TW202014256A - Ladle for molten metal - Google Patents

Abstract

The present invention provides a ladle for molten metal including a ladle body with trunnion shafts, and a refractory layer provided on an inside of the ladle body. A horizontal cross section of the ladle body at the trunnion shafts has a non-circular shape and includes a first circular arc having a center point on an axis line connecting the trunnion shafts, a second circular arc having a center point on a center axis perpendicular to the axis line, and a curving portion connecting the first circular arc and the second circular arc. A radius of curvature R1 of the first circular arc, a radius of curvature R2 of the second circular arc, and a minimum radius of curvature R3MIN satisfy following equations (1) to (3). 0.401×R1>R3MIN>R1 Equation (1) 0.401×R2>R3MIN>R2 Equation (2) R1≦R2 Equation (3)

Description

Ladle for molten metal

Field of invention The present invention relates to a molten metal ladle for holding molten metal such as molten iron or molten steel at an ironworks or the like. This application claims priority based on Japanese Patent Application No. 2018-152619 for which a patent application was filed in Japan on August 14, 2018, and the contents are cited here.

Background of the invention For example, in ironworks, etc., molten iron or molten steel from a converter or torpedo car is held in a ladle (a ladle for molten metal) for transportation. In this molten metal ladle, since the molten metal at a high temperature is to be maintained, it has a structure including a ladle body made of iron and a refractory layer disposed inside the ladle body. In addition, a trunnion is provided on both sides in the width direction of the ladle body, and the trunnion can be lifted by a crane or the like and tilted about the trunnion. Conventionally, as the above-mentioned molten metal ladle, for example, as shown in Patent Document 1, there has been proposed an object in which the horizontal cross-sectional shape of the ladle body has a circular shape or an oval shape.

Since the ladle for molten metal is a molten metal that maintains a high temperature, the refractory layer disposed inside the ladle body is thermally degraded to cause cracks and the like. Therefore, the refractory layer must be repaired regularly according to a certain number of uses. Here, by increasing the barrel volume of the molten metal ladle, the amount of molten metal processed before the repair operation of the refractory layer can be increased, and the manufacturing cost can be reduced.

In order to increase the volume of the ladle for molten metal, it is conceivable to increase the outer shape of the ladle body. However, when increasing the outer shape of the molten metal ladle, in order to adapt the crane and other equipment to the outer shape of the molten metal ladle, a substantial modification of the entire equipment is required, which is not practical. Thus, for example, in Patent Document 2, there has been proposed a molten metal ladle which enlarges the volume of the barrel without greatly changing the outer shape of the molten metal ladle. In the molten metal ladle described in this Patent Document 2, the horizontal volume of the ladle body is approximated to a rectangular shape to increase the volume of the ladle. In addition, by forming a horizontal cross section with a circular arc, the concentration of stress in the corners is suppressed. Prior technical literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2000-256728 Patent Document 2: Japanese Patent Laid-Open No. 2016-059940

Summary of the invention Problems to be solved by invention In addition, recently, in order to further reduce the manufacturing cost, there is a demand for a molten metal ladle to further reduce the number of repairs of the refractory layer. Here, in the ladle for molten metal described in Patent Document 2, although a horizontal cross section is formed by an arc to suppress stress concentration at the corners, the stress on the refractory layer is not sufficiently reduced, and there is a refractory layer The number of repairs may increase. In addition, recently, it is required to extend the service life of the molten metal ladle. It is necessary to reduce the thermal stress on the ladle body to suppress the deformation of the ladle body.

The present invention has been made in view of the foregoing circumstances, and its object is to provide a molten metal pouring pot that can increase the volume of the molten metal ladle and can reduce the number of repairs by suppressing the thermal stress acting on the molten metal ladle. barrel. Means to solve the problem

To solve the above problem, the molten metal ladle of the present invention is a molten metal having a ladle body and a refractory layer disposed inside the ladle body, and having trunnions on both sides of the ladle body A ladle, characterized in that the horizontal cross section of the ladle body including the trunnion is made into a non-circular shape, and is provided with: a first arc, having a center on the axis connecting the trunnions, and a radius of curvature of R1, which includes a portion orthogonal to the trunnion; the second arc, which has a center on the central axis orthogonal to the axis and a radius of curvature of R2, and includes a portion orthogonal to the central axis; and a curve Part, connecting the first arc and the second arc, and the minimum radius of curvature is R3 _MIN , and the radius of curvature R1 of the first arc, the radius of curvature R2 of the second arc, the minimum of the curve The radius of curvature R3 _MIN satisfies the following equations (1) to (3). (1) Formula: 0.401×R1<R3 _MIN <R1 (2) Formula: 0.401×R2<R3 _MIN <R2 (3) Formula: R1≦R2

