JP4160175B2 - Metallurgical furnace stave - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a stave used in a metallurgical furnace such as a blast furnace.
[0002]
[Prior art]
The furnace wall structure of the blast furnace has a structure in which a stave (cooling stave) provided with an internal cooling mechanism is provided inside the iron shell via a refractory, and the refractory in the furnace is held inside the stave. Conventionally, cast iron is widely used as a blast furnace stave, and among them, a structure in which a cooling pipe is casted with cast iron is generally used.
[0003]
When the blast furnace is operated for a certain period, the refractory in the furnace falls off the stave due to damage or the like, and the stave is directly exposed to the inside of the furnace. In this state, especially in the high heat load area at the bottom of the blast furnace where the molten slag exists (morning glory part, upright part, shaft lower part), high thermal stress is easily generated in the stave body, and this crack is likely to occur in the cooling pipe. Propagates water leakage accidents easily. Even if such damage does not occur, the stave body exposed to the inside of the blast furnace after the refractory in the furnace is dropped gradually wears, and finally, this wear reaches the cooling pipe. For this reason, it is necessary to replace the damaged or worn stave with a new stave during the long-term operation of the blast furnace.
[0004]
When replacing an existing stave with a new stave, it is preferable to use a copper (or copper alloy, the same applies hereinafter) stave. Since copper has a higher thermal conductivity than cast iron, the copper stave has the advantage that the temperature inside the main body is always kept low, but due to its high cooling capacity, especially in the high heat load region below the blast furnace, The effect is obtained. That is, even when the furnace inner refractory falls off the stave body in the high heat load region at the bottom of the blast furnace, the molten slag solidifies as soon as it comes into contact with the stave surface, and a hardly peelable solidified slag layer is generated on the stave surface. Since this hardly peelable solidified slag layer has a very low thermal conductivity, the copper stave is protected from the high heat load of the furnace, and heat removal from the furnace by the stave is appropriately suppressed.
[0005]
Therefore, it can be said that a copper stave is optimal for extending the life of the blast furnace, reducing energy loss due to overcooling in the high heat load region, simplifying the furnace wall structure, and thereby reducing costs. Even when a new stave is replaced with a worn existing cast iron stave, it is preferable to use a copper stave as the new stave.
[0006]
[Problems to be solved by the invention]
By the way, since a copper stave has a higher thermal conductivity than a cast iron stave, when replacing a part of an existing cast iron stave with a copper stave, a copper stave having a thickness smaller than that of a cast iron stave (for example, a cast iron stave). If the thickness is about 200 to 300 mm, the thickness of the copper stave is about 150 mm). However, when a copper stave with such a small thickness is installed adjacent to an existing cast iron stave, a so-called back wind is generated because the inside profile of the furnace is damaged, and this back wind is generated on the back side of the stave (iron side). ) Causes a problem that the refractory on the back side of the stave is worn out.
[0007]
On the other hand, conventionally, as a copper stave used alone for a blast furnace, a type obtained by machining a rolled material or a forged material (for example, Japanese Examined Patent Publication No. 63-56283) and a cooling pipe made of cast copper. A cast type is known, and a jacket type is also known as a copper stave used in combination with a cast iron stave.
[0008]
However, these conventional copper staves have the following problems.
First, a copper stave obtained by machining a rolled material or a forged material has drawbacks such as complicated machining, high production costs, and low shape freedom. Specifically, the following problems can be mentioned, for example.
(1) The stave body needs to have a curvature according to the furnace inner diameter, but such a curvature when manufacturing a stave by machining a rolled material, etc. It is extremely difficult. For this reason, the stave body must be designed in a flat plate shape, and as a result, the operating volume of the furnace is reduced.
[0009]
(2) Although it is necessary to provide bosses and ribs for fixing to the iron skin on the back of the stave, these parts must be processed and welded, which increases the cost.
(3) If a rib is provided on the back side of the stave or a protrusion or groove for holding a refractory or solidified slag is provided on the cooling operation surface side, it is necessary to cut out from a thick plate material, resulting in high manufacturing costs. Become.
(4) When the stave is applied to the part from the hearth (cut) to the shaft, it is necessary to make the stave shape “vertical” in the vertical direction, which requires cutting and bending. This increases the manufacturing cost.
[0010]
Furthermore, in a copper stave obtained by machining a rolled material or a forged material, the refrigerant passage inside the stave needs to be formed by drilling, and in order to form the corner portion of the refrigerant passage, the passage must be formed. It is necessary to plug weld one end of the holes after making the holes perpendicular to each other, but the corners of the passages thus provided are L-shaped, so that the refrigerant (usually cooling water) flowing through the passages There is a problem that the pressure loss increases and the energy loss is large. In addition, since the cooling water stagnates in such an L-shaped corner, deposits are likely to be formed on the inner surface of the passage of this portion, and if such deposits grow with time, it may cause pressure loss of the cooling water. Moreover, the heat transfer efficiency between the cooling water and the stave is lowered, and the cooling action by the cooling water is lowered. Furthermore, when the stagnation of the cooling water as described above occurs, bubbles are generated due to the disturbance of the cooling water flow, and these bubbles also reduce the cooling action by the cooling water. When the pressure loss as described above becomes significant, the flow rate of the cooling water is also affected, and this influence and the reduction of the cooling action also cause the function of the stave to be lowered.
