JP3002119U - Immersion pipe for RH vacuum degassing equipment - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a dip tube for an RH vacuum degassing facility, which facilitates the production of the dip tube and prevents the outer-wrapped brick from collapsing and falling during operation. The purpose is to According to the present invention, in an immersion pipe which is immersed in molten steel and subjected to vacuum degassing, an outer brick is placed and arranged on the outer side of a seal metal object with an irregular shaped refractory material being separated from the seal metal object. Characteristically, the outer winding brick and the seal metal member may be fixed by a bolt group, and the bolt may be made of ceramics.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dip tube for RH equipment.

[0002]

[Prior art]

 RH type vacuum degassing equipment, that is, the degassing tank is provided with two dipping pipes for raising and lowering, and the dipping pipe is immersed in the molten steel in the ladle to make the inside of the degassing chamber vacuum, and By blowing gas such as argon or nitrogen from the immersion pipe (upward pipe), molten steel flows into the tank, is scattered and degassed. The degassed molten steel is discharged from the other immersion pipe (downward pipe). It is discharged and returned to the ladle. This is a degassing facility that degasses molten steel by continuing this process.

The immersion pipe used in such a degassing facility has a horizontal brick (in which a plurality of studs and the like are planted on the outer surface thereof) formed on the inner surface of a cylindrical steel seal metal piece in the circumferential direction. Hereinafter, inner bricks will be lined by joining them in multiple stages to form an inner cylinder (inner bricks made of one piece are also used), and between the inner bricks and the seal hardware, and the seal hardware. The outer circumference is made by casting castable refractory and other irregular-shaped refractories into an outer cylinder, and a plurality of gas injection pipes penetrating the inner and outer cylinders are arranged and integrated.

By the way, when the above immersion pipe is immersed in the molten steel in the ladle and subjected to vacuum degassing treatment, the high temperature of the molten steel and the wear due to the shocking turbulence accompanying the circulation of the molten steel, or repeated Rapid heating due to use and spalling due to rapid cooling occur and are promoted and worn. In particular, the irregular refractory forming the outer cylinder is generally inferior to the refractory bricks in terms of corrosion resistance and damage.Therefore, frequent repairs such as spraying using irregular refractory such as spray material are required. Will be done. In addition, slag, metal, etc. are adhered to the outer peripheral surface, and the work to remove the adhered slag is performed at high temperatures. Therefore, focus is placed on measures to reduce spray repair and slag. There is a demand for measures to prevent slag adhesion, etc., and as a measure to reduce this spray repair and to prevent slag adhesion, there is a dipping pipe in which an outer-wrapping brick is directly placed around the outer periphery of the dipping pipe sealing metal.

At the same time, in the case of arranging outer bricks around the outer periphery of the immersion pipe, a plurality of gas injection pipes for circulating molten steel are annularly arranged on the outer peripheral surface of the metal seal. When the sealing metal and the outer wound brick are in close contact with each other, it is necessary to form a groove on the inner peripheral surface side of the outer wound brick according to the pipe condition of the gas blowing pipe, which makes the production of the immersion pipe extremely complicated. . In addition, the outer-wrapped bricks are usually provided with one or more horizontal bricks that are divided in the circumferential direction and are joined together in one or more stages. If you just adhere with, it will fall outside during operation and fall off.

In view of this, the present invention provides a dip tube for an RH vacuum degassing facility, which facilitates the production of the dip tube and prevents the outer brick from collapsing and falling during operation. It was made for the purpose.

[0007]

[Means for Solving the Problems]

 In order to solve the problems of the above-mentioned conventional techniques, the present invention is an immersion pipe that is immersed in molten steel for vacuum degassing treatment. The outer bricks and the seal metal fitting may be fixed by a bolt group, and the bolt may be made of ceramics.

