JP3738578B2 - Stave - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stave made of copper or copper alloy.
[0002]
[Prior art]
A stave cooling system is known as a cooling system for a furnace body in a blast furnace. Conventional stave is generally made of cast iron, but under the condition of repeated heat fluctuations in the furnace, it is made of cast iron, so the surface layer inside the furnace becomes high temperature due to insufficient cooling capacity and material deterioration and wear. Has progressed, or warpage has occurred due to thermal stress, causing problems in the profile inside the furnace, or cracking in the stave itself, shortening the furnace life.
[0003]
Therefore, recently, a stave using copper or a copper alloy superior in physical properties such as thermal conductivity and ductility has been developed. By using copper or a copper alloy, the stave body has a uniform temperature distribution at a lower temperature, the generated thermal stress can be suppressed, and the amount of deformation is also reduced. For this reason, damage to the stave body is reduced, and the life of the furnace can be extended.
However, if the stave material is changed from cast iron to copper, the cooling effect on the contents by the stave increases because copper is excellent in thermal conductivity. For this reason, depending on the installation location of the stave, the amount of heat removal becomes excessive, and there may be a problem that the furnace filling is cooled more than necessary, resulting in an increase in the fuel ratio.
[0004]
In order to solve this problem, for example, there is an invention of a cooling plate for a vertical furnace disclosed in Japanese Patent Publication No. 63-56283.
10 is a rear view of the stave disclosed in the publication, and FIG. 11 is a cross-sectional view taken along line AA in FIG. In the present specification, the back surface of the stave means a surface that becomes the outside of the furnace (iron skin) when the stave is installed in the furnace body, and the front surface means a surface that becomes the inside of the furnace.
[0005]
The structure of a conventional stave will be described with reference to FIGS. Reference numeral 50 denotes a rectangular plate-shaped stave made of copper or a copper alloy, and a cooling water channel 53 is formed therein. Reference numeral 55 denotes an inlet / outlet pipe connected to the cooling water passage 53 and connected to a cooling water supply side (not shown). A mounting bolt (not shown) for fixing the stave body to the iron skin is provided on the back of the stave.
Reference numeral 57 denotes a plurality of horizontal grooves formed on the front surface of the stave, and a fireproof material (not shown) is attached to the plurality of grooves 57. Accordingly, copper and refractory material are alternately arranged on the front surface of the stave.
[0006]
In the conventional stave as described above, the amount of heat extraction can be reduced by reducing the area of copper on the front side of the stave.
[0007]
[Problems to be solved by the invention]
However, in the conventional stave as described above, since the refractory material is installed in an exposed state inside the furnace, the refractory material on the front surface of the stave is reduced due to contact wear and cracking with the filling in the furnace, The exposed area of copper will increase over time, and the heat extraction will gradually increase. Therefore, even though the amount of heat removal can be suppressed to a certain extent at the beginning, there is a problem that the amount of heat removal becomes large due to the volume reduction of the refractory material due to aging.
[0008]
In addition, in order to suppress the aging change as described above, it is necessary to select a refractory material to be installed on the front surface of the stave, which has a thermal shock and is difficult to break. Therefore, the thermal conductivity is simply low. In reality, it is impossible to select one, and it is necessary to employ a limited and expensive refractory material. For this reason, the heat transfer rate from the cooling layer (layer with water channel) to the front surface of the stave is increased not only due to aging but also in the initial stage, and the amount of heat removal becomes excessive.
[0009]
For this reason, it is possible to extend the life of the furnace by adopting a copper stave, but depending on the part used, it may be due to an increase in the amount of heat extracted due to changes in the usage condition due to material and aging. The problem of an increased fuel ratio remained.
Further, since the refractory material is exposed, there is a problem in workability that it is necessary to consider that external force does not act on the refractory material during installation.
[0010]
The present invention has been made to solve such a problem, and an object of the present invention is to obtain a stave made of copper or a copper alloy and capable of stably reducing the amount of heat removal.
[0011]
[Means for Solving the Problems]
The stave according to the present invention is made of copper or a copper alloy, and is characterized in that a heat insulating layer is provided only between the cooling medium passage and the furnace inner front surface.
[0012]
In addition, the heat insulating layer is configured to be filled with a heat insulating refractory.
