KR20040074049A - Lining at restriction part of converter - Google Patents

Abstract

An object of the present invention is to provide a lining of a converter which can suppress the fall of the bricks compared with the conventional one even if the brick of the restricting portion is "stacked". In the lining of the converter limiting line lining the refractory bricks inclined to the iron bar of the converter limiting, and protecting the melted by hot molten steel and slag, the convex bent portion is formed on the upper and lower surfaces of the refractory brick upwards, This locking portion on the lower surface of the fire bricks stacked up and the locking portion on the upper surface of the fire bricks stacked on the lower side were overlapped with each other.

Description

Lining at rest restriction {LINING AT RESTRICTION PART OF CONVERTER}

The converter is one of metallurgical vessels used for melting molten steel. As shown in FIG. 6, the overall structure is a furnace port 1 used for input of raw materials and discharge of slag generated by refining, a furnace section 2 for supporting molten steel or slag, and a furnace section 3 for refining. ), And the limiting portion 4 which gradually narrows the diameter upwards, from the above-mentioned large-scale scallions 2 to the furnace holes 1. And the outer side of this converter 5 is formed with the shell 6, and the inside which contacts high temperature molten steel and slag puts refractory materials, such as the refractory brick 7, inside, so that the part may be protected. It is.

By the way, the lining of the "limiting part" (4) is a "horizontal stacking" stacked on the brick surface horizontally, as shown in Fig. 4, as shown in Fig. 4, or as shown in Fig. 5 In general, it is generally constructed as a "slope stack" in which the brick surface is inclined horizontally. In addition, there is a technique that has performed the following special research when laying bricks.

For example, it is proposed to stack a brick surface vertically with respect to the iron skin surface of a restriction | limiting part (refer patent document 1). Moreover, the technique which prevents the brick of this limitation part from falling by equipping the brick of a restriction part and making it hold | hang each other is disclosed (refer patent document 2 and 3). Moreover, the technique of digging | drilling a brick in advance at the time of construction, and integrating adjacent bricks together and preventing fall is disclosed (refer patent document 4 and 5).

And according to the experiences so far, in order to achieve the long life of the restriction | limiting part 4, the structure of "tilt stacking" rather than said "horizontal stacking" is good. Erosion by molten steel or slag generally progresses from the road part 2 toward the limit part 4, and in the case of "horizontal stacking", the downward force applied to the brick located above the dragon hand part. Because it is easy to break down bricks by. And when the brick is broken and a part of it is lost, the mutual support of the brick around the limited portion is lost, causing an accident that the whole brick is dropped, causing trouble to the operation.

On the other hand, in the "slope stacking", since the downward force is reduced and reduced, the bending of the brick is reduced as compared with the "horizontal stacking". And in order to exhibit this effect to the maximum, as disclosed in the said patent document 1, it is good to stack a brick surface at right angles with respect to a furnace wall surface.

However, in the technique of this patent document 1, when the inclination of a furnace wall is severe, since a brick slips off in an axis line, there exists a problem that an axis line operation cannot be performed smoothly. In particular, when the converter is used for the first time (operation), coke is charged into the furnace and heated, the processed lining is dried, and the coke is discharged in reverse. In addition, as a countermeasure against dropping of the limited part brick, there is a technique of equipping the brick with metal as described in Patent Documents 2 and 3, but the material cost increases. In addition, as described in Patent Documents 4 and 5, integrating the grooves in advance in the restricting bricks requires a separate work of making the grooves, so that there is a problem that the number of working steps is increased and the cost is increased. In forming the grooves as disclosed in Patent Documents 4 and 5 in the form used when pressing bricks to form concavities and convexities corresponding to the grooves, when the bricks are later heat treated, the grooves are formed from the corners of the grooves. Cracks tend to occur. Therefore, grooving must be performed separately after the brick is manufactured.

In view of the above circumstances, an object of the present invention is to provide a lining of a converter which can suppress the fall of the bricks compared with the conventional one even if the brick of the restricting portion is "stacked".