According to the molten metal ladle of this configuration, the horizontal section of the ladle body including the trunnion is made into a non-circular shape, and is provided with: a first arc having a center on the axis connecting the trunnions, and The radius of curvature is R1 and includes a portion orthogonal to the trunnion; the second arc has a center on the central axis orthogonal to the axis and the radius of curvature is R2 and includes a portion orthogonal to the central axis ; And the curved portion, connecting the first arc and the second arc, and the minimum radius of curvature is R3 _MIN , and the minimum radius of curvature R3 _MIN of the curved portion is set to R3 _MIN <R1, R3 _MIN <R2, Therefore, the first arc and the second arc with a large radius of curvature are connected by a curved portion with a small radius of curvature so that the horizontal cross section is approximately rectangular, and the ladle body can be formed into a circular shape relative to the horizontal cross section To expand the volume of the barrel.

In addition, the minimum radius of curvature R3 _{MIN of the} curved portion satisfies 0.401×R1<R3 _MIN and 0.401×R2<R3 _MIN . Therefore, the minimum radius of curvature R3 _MIN of the curved portion relative to the first arc and the second arc The radius of curvature does not become too small, and the concentration of stress in the connection between the first arc and the curved portion and the second arc and the curved portion can be suppressed, and the deformation of the ladle body or the deterioration of the refractory layer can be suppressed. In this way, the number of refractory repairs in the ladle for molten metal can be reduced. Therefore, the barrel volume of the molten metal ladle can be enlarged, and the thermal stress acting on the molten metal ladle can be suppressed to reduce the number of repairs.

Here, in the ladle for molten metals of the present invention, the refractory layer includes: a first refractory layer disposed on the side of the ladle body, and a second refractory layer disposed inside the first refractory layer For the refractory layer, the first refractory layer may be composed of refractory bricks, and the second refractory layer may be composed of an amorphous refractory. At this time, even if stress is applied to the refractory layer to cause cracking, the propagation of the crack to the first refractory composed of refractory bricks can be suppressed, as long as the second refractory disposed further inside the first refractory layer is repaired The object layer is sufficient. Since the second refractory layer is formed of an amorphous refractory, it can be repaired relatively easily. Furthermore, by suppressing the thermal stress acting on the second refractory layer, the repair cost can be further reduced. Invention effect

As described above, according to the present invention, it is possible to provide a molten metal ladle which can increase the volume of the molten metal ladle and can reduce the number of repairs while suppressing the thermal stress acting on the molten metal ladle.

Forms for carrying out the invention Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the present invention is not limited to the following embodiments.

The molten metal ladle 1 of this embodiment includes a ladle body 10 and a refractory layer 20. The ladle body 10 is provided with trunnions 18 and 18 on both sides in the width direction, and is configured to be transported by a crane or the like using the trunnions 18 and 18, and can also be tilted about the trunnions 18 and 18 as a center.

Moreover, in this embodiment, as shown in FIG. 3, the horizontal cross section including the trunnion 18 of the ladle body 10 is made into a non-circular shape. Specifically, the shape is such that the first arc 11 has a center on the axis S1 connecting the trunnions 18 and 18, has a radius of curvature R1, and includes a portion orthogonal to the trunnion 18; the second The circular arc 12 has a center on a central axis S2 orthogonal to the axis S1, and has a radius of curvature R2, and includes a portion orthogonal to the central axis S2; and a curved portion 13, connecting the first circular arc 11 and the second circle Arc 12, and the minimum radius of curvature is R3 _MIN . In the present embodiment, the radius of curvature R1, R2, R3 _MIN of the horizontal section of the ladle body 10 is set to the radius of curvature measured on the inner wall surface of the ladle body 10.

