Method for repairing oven wall of coke oven

Abstract

An object is to provide a coke oven wall repairing method that can perform an oven wall repair while taking into account the time required for the oven wall repair. A coke oven wall repairing method for repairing an oven wall of a carbonization chamber constituting a coke oven includes an acquiring step of acquiring an oven wall profile by measuring irregularities of the oven wall; a repair plan creating step of creating a repair plan for repairing the irregularities; a modifying step of modifying the oven wall profile to correspond to the repair plan; a pushing force estimating step of estimating, using the modified oven wall profile, pushing force with which a pusher machine pushes a coke cake out of the carbonization chamber; a repair time calculating step of calculating time required to execute the repair plan; and a repairing step of repairing the oven wall in accordance with the repair plan.

Description

Technical Field

[0001] The present invention relates to a coke oven wall repairing method that calculates the time required for repairing an oven wall.Background Art

[0002] In the steel industry, coke ovens are used to produce coke from coal. In recent years, there have been a growing number of aging coke ovens that are 40 or more years old since construction. A coke oven is built by stacking bricks while bonding them with thin mortar layers. The shape of the coke oven is maintained by fastening the bricks from the front, back, and both right and left sides. The coke oven has a structure in which a regenerative chamber is on the foundation, carbonization chambers (about 6 m high, about 400 mm wide, and about 16 m deep) and combustion chambers (about 900 mm wide) for combustion of fuel gas are alternately arranged in the width direction on the upper side of the regenerative chamber, and a brick ceiling is at the top.

[0003] In the coke oven, the carbonization chambers are internally heated to 1000°C or above by heat which is generated by combustion of fuel inside the combustion chambers through brick walls of the combustion chambers. Coal is then charged through charging holes at the top of the carbonization chambers and carbonized to produce coke. After the carbonization, the coke cake is pushed by inserting a pusher machine through one of end flues about 6 m high and about 400 mm wide at both ends of each carbonization chamber, and discharged through the other end flue. After completion of construction of the coke oven, fuel is internally combusted to gradually heat the bricks to 1000°C or above. The temperature of the bricks is kept until the coke oven is shut down.

[0004] A brick wall that separates the combustion chamber and the carbonization chamber is called an oven wall, which has the function of blocking the entry of combustion gas into the carbonization chamber, conducting combustion heat to the carbonization chamber, and supporting the ceiling. A ceiling load and bracing force constantly act on the oven wall, whereas a pusher machine load and pushing frictional force temporarily act on the oven wall during pushing of the coke cake. The ceiling load and the bracing force have the function of stabilizing the oven wall structure. However, as the coke oven ages, problems occur which include erosions where bricks are worn and thinned over a wide surface of the oven wall, and bulges where bricks tilt and bulge into the carbonization chamber.

[0005] Bricks may collapse if bracing force or pushing force acts on the oven wall having such a problem. If irregularities, such as erosions and bulges, are formed in the oven wall, the distance (oven width) between the oven wall surfaces on the right and left of the carbonization chamber deviates from the designed value, and this increases the pushing force of the pusher machine. Excessive pushing force makes it difficult to discharge the coke cake from the carbonization chamber, and causes phenomena called pushing stoppings or pushing cloggings. The occurrence of pushing stoppings or pushing cloggings leads to reduced pushing cycles by the pusher machine and may significantly decrease productivity.

[0006] As a technique for estimating pushing force of the pusher machine, Patent Literatures 1 and 2 disclose a pushing force estimating method which involves acquiring an oven wall profile of a carbonization chamber using a laser-based three-dimensional shape measuring device, and estimating pushing force on a coke cake using the acquired oven wall profile. Patent Literatures 1 and 2 also disclose a coke oven repairing method which involves identifying an oven wall repair area where pushing force can be reduced using the pushing force estimating method, and repairing the identified repair area.Citation ListPatent Literature

[0007] PTL 1: Japanese Patent No. 5590270 PTL 2: Japanese Patent No. 6699616 Summary of InventionTechnical Problem

[0008] In oven wall repairs based on pushing force, it is common to level out all irregularities of the oven wall, which can take an excessive amount time to repair the oven wall. The present invention has been made in view of such problems in the prior art. An object of the present invention is to provide a coke oven wall repairing method that can carry out an oven wall repair while taking into account the time required for the oven wall repair. Solution to Problem

