JP2020030012A - Replacement method of lining material - Google Patents

Abstract

To effectively replace the lining material of an induction furnace without requiring troublesome preparation before the replacement work.SOLUTION: A replacement method of a lining material attached to the inside of an induction furnace, according to the present invention, comprises the steps of: preparing a replacement tool for replacement having multiple arm members extending outward from a center; opening holes at multiple parts of the lining material on the same plane orthogonal to a central axis of the induction furnace; fixing the arm members to the multiple holes; and hanging up the replacement tool together with the lining material from the upper side of the induction furnace.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method for replacing a lining material installed inside an induction furnace.

  In a typical induction furnace, the steel material is melted using Joule heat generated by the electromagnetic induction of the coil. Since the melting is performed many times in the same induction furnace, a lining material is attached inside the furnace wall to prevent damage to the furnace wall inside the induction furnace. This lining material is also damaged by the high temperature and needs to be replaced periodically.

  Conventionally, when replacing a lining material, an operator enters the induction furnace using a ladder or the like, crushes the old lining material with a tool, and inclines the entire induction furnace to collect fragments at once. However, in the recovery operation, when the induction furnace is tilted, it is necessary to remove wirings and the like connected to the surrounding induction furnace, and the work of removing the wiring is extremely troublesome. That is, the preparation before replacing the lining material is a burden on the operator.

On the other hand, as a replacement work of the lining material that does not require removal of the wiring or the like, it is conceivable to attach a rope or the like to the relatively large crushed lining material and pull it up with a crane from above the induction furnace. However, in this case, if the number of large lining materials is large after crushing, it is necessary to perform the lifting operation many times, which may take a long time.

JP-A-6-111771

The present invention has been made in view of the above problems, the problem to be solved by the present invention, when replacing the lining material of the induction furnace, without the need for cumbersome preparation before the replacement work, And to perform the work efficiently.

The present inventors have made intensive studies and found that this problem can be solved. The specific means are as follows. First, a first invention is a method of replacing a lining material attached to the inside of an induction furnace, comprising a preparing step of preparing a replacement jig for replacement having a plurality of arm members extending outward from the center; A piercing step of making holes at a plurality of locations of the lining material on the same plane orthogonal to the central axis of the induction furnace, a fixing step of fixing the arm member to the holes at the plurality of locations, and lining the replacement jig with the lining. A method for replacing a lining material, comprising a lifting step of lifting the material together with the material from above the induction furnace. According to the first aspect, since only the replacement jig needs to be prepared, the burden is reduced as compared with the conventional replacement work. In addition, since the entire lining material can be lifted at once, the lining material can be replaced very efficiently.

Next, a second invention is the method for replacing a lining material according to the first invention described above, wherein in the opening step, the hole is opened at a position equal to or less than half the height of the induction furnace. Features. According to the second invention, the lining material can be lifted more reliably during the lifting process.

Next, a third invention is the method for replacing a lining material according to the first invention or the second invention described above, wherein the plurality of arm members are arranged in a cross direction. . According to the third aspect, the lining material can be lifted in a more stable state.

Next, a fourth invention is the method for replacing a lining material according to any one of the first to third inventions described above, wherein the arm member is capable of extending outward from the center. Features. According to the fourth aspect, even when the diameter of the induction furnace changes, the lining material can be easily replaced.

As described above, according to the method for replacing a lining material according to the present invention, the worker can efficiently replace the lining material without requiring particularly troublesome preparation when replacing the lining material. Thereby, the physical load on the worker is reduced, and the replacement work can be completed in a short time.

It is sectional drawing which showed the cross section of the crucible type induction furnace which concerns on embodiment. It is sectional drawing which showed the cross section when the crucible-type induction furnace which concerns on embodiment was seen from above. It is an outline view of a replacement jig concerning an embodiment. It is sectional drawing which shows the state of the opening process which concerns on embodiment. FIG. 5 is a cross-sectional view of the opening step according to the embodiment as viewed from a plane AA in FIG. 4. It is sectional drawing which shows the state of the insertion process which concerns on embodiment. FIG. 7 is a cross-sectional view of the insertion step according to the embodiment as viewed from the plane BB in FIG. 6. It is sectional drawing which shows the state of the lifting process which concerns on embodiment. It is sectional drawing which looked at the lifting process which concerns on embodiment from CC plane of FIG.

