JPH07266024A - Structure of furnace bottom in molten metal vessel - Google Patents

Abstract

PURPOSE:To reduce a joint part accupancy area and to sufficiently obtain the releasing capacity to mechanical stress by arranging while combining plural pieces of the shaped refractories having shape of the working surface of a quadrangle, in which one side is not equal to the other side, or parallelogram. CONSTITUTION:A ladle 1 is lined with permanent bricks at the bottom surface of the outer shell 3 and lined with monolithic refractory 4 at the upper surface thereof and the inner wall surface except a molten metal padding part 2. The molten metal padding part 2 in the furnace bottom structure is formed by arranging plural trapezoid shaped refractories 6 while alternately combining the short wall side and long wall side. In the case of forming the rectangular shape having 90 deg. inside angle of the molten metal padding part 2, and forming the side wall of each quadrangular fixed shape refractory 6 arranged there and having no orthogonal crossing or no parallel with other side wall in the molten metal padding part 2, the joint line formed with this arrangement becomes non- orthogonal crossing. By this method, the joint part accupancy of the molten metal padding part brick can be restrained to the min.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot metal ladle, a molten steel ladle and the like, and a furnace bottom structure of a molten metal container used as a carrier for refining molten iron, a refining container or a holding container.

[0002]

2. Description of the Related Art Conventionally, as a molten metal container furnace bottom structure used for transporting and refining molten iron such as a hot metal ladle and a molten steel ladle, as shown in FIGS. The working surface of the product, that is, the hot water contact surface, is constructed by bricks having a square shape and / or a rectangular shape, which are piled up in a mesh or in parallel.

Since the bottom of this molten metal container generally serves as a molten metal contact part when pouring molten iron, the refractory used therein receives a drop impact of the molten iron and the thermal stress inside the refractory rises. Since it is easy to do so, abnormal abnormal wear due to an increase in mechanical stress is remarkable.

In particular, the joint portion of the regular refractory is provided for the purpose of alleviating the mechanical stress, so that the joint portion is also a portion where the stress is likely to concentrate. Further, the joint portion is generally formed of refractory mortar, and its properties such as corrosion resistance and strength are significantly inferior to those of the standard refractory material.
Therefore, abnormal wear of the furnace bottom structure of the molten metal container is likely to occur mainly around the joints between the fixed refractories.

As a countermeasure against this, attempts have been made to improve the refractory material and / or the joint material, but it is still insufficient.
In order to reduce the area and number of joints that are severely damaged, it has been attempted to increase the size of regular refractory materials and to apply irregular refractory materials.In the former case, the mechanical components absorbed by the joints were used. Since the impact is insufficiently mitigated, the joints that form the boundaries of large-sized standard refractories have large stress increases,
Once damaged, its spread rapidly and can be fatal. In the latter case, the amorphous refractory is a refractory that is easier to absorb mechanical impact than the regular refractory, but the abrasion and wear due to the impact received when the molten iron falls is severe, and the corrosion resistance to molten iron is poor. , Can't get enough durability.

Further, as described in Japanese Utility Model Publication No. 63-50070, a large refractory block is adopted in the hot water contact portion to prevent the intrusion of the metal from the mortar joint by the integral structure without joints. It has also been proposed to insert a metal into the periphery of the large refractory block or apply a material with a small amount of metal adhesion to average the melting speed of the large refractory block to extend the life.

However, due to this, cracks are generated due to expansion and contraction of the enlarged refractory block, and a measure for mitigating thermal stress generated in the refractory block due to a large thermal shock received when pouring into the ladle-laying hot water contact portion. There is a problem that is required.

Further, in Japanese Utility Model Laid-Open No. 58-33166, a bottom brick of a molten metal holding container is covered with a joint to protect the joint from damage by making the joint into an inclined surface with respect to the flow direction of the molten metal. Prolonging life is also proposed.

It is effective to prevent the joint from melting by preventing the joint from directly passing in the flow direction of the molten metal.
The pattern of joint opening and metal infiltration due to the expansion and contraction of bricks cannot be the means to prevent the thermal stress generated inside the bricks, which is the main cause of the same wear as in the past, and the bricks themselves have sharp corners. There is a problem that due to thermal shock at the time of pouring molten metal, the corners of the acute-angled bricks are worn ahead of time, which rather accelerates the melting damage of the joints.