Furthermore, the area ratio of the main heat passage cross section of the copper part in the heat insulation layer is 35% to 40%.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 is a side view of a first embodiment of the present invention, FIG. 2 is a plan view, FIG. 3 is a rear view in FIG. 1, and FIG. 4 is a cross-sectional view taken along line AA in FIG. Hereinafter, the configuration of the first embodiment will be described with reference to FIGS.
A rectangular plate-shaped stave body 1 is made of copper or a copper alloy (hereinafter referred to as “copper or the like”). Reference numeral 3 denotes a cooling water passage formed on the back side inside the main body 1, and reference numerals 5 to 11 denote entrance / exit pipes through which cooling water is connected to the cooling water passage 3. A mounting bolt (not shown) for fixing the main body 1 to the iron skin is provided on the back of the stave.
[0014]
Reference numeral 15 denotes a heat-insulating refractory installed between the cooling water channel 3 and the front surface of the main body 1. As shown in FIGS. 2 and 4, the heat-insulating refractory 15 is formed of a rectangular rod-like body having a certain width and thickness, and a plurality of the heat-insulating refractories 15 are arranged in the longitudinal direction in the width direction of the main body 1 with a certain interval therebetween. . Therefore, as shown in FIG. 4, in the cross section where the heat insulating refractory 15 is installed, a heat insulating layer made of the heat insulating refractory 15 and copper or the like is formed in the width direction of the main body 1.
[0015]
Here, the area ratio of copper or the like in the heat insulating layer will be described. From the viewpoint of suppressing the amount of heat removal, it is desirable to reduce the area ratio of copper or the like, but on the other hand, if the area ratio of copper or the like is too small, the stave front copper portion (in the main body 1 in the main body 1) in front of the heat insulating layer. There is a concern that the portion near the front surface from the heat insulating layer will be overheated by the heat in the furnace and the original shape cannot be maintained. Therefore, it is desirable to increase the area ratio of copper or the like from the viewpoint of protecting the front copper portion of the stave.
Therefore, the inventors studied how much the area ratio of copper or the like can be used to suppress the amount of heat removal and protect the copper portion of the front surface of the stave. As a result, the copper portion in the heat insulating layer (main heat passage cross section) It was found that the area ratio is preferably about 35% to 40%.
[0016]
Next, the shape of the stave front copper part in the stave will be described.
The front surface inside the furnace in the copper portion on the front surface of the stave is flat in order to keep the furnace inner profile by flattening the contact surface with the filling in the furnace. Also, make the thickness of the stave front copper as thin as possible.
[0017]
The reason why the thickness is made as thin as possible is that the distance between the furnace inner front surface and the cooling water channel 3 is made as short as possible so that the furnace inner front surface is not overheated by exerting a cooling effect on the furnace inner front surface. Thus, by preventing the furnace inner front surface from overheating, the shape of the furnace inner front surface can be maintained and the furnace inner profile can be maintained.
[0018]
In the present embodiment configured as described above, the heat removal amount is suppressed by the heat insulating layer made of copper or the like and the heat insulating refractory material 15 formed inside the stave restricting the passage of heat. The ratio can be prevented from deteriorating.
FIG. 5 is a graph for explaining the effect of the present embodiment, and shows a comparison of the heat forward rate of the stave. In the figure, graph B shows the heat transfer rate in the initial state of the conventional copper stave shown in FIGS. 10 to 12, and graph A shows the state in which the refractory material peels off due to aging of the conventional stave and the copper surface is completely exposed. The graph shows the heat transfer rate of the present embodiment. In each graph, the heat transmittance in the initial state in the conventional example shown in graph B is set to 1, and the others are shown as a comparison with this.
[0019]
As can be seen from the graph, in the case of the conventional stave, the amount of heat removal has increased by a factor of about 2 due to secular change (see graph A), whereas in the present embodiment, it is the same as the initial stage. (See graph C).
In addition, regarding the heat removal amount in the initial state, the heat removal amount of the present embodiment is smaller than that of the conventional one (see graphs B and C). This is because the present embodiment has a structure in which a heat-insulating refractory material is provided inside the stave, so that the heat-insulating refractory material can be selected simply by giving priority to heat-insulating properties without much consideration for durability.
