Title of invention: Nozzle for casting
Technical field
[0001]
　The present invention relates to a casting nozzle used in continuous casting of molten steel.
Background art
[0002]
　In the continuous casting of molten steel, when the molten steel is discharged from the ladle to the tundish, a long nozzle as a casting nozzle is used to suppress oxidation of the molten steel and entrapment of slag existing on the upper surface of the tundish into the molten steel. It is common to use nozzles. In addition, in pouring from a tundish into a mold, it is common to join an immersion nozzle as a casting nozzle below a lower nozzle attached to a lower part of the tundish.
[0003]
　Hereinafter, a long nozzle will be mainly described as an example among these casting nozzles.
　The long nozzle is joined to a lower nozzle installed at the bottom of the ladle via a packing material or the like. Between the long nozzle and the lower nozzle, (a) mixing of air (oxygen or the like) into the molten steel, (b) leakage of the molten steel from the joint, (c) the long nozzle and the lower nozzle made of a material containing carbon. A high degree of adhesion (sealability) is required to suppress wear due to oxidation and the like near the nozzle joint. The long nozzle is attached to and detached from the lower nozzle each time the ladle is replaced, and this attachment and detachment is repeated as many times as the ladle is replaced.
　In such a joint portion between the long nozzle and the lower nozzle, a gap may be formed due to a decrease in adhesion due to attachment / detachment work, adhesion of molten steel, slag, etc., damage to the nozzle, and the like. When such a gap is formed, the sealing performance is reduced, and there is an increased danger that air is drawn into the nozzle to cause damage due to oxidation of molten steel and oxidation of the nozzle made of carbon-containing refractory.
[0004]
　As one of the measures, a method of blowing out an inert gas from near the upper end of the long nozzle is adopted. For example, Patent Documents 1 to 3 disclose a long nozzle having a structure in which a metal case surrounds an outer periphery of an upper end portion of a nozzle body made of a refractory material of a long nozzle and blows gas from a gap between the upper end portion of the nozzle body and the metal case. Have been. In these patent documents, a gap for gas flow (hereinafter also referred to as a “gas pool”) is provided between the outer peripheral surface of the upper end of the nozzle body and the inner peripheral surface of the metal case.
[0005]
　Further, for example, Patent Document 4 discloses a long nozzle having a structure in which a periphery of an upper end portion of a nozzle body made of a refractory material of a long nozzle is surrounded by a metal case and gas is blown out from a part of an inner hole below a joint. ing. In Patent Document 4, the gas pool is also provided between the outer peripheral surface of the upper end portion of the nozzle body and the inner peripheral surface of the metal case.
Prior art literature
Patent literature
[0006]
Patent Document 1: Japanese Patent Application Laid-Open No. 2011-212721
Patent Document 2: Japanese Patent Application Laid-Open No. 2014-133241
Patent Document 3: Japanese Patent Application Laid-Open No. 5-23808
Patent Document 4: Japanese Patent Application Laid-Open No. 62-130753
Summary of the Invention
Problems to be solved by the invention
[0007]
　In a long nozzle having a gap as a gas pool between the outer peripheral surface of the upper end portion of the nozzle body and the inner peripheral surface of the metal case as in these Patent Documents, the upper end portion of the nozzle body in any region where this void exists. May cause breakage such as cracks. When such destruction occurs, the blowing of gas becomes non-uniform, and the risk of entrapping outside air (oxygen) into the inner hole or causing steel leakage increases.
　There is a similar problem in the immersion nozzle installed between the tundish and the mold.
　The problem to be solved by the present invention is to suppress or prevent such breakage of the casting nozzle body.
Means for solving the problem
[0008]
　The present invention provides the following 1 to 10 casting nozzles.
1.
　And surrounds the nozzle body upper portion in the metal case, the in nozzle casting and a gas pool between the outer peripheral surface of the nozzle body upper portion and the inner circumferential surface of said metal case,
　said at least one gas pool A casting portion, comprising: a portion that bridges an outer peripheral surface of an upper end portion of the nozzle body and an inner peripheral surface of the metal case.
