JP2017020057A - Method for replacing stave cooler mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for replacing a stave cooler mounting structure in which a stave cooler is fixed at a first height position on an upper side and at a second height position on a lower side, which is capable of suppressing deformation in the vicinity of the height positions and capable of suppressing bending.SOLUTION: A stave cooler 11 is fixed by fixing members 14 disposed at a third height position 93, a fourth height position 94, a fifth height position 95, and a sixth height position 96. At that time, the third height position 93 is set to coincide with a first height position 91 or set between an upper end 11d of the stave cooler 11 and the first height position 91, the fourth height position 94 is set between the upper end 11d of the stave cooler 11 and the third height position 93, the fifth height position 95 is set to coincide with a second height position 92 or set between a lower end 11e of the stave cooler 11 and the second height position 92, and the sixth height position 96 is set between the lower end 11e of the stave cooler 11 and the fifth height position 95.SELECTED DRAWING: Figure 4A

Description

  The present invention relates to a method for updating a mounting structure of a copper or copper alloy stave cooler.

  In a blast furnace, which is a metallurgical furnace, operations are often directed to increasing the amount of tapping and improving tapping efficiency, and accordingly, the heat load on the blast furnace body is increasing. For this reason, in the stave cooler that is a furnace body cooling device, a copper or copper alloy stave cooler (hereinafter, simply referred to as “copper stave cooler”) is used instead of the cast iron stave cooler. became. This is because the copper stave cooler has higher thermal conductivity and excellent cooling capacity than the cast iron stave cooler.

  On the other hand, since copper and copper alloys have a higher coefficient of thermal expansion than cast iron, a copper stave cooler has a larger amount of thermal expansion when the temperature rises than a cast iron stave cooler. For this reason, if thermal expansion is restrained when the temperature rises, the stave cooler may be plastically deformed (permanently deformed) due to thermal stress. Even when copper and copper alloy have lower strength than cast iron, the copper stave cooler is more likely to be plastically deformed than the cast iron stave cooler when thermal stress occurs. Further, if cyclic temperature rise and fall are repeatedly applied, fatigue cracks may occur in the copper stave cooler. Therefore, the copper stave cooler employs an attachment structure that allows a certain degree of thermal expansion.

  1A and 1B are schematic views showing an example of a conventional stave cooler mounting structure, in which FIG. 1A is a side view and FIG. 1B is a rear view of the stave cooler. FIG. 1A shows a blast furnace body 10, and the furnace body 10 includes an outer skin 12, a stave cooler 11 for cooling the furnace body 10, and a space between the furnace body 10 and the stave cooler 11. And an irregular refractory 13 to be arranged. In FIG. 1A, the symbol I is marked inside the furnace and the symbol O is marked outside the furnace.

  A stave cooler 11 shown in FIGS. 1A and 1B is arranged inside the iron skin 12 and is fixed to the iron skin 12 by bolts 14 (fixing members). The bolts 14 are arranged side by side along the longitudinal direction of the stave cooler 11 (the height direction of the blast furnace, see the bold arrow in FIG. 1B). Specifically, the upper first height position 91 and the lower first Two height positions 92 are arranged. Moreover, the volt | bolt 14 is arrange | positioned along with the width direction (the circumferential direction of a blast furnace, see the broken-line arrow of FIG. 1B) of the stave cooler 11 in each height position. In this way, the stave cooler 11 is fixed at the first and second height positions (91, 92). Thereby, thermal expansion of the stave cooler 11 can be allowed to some extent while the stave cooler 11 is securely attached to the iron skin 12 (outer wall portion).

  Here, the length L of the stave cooler 11 is, for example, 1500 to 3200 mm. In this case, the distance D1 (mm) from the upper end 11d of the stave cooler 11 to the first height position 91 is a ratio (D1 / L) to the length L (mm) of the stave cooler 11 and is 16 to 33%. . The distance D2 (mm) from the lower end 11e of the stave cooler 11 to the second height position 92 is a ratio (D2 / L) to the length L (mm) of the stave cooler 11 and is 16 to 33%.

  The stave cooler 11 shown in the figure has four cooling paths 11a inside. The cooling path 11a extends along the longitudinal direction and is arranged side by side in the width direction. In order to supply and discharge cooling water to and from the cooling path 11a, a cooling water supply port 11b is provided at the lower end of the cooling path 11a, and a cooling water supply pipe 15 is connected to the supply port 11b. A cooling water discharge port 11c is provided at the upper end of the cooling path 11a, and a discharge pipe 16 is connected to the discharge port 11c. In order to supply cooling water from the outside of the furnace and discharge the cooling water to the outside of the furnace, the supply pipe 15 and the discharge pipe 16 both penetrate the iron skin 12.

