JPH069738U - Nozzle for molten metal container - Google Patents

Abstract

(57) [Summary] [Purpose] The present invention aims to facilitate the operation of taking out the residual solidified metal generated after the processing of the molten metal processing container. [Structure] In a nozzle refractory for a molten metal container, in order to prevent thermal stress cracking due to a temperature difference between an inner surface and an outer surface of a nozzle hole in which the nozzle main body is made of a low-strength heat-insulating MgO refractory, which initially occurs , Nozzle refractory with a thin-walled refractory sleeve inside the nozzle bore and a metal case on the outer circumference, and the stress that the nozzle refractory gives to the nozzle when the coagulated metal is taken out when the coagulated metal in the nozzle bore occurs after the molten metal treatment. By easily destroying the nozzle refractory, the workability of the solidified metal can be greatly improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a nozzle to be attached to the bottom wall of a molten metal container such as a ladle and a tundish.

[0002]

[Prior art]

 Since slag usually floats on the upper surface of the molten metal contained in a molten metal container such as a ladle and a tundish, when the entire amount of this molten metal is cast, the slag is mixed in the slab and the slag is The quality is significantly impaired. For this reason, normally, the casting is completed with a slight amount of molten metal remaining at the bottom of the molten metal container. The molten metal remaining in the container is rapidly cooled and solidified. Since this solidified metal remains in the nozzle provided on the bottom wall of the molten metal container, it must be removed before the molten metal in the next charge is stored.

[0003]

[Problems to be solved by the device]

 The method of removing the solidified metal was to weld a hanging piece or the like to the upper surface of the solidified metal and hang it with a crane or the like. However, since the nozzle is made of a high-strength refractory material such as high-alumina material, the solidified metal in the nozzle and the refractory material do not easily separate. For this reason, conventionally, it was necessary to remove the solidified metal in the nozzle from above by melting and cleaning with a jet lance using oxygen.

Particularly in horizontal continuous casting, when the molten metal in the tundish is cast until the level of the molten metal becomes lower than the upper end level of the mold, cavities are formed in the upper end portion of the slab, so that a considerable amount of molten metal remains in the tundish. Have finished casting. Moreover, since the nozzle of the tundish for horizontal continuous casting is lateral, the solidified metal in the nozzle functions to prevent the lifting operation of the solidified metal in the tundish, so the nozzle is not easily destroyed.

Therefore, conventionally, it is necessary to melt and wash the solidified metal remaining in the nozzle from the outside of the tundish with a jet transformer or the like. In addition, when this work was carried out, there was a problem that the SN plate brick attached to the front surface of the nozzle was severely damaged by the molten metal and slag. An object of the present invention is to easily take out solidified metal remaining in a molten metal container such as a ladle and a tundish.

[0006]

[Means for Solving the Problems]

 The nozzle for a molten metal container of the present invention is a nozzle inserted into the bottom wall of a molten metal container, the main body of which is made of a mixture of refractory and organic fiber. A nozzle for a molten metal container is provided, in which a tubular sleeve made of refractory is inserted in the nozzle hole, and a metal case is fitted in the outer peripheral surface.

[0007]

[Action]

 The molten metal container nozzle of the present invention has low strength because the nozzle body is made of a mixture of refractory and organic fibers. Therefore, when the solidified metal remaining in the molten metal container is lifted, the solidified metal in the nozzle easily breaks the nozzle, so that the solidified metal can be easily lifted.

[0008]

【Example】

 Hereinafter, the present invention will be described based on embodiments. FIG. 1 shows a nozzle for a molten metal container according to the present invention. The nozzle 1 of the present invention comprises a nozzle body 2, a cylindrical sleeve 3 inserted in the nozzle hole of the nozzle body 2, and a metal case 4 fitted on the outer peripheral surface of the nozzle body 2.

Among the nozzle main body 2 and the tubular sleeve 3, at least the refractory material used for the nozzle main body 2 is, as shown in Table 1, MgO as a main component, which has a small bending strength and a low thermal conductivity. It is preferable that it is molded with. This refractory material is made of natural or artificial MgO powder as the main raw material, added with 2% by weight or more of organic fibers obtained by disintegrating Japanese paper or pulp into a fibrous form, and kneading the mixture with an organic binder such as resin and using a mold or the like. It is formed into a tubular shape. This organic fiber and organic binder are burned and volatilized by preheating before receiving the molten metal and high temperature heat when receiving the molten metal to form voids, which lowers the bending strength of the nozzle and further improves the heat insulating property. .

Table 1

With the nozzle body 2 alone, when the hot molten metal passes through the nozzle hole, the refractory in the inner peripheral portion of the nozzle hole thermally expands, and the outer peripheral portion of the nozzle is compared with the inner peripheral portion of the nozzle hole. Since the temperature is low, tensile stress is generated in the outer peripheral portion of the nozzle. Since the nozzle body 2 has a low strength as described above, the tensile stress causes a crack in the nozzle body 2 and the molten metal may leak out.

