JP2710094B2 - Closed tundish - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tundish used for continuous casting, and more particularly to a closed tundish for performing an oxidation-free operation without requiring a water cooling structure.

[0002]

2. Description of the Related Art Conventionally, a closed type tundish used for continuous casting has a tundish body and a shield lid having a water-cooled structure to prevent a rise in the temperature of the tundish during operation and the accompanying deformation of the tundish. And had

[0003]

However, in the conventional closed-type tundish having a water-cooled structure, deformation of the shield lid is promoted by water cooling, and the shield lid that has been deformed after continuous use can be repaired. In some cases, the jacket part had to be replaced all at once, which increased repair costs. This tendency is remarkable especially during operation because the tundish body and the shield lid are fastened with bolts.

[0004] Further, due to the water-cooled structure, if water leaks during operation or repair, there is a possibility that an explosion may occur due to the pressure of steam. For this reason, it is necessary to constantly detect and confirm water leaks, and much effort is required to ensure safety.

Further, it is necessary to equip a tundish and a tundish car with a valve stand, piping, instrumentation equipment, and the like, and the work space is reduced to deteriorate the workability, and the piping and the like are damaged and water leakage is caused. There are risks that arise.

As described above, the tundish main body and the shield lid are fastened by bolts, and the flange portion of the tundish receives heat from molten steel when the refractory applied in the tundish receives heat from molten steel, and thermally expands above the tundish. When you do
The structure is such that the thermal expansion of the refractory is restrained by the flange and the shape of the refractory during construction is maintained. However, if the refractory is melted and damaged with the use of the tundish, the tip of the flange on the molten steel side is deformed, and the flange on the base end side is also deformed accordingly. For this reason, the tundish body and the shape of the shield lid cannot be reliably sealed.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above, and it is intended to prevent the deformation of a shield lid due to thermal expansion and contraction as much as possible and to provide a hermetic seal without the need for a water cooling structure which may cause an explosion accident. Maintains the condition, and even when the refractory applied in the tundish is melted down due to long-term continuous use, securely supports the upper end of the refractory and secures the sealability to improve durability. It is intended to provide a closed tundish, and a tundish with a flange on the upper opening edge, refractory is installed on the inner surface, so as to face the tundish flange,
A shield lid having a flange extending inward from the outer periphery of the lower surface, an elastic sealing material laid between the flange of the tundish and the flange of the shield lid, and fastening means for fastening the tundish and the shield lid In addition to the above, the flange of the tundish is characterized in that the tip portion inside the tundish is thinner than the base portion.

[0008]

According to the above construction, the elasticity is provided between the flange provided at the opening edge of the upper surface of the tundish and the flange extending from the outer periphery of the lower surface of the shield lid toward the inside so as to face the flange. The sealing material is laid, and the tundish and the shield lid are fastened by fastening means.

Therefore, even if the temperature distribution near the center of the shield lid increases during operation and slight thermal deformation occurs, the shield lid and the tundish main body are tightened by the fastening means and the sealing material expands and contracts. Flame and hot gas do not leak or leak from between the flanges, preventing deformation of the shield lid due to thermal expansion and contraction as much as possible and sealing without the need for a water cooling structure that may cause an explosion accident etc. I can keep my condition.

[0010] Furthermore, the flange of the tundish is made thinner at the tip end inside the tundish than at the base end, so that when the refractory material installed in the tundish is melted by long-term continuous use, Even if deformation occurs due to the thin end of the flange on the molten steel side, it is thin enough to cause deformation in the thick base flange which is thick when constrained by the fastened lid. Since there is no thermal stress, only the front end flange itself is deformed, and the thickened base end flange is not deformed. In addition, since the base end flange is sound, the upper end portion of the refractory can be restrained, and the thermal expansion of the refractory is restrained by the flange, and the shape of the refractory at the time of construction is maintained. It is possible to keep the molten steel from being inserted into the gap. Therefore, since the base end is sound, the upper end of the refractory can be reliably held in place, and the base end flange and the seal lid will be in close contact with each other during the next use of the tundish, ensuring sealing performance. As a result, the durability can be improved.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a tundish according to an embodiment of the present invention, and FIG. 2 is a plan view of a shield lid.

In the tundish 1, a refractory 3 is installed inside a boat-shaped steel shell 2, and a flange 4 extending toward both the inside and the outside of the steel shell 2 is provided on the upper opening edge of the steel shell 2. It is provided. The gap between the steel shell 2 or the flange 4 and the refractory 3 is filled with a stamp material (not shown) to fill the gap.

A bar member 5 extends outward from the steel shell 2 below the flange 4 and extends outward.
Between them, the partition members 6, 7 are bridged between the outer part and the middle part,
The box part 8 is constituted by the flange 4, the crosspiece member 5, and the partition members 6 and 7. The tip 9 of the flange 4 extending from the steel shell 2 toward the inside of the tundish 1
It is made of a member thinner than the flange 4 on the base end side.
In order to make the distal end 9 thinner than the base end in this way, for example, a thin metal piece may be spot-welded to the distal end 9 of the flange 4.

