TW202133969A - Bubbling plate for sliding nozzle - Google Patents

Abstract

The objective of the present invention is to prevent penetration of molten steel into a gas pool in a bubbling plate having a structure in which a ring is disposed in an inner bore of a plate main body. In a bubbling plate according to the present invention, a ring-shaped component (ring 3) having a gas permeation function is fitted into an inner hole 2d of a plate main body 2, in a bubbling plate 1 for a sliding nozzle used in continuous casting of steel. A stepped portion 3a, or a protruding portion or a recessed portion, is provided in a lower end surface of the ring 3, and a stepped portion 2a, or a recessed portion or a protruding portion, which opposes and is capable of engaging with the stepped portion 3a, or the protruding portion or the recessed portion, is provided in an upper surface of the plate main body 2 that is in contact with the lower end surface of the ring 3. A part (mating portion A) where the stepped portion 3a, or the protruding portion or the recessed portion, on the ring 3 side and the stepped portion 2a, or the recessed portion or the protruding portion, on the plate main body 2 side mate with one another has a length of at least 2 mm in the central axis direction of the inner bore 2d (vertical direction), and mortar is interposed in at least a vertical direction joint portion of the mating portion A.

Description

Blow plate for sliding mouth

The present invention relates to the structure of a so-called bubbling plate with a blowing function for sliding nozzles used in continuous casting of steel.

In order to blow gas into molten metal on the upper plate of the sliding nozzle device, a so-called blower plate in which a gas-permeable refractory is arranged in the inner hole is often used. The blowing plate has a function of blowing inert gas such as argon into the inner hole (nozzle hole) of each nozzle as a discharge path of molten steel to prevent inclusions such as alumina from adhering to the inner hole (nozzle hole).

As such an air blowing plate, Patent Document 1 discloses an air blowing device in which an air blowing ring (cylindrical gas-permeable refractory) is arranged in an inner hole of a bottom plate (plate main body). In this blowing device, a blowing ring with an iron cylinder on its outer peripheral surface is arranged so that the bottom surface of the blowing ring is in contact with and locked under the inner hole of the bottom plate (plate body) The reduced diameter part.

Patent Document 2 discloses an upper plate for air blowing, in which a ring-shaped dowel is formed on the refractory of the upper plate (the plate main body), and a gas passage ( Cylindrical gas-permeable refractory). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 6-41962 Gazette [Patent Document 2] JP 2004-268106 A

[The problem to be solved by the invention]

The aforementioned patent documents all adopt a structure in which a cylindrical gas-permeable refractory, that is, a ring-shaped part with a gas-permeable function (hereinafter also referred to as a "ring body") is installed in the inner hole of the plate body, so that the ring body is The lower end surface is in contact with the upper surface of the board main body (including the case of penetrating mortar) to fix the ring body. However, in the conventional ring body installation structure like this, a gas chamber (hereinafter referred to as "air chamber") provided between the outer circumference of the ring and the main body of the plate allows molten steel to invade and solidify to cause the gas toward the ring body Failure of supply stop often occurs.

The problem to be solved by the present invention is to prevent the intrusion of molten steel toward the air chamber in the blower plate of the structure in which the ring body is arranged in the inner hole of the plate main body. [Technical means to solve the problem]

