JP2011191044A - Furnace bottom of electric furnace of structure to extend service life of tap hole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of a furnace bottom of an electric furnace having a tap hole of a structure capable of dispensing with replacement of the tap hole brick eroded at its upper part in tapping molten steel by changing the structure of the tap hole brick, and extending a service life of the tap hole brick, with respect to the structure of the brick of the eccentric bottom tapping type electric furnace having the tap hole. <P>SOLUTION: In the eccentric bottom tapping type electric furnace 13, the tap hole bricks 1 having the tap holes 1a and having a length longer than a length of peripheral sleeve bricks 2 are formed on the furnace bottom 7 of the electric furnace, and upper ends of the tap hole bricks 1 are projected upward with respect to upper ends of the peripheral sleeve bricks 2. Further, on the furnace bottom 7 of the electric furnace having the tap hole bricks 1 and the peripheral sleeve bricks 2, a monolithic refractory 4 is appropriately placed on the sleeve bricks 2 and a monolithic refractory 3 forming the furnace bottom to fill a space to a height of the tap hole bricks 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tap hole of an electric furnace that passes when molten steel is transferred from an eccentric furnace bottom steel type electric furnace to a ladle, and more particularly to an extension of the tap hole life by changing the structure of the tap hole brick.

  When transferring molten steel from an electric furnace that melts steel for steelmaking to a ladle, a tap with a hollow tap hole attached to the bottom of the electric furnace of an eccentric furnace bottom steel type Steel is produced from hall bricks. Tap hole bricks are heavily consumed due to friction and heat with molten steel when steel is output, and the inner diameter of the tap hole increases each time steel is output. In particular, the upper and lower parts of the tap hole bricks were severely damaged and melted in the form of a trumpet. Therefore, it was necessary to replace the tap hole bricks every time they were damaged.

  As a method for extending the life of a tap hole brick, there is a repair method in which an iron pipe is inserted into the inner side surface of the tap hole and mortar is poured between the inner side surface and the iron pipe to solidify (see, for example, Patent Document 1). However, in this repair method, repair is not possible unless the iron pipe is melted to a diameter that allows insertion, and the upper part of the tap hole brick may be melted greatly by the time. When the erosion progresses in this way, the erosion will occur up to the upper part of the sleeve brick around the tap hole brick. There is a method of replacing the tap hole brick relatively easily, but replacement of the sleeve brick cannot be easily performed from the viewpoint of work time and labor and cost. Once the sleeve brick is melted, even if the melted part is repaired with a refractory, the refractory is weaker than the brick, so the erosion is progressing. If it becomes like this, the melting loss of a tap hole brick will also become large. For this reason, it is necessary to replace the tap hole brick before the tap hole brick around the upper part of the tap hole is severely melted.

  With the conventional method of inserting and placing an iron pipe in the upper part of the tap hole of a melted tap hole brick, repair is impossible unless the iron pipe is melted to a diameter where it can be inserted. In some cases, the upper part of the tap hole brick is greatly melted and the tap hole brick may be replaced because of the upper part of the brick.

JP 2001-215084 A

  The problem to be solved by the present invention is to eliminate the need to replace a tap hole brick whose upper part has been eroded by molten steel in the structure of an eccentric furnace bottom steel type electric furnace brick having a tap hole, and Providing the bottom of an electric furnace with a tap hole that has a structure that extends the life of the tap hole brick, while eliminating the need to place an iron pipe on top of the tap hole of the melted tap hole brick It is to be.

  The means of the present invention for solving the above-mentioned problems is, in the invention of claim 1, an eccentric furnace bottom steel type electric furnace. The length of the tap hole brick at the bottom of this electric furnace is formed longer than the length of the surrounding sleeve brick, and the upper end of this tap hole brick is formed from a structure protruding above the upper end of the surrounding sleeve brick. The bottom of an electric furnace having a tap hole brick and a sleeve brick surrounding the tap hole brick.

  In the invention of claim 2, the structure in which the upper end of the tap hole brick protrudes upward from the surrounding sleeve brick is the top of the sleeve brick and the sleeve which are steps formed by the tap hole brick and the surrounding sleeve brick. 2. The tap hole brick according to claim 1, characterized by having a structure in which an amorphous refractory is buried and reinforced up to an upper surface position of the tap hole brick on an irregular refractory on the furnace bottom outside the brick. It is the bottom of an electric furnace with surrounding sleeve bricks.