[0020]
As described above, in the stave of the present embodiment, the heat insulating layer made of copper or the like and the heat insulating refractory 15 is provided between the stave front copper portion in contact with the blast furnace filling and the layer having the cooling water channel 3 inside the stave. As a result, the thermal resistance of the front surface of the stave increases and the amount of heat removed can be suppressed.
In addition, since the heat-insulating refractory 15 of the present embodiment has a structure confined inside the stave, the heat-insulating refractory 15 does not come into contact with the filling in the furnace, and there is no volume loss due to wear or cracking, which is stable. Volume maintenance becomes possible. For this reason, the amount of heat removal can be stably suppressed without changing the amount of heat removal due to aging as in the conventional example.
[0021]
Furthermore, since the heat-insulating refractory 15 is confined inside the stave, it is possible to simply select a refractory with low thermal conductivity without placing importance on durability, thus reliably reducing heat removal performance. You can make it. In addition, it is possible to select a relatively inexpensive heat-insulating refractory material and to reduce costs.
Furthermore, since the heat insulating refractory 15 is inside the stave, handling during installation becomes very easy.
[0022]
Embodiment 2. FIG.
6 is a side view of the second embodiment of the present invention, FIG. 7 is a plan view, FIG. 8 is a rear view in FIG. 1, and FIG. 9 is a sectional view taken along line AA in FIG. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals.
In this embodiment, the heat insulating refractory material 15 is arranged in the horizontal direction. By arrange | positioning in this way, it can prevent that a heat insulation refractory material falls out.
In addition, it is the same as that of Embodiment 1 that the area ratio of a copper part shall be about 35%-40%, and it cannot be overemphasized that the effect similar to Embodiment 1 is acquired.
[0023]
In addition, the heat-insulating refractories 15 and 20 in the first and second embodiments may be formed bricks inserted into the space formed in the main body 1, or an unshaped refractory is poured into the space. It may be formed into a rod-shaped body. Further, the heat-insulating refractories 15 and 20 themselves may be any heat-insulating material that can be placed in the space without forming a rod-like body and can form a heat-insulating layer.
[0024]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0025]
A stave mainly made of copper or copper alloy, and a heat insulating layer is provided only between the cooling medium passage and the front surface inside the furnace, so that the heat insulating layer is not exposed to the outside, Since the heat insulation layer can be prevented from being broken by contact or the like, the amount of heat removal can be stably suppressed. As a result, copper staves can be used even in areas where excessive heat removal from the furnace is a concern, and the amount of heat removal does not increase over time, and as a result, copper staves can be used throughout the furnace. This makes it possible to extend the furnace life significantly.
[0026]
In addition, the heat insulation layer is constructed by filling the heat insulation refractory, so that the refractory is confined inside the stave, so simply select a refractory with low thermal conductivity without placing importance on durability. It is possible to reliably reduce the heat removal performance. In addition, it is possible to select a relatively inexpensive refractory and to reduce costs.
Furthermore, since the refractory is inside the stave, handling during installation becomes very easy.
[Brief description of the drawings]
FIG. 1 is a side view of a first embodiment of the present invention.
FIG. 2 is a plan view of the first embodiment of the present invention.
FIG. 3 is a rear view of the first embodiment of the present invention.
4 is a cross-sectional view taken along the line AA in FIG.
FIG. 5 is a graph for explaining the effect of the first embodiment.
FIG. 6 is a side view of Embodiment 2 of the present invention.
FIG. 7 is a plan view of Embodiment 2 of the present invention.
FIG. 8 is a rear view of the second embodiment of the present invention.
9 is a cross-sectional view taken along the line AA in FIG.
FIG. 10 is a rear view of a conventional example.
11 is a cross-sectional view taken along line AA in FIG.
[Explanation of symbols]
1 Body 3 Cooling channel 15 Insulating fireproof material

Claims (3)

A stave made of copper or a copper alloy, wherein a heat insulating layer is provided only between the coolant passage and the front surface inside the furnace.   The stave according to claim 1, wherein the heat insulating layer is formed by filling a heat insulating refractory. The stave according to claim 1 or 2, wherein an area ratio of a main heat passage cross section of the copper portion in the heat insulating layer is 35% to 40%.

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