[0009] The present invention that can solve the problems described above is summarized below. [1] A coke oven wall repairing method for repairing an oven wall of a carbonization chamber constituting a coke oven includes an acquiring step of acquiring an oven wall profile by measuring irregularities of the oven wall; a repair plan creating step of creating a repair plan for repairing the irregularities; a modifying step of modifying the oven wall profile to correspond to the repair plan; a pushing force estimating step of estimating, using the modified oven wall profile, pushing force with which a pusher machine pushes a coke cake out of the carbonization chamber; a repair time calculating step of calculating time required to execute the repair plan; and a repairing step of repairing the oven wall in accordance with the repair plan. [2] In the coke oven wall repairing method according to [1], the acquiring step estimates the pushing force using the acquired oven wall profile. [3] In the coke oven wall repairing method according to [1] or [2], the acquiring step acquires the oven wall profile by irradiating the oven wall with laser light from a laser-based three-dimensional shape measuring device. [4] In the coke oven wall repairing method according to [3], the oven wall profile is acquired by irradiating each of oven walls on right and left of the carbonization chamber with laser light. [5] In the coke oven wall repairing method according to any one of [1] to [4], the repair plan creating step gives priority to creating, of repair plans for cutting convex portions of the oven wall and for filling concave portions of the oven wall, a repair plan for repair work that provides a greater reduction in pushing force per unit time of repair work. [6] In the coke oven wall repairing method according to any one of [1] to [5], if any convex portion of the oven wall causes an oven width to be narrower than a predetermined width, the repair plan creating step creates a repair plan for cutting convex portions of the oven wall until the oven width becomes greater than or equal to the predetermined width before creating a repair plan for filling concave portions of the oven wall. [7] In the coke oven wall repairing method according to any one of [1] to [6], the pushing force estimating step determines whether the estimated pushing force is less than or equal to a target value of the pusher machine, and changes the repair plan if the estimated pushing force is greater than the target value. [8] In the coke oven wall repairing method according to any one of [1] to [7], the repair time calculating step determines whether the calculated time is within predetermined target time, and changes the repair plan if the calculated time is longer than the target time. Advantageous Effects of Invention

[0010] In the present invention, before an oven wall repair of the carbonization chamber in the coke oven, the time required for the oven wall repair is calculated, and the pushing force on the coke cake after the oven wall repair is estimated. This allows the oven wall repair to be carried out by taking into account the time required for the oven wall repair and the pushing force after the oven wall repair. It is thus possible, without spending an excessive amount time on the oven wall repair in the coke oven, to carry out the oven wall repair of the carbonization chamber while appropriately balancing the oven wall repair time and the pushing force in accordance with the conditions of the coke oven.Brief Description of Drawings

[0011] [Fig. 1] Fig. 1 is a plan view illustrating a carbonization chamber constituting a coke oven. [Fig. 2] Fig. 2 is a cross-sectional view illustrating how a coke cake is pushed out of the carbonization chamber with oven walls deformed due to aging. [Fig. 3] Fig. 3 is a flow chart explaining a coke oven wall repairing method according to the present embodiment. [Fig. 4] Fig. 4 is a diagram illustrating an exemplary configuration of a pushing force estimating device. [Fig. 5] Fig. 5 is a graph illustrating an example of pushing force on the coke cake estimated by the pushing force estimating device. [Fig. 6] Fig. 6 is a flow chart explaining another embodiment of the coke oven wall repairing method according to the present embodiment. [Fig. 7] Fig. 7 is a diagram illustrating an oven wall profile before an oven wall repair and an estimate of pushing force on the coke cake. [Fig. 8] Fig. 8 is a diagram illustrating an oven wall profile modified in accordance with an oven wall repair plan and an estimate of pushing force on the coke cake. [Fig. 9] Fig. 9 is a diagram illustrating an oven wall profile modified by an oven wall repair plan and an estimate of pushing force on the coke cake. [Fig. 10] Fig. 10 is a diagram illustrating an oven wall profile modified by an oven wall repair plan and an estimate of pushing force on the coke cake. Description of Embodiments

[0012] Embodiments of the present invention will now be described in detail with reference to the drawings. The following embodiments are preferred examples of the present invention and are not limited by these examples.

[0013] Fig. 1 is a plan view illustrating a carbonization chamber 10 constituting a coke oven. The carbonization chamber 10 is configured to be separated from adjacent combustion chambers by oven walls 12 and 14. Coal is charged into and carbonized in the carbonization chamber 10 to produce a coke cake 16. The coke cake 16 is pushed in a pushing direction A1 by a pusher machine 18 inserted from a machine side of the coke oven (or from the lower side of Fig. 1, which may hereinafter be referred to as "MS"), and discharged into a guide car (not illustrated) standing by on a coke side (or on the upper side of Fig. 1, which may hereinafter be referred to as "CS") opposite the machine side across the carbonization chamber 10. To facilitate pushing of the coke cake 16 out of the carbonization chamber 10, the inner wall surfaces of the oven walls 12 and 14 are tapered in such a way that the oven width on the CS is wider than that on the MS.

[0014] In the carbonization chamber 10, the oven walls 12 and 14 are undeformed upon completion of construction of the coke oven. This means that the tapered shape of the inner wall surfaces is maintained, and the width of the coke cake 16 is narrower than the oven width in the process of pushing in the pushing direction A1. Therefore, the coke cake 16 is pushed out without coming into contact with the oven walls 12 and 14 at any lateral position of the coke cake 16.

