JP5672093B2 - Converter repair method - Google Patents

Description

  In the converter, after cutting the furnace body and separating the furnace bottom part from the furnace body part in the converter, the new furnace bottom part is joined to the furnace body part which is the old furnace body, so that only the furnace bottom part is partially obtained. This is related to the method of repairing the furnace.

Since the converter for steel making is particularly easily worn at the bottom of the furnace, the furnace is repaired when used for a certain period of time. In recent converters, there is a structure in which the furnace body is divided into 2-3 in the vertical direction so that each part can be appropriately replaced (for example, Patent Documents 1 to 3). The furnace repair for renewing the furnace bottom can be completed easily and in a short time by replacing only the furnace body part constituting the furnace bottom.
However, in the case of renewing the furnace bottom in an integrally structured converter that has been used in the past, the furnace body is cut to separate the furnace bottom from the furnace body, and the newly manufactured furnace bottom is the old furnace body. It is necessary to repair the furnace to join the furnace body.

JP-A-4-235209 JP-A-8-233466 Japanese Patent Laid-Open No. 11-61224

However, in the furnace repair that partially updates the bottom of such a monolithic converter, the old furnace body and the new bottom of the furnace that have been swelled (change in circumference) due to long-term use. In many cases, a large misalignment occurs on the skin-matching surface, and it takes a lot of time for construction (additional work) on site to correct this misalignment. For this reason, there is a problem that the furnace repair work takes a long time and the converter downtime is prolonged.
Therefore, the object of the present invention is to minimize the time required for repairing the furnace on site, and to shorten the downtime of the converter due to furnace repair as much as possible when performing furnace repair that partially updates only the bottom of the converter. An object of the present invention is to provide a furnace repair method for a converter.

The gist of the present invention for solving the above problems is as follows.
[1] After cutting the furnace body and separating the furnace bottom (y 2 _{O 3} ) from the furnace body (x), the new furnace bottom (y _N ) is joined to the furnace body (x) to convert the converter Of renewing only the bottom of the furnace,
A step of tentatively determining a cutting position (p ₀ ) for separating the furnace bottom (y _O ) from the furnace body (x) and measuring the three-dimensional shape of the outer surface of the furnace body at the cutting position (p ₀ ) by a three-dimensional measuring device. (A) and
Based on the three-dimensional shape measurement result of the outer surface of the furnace body in the step (A), a step (B) of manufacturing a new furnace bottom (y _N );
Immediately before cutting the furnace body and separating the furnace bottom part (y 2 _O 3) from the furnace body part (x), the cutting position (p ₀ ) and the three-dimensional shape of the outer surface of the furnace body around the cutting position (p ₀ ) are measured. (C) determining the cutting position (p) in consideration of the three-dimensional shape measurement result of the outer surface of the furnace body and the shape of the new furnace bottom (y _N );
After cutting the furnace body at the cutting position (p) determined in the step (C) and separating the furnace bottom part (y 2 _{O 3} ) from the furnace body part (x), the new furnace bottom part (y _N ) is replaced with the furnace body part. A furnace repair method for a converter, comprising the step (D) of bonding to (x).

[2] In the furnace repair method according to [1], the furnace body (x) at the cutting position (p) determined in the step (C) between the step (C) and the step (D). A furnace repair method for a converter, comprising a step (E) of additionally processing a new furnace bottom (y _N ) in accordance with the shape of the side.
[3] In the furnace repair method of [2] above, the three-dimensional shape of the outer surface of the portion to be joined to the furnace body (x) is three-dimensionally for the new furnace bottom (y _N ) manufactured in the step (B). In the step (E), the measurement result is measured, and the three-dimensional shape measurement result is compared with the cutting position (p ₀ ) obtained in the step (C) and the three-dimensional shape measurement result of the outer surface of the furnace body in the vicinity. In addition, the new furnace bottom (y _N ) is additionally processed so that the difference in the skin contact surface between the furnace body (x) to be joined and the new furnace bottom (y _N ) is minimized. How to repair the converter.
[4] In the furnace repair method according to any one of [1] to [3], in step (B), a new furnace bottom (y _N ) divided into a plurality of components in the furnace height direction is manufactured. A method for repairing a converter.
[5] In the furnace repair method of [4], the bottom of the new furnace (y _N ) is divided into two parts, an upper component (y _N1 ) and a lower component (y _N2 ). How to repair the converter.
[6] In the furnace repair method of [4] or [5] above, in the step (E), only the uppermost constituent member in the furnace height direction is additionally machined among the constituent members of the new furnace bottom (y _N ). A furnace repair method for a converter.