  In each of the cooling water supply pipe 15 and the discharge pipe 16, a part of the outer portion of the iron skin 12 is covered with the expansion tube 17 in the pipe. One end of the telescopic tube 17 is welded to the iron skin 12, and a seal member 18 is disposed at the other end. The gap between the pipe (15, 16) and the expansion / contraction pipe 17 is sealed by the seal member 18. Providing the expansion tube 17 and the seal member 18 in this manner prevents leakage of furnace gas while absorbing displacement of the pipes (15, 16) due to thermal deformation of the stave cooler 11.

  The amorphous refractory 13 is disposed so as to prevent the temperature rise of the iron shell 12 due to contact with the furnace gas, and covers the inner surface of the iron shell 12, and the back surface of the stave cooler 11 is in contact with the irregular refractory 13. To do. In the front of the stave cooler 11 shown in the figure, grooves extending in the width direction are arranged in the longitudinal direction, and the grooves are filled with an irregular refractory (not shown). Since the charged raw material (not shown) descends on the front side (inside) of the stave cooler 11, the front surface of the stave cooler 11 comes into contact with the charged raw material and the furnace gas.

  By the way, Patent Documents 1 and 2 propose a stave cooler mounting structure that further allows thermal expansion. In the mounting structure proposed in Patent Document 1, a copper cooling plate (stave cooler) is coupled to a furnace armor plate (iron skin) by a fixed point-fixing member, and the fixed point-fixing member is welded to the furnace armor plate. . In addition, it is proposed that the copper cooling plate is additionally connected to the furnace armor plate by a movable point-fixing member, and that the movable point-fixing member allows the thermal expansion movement of the copper cooling plate in horizontal and vertical directions. Has been.

  Patent Document 2 proposes that a member for fixing the stave cooler to the outer wall portion of the metallurgical furnace is arranged at one height position in the height direction of the metallurgical furnace. Thereby, in a stave cooler, it is supposed that the compressive stress resulting from the thermal expansion by the temperature rise at the time of operation of a blast furnace can be substantially eliminated.

Special table 2003-509588 gazette JP 2003-013124 A

  As described above, in the case of a copper or copper alloy stave cooler, if the thermal expansion is restricted when the temperature rises, the stave cooler may be plastically deformed (permanently deformed) due to thermal stress. If the temperature rises and falls repeatedly, fatigue cracks may occur in the stave cooler. Therefore, in the conventional mounting structure as shown in FIGS. 1A and 1B, although the thermal expansion of the stave cooler is allowed to some extent, the stave cooler has a first height position and a second height due to the deformation behavior described later. It may be bent at the position, and the cooling water supply pipe and discharge pipe may be damaged.

  2A to 2C are side views schematically showing the deformation behavior of the stave cooler in the conventional mounting structure. FIG. 2A is a high heat load when there is no amorphous refractory, and FIG. 2B is an irregular refractory. FIG. 2C shows the temperature drop in the furnace when there is an irregular refractory, respectively. 2A to 2C show the stave cooler 11, the iron skin 12, the cooling water supply pipe 15 and the discharge pipe 16, and the bolt 14 that fixes the stave cooler 11 to the iron skin 12. 2B and 2C further show the amorphous refractory 13.

  Assuming that there is no amorphous refractory, the back surface of the stave cooler 11 can be freely deformed, so that the stave cooler 11 is deformed into a convex shape as shown in FIG. 2A. This is because a temperature difference is generated between the inside (front side) and the outside (back side) of the stave cooler, so that the amount of thermal expansion on the inside is larger than that on the outside. The temperature difference of the stave cooler is generated when the inside contacts the hot furnace gas while the outside is cooled by the cooling water. When the heat load increases, for example, when the temperature in the furnace becomes high due to a rapid temperature rise, the temperature difference increases, so that the convex deformation also increases.

  By the way, in an actual blast furnace, the irregular refractory 13 is arranged between the back surface of the stave cooler 11 and the iron skin 12. For this reason, as shown in FIG. 2B, a portion of the stave cooler 11 between the upper end 11 d and the first height position 91 (hereinafter also referred to as “upper part”), the lower end 11 e and the second height position 92. Unlike the case where the amorphous refractory 13 is not provided, the convex deformation is limited by the amorphous refractory 13 in the intermediate portion (hereinafter also referred to as “lower part”). On the other hand, the portion between the first height position 91 and the second height position 92 (hereinafter, also referred to as “intermediate portion”) is likely to be deformed into a convex shape at the time of heat load, as in the case where there is no amorphous refractory. However, since it is suppressed by the irregular refractory 13, compressive stress is generated in the vicinity of the first height position 91 and the second height position 92, as indicated by the thick arrows in FIG. 2B, and the heat load is high. Then, it may lead to plastic deformation.

