JP2016059940A - Ladle for molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ladle for molten metal capable of increasing a ladle volume without enlarging an outer diameter size, and having excellent practicability.SOLUTION: In a ladle for molten metal which has an inner surface of a steel shell 1 lined with refractory 2 and is provided with trunnion shafts 3 on both sides, a horizontal cross-section of the ladle for molten metal has a non-circular shape constituted with a long edge side circular arc which has a center on an axial line 4 obtained by connecting the trunnion shafts and has a curvature radius of R2, a short edge side circular arc which has a center on a central axial line 5 orthogonal to the axial line 4 and has a curvature radius of R3 and a corner part circular arc which connects both circular arcs and has a curvature radius of R1. Therein, relations of R1<R2, R1<R3, R2≤R3 are provided, when R2 and R3 are made infinite, a straight line-shaped long edge of length A and a straight line-shaped short-edge of length B are provided, and the non-circular shape is obtained by connecting the long edge and the short edge to each other by the use of the corner part circular arc having the curvature radius R1 between the long edge and the short edge.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a ladle for molten metal that receives hot metal or molten steel from a converter or torpedo car.

  In a steel factory, a large ladle having a ladle volume of 100 tons or more is used as a ladle for molten metal that receives molten iron from a converter or torpedo car or molten steel. This ladle for molten metal has a structure in which the inner surface of the iron skin is lined with a refractory and has trunnion shafts on both sides in the width direction. Such a ladle for molten metal is lifted by an overhead traveling ladle crane and can be tilted about a trunnion shaft.

  Since the ladle for molten metal injects and discharges a high-temperature molten metal exceeding 1100 ° C., a large thermal stress is repeatedly applied to the iron skin, which may cause thermal deformation. Therefore, a ladle for molten metal having a circular horizontal section and increased strength against thermal stress has been used for a long time. In addition, as shown in Patent Document 1, Non-Patent Document 1, and the like, a horizontal section having an elliptical shape is also used.

  Such a conventional ladle for molten metal having a circular or elliptical horizontal section is sufficient in terms of strength against thermal stress. On the other hand, however, the cross-sectional area is smaller than that of a rectangle with two sides of the major and minor axes, and the cross-sectional area in the case of a circular cross-section is about 78% of the cross-sectional area of the square with the same outer diameter. The volume is also reduced accordingly.

  Therefore, when it is desired to increase the pot volume, first, expansion of the outer diameter dimensions (width, length, height) of the ladle for molten metal can be considered. However, changing the height may cause the ladle for the molten metal to interfere with the converter, so the ground of the factory must be dug down or the hook of the ladle crane that lifts the ladle for the molten metal must be modified. However, it costs a lot.

  In addition, when the width (dimension in the trunnion axis direction) is increased, it is necessary to increase the hanger span of the ladle crane and to widen the pan receiving cart, which also requires significant costs. For this reason, when it is desired to expand the pan volume, it has been necessary to make it an elliptical shape with the width kept constant, but as the horizontal cross-sectional shape becomes an elliptical shape, thermal deformation tends to occur. Therefore, there was a limit to the length expansion.

  Theoretically, if the horizontal section is square, the maximum pan volume can be obtained without increasing the outer diameter. However, if a square shape is used, a very large stress acts on the corner portion, so the external reinforcement ring (trunnion ring) must be enlarged, and the corner portion of the refractory that is lined is likely to be unreasonable, resulting in poor practicality. .

JP 2000-256728 A

IRON AND STEEL ENGNEER, MARCH, 1952 LS-4

  Therefore, the object of the present invention is to solve the above-mentioned conventional problems, and can be used to expand the pan volume without increasing the outer diameter such as width, length, height, etc. Is to provide a ladle.

