SUBMERGED NOZZLE REPLACEMENT APPARATUS

Abstract

 The present invention provides a submerged nozzle replacement apparatus capable of quickly and easily moving a blank plate to a standby position. The submerged nozzle replacement apparatus 1 of the present invention comprises: a pressing section to press a lower surface of a flange portion of a submerged nozzle 200; an introducing section 4 to, when attaching the submerged nozzle 200, guide said submerged nozzle to the pressing section; an ejecting section 5 to, when detaching the submerged nozzle 200 from the pressing section, guide said submerged nozzle to a detaching position; and a holding section 6 that holds a blank plate 300. The holding section 6 is movable between a first position where the blank plate 300 is opposed to the submerged nozzle 200 in a state of being supported by the pressing section, and a second position where the lower surface of the flange portion of the submerged nozzle can be supported by the holding section 6 and the introducing section 4.

Description

TECHNICAL FIELD

[0001] The present invention relates to an immersion or submerged nozzle replacement apparatus mounted to the under side of a molten steel discharge port of a tundish.

BACKGROUND ART

[0002] In continuous casting of steel, molten steel is poured into a mold from a molten steel discharge port provided at the bottom of a tundish via an immersion or submerged nozzle. In such continuous casting of steel, the submerged nozzle is used under severe conditions in which an inner bore thereof is in contact with molten steel being flowing, and an outer surface thereof is in touch with outside air, so that it often receives a damage such as wear, chipping, or fracture. Thus, frequent replacement is required according to the damage.

[0003] For this purpose, a submerged nozzle replacement apparatus as disclosed in, e.g., Patent Document 1, has heretofore been used. In a normal state, such a submerged nozzle replacement apparatus is used to replace a used submerged nozzle with a new submerged nozzle. However, in order to stop the outflow of molten steel in an emergency, it can be used to replace a submerged nozzle with a closing refractory, i.e., a blank plate.

[0004] During continuous casting, the blank plate is kept in a standby position on the rear side of a submerged nozzle in use. For this reason, in the conventional submerged nozzle replacement apparatus, after replacing the used submerged nozzle with a new submerged nozzle, a worker has performed an operation of moving the blank plate to the standby position.

[0005] The movement of the blank plate to the standby position needs to be completed quickly and easily. However, the conventional submerged nozzle replacement apparatus has not been able to fulfill such a need.

CITATION LIST

[Patent Document]

[0006] Patent Document 1: JP 3232294 B2

SUMMARY OF INVENTION

[Technical Problem]

[0007] A technical problem to be solved by the present invention is to provide a submerged nozzle replacement apparatus capable of quickly and easily moving a blank plate to a standby position.

[Solution to Technical Problem]

[0008] According to one aspect of the present invention, the following submerged nozzle replacement apparatus is provided.

[0009] A submerged nozzle replacement apparatus mounted to an under side of a molten steel discharge port of a tundish, the submerged nozzle replacement apparatus comprising: a pressing section to press a lower surface of a flange portion of a submerged nozzle; an introducing section to, when attaching the submerged nozzle, guide said submerged nozzle to the pressing section; an ejecting section to, when detaching the submerged nozzle from the pressing section, guide said submerged nozzle to a detaching position; and a holding section that holds a blank plate, wherein the holding section is movable between a first position where the blank plate is opposed to the submerged nozzle in a state of being supported by the pressing section, and a second position where the lower surface of the flange portion of the submerged nozzle can be supported by the holding section and the introducing section.

[Advantageous Effects of Invention]

[0010] The submerged nozzle replacement apparatus according to the present invention is capable of quickly and easily moving the blank plate to the standby position.

BRIEF DESCRIPTION OF DRAWINGS

[0011] 

FIG. 1A is a perspective view of a submerged nozzle replacement apparatus according to one embodiment of the present invention as viewed obliquely upwardly from a rear and lower side of the submerged nozzle replacement apparatus (in a state in which a holding section is in a first position).

FIG. 1B is a perspective view of the submerged nozzle replacement apparatus according to the one embodiment of the present invention as viewed obliquely downwardly from a front and upper side of the submerged nozzle replacement apparatus.