  When the furnace temperature decreases, the temperature difference between the inside and outside decreases, and the intermediate portion of the stave cooler 11 is reduced in convex deformation as shown in FIG. 2C, and returns to a shape along the amorphous refractory 13. . When the above-described plastic deformation occurs during a high heat load, the compressive strain remains in the vicinity of the first height position 91 and the second height position 92 even if the temperature is lowered. For this reason, the stave cooler 11 is bent at the first height position 91 and the second height position 92, and the upper and lower portions of the stave cooler 11 are respectively inclined inward.

  When the rise and fall of the furnace temperature are repeated, plastic deformation occurs near the first height position 91 and the second height position 92 every time a high thermal load is applied, and compressive strain accumulates. Along with this, the inclination of the upper and lower portions of the stave cooler also increases. As a result, the cooling water supply pipe 15 and the discharge pipe 16 are drawn into the furnace (in the iron skin 12). In this case, the pipes (15, 16) may be displaced beyond the range that can be absorbed by the above-mentioned telescopic pipe, and the telescopic pipe and the pipes (15, 16) may be damaged.

  Therefore, at the time of maintenance of the blast furnace, the stave cooler 11 is replaced by replacing the bent stave cooler 11. At that time, it has been desired to take measures to suppress deformation in the vicinity of the first height position 91 and the second height position 92. In addition, it has been desired to take measures to prevent the bending of the stave cooler that is not bent.

  In order to suppress the bending of the stave cooler 11, it is conceivable to remove the telescopic pipe 17 from the mounting structure shown in FIG. 1A and fix the cooling water supply pipe 15 and the discharge pipe 16 to the iron skin 12 by welding. In this case, the pipes (15, 16) are directly fixed to the iron skin 12 without the telescopic pipe 17, but the portion of the iron skin 12 through which the pipes (15, 16) are passed has an opening. Many are low in strength. For this reason, there exists a possibility of causing damage to the iron skin 12, and there exists a possibility of damaging piping (15, 16). Therefore, the mounting structure for directly fixing the pipes (15, 16) to the iron skin is unsuitable.

  In the above-mentioned patent document 1, it is proposed to couple a copper cooling plate (stave cooler) to a furnace armor plate (iron skin) by a fixed point-fixing member. In addition, the copper cooling plate is coupled to the furnace armor plate by a movable point-fixing member to allow thermal expansion. However, even when the movable point-fixing member is used, when the thermal load increases, the deformation occurs near the fixed point-fixed member due to the temperature difference between the inside and the outside of the copper cooling plate.

  In Patent Document 2 described above, it is proposed to arrange a member for fixing the stave cooler to the outer wall of the metallurgical furnace at one height position in the height direction of the metallurgical furnace. However, even if the height position where the stave cooler is fixed is reduced to one, if the heat load increases, the temperature difference between the inside and outside of the copper cooling plate will cause deformation near one height position. Bends.

  An object of the present invention is to provide a stave cooler mounting structure fixed at an upper first height position and a lower second height position, so that deformation can be suppressed in the vicinity of those height positions, and bending can be suppressed. It is to provide a method for updating the mounting structure of the stave cooler.

  According to an embodiment of the present invention, there is provided a method for updating a stave cooler mounting structure, which is fixed to an outer wall portion of a metallurgical furnace by fixing members disposed at an upper first height position and a lower second height position. This is a method for updating the mounting structure of a copper or copper alloy stave cooler. The update method includes a step of fixing the stave cooler by fixing members arranged at a third height position, a fourth height position, a fifth height position, and a sixth height position. In the step of fixing the stave cooler, the third height position is provided so as to coincide with the first height position or between an upper end of the stave cooler and the first height position, 4 height positions are provided between the upper end of the stave cooler and the third height position, and the fifth height position is matched with the second height position, or the lower end of the stave cooler. And the second height position, and the sixth height position is provided between the lower end of the stave cooler and the fifth height position.

  In the step of fixing the stave cooler, the third height position is provided so as to coincide with the first height position, and the fifth height position is provided so as to coincide with the second height position. It is preferable to provide it.