Since the first circular arc 11 has a center on the axis S1 connecting the trunnions 18 and 18, the surface on which the trunnions 18 and 18 are arranged becomes the first circular arc 11 described above. In addition, since the second circular arc 12 has a center on the central axis S2 orthogonal to the axis S1 connecting the trunnions 18 and 18, it is formed in a direction orthogonal to the first circular arc 11. In addition, the curved portion 13 is disposed at a corner portion where the first arc 11 and the second arc 12 intersect.

Here, the radius of curvature R1 of the first circular arc 11, the radius of curvature R2 of the second circular arc 12, and the minimum radius of curvature R3 _{MIN of the} curved portion 13 satisfy the following equations (1) to (3). (1) Formula: 0.401×R1<R3 _MIN <R1 (2) Formula: 0.401×R2<R3 _MIN <R2 (3) Formula: R1≦R2

As described above, the minimum radius of curvature R3 _MIN of the curved portion 13 is set to R3 _MIN <R1 and R3 _MIN <R2 with respect to the radius of curvature R1 of the first arc 11 and the radius of curvature R2 of the second arc 12. The intersecting portions (corners) of the first arc 11 and the second arc 12 will protrude outwards to have an approximately rectangular shape, and the outer shape of the ladle body having a circular cross section can be maintained without changing the shape In the case of, increase the volume. In addition, in order to secure the volume, the upper limit of the minimum radius of curvature R3 _MIN of the curved portion 13 is preferably 0.9×R1 and 0.9×R2.

The minimum radius of curvature R3 _MIN of the curved portion 13 is 0.401×R1<R3 _MIN and 0.401×R2<R3 _MIN with respect to the radius of curvature R1 of the first arc 11 and the radius of curvature R2 of the second arc 12. . That is, there is a predetermined lower limit of the minimum radius of curvature R3 _MIN of the curved portion 13. In this way, by specifying the lower limit of the minimum radius of curvature R3 _MIN of the curved portion 13, it is possible to suppress the concentration of stress in the connection portion between the first arc 11 and the curved portion 13, and the second arc 12 and the curved portion 13. This can suppress deformation of the ladle body 10, deterioration of the refractory layer 20, and the like.

In addition, in order to further suppress the concentration of stress in the connection between the first arc 11 and the curved portion 13 and the second arc 12 and the curved portion 13, the lower limit of the minimum radius of curvature R3 _MIN of the curved portion 13 is preferably 0.41 ×R1 and 0.41×R2 are preferably 0.42×R1 and 0.42×R2, and more preferably 0.45×R1 and 0.45×R2.

Further, in this embodiment, as shown in FIG. 4, the refractory layer 20 includes a first refractory layer 21 disposed on the side of the ladle body 10 and an inner side of the first refractory layer 21的second refractory layer 22 Here, in the present embodiment, the first refractory layer 21 is formed by depositing refractory bricks. In addition, the second refractory layer 22 is formed of an amorphous refractory. In addition, in the region where the liquid surface of the molten metal is located, the second refractory layer 22 may be formed of refractory bricks in order to suppress melting loss. The ratio t2/t1 between the thickness t1 of the first refractory layer 21 and the thickness t2 of the second refractory layer 22 is preferably 1 or more, and more preferably 2 or more.

In addition, in the molten metal ladle 1 of the present embodiment, after receiving molten iron or molten steel from a converter or torpedo-type mixed iron truck, the hook of the overhead crane is locked to the trunnions 18, 18 for transportation, and Tilt the trunnions 18 and 18 as the center, thereby transferring molten iron or molten steel toward the container in the next step. In this way, the molten metal ladle 1 will be injected and discharged with high-temperature molten iron or molten steel, and therefore will have a severe thermal stress repetitive effect. In addition, when the refractory layer 20 disposed inside the ladle body 10 is cracked or the like, the refractory layer 20 is repaired and used again.

According to the molten metal ladle 1 of the present embodiment configured as described above, the horizontal cross section of the ladle body 10 including the trunnion 18 is made into a non-circular shape, and it is provided with: The trunnions 18, 18 have a center on the axis S1, and the radius of curvature is R1, and include a portion orthogonal to the trunnion 18; the second circular arc 12, has a center on the central axis S2 orthogonal to the axis S1, and The radius of curvature is R2, and includes a portion orthogonal to the central axis S2; and the curved portion 13, connecting the first arc 11 and the second arc 12, and the minimum radius of curvature is R3 _MIN , and the minimum curvature of the curved portion 13 The radius R3 _MIN is set to R3 _MIN &lt; R1, R3 _MIN &lt; R2, so the horizontal cross-section is approximately rectangular, and the drum volume can be expanded with respect to the ladle body formed into a circular shape with respect to the horizontal cross-section.