According to the converter repair method of the present invention, after cutting the furnace body and separating the furnace bottom (y 2 _{O 3} ) from the furnace body (x), the new furnace bottom (y _N ) is replaced with the furnace body ( When only the bottom of the converter is updated by bonding to x), the temporarily determined cutting position (p ₀ ) and the three-dimensional shape of the outer surface of the furnace body in the vicinity thereof are measured with a three-dimensional measuring device. Dimensional shape measurement results are reflected in the manufacture of the new furnace bottom (y _N ) and the final cutting position (p), and also in the additional machining of the new furnace bottom (y _N ) after the cutting position is determined. Therefore, there is no significant difference in the skin contact surface between the old furnace body (x) and the new furnace bottom (y _N ). No additional work is required. Thereby, the construction time on site can be greatly shortened, and the production stoppage period of the converter can be greatly shortened.

Further, for the new furnace bottom (y _N ), the three-dimensional shape of the outer surface of the portion to be joined to the furnace body (x) is measured with a three-dimensional measuring device, and the three-dimensional shape measurement result and cutting position (p ₀ ). And the three-dimensional shape measurement result of the outer surface of the furnace body in the vicinity thereof, so that the difference between the furnace body (x) to be joined and the new furnace bottom (y _N ) is minimized. by alteration of (y _N), Rodo unit (x) and the new furnace bottom (y _N) tongue and groove skin mating surface of the can be made smaller, also the new furnace bottom (y _N) The additional machining itself can be performed with high accuracy and in a short time.

Drawing that shows the inner diameter of the bottom of the converter measured with a laser distance meter in comparison with the design dimensions of the converter that required the furnace bottom to be updated. Explanatory drawing which shows the measurement position of the internal diameter of the furnace bottom part shown by FIG. Explanatory drawing showing the measurement status of the three-dimensional shape of the furnace body outer surface (furnace body outer surface around the tentatively determined cutting position) using a laser scanner Drawing which shows an example of the three-dimensional shape of the furnace body outer surface obtained by the measurement of FIG. Drawing showing displacement of bottom furnace bottom welding line found by measurement of FIG. Perspective view showing an embodiment of a new furnace bottom y _N In the production process of the new furnace bottom y _N, illustrates a additional machining before and after the shape Perspective view showing another embodiment of the new furnace bottom y _N It illustrates a three-dimensional shape of the joint portion s of the new furnace bottom y _N measured by laser scanner Explanatory drawing which shows the procedure from a process (C) to a process (D).

RoOsamu method of the converter of the present invention, after disconnecting the furnace bottom y _O from Rodo unit x by cutting the furnace body, by joining the new furnace bottom y _N in the furnace barrel x, converter When only the bottom of the furnace is updated, a three-dimensional measuring device capable of measuring the three-dimensional shape of the outer surface of the furnace body is used to measure the three-dimensional shape of the temporarily determined cutting position p ₀ and the surrounding outer surface of the furnace body. and, the measurement result, the determination of the production and the final cutting position p of a new furnace bottom y _N, by further be reflected in additional machining of the new furnace bottom y _N after cutting position determination, Rodo unit x to minimize the tongue and groove of the skin mating surfaces of the (Kyurotai) and the new furnace bottom y _N, to avoid having to perform additional work industry in the field to fix the tongue and groove of the skin mating surface It is a thing. That is, this invention has the following process (A)-(D), and also has the following process (E) between a process (C) and a process (D) as needed.
Here, the converter consists of an iron shell (steel outer shell) and a refractory lined on it, but the furnace body and the furnace body / bottom of the present invention are the iron skin. is there.

