WO2013180219A1

WO2013180219A1 - Lining structure for molten-metal container

Info

Publication number: WO2013180219A1
Application number: PCT/JP2013/065045
Authority: WO
Inventors: 井上　明彦; 清田　禎公
Original assignee: Ｊｆｅスチール株式会社
Priority date: 2012-05-30
Filing date: 2013-05-30
Publication date: 2013-12-05
Also published as: KR20150004880A; CN104334750A; JPWO2013180219A1; KR101571644B1; JP5494898B1; CN104334750B; IN2014KN02725A

Abstract

A lining structure for a molten-metal container for containing a molten metal, wherein the lining structure is provided with: a steel shell constituting the outermost layer of the molten-metal container, the steel shell having a plurality of through-holes passing through an outer surface and an inner surface; a single-layer or double-layer permanent refractory layer provided on the inner side of the steel shell; a workpiece refractory layer provided on the inner side of the permanent refractory layer and at least partially composed of a castable refractory, the workpiece refractory layer forming an operation surface contacting the molten metal; and a plurality of layers of an insulating material that is a sheet-shaped polygonal member adjacently disposed with respect to the inner surface of the steel shell, the layers of the insulating material being installed between the steel shell and the permanent refractory layer or between two layers of the permanent refractory layer. A gap is formed between one of the insulating layers and at least one of the other insulating layers adjacently disposed with respect to the insulating layer, the gap being positioned on a through hole and having a thickness equal to or greater than the insulating material.

Description

Lining structure of molten metal container

The present invention relates to a lining structure of a molten metal container.

The lining structure of a molten metal container (hereinafter also simply referred to as “container”) that contains molten metal such as hot metal or molten steel has a structure in which an iron skin as an outermost layer supports a refractory.
Refractories used for molten metal containers include regular refractories and irregular refractories. In particular, the amorphous refractory is also called a castable and is often used as a refractory constituting a work refractory layer in contact with molten metal because of its ease of construction.
The amorphous refractory is generally formed into a lining shape by adding water to a mixture of powder and particles of a high melting point material such as alumina and fluidizing the mixture into a container.

By the way, since many metals such as iron have a melting point as high as several hundred to several hundreds of degrees Celsius, molten metal containers are required to have heat resistance as well as fire resistance.
Conventionally, as a method of imparting heat insulation to a molten metal container, a method of inserting a heat insulating material on the back side of the workpiece refractory layer has been proposed. For example, Patent Document 1 uses silica fine particles as a main material. A heat insulating material which is a microporous molded body is disclosed.

JP 2008-249317 A

When molten steel or the like is charged in the molten metal container, if moisture remains in the amorphous refractory constituting the workpiece refractory layer, the water vapor pressure rises to, for example, 10 atm or more at 200 ° C., The amorphous refractory may explode and be damaged.
Therefore, when the molten metal container is used, the amorphous refractory is previously dried by heating (hereinafter also referred to as “pre-drying”). The pre-drying is performed over a long period of time at a relatively low temperature in order to prevent the irregular refractory from being damaged by water vapor pressure.

Since pre-drying is performed from the inside of the container using a burner or the like, the temperature at the beginning of pre-drying is as low as 100 ° C. or less at the outer surface side of the irregular refractory, and steam is emitted from the inside of the irregular refractory. Part of the water condenses into liquid water. Thereafter, the portion on the outer surface side of the irregular refractory gradually becomes 100 ° C. or higher, and the moisture becomes steam.
A through-hole is formed in the iron skin, which is the outermost layer of the container, and the vapor emitted from the amorphous refractory by pre-drying is exhausted to the outside through this through-hole.

However, when a heat insulating material is inserted on the back side of the workpiece refractory layer, exhaust from the through hole is obstructed. Moreover, since the inner surface side of the amorphous refractory is already solidified and partially sintered by pre-drying, the steam that has not been exhausted from the through-hole is not easily exhausted from the inner surface side, and remains inside.
Therefore, even though moisture remains inside the amorphous refractory, it is misunderstood that the pre-drying has been completed, and the molten metal is charged into the container, resulting in explosion breakage of the amorphous refractory. There is a fear.

