JP7852533B2 - Coke oven monitoring device - Google Patents

Description

This invention relates to a monitoring device for a coke oven, and more particularly to a device for monitoring the tightening of the furnace wall of a coke oven.

One management method that contributes to extending the lifespan of coke ovens is oven clamping management. Oven clamping management means maintaining the elastic force of the oven clamping springs, which clamp the oven walls in the oven's longitudinal direction, at an appropriate level. Specifically, the length of the oven clamping springs in their compressed state is measured, and the oven clamping force is adjusted based on that length.

The installation environment for furnace clamping springs is harsh, involving high temperatures and dust. Therefore, installing sensors to measure the length of compressed furnace clamping springs near the springs is unsuitable due to the sensor's operating environment. Consequently, measuring and adjusting the length of furnace clamping springs sometimes has to be done manually. Manual measurement and adjustment can lead to variations in accuracy depending on the individual, and performing these measurements and adjustments in harsh environments raises safety concerns.

Therefore, devices for measuring the length of the compressed furnace clamping springs that tighten the furnace wall have been conventionally studied. Patent Document 1 describes, as Example 1, a measuring device that measures the displacement of the cylinder's stroke by placing a cylinder between the retaining plates on both sides of the furnace clamping spring when the extruder that pushes coke out of the carbonization chamber of a coke oven stops. This measuring device measures the length of the furnace clamping spring based on the measured cylinder stroke displacement. Patent Document 1 also describes, as Example 2, a measuring device in which a support projection is integrally attached to one of the retaining plates on both sides of the furnace clamping spring, and when the extruder stops, the cylinder is pressed against the support projection to measure the cylinder's stroke displacement. Similar to the device in Example 1, this measuring device measures the length of the furnace clamping spring based on the measured cylinder stroke displacement. Furthermore, Patent Document 1 describes, as Example 3, a non-contact type measuring device that measures the length of the furnace clamping spring by irradiating the support projection with a laser from a laser rangefinder when the extruder stops.

Japanese Patent Application Publication No. 3-264807

In Examples 1 to 3 of Patent Document 1, measuring devices using cylinders or non-contact type measuring devices are used in harsh environments, which increases the possibility of malfunctions or failures in these devices. Furthermore, coke ovens have numerous clamping springs. Therefore, if a measuring device malfunctions or fails while measuring the length of any of the clamping springs, maintenance of the device may have to be performed in harsh environments. Moreover, the work is performed at high altitudes and in high-temperature environments, posing safety problems. In other words, the overall maintainability of the device is poor. Additionally, in the devices of Examples 2 and 3 of Patent Document 1, support protrusions must be installed on the retaining plates of all the clamping springs installed in the coke oven, resulting in a high workload.

This invention was made to solve the above-mentioned problems, and aims to provide a coke oven monitoring device that can measure the length of the furnace clamping spring without performing any work on the coke oven, and moreover, the device as a whole has good maintainability.

To achieve the above objectives, the present invention
[1] A coke oven comprising a furnace wall extending in the furnace length direction, backstays positioned on both sides of the furnace wall in the furnace length direction, an upper cross tie rod installed on the upper part of the furnace wall and extending in the furnace length direction, an upper cross tie rod spring attached to the end of the upper cross tie rod on the extruder side of the coke oven in the furnace length direction, and spring receiving portions provided on each side of the upper cross tie rod spring, wherein the spring receiving portions sandwich the upper cross tie rod spring in the furnace length direction and are on the outside of the coke oven A coke oven monitoring device comprising: a camera that photographs the one spring support portion and the other spring support portion on the inside of the coke oven, sandwiching the upper cross tie rod spring in the furnace length direction, and pressing the other spring support portion on the inside of the coke oven against the backstay by the elastic force of the upper cross tie rod spring, the camera comprising: a camera that photographs the one spring support portion and the other spring support portion together, and an analysis device that measures the distance between the one spring support portion and the other spring support portion based on the image data captured by the camera.
[2] The imaging device is the coke oven monitoring device described in [1] above, which is provided on the extruder.
[3] The coke oven monitoring device described in [2] above, wherein the photographic device photographs the one spring support and the other spring support together when the extruder is stopped in the carbonization chamber in order to push coke out of the carbonization chamber of the coke oven.
[4] The coke oven monitoring device according to [1] above, further comprising an illumination device that illuminates both the one spring support and the other spring support together.
[5] The coke oven monitoring device described in [1] above, wherein the field of view of the photographic device is predetermined.
[6] The coke oven monitoring device according to [1] above, further comprising an adjustment device for adjusting at least one of the height of the imaging device and the imaging angle of the imaging device with respect to the horizontal plane.
[7] A coke oven monitoring device according to any one of [1] to [6] above, further comprising a warning means for issuing a warning when the distance is above a preset upper limit or below a preset lower limit.

