Method for monitoring the wear of a refractory lining of a blast furnace

Patent metadata

Field	Value
Publication number	US-12270606-B2
Application number	US-201817284859-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Oct 22, 2018
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

A method for monitoring the wear of a refractory lining of a blast furnace using modelling of a part of the blast furnace and thermal field calculation. Computer program allowing to perform such a method.

First claim

What is claimed is:

1. A method for monitoring the wear of a refractory lining of a blast furnace, the method comprising, using a computer:
a. modelling in at least two dimensions at least a part of the blast furnace at an initial known state;
b. defining internal thermal boundary conditions and external thermal boundary conditions of the modelized part of step (a);
c. calculating a thermal field within said modelized part of the blast furnace considering refractory lining thermal characteristics and the internal and external thermal boundary conditions, said thermal field including a temperature field and heat path lines (Ln), a starting point of each path line (Ln) being a measurement point (Pn) and an end point being the internal boundary;
d. measuring, by thermal sensors, a temperature (T meas_n ) at each measurement point (Pn), the thermal sensors being embedded at least per two at the same height of the wall or width of the pad, but each of the two being embedded at a different depth within the refractory lining, each group of thermal sensors forming one of the measurement points (Pn);
e. based on the thermal field calculation of step (c):
e1—using the measured temperature (T meas_n ) at each measurement point (Pn) as a starting value, moving a control point (Xn) along each heat path line (Ln) and determining a position (In) where said control point (Xn) reaches a critical temperature T crit ,
e2—determining a position of the hot metal solidification isotherm, said isotherm being a curve linking all previously determined positions (In) at which the critical temperature T crit is reached;
f. calculating a new thermal field using the previously determined position of the hot metal solidification isotherm as new internal thermal boundary conditions;
g. estimating a temperature T est_n at each measurement point (Pn) using the newly calculated thermal field;
h. calculating a convergence criterion CC between each estimated temperature T est_n and respective measured temperature T meas_n ;
if this convergence criterion CC is below a predefined target Δ, determining a wear surface of the refractory lining based on the position of the hot metal solidification isotherm,
if this convergence criterion CC is above the predefined target Δ, iterating steps e to h until the convergence criterion CC is below the predefined target Δ; and
i. outputting the wear surface of the refractory lining determined based on the position of the hot metal solidification isotherm to identify a portion of the refractory lining as being a damaged portion based on the position of the hot metal solidification isotherm.

2. The method according to claim 1 wherein said convergence criterion CC is a minimum square root method.

3. The method according to claim 1 , wherein in the modelling step only a hearth of the blast furnace is modelized.

4. The method according to claim 3 wherein only a vertical slice of the hearth is modelized, said vertical slice comprising a pad with a width W, a wall having a height H and a corner making a junction between the pad and the wall.

5. The method according to claim 4 wherein the method is performed for at least six vertical slices around hearth periphery.

6. The method according to claim 4 wherein for each slice, at least four measurement points Pn are defined at different heights within the wall, at least three measurements points Pn are defined along the width within the pad and at least two measurement points Pn are defined within the corner.

7. The method according to claim 1 wherein the refractory lining thermal characteristics at said one of the measurement points (Pn) are calculated using the temperature measured by the thermal sensors at different depth.

8. The method according to claim 1 , wherein the critical temperature T crit is 1150° C.

9. The method according to claim 1 , wherein if, after a predefined number of iterations, the convergence criterion CC is still above the target Δ, a refining step is performed wherein the difference between the temperature measured by the thermal sensor and the temperature estimated at the measurement point is further minimized using a bisection method.

10. The method according to claim 9 wherein the predefined number of iterations is lower or equal to 5.

11. The Method according to claim 1 , wherein the blast furnace comprises a cooling system and the external boundary conditions of the thermal field calculation step is defined considering the thermal impact of such a cooling system.

12. Non-transitory computer readable media, having stored thereon, computer executable process steps operative to control a computer to perform the steps of claim 1 .

13. A method of maintaining a blast furnace comprising:
performing the method for monitoring the wear of the refractory lining of the blast furnace as recited in claim 1 ; and
repairing the damaged portion.

14. The method as recited in claim 13 wherein the damaged portion is a portion of the refractory lining in front of the position of the hot metal solidification isotherm.

15. The method as recited in claim 13 wherein the repairing of the damaged portion includes performing guniting.

Assignees

• Arcelormittal

Inventors

• Picard Michel
• Zaimi Sami-Alex
• Huang Dianbing
• Abbana Bennani Mouna

Classifications

• F27D21/04

  Arrangement of indicators or alarms · CPC title

• F27D1/0006

  Linings or walls formed from bricks or layers with a particular composition or specific characteristics · CPC title

• F27B1/28

  Arrangements of monitoring devices, of indicators, of alarm devices · CPC title

• C21B7/06

  Linings for furnaces · CPC title

• C21B2300/04

  Modeling of the process, e.g. for control purposes; CII · CPC title