The above-described flange 4 serves as a sealing surface between the shield 4 and a shield lid 13 described later, and also serves to support the refractory 3 installed inside. However, when the tundish 1 is continuously used, the refractory 3 may be melted and the flange 4 may be directly exposed to the hot gas inside the tundish 1 and deformed as shown by a dotted line in the figure. Therefore, as described above, by making the distal end 9 of the flange 4 thinner than the base end, even if the distal end 9 of the flange 4 is deformed, the shield lid fastened by the fastening member 22 described later. Under the condition constrained by 13, there is no thermal stress enough to cause deformation of the thick base end flange, the base end is not easily deformed, and reliably functions as a sealing surface with the shield lid 13. can do. In addition, since the base end side is sound, the constraint on the upper end of the refractory 3 can be reliably maintained.

A support member 10 extending from the outer surface of the steel shell 2
, A base end of a bolt 11 functioning as a fastening member 22 is rotatably attached thereto, and a nut 12 is attached to a distal end of the bolt 11.

The shield lid 13 has a three-part structure that covers the molten steel injection part 14, the plasma heating part 15, and the molten steel discharge part 16, respectively. A box part 18 is provided downward from both ends of the upper metal part 17, and a box part 18 is provided. A flange 19 extends from the lower surface to the inner side, and a refractory 20 is installed between the upper metal member 17 and the flange 19. Further, a plurality of fastening members 22 having a bolt engaging portion 21 at the tip are provided on both sides in the length direction of the upper metal member 17, and an inert gas inlet 23 and the like are opened at appropriate places. is there.

In order to attach the shield lid 13 to the tundish 1, a sealing material 24, for example, kao wool having a thickness of about 25 mm, is spread between the flange 4 of the tundish 1 and the shield lid 13, and bolt engagement of the fastening member 22 is performed. Part 2
1 is engaged with the bolt 11 and the nut 12 is tightened from the tip of the bolt 11. The tightening force of the nut 12 may be such that the thickness of the sealing material 24 is reduced by about 20 to 25%. Sealing such as kao wool is also provided between the divided shield lids 13 for sealing.

[0018]

As described above, according to the present invention, the flange provided on the opening edge of the upper surface of the tundish and the flange extending inward from the outer periphery of the lower surface of the shield lid so as to face the flange. An elastic sealing material is laid between them, and the tundish and the shield lid are fastened by fastening means. Therefore, during operation, the temperature distribution near the center of the shield lid where the plasma heating chamber is located is high, and even if slight thermal deformation occurs, the tundish and the shield lid are tightened by the fastening means,
Further, since the thermal deformation is absorbed by the expansion and contraction of the sealing material, the hermetically sealed state is maintained, and no flame or hot gas flows out or leaks from between the shield lid and the flange of the tundish main body. For this reason, the deformation of the shield lid due to thermal expansion and contraction can be prevented as much as possible, and the hermetically sealed state can be maintained without the need for a water-cooled structure that may cause an explosion accident or the like.

The flange of the tundish is thinner at the tip inside the tundish than at the base. Therefore, even if the refractory installed in the tundish is damaged by long-term continuous use, only the top end of the flange is deformed, and the upper end of the refractory is securely supported by the base end that is unlikely to deform. And the durability can be improved by securing the sealing performance.

Further, in combination with the above-mentioned effects, the non-oxidizing atmosphere in the tundish can be maintained for a long period of time, so that maintenance can be easily repaired and the cost can be reduced. As described above, since the sealability of the tundish body and the shield lid can be prevented from deteriorating for a long period of time, continuous use of the tundish, particularly continuous use of several hundred charges as in hot rotary operation, has become possible.

[Brief description of the drawings]

FIG. 1 is a sectional view of a closed type tundish according to the present invention.

FIG. 2 is a plan view of a shield lid.

[Explanation of symbols]

 1 Tundish 4 Flange (Tundish) 8 Box (Tundish) 9 Flange Tip 11 Bolt 12 Nut 13 Shield Lid 18 Box (Shield Lid) 19 Flange (Shield Lid) 20 Refractory (Shield Lid) 24 Sealing Material

Claims (1)

(57) [Claims] 1. A closed-type tundish used for continuous casting, comprising: a tundish having a flange provided on an opening edge of an upper surface; and a refractory being applied to an inner surface of the tundish. A shield lid having a flange extending inward, an elastic sealing material laid between the flange of the tundish and the flange of the shield lid, and fastening means for fastening the tundish to the shield lid. A sealed tundish, characterized in that the tundish flange is thinner at the tip inside the tundish than at the base.