[Patent Document 1]

Japanese Utility Model Publication No. 3-67050

[Patent Document 2]

Japanese Unexamined Patent Publication No. Hei 1-309915

[Patent Document 3]

Japanese Utility Model Publication No. 5-37950

[Patent Document 4]

Japanese Patent Publication No. 58-32311

[Patent Document 5]

Japanese Patent Laid-Open No. 5-279719

TECHNICAL FIELD The present invention relates to the lining of converters and, more particularly, to the lining bricks of converters used in the molten steel solvent, in particular the brick stacking structure of the furnace.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross sectional view showing an entire image of a converter limiting part according to the present invention.

Fig. 2 is a cross sectional view showing in detail a converter limitation portion according to the present invention.

3 is a view showing the life of the limiting part of the converter having a limiting part and a conventional limiting part according to the present invention.

Fig. 4 is a cross sectional view showing a restricting portion of a converter by a conventional " horizontal stacking ".

Fig. 5 is a cross sectional view showing a restricting portion of a converter by a conventional " tilt stacking ".

Fig. 6 is a cross-sectional view showing the structure of a general upsetting converter.

It is a figure which shows an example of the magnitude | size and shape of the brick which concerns on this invention, (a) is a side surface, (b) is a plane.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described with reference to drawings.

The whole image of the lining of the converter limitation part which concerns on this invention is shown in FIG. As shown in FIG. 1, the brick 7 used for this lining is inclinedly piled up on the road part brick 8 piled horizontally of the road part 2. And the important point is not the brick which has a flat surface just like a normal brick, but employ | adopted the brick which formed the convex bending part 9 in the part of brick surface as shown by the cross section in FIG. . That is, this locking part 9a of the lower surface of the brick piled up on the upper side and the locking part 9b of the upper surface of the brick piled up on the lower side overlap each other. In this case, the bricks adjacent to each other in the upper and lower sides are caught by each other, so that even if the brazing loss of the brick part 8 of the road part brick 8 or the limiting part 4 advances to some extent and the brick supporting the lower part is lost, This is because the bricks do not fall easily. Moreover, the concave part 9 is convex upward because when it recesses up, it becomes easy to slip when it piles up and down, and a brick falls out when an external force is applied.

In addition, in such a lining, when the bricks are stacked, the worker who enters the furnace pushes the bricks 7 directly from the front side to the metal shell side and drops the hooking portions 9a of the bricks stacked on the upper side to the hooking portions 9b of the bricks stacked on the lower side. Since it can be installed just by putting it down, it does not increase the load on the shaft work. In addition, the manufacture of bricks does not require a special cost as well as to manufacture a mold capable of exhibiting the shape as described above. In addition, since the converter lining brick is applied to the annular bark, there is a general case that two opposite surfaces of adjacent bricks are not parallel, rather than rectangular. In the present invention, the convex bending is made on the brick to be a polyhedron, so that no problem occurs in construction.

By the way, in the technical field different from a converter, the firebrick which has a latching part is already used for preventing the fall of a brick, for example in the inner wall of a hot stove etc., especially the ceiling part. A typical example of the refractory brick used in a hot stove or the like has the above-described locking portion (equivalent to 9a in FIG. 1) near the center of the lining thickness direction, and the step height of the locking portion is about 25 mm, and the inclined portion (equivalent to 9c) reaches the step. Is comprised so that the angle (theta (1) equivalency) of about 30 degrees with respect to the horizontal surface of a brick may be achieved. However, such a shape was difficult to apply to the lining of the converter due to the following circumstances.

First, the damage of refractory bricks, such as a hot stove, is relatively small, and the lifespan until replacement is generally 10 years or more. On the other hand, the inner wall of the converter is always subjected to erosion by molten steel, so that its lifetime is about 1 year. In addition, when the erosion of the lining reaches the locking portion, the locking effect is naturally lost, so that the risk of brick breakdown increases rapidly. Therefore, as used in the hot stove, if the locking portion is near the center portion of the lining thickness direction, the risk of brick dropout increases when the brick is half eroded, causing a problem of frequent brick exchange.

