JPH06229684A - Measuring method of change in furnace shape of industrial furnace and marker used in measuring - Google Patents

Abstract

PURPOSE:To measure the expansion amount of a furnace body due to enlargement of a crack and a wear amount of a furnace wall to grasp the state of a damage of an industrial furnace. CONSTITUTION:Markers 2A and 2B are buried in the surface of a furnace wall, and photographed by correspondent cameras 5A and 5B. Distances between the cameras 5A and 5B and a reference point 15 are respectively measured. The locations of the markers 2A and 2B on the cameras 5A and 5B are converted into coordinates with the reference point 15 as the origin based on the distances between markers 2A and 2B and the reference point 15, and the expansion of the furnace body is measured based on changes in the relative distances between the markers 2 converted into the coordinates. The wear amount is measured based on changes with time in the outside shapes of the markers 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for accurately measuring changes in the shape of a furnace body of various industrial furnaces, that is, expansion of the furnace body and wear of the furnace wall, and a marker used therefor.

[0002]

2. Description of the Related Art The furnace walls of industrial furnaces such as coke ovens, blast furnaces, heating furnaces, etc. are constructed of refractory materials, but this furnace wall is subject to melting loss due to heat or contact with the material to be treated. May cause damage such as cracks. Since this damage is a factor that accelerates the deterioration of the furnace, it is important to determine the damage condition and repair the furnace at an appropriate timing in order to use the furnace for a long time.

As one of the indicators of the state of damage to a furnace, a method of measuring the expansion amount of a refractory forming the furnace has been conventionally used. For example, taking a coke oven as an example,
The furnace body is made of bricks and is operated at a temperature of 1100 to 1300 ℃. The damage of this coke oven is caused by changes in the furnace temperature due to changes in the operating rate, changes in the furnace temperature due to carbonization, carbonization, and kiln removal.
It is generated by the coefficient of expansion during coal carbonization and the pressure of the coke extrusion against the furnace wall. Due to these causes, damage such as joint breakage and cracks of bricks occurs and progresses, and eventually the coke oven deteriorates.

Among the above damages, the crack expansion is caused by the elongation of the furnace body in the furnace length direction. Therefore, by measuring the length in the furnace length direction at regular intervals, it is possible to quantitatively grasp the progress of the furnace body expansion, that is, the crack expansion. Therefore,
On the contrary, if the furnace length can be measured with high accuracy, it is extremely effective for estimating the furnace life of the coke oven furnace body and implementing appropriate aging measures.

Conventionally, the method for measuring the length of a coke oven uses a transit, which is disclosed in, for example, Japanese Utility Model Laid-Open No. 61-39136, a distance from a furnace clamp surface or a protective plate to a reference point provided outside the furnace. There is a method to measure indirectly.
Further, Japanese Patent Application Laid-Open No. 3-245009 discloses a method for measuring the elongation of the entire furnace by measuring the extruder-side furnace opening and the digester-side furnace opening using a laser displacement meter.

[0006]

Of the above-mentioned conventional techniques,
Since the method according to Japanese Utility Model Laid-Open No. 61-39136 is a manual measurement, an error is likely to occur due to an individual difference of a person who measures.

Further, in the method disclosed in Japanese Patent Laid-Open No. 3-245009, thermal distortion occurs in the metal which is the protective plate of the furnace lid due to aging, and it is difficult to extract only the amount of change due to the elongation of the brick. . Furthermore, due to the abnormal seri- lization of the roof of the furnace, a gap is created between the protective plate and the brick surface, and it is difficult to extract only the amount of change due to the elongation of the brick.

Further, these conventional techniques also cause the same problem when they are applied to other than the coke oven.

On the other hand, when it is possible to know the amount of wear (amount of wear) of the bricks forming the wall surface when predicting the life of the coke oven and taking repair measures based on it, it is extremely effective, but this is quantitative. Currently, there is no effective way to know.

