JPH0550198A - Slide gate - Google Patents

Abstract

PURPOSE:To efficiently prevent absorption of air from sliding face in a plate by setting seal material to a slider or a hausing and sealing space surrounded with the hausing and the slider. CONSTITUTION:By inserting the seal material 3 between a base 1 and the hausing 7 fixing and supporting the upper plate 4, invasion of the air from a tundish side of the upper plate 4 is prevented. By settinh the seal material 9 to the slider 8, sliding between the slider and the hausing 7, is executed. In the seal material 9, elasticity and flexibility are held so as to able to follow the dispersion of the size of a refractory in the upper plate 4, lower plate 6, etc., and thermal deformation of hardware of the hausing 7, slider 8, etc., and the refractory, and while sliding sealing face 10 in the hausing 7 according to movement of the slider 8, the invasion of air into closing sealed chamber 5 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slide gate installed in a molten steel discharge hole portion of a tundish used for continuous casting of steel, and particularly to a two-layer structure capable of preventing air from entering from a sliding portion. The present invention relates to the improvement of the slide gate.

[0002]

2. Description of the Related Art In a continuous casting process, a slide gate or a stopper type control device is used as a method for controlling the amount of molten steel injected from a tundish into a mold.
Slide gates are often used in continuous casting machines because they have better controllability than stoppers.

However, even with this slide gate,
Increasing of slab inclusions or pinholes due to suction of air from sliding surface or refractory ground, reduction of refractory life due to chemical reaction between suction air and refractory, reaction between suction air and Al in steel There is a problem that Al ₂ O ₃ adheres to the inner wall of the immersion nozzle due to the above.

Therefore, as a countermeasure against these problems, a seal using an inert gas (Japanese Patent Laid-Open No. 56-14196).
1), a hood for sealing atmosphere is attached (JP-A-57-52564), or a closed slide gate (JP-A-61-3653, JP-B-64-4872). JP-B-60-32924) and the like have been proposed.

[0005]

However, the method proposed above also has the following problems.

First, since the method of sealing with an inert gas only sprays the inert gas around the air suction portion, even if a shielding hood is provided, the sealing performance is insufficient, and a large amount of air is used. Requires sealing gas.
Further, when the shielding hood is provided, the amount of gas can be slightly reduced, but the shielding hood becomes large, which is unsuitable for tundish.

Next, the method of additionally providing a hood for a sealed atmosphere has the same drawbacks as the above method of sealing with an inert gas, and the provision of grooves or gas supply holes in the refractory material makes it difficult. Not only does it increase in size and cost, but it also has the drawback of promoting cracking of refractory materials.

Next, the method using the closed slide gate can be applied only to the three-layer slide gate and cannot be applied to the two-layer slide gate. In other words, since the two-layer slide gate has a small number of refractory plates, it is economical because the running cost is low, and since the air sucked from the sliding surface is small, the sealing performance is not so improved compared with the conventional one. Because it was not tried. However, when the sealing property of the joint surface between the immersion nozzle and the lower plate is improved, the sealing property of the sliding surface cannot be ignored even with the two-layer type. This is because in a two-layer slide gate, static pressure of molten steel acts on the sliding surface, but negative pressure is generated immediately after the flow rate is throttled to control the flow rate of molten steel. This is because when the object is downsized, it becomes easier to suck air.

The present invention has been made in view of the above problems of the conventional slide gate, and an object thereof is to provide an economical two-layer slide gate with improved sealability. There is.

[0010]

In order to achieve the above object, a slide gate according to the present invention is a two-layer type slide gate having a fixed upper plate and a sliding lower plate, wherein the upper plate is In the space surrounded by the housing for fixed support and the slider for slidably supporting the lower plate, the slider portion or the housing portion is provided with a seal member for sliding between the housing and the slider. There is.

[0011]

In the slide gate according to the present invention, a seal member is installed on the slider or the housing in order to slide between the housing that fixedly supports the upper plate or the slider that slidably supports the lower plate. Since the space surrounded by the housing and the slider is sealed, it is possible to effectively prevent suction of air from the sliding surface of the plate.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A two-layer slide gate according to the present invention will be described below based on an embodiment shown in the accompanying drawings. 1 is a front view showing a cross section of a slide gate of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a view taken in the direction of arrow B of FIG.

In the drawings, reference numeral 1 denotes a base which is seal-welded to an iron skin 2 at the bottom of a tundish, and a seal member 3 is interposed between the base 1 and a housing 7 for fixedly supporting an upper plate 4, The invasion of air from the tundish side of the upper plate 4 is prevented.

Reference numeral 8 denotes a slider for slidably supporting the lower plate 6 arranged in contact with the lower surface of the upper plate 4, and a seal member 9 is installed on the slider 8 to slide it with the housing 7. The closed chamber 5 is configured by moving the slide gate refractory, which is composed of the upper plate 4 and the lower plate 6 and the like.

The sealing material 9 is elastic and flexible so as to follow variations in the size of the refractory material such as the upper plate 4 and the lower plate 6 and metal objects such as the housing 7 and the slider 8, or the thermal deformation of the refractory material. Flexibility, slider 8
The air is prevented from entering the sealed chamber 5 while sliding on the sealing surface 10 of the housing 7 in accordance with the movement of.

Reference numeral 11 denotes a seal gas introduction hole to the closed chamber 5, which is opened in the housing 7. In this way, by introducing the seal gas into the closed chamber 5, it is possible to reliably prevent air from entering the closed chamber 5. The amount of the inert gas required for the seal supplied from the seal gas introduction hole 11 is about 1/10 as compared with the amount described in JP-A-56-141961, and a sufficient effect can be obtained. Has been confirmed.

Reference numeral 12 denotes a passage for a cooling fluid such as compressed air which is opened in the housing 7 and the slider 8. The seal material 9 is burned by heat during operation, and the housing 7 and the slider 8 are thermally deformed. It is provided to prevent this. In addition, 13 is a submerged nozzle, 14 is a holding device for the submerged nozzle 13, 15 is a sealing material for the submerged nozzle portion, 16 is a sliding surface 1 between the lower plate 6 and the upper plate 4.
7 is a surface pressure load device, 18 is a seal member 9 is a slider 8
It is a fixed hardware for mounting on. In this embodiment, the sealing material 9 is attached to the slider 8 side. However, it goes without saying that it may be attached to the housing 7 side.

[0018]

As described above, according to the present invention,
Only by adding a small amount of equipment such as sealing material to the conventional two-layer slide gate, it is possible to obtain an economical slide gate with higher sealing performance than the conventional slide gate, and the internal quality of continuous cast slabs. You will be able to maintain soundness. Of course, the slide gate of the present invention has no difference in workability from the conventional slide gate.

[Brief description of drawings]

FIG. 1 is a front view showing a cross section of a slide gate of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a view on arrow B of FIG.

[Explanation of symbols]

 4 Upper plate 6 Lower plate 7 Housing 8 Slider 9 Seal material 17 Sliding surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Ito 1850 Minato, Wakayama, Wakayama Sumitomo Metal Industries, Ltd. Wakayama Steel Works (72) Inventor Tadao Saigo 4-7 28 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Heavy Industries Casting Co., Ltd.

Claims (1)

[Claims] 1. A two-layer slide gate having a fixed upper plate and a sliding lower plate, which is surrounded by a housing for fixedly supporting the upper plate and a slider for slidably supporting the lower plate. A slide gate, wherein a sealing material for sliding between the housing and the slider is installed in the slider or the housing in the space.