JP2882264B2 - Method for measuring furnace body shape change of industrial furnace and marker used in the method - Google Patents

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 a change in the shape of a furnace in various industrial furnaces, that is, a method for accurately measuring the expansion of the furnace body and the wear of the furnace wall, and a marker used for the method.

[0002]

2. Description of the Related Art The furnace walls of industrial furnaces such as coke ovens, blast furnaces, and heating furnaces are constructed of refractory materials. Damage such as cracks may occur. Since this damage causes deterioration of the furnace, it is important to determine the damage state and repair the furnace at an appropriate timing for a long use of the furnace.

[0003] As one of the indicators of the state of damage to a furnace, a method of measuring the expansion amount of a refractory constituting the furnace has been conventionally used. For example, in the case of a coke oven,
The furnace body is made of bricks and is operated at a temperature of about 1100-1300 ° C. Damage to 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 coal charging, carbonization, and removal from the kiln.
It is generated due to the expansion coefficient at the time of coal dry distillation, the pressure on the furnace wall of coke extrusion, and the like. Due to these causes, damages such as joint breaks and cracks of the bricks occur and develop, and the aging of the coke oven further progresses.

[0004] Among the above-mentioned damages, crack propagation is caused by elongation of the furnace body in the furnace length direction. Therefore, if the length in the furnace length direction is measured at regular intervals, the expansion of the furnace body, that is, the progress of crack expansion can be quantitatively grasped. Therefore,
Conversely, if the furnace length can be measured accurately, it is very effective for estimating the life of the coke oven body and taking appropriate countermeasures for aging.

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

[0006]

SUMMARY OF THE INVENTION Among the above prior arts,
The method disclosed in Japanese Utility Model Laid-Open Publication No. 61-39136 is a method in which measurement is performed manually, and therefore, errors tend to occur due to individual differences among persons to be measured.

Further, according to the method disclosed in Japanese Patent Application Laid-Open No. Hei 3-245009, heat distortion occurs in the metal which is the protection 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, a gap has been formed between the protective plate and the brick surface due to abnormal cell projection of the ceiling of the furnace, and it is difficult to extract only the amount of change due to the elongation of the brick.

[0008] These prior arts also cause the same problem when they are employed in other than coke ovens.

On the other hand, when the life of a coke oven is predicted and repair measures are taken based on the same, it is extremely effective to know the amount of wear (abrasion) of the bricks constituting the wall surface. At present, there is no effective way to find out.

Accordingly, an object of the present invention is to accurately measure the expansion amount of a furnace body due to crack propagation in various industrial furnaces such as a coke oven, to grasp the damage state of these industrial furnaces, and to estimate the life estimation of the furnace. Is to improve. Another object of the present invention is to quantitatively detect wall wear as an indicator of damage to an industrial furnace, thereby improving the accuracy of furnace life estimation and taking appropriate repair measures.

[0011]

According to a first aspect of the present invention, there is provided a method for measuring the expansion of a furnace body of an industrial furnace, wherein each of the measuring points is measured by an imaging device arranged corresponding to a plurality of measuring points on the inner wall surface of the furnace. Take an image of the vicinity, measure each separation distance between each of the imaging devices and the reference point, and position each measurement point on each of the imaging devices, based on each of the separation distances, coordinates based on the reference point. Then, 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 according to the second aspect of the present invention, which is effective for measuring the expansion of the furnace body, is a marker to be imaged by an imaging device, and is buried in the inner wall of the furnace and has a depth of the wall. A head having a diameter gradually reduced in the direction, an anchor portion, and a neck portion having a small diameter between the head and the anchor portion, and an outer surface of the head is buried flush with the wall surface, and at least the The index portion having a certain length in the depth direction of the wall of the head is made of a material that wears at substantially the same speed as the other wall portions, and the index portion is distinguished from the other wall portions by imaging when imaged. It is characterized in that it is in a state of being performed.

Further, the method for measuring the amount of wear on the furnace wall of an industrial furnace according to the third invention of the present application is characterized in that a marker having a head whose outer diameter gradually narrows in the depth direction of the wall is provided on the wall of the industrial furnace. The surface is buried flush with the wall surface, the marker is imaged by an imager looking at the wall surface, and three or more points on the imaged marker are extracted, and are assumed under always constant conditions passing through these extracted points. The diameter or area of the figure is calculated, and the amount of wear of the wall is measured based on the change over time in the diameter or area.