Therefore, an object of the present invention is to accurately measure the amount of expansion of the furnace body due to crack expansion in various industrial furnaces such as coke ovens, grasp the damage situation of these industrial furnaces, and estimate the life of the furnace. To improve. Further, it is to detect the wear of the wall surface quantitatively as an index of the damage of the industrial furnace so that the accuracy of estimating the life of the furnace can be improved and appropriate repair measures can be taken.

[0011]

A method for measuring the expansion of a furnace body of an industrial furnace according to the first aspect of the present invention, which has solved the above-mentioned problems, is to measure each measurement point by an imaging device arranged corresponding to a plurality of measurement points on the inner wall surface of the furnace. An image of the vicinity is taken, each separation distance between each of the imaging devices and the reference point is measured, and each measurement point position on each of the imaging devices is based on the separation distance, and coordinates based on the reference point. And the expansion of the furnace body is measured based on the change over time in the relative distance between the measurement point positions on the converted coordinates.

The wall marker of the industrial furnace of the second invention of the present application, which is effective for measuring the expansion of the furnace body, is a marker to be imaged by the image pickup device, and is embedded in the wall surface of the furnace and has a depth of the wall. A head having a diameter that is successively reduced in a direction, an anchor portion, and a neck portion having a small diameter between the head portion and the anchor portion, the outer surface of the head portion being embedded flush with the wall surface, and at least the The index part of a certain length in the wall depth direction of the head is made of a material that wears at substantially the same speed as other wall parts, and the index part is image-wise distinguished from other wall parts when imaged. It is characterized by being in the state of being.

Further, in the method for measuring the amount of wear of the furnace wall of the industrial furnace according to the third invention of the present application, a marker having a head portion whose outer diameter is gradually narrowed in the wall depth direction is provided on the wall surface of the industrial furnace. The surface is embedded so as to be flush with the wall surface, the marker is imaged by an imaging device that gazes at the wall surface, three or more points on the imaged marker are extracted, and it is assumed that the markers pass through these extraction points and are always under constant conditions. It is characterized in that the diameter or area of the figure is determined, and the amount of wear of the wall is measured based on the change over time of the diameter or area.

[0014]

[Action]

(Operation of the first invention) According to the first invention, an image pickup device arranged corresponding to a plurality of measurement points on the inner wall surface of the furnace is used to image the vicinity of each measurement point, and the respective separation distances between the respective image pickup devices and the reference point are measured. By measuring and converting each measurement point position on each of the image pickup devices to coordinates with the reference point as a reference, based on each of the separation distances, between the measurement point positions on the converted coordinates. You can know the relative distance of. Therefore, if the change with time of the relative distance between the respective measurement point positions on the converted coordinates is measured, the expansion of the furnace body will be measured as a result.

In such a measuring method, although it basically depends on the optical measurement, since the artificial element can be eliminated, the measuring accuracy becomes high. Moreover, since the measurement points are set on the furnace wall itself, the expansion of only the furnace wall brick can be measured, the true furnace body expansion can be accurately measured, and as a result, the life of the furnace can be accurately grasped.

(Operation of the second and third inventions) As a measuring point used in the first invention, for example, when considering a coke oven, it is worn due to friction in the process of charging coal and discharging coke, and also has a high temperature. Since it is placed underneath, at least abrasion resistance and heat resistance are required. Further, it is required that even if mechanical force is applied, it does not easily fall off. In this case, if a marker with extremely high wear resistance is used as the measurement point, when the brick wall of the coke oven is worn out, the marker will protrude from the brick wall and leave it alone. Then, there is a risk that it will break due to contact with coal or coke, or the embedded marker will fall off.

However, according to the second aspect of the present invention, when the marker made of a material that wears at substantially the same speed as the furnace wall brick is used, the marker does not break or fall off. Further, by forming the neck portion in the wall depth direction of the marker and forming the anchor portion at the tip from the neck portion, it is possible to reliably prevent the marker from falling off after the marker is embedded.

On the other hand, a head whose diameter is successively reduced in the depth direction of the wall is embedded with its outer surface flush with the wall surface, and this head is visually distinguished from other wall surface portions when imaged. , For example, by using a different material from brick, the marker itself will wear as the wall wear progresses,
Since the area of the outer surface is gradually reduced, the wear amount of the wall surface can be obtained conversely by grasping the change in the area or the diameter with time, and the life of the furnace can be predicted.

