JP6674352B2 - Repair method of coke oven - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a repair method for newly constructing a coke oven after disassembling a combustion chamber and a heat storage chamber when repairing the coke oven.

  FIG. 1 is a vertical sectional view schematically showing a main part of a coke oven. Generally, as shown in FIG. 1, a coke oven has a carbonization chamber 2 for carbonizing coal, a wall body 3 having a combustion chamber for burning fuel gas therein, and a fuel gas or combustion air utilizing residual heat of combustion exhaust gas. Is preliminarily heated, and the walls 3 of the combustion chamber and the carbonization chamber 2 are arranged alternately. The wall 3 shown in FIG. 1 has a structure as shown in FIG. 5, and the combustion chamber 1 is formed inside the wall 3 on which refractory bricks are stacked.

  Then, during the operation of the coke oven, the operation of charging coal into the carbonization chamber 2 and further carbonizing the coal by the combustion heat generated in the combustion chamber 1 and then discharging the obtained coke from the carbonization chamber 2 is repeatedly performed. As a result, the wall 3 formed of the refractory brick is worn away, and a problem occurs in that the combustion exhaust gas and unburned fuel gas leak from the combustion chamber 1 into the carbonization chamber 2.

  In addition, a strength member (hereinafter, referred to as a column) that supports the heat storage chamber 4 and a heat storage body that is stacked between the columns and stores heat are also formed of refractory bricks, and deteriorate with time. Damage (eg, deformation, cracks, defects, etc.) and clogging may occur. If the pillars or the heat storage body are damaged or clogged, the flow of the fuel gas or the combustion air is partially obstructed, and the temperature distribution of the wall increases, which causes deterioration of coke quality. In addition, the amount of stored heat is reduced, which causes an increase in the amount of fuel gas used.

Therefore, the combustion chamber 1 and the heat storage chamber 4 must be repaired as appropriate. However, if the combustion chamber 1 and the carbonization chamber 2 of the coke oven are stopped and repaired, the production of coke is hindered. Therefore, while operating the coke oven, the combustion is stopped only in the combustion chamber 1 to be repaired, and the repair is performed. The repair procedure is as follows:
(A) The combustion chamber 1 and the heat storage chamber 4 to be repaired are dismantled and taken out of the furnace,
afterwards,
(B) The process is roughly divided into a two-stage process of newly constructing the combustion chamber 1 and the heat storage chamber 4.

  Conventionally, in the step (B), a worker builds up the refractory bricks one by one in the furnace to construct the combustion chamber 1 and the heat storage chamber 4. However, since the refractory bricks are manually stacked, it takes an extremely long time. In addition, since the working environment is at a high temperature, equipment for ensuring the safety of the workers is required, which leads to an increase in construction costs.

  In the related art, after the repair of the combustion chamber 1 is completed, the refractory brick at the end of the heat storage chamber is removed, and an operator enters the room to replace the heat storage body. However, since the working place is small and the temperature is higher than 50 ° C., the working efficiency is very poor and safety is not preferable. Further, due to the structure of the heat storage chamber 4, there is a coke oven in which a worker cannot enter from the end and cannot be repaired.

  Therefore, in repairing the combustion chamber 1, a refractory brick aggregate (hereinafter, referred to as a brick aggregate block) formed by stacking refractory bricks and forming a predetermined shape (for example, see FIG. 5) is preliminarily obtained at a ground site outside the furnace. Repair work has been started, in which the brick assembly block is transported into the furnace in the above step (B) to construct the combustion chamber 1 (see Patent Document 1). By using the brick aggregate block, the repair work can be performed efficiently, and the construction period can be shortened. In addition, the effect of reducing the load on the worker and improving safety can be obtained.

  In the repair of the heat storage chamber 4, a repair technique for filling a repaired material into a damaged portion of the refractory brick has been developed (see Patent Document 2). However, when the crack generated in the refractory brick is deep, it is difficult to allow the repair material to penetrate deeply into the deep portion, so that it is difficult to sufficiently repair the crack. If the refractory brick is damaged over a wide area, it takes a long time to fill the defect with the repair material. Therefore, if the brick assembly block is used also in the repair of the heat storage chamber 4, shortening of the construction period, reduction of the work load, and improvement of safety can be expected.