[0008]

[Action]

 In the present invention, since the outer winding bricks of the immersion pipe are arranged and arranged apart from the sealing metal object, a plurality of annular pipes are annularly piped to the outer peripheral surface of the sealing metal object according to the piping condition of the gas blowing pipe. Since it is not necessary to form a groove on the inner peripheral surface of the outer winding brick, the dipping pipe can be easily manufactured. In addition, by fixing the outer-wrapping brick and the seal hardware with bolts, it is possible to prevent the outer-wrapping brick from collapsing and falling off during operation. Therefore, it is possible to reduce the damage by arranging bricks, which have higher corrosion resistance than the amorphous refractory, on the outer peripheral surface side, and can extend the life of the immersion pipe significantly.

[0009]

【Example】

 Hereinafter, the present invention will be described in more detail with reference to an embodiment shown in the drawings.

FIG. 1 shows a vertical cross section of a dip tube according to the present invention, and FIG. 2 shows a horizontal cross section corresponding to the line AA of FIG. The inner-walled bricks 3 made of laterally squeezing bricks, which are divided into a plurality of circumferential directions, are joined to the inner circumference of a cylindrical steel-made metal fitting 2 having a large number of studs 1 and the like planted on the outer surface. By lining them together, an inner cylinder 6 is formed. Between the inner brick 3 and the seal metal piece 2 and on the outer periphery of the seal metal piece 2, an irregular refractory material 4 such as castable refractory material and an outer brick 11 are constructed. Then, the outer cylinder 7 is formed by arranging a plurality of gas blow-in pipes 5 that sequentially penetrate the irregular-shaped refractory 4, the metal seal 2 and the inner cylinder 6 and integrate them.

In the illustrated embodiment, the inner bricks 3 are stacked in three layers in the vertical direction, and a U-shaped hooking portion is formed on the back surface (outer peripheral surface) of the innermost brick 3 at the lowermost stage to seal the inner bricks. The metal fitting 2 is configured to be suspended entirely by a support metal fitting 2a which is provided on the inner peripheral side at a position slightly above the lower end of the metal fitting 2.

The outer bricks 11 are circumferentially arranged and arranged on the outermost side away from the metal seal 2 through the irregular refractory material 4.

The use of this outer-rolled brick 11 means that when the immersion pipe is immersed in molten steel for degassing, the outer peripheral surface immersed in the molten steel due to the high temperature and slag possessed by the molten steel Prevents damage from progressing rapidly, reduces the amount of repair work that requires frequent repairs by means such as spray repairs, or prevents slag, metal, and other slag from adhering It is provided for the purpose (MgO-C brick does not easily adhere to slag), and if it is installed and placed around the entire outer side of the sealing metal article 2, the strength of the outer tube refractory can be increased and the life can be extended. A plurality of gas injection pipes 5 for circulating molten steel are annularly arranged on the outer peripheral surface of the pipe, and when the sealing metal fitting 2 and the outer brick 11 are brought into close contact with each other, the gas injection pipe 5 is in the pipe state. Together with the outer brick 11 Since it is necessary to form a groove on the peripheral surface side, the production of the dip pipe becomes extremely complicated, so the number is limited to the minimum necessary, and as shown in an enlarged view of Fig. 3, an irregular fire resistance is provided on the outside of the metal seal 2. One side or a plurality of side-by-side bricks divided in the circumferential direction according to the size of the immersion pipe at a position apart from the seal metal 2 through the object 4, and below the flange 8 It is provided in the position.

Since the outer winding brick 11 is fixed by the bolt 9 at a position distant from the seal metal fitting 2, a through hole 11a having a step at a predetermined position and size is provided, and the outside of the through hole 11a is It is preferable that the rear side is formed to have a large trapezoidal cross section so that the irregular shaped refractory 4 can be filled in the gap after fixing.

As a material of the outer winding brick 11, in order to prevent adhesion of slag and improve durability, quality of the outer brick 11 such as high carbon content, small thermal expansion coefficient, high corrosion resistance, and high spalling resistance. A MgO-C material that can ensure the characteristics can be applied, but the refractory material having equivalent properties is not limited to the MgO-C material.

The bolt 9 is made of, for example, ordinary steel such as rolled steel for general structure, or special steel such as stainless steel, has a predetermined diameter dimension and length dimension, and is threaded on the tip side to form a base. The end side is welded to the outer surface of the seal metal piece 2, or both ends are threaded and fixed at a predetermined position by means such as screwing the base end side to a nut fixed to the outer surface of the seal metal piece 2 at a predetermined position. .

