JPH0320041Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention is a molten steel ladle used as a container for transporting molten steel produced in a converter to the next process of continuous casting equipment or ingot making equipment. This invention relates to an improvement of a refractory lining for a ladle such as a hot metal ladle having a shape similar to this.

(Prior art) The molten steel ladle and hot metal ladle for the above purpose have an overall shape of approximately 2.5 to 4.5 m in diameter, a height of 2.5 to 4.5 m, an upward opening, an upwardly expanding teacup, and a main body with a plate thickness of 25 to 40 mm. It is made by lining the inner surface of the iron shell with refractory bricks such as low stone, zircon, or alumina. At the upper opening, an integral annular presser is attached to the inner periphery of the steel shell to press the upper part of the refractory brick part either directly or through a monolithic refractory to prevent it from falling off. A conventional presser foot has a structure in which a vertical rib part is provided on the lower side of an integral annular horizontal part, and is bolted to the molten steel ladle flange. This structure is intended to resist deformation by the tensile stress of the reinforcing ribs when the horizontal part of the presser foot is pushed up due to thermal expansion of the lining brick.

(Problems to be Solved by the Invention) The presser foot of the prior art has poor deformation resistance as described above. Also, the presence of the lower reinforcement ribs makes it difficult to install the refractory lining.

Furthermore, when a molten steel ladle is used for a long period of time, thermal deformation and melting loss occur in the presser foot, and the upper refractory often breaks or falls off.

In order to repair a damaged presser foot, since the presser foot is one-piece or nearly so large, it can be gas-cut to partially cut and connect, or to renew the whole thing, gas-cut it to make it lighter and remove it. However, since new flange-shaped hardware was installed, there were problems such as increased repair work and construction time.

The present invention solves the above-mentioned problems of the conventional technology, and has an excellent function of suppressing the refractory in response to thermal expansion.The present invention is a molten steel that has an excellent ability to suppress the refractory in response to thermal expansion, has good workability for the refractory, is excellent in maintainability, and is advantageous for implementing life-extension measures. The purpose is to provide a refractory presser for pots.

(Means, effects, and embodiments for solving the problems) The above object is to provide a refractory presser of a molten steel ladle by 45 to 20 mm in the circumferential direction, taking into account the heat rise of the iron skin of the molten steel ladle body. It shall consist of divided bodies divided into equal parts with a central angle of 8 to 18 degrees, each divided body consisting of a fan-shaped horizontal part and a vertical rib part integrally connected above it, with a mutual interval between the fan-shaped horizontal parts. This is accomplished by welding the outer edges of the fan-shaped horizontal part and the vertical rib part to the inner periphery of the steel shell of the molten steel ladle, and embedding it in the amorphous lining refractory.

That is, the structure of the refractory presser for a molten steel ladle of the present invention is such that each segment is divided into arcs in the circumferential direction as a presser for the lining refractory that is attached to the steel shell at the inner periphery of the upper opening of the molten steel ladle. Each center angle 8
It is made of a ~18° fan-shaped horizontal part and a vertical rib part integrally connected above it, and the outer edge of the fan-shaped horizontal part and vertical rib part is attached to the iron skin of the molten steel ladle, keeping a mutual distance from the adjacent divided body. It is characterized by consisting of a set of divided bodies configured to be welded to the inner periphery and embedded in the monolithic lining refractory.

Hereinafter, the present invention will be specifically described with reference to the accompanying drawings and embodiments. FIG. 1 is a perspective view showing one of the divided bodies of the refractory presser of the molten steel ladle of the present invention.

This divided body 1 is an arc-shaped body divided in the circumferential direction of the molten steel ladle, and in this example, two vertical rib portions 3 are formed integrally with a fan-shaped horizontal portion 2 having a divided length and above the horizontal portion 2. The central angle (θ) formed by both edges of the sector of the horizontal portion 2 with respect to the center of the molten steel ladle is 8 to 18 degrees. Welding grooves 4 and 5 for welding to the main body skin of the molten steel ladle are formed on the outer edge of the sector-shaped horizontal portion 2 on the side indicated by arrow a, that is, on the long arc portion side, and on the outer edge of the vertical rib portion, respectively. In order to obtain good welding results, the ends of welding grooves 4 and 5 are hollowed out and scalloped 6.
It is a good idea to provide It is preferable to provide a fillet 7 at the orthogonal portion where the horizontal portion 2 and the vertical portion 3 connect. Such a divided body 1 can be made of, for example, SC42 cast steel, and the above-mentioned parts can be formed simultaneously using a wooden mold to be used.

As shown in FIG. 2, this presser foot divided body 1 is
Grooves 4 and 5 are made on the upper inner circumference of the main body shell 8 of the molten steel ladle.
Attach by welding 9 and 10. Figure 3 is a plan view showing the entire refractory presser, and the number of divisions is 1.
are arranged side by side with mutual spacing 11 between the fan-shaped horizontal parts 2. After installation, it is buried in the monolithic refractory 13 above the refractory bricks 12 lining the inside of the steel shell. However, FIG. 3 shows a divided body having one vertical rib portion. Reference numeral 14 shown in FIGS. 2 and 3 is a flange on the upper edge of the main shell, and arrows 13 and 14 indicate directions of expansion and contraction of the shell.

