KR100328033B1 - Refractory constructing device for protecting inclined lance nozzle of vacuum degassing equipment - Google Patents

Abstract

PURPOSE: A refractory constructing device for protecting inclined lance nozzle of vacuum degassing equipment is provided to reduce repairing frequency of a degassing tank by extending life cycle thereof, effectively perform degassing by increasing decarburization efficiency, and perform stable operation by reducing metal adhered into the degassing tank. CONSTITUTION: In a refractory constructing device for protecting an inclined lance nozzle for blowing oxygen into a vacuum degassing equipment, the refractory constructing device for protecting the inclined lance nozzle of the vacuum degassing equipment comprises a fire brick projection(30) that is formed at the circumference of the oxygen injection nozzle(130) inserted into the inner side of a degassing tank so that the layer of fire bricks(140) is projected to a certain height from the inner wall of the degassing tank; an oxygen injection nozzle(130) the lower part(130a) of which is positioned at the lower surface of the fire brick projection(30) and at the corner part(30b) of wall body refractories adjacent to the lower surface of the fire brick projection(30); and a layer of fire bricks(140) on which the fire brick projection(30) is formed, and which is dividingly supported by a plurality of brackets that are extended from a metal case(132) by penetrating permanent lining refractory layers(135,137) so that the fire brick projection(30) is partially replaced with new fire bricks, wherein thickness (T) of the fire bricks(140) which are positioned in the fire brick projection(30) is 1.1 to 1.5 times of thickness (t) of the wall body refractories, and length of the brackets is 1.1 to 1.5 times of thickness of the permanent lining refractory layers(135,137).

Description

Refractory construction device for inclined lance nozzle protection of vacuum degassing device

The present invention relates to a refractory construction apparatus for protecting an inclined lance nozzle that injects oxygen into a vacuum degassing apparatus from erosion by molten steel, and more particularly, to prevent molten steel erosion of the lance nozzle and to prolong the lifetime thereof. Refractory construction for inclined lance nozzle protection of the vacuum degassing device to reduce the number of repairs of the tank, to improve the decarburization efficiency, to enable quick and effective degassing operation, and to reduce the amount of deposition in the degassing tank to perform stable operation. Relates to a device.

In general, the vacuum degassing equipment 100, as shown in Figure 1, the upper and lower tub 110, 112 to form a vacuum therein, from the one side of the lower pipe 112, sedimentation tube 115 The molten steel 120 is raised to form the circulation of the molten steel 120 is lowered to the other side of the lower pipe 112, the lower pipe 112, the lance nozzle 130 into the upper, lower tub 110, 112. Oxygen is blown using to remove impurities in the molten steel 120.

In this vacuum degassing facility 100, the oxygen blowing technology is a method of blowing oxygen from the nozzle deposited in the molten steel 120, and from the lance inserted from the degassing tank ceiling cover into the inside of the degassing tank on the molten steel surface. There is a method of blowing oxygen, and as shown in FIG. 1 and FIG. 2, a method of blowing oxygen obliquely on the upper surface of the molten steel 120 from the nozzle 130 located on the side wall of the degassing tank. have. In particular, in the third method, as shown in FIG. 1, the inclined lance nozzles 130 are disposed in all directions of the degassing tank, and inject oxygen while maintaining the inclination of approximately 20 degrees with respect to the fireproof wall.

Among the oxygen blowing methods, the first method is generally adopted because of its high decarburization efficiency and equipment stability, but there is a problem that a large amount is now attached to the wall of the degassing tank due to the splash of molten steel during oxygen injection. In the second method, the CO gas generated during the decarburization treatment and the secondary combustion of the injected oxygen are emphasized, so that the decarburization rate in the high carbon and low oxygen region can be improved and the molten steel temperature decrease during the RH treatment can be reduced. The investment cost is high. On the other hand, the third method is more economical than the second method because it can achieve the same or more effect than the second method, while the third method is economical, while the front end of the lance nozzle 130 located on the wall moving surface and its surroundings. Early damage to the refractory is a problem.

The detailed structure of the nozzle 130 related to the third gradient injection method of the above oxygen injection method is shown in FIG. 3. The nozzle 130 has a permanent field refractory layer 135, such as dolomite, is formed inside the cylindrical shell 132 forming a degassing tank, and a permanent field refractory layer 137, such as magnesia, is formed therein. The refractory brick 140 is built to a predetermined thickness. Then, the inclined lance nozzle 130 is inserted through the iron shell 132, the permanent field refractory 135, 137, the inner and the brick 140, and approximately at the tip of the nozzle 130 with respect to the refractory wall. Oxygen is injected at an angle of 20 °. However, in this injection method, the front end of the nozzle 130 is broken as the refractory brick 140 around the nozzle 130 is eroded concave in a dome shape as shown by a dotted line in FIG. 3. Erosion of this partial refractory brick 140 is because the nozzle neck 150 (neck) is located approximately 170mm inward from the tip 130a of the lance nozzle 130, the nozzle neck 150 portion of this lance Firebrick 140 is eroded so as to damage the nozzle neck 150. In this case, since it is impossible to control the amount of oxygen supply through the lance nozzle 130, it is a great risk factor for safe operation of the degassing tank. In this case, depending on the degree of erosion, the operation of the degassing tank is stopped and the corresponding fireproof eroded. Repair work to replace the brick 140 and the lance nozzle 130 and the like.