In this invention, the distance between one spring support and the other spring support, located on either side of the furnace clamping spring, is measured based on image data captured by a camera. Since this distance is the length of the upper tie rod spring, the invention allows for the measurement of the upper tie rod spring length without requiring any modifications to the coke oven, as described above. Furthermore, furnace clamping management of the coke oven can be performed based on the length of the upper tie rod spring. Additionally, because the monitoring device of this invention has virtually no parts that operate in harsh environments, it is less prone to malfunctions and failures. Therefore, the overall maintainability of the device is excellent.

This figure shows an example of a coke oven according to an embodiment of the present invention. This is a perspective view showing an example of a furnace wall. This is a view from arrow A shown in Figure 2. This is a diagram showing a magnified view of a portion of the furnace wall. This figure shows an example of the configuration of a monitoring device. This diagram illustrates the conditions for photographing a pair of upper spring support parts using a monitoring device. This diagram shows the extruder stopped at a predetermined position adjacent to the carbonization chamber, in order to push coke out of the carbonization chamber. This figure shows an example of image processing.

The present invention will be described in detail below through embodiments of the present invention. The following embodiments are preferred examples of the present invention and are not limiting in any way.

Figure 1 shows an example of a coke oven according to an embodiment of the present invention. The coke oven shown in Figure 1 is a chamber-type coke oven 1. The coke oven 1 comprises a carbonization chamber 2 for carbonizing coal and a combustion chamber (not shown) for burning fuel gas, with the carbonization chambers 2 and combustion chambers arranged alternately. The direction in which the carbonization chambers 2 and combustion chambers are arranged is the furnace direction.

The heat generated by the combustion of fuel gas in the combustion chamber is transferred to the carbonization chamber 2 via a furnace wall (not shown) between the combustion chamber and the carbonization chamber 2, causing the coal in the carbonization chamber 2 to undergo carbonization. The furnace wall is primarily made of refractory material and is tightened with a preset clamping force in the furnace length direction (left-right direction in Figure 1) of the coke oven 1. Specifically, at one end of the furnace wall on the extruder 4 side, a furnace clamping spring (not shown) is provided, and the furnace wall is tightened by this spring. In this embodiment, a monitoring device 3, which manages the aforementioned clamping force by monitoring the length of the furnace clamping spring, is provided above the extruder 4 that pushes coke out of the carbonization chamber 2. The monitoring device 3 will be described later.

The coke oven 1 is configured to allow the charging car 5 to travel above it. The charging car 5 is responsible for charging the carbonization chamber 2 with coal. It receives coal stored in a coal tower (not shown), transports it to the coke oven 1, and charges the carbonization chamber 2 with it.

A heat storage chamber 6 is provided below the carbonization chamber 2 and the combustion chamber. This chamber stores heat from the combustion exhaust gas and uses that stored heat to preheat the fuel gas or air supplied to the combustion chamber.

Rails 7 extending in the furnace direction are installed on both sides of the coke oven 1 in the furnace length direction. In Figure 1, an extruder 4 is installed so as to be movable along the rail 7 on the right side of the coke oven 1. The extruder 4 is a device that stops at a predetermined position in each carbonization chamber 2 to discharge coke from the carbonization chamber 2. The extruder 4 is equipped with an extrusion ram 8 that moves back and forth in the furnace length direction, and the extrusion ram 8 pushes the coke out of the carbonization chamber 2 on the opposite side of the coke oven 1 from the extruder 4 in the furnace length direction.

In Figure 1, a guide vehicle 9 is provided, movable along the rail 7 on the left side of the coke oven 1. The guide vehicle 9 travels along the rail 7 in conjunction with the extruder 4, receiving the coke extruded from the carbonization chamber 2 by the extruder 4 and guiding it to the fire extinguishing vehicle 10. The fire extinguishing vehicle 10 is configured to transport the coke extruded from the carbonization chamber 2 to a fire extinguishing tower (not shown) or a CDQ (Cokes Dry Quenching System) (not shown).

