System and method for determining the chemical composition of liquid metallurgical products

Patent metadata

Field	Value
Publication number	US-12510485-B2
Application number	US-202118280429-A
Country	US
Kind code	B2
Filing date	Mar 10, 2021
Priority date	Mar 10, 2021
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

A device for determining the chemical composition of a liquid metallurgical product emitting electromagnetic radiations. The device including a collection probe configured to acquire the electromagnetic radiations emitted by the metallurgical product in a predetermined wavelength range Δλ, a spectroscopic device connected to the collection probe and configured to generate a spectral signal of the acquired electromagnetic radiations and processing means including a database of reference radiances. A method using the device is also provided.

First claim

What is claimed is:

1 . A device for determining the chemical composition of a liquid metallurgical product emitting electromagnetic radiation, the device comprising:
a collection probe configured to acquire the electromagnetic radiation emitted by the metallurgical product in a predetermined wavelength range 4 ; a spectroscopic device connected to the collection probe and configured to generate a spectral signal of the acquired electromagnetic radiation; and a processor configured to calculate an observed radiance L obs (λ, T est ) from the generated spectral signal, and to estimate, from the calculated observed radiance L obs (λ, T est ), the temperature T est and the spectral emissivity ε est (λ, T est ) of the metallurgical product in the predetermined wavelength range Δ, wherein the processor includes a database of reference radiances L ref,i (λ, T erf,n ) of X samples i, i varying from 1 to X, in the predetermined wavelength range Δλ and Z reference temperature T ref,n , n varying from 1 to Z, comprising for each reference radiance:
reference spectral emissivities ε ref,i (λ, T ref,n ), associated to reference temperatures T ref,n in the predetermined wavelength range Δλ, and
chemical compositions of the samples i,
the processor configured to compare estimated spectral emissivity ε est (λ, T est ) and estimated temperature T est with reference temperatures T ref,n and reference spectral emissivities ε ref,i (λ, T ref,n ) in the predetermined wavelength range Δλ and at estimated temperature T est included in said database, to determine a best fitting reference radiance L bf (A, T ref ) with the observed radiance L obs (λ, T est ), and to determine the chemical composition of the liquid metallurgical product from the determined best fitting reference radiance L bf (λ, T ref ).

2 . The device as recited in claim 1 wherein the spectroscopic device includes a plurality of spectrometers, each spectrometer being connected to the collection probe and configured to generate a part of the spectral signal in a determined fraction of the predetermined wavelength range Δλ.

3 . The device as recited in claim 1 wherein the spectroscopic device configured to generate the spectral signal in a spectral range between 200 and 12000 nanometres corresponding to the predetermined wavelength range Δλ.

4 . The device as recited in claim 1 wherein the processor is also configured to correct each part of the spectral signal with at least a calibration constant calculated by said processor and associated with the considered spectrometer.

5 . A method for determining a chemical composition of a liquid metallurgical product emitting electromagnetic radiation with the device as recited in claim 1 , the method comprising the following steps:
i. acquiring the electromagnetic radiations emitted by the metallurgical product in the predetermined wavelength range Δλ; ii. generating a spectral signal by separating and measuring spectral components of said electromagnetic radiation emitted by the metallurgical product; iii. generating an observed radiance L obs (λ, T est ) of the metallurgical product from the spectral signal; iv. estimating from said observed radiance L obs (λ, T est ) the temperature T est and the spectral emissivity ε est (λ, T est ) in the predetermined wavelength range of the metallurgical product; v. comparing the estimated spectral emissivity ε est (λ, T est ) and temperature T est with the reference spectral emissivity ε ref,i (λ, T ref ) and the reference T ref temperature of each reference radiance L ref,i (λ, T ref ) from the database; vi. determining the best fitting reference radiance L bf (λ, T ref ) (E 6 ) with the observed radiance L obs (λ, T est ), and vii. determining the chemical composition (E 7 ) of the emitting metallurgical product.

6 . The method as recited in claim 5 wherein an attenuation coefficient of the atmosphere is also estimated from the observed radiance in step iv, the observed radiance being correlated with the attenuation coefficient.

7 . The method as recited in claim 5 wherein step iii is implemented following the following sub-steps:
converting the spectral signal into an ideal black body radiance L BB (λ, T);
correcting the ideal black body radiance L BB (λ, T) with at least a calibration constant calculated by the processor and associated with the spectroscopic device, the calibration constant being calculated using a calibration lamp of known emitting temperature and known emissivity in the wavelength range.

8 . The method as recited in claim 5 wherein step iv is implemented following the following sub-steps:
determining a vector which coordinates are randomly chosen variables representing at least the emitting temperature and the emissivity in the wavelength range;
calculating an expected radiance L exp (λ, T) based on the chosen variables;
fitting an inference probabilistic model by comparing observed radiance and expected radiance, to randomly modify expected variance by randomly modifying the chosen variables, until convergence of the expected radiance L exp (λ, T) towards the observed radiance L obs (λ, T est );
estimating the emitting temperature T est and the spectral emissivity ε est (λ, T est ) in the wavelength range Δλ of the liquid metallurgical product ( 2 ) by using such fitted inference probabilistic model.

9 . The method as recited in claim 8 wherein one of the coordinates of the vector comprises the attenuation coefficient of the atmosphere, and wherein said attenuation coefficient is also estimated by using such fitted inference probabilistic model.

10 . The method as recited in claim 8 wherein step iv is implemented using a reduced set of wavelengths which are determined from the wavelength range using a triangular transfer function.

11 . The method as recited in claim 5 wherein steps v to vii are carried out by a multilayer perceptron implemented by the processor.

Assignees

• Arcelormittal

Inventors

• Vicente Rojo Asier
• Picon Artzai
• Alvarez Gila Aitor

Classifications

• G01N33/205

  in liquid state, e.g. molten metals · CPC title

• G01N33/202

  Constituents thereof · CPC title

• G01N21/25

  Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands · CPC title

• G01N21/71 Primary

  thermally excited · CPC title