JP3078701B2 - Inflatable plug for closing tap hole of metallurgical vessel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflatable plug for closing a tapping hole of a metallurgical container, which is inserted into the tapping hole of the metallurgical container and prevents slag from flowing into the receiving container.

[0002]

2. Description of the Related Art The effect of using an inflatable plug for closing a tapping port of a metallurgical vessel will be described with reference to FIGS. As shown in FIG. 4, when the metal is melted, slag S is formed on the surface. When the metallurgy container A is rotated in this state, the slag S flows out of the tapping port B into the receiving container. On the other hand, as shown in FIG. 5, if the tapping port B of the metallurgical vessel A is closed with the plug P and the plug P is pulled out after rotation or the plug P is extinguished, the slag S is placed in the receiving vessel. No spills. As described above, the inflatable plug P for closing the tapping hole is inserted into the tapping port B in advance in order to prevent the slag S from flowing out before the metal in the metallurgical vessel A exits into the receiving vessel. A block is formed by expanding, expanding, and preventing the slag S from flowing out.

As a prior art of an inflatable plug for closing a tapping outlet of a metallurgical vessel, Japanese Patent Application Laid-Open No. Hei 2-1262 discloses a plugging material for an outflow hole of a metallurgical vessel and a method of cleaning internal slag of the metallurgical vessel. Have been. This is a method of preventing slag outflow by combining an inert plug and an inflatable plug. At present, however, in many cases, an inflatable plug alone is used as a tip outflow preventing method.

The inflatable plug described in Japanese Patent Application Laid-Open No. Hei 2-112262 accommodates a temperature-responsive core member that expands immediately upon being heated, and a material that encloses the core and that contains a substance that is softened by heat. And an outer surface layer that can be extended.

[0005]

However, the inflatable plug described in Japanese Patent Application Laid-Open No. 2-1262 is complicated and expensive to manufacture, is heavy, and difficult to insert into metallurgical containers. There were technical problems such as time required for expansion. In particular, a large diameter tap hole requires a large inflatable plug.
The weight was even greater, making insertion into the tapping hole more difficult. That is, the conventional expandable plug is not suitable as an expandable plug having a large diameter tap hole.

In addition, as shown in FIG. 6, the hole diameter φA of the tapping hole increases with the number of uses near the inside of the furnace due to erosion 10, and conversely, slag and metal 11 adhere near the outside of the furnace. In some cases, the diameters φA and φB are not constant, and the inflatable plug may not be inserted smoothly.

In order to cope with such a situation, a plug having a small diameter and a large expansion coefficient that can be inserted even into a tap hole having a small diameter is required, and the diameter of the furnace inside can be sufficiently expanded and closed. Must be something. Even if a block is formed by inserting an inflatable plug in the middle of the tap hole and expanding and expanding it, the tip of the slag will reach the plug insertion position of the tap hole when the metallurgical vessel is tilted. As a result, the slag could not be completely prevented from flowing out. Therefore, it is necessary to form a block by inserting and expanding and expanding an expandable plug further inside the furnace at the tapping opening.

However, the maximum expansion coefficient of the expandable plug of the prior art is about 30%, and the small-sized expandable plug that passes through the reduced tap hole outside the furnace completely fills the tap hole inside the furnace. The slag could not be closed, and as a means for preventing the slag tip from flowing out, the effect was greatly reduced. In particular, when there is a portion where the tapping diameter is larger than the diameter when the conventional expansible plug is expanded to the maximum, the expansible raw material and the softening raw material are axially oriented as shown in FIG. There is a technical problem that the resin overflows in the length direction and the expansion rate decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has a large diameter metallurgical vessel with a small tapping hole and a small tapping hole outside the furnace and a large tapping diameter inside the furnace. An object of the present invention is to provide an inflatable plug for closing a tapping port of a metallurgical vessel, which can completely block even a steel port or the like and can completely prevent the slag tip from flowing into a receiving vessel.

[0010]

An inflatable plug for closing a tapping hole of a metallurgical container according to the present invention is inserted into a tapping hole of a metallurgical container to prevent slag from flowing into a receiving container. Plugs for closing tapping holes in metallurgical containers for metallurgy, 30-80% by weight of expansive raw materials such as vermiculite, 20-70% by weight of heat-softening raw materials such as glass dust and frit, and 10% by weight of alkali silicate
An inflatable member of up to 50% by weight is filled in a cylindrical metal frame having a slit in the axial direction of the cylindrical peripheral surface. In addition, the metal frame is approximately 2 at the center.
It is characterized in that it is divided and both are opposed to each other and connected and fixed by a metal rod. Further, 8 to 15 slits are formed in the axial direction of the cylindrical peripheral surface of the metal frame, and the thickness of the metal is 0.2 to 1.5 mm.