Step (A): A cutting position p _{0 at} which the furnace bottom y _O is cut off from the furnace body x is provisionally determined, and the three-dimensional shape of the outer surface of the furnace body at the cutting position p ₀ is measured by a three-dimensional measuring device.
Step (B): step based on the three-dimensional shape measurement result of the furnace outer surface of (A), to manufacture a new furnace bottom y _N. Here, the "fabricating new furnace bottom y _N", relative to the base member of the new furnace bottom placed made previously (which was manufactured as designed drawings), including the case that subjecting only the portion processed.
Step (C): by cutting the furnace body from Rodo unit x immediately before disconnecting the furnace bottom portion y _O, the cutting position p ₀ and the three-dimensional shape of the furnace outer surface near its measured by the three-dimensional measuring device, the three-dimensional shape measurement and shape of the new furnace bottom y _N of the furnace outer surface in view to determine the final cutting position p.
Step (D): after disconnecting the furnace bottom y _O from Rodo unit x by cutting the furnace body at the determined cutting position p in step (C), joining the new furnace bottom y _N in Rodo unit x .
Step (E): additional machining a new furnace bottom y _N in accordance with the Rodo portion x side of the shape of the cutting position p determined in step (C).

FIG. 1 shows the result of investigating the deformation state of the furnace body for a converter that requires renewal of the furnace bottom. Two positions a and b (a: a height of 2083 mm from the bottom of the furnace body, b: a height of 1690 mm from the bottom of the furnace body, near the furnace bottom part separation position (cutting position) as shown in FIG. Position), the inner diameter of the furnace body was measured with a general laser distance meter, and the result was shown in comparison with the design dimensions. According to this, the measured dimension of the furnace body shows a deviation (bulge) of 200 mm or more with respect to the design dimension. In the renewal of the bottom of the furnace, there is a problem of matching the furnace body, which is an old furnace body with such swelling (peripheral change), with the newly created furnace bottom. Therefore, in the present invention, the three-dimensional shape of the cutting position p ₀ tentatively determined as described above is measured with a three-dimensional measuring device, and the measurement result is produced as the new furnace bottom y _N and the final cutting position p. decision, further to reflect the additional machining of Shin furnace bottom portion y _N after cutting position determination, but to minimize the tongue and groove of the skin mating surfaces.

Hereinafter, steps (A) to (D) constituting the present invention and steps (E) performed as necessary between steps (C) to (D) will be described in order.
・ Process (A)
In this first step, a cutting position p ₀ for cutting the furnace body and separating the furnace bottom y _O from the furnace body x is provisionally determined, and the cutting position p is determined using a three-dimensional measuring device (three-dimensional shape measuring device). The three-dimensional shape of the outer surface of the _zero furnace body is measured. Here, at least the three-dimensional shape of the outer surface of the furnace body at the cutting position p ₀ may be measured. However, if necessary, the three-dimensional shape of the outer surface of the furnace body may be measured.
Any type of three-dimensional measuring apparatus can be used as long as it can measure the three-dimensional shape of the outer surface of the furnace body. However, since a laser scanner is generally used, an example in which a laser scanner is used will be described here. .

FIG. 3 shows a measurement state of the three-dimensional shape (furnace body profile) of the outer surface of the furnace body by the laser scanner 2. In FIG., P ₀ is temporarily determined by the cutting position, x is Rodo unit, y _O are furnace bottom decoupled from the Rodo unit x. In order to accurately measure the three-dimensional shape of the outer surface of the furnace body in the furnace body circumferential direction (360 °), as shown in the figure, it is measured by the laser scanner 2 at several places in the furnace body circumferential direction (usually 3 to 4 places). Need to do. For this reason, the laser scanner 2 is moved to several locations in the furnace body circumferential direction to perform measurement. And the data (three-dimensional shape) of the whole furnace body can be obtained by combining (synthesizing) the measurement data at a plurality of locations in the furnace body circumferential direction.

There are various types of laser scanners 2. For example, in a type in which measurement is performed by setting a reference point, it is preferable to perform measurement in consideration of the following points (1) and (2).
(1) The reference point must be in the measurement field of view. (2) The range in which the laser beam is reflected back from the object to be measured is sufficiently overlapped with the data superimposed after measurement. If it is not reflected in the measurement, noise may be mixed into the data, or an accurate measurement value of 360 ° may not be obtained.