In the nozzle of the present invention, the metal case 4 is fitted to the outer peripheral surface of the nozzle body 2 in order to suppress the tensile stress generated in the outer peripheral portion of the nozzle. It is sufficient that the length of the metal case 4 is about 1/2 or more of the total length of the nozzle 1 as shown in the figure. If the metal case 4 is provided over the entire length of the nozzle 1, the end surface of the metal case 4 may come into contact with the molten metal and melt. On the other hand, by inserting the tubular sleeve 2 into the nozzle hole of the nozzle body 2, the wall thickness of the nozzle body 2 can be reduced, and the occurrence of cracks due to the thermal expansion of the nozzle body 2 can be further prevented. The cylindrical sleeve 3 is adhered by a mortar 5 similar to the nozzle body 2.

The tubular sleeve 3 is preferably made of a refractory material having a low bending strength like the nozzle body 2, but other refractory materials may be used. By reducing the wall thickness of the tubular sleeve 3, the temperature difference between the inner peripheral portion and the outer peripheral portion of the tubular sleeve becomes small, and the tubular sleeve 3 does not crack due to thermal expansion. A suitable thickness of the tubular sleeve 3 is 10 to 20 mm. When a refractory material having high thermal conductivity and high strength is used, the tubular sleeve 3 needs to be able to be thickened to some extent. Further, when a refractory material having low thermal conductivity and low strength is used, the wall thickness can be reduced.

FIG. 2 is a cross-sectional view of the nozzle 1 of the present invention installed as a molten metal container in a tundish for horizontal continuous casting, in which the solidified metal 7 remains at the bottom of the tundish 6 when the casting is completed. Indicates. The nozzle 1 is inserted in a tuyere brick 8 attached to the bottom of the wall surface of the tundish 6. A sliding nozzle 9 is attached to the nozzle 1. The plate brick 10b is in a closed state, and the nozzle 1 and the plate bricks 10a and 10b are filled with the solidified metal 7. Since the solidified metal 7 may adhere to the plate bricks in some cases, a tubular sleeve 3 is attached to each plate brick in the same manner as the nozzle 1 in order to facilitate the removal of each plate brick.

A hanging piece 11 is welded to the remaining solidified metal 7 at a portion near the wall in the tundish. In the tundish 6, a refractory material 13 is lined on the inner surface of a steel shell 12, and a refractory heat insulating board material 14 is lined on the surface of the refractory material 13. Since the nozzle 1 of the present invention has low strength, when the solidified metal 7 is lifted by an overhead crane or the like, it is easily broken, so that the solidified metal 7 can be easily lifted out of the tundish 6. is there.

FIG. 3 shows a working state in which the solidified metal 7 is lifted from the tundish 6. In FIG. 3, the solidified metal 7 is lifted by the wire 15 in a state where the nozzle 1 is broken and a part of the nozzle 1 is missing and falls outside the tundish 6. As can be understood from this state, the solidified metal 7 can be lifted to the outside of the tundish 6 without being locked by the nozzle 1.

[0017]

[Effect of device]

 The molten metal container nozzle of the present invention easily breaks the solidified metal remaining in the molten metal container when it is lifted. For this reason, the work environment is improved and the remaining solidified metal can be easily removed, because the high heat and dust work by jet lance etc., which was conventionally performed to remove the solidified metal remaining in the nozzle hole, is improved. Since it can be taken out, the working time has been shortened to 1/5 of the conventional time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a molten metal container nozzle according to the present invention.

FIG. 2 is a sectional view of the molten metal container nozzle of the present invention attached to a tundish.

FIG. 3 is a cross-sectional view showing a state in which a solidified metal is suspended from the tundish.

[Explanation of symbols]

 1 ... Nozzle for molten metal container of the present invention 2 ... Nozzle body 3 ... Cylindrical sleeve 4 ... Metal case 5 ... Mortar 6 ... Tundish 7 ... Solidified metal 8 ... Tuyere brick 9 ... Sliding nozzle 10a ... Plate brick 10b ... Plate bricks 11 ... Hanging pieces 12 ... Iron skin 13 ... Tundish-lined refractory materials 14 ... Fire-resistant heat-insulating board material 15 ... Wires

Claims (1)

[Scope of utility model registration request] 1. A nozzle to be inserted into a bottom wall of a molten metal container, the main body of the nozzle being formed of a mixture of refractory material and organic fiber, and the refractory material being provided in a nozzle hole of the nozzle body. A nozzle for a molten metal container, wherein a tubular sleeve made of metal is inserted, and a metal case is fitted on the outer peripheral surface.