JP5987620B2 - Immersion member - Google Patents

Description

  The present invention relates to an improvement of a dipping member that is used in refining by dipping in a molten metal such as hot metal or molten steel.

  RH, DH, CAS, etc. are used as secondary refining equipment for molten steel. These refining equipment is provided with a member immersed in molten steel called a dip tube or dip tank at its lower end.

  These immersion members are members that are immersed in high-temperature molten steel and have an important function of blocking the molten steel from the surrounding atmosphere, and have a structure in which both inner and outer surfaces of the cylindrical iron skin are covered with a refractory. As the refractory, an irregular refractory is used, and as shown in Patent Document 1, Y-shaped studs are welded to both the inner and outer surfaces of the cylindrical iron skin to hold the refractory.

  However, these immersion members tend to adhere to the lower end of the dip metal, and if they are left as they are, they will gradually grow and may contact the molten steel pan before the refining operation starts or contact the molten steel pan during immersion, resulting in damage to the refractory. is there. Moreover, although the operation | work which removes the metal which adhered at the time of a maintenance is performed, a refractory material may peel from the cylindrical iron shell with a metal, and may fall off. If the refractory is damaged, the cylindrical iron skin is exposed and there is a risk of melting.

  In addition, the adhesion of the metal is assumed to be because cracks are first generated in the refractory due to repeated heating and cooling, and slag, hot metal, or molten steel enters the cracks and gradually grows. Since the grown bullion is integrated with roots growing in the refractory, the Y-stud cannot support the refractory during the removal of the refractory, and the refractory is at the bottom of the cylindrical iron skin. It is easy to drop off from the part.

JP-A-10-110213

  Accordingly, an object of the present invention is to provide an immersion member that can solve the above-described conventional problems and can suppress the refractory from falling off during the removal work of the attached metal.

  The present invention made to solve the above problems is a dipping member that has a structure in which both inside and outside of a cylindrical iron skin are covered with a refractory, and is used by dipping in a molten metal. A plurality of through holes are formed in the iron skin, and the outer refractory and the inner refractory of the cylindrical iron skin are integrated by a refractory filled in these through holes.

  In addition, it is preferable to make the said through-hole into the structure formed in the part immersed in the molten metal of a cylindrical iron skin. Further, it is preferable that a reinforcing pipe is inserted into the through hole and a refractory is filled therein. The through holes are preferably arranged in a staggered manner, and the through holes preferably have an inner diameter of 20 to 200 mm.

  The immersion member of the present invention has a structure in which a plurality of through holes are formed in a cylindrical iron skin, and an outer refractory and an inner refractory of the cylindrical iron skin are integrated by a refractory filled in these through holes. Therefore, the outer refractory and the inner refractory are firmly held by the cylindrical iron skin. For this reason, even if the work of removing the attached metal is performed, only the metal can be detached from the refractory, and the refractory does not fall off together with the metal.

  In addition, since the said through-hole may impair the airtightness of a cylindrical iron skin, it is preferable to form only in the part immersed in the molten metal of a cylindrical iron skin. If the structure in which the reinforcing pipe is inserted into the through hole is used, the area for supporting the weight of the refractory increases, so that the refractory can be supported more firmly.

  Further, if the through holes are arranged in a staggered arrangement, the load supporting points of the refractory are dispersed as compared with the case where the through holes are arranged on the same line, and the refractory can be prevented from falling off more reliably.

It is sectional drawing of the CAS dip tube of embodiment. It is a partial expanded view of an iron skin. It is a horizontal sectional view of FIG. It is explanatory drawing of a manufacturing process. It is sectional drawing which shows the advantage of the immersion member of this invention. It is sectional drawing which shows the problem of the conventional immersion member.

Preferred embodiments of the present invention are shown below.
1-3 is a figure which shows the CAS dip tube which is embodiment of this invention, In these figures, 1 is the cylindrical iron skin, 2 is the flange 2 formed in the upper end part. A large number of Y-shaped studs 3 similar to the conventional one are welded to the inner and outer surfaces of the cylindrical iron skin 1 at a predetermined interval. These Y-shaped studs 3 are members that hold the outer refractory 4 and the inner refractory 5.

  A plurality of through-holes 6 are formed in the lower half of the cylindrical iron skin 1 that is immersed in the molten metal. It is preferable that the through hole 6 is disposed so as to be displaced from the Y-shaped stud 3. As described above, since the immersion member is a member that is immersed in high-temperature molten steel and plays an important role in blocking the molten steel and the surrounding atmosphere, the through-hole 6 is formed in the portion of the cylindrical iron skin 1 that is not immersed in the molten steel. It is not preferable to form.