The present invention has been made in view of the above points, and an object of the present invention is to improve air permeability during pre-drying of an amorphous refractory in a lining structure of a molten metal container provided with a heat insulating material.

The present inventors have intensively studied to achieve the above object. As a result, it has been found that by making the heat insulating material, which is a sheet-like polygonal member, a specific arrangement, the vapor permeability can be improved during the preliminary drying of the irregular refractory, and the present invention has been completed.
That is, the present invention provides the following (1) to (3).

(1) A lining structure of a molten metal container for containing a molten metal, which constitutes the outermost layer of the molten metal container, and has an iron skin having a plurality of through holes penetrating an outer surface and an inner surface; One or two permanent refractory layers provided on the inner side of the iron skin, and provided on the inner side of the permanent refractory layer, forming an operating surface in contact with the molten metal, at least a part of which is an amorphous refractory A workpiece refractory layer composed of a sheet-like polygonal member, which is constructed between the iron skin and the permanent refractory layer, or between the two layers of the permanent refractory layer, A plurality of heat insulating materials arranged adjacent to each other along the inner surface of the iron skin, and one heat insulating material and at least one of the other heat insulating materials arranged adjacent to the heat insulating material. A gap is formed between them, and the gap is positioned on the through hole. And has a thickness or width of the heat insulating material, the lining structure of the molten metal container.

(2) The molten metal container lining structure according to (1), wherein a width of the gap is equal to or less than a thickness of the iron skin.

(3) The molten metal container lining structure according to (1) or (2), wherein the heat insulating material is housed in a waterproof covering material.

According to the present invention, in the lining structure of the molten metal container in which the heat insulating material is applied, the air permeability during the pre-drying of the irregular refractory can be improved.

It is a side view which cuts and shows the molten steel pan 1 partially. It is the schematic diagram which looked at the several heat insulating material 5 arrange | positioned along the inner surface shape of the iron shell 2 from the inner side of the molten steel pan 1. FIG. 6 is a graph showing the relationship between the ratio of the width of the gap G to the thickness of the heat insulating material 5 and the temperature of the gap G on the iron skin 2 side. (A) is an infrared thermal image showing the molten steel pan 1 in which the thickness of the iron skin 2 is 30 mm and the width of the gap G of the heat insulating material 5 is 40 to 50 mm, and (b) is the infrared thermal image of (a). It is a graph which shows the temperature distribution of the lines A and B in an image. It is a graph which shows the relationship between the ratio of the width | variety of the gap | interval G with respect to the thickness of the iron skin 2, and the radiation heat dissipation amount of the iron skin gap | interval part 2a. (A) is an infrared thermal image showing the molten steel pan 1 in which the thickness of the iron skin 2 is 30 mm and the width G of the heat insulating material 5 is 20 to 30 mm, and (b) is the infrared thermal image of (a). It is a graph which shows the temperature distribution of the lines A and B in an image.

Hereinafter, an embodiment of the present invention will be described. Embodiment described below is an application example to the molten steel pan 1 which accommodates the molten steel 61 as a molten metal.

FIG. 1 is a side view showing the molten steel pan 1 with a part cut away. The molten steel ladle 1 shown in FIG. 1 accommodates and holds a molten steel 61 converted from molten iron in a converter. A slag (not shown) floats on the surface of the molten steel 61. In the molten steel pan 1, a secondary refining process is performed in which impurities are removed from the molten steel 61 and additional elements are added. The molten steel 61 that has undergone secondary refining is transported by the molten steel pan 1 and subjected to a continuous casting process.

The lining structure of the molten steel pan 1 basically has an iron skin 2, a permanent refractory layer 3, and a workpiece refractory layer 4 in order from the outside. Furthermore, the heat insulating material 5 which exhibits a heat insulation function is constructed in the side surface part etc. of the molten steel pan 1.
Below, based on FIG. 1, the permanent refractory layer 3 and the workpiece | work refractory layer 4 are demonstrated first.

