JP7372548B2 - Coke oven furnace body tightening method and furnace clamping force transmission device - Google Patents

Description

The present invention relates to a coke oven furnace body tightening method and an oven clamping force transmission device.

In a coke oven for producing coke used in a blast furnace, the furnace body is tightened in order to stably use the coke oven for a long period of time. This furnace body tightening must maintain the brickwork structure of the furnace body and exhibit a stable effect against the expansion of the furnace body over time, and the distribution of the furnace tightening force must be uniform in the height direction. That is required.

For example, Patent Document 1 listed below describes a technique for pressurizing a combustion chamber with a constant furnace clamping force regardless of the deformation of the backstay. However, the equipment cost is higher when compared to furnace clamps. The number of carbonization chambers and combustion chambers per coke oven is usually 40 to 50, and even if six furnace clamping devices are placed in each backstay at both ends of the combustion chamber, the number will be 480 to 600, which is a large amount of money. equipment investment is required.

In addition, since they are used in an environment where high-temperature coke is discharged or a high-temperature carbonization chamber is opened during operation, there is a possibility that hydraulic fluid, which is often used as a pressurizing medium, may leak.

Further, Patent Document 2 listed below discloses a technique for tightening the furnace body by utilizing heat transfer from a coke oven without using furnace clamping parts. In other words, by covering the part of the backstay that comes into contact with the protection plate with a heat insulating material, thermal distortion is generated due to the temperature difference between the part covered with the heat insulating material and the part on the opposite side of the backstay, which faces the combustion chamber of the coke oven. This prevents the intermediate portion in the height direction from curving away from the combustion chamber.

However, since the method disclosed in Patent Document 2 utilizes thermal strain, the front and back sides of the backstay are affected by changes in carbonization temperature due to changes in coke oven operating rate, seasonal changes in summer and winter, cooling during rainy weather, etc. If the temperature difference between the two parts changes, the amount of deformation of the backstay will also change, making it difficult to maintain a constant furnace clamping force to the combustion chamber of the coke oven.

In addition, general heat insulating materials maintain a large number of pores inside to ensure their heat insulating function. If dust from coke manufacturing or tar from coke oven gas enters these pores, the insulation performance will gradually decrease, and thermal conductivity will gradually increase, causing the backstay to deform and move away from the combustion chamber. This results in a situation where excessive furnace clamping force is applied to the middle part of the combustion chamber in the height direction. If this happens, it may lead to damage to the combustion chamber bricks.

Furthermore, the method disclosed in Patent Document 3 is to provide an auxiliary furnace tightening device dedicated to the fixed end of the combustion chamber wall near the bottom of the coking chamber of the coke oven, which has a greater tightening effect than the furnace body tightening using only the backstay. Although this can be expected, when hydraulic pressure is used, there is a problem of fluid leakage as in Patent Document 2.

In addition, the method disclosed in Patent Document 4 is to install springs and metal fittings in multiple stages in the height direction of the part of the backstay facing the combustion chamber, two each in the direction of the furnace furnace, between the furnace clamp and the door frame. A furnace clamping force transmission device consisting of the following is provided. In the method disclosed in Patent Document 4, since the structure of the furnace clamping transmission device is complicated, there arise problems such as a decrease in maintainability and an increase in manufacturing cost.

Publication No. 55-116051 Japanese Patent Application Publication No. 3-287692 Japanese Patent Application Publication No. 2004-137336 Patent No. 6421572

As explained above, the method disclosed in Patent Document 1 not only requires a large capital investment, but also raises the possibility of hydraulic fluid leakage, resulting in management costs. Further, since the methods disclosed in Patent Documents 2 and 3 utilize thermal strain, it is difficult to maintain a constant furnace clamping force to the combustion chamber. Further, the method disclosed in Patent Document 4 has a complicated structure, which may result in cost or maintenance burden.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a novel and excellent method for stably tightening the furnace body of a coke oven with a relatively simple configuration. It is an object of the present invention to provide a method for tightening a furnace body and a device for transmitting a furnace tightening force.

In order to solve the above-mentioned problems, according to one aspect of the present invention, the combustion chamber is disposed outside the oven at both ends in the oven length direction of at least one combustion chamber of a coke oven, and at the upper and lower ends in the height direction of the coke oven. A furnace clamping force transmission device is installed along the height direction between the backstay connected by the installed cross tie rods and the door frame or protection plate located at both ends of the combustion chamber in the furnace length direction. and transmitting the furnace clamping force obtained by furnace clamping springs provided at both ends of the cross tie rod to the door frame or the protection plate via the furnace clamping force transmission mechanism. There is provided a method for tightening a coke oven furnace body, wherein the furnace clamping force transmission device includes a distance piece and a disc spring.

The thickness of the distance piece is determined based on the deflection distribution of the backstay calculated using a beam model in which the furnace clamping force transmitted to the combustion chamber is distributed evenly in the height direction of the combustion chamber. May be requested.

The spring constant of the disc spring may be set according to the position in the height direction where the furnace clamping force transmission device is provided.

The spring constant of the disc spring may be set to have a normal distribution with respect to the position in the height direction where the furnace clamping force transmission device is provided.

In order to solve the above-mentioned problems, according to another aspect of the present invention, the combustion chamber is arranged outside the oven at both ends in the oven length direction of at least one combustion chamber of the coke oven, and is arranged at the upper and lower ends of the coke oven in the height direction. A furnace clamping force transmission device installed along the height direction between the backstay connected by cross tie rods installed in the combustion chamber and the door frame or protection plate located at both ends of the combustion chamber in the furnace length direction. The furnace clamping force transmission device includes a distance piece and a disc spring, and transmits the furnace clamping force obtained by the furnace clamping springs provided at both ends of the cross tie rod through the distance piece and the disc spring. , there is provided a furnace clamping force transmission device characterized in that the furnace clamping force is transmitted to the door frame or the protection plate.

As described above, according to the present invention, there is provided a new and excellent furnace body tightening method and furnace clamping force transmission device that can stably tighten the furnace body of a coke oven with a relatively simple configuration. Ru.