[0015] However, as the carbonization chamber 10 ages, the oven walls 12 and 14 deform to cause irregularities. Examples of deformation of the oven walls due to aging include erosions where the inner wall surfaces of the oven walls are thinned (hereinafter, erosions may be referred to as "concave portions") and bulges where bricks tilt and bulge into the carbonization chamber (hereinafter, bulges may be referred to as "convex portions").

[0016] Fig. 2 is a cross-sectional view illustrating how the coke cake 16 is pushed out of the carbonization chamber 10 with the oven walls deformed due to aging. As illustrated in Figs. 2(a) and (b), when the oven walls 12 and 14 deform due to aging, the outer shape of the coke cake 16 conforms to the shape of the inner wall surfaces of the oven walls 12 and 14 deformed. That is, if the inner wall surfaces of the oven walls 12 and 14 have a concave portion, the coke cake 16 has a convex portion at the corresponding position, whereas if the inner wall surfaces of the oven walls 12 and 14 have a convex portion, the coke cake 16 has a concave portion at the corresponding position.

[0017] In the carbonization chamber 10 that is aged, in areas where the width of the coke cake 16 passing through during the process of pushing the coke cake 16 is greater than the oven width of the carbonization chamber 10, the coke cake 16 is pushed out while being compressed to an extent that the oven width is narrower, and this increases the pushing force on the coke cake 16. When the oven walls 12 and 14 of the carbonization chamber 10 deform as described above, the pushing force of the pusher machine 18 on the coke cake 16 increases. Excessive pushing force on the coke cake 16 causes phenomena called pushing stoppings or pushing cloggings which make it difficult to push the coke cake 16 out of the carbonization chamber 10. The occurrence of pushing stoppings or pushing cloggings leads to reduced pushing cycles of the coke cake 16 and significantly decreases productivity. Therefore, before the pushing force of the pusher machine 18 becomes too large, the oven walls of the carbonization chamber 10 are to be repaired so as to limit the increase in the pushing force of the pusher machine 18 on the coke cake 16.

[0018] In a coke oven wall repairing method according to the present embodiment, for repairing the oven walls 12 and 14 having irregularities due to aging, first an oven wall repair plan is created on the basis of an oven wall profile of the carbonization chamber 10. Next, the pushing force on the coke cake 16 after an oven wall repair according to the repair plan is estimated, and the time required to execute the repair plan created is calculated. This eliminates the need to spend an excessive amount of time on the oven wall repair of the carbonization chamber 10, and allows the oven wall repair of the carbonization chamber to be carried out while appropriately balancing the oven wall repair time and the pushing force in accordance with the conditions of the coke oven.

[0019] Fig. 3 is a flow chart explaining a coke oven wall repairing method according to the present embodiment. Each step of the coke oven wall repairing method according to the present embodiment will be explained using Fig. 3. In the coke oven wall repairing method according to the present embodiment, first, an oven wall profile of the carbonization chamber 10 to be repaired is acquired (step S101). This step is an acquiring step. The oven wall profile of the carbonization chamber 10 is generated, for example, by a laser-based three-dimensional shape measuring device.

[0020] The laser-based three-dimensional shape measuring device irradiates the inner wall surfaces of the oven walls 12 and 14 of the carbonization chamber 10 with laser light to measure the shape of irregularities of the inner wall surfaces, and generates the oven wall profile of the carbonization chamber 10. It is preferable that the laser-based three-dimensional shape measuring device 40 perform measurement by irradiating each of the oven walls 12 and 14 on the left and right with laser light. This can increase the incident angle of laser light with respect to the oven walls 12 and 14, so that the shape of irregularities on the oven wall can be measured even if the inner wall surfaces of the oven walls 12 and 14 have a convex portion. Initial profile data of the oven walls 12 and 14 of the carbonization chamber 10 upon completion of construction may be stored in the laser-based three-dimensional shape measuring device 40, so as to generate an oven wall profile representing the amount of irregularities of the inner wall surfaces with respect to the initial shape. The oven wall profile representing the amount of irregularities of the inner wall surfaces with respect to the initial shape is generated by comparing the oven wall profile generated by measurement with the initial profile data upon completion of construction.