FIG. 2 is a sectional view of a relevant part of the submerged nozzle replacement apparatus in FIGS. 1A and 1B, in a state in which the submerged nozzle replacement apparatus is mounted to a tundish (enlarged sectional view taken along the line A-A of FIG. 1B).

FIG. 3 is a perspective view of the submerged nozzle replacement apparatus according to the one embodiment of the present invention as viewed obliquely upwardly from a rear and lower side of the submerged nozzle replacement apparatus (in a state in which the holding section is in a second position).

FIG. 4 is a perspective view of the submerged nozzle replacement apparatus according to the one embodiment of the present invention as viewed obliquely upwardly from the rear and lower side of the submerged nozzle replacement apparatus (in a state in which a new submerged nozzle is placed on the rear side of a used submerged nozzle).

FIG. 5 is a view when FIG. 4 is viewed in a direction of an arrowed line B in FIG. 4.

FIG. 6 is a view showing a state in which a pusher is rotated downwardly from an upper limit position in FIG. 5.

FIG. 7 is an exploded perspective view of the holding section and ancillary members thereof.

FIG. 8 is a perspective view of the blank plate as viewed obliquely upwardly from a lower side of the blank plate.

FIG. 9 is a view when FIG. 1A is viewed in a direction of an arrowed line B in FIG. 1A.

FIG. 10 is a perspective view showing a state in which the holding section is being moved.

FIG. 11 is a bottom view of the submerged nozzle replacement apparatus in FIG. 1A.

FIG. 12 is a perspective view showing a state after a submerged nozzle in use is replaced with the blank plate.

DESCRIPTION OF EMBODIMENTS

[0012] FIG. 1A and FIG. 1B show a submerged nozzle replacement apparatus according to one embodiment of the present invention, in the form of a perspective view as viewed obliquely upwardly from a front and lower side thereof and a perspective view as viewed obliquely downwardly from a rear and upper side thereof, respectively. FIG. 2 shows a relevant part of the submerged nozzle replacement apparatus in a state of being mounted to a tundish, in the form of an enlarged sectional view taken along the line A-A of FIG. 1B. It should be noted that, as used in this specification, the terms "front side" and "rear side" are based on a moving direction of a submerged nozzle when replacing the submerged nozzle with a new one in the submerged nozzle replacement apparatus. More specifically, the "front side" refers to a front side (leading side) in the moving direction of the submerged nozzle, and the "rear side" refers to a rear side (trailing side) in the moving direction of the submerged nozzle.

[0013] As shown in FIG. 2, the submerged nozzle replacement apparatus 1 is mounted to the under side of a molten steel discharge port 101 of a tundish 100. Specifically, a frame 2 of the submerged nozzle replacement apparatus 1 is fixed to a shell 102 at the bottom of the tundish 100 by bolts or the like.

[0014] Referring to FIGS. 1A and 1B together with FIG. 2, the submerged nozzle replacement apparatus 1 comprises: a pressing section 3 to press a lower surface of a flange portion 201 of a submerged nozzle 200; an introducing section 4 to, when attaching the submerged nozzle 200, guide said submerged nozzle to the pressing section 3; an ejecting section 5 to, when detaching the submerged nozzle 200 from the pressing section 3, guiding the submerged nozzle 200 to a detaching position; and a holding section 6 to hold a blank plate 300. The submerged nozzle replacement apparatus 1 also comprises a support section 7 to support a tundish nozzle 400. The tundish nozzle 400 has a flange portion 401 and a tubular portion 402. The tubular portion 402 of the tundish nozzle 400 is inserted into the molten steel discharge port 101 of the tundish 100. Further, a lower surface of the flange portion 401 of the tundish nozzle 400 is joined to an upper surface of the flange portion 201 of the submerged nozzle 200. In this way, molten steel in the tundish 100 is transferred to a mold via the tundish nozzle 400 and the submerged nozzle 200.