[0019]

The present invention will be described in more detail by way of examples with reference to the drawings. In the following description, a coke oven is described as a representative example of the industrial furnace, but it is obvious that the present invention can be applied to other industrial furnaces.

(First Invention) In the first invention, FIG.
As shown in FIG. 3, markers 2A and 2B as measurement points serving as measurement marks are embedded in the in-furnace refractory surface of the coke oven 1. The number of the markers is not limited as long as it is plural, but two markers are provided in the embodiment.

Imaging devices 5A and 5B, which are television cameras or the like, which gaze at the markers 2A and 2B respectively.
Is installed in the measurement rack 3, and the observation window 4
Images around the markers 2A and 2B are taken through A and 4B, respectively. Coordinate positions X1, Y1, X2, Y2 in the visual fields of the markers 2A, 2B are measured in the respective images 7A, 7B obtained by the imaging devices 5A, 5B. On the other hand, the distance measuring device 6 composed of a transit or the like is used to separate the distances L1 and L2 between the imaging devices 5A and 5B and the arbitrary reference point 15.
Is measured.

Coordinate positions X1, Y1, of the above-mentioned markers
The values of X2, Y2 and the distances L1, L2 are input to the arithmetic unit 8 and the relative positions of the markers 2A, 2B and the reference point 15 are calculated.

In this case, the position of the distance measuring device 6 is used as the reference point 15. The reference point is preferably a position where the distance measuring device 6 is located for convenience of measurement, but may be another position.

Next, a method of converting the positions of the markers 2A and 2B on the visual field image into coordinates with the reference point 15 as a reference based on the above-mentioned measured values will be described. FIG. 4 shows the reference point 1
It is a figure which shows the positional relationship of 5 and the markers 2A and 2B. Now, assuming that a coordinate system whose origin is the reference point 15 set at the position of the distance measuring device 6 is an xy coordinate system, in this xy coordinate system, the position coordinates (x ₁ , y ₁ of the markers 2A, 2B are represented. ) And (x ₂ , y ₂ ), as shown in FIG. x ₁ = L1 + X1 x ₂ = L2 + X2 y ₁ = Y1 y ₂ = Y2 The marker 2 is obtained by knowing the position coordinates (x ₁ , y ₁ ) and (x ₂ , y ₂ ) of these markers 2A and 2B at regular intervals.
The moving amount of A and 2B can be measured, and this value can be used as a representative value of the expansion amount (contraction amount) of the furnace body. Specifically, the expansion of the furnace body can be measured by obtaining the relative distance between the markers in the horizontal direction and the vertical direction by the following equation. Horizontal marker distance = | L2-L1 | + | X2-X
1 | Vertical distance between markers = | Y2-Y1 | Thus, since the relative position between the markers set on the furnace wall surface can be directly measured by the above formula, the measured distance between the markers is the refractory material constituting the furnace. It is possible to make it depend only on the elongation of the wall surface. Therefore, unlike the conventional example, it is possible to extract only the amount of change due to the elongation of the brick.

On the other hand, as a method of measuring the distance between the image pickup devices 5A and 5B and the reference point 15, the measurement rack 3 shown in FIG.
Of the image pickup device 5A, 5B by a method of measuring the insertion amount when inserting into the furnace 1 by, for example, feeding the screw screws 5C, 5C, or by a lightwave rangefinder or a transit used for construction, civil engineering, etc. Examples include a method of measuring as a target.

When the distance is measured by the light wave range finder, the light wave range finder uses the speed of light because of its principle.
The speed of light in the atmosphere depends on the refractive index, which changes with atmospheric temperature. Therefore, in order to improve the measurement accuracy of the light distance measuring device, it is desirable to suppress the atmospheric temperature distribution in the measuring device. As a method for suppressing the atmospheric temperature distribution, for example, there is a method in which the measuring device is covered with a heat insulating material to suppress the transfer of heat from the furnace wall surface or to provide a means for cooling the inside of the measuring device.