[0010]

DISCLOSURE OF THE INVENTION The present invention solves the problems in the conventional molten metal container hearth structure, reduces the area occupied by joints between fixed refractories, and reduces mechanical stress. It is an object of the present invention to provide a furnace bottom structure in which

[0011]

DISCLOSURE OF THE INVENTION The present invention is directed to a molten metal container hearth structure consisting of a fixed refractory or a combination of a fixed refractory and an irregular refractory, particularly in a structure of a hot water part, It was completed as a result of finding that it is extremely effective in relaxing the mechanical stress that the joints formed on the surface are not orthogonal.

In order to prevent the joints formed between the regular refractories from being orthogonal to each other, the planar shape of the working surface of the regular refractory that is mainly used is a rectangle in which at least one side is not equal to the length of the other side. For example, a plurality of fixed refractories having parallelograms, trapezoids, or similar shapes are arranged in combination.

The fixed refractory used in the present invention means a shaped refractory having a fixed shape such as a fired brick, an unfired brick, or an amorphous block when used.

The standard refractory used in the present invention does not necessarily need to have the entire bottom surface of the furnace formed by this.
Even if only the main part is formed, the purpose is sufficiently achieved.

[0015]

[Function] By arranging a plurality of fixed refractories each having at least one side that is not equal to the length of the other side or a parallelogram, the joints formed between the fixed refractories cannot be orthogonal. First, it is possible to relieve the mechanical stress.

[0016]

FIG. 1 is a side sectional view showing a furnace bottom structure of the present invention.
And the hot water contact portion 2 of the ladle 1 shown in FIG. 2 showing the bottom plane. As shown in these figures, the ladle 1 has an outer shell 3
Has a permanent brick on its bottom surface, and has an amorphous refractory 4 on its upper surface and inner wall surface except for the hot water contact portion 2. In FIG. 2, 5A indicates a gas blowing portion, and 5B indicates a nozzle brick.

As shown in FIG. 2, the hot water contact portion 2 of the furnace bottom structure is provided with a combination of a plurality of quadrilateral shaped refractories, at least one side of which is not equal to the length of the other side.
In the case of FIG. 2, the trapezoidal shaped refractory materials 6 are alternately combined on the short side and the long side to form the hot water contact portion 2.

FIG. 3 is a view showing this trapezoidal shaped refractory 6, in which the angles A and B at the corners with the short sides of one side form obtuse angles. Therefore, the joint line when the hot water contact portion 2 is formed by alternately combining the short side and the long side of the trapezoidal shaped refractory 6 shown in FIG. 2 is shown by 71 and 72 in FIG. Formed in the direction, and the intersecting angle thereof forms a so-called non-orthogonal state deviated from the orthogonal axes X and Y.

That is, when the hot water contact portion 2 shown in FIG. 2 has a rectangular shape having an internal angle of 90 degrees, the quadrilateral shaped regular refractory 6 is orthogonal to each side of the hot water contact portion 2 or When there are non-parallel sides, the joint lines formed by this arrangement form the so-called non-orthogonal joint lines 7 according to the present invention.

In FIG. 4, the hot water contact portion 2 has an inner angle of 90.
In the case of a rectangular shape having a degree, an arrangement example of the fixed refractory 6 for preventing the joint lines 7 formed by the fixed refractory 6 arranged therein from intersecting at right angles is shown.

FIG. 4A shows an example of the shape shown in FIGS. 2 and 3, and FIGS. 4B, 4C and 4D show modified examples thereof. In any case, when a brick having at least one obtuse corner is arranged in the hot water contact portion 2 having a right-angled corner, the joint lines 7 formed are all non-orthogonal. As shown in FIG. 4 (a), the joints in the x ₁ direction inclined with respect to the sides of the hot water contact part 2 contribute to the relaxation of mechanical stress in both the x and y directions, and have a conventional structure having orthogonal joint lines. It has the same stress relaxation ability as.

5 (a) and 5 (b) show an example of a parallelogram fixed brick 61 as an example other than the trapezoidal fixed brick 6 shown in FIG. In this case, the hot water contact portion is not formed in a rectangular shape, and the shape obtained as a result of combining the parallelogram regular shaped bricks 61 is used as it is as the hot water contact portion 21. Also in this case, the joint line 71 formed is non-orthogonal.

Further, FIG. 6 shows a state where the trapezoidal bricks 6 and the parallelogram bricks 61 shown in FIG. 4 and FIG. Also in this case, the joint line 72 formed is non-orthogonal.

FIG. 7 is a modification of the rectangular hot water contact portion 2 shown in FIGS. 1 to 4, in which the surface shape formed by the fixed bricks arranged to form the non-orthogonal joint line 7 is unchanged. The example of the hot water contact part 23 is shown.
The outer shape of 3 can be arbitrary like an ellipse, and the boundary thereof may not be a simple straight line such as unevenness due to the relationship with the outer circumference.