  In the invention of claim 3, the structure formed by filling the step formed by the tap hole brick and the surrounding sleeve brick with the irregular refractory is replaced by replacing the lower part of the irregular refractory with the refractory brick. The bottom of an electric furnace having a tap hole brick and a sleeve brick around the tap hole brick according to claim 2, characterized in that the structure is reinforced by filling up the upper surface of the tap hole brick with an irregular refractory. is there.

  With the electric furnace having the structure of the above-mentioned means of claim 1, there is no case where the tap hole brick is replaced due to melting damage on the upper part of the tap hole brick, and the life of the upper part of the tap hole brick is extended by 20 to 30%. be able to.

  Further, the electric furnace having the structure of the means of claim 2 eliminates the case where the tap hole brick is replaced due to the melting of the upper part of the tap hole brick, thereby reducing the upper part of the tap hole brick to the life of the tap hole brick. The effect which can be extended 20 to 30% can be acquired more appropriately.

  Furthermore, the electric furnace having the structure of the means of claim 3 eliminates the case of replacing the tap hole brick because of the melting damage of the upper portion of the tap hole brick, and extends the life of the upper portion of the tap hole brick by 20 to 30%. The effect that can be obtained can be obtained more accurately.

It is the side view which showed typically the cross section of the electric furnace of the eccentric furnace bottom-out steel type of this invention. FIG. It is the figure which showed typically the state which the tap hole brick of this invention protrudes upwards rather than the sleeve brick. It is the figure which showed typically the state which filled the level | step-difference part of the tap hole brick and sleeve brick of this invention with the irregular refractory material, (a) reinforces the level | step-difference part flush, (b) is a tap. It is the figure which reinforced the hole brick edge as the highest thing of the same height. It is the figure which showed typically the state which reinforced the level | step-difference part of the tap hole brick and sleeve brick of this invention with the firebrick and the irregular refractory material on it. It is the figure which showed typically the state by which the upper part of the tap hole brick of FIG. It is the figure which showed typically the state by which the amorphous refractory which reinforced the upper part and periphery of the tap hole brick of FIG. It is the figure which showed typically the state where the tap hole brick of FIG. It is the figure which showed typically the furnace bottom provided with the general conventional tap hole brick. It is the figure which showed typically the state where the tap hole brick shown in FIG. FIG. 10 is a diagram schematically showing a state in which the steel is produced without performing repair in the state of FIG. 9 and the sleeve brick is melted in addition to the tap hole brick.

  First, the structure of the tap hole brick 8 and the surrounding furnace bottom 7 of the conventional eccentric bottom steel-type electric furnace will be described with reference to the accompanying drawings. FIG. 8 schematically shows a tap hole brick 8 having a conventional tap hole 8 a, a sleeve brick 2 provided around the tap hole brick 8, and an irregular refractory 3 that forms a furnace bottom 7. As described above, the molten steel melted in the electric furnace flows down the tap hole 8a of the conventional tap hole brick 8 by the outgoing steel, so that the upper portion of the tap hole 8a has a trumpet shape due to the friction of the molten steel and the heat of the molten steel. It expands and melts down.

  FIG. 9 shows the tap hole brick 9 in which the upper part of the tap hole brick 8 is melted and the upper part of the periphery of the tap hole 8a becomes the melted part 12 by the conventional tap hole brick 8 shown in FIG. The state is shown schematically. However, in the state of FIG. 9, the upper part of the sleeve brick 2 has not yet melted. However, since there is little melting damage of the center part of the tap hole 8a of this tap hole brick 9, it cannot repair by the conventional repair method (for example, refer patent document 1). However, as described above, since the upper part of the sleeve brick 2 is melted and damaged when it is used as it is, the upper part of the sleeve brick 2 is melted. .

  FIG. 10 shows the state of the tap hole brick 9 in which the upper portion shown in FIG. 9 is melted, and as a result of repeated steel extraction without repair, the upper portion of the tap hole brick 9 and the periphery of the inner diameter of the tap hole 8a are as follows. The state which melted and expanded and the upper part of the sleeve brick 10 around the tap hole brick 9 is melt | dissolved typically is shown. However, if it becomes like this, as mentioned above, it will become impossible to replace the melted sleeve brick 10 easily in terms of working time, labor, and cost.