[0011]
Further, the cast copper stave for casting the cooling pipe has the following problems, and particularly the following problems (1) to (3) are caused. Therefore, its practical use is difficult.
(1) Since the cooling pipe and the cast part that casts the cooling pipe are not welded and are in a close contact state at most, a gap is usually formed between them. Due to the existence of this gap, the heat conduction between the cooling pipe and the casting part is not sufficient, and the casting part is likely to be damaged by the heat load from the inside of the furnace. Then, the cooling pipe exposed due to the breakage of the casting part is deformed and worn, and eventually breaks and leaks water.
(2) The cooling pipe may recrystallize due to the heat during casting, which may cause the cooling pipe strength to decrease and cause damage.
[0012]
(3) Since the melting point of the copper cooling pipe and the melting point of the copper casting are the same, the cooling pipe may be melted depending on the casting temperature. If the casting temperature is lowered to avoid this, gas defects are likely to occur. Moreover, when only the cooling pipe is made of iron in order to avoid such a problem, the cooling ability of the entire stave is lowered because the thermal conductivity of iron is small.
(4) In order to form the refrigerant passage inside the stave, it is necessary to bend the cooling pipe with high accuracy, and sometimes it is also necessary to bend into a complicated shape, so that the manufacturing cost is high.
(5) When casting the cooling pipe, it is difficult to position the pipe accurately, and the product as designed may not be obtained. In particular, in the bent part of the cooling pipe, the curvature dimension before casting may be extended, and the dimensional accuracy may deteriorate.
[0013]
In addition, even when a jacketed cast copper stave used in combination with a cast iron stave is used alone, there are the following problems.
(1) The amount of cooling water that can be supplied to each stave has a certain limit due to pump capacity limitations, but the jacket-type cast copper stave has a large cross-sectional area of the refrigerant passage, which inevitably reduces the cooling water flow rate. . In general, in order to withstand the heat load from the inside of the furnace, the cooling water in the refrigerant passage requires a flow rate of about 1 to 3 m / sec, but with a jacket type cast copper stave, it is less than 1 m / sec (generally 0.3 m Only a cooling water flow rate of / sec or more and less than 1 m / sec) can be obtained, and there is a risk of melting due to a heat load from the inside of the furnace.
[0014]
(2) In a jacket-type cast copper stave, if multiple independent refrigerant passages are provided, the structure becomes complicated, and the cross-sectional area per refrigerant passage is large as described above. Only the refrigerant passage of the system level can be provided. For this reason, even when the stave is partially melted, there is a risk that the function of the refrigerant passage is completely lost. Even if water leakage from the refrigerant passage is caused by partial melting, if the cooling water supply is stopped or reduced for inspection or repair, the stave may be completely melted. It is not possible to check or even repair leaks.
[0015]
(3) In the jacket structure, since the number of turns in the refrigerant passage increases, the pressure loss of the cooling water increases and the energy loss increases. Further, it is necessary to provide a mounting boss (mounting hole) for fixing to the iron skin on the back surface of the stave, but in the jacket structure, a part of this boss protrudes to the refrigerant flow path, and this becomes a resistance of the cooling water. Therefore, it becomes a factor which produces the pressure loss of cooling water. Furthermore, since the cooling water stagnates at the corners of the jacket structure, deposits are likely to form on the inner surface of the passage of this portion, and if such deposits grow over time, the heat transfer efficiency between the cooling water and the stave decreases. Resulting in. Moreover, when the stagnation of the cooling water as described above occurs, bubbles are generated due to the disturbance of the cooling water flow, and the bubbles reduce the cooling action by the cooling water. These problems also cause the stave function to deteriorate.
[0016]
Therefore, the object of the present invention is to solve such problems of the prior art, and to replace the existing cast iron stave that has been damaged or worn out with the refractory material on the iron skin side caused by the occurrence of back wind. It is an object of the present invention to provide a metallurgical furnace stave made of copper or copper alloy which can prevent wear and tear appropriately.
Another object of the present invention is to maintain a proper function over a long period of time even when applied to a high heat load region at the bottom of the blast furnace, and also causes the problems of the conventional copper stave as described above. There is no metallurgical furnace stave.
[0017]
[Means for Solving the Problems]
The present inventors have repeatedly investigated the structure of a copper or copper alloy stave that can solve the above-mentioned problems, and as a result, by projecting ribs under predetermined conditions on the surface of the stave body that becomes the iron skin side, It has been found that the occurrence of the back wind described above can be appropriately prevented, and that it is also effective for cooling and holding the refractory on the iron skin side.
[0018]
Furthermore, the present inventors can maintain the proper function of the copper stave applied to the high heat load region by generating a solidified slag layer on the surface of the stave even after the furnace refractory falls off. From the viewpoint of being optimal as a stave applied to the high heat load region of a blast furnace, as a result of various investigations to obtain a copper stave that does not cause the problems as in the prior art, a stave body made of copper or copper alloy Cast copper stave made by simultaneously forming the coolant passage with the core at the time of casting, without causing problems as in the prior art, and being able to demonstrate extremely superior performance beyond expectations I found out.
[0019]
  The present invention has been made based on such findings, and the features thereof are as follows.