1 is a cross-sectional view showing an example of a schematic configuration of a furnace clamping force transmission device according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing an example of a schematic configuration of the furnace clamping force transmission device according to the same embodiment. FIG. 3 is a diagram showing a model for verifying changes in the shape of the furnace body of a coke oven. 3 is a graph showing the results of calculating changes in the distribution of the furnace body linear load over time, the displacement ratio of the protection plate attached to the furnace body, and the displacement ratio of the backstay using a distance piece model. It is a graph showing the distribution of the initial gap set, the change over time in the gap between the distance piece and the backstay set at the initial gap, and the change over time in the reaction force ratio generated in the distance piece. FIG. 3 is a diagram used to explain the setting of the thickness of the distance piece. FIG. 3 is a diagram used to explain the setting of the thickness of the distance piece. It is a figure provided for the purpose of explanation about the setting of the board thickness of the distance piece of a furnace clamping force transmission device, and the spring height of a disc spring. 1 is a flowchart showing a method for tightening a coke oven furnace body according to the present embodiment. It is a sectional view showing an example of a schematic structure of a furnace clamping force transmission device concerning one modification of a 1st embodiment of the present invention. It is a sectional view showing an example of a schematic structure of a furnace clamping force transmission device concerning another modification of a 1st embodiment of the present invention. FIG. 3 is a sectional view of a furnace clamping force transmission device according to a second embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of a schematic configuration of a furnace clamping force transmission device as a comparative example. FIG. 3 is a diagram showing initial gaps set in the furnace clamping force transmission device at each stage as an example. It is a figure which shows the spring constant of the disc spring set in the furnace clamping force transmission device based on this invention as an Example. As an example, this is the pressure ratio distribution in the furnace in the furnace height direction obtained by simulation analysis. FIG. 2 is a cross-sectional view showing an example of a schematic configuration of a furnace clamping force transmission device as a comparative example. As an example, it is a graph showing the standard deviation ratio of the furnace body pressure ratio distribution. FIG. 1 is an external perspective view showing the structure of a coke oven. FIG. 2 is a cross-sectional view of the coke oven in the oven length direction. FIG. 2 is a diagram schematically showing how the furnace clamping force is transmitted to the furnace body of the coke oven.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals and redundant explanation will be omitted.

(Coke oven configuration)
First, a schematic configuration of the furnace body clamping structure of the coke oven 1 will be described with reference to FIGS. 13 and 19 to 21. FIG. 19 is a perspective view showing a part of the external appearance of the coke oven 1, and FIG. 20 is a sectional view of the coke oven 1 in the oven length direction.

As shown in FIG. 19, a coke oven 1 is a structure constructed of bricks, and a heat storage chamber 2 is provided at the bottom of the furnace body to preheat fuel gas and combustion air using sensible heat of combustion exhaust gas. Combustion chambers 4 for burning fuel gas and carbonization chambers 3 for carbonizing coal are arranged alternately above the heat storage chamber 2.

The front-rear direction perpendicular to the plane of the paper in FIG. 20 in which the combustion chamber 4 and the carbonization chamber 3 are layered is called the furnace furnace direction, and the left-right direction in the plane of FIG. 20 is called the furnace length direction.

The combustion chamber 4 is divided into about 25 to 30 flues in the furnace length direction, and these flues are also constructed of brick structures. In FIG. 20, a part of the combustion chamber 4 (for 5 flues) is shown in the same cross section as the carbonization chamber 3 for the sake of explanation. Combustion heat generated when fuel gas is combusted in the combustion chamber 4 is transmitted to the carbonization chamber 3 through the furnace wall of the combustion chamber 4, and carbonizes the coal charged inside the carbonization chamber 3.

The coke oven 1, which is a brick structure made of bricks as described above, has a structure in which the oven body is tightened from the outside in order to hold the brick structure. The clamping force of the furnace body in the coke oven 1 may be hereinafter simply referred to as "furnace clamping force" or "furnace clamping force".

As shown in FIG. 19, a pair of backstays 5 for applying furnace clamping force are arranged at both ends of each combustion chamber 4 in the furnace length direction of the brick structure in which the combustion chamber 4 and the carbonization chamber 3 are constructed. ing. The backstay 5 is a long columnar member, and is arranged so that its longitudinal direction runs along the furnace height direction. A door frame 6 that holds a furnace lid (not shown) and a protection plate 7 that attaches the door frame 6 are provided between the backstay 5 and the combustion chamber 4, and the furnace clamping force from the backstay 5 is applied to the door It is transmitted to the combustion chamber 4 and carbonization chamber 3, which are brick structures, via the frame 6 or the protection plate 7.

Here, there are various methods for transmitting the furnace clamping force, and one example is a method of transmitting the furnace clamping force to the furnace body using furnace clamps. FIG. 21 is a diagram schematically showing how the furnace clamping force is transmitted to the furnace body. Backstays 5 arranged at both ends of each combustion chamber 4 in the oven length direction are connected by cross tie rods 10 at two locations at the top and bottom ends of the coke oven 1 in the height direction, and are attached to both ends of the cross tie rods 10. The furnace clamping force is applied by the furnace clamping spring 11. This furnace clamping force is applied to the combustion chamber of the brick structure through the door frame 6 and protection plate 7 by furnace clamps 12 installed in multiple stages in the height direction in the part of the backstay 5 facing the combustion chamber 4. It is transmitted to the chamber 4 and the carbonization chamber 3.

Furnace clamps 12 installed in multiple stages are, for example, as shown in FIG. The furnace clamping force is transmitted through this steel piece.

Further, as shown in FIG. 17 as another example of the furnace clamp 12, the furnace clamp 12 may be attached with a predetermined load using a built-in coil spring. In this case, generally, the furnace clamps 12 are installed in multiple stages in the height direction of the combustion chamber 4 for one backstay 5, and a plurality of furnace clamps 12 are installed on each side, two on the left and right sides in the direction of the furnace cluster.

By the way, the backstay 5 that transmits the furnace clamping force of the cross tie rod 10 is longer than the height of the part facing the combustion chamber 4, and the intermediate part in the height direction is curved away from the combustion chamber 4. It cannot be avoided. In particular, once the coke oven 1 starts operating, it will operate for a long period of 30 to 50 years, during which time it will continue to produce coke by carbonizing coal at high temperatures, and the above-mentioned curved state will continue.

