Furnace wall shape change measuring device and method for repairing coke oven

Abstract

A furnace wall shape change measuring device according to the present invention is for measuring a shape change of a furnace wall, and comprises: an irradiation unit that irradiates the furnace wall with laser light at a distance from the furnace wall so that the laser light has a certain parallelism or less; a measurement unit that measures the distance to a measurement object on the basis of a round-trip time until the laser light emitted from the irradiation unit returns by being reflected by the surface of the measurement object; and a detection unit that detects the shape change of the furnace wall using the distance value measured by the measurement unit.

Description

Oven wall shape change measuring device and coke oven repair method

[0001] The present invention relates to an oven wall shape change measuring device and a coke oven repair method.

[0002] The steel industry requires a stable supply of coke, a raw material for producing molten iron in blast furnaces. Coke is produced by carbonizing coal in a coke oven. Coke ovens are constructed by stacking refractory bricks. They consist of a cavity called a coking chamber, approximately 7 m high, 400 mm wide, and 16 m deep, and a combustion chamber, approximately 900 mm wide, where fuel gas is burned, arranged alternately across the width. In a coke oven, heat from burning fuel in the combustion chamber is passed through the wall bricks of the combustion chamber, raising the temperature of the chamber to over 1000°C, and carbonizing the coal inside to produce coke cakes. Coke ovens are classified into two types, depending on the coal charging method: top-charge and bottom-load. The top-load method involves charging coal through a charging hole at the top of the coking chamber. The stamp-load method involves charging a coal cake, previously compacted by stamping, into the coking chamber. In either method, an extrusion ram is inserted into one opening of the carbonization chamber, and the coke cake is discharged from the other opening.

[0003] During coke oven operation, aging and long-term operation can cause brick chipping and protrusion on the coke chamber walls, as well as carbon deposition due to coal volatiles. These convexities on the walls create resistance when pushing the coke cake, making it difficult to push the coke cake stably and leading to operational problems. Furthermore, as the use of lower-quality coal increases due to the depletion of coal feedstock, the carbon deposition on the walls increases due to the increased coal volatiles, potentially increasing the number of convexities on the walls. Therefore, it is important to frequently monitor the carbon deposition-related convexities on the walls. Conventionally, the condition of oven walls has been assessed primarily by visual inspection by operators. Therefore, there has been a demand for measurement techniques to quantitatively assess the condition of oven walls. For example, Patent Document 1 discloses a technology that uses a laser 3D measurement device outside the oven to acquire the shape of the wall surface as point cloud data, and calculates the deviation from the design shape of the oven wall as oven wall displacement. Patent Document 2 discloses a technology for diagnosing the furnace wall by emitting a laser beam into the furnace through a peephole on the furnace, scanning the furnace wall while continuously or intermittently changing the irradiation angle of the laser beam, and obtaining the unevenness of the furnace wall based on the relationship between the irradiation angle and the distance to the irradiated part of the furnace wall.

[0004] Japanese Patent No. 5987605 Japanese Patent Laid-Open No. 2002-47491

[0005] However, the technology disclosed in Patent Document 1 acquires large-scale point cloud data of the furnace wall using a laser 3D measurement device, which is generally very expensive. Therefore, the technology disclosed in Patent Document 1 has problems such as high costs and the long time required to detect changes in the furnace wall shape. The technology disclosed in Patent Document 2 has a problem in that the peephole on the furnace has only a limited field of view, so if there is a structural protrusion of the furnace between the peephole and the furnace wall, it is not possible to diagnose the area of ​​the furnace wall that the laser light does not directly reach. Furthermore, while detailed information on the unevenness of the furnace wall can be obtained, the accuracy of the laser rangefinder can vary depending on environmental conditions between close and distant objects, resulting in a problem of reduced measurement accuracy of the unevenness of the furnace wall when it is far from the laser rangefinder.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide an oven wall shape change measuring device and a coke oven repair method that can prevent high costs and the long time required to detect oven wall shape changes.

[0007] In order to solve the above-mentioned problems and achieve the object, (1) the oven wall shape change measuring device according to the present invention is an oven wall shape change measuring device that measures changes in the shape of an oven wall, and is characterized by comprising: an irradiation unit that irradiates the oven wall with laser light at a distance from the oven wall so that the laser light has a certain parallelism or less; a measurement unit that measures the distance to the measurement object based on the round-trip time it takes for the laser light irradiated from the irradiation unit to be reflected by the surface of the measurement object and return; and a detection unit that detects changes in the shape of the oven wall using the distance value measured by the measurement unit.

