JP2589629Y2 - Immersion tube for vacuum degassing equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dip tube for vacuum degassing equipment.

[0002]

2. Description of the Related Art An RH type vacuum degassing system, that is, two immersion pipes for suction and discharge are provided in a degassing tank, and the immersion pipe is immersed in molten steel in a ladle to evacuate the tank. The molten steel flows into the tank by blowing gas such as argon or nitrogen from one immersion tube, and is scattered to degas.
The degassed molten steel is discharged from the other dip tube and returns to the ladle. There are degassing facilities that degas by continuing this.

[0003] A dip tube used in such a degassing device is a horizontal brick (divided into a plurality in the circumferential direction) on the inner periphery of a cylindrical steel seal fitting having a large number of studs or the like implanted on its outer surface. (Hereinafter referred to as inner winding bricks) is joined in multiple steps to form an inner cylinder. And a plurality of gas injection pipes penetrating through the inner and outer cylinders.

By the way, when the above-mentioned immersion tube is immersed in molten steel in a ladle and subjected to vacuum degassing, friction due to the high temperature of the molten steel and the impact of turbulent flow accompanying the reflux of the molten steel, or repeated use. Rapid heating due to rapid cooling, friction due to rapid cooling, and spalling occur and are promoted and worn. In particular, the innermost brick at the lowermost stage generally has a hook portion having an L-shaped or U-shaped cross section on the back surface (outer peripheral surface) in order to support the entire innermost brick.
This was hooked and hung on a support protruding from the sealing hardware. However, according to this, thermal stress was concentrated on the hook portion during use, and cracks were easily generated in the portion, and the crack was generated. However, molten steel penetrates through the cracks during immersion, erodes the support and seal metal, and the inner bricks fall off in a chain.

[0005] In order to solve such problems,
Conventionally, there is one disclosed in Japanese Utility Model Publication No. 4-48. The dip tube described in this publication (FIG. 1 in the publication) has an inclined portion which is inclined toward the inner peripheral side at the lower end which is not more than 1/3 of the length of the sealing metal, and the outer periphery of the inner winding brick is formed by the same. By contacting these inclined surfaces as inclined surfaces that match the inclination, the inner winding brick is supported on the sealing hardware. FIG. 2 shows a conventional example of the above-mentioned publication in which the above-mentioned hook portion is used, and FIG.
It describes that the inner winding brick is supported by the support metal.

[0006]

However, in the structure described in FIG. 1 of the above-mentioned publication, the seal is formed as a reverse-conical frustoconical shape of a lower squeeze over a length of 1/3 or less of the lower part of the seal fitting. When manufacturing metal parts, it is necessary to manufacture the upper cylindrical part and the lower conical part separately and join them by welding to integrate them. Not only that, it takes much time and labor for welding, requires twice or more times and time as compared with the conventional cylindrical type, and is complicated and expensive. When exposed to the harsh conditions during use, there is a danger that, as in the past, welding breakage occurs at the joint by welding, and the inner winding brick falls off.

[0007] Further, the support fitting shown in Fig. 3 described as a conventional example of the above-mentioned publication comprises a plate-shaped receiving plate portion which comes into contact with the inclined surface of the lower periphery of the inner winding brick and a receiving shaft which supports the same. However, in the part supporting the lowermost inner winding brick,
The lower part of the seal metal is opened and deformed in a flare skirt shape due to the high temperature of the molten steel, and the support fitting integrally welded to the seal metal also opens integrally. For this reason, the expansion of the inner winding brick does not become larger than the expansion of the sealing hardware. Therefore, in the conventional structure (FIG. 3 in the above-mentioned publication), the inclination angle is cut large to facilitate the mounting of the support bracket. Therefore, if the inner diameter of the support bracket expands and deforms integrally with the seal hardware, the inner end brick will be supported at one point only by the upper end of the receiving plate, and cracks will occur in the direction of dividing the axial direction due to the concentration of thermal stress. There is a problem that will occur.

In view of the above, the present invention provides an immersion pipe for a vacuum degassing facility in which it is easy to manufacture a seal metal and a supporting portion of an inner brick and can surely support the inner brick. It is done for the purpose of.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, an object of the present invention is to provide an immersion pipe which is immersed in molten steel and subjected to a vacuum degassing treatment. The outer periphery is formed on a squeezed inclined surface, and a plurality of block-shaped support brackets having the same upwardly inclined surface as the inclined surface of the inner brick on the inner peripheral surface of the cylindrical sealing hardware are spaced apart in the circumferential direction. The inclined surface of the inner brick is placed on the inclined surface of these support brackets with an expansion absorbing material interposed between them.
In this case, the inner winding brick is supported through the expansion absorbing material .