[0021] After acquisition of the oven wall profile, an oven wall repair plan is created using the acquired oven wall profile (step S102). This step is a repair plan creating step. The repair plan creating step determines, using the acquired oven wall profile, the locations and volumes for filling concave portions of the oven walls 12 and 14, the locations and volumes for cutting convex portions of the oven walls 12 and 14, and a work sequence. Since both a thermal spraying operation for leveling concave portions of the oven wall and a cutting operation for leveling out bulges on the oven wall using sandblasting generate a significant amount of dust in the carbonization chamber 10, these operations cannot be performed in parallel. The time required to fill a 1 m 3< concave portion by thermal spraying is shorter than the time required to cut a 1 m 3< convex portion by sandblasting, and the amount of reduction in pushing force per unit time of repair work is greater. Therefore, in the repair plan creating step, it is preferable to give priority to creating a repair plan for filling concave portions of the oven wall, in which a greater reduction in pushing force per unit time of repair work can be achieved. It is preferable that if the pushing force is still above the target even after filling the concave portions, a repair plan for cutting convex portions of the oven wall by sandblasting be created. This can make the coke cake pushing force less than or equal to the target pushing force while limiting an increase in oven wall repair time. The target pushing force is determined on the basis of the pushing force at which a pushing stopping or a chamber blockage occurs. If repair work for cutting convex portions of the oven wall achieves a greater reduction in pushing force per unit time of repair work than repair work for filling concave portions of the oven wall, priority may be given to creating a repair plan for cutting convex portions of the oven wall.

[0022] If any convex portion causes the width between the oven walls 12 and 14 to be narrower than the width of the pusher machine 18, it is preferable to give priority to creating a repair plan for cutting convex portions of the oven walls 12 and 14 by sandblasting until the width between the oven walls 12 and 14 becomes greater than or equal to the width of the pusher machine 18. If the width between the oven walls 12 and 14 becomes narrower than the width of the pusher machine 18, the pushing force of the pusher machine 18 increases rapidly. Therefore, in such a case, it is preferable to give priority to cutting the convex portions of the oven walls 12 and 14 by sandblasting until the width between the oven walls 12 and 14 becomes greater than or equal to the width of the pusher machine 18. Note that the width of the pusher machine 18 is an example of a predetermined oven width. The predetermined oven width may be a width obtained by multiplying the width of the pusher machine 18 by a predetermined safety factor, or may be a width determined by other factors.

[0023] After a repair plan is created, the oven wall profile is modified to correspond to the repair plan (step S103). This step is a modifying step. For example, if a repair plan to fill half of a concave portion is created, the modifying step modifies the depth of the concave portion in the oven wall profile to half.

[0024] After the oven wall profile is modified, pushing force on the coke cake 16 is estimated using the modified oven wall profile (step 104). This step is a pushing force estimating step. Fig. 4 is a diagram illustrating an exemplary configuration of a pushing force estimating device 20. The estimation of pushing force in step S104 may be performed using the pushing force estimating device 20 illustrated in Fig. 4.

[0025] The pushing force estimating device 20 is implemented using, for example, a general-purpose computer, such as a workstation or a personal computer, and performs a pushing force estimation process for estimating pushing force on the coke cake 16. The pushing force estimating device 20 includes an input unit 22, a display unit 24, a storage unit 26, and a processor 28 as main functional units.

[0026] The input unit 22 is implemented by input devices, such as a keyboard, a mouse, a touch panel, and various switches, and outputs an input signal to the processor 28 in accordance with an operation input. The display unit 24 is implemented by a display device, such as an LCD, an EL display, or a CRT display, and displays various screens on the basis of a display signal received from the processor 28.

[0027] The storage unit 26 is implemented by an information recording medium, such as an updatable and recordable flash memory, a built-in hard disk or a hard disk connected through a data communication terminal, or a memory card, and a read and write device thereof, and a recording device suitable for its use can be appropriately adopted and used. In this storage unit 26, for example, programs for operating the pushing force estimating device 20 and implementing various functions of the pushing force estimating device 20, and data used during execution of the programs, are recorded in advance or temporarily recorded each time a process is performed.

[0028] The processor 28 is implemented, for example, by a CPU, and controls the operation of the pushing force estimating device 20 by giving an instruction to each component of the pushing force estimating device 20 and transferring data thereto on the basis of an input signal received from the input unit 22 and a program and data stored in the storage unit 26. By executing a program stored in the storage unit 26, the processor 28 functions as an oven wall profile acquiring unit 30, a coke shape estimating unit 32, and a pushing force estimating unit 34.

[0029] First, the principle of a pushing force estimation process performed by the pushing force estimating device 20 will be explained. The pushing force estimating device 20 estimates pushing force on the coke cake 16 by using an earth pressure theory, which determines earth pressure acting on the surface where a retaining wall or the like comes into contact with the soil. That is, the oven walls 12 and 14 of the carbonization chamber 10 are regarded as retaining walls, and the coke cake 16 inside the inner wall surfaces of the coke oven walls where deformations, such as irregularities, may occur is regarded as soil. Then, by estimating the occurrence of active earth pressure and passive earth pressure in the earth pressure theory on the basis of the oven wall profile, pushing force directly acting on the coke cake 16 is estimated. Of the earth pressures, the earth pressure exerted when the direction of principal stress is vertical and the retaining wall moves away from the soil is called active earth pressure. Of the earth pressures, the earth pressure exerted when the direction of principal stress is horizontal and the retaining wall pushes against the soil is called passive earth pressure. Normal force generated under passive earth pressure is greater than that generated under active earth pressure.