  However, the brick aggregate block is formed by stacking fire-resistant bricks and bonding and fixing the fire-resistant bricks with a fixing material (for example, mortar or the like). For this reason, when transporting the brick aggregate block during repair and further assembling it, the brick aggregate block is likely to be damaged or the brick will fall off, and after the repair is completed and operation starts, the heat of the refractory brick and the adhesive material will be Due to the difference in the amount of expansion, cracks are likely to occur in the joints (so-called joints) of the refractory bricks or the refractory bricks, or problems such as deformation of the brick assembly blocks are likely to occur.

JP 2001-19969 A JP-A-10-219252

  The present invention solves the problems of the conventional technology, and makes it possible to efficiently perform repair work on the combustion chamber and the heat storage chamber of a coke oven, thereby shortening the construction period, reducing the work load, and improving safety. It is an object of the present invention to provide a repairing method that can improve the durability after repairing.

  The present inventor has conducted a repair work efficiently, shortened the construction period, reduced the work load, and improved the safety, since the brick aggregate block is effective, cracks and the like that occur in the brick aggregate block The technology to prevent deformation was studied. As a result of studying that the brick assembly block is made of two types of materials (that is, refractory bricks and adhesives), it is a cause of cracking and deformation, and as a result, it is similar to the conventional brick assembly block. It has been found that cracking and deformation can be prevented by molding a shaped block with a single material. In other words, a block integrally formed of a single material (hereinafter, referred to as an integrally formed block) has a uniform thermal expansion amount, so that cracks and deformation can be prevented.

The present invention has been made based on such findings.
That is, the present invention relates to a repair method for repairing a combustion chamber and a heat storage chamber of a coke oven, wherein a wall forming the combustion chamber, a pillar forming the heat storage chamber, and a heat storage body stacked between the pillars to store heat. Is divided into a plurality of blocks, each containing 96 to 97.3 % by mass of fused silica, 2.5 to 3.5% by mass of phosphate and / or calcium oxide, and a heat-resistant material composed of unavoidable impurities in the form. Pour in, raise the temperature to 1000-1200 ° C at a rate of 10-25 ° C / hour, hold for at least 24 hours, and then cool to room temperature at a cooling rate of 10-25 ° C / hour. After the wall, column, and heat storage body are dismantled and taken out of the furnace, the wall, column, and heat storage are newly loaded and integrated. In the coke oven repair method that builds each body is there.

  According to the present invention, it is possible to efficiently perform repair work on the combustion chamber and the heat storage chamber of a coke oven, thereby shortening the construction period, reducing the work load, improving safety, and further, after repair. Since the durability can be improved, an industrially significant effect is achieved.

It is a vertical sectional view showing the important section of a coke oven typically. FIG. 2 is a vertical cross-sectional view schematically illustrating an example in which a wall body and a heat storage chamber in FIG. 1 are disassembled and carried out of a furnace. FIG. 4 is a vertical sectional view schematically showing an example in which a heat storage chamber is constructed using an integrally formed block. FIG. 4 is a vertical cross-sectional view schematically illustrating an example in which a wall of a combustion chamber is constructed using an integrally formed block. It is a top view which shows typically the example of the brick aggregate block of a combustion chamber wall. It is a top view which shows typically the example of the integral molding block of a combustion chamber wall. FIG. 4 is a perspective view schematically illustrating an example of an integrally molded block for a column in FIG. 3. FIG. 4 is a perspective view schematically showing an example of an integrally molded block for a heat storage body in FIG. 3.

  FIG. 2 is a vertical sectional view schematically showing an example in which the wall 3 and the heat storage chamber 4 of FIG. 1 are disassembled and carried out of the furnace. Reference numeral 4a in FIG. 2 denotes a refractory brick pillar that supports the heat storage chamber 4, and reference numeral 4b denotes a refractory brick regenerator stacked between the pillars 4a to store heat.

  FIG. 3 is a vertical sectional view schematically showing an example in which a heat storage chamber is constructed by stacking integrally formed blocks in the space of the heat storage chamber of FIG. 7 is a perspective view schematically showing an example of an integrally formed block for a column in FIG. 3, and FIG. 8 is a perspective view schematically showing an example of an integrally formed block for a heat storage body in FIG. FIG.

  The integrally molded block 5 for a column contains 96 to 99% by mass of fused silica (purity of 97% by mass or more) and 2.5 to 3.5% by mass of a binder (phosphate and / or calcium oxide) as a heat-resistant material, and the balance A mixture of impurities inevitably mixed into the mold (hereinafter referred to as inevitable impurities) is poured into a mold, and heated at a rate of 10 to 25 ° C / hour to a temperature range of 1000 to 1200 ° C for another 24 hours. After holding as described above, it is integrally molded by cooling to room temperature at a cooling rate of 10 to 25 ° C./hour.

  The integrally molded block 5 for a column thus manufactured has a sufficiently small thermal expansion coefficient of 0.01 to 0.20%, a cold compressive strength of 30 MPa or more, and a load softening point of 1400 ° C. or more. As a result, cracks and deformation do not occur, and the load of the integrally formed block for the wall described later can be supported.

  If the weight of one integrated block 5 for the column is too small, the number of times of carrying into the furnace increases, so that the efficiency of the repair work of the heat storage chamber decreases. On the other hand, if the weight is too large, it takes a long time to carry into the furnace, and thus the efficiency of the repair work on the heat storage chamber decreases. Therefore, it is preferable that the weight of one integrated block 5 for a column is in the range of 300 to 3000 kg / piece.

  The heat storage unit integrally-formed block 6 contains 96 to 99% by mass of fused silica (purity of 97% by mass or more) and 2.5 to 3.5% by mass of a binder (phosphate and / or calcium oxide) as a heat-resistant material, and the remainder. A mixture of impurities inevitably mixed into the mold (hereinafter referred to as inevitable impurities) is poured into a mold, and heated at a rate of 10 to 25 ° C / hour to a temperature range of 1000 to 1200 ° C for another 24 hours. After holding as described above, it is integrally molded by cooling to room temperature at a cooling rate of 10 to 25 ° C./hour.

  The integrally formed block 6 for a heat storage body manufactured in this manner has a sufficient thermal expansion coefficient of 0.01 to 0.20%, a cold compressive strength of 30 MPa or more, and a load softening point of 1400 ° C. or more. As a result, cracks and deformation do not occur and a large amount of heat can be stored.

  If the weight of one unit block 6 for a heat storage unit is too small, the number of times of loading into the furnace increases, so that the efficiency of the repair work of the heat storage chamber decreases. On the other hand, if the weight is too large, it takes a long time to carry into the furnace, and thus the efficiency of the repair work on the heat storage chamber decreases. Therefore, it is preferable that the weight of one integrated molding block 6 for a heat storage element be in the range of 100 to 2000 kg / piece.

  FIG. 4 is a vertical cross-sectional view schematically showing an example in which the integrally formed blocks 7 are stacked in the space above the heat storage chamber in FIG. 3 to form a wall of the combustion chamber. FIG. 6 is a plan view schematically showing an example of the integrally formed block 7 for a wall.

  The integrally formed block 7 for a wall contains 96 to 99% by mass of fused silica (purity of 97% by mass or more) and 2.5 to 3.5% by mass of a binder (phosphate and / or calcium oxide) as a heat-resistant material, and the balance A mixture of impurities inevitably mixed into the mold (hereinafter referred to as inevitable impurities) is poured into a mold, and heated at a rate of 10 to 25 ° C / hour to a temperature range of 1000 to 1200 ° C for another 24 hours. After holding as described above, it is integrally molded by cooling to room temperature at a cooling rate of 10 to 25 ° C./hour.

