattern. By passing an electric current through the molten glass between the electrodes, the glass is heated by the Joule effect. The material batch may include raw materials, cullet, and other recycled materials. By continuously or discontinuously supplying these batches to the upper surface of the pool, a material source and a barrier layer or crust formed on top of it are provided. However, as this batch gradually melts and additional molten glass is formed, the thickness of the layer decreases, and the heat lost from the molten glass body in the furnace through the batch increases. Conversely, when additional batch material is distributed to the upper surface of the molten glass, the layer thickens, and the heat lost through this thicker layer decreases. The batch is typically supplied in a predetermined pattern by a mobile feeder, conveyor, or sprinkler, which allows for precise volume control and maintains a minimum thickness on the upper surface of the pool, resulting in reduced heat loss, protected feeders, and avoidance of furnace overflow. It is common practice to inspect the interior of a glass melting furnace using infrared optical systems positioned within the furnace walls. These systems allow for human observation of the stability of material batches. Japanese Patent Publication No. 53-39204 (JEOL Ltd., April 11, 1978), Japanese Patent Publication No. 7-216422 (Nippon Steel Corporation, August 15, 1995), Japanese Patent Publication No. 2010-2150 (Takuma Corporation, January 7, 2010), and U.S. Patent Application Publication No. 2018/231875 (Canada [CA], representing Her Majesty the Queen through the Minister of Natural Resources, August 16, 2018) describe an inspection system comprising an infrared unit positioned in front of a viewing window installed within a furnace wall. In this technical field, more advanced systems are also available for measuring parameters related to several characteristics of material batches. International Publication No. 80/02833 (OWENS CORNING FIBERGLASS CORP [US], December 24, 1980) describes a system for controlling the batch level, or thickness, of material in an electric melting furnace for glass. This system includes an infrared sensor mounted on or adjacent to the feeder, which non-contactively measures the temperature of the outer surface of the batch. By comparing the measured temperature to a set temperature and adjusting the feeder's supply rate according to an experimental relationship between the batch thickness and the outer surface temperature, the batch level, or thickness, is increased or decreased. U.S. Patent No. 4,194,077 (OWENS CORNING FIBERGLASS COLP [US], March 18, 1980) describes a system for controlling the level of material batches in an electric melting furnace for glass. This system includes an ultrasonic sensor, which is mounted on a feeder and moves with the feeder above the batch. A non-contact measurement of the batch level is obtained, and based on this measurement, the batch thickness can be calculated from a relationship between the density of the batch and the molten glass and their levels. U.S. Patent No. 4,409,012 (OWENS ILLINOIS INC. [US], October 11, 1983) describes a method and apparatus for monitoring the surface coating of a batch of material floating in a pool of molten material by processing video recordings of the top surfaces of both the batch and the molten material in a glass melting furnace. Subsequently, a bimodal distribution of pixel counts corresponding to gray levels is plotted from the recorded images, and after separating the two modes by thresholding, the relative amounts of the batch and molten material are estimated by integrating the area occupied by each mode across different regions of the furnace. Japanese Patent Publication No. 6-56432 (Nippon Electric Glass Co., Ltd., March 1, 1994) describes a method and system for measuring the level of a batch of material floating in a pool of molten material by processing an image of a portion of the top surface of the batch illuminated by an illumination device. The image is binarized, and the centroid coordinates of the white pixels are calculated. The changes in the centroid coordinates thus calculated are assumed to reflect the changes in the batch level caused by variations in the amount of light reflected by the illuminated portion of the batch as the batch level rises and falls. International Publication No. 02/48057 (SOFTWARE & TECH GLAS GMBH [DE], June 20, 2002) describes a method for measuring the linearized increase in the level of batch coverage in a pool of molten material by processing images of the top surfaces of both the batch and t