JPH0231253Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a lower nozzle for a sliding nozzle, a plate brick for a sliding nozzle, and a nozzle for a sliding nozzle, which are used when flowing molten metal from a container such as a ladle or tundish. The present invention relates to a nozzle holding case that holds nozzles, such as a flow rate adjustment nozzle for an output nozzle and a porous pouring nozzle into which gas can be blown, in an accurate position.

[Conventional technology]

Nozzles such as the lower nozzle for sliding nozzles, plate bricks for sliding nozzles, flow rate adjustment nozzles for pouring nozzles, and porous pouring nozzles that can be blown with gas improve the strength of the nozzle bricks that make up the nozzle body. To prevent cracking, a metal case is attached to the nozzle brick. The commonly used method for attaching a metal case to a nozzle brick is to apply mortar to a specified thickness on either the nozzle brick or the metal case, and then manually insert and fix the two. It is something.

This method will be explained with reference to FIG.
FIG. 3 shows the manufacturing process of the sliding nozzle. Centering rubber 3 is applied to multiple locations along the circumferential direction near the large-diameter end of the nozzle body 2 in which the nozzle hole 1 is bored, and the nozzle body 2 is inserted through the centering rubber 3. Insert the metal case 4 into the Then, a centering rod 6 is inserted into the other end of the nozzle body 2 on the small diameter side so as to keep the gap 5 between the nozzle body 2 and the metal case 4 constant. In this way, the gap 5 is maintained uniformly over the entire circumference of the nozzle body 2, and the nozzle body 2 is centered. In this state, mortar is poured into the gap 5 and the nozzle body 2 is fixed to the metal case 4.

However, when such manual work is used, the number of pieces produced is only about 20 pieces per day even by skilled workers, resulting in low production efficiency. Furthermore, when manually inserting the nozzle brick into the metal case, it was difficult to center the nozzle brick, and uneven thickness tended to occur in the mortar layer.

If there is such an uneven thickness, the nozzle brick cannot be installed accurately, and especially in sliding nozzles, an undesirable gap may be created between the nozzle brick and surrounding members, or the centering of the nozzle hole may be incorrect. This will cause you not to be able to go. As a result, the flow of molten metal may be obstructed or air may be drawn in during tapping. This air entrainment is a problem that must be avoided because it promotes oxidation of the molten metal and increases the amount of nonmetallic inclusions remaining in the product.

Further, the uneven thickness causes a temperature difference in the nozzle, which causes cracks to occur. This crack is
This will encourage air to enter the nozzle.
Depending on the material of the nozzle, a low melting point compound is generated due to an oxidation reaction, causing abnormal erosion of the nozzle. Furthermore, as a result of the uneven thickness, the strength of the thin nozzle portion decreases due to poor insulation, and base metal tends to adhere to the nozzle portion where the temperature is relatively low.

In this way, uneven thickness deteriorates the quality of the nozzle as a product.

Further, after pouring the mortar into the gap 5, it is necessary to remove the centering rubber 3. However, since this extraction is performed after the mortar has solidified, there may be cases where the centering rubber 3 cannot be removed.

A device that eliminates manual labor that requires such skill and produces nozzles with no uneven thickness was developed in the 1980s.
It is disclosed in Publication No. 30717. The device disclosed in this publication includes a mechanism for applying mortar to the outer periphery of the nozzle body and then fitting the metal case into the nozzle body while maintaining a predetermined positional relationship. When this device is used, accurate centering work can be performed stably, and a mortar layer without uneven thickness can be formed.

[Problem that the invention attempts to solve]

The proposal of this Japanese Utility Model Publication No. 60-30717 is to ensure that accurate centering work is performed.
However, this requires specialized equipment. That is, although a product of excellent quality can be obtained, this method requires a dedicated device, so it cannot be said to be a practical solution.

Therefore, the present invention makes it possible to easily perform centering work when inserting the metal case into the nozzle body without requiring such a dedicated device, and provides a nozzle with excellent quality. The purpose is to

[Means for solving the problem] The nozzle holding case for a molten metal container of the present invention has the following features:
In order to achieve this purpose, it is characterized by being formed into a cylindrical shape, with an inner surface having a plurality of protrusions per circumference, and the protrusions supporting the outer wall of the nozzle body disposed inside. do.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained with reference to the embodiments shown in FIGS. 1 and 2.

FIG. 1 shows the nozzle body fitted with a metal case. This metal case 4 has a plurality of protrusions 7 formed near its upper end and near its lower end. Three to five protrusions 7 are provided on the circumferential surface of the metal case 4 per round. metal case 4
Since the outer wall of the nozzle body 2 contacts this protrusion 7 inside, the gap 5 between the nozzle body 2 and the metal case 4 is regulated by the protrusion 7. As a result, the nozzle hole 1 will be maintained in a fixed position.

Note that, of course, the circumferential surface of the metal case 4 where the plurality of protrusions 7 are formed is not limited to the circumferential surface that is geometrically on the same plane. That is, as long as the nozzle body 2 is supported by the plurality of protrusions 7 provided on the circumferential surface of the metal case 4, the plurality of protrusions 7 are arranged on the circumferential surface of the metal case 4 with a slight shift in the vertical direction. It's okay if it's done.

In this state, a refractory material is poured into the gap 5, the nozzle body 2 is fixed to the metal case 4, and the nozzle body 2 is assembled into a sliding nozzle device. Alternatively, depending on the application, the state shown in FIG. 1 can be used as a nozzle for a molten metal container.

