JPH04344855A - Method for heating tundish for continuous casting - Google Patents

Abstract

PURPOSE:To prevent the damage of a sliding nozzle by specifying the position of a steel-made pipe inserted into a molten steel supplying hole in the sliding nozzle to be heated. CONSTITUTION:In the case of heating a tundish 21 for continuous casting by setting the sliding nozzle 25 at a lower part after removing slag, the steel-made pipe 1 having the same outside diameter as the inside diameter of the molten steel supplying hole is inserted into the molten steel supplying hole in the sliding nozzle 25 so that the upper end positions are higher than upper face of a bottom part refractory 23 in the sliding nozzle 25 and the lower end positions is lower than lower end of a lower nozzle 28 and heated. By this method, an upper nozzle 24, the sliding nozzle 25 and the lower nozzle 28 of the tundish 21 for continuous casting are not damaged.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for heating a continuous casting tundish used in continuous casting of steel.

0002

[Prior Art] Tundishes used in continuous steel casting have conventionally been cooled after each casting in order to replace the refractories and maintain the sliding nozzle for pouring molten steel into the mold. was. However, recently, the lifespan of refractories has been extended, so instead of cooling the tundish and replacing the refractories after each casting, it is now possible to perform several consecutive castings by simply servicing the sliding nozzle. (called hot tundish rotation). In such hot tundish rotation, after the sliding nozzle has been serviced, a heating source is placed above the tundish so that the molten steel for the next pouring is not cooled when it is injected. The refractory material in the tundish is heated.

0003

[Problem to be Solved by the Invention] However, when the refractory of the tundish is heated in this way, the slag and base metal remaining on the refractory from the previous casting start to melt, causing problems in the sliding nozzle. It flows into the molten steel inlet and damages the upper nozzle (argon gas blowing nozzle) located above the sliding nozzle, the fixed plate and sliding plate of the sliding nozzle, and the lower nozzle located below the sliding nozzle (erosion due to slag). , clogging of the gas injection brick part of the argon gas injection nozzle, etc.)
There is a problem with that. Conventionally, no method has been established for preventing such damage to the sliding nozzle.

An object of the present invention is to provide a heating method for a continuous casting tundish that prevents damage to the sliding nozzle and the like during heating of the tundish during hot tundish rotation, which has not been seen before.

[0005]

[Means for Solving the Problems] A heating method for a continuous casting tundish according to the present invention is a heating method for heating a continuous casting tundish after slag has been discharged while keeping the sliding nozzle in a downward position. At the molten steel supply port of the nozzle, place a steel or refractory pipe with an outer diameter approximately the same as the inner diameter of the supply port, with its upper end located at a higher position than the top surface of the bottom refractory of the sliding nozzle, and whose lower end is located at a lower position. It is heated by fitting the nozzle so that it is located below the lower end of the nozzle.

[0006] In the above method, a steel pipe having an outer diameter larger than the outer diameter of the steel or refractory pipe is placed above the steel or refractory pipe to be fitted into the molten steel supply port of the sliding nozzle. This is a method of connecting and heating.

Furthermore, in the heating method of heating the continuous casting tundish after slag is discharged while keeping the sliding nozzle in a downward position, the above-mentioned supply is placed on the upper surface of the refractory which is continuous with the molten steel supply port of the sliding nozzle. This is a method of heating by placing a steel or refractory pipe with an inner diameter larger than the inner diameter of the mouth.

[0008]

[Operation] The continuous casting tundish heating method according to the present invention is a heating method in which the continuous casting tundish after slag is heated while the sliding nozzle is kept in a downward position. The sliding nozzle is protected by a steel or refractory pipe to prevent damage to the sliding nozzle from inflow of slag or metal that has melted due to heating.

[0009]

[Example] Fig. 1 shows a heating method for a continuous casting tundish according to a first embodiment of the present invention, Fig. 2 shows a heating method for a continuous casting tundish according to a second embodiment, and Fig. 2 shows a heating method for a continuous casting tundish according to a second embodiment of the present invention. A method of heating a casting tundish will be explained with reference to FIG. Figure 1~
In FIG. 3, reference numeral 21 is a tundish, 22 is an iron shell of the tundish, 23 is a refractory of the tundish, 2
4 is an upper nozzle, 25 is a sliding nozzle, 26 is a fixed plate of the sliding nozzle, 27 is a sliding plate of the sliding nozzle, and 28 is a lower nozzle.

