INSTALLATION STRUCTURE FOR NOZZLE/PLUG SEATING BLOCK

Abstract

Provided is a seating block installation structure capable of preventing the occurrence of a gap between a nozzle or plug installed in a bottom portion of a molten metal vessel and a plate or the like located on the lower side of the nozzle or plug, and a gap between the nozzle or plug and a seating block located on the upper side of or on the outer peripheral side of the nozzle or plug. In the seating block installation structure, a seating block disposed to surround a nozzle for discharging therethrough molten metal downwardly from the bottom portion of the molten metal vessel or a plug is fixed to a shell of the bottom portion of the molten metal vessel by a connecting member.

Claims

1. A seating block installation structure for a molten metal vessel comprising a shell with a bottom portion provided with a nozzle for discharging therethrough molten metal downwardly, or a plug, the seating block installation structure comprising: a seating block disposed to surround the nozzle or the nozzle or the plug; a connecting member installed to an inner side of the shell and configured to fix the seating block to the inner side, so as to prevent the searing block from being displaced in an inward direction of the molten metal vessel; wherein the connecting member is composed of a plurality of independent members configured to connect between the seating block and the shell, in a manner allowing assembling and disassembling by means of one or more members selected from the group consisting of a thread engagement structure, a hooking structure, a fitting structure, a sliding structure, and a bayonet structure.

2. The seating block installation structure as claimed in claim 1, wherein a joined portion of the connecting member to the shell has a contact structure between the connecting member and an outer surface of the shell defining a periphery of an opening of a through-hole penetrating through the shell.

3. The seating block installation structure as claimed in claim 1, wherein a contact portion of the connecting member with the seating block is at least partly in contact with the seating block through one selected from the group consisting of a metal plate, a metal casing, and a sheet consisting mainly of an inorganic material or carbon.

4. The seating block installation structure as claimed in claim 1, wherein a joining portion of the connecting member exists in a manner distributed at least two positions equally dividing an outer periphery of the seating block.

5. The seating block installation structure as claimed in claim 1, which is configured such that at least a part of the connecting member is covered so as not to be exposed to outside.

6. The seating block installation structure as claimed in claim 1, which is configured such that an unshaped refractory material is provided in at least a part of a region on an upper or outer peripheral side of the connecting member.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0031] FIG. 1 is a vertical sectional view schematically showing a seating block installation structure according to a first embodiment of the present invention.

[0032] FIG. 2 is a vertical sectional view schematically showing a seating block installation structure according to a second embodiment of the present invention.

[0033] FIG. 3 is a vertical sectional view schematically showing a seating block installation structure according to a third embodiment of the present invention.

[0034] FIG. 4 is a vertical sectional view schematically showing one example of a modification of the seating block installation structure according to the third embodiment.

[0035] FIG. 5A is a vertical sectional view schematically showing a seating block installation structure according to a fourth embodiment of the present invention.

[0036] FIG. 5B is a vertical sectional view schematically and enlargedly showing one example of a modification of an area A in FIG. 5A.

[0037] FIG. 6A is a top plan view schematically showing a seating block installation structure according to a fifth embodiment of the present invention.

[0038] FIG. 6B is a vertical sectional view schematically showing the seating block installation structure in FIG. 6A.

[0039] FIG. 7A is a top plan view schematically showing one example of a modification of the seating block installation structure according to the fifth embodiment.

[0040] FIG. 7B is a vertical sectional view schematically showing the modification in FIG. 7A.

[0041] FIG. 8A is a top plan view schematically showing another example of the modification of the seating block installation structure according to the fifth embodiment.

[0042] FIG. 8B is a vertical sectional view schematically showing the modification in FIG. 8A.

[0043] FIG. 9A is a top plan view schematically showing yet another example of the modification of the seating block installation structure according to the fifth embodiment.

[0044] FIG. 9B is a vertical sectional view schematically showing the modification in FIG. 9A.

