JP-2026075401-A - Breakout detection device, breakout monitoring method, and continuous casting method for metals

Abstract

[Problem] To provide a breakout detection device that can accurately and early detect the occurrence of breakouts in a continuous casting facility. [Solution] A pressure pipe 51 with fluid sealed inside is arranged in the region on the outlet side of the mold 30, and the system includes a pressure detection means 56 for detecting the pressure in the pressure pipe 51, and a breakout detection means 57 for detecting the occurrence of a breakout according to the pressure detected by the pressure detection means 56. The open end of the pressure pipe 51 is sealed with a sealing material with a melting point of 400°C or higher, and the relationship F1 = 4(P1-P2)/d²/L/π ≥ 0.9 is satisfied when the normal pressure inside the pressure pipe 51 is P1 (MPa), the detection pressure for detecting the occurrence of a breakout is P2 (MPa), the inner diameter of the part of the pressure pipe 51 that is closest to the cast slab 1 produced from the outlet of the mold 30 is d (m), and the total length of the pressure pipe 51 located on the cast slab 1 side of the pressure detection means 56 is L (m). [Selection Diagram] Figure 2

Inventors

• 藤井 忠幸
• 駒場 大輔
• 七辺 寛幸
• 佐藤 康弘
• 新妻 峰郎
• 柴本 浩児
• 大谷 吉彦
• 関 健

Assignees

• 日本製鉄株式会社

Dates

Publication Date

20260508

Application Date

20241022

Claims (8)

1. A breakout detection device for detecting breakouts in a continuous casting facility, It comprises a pressure pipe containing a fluid, a pressure detection means for detecting the pressure in the pressure pipe, and a breakout detection means for detecting the occurrence of a breakout in accordance with the pressure detected by the pressure detection means. The pressure piping comprises an opposing pipe positioned opposite to the surface of the cast slab, and a connecting pipe connecting the opposing pipe to the pressure sensing means, wherein at least a portion of the opposing pipe is arranged in a region up to 3 m from the bottom end of the mold. Let P1 (MPa) be the normal pressure inside the pressure piping, P2 (MPa) be the detection pressure for detecting the occurrence of a breakout, d (m) be the average inner diameter of the pressure piping, and L (m) be the total length of the pressure piping located on the cast slab side of the pressure detection means. The relationship is F1 = 4(P1 - P2)/ d² /L/π ≥ 0.9 A breakout detection device characterized by satisfying the following conditions.
2. The breakout detection device according to claim 1, characterized in that the open end of the pressure piping is sealed with a sealing material with a melting point of 400°C or higher.
3. The breakout detection device according to claim 1, characterized in that the constant pressure P1 in the pressure piping is 0.1 MPa or higher.
4. The breakout detection device according to claim 1, characterized in that the wall thickness of the pressure piping is 1.0 mm or less.
5. The breakout detection device according to claim 1, characterized in that the material of the pressure piping is stainless steel.
6. The breakout detection device according to claim 1, characterized in that at least a portion of the opposing piping is arranged in a region extending 2 m from the lower end of the mold.
7. A method for monitoring breakouts in a continuous casting facility, A method for monitoring breakouts, characterized by detecting the occurrence of a breakout using a breakout detection device according to any one of claims 1 to 6.
8. A continuous casting method for metals, which involves pouring molten metal into a mold to continuously produce cast slabs, A method for continuous casting of metal, characterized in that when a breakout is detected by the breakout detection device according to any one of claims 1 to 6, the injection of molten metal is stopped and the casting speed is reduced.

Description

This invention relates to a breakout detection device for detecting breakouts in a continuous casting facility, a breakout monitoring method, and a continuous casting method for metals. During continuous casting, breakouts—where the solidified shell ruptures and molten metal leaks out—are a serious problem that can cause significant damage to production and equipment. When a breakout occurs, it is necessary to detect it early and immediately stop the injection of molten metal into the mold to minimize the amount of molten metal leaked. Therefore, various methods for detecting breakouts have been proposed. For example, Patent Documents 1 and 2 propose a method for determining breakouts from images of the cast slab captured by a camera placed near the mold exit. Furthermore, Patent Documents 3 and 4 propose a method in which a pressure pipe filled with a fluid such as N2 gas is placed in the support roll installation area on the mold outlet side, and the pressure in this pressure pipe is measured. In this case, when a breakout occurs, the pressure pipe melts due to the leaked molten metal, the fluid such as N2 gas sealed inside the pressure pipe leaks out, and the pressure inside the pressure pipe drops, making it possible to detect the breakout. Japanese Patent Application Publication No. 10-071453Japanese Patent Publication No. 2003-251443Japanese Patent Publication No. 2021-151663Japanese Patent Publication No. 2023-118168 This is a schematic diagram illustrating a continuous casting facility to which a breakout detection device, which is an embodiment of the present invention, is applied.This is a side view illustrating an embodiment of the breakout detection device of the present invention.This is a top view diagram illustrating an embodiment of the breakout detection device of the present invention.This is a magnified diagram illustrating the open end of a pressure pipe.This is an explanatory diagram of a breakout detection device, which is another embodiment of the present invention.This is an explanatory diagram of the experimental apparatus used in the example.This graph shows the response time until a breakout occurs in the example.This graph shows the relationship between the relational expression F1 = 4(P1 - P2)/ d² /L/π in the embodiment and the response time until breakout is detected. The following describes embodiments of the present invention, including a breakout detection device, a breakout monitoring method, and a continuous metal casting method, with reference to the attached drawings. However, the present invention is not limited to these embodiments. Furthermore, in these embodiments, the metal to be manufactured is steel. First, we will describe the continuous steel casting facility 10 in which the breakout detection device 50 of this embodiment is installed. As shown in Figure 1, the steel continuous casting equipment 10 in this embodiment comprises a ladle 11, a long nozzle 12, a tundish 13, an immersion nozzle 14, a mold 30, and a support roll group 20 consisting of a plurality of support rolls 21 located below the mold 30. It is a vertical bending type continuous casting equipment having a vertical section 23 for pulling out the cast slab 1 vertically downward, a bending section 24 for bending the cast slab, a straightening section 25 for bending the bent cast slab back, and a horizontal section 26 for conveying the cast slab horizontally. In this continuous steel casting apparatus 10, molten steel is transferred from a converter (not shown) via a ladle 11, then transferred to a tundish 13 via a long nozzle 12. After separating impurities such as inclusions in the tundish 13, the molten steel is supplied into the mold 30 via an immersion nozzle 14, and slabs 1 are continuously cast. The slabs 1 drawn from the mold 30 have an unsolidified portion 3 inside. As they move along the support roll group 20, cooling progresses, gradually increasing the thickness of the solidified outer shell 2 until complete solidification occurs. In this embodiment, the mold 30 comprises a pair of long side walls and a pair of short side walls, and is designed to cast a rectangular slab 1. Furthermore, the mold 30 is structured such that the pair of short side walls are sandwiched between the pair of long side walls, allowing the width of the slab 1 to be changed by moving the pair of short side walls. Furthermore, the breakout detection device 50 in this embodiment is positioned below the mold 30, as shown in Figure 2. This breakout detection device 50 includes a pressure pipe 51 disposed in the region where the support roll 21 of the vertical section 23 is disposed, a pressure detection means (a pressure gauge 56 in this embodiment) for detecting the pressure in the pressure pipe 51, and a breakout detection unit 57 for detecting the occurrence of a breakout according to the pressure in the pressure pipe measured by the pressure gauge 56. In this embodiment, as shown in Figure 2, the pressure piping 51