JPH1129817A - Method for laying outer lining brick for rh immersion tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a peripherally laying method of an outer lining brick for RH immersion tube easily executed in the case of peripherally laying the outer lining brick around a seal metal in a state apart from the seal metal. SOLUTION: In the manufacturing the immersion tube for executing the vacuum degassing treatment by dipping molten metal, many pieces of the outer lining bricks 8 divided in the circular direction constituting the outside of this immersion tube are assembled beforehand into an integral cylindrical body 12 fastened by winding belts 13, 16 on the outer periphery, this cylindrical body 12 is fixed by hanging and inserting into the outer periphery of the seal metal positioned at the inside of the immersion tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for constructing an externally wound brick for an RH immersion pipe.

[0002]

2. Description of the Related Art A conventional RH type vacuum degassing system is provided with two immersion pipes for ascending and descending in a degassing tank, and immersing the immersed pipes in molten steel in a ladle. The inside of the tank is evacuated.

[0003] The vacuuming is performed by blowing an inert gas such as argon from one immersion pipe (rising pipe) to flow molten steel into a degassing tank to scatter and degas the molten steel. Then, the gas is discharged from the other immersion pipe (downcomer), returns to the ladle, and is degassed (evacuated) by repeating this operation.

A conventional immersion pipe used in such a degassing apparatus is a horizontal brick in which a plurality of circumferentially divided sections are provided on the inner surface of a cylindrical steel seal fitting having a large number of studs or the like implanted on its outer periphery. (Hereinafter referred to as inner winding brick) in multiple steps, or lined with an integral inner winding brick to form an inner cylinder, and a castable refractory, etc. between the inner winding brick and the sealing hardware Refractory is filled.

[0005] On the other hand, an unrefractory material such as a castable refractory material is similarly applied to the outer periphery of a seal fitting to form an outer cylinder, and a plurality of gas injection pipes penetrating these outer cylinders are arranged and integrated. It is composed of

When such a conventional immersion pipe is immersed in molten steel in a ladle and subjected to vacuum degassing, wear caused by the turbulent flow caused by the high temperature of the molten steel and the reflux of the molten steel, or repeated wear. Due to wear due to use or rapid heating / cooling,
When spalling occurs and this spalling is promoted and not only wears out, but also is exposed to such severe conditions, there occurs a problem that the lower portion of the cylindrically formed seal metal expands and deforms in the diameter direction. .

[0007] In particular, irregular-shaped refractories forming the outer cylinder generally have lower corrosion resistance than refractory bricks, so that damage is increased, and slag, slag and the like stick to the outer peripheral surface.

For this reason, repairs are frequently performed by means such as spray repair using an amorphous refractory such as a spray material.

However, since the spraying repair work and the work for removing the adhered slag are performed at a high temperature, measures for reducing the spray repair and preventing slag and the like from being slag are intensively demanded.

Conventional techniques for reducing the spray repair and preventing sticking are disclosed in, for example, JP-A-7-34119 and JP-A-7-51821.

The former dip tube for a vacuum degassing device has an inner fixed brick in which a molten steel channel is formed inside a cylindrical iron core, so that it has good erosion resistance to molten steel flow. In addition to the iron core, there is also an outside fixed brick outside, so the erosion resistance to molten steel and the slag component on the molten steel surface placed in a ladle, etc. is good, and the service life of the immersion pipe is extended, so repair is performed It is said that the number of times can be reduced.

The latter immersion pipe for a vacuum degassing apparatus has a slag line on the outer peripheral side thereof which is made of MgO-
It is based on the use of C material, which is said to have the effect of extremely reducing the melting speed of the slag line portion.

[0013]

However, in a dip tube in which the outer brick is disposed around the outer periphery, it is necessary to annularly form a plurality of gas injection tubes for circulating molten steel on the outer peripheral surface of the seal metal. is there.