In this situation, the distance between the backstay 5 and the door frame 6 increases, creating a gap in the distance piece part of the furnace clamp 12, and the furnace clamping force of each furnace clamp 12 decreases. descend.

When the individual furnace clamping force of the furnace clamping member 12 located at the middle part in the height direction of the part facing the combustion chamber 4 decreases, the furnace clamping force provided in the height direction in the part of the backstay 5 facing the combustion chamber 4 decreases. The furnace clamping force distribution of the clamping material 12 becomes uneven. This unevenness in the furnace clamping force impairs the robustness of the combustion chamber 4 constructed of bricks, leading to a shortened lifespan of the coke oven 1.

In addition, if the furnace clamping force of one of the furnace clamps 12 placed on the left and right sides of the combustion chamber 4 in the direction of the furnace group decreases due to the above reasons, it is possible to apply the furnace clamping force only with the other furnace clamp 12. As a result, uneven furnace clamping force acts on the brick structure of the combustion chamber 4. This uneven furnace clamping force may cause deformation of the brick structure.

Further, as described above, the door frame 6 is a member that holds the furnace lid installed in the carbonization chamber 3, and its end protrudes toward the combustion chamber 4 side. It has a structure in which the door frame 6 is directly pressed. Therefore, the furnace clamp 12 is disposed close to the coke chamber 3 in the direction of the furnace group, and when discharging high-temperature coke from the coke chamber 3, the temperature of the furnace clamp 12 is increased. The built-in coil spring may become hot and deteriorate due to heat.

<First embodiment>
Further, the inventors of the present invention further conducted extensive studies and obtained the following knowledge. That is, first, the distribution in the height direction of the distance between the backstay 5 and the door frame 6 or between the protective plates 7 is determined by the distribution of the distance in the height direction between the backstay 5 and the door frame 6 or between the protective plates 7, even if the distribution in the height direction of the expansion of the bricks of the coke oven 1 over time is constant. The finding is that it does not change over time. Furthermore, secondly, when the amount of deformation of the backstay due to the required furnace clamping force, which is a prerequisite for its expansion over time, is determined and made to match the initial gap between the backstay 5 and the door frame 6 or between the protective plates 7. It is the knowledge that the most stable furnace clamping force transmission can be obtained. However, since the distance piece has a simple contact structure, there is a possibility that the transmission of the furnace clamping force will become unstable if there is a disturbance to the furnace clamping force transmission mechanism such as slight operational fluctuations or thermal deformation of the protection plate 7. be. In this way, in order to operate the coke oven 1 stably, the causes of changes in the furnace clamping force should be appropriately evaluated, and changes in the distance between the oven body 1A and the backstay 5 based on complex factors should be adjusted. It is necessary to respond.

(Configuration of furnace clamping force transmission device)
Therefore, the present inventors developed an oven clamping force transmission device 100, which is characterized by a configuration consisting of a combination of a distance piece 110 and a disc spring 120, to transmit the oven clamping force of the coke oven 1 from the backstay 5 to the protection plate 7. We came up with the idea of transmitting the information through the . Hereinafter, the configuration of a furnace clamping force transmission device 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the following description, parts common to those in FIGS. 19 to 21 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the coke oven 1 according to the present embodiment, in order to apply the furnace clamping force, the furnace clamping force transmission device 100 is attached to the part of the backstay 5 facing the combustion chamber 4, as in the embodiment shown in FIG. Installed in multiple stages in the height direction. As an example, the furnace clamping force transmission device 100 is installed in 13 stages in a portion of the backstay 5 facing the combustion chamber 4. Further, as shown in FIG. 1, two furnace clamping force transmission devices 100 are provided in parallel in the furnace group direction at each stage of the portion of the backstay 5 facing the combustion chamber 4. The furnace clamping force is transmitted to the furnace body 1A of the coke oven 1 by the furnace clamping force transmission device 100.

As shown in FIG. 1, the backstay 5 is, for example, an H-shaped steel. In this case, the flange 5A of the H-shaped steel serving as the backstay 5 is installed in the direction of the furnace furnace, and the web 5B is installed in the direction along the furnace length direction. In this case, the flange 5A of the backstay 5 becomes a portion facing the combustion chamber 4. As shown in FIG. 1, the furnace clamping force transmission device 100 is provided between the flange 5A and the combustion chamber 4.

FIG. 2 is an enlarged cross-sectional view of the furnace clamping force transmission device 100. In FIG. 2, the vertical direction of the page is the furnace length direction, the top side of the page is the inside of the furnace, and the bottom side of the page is the outside of the furnace. As shown in FIG. 2, the furnace clamping force transmission device 100 includes a distance piece 110 and a disc spring 120. The distance piece 110 is provided on the combustion chamber 4 side at a position facing the disc spring 120. Further, the disc spring 120 is provided on the backstay 5 side at a position facing the distance piece 110. That is, the furnace clamping force transmission device 100 includes a distance piece 110 and a disc spring 120 that face each other, and when the two come into contact with each other, the furnace clamping force is transmitted from the backstay 5 to the combustion chamber 4. As shown in FIG. 2, as an example, two furnace clamping force transmission devices 100 are provided side by side in the direction of the furnace group. This makes it possible to equally transmit the furnace clamping force transmitted by the furnace clamping force transmission device 100 to the internal structures of the combustion chamber 4 on the left and right sides. That is, the furnace clamping force can be transmitted to the structure constituting the combustion chamber 4 shown in FIG. 1 evenly on both sides in the left-right direction in the plane of FIG.

Specifically, the distance piece 110 is attached to the protection plate 7 on the combustion chamber 4 side. The distance pieces 110 can be attached to the protection plate 7 at equal intervals in the furnace height direction. The distance piece 110 is a flat plate member. The distance piece 110 is attached to the protection plate 7 so that the thickness direction thereof faces the disc spring 120. In other words, as shown in FIG. 2, the distance piece 110 is attached to the protection plate 7 so that the contact surface 111 faces the disc spring 120. Generally, the temperature of the protection plate 7 is higher than that of the backstay 5, and there may be a difference in thermal deformation in the height direction, but in this case, the height of the distance piece 110 may be provided with an allowance. Further, although the details will be described later, by setting the plate thickness of the distance piece 110 to a predetermined value, a change occurs in the dimension between the furnace body 1A and the backstay 5 between the distance piece 110 and the disc spring 120. A previous gap (hereinafter sometimes referred to as "initial gap") is defined.