  The update method may further include a step of removing the first stave cooler fixed to the outer wall portion and replacing it with a second stave cooler. In this case, in the step of fixing the stave cooler, the second stave cooler is fixed and attached.

  According to the method for updating the mounting structure of the present invention, the upper portion of the stave cooler is fixed at two height positions, and the lower portion of the stave cooler is fixed at two height positions. Thereby, the deformation amount can be greatly reduced at the upper end and the lower end of the stave cooler, and accordingly, the deformation amount can also be reduced at the intermediate portion of the stave cooler. For this reason, a deformation | transformation can be suppressed in the vicinity of those height positions, and the bending of a stave cooler can be suppressed. As a result, it is possible to prevent the cooling water supply / discharge piping and the expansion tube from being damaged, and to improve the durability of the stave cooler.

FIG. 1A is a side view schematically showing an example of a conventional stave cooler mounting structure. FIG. 1B is a rear view of the stave cooler shown in FIG. 1A. FIG. 2A is a side view schematically showing the deformation behavior of the stave cooler in the conventional mounting structure, and shows a high heat load when there is no amorphous refractory. FIG. 2B is a side view schematically showing the deformation behavior of the stave cooler in the conventional mounting structure, and shows a high heat load when there is an irregular refractory. FIG. 2C is a side view schematically showing the deformation behavior of the stave cooler in the conventional mounting structure, and shows when the temperature in the furnace is lowered when there is an irregular refractory. FIG. 3A is a side view schematically showing a deformed state of the stave cooler under a high heat load, and shows a case of a conventional mounting structure. FIG. 3B is a side view schematically showing a deformed state of the stave cooler at the time of high heat load, and shows a case where a fixing member is added at the center. FIG. 3C is a side view schematically showing a deformed state of the stave cooler during a high heat load, and shows a case where fixing members are added to the upper part and the lower part. FIG. 4A is a side view schematically showing an example of an installation structure of the stave cooler after being updated by the updating method of the present invention. FIG. 4B is a rear view of the stave cooler shown in FIG. 4A. FIG. 5 is a top view showing a deformed state of the stave cooler during a high heat load. FIG. 6A is a side view schematically showing a mounting structure (case A) before update of the embodiment (conventional). 6B is a rear view of the stave cooler shown in FIG. 6A. FIG. 7A is a side view schematically showing the updated mounting structure (case B) of the embodiment. FIG. 7B is a rear view of the stave cooler shown in FIG. 7A. FIG. 8A is a side view schematically showing a mounting structure (case C) of a comparative example. FIG. 8B is a rear view of the stave cooler shown in FIG. 8A. FIG. 9A is a side view schematically showing a mounting structure (case D) of a comparative example. FIG. 9B is a rear view of the stave cooler shown in FIG. 9A.

[Basic analysis]
As described above, the attachment structure of the copper or copper alloy stave cooler has adopted an attachment structure that allows a certain degree of thermal expansion in order to prevent plastic deformation and fatigue cracks. However, when the thermal load increases, due to the temperature difference between the inside and outside of the stave cooler, plastic deformation occurs near the first height position and the second height position, and compressive strain remains inside. Bends. A countermeasure for allowing thermal expansion by a movable point-fixing member as in Patent Document 1 is not sufficient for bending due to this temperature difference. Moreover, the countermeasure which reduces the height position which fixes a stave cooler like patent document 2, and makes it one is not enough.

  Then, the present inventors examined suppressing the bending of a stave cooler by increasing the height position which arrange | positions a fixing member (bolt).

  3A to 3C are side views schematically showing a deformed state of the stave cooler under a high heat load. FIG. 3A shows a conventional mounting structure, and FIG. 3B shows a fixing member (bolt) at the center (intermediate portion). 3C shows a case where fixing members are added to the upper part and the lower part, respectively. 3A to 3C show the deformed stave cooler 11 and the bolts 14 that fix the stave cooler 11 to the iron skin 12. Moreover, the stave cooler before a deformation | transformation is shown with a broken line.

  3A to 3C show the results of thermal stress analysis when it is assumed that there is no amorphous refractory. In the thermal stress analysis, a temperature distribution simulating a high heat load was applied to the stave cooler 11 to provide a temperature difference between the inside and outside of the stave cooler. The temperature distribution simulating a high heat load was obtained by heat transfer analysis, and the measurement result of the back temperature of the stave cooler was used in the heat transfer analysis.

  As shown in FIG. 3A, in the conventional mounting structure, the stave cooler 11 is fixed at the upper first height position 91 and the lower second height position 92. In this case, due to the temperature difference between the inside and outside of the stave cooler 11, the stave cooler 11 is warped and deformed into a convex shape.