Secondly, the furnace temperature in the hot stove is about 1200 ° C., but since the furnace temperature of the converter exceeds 1700 ° C., the environment such as the converter has a higher heat load than the hot stove. In addition, the thermal conductivity is higher than that of quartz bricks used in hot stoves, and the MgO-C bricks (magnesia carbon) used in converters are larger. There is a problem that it becomes larger than in the case of furnace.

In order to solve the first problem, it is required to install the locking part as close as possible to the side of the lining in the lining thickness direction, while the second problem is to install the locking part near the end of the brick or to increase the protrusion of the locking part. It is making it difficult to raise power. In order to satisfy this conflicting requirement, the present inventors have tested various shapes and dimensions and found that the following shapes can be solved by solving the above problems.

First, in the present invention, about the shape of this bent convex concave portion, the shape of the so-called "key", the stepped angle and the inclined step like a step, the "へ" shape of the Japanese hiragana and the "S" of the Roman letter What is necessary is just to have an effect of hanging each other, such as a shape. However, in terms of the balance between the locking force and the strength of the locking portion, a gentle S shape as shown in Fig. 2 is most preferable. Moreover, it is preferable to make the convex part 9a into a curved surface instead of an angle, and to make it larger than a right angle as an angle. This is because cracking starting from the bent edge can be suppressed by stress concentration.

Incidentally, the inclination angle θ1 formed by the inclined portion 9c with the horizontal surface of the brick is preferably about 30 ° to less than 90 °, more preferably about 45 ° to 75 °. In other words, if the angle is too small, the locking force is insufficient, especially in the inclined stacking perpendicular to the furnace wall surface. On the other hand, when the angle is too large, the locking portion is easily broken.

And in this invention, it is good to set the height of the concave hooked part 9 to 5-20 mm. The reason for this is that when the thickness is less than 5 mm, the latches of the bricks are unstable, and there is a possibility that the bricks may be pulled out even with a small external force. When the thickness is larger than 20 mm, the locking effect may be saturated, and the locking portions may be weak.

Moreover, in this invention, it is more preferable to make the position of the hooking part 9 which convex upwards be 1/15-1/3 of the total length of the lining thickness direction at the edge part of a brick. If the location of the catch is less than 1/15 of the full length at the end of the brick, the remainder of the brick cannot be completely protected by the remaining brick if the brick is broken. It is easy to fall out when the force is applied. Also preferably, 1/15 to 1/10 of the entire length of the brick is particularly preferable. Moreover, since the above-mentioned bending part is simple in shape, it can be easily formed by forming the unevenness | corrugation corresponding to a bending part in the form at the time of brick manufacture. Moreover, although the kind of brick is irrespective, application of the magnesia carbon system is preferable as mentioned above. The angle of inclination (θ2 in FIG. 1) in which the bricks 7 are stacked may be inclined to some extent (for example, about 10 °), but is preferably 15 ° or more, and the brick plane is perpendicular to the steel surface. Most preferred. It is because the effect which components the downward force applied to the brick 7 is large.

The inventors earnestly studied to achieve the above object, and embodied the results in the present invention.

That is, the present invention is lining the refractory brick lining the iron shell of the converter limiting portion, and in the lining of the converter limiting portion to protect the melted by hot molten steel and slag, convex upward on the upper and lower surfaces of the refractory brick. It is a lining part of the converter limitation part provided with the bending part, and this latch part of the lower surface of the refractory brick piled up on the upper side, and the latch part of the upper surface of the refractory brick stacked on the lower side overlap each other.

In addition, the present invention is the upper surface and the lower surface of the refractory brick is perpendicular to the surface of the steel bar, the height of the bent convex hook portion is 5 to 20mm, or the position of the bent concave hook portion is the position of the refractory brick It is good to set it as 1/15-1/3 of the full length of a brick at the end part of a skin side.

According to the present invention, the newly formed up-convex bent portion hooks the adjacent bricks up and down, so that the bricks do not fall off easily even if the erosion of the worn portion proceeds. In addition, when the bricks are stacked or the reverse of the bricks can be prevented from falling out. That is, according to the present invention, even if the brick of the restricting portion is "sloped", the fall of the brick can be suppressed more than before, and the lining of the converter excellent in workability at the time of construction can be provided at low cost.