2.
　2. The casting nozzle according to claim 1, wherein the cross-linked portion is an iron round bar or square bar or a combination thereof.
3.
　The casting nozzle according to claim 2, wherein the cross-linking portion extends in a vertical direction, and a part or all of each cross-linking portion is welded to the metal case.
4.
　2. The casting nozzle according to item 1, wherein the crosslinked portion is formed by filling with heat resistant particles.
5.
　5. The casting nozzle according to the item 4, wherein the heat-resistant particles are filled in the gas pool without being bonded to each other and not bonded to any surface in the gas pool.
6.
　6. The casting nozzle according to 4 or 5, wherein the heat-resistant particles have a particle size of 0.65 mm or more.
7.
　7. The casting nozzle according to any one of 4 to 6, wherein the heat-resistant particles have a substantially spherical shape or a substantially elongated spherical shape.
8.
　The casting nozzle according to any one of the above items 4 to 7, wherein the heat-resistant particles are made of an inorganic substance or one or more materials selected from iron-based metals and copper-based metals.
9.
　The inorganic material is at least one selected from alumina, silica, spinel, magnesia, zirconia or zircon, Ca-containing cement, carbon, carbide, sialon-based ceramics, and glass. 9. The casting nozzle according to 8 above.
10.
　The gas pool includes one or more gas inlets, gas outlets, or holes (hereinafter, collectively referred to as “gas inlets”) as paths communicating with the gas outlets. The casting nozzle according to any one of items 4 to 9, wherein the minimum dimension of at least the gas pool inner surface position in a cross section perpendicular to the gas flow direction is smaller than the minimum particle size of the heat-resistant particles.
The invention's effect
[0009]
　According to the present invention, at least a portion of the gas pool is provided with a portion that bridges the outer peripheral surface of the upper end portion of the nozzle body and the inner peripheral surface of the metal case, so that the outer peripheral surface of the upper end portion of the nozzle body can be connected to the metal case. It is possible to suppress the occurrence of breakage of the upper end of the nozzle main body of the casting nozzle in which the gas pool is installed between the inner peripheral surface of the nozzle and the casting nozzle. As a result, it is possible to prevent or reduce oxidation near the inner hole of the casting nozzle and the joint with the lower nozzle and erosion due to iron oxide, etc., and to prevent leakage of steel from near the joint and deterioration of steel quality. be able to.
[0010]
　In addition, in the embodiment in which the gas pool is filled with heat-resistant particles as the cross-linking part, the heat-resistant particles have an effect of dispersing the stress, so that the upper end of the nozzle body is prevented from being broken. Or it can be prevented.
　In the case where the heat-resistant particles are not bonded to each other or between the heat-resistant particles and the nozzle body or the metal case, even if the gas pool is deformed, the heat-resistant particles move by themselves to reduce stress concentration. The effect of suppressing or preventing can be obtained.
　Furthermore, it is only necessary to fill the gas pool with heat-resistant particles and restrain it by mechanical external force such as pressing down the filled part. Therefore, the manufacturing process is simple and easy, and it can be manufactured in a short time and at low cost.
BRIEF DESCRIPTION OF THE FIGURES
[0011]
FIG. 1 is a longitudinal sectional view of an example of a long nozzle among casting nozzles according to a first embodiment of the present invention (an example of a structure in which a joint with a lower nozzle has an angle).
FIG. 2 is an image diagram showing a force applied to a joint and a reaction force in a radial direction in the example of FIG. 1.
FIG. 3 is a vertical cross-sectional view of an example of a long nozzle among casting nozzles according to the first embodiment of the present invention (an example of a structure in which a joint with a lower nozzle has no angle in a horizontal direction).
FIG. 4 is a longitudinal cross-sectional view showing an example of a conventional long nozzle together with a joint structure with a lower nozzle. Note that this example is an example in which a ceramic sheet or a sealing material is provided at the joint.