[1] In a metallurgical furnace stave having a coolant passage inside a stave body made of copper or copper alloy, ribs along the width direction of the stave body are formed on the surface of the stave body on the iron skin side.At one or more positions between the upper and lower positions of the stave body.Metallurgical furnace stay characterized byB
[0020]
[ 2 ]the above[ 1 ]The metallurgical furnace is characterized in that the stave body is formed of a cast body made of copper or a copper alloy that is integrally cast, and has a refrigerant passage formed in the stave body during casting. Stave for.
[ Three ]the above[ 2 ]In the metallurgical furnace stave, a bent portion of the refrigerant passage is provided with a curvature.
[ Four ]the above[ Three ]The metallurgical furnace stave according to claim 1, wherein the curvature of the bent portion is at least three times the representative inner diameter of the refrigerant passage.
[0021]
[ Five ]the above[ Three ]Or[ Four ]In the metallurgical furnace stave, the refrigerant passage is coupled to the main passage portion through a corner portion having a curvature at each end portion of the main passage portion, or an entrance-side passage portion coupled with a curvature, and A metallurgical furnace stave comprising an outlet-side passage portion, and each end portion of the inlet-side passage portion and the outlet-side passage portion constitutes an inlet and an outlet of the refrigerant.
[ 6 ]the above[ 2 ]~[ Five ]The metallurgical furnace stave according to any one of the above, characterized in that the stave body has two or more independent refrigerant passages formed at the time of casting.
[0022]
[ 7 ]the above[ 2 ]~[ 6 ]In any metallurgical furnace stave, the cross-sectional area of the refrigerant passage is 2500 mm.²A metallurgical furnace stave characterized by:
[ 8 ]the above[ 2 ]~[ 7 ]In the metallurgical furnace stave of any one of the above, the cross section passing through the approximate center of the stave body or the vicinity thereof, and in the cross section of the stave body in the direction orthogonal to the axial direction of the plurality of main passage portions of the refrigerant passage, The total cross-sectional area s of the passage and the stave body (however, the stave body portion excluding the ribs, and the protrusions and / or grooves are formed on the cooling operation surface and / or the iron skin side of the stave body) The ratio s / S to the cross-sectional area S of the stave main body portion excluding the thickness of the portion where the protrusion and / or groove is formed is 0.05 to 0.15, Metallurgical furnace stave.
[0023]
[ 9 ]Above [1] ~[ 8 ]A metallurgical furnace stave according to any one of the above, wherein a protrusion and / or a groove is formed on substantially the entire cooling operation surface of the stave body.
[ Ten ]Above [1] ~[ 9 ]A metallurgical furnace stave according to any one of the above, characterized in that a refractory inside the furnace is fixed to the cooling operation surface of the stave body.
[ 11 ]Above [1] ~[ Ten ]A metallurgical furnace stave according to any one of the above, characterized in that a refractory layer is provided by applying a castable to the surface of the stave body provided with ribs on the iron skin side.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show one embodiment of the stave for metallurgical furnace of the present invention. FIG. 1 is a rear view (back view seen from the iron skin side), FIG. 2 is a side view, and FIG. It is sectional drawing which follows III-III.
In the figure, 1 is a stave body made of copper or copper alloy (hereinafter, a copper stave body will be described as an example), 2a to 2d are refrigerant passages formed inside the stave body 1, and usually a stave body. The refractory material 3 in the furnace as shown by phantom lines in FIGS. 2 and 3 is fixed to the cooling operation surface 1 of 1 by appropriate fixing means. This fixing means is optional, but, for example, a plurality of rod-shaped support fittings are provided on the cooling operation surface a of the stave body 1, and these support fittings are formed on each refractory brick constituting the furnace refractory 3. For example, a structure for supporting and fixing the in-furnace refractory 3 to the stave body 1 can be adopted.
[0025]
On the surface (back surface) on the iron skin side of the sub body 1, a plurality of ribs 10 are provided along the stave main body width direction at intervals in the stave main body height direction.
As mentioned earlier, the copper stave has higher thermal conductivity than the cast iron stave, so when replacing it with a part of the existing cast iron stave, the thickness is smaller than the cast iron stave (for example, cast iron If the thickness of the made stave is about 200 to 300 mm, the thickness of the copper stave is about 150 mm). Therefore, by providing the rib 10 as described above, when it is provided adjacent to an existing cast iron stave, it is possible to obtain a thickness substantially equal to that of this existing cast iron stave. Maintaining and preventing the occurrence of back wind.
[0026]
FIG. 4 schematically shows a structure in which the stave of the present invention is replaced with a part of an existing cast iron stave and is provided adjacent to the existing cast iron stave, where A is the stave of the present invention, A 'is an existing cast iron stave, B is an iron skin, 9 is a refractory on the back side of the stave, and 11 is a fixing bracket for fixing the stave A to the iron skin B.
As shown in the figure, since the copper stave A of the present invention has the rib 10 on the back side, the thickness is almost equal to that of the adjacent cast iron stave A ′, so that there is a large step in the profile inside the furnace. It has not occurred.
[0027]
Further, when the existing cast iron stave A ′ adjacent to the copper stave A of the present invention is worn as indicated by the phantom line a ′ in the figure, the back wind is on the back side of the copper stave A because of the rib 10. It is prevented from going around.
Further, the plurality of ribs 10 have a function of cooling and holding the refractory 9 on the back side of the stave. That is, since the refractory 9 is cooled and held between the upper and lower ribs 10, the refractory 9 is stably maintained over a long period of time without causing wear or dropping.
