JPS58117990A - Furnace building method for lining structure in high-temperature vessel - 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 The present invention provides for the construction of lining structures for blast furnaces, converters, etc.
The present invention relates to the provision of a new means for building a furnace that is improved so as to prevent damage to the main refractory bricks, particularly cracking caused by the zeal of the bricks.

For example, in a high-temperature furnace (furnace) that uses a refractory brick structure as the lining, such as a blast furnace,
It is no exaggeration to say that the damage to the bricks determines the lifespan of the container (furnace) or the time for repairs, and it is also true that cracks caused by the force of the brick are a major factor in the damage to the bricks. It is well known.

Now there is a theory about the lid between the cracks in this refractory brick WA
In Fig. 1 (A) and (b), (&) is a partial model diagram of a single refractory brick divided into two from the center, (
b) shows the FEM split diagram, but in the case of the blast furnace barrel,
The inner lining structure is assembled in a circular shape using a plurality of refractory bricks (1), and the outer shell (2) and bricks (
1) is usually joined using a stamp (3). The reason why only the negative part of the firebrick itself is shown here is to take into consideration the inserted joints for absorbing thermal expansion, and because of its symmetry, only the negative part is shown as a model. (a) (b) In both figures, the line CC indicates the center line. In such a model, during the temperature rise caused by blast furnace operation, the temperature of only the inner surface of the brick (1) increases, as shown in Figure 1 (e), where the dotted line shows the initial shape and the solid line shows the shape at high temperature. (a)
In the figure, f indicates the joint thickness. Due to this thermal expansion, the refractory brick (1) comes into contact with the adjacent brick (1), but the contact state is as shown in Figure 2, and the contact with the adjacent brick is as shown in the figure. As shown in the compression force model diagram in the figure, the area subjected to compression force P in the σ direction is applied to the WX slope of approximately i on the inner surface side. Therefore, if the partial compressive force is applied in the θ direction, the area where the compressive force is acting and the boundary point E between the area where the compressive force is acting and l[ where it is not acting (L from the inner surface of the brick)
O length), that is, a tensile stress cr is generated in the r direction of the singular point E as shown in the distribution diagram in Figure 4, and by exceeding the tensile strength 6''B, Cracks occur.

The present invention focuses on the mechanism of such cracking, and changes the content of the furnace construction of a multi-structure lined with refractory bricks and joints, thereby effectively and accurately preventing cracking. Therefore, its characteristics are that in high-temperature containers that use refractory brick structures as the lining of blast furnaces, converters, etc., when constructed using the refractory bricks and joints of the lining 9 structure, the container (furnace) Joint thickness on the inner (high temperature) side (
The joint thickness (gap between bricks) on the outside (low temperature) side of the container (furnace) is made thinner, and the joint thickness (brick gap dimension) is changed within one contact surface between adjacent bricks. The point is to carry out its construction.

The present invention will be described in detail below based on the illustrated embodiment. In explaining the mechanism of cracking in the firebrick (1) mentioned above, what determines the tensile gk stress at the singular point Σ is:
It is not the compressive force P itself, but the gradient of the compressive force P. Fifth
The figure shows a diagram of the relationship, the vertical axis shows the generated tensile stress 6'r, and the horizontal axis shows the lateral pressure gradient Po / L. As shown by curve A (, the gradient of compressive force P It is clear that if the slope is steep, the tensile stress increases, and if the slope is gentle, the tensile stress decreases.