A brick as shown in FIG. 2 is produced for the restricting part of the converter, and the brick 7 is constructed in the restricting part 4 of the converter 5 so as to be perpendicular to the bar (Example of the present invention), and the molten steel is melted in the converter. The operation was performed. Moreover, operation in the converter constructed with the brick which has a normal flat surface was also performed (comparative example). These bricks 7 are made of MgO-C (magnesia-carbon), and are made by pouring a mixed powder of MgO and C into their molds, forming them, and drying them to form a so-called "fluorine-free." It is a brick of. Moreover, as shown in FIG. 7, the size of the brick which concerns on this invention is set to height 150mm x length (lining thickness direction) 810mm x width 75mm, and the bending part 9 which convex | convex on the upper and lower sides respectively is shown. Formed. The concave bent portion 9 formed thereon forms an inclined step as shown in FIG. 2 at a position of 75 mm from the end to be the side of the iron side, and sets the height of the step to 15 mm. Moreover, each part of the converter 5 other than the restricting part 4 is constructed by the normal brickwork. The inclination angle (θ1: see FIG. 2) of the inclination 9c of the inclined portion reaching the step was 60 °. In addition, as a construction method of the said restriction | limiting part brick, the comparative example 1 is the conventional "horizontal stacking" ((theta) 2 = 0 degree), the comparative example 2 is the "slope stacking" whose inclination angle (theta) 2 is 12 degrees, and the example of this invention is a steel skin surface. It is a `` slope stacking '' with the brick face upright. Moreover, in the conventional flat brick, it was difficult to make more than this inclination. Moreover, the inclination ((theta2): refer FIG. 1) of the brick from the horizontal surface at the time of inclining perpendicularly to the iron skin surface (the furnace wall surface) was about 30 degrees. In the present invention, the effect is maximized by stacking vertically (θ3 = 90 °, (see FIG. 1)) on the shell of the converter limitation part, but confirms that θ3 (see FIG. 1) is effective even at 95 ° to 105 °. (See FIG. 3). In the operation, although a large number of various solvents including various types of steel, including carbon steel, were charged, the averaged steel grades (compositions) were obtained on average in Comparative Examples and Inventive Examples.

The operation results in these converters are evaluated in terms of the life index (based on the life in horizontal stacking) of the converter limiting unit and are shown in FIG. 3. According to the present invention from FIG. 3, it is clear that the lifespan of the converter limiting part can be improved to about twice the conventional level. This is because, in the conventional horizontal stacking and inclined stacking, the brick was consumed as a combination of cracking and melting, but by stacking vertically on the steel bar, the force applied to the limiting brick was dispersed and the cracking of the brick could be suppressed. In addition, when constructing the lining of the converter according to the present invention, there is no increase in the number of steps in the shaft operation as compared with the conventional construction, and the cost of the brick is only to produce a new mold, and the manufacturing cost of the brick does not increase. Did not.

Claims (5)

In the lining of the converter limiting part to protect the melting damage by hot molten steel and slag by lining the firebrick to the bark of the converter limiting part, Lining of the converter limiting portion is provided on the upper surface and the lower surface of the refractory brick, and the upper and lower concave bending portion is provided, and the engaging portion of the lower surface of the refractory brick stacked on the upper side and the engaging portion of the upper surface of the refractory brick stacked on the lower side overlap each other. The lining of the converter limiting part according to claim 1, wherein the upper and lower surfaces of the firebrick are made perpendicular to the surface of the steel bar. The lining of the converter limiting part according to claim 1 or 2, wherein a height of the upwardly convex engaging portion is 5 to 20 mm. 4. The lining of the converter limiter according to any one of claims 1 to 3, wherein the position of the hooked up convex portion is 1/15 to 1/3 of the full length of the brick at the end portion of the refractory brick. Magnesium-carbon firebrick, which is a substantially rectangular brick mainly composed of MgO and C, and has a bent convex portion at the upper and lower surfaces of the brick at 1/15 to 1/3 of the total length at the end portion in the longitudinal direction of the brick.