The present invention is the air blowing board described in 1 to 7 below. 1. A blower plate, which is attached to the blower plate for sliding nozzles used in continuous casting of steel, Install a ring-shaped part (hereinafter referred to as "ring body") with ventilation function in the inner hole of the main body of the board, The lower end surface of the aforementioned ring body is provided with a stepped portion or a convex portion or a concave portion, The upper surface of the plate main body which is in contact with the lower end surface of the ring body is provided with a stepped portion or a concave portion or a convex portion which can be opposed to and fitted with the stepped portion or the convex portion or the concave portion, The stepped portion, convex portion, or concave portion on the ring body side and the portion where the stepped portion, concave portion or convex portion on the side of the plate body engages each other (hereinafter referred to as the “fitting portion”) in the direction of the center axis of the inner hole (hereinafter (Referred to as the "longitudinal direction") the length is 2mm or more, The mortar is inserted into at least the longitudinal joint part of the aforementioned fitting part. 2. The blowing board as described in 1 above, wherein: The step portion on the ring body side is such that the outer peripheral side of the ring body protrudes downward than the inner hole side of the ring body, The step portion on the side of the plate main body is such that the inner hole side of the plate main body protrudes upward than the outer peripheral side of the plate main body. 3. The blowing board as described in 1 or 2 above, wherein: A part or all of the longitudinal surface of each step portion is parallel to the central axis of the inner hole. 4. The blowing board as described in 1 above, wherein: In the fitting portion formed by the convex portion on the ring body side and the concave portion on the plate main body side, a part or all of the longitudinal direction of the fitting surface on the inner hole side is parallel to the central axis of the inner hole. 5. The blowing board as described in 1 above, wherein: In the fitting portion formed by the concave portion on the ring body side and the convex portion on the plate main body side, part or all of the longitudinal direction of the fitting surface on the outer peripheral side is parallel to the central axis of the inner hole. 6. The blowing board as described in any one of 1 to 5 above, wherein: The air-permeable part of the aforementioned ring body is composed of porous refractory. 7. The blowing board as described in any one of 1 to 5 above, wherein: The air-permeable part of the aforementioned ring body is a refractory part provided with one or more through holes. [Effects of Invention]

According to the present invention, in a blower plate with a structure in which a ring body is arranged in the inner hole of the plate main body, the intrusion of molten steel toward the air chamber can be prevented. By this, it is possible to prevent the occurrence of adverse effects on the operation caused by the deterioration of the steel quality due to the stop of the air blowing function and the clogging of the molten steel passage (inner hole).

As shown in Fig. 5, in the conventional air blowing plate 1, the lower end surface of the ring body 3 installed in the inner hole 2d of the plate main body 2 and the upper surface of the plate main body 2 (hereinafter referred to as " "Joint surface") is a plane with substantially no unevenness. The inventors of the present invention found from the observation results of the main metal intrusion product that the main metal intrusion into the gas chamber 4 is mainly generated through this joint surface. The main reasons for this include the inclination at the time of installation of the ring body 3, the uneven thickness of the seam, etc., the accuracy of the ring body 3 and the plate main body 2, and the like. Especially in the case of the structure in which the ring body 3 and the plate body 3 are linearly connected, due to the relative movement or deviation of the two, there is a tendency to generate a gap in the joint between the two, or the mortar at the joint Sometimes it disappears due to partial destruction, etc. Furthermore, by making the ring body 3 and the plate main body 2 linearly contact each other, the resulting gap can easily communicate with the air chamber 4 on the outer peripheral side.

For this reason, in the present invention, as illustrated in Figures 1 to 3, the ring body 3 and the plate main body 2 are not linearly connected, that is, on the lower end surface of the ring body 3. Equipped with a stepped portion 3a, a convex portion 3b, or a concave portion 3c, and the upper surface of the plate body 2 contacting the lower end surface of the ring body 3 is provided with a stepped portion 3a or convex portion 3b or concave portion 3c on the side of the ring body 3 The stepped portion 2a, the recessed portion 2b, or the convex portion 2c that is fitted in parallel is used to fit the lower end surface of the ring body 3 and the upper surface of the plate main body 2 through the joint by using the stepped portion or the concave-convex portion.

Specifically, in the air blowing plate 1 shown in FIG. In the blower plate 1 shown in FIG. 2, the convex portion 3b on the side of the ring body 3 and the concave portion 2b on the side of the plate main body 2 are fitted to form a fitting portion A. As shown in FIG. In the blower plate 1 shown in FIG. 3, the concave portion 3c on the side of the ring body 3 and the convex portion 2c on the side of the plate main body 2 are fitted to form a fitting portion A. In addition, the symbol 7 in FIGS. 1 to 3 and FIG. 5 is a gas introduction path for introducing gas into the gas chamber 4.