Here, the material of the metal case 4 is steel, Fe alloy, Ni alloy, Cr alloy, which has excellent heat resistance, oxidation resistance, wear resistance, etc., considering the usage conditions of the nozzle.
There are Ni-Cr alloy, Ni-Fe alloy, Ni-Cr-Fe alloy, etc. Furthermore, the size of the metal case 4 is determined depending on the size of the nozzle body 2;
Approximate height 200-300mm, minor diameter 140-180mm
It is made of a metal plate approximately 12mm thick. The protrusion 7 is formed to have a height of approximately 1.5 to 2.5 mm.

Furthermore, examples of the refractory material poured into the gap 5 include mortar, castable refractories, and range-covered refractories for pouring. Moreover, examples of the refractory aggregate to be mixed with this include alumina, mullite, silica, clay, zircon, and zirconia. These monolithic refractories are supplied to the gap 5 between the nozzle body 2 and the metal case 4 by a casting method. When the monolithic refractory is poured while applying vibration, it can be sufficiently spread into the gap 5 between the nozzle body 2 and the metal case 4. Alternatively, a method may be adopted in which the nozzle body 2 is coated with an amorphous refractory and the metal case 4 is placed over it. The refractory material applied in this way is then hardened by drying or heating.

FIG. 2 shows an example of a sliding nozzle device incorporating a nozzle with a metal case manufactured in this manner.

The sliding nozzle is attached to the bottom 8 of the molten metal vessel. A fixed plate 10 is housed in an upper metal frame 9 fixed to the bottom part 8, and a sliding plate 13 is housed in a sliding metal frame 12 that slides along a lower metal frame 11. The sliding plate 13 is arranged so as to be able to slide relative to the fixed plate 10. A lower nozzle 14 is attached to the sliding plate 13, and molten metal is tapped from the container through the lower nozzle 14.

In this example, a metal case 15 is attached to the fixed plate 10, sliding plate 13, and lower nozzle 14 of the sliding nozzle. Protrusions 16 are provided at appropriate locations on the metal case 15.
are provided to form an appropriate gap between the fixed plate 10, the sliding plate 13, and the refractory material forming the main body of the lower nozzle 14. The projections 16 ensure that the positional relationship between the metal case 15 and the refractory material constituting the main body is maintained accurately, and the nozzle holes do not shift between the fixed plate 10, the sliding plate 13, and the lower nozzle 14.

Especially in the lower nozzle 14, the case 1
Since the position relative to 7 is maintained accurately, for example, when the case 17 is attached to the sliding metal frame 12 using a bayonet method, the alignment of the nozzle holes of the sliding plate 13 and the lower nozzle 14 is ensured. .
Furthermore, the work of removing the lower nozzle 14 from the case 17 becomes easier.

Therefore, tapping is ensured while maintaining the effective nozzle diameter as designed, and air is not drawn in from the outside into the tapped molten metal flow. Also, a fixed plate 10, a sliding plate 13, and a lower nozzle 14
Since there is no bias in the temperature distribution in the nozzle, cracks due to thermal stress do not occur in the nozzle body, and the durability of the nozzle is improved.

Returning to FIG. 1 again, other functions of the protrusion 7 will be explained. The nozzle hole 1 of the nozzle body 2 is
As the nozzle body 2 is used, the refractory material constituting the body is eroded, resulting in a size larger than the originally designed size. If the deformation of the nozzle hole 1 exceeds a permissible value, the nozzle body 2 must be repaired.

When performing this repair, in the nozzle of the present invention, the refractory material constituting the nozzle body 2 is held in a state where it is caught on the protrusion 7 provided on the metal case 4. Therefore, even if the nozzle is removed from the device as shown in FIG. 2, the refractory will not come off from the metal case 4. Therefore, the nozzle can be repaired as follows by using the refractory material remaining in the metal case 4 as an outer layer.

First, place the nozzle hole 1 at the center of the nozzle body 2.
Insert a core of size equivalent to . Then, a castable or other refractory is poured into the gap between the remaining refractory and the core and solidified. As a result, a nozzle body 2 having a nozzle hole of the designed size is completed.

In this way, the holding case of the present invention has the effect of making the work easier even in the case of nozzle repair.

[Effect of idea]

As described above, in the nozzle holding case for a molten metal container of the present invention, the nozzle body is held in an accurate position by the projections provided on the inner surface of the metal case. Therefore, the metal case can be attached to the nozzle body without requiring a special machine. Therefore, the thickness of the refractory material layer formed between the nozzle body and the metal case is uniform, making it easy to install the nozzle into an actual machine.
Accurate centering of the nozzle hole is possible, and temperature distribution is made uniform when the nozzle is in use. As a result, the molten metal can flow out under favorable conditions, and the durability of the nozzle is also improved. Further, even when repairing a nozzle that has been melted and damaged as a result of use, the nozzle holding case also functions as a formwork, making the repair work easier. In this way, the present invention exhibits great effects.

[Brief explanation of drawings]

FIG. 1 shows a nozzle body equipped with a nozzle holding case for a molten metal container according to an embodiment of the present invention.
FIG. 2 shows an example in which the nozzle body is incorporated into a sliding nozzle device. Further, FIG. 3 shows an example of conventional manual mounting of a metal case.

Claims (1)

[Scope of utility model registration request] It has an inner surface with multiple protrusions per circumference,
1. A nozzle holding case for a molten metal container, characterized in that the case is formed into a cylindrical shape so as to support the outer wall of a nozzle body disposed inside with the protrusion.