JPS6017691A - Metallic flask for hot execution of amorphous refractory material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Z! ! = The invention relates to a metal frame used when hot-casting a fluid, amorphous refractory material, and its purpose is to form a uniform plate without any internal defects ("I+").
To provide a metal frame capable of forming a construction body having 4'C durability and excellent corrosion resistance.

Conventionally, spraying methods have been frequently used for hot repairs of converters, molten metal containers, and degassing devices such as RH. However, the sprayed material has inferior physical properties among various types of monolithic refractory materials, and its durability is also unsatisfactory. In particular, due to high-temperature operation associated with the recent increase in the quality of steel, its lifespan has decreased to 11, and often only has a lifespan of 1 to 2 channels.

Furthermore, due to the increase in the continuous casting ratio, the time between operations is shortened, and there is often no time available for spraying repairs, so there is a strong desire to establish a hot repair method as an alternative to spraying repairs.

In addition, hot pouring materials are often used to repair the tap walls or charging walls of converters, but hot pouring materials are easy to install on horizontal areas, but cannot be installed horizontally, such as on converter trunnions. A metal frame is required for construction on the area. Even if a metal frame is used for construction, it has the major drawback of causing internal defects, so it has not yet been put into practical use. In other words, monolithic refractory material in the form of a slurry poured into a metal frame using a pressure feed or a spray nozzle is
Boiling II due to the retained heat of the furnace! 1. The hardening process progresses through heat reception, so if heat is received from the metal frame side, such as at the converter trunnion, by the width elbow heat, the repaired surface, which is the base material, Hardening will proceed from both sides of the metal frame surface.

As a result, a region of weak strength with poor physical properties is created in the center of the construction body, and during use, the construction body peels from this weak area, making only half of the installed monolithic refractory material useful. It often doesn't work.

This can be schematically shown in Figures 1 (A), (B), and (C). That is, as shown in the initial stage of construction (A), slurry-like monolithic refractory material (1
) is put between the metal frame (4) and the furnace wall (6), a layer of hardened monolithic refractory material (2) is formed at the bottom, but nitrification occurs during the middle of construction (13) due to the above-mentioned reasons. to the end of construction (C
), and as a result, the internal defect part (3
) is formed in a layer in the central part, and after the metal frame (4) is removed, peeling occurs from this defective area (3).

On the other hand, the widely known method of constructing a metal frame over the repaired area by pressure-feeding CeraL monolithic refractory material is R[1
Regarding V7J repair of the immersion pipe of a degassing device, it is usually carried out at a temperature of 200 to 400 degrees Celsius because the construction is simple and the lower the construction temperature, the better the durability of the construction material with low porosity. Common.

However, as the continuous casting ratio has increased in recent years, degassing equipment has also come to be used continuously, and even in the repair of degassing equipment,
Although construction is often carried out at temperatures above 0°C,
As the construction temperature increases, its durability also decreases.

This decrease in service life is due to the fact that the monolithic refractory material is not designed for hot construction, and the construction metal frame is not designed for hot rIIl construction, resulting in defects inside the construction body. ing. In other words, a monolithic refractory material that is pumped into a high-temperature frame in a slurry state will harden from the bottom, but a considerable amount of moisture remains inside the construction body immediately after hardening.1 This moisture is・The water vapor resists and leaves the construction body, but since a metal frame is set on the surface, the water vapor must pass through the interior of the construction body and exit. During construction, the material pumped into the metal frame will harden from the bottom, so there will be areas in the metal frame that harden from the bottom to form a structure, semi-hardened areas, and boiling slurry. As mentioned above, moisture remains in the area that has hardened into a structure, and when this moisture is emitted and passes through the semi-hardened area, Not only does it hinder curing, but it also causes large bubbles to form in the construction body, causing internal defects.
These internal defects become larger as the area where water evaporates (°C) decreases relative to the amount of unshaped refractory material installed. Additionally, as the construction temperature increases, the rate of water evaporation increases, and defects tend to expand.

The present invention solves such problems in the construction of monolithic refractory materials, and makes it possible to form a construction body with a uniform structure with almost no internal defects and excellent corrosion resistance. The purpose is to provide metal frames for temporary construction.
Its characteristics are as follows.