In addition, the minimum radius of curvature R3 _MIN of the curved portion 13 is set to 0.401×R1<R3 _MIN and 0.401×R2<R3 _MIN . Therefore, the minimum radius of curvature R3 _{MIN of the} curved portion 13 does not become too small, and the first circle can be suppressed The stress in the connection between the arc 11 and the curved portion 13 and the second arc 12 and the curved portion 13 is concentrated, and the deformation of the ladle body 10 or the deterioration of the refractory layer 20 can be suppressed. This can reduce the number of repairs of the ladle 1 for molten metal.

In the present embodiment, the refractory layer 20 includes a first refractory layer 21 disposed on the side of the ladle body 10 and a second refractory layer 22 disposed inside the first refractory layer 21 , When the first refractory layer 21 is composed of refractory bricks, and the second refractory layer 22 is composed of an amorphous refractory, the first refractory layer 21 disposed on the side of the ladle body 10 can be suppressed The stress is concentrated, and the life of the first refractory layer 21 can be further extended. In addition, even if stress is applied to the refractory layer 20 and cracks are generated, the propagation of the cracks to the first refractory layer 21 made of refractory bricks can be suppressed, as long as the inner side of the first refractory layer 21 is repaired The second refractory layer 22 may be sufficient. Since the second refractory layer is formed of an amorphous refractory, it can be repaired relatively easily, and the repair cost can be further reduced.

The molten metal ladle according to the embodiment of the present invention has been specifically described above, but the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the invention. For example, in the present embodiment, the molten metal ladle having a trunnion having the structure shown in FIG. 1 has been described as an example, but it is not limited to this, and it may be a trunnion having another structure. Things.

In addition, in the present embodiment, although the description has been given of holding and transferring molten iron and molten steel, it is not limited to this, and may be a material that handles other molten metals. In addition, in this embodiment, although the refractory layer has been described with the object having the first refractory layer and the second refractory layer, it is not limited to this, and may be one having one refractory layer , And can also be three or more refractory layers. Examples

Hereinafter, the experimental results carried out to confirm the effects of the present invention will be described.

>Example 1> As an example of the present invention, a ladle for molten metal described in the above embodiment was prepared. Further, the radius of curvature R1 of the first arc is 4170 mm, the radius of curvature R2 of the second arc is 4170 mm, and the minimum radius of curvature R3 _{MIN of the} curved portion is 1700 mm. That is, it is set to satisfy 0.401×R1<R3 _MIN <R1, 0.401×R2<R3 _MIN <R2, and R1≦R2. As a comparative example, the radius of curvature R1 of the first arc is 4170 mm, the radius of curvature R2 of the second arc is 4170 mm, and the minimum radius of curvature R3 _{MIN of the} curved portion is 1150 mm. That is, the relationship of R3 _MIN <0.401×R1, R3 _MIN <0.401×R2 is established.

Using the ladle for molten metal of the examples of the present invention and the comparative example, the minimum value of the remaining thickness of the refractory layer after use was measured. In FIG. 5, the initial thickness of the inventive example and the comparative example is set to "1" and is displayed as a relative value: when the number of uses of the invention to reach the service life of the refractory is set to 1, it is achieved in the comparative example The relationship between the service life of the refractory and the minimum value of the remaining thickness of the refractory layer. As shown in FIG. 5, it was confirmed that the molten metal ladle of the example of the present invention has a thicker residual thickness of the refractory layer after use compared to the molten metal ladle of the comparative example, which can extend the service life. Furthermore, in the molten metal ladle of the example of the present invention, the volume of the ladle can be enlarged compared to the molten metal ladle having a horizontal cross section.

>Example 2> As Test Nos. A to H, a molten metal ladle was prepared, the shape of which is in a horizontal section including the trunnion 18, and includes: a first arc with a center on the axis connecting the trunnions , And the radius of curvature is R1, and includes the part orthogonal to the trunnion; the second arc has a center on the central axis orthogonal to the axis, and the radius of curvature is R2, and includes the orthogonal to the central axis And the curved part, connecting the first arc and the second arc, and the minimum radius of curvature is R3 _MIN . Table 1 shows the relationship between R1, R2, and R3 _MIN . The ratio t2/t1 of the thickness t1 of the first refractory layer (refractory brick) to the thickness t2 of the second refractory layer (unshaped refractory) is shown in Table 1.