[0011]

The inflatable plug for tapping the tap hole of the metallurgical vessel according to the present invention covers the outer periphery of the inflatable member with a metal frame. Without overflowing in the length direction of the tapping port B, the tapping port of the metallurgical vessel having a large diameter and the tapping port whose furnace outside diameter is small and the inside diameter of the furnace has become large can be completely closed, It is possible to completely prevent the slag tip from flowing into the receiving container.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. As shown in the figure, the expansible plug according to the present invention has two types of materials: an expansive raw material that promotes rapid expansion by heating, and a thermosoftening raw material that softens by heat and serves as a binder for the expansible plug. An inflatable member 5 made of a raw material and a slit 2 extending in the axial direction at several locations on the peripheral wall to prevent the inflatable member 5 from overflowing from the inflatable plug when used in an inserted state.
It comprises a divided metal frame 1, a metal rod 3 for fixing and fixing the metal frame 1, and a tightening nut 4.

That is, in the inflatable plug according to the present invention, the inflatable member 5 is housed inside the cylindrical metal frame 1 having the slits 2 at several places, and the two metal frames 1 are opposed to each other. A metal bar 3 is inserted into the center of the bottom plate of the metal frame 1 and the bottom plate of each metal frame 1 is fixed to the metal bar 3 with a nut 4. The metal frame 1 may be manufactured by cutting one cylindrical frame, or may be manufactured separately.

Here, the expansive raw material is a raw material which generates steam when heated and rapidly expands. For example, vermiculite, perlite or the like is used. It is a substance that separates at temperature and generates steam, and its volume expansion is said to be about 6 to 20 times. This vermiculite is also known as vermiculite, and the one that has been heated and expanded is generally widely used for horticultural construction. Also, perlite is widely known under the name of pearlite, and heat-expanded one similar to vermiculite has been widely used as a building material and a heat insulating material and has been used for a long time. The expandable raw material is added in an amount of 30 to 80% by weight. If the addition amount is 30% by weight or less, a sufficient amount of expansion required to close the tap hole cannot be obtained, and therefore, when the metallurgical container is tilted, it falls out and slag flows out into the receiving container. Also, if 80% by weight or more of the expansive raw material is added, sufficient strength as a block body cannot be obtained, and when the slag passes through the block body, it may fall into the receiving container at the same time as the slag. It cannot prevent slag outflow.

Further, as the heat-softening raw material, glass dust typified by sheet glass and bottle glass, frit, and the like can be used. The heat-softening raw material is added as a binder for the thermally expanded expansive raw material, and plays an important role in maintaining the shape retention and strength of the expanded and expanded block. Powdery or liquid alkali silicate is added to the thermosoftening raw material in addition to glass dust and frit. Alkali silicate is an additive material that plays the same role as glass dust and frit, and at the same time plays a role of a filling aid and a binder at the time of producing an inflatable plug. As alkali silicate, sodium silicate, potassium silicate,
Lithium silicate or the like is used.

The amount of addition is 20 to 70% by weight of glass swarf and frit alone or as a mixture.
50% by weight. If the amount of glass frit added is less than 20% by weight, the strength of the expanded and expanded block body cannot be obtained,
On the other hand, when the content is 70% by weight or more, the viscosity of the expandable plug during heating is greatly increased, which causes the expansion of the expandable raw material to be significantly reduced. Alkali silicate has the same phenomenon as the above glass dust and frit in the increase and decrease of the addition amount, and 10%
Below this, the formability of the expandable plug is reduced, making it difficult to fill the metal frame.

Further, the thickness of the metal frame 1 is 0.2 to 0.2.
A material of about 1.5 mm is preferable, and any material may be used as long as it can change its shape in any way by the expansion of the expandable member and can hold the expandable member 5 firmly. In view of the above, aluminum and soft iron are particularly preferable. The reason for limiting the thickness of the metal frame is 0.2 m
If it is less than m, it is excellent in softening deformation, but lacks sufficient force to hold the expandable member 5, and if it is more than 1.5 mm, it lacks softening deformation. A metal frame 1 has a slit 2
The reason for disposing is to maximize the inflation force of the inflatable member 5 and to firmly adhere to the inner wall of the tapping port B. The number of the slits 2 can be appropriately selected in consideration of the shape and the like. However, if the number of the slits 2 is small, the expansion force of the expandable member 5 cannot be utilized. Usually, it is preferable to set 8 to 15 places because the overflow of the sexual member 5 easily occurs.