FIG. 5 is an image diagram showing an example of an arrangement of a cross-linking portion of the present invention by developing the inner peripheral surface side of the metal case or the outer peripheral surface side of the long nozzle body. This example is an example in which a plurality of pillar-shaped cross-linking portions extend in the vertical direction and are arranged, and it is not necessary to limit the cross-section of the cross-linking portion in the horizontal direction.
FIG. 6 is an image diagram showing another example of the arrangement of the cross-linking portion of the present invention by developing the inner peripheral surface side of the metal case or the outer peripheral surface side of the long nozzle body. This example is an example in which pillar-shaped cross-linking portions shown in FIG. 5 are arranged obliquely.
FIG. 7 is an image diagram showing another example of the arrangement of the cross-linking portion of the present invention, in which the inner peripheral surface side of the metal case or the outer peripheral surface side of the long nozzle body is developed. This example is an example in which pillar-shaped cross-linking portions shown in FIG. 6 are arranged obliquely and cross each other.
FIG. 8 is an image diagram showing another example of the arrangement of the cross-linking portion of the present invention by developing the inner peripheral surface side of the metal case or the outer peripheral surface side of the long nozzle body. This example is an example in which the long side of a columnar cross-linking portion is arranged in the horizontal direction.
FIG. 9 is an image diagram showing another example of the arrangement of the cross-linking portion of the present invention by developing the inner peripheral surface side of the metal case or the outer peripheral surface side of the long nozzle body. This example is an example in which pillar-shaped cross-linking portions are vertically and separately cut and dispersed.
FIG. 10 is an image diagram showing another example of the arrangement of the cross-linking portion of the present invention by developing the inner peripheral surface side of the metal case or the outer peripheral surface side of the long nozzle body. This example is an example in which cylindrical cross-linking portions are dispersedly arranged with the circular surface facing the outer peripheral surface of the long nozzle body.
FIG. 11 is an image diagram showing an example of the type and arrangement of the shape of the cross-linking portion of the present invention in a transverse cross section of a space as a gas pool between the outer peripheral surface of the long nozzle body and the inner peripheral surface of the metal case. , (A) is an example in which the long side of a round rod as a cylinder is vertically arranged, (b) is an example in which the long side of a square rod as a square pillar is vertically arranged, (c) is a cylinder or This is an example in which the long sides of the prisms are arranged in the horizontal direction so as to match the curvature.
FIG. 12 is a longitudinal sectional view of an example of a long nozzle among casting nozzles according to a second embodiment of the present invention (an example of a structure in which a joint with a lower nozzle has an angle).
FIG. 13 is an image diagram schematically illustrating a space between heat-resistant particles when the gas pool is filled with the heat-resistant particles of the casting nozzle of the present invention as an inscribed circle.
FIG. 14 is an image diagram showing an example of the casting nozzle of the present invention in a state where a gas pool is filled with spherical particles.
FIG. 15 shows the arrangement and arrangement of holes (gas inlets, etc.) as a gas inlet, a gas outlet, or a path communicating with the gas outlet of a gas pool filled with particles, for a long nozzle among the casting nozzles of the present invention. It is an image figure showing an example of relative size etc.
FIG. 16 is an image diagram showing an example of a long nozzle among the casting nozzles of the present invention, in which a filter or the like for preventing heat-resistant particles from flowing out from a gas inlet of a gas pool filled with particles is installed. It is.
BEST MODE FOR CARRYING OUT THE INVENTION
[0012]
　Hereinafter, embodiments and examples of the present invention will be described with reference to the drawings as appropriate, taking a long nozzle as an example.