  A method for replacing a lining material applied to a crucible-type induction furnace according to one embodiment of the present invention will be described in detail. FIG. 1 shows a cross section of a crucible type induction furnace 10. The crucible-type induction furnace 10 has an opening 11 at its upper part and a bottom part 12 at its lower part. Further, a furnace wall 13 is provided in the left-right direction (actually, the circumferential direction of the opening 11) of the crucible-type induction furnace 10 viewed in FIG. Further, a backing material 14 and a lining material 15 are sequentially attached inside the furnace wall 13. The backing material 14 has a role of buffering the furnace wall 13 and the lining material 15.

  At an actual site, a steel material is charged through the opening 11, and the inside of the crucible-type induction furnace 10 is heated to high temperature by Joule heat generated by electromagnetic induction of a coil (not shown). Become. Since the input operation of the steel material is repeated many times, the life of the lining material is extended. Therefore, an operation of replacing the lining material 15 is required.

  FIG. 2 shows a cross section when the crucible-type induction furnace 10 is viewed from above. As shown in FIG. 1, the lining material 15 has a cup shape, and as shown in FIG. 2, its diameter is formed slightly smaller than the diameter of the crucible-type induction furnace 10. The lining material 15 is fixed (attached) by a backing material 14 made of an inorganic material between the furnace wall 13 of the crucible-type induction furnace 10 and the lining material 15. The lining material 15 is made of a fire-resistant material such as alumina and silica.

  Next, a method of replacing the lining material 15 attached inside the crucible-type induction furnace 10 in the state of FIG. 1 will be described.

  First, a replacement jig for replacement is prepared (preparation step). FIG. 3 shows the appearance of the replacement jig 20. The replacement jig 20 has a plurality of arm members 23 extending outward from the center T thereof. In the present embodiment, the replacement jig 20 has a substantially square main body 21, and the arm members 23 are arranged in a cross direction extending from the center T of the main body 21 in the east-west-north-south direction. In the present embodiment, the four arm members 23 are arranged in the cross direction, but may be formed in a bifurcated shape having two arm members or a trifurcated shape having three arm members. Further, when the lining material 15 is replaced, only a replacement jig needs to be prepared, so that no particularly troublesome work is required.

  The main body 21 has a cross-shaped cross portion 21a made of a hollow steel material into which a part of the arm member 23 can be inserted, and a reinforcing portion 21b for preventing the arm member 23 from being bent due to a load applied in a lifting process described later. It is composed of The cross member 21a is configured such that the arm member 23 can be freely inserted into the inside of the cross member 21a at the end located at the tip of the cross, and the nut-shaped adjusting member 24 is fastened to the cross member 21a. The position of the arm member 23 is fixed. That is, the length of the arm member 23 can be adjusted by the adjusting member 24. Thus, even when the diameter of the induction furnace 10 is different, the length of the arm member 23 may be adjusted, so that there is no need to prepare the replacement jig 20 every time the diameter of the induction furnace 10 changes. Further, since the arm members 23 are arranged in the cross direction, the arm members 23 can be fixed to the lining material 15 at equal intervals in four directions, and the lining material 15 can be lifted in a stable state. Further, as shown in FIG. 3, one hook portion 26 for hooking a wire or the like is formed on the upper portion of the main body 21. The replacement jig 20 is tied to the leading end of the wire at the hooking portion 26, so that it can be lifted by a crane. As shown in FIG. 3, each arm member 23 has a pyramid-shaped head 25 tapered outward.