[0008] (2) The oven wall shape change measuring device of the present invention is characterized in that, in the invention (1) above, the detection unit detects a change in the shape of the oven wall when the distance value is different from a predetermined reference distance value.

[0009] (3) The oven wall shape change measuring device according to the present invention is characterized in that, in the invention (1) or (2) above, the detection unit calculates a differential distance value, which is the difference between the distance value and a predetermined reference distance value, and detects a change in the oven wall shape using a threshold value that is predetermined for the differential distance value.

[0010] (4) The furnace wall shape change measuring device according to the present invention is characterized in that, in any one of the inventions (1) to (3) above, the irradiation unit is installed in a position facing the furnace mouth.

[0011] (5) The oven wall shape change measuring device according to the present invention is any one of the inventions (1) to (4) above, characterized in that the irradiation unit is installed so that an imaginary plane parallel to the depth direction on the oven wall and the laser light have a certain degree of parallelism or less, and the distance in the width direction between the imaginary plane of the oven wall and the laser light is a constant distance across the depth direction.

[0012] (6) The oven wall shape change measuring device according to the present invention is characterized in that, in the invention (5) above, the certain distance is set based on the amount of change in the oven wall convex portion.

[0013] (7) The oven wall shape change measuring device according to the present invention is characterized in that, in the invention of (5) or (6) above, the irradiation unit irradiates laser light from the horizontal direction to the vertical direction while rotating it, and the detection unit detects the presence or absence of an oven wall convex portion that exceeds the certain distance on the oven wall.

[0014] (8) The method for repairing a coke oven according to the present invention is a method for repairing a coke oven in which carbonization chambers and combustion chambers are arranged alternately in series, and is characterized in that the oven wall is repaired based on changes in the shape of the oven wall of the carbonization chamber detected using an oven wall shape change measuring device according to any one of the inventions (1) to (7) above.

[0015] The oven wall shape change measuring device and coke oven repair method according to the present invention have the effect of suppressing high costs and the long time required to detect oven wall shape changes.

[0016] FIG. 1 is a diagram showing a schematic configuration of a coke oven according to an embodiment. FIG. 2 is a block diagram showing a measuring device and a display device according to an embodiment. FIG. 3(a) is a conceptual diagram showing a top view of a furnace wall of a coke oven having a reflector installed at the first kiln opening and a measuring device installed on the deck. FIG. 3(b) is a side view of the furnace wall of FIG. 3(a) as seen from the width direction. FIG. 4(a) is a conceptual diagram showing a top view of a furnace wall of a coke oven having a reflector installed at the second kiln opening and a measuring device installed on the deck. FIG. 4(b) is a side view of the furnace wall of FIG. 4(a) as seen from the width direction. FIG. 5(a) is a conceptual diagram showing a top view of a furnace wall of a coke oven and a measuring device positioned and installed on the deck. FIG. 5(b) is a side view of the furnace wall of FIG. 5(a) as seen from the width direction. Fig. 6 is a graph showing the relationship between the rotation angle of the irradiation unit when it is rotated from the horizontal direction to the vertical direction from the start of measurement to the end of measurement and the measured distance. Fig. 7(a) is a conceptual diagram showing a top view of the oven wall of the coking chamber where carbon deposits are present and the measurement device positioned and installed on the deck. Fig. 7(b) is a side view of the oven wall where carbon deposits are present in Fig. 7(a) as viewed from the width direction. Fig. 8 is a graph showing the relationship between the rotation angle of the irradiation unit when it is rotated from the horizontal direction to the vertical direction from the start of measurement to the end of measurement in a state where carbon deposits are present on the oven wall and the measured distance. Fig. 9 is a graph showing the relationship between the rotation angle of the irradiation unit and the differential distance value. Fig. 10 is a flowchart showing an example of control of oven wall shape change measurement performed by the measurement device according to the embodiment.

[0017] Hereinafter, an embodiment of the oven wall shape change measuring device and coke oven repair method according to the present invention will be described. However, the present invention is not limited to these embodiments. For example, in this embodiment, an example of application to a stamp charge type coke oven, which is a coke manufacturing facility in the steel industry, is shown as an example of a process in which the device is used. The present invention is not limited to stamp charge type coke ovens, and can also be applied to top charge type coke ovens.