Further, the stave of the present invention has a structure in which the thickness of the stave body 1 is small and the thickness is secured by the ribs 10, so that the weight of the stave body 1 can be reduced and the manufacturing cost can be reduced.
[0028]
The height of each rib 10 (height in the thickness direction of the stave) is taken into consideration the thickness of the adjacent existing cast iron stave at the applicable location when used in place of the existing cast iron stave. And selected so that the profile inside the furnace is maintained.
The number of ribs 10 is arbitrary, but in order to prevent the back air from wrapping around the refractory on the back side of the stave and to obtain a sufficient cooling / holding function for the refractory on the back side of the stave, It is preferable to provide at least one strip, preferably two or more strips between the upper and lower ends of the main body 1.
[0029]
Conventionally, when replacing an existing stave with a new stave, the new stave is fixed to the inside of the iron skin with a fixing bracket, and then castable is injected into the back side of the stave (that is, between the stave and the iron skin). The method to be taken is taken. This stave replacement work is performed using the furnace's downtime, but since it takes a relatively long time to inject the castable, the castable is performed to every corner on the back side of the stave within the limited downtime. For this reason, there is a possibility that a cavity is formed in a part on the back side of the stave.
[0030]
On the other hand, when constructing the metallurgical furnace stave of the present invention, a castable is directly constructed on the surface (back surface) of the stave outside the furnace in advance to provide a refractory layer. Can be installed inside the iron shell, so that the construction can be completed in a very short time even when the castable injection after the installation of the stave is omitted or injected. That is, since the stave of the present invention has the rib 10 on the back surface, even if the castable is directly applied to the back surface of the stave, the rib 10 can hold the refractory layer formed by the castable. It is possible to construct and provide a refractory layer. And since such a construction method can be adopted, there is almost no possibility that a cavity is generated in the refractory layer on the back side of the stave as in the conventional construction method.
[0031]
Stave for metallurgical furnace of the present invention is a stave in which a stave body is integrally cast, a stave obtained by machining a rolled material or a cast material, a stave of a type in which a cooling pipe is cast-cast with copper, a jacket type Any type of stave, etc. may be used, but it has the most excellent function especially as a stave, and maintains an appropriate function for a long period of time even when applied to a high heat load region at the bottom of the blast furnace. From the viewpoint that the stave body is integrally cast, it is most preferable.
The embodiment shown in FIGS. 1 to 3 is also a stave of this type, and the stave body 1 is formed of a cast body made of copper or copper alloy integrally cast, and is formed inside the stave body 1 at the time of casting. The refrigerant passages 2a to 2d are provided.
[0032]
In the stave having such a structure, the refrigerant passage 2 is simultaneously formed using a core having a small cross-sectional area when the stave body 1 is cast.
As described above, as the conventional cast copper stave, only a cast copper stave in which a cooling pipe is cast and a jacket type cast copper stave are known, and the stave body 1 is integrated as in this embodiment. There is no known structure having a structure in which the coolant passage 2 is formed simultaneously with the casting of the stave body by a core having a small cross-sectional area.
[0033]
The number of refrigerant passages 2 formed inside the stave body 1 is arbitrary. However, in consideration of maintaining the cooling function even when a part of the refrigerant passage is damaged, there are 2 inside the stave body 1. It is preferable to form independent refrigerant passages that are higher than the system, and in this embodiment, four independent refrigerant passages 2a to 2d are formed. A refrigerant such as cooling water (hereinafter, cooling water will be described as an example) is introduced into these refrigerant passages 2 from one end side, and the cooling water cools the inside of the stave body and then the other end of the refrigerant passage. Discharged from the side.
[0034]
In the refrigerant passage 2, it is preferable that all the bent portions such as corner portions have a curvature in order to reduce the pressure loss of the cooling water as much as possible and prevent the cooling water from becoming stagnation.
The refrigerant passages 2a to 2d of the present embodiment include a linear main passage portion 20 along the stave longitudinal direction or the width direction, and corner portions 23 having a predetermined curvature at each end portion of the main passage portion 20. Each of the inlet side passage portion 21 and the outlet side passage portion 22 are coupled to each other with a predetermined curvature. 4 and outlet 5 are respectively configured. Pipes (not shown) are connected to the inlet 4 and the outlet 5 by welding or the like.
[0035]
Curvature R (curvature R of the bent portion) of each corner portion 23, inlet-side passage portion 21 and outlet-side passage portion 22 itself of refrigerant passages 2a to 2d reduces the pressure loss of cooling water as much as possible. From the viewpoint of preventing stagnation, it is preferable to set it to 3 times or more of the representative inner diameter. If the curvature R is less than three times the representative inner diameter, the energy loss due to the pressure loss of the cooling water flowing through the passage becomes large, which is not preferable. In addition, if the curvature R of the bent portion is small, it becomes easy to cause stagnation of the cooling water. Therefore, deposits are likely to be formed on the inner surface of the passage of this portion. In addition, the heat transfer efficiency between the cooling water and the stave is lowered, and the cooling action by the cooling water is lowered. Furthermore, if the stagnation of the cooling water as described above occurs, bubbles are likely to be generated due to the disturbance of the cooling water flow, and these bubbles also reduce the cooling action by the cooling water. When the pressure loss as described above becomes significant, the flow rate of the cooling water is also affected, and this influence and the reduction of the cooling action also cause the function of the stave to be lowered.