  As shown in FIG. 3B, in the conventional mounting structure, the bolt 14 is added to the center in the longitudinal direction of the stave cooler 11, in other words, the intermediate portion (between the first height position and the second height position 92). In this case, the deformation amount can be reduced at the upper end 11d and the lower end 11e of the stave cooler 11. This is because the center in the longitudinal direction of the stave cooler 11 is pulled outward during high heat load as the center in the longitudinal direction of the stave cooler 11 is fixed. As a result, the deformation amount of the intermediate part can also be reduced.

  As shown in FIG. 3C, in the conventional mounting structure, bolts 14 are provided at the upper part (between the upper end 11d and the first height position 91) and the lower part (between the lower end 11e and the second height position 92) of the stave cooler. Add Thereby, the deformation amount can be greatly reduced at the upper end 11d and the lower end 11e of the stave cooler. This is because the upper and lower portions of the stave cooler 11 are pushed inward by the added bolt. As a result, the deformation amount of the intermediate part can also be reduced.

  From these, it has been found that if a fixing member is added to the upper and lower portions of the stave cooler, the amount of deformation can be greatly reduced at the upper and lower ends of the stave cooler, and the amount of deformation at the intermediate portion can also be reduced. Based on this finding, the present invention has been completed and the above-described configuration has been adopted.

[How to update the mounting structure]
The update method of this embodiment will be described below with reference to the drawings.

  FIG. 4A and FIG. 4B are schematic views showing an example of a structure for attaching a stave cooler after updating by the updating method of the present invention, FIG. 4A is a side view, and FIG. 4B is a rear view of the stave cooler. FIG. 4A shows a blast furnace body 10. The furnace body 10 has the same basic configuration as the furnace body 10 shown in FIG. 1A, and has a height position where the bolts 14 are disposed. The stave cooler 11 shown in the figure is fixed to the iron skin 12 (outer wall portion) by a bolt 14 which is a fixing member. For example, a pin or the like may be adopted as the fixing member.

  The update method of this embodiment is made of copper or a copper alloy fixed to an outer wall portion of a metallurgical furnace (for example, an iron skin of a blast furnace) at an upper first height position 91 and a lower second height position 92. The stave cooler 11 is a target. For example, the attachment structure shown in FIGS. 1A and 1B can be targeted. The update method of the present embodiment can employ a method (hereinafter referred to as “first embodiment”) in which only the arrangement of the fixing members is changed without replacing the stave cooler 11. Alternatively, when changing the arrangement of the fixing members, a method of removing and replacing the stave cooler 11 (hereinafter referred to as “second embodiment”) can also be employed.

  In the first embodiment, the stave cooler 11 fixed at the upper first height position 91 and the lower second height position 92 is replaced with a third height position 93, a fourth height position 94, The fifth height position 95 and the sixth height position 96 are fixed. For example, the bolt 14 is removed at the upper first height position 91 and the lower second height position 92 to release the fixing, and the third height position 93, the fourth height position 94, the fifth What is necessary is just to fix with the volt | bolt 14 arrange | positioned at the height position 95 and the 6th height position 96. FIG. The third to sixth height positions (93 to 96) will be described in detail later.

  In the second embodiment, first, for example, the fixing is released by removing the bolt 14, and the first stave cooler 11 to be repaired is removed from the iron skin 12 (outer wall portion). The removed first stave cooler (used) is replaced with a second stave cooler different from the first stave cooler. For example, a new stave cooler may be used as the second stave cooler. Subsequently, the replaced second stave cooler 11 is fixed by the bolts 14 arranged at the third height position 93, the fourth height position 94, the fifth height position 95, and the sixth height position 96. And attach.

  In the update method of the present embodiment, as shown in FIGS. 4A and 4B, the third height position 93, the fourth height position 94, the fifth height position 95, and the sixth height position 96 are fixed. . The third height position 93 is provided so as to coincide with the first height position 91 or between the upper end 11 d of the stave cooler 11 and the first height position 91. Further, the fourth height position is provided between the upper end 11 d of the stave cooler 11 and the third height position 93. Thereby, the upper part of the stave cooler 11 is fixed at two height positions.

  In addition, the fifth height position 95 is provided so as to coincide with the second height position 92 or between the lower end 11 e of the stave cooler 11 and the second height position 92. The sixth height position 96 is provided between the lower end 11 e of the stave cooler 11 and the fifth height position 95. Thereby, the lower part of the stave cooler 11 is fixed at two height positions.