[0018] FIG. 1 is a diagram showing a schematic configuration of a coke oven 1 according to an embodiment.

[0019] As shown in FIG. 1 , a coke oven 1 according to this embodiment includes multiple coke chambers 11 and multiple combustion chambers 12. The coke chambers 11 and the combustion chambers 12 are alternately connected to form a furnace battery. In the coke oven 1, raw coal is charged into each coke chamber 11, fuel gas is supplied to each combustion chamber 12, and each coke chamber 11 is heated by heat generated by the adjacent combustion chambers 12 on both sides in the width direction, thereby carbonizing the coal in each coke chamber 11 to produce a coke cake. The coke cake in each coke chamber 11 is pushed by an extrusion ram of an extruder (not shown) in the depth direction of each coke chamber 11 from the first kiln opening 110 side to the second kiln opening 112 side (see FIG. 3 ) and discharged. Note that in this embodiment, the “width direction” is defined as the width direction of the coke chamber 11, which is parallel to the direction in which the coke chambers 11 and the combustion chambers 12 are aligned. In the following description, the "depth direction" is defined as the depth direction (furnace length direction) perpendicular to the width direction and height direction of the coking chamber 11.

[0020] The stamp-charge coke oven used in this embodiment uses a larger amount of inferior coal than the top-charge coke oven. Therefore, the stamp-charge coke oven releases more volatile coal during coal carbonization than the top-charge coke oven, resulting in increased carbon deposition on the walls of the coke chamber (hereinafter referred to as "deposited carbon"). Furthermore, the carbon deposition grows in the width direction of the coke chamber, increasing the number of convexities on the walls. When the coke cake is discharged from the coke chamber, the carbon deposition collides with the coke cake, causing the coke cake to collapse and resulting in operational problems. Therefore, in the stamp-charge coke oven, it is important to detect the changes in the walls, which are convexities on the walls caused by the carbon deposition during coal carbonization, more frequently than in the top-charge coke oven, and to manage the condition of the walls in the coke chamber.

[0021] Here, the term "oven wall protrusion" refers to a localized protrusion on the surface of the oven wall that indicates a deviation from the design shape of the oven wall. Specifically, the term "oven wall protrusion" is defined as a portion of the oven wall whose distance from a reference plane exceeds a predetermined reference distance. This allows for quantitative evaluation of the degree of change in oven wall shape and deterioration, and serves as an index for preventing an increase in resistance force during coke cake extrusion and the occurrence of operational problems.

[0022] In the coke oven 1 according to the embodiment, a measuring device 3, which is a furnace wall shape change measuring device for detecting furnace wall changes in the furnace wall 111, is installed on the deck 2 located opposite the first kiln port 110 (kiln port) outside the furnace, in accordance with the height of the bottom of the furnace wall 111 of the coking chamber 11. By installing the measuring device 3 on the deck 2 located opposite the first kiln port 110, which is the opening of the coking chamber 11 outside the furnace, the overall unevenness of the furnace wall 111 can be measured with high precision. In addition, the measuring device 3 is installed on the deck 2 so that the laser light LB is approximately parallel to the furnace wall 111 and so that the laser light LB is spaced a certain distance from the furnace wall 111 in the width direction of the coking chamber 11. The measuring device 3 detects the furnace wall changes by utilizing the collision of the laser light LB irradiated from the measuring device 3 with the furnace wall changes only when the state of the furnace wall 111 changes such that a height change of more than a predetermined distance occurs in the width direction of the coking chamber 11.

[0023] FIG. 2 is a block diagram showing a measurement device 3 and a display device 4 according to the embodiment.

[0024] As shown in Fig. 2, the measurement device 3 has an irradiation unit 31, a measurement unit 32, and a detection unit 33. In the measurement device 3, the measurement unit 32 measures the round-trip time it takes for the laser light LB irradiated from the irradiation unit 31 to be reflected by the surface of the measurement target and return, and calculates the distance to the measurement target based on the measured round-trip time. In addition, in the measurement device 3, the detection unit 33 detects oven wall changes such as oven wall protrusions on the oven wall 111 based on the distance to the measurement target calculated by the measurement unit 32. Information about the oven wall changes detected by the detection unit 33 of the measurement device 3, for example, information about the position of the oven wall changes on the oven wall 111, is transmitted to a display device 4 having a display screen via wireless or wired communication and displayed on the display screen of the display device 4.