First, the first feature is a metal frame for hot construction of monolithic refractory materials, which is equipped with a water cooling device. Due to this, the slurry-like monolithic refractory material fed into the metal frame will harden only from the sparse tile surface of the base material, resulting in a uniform construction with no internal defects.

In addition, the second feature is that the metal frame for hot construction of monolithic refractory materials has deaeration holes in the metal frame for hot construction of monolithic refractory materials8. By evaporating it through the deaeration hole provided in the metal frame, it is possible to obtain a construction body with almost no internal defects.

Furthermore, the third feature is that a water cooling system is attached to the metal frame for hot construction of monolithic refractory material, and the metal frame has deaeration holes whose minimum dimension is smaller than the maximum particle size of the monolithic refractory material. It is located at the second location.

By doing so, the effects of the first feature and the second feature described above are achieved in tandem, which is more beneficial.

Here, the deaeration hole provided in the metal frame is as explained in detail later.
There are a large number of holes of appropriate size over the entire surface of the metal frame, and it is preferable that the total area of the deaeration holes be 3.about.20% of the total area of the metal frame.

Now, in the present invention described above, the reason why a water cooling device is attached to the metal frame for hot construction of monolithic refractories is that first, the hardening of the monolithic refractories that has been hot-constructed progresses only from the surface of the base material, thereby preventing internal defects. This is to make the construction body free of blemishes. In addition, by cooling the metal frame with water, the construction temperature is lowered to a sufficient amount of heat to boil and harden the monolithic refractory material, thereby making it possible to create a dense construction body with W.

On the other hand, providing a deaeration hole in the metal frame allows moisture remaining in the hardened construction body to be evacuated through the deaeration hole provided in the metal frame without passing through the semi-cured construction body, thereby eliminating internal defects. Shi: [To make it into a body.

The shape of this deaeration hole is not limited to circular, oval, oval, square, rectangular, etc., but its minimum dimension (hereinafter referred to as short axis) is the maximum particle size of the particles constituting the amorphous refractory material used. Needs to be smaller. A portion of the monolithic refractory material that is pumped into the metal frame in a slurry state flows out through this degassing hole.

If the construction is carried out hot and the minor axis is smaller than the maximum particle size of the monolithic refractory material, the amount of outflow will be small and will not pose a problem.

However, if the short axis is larger than the maximum particle diameter of the monolithic refractory material, the amount of outflow increases, which is uneconomical.

Further, the total area of the deaeration holes is preferably 3 to 20% of the total area of the metal frame. If the area ratio of the degassing holes is less than 3%, water vapor will not evaporate sufficiently from the degassing holes, which may cause defects inside the construction body, which is not preferable. In addition, if the ratio exceeds 20%, not only will the monolithic refractory material leak out from the metal frame, making it uneconomical, but the construction itself will have a mixture with a large amount of coarse particles, resulting in a construction with poor durability. Undesirable.

A part of the monolithic refractory material installed in a metal frame having a deaeration hole having a short diameter smaller than the maximum particle diameter of the monolithic refractory material flows out through the deaeration hole. However, since this effluent is composed of medium particles and fine particles, the constructed body around the deaeration hole has a coarser particle composition compared to other parts, resulting in a structure with a high air permeability. the result,
Moisture remaining in the hardened construction body evaporates preferentially through the deaeration holes installed in the metal frame without causing defects in the upper semi-hard construction part.

Furthermore, by using a hot-segment metal frame with deaeration holes, it has the advantage of shortening the construction time of the monolithic refractory material. In other words, in hot-constructed monolithic refractory materials, moisture remains inside the construction after hardening.
A curing time is required to completely evaporate this water, but since the movement of water vapor inside the construction body after hardening is carried out by diffusion, a long curing period is necessary.

In particular, long curing is required when degassing is limited to a narrow area at the top of a vertically long workpiece, such as press-fit repair of a immersion pipe in a degassing device. Against this 1. The metal frame for hot construction according to the present invention has a large number of deaeration holes, and not only has a large deaeration area but also a short diffusion distance of water vapor, so that the curing time can be shortened to 1]. It is possible.

The present invention will be explained below based on embodiments shown in the drawings.