The disc spring 120 is attached to the flange 5A of the backstay 5. The shape etc. of the disc spring 120 can be appropriately set according to the furnace clamping force applied to the furnace body 1A of the coke oven 1. Furthermore, although the details will be described later, the spring height of the disc spring 120 is determined to be a predetermined spring height depending on the thickness of the distance piece 110 and the initial gap. The disc spring 120 is a disk-shaped spring member when viewed from above, and its outer peripheral portion 120A is held by a holding portion 121. The holding portion 121 is a portion formed to cover the outer peripheral portion 120A of the disc spring 120 from the outside. When the holding portion 121 engages with the outer peripheral portion 120A of the disc spring 120, the disc spring 120 is attached to the flange 5A of the backstay 5. That is, the disc spring 120 is arranged such that the outer peripheral portion 120A of the disc spring 120 contacts the backstay 5, and the inner peripheral part 120B contacts the distance piece 110.

The materials of the members constituting the furnace clamping force transmission device 100 include, for example, general structural rolled steel (SS material). By using the SS material, sufficient strength is ensured for the furnace clamping force transmission device 100, while reducing costs and improving ease of procurement.

Here, as described above, a change in the furnace clamping force distribution due to the long-term operation of the coke oven 1 is caused by a change in the shape of the furnace body 1A of the coke oven 1 due to thermal expansion. That is, as a result of the shape of the furnace body 1A of the coke oven 1 changing due to thermal expansion, the distance between the backstay 5 and the combustion chamber 4 changes.

In order to further study the above-mentioned shape change, the present inventors modeled the coke oven 1 and the backstay 5 and verified the dimensional change and the load change accompanying it. The knowledge obtained using this model will be explained below with reference to FIGS. 3 to 5. FIG. 3 is a diagram showing a model for verifying changes in the shape of the furnace body 1A of the coke oven 1. As shown in FIG. 3, in this model, in a form in which only the distance piece 110 according to the present embodiment is attached to the coke oven 1 (hereinafter sometimes referred to as a distance piece method), the upper side of the coke oven 1 ( It is assumed that a change in the shape of the furnace body 1A (for example, expansion of the brick structure 20) occurs in the combustion chamber 4 or carbonization chamber 3 side). On the other hand, it is assumed that the influence of changes in the shape of the furnace body 1A on the lower side of the backstay 5 (on the heat storage chamber 2 side) is small.

FIG. 4 shows the calculation of changes in the distribution of the linear load on the furnace body due to aging, the displacement ratio of the protection plate 7 attached to the furnace body 1A, and the displacement ratio of the backstay 5 using the above-mentioned distance piece method model. This is the result. Further, the furnace body line load is a line load generated between the backstay 5 and the protection plate 7. The vertical axis of the graph showing the change in the distribution of the furnace body linear load due to aging, the displacement ratio of the protection plate 7 attached to the furnace body 1A, and the displacement ratio of the backstay 5 in FIG. This corresponds to the position in the furnace height direction in the model shown in . As shown in FIG. 4, the furnace body linear load ratio distribution has hardly changed compared to the initial state even after 5, 10, 20, and 30 years have passed from the initial state. On the other hand, the displacement ratio of the protection plate 7 and the displacement ratio of the backstay 5 gradually change over time. That is, although the protection plate 7 and the back stay 5 have gradually been displaced due to aging, the distribution of the load ratio between the protection plate 7 and the back stay 5 has hardly changed. Based on these facts, it can be seen that the relative values of the displacements of the protection plate 7 and the backstay 5 due to aging are relatively small values.

Based on the results shown in FIG. 4, the initial gap between the distance piece 110 attached to the furnace body 1A and the backstay 5 is set, and the state of secular change between the backstay 5 and the distance piece 110 in this setting. I looked into it. FIG. 5 shows the distribution of the set initial gap, the change over time in the gap between the distance piece 110 and the backstay 5 (DP section gap) set at the initial gap, and the change over time in the reaction force ratio generated in the distance piece 110. FIG. Here, the reaction force ratio refers to the ratio of the reaction force at each height position (level) to the maximum value of the measured reaction force.

As shown in FIG. 5, an initial gap is set according to each height position of the backstay 5 based on the displacement amount of the backstay 5 and the protection plate 7 shown in FIG. As a result, as shown in FIG. 5, the gap between the distance piece 110 and the backstay 5 (DP section gap) is different from the initial gap setting value (0 Year) after 5 years, 10 years, 20 years, and 30 years. Not much has changed since then. In fact, the DP gap after deformation between the backstay 5 and the protection plate 7 due to aging was a very small value (for example, within 0.5 mm). Furthermore, as shown in FIG. 5, if the change in the amount of expansion of the furnace body 1A at each position in the height direction is constant, the position of the distance piece 110 that comes into contact with it will not change, resulting in the amount of expansion of the furnace body 1A. Regardless, the reaction force ratio generated in the distance piece 110 was not affected by aging. That is, it can be seen that the pressure inside the furnace remains constant even after the passage of time.

In this way, if the initial gap between the distance piece 110 and the backstay 5 is set using the above model, optimization of a very small gap (for example, within 0.5 mm) is sufficient for some variations. The present inventors found this. On the other hand, it is difficult to set this small gap in advance due to the uncertainty of aging due to various factors such as operational fluctuations, as described above. Therefore, in the present invention, in order to further cope with aging of the gap between the backstay 5 and the furnace body 1A, it has been conceived to provide a disc spring 120 at a position facing the distance piece 110 in the furnace clamping force transmission device 100. .

The thickness of the distance piece 110, the spring height of the disc spring 120, and the settings of the initial gap between the distance piece 110 and the disc spring 120 will be described below with reference to FIGS. 6 and 7. 6 and 7 are diagrams for explaining the setting of the thickness of the distance piece 110. First, the setting of the plate thickness of the distance piece 110 will be described using a case where the distance piece 110 is only formed as a premise of this embodiment.