[0013]
To
　be described with reference to the conventional long nozzle shown in FIG. 4, the outer peripheral surface of the long nozzle body 3 (also referred to simply as the “main body outer peripheral surface” in this specification) and the inner peripheral surface of the metal case 4 are described. In the long nozzle body 3 (hereinafter, also simply referred to as “body”) in which the gas pool 2 is installed between the lower nozzle 7 and the destruction such as a crack occurs at the joint with the lower nozzle 7 in the steel passing direction of the long nozzle. (It is a vertical direction, and is also simply referred to as “vertical direction” hereinafter.) This is because a force is applied in a radial direction from the center axis, that is, in a radial direction (hereinafter, also simply referred to as “lateral direction”).
[0014]
　This radial force mainly occurs in one of two forms: (1) crimping at the time of joining the lower nozzle and the long nozzle, or (2) partial contact between the lower nozzle and the long nozzle at the joint or local pressurization. It is caused by one or a combination of these.
[0015]
　In the crimping mode in the joining of the lower nozzle and the long nozzle in the above (1), the joining portion between the lower nozzle and the long nozzle has an angle with respect to the lateral direction of the long nozzle as the joining portion 10 shown in FIG. In other words, when the joining surface is in a direction other than 90 ° with respect to the vertical direction, the crimping force at the time of joining in the vertical direction produces a radial vector as shown in FIG. Pulling in the circumferential direction causes mainly longitudinal cracks or fractures.
[0016]
　In the form of the partial contact between the lower nozzle and the long nozzle or the local pressurization at the joint (2), circumferential contact such as joining at a position where the center axis of the lower nozzle and the long nozzle is displaced from each other. A local radial force is applied only to a portion of the long nozzle body, and a longitudinal pulling force of the long nozzle body or a lateral bending force acting near the joint causes a crack or fracture. (Refer to the illustration by the arrow when the center axis of the lower nozzle deviates from the center axis of the long nozzle in FIG. 3.)
[0017]
　In the structure of the prior art, as shown in FIG. 4, since the gas pool 2 is merely a space, there is nothing to restrict the long nozzle body. If the above-mentioned phenomena (1) and (2) exist in such a conventional structure, the long nozzle body is broken.
[0018]
　Therefore, the long nozzle of the present invention includes a portion 1 that bridges the outer peripheral surface of the main body 3 and the inner peripheral surface of the metal case 4 in at least a part of the gas pool 2 as illustrated in FIG. The bridge portion 1 restricts the radial direction of the outer peripheral surface of the main body 3 so that when a force is applied to the long nozzle main body due to the above-described phenomena (1) and (2), the long nozzle main body 3 moves toward the gas pool 2 side. The long nozzle body 3 is restrained from being deformed or moved so as to be hardly deformed, thereby preventing or suppressing the occurrence of cracks or breakage in the long nozzle body 3.
[0019]
　Therefore, in the long nozzle according to the present invention, the cross-linking is formed in a part or the entirety of the gas pool area corresponding to at least the joint with the lower nozzle, that is, the joint with the lower nozzle is projected on the outer peripheral side of the long nozzle body. It is preferable that a portion to be installed is provided.
　For example, a force is applied only to a specific direction or a specific portion, such as only the sliding direction of a sliding nozzle plate installed above the lower nozzle, or only a specific operating direction of the long nozzle mounting device, and the direction or the portion is applied. When a crack or breakage occurs in the long nozzle body, the cross-linking part may be provided only in the gas pool area in a specific direction or part thereof.
　When a force is applied to the entire long nozzle body in the circumferential direction, it is preferable that the long nozzle body is arranged at least three places on the circumference substantially uniformly, and it is more preferable that the long nozzle body is installed at as many places as possible or as wide as possible.
[0020]
　Since the gas pool is a space for allowing the inert gas to flow through the gas discharge port (for example, the portion denoted by reference numeral 6 in FIG. 1), necessary portions are provided so that the cross-linked portion does not hinder the gas flow. It is necessary to provide a space, that is, a discontinuous portion, in the gas flow path. However, it is only necessary that the gas flow path exists only above the vertical area of ​​the joint, and it is not necessary to distribute the gas in the lower gas pool area. May be provided with a continuous cross-linked portion over the entire circumferential direction.