[0025] In this embodiment, a reference for comparison is created in advance to capture changes in the oven wall shape of the coking chamber 11. Specifically, the oven wall 111 of the coking chamber 11 is repaired in advance to restore the oven wall 111 to a sound state, and then the position of the measuring device 3 is adjusted to measure the reference distance. In this embodiment, a one-dimensional laser rangefinder is used as the measuring device 3. The one-dimensional laser rangefinder used as the measuring device 3 is a time-of-flight type that irradiates a laser beam and measures the distance based on the time it takes for the laser beam to reflect off the target surface and return. By combining the laser rangefinder with a rotation mechanism that can rotate from the horizontal to the vertical direction, the laser rangefinder can be rotated along the oven wall 111 to scan the laser beam. This makes it possible to detect changes in the entire surface of the oven wall 111 using the measuring device 3. Note that the method of rotating the laser rangefinder from the horizontal to the vertical direction is not limited to the rotation mechanism described above. For example, a method in which the laser rangefinder itself is fixed and rotated using a mirror is also possible.

[0026] The measurement device 3 is installed using a positioning jig so that the laser beam LB and the furnace wall 111 are parallel to each other at a certain level (based on JIS B 0621:1984) or less, and so that the distance between the furnace wall 111 and the laser beam LB in the width direction is approximately constant throughout the depth direction. Note that the surface of the furnace wall 111, which is made of bricks, may have some irregularities. Therefore, for example, the measurement device 3 may be installed so that the parallelism between the laser beam LB and an imaginary plane on the furnace wall 111 parallel to the depth direction is a certain level or less, and so that the distance between the laser beam LB and the imaginary plane on the furnace wall 111 in the width direction is a constant throughout the depth direction.

[0027] Fig. 3(a) is a conceptual diagram of the oven wall 111 of the coking chamber 11, in which a reflector 5 is installed at the first kiln opening 110, and the measuring device 3 installed on the deck 2, viewed from above. Fig. 3(b) is a side view of the oven wall 111 of Fig. 3(a) viewed from the width direction. Fig. 4(a) is a conceptual diagram of the oven wall 111 of the coking chamber 11, in which a reflector 5 is installed at the second kiln opening 112, and the measuring device 3 installed on the deck 2, viewed from above. Fig. 4(b) is a side view of the oven wall 111 of Fig. 4(a) viewed from the width direction.

[0028] In this embodiment, a line on the bottom of the furnace wall 111, which is located at the same height as the laser light LB irradiated horizontally from the irradiation unit 31 of the measurement device 3, is set as the reference line of the furnace wall 111. Then, to check the parallelism of the laser light LB with respect to this reference line, an operator installs reflectors 5 at the first kiln opening 110 and the second kiln opening 112 at different times.

[0029] 3(a), the worker places the reflector 5 at the first kiln opening 110 and irradiates the reflector 5 with laser light LB from the irradiation unit 31 of the measuring device 3, thereby generating a first bright point P1 on the reflector 5. Then, the worker measures and determines the distance x1 in the width direction between the furnace wall 111 on the first kiln opening 110 side and the first bright point P1 in the depth direction.

[0030] 4(a), the worker places a reflector 5 at the second kiln opening 112 and irradiates the reflector 5 with laser light LB from the irradiation unit 31 of the measuring device 3, thereby generating a second bright point P2 on the reflector 5. Then, the worker measures and determines the distance x2 in the width direction between the furnace wall 111 on the second kiln opening 112 side and the second bright point P2 in the depth direction.

[0031] The difference between the distance x1 and the distance x2 thus determined is calculated as the parallelism of the laser beam LB with respect to the furnace wall 111. It is desirable to keep the parallelism of the laser beam LB with respect to the furnace wall 111 at a certain value or less by adjusting the irradiation direction of the laser beam LB and the installation position of the measuring device 3, so that the laser beam LB is nearly parallel to the furnace wall 111. In this embodiment, the measuring device 3 is installed so that the parallelism of the laser beam LB with respect to the furnace wall 111 is 10 mm or less. The design criterion for the parallelism may be determined according to the amount of change (amount of convexity) of the furnace wall change portion (furnace wall convex portion) to be detected. The design criterion for the parallelism must be smaller than the distance between the furnace wall 111 and the laser beam LB in the width direction.