[0030] The pushing force estimating device 20 treats the coke cake 16 produced by carbonization inside the oven walls 12 and 14 as a single elastic or plastic body. The lateral position where the inner wall surfaces of the oven walls 12 and 14 facing both sides of the coke cake 16 move outward and away from the coke cake 16 is defined as an active state. On the other hand, the lateral position where the inner wall surfaces of the oven walls 12 and 14 facing both sides of the coke cake 16 move inward and become closer to the coke cake 16 is defined as a passive state.

[0031] As long as the oven walls 12 and 14 are not deformed due to aging and the inner wall surfaces maintain the tapered shape illustrated in Fig. 1, the width of the coke cake 16 is always narrower than the oven width in the process where the coke cake 16 is pushed in the pushing direction A1. Therefore, the coke cake 16 is pushed out in a state where it is not in contact with the oven walls 12 and 14 at any lateral position, that is, in an active state where active earth pressure is generated.

[0032] On the other hand, when the oven walls 12 and 14 have irregularities, the outer shape of the coke cake 16 produced in the carbonization chamber 10 generally conforms to the inner wall surfaces of the oven walls 12 and 14. That is, both sides of the coke cake 16 are concave in an area where the inner wall surfaces of the oven walls 12 and 14 have a convex portion, and are convex in an area where the inner wall surfaces of the oven walls 12 and 14 have a concave portion.

[0033] In the process where the coke cake 16 with such an outer shape is pushed in the pushing direction A1, the width of the coke cake 16 passing through may be wider than the oven width at a position where the oven wall has a convex portion. In this case, the coke cake 16 is compressed to an extent that the oven width is narrower, and pushed out in a state where passive earth pressure is generated. Since normal force generated under passive earth pressure is greater than that generated under active earth pressure, the pushing force required to push out the coke cake 16 increases.

[0034] The determination of whether the coke cake 16 is in an active state or in a passive state is made depending on whether the width of the coke cake 16 is narrower or wider than the oven width at a passing position. Therefore, the coke cake 16 passing through a position where the oven wall has a convex portion is not necessarily in a passive state. The width of the coke cake 16 is narrow on the MS and wide on the CS. When a narrow coke width portion of the coke cake 16 on the MS passes through a position where the oven wall has a convex portion, the coke width is narrower than the oven width and the coke cake 16 is not in a passive state.

[0035] Therefore, in the estimation of pushing force, the position of the coke cake 16 in the pushing direction A1, pushed out by the pusher machine 18, in the carbonization chamber 10 is virtually reproduced. Then, for each virtually reproduced position, the width of the coke cake 16 is compared with the oven width at the passing position, and the pushing force is estimated after definition of whether the coke cake 16 is in an active state or in a passive state. By repeating this operation while moving the position of the coke cake 16 from the MS to the CS by a predetermined amount, the pushing force at the corresponding position in the pushing direction can be sequentially estimated.

[0036] In estimating the pushing force on the coke cake 16, first, the oven wall profile acquiring unit 30 of the pushing force estimating device 20 acquires the oven wall profile modified in step S103. The oven wall profile acquiring unit 30 outputs the acquired oven wall profile to the coke shape estimating unit 32.

[0037] The coke shape estimating unit 32 estimates the outer shape of the coke cake 16 produced in the carbonization chamber 10. The coke shape estimating unit 32 identifies the outer shape of both sides of the coke cake 16 after the oven wall repair, along the inner wall surfaces of the oven walls 12 and 14 after the repair indicated by the oven wall profile, and generates outer shape data of the coke cake 16. The coke shape estimating unit 32 divides the generated outer shape data into a predetermined number of sections to set computational meshes. The coke shape estimating unit 32 outputs, to the pushing force estimating unit 34, the outer shape data of the coke cake 16 for which the computational meshes are set and the oven wall profile.

[0038] By using the oven wall profile of the carbonization chamber 10 and the outer shape data of the coke cake 16 for which the computational meshes are set, the pushing force estimating unit 34 sequentially estimates the pushing force at the corresponding position in the pushing direction while moving the position of the pusher machine 18 from the MS to the CS by a predetermined amount.