[0021]
　The point of contact or connection between the bridged portion and the outer peripheral surface of the long nozzle body or the inner peripheral surface of the metal case shall be a point, a line, or a line, as long as the function of restraining between the outer peripheral surface of the long nozzle body and the inner peripheral surface of the metal case is obtained. Or it may be either of the surface. However, from the viewpoint of enhancing the stress dispersing effect so as not to cause breakage, the contact portion or the joint portion is preferably as wide as possible, and the line is more preferable than the point and the surface is more preferable than the line (FIGS. 11A to 11C). reference).
　When a part has a surface, various shapes such as a circle, an ellipse, a polygon, and a fan shape are acceptable, and the shape may be a column or a cone.
　In addition, since the gas pool extends in the circumferential direction of the long nozzle body, the surface of the bridge portion that contacts the outer peripheral surface of the long nozzle body and the inner peripheral surface of the metal case has a curved surface that matches those curvatures.
[0022]
　The cross-linked portion may be made of a different material such as the same or same refractory as the long nozzle body, a breathable refractory or the like, or may be metal. Since the gas pool section also has a cooling effect by the flowing gas, the temperature during operation is generally about 1200 ° C. or less (up to several hundred ° C.). Therefore, any material that can exist in such an operating temperature range may be used. Specific refractories may be alumina, alumina-silica, alumina-graphite, and other general refractories used for casting, as well as low refractory materials such as chamotte and glass. . Further, metals such as ordinary steel, for example, metals used for metal cases and the like, and commercially available building materials and other iron-made round bars and square bars for other uses can be used.
[0023]
　The crosslinked portion may be in contact with or joined to, ie, fixed to, the outer peripheral surface of the long nozzle body or the inner peripheral surface of the metal case. However, from the viewpoint that the installation position can be maintained, it is preferable to be fixed to one of the outer peripheral surface of the long nozzle body and the inner peripheral surface of the metal case. Therefore, the cross-linking portion may be in a form integral with the long nozzle body or the metal case, or in a form in which a separate object is installed. The form of the structure integral with the long nozzle body or the metal case includes a convex portion protruding from the long nozzle body or the metal case. The convex portion from the metal case can be formed by pressing or drawing the metal case.
[0024]
　In the case where the cross-linking portion is an iron round bar, a square bar, or the like, a part or the whole thereof can be fixed to the metal case by welding. The method of welding these rod-shaped members by setting the longitudinal direction to the longitudinal direction is relatively inexpensive because of the use of widely distributed materials and the need to form curved surfaces that match the circumference. Yes, easy to manufacture. In other words, from the viewpoints of cost, ease of manufacture, and the like, the cross-linking portion is preferably an iron round bar or square bar or a combination thereof, and the cross-linking portion extends in the vertical direction. More preferably, part or all of the cross-linking portion is welded to the metal case. Here, “the cross-linking portion extends in the vertical direction” means that the cross-linking portion is inclined in the radial direction but not in the circumferential direction when the gas pool is provided in a tapered shape. It shall include forms that are not inclined.
[0025]

[Example A] In
　Example A, in the structure shown in Fig. 1, a cross-linking portion is made of an iron round bar, and eight points are welded on the inner circumferential surface of the metal case on the circumference. This is an example in which it is arranged so as to extend in a direction (longitudinal direction) parallel to the longitudinal direction of the long nozzle.
　In the actual operation, in the conventional structure having no cross-linking portion (comparative example (the structure of FIG. 1 (Example A) excluding the cross-linking portion 1)), the long nozzle body has a vertical crack or a fracture that separates from the crack. However, as a result of providing the long nozzle of the present invention of Example A, the occurrence of destruction including a crack in the long nozzle body was completely eliminated.