Figure 2 shows a metal frame with a water-cooled pipe attached, and Figure 3 shows a metal frame with a water-cooled box attached. (A) is a front view of the metal frame, and (B) is a view of the metal frame installed at the repair location. FIG.

FIGS. 4 and 5 show the internal structure of a water-cooled box provided with baffles. These figures 2 (A) to 5 show a metal frame (4) for construction of monolithic refractory materials, and a water cooling device (9).
(5) is a pressurized pipe made of monolithic refractory material, (6) is a furnace wall, (7) is a cooling water conduit, a water pipe, (7a)
) is a cooling water injection pipe, (7b) is a cooling water outflow pipe, (8) is a water cooling box, and the arrows indicate the flow of cooling water.

Figure 6 shows a deaeration hole (1
0), and this degassing hole (lO)
The total area of the metal frame is 3 to 20% of the total area of the metal frame.

Here, the shape of the deaeration hole (10) is shown in FIGS. 7(A) to (C).
Although the shape is not limited, it is necessary that the short diameter Ω of the deaeration hole (10) be smaller than the maximum particle size of the particles constituting the amorphous refractory material used, and the reason for this is as described above.

Figure 8 shows a water cooling device (
9), and a deaeration hole (10) is provided in this metal frame (4). In this case, the deaeration hole (10
) is the same as in Figure 6, and the water cooling system (
9) is the same as FIGS. 2 to 5, but FIG. 8 shows an example in which the water cooling device is of the flexible pipe type shown in FIG. 2 (^). Note that (7) is a cooling water conduit.

An example of construction using the metal frame (4) for constructing monolithic refractory materials according to the present invention having the above configuration is as shown in the implementation side below.
This greatly contributes to extending the service life of monolithic refractory materials.

Example 1. Comparative Example 1 A metal frame (4) with a copper tubular water cooling device (9) on one side shown in Figure 2 was set in a gas furnace heated to 1000°C, and 10 minutes after setting, The effectiveness of the water cooling device (9) installed in the metal frame (4) was confirmed by pouring a thermal pouring material having the quality indicated above using a spray nozzle with a moisture content of 23 weight (external). Table 2 shows the physical properties of each part of the obtained construction body in comparison with Comparative Example 1 in which a metal frame of the same shape without a water cooling pipe was used.

As shown in the comparative example, the conventional metal frame that receives heat from both sides has a region with high porosity and low strength in the center of the construction body, but the metal frame of the present invention, which has a water cooling device on the metal frame, When used, a fairly uniform construction body was obtained.

Table 1 Table 2 Example 2. Comparative Example 2 A deaeration hole having the shape of FIG. 7(B) and a short diameter of 3 mm was provided in the metal frame (4) shown in FIG. 6 so that the total area was 6% of the metal frame. Inner volume of frame (4) heated to 1000℃: 1000
Xl, 000 x 1000 Cera 1 on the side wall of the gas furnace
- After kneading the hot pouring material shown in Table 1, which is the same as in Example 1, at a moisture content of 18 wt % (external layer), it was introduced from the top. Comparative Example 2 is a case in which a metal frame having the same shape as in the example but without a degassing hole is used, and Table 3 shows the physical properties of each part of each construction body.

As shown in Table 3, in the conventional metal frame without degassing holes, there is a significant difference in physical properties between the upper and lower parts, especially in terms of strength, the deterioration of the upper part is large, whereas in the case of the conventional metal frame with degassing holes, When a frame is used, the structure is almost uniform from the top to the bottom.

Table 3 Example 3. Comparative Example 3 Press-fit repair of the immersion pipe of a 90t RIl degassing device at Steelworks A was carried out using a metal frame having degassing holes according to the present invention.

The shape of the deaeration hole was the same as in Example 2, and the total area thereof was 5% of the total area of the metal frame. The quality of the press-fitting material used is shown in Table 4, and the results are shown in Table 5.

The results are shown in Table 5 as a comparative example in which a conventional metal frame without degassing holes was used.

As shown in Table 4 and Table 5, Example 3, by using a metal frame with degassing holes, even when the same material was used, the durability was 1.4 times longer than that of the conventional one, and in particular, If the metal frame of the present invention is used in construction where the deaeration area is small compared to the amount of construction of conventional monolithic refractory materials, a constructed body with excellent durability can be obtained.