FIG. 4 shows an example of a three-dimensional shape measurement result of the cutting position p ₀ obtained by measurement with the laser scanner 2 as shown in FIG. 3 and obtained based on the measurement data. The “reference circle” on the vertical axis in FIG. 4 means a design value. Moreover, the measurement data (two points) by a laser distance meter (conventional method) are shown in the figure. In this measurement example, when looking at the profile at the weld line height +595 mm (position corresponding to the cutting position p ₀ ), a bulge of 280 mm on the reject side and 137 mm on the steel output side is seen, and a bulge of about 417 mm in diameter is seen. become. The measurement difference from the laser distance meter that measured the inside of the furnace is about 51 mm (= 417 mm-366 mm). Further, as shown in FIG. 5, it was confirmed that the furnace bottom lower weld line was lowered 55 mm from the reference position on the steel output side and the discharge side.

・ Process (B)
In this process, based on the three-dimensional shape measurement result of the furnace outer surface in the above step (A), to manufacture a new furnace bottom y _N in fabrication plants. Here, assuming that the furnace bottom y _O to be updated is separated by temporarily determined by the cutting position p _0, fabricating a new furnace bottom y _N.
Figure 6 shows one embodiment of a new furnace bottom y _N fabricated, s is the portion (hereinafter to be joined with Rodo portion (Kyurotai) side, called for convenience "junction s" Description ). Usually, when fabricating a new furnace bottom y _N, as shown in FIG. 7 (A), first, make the furnace bottom blueprints Street (e.g., a circular furnace bottom portion), then as shown in FIG. 7 (a) Furthermore, the difference in the skin-matching surface between the furnace body x (old furnace body) side is minimized while only the joint portion s side of the furnace bottom is aligned with the furnace body (old furnace body) side. As described above, processing is performed by pressing or the like (for example, processing a circle into a different circle). This allows the skin alignment of the Rodo portion x and the new furnace bottom y _N accompanied the old furnace body side bulge (the peripheral length change).
Incidentally, as mentioned previously, the term "fabricated new furnace bottom y _N", it includes the case that performing only partial processing with respect to the base material of the new furnace bottom placed made in advance.

New furnace bottom y _N does this may be made integrally, but according to the shape of Rodo portion x (Kyurotai) side with a bulge, is processing the single new furnace bottom y _N If it is difficult to manufacture a new furnace bottom y _N which is divided into a plurality of components in the furnace height direction, (junction s components) uppermost component in the furnace height direction only Rodo portion You may make it process according to the shape of x (old furnace body) side. In this case, the number of components of the new furnace bottom y _N are arbitrary. Figure 8 is an illustration of one embodiment of a new furnace bottom y _N which is divided into two upper component y _N1 and the lower component y _N2, if this field, the bonding of the upper component y _N1 The part s is processed according to the shape on the furnace body x (old furnace body) side.
Produced a new furnace bottom y _N which is divided into a plurality of components in Rodaka direction as described above, (junction s components) uppermost component in the furnace height direction only Rodo portion x (formerly The ring-shaped member such as the upper constituent member _yN1 is processed to process the joint portion s rather than the bottomed member such as the lower constituent member _yN2. This is because (for example, processing from a circular shape to a different circular shape) is easy. Since the lower end of the upper component y _N1 which is joined to the lower component y _N2 not processed after it is basically no eye difference between the lower component y _N2. Even if a slight difference occurs due to the processing of the upper component member _yN1 , the degree of difference does not hinder the joining of the upper component member _yN1 and the lower component member _yN2 .

In the method of this manner produced by dividing the new furnace bottom y _N multiple components, if additional machining a new furnace bottom y _N immediately before the update furnace bottom portion (i.e., below the step (E) In the case of carrying out), only the joining portion s of the uppermost constituent member (the upper constituent member y _{N1 in} FIG. 8) needs to be additionally machined.
9, the bonding portion s of the new furnace bottom y _N, illustrates an example of a three-dimensional shape of the circumferential direction measured by a laser scanner. The three-dimensional shape of the new furnace bottom y _N well is measured using a three-dimensional measurement apparatus and techniques the used in step (A). By previously measuring a three-dimensional shape of the joint portion s of such new furnace bottom y _N, determining a new furnace bottom y _N to the cutting position of the three-dimensional shape measurement results in the next step (C) This can be reflected in the additional work, and the additional work can be performed with high accuracy and in a short time.