[0036]
The main passage portion 20 of the refrigerant passage 2 can take an appropriate form other than the linear shape as in the present embodiment, and may be, for example, curved or S-shaped, It is good also as a main channel | path part which has 2 or more linear form by giving the above curvature to a corner part.
There is no special restriction | limiting in the cross-sectional shape of channel | path 2a-2d for refrigerant | coolants, Arbitrary cross-sectional shapes, such as circular, a square, an ellipse, and a polygon, can be employ | adopted.
[0037]
Moreover, in order to ensure the cooling water flow velocity in the refrigerant | coolant channel | path 2, the cross-sectional area (radial direction cross-sectional area) of the refrigerant | coolant channel | paths 2a-2d is 2500 mm.²The following (more preferably, 2000 mm²Or less). As described above, when the cooling water flow velocity (cooling water linear velocity) in the passage is less than 1 m / sec, the cooling ability of the stave is lowered, and the stave may be melted by the heat load from the furnace. However, in view of the general pumping capacity for supplying cooling water to the refrigerant passage 2, the sectional area of the refrigerant passage 2 is 2500 mm.²If it exceeds, the cooling water flow rate of 1 m / sec or more may not be secured.
[0038]
The stave applied to the furnace body generates a solidified slag layer having a low peelability and a low thermal conductivity on the cooling operation surface due to its cooling ability even when the furnace inner refractory 3 is dropped from the stave body 1. It is necessary to be able to withstand the high heat load from the inside of the furnace with the layer, and even when applied to the high heat load area at the bottom of the blast furnace, it is appropriate for a long period of time without causing melting or cracking. The function can be maintained. However, although the solidified slag layer generated on the cooling operation surface of the stave body 1 is hardly peelable, for example, when a sudden thermal shock is applied, peeling may occur. In such a case, it is necessary to quickly regenerate the solidified slag layer by adhering slag to the cooling operation surface of the stave body 1, and if the regeneration of the solidified slag layer is delayed, the stave body is subjected to a high heat load from the inside of the furnace. It becomes impossible to endure, and it becomes easy to cause melting damage and cracking.
[0039]
FIG. 5 shows the transition of the temperature inside the stave body before and after peeling and the regenerated (reattached) after the solidified slag layer is peeled off when the solidified slag layer formed on the cooling operation surface of the stave body 1 is peeled off. ) Shows the regeneration time t. According to this, immediately after peeling of the solidified slag layer occurs, the temperature of the stave body 1 rises from about 80 ° C. to 200 ° C. at once, and the temperature gradually decreases from this temperature as the slag begins to reattach. After a certain time (regeneration time t) has elapsed, the temperature returns to a steady temperature of around 80 ° C.
[0040]
In order to prevent damage (melting damage or cracking) of the stave body due to a high heat load from the inside of the furnace when the solidified slag layer is peeled in this way, it is necessary to shorten the regeneration time t of the solidified slag layer as much as possible. Therefore, it is indispensable to maintain the flow rate of the cooling water flowing in the refrigerant passage 2 at a certain level or higher. FIG. 6 shows the relationship between the flow rate of the cooling water flowing in the refrigerant passage 2 and the regeneration time t of the solidified slag layer after separation, and when the flow rate of the cooling water is less than 1 m / sec, the solidified slag is shown. It can be seen that because the layer regeneration time t is too long, the stave body 1 may be damaged by a high heat load. On the other hand, when the cooling water flow rate is 1 m / sec or more, the stave body 1 is hardly damaged by a high heat load. In addition, since the effect beyond it cannot be expected even if a cooling water flow rate exceeds 4 m / sec, it is preferable that a cooling water flow rate shall be 4 m / sec or less from the surface of economical efficiency.
[0041]
Further, in order to ensure an appropriate cooling capacity of the stave body 1, it is preferable that the ratio of the cross-sectional area (total cross-sectional area) of the refrigerant passage 2 in the cross section of the stave body is within a predetermined range. That is, as shown in FIG. 7, a cross-section passing through the approximate center of the stave body 1 or the vicinity thereof, and a cross-section A of the stave body 1 in a direction perpendicular to the axial direction of the plurality of main passage portions 20 of the refrigerant passage 2. In -A, the ratio s / S between the total sectional area s of the refrigerant passage 2 and the sectional area S of the stave body 1 is preferably 0.05 to 0.15.
[0042]
As shown in FIG. 7, the cross-sectional area S of the stave body 1 is a cross-sectional area of the stave body portion excluding the ribs 10, and the front surface (cooling operation surface a) and / or the back surface of the stave body 1 ( When protrusions and / or grooves (grooves 6 in the case of FIG. 7) are formed on the surface (the iron skin side), the stave body part excluding the thickness x of the part where the protrusions and / or grooves are formed The cross-sectional area of
If the ratio s / S is less than 0.05, the cooling ability of the stave is low, so that the stave may be melted by the heat load from the inside of the furnace. On the other hand, even if the ratio s / S exceeds 0.15, no further effect can be expected, and the strength of the stave body may be reduced.
[0043]
The solidification slag as described above for the cooling operation surface a after the furnace inner refractory 3 is dropped (slag solidified in contact with the cooling operation surface a) is provided on the substantially entire surface of the cooling operation surface a of the stave body 1. Is formed, and a groove 6 is formed to hold it. The mode of formation of the groove 6 (groove depth, formation density, etc.) is arbitrary, and projections may be provided in place of or along with the groove 6.