  In such an updating method of the present embodiment, the upper portion of the stave cooler 11 is fixed at the third height position 93 and the fourth height position 94 by updating the mounting structure, and the lower portion is fixed at the fifth height position 95 and Fix at a sixth height position 96. In this case, by providing the fourth height position 94, the upper side of the third height position 93 is pushed inward during a high heat load, and the deformation amount can be greatly reduced at the upper end of the stave cooler 11. Further, by providing the sixth height position 96, the lower side of the fifth height position 95 is pushed inward during a high heat load, and the deformation amount can be greatly reduced at the lower end of the stave cooler 11. As a result, the amount of deformation of the portion between the third height position 93 and the fifth height position 95 can also be reduced.

  Accordingly, in the vicinity of the third height position 93 and the fifth height position 95, the compressive stress inside the stave cooler due to the thermal load can be greatly reduced, and plastic deformation can be suppressed. For this reason, it is possible to prevent the stave cooler 11 from being bent due to repeated increases and decreases in the furnace temperature. As a result, the displacement of the piping (15, 16) of the cooling water during a high heat load is within a range that can be absorbed by the expansion / contraction tube 17, and the piping (15, 16) and the expansion / contraction tube 17 can be prevented from being damaged. Further, the durability of the stave cooler 11 can be improved by updating the mounting structure.

  When fixing the stave cooler 11, the third height position 93 is provided so as to coincide with the first height position 91, and the fifth height position 95 is provided so as to coincide with the second height position 92. Is preferred. Thereby, the bolt hole and pin hole for fixing members provided in the iron skin 12 (outer wall part) can be reused, and cost and work efficiency can be improved. In this case, in the first embodiment, for example, the third height position 93 and the first height position 91 and the second height position 92 on the upper side are removed as they are without removing the fixing member and releasing the fixing at the lower second height position 92. A fixing member may be added at the fifth height position 95 and at the fourth height position 94 and the sixth height position 96.

  Here, at the time of high heat load, the stave cooler 11 is warped in a convex shape due to a temperature difference between the inside and the outside in the width direction.

  FIG. 5 is a top view showing a deformed state of the stave cooler during a high heat load. In the figure, the stave cooler 11, the bolt 14, and the cooling water discharge pipe 16 are shown, and the shape of the stave cooler 11 before deformation is shown by a two-dot chain line. As shown in FIG. 5, at the time of high heat load, the stave cooler 11 is deformed into a convex shape while warping in a bow due to a temperature difference between the inside and the outside. In addition, since the width | variety of the stave cooler 11 is short, even if it deform | transforms convexly in the width direction, the thermal stress which generate | occur | produces is small and does not develop to plastic deformation.

  The fixing members are arranged at the third to sixth height positions (93 to 96) by updating the mounting structure, respectively. In the mounting structure example shown in FIGS. 4A and 4B, the fixing member is linearly arranged along the longitudinal direction of the stave cooler 11. In this case, the cross section at any position of the stave cooler 11 is uniformly deformed.

  On the other hand, when the position of the fixing member is changed in the width direction of the stave cooler without being arranged in a straight line, the deformed state changes in a part of the cross section of the stave cooler. Thus, when the cross-sectional shape of the stave cooler 11 changes in the longitudinal direction, the stave cooler has undulations in the longitudinal direction and the width direction. In this case, there is a possibility that a protrusion is generated in the stave cooler. A protrusion part is a site | part which protrudes inward locally among stave coolers.

  When the protrusion is generated, the ore of the charging raw material collides with the protrusion and the protrusion is worn. Since copper has a lower hardness than ore and is easily worn by collision with ore, it is preferable to avoid the occurrence of protrusions. Further, when the end portion in the width direction of the stave cooler 11 is deformed inward, the high temperature gas in the furnace easily flows around the back surface of the stave cooler 11. From the viewpoint of preventing the hot gas from wrapping around, it is preferable to suppress complex deformation with undulations. From these, it is preferable that the fixing member is arranged linearly along the longitudinal direction of the stave cooler 11.

  In the mounting structure examples shown in FIGS. 4A and 4B, two fixing members are arranged side by side along the width direction. The number of fixing members in the width direction may be set as appropriate according to the width of the stave cooler.

  The update method of the present embodiment is not limited in the dimension of the stave cooler and can be applied to a conventionally used stave cooler. For example, the present invention can be applied to a stave cooler whose length L is 1500 to 3200 mm. In this case, the distance D1 (mm) from the upper end 11d of the stave cooler 11 to the upper first height position 91 is a ratio (D1 / L) to the length L (mm) of the stave cooler 11, and is 16 to 33%. It is. The distance D2 (mm) from the lower end of the stave cooler 11 to the lower second height position 92 is a ratio (D2 / L) to the length L (mm) of the stave cooler 11, and is 16 to 33%. is there.

