JPS5992150A - Preheating method of tundish and tundish used therefor - Google Patents

Abstract

PURPOSE:To remove the moisture of refractory bricks by evaporation and to improve the thermal efficiency of a preheating burner by sandwiching carbon refractories between a heat insulation zone in a tundish and the refractory bricks and using an electrical heating means for the carbon refractories. CONSTITUTION:The drying and heating of the lining in a tundish 1 is necessary to assure safety and to prevent the adhesion of a molten metal but refractory bricks 4 transmit poorly heat and the removal of the internal moisture is not easy even if a burner 7 is used for preheating. Carbon refractory bricks 3 are sandwiched between the heat insulating zone 2 and the bricks 4 in the tundish 1 and are electrically heated, by which the internal moisture is evaporated off quickly and the preheating efficiency of the preheating burner 7 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preheating a tundish and a tundish used for cooking, and more particularly, to a method for preheating a tundish that can uniformly and completely heat the inside of the tundish. Used for Rabiniso Jl - "Related to Tanditshu".

In continuous casting equipment, a tongue tissue guides molten steel from a large-capacity container such as a ladle to a mold (an intermediate ladle is used, and a tongue tissue is used to introduce molten steel from two or more nozzles into the mold). The molten steel is injected into the mold, and the molten steel injection V into the mold is always kept constant.This tundish is usually made of bricks on the inside of the outer shell, lined with a monolithic refractory, and injected into the bottom. A nozzle is provided.The injection nozzle is replaced after each unit casting. L- or 1
．． In addition to replacing the nozzle, the inner surface of the tanditshu and
However, it is easy for bullion and slag to accumulate (because if it is used as it is for the first casting, the quality of the slab may change or deteriorate due to the contamination of deposits, so remove the deposits after each unit casting. Removal of refractory linings is carried out, and when the refractory lining is damaged due to its removal, repair of the damaged parts is also carried out.

From this point of view, 7-gnesia boards and magnesia-based coating materials are used in the refractory lining layer of tan tissue and the parts that come into direct contact with the welding process, from the perspective of cleaning the steel and simplifying the disposal of residual steel. In addition, it is used to prevent the temperature of molten steel from decreasing and to remove water used during tanditshu construction.

The tandish is usually preheated from the top with a burner. However, in the conventional preheating method, the internal mixing temperature is lower than the surface temperature of the refractory lining layer, and when the molten steel is fused, the temperature of the molten steel decreases due to heat loss to the refractory lining.

Since the moisture during construction of the tandish is not completely removed during preheating, moisture enters the ladle and causes the problem of contamination of the molten steel.

ffx In other words, the refractory lining is usually preheated by applying a burner from the top of the refractory lining as described above.With this preheating method, the surface of the refractory lining is [Although the temperature exceeds 1000C, the temperature of the inner lining brick does not rise that much, and furthermore, the temperature at the interface between the lining brick and the outer steel skin]
Around 00 C 11 Cl - It's definitely powerful.

Therefore, when receiving molten steel, the heat retained in the molten steel inside the refractory lining is lost, and the degree of molten steel decreases.11. Moisture remaining during preheating during construction of the tanditsu enters the received molten steel and contaminates the molten ladle.

Regarding this point, 12. JP-A No. 52-116731 proposes a method of preheating the bottom of a tundish through an electric resistance heating element, but even with this preheating method, only the surface of the refractory lining is preheated. However, the same problem remains.

The present invention aims at the above-mentioned drawbacks and specifically.

The refractory lining allows for uniform heating inside.

We propose a preheating method and its tundish that can reduce the temperature of molten steel by 8 degrees at the initial stage of casting and remove moisture during tundish construction.

-f- Kawachi 1 Lining the inner surface of the tanditsu iron shell for continuous casting with a refractory through an insulating zone carbon-based refractory 1-1 This carbon-based refractory is energized and heated 7 1. A tanditshu according to the present invention is characterized in that the inner surface of the tanditshu iron shell is lined with an insulating zone, and the inner surface of the insulating zone is lined with a carbon-based refractory.2. Furthermore, it is characterized in that the inner surface of the carbon-based refractory is lined with a large resistant material.