Figure 2 is a perspective view showing an example of a furnace wall 11, and Figure 3 is a view taken along arrow A in Figure 2. The furnace wall 11 shown in Figures 2 and 3 is primarily formed of refractory materials such as refractory bricks, and backstays 12 are positioned on both sides of the furnace wall 11 in the furnace length direction. The backstays 12, together with the upper cross tie rod 13 and lower cross tie rod 17 described below, restrain the furnace wall 11 and extend in the furnace height direction of the coke oven 1.

An upper cross tie rod 13 is provided on the upper side of the furnace wall 11. In the example shown in Figure 2, upper cross tie rods 13 are provided on both sides of the furnace wall 11 in the furnace direction. An upper cross tie rod spring (hereinafter simply referred to as the upper spring) 14, corresponding to the furnace clamping spring in this embodiment, is attached to one side of the upper cross tie rod 13, specifically to one end on the extruder 4 side in the furnace length direction. A pair of upper spring support portions 15 and 16 are provided on each side of the upper spring 14 so as to be movable along the upper cross tie rod 13. The other end of the upper cross tie rod 13 is fixed to the backstay 12 by a fixing means (not shown).

A nut (not shown) is attached to the coke oven 1 outside the upper spring support portions 15 and 16 of the upper cross tie rod 13 in the furnace length direction, preventing the upper spring support portions 15 and 16 from moving beyond the nut. Specifically, one of the upper spring support portions 15 and 16 is in contact with the nut, while the other upper spring support portion 16 is pressed against the backstay 12 by the elastic force of the upper spring 14. The upper spring 14 is positioned in a compressed state between the upper spring support portions 15 and 16, and the elastic force of the upper spring 14 constantly acts as a furnace clamping force on the furnace wall 11 via the backstay 12. The furnace clamping force is indicated by a black arrow in Figure 3.

A lower cross tie rod 17 is provided on the lower side of the furnace wall 11. In the example shown in Figure 2, lower cross tie rods 17 are provided on both sides of the furnace wall 11 in the furnace direction. A lower cross tie rod spring (hereinafter simply referred to as the lower spring) 18 is attached to one side of the lower cross tie rod 17, specifically to one end on the extruder 4 side in the furnace length direction. A pair of lower spring supports 19 and 20 are provided on each side of the lower spring 18 so as to be movable along the lower cross tie rod 17.

A nut (not shown) is attached to the coke oven 1 outside the lower spring support portions 19 and 20 of the lower cross tie rod 17 in the furnace length direction, preventing the lower spring support portions 19 and 20 from moving beyond the nut. Specifically, one of the lower spring support portions 19 and 20 contacts the nut, while the other lower spring support portion 20 is pressed against the backstay 12 by the elastic force of the lower spring 18. The lower spring 18 is positioned in a compressed state between the lower spring support portions 19 and 20, and the elastic force of the lower spring 18 constantly acts as a furnace clamping force on the furnace wall 11 via the backstay 12.

As shown in Figures 2 and 3, protective plates 21 are provided between the furnace wall 11 and the backstay 12 in the furnace length direction, covering both sides of the furnace wall 11 in that direction. As shown in Figure 3, inner springs 22 are arranged in a compressed state at regular intervals in the furnace height direction between the backstay 12 and the protective plates 21 in the furnace length direction. In addition to the upper spring 14 and lower spring 18, the elastic force of the inner springs 22 constantly acts as a furnace clamping force on the furnace wall 11 via the backstay 12.

Figure 4 is an enlarged view of a portion of the furnace wall 11. As shown in Figure 4, nuts 23 are attached to the outside of the coke oven 1 beyond the upper spring support portions 15 and 16 on the upper cross tie rod 13 in the furnace length direction. The nuts 23 prevent the upper spring support portions 15 from moving outwards from the coke oven 1 in the furnace length direction. A reaction force receiving portion 24 is provided on the upper cross tie rod 13, further outwards from the coke oven 1 in the furnace length direction than the nuts 23. Another nut 25 is provided further outwards from the coke oven 1 in the furnace length direction than the reaction force receiving portion 24. The other nut 25 prevents the reaction force receiving portion 24 from moving outwards from the coke oven 1 in the furnace length direction.

The reaction force receiving section 24 is used to adjust the length of the upper spring 14, i.e., the furnace clamping force. To briefly explain the method of adjusting the furnace clamping force, a hydraulic jack is placed between the reaction force receiving section 24 and one of the pair of upper spring receiving sections 15 and 16, specifically the upper spring receiving section 15 on the outside of the coke oven 1 in the furnace length direction. The upper spring 14 is compressed by the hydraulic jack, and the furnace clamping force by the upper spring 14 is adjusted by changing the position of the nut 23 on the upper cross tie rod 13 in this state. Note that a reaction force receiving section is configured at one end of the lower cross tie rod 17 in much the same way as at one end of the upper cross tie rod 13, so its description is omitted.

