Mass blocks and methods for installing mass blocks

Abstract

The present invention provides a mass block and a method for installing the mass block that allow for easy filling of the space between the construction frame and the mass block with amorphous refractory material, while preventing the mass block from floating up during use and falling when draining residual hot water. [Solution] The mass block 10 installed at the bottom of the molten metal container comprises a rectangular body 1 in plan view and a protrusion 2 projecting outward from the outer peripheral surface 1a on the lower side of the body 1. The protrusion 2 has a first surface 2a that overlaps with the outer peripheral surface 1a and is located inside the corner 11 of the body 1 in a view perpendicular to the outer peripheral surface 1a.

Description

Technical Field

[0001] The present invention relates to a nozzle receiving refractory (also referred to as a tuyere block or a mass block. Hereinafter, it is referred to as a mass block) disposed at the bottom of a molten metal container such as a tundish or a ladle.

Background Art

[0002] A mass block, which is a nozzle receiving refractory, is installed at the location where molten metal is discharged at the bottom of a molten metal container so as to surround the upper nozzle. The mass block is a precast block in which amorphous refractory is pre-cast into a predetermined shape or a shaped refractory. The mass block is placed in a construction frame provided at the bottom of the molten metal container, and is fixed to the bottom by constructing amorphous refractory in the space between the construction frame and the mass block.

[0003] Patent Document 1 discloses a mass block in which upper and lower mass blocks are integrated to eliminate joints, increase the effective remaining dimension, and improve durability. By integrating the upper and lower mass blocks, the occurrence of cracks in the upper nozzle at the interface between the upper mass block and the lower mass block is suppressed, leading to an extended service life of the nozzle.

[0004] Patent Document 2 discloses a block refractory that is disposed on the laying part of a steelmaking ladle and has convex portions on the entire outer peripheral surface of the end portion on the side that contacts the iron skin constituting the laying part. Amorphous refractory is constructed around the block refractory.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The integrated upper and lower mass block described in Patent Document 1 is supported only by amorphous refractory material that contacts the outer surface of the mass block. Therefore, there was a risk of the mass block lifting up during use or falling when draining residual molten metal. In addition, problems such as metal punctures due to gaps in the joints between the mass block and the amorphous refractory material could occur.

[0007] As described in Patent Document 2, when a mass block has protrusions across its entire outer surface, applying amorphous refractory material to the upper surface of the protrusions can prevent the mass block from floating up during use and from falling when draining residual molten metal. However, when installing a mass block on a construction frame formed from a fixed-shape refractory material, it is necessary to apply amorphous refractory material between the construction frame and the mass block. However, the presence of protrusions narrows the space between the construction frame and the mass block, making it difficult to insert tools into the space and thus difficult to fill with amorphous refractory material.

[0008] Therefore, there is a need to realize a mass block and a method for installing the mass block that can easily fill the space between the construction frame and the mass block with amorphous refractory material, while preventing it from floating up during use and falling when draining residual hot water. [Means for solving the problem]

[0009] The mass block according to the present invention is a mass block installed at the bottom of a molten metal container, comprising a rectangular body in plan view and a protrusion projecting outward from the outer peripheral surface on the lower side of the body, wherein the protrusion has a first surface that overlaps with the outer peripheral surface inward from the corner of the body when viewed in a direction perpendicular to the outer peripheral surface.

[0010] With this configuration, when amorphous refractory material is installed around the mass block, the amorphous refractory material is positioned on the upper surface of the protrusions. As a result, the protrusions catch on the amorphous refractory material, fixing the mass block in place and preventing it from floating up or falling during use. Furthermore, since there are no protrusions formed at the corners of the main body, and the thickness of the protrusions near the corners is small, a gap can be created between the corner and the construction frame when installing the mass block, allowing a tool to be inserted and the amorphous refractory material to be filled into this gap. This makes it easier to install the mass block even with conventionally shaped construction frames.

[0011] In one embodiment of the present invention, the mass block preferably has a protrusion that extends from the corner.