  The ladle for molten metal of the present invention made to solve the above problems is a ladle for molten metal lined with a refractory and provided with trunnion shafts on both sides, the horizontal section of which is a trunnion shaft. A long side arc having a radius of curvature R2 having a center on the connecting axis, a short side arc having a radius of curvature R3 having a center on the central axis perpendicular to the axis, and a radius of curvature connecting these two arcs. It is a non-circular shape composed of a corner arc of R1, and R1 <R2, R1 <R3, and R2 ≦ R3.

  In addition, as described in claim 2, R2 and R3 are infinite, a straight long side having a length A and a straight short side having a length B, and a corner having a radius of curvature R1 between them. A non-circular shape connected by an arc and A ≦ 4R1 and B ≦ 4R1 are also possible.

  The ladle for molten metal of the present invention has a horizontal cross section that is closer to a quadrangle compared to the conventional horizontal cross section having an elliptical shape, without expanding the outer diameter dimensions such as width, length, height, The pan volume can be expanded. And since each part is comprised by the circular arc, it is hard to produce the deformation | transformation by a thermal stress, and the lining of a refractory is also unreasonable. Therefore, it can be set as the ladle for molten metal excellent in practicality which expanded the pot volume.

It is a horizontal sectional view showing the 1st embodiment of the present invention. It is a longitudinal cross-sectional view which shows the 1st Embodiment of this invention. It is a ladle for molten metal currently used. It is a horizontal section top view showing a 2nd embodiment of the present invention.

Embodiments of the present invention will be described below.
1 and 2 are sectional views showing a ladle for molten metal according to a first embodiment of the present invention. As in the prior art, this ladle for molten metal has a structure in which a refractory 2 is lined inside the iron shell 1 and trunnion shafts 3 and 3 are provided on both sides in the width direction. However, as shown in FIG. 1, the ladle for molten metal according to the present invention has a non-circular shape in which the horizontal cross section is basically a combination of three types of arcs R1, R2, and R3. In the present specification, “horizontal section” means a horizontal section in the vicinity of the liquid surface, and is substantially the same as the shape of the upper end surface.

  The arc R2 is a long side arc having a radius of curvature R2. The center O2 is on the axis 4 connecting the trunnion shafts 3 and 3 on both sides. Since the shape is bilaterally symmetric, the arc R2 is on both the left and right sides. The arc R3 is a short-side arc with a radius of curvature R3, and the center O3 is on the central axis 5 orthogonal to the axis 4. Since it has a symmetrical shape above and below the axis 4, the arc R3 is on both sides. The arc R1 is a corner arc with a radius of curvature of R1, and smoothly connects the arcs of R2 and R3. There are four arcs R1. As described above, the refractory 2 is lined on the iron shell 1, and the above-described curvature radii represent the outer surface shape of the refractory 2, that is, the inner surface shape of the iron skin 1. As described above, the ladle for molten metal according to the present invention is basically composed of three kinds of arcs R1, R2, and R3 in the horizontal cross section, but there is a fourth arc portion in the vicinity of the connecting portion by the arc R1. It doesn't matter.

  These arcs have a relationship of R1 <R2, R1 <R3, and R2 ≦ R3. By establishing these relationships, the ladle for molten metal of the present invention has a more square shape than a circle or an ellipse, and the cross-sectional area can be increased while keeping the outer diameter dimension the same. Enlarged.

  In addition, since the entire circumference of this shape is constituted by arcs R1, R2, and R3, deformation due to thermal stress is unlikely to occur. The present inventor conducted stress analysis on the ladle for molten metal having this shape, but no significant increase was observed in both stress and thermal stress due to load compared to the conventional ladle for molten metal. Further, the refractory 2 to be lined has a structure in which block-shaped bricks are stacked, but since the inner surface of the iron skin 1 has an arc shape, it has an arch structure and has an advantage that it is difficult to fall off due to stress in the circumferential direction.

  A specific example will be described below. FIG. 3 shows a ladle for molten metal currently used, which has a shape composed of two upper and lower arcs and a straight line connecting the upper and lower arcs. Its width is 4868 mm, length is 5266 mm, height is 4676 mm, and its pan volume is 270 tons. These sizes are all the maximum outer diameter dimensions (excluding the trunnion shaft).