Moreover, in this embodiment, the inside of the said groove | channel 6 is filled with the refractory 7 and the cooling operation surface side is planarized, The furnace inner refractory 2 is attached and fixed to this surface.
[0044]
In the stave formed of a cast body in which the stave body is integrally cast as in the present embodiment, the inner surface of the refrigerant passage 2 formed inside the stave body 1 has a relatively rough surface (casting). Skin surface). And the fact that the inner surface of the refrigerant passage 2 has a rough surface in this way, combined with the fact that the stave body is made of copper or copper alloy, has the following great advantages in terms of the cooling capacity of the stave. It turned out that it becomes.
[0045]
That is, the conventional stave obtained by machining a rolled material or a forged material as described above is provided with a refrigerant passage by drilling by machining, and therefore the inner surface of the refrigerant passage is rough. Small and smooth surface. By the way, when an unsteady and extremely high heat load acts on the stave (for example, when the solidified slag layer on the cooling operation surface peels off as described above), the cooling water flowing in the refrigerant passage It is preferable to take heat away from the nucleate boiling phenomenon and cool the stave body 1 quickly. The cooling water nucleate boiling phenomenon is more likely to occur when the heat transfer surface (in this case, the inner surface of the refrigerant passage) is rough.
[0046]
Therefore, the above-mentioned conventional type of the stave body in which the inner surface of the refrigerant passage has a smooth processed surface is unlikely to cause a nucleate boiling phenomenon, and therefore the stave body is likely to become hot when a high heat load is applied. The descent speed is also small. On the other hand, in the stave body of the present invention in which the inner surface of the refrigerant passage 2 has a rough casting surface, the nucleate boiling phenomenon easily occurs in the refrigerant passage, thereby instantly depriving a large amount of heat. 1 can be quickly reduced. And the difference of such an effect is especially remarkable when the material of a stave body is copper or copper alloy with high heat conductivity. Therefore, the integrally cast stave which is one embodiment of the present invention is It can be said that it has an excellent cooling ability as compared with a conventional type stave obtained by machining a rolled material or a forged material.
[0047]
When the stave body 1 is made of a copper alloy, for example, CuC1, CuC2, CuC3, etc. defined in JIS H 5100 are used. When the stave body 1 is made of a copper alloy, for example, chrome zircon copper, beryllium copper, etc. The low alloy copper is used.
In the other drawings, reference numeral 8 denotes mounting holes formed at a plurality of positions on the back surface of the stave body 1, and the mounting holes 8 can be formed at the time of casting or by drilling after casting.
As shown in FIG. 4, the stave A of the present invention is arranged on the inner side of the iron skin B via a refractory 9 and is fixed to the iron skin B by a fixing metal fitting 11 inserted into the mounting hole 8.
[0048]
An integrally cast stave according to an embodiment of the present invention is manufactured by integrally casting a stave body 1 using copper or a copper alloy as a raw material, and simultaneously forming a refrigerant passage 2 by a core at the time of casting. In general, a sand core is used as the core.
In addition, the integrally cast stave has a relatively small cross-sectional area of the coolant passage 2 in order to increase the flow rate of the cooling water, so that when the heat partially concentrates on the sand core during casting, the shape of the sand core Core sand (such as conventional)₂It is almost impossible to reliably form the refrigerant passage 2 having a small cross-sectional area.
[0049]
In order to reliably form the refrigerant passage 2 having a small cross-sectional area, it is necessary to use a sand core having high thermal conductivity, a large heat capacity, and fire resistance. It becomes possible to do. As such core sand, thermal conductivity: 0.5 to 1.5 kcal / m · hr · ° C., fire resistance Zeger cone (SK): 17 to 37, thermal expansion coefficient (500 ° C.): 0.5 to ZrO having physical properties of 1.5% and melting point of about 1750-2000 ° C₂It is preferable to use sand mainly composed of so-called zircon sand. In addition, as a casting method, it is preferable to perform casting while inserting a metal pipe into the core sand and blowing a coolant such as air into the pipe to cool the core. And by adopting a combination of such a special material sand core and the above-mentioned special casting method, the cross-sectional area: 2500 mm²An integrally cast stave having a refrigerant passage with a small cross-sectional area as described below can be manufactured.
[0050]
The integrally cast metallurgical furnace stave as described above has the following advantages over the conventional copper stave.
(1) Even when it is applied to the high heat load area at the bottom of the blast furnace, it can maintain its proper function for a long time without causing melting or cracking, and even when the refractory 3 inside the furnace falls off Because of its excellent cooling capacity, a solidified slag layer with low peelability and low thermal conductivity is formed on the cooling operation surface, so it can withstand high heat loads from the furnace and appropriately suppresses heat removal from the furnace. Is done.
[0051]
(2) Since the inner surface of the refrigerant passage 2 formed inside the stave body 1 has a relatively rough surface (cast surface) as a cast body, when a high heat load acts unsteadily However, the nucleate boiling phenomenon easily occurs in the refrigerant passage, which can instantly take away a large amount of heat and quickly reduce the temperature of the stave body 1, and the material of the stave body can be copper or copper having high thermal conductivity. Combined with the copper alloy, an excellent cooling effect can be exhibited.
[0052]
(3) Since the stave body 1 is composed of a cast body that is integrally cast, and the refrigerant passage 2 therein is also formed when the stave body is cast, a conventional rolled material or forged material is machined. The shape and structure of the main body 1 of the stave body 1 does not require any complicated machining such as the obtained copper stave, and does not cause a problem in manufacturing cost unlike the stave obtained by machining because it is a cast body. Can be selected arbitrarily. In addition, an arbitrary curvature R can be given to a bent portion such as the corner portion 23 of the refrigerant passage 2, and the pressure loss of the cooling water flowing through the refrigerant passage 2 can be appropriately prevented. It is also possible to prevent stagnation of cooling water.
[0053]
(4) Since the coolant passage 2 is directly formed inside the stave body 1 by casting, it is caused by a problem such as a conventional cast copper stave for casting the cooling pipe, that is, a gap between the cooling pipe and the casting portion. Damage to the casting or cooling pipe, ensuring processing accuracy when bending the cooling pipe, deterioration of dimensional accuracy due to elongation of the bending part of the casting, deterioration of cooling pipe strength due to heat during casting, erosion, etc. There is no fear of causing any problems.
[0054]
(5) Since the coolant passage 2 has a small cross-sectional area formed by casting the stave body 1, the coolant flow rate in the coolant passage 2 is increased as compared to the conventional jacketed cast copper stave (cooling water flow rate). 1 m / s or more), and a high cooling capacity capable of withstanding a high heat load from the inside of the furnace is obtained. In addition, this high cooling capacity enables the solidified slag layer to be quickly regenerated even when the solidified slag layer adhering to the cooling operation surface is peeled off due to sudden thermal shock, etc. Stave damage due to load can be prevented appropriately.
[0055]
Similarly, since the refrigerant passage 2 is configured to have a small cross-sectional area by casting the stave body 1, independent multi-system refrigerant passages can be provided, and the function of the refrigerant passage 2 can be achieved even when the stave is partially melted. The cooling water is supplied to some of the refrigerant passages 2 even when water leaks from the refrigerant passages 2 due to partial melting of the stave. By stopping or reducing the above, it is possible to easily perform inspection / repair such as water leakage while continuing normal operation.
[0056]
(6) Also, instead of a complicated refrigerant passage having many turns like the conventional jacketed cast copper stave, a straight refrigerant passage 2 can be formed, and an iron skin is attached in the middle of the passage. Since there is no part of the boss for overhanging, the pressure loss of the cooling water is small.
Thus, the integrally cast metallurgical furnace stave according to an embodiment of the present invention has an excellent function, and therefore, a molten slag existing area (usually a morning glory of a blast furnace) that is an area having the highest thermal load in the blast furnace. It is particularly suitable as a stave applied to a part, a vertical part, and a shaft lower part.
[0057]
Moreover, the metallurgical furnace stave of the present invention can be applied to shaft metallurgical furnaces other than blast furnaces such as scrap melting furnaces, and various metallurgical furnaces such as smelting reduction furnaces and electric furnaces.
The metallurgical furnace stave according to the present invention is particularly suitable for replacement with an existing cast iron stave as described above, but its usage is not limited to this, and a newly established stave Needless to say, it can be applied to a metallurgical furnace.
[0058]
【The invention's effect】
As described above, the metallurgical furnace stave according to the present invention is suitable for the wear of the refractory on the back side of the stave due to the occurrence of back wind even when it is installed in place of a damaged or worn existing cast iron stave. Can be prevented.
Further, in the invention according to claim 3 of the present application, even when applied to a high heat load region at the bottom of the blast furnace, an appropriate function can be maintained for a long period without causing melting or cracking, and the furnace. Even when the inner refractory falls off, a solidified slag layer with low peelability and low thermal conductivity is formed on the cooling operation surface due to its excellent cooling ability, and can appropriately withstand the high heat load of the furnace, and Heat removal from the furnace can also be prevented appropriately. In addition, since the stave body including the refrigerant passage is integrally manufactured by casting, there is an advantage that it can be manufactured easily and at low cost.
[0059]
In the inventions according to claims 4 and 5 of the present application, since the bent portion of the refrigerant passage is provided with a curvature, the pressure loss of the cooling water flowing in the passage is minimized, and the appropriate flow rate of the cooling water is set. Since the cooling water does not stagnate, there is no pressure loss due to this stagnation, no decrease in cooling effect due to bubble generation, or the like.
[0060]
In the invention according to claim 6 of the present application, the refrigerant passage is coupled to the main passage portion and each end portion of the main passage portion via a corner portion having a curvature, or is coupled to the entrance side with a curvature. Since the end portion of the inlet side passage portion and the outlet side passage portion constitutes an inlet and an outlet of the refrigerant, respectively, the inside of the stave is efficiently cooled by the cooling water. In addition, the pressure loss of the cooling water flowing in the refrigerant passage can be minimized to ensure an appropriate flow rate of the cooling water, and the cooling water does not stagnate. There will be no pressure loss due to the occurrence of this phenomenon, or a decrease in cooling effect due to the generation of bubbles.
[0061]
In the invention according to claim 7 of the present application, since there are two or more independent refrigerant passages formed at the time of casting inside the stave body, the function of the refrigerant passage can be achieved even when the stave is partially melted. Is less likely to be lost, and even if water leakage from the refrigerant passage occurs due to partial melting, the supply of cooling water to some refrigerant passages is stopped or reduced. Therefore, it is possible to easily check and repair water leakage while continuing steady operation.