[0012] This configuration allows for an increase in the area ratio of the protrusions to the main body, thereby increasing the area of ​​the amorphous refractory material in contact with the upper surface of the protrusions. This increases the grip between the protrusions and the amorphous refractory material, making it easier for the mass block to be fixed in place by the amorphous refractory material, thus preventing the mass block from floating up or falling during use.

[0013] In one embodiment of the present invention, it is preferable that the adjacent sides of the mass block, straddling the corner, are on the same plane.

[0014] With this configuration, after forming a conventionally shaped protrusion that covers the entire outer surface and corners of the main body, a protrusion can be created by cutting off a portion of the protrusion near the corner. Therefore, there is no need to create a new mold when forming the protrusion, and the manufacturing cost of the mold can be reduced.

[0015] In one embodiment, the mass block according to the present invention preferably has a side surface that extends perpendicularly from the outer peripheral surface.

[0016] This configuration allows for a wider space between the mass block and the construction frame, enabling the insertion of tools into the space and facilitating the filling of amorphous refractory material.

[0017] In one aspect, it is preferable that the convex portion of the mass block according to the present invention has an upper surface that inclines upward as it approaches the outer peripheral surface.

[0018] According to this configuration, during the construction or use of the mass block, it is possible to suppress the concentration of stress acting on the mass block at the boundary between the outer peripheral surface of the main body and the upper surface of the convex portion, and it is possible to suppress the occurrence of cracks at the boundary between the main body and the convex portion.

[0019] A method of installing the mass block according to the present invention preferably includes a step of installing the mass block with respect to a rectangular construction frame such that the side of the construction frame and the side of the main body are non-parallel, and a step of constructing a stamp material between the construction frame and the mass block.

[0020] According to this configuration, the space between the construction frame and the mass block can be widened, so the amount of the amorphous refractory constructed in the space can be increased, and it becomes easier to fix the mass block to the bottom of the molten metal container. Also, since it is easy to insert a tool into the space, it is easy to fill the amorphous refractory, and the workability can be improved.

[0021] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments.

Brief Description of the Drawings

[0022] [Figure 1] It is a plan view of the mass block according to the first embodiment. [Figure 2] It is a cross-sectional view of the mass block according to the first embodiment. [Figure 3] It is a view showing a conventional method of installing a mass block. [Figure 4] It is a view showing a method of installing the mass block according to the first embodiment. [Figure 5] It is a plan view of the mass block according to the second embodiment. [Figure 6]It is a cross-sectional view of a mass block according to another embodiment.

Embodiments for Carrying Out the Invention

[0023] Embodiments of the mass block according to the present invention will be described with reference to the drawings. The mass block is not limited to the following embodiments, and various modifications are possible without departing from the gist thereof.

[0024] 〔First Embodiment〕 As shown in FIGS. 1 and 2, the mass block 10 according to this embodiment includes a rectangular main body 1 in plan view and convex portions 2 protruding outward from the outer peripheral surface 1a at the lower part of the main body 1. Since the convex portions 2 are provided on each of the outer peripheral surfaces 1a of the main body 1, the mass block 10 has a total of four convex portions 2. A hole is formed in the main body 1 penetrating from the upper surface to the lower surface, and an upper nozzle is inserted into the hole. The central axis of the hole is the central axis X of the mass block 10.

[0025] The convex portion 2 is continuously provided on the lower surface of the main body 1. Therefore, the lower surface of the convex portion 2 and the lower surface of the main body 1 are on the same plane. The upper surface 2c of the convex portion 2 is parallel to the upper surface of the main body 1. Further, as shown in FIG. 1, the convex portion 2 has a first surface 2a that overlaps the outer peripheral surface 1a inside the corner portion 11 of the main body 1 in a direction perpendicular to the outer peripheral surface 1a. The corner portion 11 of the main body 1 is the boundary between the outer peripheral surfaces 1a of the main body 1, and the region inside the corner portion 11 refers to the region between a pair of corner portions 11, 11 at both ends of one outer peripheral surface 1a that does not include the pair of corner portions 11, 11. The first surface 2a may be parallel to the outer peripheral surface 1a, may be inclined with respect to the outer peripheral surface 1a, or may be rounded by chamfering.