When surrounding and arranging the outer bricks 11, the spacers 12 having predetermined diameter and length dimensions are fitted and then inserted into the through holes 11a provided in the outer bricks 11. The tip side is fixed by tightening with the nut 10. Then, after the outer brick 11 is tightened with the nut 10, the mounting hole 11b is filled with the irregular refractory 4 so that the bolt, the nut and the like are not exposed.

Therefore, with the above structure, the outer brick 11 is circumferentially arranged and arranged on the outer side away from the seal metal fitting in place of the conventional irregular refractory material 4 in the circumferential direction of the outer peripheral surface of the immersion pipe, and is fixed by the bolt 9. Not only is it easy to manufacture the immersion pipe, but it does not collapse or fall off during operation, and it is possible to significantly reduce damage due to the high temperature and slag that the molten steel possesses. Not only can the work be reduced, but it is possible to prevent the adherence of slag, slag, and metal slag.

The bolt 9 is provided so as to project from the outside of the seal metal member 2, and a ceramic material such as zirconia, alumina, or sialon can be used instead of steel, and the bolt 9 can be used. It is also possible to prevent melting due to high temperatures and to prolong the service life significantly.

In the illustrated embodiment, the inner bricks 3 are stacked in three layers to form a U-shaped hooking portion on the back surface of the innermost brick 3 at the lowermost stage. Inner-wrapped bricks, the hooks are formed in an L-shape, the lower part of the innermost-covered bricks is tapered toward the bottom, and the lower part of the innermost-covered bricks is An irregular shaped refractory layer can be provided on the. Further, although the stepped through hole 11a and the mounting hole 11b of the outer winding brick 11 are shown in the case where the mounting hole 11b is formed in a trapezoidal cross section, the outer winding brick 11 may be formed in a rectangular cross section. Needless to say, it may be extended to the position directly below the flange 8 and provided around it.

[0021]

[Effect of device]

 As described above, according to the present invention, in an immersion pipe that is immersed in molten steel for vacuum degassing, an outer brick is placed outside the sealing metal object with an irregular shaped refractory material and separated from the sealing metal object. Since it is arranged, it is not necessary to form a groove on the inner peripheral surface of the outer wound brick according to the pipe condition of the gas injection pipe that is annularly piped to the outer peripheral surface of the sealing metal object. It can be easily manufactured.

When the sealing metal and the outer wound brick are fixed with bolts to immerse the dipping pipe in the molten steel for degassing, a refractory brick having higher corrosion resistance than the conventional amorphous refractory is used. It can be applied without collapsing or falling off during operation, and damage on the outer peripheral surface of the immersion pipe can be greatly reduced, and as a result, repair work such as spray repair can be significantly reduced. .

Further, by applying a MgO-C quality or equivalent refractory material to which no slag is easily attached to the outer brick, it is possible to prevent the slag from adhering during operation and reduce the slag removal work, and thus to dip it. The life of the pipe can be greatly extended.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of the present invention.

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

FIG. 3 is a partial vertical cross-sectional view showing an example of fixing an outer winding brick with bolts.

[Explanation of symbols]

 1 Stud 2 Sealing Hardware 3 Inner Brick 4 Unshaped Refractory 5 Gas Blow Pipe 6 Inner Cylinder 7 Outer Cylinder 8 Flange 9 Bolt 10 Nut 11 Outer Brick 12 Spacer

Claims (3)

[Scope of utility model registration request] 1. An immersion refractory 4 is provided on the outer side of a metal seal 2 in a dip tube which is immersed in molten steel for vacuum degassing.
An immersion tube for an RH vacuum degassing facility, characterized in that the outer wound brick 11 is circumferentially disposed and arranged apart from the sealing metal object via the. 2. The immersion pipe for an RH vacuum degassing facility according to claim 1, wherein the outer winding brick 11 and the seal metal piece 2 are fixed by a large number of bolts 9. 3. The immersion pipe for an RH vacuum degassing facility according to claim 1, wherein the bolt is made of ceramics.