In the present invention, the length in the longitudinal direction of the fitting portion A (hereinafter referred to as "fitting length") is set to 2 mm or more. That is, the inventors of the present invention found that in the fitting portion A of the ring body 3 and the plate body 2, in order to maintain the two mechanically fixed to each other, that is, in order to maintain the structure in which they are butted in a mutually fixed manner, a 2 mm or more insert The combined length is necessary. The fitting length here is, for example, as shown in FIG. 4, the length in the longitudinal direction of the fitting portion A except for the thickness of the horizontal seam portion 5 between the lower end surface of the anchor body 3 and the upper surface of the plate body 2 L. As shown in Figures 2 and 3, when the fitting portion A is composed of concave and convex portions, the fitting length exists at two places on the inner hole side and the outer peripheral side. In the present invention, as long as the fitting length of any one of them is 2mm That's all. The upper limit of the fitting length is not particularly limited. For practical purposes, it is necessary to ensure the joint between the ring body and the plate body (for example, a length of about 5 to 10 mm from the upper end of the ring body and the plate body) and the longitudinal direction of the air chamber. Below the length, the longitudinal length of the inner hole of the plate body can be set to be less than the dimension (for example, about 40 mm) of the longitudinal length of the joint portion and the air chamber.

In the present invention, at least the longitudinal joint portion 6 (refer to FIG. 4) of the fitting portion A is inserted with mortar. That is, in the blower plate 1 shown in FIG. 1, the mortar is inserted into the longitudinal joint portion of the fitting portion A formed by the step portion 3a on the side of the ring body 3 and the step portion 2a on the side of the plate main body 2 . 2 and 3, when the fitting portion A is composed of concave and convex portions, the longitudinal seam portion of the fitting portion A exists in two places on the inner hole side and the outer peripheral side. In the present invention, any Just let mortar intervene in the longitudinal seam of one. In this way, the mortar is inserted into the longitudinal seam of the fitting part A, and even if the ring body 3 is slightly inclined with respect to the plate main body 2, at least the longitudinal seam is less likely to generate gaps. Incidentally, in the air blowing plate 1 shown in Figures 1 to 3, mortar is inserted into all the joints of the fitting part.

According to the present invention, with these structures, the ring body 3 and the plate main body 2 are made non-linear, and a contact surface that is not easily affected by the offset when the ring body 3 is installed can be provided, thereby preventing The molten steel in the gas chamber 4 on the outer peripheral side invades.

In addition to the aforementioned factors, the inventors of the present invention have also discovered factors caused by thermal conditions during casting (use). That is, the plate main body 2 is denser than the ring body 3, and is mostly composed of refractories composed of components with high thermal conductivity. There are many surfaces in contact with molten steel during casting, and therefore relatively large thermal expansion occurs. In contrast, the ring body 3 that is continuously cooled by the gas has a lower temperature than the plate main body 2, and even though it has the same thermal expansion characteristics, the thermal expansion of the ring body 3 is smaller than that of the plate main body 2. In this way, a gap may be generated in the joint portion, and the molten steel may invade the gas chamber 4.

For this reason, the present invention is preferably configured such that the plate body 2 having a relatively larger thermal expansion than the ring body 3 is arranged on the inner hole side, and the ring body 3 having a relatively smaller thermal expansion than the plate body 2 is arranged on the outer peripheral side. In this way, the plate main body 2 uses its expansion to compress the ring body 3, thereby compressing the longitudinal joint portion therebetween, and making it less likely to generate a gap. Specifically, as shown in FIG. 1, when the stepped portions are fitted with each other, the stepped portion 3a on the side of the ring body 3 is such that the outer peripheral side of the ring body 3 protrudes downward than the inner hole 2d side of the ring body 3 The stepped portion 2a on the side of the plate main body 2 has a structure in which the inner hole 2d side of the plate main body 2 protrudes upward than the outer peripheral side of the plate main body 2 to include a portion where the two are fitted with each other. In addition, as shown in FIG. 2, the convex portion 3b on the side of the ring body 3 and the concave portion 2b on the side of the plate body 2 are fitted, or the concave portion 3c on the side of the ring body 3 and the convex portion on the side of the plate body 2 as shown in FIG. In the case of 2c fitting, in the radial direction of the inner hole 2d, the plate body 2 will inevitably form a surface closer to the inner hole 2d side than the ring body 3. The plate body 3 uses its expansion to compress the ring body 3, thereby connecting the two The longitudinal seam between the persons is compressed, and it becomes less likely to generate gaps.