The present invention will be described in detail with reference to the following drawings.
1. .

FIG. 1d is a sectional view showing a part of a tongue tissue according to one embodiment of the present invention.

The inside of the iron skin is lined with, for example, insulating bricks to form an insulating zone 2, and the inner surface of this insulating zone 2 is lined with a carbon-based refractory 3. This carbon-based refractory and 1.
As mentioned below (: iIJ electric power 2) You can use anything that generates heat.

Generally, ordinary carbon-based refractory bricks are used.

Next, a refractory lining is applied to the inner surface of the carbon-based refractory 3 in the usual manner.
For example, as shown in FIG.
-ru (in addition) 1t/ (in which the code 6 indicates the lid)
.

The tundish r having the above structure (in which the terminal is brought into contact with the carbon-based refractory 3 during preheating (F') 41M) causes the refractory 3 to generate heat. By preheating in this way, the lining refractory bricks 4 and the like are heated uniformly and completely from the inside of the lining.

For this preheating, the carbon-based refractory 3 is heated by electricity, and at the same time, the inner lining fire brick 4 and the surface of the monolithic refractory 5 are preheated using the usual method (gas burner 7 Vc). By preheating in this way, the WJJ refractory lining can be preheated more uniformly and completely by being heated from the inner and outer surfaces.

That is, since the carbon refractory brick has the property of generating heat when an electric current is passed through it, the lining brick 4 inside the refractory 3 is preheated. In this case, the heat value of the two refractory bricks 3 should be as long as a current that can heat the bricks to at least JOTl'C is applied.

In addition, since the refractory lining is preheated by the burner 7 as shown in Figure 1, the inner wall of the lining 11 and the large bricks 4 are heated to a high temperature that does not cause any trouble. At the same time, all the moisture contained in the lining brick part is evaporated and removed by this internal and external heating, and the inner wall of the lining brick reaches a high temperature that is a problem when receiving steel. Furthermore, if the tundish is used afterwards, all remaining water will be removed, eliminating the conventional problem of hot water contamination. Generally, when receiving steel, 1. It is necessary to heat the innermost wall of the tundish to a high temperature of 1,500 t:' or higher, and therefore the heating of the tundish by the burner RC is aimed at this temperature value. However, in the present invention, the internal carbon-based refractory bricks are heated to slightly (necessary for evaporation and removal of moisture) a little over 00 CJJ by energizing them.

There is no problem in this respect either.

In addition, the monolithic refractory on the surface of the lining refractory brick may be made of magnesia board or magnesia coating material, and the insulation zone has the purpose of preventing the heat of the carbon-based refractory brick for heating from escaping to the outside and has insulation properties. (1) Usually, alumina-based insulating bricks are used.17.Furthermore, it is sufficient to use low stone or alumina-based refractory bricks for the lining refractory bricks.

Also, by the way, the temperature of the t-roller preheated by a tundish having the structure shown in FIG. 1 was conventionally around 100C. The back thermal fatigue of the inner refractory brick is approximately 80 Tl t? [1] It was possible to reduce the temperature drop of the molten metal and completely remove the residual moisture in the tundish.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a part of a tundish according to one embodiment of the present invention. Code]...Iron shell 2...Insulating zone 3...Carbon-based firebrick 4...Lining brick 5...Amorphous Refractory 6... Shoes 7... Burner Patent Applicant Kawasaki Steel Co., Ltd. Agent Patent Attorney Yoshikatsu Matsushita Attorney Fumio Soejima Figure 1

Claims (1)

[Claims] ]) Lining the inner surface of the tundish iron shell for gauze casting with a lining refractory via an insulating zone and an elemental refractory, and preheating this carbon-based refractory by rectangular heating. A method of preheating a tanditshu characterized by the following. 2) The inner surface of the tanditshu iron skin is lined with an insulating zone, the inner surface of the insulating zone is lined with a carbon-based refractory, and the inner surface of the carbon-based refractory is further lined with a lining refractory. Features Tanditshu.