  On the other hand, the ladle for molten metal of the first embodiment shown in FIG. 1 has R2 = 4170 mm, R3 = 4170 mm, R1 = 1150 mm, its width is 4868 mm, length is 5266 mm, and height is 4676 mm. However, the outer diameter dimension is completely the same as that shown in FIG. However, the pan volume was 290 tons, which could be increased by 20 tons (7.4%) than before. When R1 was increased to 1670 mm with R2 = 4170 mm and R3 = 4170 mm, the pan volume was 286 tons, which could be increased by 16 tons (5.9%) than before. As a result of stress analysis, it has been confirmed that there is no problem with stress. About deformation, an increase of about 0.05% was recognized compared to the conventional case. However, it has been confirmed that such a deformation can be sufficiently dealt with by changing the shape of the trunnion ring 8 shown in FIG.

  FIG. 4 is a cross-sectional view showing a ladle for molten metal according to a second embodiment of the present invention. This ladle for molten metal is the one described in claim 2, wherein R2 and R3 are infinite, and a linear long side 6 of length A and a linear short side 7 of length B are used. . The long side 6 and the short side 7 are connected by a corner circular arc having a radius of curvature R1, and have a non-circular shape. When the linear long side 6 and the short side 7 are incorporated in this way, A ≦ 4R1 and B ≦ 4R1. If A and B exceed 4R1, the overall shape becomes nearly rectangular, and the stress at the corner becomes excessive, which is not preferable.

  As a specific example, when the length A of the long side 6 is 2880 mm, the length B of the short side 7 is 3300 mm, and R1 = is 790 mm, the pan volume is 330 tons, which is increased by 60 tons from the conventional one. I was able to. The hanging ability of the used ladle crane was a maximum of 500 tons.

  As described above, according to the present invention, the pot volume can be expanded without increasing the outer diameter dimensions such as the width, length, and height of the ladle for molten metal. If the total mass of the pan itself and the pan volume (molten steel mass) after this expansion is less than the maximum lifting mass of the ladle crane, the crane capacity / structure, overhead crane runway reinforcement, structural reinforcement of the building itself, etc. No major equipment modifications are required. Moreover, the ladle for molten metal according to the present invention has a small thermal stress because each part constituting the horizontal cross section is constituted by an arc, and therefore, deformation due to the thermal stress is difficult to occur, and it is difficult to line the refractory. There are advantages such as not.

  In the above-described embodiment, the case of remodeling based on the current product having a pan volume of 270 tons has been described, but it goes without saying that the pan volume of the ladle for molten metal is not limited to this. That is, the ladle volume of the ladle for molten metal is usually 250 to 300 tons, but reaches 500 tons at the maximum level. Moreover, in the steel factory which manufactures small-section slabs, such as billets, a thing with a pan volume of about 60 to 90 tons is used. The present invention can be applied regardless of the pan volume.

DESCRIPTION OF SYMBOLS 1 Iron skin 2 Refractory 3 Trunnion shaft 4 Axis 5 Center axis orthogonal to the axis 6 Long side 7 Short side 8 Trunnion ring

Claims (2)

A ladle for molten metal lined with refractories and equipped with trunnion shafts on both sides,
The horizontal section has a long side arc with a radius of curvature R2 centered on the axis connecting the trunnion axis, a short side arc with a radius of curvature R3 centered on the central axis perpendicular to the axis, and Is a non-circular shape composed of a corner arc with a radius of curvature connecting the two arcs of R1,
And the ladle for molten metal characterized by R1 <R2, R1 <R3, R2 ≦ R3. A non-circular shape in which R2 and R3 are infinite, a linear long side of length A and a linear short side of length B are connected by a corner arc having a radius of curvature R1,
And it is A <= 4R1, B <= 4R1, The ladle for molten metals of Claim 1 characterized by the above-mentioned.

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