The monitoring device 3 will now be described. The monitoring device 3 manages the furnace clamping force by measuring the distance between one upper spring support 15 and the other upper spring support 16, i.e., the length of the upper spring 14. Figure 5 shows an example of the configuration of the monitoring device 3. As shown in Figure 5, the monitoring device 3 is equipped with a camera 26, which corresponds to the imaging device in this embodiment. The camera 26 is designed to photograph both the pair of upper spring support 15 and 16 located on both sides of the upper spring 14 together. The monitoring device 3 measures the distance between the upper spring support 15 and 16 based on the image data captured by the camera 26. Therefore, the imaging conditions by the monitoring device 3 are approximately constant for each of the numerous pairs of upper spring support 15 and 16 installed in the coke oven 1. Here, "photographing both the pair of upper spring support 15 and 16 together" means that both the pair of upper spring support 15 and 16 are within the field of view of the camera 26, or within the range of imaging by the camera 26, and are photographed in that state.

The reason for measuring the length of the upper spring 14 to manage the furnace clamping force is explained below. The upper spring 14 transmits various forces, such as the vertical load of the coke oven equipment and the brick expansion force, compared to the lower spring 18. These forces cause the upper spring 14 to repeatedly expand and contract, which can lead to loosening of the nut 23 and a change in the length of the upper spring 14. The brick expansion force refers to the force exerted by a brick on other bricks or other components when the brick expands due to heat transmitted from the combustion chamber.

Figure 6 illustrates the imaging conditions of the pair of upper spring support sections 15 and 16 by the monitoring device 3. As shown in Figure 6, when the extruder 4 moves to a predetermined position and stops, the distance D1 between the camera 26 and the backstay 12 in the horizontal direction remains approximately constant. Furthermore, the distance D2 between the camera 26 and the middle section of the upper spring 14 in the horizontal direction, and the distance D3 between the camera 26 and the upper spring support sections 15 and 16 in the furnace height direction, remain approximately constant. Additionally, the field of view of the camera 26 and the imaging angle θ of the camera 26 relative to the horizontal plane remain approximately constant.

Returning to the explanation of Figure 5, as shown in Figure 5, the image data captured by the camera 26 is output to the analysis device 27, which calculates the distance between the upper spring support parts 15 and 16. The analysis device 27 is primarily composed of a microcomputer and performs calculations using the input data, pre-stored data, and calculation formulas. It is configured to output the calculation result, i.e., the distance between the upper spring support parts 15 and 16, to the output unit 28.

The input data is, for example, image data captured by the camera 26 described above. The data stored in advance is, for example, the shooting conditions described above. Furthermore, the upper and lower limits of the distance between the upper spring support parts 15 and 16 are determined in advance, and these values are stored in the analysis device 27 as thresholds. In addition, image data for when the distance between the upper spring support parts 15 and 16 is at the upper limit, and image data for when it is at the lower limit, are captured in advance under the shooting conditions described above, and these image data are stored in the analysis device 27 in advance.

The output unit 28 may be, for example, a monitor that displays to the operator the distance between the upper spring support parts 15 and 16 calculated by the analysis device 27. Alternatively, the output unit 28 may include warning means that notify the surroundings with sound, vibration, or light, or issue a warning, if the distance between the upper spring support parts 15 and 16 calculated by the analysis device 27 is above an upper limit or below a lower limit. The camera 26 may also be equipped with an illumination device to light the object being photographed, and may also be equipped with an adjustment device to adjust the height and shooting angle of the camera 26 during shooting. These illumination and adjustment devices may be configured in substantially the same manner as conventionally known illumination and adjustment devices.

Next, the operation and effects of the monitoring device 3 for the coke oven 1 according to this embodiment will be explained. When the carbonization of coal in the coke oven 1 is complete, the extruder 4 moves to a predetermined position adjacent to the carbonization chamber 2 in order to push out the coke from the carbonization chamber 2 and stops. Figure 7 shows this state. As shown in Figure 7, the monitoring device 3 is installed on top of the extruder 4, and the shooting angle θ and height of the camera 26 of the monitoring device 3 are preset. In other words, the field of view of the camera 26 is approximately constant, as described above, and the pair of upper spring support parts 15 and 16, which are the objects of photography, are included in that field of view. Therefore, each time the extruder 4 stops at a predetermined position in order to push out the coke from each carbonization chamber 2, the pair of upper spring support parts 15 and 16, which are the objects of photography, are included in the field of view of the camera 26.