The permanent refractory layer 3 is provided inside the iron skin 2. The permanent refractory layer 3 is a brick layer that is constructed in order to ensure safety so that the molten steel 61 does not leak even when (a part of) the workpiece refractory layer 4 described later is damaged and falls off. The permanent refractory layer 3 may be a single layer or two layers as shown in FIG.
As the refractory material (also referred to as “permanent refractory material”) 31 constituting the permanent refractory layer 3, for example, a fixed refractory material (formed brick) such as a wax brick is used. As shown in FIG. 1, the refractory 31 is constructed by brick using a mortar 32 as a joint material.

The thickness of the permanent refractory layer 3 is preferably 40 mm or more from the reason that the molten steel 61 does not leak immediately even if the workpiece refractory peels off for some reason, and for the reason of preventing the molten steel 61 from flowing out through the joint. Two-layer construction is more preferable.

The workpiece refractory layer 4 is provided inside the permanent refractory layer 3. The workpiece refractory layer 4 is a layer that forms an operating surface that contacts the molten steel 61.
FIG. 1 shows an example in which an amorphous refractory is used as the refractory (also referred to as “work refractory”) 41 constituting the work refractory layer 4. When the amorphous refractory 41 is used, a mixture of powder and particles of a high melting point material such as alumina (Al ₂ O ₃ ) or magnesia (MgO) added to fluidize the permanent refractory layer 3. Pour between molds (not shown) to form a lining.

By the way, if moisture remains in the amorphous refractory 41 when the molten steel 61 is charged into the molten steel pan 1, the water vapor pressure inside the amorphous refractory 41 rises to 10 atm or more at 200 ° C., for example. The unshaped refractory 41 may explode and be damaged. Therefore, in order to prevent such breakage, preliminary drying is performed at a relatively low temperature for a long time.
The pre-drying is generally performed from the inside of the molten steel pan 1 (that is, the working surface side of the workpiece refractory layer 4) using a burner or the like. Therefore, the temperature of the part on the outer surface side of the irregular refractory 41 (that is, the iron skin 2 side of the workpiece refractory layer 4) is as low as 100 ° C. or less in the early stage of pre-drying, and comes out of the irregular refractory 41. A part of the vapor condenses into liquid water. Thereafter, in the middle stage to the final stage of pre-drying, the portion on the outer surface side of the irregular refractory 41 becomes 100 ° C. or higher, and the moisture becomes vapor and is exhausted from a through hole H described later formed in the iron skin 2.

As the thickness of the workpiece refractory layer 4 (unshaped refractory 41), it is advantageous to increase the thickness in order to reduce the repair frequency and increase the operation rate. However, if the difference in thickness between the initial stage of use and the end stage is large and the internal volume fluctuation is large, the bath surface height and the holdable amount fluctuate and the operability decreases, and the container weight increases and the equipment scale increases. For this reason, the thickness of the workpiece refractory layer 4 (unshaped refractory 41) is preferably 100 to 250 mm, and the vicinity of the boundary with the laying part (bottom part) is exposed to the molten steel flow or residual slag, so that it is thick. The other parts are thin, and it is more preferable to change the thickness for each part.

Next, the iron skin 2 will be described. The iron skin 2 is a steel structure that supports a refractory (refractory 31, refractory 41) as the outermost layer of the molten steel pan 1.
As for the thickness of the iron skin 2 (the length indicated by T2 in FIG. 1), the lower limit is determined from the strength calculation. The thicker it is, the harder it is to be deformed and the longer the life is. There are many examples to do.

A plurality of through holes H penetrating the outer surface and the inner surface of the iron skin 2 are formed in the iron skin 2. The through-hole H allows the vapor emitted from the amorphous refractory 41 to pass through the above-described preliminary drying.
Although the hole diameter of the through-hole H is not specifically limited, It is preferable that it is 6 mm or more from a viewpoint of prevention of clogging with a refractory piece. On the other hand, as long as it can prevent clogging, sufficient air permeability can be ensured, so it is often 30 mm or less.

Next, the heat insulating material 5 will be described. Although the heat insulating material 5 is constructed at least on the side surface portion of the molten steel pan 1, it may also be constructed on the laying portion (bottom surface portion).
As a construction position of the heat insulating material 5, when two permanent refractory layers 3 are provided, it may be between these two layers. However, for the reason that the temperature of the heat insulating material 5 can be operated low and the heat insulating performance can be exhibited for a long time (for example, 2 years or more), the space between the iron skin 2 and the permanent refractory layer 3 is preferable as shown in FIG. .
Below, although the case where the heat insulating material 5 is constructed between the iron skin 2 and the permanent refractory layer 3 is demonstrated to an example, this invention is not limited to this.