[0032] In this way, the position of the measuring device 3 is adjusted so that the desired parallelism is achieved according to the amount of change (amount of convexity) of the detected furnace wall change portion (furnace wall convex portion), and then the reference distance is measured using the measuring device 3.

[0033] Fig. 5(a) is a conceptual diagram of an oven wall 111 of the coking chamber 11 and a measuring device 3 positioned and installed on the deck 2, viewed from above. Fig. 5(b) is a side view of the oven wall 111 of Fig. 5(a) as viewed from the width direction.

[0034] As shown in Figures 5(a) and 5(b), when measuring the reference measurement value using the measuring device 3, the first kiln opening 110 is opened to introduce the laser light LB irradiated from the irradiation section 31 of the measuring device 3 into the carbonization chamber 11, but the second kiln opening 112 is closed by the furnace lid 113.

[0035] In this embodiment, the distance x3 between the oven wall 111 and the laser beam LB in the width direction is set to 15 mm. The distance x3 between the oven wall 111 and the laser beam LB may be appropriately designed depending on the amount of change (protrusion amount) of the oven wall change portion (oven wall convex portion) to be detected. For example, a gap is generally provided between the oven wall 111 and the coke cake (charged coal cake) by design. The distance x3 between the oven wall 111 and the laser beam LB is set based on the design value of this gap. If the distance x3 and the design value of the gap are set to the same value, this means that the coke cake will collide with the oven wall convex portion, which is the oven wall change portion, when pushed and discharged by the extrusion ram of the extruder. Therefore, the distance x3 between the oven wall 111 and the laser beam LB is set to a value equal to or smaller than the design value of the gap. Therefore, in this embodiment, since the design value of the gap is 15 mm, the distance x3 between the oven wall 111 and the laser beam LB is set to 15 mm, which is the same value.

[0036] 5(b), the measurement device 3 rotates the irradiation unit 31 so that the laser beam LB is irradiated from the horizontal direction to the vertical direction, and intermittently irradiates the laser beam LB from the irradiation unit 31 toward the furnace lid 113 and the furnace ceiling 114. For example, the irradiation unit 31 irradiates the laser beam LB horizontally toward the furnace lid 113, and then irradiates the laser beam LB at regular rotation angles. As a result, the laser beam LB is irradiated from the bottom to the top in the height direction of the furnace lid 113 that closes the second kiln opening 112, and then irradiates from the second kiln opening 112 side toward the first kiln opening 110 side in the depth direction of the furnace ceiling 114. In the reference state of the furnace wall 111, where there is no furnace wall change portion (furnace wall protrusion) to be detected, the laser beam LB is irradiated from a certain distance (distance x3) from the furnace wall 111 in the width direction, so that the laser beam LB does not collide with the furnace wall 111.

[0037] FIG. 6 is a graph showing the relationship between the rotation angle when the irradiation unit 31 is rotated from the horizontal direction to the vertical direction from the start of measurement to the end of measurement, and the measured distance.

[0038] The interior of the coking chamber 11 is generally rectangular, and a graph Gr1 showing the relationship between the rotation angle and the measured distance when the irradiation unit 31 of the measurement device 3 is rotated from the horizontal direction to the vertical direction from the start of measurement to the end of measurement is curved. Specifically, as shown in Fig. 6, within the range of rotation angles in which the laser beam LB is irradiated from the bottom to the top in the height direction of the furnace lid 113, the graph is curved such that the measured distance gradually increases. Also, as shown in Fig. 6, within the range of rotation angles in which the laser beam LB is irradiated from the second kiln opening 112 side to the first kiln opening 110 side in the depth direction of the furnace ceiling 114, the graph is curved such that the measured distance gradually decreases.

[0039] Fig. 7(a) is a conceptual diagram showing an oven wall 111 of the coking chamber 11 on which the adhering carbon 130 exists, and a measuring device 3 positioned and installed on the deck 2, viewed from above. Fig. 7(b) is a side view of the oven wall 111 on which the adhering carbon 130 exists in Fig. 7(a) as viewed from the width direction.

