JP3016335U - Mortar fall prevention nozzle holding case - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevents mortar from falling off between the nozzle brick and nozzle holding case with a simple and inexpensive structure, maintains mechanical strength and heat insulation properties, and extends the life of the nozzle brick. (EN) Provided is a mortar drop prevention nozzle holding case. In a nozzle holding case (14) for surrounding a nozzle brick (11) for discharging molten metal from a molten metal container (18) in a cylindrical shape and holding the nozzle brick (11) through a mortar (12), an upper end portion of the nozzle holding case (14) and An annular body 1 for preventing the mortar 12 from falling off at the lower end portion.
3, 13a are arranged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mortar drop prevention nozzle holding case that fixes and protects a lower nozzle for a sliding nozzle provided at the bottom of a molten metal container such as a ladle and a tundish.

[0002]

[Prior art]

 Conventionally, in the case of casting nozzles such as lower nozzles used during molten metal processing, the nozzle bricks that make up the casting nozzle are used to improve the durability and prevent cracking of the nozzle bricks. It is used by surrounding a metal case. The method usually used to attach a metal case to this nozzle brick is to apply mortar to a specified thickness on either the nozzle brick or the metal case, and then fit and fix it manually. By interposing such a mortar, the heat insulating property is enhanced and the mechanical strength is maintained. However, there are problems that the central axes of the nozzles are not aligned due to the degree of variation in the thickness of the mortar layer, and the mechanical strength is impaired. As a technique for solving this, for example, Japanese Utility Model Publication No. 2-31253. Japanese Patent Laid-Open Publication No. 2003-242242 describes a technique for uniformizing the thickness of a mortar layer by previously providing a plurality of protrusions on the inner surface of a nozzle holding case.

[0003]

[Problems to be solved by the device]

 However, in the technique disclosed in Japanese Utility Model Publication No. 2-31253, although the mortar can be made uniform, a processing step for forming protrusions on the nozzle holding case is required, which is costly and the upper end portion of the nozzle brick. Alternatively, when the mortar at the lower end is deteriorated and crushed due to heat and mechanical vibration during the treatment of molten metal, the crushed mortar does not fall out from the gap between the nozzle holding case and the nozzle brick. However, when replacing the immersion nozzle, long nozzle, or sliding nozzle, the mortar fell off and the tip of the mortar broke, making it impossible to reuse the nozzle.

This will be described in more detail with reference to FIG. 3. The lower nozzle 50 is attached to the lower part of the sliding nozzle 51, and the long nozzle 52 is arranged below the lower nozzle 50. The lower nozzle 50 is composed of a nozzle brick 53 and a nozzle holding case 55 surrounding and fixing the nozzle brick 53 via a mortar 54 (FIG. 3A). However, in the molten metal treatment, when the molten metal passes through the lower nozzle 50, it is subjected to thermal load and mechanical vibration, and the mortar 54 at the lower end and the upper end of the lower nozzle 50 is deteriorated and crushed. The mortar 54 on the lower end side falls off to form a void (FIG. 3 (b)). Therefore, during continuous casting or the like in which the long nozzle 52 is attached or detached, the long nozzle 52 may be twisted, and the nozzle brick 53 alone receives an external force, which causes the mortar 54 to drop and expose the lower nozzle. Mechanical stress concentrates on the lower end portion of the nozzle 50 and breaks and breaks (FIG. 3C), making it impossible to reuse the lower nozzle 50. The present invention has been made in view of such circumstances, and prevents the mortar from falling off between the nozzle brick and the nozzle holding case with a simple and inexpensive structure to maintain the mechanical strength and the heat insulating property. An object of the present invention is to provide a mortar fall prevention nozzle holding case that can extend the life of the nozzle brick.

[0005]

[Means for Solving the Problems]

 A mortar drop prevention nozzle holding case according to claim 1, which is in line with the above object, wherein a nozzle brick for discharging molten metal from a molten metal container is surrounded by a cylinder, and the nozzle brick holds the nozzle brick via mortar. In the case, an annular body for preventing the mortar from falling off is fixed to the inner lower end of the nozzle holding case. The mortar fall prevention nozzle holding case according to claim 2 is the mortar fall prevention nozzle holding case according to claim 1, wherein the annular body is made of a steel ring, and the steel ring is fixed to the nozzle holding case by welding. Is configured to be. The mortar fall prevention nozzle holding case according to claim 3 is the mortar fall prevention nozzle holding case according to claim 1, wherein an annular body is fixed to an inner upper end portion of the nozzle holding case. . The mortar fall prevention nozzle holding case according to claim 4 is the mortar fall prevention nozzle holding case according to claim 3, wherein the upper and lower annular bodies are made of steel rings, and the steel rings are welded to the nozzle holding case. It is configured to be fixed to each.