  The integrally molded block 7 for a wall body manufactured in this way has a sufficiently small coefficient of thermal expansion of 0.01 to 0.20%, a cold compressive strength of 30 MPa or more, and a load softening point of 1400 ° C. or more. As a result, no cracking or deformation occurs, and excellent durability is provided.

  Also, if the weight of one unitary block 7 for the wall is too small, the number of times of carrying into the furnace increases, and the efficiency of the repair work of the combustion chamber decreases. On the other hand, if the weight is too large, it takes a long time to carry into the furnace, and the efficiency of repair work on the combustion chamber is reduced. Therefore, the weight of one unitary block 7 for the wall is preferably in the range of 300 to 3000 kg / unit.

  As shown in Fig. 2, the wall of one combustion chamber of a coke oven (furnace height: 6 m, furnace length: 34 flue), the column of the heat storage chamber below it, and the heat storage bodies on both sides are all dismantled and taken out of the furnace. After the above-mentioned (A) step, as shown in FIG. 3, the integrally formed blocks for the pillars were stacked, and the integrally formed blocks for the heat storage body were further stacked to construct a heat storage chamber.

  The one-piece molded block (weight 1500 kg / piece) used for the column contains 98.4% by weight of fused silica: 97.3% by weight, and a binder consisting of phosphate and calcium oxide: 2.6% by weight, and the remainder is inevitable. The mixture, which is an impurity, is poured into a mold, heated to 1120 ° C at a heating rate of 17.7 ° C / hour, held for an additional 27 hours, and then cooled to room temperature at a cooling rate of 17.1 ° C / hour. It is molded.

The components and molding method of the used heat storage element integrally formed block (weight: 610 kg / piece) are the same as those of the above-described integrally formed block for the column.
Next, as shown in FIG. 4, the integrally formed blocks for the wall were stacked in the space above the heat storage chamber to construct the wall of the combustion chamber.
The components and molding method of the used integrally molded block for the wall (weight 2200 kg / piece) are the same as those of the above-described integrally molded block for the column.
This is an example of the invention.

On the other hand, conventionally, after dismantling all the walls and carrying them out of the furnace (step (A) above), workers stack fire-resistant bricks and reconstruct the walls (step (B) above). I was In addition, after the stacking of the walls of the combustion chamber was completed, the refractory brick at the end of the heat storage chamber was removed from the heat storage chamber, and a worker entered there to replace the heat storage body.
This is a conventional example.

When the number of days required for the step (B) was compared between the invention example and the conventional example, the required days M of the invention example was about 1/2 of the required days N of the conventional example. .
Furthermore, in the invention example, after the repair work was completed, the operation was started again, and when six months had elapsed, the inside of the furnace was inspected from the inspection hole, and no crack or deformation of the integrally molded block was found.

Reference Signs List 1 combustion chamber 2 carbonization chamber 3 wall 4 heat storage chamber
4a pillar
4b Thermal storage 5 Integrated block for pillar 6 Integrated block for thermal storage 7 Integrated block for wall

Claims (1)

In a repair method for repairing a combustion chamber and a heat storage chamber of a coke oven, a wall body forming the combustion chamber, a pillar body forming the heat storage chamber, and a heat storage body stacked between the pillar bodies to store heat, Each of the blocks is divided into a plurality of blocks to contain 96 to 97.3 % by mass of fused silica, 2.5 to 3.5% by mass of phosphate and / or calcium oxide, and the remainder is poured into a mold with a heat-resistant material composed of unavoidable impurities. The temperature is raised to a temperature range of 1000 to 1200 ° C at a rate of 10 to 25 ° C / hour, and after holding for more than 24 hours, it is cooled to room temperature at a cooling rate of 10 to 25 ° C / hour to form a single piece After previously manufacturing the integrally formed block, disassembling the wall body, the column body, and the heat storage body and carrying out the outside of the furnace, carrying in the integrally formed block and newly adding the wall body and the column Body and the heat storage And a method for repairing a coke oven.

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