That is, in order to reduce the compressive force P and the tensile stress r,
It is sufficient to increase the contact area between adjacent bricks (1) (1) in hot conditions, and this rounding K should be constructed using refractory bricks and joints, taking into account the expansion allowance in hot conditions. . As mentioned earlier, the temperature of the refractory brick in hot conditions is higher on the inner surface and lower on the outer surface. As can be seen from the difference in thermal expansion in h. The present invention is characterized by such construction contents, and FIG. 6 shows a basic example thereof in comparison with the conventional method. Figure (b
) shows the conventional method, but in the present invention, as shown in the figure,
When taking gaps (joints) between adjacent refractory bricks (1) (1) at their opposing joint sides (IliXI&), make sure to make the gaps (joints) larger in the areas that go inside the furnace (high temperature areas), In the part facing the outside (low temperature part), take a small value of 1 < iD, that is, at the same time, in terms of the joint thickness, the joint facing the inside of the furnace is thicker, and the joint facing the outside of the furnace is thinner, so the gap between them (the joint ) Thickness and thinness (large and small) over the entire length shall gradually decrease from the inside of the furnace to the outside of the furnace.

To specifically illustrate this in the case of a blast furnace in FIG. 6(a), (in the gradient diagram, on the inner surface side of the brick (1) facing into the furnace, the brick width: la, the temperature: T
a, Brick gap: /a, Hot shrinkage rate between Mumu 1: ε
a, and on the outer surface side of the brick (1) facing outside the furnace, the brick width: lb, the temperature: Tb, the brick gap: fb, the hot shrinkage rate of BB": εb, and the coefficient of thermal expansion. In order to achieve the purpose of the present invention, if α is εa - εb, then the adjacent joining surfaces (Ia) (1 m) are in uniform contact with each other on both the inner and outer sides, as described above. It is possible to reduce the slope of the compressive force P and thus the tensile stress.

,-, o'h/clb = crab j-! It is sufficient if the b-Tb formula is satisfied. In the case of a blast furnace, its/a+0
．． 8 fb, Ta + 1500℃, 'rb +
If the temperature is about 250℃, efa //b
It is desirable that the joint thickness be around medium 5 (the width of the gap between the bricks).
The range of a // b < 8.0 is considered to be effective, and within this range, as mentioned earlier, the soil thickness (gap between bricks) is gradually changed from the inside of the furnace to the outside of the furnace. Then, all you have to do is build the furnace using the refractory bricks and joints one by one.

The present invention is as described above, and according to this furnace construction content, it is possible to effectively prevent the occurrence of cracks in refractory bricks, thereby preventing damage to the bricks, shortening the lifespan of the furnace, and frequent repairs. This eliminates repetition and ensures relatively long-term operation. Particularly, in the present invention, conventional firebricks (11) are used, and the joint thickness (gap between bricks) between adjacent firebricks (1) (1) is simply calculated as shown in Fig. 6 (al) K.
In the conventional method shown above, the joint thickness is the same over the entire length extending inside and outside the furnace (same gap), and it is only necessary to change it as shown in Section 6 II (a) K. By reducing the gradient of the compressive force P shown in FIG. 5, the compressive force P and the resulting tensile stress fr The effect is precise, and there is no disadvantage in terms of materials and man-hours for furnace construction, and it is an advantageous measure for improving the gkg structure of using refractory bricks in high-temperature containers. It is.

[Brief explanation of the drawing]

Figure 1 is an analytical model diagram of thermal deformation in a refractory brick, Figure 2 is an explanatory diagram of the brick contact state at the same high temperature, Figure 3 is a model diagram of the compressive force acting on the inner surface of the brick, and Figure 4 is the tensile stress distribution of the same brick. Figure 5 is a graph of the relationship between tensile stress and partial pressure gradient,
FIG. 6 is a diagram illustrating a comparison between an embodiment of the method of the present invention and a conventional method. (1)...Firebrick, (2)...Iron shell, (3)-
Stamp, (Im)...Joining side. Patent applicant: Kobe Seisakusho Co., Ltd.

Claims (1)

[Claims] 1'i & In high-temperature storage parts that use refractory brick structures as the lining of furnaces, converters, etc., the joints on the (high temperature) side of the container (furnace) Increase the thickness (gap between bricks), reduce the thickness of the ground outside the container (furnace) (low temperature) @01 (between reno ff1ll11), and change the joint thickness (dimension of the gap between bricks) within one contact surface between adjacent bricks. A method for constructing a lining structure in a high-temperature IFIIIK, the method comprising: