JP2014218720A - Method of preventing wear of liner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of preventing wear of a liner for protection of an inner wall in a furnace top bunker for storing a raw material to be charged into a blast furnace which can extend the life without a significant design change of the liner itself.SOLUTION: In arranging a wear-resistant square bar for protection of the surface of a liner on the linear surface in an area where a raw material charged into a furnace top bunker impinges, the wear-resistant square bar is fixed at an angle for L-formed fixing. While one side of the angle for fixation is attached to the liner surface by welding, the wear-resistant square bar is fixed by bolt fastening in the upper surface of the other side of the angle for fixation extending inward within the furnace top bunker.

Description

  The present invention relates to a method for preventing wear of a liner for protecting an inner wall in a furnace top bunker for storing raw materials charged into a blast furnace.

  The raw material charged into the blast furnace is transported to the top of the blast furnace by a belt conveyor, and then put into a top bunker provided at the top of the furnace, where a segregation control plate (raw material particle size adjustment plate) with variable angle is placed. After passing, it is temporarily stored in the furnace top bunker. The raw material stored in the furnace top bunker is sequentially charged into the blast furnace through the adjustment gate provided at the lower part of the furnace top bunker and the collecting hopper.

For such furnace top bunker, in order to avoid wear due to contact with the raw material when the raw material is charged, for example, a high chrome cast iron liner is attached to the region where the raw material collision is expected, thereby protecting the inner wall. ing.
Also, since this liner wears due to contact with the raw material, if the wear progresses, life-saving measures such as replacement of the liner itself or build-up repair are taken during inspections during wind breaks, etc. Is the current situation.

  By the way, the above-mentioned liner is, for example, a width: about 900 mm, a length: about 900 mm, a thickness: about 80 m, and the size per sheet is large and its weight is about 500 kg. It is difficult to perform efficient replacement in a small space. In addition, life-prolonging treatment such as the above-described overlay repair has better work efficiency than replacement, but its effect is only temporary, and eventually the liner itself needs to be replaced.

  As a technique relating to such a liner replacement, Patent Document 1 discloses that a liner attaching / detaching device is carried into a hopper using a conveying means, and the liner is damaged by a stud welding gun provided in the liner attaching / detaching device. There has been proposed a method and an apparatus for removing the liner from the inner wall of the hopper and unloading the liner from the inner wall of the hopper by electroplanting the studs and pulling the studs.

  In addition, as a technique for extending the life of the liner, Patent Document 2 includes a shelf that protrudes from the vertical inner wall of the bunker inner wall toward the inside of the bunker, and the bunker inner front end of the shelf is inserted. A cell flying structure has been proposed in which the shelf is fixed to the bunker body skin as a raw material receiving portion.

JP-A-8-313172 JP 2011-106001A

  However, the technique disclosed in Patent Document 1 is intended to improve the working environment by reducing the amount of work in the hopper at the time of liner replacement, and is not necessarily in terms of efficient replacement of the liner. It's not enough technology.

Moreover, although the technique disclosed in Patent Document 2 can effectively extend the life as compared with the conventional liner, further life extension is desired in order to further increase the replacement period.
In addition, since the technique of Patent Document 2 is to attach a shelf portion uniformly to the liner (installation steel plate) surface, a significant design change of the liner itself is required. Difficult to apply and costs increase.

  The present invention has been developed in view of the above-described present situation, and an object of the present invention is to provide a liner wear prevention method capable of extending the life of a liner without significantly changing the design of the liner itself. And

Now, the inventors have made extensive studies to achieve the above object.
As a result, when installing the wear-resistant square material for protecting the liner surface on the liner surface in the region where the raw material charged into the furnace top bunker collides, a wear-resistant square material having a relatively large thickness is used. It was found that by fixing the wear-resistant square material with an L-shaped fixing angle, the life of the liner can be greatly extended with little design change of the liner itself.
The present invention is based on the above findings.

That is, the gist configuration of the present invention is as follows.
1. In a furnace top bunker that is disposed at the top of the blast furnace and stores the raw material charged into the blast furnace, a liner wear prevention method that covers the inner wall to protect the inner wall of the furnace bunker. There,
When the wear-resistant square member for protecting the liner surface is installed on the liner surface in the region where the raw material charged into the furnace top bunker collides, the wear-resistant square member is fixed with an L-shaped fixing angle;
One side of the fixing angle is attached to the liner surface by welding, and the wear-resistant square member is fixed by bolting on the upper surface of the other side of the fixing angle extending inward in the furnace top bunker. A method for preventing liner wear.