[0026]
　In addition, for example, as shown in FIGS. 6 to 8 and FIG. 10, the discontinuous portion 14 in the vertical direction does not penetrate, or the discontinuous portion 14 in the vertical direction includes a narrow portion or a portion extending in the horizontal direction. In the case of another structure having a high effect of restraining in the horizontal direction or dispersing stress in the horizontal direction, the effect of suppressing or preventing fracture such as cracks is considered to be higher than that of the structure of Example A.
　However, in the structure of Example A in which the cross-linking portion and the outer peripheral surface of the long nozzle body are in linear contact in the longitudinal direction of the long nozzle, and the discontinuous portion penetrates in the longitudinal direction, the structure of Example A described above may cause breakage such as cracks. Although it is considered that longitudinal cracks in the long nozzle body are more likely to occur than in a structure having a higher suppression or prevention effect, almost perfect crack suppression or prevention effect is also obtained in Example A. .
　Therefore, a structure with a higher suppression or prevention effect as described above may cause cracks such as cracks such as the degree of force applied to the long nozzle body during operation, for example, when the pressure between the long nozzle and the lower nozzle is large. What is necessary is just to select suitably according to the relevant individual conditions.
[0027]
In
　this embodiment, as shown in FIG. 12, at least a part (partly or substantially all) of the gas pool 2 is filled with heat-resistant particles 1A. The above-mentioned crosslinked portion (crosslinked portion) 1 is formed by filling the heat resistant particles 1A. As described above, the bridge portion 1 restricts the radial direction of the outer peripheral surface of the main body 3 as described above, and the heat-resistant particles 1A constituting the bridge portion 1 have an effect of dispersing stress. Can be suppressed or prevented.
[0028]
　In the present invention, the heat-resistant particles 1A are not bonded to each other, and are in contact with any surface in the gas pool but are not bonded (joined) in the gas pool (substantially of the gas pool). It is preferable that the entire region is filled (constrained). That is, it is preferable that the heat-resistant particles 1A are relatively movable, although they are constrained between the particles or the inner surface of the gas pool. Then, the heat-resistant particles move so as to shift themselves according to the change in stress mainly due to the external force generated from the inner hole side, so that the stress is always automatically and uniformly distributed over the entire gas pool area filled with the heat-resistant particles. And destruction of the nozzle body due to stress concentration can be prevented. Furthermore, even if the gas pool is deformed due to deformation of the metal case at the time of receiving heat or after receiving heat, the heat-resistant particles can move in the gas pool according to the shape of the gas pool. The function of dispersing throughout is easily maintained.
[0029]
　In order to uniformly disperse such stress, the heat-resistant particles are filled so as to press them when they are filled, and the heat-resistant particles naturally flow in the gas pool (unless external force acts). It is preferable that the gas is restrained in the gas pool so as not to flow. Specifically, the heat-resistant particles may be filled in a gas pool in a dry state without using an adhesive or the like, and may be restrained by, for example, closing a lid so as not to flow naturally. On the other hand, for example, when fixing the inside of the gas pool with parts of a specific size, it is necessary to install the parts while adjusting the accuracy of the shape inside the gas pool. It is easy to manufacture, and can be manufactured in a short time and at low cost.
[0030]
　Even if the heat-resistant particles are bonded to each other or to any surface in the gas pool, the effect of dispersing the stress by filling the heat-resistant particles can be obtained to a considerable extent. Destruction of the nozzle body can be suppressed or prevented. Even if the heat-resistant particles are filled in only a part of the gas pool, the effect of dispersing the stress can be obtained in at least a part of the gas pool. it can.
[0031]
　Since the gas pool itself is a gas flow path and has a function of accumulating or equalizing pressure, gas can flow between the heat-resistant particles and between the heat-resistant particles and the inner surface of the gas pool. It has space.
　The space between the heat-resistant particles is, for example, based on a standard porous refractory for gas passage having a maximum pore diameter of about 50 μm or more and an average pore diameter of about 100 μm. However, when the average space diameter is approximately 100 μm or more, a space through which gas can flow smoothly can be secured.