[0039] The pushing force estimating unit 34 first sets the position of the pusher machine 18 to the initial position (at the end portion of the carbonization chamber 10 on the MS). Next, by using the oven wall profile of the oven walls 12 and 14 and the outer shape data of the coke cake 16 for which the computational meshes are set, the pushing force estimating unit 34 determines, for each computational mesh, whether the width of the coke cake 16 is greater or smaller than the oven width in accordance with the position of the coke cake 16. For a computational mesh where the width of the coke cake 16 is narrower than the oven width, the pushing force estimating unit 34 defines the active earth pressure together with the width difference, whereas for a computational mesh where the width of the coke cake 16 is wider than the oven width, the pushing force estimating unit 34 defines the passive earth pressure together with the width difference. This process is performed for all the computational meshes.

[0040] Then, the pushing force estimating unit 34 calculates the oven wall frictional force for each computational mesh, and estimates the sum of the oven wall frictional forces as pushing force. The pushing force estimating unit 34 processes all the computational meshes in sequence, and calculates the oven wall frictional force for each computational mesh in accordance with the definition of the active or passive state for the computational mesh being processed. An apparent Young's modulus (elastic modulus) used to calculate the oven wall frictional force is statistically determined and set in advance on the basis of pushing force measured when the coke cake 16 actually produced in the coke oven is pushed out and the oven wall profile. Then, on the basis of the definition of the active or passive state and the width difference for the computational mesh being processed, the normal force or stress that expands or compresses the computational mesh being processed as it passes between opposite oven widths is determined using the apparent Young's modulus, and the oven wall frictional force is calculated by multiplying the normal force or stress by a frictional coefficient. The oven wall frictional force for each computational mesh can thus be obtained.

[0041] For oven bottom frictional force, the computational meshes are also processed in sequence, so that oven bottom frictional forces for all the computational meshes are calculated. An oven bottom frictional coefficient used to calculate the oven bottom frictional force is a fixed value and is set in advance. Since the volume of the computational mesh can be determined, the weight is determined from a coke density determined in advance, and the oven bottom frictional force is calculated by multiplying the determined weight by the oven bottom frictional forces. The oven bottom frictional forces for all the computational meshes are thus obtained.

[0042] Then, by adding up the sum of the oven wall frictional forces for the respective computational meshes and the sum of the oven bottom frictional forces for the respective computational meshes, the pushing force required to push the coke cake 16 at the current position can be estimated. After estimating the pushing force as described above, the pushing force estimating unit 34 moves the pusher machine position toward the CS by a predetermined amount to update it, and repeats the process described above until the position of the coke cake 16 reaches the position of the end portion on the CS of the carbonization chamber 10. The pushing force estimating unit 34 thus estimates the pushing force on the coke cake 16 in the carbonization chamber 10.

[0043] Fig. 5 is a graph illustrating an example of pushing force on the coke cake 16 estimated by the pushing force estimating device 20. In Fig. 5, the horizontal axis represents the position (m) of the pusher machine 18, and the vertical axis represents the pushing force (kN). As illustrated in Fig. 5, the maximum pushing force on the coke cake was observed near the MS, and the pushing force gradually decreased toward the CS.

[0044] Referring back to Fig. 3, in step S105, the time required to execute the repair plan created in step S102 is calculated. This step is a repair time calculating step. In the oven wall repair, concave portions are filled by thermal spraying, and convex portions are cut by sandblasting. Since the processing time for filling per cubic meter and the processing time for cutting per cubic meter can be determined from past work results, the time required to execute the repair plan can be calculated from these processing times per unit volume and the filling and cutting volumes in the oven wall repair plan.

[0045] After estimation of the pushing force following the oven wall repair and calculation of the oven wall repair time, the oven wall repair is carried out (step S106). This step is a repairing step. Thus, in the coke oven wall repairing method according to the present embodiment, the time required for the oven wall repair is calculated and the pushing force on the coke cake 16 after the oven wall repair is estimated before the coke oven wall repair is carried out. Thus, in the coke oven wall repairing method according to the present embodiment, an oven wall repair can be carried out while taking into account the pushing force after the oven wall repair and the time required for the oven wall repair. This eliminates the need to spend an excessive amount of time on the oven wall repair of the carbonization chamber 10, and allows the oven wall repair to be carried out while appropriately balancing the pushing force after the oven wall repair and the time required for the oven wall repair.

[0046] Although the coke oven wall repairing method according to the present embodiment has been described, the present invention is not limited to the embodiment described above and various changes can be made to the present invention. In the embodiment described above, in an example of estimation of the pushing force in step S104, the pushing force in the carbonization chamber 10 after repair is estimated using a modified oven wall profile. In addition to this, an oven wall profile before modification may be used to estimate the pushing force. The oven wall profile before modification is an oven wall profile that reflects the conditions of the oven walls of the carbonization chamber 10 before oven wall repair. By estimating the pushing force using the oven wall profile before modification, the pushing force on the coke cake 16 in the carbonization chamber 10 before the oven wall repair can be estimated. This makes it possible to carry out the oven wall repair after the necessity for repairing the oven walls of the carbonization chamber 10 is determined.