[0015] As mentioned above, in a normal state, the submerged nozzle replacement apparatus 1 is used to replace a used submerged nozzle with a new submerged nozzle. However, in order to stop the outflow of molten steel in an emergency, it can be used to replace a submerged nozzle with the blank plate. For this purpose, during continuous casting, the blank plate 300 is kept in a standby position on the rear side of the submerged nozzle 200 in use, as shown in FIG. 1A. More specifically, during continuous casting, the holding section 6 that holds the blank plate 300 is in a first position where the blank plate 300 is opposed to the submerged nozzle 200 in use, i.e., in a state of being supported by the pressing section 3.

[0016] On the other hand, when a used submerged nozzle is replaced with a new submerged nozzle, the blank plate 300 is retracted to a retracted position where the blank plate 300 does not hinder the replacement between the submerged nozzles, as shown in FIG. 3. More specifically, when replacing a used submerged nozzle with a new submerged nozzle, the holding section 6 that holds the blank plate 300 is moved from the first position illustrated in FIG. 1A to a second position illustrated in FIG. 3. Then, a new submerged nozzle 200' is placed on the rear side of the used submerged nozzle 200, as shown in FIG.4.

[0017] FIG. 5 is a view when FIG. 4 is viewed in a direction of an arrowed line B in FIG. 4. As is clearly appearing in FIG. 5, the new submerged nozzle 200' is placed on the rear side of the used submerged nozzle 200, in a state in which a lower surface of a flange portion 201' of the new submerged nozzle 200' is supported by the holding section 6 lying in the second position and the introducing section 4. In this embodiment, the introducing section 4 is composed of a guide rail to support one side of the lower surface of the flange portion 201' of the new submerged nozzle 200', and is configured to, when attaching the new submerged nozzle 200', guide said new submerged nozzle 200' to the pressing section 3, in cooperation with the holding section 6 lying in the second position.

[0018] Further, in this embodiment, the pressing section 3 is composed of a plurality of keyboard-shaped pressing members 31 to press the submerged nozzle 200 against the tundish nozzle 400, as appearing in FIG. 2. More specifically, the plurality of pressing members 31 are configured to support the lower surface of the flange portion 201 of the submerged nozzle 200. Each of the pressing members 31 is configured to press the submerged nozzle 200 against the tundish nozzle 400 by an elastic force of a coil spring 81 as an elastic body housed in a spring box 8.

[0019] Further, in this embodiment, as appearing in FIG. 1B, the ejecting section 5 is composed of a pair of guide rails capable of supporting one side and the other side of the lower surface of the flange portion 201 of the submerged nozzle 200, respectively, and is configured to, when detaching the submerged nozzle 200 from the pressing section 3, guide said submerged nozzle 200 to the detaching position.

[0020] The submerged nozzle replacement apparatus 1 comprises: a pusher 9 as a pushing tool to push the new submerged nozzle 200' placed on the rear side of the used submerged nozzle 200, as shown in FIG. 4, and move the new submerged nozzle 200' forwardly in the direction B in FIG. 4; and a hydraulic cylinder 10 as a drive device to move the pusher 9 forwardly in the direction B or backwardly in a direction opposite to the direction B. The hydraulic cylinder 10 is fixed to a portion of the frame 2 on the side of the introducing section 4. A base end 91 of the pusher 9 is connected to a rotary member configured to rotate along with forward and backward movements of a cylinder rod of the hydraulic cylinder 10, and is configured to be swung downwardly and upwardly along with the forward and backward movements of the cylinder rod of the hydraulic cylinder 10. Specifically, as shown in FIG. 5, when the cylinder rod of the hydraulic cylinder 10 is in a backward limit position, the pusher 9 is swung upwardly to a position above an upper surface of the flange portion 201' of the new submerged nozzle 200'. Then, when the cylinder rod of the hydraulic cylinder 10 is slightly moved forwardly, the pusher 9 is swung downwardly to a position overlapping the flange portion 201' of the new submerged nozzle 200', as shown in FIG. 6. In this state, the cylinder rod of the hydraulic cylinder 10 can be further moved forwardly to allow the pusher 9 to push and move the flange portion 201' of the new submerged nozzle 200' forwardly in the direction B in FIG. 4. After completion of the above operation, when the cylinder rod of the hydraulic cylinder 10 is returned to the backward limit position, the pusher 9 is returned to the original position in FIG. 5.