Expansion allowance l due to temperature rise of the steel shell of the molten steel ladle body is determined by the shell diameter D, temperature difference δt, and linear expansion coefficient α, as follows: l=
It is given by πDδtα. Assuming that the temperature can be raised to 400°C, and assuming that δt is 130°C to 400°C, the diameter D is 4500 mm, and the linear expansion coefficient α12×10 ^-6 means that the expansion margin l≒22 to 70.
mm. Assuming that this expansion allowance is equally distributed in the circumferential direction with an interval 11 of 0.5 to 3.5 mm, the number of divisions of the refractory presser of the present invention will be 45 to 20, and the central angle θ of the division body 1 will be 8° to 18°. It becomes ゜. If the center angle of the split body 1 is larger than 18 degrees, it becomes practically impossible to reduce the deformation, and if it is made smaller than 8 degrees, the number of man-hours for manufacturing and installation will increase, and the performance will improve despite the burden. do not.

The vertical expansion of the refractory bricks 12 is primarily suppressed by the fan-shaped horizontal portion 2, but the reaction force is mainly received by the compression of the vertical rib portion 3, and therefore acts on the welded portion 9 at the base of the fan-shaped horizontal portion 2. The bending stress is very small, and since the vertical rib portion 3 is not a tensile member unlike the conventional technology, there is no influence of strength reduction due to welding efficiency, and the whole has high strength and long life. Effectively suppresses breakage and falling off caused by deformation. Since the reinforcing ribs 3 are located on the upper part, the monolithic refractory 13 is easy to construct and is sound. As a result of these, damage to the presser foot is less likely to occur. Furthermore, if the surface of the divided body 1 is subjected to ceramic spraying after welding and attachment, the life can be further extended. Even if melting damage etc. occurs,
It is only necessary to repair each divided body 1, and since the unit weight of the divided body 1 is light enough to be handled by hand, the number of man-hours, construction period, and cost of repair work are significantly reduced compared to those of the conventional method.

The material of the split body 1 is cast steel as an example, but the C content
0.35 to 0.45%, and can also be made by can manufacturing welding assembly technology, if low alloy steel is used.
Effective for improving strength.

FIG. 4 shows a modified embodiment of the divided body of the holding hardware of the present invention, and parts equivalent to those of the previous embodiment are indicated by the same reference numerals and redundant explanation will be omitted. Mainly to reduce weight, a mouse hole 15, a punch hole 16, an arcuate notch edge 17, etc. are provided. These hollows can be formed during casting when using cast steel, but when using a welded structure, they can also be easily formed by automatic gas cutting using NC, eye tracer, etc. Welding groove 4,
The formation of 5 is also similar.

Next, numerical values of an example of the present invention will be shown. A refractory presser for a 250-ton molten steel ladle was made of cast steel into 24 divisions in the shape shown in Figure 1. Its central angle is 13°, thickness
25mm, horizontal part radial width 200mm, vertical rib part height 73mm, radial width 180mm, and its single weight is 24
It was Kg.

The divided body shown in Figure 4 is made of cast steel and has 28 sections with a center angle of 12 degrees, reducing the unit weight to 20 kg. Moreover, it was confirmed that it had a stress relaxation effect comparable to that of 56 divisions.

(Effects of the invention) According to the invention, deformation and damage such as angular deformation, contraction deformation, expansion deformation, buckling deformation, cracks, and weld breakage of the ladle are reduced when used as a refractory presser for molten steel ladle, hot metal ladle, etc. This reduces damage such as cracks, breakage, and falling off of refractory bricks and castables, improves the maintainability of repairs, and reduces man-hours, construction period, and construction costs, resulting in labor savings and improved production on steel production lines. It has the effect of improving sexual performance.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one of the divided bodies of the refractory presser of the molten steel ladle of the present invention, Fig. 2 is a longitudinal cross-sectional side view of a portion showing the installation state of the refractory presser in the molten steel ladle, and Fig. 3 is the refractory presser. FIG. 4A is a plan view showing one modified embodiment of the divided body of the presser foot of the present invention, and FIG. 4B is a vertical side view thereof. It is. 1... Divided body, 2... Fan-shaped horizontal part, 3... Vertical rib part, 4, 5... Welding groove, 6... Scalp, 7... Fillet, 8... Main body iron skin, 9, 10 …
...Welding, 11... Mutual spacing, 12... Refractory brick, 13... Monolithic refractory, 14... Flange,
15... Mouse hole, 16... Extraction hole, 17...
Notch edge, θ...center angle, a...pointed arrow.

Claims (1)

[Scope of utility model registration request] As a presser for the inner refractory lining to be attached to the main body shell on the inner periphery of the upper opening of the molten steel ladle, each divided body divided in an arc shape in the circumferential direction has a center angle of 8~
It is made of an 18° fan-shaped horizontal part and a vertical rib part integrally connected above it, and the outer edges of the fan-shaped horizontal part and the vertical rib part are separated from each other by the outer edges of the fan-shaped horizontal part and the vertical rib part, keeping a mutual distance from the adjacent divided parts. 1. A refractory presser for a molten steel ladle, comprising a set of divided bodies welded to the periphery and embedded in a monolithic lining refractory.