[0014]

[Action]

(Operation of the First Invention) According to the first invention, the vicinity of each measurement point is imaged by an imaging device arranged corresponding to a plurality of measurement points on the inner wall surface of the furnace, and each separation distance between each imaging device and a reference point is determined. By measuring and converting each measurement point position on each of the imaging devices to coordinates based on the reference point based on each of the separation distances, the distance between each measurement point position on the converted coordinates is calculated. You can know the relative distance of Therefore, by measuring the change over time of the relative distance between the measurement points on the converted coordinates, the expansion of the furnace body is measured as a result.

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

(Operation of the Second and Third Inventions) As a measurement point used in the first invention, for example, considering a coke oven, it wears due to friction in the process of charging coal and discharging the coke, and has a high temperature. Since it is placed below, at least abrasion resistance and heat resistance are required. Furthermore, it is required that even if a mechanical force acts, it does not fall off easily. In this case, if a marker having extremely high abrasion resistance is used as a marker as a measurement point, when the furnace wall brick of the coke oven is worn, the marker protrudes from the furnace wall brick and is left as it is. Eventually, there is a risk that the marker may break due to contact with coal or coke or the embedded marker may fall off.

According to the second aspect of the present invention, when the marker is made of a material that wears at substantially the same speed as the furnace wall brick, the marker does not break or fall off. Further, by forming the neck portion in the depth direction of the marker wall 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 buried.

On the other hand, a head whose diameter is gradually reduced in the depth direction of the wall is buried with its outer surface flush with the wall surface, and this head is distinguished from other wall portions when it is imaged. For example, by using a different material from the brick, the marker itself wears with the progress of wall wear,
Since the area of the outer surface gradually decreases, the amount of wear on the wall surface can be determined by grasping the change over time in the area or diameter, and the life of the furnace can be predicted.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In the following description, a coke oven will be described as a typical example of an industrial furnace, but it is apparent that the present invention can be applied to other industrial furnaces.

(Regarding the First Invention) In the first invention, FIG.
As shown in (1), markers 2A and 2B as measurement points serving as markers for length measurement are embedded in the refractory surface in the furnace 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.

Image pickup devices 5A and 5B, such as television cameras and the like, corresponding to the markers 2A and 2B, respectively.
Are installed in the measurement rack 3, and the observation window 4 is
Images near the markers 2A and 2B are taken through A and 4B, respectively. In each of the images 7A and 7B obtained from the imaging devices 5A and 5B, coordinate positions X1, Y1, X2, and Y2 in the visual field of the markers 2A and 2B are measured. On the other hand, the distances L1 and L2 between the imaging devices 5A and 5B and the arbitrary reference point 15 are measured by the distance measuring device 6 including a transit.
Is measured.

The coordinate positions X1, Y1,
The values of X2, Y2 and the separation 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 at a certain position of the distance measuring device 6 for convenience of measurement, but may be at any other position.

Next, a method of converting the positions of the markers 2A and 2B on the visual field image into coordinates based on the reference point 15 based on the measured values will be described. FIG. 4 shows the reference point 1
FIG. 5 is a diagram showing a positional relationship between a marker 5 and markers 2A and 2B. Now, assuming that a coordinate system having the origin at the reference point 15 set at the position of the distance measuring device 6 is an xy coordinate system, the position coordinates (x ₁ , y ₁₎ of the markers 2A and 2B in this xy coordinate system. ) And (x ₂ , y ₂ ) are as follows, as shown in FIG. _{x 1 = L1 + X1 x 2} = L2 + X2 y 1 = Y1 y 2 = Y2 these markers 2A, 2B position coordinates (x _1, y ₁₎ and (x _2, y ₂₎ Marker 2 Knowing the at regular intervals
The movement amounts of A and 2B are measured, and this value can be used as a representative value of the expansion amount (shrinkage 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 can be directly measured by the above equation, the measured value of the distance between the markers is the refractory constituting the furnace. It becomes possible to depend only on the elongation of the wall. Therefore, unlike the conventional example, only the amount of change due to the elongation of the brick can be extracted.

On the other hand, as a method of measuring the distance between the imaging devices 5A and 5B and the reference point 15, the measuring rack 3 shown in FIG.
For example, a method of measuring the insertion amount when inserting into the furnace 1 by screw screws 5C, 5C feed, or the like, or the parts of the imaging devices 5A, 5B using an optical distance measuring instrument or transit used for construction, civil engineering, etc. A method of measuring as a target can be given.