2. 2. The liner wear prevention method according to 1 above, wherein a fixed position of the wear-resistant square member is set in the vicinity of the welded portion.

3. 3. The liner wear prevention method according to 1 or 2, wherein the wear-resistant square member is fixed with two or more fixing angles.

According to the present invention, it becomes possible to prevent the liner from being worn with a slight design change with respect to the liner, and this makes it possible to dramatically extend the life of the liner.
The liner wear method of the present invention can be applied to an existing liner as it is, which is very advantageous in terms of cost reduction and repair work time reduction.

It is a figure which shows typically the path | route of the raw material charged into a blast furnace. It is a figure which shows typically the path | route of the raw material which passes along a segregation control board. It is a figure which shows typically the furnace top bunker inner wall part at the time of applying the liner abrasion prevention method of this invention, (a) is sectional drawing, (b) is a perspective view. It is a schematic diagram when a plurality of wear-resistant square members are installed on the liner surface of the furnace top bunker.

Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 1 is a diagram schematically showing a route of raw materials charged into a blast furnace, in which 1 is a blast furnace, 2 is a furnace bunker, 3 is a liner, 4 is a segregation control plate, and 5 is a belt conveyor. , 6 is a receiving chute, 7 is a collecting hopper, and 8 is a raw material.

As shown in FIG. 1, the raw material 8 charged into the blast furnace 1 is conveyed to the furnace top of the blast furnace 1 by a belt conveyor 5 and passes through a segregation control plate 4 that allows the angle to be changed. 2 is once stored.
At this time, since the liner 3 installed on the inner wall of the furnace top bunker 2 and the raw material 8 come into contact with each other, the liner 3 in a region where the raw material 8 collides usually wears.
As described above, since the segregation control plate 4 is variable in angle, the region where the raw material collides changes depending on the tilting state of the segregation control plate 4. FIG. 2 schematically shows a path of the raw material 8 passing through the segregation control plate 4.

  Next, FIGS. 3A and 3B schematically show the inner wall of the top bunker when the liner wear prevention method of the present invention is applied. 3A is a cross-sectional view, and FIG. 3B is a perspective view. In the figure, reference numeral 9 is an inner wall (iron skin) of the furnace top bunker, 10 is an L-shaped fixing angle, 11 is a wear-resistant square, 12 is a bolt, and 13 is a weld.

  As shown in FIGS. 3 (a) and 3 (b), in the liner wear prevention method of the present invention, when the wear-resistant square member 11 is installed on the surface of the liner 3, the wear-resistant square member is formed with an L-shaped fixing angle 10. 11 is fixed. Here, the L-shaped fixing angle 10 is welded on one side thereof to the surface of the liner 3, while the wear-resistant square member 11 is fixed with bolts 12 on the upper surface of the other side extending inward in the furnace top bunker. It is structured. In addition, the welding method of the L-shaped fixing angle is not particularly limited, and may be performed in accordance with an ordinary method.

  As described above, by installing the wear-resistant square bar 11 on the liner 3, a part of the raw material 8 put into the furnace top bunker is deposited on the wear-resistant square bar 11. The accumulated raw material and wear-resistant square member 11 can prevent the liner 3 and the raw material 8 from directly colliding with each other, and as a result, the wear of the liner is greatly reduced.

In addition, by fixing the wear-resistant square member 11 as described above, the L-shaped fixing angle 10 has sufficient strength to support the wear-resistant square member 11, so that the wear-resistant square member is obtained. 11 thickness can be increased. As a result, the replacement cycle of the wear-resistant square member 11 itself due to wear can be greatly extended, and as a result, the life of the liner can be extended.
From the viewpoint of securing the strength and preventing the fall, one end of the L-shaped fixing angle 10 welded to the surface of the liner 3 is directed downward as shown in FIGS. 3 (a) and 3 (b). Should.

Here, representative dimensions of the wear-resistant square bar and the fixing angle are as follows.
Wear resistant square (see Fig. 3 (a), (b))
Width a: 80mm
Length b: 300mm
Thickness c: 50mm
L-shaped fixing angle (see Fig. 3 (a), (b))
Side d: 65mm
Other side e: 65mm
Length f: 50mm
Thickness g: 6mm
The cross-sectional shape of the fixing angle does not necessarily have to be a perfect L shape with a bending angle θ of 90 °, and may be an angle that matches the shape of the liner.