　When the diameter of the pores (the diameter of the void portion) is calculated by a simple geometric model, the inscribed circle of the space surrounded by three spheres is compared with the diameter Ds when the heat-resistant particles are regarded as spheres. The diameter of 17s (see FIG. 13) is about 0.155 times Ds. Assuming this to be 100 μm, it is preferable that the particle size (diameter in the case of a sphere) of the heat-resistant particles is about 0.65 mm or more.
　Note that there is actually a space around the inscribed circle 17s, and the space between the heat-resistant particles and the inner surface of the gas pool is larger than the space between the heat-resistant particles. Is larger than this.
　Here, that the particle size of the heat-resistant particles is 0.65 mm or more means that the heat-resistant particles have a size remaining on a virtual sieve having an aperture of 0.65 mm.
[0032]
　From the viewpoint of increasing the gas permeability (air permeability) as described above, it is preferable to fill the gas pool with heat-resistant particles having a size near the maximum size that can be filled.
　The heat-resistant particles preferably have a curved surface in order to secure a sufficient space 17 (see FIG. 14) between the particles, more preferably have a substantially spherical shape or a substantially elongated shape, and have a spherical shape. Is most preferred.
[0033]
　On the other hand, in order to maximize the size of the space between the heat-resistant particles from the viewpoint of air permeability, the size of the heat-resistant particles should be set to the maximum size that can be filled in the gas pool. Since the number of contact points (reference numerals 18b and 18c in FIG. 14) of the heat-resistant particles with the inner surface of the gas pool decreases as the size of the gas pool approaches the size of the gas pool, the stress dispersion effect decreases.
[0034]
　Therefore, the size of the heat-resistant particles depends on the operating conditions, ie, the gas pressure in the gas pool, the size of the gas pool, the length of the gas passage, the area of ​​the gas discharge port, the gas discharge amount, etc. It is preferably determined by the balance between air permeability and air permeability.
　The small size of the heat-resistant particles is disadvantageous from the viewpoint of air permeability, but the smaller the size of the heat-resistant particles, the higher the internal pressure in the gas pool. This is advantageous from the viewpoint of uniformity. Therefore, it is preferable that the size of the heat-resistant particles be determined in consideration of the uniformity of the ventilation rate.
[0035]
　Further, as shown in FIG. 15, for example, the gas pool has one gas inlet 5p, one gas outlet 6, or a hole 12 (hereinafter referred to as a "gas inlet or the like") as a path communicating with the gas outlet. In order to prevent heat-resistant particles from flowing out of the gas pool from the gas inlet, etc., the minimum size of at least the gas pool inner surface position in a cross section perpendicular to the gas flow direction is as follows: It is preferably smaller than the minimum particle size of the heat-resistant particles.
　Further, as shown in FIG. 16, for example, a filter 16 or the like for preventing heat-resistant particles from flowing out may be provided at a gas inlet or the like. In this case, the minimum size of at least the inner surface of the gas pool in the cross section perpendicular to the gas flow direction such as the gas inlet may be larger than the minimum particle size of the heat-resistant particles. It is preferably smaller than the minimum particle size of the heat-resistant particles.
[0036]
　Here, the heat resistance means a property that does not soften, melt or disappear when exposed to the maximum temperature of the gas pool. Specifically, it is only necessary to be able to withstand the temperatures of individual gas pools, which fluctuate depending on conditions such as operating conditions, the structure and arrangement of the gas pool, and the cooling effect (flow rate, etc.) of the gas.
　In the case of many long nozzles and immersion nozzles, the temperature during gas discharge is about 800 ° C. or less, and at most about 1200 ° C. or less.
　Therefore, the heat-resistant particles referred to in the present invention are materials capable of withstanding such a temperature condition, for example, one or more selected from inorganic materials, iron-based metals or copper-based metals, or alloys thereof. It can be a material.
