JPH1190592A - Lower nozzle of ladle for continuous casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the stagnation of flow around the connecting part, a long nozzle to effectively prevent the sticking of the metal in a nozzle. SOLUTION: In a lower nozzle 2 of a ladle for continuous casting, the lower nozzle 2 is formed as the inclination 2T in the inner surface of the nozzle so that the pouring passage in the nozzle 2 enlarges toward the outlet at the lower end of the nozzle. The outlet at the lower end of this lower nozzle 2 is connected with the inlet at the upper end of the long nozzle 3 arranged so as to pour the molten metal into the tundish at the time of continuously casting. In such a way, the stagnation of the flow is eliminated by forming the inclination, and the metal is not stuck to the nozzle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lower nozzle of a ladle for continuous casting, and more particularly to a shape of the lower nozzle.

[0002]

2. Description of the Related Art In continuous casting of steel, for example, as shown in FIG. 3, molten metal (molten steel) is first injected into a tundish 4 from a ladle 1 via a lower nozzle 2 and a long nozzle 3 in order. From there, the tundish intermediate nozzle 5,
This is performed in a process of being injected into the mold 7 through the immersion nozzle 6. Then, the solidified shell formed in the mold 7 is continuously pulled out by the roll 8.

When the molten steel in the ladle 1 runs out, the ladle 1 is replaced while the molten steel remaining in the tundish 4 is poured into the mold 7. Meanwhile, at the time of casting molten steel, as shown in FIG.
The stagnation of molten steel occurs just below the connection between the metal and the long nozzle 3, and the metal 11 adheres. In FIG. 3, reference numeral 9 denotes a sliding nozzle as a molten steel passage opening / closing valve, and reference numeral 10 denotes a seal packing for sealing a gap between a connecting portion between the lower nozzle 2 and the long nozzle 3.

If the metal is not removed at the time of ladle replacement, poor sealing occurs between the lower nozzle and the long nozzle at the next ladle injection, causing serious problems in quality and operation such as reoxidation of molten steel. . Therefore, at present, during ladle replacement work,
As shown in the figure, the worker removes the bullion 11 by peeling it off with a crowbar 14 or washing it with oxygen. FIG.
, 12 is a long nozzle holder.

[0005] Regarding oxygen cleaning, Japanese Patent Application Laid-Open Nos. 57-115968 and 4-270038 propose a method for efficiently or safely removing metal. On the other hand, from the viewpoint of preventing metal adhesion, Japanese Patent Application Laid-Open No. 4-294847 proposes a method of forming a heat insulating layer in a nozzle to suppress metal adhesion.

[0006]

The conventional method of removing metal by using bur and oxygen scrubbing has a low work efficiency.
There were also safety issues (burns, etc.). Further, Japanese Patent Application Laid-Open No.
The technology disclosed in Japanese Patent Application Laid-Open No. 115968/1992 and Japanese Patent Application Laid-Open No. 4-270038 has a problem that the work load of the sliver removal by the operator is increased. Further, the technique disclosed in Japanese Patent Application Laid-Open No. 4-294847 has a problem in that the method of manufacturing the nozzle is complicated, the nozzle cost is increased, and the strength of the refractory is increased.

In view of the above, the present invention provides a lower nozzle of a continuous casting ladle having a shape which does not cause flow stagnation around a connection portion with a long nozzle in order to effectively prevent adhesion of metal in the nozzle. The purpose is to do.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a lower nozzle of a ladle for continuous casting, in which the inner surface of the nozzle is inclined so that the molten metal flow path in the nozzle expands toward the nozzle lower end outlet. It is a lower nozzle of a ladle for continuous casting. The nozzle lower end outlet is connected to an upper end inlet of a long nozzle provided for pouring into a tundish during continuous casting.

[0009]

FIG. 1 is a sectional view showing an example of the present invention. In FIG. 1, 2T is an inclination, and the same or corresponding parts as those in FIG.
As shown in the figure, in the present invention, in the lower nozzle 2 of the ladle for continuous casting, the inner surface of the nozzle is inclined 2 so that the molten metal flow path in the nozzle expands toward the nozzle lower end outlet.
The gist is to add T. The nozzle lower end outlet is connected to an upper end inlet of a long nozzle 3 provided for pouring into a tundish during continuous casting.

FIG. 2 is a diagram illustrating the operation of the present invention. In FIG. 2, 13 is a molten steel flow, (a) is a conventional example, and (b) is an invention example, and the same or corresponding parts as those in FIG. As shown in FIG. 2A, the lower nozzle 2 is connected to the long nozzle 3 in such a manner that the lower end of the lower nozzle is fitted into the upper end of the long nozzle 3. The cross-sectional area of the road is constant in the casting direction, so that a step corresponding to the thickness of the lower end of the lower nozzle 2 is formed at this connection portion,
Since the molten steel flow 13 inevitably forms stagnation at the corners formed by the steps, the metal 11 has adhered to the corners.

On the other hand, according to the present invention, FIG.
As shown in the figure, the inclined surface 2T in which the outlet expands is provided on the inner surface near the nozzle lower end outlet of the lower nozzle 2, so that the steps and corners are eliminated, and the molten steel flow 13 remains on the inner surface of the nozzle even near the connecting portion. The stagnation does not occur because the stagnation does not occur by flowing smoothly along the slab. Incline 2T
About the angle and the like can be appropriately determined by a model experiment or the like corresponding to each continuous casting facility.

Although the present invention has been described with reference to continuous casting of molten steel as an example, it is obvious from the above-mentioned operation that the present invention is applicable to continuous casting of molten metal other than molten steel. It is.

[0013]

As described above, according to the present invention, it is possible to prevent sticking of metal in the long nozzle simply by inclining the lower end inside the nozzle of the ladle lower nozzle, so that it can be performed manually without increasing the cost of the nozzle or reducing the refractory strength. Ingot removal work can be omitted,
It has an excellent effect that the safety and efficiency of ladle replacement work are significantly improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of the present invention.

FIG. 2 is an explanatory diagram of the operation of the present invention.

FIG. 3 is an explanatory view of a continuous casting method.

FIG. 4 is an enlarged view of a portion A in FIG. 3;

FIG. 5 is an explanatory view showing a conventional example of a method for removing adhered metal in a nozzle.

[Description of Signs] 1 Ladle 2 Lower Nozzle 2T Incline 3 Long Nozzle 4 Tundish 5 Tundish Intermediate Nozzle 6 Immersion Nozzle 7 Mold 8 Roll 9 Sliding Nozzle 10 Seal Packing 11 Metal 12 Long Nozzle Holder 13 Molten Steel Flow 14 Bar

Claims (2)

[Claims] 1. A lower nozzle of a ladle for continuous casting,
A lower nozzle of a ladle for continuous casting, wherein an inner surface of the nozzle is inclined so that a molten metal flow path in the nozzle expands toward a nozzle lower end outlet. 2. The lower nozzle according to claim 1, wherein the lower end outlet of the nozzle is connected to an upper end inlet of a long nozzle provided for pouring into a tundish during continuous casting.