Therefore, when the sealing hardware and the outer brick are brought into close contact with each other, it is necessary to form a groove on the inner peripheral surface side of the outer brick in accordance with the piping condition of the gas blowing pipe. There is a problem that the manufacture of the hologram is extremely complicated.

[0015] As the externally wound brick, a brick of a horizontal shape in which a circumferential direction is divided into a plurality of pieces is usually used. An irregular refractory, such as a castable refractory, is filled and integrated.

[0016] In addition, as the outer brick, MgO-C is generally used as a material as shown in the prior art.
When the OC quality is applied, the joints are constructed with empty joints.

Therefore, it is necessary to pipe the gas injection pipe from the periphery of the seal fitting to the inner diameter side of the inner winding brick, and then to surround the outer brick in a state separated from the sealing fitting.

[0018] For the peripheral installation, it is necessary to arrange a plurality of horizontal pressing bricks, each of which has a circumferential direction divided into a plurality of pieces, at a predetermined position, and to fix them in advance so that they do not move. There was a problem that the construction was troublesome.

Further, when the refractory is placed on an irregular-shaped refractory, even when the outer brick is separated from the sealing hardware, the irregular-shaped refractory on the lower portion (flange side) is once constructed and deframed. After that, there is a problem in that the fixed brick and the irregular-shaped refractory hardly adhere to each other, and the joint is easily opened, so that the ingot is invaded.

[0020]

DISCLOSURE OF THE INVENTION The present invention relates to an externally wound brick for an RH immersion pipe, which can be easily installed even when the externally wound brick is installed around the seal metal while being separated from the seal metal. It is an object to provide a construction method.

That is, according to the present invention, in an immersion pipe which is immersed in molten steel and subjected to vacuum degassing, a plurality of circumferentially divided outer winding bricks constituting the outer side of the immersion pipe are pre-assembled and provided on the outer periphery thereof. It is characterized in that it is an integral cylinder tightened by banding, and this cylinder is inserted and fixed to the outer periphery of a seal fitting located inside the dip tube by hanging.

Therefore, after the piping of the gas injection pipe is completed, the outer brick is constructed by setting the cylindrical body integrally formed on the outer periphery of the seal metal, so that the joints may be loosened or the individual outer windings may be loosened. Without the bricks falling over,
It can be installed quickly in a stable state.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for installing an externally wound brick for an RH immersion pipe according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 1 is a cross-sectional view showing an example of a dip tube in which an outer brick is disposed on the outer periphery, and FIG. 2 is a horizontal cross-sectional view taken along a line AA in FIG.

The basic structure of the dip tube 1 shown in FIG. 1 is the same as that of the above-mentioned conventional dip tube, and has a cylindrical steel seal fitting 4 having an upper end fixed to a flange 2 and a large number of studs 3 implanted on its outer surface. Is provided with an inner cylinder 6 lined by joining one or more steps of an inner winding brick 5 made of a horizontal pressing brick whose circumferential direction is divided into a plurality of pieces.
An irregular-shaped refractory 7 such as a castable refractory is provided between the metal fittings 4 and the seal fitting 4. On the outer periphery of the seal fitting 4, there is an outer cylinder 9 on which an outer brick 8 is constructed via an irregular-shaped refractory 7 such as a castable refractory, and a plurality of gasses penetrating the inner cylinder 6 and the outer cylinder 9. The structure is integrated with the blowing pipe 10.

The lower end of the inner winding brick 5 is entirely suspended by a support fitting 4a protruding inward from the lower end of the seal fitting 4, and an irregular refractory 7 is disposed below the lower end thereof. Has been established.

In the embodiment shown in FIG. 1, the outer winding brick 8 is arranged in a circle outside the seal fitting 4 at a position away from the seal fitting 4 via an irregular refractory 7 according to the size of the immersion pipe 1. One stage is joined in a laterally-closed shape divided into a plurality in the circumferential direction, and provided at a position immediately below and below the flange 2.