Examples 4 to 6 A metal frame (4) (4000 x 4000 x 100 nn
The hot pouring material used in Example 1 was made into a slurry with a water content of 16% by weight, and the furnace wall temperature was set at 70%.
Construction was carried out by pressure-feeding at 0 to 800°C.

The metal frame (4) used had the structural shape shown in Fig. 2 and was equipped with a serpentine water cooling device (9) (40 mmφ x 60 m) (Example 4), and the structure shown in Fig. 6. The shape of the deaeration hole (1o) is as shown in FIG. 7(c), and the deaeration hole is provided so that the total area is 5% of the metal frame (Example 5). In the shape shown in Fig. 8, a serpentine water cooling device (40 mm φ x 50 m) was installed, and the shape shown in Fig.
Example 7 was used in which degassing holes in the shape of c) were provided so that the total area thereof was 4% of the metal frame.

In addition, as a comparative example (4), the water cooling device (9) also has deaeration holes (
10) Using a conventional metal frame that does not have the same material as in the example, the results of construction in the same manner are also shown in the sixth example.
Table 6 As shown in Table 6, by using the hot construction metal frame of the present invention, it is possible to install a water cooling device more easily than when using a conventional metal frame. The durability is approximately 2.5 times longer when the air conditioner is equipped with a vent hole, and 3.5 times longer when a degassing hole is provided.
By using these together, durability is improved by more than 5 times.

As shown in the examples above, the present invention is suitable for the construction of a monolithic refractory material that has a uniform structure with almost no internal defects and has excellent corrosion resistance. It is a metal frame and is extremely effective in forming repair walls for converters, molten metal containers, R1 degassing equipment, etc.

[Brief explanation of the drawing]

Figures 1 (A), (B), and (C) are schematic cross-sectional views showing the occurrence of internal defects when a conventional metal frame t1 is used and monolithic refractory material is constructed; Early, (B)
indicates the middle stage of construction, and (C) indicates the final stage of construction. FIGS. 2 to 5 show examples of metal frames equipped with the water cooling device of the present invention, and FIGS. 2(A), 3(A), 4, and 5 are front views, and FIGS. 2(B) and 3(B) are cross-sectional views. FIG. 6 shows an example of a metal frame provided with deaeration holes, in which (A) is a front view and (B) is a sectional view. FIG. 7 is an enlarged front view showing an example of the shape of the degassing hole. Figure 8 (Δ
) (B) is a diagram showing an example of a metal frame having both a water cooling device and a deaeration hole, (Δ) is a front view, and (B) is a sectional view. (1) Slurry of monolithic refractory material (2) Hardened monolithic refractory material (3) Internal defective parts of construction body (4) Metal frame (5) Monolithic refractory material pressure feeding pipe (6) Furnace wall (7) , Cooling water conduit (7a) Cooling water injection pipe (7b) Cooling water outflow pipe (8) Water cooling box (9) Water cooling device (10) Deaeration hole Q Over the short diameter of the deaeration hole Applicant Nippon Steel Corporation Kyushu Refractory brick Sanoesha proxy statement - Buried earth Hirozo Mori Figure 1 (A) (B) (C) Figure 2 (B) (A) Figure 3 Figure 4 Figure 5 Prisoner Figure 6 (A) (B) Figure 7 (A) [? '. (B) KoV;IQ (0)=〒-°0 8th (A) (8)

Claims (1)

[Scope of Claims] 1. A metal frame for hot construction of monolithic refractory material, characterized in that the metal frame for hot construction of monolithic refractory material is provided with a water cooling device. 2. A metal frame for hot construction of monolithic refractory material, characterized in that the metal frame for hot construction of monolithic refractory material is provided with a deaeration hole whose minimum dimension is smaller than the maximum grain size of the monolithic refractory material. . 3. A monolithic refractory material, characterized in that a metal frame for constructing the monolithic refractory material is provided with a water cooling device, and the metal frame is provided with deaeration holes whose minimum dimension is smaller than the maximum grain size of the monolithic refractory material. Metal frame for hot construction.