[0045] FIG. 10 is a vertical sectional view schematically showing still another example of the modification of the seating block installation structure according to the fifth embodiment.

[0046] FIG. 11 is a top plan view schematically showing yet still another example of the modification of the seating block installation structure according to the fifth embodiment.

[0047] FIG. 12 is a vertical sectional view schematically showing a substantial part of another further example of the modification of the seating block installation structure according to the fifth embodiment.

[0048] FIG. 13 is a top plan view schematically showing one example of installation positions of connecting members.

[0049] FIG. 14 is a top plan view schematically showing another example of the installation positions of the connecting members.

[0050] FIG. 15 is a top plan view schematically showing yet another example of the installation positions of the connecting members.

[0051] FIG. 16 is a top plan view schematically showing still another example of the installation positions of the connecting members.

[0052] FIG. 17 is a vertical sectional view schematically showing a seating block installation structure in a state in which a conventional problem occurs, by taking an upper nozzle as an example.

DESCRIPTION OF EMBODIMENTS

[0053] With reference to the drawings, the present invention will now be described based on various embodiments thereof.

[0054] A seating block installation structure according to a first embodiment of the present invention will be described with reference to FIG. 1.

[0055] In the first embodiment, a seating block 2 has a horizontally protruding portion at a lower end thereof, wherein the protruding portion is formed with a through-hole extending vertically. Further, a shell 4 of a bottom portion of a molten metal vessel has an internally threaded hole (hereinafter referred to as “screw hole”) at a position corresponding to the through-hole. The seating block 2 is fixed to the shell 4 by a connecting member (bolt) 3 having an externally threaded structure, in other words, screwed structure, conforming to the through-hold of the seating block 2 and the screw hole of the shell 4.

[0056] A seating block installation structure according to a second embodiment of the present invention will be described with reference to FIG. 2.

[0057] In the second embodiment, a seating block 2 has a downwardly expanding portion at a lower end thereof. A first connecting member 3 made of metal (a metal plate or metal casing 12) formed with a through-hole extending vertically is installed to constrain (hook) the expanding portion of the seating block 2 downwardly. Further, a shell 4 of a bottom portion of a molten metal vessel has a screw (internally threaded) hole at a position corresponding to the through-hole. The seating block 2 is fixed to the shell 4 by a second connecting member (bolt) 3 having an externally threaded structure conforming to the through-hold of the first connecting member 3 (the metal plate or metal casing 12) and the screw hole of the shell 4.

[0058] Further, in the second embodiment, after installation and fixing of the seating block, an unshaped refractory material 11 is formed on an upper and/or outer peripheral sides of the first and second connecting members 3.

[0059] A seating block installation structure according to a third embodiment of the present invention will be described with reference to FIG. 3.

[0060] The seating block installation structure according to the third embodiment is based on the seating block installation structure according to the first embodiment, and additionally configured such that a metal plate or sheet 12, or a sheet 13 consisting mainly of an inorganic material or carbon, is installed between the connecting member 3 and the seating block 2, or between the connecting member 3 and each of the seating block 2 and the shell 4, wherein the seating block 2 and the shell 4 are fixed together by the connecting member 3 through the metal plate or sheet 12 or the sheet 13.

[0061] The metal plate or sheet 12 or the sheet 13 consisting mainly of an inorganic material or carbon functions to relax local stress concentration or the like in a contact region of the seating block 2 with the connecting member 3 or the shell 4, thereby preventing breaking of the seating block 2.

[0062] A material and the like of the metal plate or sheet 12 may be appropriately selected depending on the temperature of the metal plate or sheet 12 during casting operation. In a case where the metal plate or sheet 12 is used in a molten steel or molten iron vessel, it may be made of commonly-used iron or stainless steel.

[0063] A material and the like of the sheet 13 consisting mainly of an inorganic material or carbon may also be appropriately selected depending on the temperature of the sheet 13 during casting operation. In a case where the sheet 13 is used in a molten steel or molten iron vessel, it may be made of an inorganic material such as commonly-used “alkaline earth silicate fiber (AES)” or so-called “RCF (refractory ceramic fiber)”, or a material consisting mainly of carbon such as graphite or carbon-based fibers.

[0064] The metal plate or sheet 12 or the sheet 13 consisting mainly of an inorganic material or carbon may be used in such a manner that it surrounds a part of the seating block, or may be used in such a manner that it is sandwiched and interposed between the seating block and the connecting member or the shell, like a washer. As one modification, as shown in FIG. 4, the seating block 2 may be provided with a metal casing 12 which covers a relatively wide region of an outer peripheral surface of the seating block 2 and includes a contact portion with the connecting member 3, wherein the contact portion (lower end) of the metal casing 12 may be clamped by the connecting member 3.

[0065] A seating block installation structure according to a fourth embodiment of the present invention will be described with reference to FIGS. 5A and 5B.

[0066] The seating block installation structure according to the fourth embodiment is based on the seating block installation structure according to the first embodiment, and additionally configured such that a cover member 14 is provided above a region corresponding to a screw head of the connecting member 3 to prevent at least a part of the screw head from being exposed to the outside.

[0067] In the fourth embodiment, after installation and fixing of the seating block, an unshaped refractory material may be provided on an upper and/or outer peripheral sides of a joined portion of the seating block 2 on site, in the same manner as that in the second embodiment illustrated in FIG. 2. This is advantageous in allowing a refractory layer of the bottom portion of the molten metal vessel to be formed on an upper and/or outer peripheral sides of the seating block 2, without any space therebetween.

[0068] Particularly in the case where the unshaped refractory material is provided as mentioned above, the unshaped refractory material is directly and tightly filled and solidified in a region in which the connecting member 3 such as the screw head is supported and to be manipulated, leading to difficulty in disassembling. A cover such as the cover member 14 is provided to prevent such a situation. In the fourth embodiment, as shown in FIG. 5B, the seating block 2 may have a concave portion formed at an upper end of the through-hole penetrating through the seating block 2 and receiving therein the connecting member 3, to surround the entire screw head of the connecting member.

[0069] A seating block installation structure according to a fifth embodiment of the present invention will be described with reference to FIG. 6A to FIG. 12.

[0070] In the fifth embodiment, a cross-sectionally square-shaped seating block 2 has a portion expanding obliquely downwardly at least a part of a lower end thereof, and a connecting member 3 formed to have a surface conforming to an outer shape of the expanding portion of the seating block 2 is installed to a shell 4 of a bottom portion of a molten metal vessel in the form of a single piece or divided pieces arranged at a plurality of positions, such that at least a part of the seating block 2 is attached between the connecting member 3 and the shell 4 in a close contact manner, wherein a space defined between the connecting member 3 and the shell 4 is opened at least one direction along a region thereof corresponding to an outer periphery of the seating block 2. That is, in the fifth embodiment, the expanding portion of the seating block 2 is slidingly fitted into the space between the connecting member 3 and the shell 4, thereby fixing the seating block 2 to the shell 4.

[0071] A joined portion of the connecting member 3 to the shell 4 may be one or more appropriately selected from the group consisting of a welded structure (FIGS. 6A and 6B), a thread engagement structure, in other words, screwed structure (FIGS. 7A, 7B, 8A, 8B, 9A and 9B), and a contact structure between the connecting member 3 and an outer surface of the shell 4 defining the periphery of an opening of a through-hole penetrating through the shell 4 (i.e., a contact structure between the outer surface of the shell 4 and the connecting member 3 such as a rivet or a bolt (in a set of bolt and nut) inserted in a through-hole penetrating between the outer surface of the molten metal vessel defined by the shell 4 and an inner surface of the shell 4, FIG. 10).

[0072] It should be understood that this structure using a combination of a through-hole and a rivet or a set of bolt and nut may be applied to not only the fifth embodiment but also the first to fourth embodiments

[0073] The seating block may be provided with a metal plate or casing or a sheet consisting mainly of an inorganic material or carbon. In this case, as shown in FIGS. 7A and 7B, a wedge 3W may be attached to the expanding portion of the seating block 3 at a position between the connecting member 3 and the expanding portion to strengthen the fixing.

[0074] As one modification of the fifth embodiment, the seating block 2 may be formed in a cylindrical shape to have an expensing portion at at least a part of a lower end thereof in the same manner as that described above, wherein the seating block 2 can be fixed to the shell 5 by: disposing the expanding portion between adjacent two of a plurality of connecting members 3; and rotating the seating block 2 to fittingly insert the expanding portion into a space defined between one of the connecting members 3 and the shell 4 (so-called “bayonet structure”, FIGS. 8A and 8B).

[0075] In the slidingly attaching type or the rotationally attaching type, a holder 3H as an independent component may be attached to the seating block 2 at a position between the seating block 2 and the connecting member 3 (FIGS. 9A and 9B). This holder 3H has a horizontally protruding portion 3HC at least in a region joinable to the connecting member 3, wherein the seating block 2 is fixed by slidingly or rotationally attaching the protruding portion 3HC to the connecting member 3 (FIGS. 11 and 12). In particular, a distance between the connecting member 3 and the protruding portion 3HC, or a thickness of the protruding portion 3HC, may be reduced in an attaching (sliding or rotation) direction. This makes it possible to gradually increase the strength of the fixing. Further, during disassembling, the seating block 2 can be easily detached by sliding or rotating the seating block 2 in the reverse direction.

[0076] It should be understood that the structure using such a holder 3H may be applied to any other suitable attaching type other than the slidingly and rotationally attaching types.

[0077] FIGS. 13 to 16 show various examples of installation positions of connecting members 3. As shown in FIGS. 13 to 16, the connecting member 3 (joining portion of the connecting member 3) preferably exists in a manner distributed at least two position equally dividing an outer periphery of the seating block 2.

[0078] Basically, the shell of the molten metal vessel is repeatedly used for a long period of time, and it is necessary to avoid degradation of the shell. Repetitive welding operations are undesirable because they become a factor causing deterioration of the shell and serious damage such as crack formation or breaking. Moreover, the repetitive operation of disassembly and welding is undesirable in terms of productivity and cost, because it requires a lot of time, effort and cost.

[0079] Therefore, in a case where the seating block installation structure includes welding to the shell, it is preferable to combinationally use fixing based on a detachable component with respect to the seating block, such as a thread engagement structure, in other words, screwed structure, a hooking structure, a sliding structure, a bayonet structure, etc., as mentioned above, so as not to repeat welding and disassembling.

LIST OF REFERENCE SIGNS

[0080] 1: upper nozzle [0081] 2: seating block [0082] 3: connecting member [0083] 3F: joined portion of connecting member to shell [0084] 3H: part of connecting member (in example where a holder or the like is disposed at a mid position) [0085] 3HC: protruding portion of holder in the above example [0086] 3W: part of connecting member (in example where a wedge or the like is disposed at a mid position) [0087] 4: shell of bottom portion of molten metal vessel [0088] 5: joint between upper nozzle and seating block [0089] 6: joint between upper nozzle and lower nozzle (e.g., plate) [0090] 6S: thickness of gap formed between upper nozzle and lower nozzle (e.g., plate) [0091] 7: lower nozzle [0092] 8: inner bore [0093] 9: gap formed between seating block and shell of bottom portion of molten metal vessel [0094] 9S: thickness gap 9 [0095] 10: refractory layer (surroundings (peripheral region) of seating block) [0096] 11: unshaped refractory layer (surroundings (peripheral region) of seating block) [0097] 12: metal plate or metal casing [0098] 13: sheet material [0099] 14: cover member for connecting member