Here, mortar refers to a refractory material that can be filled and fixed by filling the space between the nozzle brick and the nozzle holding case, and any one of alumina, mullite, silica, zirconia, and zirconia or Refractory mortar, castable, etc. made into a dough by adding a binder and water to a mixture consisting of a combination of two or more kinds is poured into the voids or arranged by means such as trowel coating, and then cured. To be used. The annular body is an encapsulant made of a metal material or another refractory material formed so as to hold the mortar between the nozzle holding case and the nozzle brick. The steel ring is a member for sealing an annular mortar that can be welded to the nozzle holding case, and Fe alloy such as stainless steel can be used in addition to general steel.

[0007]

[Action]

 In the mortar drop prevention nozzle holding case according to any one of claims 1 to 4, since the annular body for preventing the mortar from falling off is fixed to the inner lower end portion of the nozzle holding case, the mortar portion is deteriorated and crushed when the nozzle is used. Even if it is, it is held without falling off between the nozzle holding case and the nozzle brick. Particularly, in the mortar drop prevention nozzle holding case according to the second aspect, since the annular body is made of a steel ring and the steel ring is fixed to the nozzle holding case by welding, it is extremely easy and inexpensive. The mortar can be sealed, and the steel ring is welded to the nozzle holding case, so that the lower end surface of the nozzle holding case can be reinforced. In the mortar drop prevention nozzle holding case according to claim 3, since the annular body is fixed to the inner upper end portion of the nozzle holding case as well, even when mechanical impact is applied to the upper part of the nozzle when replacing the nozzle. Thus, the mortar is retained and the heat insulating property is not impaired, and the solidification of molten steel on the nozzle inner surface can be prevented. In the mortar drop prevention nozzle holding case according to claim 4, since the upper and lower annular bodies are made of steel rings, and the steel rings are fixed to the nozzle holding case by welding, the mortar can be easily and inexpensively. Not only can it be sealed, but the upper and lower end surfaces of the nozzle holding case can be protected, and the number of times the nozzle is used can be increased.

[0008]

【Example】

 Next, an embodiment of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. 1 (A) and 1 (B) are side cross-sectional views illustrating a lower nozzle equipped with a mortar drop prevention nozzle holding case according to an embodiment of the present invention, and FIG. 2 is a side view illustrating the same nozzle holding case. It is explanatory drawing of the usage method of a lower nozzle.

First, as shown in FIG. 1B, a mortar drop prevention nozzle holding case 10 according to an embodiment of the present invention is a metal case 14 which is an example of a nozzle holding case, and an example of an annular body. It is composed of steel rings 13 and 13a, and the entire lower nozzle 15 is formed by fixing the mortar fall prevention nozzle holding case 10 around the nozzle brick 11 via the mortar 12. The material of the metal case 14 is steel, Fe alloy, Ni alloy, Cr alloy, Ni-Cr, which has excellent heat resistance, oxidation resistance, abrasion resistance, etc., in consideration of the usage conditions of the lower nozzle 15. -Fe alloy etc. can be used. The metal case 14 is formed by punching, drawing, etc., a steel plate or the like into a substantially cylindrical shape according to the shape of the nozzle brick 11, and has a height of 200 to 300 mm and a short diameter as shown in FIG. It is a protective case of a nozzle brick 11 having a side diameter of 140 to 180 mm and a thickness of about 1 to 3 mm. The gap between the nozzle brick 11 and the metal case 14 is set to be in the range of about 1 to 4 mm, and the mortar 12 is filled therein to fix the two.

The nozzle brick 11 has upper and lower joint fitting portions 17 and 17a for the sliding plate 22 of the sliding nozzle and the long nozzle 23 or the immersion nozzle, respectively, and is made of alumina, alumina carbon, or alumina silica. It consists of a refractory material whose main component is.

The mortar 12 used is a clay-like material obtained by kneading a mixture of a refractory material such as alumina, silica, mullite, zircon, or zirconia with a binder such as hydraulic cement or resin and water or the like. be able to. Then, after holding the nozzle brick 11 at a predetermined position in the metal case 14, the nozzle 12 is poured and filled. At this time, the nozzle brick 11 and / or the metal case 14 is vibrated by using a vibrator or the like. It is preferable that the mortar 12 is filled without leaving any details of the voids. Moreover, the mortar 12 is applied to the outside of the nozzle brick 11 or the inside of the metal case 14 in advance, and the mortar 12 is pressed by covering the nozzle brick 11 with the metal case 14 to remove the excess mortar 12 from the nozzle brick. It is also possible to fill the mortar 12 while discharging it from the upper and lower openings formed by 11 and the metal case 14. Finally, the mortar 12 on the inner side of the upper and lower ends of the metal case 14 is removed by a spatula jig to form the fitting portions 16 and 16a of the steel rings 13 and 13a. It is also possible to omit the step of removing the mortar 12, and in this case, it is necessary to mount the steel rings 13 and 13a before hardening of the mortar 12 or the metal case 14. The steel rings 13 and 13a may be located outside the ends. The nozzle brick 11 and the metal case 14 are bonded to each other as shown in FIG. 1A by drying or heating the mortar 12 thus filled to cure it.