・ Process (C), (E)
In this step (C), immediately before disconnecting the furnace bottom portion y _O from Rodo unit x by cutting the furnace body, a three-dimensional shape of the cutting position p ₀ near the furnace outer surface was measured by a three-dimensional measuring device, 3-dimensional shape measurement and the new furnace bottom y _N of the shape of the furnace outer surface (e.g., 3-dimensional shape shown in FIG. 9) in consideration of, a final decision cutting position p.
In other words, the step (A) needs to be performed when the converter is not operating, but there is not always a timing at which the operation of the converter can be temporarily stopped, so the step (A) is performed when it can be performed. It is necessary to keep it. Also it requires a considerable period in the fabrication of the new furnace bottom y _N that are performed based on the measurement result of step (A). For this reason, after measuring the three-dimensional shape of the outer surface of the furnace body in the step (A), it takes a long period of time (for example, about several months to half a year) from the actual cutting of the furnace body (separation of the furnace bottom y _O ). In many cases, the swelling of the furnace body may have changed from the time of measurement in the step (A). Therefore, to measure the re-cutting position p ₀ and the three-dimensional shape of the furnace outer surface of the periphery. Then, taking into account the three-dimensional shape measurement and shape of the new furnace bottom y _N of the measured furnace outer surface, determining the most appropriate cutting position p to joining new furnace bottom y _N. Naturally, there is a case where the cutting position p ₀ = the cutting position p. The measurement of the three-dimensional shape of the outer surface of the furnace body in this step is performed using the three-dimensional measuring apparatus and method used in the step (A).

Incidentally, disconnect the furnace bottom portion y _O from Rodo unit x and the measurement of three-dimensional shape to the "just before" the "measurement of three-dimensional shape" is between "detach the furnace bottom y _O", the furnace It means that the bulge of the body is changed at a time interval that does not change (a change that requires further modification), and therefore, if necessary, after measuring the three-dimensional shape in step (C) factory performs additional work for the new furnace bottom y _N (= step (E)), may be followed immediately proceeds to step (D). If it says from a general work schedule, it will transfer to a process (D) within about 1 to 2 months from the measurement of the three-dimensional shape in a process (C).

At the stage of determining the cutting position p as described above, further, if necessary additional machining a new furnace bottom y _N in accordance with the Rodo portion x side of the shape of the cutting position p occurs, the step (E ), Additional processing of the joining portion s is performed by press working or the like at the production factory. In this case, it is possible to utilize a three-dimensional shape measurement result of the joint portion s of the new furnace bottom y _N measured in 3-dimensional measuring device. That is, comparing the three-dimensional shape measurement result with the cutting position p ₀ obtained in the step (C) and the three-dimensional shape measurement result of the outer surface of the furnace body in the vicinity, the furnace body portion x to be joined and the new furnace as eye difference between the bottom y _N is minimized by additional machining of the new furnace bottom y _N, we can further reduce the tongue and groove of the skin mating surface between Rodo portion x and the new furnace bottom y _N, also Further, the additional work itself can be performed with high accuracy and in a short time. Thereby, for example, it is possible to ensure the additional machining accuracy such that the difference in the skin mating surface with the furnace body x (old furnace body) side is 10 mm or less.
Further, when the new furnace bottom y _N is one that is divided into a plurality of components in the furnace height direction it may be additionally processed only top components, new furnace bottom y _N as shown in FIG. 8 Is divided into the upper component member _N1 and the lower component member _yN2 , the upper component member _yN1 only needs to be additionally processed.

・ Process (D)
As shown in FIGS. 10A to 10C, after the furnace body is cut at the cutting position p determined in the step (C) to separate the furnace bottom y _O from the furnace body x, the new furnace bottom y _N is bonded to the furnace body x. Usually, the cutting of the furnace body is carried out by gas blowing, also new furnace bottom y _N are joined by welding to Rodo unit x. When joining the new furnace bottom y _N in Rodo unit x, although skin alignment Rodo portion x (Kyurotai) the new furnace bottom portion y _N is performed, the three-dimensional shape measurement result of the furnace outer surface is reflected and production of new furnace bottom y _N, the determination of the cutting position p, since being made more additional machining of the new furnace bottom y _N, the tongue and groove of the furnace bottom portion y _N of the new and Rodo unit x (Kyurotai) It can be kept to a minimum, and no additional work on site is required to correct the misalignment of the skin-matching surface.

