JP2001215084A - Life extension method of electric furnace tap hole - Google Patents

Abstract

(57) [Summary] [Problem] To extend the life of tap holes of an electric furnace, replace tap hole bricks when it is convenient for the operation of the electric furnace (for example, during regular repair of the electric furnace), and reduce productivity. The purpose is to prevent. SOLUTION: When a tap hole brick 3 used for transferring molten steel of an electric furnace to a ladle is worn out and the tap hole 2 is enlarged, an iron pipe 7 is provided on the inner surface of the enlarged tap hole brick 3 of the tap hole 2. By inserting the mortar 9 into the gap between the iron pipe 7 and the tapped hole brick 3, the diameter of the tapped hole 2 is made approximately the same as before the consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tap hole through which molten steel is transferred from an electric furnace to a ladle, and more particularly to a method for extending the life of the tap hole.

[0002]

2. Description of the Related Art When transferring molten steel from an electric furnace for melting steel for steelmaking to a ladle, it has a hollow structure with a diameter of 250 mm and a length of about 1000 mm attached to the furnace bottom of the electric furnace. Tapping from taphole brick. Taphole bricks are heavily consumed due to friction and heat with molten steel when tapping, and when used about 150 times, the diameter of the taphole becomes large, the brick under the taphole is melted, and the molten steel scatters without entering the ladle. Become like In that case, the taphole bricks had to be replaced each time, which hindered the operation. The replacement took about three hours, which caused a decrease in productivity.

[0003]

SUMMARY OF THE INVENTION The present invention extends the life of a tap hole to replace tap hole bricks when it is convenient for the operation of the electric furnace (for example, during regular repair of the electric furnace), thereby improving productivity. The purpose is to prevent decline.

[0004]

According to a first aspect of the present invention, there is provided a method of transferring molten steel from an electric furnace to a ladle, in which taphole bricks used for transferring molten steel to a ladle are consumed. When the tap hole is enlarged, an iron pipe is inserted into the inner surface of the tap hole brick of the enlarged tap hole, and mortar is poured into the gap between the iron pipe and the tap hole brick, so that the diameter of the tap hole is the same as before exhaustion. This is a method for extending the life of a tap hole, characterized in that the diameter is about the same.

According to a second aspect of the present invention, there is provided the tap according to the first aspect, wherein an insertion position of the iron pipe into the consumed tap hole brick is eccentric to a side where the mortar on the side where the tap hole is damaged is thicker. This is a way to extend the life of the hall.

That is, in the invention of claim 1, for example,
An iron tube (SS400) having a diameter of 250 mm, a length of 1000 mm, and a wall thickness of about 5 mm is inserted into the inner surface of a tap hole brick of a tap hole having a diameter increased to about 300 mm due to contact with molten steel. By pouring the mortar into the gap between the tap hole brick and the tap hole, the diameter of the tap hole is made approximately the same as that at the start of use. In this case, the iron pipe used has a meaning for shaping the mortar.

According to the second aspect of the present invention, in the above, the insertion position of the iron pipe is such that the thickness of the mortar is 10 mm from the center position.
It is possible to decenter to the extent of the position of the degree.
However, the life is the longest when it is eccentric about 20 mm from the center toward the center of the electric furnace. In addition, by using a cap having a shape in which a conical iron plate with a bottom diameter of 260 mm and a height of about 300 mm is stuck on the top and bottom, by covering the top of the iron tube, it is possible to prevent the mortar from flowing into the iron tube. The mortar shall be poured into the gap between the iron pipe and the tap hole brick.

In the above method, asbestos is applied to the tap hole opening / closing lid at the lower part of the tap hole, and an iron pipe is placed thereon, thereby preventing the mortar from attaching to the tap hole and preventing the mortar from entering the iron pipe. Can be prevented.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a positional relationship between an electric furnace and a tap hole. In FIG. 1, reference numeral 1 denotes molten steel in an electric furnace, 2 denotes a tap hole used to tilt the electric furnace and transfer molten steel to a ladle, 3 denotes a tap hole brick consumed by contact with the molten steel, and 4 denotes a tap hole. It is a tap hole opening / closing lid that prevents molten steel from flowing out until steel. As described above, the taphole brick 3 is melted and damaged by tapping the brick 3 at the lower portion of the taphole 2 by using the taphole brick 3 about 150 times due to friction and heat with the molten steel. Each time, the taphole brick 3 had to be replaced.

FIG. 2 schematically shows the flow of molten steel during tilting of tapping. When the electric furnace is tilted and the tap opening / closing lid 4 is opened, the molten steel 1 moves to the ladle through the tap hole 2. Taphole brick 3 that comes down when the electric furnace is tilted
Has larger erosion. This portion is referred to as a large tap hole erosion side 5 in the present invention.

FIG. 3 schematically shows a method of extending the life of the tap hole 2. In FIG. 3, the asbestos 6 is put on the tap hole opening / closing lid 4. Thereafter, an iron pipe 7 having a diameter of 250 mm, a length of 1000 mm and a thickness of about 5 mm is inserted into the tap hole brick 3. At this time, if the position of the iron pipe is decentered by about 20 mm so that the thickness of the mortar 9 on the large erosion side 3 of the tap hole to be hit by the molten steel at the time of tapping becomes longer, the life can be further extended. In order to prevent the mortar 9 to be poured from entering the inserted iron tube 7, the bottom diameter is 260 mm and the height is 30 mm.
A cap 8 having a shape in which a steel plate having a conical shape of about 0 mm is stuck up and down symmetrically is placed on the tap hole 2.
After such preparation, the mortar 9 is poured between the iron pipe 7 and the tap hole brick 3, and the diameter of the tap hole 2 is set to be substantially the same as the diameter at the start of use. When the mortar 9 is solidified, the cap 8 is removed from above the tap hole 2.

By performing the above operation, the life of the tap hole 2 which has been replaced by about 150 times in the past can be extended by about 50 times to about 200 times, and the life can be extended until the electric furnace regular maintenance. It is now possible to replace taphole bricks without causing a drop in productivity.

[0013]

As described above, according to the present invention,
The life of the tap hole can be extended, and the reduction in the productivity of the electric furnace due to the replacement of the tap hole brick can be minimized.

[Brief description of the drawings]

FIG. 1 is a view schematically showing an outline of an electric furnace and a tap hole.

FIG. 2 is a diagram schematically showing a flow of molten steel when the electric furnace is tilted.

FIG. 3 is a diagram schematically showing a method of extending the life of a tap hole.

[Explanation of symbols]

 Reference Signs List 1 molten steel 2 tap hole 3 tap hole brick 4 tap hole opening / closing lid 5 tap hole large erosion side 6 asbestos 7 iron pipe 8 cap 9 mortar

Claims (2)

[Claims] 1. A tap hole brick used when transferring molten steel from an electric furnace to a ladle is worn out and the tap hole is enlarged. An iron pipe is inserted into an inner surface of the tap hole brick of the enlarged tap hole. A method for extending the life of a tap hole, characterized in that mortar is poured into a gap between an iron pipe and a tap hole brick so that the diameter of the tap hole is approximately the same as before exhaustion. 2. The method for extending the life of a tap hole according to claim 1, wherein the insertion position of the iron pipe into the consumed tap hole brick is eccentric to the side where the mortar on the side of the large loss of the tap hole is thickened. .