[0062]
In the invention according to claim 8 of the present application, the cross-sectional area of the refrigerant passage is 2500 mm.²Since it is the following, the flow rate of the cooling water flowing in the passage can be increased, thereby obtaining a high cooling capacity capable of withstanding a high heat load from the furnace. In addition, this high cooling capacity enables the solidified slag layer to be quickly regenerated even when the solidified slag layer adhering to the cooling operation surface is peeled off due to sudden thermal shock, etc. Stave damage due to load can be prevented appropriately.
In the invention according to claim 9 of the present application, by setting the ratio of the cross-sectional area of the refrigerant passage in the cross section of the stave body within a predetermined range, it is possible to ensure a more appropriate cooling capacity of the stave body.
[0063]
In the invention according to claim 10 of the present application, since protrusions and / or grooves are formed on the cooling operation surface of the stave body, solidified slag (contacted with the cooling operation surface) even when the furnace inner refractory falls off. The solidified slag) can be reliably attached and retained, and the solidified slag layer with low thermal conductivity can appropriately withstand high heat loads and can also appropriately suppress heat removal from the furnace. .
In the invention according to claim 12 of the present application, the construction can be completed in a very short time even when injection of castable after installing the stave inside the iron skin is omitted or infused. It can prevent appropriately that a cavity arises in a physical layer.
[Brief description of the drawings]
FIG. 1 is a rear view showing an embodiment of a metallurgical furnace stave according to the present invention.
FIG. 2 is a side view of the metallurgical furnace stave shown in FIG.
3 is a sectional view taken along line III-III in FIG.
FIG. 4 is a side view showing the metallurgical furnace stave according to the present invention attached to the inside of the iron core of the furnace.
FIG. 5 shows the transition of the temperature inside the stave body before and after peeling and the solidified slag layer is regenerated (reattached) after peeling when the solidified slag layer generated on the cooling operation surface of the stave body is peeled off. Graph showing regeneration time t until
FIG. 6 is a graph showing the relationship between the flow rate of cooling water flowing in the refrigerant passage and the regeneration time t of the solidified slag layer after separation occurs
FIG. 7 is an explanatory view showing a cross section AA of the stave body in a direction passing through substantially the center of the stave body or the vicinity thereof and perpendicular to the axial direction of a plurality of main passage portions of the refrigerant passage.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stave body, 2, 2a-2d ... Refrigerant passage, 3 ... Furnace inside refractory material, 4 ... Inlet, 5 ... Outlet, 6 ... Groove, 7 ... Refractory material, 8 ... Mounting hole, 9 ... Refractory material, 10 DESCRIPTION OF SYMBOLS ... Rib, 11 ... Fixing bracket, 20 ... Main passage part, 21 ... Inlet side passage part, 22 ... Outlet side passage part, 23 ... Corner part, A ... Stave, B ... Iron skin, a ... Cooling operation surface

Claims (11)

In a metallurgical furnace stave having a refrigerant passage inside a copper or copper alloy stave body, ribs along the width direction of the stave body are formed on the surface of the stave body on the iron skin side, and the top and bottom positions of the stave body If, metallurgical furnaces stave, characterized in that provided in one or more positions therebetween. 2. The metallurgical furnace according to claim 1 , wherein the stave body is formed of a integrally cast copper or copper alloy casting body and has a coolant passage formed in the stave body during casting. Stave. The metallurgical furnace stave according to claim 2 , wherein the bent portion of the refrigerant passage is provided with a curvature. The metallurgical furnace stave according to claim 3 , wherein the curvature of the bent portion is three times or more the representative inner diameter of the refrigerant passage. The refrigerant passage is composed of a main passage portion, and an inlet-side passage portion and an outlet-side passage portion that are coupled to each end of the main passage portion through a corner portion having a curvature or are coupled with a curvature. The metallurgical furnace stave according to claim 3 or 4 , wherein each of the end portions of the inlet-side passage portion and the outlet-side passage portion forms an inlet and an outlet of the refrigerant. The metallurgical furnace stave according to claim 2, 3, 4 or 5 , wherein the stave body has two or more independent refrigerant passages formed during casting. The metallurgical furnace stave according to claim 2, 3, 4, 5, or 6 , wherein the cross-sectional area of the refrigerant passage is 2500 mm ² or less. The cross section passing through substantially the center of the stave main body or the vicinity thereof, and in the cross section of the stave main body in the direction perpendicular to the axial direction of the plurality of main passage portions of the refrigerant passage, the total cross sectional area s of the refrigerant passage and the stave main body (However, when a protrusion and / or a groove is formed on the stave body portion excluding the rib and on the cooling operation surface and / or the iron skin side of the stave body, the protrusion and / or The ratio s / S with respect to the cross-sectional area S of the stave main body portion excluding the thickness of the portion where the groove is formed is 0.05 to 0.15. , 6 or 7 metallurgical furnace stave. The metallurgical furnace stave according to claim 1, 2, 3, 4, 5, 6, 7 or 8 , wherein a protrusion and / or a groove is formed on substantially the entire cooling operation surface of the stave body. The metallurgical furnace stave according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9 , wherein a refractory inside the furnace is fixed to a cooling operation surface of the stave body. A refractory layer is provided by casting on a surface of the stave body provided with ribs on the iron skin side, wherein a refractory layer is provided. The stave for metallurgical furnaces as described in 9 or 10 .

Images