The heat insulating material 5 is a sheet-like member, and is composed of, for example, a microporous molded body mainly composed of fine particles such as silica (SiO ₂ ) and alumina (Al ₂ O ₃ ).
By the way, the microporous material formed by molding fine particles such as silica is fluidized when it comes into contact with moisture of the liquid and loses heat insulation. Therefore, when the amorphous refractory 41 constructed by adding moisture is used, the heat insulating property of the heat insulating material 5 may be lowered.
Therefore, it is preferable that the heat insulating material 5 is housed in a waterproof covering material 51 to prevent deterioration due to moisture. The material of the covering material 51 is not particularly limited as long as it is waterproof, and examples thereof include a resin film. Specifically, for example, a resin such as polypropylene or polyethylene is suitable. In addition, a material obtained by laminating an aluminum foil with these resins in order to improve the moisture barrier property is also used.

The thickness of the heat insulating material 5 (the length indicated by T5 in FIG. 1) is not particularly limited. However, even when the molten steel 61 contacts the heat insulating material 5 for some reason, the molten steel 61 causes the heat insulating material 5 to melt. For the purpose of preventing extension over a wide range, it is preferably 15 mm or less, more preferably 3 to 10 mm. Note that the thickness of the heat insulating material 5 includes the covering material 51.

FIG. 2 is a schematic view of a plurality of heat insulating materials 5 arranged along the inner surface of the iron skin 2 as viewed from the inside of the molten steel pan 1. In FIG. 2, configurations other than the iron skin 2 and the heat insulating material 5 are omitted.

FIG. 2 shows a rectangular shape as the sheet-like heat insulating material 5. However, the shape of the heat insulating material 5 is not particularly limited as long as it is a polygonal shape, and examples thereof include a shape such as a trapezoid and a triangle in addition to a rectangle. Specifically, for example, when the iron skin 2 has a truncated cone shape, the shape of the heat insulating material 5 can be a trapezoid.

As shown in FIG. 2, a plurality of heat insulating materials 5 are arranged adjacent to each other along the inner surface of the iron skin 2. The heat insulating material 5 is fixed to the inner surface of the iron skin 2 with, for example, an adhesive tape made of the same material as the covering material 51 (see FIG. 1).
At this time, a gap G is formed between one heat insulating material 5 and at least one of the other heat insulating materials 5 adjacent thereto.
For example, in FIG. 2, other heat insulating materials 5b to 5e are arranged adjacent to each other around the heat insulating material 5a. Among these, the gap | interval G is formed in the position between the heat insulating material 5a and the heat insulating material 5b, and between the heat insulating material 5a and the heat insulating material 5d, respectively. Therefore, in FIG. 2 in which the permanent refractory layer 3 and the workpiece refractory layer 4 are omitted, the iron skin 2 is exposed from the gap G.

At this time, the heat insulating material 5 is arranged so that the gap G to be formed is positioned on the through hole H. “The gap G is positioned on the through hole H” means that the heat insulating material 5 that forms the gap G shields a part of the through hole H, and the heat insulating material 5 that forms the gap G is the through hole H. The concept includes the case of exposing without shielding.

2 shows the through holes H arranged in a straight line along the gap G formed in a straight line, the arrangement of the through holes H is not limited to this.

And in this invention, the width | variety (length shown by W in FIG. 2) of the clearance gap G of the heat insulating material 5 shall be more than the thickness (length shown by T5 in FIG. 1) mentioned above. . Such a lower limit value of the width of the gap G is set from the viewpoint of ensuring air permeability.