On the other hand, in the conventional refractory construction device as described above, if you want to replace the eroded refractory brick 140, the refractory brick 140 around the lance nozzle 130 must be replaced a considerable amount, which is shown in Figure 8 , Not only the refractory brick 140 around the lance nozzle 130, but also all the refractory bricks 140 to the upper side reinforcement bracket 152 of the degassing tank must be replaced, and the refractory bricks 140 are sequentially stacked from the bottom. Because of the raised structure, it is impossible to replace only the nozzle 130, and doubled around the nozzle 130, requiring a large amount of refractory brick 140 to be replaced.

Therefore, the conventional refractory construction apparatus as described above has a problem that the operation time of the degassing tank is shortened due to the loss of a large amount of refractory bricks 140 during the replacement operation of the eroded refractory, and requires much cost for maintenance of refractory maintenance. .

The present invention is to solve the problems posed by the third inclined blowing method, to prevent the molten steel erosion of the lance nozzle, to extend the service life of the degassing tank to reduce the number of repairs, due to the increase in decarburization efficiency The purpose of the present invention is to provide a refractory build-up device for inclined lance nozzle protection of a vacuum degassing device, which enables improved and efficient degassing operation and saves time and money related to refractory replacement as a quick maintenance. It is.

1 is a block diagram of a general vacuum degassing apparatus;

2 is a cross-sectional view of a general vacuum degasser;

3 is a view showing the structure of the refractory construction apparatus according to the prior art showing the configuration and erosion around the inclined lance nozzle;

Figure 4 shows a refractory construction device of the present invention,

a) is a cross-sectional view showing a configuration in which the inclined lance nozzle is located on the firebrick;

b) is a cross-sectional view showing a configuration in which the inclined lance nozzle is located under the refractory brick wall;

5 is a layout view of a bracket provided in the refractory construction device for inclined lance nozzle protection of the present invention;

6 is a cross-sectional view of the bracket provided in the refractory construction device for inclined lance nozzle protection of the present invention;

7 is a block diagram showing the refractory dismantling portion when dismantling the refractory body using the refractory construction device for inclined lance nozzle protection of the present invention;

8 is a block diagram showing the refractory dismantling portion when dismantling the refractory using the refractory construction device according to the related art.

Explanation of symbols on the main parts of the drawings

30 ..... Fireproof Jaw 50 ..... Bracket

110 .... upper part 112 .... lower part

120 ... Molten steel 130 ... Lance nozzle

132 .... Iron 135,137 ... Permanent field refractory layer

140 .... Firebrick 150 .... Nozzle Throat

P ...... Erosion line

In order to achieve the above object, the present invention provides an inclined lance nozzle protection refractory construction device for injecting oxygen into a vacuum degassing apparatus, wherein the refractory brick layer around the oxygen injection nozzle inserted into the degassing tank has a A refractory brick jaw is formed to protrude a predetermined height from the inner wall, and a fireproof part is formed at the lower surface of the refractory brick jaw and the lower edge of the lance nozzle is located at an adjacent edge portion of the wall refractory adjacent thereto. Refractory for inclined lance nozzle protection of a vacuum degassing apparatus, characterized in that the brick layer is partitioned and supported by a plurality of brackets extending through the permanent field refractory layer from the bark. By providing a construction device.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

As shown in FIG. 4, the refractory forming apparatus 20 for inclined lance nozzle protection of the vacuum degassing apparatus of the present invention removes the refractory brick 140 layer around the oxygen injection nozzle 130 inserted into the degassing tank. The fireproof brick projections 30 are formed to protrude a predetermined height from the inner wall of the gas tank.

And, as shown in Figure a), the lower end 130a of the lance nozzle 130 is to be located at one side of the lower edge 30a of the refractory brick jaw (30). In this case, the refractory brick 140 located in the refractory brick wall 30 has a thickness T of 1.1 to 1.5 times the thickness t of the wall refractory material. It is difficult to obtain the erosion suppression effect by forming the same level as the wall refractory material (30). If the thickness ratio is 1.5 times or more, the refractory brick wall 30 excessively protrudes from the wall refractory material, causing excessive erosion. In the structure as described above, as shown by the dotted line in Figure 4a, when the erosion line (p) is generated, the erosion portion of the refractory brick 140 is made quickly to the nozzle neck 150 to the nozzle neck ( It can damage the parts.

On the other hand, in Figure 4b) as shown in Figure 4a), to form a refractory brick wall 30 so that the refractory brick 140 layer protrudes a predetermined height from the inner wall of the degassing tank, the lower end portion 130a of the lance nozzle 130 Is to be located in the lower surface of the refractory brick wall 30 and the adjacent edge portion 30b of the wall refractory adjacent thereto. Even in such a case, the refractory brick 140 located on the refractory brick wall 30 has a thickness T of 1.1 to 1.5 times the thickness t of the wall refractory material, and in the above structure, FIG. 4B. As shown by the dotted line in the), when the erosion line (p) is generated, the eroded portion of the refractory brick 140 does not reach the nozzle neck 150, and thus the nozzle neck 150 is molten steel 120 It is protected from erosion by the product and greatly extends its lifespan.

As a result of measuring the erosion degree by actually configuring the structures of FIGS. 4A) and 4B, respectively, the structure of FIG. 4B) was able to achieve at least twice the lifespan compared to the structure of FIG. 3 and the structure of FIG. 4A). , Replacement of the refractory brick 140 and the lance nozzle 130 was to be extended more than twice.

5 and 6, the bracket 50 of the refractory construction device according to the present invention is mounted. The brackets 50 extend the refractory brick 140 forming the refractory brick wall 30 from the shell 132 through the permanent field refractory layers 135 and 137. ) Can be partially replaced. The brackets 50 have a length L of 1.1 to 1.5 times the thickness k of the permanent refractory refractory layers 135 and 137. If the brackets 50 are less than 1.1 times, the refractory on the upper side of the bracket 50 is formed. If the supporting force is weak and 1.5 times or more, the space occupied by the bracket 50 between the refractory brick 140 and the refractory brick 140 is too large, and the refractory brick 140 is processed to position the bracket 50. The volume is too big to work with.

In addition, the brackets 50 are formed in a line 50a at the upper boundary line that partitions the firebrick jaw 30 from the wall refractory, and each line 50b, 50c is formed at the lower boundary line and the upper side thereof. It consists of three lines as a whole, and the width of each of these extends beyond the width of the part of the refractory protrusion (30). Therefore, in the case of repairing the refractory projection step 30, it is possible to replace only the refractory brick 140 of the corresponding part, which is the refractory on the upper side of the upper boundary line of the refractory projection step 30 as shown in FIG. The bricks 140 are supported by the upper side brackets 50 so that the bricks 140 are firmly supported even when the refractory protrusions 30 are replaced to prevent the dropping out. In addition, the refractory projections 30 are supported by brackets of the two rows 50b and 50c of the lower side, and thus do not cause any damage to the lower wall refractory when the refractory projections 30 are replaced.

According to the present invention as described above, the refractory brick 140 to form a refractory brick jaw 30 so as to protrude a predetermined height from the inner wall of the degassing tank, the lower end 130a of the lance nozzle 130 is the refractory brick By positioning the lower surface of the jaw 30 and the adjacent edge portion 30b of the wall refractory adjacent thereto, it prevents the molten steel erosion of the lance nozzle 130 and extends the life, thereby reducing the number of repairs of the degassing tank and decarburizing efficiency. The increase in speeds up the rapid and effective degassing operation. And, it has a bracket (50) for partitioning the refractory brick jaw (30) from the wall refractory, and the improved effect of saving the cost and time associated with the refractory replacement as a quick maintenance during the replacement of the refractory projection jaw (30) It is obtained.

Claims (4)

In a refractory construction device for inclined lance nozzle protection that injects oxygen into a vacuum degassing apparatus, the refractory brick (140) layer around the oxygen injection nozzle (130) inserted into the degassing tank protrudes a predetermined height from the inner wall of the degassing tank. The refractory brick wall 30 is formed so that the lower end portion 130a of the lance nozzle 130 is positioned at a lower surface of the fire brick wall 30 and an adjacent edge 30b of the wall refractory material adjacent thereto. The firebrick 140 layer forming the firebrick jaw 30 is partitioned by a plurality of brackets 50 extending from the shell 132 through the permanent field refractory layers 135 and 137. Refractory building device for inclined lance nozzle protection of the vacuum degassing apparatus, characterized in that configured to enable partial replacement of the refractory brick wall (30). The refractory brick 140 of claim 1, wherein the refractory brick 140 positioned at the refractory brick wall 30 is configured such that its thickness T is 1.1 to 1.5 times the thickness t of the wall refractory material. Refractory build-up device for inclined lance nozzle protection of gas equipment. The refractory construction for inclined lance nozzle protection of a vacuum degassing apparatus according to claim 1, wherein the brackets (50) have a length of 1.1 to 1.5 times the thickness of the permanent long refractory layer (135) (137). Device. According to claim 3, The brackets 50 are formed in a line 50a at the upper boundary line for partitioning the refractory brick wall 30 from the wall refractory, and each line 50b (50c) to the lower boundary line and its upper side Refractory building for forming the gradient lance nozzle protection of the vacuum degassing apparatus, characterized in that formed by each, three rows as a whole.

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