As shown in FIG. 6, consider a furnace clamping force transmission device at a certain location A (height h) in the furnace height direction. When the furnace clamping force transmission device is made up of the distance piece 110, the surface position of the backstay (as shown in FIG. 7 B position) in the initial state (that is, before operation of the coke oven 1) is L _h0 , the height of the distance piece 110 at the same height position is H _DPh0 , and the initial gap amount at the same height position G _h0 Then, the following relational expression (1) holds true.
G _h0 =L _h0 -H _DPh0 ...(1)

Here, if the amount of deformation of the backstay 5 during operation of the coke oven 1 at the same height position is Δδ _BSh , the following relational expression (2) holds for the gap G _h between the two during operation.
G _h = G _h0 -Δδ _BSh = L _h0 -H _DPh0 -Δδ _BSh ...(2)

Therefore, in the above equation (2), when the gap G _h =0, it means that the backstay 5 and the distance piece 110 are in contact with each other during the operation of the coke oven 1. In other words, assuming that the backstay 5 and the distance piece 110 come into contact during the operation of the coke oven 1, the height of the distance piece 110 is calculated as follows, assuming that G _h =0 in the above equation (2). It is calculated as shown in equation (3).
H _DPh0 = L _h0 -Δδ _BSh ...(3)

Based on the above equation (3), the amount of deformation Δδ _BSh of the backstay 5 during operation of the coke oven 1 is determined. Specifically, the deflection of the backstay 5 is calculated using a known material mechanics calculation method regarding the deflection of a beam, and the amount of deflection is estimated as the amount of deformation Δδ _BSh of the backstay 5. Note that the cross-sectional shape of the backstay 5 is assumed to be H-shaped because H-shaped steel is generally used as the backstay 5. Further, it is assumed that the load applied to the backstay 5 is a reaction force from the furnace body 1A, and is a uniform load. If the amount of deflection thus derived using the beam model of the backstay 5 is Δδ _BSh , the design height of the distance piece 110 can be determined using the above equation (3).

However, as mentioned above, the oven clamping force changes due to operational fluctuations in the coke oven 1, physical properties, and other various variations and factors. is not necessarily stable, making it difficult to obtain stable furnace clamping force during operation. Therefore, the furnace clamping force transmission device 100 according to the present embodiment is configured to include a distance piece 110 and a disc spring 120. With reference to FIG. 8, the arrangement of the distance piece 110 and the disc spring 120 in the furnace clamping force transmission device 100 according to this embodiment will be described. FIG. 8 is a diagram for explaining the setting of the plate thickness of the distance piece 110 and the spring height of the disc spring 120 of the furnace clamping force transmission device 100.

As shown in FIG. 8, in the furnace clamping force transmission device 100, the surface position of the backstay 5 (point C in FIG. 8) located at the same height as the furnace clamping force transmission point of the protection plate 7 (point C in FIG. 8) B position) is the initial distance (that is, before operation) to L _h0 , the height (plate thickness) of the distance piece 110 at the same height position is H _DPh0 , and the spring height of the disc spring 120 at the same height position is When H _SPh0 , as shown in FIG. 8, the initial gap amount G _h0 at the same height position is expressed by the following equation (4).
G _h0 =L _h0 -H _DPh0 -H _SPh0 ...(4)

Here, if the amount of deformation of the backstay 5 during operation at the same height position is Δδ _BSh , the gap G _h between the two during operation is expressed by the following formula (5): G _h = G _h0 - Δδ _BSh =L _h0 -H _DPh0 -H _SPh0- Δδ _BSh ...(5)

The amount of deformation Δδ _BSh of the backstay 5 is obtained by calculating the amount of deflection, assuming that the backstay 5 is a beam, similarly to the form of only the distance piece 110 that is the object of comparison described above. If the amount of deflection derived in this way is Δδ _BSh , the design height of the distance piece 110 and the spring height of the disc spring 120 can be determined using the above equation (5).

Here, as the design limit value of the disc spring 120, a known design index can be adopted. For example, when the disc spring 120 is used under a static load, or when it is subjected to a repeated load of 5000 times or less within a period of use under a dynamic load, the service limit deflection amount is set to 75% or less of the initial spring height, and the The specifications of the disc spring 120 may be set based on a design index such that the absolute value of the maximum compressive stress does not exceed 2500 MPa.

Further, the spring constant of the disc spring 120 provided in the furnace clamping force transmitting device 100 is set according to the position of the furnace clamping force transmitting device 100 in the height direction. That is, the spring constant of the disc spring 120 is set for each stage of the furnace clamping force transmission device 100. For example, in the furnace height direction, the spring constant of the disc springs 120 of the furnace clamping force transmitting devices 100 of the 1st stage and the 13th stage (top stage) is the same as that of the disc springs 120 of the furnace clamping force transmitting devices 100 of the other stages. It may be set lower than the constant. Specifically, the spring constants of the disc springs 120 of the 1st stage and 13th stage (top stage) furnace clamping force transmission devices 100 are equal to the spring constants of the disc springs 120 of the furnace clamping force transmission devices 100 of the other stages. It can be set to a value of about 1/5 to 1/2.

By setting the spring constant of the disc spring 120 of the furnace clamping force transmission device 100 as described above, the furnace clamping force can be increased at the 1st stage and the 13th stage (top stage) in the furnace height direction where the amount of displacement is small. This allows the furnace clamping force distribution in the furnace height direction to be made nearly uniform.

Further, the spring constant of the disc spring 120 provided in the furnace clamping force transmitting device 100 may be set to have a normal distribution with respect to the position of the furnace clamping force transmitting device 100 in the height direction. Specifically, in the normal distribution of the spring constant, the maximum value of the spring constant is set to a value about five times the minimum value. By setting the spring constant of the disc spring of the furnace clamping force transmission device 100 in this manner, the distribution of the furnace clamping force in the furnace height direction can be made more uniform.

Furthermore, the furnace clamping force transmission device 100 according to this embodiment is effective in a furnace with a relatively low furnace height. This is because because the height of the furnace is low, the thermal expansion of the bricks in the furnace in the height direction becomes nearly uniform, and the effect of the furnace clamping force transmission by the furnace clamping force transmission device 100 is more likely to occur. Specifically, the furnace clamping force transmission device 100 according to the present embodiment is particularly effective for a coke oven 1 having an oven height of about 5 to 6 m.