[0021] As just described, when the cylinder rod of the hydraulic cylinder 10 is in the backward limit position, the pusher 9 is in the position illustrated in FIG. 5. Thus, in an operation of placing the new submerged nozzle 200' on the rear side of the used submerged nozzle 200, the pusher 9 does not hinder the operation. Then, after placing the new submerged nozzle 200' on the rear side of the used submerged nozzle 200, the cylinder rod of the hydraulic cylinder 10 is moved forwardly, so that the new submerged nozzle 200' is moved from the introducing section 4 to the pressing section 3, while pushing the used submerged nozzle 200. Accordingly, the used submerged nozzle 200 is moved from the pressing section 3 to the ejecting section 5. In this way, the used submerged nozzle 200 is replaced with the new submerged nozzle 200'.

[0022] In this embodiment, the pusher 9 is configured to be automatically swung downwardly and upwardly along with the forward and backward movements of the cylinder rod of the hydraulic cylinder 10. Alternatively, the pusher 9 may be configured to be manually swung downwardly and upwardly by using, e.g., a hinge mechanism.

[0023] Next, the holding section 6 will be described in detail. FIG. 7 illustrates a holding section 6 and its accessory member in an exploded perspective view.

[0024] As mentioned above, the holding section 6 is movable between the first position illustrated in FIG. 1A and the second position illustrated in FIG. 3. Specifically, in this embodiment, the holding section 6 is swung about a hinge pin 11 as a swing center, so thar it is moved between the first position and the second position. More specifically, in this embodiment, the holding section 6 has an approximately rectangular shape in plan view, and comprises a hinge portion 61 formed at one corner thereof. The hinge portion 61 is gripped by a hinge gripper portion 121 of a hinge bracket 12, and the hinge pin 11 penetrates through a through-hole 61a of the hinge portion 61 and a through-hole 121a of the hinge gripper portion 121. Accordingly, the holding section 6 is swingable about the hinge pin 11 as a swing center.

[0025] As appearing in FIGS. 1A and 3, the hinge bracket 12 is attached to a rear side of the spring box 8 such that the hinge gripper portion 121 is located adjacent to the pressing section 3 illustrated in FIG. 2. Accordingly, the hinge pin 11 is positioned on the rear side of and adjacent to the pressing section 3. That is, in this embodiment, the holding section 6 is swung about the hinge pin 11 as a swing center, which is positioned on the rear side of and adjacent to the pressing section 3, so that it is moved between the first position and the second position.

[0026] In this embodiment, the hinge gripper portion 121 comprises an upper plate 121c and a lower plate 121b which is larger than the upper plate 121c. Since the lower plate 121b is a member to support a lower surface of the holding section 6, enlarging the lower plate 121b makes it possible to suppress downward bending of the holding section 6 that holds the blank plate 300, when said holding section 6 is swung, and thus accurately move the holding section 6 between the first position and the second position.

[0027] Further, in this embodiment, a side surface portion 62 of the holding section 6 opposed to the introducing section 4 when the holding section 6 is in the first position, and a side surface portion 63 of the holding section 6 opposed to the blank plate 300 when the holding section 6 is in the second position, are provided with a magnet 62a and a magnet 63a, respectively. A heat-resistant magnet is used as each of the magnets 62a, 63a. The magnet 62a, which appears in FIG. 3, is opposed to the introducing section 4 when the holding section 6 is in the first position. At this time, the magnet 62a fulfills a function of positioning the holding section 6 to prevent the holding section 6 from unexpectedly moving to the second position. The magnet 63a, which appears in FIGS. 1A and 7, is opposed to the hinge bracket 12 when the holding section 6 is in the second position. At this time, the magnet 63a fulfills a function of positioning the holding section 6 to prevent the holding section 6 from unexpectedly moving to the first position.