Next, as the annular body for sealing the mortar 12, in addition to the steel rings 13, 13a, steel excellent in heat resistance, oxidation resistance, wear resistance, etc., Fe alloy, Ni Materials such as alloys, Cr alloys and Ni—Cr—Fe alloys can be used, and refractory materials such as alumina and mullite or ceramic materials can also be applied. Then, the steel rings 13 and 13a made of S45C or the like were formed by a press punching method so as to have a thickness of 2.3 mm in accordance with the outer diameter of the nozzle brick 11 and the inner diameter of the metal case 14, or a belt-shaped ring. The desired size may be obtained by bending the steel plate into an annular shape and welding the respective end faces. The thickness of the steel ring is appropriately selected within the range of 1 to 4 mm depending on the mortar cost. It is not necessary that the entire circumference of the annular body is continuous, and the annular steel plate is formed by bending the strip-shaped steel plate and is used as it is without joining the ends close to each other by welding or the like. It is also possible. In this case, it is only necessary to cut the strip-shaped steel plate to a required size and bend it along the shape of the nozzle brick, so that the welding work required when forming the annular body can be omitted.

The steel rings 13 and 13 a produced by the above method are fixed by engaging them with the fitting portions 16 and 16 a formed between the outside of the nozzle brick 11 and the metal case 14 and pushing them in. Therefore, since the steel rings 13 and 13a are interposed between the nozzle brick 11 and the metal case 14, the gap between the nozzle brick 11 and the metal case 14 is kept uniform and the nozzle hole is accurately positioned. After that, the exposed ends of the steel rings 13 and 13a and the metal case 14 are welded by fusion welding means such as arc welding or gas welding, pressure welding means such as gas pressure welding, resistance welding or brazing means. At the time of this welding, it is not necessary to completely weld and seal the entire circumference, and it is only necessary to spot 2 to 10 points that divide the entire circumference almost evenly by means such as arc welding, brazing or gas welding. Good. Then, the lower nozzle 15 as shown in FIG. Further, if the steel rings 13 and 13a are previously fixed to the nozzle bricks 11 at predetermined positions by a shrink fit method, the nozzle bricks 11 can be prevented from being cracked.

FIG. 2 is a view showing a usage pattern of the molten metal flow rate control device 19 including the lower nozzle 15 equipped with the mortar drop prevention nozzle holding case 10 manufactured as described above. The molten metal flow rate control device 19 arranged at the bottom of the molten metal container 18 such as a ladle is composed of an upper nozzle 20, a fixed plate 21, a sliding plate 22, a lower nozzle 15 and a long nozzle 23. The lower nozzle 15 is arranged such that the upper joint fitting portion 17 of the lower nozzle 15 is fitted to the lower portion of the slide plate 22, and the lower joint fitting portion 17a of the lower nozzle 15 is made of alumina graphite or the like. It is fitted and attached to the upper part of the nozzle 23. Therefore, by sliding the sliding plate 22 to match the positions of the respective pouring holes arranged on the fixed plate 21 and the sliding plate 22, the pouring in the lower nozzle 15 and the long nozzle 23 is performed. The molten metal in the molten metal container 18 is discharged through a hole into a tundish (not shown). At this time, the lower nozzle 15 is rapidly heated by the molten metal flowing out and is subjected to mechanical vibration. However, since the end of the metal case 14 is sealed by the steel rings 13 and 13a, the nozzle brick 11 and the metal are blocked. Crushing of the mortar 12 interposed between the cases 14 is prevented, and even if the mortar 12 is crushed, the crushed pieces are held without falling off.