More RoOsamu method of the present invention, as described, after disconnecting the furnace bottom y _O from Rodo unit x by cutting the furnace body, by joining the new furnace bottom y _N in the furnace body portion x, When renewing only the bottom of the converter, the newly determined cutting position p ₀ and the three-dimensional shape of the outer surface of the furnace body are measured with a three-dimensional measuring device and the new three-dimensional shape measurement result is reflected. determination of bottom y _N manufacture and final cutting position p of, since more additional machining of the new furnace bottom y _N after cutting position determination is made, which is the old furnace body Rodo portion x and the new furnace bottom y _N There will be no major mistakes in the skin mating surface. This eliminates the need for additional work at the site for correcting the misalignment of the skin-matching surface, and greatly reduces the construction time at the site. Moreover, the new furnace bottom y _N, measured by the three-dimensional measuring device the three-dimensional shape of the outer surface of the portion to be joined with Rodo unit x, the three-dimensional shape measurement result and the cutting position p ₀ and the periphery of the furnace body that and comparing the three-dimensional shape measurement result of the outer surface, eye differences in skin mating surface between Rodo portion x and the new furnace bottom y _N to be joined are so minimized, additional machining of the new furnace bottom y _N by, it is possible to further reduce the tongue and groove of the skin mating surface between Rodo portion x and the new furnace bottom y _N, also additional work itself of the new furnace bottom y _N may be carried out with high accuracy in a short time it can.

1 Furnace 2 Laser scanner p ₀ , p Cutting position x Furnace body y _O Furnace bottom y _N New furnace bottom

Claims (6)

After cutting the furnace body and separating the furnace bottom part (y 2 _{O 3} ) from the furnace body part (x), the new furnace bottom part (y _N ) is joined to the furnace body part (x) to obtain the furnace bottom part of the converter The only way to update
A step of tentatively determining a cutting position (p ₀ ) for separating the furnace bottom (y _O ) from the furnace body (x) and measuring the three-dimensional shape of the outer surface of the furnace body at the cutting position (p ₀ ) by a three-dimensional measuring device. (A) and
Based on the three-dimensional shape measurement result of the outer surface of the furnace body in the step (A), a step (B) of manufacturing a new furnace bottom (y _N );
Immediately before cutting the furnace body and separating the furnace bottom part (y 2 _O 3) from the furnace body part (x), the cutting position (p ₀ ) and the three-dimensional shape of the outer surface of the furnace body around the cutting position (p ₀ ) are measured. (C) determining the cutting position (p) in consideration of the three-dimensional shape measurement result of the outer surface of the furnace body and the shape of the new furnace bottom (y _N );
After cutting the furnace body at the cutting position (p) determined in the step (C) and separating the furnace bottom part (y 2 _{O 3} ) from the furnace body part (x), the new furnace bottom part (y _N ) is replaced with the furnace body part. A furnace repair method for a converter, comprising the step (D) of bonding to (x). Furthermore, a new furnace bottom (y _N ) is formed between the process (C) and the process (D) in accordance with the shape of the furnace body (x) side at the cutting position (p) determined in the process (C). The method of repairing a converter according to claim 1, further comprising a step (E) of additionally processing the iron. New furnace bottom fabricated in step (B) for (y _N), was measured by the three-dimensional measuring device the three-dimensional shape of the outer surface of the portion to be joined Rodo section and (x), the step (E), the By comparing the three-dimensional shape measurement result with the cutting position (p ₀ ) obtained in the step (C) and the three-dimensional shape measurement result of the outer surface of the furnace body in the vicinity, the furnace body (x) to be joined and the new The method of repairing a converter according to claim 2, wherein the new furnace bottom (y _N ) is additionally machined so that the difference in skin-matching surface with the furnace bottom (y _N ) is minimized. In the step (B), a new furnace bottom portion (y _N ) divided into a plurality of components in the furnace height direction is manufactured, and the furnace repair method for a converter according to any one of claims 1 to 3 . The method of repairing a converter according to claim 4, wherein the new furnace bottom (y _N ) is divided into two parts: an upper component (y _N1 ) and a lower component (y _N2 ). . The converter furnace according to claim 4 or 5, wherein in the step (E), only the uppermost constituent member in the furnace height direction is additionally machined among the constituent members of the new furnace bottom (y _N ). How to fix.

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