[0040] 7( a) and 7(b), when the carbon deposits 130 present on the furnace wall 111 grow at a distance greater than a certain distance in the width direction, the laser light LB that had been reflected by the furnace lid 113 is reflected again by the carbon deposits 130. As a result, the distance value measured by the measurement unit 32 of the measurement device 3 changes significantly from the reference distance value. The detection unit 33 of the measurement device 3 then detects the furnace wall change (furnace wall convexity) based on this change in distance value. In this way, by detecting the amount of change (amount of convexity) of the furnace wall change (furnace wall convexity) at a distance greater than a certain distance from the furnace wall 111, the influence of environmental conditions is reduced compared to direct distance measurement, and the presence or absence of the furnace wall change (furnace wall convexity) on the entire furnace wall 111 can be detected with high accuracy.

[0041] FIG. 8 is a graph showing the relationship between the rotation angle of the irradiation unit 31 when it is rotated from the horizontal direction to the vertical direction from the start of measurement to the end of measurement, and the measured distance, when the carbon deposit 130 is present on the furnace wall 111.

[0042] The "furnace lid" region in FIG. 8 represents the range of rotation angles of the irradiation unit 31 irradiating the laser beam LB from the bottom to the top in the height direction of the furnace lid 113. The "furnace ceiling" region in FIG. 8 represents the range of rotation angles of the irradiation unit 31 irradiating the laser beam LB from the second kiln opening 112 side to the first kiln opening 110 side in the depth direction of the furnace ceiling 114. In FIG. 8 , in the rotation angle range where no carbon deposits 130 are present, the relationship between the rotation angle and the measured distance is represented by a curved graph Gr11 similar to the reference distance value graph Gr1 shown in FIG. 6 . On the other hand, in the rotation angle range where carbon deposits 130 are present, the laser beam LB collides with the carbon deposits 130, resulting in a shorter measured distance than the reference distance value. Therefore, the relationship between the rotation angle and the measured distance is represented by a curved graph Gr12 in which the measured distance is shorter than the imaginary graph Gr13 corresponding to the graph Gr1 shown in FIG. 6 , in the same rotation angle range where carbon deposits 130 are present.

[0043] In this way, the presence of the adhering carbon 130 causes a difference between the distance value measured by the measuring device 3 and the reference distance value. Then, by comparing this difference, it becomes possible to detect changes in the oven wall 111. As an example, the detection unit 33 of the measuring device 3 according to the embodiment calculates a differential distance value, which is the difference between the measured distance value and the reference distance value, and sets a detection threshold Th1 for the differential distance value to detect changes in the oven wall.

[0044] FIG. 9 is a graph showing the relationship between the rotation angle of the irradiation unit 31 and the differential distance value.

[0045] 9, in the range of rotation angles where no carbon adherence 130 exists on the irradiation unit 31, the linear graphs Gr21 and Gr23 showing the relationship between the rotation angle and the differential distance value show a differential distance value of 0 [mm]. On the other hand, in the range of rotation angles where carbon adherence 130 exists on the irradiation unit 31, the curved graph Gr22 showing the relationship between the rotation angle and the differential distance value shows a differential distance value of approximately −2000 [mm].

[0046] Therefore, as shown in Fig. 9, by referring to the rotation angle at which the differential distance value is equal to or greater than a preset detection threshold Th1 and the differential distance value, it is possible to identify, for example, the position of a furnace wall change portion where carbon deposits 130 exist on the furnace wall 111. Note that in Fig. 9, the detection unit 33 of the measuring device 3 calculates the differential distance value from the measured distance value and the reference distance value, and detects the furnace wall change portion (furnace wall convex portion) using the detection threshold Th1, but this is not limiting. For example, the detection unit 33 of the measuring device 3 may detect the furnace wall change (furnace wall convex portion) from the discontinuity of the measured distance value without using the reference distance value.

[0047] Furthermore, when setting the detection threshold Th1, since there is measurement variation in the measurement device 3 itself, it is desirable to set the detection threshold Th1 sufficiently larger than the measurement variation. Generally, the measurement variation of the measurement device 3, which is a laser distance measuring device that measures on the order of about 10 [mm] as in this embodiment, is about a few [mm]. Therefore, taking the measurement variation of the measurement device 3 into full consideration, the detection threshold Th1 may be set, for example, to an absolute value of about 10 [mm] at the minimum. Furthermore, depending on the surface condition of the furnace wall 111 to be measured, there is a possibility that measurement errors will occur in the measurement device 3, resulting in missing measurement data. In this case, the measurement data may be interpolated, for example, by linearly interpolating points before and after the measurement data.