The molten steel was transferred using the molten metal ladle. The effective volume of the ladle at this time, the number of uses, the minimum value of the remaining thickness of the refractory layer, and the presence or absence of cracks in the refractory layer in the curve portion were evaluated. In addition, various evaluations are based on Test A (=1) and are made relative evaluations. The evaluation results are shown in Table 1.

※t2/t1 ：第1耐火物層(耐火磚)的厚度t1與第2耐火物層(不定形耐火物)的厚度t2之比[Table 1]

※T2/t1: ratio of the thickness t1 of the first refractory layer (refractory brick) to the thickness t2 of the second refractory layer (unshaped refractory)

In the test No. G for R3 _MIN = 0.3×R1, R3 _MIN = 0.3×R2, and the test No. H for R3 _MIN = 0.25×R1, R3 _MIN = 0.25×R2, in the curve The refractory layer cracked.

In the test Nos. B to F satisfying 0.401×R1<R3 _MIN <R1, 0.401×R2<R3 _MIN <R2, the effective volume is larger than the test No.A in which the horizontal cross section is formed into a circular shape. In addition, cracking of the refractory layer in the curved portion can be suppressed. In addition, after comparing NoE and No. F of R3 _MIN = 0.401×R1 and R3 _MIN = 0.401×R2, the thickness t1 of the first refractory layer (refractory brick) and the second refractory layer (unshaped refractory) In the No. E where the ratio t2/t1 of the thickness t2 is set to 1, compared to No. F where t2/t1 is set to 0.5, the number of uses of the refractory until the remaining thickness of the refractory layer reaches 40 mm As the number increases, the life of the refractory layer can be increased. Industrial availability

According to the present invention, it is possible to provide a molten metal ladle which can increase the volume of the molten metal ladle and can reduce the number of repairs while suppressing the thermal stress acting on the molten metal ladle.

1: pouring bucket for molten metal 10: Drum body 11: 1st arc 12: 2nd arc 13: Curve part 18: trunnion 20: Refractory layer 21: 1st refractory layer 22: 2nd refractory layer R1, R2, R3: radius of curvature S1: axis S2: Central axis t1, t2: thickness

FIG. 1 is a side explanatory view showing an example of a molten metal ladle according to an embodiment of the present invention. Fig. 2 is an explanatory view of the upper surface showing an example of a molten metal ladle according to an embodiment of the present invention. 3 is an explanatory view showing a horizontal cross-sectional shape of a ladle body of a molten metal ladle according to an embodiment of the present invention. 4 is an explanatory diagram showing the structure of a refractory layer in a molten metal ladle according to an embodiment of the present invention. 5 is a graph showing the results of Example 1. FIG.

11: 1st arc

12: 2nd arc

13: Curve part

R1, R2, R3: radius of curvature

S1: axis

S2: Central axis

Claims (2)

A molten metal ladle has a ladle body and a refractory layer disposed inside the ladle body, and is provided with trunnions on both sides of the ladle body. The molten metal ladle is characterized by : The horizontal section of the ladle body including the trunnion is made into a non-circular shape, and is provided with: a first arc, having a center on the axis connecting the trunnion, and a radius of curvature of R1, including A part perpendicular to the trunnion; a second arc having a center on the central axis orthogonal to the aforementioned axis, with a radius of curvature R2, and including a part orthogonal to the central axis; and a curved portion connecting the first the second circular arc circular arc, and a minimum radius of curvature R3 _MIN, and, the first radius of the arc of curvature R1, the radius of curvature of the second arc R2, the minimum radius of curvature of the curved portion satisfies the following R3 _MIN The formulas (1) to (3), (1): 0.401×R1<R3 _MIN <R1 (2): 0.401×R2<R3 _MIN <R2 (3): R1≦R2. The ladle for molten metal according to claim 1, wherein the refractory layer includes: a first refractory layer disposed on the side of the ladle body, and a second refractory disposed inside the first refractory layer layer, The first refractory layer is composed of refractory bricks, and the second refractory layer is composed of an amorphous refractory.

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