The distance measuring device is used for each of the image pickup devices 5A and 5B.
For example, it is considered unnecessary if they are integrated via the measurement rack 3 and the distance between them is known, but due to the reason that the length of the measurement rack 3 changes due to thermal expansion during insertion into the furnace, To improve the measurement accuracy of the expansion degree,
The distance measurement described above is necessary.

FIG. 2 shows a second embodiment of the first invention, in which the corner cubes 9A and 9B are provided in the measurement rack 3 in association with the television cameras 5A and 5B, and the light waves placed outside the furnace are shown. This is an example in which the distances L1 and L2 to the corner cubes 9A and 9B are measured by the rangefinders 10A and 10B. Reference numeral 7 is an image processing device. The measurement principle is the same as that of the first embodiment, and the description thereof is omitted.

FIG. 3 shows a third embodiment of the first invention, in which a mirror 13 and a beam splitter 14 are provided in the measurement rack 3, and a marker 2A is provided by a television camera 5 which is an image pickup device provided outside the furnace. , 2B near the image is obtained.

The mirror 13 and the beam splitter 14 are installed at an angle of 45 ° with respect to the image pickup direction of the television camera 5, and reflect the images of the markers 2B and 2A, respectively, and project the projection by the television camera 5 by the corresponding mirror 13. Also, an image is taken by adjusting the focal length to the beam splitter 14. L1 and L2 measurement and markers 2A and 2B
The position calculation method of is the same as that of the first embodiment.

In this third embodiment, the measuring rack 3
Since only the optical components including the mirror 13, the beam splitter 14, and the corner cubes 9A and 9B are provided inside,
Compared to the first and second embodiments, less cooling capacity is required.

Any marker may be used as long as it is provided on the refractory and moves according to the behavior of the wall surface of the refractory. For example, the joints of the bricks forming the wall surface of the furnace may be used, or a part of the brick surface may be processed, for example, unevenly processed. Alternatively, when the joints and the like of these bricks are difficult to visually recognize, a marker made of a refractory material such as ceramics and different from the background may be directly embedded in the brick for use.

(Regarding the second and third inventions) As described above, when predicting the life of the coke oven, the wear of the oven wall can be effectively used as an index in addition to the expansion of the oven body. Therefore, the second invention provides a marker that is suitable for measuring the amount of wear (wear) of the furnace wall and does not fall off the furnace wall.

Therefore, in the second aspect of the invention, the marker 2 is embedded in the brick wall of the furnace. Marker 2 (Marker 2A
(Corresponding to), as shown in FIG.
It can be embedded in a hammer brick 19 (see FIG. 6, the dimensions are shown together) which is relatively close to the brick opening at a distance of 1.5 m from the kiln where damage to the brick is relatively small and which is unlikely to crack. The number of embeddings in the height direction may be one or more. In the case of embedding a plurality of pieces, it is possible to make a comprehensive judgment by averaging the amount of wear.

An example of the shape of the marker 2 is shown in FIG. That is, a conical head 20 having a diameter that is gradually reduced in the depth direction of the wall,
It has an anchor portion 21 and a neck portion 22 having a small diameter between them. The outer surface of the head portion 20 is flush and embedded in the wall surface, that is, the hammer brick 19. The marker 2 is made of a material that wears at substantially the same speed as the hammer brick 19. Here, only the wear index portion, for example, a depth portion from the surface of the head 20 is hammer-bricked 1
It is also possible to use a material that wears at substantially the same speed as that of No. 9 and the other portions to be formed of a non-wearing material. In the embodiment, the whole is made of the same material. Head 20
In order to show the center point 25, a cross cut, a punch hole or the like is engraved on the outer surface of the.