[0047] Fig. 6 is a flow chart explaining another embodiment of the coke oven wall repairing method according to the present embodiment. The flow illustrated in Fig. 6 differs from the flow illustrated in Fig. 3 in that it includes step S201 for determining whether the estimated pushing force is less than or equal to a predetermined target value, and step S202 for determining whether the calculated repair time is less than or equal to target time. In Fig. 6, the same operations as those in Fig. 3 are given the same step numbers and their description will be omitted.

[0048] In the flow illustrated in Fig. 6, after the pushing force is estimated in step S104, a determination is made as to whether the estimated pushing force is less than or equal to a predetermined target value of pushing force (step S201). If the pushing force estimated in step S104 is less than or equal to the predetermined target value of pushing force (step S201: Yes), the process proceeds to step S105. On the other hand, if the pushing force estimated in step S104 exceeds the predetermined target value (step S201: No), the process returns to step S102, and the process from step S102 to step 104 may be repeated until creation of an oven wall repair plan that makes the estimated pushing force less than or equal to the predetermined target value. This can prevent the pushing force on the coke cake 16 from exceeding the target value.

[0049] After the repair time is calculated in step S105, a determination is made as to whether the calculated repair time is shorter than or equal to target time (step S202). If the repair time calculated in step S105 is shorter than or equal to predetermined target time (step S201: Yes), the process proceeds to step S106. On the other hand, if the repair time calculated in step S105 is longer than the target time (step S201: No), the process returns to step S102, and the process from step S102 to step S104 and step S201 and step S105 may be repeated until creation of an oven wall repair plan that makes the repair time shorter than or equal to the target time. This prevents the repair time from exceeding the predetermined target time, and can avoid the need to spend an excessive amount of time on the oven wall repair.EXAMPLES

[0050] Examples will now be described in which, for an aged carbonization chamber where pushing stoppings occurred, a repair plan was created, coke cake pushing force was estimated, and repair time was calculated. Fig. 7 is a diagram illustrating an oven wall profile before an oven wall repair and an estimate of pushing force on the coke cake 16. Fig. 7(a) illustrates an oven wall profile of one side before oven wall repair. Fig. 7(b) is a graph illustrating an estimate of pushing force on the coke cake 16 before oven wall repair, estimated using Fig. 7(a).

[0051] As illustrated in Fig. 7(a), there were a bulge (convex portion) and an erosion (concave portion) before oven wall repair. Therefore, as illustrated in Fig. 7(b), the pushing force on the coke cake 16 in this carbonization chamber was estimated to be 485 kN, which exceeded a target pushing force value of 450 kN, and there were concerns about the occurrence of pushing stoppings and pushing cloggings.

[0052] Fig. 8 is a diagram illustrating an oven wall profile modified in accordance with an oven wall repair plan and an estimate of pushing force on the coke cake 16. Fig. 8 illustrates an example in which an oven wall repair plan for leveling a erosion of the oven wall by thermal spraying was created. Fig. 8(a) illustrates an oven wall profile of one side, modified in accordance with the oven wall repair plan. Fig. 8(b) is a graph illustrating an estimate of pushing force on the coke cake 16 after oven wall repair, estimated using Fig. 8(a).

[0053] As illustrated in Fig. 8(a), in the modified oven wall profile, the erosion in Fig. 7(a) is leveled by thermal spraying. It was estimated that by leveling the erosion, as illustrated in Fig. 8(b), the pushing force on the coke cake 16 would decrease from 485 kN to 426 kN, which was less than or equal to a target value of 450 kN. The oven wall repair time can be calculated using an erosion volume of 0.4 m 3< obtained from the oven wall profile, a spray rate of 80 kg / h, a spray material density of 1700 kg / m 3< , a spray yield of 85%, and the following formula (1). The oven wall repair time for repairing the erosion was calculated to be 10 hours.

[0054] Fig. 9 is a diagram illustrating an oven wall profile modified in accordance with an oven wall repair plan and an estimate of pushing force on the coke cake 16. Fig. 9 illustrates an example in which an oven wall repair plan for leveling out a bulge of the oven wall by cutting using sandblasting was created. Fig. 9(a) illustrates an oven wall profile of one side, modified in accordance with the oven wall repair plan. Fig. 9(b) is a graph illustrating an estimate of pushing force on the coke cake 16 after oven wall repair, estimated using Fig. 9(a).

[0055] As illustrated in Fig. 9(a), in the modified oven wall profile, the bulge in Fig. 7(a) is leveled out by cutting using sandblasting. It was estimated that by leveling out the bulge, as illustrated in Fig. 9(b), the pushing force on the coke cake 16 would decrease from 485 kN to 390 kN, which was less than or equal to a target value of 450 kN. The oven wall repair time can be calculated by dividing a bulge volume of 0.6 m 3< obtained from the oven wall profile by a cutting rate of 0.016 m 3< / h. The oven wall repair time required to repair the bulge was calculated to be 38 hours.