[0028] FIG. 8 is a perspective view of the blank plate 300 to be held by the holding section 8 as viewed obliquely upwardly from a lower side of the blank plate 300. The blank plate 300 is replaced with a submerged nozzle in use, i.e., the submerged nozzle 200 in a state of being supported by the pressing section 3, in order to stop the outflow of molten steel in an emergency. For this purpose, the blank plate 300 has substantially the same outer shape as that of the flange portion 201 of the submerged nozzle 200.

[0029] As appearing in FIG. 8, a protrusion 301 is provided on a lower surface of the blank plate 300. On the other hand, as appearing in FIG. 7, a cutout 64 having an opening 641 at one end thereof is provided in the holding section 6 to hold the blank plate 300. The blank plate 300 is held by the holding section 6, in a state in which the protrusion 301 is inserted from the side of the one end of the cutout 64.

[0030] Here, the opening 641 of the holding section 6 faces the front side, i.e., the pressing section 3, when the holding section 6 is in the first position, as shown in FIG. 1A. The blank plate 300 is pushed forwardly toward the pressing section 3 in an emergency. In this process, the protrusion 301 of the blank plate 300 is pushed out through the opening 641of the cutout 64 of the holding section 6. Thus, the blank plate 300 can be moved toward the pressing section 3. Further, in this process, the blank plate 300 is moved while the protrusion 301 on the lower surface thereof is guided by the cutout 64. This makes it possible to smoothly move the blank plate 300 toward the pressing section 3.

[0031] The length L1 of the blank plate 300 in the moving direction thereof is less than the length L2 of the holding section 6. Thus, when the holding section 6 is in the second position, as illustrated in FIG. 4, the lower surface of the flange portion 201' of the new submerged nozzle 200' is supported by the holding section 6 and the introducing section 4, as appearing in FIG. 5. As just described, in this embodiment, the holding section 6 comprises a first holding portion 6A to hold the blank plate 300, and a second holding portion 6B capable of supporting the lower surface of the flange portion 201' of the new submerged nozzle 200'. In this embodiment, the first holding sub-section 6A and the second holding sub-section 6B lie in the same plane, and the second holding sub-section 6B is located on the front side of the first holding sub-section 6A in the moving direction of the blank plate 300. Since the first holding sub-section 6A and the second holding sub-section 6B lie in the same plane, and the height level of the first holding sub-section 6A and the second holding sub-section 6B is substantially the same as the height level of the pressing section 3, the movement of the blank plate 300 toward the front side, i.e., toward the pressing section 3 is not hindered.

[0032] On the other hand, the width W 1 of the blank plate 300 in a direction orthogonal to the moving direction is greater than the width W2 of the holding section 6. Thus, when the holding section 6 is in the first position, as illustrated in FIG. 1A, a part of the lower surface of the blank plate 300 on one side in the width direction is supported by the introducing section 4, as appearing in FIG. 9 which is a view when FIG. 1A is viewed in a direction of an arrowed line B in FIG. 1A.

[0033] With a view to preventing the blank plate 300 held by the first holding sub-section 6A from unexpectedly moving toward the second holding sub-section 6 B, the first holding section 6A may be provided with positioning means, such as a magnet, for positioning the blank plate 300.

[0034] Next, the operation of the submerged nozzle replacement apparatus 1, in particular, the operation of the holding section 6 and the blank plate 300, will be described.

[0035] As mentioned above, during continuous casting, the holding section 6 is in the first position as shown in FIG. 1A. Then when the used submerged nozzle 200 is replaced with the new submerged nozzle 200', the holding section 6 is moved to the second position as shown in FIG. 3, and the new submerged nozzle 200' is placed on the rear side of the used submerged nozzle 200 as shown in FIG. 4. At this time, the lower surface of the flange portion 201' of the new submerged nozzle 200' is supported by the second holding sub-section 6B of the holding section 6 lying in the second position and the introducing section 4, as appearing in FIG. 5. Subsequently, the cylinder rod of the hydraulic cylinder 10 is moved forwardly as mentioned above, so that the new submerged nozzle 200' is moved from the introducing section 4 to the pressing section 3 while pushing the used submerged nozzle 200. Accordingly, the used submerged nozzle 200 is moved from the pressing section 3 to the ejecting section 5. When the holding section 6 is in the second position, the second holding sub-section 6B is positioned with respect to the pressing section 3 such that it is continuous with the pressing section 3. Further, the introducing section 4 is also positioned with respect to the pressing section 3 such that it is continuous with the pressing section 3. This makes it possible to smoothly move the new submerged nozzle 200' from the introducing section 4 to the pressing section 3 while pushing the used submerged nozzle 200.