  Next, the structure of the tap hole brick 1 and the surrounding furnace bottom 7 of the electric furnace 13 of the eccentric furnace bottom steel type having the electrode 14, the tap hole 6a and the tap hole 15 shown in FIG. I will explain. FIG. 2 shows the periphery of the tap hole brick 1 on the bottom 7 of the electric furnace, which has the configuration according to the basic structure of the present invention. The length of the tap hole brick 1 having the tap hole 1a at the center is longer than that of the sleeve brick 2 fitted around the tap hole brick 1 and the longer part of the tap hole brick 1 is the sleeve brick 2 and its surroundings. The structure of the furnace bottom 7 of the electric furnace which has a structure provided so as to protrude upward from the amorphous refractory 3 forming the furnace bottom 7 is schematically shown. The lower ends of the tap hole brick 1 and the sleeve brick 2 are located on the same plane.

  FIG. 3 shows the periphery of the tap hole brick 1 on the bottom 7 of the electric furnace in the configuration according to the second invention. In this structure, the stepped portion formed between the portion projecting upward of the long tap hole brick 1 of the present invention and the sleeve brick 2 around the tap hole 1 and the irregular refractory 3 on the furnace bottom is indefinite. The state filled with the regular refractory 4 is schematically shown. Also in this case, the lower ends of the tap hole brick 1 and the sleeve brick 2 are located on the same plane. Among these, (a) of FIG. 3 shows the step portion formed by the upper surface of the tap hole brick 1 and the upper surface of the sleeve brick 2 and the upper surface of the irregular refractory 3 on the furnace bottom by the irregular refractory 4. The upper surface of the irregular refractory 4 is filled with the same height as the upper surface of the tap hole brick 1. On the other hand, (b) of FIG. 3 shows that the upper surface of the irregular refractory 4 in which the stepped portion on the upper surface of the tap hole brick 1 is filled is the highest position at the same position as the upper surface of the tap hole brick 1, The upper surface of the object 4 is placed while being inclined downward from the high position to the upper part of the amorphous refractory 3 at the bottom of the furnace.

  FIG. 4 is a configuration according to the third aspect of the invention and shows the periphery of the tap hole brick 1 at the bottom 7 of the electric furnace. In this structure, a stepped portion formed between a portion protruding above the long tap hole brick 1 of the present invention and the sleeve brick 2 around the tap hole 1 and the irregular refractory 3 at the bottom of the furnace, A refractory brick 5 is placed on the sleeve brick 2, and the refractory brick 5 is further filled with an irregular refractory 4. The state of being filled with the irregular refractory 4 is schematically shown. Also in this case, the lower ends of the tap hole brick 1 and the sleeve brick 2 are located on the same plane.

  FIG. 5 schematically shows the state of the tap hole brick 6 in a state where the upper part of the tap hole brick 1 having the basic structure shown in FIG. 2 is melted and damaged by the molten steel discharged from the electric furnace. FIG. In FIG. 5, a portion indicated by a virtual line is the melted portion 12. Since the tap hole brick 1 in FIG. 2 protrudes upward, the melted damage of the protruding portion of the tap hole brick 6 in the melted state shown in FIG. 5 is large, but the sleeve brick 2 has not yet reached the point of melting. Not in. Therefore, in this state, the steel can still be produced without repair.

  FIG. 6 shows the tap hole brick 1 having the structure shown in FIG. 3, the sleeve brick 2 and the electric furnace 3 in which the upper part of the irregular refractory 3 forming the furnace bottom is filled with the irregular refractory 4, from the electric furnace. It is a figure which shows typically the state with which the tap hole brick 6 of the state of melting and the said irregular refractory 4 were damaged partially. In FIG. 6, a portion indicated by an imaginary line is the melted portion 12. Compared to FIG. 5, the outer periphery of the protruding portion of the tap hole brick 6 is protected by the irregular refractory 4, so that the melting loss is small. Therefore, in this state, the steel can still be produced without repair.

  7 shows the tap hole brick 1 having the structure shown in FIG. 4 and the upper part of the sleeve brick 2 and the irregular refractory 3 forming the furnace bottom, and the refractory brick 5 is placed on the upper surface of the sleeve brick 2 portion. Furthermore, the tap hole brick 1 and the indefinite lower refractory 3 are melted by the steel from the electric furnace in which the indefinite refractory 3 forming the furnace bottom is filled with the indeterminate refractory 4. The tapped hole brick 6 in the melted state and the upper amorphous refractory 4 are schematically shown in a worn state. Compared with FIG. 6, the sleeve brick 2 on the outer periphery of the tap hole brick 6 is protected by the refractory brick 4 so that there is no melting damage. In FIG. 7, a portion indicated by an imaginary line is the melted portion 12.