When burying the marker 2, in the case of a new coke oven, bricks in which the marker 2 is embedded can be stacked in advance, but when burying in the existing coke oven,
Since the width of the carbonization chamber is as narrow as 400 to 460 mm, the burying work can be performed in the mode shown in FIG. 8, for example. That is, the work carriage 51 traveling on the rail 50 in the furnace group direction
The work scaffolding chamber 53 is advanced into the furnace while being suspended from the work deck 52 by the chain block 54, and a worker drills through the window of the work scaffolding chamber 53 with the marker 2
The holes are accurately drilled, the markers 2 are inserted into the holes together with the anchor material 23 interposed at intervals of 90 degrees in the circumferential direction, and the markers 2 are fixed by the refractory mortar 24. This buried state is shown in FIG. In this way, since the burying work space is narrow, the drilling work by the drill is oblique. Therefore, as shown in FIG. 7, the marker 2 also has an axis of about 60 degrees with respect to the depth direction of the furnace wall. Is tilted at an angle of. For a newly installed coke oven, such a device is not necessary.

In selecting the material of the marker 2, the wear rate as well as the background of the image when the marker 2 was imaged,
That is, it must be distinguishable from bricks.

For this reason, the material of the marker 2 is
It is possible to use the same bricks or some ceramics. When the material is the same as that of the brick, it is not possible to distinguish it from the background brick, so that it is possible to form a layer containing a coloring material on the surface by ceramics spraying or the like, in which a coloring material is mixed.

Generally, if the materials are different, it is easy to distinguish images. Therefore, it is desirable that the marker 2 be made of a ceramic material different from that of the brick. Among the ceramic materials, as a material exhibiting almost the same wear resistance as the brick, for example, when the furnace wall brick is a silica brick, a ceramic containing 99% alumina and the remaining silicon nitride can be preferably used. Further, this ceramic has a lower coefficient of thermal expansion than silica brick, is less likely to change its shape due to volume fluctuation (partial expansion), and is unlikely to have an elliptical outer surface of the head. Also, since it is mainly composed of alumina, it has good corrosion resistance and heat resistance, and there is little risk of cracking. The amount of alumina is preferably 90 to 99.6%. When the content of alumina is small, the amount of wear is small and it is difficult to serve as an index of the amount of wear.

In order to measure the expansion of the furnace body, a plurality of such markers 2 are embedded in the furnace length direction as in the first invention, and the center point 25 thereof is used as a coordinate point to measure the expansion of the furnace body. To be

On the other hand, the marker 2 alone can be used as an index of wear of the furnace wall. That is, the marker 2 itself is worn at the same time as the brick is worn. As the marker 2 wears, the area of the exposed outer surface of the conical head 20 in the furnace also gradually decreases. Therefore, the amount of wear of the furnace wall can be known by capturing the area change on the outer surface of the head 20 over time.

For example, as described above, the marker 2 is imaged by the imaging device that gazes at the wall surface, and a plurality of points on the obtained image, for example, four points A, B, C, D are shown in FIG. Is extracted, and the area of the circle is determined as a figure assumed under a constant condition that passes through these extraction points, that is, a circle in the illustrated example. In this calculation, A, B, C, D
4 points are converted into coordinates, and (X _A , Y _A ), (X _B ,
Y _B), and _{(X C, Y C),} (X D, Y D). The distance (radius) r _A , r _B from the center point 25 of each of these coordinates,
r _C and r _D are calculated by the following equations (1) to (4), respectively.

[0043]

[Equation 1]

These calculated radii r _A , r _B , r _C ,
From the value of r _D , the average radius r of the head of the marker 2 is calculated by the equation (5).

[0045]

[Equation 2]

Twice the average radius r of the marker 2 is its average diameter D. The amount of wear of the marker 2 is inversely proportional to the average diameter D of the marker 2. Therefore, this relationship can be expressed by the following expression (6). S = KD + n (K and n are constants) (6) Therefore, the arithmetic unit 8 can measure the amount of wear of the marker 2, that is, the amount of wear of the furnace wall based on the equation (6).

Although the head shape of the above-mentioned marker is conical, it may be pyramidal, for example, and the cross-sectional shape is not limited. Further, when obtaining the area, the number of extraction points may be three or more. However, since the change over time is obtained, it is necessary to always assume a figure under constant conditions. The head gradient does not have to be uniform, although the calculation is slightly complicated.