　Examples of the inorganic substance include alumina, silica, spinel, magnesia, zirconia or zircon, carbon, carbide, sialon ceramics, and glass. Since an inert gas is passed through the gas pool, the heat-resistant particles are less likely to be oxidized, or a material that is easily oxidized, such as a carbon-based material, can be used.
　That is, any material generally used as a raw material for refractory materials such as a molten metal processing furnace, a vessel, an atmosphere furnace, and a nozzle can be used.
　As the metal or alloy, a metal or alloy having a melting point exceeding the maximum temperature under individual operating conditions (for example, about 800 ° C. or higher) or more can be used, and specifically, has a relatively low cost and a high melting point. Iron-based is most preferred.
Explanation of reference numerals
[0037]
　1 Cross-linked part
　1A Heat-resistant particles
　2 Gas pool
　3 Long nozzle body (main body)
　3-1 Long nozzle body (materials other than joints)
　3-2 Long nozzle body (materials near joints)
　4 Metal case
　5 Gas introduction Part
　6 Gas discharge port
　7 Lower nozzle
　8 Inner hole
　9 Center axis
　10 Joint part between lower nozzle and long nozzle
　11 Filler
　12 Hole
　13 as passage communicating with gas discharge port 13 Ceramic sheet or sealing material
　14 Discontinuous portion
　15a Nozzle body A gap
　15b between the upper end surface and the metal case above the gap 15b A gap near the nozzle metal case at the gas inlet
　16 A filter for preventing the outflow of heat-resistant particles (wire mesh, or a metal part with through holes or slits)
　17 Space (gas flow path)
　17s ) Inscribed circle
　18a in the space between heat-resistant particles Contact point between heat-resistant particles
　18b Contact point between
　heat-resistant particles and inner surface of gas pool ( outer peripheral surface at upper end of nozzle body) 18c Contact point between heat-resistant particles and inner surface of gas pool (inner peripheral surface of metal case)
The scope of the claims
[Claim 1]
　And surrounds the nozzle body upper portion in the metal case, the in nozzle casting and a gas pool between the outer peripheral surface of the nozzle body upper portion and the inner circumferential surface of said metal case,
　said at least one gas pool A casting part comprising: a portion that bridges an outer peripheral surface of an upper end portion of the nozzle body and an inner peripheral surface of the metal case.
[Claim 2]
　The casting nozzle according to claim 1, wherein the cross-linking portion is a round bar or a square bar made of iron or a combination thereof.
[Claim 3]
　The casting nozzle according to claim 2, wherein the cross-linking portion extends in a vertical direction, and a part or all of each cross-linking portion is welded to the metal case.
[Claim 4]
　The casting nozzle according to claim 1, wherein the cross-linking portion is formed by filling with heat-resistant particles.
[Claim 5]
　The casting nozzle according to claim 4, wherein the heat-resistant particles are filled in the gas pool without being bonded to each other and not being bonded to any surface in the gas pool.
[Claim 6]
　The casting nozzle according to claim 4, wherein the heat-resistant particles have a particle size of 0.65 mm or more.
[Claim 7]
　The casting nozzle according to any one of claims 4 to 6, wherein the heat-resistant particles have a substantially spherical shape or a substantially elongated spherical shape.
[Claim 8]
　The casting nozzle according to any one of claims 4 to 7, wherein the heat-resistant particles are made of an inorganic material or one or more materials selected from iron-based metals and copper-based metals.
[Claim 9]
　The inorganic material is at least one selected from alumina, silica, spinel, magnesia, zirconia or zircon, Ca-containing cement, carbon, carbide, sialon-based ceramics, and glass. A casting nozzle according to claim 8.
[Claim 10]
　The gas pool includes one or more gas inlets, gas outlets, or holes (hereinafter, collectively referred to as “gas inlets”) as paths communicating with the gas outlets. The casting nozzle according to any one of claims 4 to 9, wherein a minimum dimension of at least an inner surface position of the gas pool in a cross section perpendicular to the gas flow direction is smaller than a minimum particle size of the heat-resistant particles.