[0048] FIG. 10 is a flowchart showing an example of control of the measurement of changes in the shape of the furnace wall performed by the measurement device 3 according to the embodiment.

[0049] First, the measurement device 3 irradiates the coking chamber 11 with laser light LB from the irradiation unit 31 and measures the distance using the measurement unit 32 (step S1). Next, the measurement device 3 calculates a differential distance value, which is the difference between the distance value measured by the detection unit 33 and a reference distance value (step S2). Next, the measurement device 3 performs threshold processing using the detection unit 33 to compare the differential distance value for each rotation angle with a detection threshold Th1 to detect oven wall changes (oven wall protrusions) (step S3). Next, the measurement device 3 calculates and identifies the position of the oven wall changes detected by the detection unit 33 from the rotation angle of the irradiation unit 31 and the measured distance value (step S4). Then, the measurement device 3 ends the series of control operations.

[0050] As described above, in the measuring device 3 according to the embodiment, the irradiation unit 31 can be rotated from the horizontal direction to the vertical direction, and by virtue of a structure that eliminates rotation in a direction parallel to the horizontal direction, the measuring device 3 itself can be made smaller and less expensive, and the measurement time can also be reduced. Furthermore, unlike large-scale three-dimensional point cloud data measured by a 3D scanner, the measuring device 3 according to the embodiment uses only the measurement distance value, thereby reducing the processing time required to detect changes in the furnace wall and enabling high-frequency measurement and analysis.

[0051] Furthermore, the measuring device 3 according to the embodiment can be installed on the deck 2 or on the extruder, which is located opposite the first kiln mouth 110 (kiln mouth). When installing the measuring device 3 on the deck 2, the measuring device 3 is fixed to the deck 2 in a position that does not interfere with the extruder. Furthermore, when installing the measuring device 3 on the deck 2, it is possible to install multiple measuring devices 3 corresponding to each oven wall 111 of multiple coking chambers 11, making it possible to accurately detect oven wall changes for each oven wall 111.

[0052] On the other hand, when the measuring device 3 is set on the extruder, since the extruder moves, the design should take into account the movement error of the extruder, and it is possible to detect changes in the oven walls using one measuring device 3 for multiple carbonization chambers 11.

[0053] The location where the measuring device 3 is installed is not limited to on the deck 2 or on the extruder. For example, in a stamp charge type coke oven, it may be installed on the side of the stamping box.

[0054] As described above, by using the measuring device 3 according to the embodiment, it is possible to detect oven wall changes mainly caused by carbon. As a method for repairing the oven wall 111 in the coking chamber 11 of the coke oven 1, for example, the X-axis is an axis parallel to the depth direction of the oven wall 111, and the Y-axis is the height direction of the oven wall 111, and XY-axis coordinates corresponding to the oven wall 111 are set in the measuring device 3. The measuring device 3 then calculates and identifies the position of the oven wall change portion (oven wall convex portion) on the XY-axis coordinate system based on the rotation angle of the irradiation unit 31 and the measured distance value. The measuring device 3 then outputs information regarding the position (coordinate position) of the identified oven wall change portion (oven wall convex portion) to the display device 4. The operator looks at the information regarding the position of the oven wall change portion (oven wall convex portion) displayed on the display device 4 and visually confirms the position of the oven wall change portion (oven wall convex portion) toward the coking chamber 11 in which the oven wall 111 to be measured is installed. Then, an operator peels off the carbon 130 adhering to the changed portion of the furnace wall (the protruding portion of the furnace wall) from the furnace wall 111 using a push-out rod or the like, and returns the furnace wall 111 to a sound state.

[0055] Furthermore, the carbon 130 adhering to the oven wall change portion (oven wall convex portion) does not necessarily need to be manually pushed off from the oven wall 111. For example, when the detection unit 33 of the measurement device 3 detects the oven wall change portion (oven wall convex portion), first, the inside of the coking chamber 11 having the oven wall 111 to be measured is emptied. Then, the first kiln opening 110 and the second kiln opening 112 on both sides in the depth direction of the coking chamber 11 are opened, and the coking chamber 11 is heated by the heat of the combustion chamber 12 while air is sent into the coking chamber 11. This promotes the combustion of the carbon 130 adhering to the oven wall 111 itself, and by burning off the adhering carbon 130 from the oven wall 111, the oven wall 111 can be restored to a healthy state.