[0036] In this way, the used submerged nozzle 200 is replaced with the new submerged nozzle 200'. Generally, such a submerged nozzle replacement operation is performed after the continuous casting is interrupted, e.g., by fitting a well-known stopper into the tundish nozzle 400. However, this submerged nozzle replacement operation may be performed during continuous casting.

[0037] After completion of the submerged nozzle replacement operation, the holding section 6 is moved from the second position illustrated in FIG. 3 to the first position illustrated in FIG. 1A. As mentioned above, in this embodiment, the holding section 6 is moved between the first position and the second position by being swung about the hinge pin 11 as a swing center. FIG. 10 shows a state in which the holding section is being moved.

[0038] In a state after moving the holding section 6 to the first position, the blank plate 300 is held by the first holding sub-section 6A of the holding section 6 as appearing in FIG. 9, and a part of the lower surface of the blank plate 300 on one side in the width direction is supported by the introducing section 4. At this time, the blank plate 300 is opposed to the submerged nozzle 200 in use, i.e., in a state of being supported by the pressing section 3, wherein a gap S is present between the flange portion 201 of the submerged nozzle 200 in use and the blank plate 300, as appearing in FIG. 11 which is a bottom view of the submerged nozzle replacement apparatus in FIG. 1A. The presence of the gap S makes it possible to reduce the possibility that the submerged nozzle 200 and the blank plate 300 are damaged due to collision of the blank plate 300 with the submerged nozzle 200 when the holding section 6 is moved to the first position.

[0039] When stopping the outflow of molten steel in an emergency, the cylinder rod of the hydraulic cylinder 10 is moved forwardly in the same manner as the submerged nozzle replacement operation. Thus, the blank plate 300 is moved from the introducing section 4 to the pressing section 3 while pressing the submerged nozzle 200 in use, i.e., in a state of being supported by the pressing section 3, and accordingly the submerged nozzle 200 in use is moved from the pressing section 3 to the ejecting section 5. As a result, the submerged nozzle 200 in use is replaced with the blank plate 300 as shown in FIG. 12 so as to stop the outflow of molten steel.

[0040] The plurality of pressing members 31 constituting the pressing section 3 appear in FIG. 12. In FIG. 12, the blank plate 300 is pressed against the tundish nozzle 400 by the plurality of pressing members 31, in the same manner as that for the submerged nozzle 200 in use.

[0041] As above, in this embodiment, the holding section 6 is movable between the first position and the second position. Here, the first position is a standby position of the blank plate 300, and the second position is a retracted position of the blank plate 300. That is, according to this embodiment, the blank plate 300 can be moved between the standby position and the retracted position quickly and easily by moving the holding section 6 between the first position and the second position.

[0042] Further, in this embodiment, in a state in which the holding section 6 is in the second position that is the retracted position of the blank plate 300, the second holding sub-section 6 B of the holding section 6 supports the lower surface of the flange portion 201' of the new submerged nozzle 200 ', in cooperation with the introducing section 4 composed of a single guide rail, and guides the submerged nozzle 200' to the pressing section 3. In a conventional submerged nozzle replacement apparatus, a component equivalent to the introducing section 4 in this embodiment is composed of a pair of guide rails (two guide rails), as disclosed in, e.g., the Patent Document 1. Differently, in this embodiment, since the second holding sub-section 6B of the holding section 6 functions as a guide rail, as mentioned above, the introducing section 4 can be composed of only one guide rail. This makes it possible to achieve device compactification along with the advantage that a swing trajectory of the holding section 6 becomes smaller.