  As described above, by providing the fourth height position 94, the upper side of the third height position 93 is pushed inward, and the deformation amount can be greatly reduced at the upper end of the stave cooler 11. This effect increases as the distance D4 (mm) from the upper end 11d of the stave cooler 11 to the fourth height position 94 becomes shorter. Therefore, the distance D4 is a ratio (D4 / D3) to the distance D3 (mm) from the upper end 11d of the stave cooler 11 to the third height position 93, and is preferably 66% or less, and 50% or less. More preferably. On the other hand, when the distance D4 becomes too short, interference between the fixing member and the cooling water pipe or the like occurs. Therefore, the lower limit of the distance D4 is not specified because it is determined automatically.

  Further, by providing the sixth height position 96, the lower side of the fifth height position 95 is pushed inward, and the deformation amount can be greatly reduced at the lower end of the stave cooler 11. This effect increases as the distance D6 (mm) from the lower end 11e of the stave cooler 11 to the sixth height position 96 becomes shorter. Therefore, the distance D6 is a ratio (D6 / D5) to the distance D5 (mm) from the lower end 11e of the stave cooler 11 to the fifth height position 95, and is preferably 66% or less, and 50% or less. More preferably. On the other hand, if the distance D6 becomes too short, interference between the fixing member and the cooling water piping occurs. Accordingly, the lower limit of the distance D6 is not defined because it is determined automatically.

  In order to confirm the effect of the present invention, a temperature cycle was repeatedly given to the stave cooler, and the deformation amount of the stave cooler was evaluated. This test was conducted by thermal stress analysis.

  When the temperature at the center of the back of the stave cooler was measured in advance in an actual machine, a process of rapid temperature increase (temperature increase of about 150 ° C. at about 15 ° C./min) was included. Using the relationship between the temperature and elapsed time, the temperature distribution of the stave cooler was obtained by heat transfer analysis.

  A plurality of test pieces were collected from the actual copper stave cooler, and a stress-strain curve at 20 to 400 ° C. was obtained by performing a tensile test while changing the temperature condition. The stress-strain curve was used in thermal stress analysis. The tensile test was performed according to JIS G 0567.

  Since a high heat load is repeatedly applied to the actual stave cooler, the thermal stress analysis uses the kinematic hardening law as the hardening law and considers the effect of repeated plastic deformation. Since the actual stave cooler is in a high temperature environment, creep deformation occurs. In order to simulate the deformation, creep deformation was considered in the thermal stress analysis.

  The attachment structure of the stave cooler is provided with a case A that simulates the attachment structure before the update (conventional) and a case B that simulates the attachment structure after the update. Further, as comparative examples, cases C and D for adding bolts to the intermediate portion of the stave cooler are provided. The stave cooler 11 was 3000 mm long and 840 mm wide in any case.

  6A and 6B are schematic views showing a mounting structure (case A) before the update of the embodiment (conventional), FIG. 6A is a side view, and FIG. 6B is a rear view. By providing the bolts 14 at the upper first height position 91 and the lower second height position 92, the two bolts 14 are arranged in a straight line along the longitudinal direction. The distance D1 from the upper end 11d to the first height position 91 was 620 mm, and the distance D2 from the lower end 11e to the second height position 92 was 900 mm. Thus, the four bolts 14 in total were provided by arranging two bolts 14 arranged linearly along the longitudinal direction and arranging them along the width direction.

  FIG. 7A and FIG. 7B are schematic views showing the updated mounting structure (case B) of the embodiment, FIG. 7A is a side view, and FIG. 7B is a rear view. By providing the bolts 14 at the third height position 93 to the sixth height position 96, the four bolts 14 were arranged in a straight line along the longitudinal direction. The third height position 93 is set to the first height position 91 of the case A, and the fourth height position 94 is the upper end 11d and the third height position 93 so that the aforementioned D4 / D3 is 50%. Set in the center of Further, the fifth height position 95 is set to the second height position 92 of the case A, and the sixth height position 96 includes the lower end 11e and the fifth height so that the aforementioned D6 / D5 is 50%. Centered at position 95. In this manner, four bolts 14 arranged in a straight line along the longitudinal direction and two bolts 14 arranged side by side along the width direction were further arranged to provide a total of eight bolts 14.