Next, holes 30 are opened at a plurality of locations of the lining material 15 (opening step). 4 and 5 are cross-sectional views showing a state of a hole forming step according to the embodiment. As shown in FIG. 5 viewed from the AA direction in FIG. 4, four holes 30 are formed in the lining material 15 on the same plane perpendicular to the central axis S of the induction furnace 10. When the holes 30 are formed, the holes 30 are formed at four locations of the lining material 15 on a line extending in the east-west-north-south direction from the central axis S of the induction furnace 10 using a tool or the like. In addition, as shown in FIG. 4, it is preferable to form the hole 30 at a position that is less than half the height of the induction furnace 10 during the hole forming step. If the hole 30 is opened at a position higher than half the height of the induction furnace 10, a weight load equal to or more than half of the lining material 15 below the replacement jig 20 will be placed under the replacement jig 20 in a later lifting process. 20 because the load applied to the replacement jig 20 in the lifting process and the overall weight of the lining material 15 are poor. By setting the position at half or less, the replacement jig and the lining material can be lifted more reliably.

Next, the arm member 23 is fixed to the four holes 30 (insertion step). 6 and 7 are cross-sectional views illustrating a state of a fixing step according to the embodiment. 7, the replacement jig 20 and the lining material 15 are fixed by piercing the head 25 of the arm member 23 into the hole 30 as shown in FIG. The replacement jig 20 and the lining material 15 are fixed by the head 25 of the arm member 23 on the left side in FIG. Further, since the length of the arm member 23 is adjustable in the left-right direction (outward direction) as viewed in FIG. 6, the fixing step can be easily performed. Then, as shown in FIG. 6, in the fixing step, it is preferable to fix the head 25 in a state where the wire 50 is tied to the hook 26 and the replacement jig 20 is suspended from the viewpoint of work safety.

Next, the inserted replacement jig 20 is lifted together with the lining material 15 from above the induction furnace 10 (a lifting step). 8 and 9 are cross-sectional views illustrating a state of a lifting step according to the embodiment. As shown in FIG. 9 viewed from the CC direction in FIG. 8, four arm members 23 extending in the east-west-north-south direction from the center T of the replacement jig 20 are shown in FIG. Thus, the wire 50 is tied to the hook portion 26, and the replacement jig 20 is lifted from above the induction furnace 10 using a crane (not shown) in a state where the replacement jig 20 is fixed. As shown in FIG. 9, the center T of the replacement jig 20 substantially coincides with the position of the central axis S of the crucible-type induction furnace 10 shown in FIG. Here, the lining material 15 is fixed by the backing material 14 between the furnace wall 13 and the lininging material 15, but the backing material 14 has become somewhat brittle due to the operation of the induction furnace 10 with many charges. Therefore, as shown in FIG. 8, the entire lining material 15 can be easily pulled upward by the pulling force of the crane to which the wire 50 is attached.

  After the lining material 15 is lifted in the above-mentioned lifting step and the backing material 14 is removed, a new lining material 15 prepared in advance is inserted into the crucible-type induction furnace 10 with a crane. After the insertion, the backing material 14 is poured, and the lining material 15 is fixed to the furnace wall 13 again. After the charging operation of the molten metal is repeated many times, the lining material 15 can be replaced by the above replacement method.

As described above, according to the method for replacing a lining material according to the present invention, the worker can efficiently replace the lining material without any troublesome preparation when replacing the lining material.

The embodiment of the invention has been described. The present invention is not particularly limited to these embodiments, and various modifications can be made.

Reference Signs List 10 Induction furnace 13 Furnace wall 14 Backing material 15 Lining material 20 Replacement jig 23 Arm member 30 Hole S Center axis T Center

Claims (4)

A method of replacing a lining material attached inside an induction furnace,
A preparation step of preparing a replacement jig for replacement having a plurality of arm members extending outward from the center,
An opening step of opening holes at a plurality of locations of the lining material on the same plane orthogonal to the central axis of the induction furnace,
A fixing step of fixing the arm member to the plurality of holes,
A method of replacing a lining material, comprising a lifting step of lifting the replacement jig together with the lining material from above the induction furnace. 2. The method according to claim 1, wherein in the hole forming step, the hole is formed at a position equal to or less than half the height of the induction furnace. 3. 3. The method according to claim 1, wherein the plurality of arm members are arranged in a cross direction. 4. The method according to claim 1, wherein the length of the arm member is adjustable from the center toward the outside.

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