JPH09276997A - Tundish nozzle for hot rotation-tuyere structure - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To use a tundish nozzle for hot rotation used for continuous casting of molten steel in a tuyere structure, when an immersion type integrated immersion nozzle is used, due to fragmentation of mortar when the nozzle is inserted. It prevents molten steel from penetrating into joints, eliminates surface roughness on the inner surface of tuyere bricks, and prevents leakage of molten steel during casting to extend the life of tuyere bricks. SOLUTION: In a nozzle tuyere of a tundish, an uneven groove or stripe or a convex dimple is formed on the outer peripheral surface of the upper nozzle part brick of the upper nozzle integrated dipping nozzle to be inserted into the tuyere from below the tuyere, The mortar filled in the joints between the nozzle bricks and the tuyere bricks is fixed to the grooves or stripes or the convex dimples on the outer peripheral surface of the upper nozzle bricks.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle-tuyere structure of a tundish for hot rotation used for continuous casting of molten steel.

[0002]

2. Description of the Related Art In recent years, in continuous casting of molten steel, hot rotation has been carried out for the purpose of extending the life of the tundish and reducing repair work. This hot rotation means that the tundish that has been cast is used for casting again after cooling the flow control refractory such as the dipping nozzle without hot cooling and repairing as usual. The cost of lining refractory and the repair cost can be reduced.

In the tundish for hot rotation, an externally integrated type nozzle in which a portion corresponding to the upper nozzle (hereinafter, the upper nozzle portion) is integrated with a normal immersion nozzle has been put into practical use. As shown in FIG. 4, this extra-insertion-integrated nozzle 2 is provided with mortar 3 applied to the surface of the upper nozzle portion 2a, or with mortar having a joint thickness preformed in the upper nozzle shape attached to the upper nozzle portion. It is inserted from below the mouth 1 and fixed.

[0004]

In the conventional nozzle-tuyere structure, when the outer insertion integral type nozzle is inserted into the tuyere, the mortar is cut off due to the contact between the upper nozzle brick and the tuyere brick, and In some cases, mortar was not filled, and it was not possible to completely prevent molten steel from entering the joint. Also,
After casting, when pulling out to replace the nozzle,
Since the mortar solidified by the heating during casting remains on the tuyere side, hot tuyere cleaning is required. Since this tuyere cleaning mechanically removes the mortar solidified and adhered to the tuyere brick, it also removes the surface of the tuyere brick at the same time as the mortar, and the surface roughness of the inner surface of the tuyere brick reduces the life of the tuyere brick. It was the cause. In addition, the rough surface of the inner surface of the tuyere bricks results in widening the joints, and since the joints are not completely filled with mortar alone, molten steel may leak during casting. It was necessary to apply a repair material.

It is an object of the present invention to provide a tundish nozzle-tuyere structure that eliminates the need for tuyere cleaning that causes mortar breakage when the nozzle is inserted and roughening of the tuyere brick inner surface. To do.

[0006]

DISCLOSURE OF THE INVENTION The gist of the present invention is to provide a nozzle for hot tundish used for continuous casting of molten steel-a tuyere structure in which the upper nozzle is inserted into the tuyere from below the tuyere. When a groove or a strip having a plurality of steps is provided on the outer peripheral surface of the upper nozzle part brick of the integrated type immersion nozzle, when the upper nozzle integrated type immersion nozzle is attached to and detached from the tuyere brick, The mortar filled in the joints is fixed to grooves or stripes having unevenness on the outer peripheral surface of the upper nozzle brick, the nozzle-tuyere structure of the hot rotating tundish, and the molten steel. Nozzle of tundish for hot rotation used for continuous casting of a nozzle-in the structure of the tuyere, a plurality of convex dimples are formed on the outer peripheral surface of the upper nozzle part brick of the upper nozzle integrated dip nozzle to be inserted into the tuyere from below the tuyere. Provided The mortar filled in the joints between the upper nozzle brick and the tuyere brick was fixed to the convex dimples on the outer peripheral surface of the upper nozzle brick when the nozzle-integrated immersion nozzle was attached to and removed from the tuyere brick. The nozzle-tuyere structure of the tundish for hot rotation.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. 1 is a tuyere brick fixed to a tundish. Reference numeral 2 is an external insertion type immersion nozzle, which is inserted into the tuyere from below the tundish. Reference numeral 2a is an upper nozzle portion of the immersion type integrated immersion nozzle 2. An uneven groove (or line) is formed on the outer peripheral surface of the upper nozzle portion 2a. The concave and convex grooves may be concentric circles or spirals when viewed from above the upper nozzle. Further, there is no limitation on the height and pitch of the cross section of the groove having the unevenness. The cross-sectional shape of the groove may be, for example, square, triangular, trapezoidal or the like.

Further, 3 is a mortar, which is hot-applied on the outer peripheral surface of the upper nozzle portion of the dipping nozzle 2 with an integrated insertion, or is attached to the upper nozzle portion 2a in a state of being preliminarily molded into the upper nozzle shape. There is no particular limitation on the joint thickness between the tuyere brick 1 and the external insertion type immersion nozzle 2. Moreover, the inclination angle of the inner surface of the tuyere brick 1 is not particularly limited. Since the mortar 3 is in close contact with the concave and convex grooves on the surface of the immersion nozzle 2a, the upper nozzle brick and the tuyere brick are not fragmented by the shearing force when they are inserted into the external insertion type immersion nozzle, and the joint is mortar. Filled with. Therefore, it is possible to prevent the molten steel from entering the joint during casting. Reference numeral 4 is an inner hole of the immersion type integrated immersion nozzle 2 through which molten steel passes. Reference numeral 5 denotes a discharge hole of the dip nozzle 2 with an integrated insertion type, which is a hole through which molten steel flows into the mold.

FIG. 2 is a view showing an example of the convex dimple of the present invention, and 6 is the convex dimple. The convex dimple 6 is shown in FIG.
In addition to such a cylinder, a cone, a prism, a hemisphere or the like may be used. The height of the convex dimples 6 may be equal to or less than the joint thickness, and the pitch between the convex dimples is not limited.

FIG. 3 is a view showing a state in which the casting is completed and the immersion nozzle of the external insertion type is pulled out downward. Since the mortar 3 is in close contact with the mortar 3 due to the uneven grooves on the surface of the upper nozzle portion, the solidified mortar 3 does not remain on the tuyere brick 1 side even when the dipping nozzle 2 is pulled out, and the upper nozzle portion 2
It is attached to a. Therefore, the tuyere cleaning is not required, and as a result, the inner surface of the tuyere brick is not roughened and the repair is not required, the life of the tuyere brick is improved, and the possibility of molten steel leakage after the nozzle replacement is eliminated.

[0011]

According to the tundish nozzle-tuyere structure of the present invention, the mortar is the upper nozzle by providing the outer peripheral surface of the upper nozzle portion of the external insertion type immersion nozzle with uneven grooves or stripes or convex dimples. It does not fill the joint with the mortar because it does not break due to the shearing force when the nozzle is inserted. Therefore, molten steel can be prevented from entering the joints during casting, and stable casting can be realized. In addition, since the mortar is in close contact with the upper nozzle even when the nozzle is pulled out, mortar does not remain on the tuyere brick side and tuyere cleaning is not required, improving work efficiency and tuyere brick life. And the cost of repair materials is unnecessary. Furthermore, since the inner surface of the tuyere brick is not rough, it is possible to prevent molten steel from entering the joints even after the nozzle is replaced, and stable casting can be realized.

[Brief description of drawings]

FIG. 1 is a tundish nozzle-tuyere sectional structure showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a convex dimple according to another embodiment of the present invention.

FIG. 3 is a view showing a state in which an external insertion type immersion nozzle is pulled out downward.

FIG. 4 is a conventional tundish nozzle-tuyere sectional structure.

[Explanation of symbols]

 1 Tuyere brick 2 External insertion type immersion nozzle 2a External insertion type immersion nozzle Upper nozzle part 3 Mortar (joint) 4 Inner hole 5 Discharge hole 6 Convex dimple

Claims (2)

[Claims] 1. A brick outer circumference of an upper nozzle portion of an immersion nozzle integrated with an upper nozzle which is inserted into a tuyere from a lower side of a tuyere in a nozzle-tuyere portion of a hot rotating tundish used for continuous casting of molten steel. When the groove or strip having multiple steps of unevenness is provided on the surface and the upper nozzle integrated dipping nozzle is attached to or removed from the tuyere brick, the mortar filled in the joint between the upper nozzle part and the tuyere brick is A nozzle-tuyere structure for a tundish for hot rotation, characterized in that it is fixed to a groove or a strip having unevenness on the outer peripheral surface of the brick. 2. In the structure of the nozzle-tuyere part of the tundish for hot rotation used for continuous casting of molten steel, the outer periphery of the upper nozzle part of the upper nozzle integrated dipping nozzle to be inserted into the tuyere from below the tuyere. When a plurality of convex dimples are provided on the surface and the upper nozzle-integrated dipping nozzle is attached to or removed from the tuyere brick, the mortar filled in the joints between the upper nozzle portion brick and the tuyere brick is A nozzle-tuyere structure of a tundish for hot rotation, characterized in that it is fixed to a convex dimple.