[0010]

The sealing metal has a cylindrical shape, and a plurality of plate-like supporting brackets protruding from the inner peripheral surface thereof are formed on the inclined surfaces of the end faces of the expansion absorbing material.
By which it is adapted charge of the inclined surface of the lower outer surface of the inner winding brick through the attachment of the support bracket to the seal hardware is easy, yet stable well and thermal expansion of the inner winding brick
Can be absorbed and supported.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows a vertical cross section of a dip tube 1 according to the present invention, and FIG. 2 shows a horizontal cross section corresponding to the line AA in FIG. On the inner periphery of a large number of cylindrical steel seal fittings 3 planted, an inner winding brick 4 made of a horizontal pressing brick whose circumferential direction is divided into a plurality of pieces is spliced into a plurality of steps to line the inner cylinder 5. An outer cylinder 7 is formed by applying an irregular refractory 6 such as a castable refractory between the inner winding brick 4 and the seal hardware 3 and on the outer periphery of the seal hardware 3 to form an inner cylinder and an outer cylinder. A plurality of gas blowing pipes 8, 8, ... penetrating therethrough are arranged and integrated. The seal hardware 3
Is fixed to a flange 9.

In the illustrated embodiment, the inner winding bricks 4 are vertically stacked in three stages, and the outer surface of the lowermost inner winding brick 4 is formed as an inclined surface 10 in a direction of downward squeezing.

The lower end of the seal metal member 3 is located at substantially the middle in the vertical direction of the innermost brick 4 of the lowermost stage, and slightly above the lower end of the inclined surface 10 of the innermost brick 4 of the lowermost stage. A plurality of support fittings 11, 11,... Are arranged at equal intervals in the circumferential direction and protrude toward the center of the seal fitting 3 on the inner periphery of the seal fitting 3 at a position corresponding to the upper part.

As shown in FIG. 3, one of the supporting members 11 is formed in a block shape from a plate material, and one end surface thereof is directed upward at the same inclination angle as the inclined surface 10 of the inner brick 4. Inclined surface 12.

One example of mounting the support fitting 11 to the seal fitting 3 is a vertically long part in which the support fitting 11 can be inserted as closely as possible into the support fitting mounting position of the seal fitting 3 as shown in a cross section in FIG. In the state where the support fitting 11 is inserted into the mounting hole 13 and the welding 14 is performed from the outer surface side of the seal fitting 3, the support fitting 11 protrudes from the inner surface of the seal fitting 3. Can be installed.

Therefore, the inclined surface 10 formed on the outer surface below the inner winding brick 4 by the above-described structure is used as the sealing metal 3.
Since it is supported by the inclined surface 12 of the supporting bracket 11 protruding from the inner surface, the supporting member 11 is supported on a long surface in the vertical direction, and
Can be stably supported. In addition, support bracket 11
Is composed of a single part, so that it is easy to weld to the seal fitting 3.

[0017] Since the supporting bracket 11 expansion absorber 15 between the inclined surface 10 of the inclined surface 12 and the inner winding bricks 4 (Figure 5) is via <br/> standing, thermal stress during use Concentration can be reduced and absorbed, cracks can be prevented, and the useful life can be greatly extended.

In the illustrated embodiment, the case of a dip tube in which the inner winding bricks 4 are stacked in the vertical direction is shown. However, it is a matter of course that an integrated inner winding brick may be used in the vertical direction.

[0019]

According to the present invention, as described above, a plurality of plate-like support members projecting from the inner peripheral surface of the seal fitting and supporting the inclined surface of the lower outer surface of the inner winding brick are provided. The end face is a vertically long inclined surface that supports the inclined surface of the inner winding brick, so it is possible to attach the support member to the seal hardware by passing it through the through hole drilled in the seal hardware and welding from the outside As a result, the mounting is easy, and the support at the position above the lowermost inner winding brick is possible. For this reason, the inclination angle can be reduced, and one-point support caused by deformation of the hardware can be avoided and reduced. In addition to being vertically long, it can be supported on the surface during use, so that thermal stress can be reduced. The concentration can be dispersed accordingly, and as a result, the occurrence of cracks in the direction of dividing the axial direction can be prevented. Because it is possible to relax absorb thermal stress concentration by Tei Rukoto is further interposed expansion absorbing material, it can be enhanced more effectively.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a horizontal sectional view of a portion corresponding to line AA in FIG. 1;

FIG. 3 is an enlarged perspective view of a support fitting.

FIG. 4 is a cross-sectional view showing an example of a mounting structure of a support fitting.

FIG. 5 is a cross-sectional view showing an example of a case where an expansion absorbing material is used together.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Immersion pipe 3 Seal metal 4 Inner winding brick 5 Inner cylinder 6 Irregular refractory 7 Outer cylinder 8 Gas injection pipe 10 Inclined surface 11 Supporting bracket 12 Inclined surface 15 Expansion absorber

Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C21C 7/10 C21C 7/00

Claims (1)

(57) [Scope of request for utility model registration] 1. A dip tube for immersing in molten steel to perform a vacuum degassing process, wherein an outer periphery of a lower part of an inner winding brick is formed as a squeezed inclined surface, and the inner peripheral surface of a cylindrical seal fitting is formed on the inner peripheral surface. A plurality of block-shaped support brackets having the same upwardly inclined surface as the inclined surface of the brick are protruded at intervals in the circumferential direction, and the inclined surface of the inner brick is expanded between the inclined surfaces of these support members.
An immersion pipe for vacuum degassing equipment , wherein an abutting member is interposed and an inner winding brick is supported via the expanded absorbing member .