In the present invention, by setting the wear-resistant square bar to the dimensions as described above, the weight of the wear-resistant square bar is set to a weight (about 10 kg) that allows two people to carry it by hand. Yes. As a result, even in a narrow furnace top bunker, workability at the time of replacement of the wear-resistant square material can be sufficiently secured, and the work time can be greatly shortened.
In addition, if the hand-held work of two people is about 10-20kg,
Wear resistant square (see Fig. 3 (a), (b))
Width a: 80-150mm
Length b: 250-300mm
Thickness c: 50-70mm
L-shaped fixing angle (see Fig. 3 (a), (b))
Side d: 65-100mm
Other side e: 65-100mm
Length f: 50-80mm
Thickness g: 6-9mm
It is preferable to use it within a range. This is because handling is easy and durability is excellent.

  In addition, examples of the material of the wear-resistant square bar include high Cr cast iron and Cr—Mn steel, among which Cr—Mn steel is particularly preferable. The material for the fixing angle and the bolt is not particularly limited, but it is preferable to use stainless steel from the viewpoint of preventing corrosion.

  Further, the fixing position of the wear-resistant square member is preferably in the vicinity of the welding angle between the fixing angle and the liner. This is because this can prevent the raw material from directly colliding with the welded portion and protect the welded portion. Specifically, the distance h (see FIG. 3 (a)) between the fixing position at the liner-side end of the wear-resistant square and the welded end at the fixing angle is preferably within 5 mm.

  Next, as for the method of attaching the wear-resistant square member, one wear-resistant square member can be fixed with one fixing angle, but from the viewpoint of strength and stability, two or more fixing members are used. It is preferable to fix at an angle.

Further, in order to cover and protect the liner in the region where the raw material collides, as shown in FIG. 4, it is preferable to install a plurality of wear-resistant square members in the vertical direction (vertical direction) and the horizontal direction (horizontal direction). .
In this case, the longitudinal interval i (see FIG. 4) of the wear-resistant square is preferably in the range of 50 to 200 mm from the viewpoint of efficiently preventing the wear of the liner. On the other hand, it is preferable to reduce the distance between the wear-resistant square members in the lateral direction as much as possible.

  Although it is conceivable to attach the wear-resistant square material directly to the liner by welding, in that case, there is a risk that the weld-resistant square material will fall due to damage to the welded part due to collision with the raw material. Also, if the wear-resistant square is worn due to a collision with the raw material and needs to be replaced, the time required for replacement becomes longer, and the liner may be damaged during replacement, which is not preferable. . In the liner wear prevention method of the present invention, the above-mentioned problem is solved by fixing the wear-resistant square material by bolting to an L-shaped fixing angle.

  By applying the liner wear prevention method of the present invention described above, the life could be dramatically extended by 2.5 times compared with the normal liner life (about 10 months). In addition, maintenance costs were reduced to approximately 3/50, which was significantly reduced.

1 Blast Furnace 2 Furnace Bunker 3 Liner 4 Segregation Control Board 5 Belt Conveyor 6 Receiving Chute 7 Collecting Hopper 8 Raw Material 9 Furnace Bunker Inner Wall (Steel)
10 L-shaped fixing angle
11 Wear resistant square
12 volts
13 Welded part

Claims (3)

In a furnace top bunker that is disposed at the top of the blast furnace and stores the raw material charged into the blast furnace, a liner wear prevention method that covers the inner wall to protect the inner wall of the furnace bunker. There,
When the wear-resistant square member for protecting the liner surface is installed on the liner surface in the region where the raw material charged into the furnace top bunker collides, the wear-resistant square member is fixed with an L-shaped fixing angle;
One side of the fixing angle is attached to the liner surface by welding, and the wear-resistant square member is fixed by bolting on the upper surface of the other side of the fixing angle extending inward in the furnace top bunker. A method for preventing liner wear.   The liner wear prevention method according to claim 1, wherein a fixed position of the wear-resistant square member is set in the vicinity of the welded portion. The liner wear prevention method according to claim 1 or 2, wherein the wear-resistant square member is fixed with two or more fixing angles.

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