  8A and 8B are schematic views showing an attachment structure (case C) of a comparative example. FIG. 8A is a side view and FIG. 8B is a rear view. In the case C, a bolt is added to the center of the first height position 91 and the second height position 92 in the case A described above. This provided a total of six bolts.

  9A and 9B are schematic views showing a mounting structure (case D) of a comparative example. FIG. 9A is a side view, and FIG. 9B is a rear view. In case D, two height positions were added at equal intervals between the first height position 91 and the second height position 92 in case A described above. This provided a total of 8 bolts.

  In any case, the bolt 14 was modeled only on the shaft portion of the bolt. The boundary conditions of the thermal stress analysis constrained displacement at the head side end face of the shaft and allowed rotation. In addition, a rigid body surface was arranged on the back surface of the stave cooler 11 by simulating an irregular refractory.

  In the thermal stress analysis, the thermal cycle was repeated 20 times. After the thermal cycle, the horizontal deformation amount (displacement) to the furnace inside at the upper end 11d and the lower end 11e on the inner (front side) surface of the stave cooler was determined. For the thermal cycle, the temperature distribution of the stave cooler obtained at predetermined time intervals by the heat transfer analysis described above was used.

  Table 1 shows the outline of the case and the amount of deformation (mm) of the upper and lower ends of the stave cooler into the furnace.

  In the mounting structure (case A) before the update (conventional), the stave cooler is fixed at the upper first height position 91 and the lower second height position 92. In case A, the amount of deformation of the upper end 11d is 2.46 mm and the amount of deformation of the lower end 11e is 3.86 mm, as shown in Table 1.

  In the attachment structure of the comparative example (cases C and D), the bolt 14 is added between the first height position 91 and the second height position 92. In the cases C and D, the deformation amount of the upper end 11d was 50 to 55% and the deformation amount of the lower end 11e was 56 to 59% on the basis of the deformation amount of the case A, and the deformation amount was reduced.

  In the updated mounting structure (case B), the third to sixth height positions (93 to 96) are fixed, that is, the upper and lower portions of the stave cooler 11 are fixed at two height positions, respectively. In the case B, the deformation amount of the upper end 11d was 11% and the deformation amount of the lower end 11e was 16%, based on the deformation amount of the case A, and the deformation amount was greatly reduced. Further, in the case B, the deformation amounts of the upper end 11d and the lower end 11e were significantly reduced as compared with the cases C and D of the comparative example.

  From these, it became clear that the renewal method of the present invention can suppress plastic deformation and suppress bending of the stave cooler due to repeated increase and decrease of the furnace temperature.

  The renewal method of the present invention can prevent the stave cooler from being bent due to repeated increases and decreases in the furnace temperature. For this reason, it can utilize effectively in manufacture of pig iron using a blast furnace.

10: furnace body, 11: stave cooler, 11a: cooling path, 11b: supply port,
11c: discharge port, 11d: upper end, 11e: lower end, 12: iron skin (outer wall),
13: Indeterminate refractory, 14: Bolt (fixing member), 15: Cooling water supply pipe,
16: Cooling water discharge pipe, 17: Telescopic pipe, 18: Seal member
91: 1st height position, 92: 2nd height position, 93: 3rd height position,
94: 4th height position, 95: 5th height position, 96: 6th height position,

Claims (3)

A method of updating a mounting structure of a copper or copper alloy stave cooler fixed to an outer wall portion of a metallurgical furnace by a fixing member disposed at an upper first height position and a lower second height position. ,
The update method is
Fixing the stave cooler by a fixing member disposed at a third height position, a fourth height position, a fifth height position, and a sixth height position;
In the step of fixing the stave cooler,
Providing the third height position so as to coincide with the first height position or between an upper end of the stave cooler and the first height position;
Providing the fourth height position between an upper end of the stave cooler and the third height position;
The fifth height position is provided so as to coincide with the second height position or between the lower end of the stave cooler and the second height position,
A method for updating a mounting structure of a stave cooler, wherein the sixth height position is provided between a lower end of the stave cooler and the fifth height position. A method for updating a mounting structure of a stave cooler according to claim 1,
In the step of fixing the stave cooler, the third height position is provided so as to coincide with the first height position, and the fifth height position is provided so as to coincide with the second height position. A method for updating the mounting structure of the stave cooler. A method for updating a mounting structure of a stave cooler according to claim 1 or 2,
The update method is
Removing the first stave cooler fixed to the outer wall and replacing it with a second stave cooler;
In the step of fixing the stave cooler, the stave cooler mounting structure updating method, wherein the second stave cooler is fixed and mounted.

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