Furthermore, it is preferable that a part or all of the surfaces of the longitudinal direction of each step portion 3a, 2a are parallel to the central axis B of the inner hole 2d. Furthermore, in the fitting portion A (see FIG. 2) formed by the convex portion 3b on the side of the ring body 3 and the concave portion 2b on the side of the plate main body 2, part or all of the longitudinal direction of the fitting surface on the side of the inner hole 2d is relatively Preferably, it is parallel to the central axis B of the inner hole 2d. Furthermore, the fitting portion A (see FIG. 3) constituted by the concave portion 3c on the side of the ring body 3 and the convex portion 2c on the side of the plate main body 2 is preferably located on a part or all of the longitudinal direction of the fitting surface on the outer peripheral side. It is parallel to the central axis B of the inner hole 2d. By adopting such a fitting structure, the effect of pressing the ring body 3 in the radial direction of the plate main body 2 can be further improved, and the compression effect of the joints of these parts can be further improved, so that the joints The sealing is stronger.

In the present invention, the gas-permeable part of the ring body 3 can be made of refractory parts, which are composed of porous refractory or dense refractory, and are provided with a surface penetrating from the air chamber 4 on the outer peripheral side to the inner hole 2d One or more through holes in the refractory structure. The so-called porous refractory means that the refractory structure itself has the function of letting gas pass through and even spit out gas; the so-called dense refractory means that the refractory structure itself does not have the function of letting gas pass or even spit out gas.

1: Blow board 2: Board body 2a: step section 2b: recess 2c: Convex 2d: inner hole 3: ring body 3a: step section 3b: Convex 3c: recess 4: air chamber 5: The horizontal seam between the lower end surface of the ring body and the upper surface of the board body 6: The longitudinal seam of the fitting part 7: Gas introduction path A: Fitting part B: The central axis of the inner hole (longitudinal direction)

[Fig. 1] is a cross-sectional view of the main part of an air blowing plate according to an embodiment of the present invention. [Fig. 2] is a cross-sectional view of the main part of an air blowing plate of another embodiment of the present invention. Fig. 3 is a cross-sectional view of the main part of the blower plate of still another embodiment of the present invention. [Fig. 4] is an enlarged view of the fitting part of the air blowing plate of Fig. 1. [Fig. [Figure 5] An example of a conventional air blowing board.

1: Blow board

2: Board body

2a: step section

2d: inner hole

3: ring body

3a: step section

4: air chamber

7: Gas introduction path

A: Fitting part

B: The central axis of the inner hole (longitudinal direction)

Claims (7)

A blower plate, which is attached to the blower plate for sliding nozzles used in continuous casting of steel. Install a ring-shaped part (hereinafter referred to as "ring body") with ventilation function in the inner hole of the main body of the board, The lower end surface of the aforementioned ring body is provided with a stepped portion or a convex portion or a concave portion, The upper surface of the plate main body which is in contact with the lower end surface of the ring body is provided with a stepped portion or a concave portion or a convex portion which can be opposed to and fitted with the stepped portion or the convex portion or the concave portion, The stepped portion, convex portion, or concave portion on the ring body side and the portion where the stepped portion, concave portion or convex portion on the side of the plate body engages each other (hereinafter referred to as the “fitting portion”) in the direction of the center axis of the inner hole (hereinafter (Referred to as the "longitudinal direction") the length is 2mm or more, The mortar is inserted into at least the longitudinal joint part of the aforementioned fitting part. The blowing board as described in claim 1, wherein: The step portion on the ring body side is such that the outer peripheral side of the ring body protrudes downward than the inner hole side of the ring body, The step portion on the side of the plate main body is such that the inner hole side of the plate main body protrudes upward than the outer peripheral side of the plate main body. The blowing board according to claim 1 or 2, wherein: A part or all of the longitudinal surface of each step portion is parallel to the central axis of the inner hole. The blowing board as described in claim 1, wherein: In the fitting portion formed by the convex portion on the ring body side and the concave portion on the plate main body side, part or all of the longitudinal direction of the fitting surface on the inner hole side is parallel to the central axis of the inner hole. The blowing board as described in claim 1, wherein: In the fitting portion formed by the concave portion on the ring body side and the convex portion on the plate main body side, a part or all of the longitudinal direction of the fitting surface on the outer peripheral side is parallel to the central axis of the inner hole. The blowing board according to claim 1 or 2, wherein: The air-permeable part of the aforementioned ring body is composed of porous refractory. The blowing board according to claim 1 or 2, wherein: The air-permeable part of the aforementioned ring body is a refractory part with one or more through holes.

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