  In this embodiment, the diameter of the cylindrical iron skin 1 is about 1400 mm, and the through-holes 6 are formed in a staggered manner in two upper and lower stages at positions that divide the circumferential direction into 24 equal parts. The outer refractory 4 and the inner refractory 5 of the cylindrical iron shell 1 are integrated by a refractory filled inside the through hole 6. In this embodiment, the through-holes 6 are formed in a two-stage zigzag pattern, but when the height of the portion immersed in the molten steel of the cylindrical iron skin 1 is large, the through-holes 6 are arranged in three to four rows in a staggered arrangement. It is also possible to do. Such a staggered arrangement is preferable in terms of stress distribution.

  For the purpose of integrating the outer refractory 4 and the inner refractory 5 of the cylindrical iron shell 1, the inner diameter of the through hole 6 is preferably 20 to 200 mm. If the inner diameter is smaller than this, the force for integrating the outer refractory 4 and the inner refractory 5 is insufficient, and if the inner diameter is larger than this, the mechanical strength of the cylindrical iron shell 1 may be impaired. is there. In this embodiment, the inner diameter of the through hole 6 is 60 mm, and the reinforcing pipe 7 is inserted and welded therein.

  In the present invention, the reinforcing pipe 7 is not essential, but is effective in increasing the area for supporting the weight of the refractory. The length is preferably about 10 to 50% of the thickness of each of the outer refractory 4 and the inner refractory 5, and in this embodiment, a steel pipe (SPG) of 25 mm (total length 50 mm) on one side corresponding to 25% is a cylindrical iron. It is welded perpendicular to the skin 1. Its inner diameter is 50 mm and can hold 1 to 3 tons of refractory weight per piece. Therefore, the required number can be obtained by calculation from the refractory weight.

  In order to manufacture the immersion member having such a structure, as shown in FIG. 4A, the upper and lower sides of the cylindrical iron skin 1 to which the Y-shaped stud 3 and the reinforcing pipe 7 are welded in advance are reversed. The frame 9 is set on both the inner and outer sides. Next, castable refractory is poured as shown in (b). At this time, the castable refractory flows into the reinforcing pipe 7, and the outer refractory 4 and the inner refractory 5 are integrated. After injecting the castable refractory to the upper end, curing is performed until the castable refractory is cured, and then the frame is removed as shown in (c). Then, it is only necessary to invert the top and bottom as in (d). Further, before the castable refractory is cured after the injection, the castable refractory inside the outer refractory 4, the inner refractory 5 and the reinforcing pipe 7 is vibrated from the frame 9 (for example, using an electric or pneumatic vibrator). It is preferable to remove bubbles in the cast refractory poured into the outer refractory 4, the inner refractory 5, and the reinforcing pipe 7 and to make the castable refractory uniform.

  Since the immersion member of the present invention configured as described above has a structure in which the outer refractory 4 and the inner refractory 5 are integrated by the refractory filled in the through-hole 6, it is attached as shown in FIG. 5. Only the base metal 10 can be detached, and the refractory does not fall off with the base metal as in the conventional structure shown in FIG. For this reason, the service life of the immersion member can be greatly extended. At the same time, the life of the cylindrical iron skin 1 can be greatly extended.

  Although the immersion member of the above-described embodiment is a CAS immersion tube, the present invention can be applied to various immersion tubes and immersion baths such as a SAB immersion tube, an RH immersion tube, and a REDA immersion bath. Moreover, the immersion member of the present invention can be applied to various immersion pipes and immersion tanks in general for molten metal refining other than molten steel.

DESCRIPTION OF SYMBOLS 1 Cylindrical iron skin 2 Flange 3 Y-shaped stud 4 Outer refractory 5 Inner refractory 6 Through hole 7 Reinforcement pipe 8 Surface plate 9 Frame 10 Ingot

Claims (5)

It has a structure in which both inner and outer surfaces of a cylindrical iron skin are covered with a refractory, and is an immersion member used by being immersed in molten metal,
A plurality of through holes are formed in the cylindrical iron skin, a reinforcing pipe is inserted into the through hole, a refractory is filled therein, and the outer refractory of the cylindrical iron skin is filled with the refractory filled in these through holes. Immersion member characterized by integrating the object and the inner refractory.   The immersion member according to claim 1, wherein the through hole is formed in a portion of the cylindrical iron skin that is immersed in the molten metal.   The immersion member according to claim 1, wherein the through holes are arranged in a staggered pattern.   The immersion member according to claim 1, wherein the through-hole has an inner diameter of 20 to 200 mm. The immersion member according to any one of claims 1 to 4, wherein a length of the reinforcing pipe is 10 to 50% of a thickness of each of the outer refractory and the inner refractory.