  As for the embodiment of the present invention, the stepped portion between the long taphole brick 1 and the sleeve brick 2 projecting upward and the irregular refractory 3 on the bottom of the furnace shown in FIG. As shown, the refractory material 4 was filled up to the height of the upper surface of the tap hole brick 1 and reinforced. An electric furnace having this tap hole brick 1 will be described as an example. The bricks of the tap hole brick 1 and the sleeve brick 2 are made of MgC. In this embodiment, the height of the long taphole brick 1 is about 1100 mm, and the height of the sleeve brick 2 is about 1000 mm. Therefore, the stepped portion made of these bricks was 100 mm, and this 100 mm stepped portion was filled with an irregular refractory kneaded with some moisture, as shown in FIG. When the electric furnace was refined in this state, in about 160 times of steel output, as shown in FIG. 6, the sleeve brick 2 was not melted and the inner diameter side of the upper portion of the tap hole 1a of the tap hole brick 6 was melted. It was in a damaged state. When the operation was continued, as shown in FIG. 9, after 195 times of steel output, the amorphous refractory 4 was completely melted and the sleeve brick 2 was in a state immediately before being melted. Therefore, the tap hole brick 6 in the melted state was replaced with the tap hole brick 1 and backfilled again with the irregular refractory 4 in the state of FIG. 3 to operate the electric furnace.

  About the Example of this invention, on the sleeve brick 2 on the step part of the long taphole brick 1 and the sleeve brick 2 which protruded upwards shown in FIG. Place refractory brick 5 and reinforce it with amorphous refractory 4 on top of it, reinforce it with the above-mentioned amorphous refractory 4 on top of amorphous refractory 3 forming the furnace bottom, tap the upper surface of them A description will be given of a structure having the same height as the upper surface of the hole brick 1. As in the first embodiment, the tap hole brick 1, the sleeve brick 2, and the refractory brick 5 are all MgC bricks made of MgC. Also in this embodiment, the long tap hole brick 1 is about 1100 mm, and the height of the sleeve brick 2 is about 1000 mm. On the sleeve brick 2 at the step of 100 mm, an MgC brick of 250 mm in length, 150 mm in width and 95 mm in height is placed in contact with the tap hole brick 1, and a little moisture is placed on the upper portion of the 5 mm height. The amorphous refractory 4 kneaded and placed was placed and buried as shown in FIG. When the electric furnace was refined in this state, the melted portion 12 was generated as shown in FIG. 7 in about 155 times of steel output, but the sleeve brick 6 was protected by the refractory brick 5, and the sleeve brick 2 was not melted, and the inside of the tap hole 1a at the top of the tap hole brick 6 was melted. Therefore, when the operation was continued, the firebrick 5 disappeared after 190 times of steel output, and the state immediately before the sleeve brick was melted as shown in FIG. Therefore, the tap hole brick 6 in the melted state is replaced with the tap hole brick 1, and the fireproof brick 5 is formed on the sleeve brick 2, and the amorphous fireproof material 3 is formed on the fireproof brick 3 which forms the furnace bottom. The object 4 was mounted and it returned to the state of FIG. 4, and the operation of the electric furnace was implemented.

DESCRIPTION OF SYMBOLS 1 Tap hole brick 1a Tap hole 2 Sleeve brick 3 Unshaped refractory which forms a furnace bottom 4 Unshaped refractory 5 Refractory brick 6 Molten tap hole brick 7 Electric furnace bottom 8 Conventional tap hole brick 8a Tap hole 9 Conventional tap hole brick with melted upper part 10 Conventional tap hole brick with melted upper part and inner diameter part 11 Sleeve brick with melted upper part 12 Melted part 13 Electric furnace 14 Electrode 15 Outlet

Claims (3)

  In an eccentric furnace bottom steel type electric furnace, the length of the tap hole brick is longer than the length of the surrounding sleeve brick, and the upper end of the tap hole brick protrudes above the upper end of the surrounding sleeve brick. A bottom of an electric furnace having a tap hole brick and a sleeve brick around the tap hole brick.   The structure in which the upper end of the tap hole brick protrudes upward from the surrounding sleeve brick is formed from a structure in which the step formed by the tap hole brick and the surrounding sleeve brick is filled with an indefinite refractory and reinforced. The furnace bottom of the electric furnace which has the tap hole brick of Claim 1 characterized by these, and the sleeve brick of the circumference | surroundings.   3. A structure in which a step formed by a tap hole brick and a sleeve brick around the tap hole brick is filled with an irregular refractory, and the lower part of the irregular refractory is replaced with a refractory brick and reinforced. The bottom of an electric furnace having the tapped hole brick and the sleeve brick around it.

Images