In the heating method for the continuous casting tundish of the first embodiment shown in FIG. 1 is fitted into a sliding nozzle 25 and heated. At this time, the upper end 1a of the pipe 1 is connected to the upper surface 2 of the bottom refractory 23.
I am trying to make it higher than 3a, but the height H is 5
It is set to about 0 to 200 mm to prevent slag and base metal melted during heating from overflowing from the upper end 1a of the pipe 1. Further, the lower end 1b of the pipe 1 is positioned below the lower end 28a of the lower nozzle 28 to prevent slag and metal from entering.

In the method of heating a continuous casting tundish according to the second embodiment shown in FIG. I put it on and heat it. At this time, the height of the upper end 2a of the composite pipe 2 from the refractory is the same as in the first embodiment, and the lower end 2b of the composite pipe 2 is the same as in the first embodiment. Moreover, the outer diameter of the small diameter portion 2d is the sliding nozzle 25.
The tapered part 2c is the same as the through hole of the upper nozzle 24.
The taper is set to match the taper of the upper nozzle 24 to prevent slag or base metal from adhering to the upper nozzle 24.

In the heating method of the continuous casting tundish of the third embodiment shown in FIG. 3, a ring-shaped packing 4 made of mortar is placed on the bottom refractory 23 above the upper nozzle 24, and a short pipe 3 put The inner diameter of the short pipe 3 is larger than the outer diameter of the upper nozzle 24, and the upper end 3a of the short pipe 3
is placed in the same position as in the first and second embodiments.

FIGS. 4 to 8 are explanatory diagrams showing the procedure from the end of casting to heating of the tundish. As shown in FIG. 4, slag 5 and base metal 6 remain at the bottom of tundish 21 after casting. As shown in FIG.
Exhaust from 0 to outside. In the case of the first embodiment, the pipe 1 is inserted from below the sliding nozzle 25 as shown in FIG. In the case of the third embodiment, as shown in FIG. 7, a short pipe 3 with a mortar ring-shaped packing 4 fixed to the lower part is hung by a rope 8 stretched over a pulley 7, and the lid of the tundish 21 is suspended. It is lowered onto the refractory 23 through the heating burner insertion opening 31 provided in the refractory 29 .

In the case of the second embodiment as well, a hanging jig is used to suspend the heating burner from the opening 31 for insertion.

After setting the pipe in this way, as shown in FIG.
As shown in the figure, the heating burner 32 is inserted through the opening 30 and heating is started. Reference numeral 10 in FIGS. 6 and 8 indicates slag and metal that remain after the slag and steel are discharged.

In the continuous casting tundish heating method of the present invention, since they are protected by the pipe as described above, the upper nozzle, sliding nozzle, and lower nozzle are not damaged by melted slag or base metal. do not have.

[0017]

According to the present invention, the upper nozzle, sliding nozzle and lower nozzle of a continuous casting tundish are not damaged by slag or base metal.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a heating method for a continuous casting tundish according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a heating method for a continuous casting tundish according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a heating method for a continuous casting tundish according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram showing the procedure of the heating method for a continuous casting tundish of the present invention.

FIG. 5 is an explanatory diagram showing the procedure of a method for heating a continuous casting tundish according to the present invention.

FIG. 6 is an explanatory diagram showing the procedure of the method of heating a continuous casting tundish of the present invention.

FIG. 7 is an explanatory diagram showing the procedure of a heating method for a continuous casting tundish of the present invention.

FIG. 8 is an explanatory diagram showing the procedure of a heating method for a continuous casting tundish of the present invention.

[Explanation of symbols]

1 Pipe 2 Composite pipe 3 Short pipe 4 Mortar packing 5 Slag 6 Bullion 7 Pulley 8 Rope

Claims (3)

[Claims] 1. A heating method in which a continuous casting tundish after slag is heated while a sliding nozzle is kept in a downward position, wherein a molten steel supply port of the sliding nozzle is provided with an outer diameter that is approximately the same as an inner diameter of the supply port. A steel or refractory pipe is fitted and heated so that its upper end is located higher than the top surface of the bottom refractory of the sliding nozzle, and its lower end is located below the lower end of the lower nozzle. A heating method for a continuous casting tundish characterized by: Claim 2: A steel pipe having an outer diameter larger than the outer diameter of the steel or refractory pipe is connected above the steel or refractory pipe to be fitted into the molten steel supply port of the sliding nozzle. 2. The method of heating a continuous casting tundish according to claim 1, further comprising heating the continuous casting tundish. 3. In a heating method for heating a continuous casting tundish after slag discharge while keeping a sliding nozzle in a downward position, a supply port is provided on an upper surface of a refractory that is continuous with a molten steel supply port of the sliding nozzle. A method of heating a continuous casting tundish, which is characterized by heating a steel or refractory pipe with a larger inner diameter than the inner diameter of the continuous casting tundish.