Further, the furnace body pressure applied to the furnace clamping force transmitting device 100 according to the present embodiment is equalized, and the furnace clamping force by the furnace clamping force transmitting device 100 is effectively transmitted to the furnace body 1A against the furnace body pressure. Therefore, it is desirable that the protection plate 7 or the door frame 6 have a rigidity of a predetermined value or more. The configuration of the furnace clamping force transmission device 100 according to the present embodiment has been described above.

(Furnace body tightening method)
Next, a method for tightening the furnace body of the coke oven 1 according to the present embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing a method for tightening the furnace body of the coke oven 1 according to the present embodiment. As shown in FIG. 9, first, in step S101, the oven clamping force transmission device 100 is installed between the combustion chamber 4 and the backstay 5 of the coke oven 1 (S101). Specifically, the furnace clamping force transmission device 100 is provided between the flange 5A of the backstay 5 facing the combustion chamber 4 and the protection plates 7 provided at both ends of the combustion chamber 4 in the furnace length direction.

Next, the furnace clamping force is transmitted to the furnace body 1A using the furnace clamping force transmission device 100 provided in step S101 (S102). Specifically, the furnace clamping force obtained by the furnace clamping springs provided at both ends of the cross tie rod connecting the pair of backstays 5 is transmitted to the protection plate 7 using the furnace clamping force transmission device 100. In step S103, it is determined whether the termination conditions of the furnace body tightening method are satisfied, and if the termination conditions are satisfied, the furnace body tightening method is terminated. On the other hand, if it is determined that the termination condition is not satisfied, the furnace body tightening method moves to step S101. An example of the determination based on the termination condition is whether the furnace clamping force has reached a predetermined value. The method for tightening the furnace body of the coke oven 1 according to the present embodiment has been described above.

(effect)
According to this embodiment, since the furnace clamping force is transmitted via the distance piece 110 and the disc spring 120, the furnace clamping force can be effectively transmitted to the brick structure 20 that constitutes the combustion chamber 4. That is, according to the present embodiment, the distance piece 110 brings the furnace clamping force in the furnace height direction closer to uniformity. In addition, in order to respond to changes in the contact state due to various factors (that is, changes in the furnace clamping force distribution), a disc spring 120 is provided at a position facing the distance piece 110, and a furnace clamping force transmission device is used to respond to changes in the contact state. 100 can be tracked. As a result, even during long-term operation of the coke oven 1, uneven distribution of the furnace clamping force is suppressed, and stable long-term operation of the coke oven 1 is realized.

Further, according to the present embodiment, the disc spring 120 is used, which is less likely to change its spring characteristics due to ambient temperature such as thermal setting, compared to the case where a coil spring is used. It can continue to stably transmit the furnace clamping force even if it is placed in an environment with high thermal load for a long period of time.

Further, according to the present embodiment, by having the disc spring 120, it is possible to prevent not only the displacement of the backstay 5 due to aging, but also the operational fluctuations of the coke oven 1, thermal deformation of the protection plate 7, physical properties, and other various variations and factors. It is also possible to cope with the displacement that occurs when the furnace clamping force changes. As a result, a constant furnace clamping force can be more stably transmitted to the coke oven 1, and the coke oven 1 can be stably operated for a long period of time.

Furthermore, according to the present embodiment, since the structure is a combination of the distance piece 110 and the disc spring 120, the structure is simpler than, for example, a structure combining a coil spring and a fastening member. It can reduce costs and also improve maintainability. Specifically, compared to a complicated structure with a large number of parts, such as a furnace fastener 12 incorporating a coil spring and a bolt/nut structure, as shown in FIG. Since it is a spring 120 configuration, it is simple.

According to this embodiment, by transmitting the furnace clamping force using the disc spring 120 in the furnace clamping force transmission device 100, the required strength is achieved even if the spring height is lower than when using a coil spring. can be ensured. That is, the disc spring 120 can generate a predetermined furnace clamping force while downsizing the furnace clamping force transmission device 100.

Further, according to the present embodiment, the height (thickness) of the distance piece 110 is determined using a beam model in which the furnace clamping force transmitted to the combustion chamber 4 is evenly distributed in the height direction of the combustion chamber 4. It is determined based on the calculated distribution amount of deflection of the backstay 5. Therefore, the height (plate thickness) of the distance piece 110 is quantitatively set according to the position of the backstay 5 in the height direction, so that the furnace clamping force against the furnace body 1A becomes a predetermined value.

(Modified example)
Although the above embodiment has been described using an example in which the furnace clamping force transmission device 100 includes one disc spring 120, the present invention is not limited to such an example. For example, in the furnace clamping force transmission device 100, a plurality of disc springs 120 may be provided. The number of disc springs 120 is appropriately set according to the furnace clamping force required of the furnace clamping force transmitting device 100 or the initial gap of the stage where the furnace clamping force transmitting device 100 is arranged.

Furthermore, in the case where the furnace clamping force transmission device 100 has a plurality of disc springs 120, the plural disc springs 120 may be arranged in series as shown in FIG. Moreover, as shown in FIG. 11, in the furnace clamping force transmission device 100, a plurality of disc springs 120 may be arranged in parallel. The arrangement of the disc springs 120 is appropriately set according to the furnace clamping force required of the furnace clamping force transmission device 100 or the initial gap of the stage where the furnace clamping force transmission device 100 is arranged. The first embodiment of the present invention has been described above.

<Second embodiment>
Next, a furnace clamping force transmission device 100 according to a second embodiment of the present invention will be described. This embodiment differs from the first embodiment in that the disc spring 120 is used in a pre-compressed state. Note that in the description of this embodiment, the description of elements and configurations common to the first embodiment may be omitted.

First, depending on the setting conditions of the spring heights of the distance piece 110 and the disc spring 120, the gap G _h between the disc spring 120 and the distance piece 110 may be greater than or equal to zero even when the oven body 1A of the coke oven 1 is expanded. (i.e., an interval may occur). Furthermore, depending on the operating conditions of the coke oven 1, the distance piece 110 and the disc spring 120 may not come into contact with each other. As a result, it is considered that the furnace clamping force is difficult to be stably transmitted to the furnace body 1A via the furnace clamping force transmission device 100. Therefore, the present inventors came up with the idea of using the disc spring 120 in a pre-compressed state (pre-compression) in the furnace clamping force transmission device 100 according to the present embodiment.