The metal frame 1 can be fixed in one to four axes. However, when the number of axes is four or more, the softening deformation of the slit 2 is restrained and the expansion amount is greatly affected. Therefore, fixing of one or two axes is most suitable. The diameter of the shaft for fixing the metal frame 1 must be such that the metal frame can be connected and fixed even when inflated. Usually, it is preferable to use a shaft having a diameter of about 10 mm to 15 mm.

The metal rod 3 and the metal frame 1 are fixed by tightening nuts, welding stop, etc., so that the metal frame 1 does not come off from the metal rod 3 during use and the inflatable member 5 can be sufficiently held. Any method can be adopted as long as such measures are taken.

Next, for some examples, the packing ratio was compared with a comparative example. In this experiment, the temperature inside the tapping hole for metallurgy was 950 ° C, and the tapping hole shape was 175 mm minimum on the outside of the furnace and 225 mm maximum diameter on the inside of the furnace, assuming slag adhesion and erosion. Was inserted up to the nearest position having a diameter of 225 mm in the expandable plug co-furnace.

Example 1 Expansive raw material vermiculite (particle size: JIS No. 3) 30% by weight, heat softening raw material glass dust (particle size: 2 to 0 mm (maximum particle size 2 mm or less; the same applies hereinafter)) 70% by weight and 10% by weight of alkali silicate (liquid) were blended and kneaded to obtain a clay pad. Next, in order to fill the fill in the iron frame having 15 slits prepared in advance, both ends of the iron frame were fixed with nuts to obtain an inflatable plug having a diameter of φ130 mm, which was supplied to the tapping port for metallurgy. did. As a result, the inflatable plug starts to expand and expand in 60 seconds, and in 180 seconds, the tapping outlet is set to 100%.
Completely occluded. After the blowing, the metallurgical vessel was tilted, but the tilt angle at which molten steel flowed into the receiving vessel was about 1-2.
After a second, tapping was started, and no outflow of the tip slag into the receiving container was observed.

Example 2 50% by weight of vermiculite (particle size: JIS No. 3) as an expansive raw material, 50% by weight of glass dust (particle size: 2 to 0 mm) as a thermosoftening raw material, and 30% of sodium silicate (liquid) % By weight,
The kneaded mixture was obtained. Next, in order to fill the clay into a steel frame having 12 slits prepared in advance, both ends of the steel frame were fixed with nuts to obtain an inflatable plug having a diameter of φ130 mm, which was supplied to a tapping port for metallurgy. did. As a result, the expandable plug started expanding and expanding in 30 seconds and completely closed the tapping port in 120 seconds. After the end of blowing, the metallurgical vessel was tilted, but the tapping started at about 1 to 2 seconds at a tilt angle at which the molten steel flows into the receiving vessel, and no outflow of the tip slag into the receiving vessel was observed. Was.

Example 3 40% by weight of vermiculite (particle size: JIS No. 3) as an expansive raw material, 60% by weight of glass dust (particle size: 2 to 0 mm) as a thermosoftening raw material, and 30% of sodium silicate (liquid) % By weight,
The kneaded mixture was obtained. Next, in order to fill the clay into a steel frame having 12 slits prepared in advance, both ends of the steel frame were fixed with nuts to obtain an inflatable plug having a diameter of φ130 mm, which was supplied to a tapping port for metallurgy. did. As a result, the expansible plug started expanding and expanding in 45 seconds, and completely closed the tapping port in 180 seconds. After the end of blowing, the metallurgical vessel was tilted, but the tapping started at about 1 to 2 seconds at a tilt angle at which the molten steel flows into the receiving vessel, and no outflow of the tip slag into the receiving vessel was observed. Was.