The locking member 11 is used to fix and suspend the outer winding brick 8 at a position away from the seal hardware 4. This locking member 11 has the same structure as that disclosed in Japanese Patent Application Laid-Open No. 8-85818 filed by the present applicant.

That is, the locking member 11 is shown in FIG.
As shown in an enlarged view of a portion P in (A), for example, a protruding portion 11a is made of a common steel such as a rolled steel material for a general structure or a special steel such as a stainless steel, and has a protruding portion 11a provided outside the long side of the L-shaped cross section. Things.

Since the outer brick 8 is fixed to the flange 2 by the locking member 11 and suspended, the outer brick 8 has a predetermined size in which the protrusion 11a is inserted into a predetermined position on the outer peripheral surface of the upper end thereof. A concave portion 8a is formed, and a lower end is provided with an inclined surface facing upward in the outer peripheral direction (see FIG. 3), and is configured as a cylindrical body 12 of an integral structure before construction.

The short side of the locking member 11 is fixed to the flange 2 by appropriate means such as welding or screwing.

As a means for integrally forming the outer brick 8, for example, M
When the gOC material is applied, it is tentatively arranged in a cylindrical shape at an open joint (manufacture of the immersion tube is performed with the flange 2 side down as shown in FIG. 3), and a plurality of bands 13 are hung on the outer periphery. By rotating and tightening and integrally joining, the cylinder 1
Form 2

In this case, it is preferable that the outer winding brick 8 is not provided with an inclined portion on the upper end surface in order to facilitate construction.
In order to be able to be disposed at a position below and directly below the flange 2, or to be disposed around the periphery of a position below the seal metal 4 slightly apart from the flange 2, by providing a rib in the form of a skirt around the seal metal 4.
The upper end is formed horizontally.

When the outer brick 8 is arranged around the irregular refractory 7 at a position away from the seal metal 4, the space between the irregular refractory 7 and the outer brick 8 is as shown in FIG. In the case where the expansion absorbent 14 shown in FIG. 1 is interposed, the expansion absorbent 14 may be attached to the inner peripheral surface of the outer brick 8 in advance.

The cylindrical body 1 having the above-described structure and having an integral structure.
2, the middle part of the outer peripheral surface is divided into two parts and set by a suspending band 16 provided with a hook 15 on a diagonal line, and this is suspended and fitted on the outer periphery of the seal fitting 4 in which the gas blowing pipe 10 is piped; The work is completed by fixing with the locking member 11.

[0036]

As described above, according to the present invention, in the construction of an immersion pipe used for an RH type vacuum degassing equipment, the externally wound brick constituting the immersion pipe is preliminarily formed as a unitary cylindrical body on the outside of the seal fitting. Since it is arranged around the periphery, the joint is tightly integrated with little loosening, excellent in corrosion resistance, high in spalling resistance, less infiltration of slag, hard to stick, MgO-C material, sealing metal It can be installed extremely easily on the outer periphery at a position away from the outside.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view showing an RH immersion pipe according to the present invention, and FIG. 1B is an enlarged view of a portion P in FIG.

FIG. 2 is a plan view showing an AA cross section of FIG. 1;

FIG. 3 is an external view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Immersion pipe 2 Flange 4 Seal metal 5 Inner winding brick 6 Inner cylinder 7 Irregular refractory 8 Outer brick 9 Outer cylinder 10 Gas blowing pipe 11 Locking member 12 Cylindrical body 13 Band 15 Hook 16 Band

Claims (1)

[Claims] 1. A dip tube which is immersed in molten steel and subjected to a vacuum degassing process, in which a plurality of circumferentially divided outer winding bricks constituting the outer side of the dip tube are pre-assembled and banded on the outer periphery thereof. A method for constructing an externally wound brick for an RH immersion pipe, comprising forming a tightly integrated cylinder body, inserting the cylinder body into the outer periphery of a seal fitting located inside the immersion pipe by hanging and fixing the same.