When the present inventors initially arranged the heat insulating material 5 having a thickness of 6 mm so that the width of the gap G was 1 to 3 mm, the time required for the pre-drying was greatly extended. As a result of the dismantling investigation after use, this is because the mortar 32 used when constructing the permanent refractory layer 3 entered the gap G of the heat insulating material 5 and the air permeability of the gap G was impaired. found.
Therefore, the present inventors arranged the heat insulating material 5 so that the width of the gap G has various dimensions, and observed the generation of steam from the through hole H and the temperature increase of the iron skin 2 during the pre-drying. . As a result, if the thickness of the heat insulating material 5 is 6 mm, the time required for pre-drying is extended when the width of the gap G is less than 6 mm, and if the thickness of the heat insulating material 5 is 3 mm, the width of the gap G The time required for pre-drying was extended when the thickness was less than 3 mm.
In order to verify this phenomenon, the temperature during pre-drying of the mortar 32 that entered the gap G of the heat insulating material 5 was estimated by heat transfer calculation.

FIG. 3 is a graph showing the relationship between the ratio of the width of the gap G to the thickness of the heat insulating material 5 and the temperature of the gap G on the iron skin 2 side. In the graph of FIG. 3, the horizontal axis indicates the ratio (unit:%) of the width of the gap G to the thickness of the heat insulating material 5. On the other hand, the vertical axis represents the iron skin of the gap G into which the mortar 32 has entered in the pre-drying middle plate where the outer surface temperature of the amorphous refractory 41 constituting the workpiece refractory layer 4 is 120 ° C. and the vapor pressure is 2 atm. This is a value (unit: ° C) calculated from the temperature on the second side.

From the graph of FIG. 3, when the value on the horizontal axis is less than 100% (that is, when the width of the gap G is smaller than the thickness of the heat insulating material 5), the value on the vertical axis (that is, the gap G in which the mortar 32 has entered). The temperature of the iron skin 2 side) is less than 100 ° C., and not only the evaporation of the adhering water of the mortar 32 that has entered the gap G becomes slow, but also condenses when the vapor generated from the amorphous refractory 41 passes, It was confirmed that the air permeability was significantly impaired.

From the above, in the present invention, the width of the gap G of the heat insulating material 5 is set to be equal to or larger than the thickness of the heat insulating material 5. Thereby, also in the molten steel pan 1 which constructed the heat insulating material 5, the air permeability during the preliminary drying of the amorphous refractory 41 can be made favorable.

In addition, the width of the gap G of the heat insulating material 5 is less than the thickness of the iron skin 2 (the length indicated by T2 in FIG. 1) from the viewpoint of minimizing the decrease in the heat insulating effect due to the formation of the gap G. Preferably there is. Next, the upper limit value of the width of the gap G will be described.

FIG. 4A shows an infrared ray showing a molten steel pan 1 (diameter: 4.0 m, height: 4.5 m) in which the thickness of the iron skin 2 is 30 mm and the width of the gap G of the heat insulating material 5 is 40 to 50 mm. FIG. 4 (b) is a graph showing the temperature distribution of lines A and B in the infrared thermal image of FIG. 4 (a).
More specifically, the infrared thermal image of FIG. 4 (a) is a view of the molten steel pan 1 in a state in which the molten steel 61 lifted by a crane is accommodated from a slightly lower side, and is bright (color is light). It shows that the part is hotter.
Further, the graph of FIG. 4B is a temperature distribution in a range (lines A and B) that starts at the point x and ends at the other end in the infrared thermal image of FIG. The lengths of lines A and B are 1.05 m and 1.08 m, respectively. In the graph of FIG. 4B, the horizontal axis indicates the number of pixels in lines A and B with the x point as the left end, and the vertical axis indicates the temperature (unit: ° C.).

Here, for example, pay attention to line A. In line A, the temperature at the point x is about 240 ° C. In the line A, the part located in the gap G (hereinafter, also referred to as “iron gap part 2a”) of the iron skin 2 is slightly brighter in FIG. 4A, and is a mountain in the graph of FIG. There are two places other than the x point. The iron crevice gap 2a is about 20-30 ° C. higher than other parts, and a temperature rise is observed.

From the Stefan-Boltzmann law, the radiation heat radiation to the outside is proportional to the fourth power of the outer surface temperature of the iron skin 2, and the radiation heat radiation to the outside is increased by 20% in the iron skin gap 2a. From the viewpoint of suppressing a decrease in the heat insulating effect, the width of the gap G of the heat insulating material 5 is preferably as small as possible.
However, since the lower limit value of the width of the gap G described above, that is, the thickness of the heat insulating material 5 is generally about 1 to 20 mm, it is difficult to accurately construct the gap G in accordance with the lower limit value. It is.