Example 4 80% by weight of expansive raw material vermiculite (particle size: JIS No. 3), 20% by weight of heat-softening raw material glass dust (particle size: 2 to 0 mm), and 20% by weight of sodium silicate (liquid) % By weight,
The kneaded mixture was obtained. Next, in order to fill the clay into an iron frame having eight slits prepared in advance, both ends of the iron frame were fixed with nuts to obtain an inflatable plug having a diameter of 130 mm, which was supplied to a tapping port for metallurgy. did. As a result, the expandable plug started expanding and expanding in 15 seconds and completely closed the tapping port in 60 seconds. After the end of blowing, the metallurgical vessel was tilted, but the tapping started at about 1 to 2 seconds at a tilt angle at which the molten steel flows into the receiving vessel, and no outflow of the tip slag into the receiving vessel was observed. Was.

Example 5 50% by weight of vermiculite (particle size JIS No. 3) as an expansive raw material, 40% by weight of glass dust (particle size 2 to 0 mm) as a heat-softening raw material, 10% by weight of frit, and sodium silicate (Liquid) 20% by weight,
And kneaded at a composition ratio of 1. Next, in order to fill the clay into a steel frame having 12 slits prepared in advance, both ends of the steel frame were fixed with nuts to obtain an inflatable plug having a diameter of φ130 mm, which was supplied to a tapping port for metallurgy. did. As a result, the expandable plug started expanding and expanding at 35 seconds, and completely closed the tapping port at 150 seconds.
After the end of blowing, the metallurgical vessel was tilted, but the tapping started at about 1 to 2 seconds at a tilt angle at which the molten steel flows into the receiving vessel, and no outflow of the tip slag into the receiving vessel was observed. Was.

Example 6 Expansive raw material vermiculite (particle size: JIS No. 3): 60% by weight, perlite: 10% by weight, heat softening raw material: glass dust (particle size: 2 to 0 mm) 3
0% by weight and 40% by weight of sodium silicate (liquid) were blended and kneaded to obtain a clay. Next, in order to fill the clay into a steel frame having 10 slits prepared in advance, both ends of the steel frame were fixed with nuts to obtain an inflatable plug having a diameter of φ130 mm, which was supplied to a tapping port for metallurgy. did. As a result, the expandable plug started expanding and expanding in 20 seconds, and completely closed the tapping port in 70 seconds.
After the end of blowing, the metallurgical vessel was tilted, but the tapping started at about 1 to 2 seconds at a tilt angle at which the molten steel flows into the receiving vessel, and no outflow of the tip slag into the receiving vessel was observed. Was.

In any of the inflatable plugs of the first to sixth embodiments, the expansion and expansion are started in 15 to 60 seconds, and 60 to 1
In 80 seconds, the tapping port was completely closed 100%. After the end of blowing, the metallurgical vessel was tilted, and tapping started at a tilt angle at which molten steel flows into the receiving vessel about 1-2 seconds later, but no outflow of the tip slag into the receiving vessel was observed. Was.
Holding the block with the inflatable plug for 1 to 2 seconds at a predetermined tilt angle is to prevent the slag tip from flowing out.
That's enough time.

In the comparative example, the inflatable raw material and the softening raw material described in the example were used for blending, kneading, and filling, and were manufactured in a conventional structure. The inside diameter of the tap hole is 175mm at the outside of the furnace and the inside diameter of the furnace is φ
225mm, each expandable plug is φ2 closest to the furnace
It was inserted to a position having a length of 25 mm, and the expansion start time and the filling rate of the tapping hole due to the expansion were visually observed.

Comparative Example 1 50% by weight of vermiculite (particle size JIS No. 3) as an expansive raw material, 50% by weight of glass dust (particle size of 2 to 0 mm) as a heat-softening raw material, and 30% of sodium silicate (liquid) % By weight,
The kneaded mixture was obtained. Next, in order to fill the bedding, an inflatable plug having a diameter of φ130 mm was provided to the tapping port without attaching an iron frame. As a result, the inflatable plug started expanding and expanding in 30 seconds, but the filling rate was 70%.
%, And the phenomenon that the tip of the slag flows out into the receiving container was observed.

Comparative Example 2 40% by weight of vermiculite (particle size JIS No. 3) as an expansive raw material, 50% by weight of glass dust (particle size 2 to 0 mm) as a heat-softening raw material, and 20% by weight of sodium silicate (liquid) % And magnesia powder in a composition ratio of 10% by weight were mixed and kneaded to obtain cup clay.
Next, in order to fill the bedding, an inflatable plug having a diameter of φ130 mm was provided to the tapping port without attaching an iron frame. As a result, the inflatable plug started to expand and expand in 40 seconds, but the filling rate remained at 65%, and a phenomenon was observed in which the slag tip flowed out into the receiving container.