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

Each of the distance measuring devices is composed of an image pickup device 5A, 5B.
It is considered unnecessary if the distance between them is known, for example, via the measurement rack 3, but the length of the measurement rack 3 changes due to thermal expansion during insertion into the furnace. In order to improve the measurement accuracy of the degree of expansion,
The above distance measurement is necessary.

FIG. 2 shows a second embodiment of the first invention, in which corner cubes 9A and 9B are provided in the measuring rack 3 in addition to the television cameras 5A and 5B, and light waves placed outside the furnace. In this example, distances L1 and L2 to the corner cubes 9A and 9B are measured by distance finder 10A and 10B. Reference numeral 7 denotes an image processing device. The principle of this measurement is the same as in the first embodiment, and a description thereof will be omitted.

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

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, respectively, and reflect the images of the markers 2B and 2A, respectively, and project their projections by the television camera 5 to the corresponding mirror 13 The image is taken by adjusting the focal length to the beam splitter 14. Measurement of L1, L2 and markers 2A, 2B
Is the same as that in the first embodiment.

In the third embodiment, the measuring rack 3
Since only optical components including the mirror 13, the beam splitter 14, and the corner cubes 9A and 9B are provided therein,
Compared with the first and second embodiments, the cooling capacity can be reduced.

The marker to be used may be any marker provided on the refractory and which moves according to the behavior of the wall surface of the refractory. For example, the joints of the bricks constituting the furnace wall surface may be used, or a part of the brick surface may be processed, for example, by processing unevenness. Alternatively, when the joints or the like of these bricks are difficult to see, a marker different from the background, which is made of a refractory material such as ceramics, may be directly embedded in the bricks for use.

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

For this purpose, in the second invention, the marker 2 is embedded in the furnace wall brick. Marker 2 (Marker 2A
), As shown in FIG.
It can be buried in the hammer brick 19 (see FIG. 6, the dimensions are also shown) which is about 1.5 m from the kiln opening where the damage of the brick is relatively small and is hard to crack. The number of buried in the height direction may be one or more. When a plurality of burials are buried, comprehensive judgment can be made by averaging the amount of wear.

FIG. 7 shows an example of the shape of the marker 2. That is, a conical head 20 whose diameter is gradually reduced in the depth direction of the wall,
An anchor portion 21 and a neck portion 22 having a small diameter are provided between them. The head 20 has its outer surface flush with 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 index portion of wear, for example, only a depth portion from the surface of the head 20 is set to the hammer brick 1.
The material may be made of a material that wears at substantially the same speed as that of the material 9, and the other parts may be made of a non-wear material. In the embodiment, the whole is made of the same material. Head 20
In order to indicate the center point 25, a cross cut, a punch hole, or the like is carved on the outer surface of the.

When burying the marker 2, in the case of a newly installed coke oven, bricks in which the marker 2 has been buried can be piled in advance.
Since the width of the carbonization chamber is as narrow as about 400 to 460 mm, the embedding work can be performed, for example, in the mode shown in FIG. That is, the work vehicle 51 traveling on the rail 50 in the direction of the furnace group
The work scaffolding room 53 is advanced into the furnace while being suspended from the work deck 52 by the chain block 54, and the worker drills the marker 2 through the window of the work scaffolding room 53.
, The marker 2 is inserted into the hole together with the anchor material 23 interposed at 90-degree intervals in the circumferential direction, and fixed with the refractory mortar 24. FIG. 9 shows this burying completed state. As described above, since the burying work space is narrow, the drilling operation by the drill is oblique. Therefore, as shown in FIG. 7, the marker 2 also has, for example, an angle of about 60 degrees with respect to the furnace wall depth direction. At an angle. Such measures are not necessary for newly installed coke ovens.

In selecting the material of the marker 2, when the marker 2 is imaged, the background,
That is, it is necessary to be distinguishable from bricks.

For this purpose, the material of the marker 2 is as follows:
The same material as the brick or some ceramics can be used. In the case of the same material as the brick, it cannot be distinguished from the background brick in terms of image, so that a layer containing a coloring material and containing a coloring material on the surface can be formed by ceramic spraying or the like.

Generally, if the material is different, it is easy to distinguish the image. 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 the material exhibiting substantially the same wear properties as the brick, for example, when the furnace wall brick is a silica brick, a ceramic which is 99% alumina and the balance is silicon nitride can be suitably used. This ceramic also has a lower coefficient of thermal expansion than a silica brick, does not easily change its shape due to volume change (partial expansion), and has an elliptical shape on the outer surface of its head. Also, since it is mainly composed of alumina, it has good corrosion resistance and heat resistance, and is less likely to crack. 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 be an index of the amount of wear.