[0026] The protrusion 2 has a pair of side surfaces 2b extending from the corner 11 of the main body 1. The side surfaces 2b are surfaces that connect the first surface 2a and the corner 11, and are inclined at an acute angle with respect to the outer peripheral surface 1a. In this embodiment, since the inclination angles of each side surface 2b with respect to the outer peripheral surface 1a are the same, adjacent side surfaces 2b, 2b across the corner 11 lie on the same plane. When adjacent side surfaces 2b, 2b across the corner 11 lie on the same plane, the protrusion 2 is easier to manufacture by processing, as will be described later. Note that the inclination angles of each side surface 2b with respect to the outer peripheral surface 1a may be different.

[0027] Because the protrusion 2 has a first surface 2a and a side surface 2b, the protrusions 2 formed on each outer peripheral surface 1a are not continuous across the corner 11, and are separated at the corner 11. That is, no protrusion 2 is formed at the corner 11, and the thickness of the protrusion 2 near the corner 11 is also small. In other words, the protrusion 2 of the mass block 10 according to the present invention has a shape in which the four corners of a rectangle formed by connecting each side of the outer peripheral surface 1a are cut out in a plan view. For this reason, compared to a conventional mass block 10 such as the one described in Patent Document 2, the area of ​​the mass block 10 in a plan view can be reduced, and interference between the construction frame on which the mass block 10 is installed and the protrusion 2 near the corner 11 can be reduced.

[0028] The height dimension of the protrusion 2 is preferably 20 mm to 150 mm, and the dimension of the protrusion 2 from the outer peripheral surface 1a to the first surface 2a is preferably 20 mm to 50 mm. By setting these dimensions within this range, when the mass block 10 is installed in the construction frame, it is easier to create a grip between the surrounding irregularly shaped refractory material and the protrusion 2, making it easier to prevent the mass block 10 from floating up or falling when residual molten metal is drained.

[0029] The material of the main body 1 and the protrusion 2 can be any material; for example, alumina, alumina-spinel, alumina-magnesia, spinel, alumina-carbon, etc., can be used. It is preferable that the main body 1 and the protrusion 2 be made of the same material.

[0030] The mass block 10 can be obtained by casting the pourable material into a mold, similar to a general precast block, followed by curing, mold removal, and drying. As the mold, a mold capable of forming the first surface 2a and side surfaces 2b may be used, or a mold in which protrusions are formed on the entire outer surface 1a and corners 11 may be used. When using a conventional mold in which protrusions are formed on the entire outer surface 1a and corners 11, the protrusions 2 are formed by cutting or grinding the four corners of the protrusions with a cutter or cutting machine so that the first surface 2a and side surfaces 2b are formed after the mass block 10 has dried. If the adjacent side surfaces 2b on either side of the corner 11 are on the same plane, cutting the four corners becomes easier.

[0031] [How to install mass blocks] Next, the method for installing the mass block 10 will be explained with reference to Figures 3 and 4. The method for installing the mass block 10 according to this embodiment includes the steps of installing the mass block 10 on a rectangular construction frame W such that the sides of the construction frame W and the sides of the main body 1 are not parallel, and installing an unshaped fire-resistant material between the construction frame W and the mass block 10.

[0032] As shown in Figures 3 and 4, the construction frame W is a space for installing a mass block 10, which is formed from a shaped refractory material installed at the bottom of a molten metal container, such as a molten steel pot. The depth dimension of the construction frame W is approximately the same as the height dimension of the mass block 10. The construction frame W is rectangular in plan view, and the area of ​​the construction frame W in plan view is larger than the area of ​​the mass block 10.

[0033] Since both the construction frame W and the mass block 10 are rectangular, if the mass block 10 is installed on the construction frame W so that their sides are parallel, the space between the construction frame W and the mass block 10 becomes narrow, and the thickness of the amorphous refractory material installed in that space becomes small. For this reason, when installing the mass block 10, the process of installing the mass block 10 is carried out so that the sides of the construction frame W and the sides of the main body 1 are not parallel. Specifically, the mass block 10 is installed on the construction frame W with its central axis X as the axis, rotated by a predetermined angle (for example, 20 to 30 degrees) from a state where the sides of the construction frame W and the sides of the mass block 10 are parallel (or perpendicular) (see Figures 3 and 4). This makes it possible to create sufficient space between the sides of the construction frame W and the sides of the mass block 10, and to install the amorphous refractory material sufficiently.