<Experimental example> Approximately 1.5 from the kiln port of the coke oven
The markers 2 and 2 were embedded in the hammer brick located at the position of m, and the wear amount of the furnace wall (= wear amount of the marker 2) and the expansion amount of the furnace were measured for 5 years. As the marker 2, a ceramic having 99% alumina and the rest silicon nitride was used. The results are shown in Table 1.

[0049]

[Table 1]

As can be seen from Table 1, it has been found that the wear amount of the furnace wall can be quantitatively grasped together with the expansion amount of the coke oven. As a result, the degree of damage to the furnace body could be accurately grasped, which was very useful for the judgment of repair timing and calculation of the life of the furnace body.

[0051]

As is apparent from the above description, according to the present invention, since the expansion amount of the furnace wall is directly measured, the measured value reflecting only the expansion amount of the furnace body due to the crack expansion of brick or the like is used. Obtainable. Furthermore, the amount of wear of the furnace wall can be accurately measured. Therefore, it becomes possible to properly carry out maintenance management such as extending the life of the reactor by taking appropriate measures against aging and reflecting it in the replacement time by improving the accuracy of estimating the life of the furnace.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the first invention.

FIG. 2 is an explanatory diagram of a second embodiment of the first invention.

FIG. 3 is an explanatory diagram of a third embodiment of the first invention.

FIG. 4 is a diagram showing the principle of marker position measurement according to the first invention.

FIG. 5 is a perspective view showing an example of an embedded position of a marker in a coke oven.

FIG. 6 is an explanatory perspective view of a hammer brick.

FIG. 7 is a perspective view of an example marker.

FIG. 8 is a schematic explanatory diagram of an example of a marker burying work mode.

FIG. 9 is a vertical cross-sectional view of the embedded state of the marker.

FIG. 10 is an explanatory diagram of an example of calculating the area of the marker head.

[Explanation of symbols]

1 ... Coke oven, 2A, 2B ... Marker, 5A, 5B ...
Imaging device, 6 ... Distance measuring device, 8 ... Computing device, 15 ... Reference point, 20 ... Head, 21 ... Anchor part, 22 ... Neck part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroji Toyama, 3rd light, Oshima, Kashima-machi, Kashima-gun, Ibaraki Prefecture, Sumitomo Metal Industries, Ltd. Kashima Steel Works (72) Takafumi Saji, Kashima-machi, Kashima-gun, Ibaraki Prefecture No. 3 Sumitomo Metal Industry Co., Ltd. Kashima Works

Claims (3)

[Claims] 1. An image pickup device arranged corresponding to a plurality of measurement points on an inner wall surface of a furnace to image the vicinity of each measurement point and measure each distance between each image pickup device and a reference point. Each measurement point position on the above, based on each separation distance, is converted into coordinates with the reference point as a reference, to the change over time of the relative distance between each measurement point position on the converted coordinates. A furnace body expansion measuring method for an industrial furnace, comprising measuring the furnace body expansion based on the above. 2. A marker as an object to be imaged by an imaging device, comprising a head embedded in a wall surface of a furnace and having a diameter gradually reduced in a depth direction of the wall, an anchor portion, and the head portion and the anchor portion. A neck portion having a small diameter therebetween, the outer surface of the head portion is embedded flush with the wall surface, and at least the index portion of a certain length in the wall depth direction of the head portion is substantially different from other wall surface portions. A wall marker of an industrial furnace, characterized in that it is made of a material that wears at the same speed, and that the index portion is in a state of being image-distinguished from other wall portions when imaged. 3. A marker having a head portion whose outer diameter is gradually narrowed in the wall depth direction is embedded in a wall surface of an industrial furnace so that the head surface is flush with the wall surface, and the marker is gazed at the wall surface. Images are picked up by the device, three or more points on the picked-up markers are extracted, and the diameter or area of the figure assumed under a constant condition that passes through these extraction points is obtained, and based on the change over time of this diameter or area. A method for measuring the amount of wear of a furnace wall of an industrial furnace, characterized in that the amount of wear of the wall is measured.