Comparative Example 3 80% by weight of vermiculite (particle size: JIS No. 3) as an expanding material, 20% by weight of glass dust (particle size: 2 to 0 mm) as a heat-softening raw material, and 20% by weight of sodium silicate (liquid) % By weight,
The kneaded mixture was obtained. Next, in order to fill the bedding, an inflatable plug having a diameter of φ130 mm was provided to the tapping port without attaching an iron frame. As a result, the inflatable plug started expanding and expanding in 15 seconds, but the filling rate was 60%.
%, And the phenomenon that the tip of the slag flows out into the receiving container was observed.

Comparative Example 4 10% by weight of vermiculite (particle size JIS No. 3) as an expansive raw material, 90% by weight of glass dust (particle size 2 to 0 mm) as a heat-softening raw material, and 30% of sodium silicate (liquid) % By weight,
The kneaded mixture was obtained. Next, in order to fill the clay into a steel frame having 12 slits prepared in advance, both ends of the steel frame were fixed with nuts to obtain an inflatable plug having a diameter of φ130 mm, which was supplied to a tapping port. As a result, the inflatable plug started to expand and expand in 300 seconds, but the filling rate remained at 25%, and a phenomenon was observed in which the slag tip flowed out into the receiving container.

The raw materials of Examples 1 to 6 and Comparative Examples 1 to 4 and the results are shown in Table 1.

[0034]

[Table 1]

As shown in Table 1, Examples 1 to
The inflatable plug of No. 6 had excellent characteristics not found in Comparative Examples 1 to 4, the inflation start time was 15 to 60 seconds, and the slag flow could be surely prevented.

[0036]

According to the present invention, the use of a metal frame having slits disposed therein makes it possible to reduce the outer diameter of the furnace due to the adhesion of slag and metal to the tapping port of a metallurgical vessel having a large diameter, resulting in erosion. For example, tapping holes with larger furnace inner diameters,
Even if the tapping diameter is not constant, the tapping can be completely closed, and the effect of completely preventing the slag tip from flowing into the receiving container can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment according to the present invention.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a schematic diagram showing a closed state of a tapping port of an expansion plug according to the present invention.

FIG. 4 is a diagram for explaining a use effect of a plug;

FIG. 5 is a diagram for explaining a use effect of a plug;

FIG. 6 is a cross-sectional view of a tapping hole deformed by adhesion of slag and ingot and melting.

FIG. 7 is a view for explaining a conventional expansion plug operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Iron frame 2 Slit 3 Iron bar 4 Nut 5 Inflation member 10 Melted part 11 Slag, base metal attachment part

──────────────────────────────────────────────────続 き Continuing on the front page (72) Takashi Miki Inventor Kashima-cho, Kashima-gun, Ibaraki 3rd floor Kashima Works, Sumitomo Metal Industries, Ltd. (72) Inventor Minoru Sato Minami 2-1-1 Hitotsubashi, Chiyoda-ku, Tokyo (72) Inventor: Masato Toyohara, 2-1-1, Hitotsubashi, Chiyoda-ku, Tokyo, Japan Josuikai Building: Within Sumitomo Corporation (56) References JP-A-7-260372 (JP, A) JP JP-A-5-245621 (JP, A) JP-A-2-11262 (JP, A) JP-A-60-255260 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22D 41 / 44 C21C 5/46 103 C04B 35/66

Claims (3)

(57) [Claims] 1. An inflatable plug for closing a tapping hole of a metallurgical container for preventing slag from flowing into a receiving container inserted into the tapping hole of the metallurgical container. An inflatable member consisting of 30 to 80% by weight of raw material, 20 to 70% by weight of thermosoftening raw material such as glass dust and frit and 10 to 50% by weight of alkali silicate is slit into a cylindrical shape and a slit in the axial direction of the cylindrical peripheral surface. An inflatable plug for closing a tapping opening of a metallurgical container, wherein the plug is filled in a metal frame having the metal frame. 2. The metallurgical container according to claim 1, wherein the metal frame is divided into two parts at substantially the center, and the two are opposed to each other and fixed by a metal rod. Inflatable plug. 3. The axial direction of the cylindrical surface of the metal frame is 8-15.
The inflatable plug for closing a tapping hole of a metallurgical vessel according to claim 1 or 2, wherein a plurality of slits are formed, and the thickness of the metal frame is 0.2 to 1.5 mm.