Therefore, when the width of the gap G is increased, the outer surface temperature of the iron skin 2 is increased, and from the Stefan-Boltzmann law, it is noted that the radiation heat radiation to the outside is proportional to the fourth power of the outer surface temperature of the iron skin 2, Conditions that do not significantly increase the radiation heat dissipation to are estimated by heat transfer calculation.

FIG. 5 is a graph showing the relationship between the ratio of the width of the gap G to the thickness of the iron skin 2 and the amount of radiant heat released from the iron skin gap 2a.
In the graph of FIG. 5, the horizontal axis indicates the ratio (unit:%) of the width of the gap G to the thickness of the iron skin 2. On the other hand, the vertical axis is a value obtained by calculating the radiation heat radiation to the outside of the core gap 2a in a state where the molten steel 61 is accommodated in the molten steel pan 1, and the horizontal axis is an index with the calculation result of 100% being 100%. It is.
From the graph of FIG. 5, it is suggested that when the width of the gap G is larger than the thickness of the iron shell 2, the radiation heat dissipation increases rapidly.

FIG. 6A is an infrared thermal image showing the molten steel pan 1 in which the thickness of the iron skin 2 is 30 mm and the width of the gap G of the heat insulating material 5 is 20 to 30 mm. FIG. It is a graph which shows the temperature distribution of the lines A and B in the infrared thermal image of (a). 6 (a) and 6 (b) are the same as FIGS. 4 (a) and 4 (b), respectively, and the description thereof is omitted. However, the lengths of the lines A and B are each 0. .58 m and 1.10 m.
6 (a) and 6 (b), it can be seen that the temperature increase in the iron-skin gap 2a, which was recognized in FIGS. 4 (a) and 4 (b), has been eliminated.
Therefore, it is preferable that the width of the gap G of the heat insulating material 5 is equal to or less than the thickness of the iron shell 2 because a significant decrease in the heat insulating effect can be suppressed.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Invention Example 1>
In the molten steel ladle 1 (diameter: 4.0 m, height: 4.5 m) in FIG. 1, a wax stone brick is used as the refractory 31 inside the iron skin 2 (thickness: 30 mm), and the mortar 32 is a joint. A permanent refractory layer 3 (thickness: 50 mm) was formed as a material. Further, the alumina-magnesia amorphous refractory 41 is poured between the permanent refractory layer 3 and a mold (not shown) as 6% by mass of the kneaded moisture, and the workpiece refractory layer 4 (thickness: 120 mm).

Moreover, the sheet | seat accommodated in the coating | covering material 51 made from a polyethylene resin film (thin which laminated | stacked aluminum foil in order to improve moisture-proof property) is provided between the iron skin 2 and the permanent refractory layer 3 except a floor part. A heat insulating material 5 (thickness: 5 mm) was applied. The heat insulating material 5 was composed of a microporous molded body mainly composed of silica and alumina fine particles, and the shape thereof was rectangular (500 to 1000 mm × 350 to 500 mm).

At this time, a plurality of the heat insulating materials 5 were fixed to the inner surface of the iron skin 2 with an adhesive tape made of the same material as the covering material 51 and arranged adjacent to each other. Although the through-hole H (hole diameter: 12 mm) was formed in the iron skin 2 in the shape of a line, the gap G positioned on the through-hole H is formed on the upper and lower sides of the heat insulating material 5 as shown in FIG. Formed.

The construction of the heat insulating material 5 was performed manually. At the time of construction, a pencil with a diameter of 8 mm was carried, and attention was paid so that the width of the gap G would be a dimension from the diameter of this pencil to twice the diameter. That is, the width of the gap G was set to 8 to 16 mm. As a result of such construction, some of the through holes H in which the gap G is positioned are shielded by the heat insulating material 5 in about a quarter.