Precompression of the disc spring 120 in the furnace clamping force transmission device 100 according to the present embodiment will be described below. That is, assuming that the height (thickness) H _DPh0 of the distance piece 110 is increased by ΔH _DPh , and assuming that the disc spring 120 is compressed by Δδ _SPh when the backstay 5 is deformed by Δδ _BSh , the above Equation (5) is expressed as the following equation (6).
L _h0 −(H _DPh0 +ΔH _DPh )−(H _SPh0 −Δδ _SPh )−Δδ _BSh =0 (6)

If the above equation (6) is rearranged with respect to the height (thickness) of the distance piece 110, it becomes equation (7).
H _DPh0 +ΔH _DPh =L _h0 -H _SPh0 +Δδ _SPh -Δδ _BSh ...(7)

Based on the above equation (7) and the amount of deformation Δδ _BSh of the backstay 5 during the operation of the coke oven 1, which was obtained using the calculation method described in the process of deriving the above equation (3), the amount of deformation Δδ BSh that may occur in the disc spring 120 The maximum reaction force F _BSh is determined. Furthermore, based on these results, the precompression ratio α of the disc spring 120 is determined. Note that the precompression ratio α is determined by the following calculation formula (8).
α=Δδ _SPh /H _SPh0 ...(8)

A disc spring 120 having a displacement and reaction force that can withstand the precompression ratio α determined by the above equation (8) is applied to the furnace clamping force transmission device 100.

According to this embodiment, in the furnace clamping force transmission device 100, the disc spring 120 is precompressed, so that the state in which the distance piece 110 and the disc spring 120 are in contact is easily maintained. As a result, the furnace clamping force is more stably transmitted to the furnace body 1A via the furnace clamping force transmission device 100.

Further, according to the present embodiment, the precompression rate α is quantitatively determined based on the above calculation formula, so that the reaction force exerted by the precompressed disc spring 120 on other members is optimized. Thereby, a predetermined furnace clamping force can be stably transmitted, and the durability of the furnace clamping force transmission device 100 is improved. The furnace clamping force transmission device 100 according to the second embodiment of the present invention has been described above.

<Third embodiment>
Next, a furnace clamping force transmission device 100 according to a third embodiment of the present invention will be described. This embodiment differs from the first and second embodiments in that the furnace clamping force transmission device 100 has an adjustment structure to accommodate changes in the distance between the protection plate 7 and the backstay 5. There is a difference. Note that in the description of this embodiment, the description of elements or configurations that are common to the first and second embodiments may be omitted.

Examples of the adjustment structure include a structure in which a shim of a predetermined thickness is sandwiched between the protection plate 7 and the backstay 5. Specifically, the adjustment structure includes a structure in which a shim is sandwiched between the disc spring 120 and the distance piece 110. By sandwiching such a shim, the furnace clamping force transmission device 100 can respond to changes in the distance between the protection plate 7 and the backstay 5. The thickness of the shim is, for example, about 10 to 50 mm. Moreover, the shape of the shim includes, for example, a disk shape or a rectangular plate shape. The furnace clamping force transmission device 100 according to the third embodiment of the present invention has been described above.

<Fourth embodiment>
Next, a furnace clamping force transmission device 100 according to a fourth embodiment of the present invention will be described with reference to FIG. 12. This embodiment differs from the first to third embodiments in that the furnace clamping force transmitted from the furnace clamping force transmission device 100 is transmitted to the furnace body via the door frame 6. Note that in the description of this embodiment, the description of elements or configurations common to the first to third embodiments may be omitted.

FIG. 12 is a sectional view of the furnace clamping force transmission device 100 according to this embodiment. As shown in FIG. 12, the furnace clamping force transmitted from the furnace clamping force transmission device 100 according to this embodiment is applied to the door frame 6 through the transmission member 140, not directly to the protection plate 7. The transmission member 140 is a metal member spanned between the door frames 6. The transmission member 140 includes a main body portion 141 and engaging portions 143 provided at both ends of the main body portion 141 in the longitudinal direction. The main body part 141 is a flat plate-shaped part, and is arranged so that the plate thickness direction is along the furnace length direction. A distance piece 110 is attached to the main body portion 141 at a position facing the flange 5A of the backstay 5.

The engaging portions 143 are portions provided at both ends of the main body portion 141 in the longitudinal direction. The engaging portion 143 faces the end of the door frame 6 , and the facing surface engages with the end of the door frame 6 . As a result, the transmission member 140 is fixed to the door frame 6.

According to this embodiment, the furnace clamping force is transmitted via the door frame 6. In other words, the furnace clamping force is not transmitted to the protective plate 7 attached to the furnace lid of the combustion chamber 4, but is transmitted from the furnace clamping force transmission device 100 to the protective plate 7 and further to the combustion chamber 4 via the furnace frame. be done. As a result, heat is less likely to be transferred from the furnace body 1A side to the furnace clamping force transmission device 100, the high temperature load on the disc spring 120 in the furnace clamping force transmission device 100 is reduced, and durability is improved. The furnace clamping force transmission device 100 according to the fourth embodiment of the present invention has been described above.

In order to evaluate the performance of the furnace clamping force transmitting device 100 and the furnace body clamping method according to the present invention, a simulation analysis was performed on a model of the furnace clamping force transmitting device 100 and the coke oven 1, and the furnace clamping that occurs in the furnace body 1A was performed. The force distribution was investigated. The evaluation results will be explained below with reference to FIGS. 13 to 18.

Specifically, the distribution of the furnace clamping force is determined using a model that takes into account the contact between the protection plate 7, the door frame 6, and the distance piece 110 and disc spring 120 as the furnace clamping force transmission device 100. In the model of the furnace clamping force transmission device 100, the precompression ratio α and the spring reaction force of the disc spring 120 were set to predetermined values and analyzed.