[0034] Figure 3 shows a schematic diagram of a mass block 10 having protrusions 2 on the entire outer surface 1a and corners 11, as described in Patent Document 2, when installed in a construction frame W. In Figure 3, the space between the construction frame W and the mass block 10 near the corners 11 is narrow, making it difficult to insert the rammer head R into the space. A rammer is a machine used to drive in shapeless refractory material. Thus, when the mass block 10 has protrusions 2 on the entire outer surface 1a and corners 11, it leads to poor workability and insufficient filling of shapeless refractory material.

[0035] In this embodiment, the mass block 10 does not have a protrusion 2 formed on the corner 11, and the thickness of the protrusion 2 near the corner 11 is also thin. Therefore, as shown in Figure 4, even when the mass block 10 is installed so that the sides of the construction frame W and the sides of the mass block 10 are not parallel, the space between the construction frame W and the mass block 10 near the corner 11 can be widened. This makes it possible to insert a rammer head R into the space, thereby improving workability. Furthermore, while amorphous refractory materials such as stamping material and pouring material are difficult to fill into narrow spaces, according to the present invention, a tool can be inserted between the construction frame W and the mass block 10, so insufficient filling of amorphous refractory material can be prevented, and the lifting and falling of the mass block 10 can be further suppressed.

[0036] Furthermore, the shapeless refractory material to be installed in the space between the construction frame W and the mass block 10 can be stamp material, pourable material, etc., and the material can be appropriately changed to match the material of the molten metal container and the mass block 10. Examples of shapeless refractory materials that can be used include alumina, alumina-spinel, alumina-magnesia, spinel, alumina-carbon, etc.

[0037] [Second Embodiment] A mass block 10 according to the second embodiment will be described with reference to Figure 5. The mass block 10 according to the second embodiment has a side surface 2b extending from the outer peripheral surface 1a. The other configurations are the same as those of the first embodiment, so the same configurations as the first embodiment will not be described.

[0038] As shown in Figure 5, the side surface 2b in this embodiment extends perpendicularly from the outer peripheral surface 1a, but the side surface 2b does not have to be perpendicular to the outer peripheral surface 1a as long as it extends from the outer peripheral surface 1a. Because the side surface 2b extends from the outer peripheral surface 1a, that is, because a protrusion 2 is not formed on the outer peripheral surface 1a near the corner 11, the space between the construction frame W and the mass block 10 can be increased when the mass block 10 is installed on the construction frame W, making it easier to fill the space with amorphous refractory material.

[0039] The distance from the corner 11 to the protrusion 2 on the outer surface 1a is preferably 1 / 8 to 1 / 5 of the distance from corner 11 to corner 11 on the outer surface 1a. The smaller the distance from the corner 11 to the protrusion 2 on the outer surface 1a, the more grip can be created between the amorphous refractory material and the protrusion 2. The larger the distance, the more the workability of the amorphous refractory material can be improved. Therefore, this distance should be determined by balancing the prevention of lifting and detachment of the mass block 10 with workability.

[0040] [Examples] A mass block 10 having a protrusion 2 was fabricated and tested in a real machine. The protrusion 2 in this embodiment has a first surface 2a parallel to the outer circumferential surface 1a of the main body 1, a side surface 2b extending from the corner 11 of the main body 1, and a top surface 2c parallel to the top surface of the main body 1. In addition, adjacent side surfaces 2b on either side of the corner 11 are located on the same plane, and the angle between the side surface 2b and the outer circumferential surface 1a is 45°. The size of the mass block 10 was 400mm × 400mm × 400mm in height, the height dimension of the protrusion 2 was 100mm, and the dimension between the outer circumferential surface 1a and the first surface 2a was 25mm.