[0056] Furthermore, the measuring device 3 according to the embodiment can detect oven wall changes (oven wall convex portions) caused by the adhesion of the deposited carbon 130 on the oven wall 111 of the coking chamber 11, as well as oven wall changes (oven wall convex portions) caused by, for example, the protruding bricks constituting the oven wall 111. Therefore, when an oven wall change (oven wall convex portion) caused by the protruding bricks is detected, the bricks at the position of the detected oven wall change (oven wall convex portion) are repaired, and the brick protrusion is eliminated, restoring the oven wall 111 to a sound state. As a result, in the coke oven 1 according to the embodiment, when the coke cake is discharged from the coke oven chamber 11, it is possible to suppress the collapse of the coke cake caused by the coke cake colliding with the protruding bricks of the oven wall 111 or the deposited carbon 130.

[0057] As described above, the measuring device 3 according to the embodiment is specialized only in detecting changes in the furnace wall (convex portions of the furnace wall), unlike conventional methods that use a 3D scanner to measure the entire furnace wall shape and calculate the displacement of the entire furnace wall. As a result, the measuring device 3 according to the embodiment can detect changes in the furnace wall more quickly and easily than conventional methods that use a 3D scanner. Furthermore, the measuring device 3 according to the embodiment can simplify the equipment configuration compared to conventional methods that use a 3D scanner, leading to lower costs.

[0058] Therefore, the measuring device 3, which is an oven wall shape change measuring device according to the embodiment, and the repair method for the coke oven 1 can prevent high costs and the long time required to detect shape changes in the oven wall 111 of the coking chamber 11.

[0059] The present invention can provide an oven wall shape change measuring device and a coke oven repair method that can prevent high costs and the long time required to detect changes in the oven wall shape.

[0060] REFERENCE SIGNS LIST 1 Coke oven 2 Deck 3 Measuring device 4 Display device 5 Reflector 11 Carbonization chamber 12 Combustion chamber 31 Irradiation unit 32 Measurement unit 33 Detection unit 110 First kiln opening 111 Oven wall 112 Second kiln opening 113 Oven cover 114 Oven ceiling 130 Adhered carbon Gr1, Gr11, Gr12, Gr21, Gr22, Gr23 Graph Gr13 Virtual graph P1 First bright point P2 Second bright point Th1 Detection threshold x1, x2, x3 Distance

Claims

1. An oven wall shape change measuring device for measuring changes in the shape of an oven wall, comprising: an irradiation unit that irradiates the oven wall with laser light at a distance from the oven wall so that the laser light has a certain degree of parallelism or less; a measurement unit that measures the distance to the measurement object based on the round-trip time it takes for the laser light irradiated from the irradiation unit to be reflected by the surface of the measurement object and return; and a detection unit that detects changes in the shape of the oven wall using the distance value measured by the measurement unit.

2. The oven wall shape change measuring device according to claim 1, characterized in that the detection unit detects a change in the shape of the oven wall when the distance value differs from a preset reference distance value.

3. The oven wall shape change measuring device described in claim 1 or 2, characterized in that the detection unit calculates a differential distance value which is the difference between the distance value and a predetermined reference distance value, and detects changes in the shape of the oven wall using a threshold value which is predetermined for the differential distance value.

4. A furnace wall shape change measuring device according to any one of claims 1 to 3, characterized in that the irradiation unit is installed in a position facing the furnace mouth.

5. A furnace wall shape change measuring device as described in any one of claims 1 to 4, characterized in that the irradiation unit is installed so that an imaginary plane parallel to the depth direction on the furnace wall and the laser light have a certain degree of parallelism or less, and so that the distance in the width direction between the imaginary plane of the furnace wall and the laser light is a certain distance across the depth direction.

6. The oven wall shape change measuring device according to claim 5, wherein the predetermined distance is set based on the amount of change in the oven wall convexity.

7. The oven wall shape change measuring device according to claim 5 or 6, characterized in that the irradiation unit irradiates the laser light from the horizontal direction to the vertical direction while rotating it, and the detection unit detects whether or not there is a protrusion on the oven wall that exceeds the certain distance on the oven wall.

8. A method for repairing a coke oven in which carbonization chambers and combustion chambers are arranged alternately in series, characterized in that the oven walls are repaired based on changes in the shape of the oven walls of the carbonization chambers detected using an oven wall shape change measuring device described in any one of claims 1 to 7.

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