[0043] Further, the smaller swing trajectory of the holding section 6 also contributes to quick and easy movement of the blank plate 300 between the standby position and the retracted position.

[0044] Further, since the holding section 6 can be placed in the second position during the submerged nozzle replacement operation, device compactification can be promoted as compared to, e.g., a case where a blank plate holding section is separately provided outside the introducing section 4. Thus, the submerged nozzle replacement apparatus can be installed even if an installation location of the tundish has a relatively narrow space.

[0045] In the above embodiment, the movement of the holding section 6 between the first position and the second position is performed by "swing motion". Alternatively, it may be performed by "translational motion". However, from a viewpoint of making it easy to avoid interference with other components constituting the submerged nozzle replacement apparatus, "swing motion" is preferable. Further, in case of "swing motion", it is preferable that the swing center thereof is set at a position adjacent to the pressing section 3, from a viewpoint of making the swing trajectory of the holding section 6 smaller.

[0046] In the above embodiment, the holding section 6 is positioned in the first or second position by utilizing a magnetic force of a magnet. Alternatively, a mechanical fitting-engagement force or the like may be utilized. Further, with a view to allowing the holding section 6 to be accurately moved to the first position when moving the holding section 6 to the first position, a taper fitting structure 13 may be provided in which the holding section 6 and the introducing section 4 are provided, respectively, with two inclined surfaces, and the holding section 6 is guided to a fixed position relative to the introducing section 4, under contact between the two inclined surfaces, as hypothetically illustrated in FIG. 9.

[0047] In the above embodiment, the submerged nozzle replacement apparatus 1 is configured to replace the submerged nozzle 200 of a type in which it is directly joined to the tundish nozzle 400. Alternatively, it may be configured to replace a submerged nozzle of a type in which it is joined to a lower nozzle of a well-known sliding nozzle device which is interposed between the tundish nozzle and the submerged nozzle.

LIST OF REFERENCE SIGNS

[0048] 

1: submerged nozzle replacement apparatus

2: frame

3: pressing section

31: pressing member

4: introducing section

5: ejecting section

6: holding section

6A: first holding sub-section

6B: second holding sub-section

61: hinge portion

61a: through-hole

62, 63: side surface portion

62a, 63a: magnet

64: cutout

641: opening

7: support section

8: spring box

81: coil spring (elastic body)

9: pusher (pressing tool)

91: base end of pusher

10: hydraulic cylinder (drive device)

11: hinge pin

12: hinge bracket

121: gripper portion

121a: through-hole

121b: lower plate

121c: upper plate

13: taper fitting structure

100: tundish

101: molten steel discharge port

102: shell (bottom of tundish)

200: submerged nozzle (in-use or used submerged nozzle)

200': submerged nozzle (new submerged nozzle)

201, 201': flange portion

300: blank plate

301: protrusion

400: tundish nozzle

401: flange portion

402: tubular portion

S: gap

Claims

1. A submerged nozzle replacement apparatus mounted to an under side of a molten steel discharge port of a tundish, the submerged nozzle replacement apparatus comprising:

a pressing section to press a lower surface of a flange portion of a submerged nozzle;

an introducing section to, when attaching the submerged nozzle, guide said submerged nozzle to the pressing section;

an ejecting section to, when detaching the submerged nozzle from the pressing section, guide said submerged nozzle to a detaching position; and

a holding section that holds a blank plate,

wherein the holding section is movable between a first position where the blank plate is opposed to the submerged nozzle in a state of being supported by the pressing section, and a second position where the lower surface of the flange portion of the submerged nozzle can be supported by the holding section and the introducing section.

2. The submerged nozzle replacement apparatus as claimed in claim 1, wherein the holding section comprises a first holding sub-section that holds the blank plate, and a second holding sub-section capable of supporting the lower surface of the flange portion of the submerged nozzle.

3. The submerged nozzle replacement apparatus as claimed in claim 1 or 2, wherein when the holding section is in the first position, a gap is present between the immersion nozzle and the blank plate.

Drawing