[0056] Fig. 10 is a diagram illustrating an oven wall profile modified by an oven wall repair plan and an estimate of pushing force on the coke cake 16. Fig. 10 illustrates an example in which an oven wall repair plan for leveling an erosion of the oven wall by thermal spraying and for leveling out a bulge of the oven wall by cutting using sandblasting was created. Fig. 10(a) is an oven wall profile of one side, modified in accordance with the oven wall repair plan. Fig. 10(b) is a graph illustrating an estimate of pushing force on the coke cake 16 after oven wall repair, estimated using Fig. 10(a).

[0057] As illustrated in Fig. 10(a), in the modified oven wall profile, the erosion in Fig. 7(a) is leveled by thermal spraying and the bulge is leveled out by cutting. It was estimated that by leveling the erosion and the bulge, as illustrated in Fig. 10(b), the pushing force on the coke cake 16 would decrease from 485 kN to 379 kN, which was less than or equal to a target value of 450 kN. Since thermal spraying and cutting cannot be performed in parallel, the oven wall repair time is calculated by adding the time required to repair the oven wall by cutting to the time required to repair the oven wall by thermal spraying. The oven wall repair time for repairing the erosion and the bulge was calculated to be 48 hours.

[0058] The results illustrated in Figs. 8 to 10 indicate, for example, that to reduce the pushing force to a target value of 450 kN or less in a short time, an oven wall repair plan for leveling the erosion in the oven wall by thermal spraying may be adopted. As illustrated in Fig. 8(b), the pushing force on the coke cake 16 is reduced to 426 kN simply by leveling the erosion. The repair time may be further reduced by reducing the volume by which the erosion to be leveled is sprayed.

[0059] As described above, the coke oven wall repairing method according to the present embodiment involves creating a repair plan for an oven wall on the basis of an oven wall profile of a carbonization chamber, estimating coke cake pushing force after oven wall repair in accordance with the repair plan, and calculating the time required to execute the created repair plan. Thus, the oven wall repair can be carried out while taking into account the pushing force after the oven wall repair and the time required for the oven wall repair. Therefore, the oven wall repair can be carried out while appropriately balancing the time required for the oven wall repair and the coke cake pushing force after the oven wall repair in accordance with the conditions of the coke oven.Reference Signs List

[0060] 10carbonization chamber 12oven wall 14oven wall 16coke cake 18pusher machine 20pushing force estimating device 22input unit 24display unit 26storage unit 28processor 30oven wall profile acquiring unit 32coke shape estimating unit 34pushing force estimating unit

Claims

1. A coke oven wall repairing method for repairing an oven wall of a carbonization chamber constituting a coke oven, the method comprising: an acquiring step of acquiring an oven wall profile by measuring irregularities of the oven wall; a repair plan creating step of creating a repair plan for repairing the irregularities; a modifying step of modifying the oven wall profile to correspond to the repair plan; a pushing force estimating step of estimating, using the modified oven wall profile, pushing force with which a pusher machine pushes a coke cake out of the carbonization chamber; a repair time calculating step of calculating time required to execute the repair plan; and a repairing step of repairing the oven wall in accordance with the repair plan.

2. The coke oven wall repairing method according to Claim 1, wherein the acquiring step estimates the pushing force using the acquired oven wall profile.

3. The coke oven wall repairing method according to Claim 1 or Claim 2, wherein the acquiring step acquires the oven wall profile by irradiating the oven wall with laser light from a laser-based three-dimensional shape measuring device.

4. The coke oven wall repairing method according to Claim 3, wherein the oven wall profile is acquired by irradiating each of oven walls on right and left of the carbonization chamber with laser light.

5. The coke oven wall repairing method according to any one of Claim 1 to Claim 4, wherein the repair plan creating step gives priority to creating, of repair plans for cutting convex portions of the oven wall and for filling concave portions of the oven wall, a repair plan for repair work that provides a greater reduction in pushing force per unit time of repair work.

6. The coke oven wall repairing method according to any one of Claim 1 to Claim 5, wherein if any convex portion of the oven wall causes an oven width to be narrower than a predetermined width, the repair plan creating step creates a repair plan for cutting convex portions of the oven wall until the oven width becomes greater than or equal to the predetermined width before creating a repair plan for filling concave portions of the oven wall.

7. The coke oven wall repairing method according to any one of Claim 1 to Claim 6, wherein the pushing force estimating step determines whether the estimated pushing force is less than or equal to a target value of the pusher machine, and changes the repair plan if the estimated pushing force is greater than the target value.

8. The coke oven wall repairing method according to any one of Claim 1 to Claim 7, wherein the repair time calculating step determines whether the calculated time is within predetermined target time, and changes the repair plan if the calculated time is longer than the target time.

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