When the extruder 4 stops at a preset position, or when the operator instructs the camera 26 to take a picture while the extruder 4 is stopped at a preset position, these trigger the camera 26 to take a picture. The image data at this point is output from the camera 26 to the analysis device 27.

The analysis device 27 calculates the distance between the upper spring support parts 15 and 16 based on the image data captured by the camera 26 at the present time. Specifically, since the upper spring support parts 15 and 16 are captured together in the aforementioned image data, image processing is performed to detect the edges of each upper spring support part 15 and 16. The image processing for detecting edges may be a conventionally known method. Figure 8 shows an example of the image processing. The "+" symbols in Figure 8 indicate the edges of each upper spring support part 15 and 16 detected by the image processing.

Based on the coordinates of each detected edge, an approximate straight line is calculated for each edge. The method for calculating the approximate straight line may be any conventionally known method. The calculated approximate straight lines are shown in Figure 8. The symbol "L1o" in Figure 8 represents the approximate straight line of the outer edge of one upper spring support portion 15 in the furnace length direction, and the symbol "L2o" in Figure 8 represents the approximate straight line of the inner edge of one upper spring support portion 15 in the furnace length direction. The symbol "L1i" in Figure 8 represents the approximate straight line of the outer edge of the other upper spring support portion 16 in the furnace length direction, and the symbol "L2i" in Figure 8 represents the approximate straight line of the inner edge of the other upper spring support portion 15 in the furnace length direction.

Next, calculate the line L3 that passes through the approximate lines L1o and L2o of each edge of one upper spring support portion 15 and intersects them perpendicularly. Also, calculate the intersection points of each approximate line L1o and L2o with line L3. These intersection points are indicated by the symbol "○" in Figure 8. Then, calculate the number of pixels between these intersection points. Furthermore, the plate thickness of one upper spring support portion 15 is fixed by design. Therefore, the length per pixel is calculated by dividing the plate thickness of one upper spring support portion 15 by the aforementioned number of pixels. Perform a similar calculation for the other upper spring support portion 16 to calculate the length per pixel in the other upper spring support portion 16.

Then, based on the length per pixel in one upper spring support portion 15 and the length per pixel in the other upper spring support portion 16, the length per pixel between each spring support portion 15 and 16, i.e., the amount of change, is calculated. Based on this amount of change, the number of pixels between each spring support portion 15 and 16, and the length between each upper spring support portion 15 and 16 are calculated.

Alternatively, the current image data and image data where the distance between the upper spring supports 15 and 16 is at the upper and lower limits can be compared to calculate the current distance between the upper spring supports 15 and 16. For example, image processing can be performed on the image data where the distance between the upper spring supports 15 and 16 is at the upper and lower limits to detect each upper spring support 15 and 16 on the image data, and the lengths of each upper spring support 15 and 16 on the image data can be measured. The image processing may be the edge detection image processing described above. On the other hand, since the upper and lower limits are determined by the design, these values can be applied to the image data.

Furthermore, the same image processing as described above is performed on the current image data captured by camera 26 to detect each upper spring support portion 15, 16 on the image data, and the length of each upper spring support portion 15, 16 on the image data is measured. In other words, the upper and lower limits of each upper spring support portion 15, 16 are predetermined. Also, the length on the image data when the length between two upper spring support portions 15, 16 is at the upper or lower limit, and the length between two upper spring support portions 15, 16 on the current image data can be calculated. Therefore, by applying these values to a proportional equation, the current length between each upper spring support portion 15, 16 is determined.

The current distance between the upper spring support sections 15 and 16, calculated by the analysis device 27, is output from the analysis device 27 to the output unit 28 and displayed.

If the current distance between the upper spring support sections 15 and 16, as calculated by the analysis device 27, is above the upper limit or below the lower limit, a warning is issued by a warning means (not shown). When a warning is issued, for example, a hydraulic jack is placed between one of the upper spring support sections 15 and the reaction force support section 24. The upper spring 14 is then compressed by the hydraulic jack, and in this state, the position of the nut 23 on the upper cross tie rod 13 is adjusted. In this way, the length of the upper spring 14, and thus the clamping force, is adjusted.