[0041] To prepare the mass block 10, a general alumina-spinel casting material was used, which consisted of 63% by mass of alumina raw material, 27% by mass of alumina-magnesia raw material, 9% by mass of binder, and 1% by mass of stainless steel fiber. These raw materials were mixed with 5% by mass of water, poured into a mold, and filled with a rod-shaped vibrator or table vibration as needed to uniformly cast into the predetermined shape. As the mold, one was used that could form protrusions on the entire outer surface 1a and corners 11. After hardening, the mold was removed and dried to obtain the mass block 10. Then, the four corners of the protrusions formed on the entire outer surface 1a and corners 11 were cut with a cutting machine and chamfered to obtain the protrusions 2 according to the present invention. This mass block 10 was placed in a construction frame W provided at the bottom of a molten metal container. During installation, the mass block 10 was rotated 20° from a state where the sides of the construction frame W and the sides of the main body 1 were parallel, using the central axis X of the mass block 10 as the axis, so that the sides of the construction frame W and the sides of the main body 1 were not parallel. Then, the stamping material was filled into the space between the construction frame W and the mass block 10.

[0042] By using the mass block 10 according to the embodiment, the space between the construction frame W and the mass block 10 could be widened, allowing tools such as a rammer to be inserted into the space. This improved the filling and workability of the stamping material, and reduced the construction time for that part by 24%. The mass block 10 did not float up or fall when draining residual molten metal during actual operation. Therefore, according to the present invention, it is possible to provide a mass block 10 that prevents floating up during use and falling when draining residual molten metal, while also making it easy to fill the space between the construction frame W and the mass block 10 with amorphous refractory material.

[0043] [Other Embodiments] (a) In the above embodiment, the upper surface 2c of the protrusion 2 is parallel to the upper surface of the main body 1, but as shown in Figure 6, the upper surface 2c of the protrusion 2 may be inclined upward as it approaches the outer peripheral surface 1a. The inclination angle of the upper surface 2c of the protrusion 2 with respect to the outer peripheral surface 1a is preferably 0° or more and 40° or less. The inclination of the upper surface 2c with respect to the outer peripheral surface 1a allows for the dispersion of stress acting on the boundary between the main body 1 and the protrusion 2 due to impacts from tools during construction and repeated heating, thereby improving crack resistance and increasing the strength of the mass block 10.

[0044] (b) In the above embodiment, the protrusion 2 is assumed to have a side surface 2b extending from the corner 11 or a side surface 2b extending from the outer peripheral surface 1a, but the side surface 2b may have a rounded shape in plan view.

[0045] The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Furthermore, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto and can be modified as appropriate without departing from the purpose of the present invention. [Industrial applicability]

[0046] This invention can be used in mass blocks installed at the bottom of molten metal containers. [Explanation of Symbols]

[0047] 1: Main unit 1a: Outer surface 2: Convex part 2a: Front page 2b: Side 2c:Top surface 10: Mass Block 11: Corner W: Construction frame X: Central axis

Claims

1. A mass block installed at the bottom of a molten metal container, It comprises a rectangular body in plan view and a protrusion projecting outward from the outer circumferential surface on the lower side of the body, The aforementioned protrusion is a mass block having a first surface that overlaps with the outer circumferential surface, located inside the corner of the main body when viewed in a direction perpendicular to the outer circumferential surface.

2. The mass block according to claim 1, wherein the convex portion has a side surface extending from the corner portion.

3. The mass block according to claim 2, wherein each of the adjacent sides with respect to the aforementioned corner is on the same plane.

4. The mass block according to claim 1, wherein the protrusion has a side surface that extends perpendicularly from the outer peripheral surface.

5. The mass block according to claim 1, wherein the protrusion has an upper surface that slopes upward as it approaches the outer peripheral surface.

6. A method for installing a mass block according to any one of claims 1 to 5 into the molten metal container, A step of installing the mass block on a rectangular construction frame such that the sides of the construction frame and the sides of the main body are not parallel, A method for installing a mass block, comprising the step of applying stamping material between the construction frame and the mass block.

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