After the molten metal in the molten metal container 18 is discharged, the long nozzle 23 is removed and the molten metal container 18 is moved to receive the next molten metal and process the molten metal. At the time of removing, the long nozzle 23 is removed by twisting it, but a mechanical load is applied to the lower end portion of the lower nozzle 15 because there is metal or the like attached to the inner holes of the lower nozzle 15 and the long nozzle 23. However, in the lower nozzle 15, the mortar 12 at the lower end of the lower nozzle 15 is completely held by the steel ring 13a, and the mortar 12 serves as a cushioning material to absorb an excessive load. When the steel rings 13 and 13a are fixed to the lower nozzle 15 by the shrink fit method at the end face of the metal case 14, the metal case 14 and the lower nozzle 15 are welded and fixed. The strength of both metal cases 14 can be further improved. Then, under these conditions, the casting time was 60 minutes, 58 minutes, 57 minutes, 57 minutes, and 65 minutes, which was a total of 297 minutes. Nothing happened, and no trouble such as missing of the lower end of the lower nozzle 15 occurred. Further, the average life and maximum life of the lower nozzle in the conventional example were 5 charges and 7 charges, respectively, whereas the average life and maximum life of the lower nozzle 15 in this embodiment were 6.3 charges, respectively. I was able to greatly improve to 12 charges.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and changes in conditions without departing from the gist are all within the scope of the present invention. For example, in the present embodiment, the case where the steel ring is fixed to the metal case by welding has been described, but the annular body is not limited to steel, and Fe alloy, Ni alloy, Cr alloy, Ni-Cr-Fe may be used. It can also be applied to metal materials such as alloys, refractory materials such as alumina and mullite, and ceramic materials, and can be fixed by mechanically pushing the annular body into the fitting part between the metal case and the nozzle brick. It can also be arranged.

[0017]

[Effect of device]

 In the mortar drop prevention nozzle holding case according to any one of claims 1 to 4, since the annular body for preventing the mortar from falling off is fixed to the inner lower end portion of the nozzle holding case, the mortar portion is deteriorated and crushed when the nozzle is used. Even if it is, it is held without falling off between the nozzle holding case and the nozzle brick. Therefore, the mechanical strength of the lower end of the nozzle brick is maintained, and since the mortar serves as a cushioning material to absorb the mechanical external force, the lower end of the lower nozzle is broken when the nozzle such as the long nozzle is replaced. In addition, the thermal insulation of the nozzle bricks is maintained, so that thermal shock during use can be avoided and the temperature of molten metal that flows out can be prevented, and the adhesion of metal to the nozzle holes can be prevented. . Further, since the annular body is inserted between the nozzle brick and the nozzle holding case, the mortar layer having a constant thickness can be maintained, and the position of the nozzle hole can be accurately defined. Particularly, in the mortar drop prevention nozzle holding case according to the second aspect, since the annular body is made of a steel ring and the steel ring is fixed to the nozzle holding case by welding, it is extremely easy and inexpensive. The mortar can be sealed, and the steel ring is welded to the nozzle holding case, so that the lower end surface of the nozzle holding case can be reinforced. Furthermore, it is easy to handle automation by industrial robots. In the mortar drop prevention nozzle holding case according to claim 3, since the annular body is fixed to the inner upper end portion of the nozzle holding case, even if a mechanical shock is applied to the upper part of the nozzle when replacing the nozzle. Thus, the mortar is retained and the heat insulating property is not impaired, and the solidification of molten steel on the nozzle inner surface can be prevented. Further, in the mortar drop prevention nozzle holding case according to claim 4, since the upper and lower annular bodies are made of steel rings, and the steel rings are fixed to the nozzle holding case by welding, respectively, it is easy. Moreover, the mortar can be sealed at low cost, and the upper and lower end surfaces of the nozzle holding case can be protected to increase the number of times the nozzle is used.

[Brief description of drawings]

1A and 1B are side sectional views illustrating a lower nozzle equipped with a mortar drop prevention nozzle holding case according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method of using a lower nozzle equipped with the nozzle holding case.

FIG. 3 is a side sectional view illustrating a nozzle holding case according to a conventional example.

[Explanation of symbols]

 10 Mortar fall prevention nozzle holding case 11 Nozzle brick 12 Mortar 13 Steel ring (annular body) 13a Steel ring (annular body) 14 Metal case (nozzle holding case) 15 Lower nozzle 16 Fitting part 16a Fitting part 17 Joining fitting Joining part 17a Joining fitting part 18 Molten metal container 19 Molten metal flow rate control device 20 Upper nozzle 21 Fixed plate 22 Sliding plate 23 Long nozzle

Claims (4)

[Scope of utility model registration request] 1. A nozzle holding case for surrounding the outer circumference of a nozzle brick for discharging molten metal from a molten metal container in a cylindrical shape, and holding the nozzle brick through mortar, wherein an inner lower end portion of the nozzle holding case comprises: A mortar drop prevention nozzle holding case, wherein an annular body for preventing the mortar from falling off is fixed. 2. The mortar drop prevention nozzle holding case according to claim 1, wherein the annular body is made of a steel ring, and the steel ring is fixed to the nozzle holding case by welding. 3. The mortar drop prevention nozzle holding case according to claim 1, wherein an annular body is also fixed to an inner upper end portion of the nozzle holding case. 4. The mortar drop prevention nozzle holding case according to claim 3, wherein the upper and lower annular bodies are made of steel rings, and the steel rings are respectively fixed to the nozzle holding case by welding.