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

On the other hand, the marker 2 alone can be used as an indicator of furnace wall wear. That is, the marker 2 itself is worn at the same time as the brick is worn. With the wear of the marker 2, 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 detecting a change in the area of the outer surface of the head 20 over time.

For example, as described above, the marker 2 is imaged by the imaging device looking at the wall surface, and a plurality of points on the obtained image, for example, four points A, B, C, and D as shown in FIG. Is extracted, and the area passing through these extraction points is calculated as a figure assumed under constant conditions, in the illustrated example, a circle. In this calculation, A, B, C, D
Are coordinated, 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 , of each of these coordinates from the center point 25
r _C and r _D are calculated by the following equations (1) to (4), respectively.

[0043]

(Equation 1)

The 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 equation (5).

[0045]

(Equation 2)

The average diameter D is twice the average radius r of the marker 2. 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 equation (6). S = KD + n (K and n are constants) (6) Accordingly, 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 expression (6).

Although the head shape of the marker is conical, the shape may be, for example, a pyramid, and the shape of the cross section is not limited. When obtaining the area, the number of extraction points may be three or more. However, since the change with time is obtained, it is necessary to always assume a figure under certain conditions. Note that the head gradient does not need to be uniform, although the calculation is slightly complicated.

<Experimental example> Approximately 1.5
Markers 2 and 2 were buried in the hammer brick at the position of m, and the amount of wear of the furnace wall (= the amount of wear of the marker 2) and the amount of expansion of the furnace were measured for 5 years. The marker 2 used was a ceramic having 99% alumina and silicon nitride as the remainder. Table 1 shows the results.

[0049]

[Table 1]

As can be seen from Table 1, it was found that the amount of wear on the furnace wall as well as the amount of expansion of the coke oven could be quantitatively grasped. As a result, the degree of damage to the furnace body could be accurately grasped, which greatly helped in determining the repair timing and the calculation of the furnace body life.

[0051]

As is apparent from the above description, according to the present invention, in order to directly measure the amount of expansion of the furnace wall, the measured value reflecting only the amount of expansion of the furnace body due to crack expansion of a brick or the like is used. Obtainable. Further, the amount of wear of the furnace wall can be accurately measured. Accordingly, it is possible to appropriately perform maintenance management such as extending the life of the furnace by taking appropriate countermeasures against aging, and reflecting the change in the replacement timing by improving the accuracy of estimating the life of the furnace.

[Brief description of the drawings]

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

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

FIG. 3 is an explanatory view 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 a marker embedding position in a coke oven.

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

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

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

FIG. 9 is a vertical sectional view of the marker in an embedded state.

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, 22 Neck.

Continued on the front page. (72) Inventor Hiroji Toyama, 3F, Oji, Kashima-cho, Kashima-gun, Ibaraki Sumitomo Metal Industries Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) F27D 1/00 C10B 41/00 G01B 11/00-11/30

Claims (3)

(57) [Claims] An imaging device arranged in correspondence with a plurality of measurement points on an inner wall surface of the furnace to image an area around each measurement point, and measure a separation distance between each of the imaging devices and a reference point; Based on the respective separation distances, the respective measurement point positions above are converted into coordinates based on the reference point, and the change over time in the relative distance between the respective measurement point positions on the converted coordinates. A method for measuring the expansion of a furnace body of an industrial furnace, comprising measuring the expansion of the furnace body based on the measurement result. 2. A marker as an object to be imaged by an imaging apparatus, wherein the head is embedded in a furnace inner wall surface, and has a diameter gradually reduced in a depth direction of the wall; an anchor portion; An outer surface of the head is buried flush with the wall surface, and at least an index portion of a certain length in the wall depth direction of the head is substantially equal to another wall portion. 2. A wall marker for an industrial furnace, wherein the marker portion is made of a material that wears at the same speed, and the indicator portion is distinguished from other wall portions by imaging when the image is taken. 3. An imaging apparatus having a head having a head whose outer diameter gradually narrows in a wall depth direction embedded in a wall surface of an industrial furnace with the head surface flush with the wall surface, and imaging the marker by looking at the wall surface. The apparatus captures an image, extracts three or more points on the captured marker, obtains the diameter or area of a figure passing under these extraction points, always under constant conditions, and calculates the diameter or area of the figure based on the change over time in this diameter or area. And measuring the amount of wear on the wall of the industrial furnace.