As described above, the coke oven 1 monitoring device 3 according to this embodiment measures the distance between the upper spring support parts 15 and 16 based on image data captured by the camera 26. Therefore, no work is required on the coke oven 1. Furthermore, even if the environment surrounding the coke oven 1 is high temperature and dusty, the coke oven 1 monitoring device 3 according to this embodiment has virtually no parts that operate in such an environment. Therefore, it can be made into a device that is less prone to malfunctions and failures. As a result, the overall maintainability of the device is improved. Also, because the distance between the upper spring support parts 15 and 16 is measured automatically, the measurement accuracy can be improved to an unprecedented degree, and the device can be made safer. Furthermore, because measurement is performed using an image sensor, manual measurement work can be minimized, reducing labor costs.

Furthermore, the present invention is not limited to the embodiments described above. For example, the imaging device of the monitoring device 3 only needs to be able to acquire image data, and a 3D laser scanner may be used instead of the camera 26 described above. Also, in this embodiment, furnace clamping management was performed by imaging the upper spring support sections 15 and 16 on the inlet side of the carbonization chamber 2, but the spring support sections to be imaging may also be the upper spring support sections 15 and 16 on the outlet side of the carbonization chamber 2. Alternatively, the lower spring support sections 19 and 20 on the inlet or outlet side of the carbonization chamber 2 may also be used. This is because the length of the upper spring 14 and lower spring 18 changes due to changes in the furnace clamping force.

1 Coke oven 1
2 Carbonization Chamber 2
3 Monitoring device 4 Extruder 5 Charging car 6 Heat storage chamber 7 Rail 8 Extrusion ram 9 Guide car 10 Fire extinguishing car 11 Furnace wall 12 Backstay 13 Upper cross tie rod 14 Upper cross tie rod spring 15, 16 Upper spring support 17 Lower cross tie rod 18 Lower cross tie rod spring 19, 20 Lower spring support 21 Protective plate 22 Inner spring 23 Nut 24 Reaction force support 25 Other nuts 26 Camera 27 Analysis device 28 Output unit D1 Distance between camera and backstay in the horizontal direction D2 Distance between camera and the middle of upper spring in the horizontal direction D3 Distance between camera and spring support in the furnace height direction

Claims (5)

A coke oven monitoring device comprising: a furnace wall extending in the furnace length direction of the coke oven; backstays positioned on both sides of the furnace wall in the furnace length direction; an upper cross tie rod installed on the upper part of the furnace wall and extending in the furnace length direction; an upper cross tie rod spring attached to the end of the upper cross tie rod on the extruder side of the coke oven in the furnace length direction; and spring receiving portions provided on each side of the upper cross tie rod spring, wherein one of the spring receiving portions on the outside of the coke oven, sandwiching the upper cross tie rod spring in the furnace length direction, is prevented from moving outward, and the other spring receiving portion on the inside of the coke oven, sandwiching the upper cross tie rod spring in the furnace length direction, is pressed against the backstay by the elastic force of the upper cross tie rod spring,
A photographing device that photographs one spring support portion and the other spring support portion together,
The system includes an analysis device that measures the distance between one spring support and the other spring support based on image data captured by the aforementioned imaging device,
The aforementioned photographic device is provided on the extruder, and
The aforementioned photographic device, in order to push coke out of the carbonization chamber of the coke oven, photographs the one spring support and the other spring support together each time the extruder stops at a predetermined position adjacent to the carbonization chamber.
The coke oven further comprises a protective plate provided between the furnace wall and the backstay in the furnace length direction, and a plurality of inner springs arranged at regular intervals in the furnace height direction between the protective plate and the backstay in the furnace length direction,
The analysis device is a coke oven monitoring device that calculates the current length of the upper cross tie rod spring by applying a proportional equation to the length of the upper cross tie rod spring calculated based on image data when the distance between one spring support and the other spring support is at an upper or lower limit, and the length of the upper cross tie rod spring calculated based on the current image data. The coke oven monitoring device according to claim 1, further comprising an illumination device that illuminates both the one spring support portion and the other spring support portion together. The coke oven monitoring device according to claim 1, wherein the field of view of the aforementioned imaging device is predetermined. The coke oven monitoring device according to claim 1, further comprising an adjustment device for adjusting at least one of the height of the imaging device and the imaging angle of the imaging device with respect to the horizontal plane. A coke oven monitoring device according to any one of claims 1 to 4, further comprising a warning means for issuing a warning when the distance is greater than or equal to a preset upper limit, or when the distance is less than or equal to a preset lower limit.