<Invention Example 2>
The heat insulating material 5 was applied in the same manner as in Invention Example 1 except that the width of the gap G was 20 to 40 mm. At the time of construction, a round bar having a diameter of 20 mm was carried, and attention was paid so that the width of the gap G would be a dimension from the diameter of this round bar to twice the diameter. By increasing the allowable range of the interval, a larger heat insulating material can be used, and the workability is improved.

<Comparative Example 1>
A heat insulating material 5 was applied in the same manner as in Invention Example 1 except that the width of the gap G was set to 2 to 4 mm. At the time of construction, a round bar having a diameter of 2 mm was carried and attention was paid so that the width of the gap G would be a dimension from the diameter of this round bar to twice the diameter.

<Evaluation>
In each example, after pouring the amorphous refractory 41 and forming the workpiece refractory layer 4, using a burner, pre-drying from the working surface side of the workpiece refractory layer 4, with the same conditions such as the heating temperature, etc. The time required from the start of pre-drying was measured. In addition, it was judged that pre-drying was complete | finished when the iron-skin outer surface temperature reached | attained 150 degreeC which is the dehydration temperature of an alumina cement.
The time required for each example was evaluated by an index with the time required for Example 1 as 100. The results are shown in Table 1 below. It can be evaluated that the smaller the index is, the shorter the time until the predrying is completed and the better the air permeability during the predrying.

Moreover, in each example, the use which accommodated the molten steel 61 in the molten steel pan 1 after completion | finish of prior drying was started, and the temperature rise of the iron-skin gap | interval part 2a was evaluated from the infrared thermal image after three-day progress. The maximum value (unit: ° C.) of the temperature difference from other parts of the core gap 2a in the core 2 is shown in Table 1 below. As the temperature difference is smaller, the temperature rise of the iron gap portion 2a is suppressed, and it can be evaluated that the heat insulation is excellent.

In each example, the use of the molten steel 61 in the molten steel pan 1 after the pre-drying was started, and the refractory situation after 14 days was inspected and evaluated for the presence or absence of peeling. Peeling wear is different from normal melting loss and is peeling off at a thickness of 10 mm or more due to an abnormality inside the refractory, and one reason is that pre-drying is not sufficient.

From the results shown in Table 1, it was found that Invention Examples 1 and 2 required a shorter time for pre-drying than Comparative Example 1, and had good air permeability during pre-drying. Further, in Comparative Example 1, peeling wear during use was observed, and there was a possibility that the drying was insufficient despite the long pre-drying time.
In addition, it was found that Invention Example 1 had a smaller temperature difference between the iron skin gap 2a and the other part of the iron skin 2 than the Invention Example 2, and the temperature increase of the iron skin gap 2a was suppressed. In Invention Example 1, the temperature rise of the iron gap portion 2a was 10 ° C. or less, and the increase in radiation heat dissipation was in a negligible range.

1 Molten steel pan (molten metal container)
2 Iron skin 2a Iron skin gap 3 Permanent refractory layer 31 Refractory (standard refractory)
32 mortar 4 work refractory layer 41 refractory (indefinite refractory)
5 Thermal insulation material 51 Coating material 61 Molten steel (molten metal)
G Gap H Through-hole T2 Iron skin thickness T5 Heat insulation thickness W Gap width

Claims

A molten metal lining structure for containing molten metal,
The outermost layer of the molten metal container, the iron skin having a plurality of through holes penetrating the outer surface and the inner surface,
One or two permanent refractory layers provided inside the iron skin;
A workpiece refractory layer provided on the inside of the permanent refractory layer, forming a working surface in contact with the molten metal, at least a part of which is formed of an amorphous refractory;
A sheet-like polygonal member, which is constructed between the iron skin and the permanent refractory layer, or between the two layers of the permanent refractory layer, and is adjacent along the inner surface of the iron skin A plurality of thermal insulators arranged;
With
A gap is formed between one of the heat insulating materials and at least one of the other heat insulating materials arranged adjacent to the heat insulating material,
The molten metal container lining structure, wherein the gap is positioned on the through hole and has a width equal to or greater than a thickness of the heat insulating material.
The lining structure of a molten metal container according to claim 1, wherein a width of the gap is equal to or less than a thickness of the iron skin.
The lining structure for a molten metal container according to claim 1 or 2, wherein the heat insulating material is housed in a waterproof covering material.