Comparative Examples 1 and 2 are cases of a furnace clamping force transmission device 10B consisting of only a distance piece 110 as shown in FIG. Comparative example 1 uses the conventional distance piece method, in which the initial gap between the backstay and the door frame or protection plate is determined by the relative displacement of the two using a beam model that takes the backstay, door frame, and protection plate into account. It is something. Further, in Comparative Example 2, the above-mentioned initial gap is determined by displacement using a beam model of only the backstay.

Note that the initial gap of the furnace clamping force transmission device 100 at each stage was set as shown in FIG. 14. Further, as shown in FIG. 15, the spring constant of the disc spring 120 in the furnace clamping force transmission device 100 was set. Specifically, in Example 1, the spring constant of the disc spring 120 at the upper and lower ends is approximately 1/2 that of other parts, and in Example 2, the spring constant of the disc spring 120 at the upper and lower ends is approximately 1/2. In Example 3, the spring constant is normally distributed (set so that the maximum value is approximately 5 times the minimum value).

FIG. 16 shows the furnace pressure ratio distribution in the furnace height direction obtained by simulation analysis. As shown in FIG. 16, the furnace body pressure ratio according to the height position in Examples 1 to 3 is compared with Comparative Examples 1 and 2. The distribution is now more even. That is, the distribution of the furnace body pressure ratio in Examples 1 to 3 was a flat curve close to the uniform line load shown in FIG. 16. Here, Comparative Example 3 is a case of a furnace clamping force transmission device 10A consisting of only a coil spring as shown in FIG. 17. As shown in FIG. 16, although Examples 1 to 3 have a relatively simple configuration of a combination of a disc spring 120 and a distance piece 110, the furnace clamping force transmission has a complicated configuration like Comparative Example 3. The furnace body pressure ratio distribution was equal to or more uniform than that of the apparatus 10A.

Furthermore, FIG. 18 is a graph showing the standard deviation ratio of the furnace body pressure ratio distribution in FIG. 16. As shown in FIG. 18, in Example 1, the standard deviation ratio was smaller than in Comparative Example 1, and the distribution of the furnace clamping force became more even. Although Comparative Example 2 has a smaller standard deviation ratio than Example 1, since it does not have the disc spring 120, the oven clamping force may change due to operational fluctuations of the coke oven 1, physical properties, and other various variations and factors. Simulation analysis showed that the furnace cannot cope with the displacement that occurs in the furnace, and as time passes, the furnace clamping force becomes uneven. In addition, although Comparative Example 3 has a smaller standard deviation ratio than Example 1, it has a complicated configuration as described above, and Example 1 has a simple configuration and has the same level of uniformity as Comparative Example 3. It was shown that the furnace has a strong clamping force. In Example 2, the standard deviation ratio was smaller than in Example 1, indicating that by optimizing the spring constant, a uniform furnace clamping force distribution could be achieved in the furnace height direction. Furthermore, in Example 3, the standard deviation ratio is smaller than in Comparative Examples 1 to 3, so by normalizing the disk spring constant, a more even furnace clamping force distribution can be achieved in the furnace height direction. became. As described above, this example shows that the furnace clamping force can be equalized by tightening the furnace body using the furnace clamping force transmission device 100 according to the present embodiment. Moreover, further simulation analysis showed that in Examples 1 to 3, a uniform furnace clamping force distribution was maintained even over time.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can come up with various modifications or applications within the scope of the technical idea stated in the claims. It is understood that these also naturally fall within the technical scope of the present invention.

For example, in the above embodiment, an example has been shown in which the distance piece 110 is arranged on the combustion chamber 4 side and the disc spring 120 is arranged on the backstay 5 side, but the present invention is not limited to such an example. For example, the distance piece 110 may be placed on the backstay 5 side, and the disc spring 120 may be placed on the combustion chamber 4 side.

Further, in the above embodiment, an example was shown in which the amount of deflection of the backstay 5 is derived using a beam model, but the present invention is not limited to such an example. For example, the amount of deflection of the backstay 5 may be derived by simulation analysis using the finite element method based on past operational results.

1 Coke oven 1A Furnace body 2 Heat storage chamber 3 Carbonization chamber 4 Combustion chamber 5 Backstay 5A Flange 5B Web 6 Door frame 7 Protective plate 10 Cross tie rod 11 Furnace clamping spring 12 Furnace clamp 100 Furnace clamping force transmission device 110 Distance piece 120 Dish Spring 121 Holding section 140 Transmission member 141 Main body section 143 Engagement section

Claims (4)

A backstay connected by cross tie rods disposed outside the oven at both ends in the oven length direction of at least one combustion chamber of the coke oven and installed at the upper and lower ends of the coke oven in the height direction; Installing a furnace clamping force transmission device along the height direction between the door frame or the protection plate arranged at both ends in the longitudinal direction, and
transmitting furnace clamping force obtained by furnace clamping springs provided at both ends of the cross tie rod to the door frame or the protection plate via the furnace clamping force transmission device;
The coke oven furnace body tightening method includes:
The furnace clamping force transmission device includes a distance piece and a disc spring ,
The thickness of the distance piece is based on the distribution amount of deflection of the backstay calculated using a beam model in which the furnace clamping force transmitted to the combustion chamber is distributed evenly in the height direction of the combustion chamber. The required coke oven furnace body tightening method. 2. The coke oven furnace body clamping method according to claim 1 , wherein the spring constant of the disc spring is set according to a position in the height direction where the furnace clamping force transmission device is provided. The coke oven furnace body tightening method according to claim 2 , wherein a spring constant of the disc spring is set to have a normal distribution with respect to a position in the height direction where the furnace clamping force transmission device is provided. . A backstay connected by cross tie rods disposed outside the oven at both ends in the oven length direction of at least one combustion chamber of the coke oven and installed at the upper and lower ends of the coke oven in the height direction; A furnace clamping force transmission device provided along the height direction between a door frame or a protection plate disposed at both ends in the longitudinal direction,
The furnace clamping force transmission device includes a distance piece and a disc spring, and transmits the furnace clamping force obtained by the furnace clamping springs provided at both ends of the cross tie rod to the door frame via the distance piece and the disc spring. or transmitting it to the protection plate ,
The thickness of the distance piece is based on the distribution amount of deflection of the backstay calculated using a beam model in which the furnace clamping force transmitted to the combustion chamber is distributed evenly in the height direction of the combustion chamber. The required furnace clamping force transmission device.