Thus, in carrying out the present invention, the hot water contact portions 2, 21, 22 and 23 to be formed are formed.
Can be formed in any shape.

Further, the hot water contact portion is not formed of only the regular refractory material but can be formed by a combination with the irregular refractory material.

FIG. 8 shows an example thereof, showing an example in which the outer periphery of the hot water contact portion 2 is formed of an irregular shaped refractory material 9. By forming the irregular shape refractory material 9 into the hot water contact portion 2
The formation of can be made into any shape corresponding to the present condition of hot water of a ladle, without being influenced by the shape of the fixed brick to be arranged. In this way, the joint thickness of the boundary with the normal brick adjacent to the outer periphery of the hot water contact part may be the normal joint thickness, or it may be expanded to a size capable of filling the irregular refractory material. .

When a plurality of standard refractory materials are combined, they are constructed on the bottom of the furnace by a conventional method, or the plurality of them are fixed by a metal case or strip or a linear object or bonded by an adhesive, mortar or the like. It can also be built in advance.

The 250t molten steel ladle having the bottom furnace structure shown in the above-mentioned embodiment of the present invention was used in an actual furnace and its durability was examined. The results are shown in Table 1. For comparison,
Using the normal shape brick 10 shown in FIG.
A conventional ladle having a bottom furnace structure having orthogonal joint lines 11 was formed as Comparative Example 1, and a conventional brick of this type shown in FIG. .

[0030]

[Table 1] In the same table, the area ratio index of the joint / standard refractory is the ratio of the area occupied by the joint and the standard refractory in the plan view, and is indexed using Conventional Example 2 as 100.
The joint stress relaxation capacity index is an index of the contractibility of joints, and the numerical value is the average value thereof in the x-axis and y-axis directions.
The lower the value, the smaller the relaxation capacity.

From the table, it can be seen that the present invention is excellent in the mechanical stress relaxation ability even though the joint / standard refractory ratio is small, and the life extension effect of the iron rope container laying portion is great. .

[0032]

According to the present invention, the following effects can be obtained.

(1) It is possible to secure the mechanical stress relaxation ability expected in the joint portion and to minimize the joint occupying area of the hot water contact brick.

(2) As a result, abnormal wear of the furnace bottom structure of the molten metal container can be suppressed, and the life can be dramatically improved.

[Brief description of drawings]

FIG. 1 shows a sectional structure of a ladle to which the present invention is applied.

FIG. 2 shows a planar structure of the bottom surface of FIG.

FIG. 3 shows a trapezoidal shaped brick of the present invention.

FIG. 4 shows an arrangement structure of a hot water contact part formed by a trapezoidal shaped brick.

FIG. 5 shows an arrangement structure of a hot water contact part by a parallelogram fixed-sized brick.

FIG. 6 shows an arrangement structure of a hot water contact portion in which trapezoidal fixed bricks and parallelogram fixed bricks are arranged in combination.

FIG. 7 shows another example of the shape of the hot water contact portion.

FIG. 8 shows an example in which a fixed brick and an irregular refractory are formed in combination in the hot water contact portion.

FIG. 9 shows a first conventional example.

FIG. 10 shows a second conventional example.

[Explanation of symbols]

1 ladle 2,21,22,2
3 Hot water contact part 3 Ladle shell 4 Unshaped refractory 5A Gas blowing part 5B Nozzle brick 6 Trapezoidal shaped refractory 10 Conventional regular shaped brick 11 Orthogonal joint line 7, 71, 72 Joint line 61 Parallel four sides Shaped brick

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mizobe Manned 1-1 Higashihama-cho, Hachimansai-ku, Kitakyushu, Fukuoka Prefecture Kurosaki Ceramics Co., Ltd. (72) Takemi Dohara 1-1, Higashihama-cho, Hachimansai-ku, Kitakyushu, Fukuoka No. Kurosaki Ceramics Co., Ltd. (72) Masaaki Yoshida Inventor Masaaki Yoshida No. 3 Hikari, Kashima-machi, Kashima-gun, Ibaraki Sumitomo Metal Industries Co., Ltd. Kashima Steel Works Co., Ltd. (72) Inventor Hiroshi Shiroguchi, Kashima-cho, Kashima-gun, Ibaraki Prefecture, Hikari No. 3 Sumitomo Metal Industries, Ltd. Kashima Works

Claims (1)

[Claims] 1. In a molten metal container hearth structure consisting of a standard refractory or a standard refractory and an irregular refractory, the plane shape of the working surface is a rectangle in which at least one side is not equal to the length of the other side, or a parallelogram. Molten metal container bottom structure with multiple fixed refractories combined.