JPH102680A - Refining furnace tap hole brick - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress propagation of a crack, occurring due to the impact of a slug stopper, to the inner side of a brick by a method wherein a different short refractory is attached to the tip on the nozzle closure side of an integral type sleeve brick used for the tap hole of a refining furnace closed by a slug stopper. SOLUTION: In a refining furnace to close a tap hole by a slug stopper, a short size, for example, 50mm, a bored brick 10 is separately attached to the output side of a tap hole brick (a sleeve brick 1). This constitution suppresses propagation of a crack 11 occurring due to the impact of a stopper. In this case, replacement of the tap hole brick is decided from shortening of the tapping time due to the increase of a hole diameter due to the damage of the brick.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tapping brick of a smelting furnace having a slag stopper for closing a tapping port.

[0002]

2. Description of the Related Art In a smelting furnace having a device for closing a tapping port with a slag stopper in order to suppress slag outflow during tapping, when a metal grows on the tapping port exit side during tapping, a slag stopper is required. Because normal clearance cannot be maintained at the time of occlusion,
The steel tapping brick is impacted via the metal and is blocked. This causes cracks in the taphole brick.

[0003] Japanese Patent Application Laid-Open No. Hei 1-305291 discloses that a tap hole is formed of an integrally formed refractory (sleeve for tapping hole) whose inner surface in contact with a molten steel flow has no joint joint, and that a molten steel flow causes a meltdown. There is disclosed a technique for reducing the pressure and increasing the life of the sleeve. When using an integrally formed sleeve brick, the crack generated on the exit side of the tap hole propagates and grows inside the tap hole, causing damage to the sleeve brick or melting from the crack, reducing the life of the brick. . Further, it is difficult to remove the grown metal after every tapping because the productivity is reduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to suppress the propagation of cracks generated by the impact of a slag stopper in a smelting furnace to the inside of a brick, thereby achieving an extension of the life of a tapping brick. .

[0005]

In order to achieve the object of the present invention, a short brick is separately attached to a steel exit brick outlet of a refining furnace. That is, the present invention provides that in a smelting furnace that closes a tapping port with a slag stopper, an integrally formed sleeve brick is used at the tapping port, and another short refractory is attached to the tip of the sleeve brick on the nozzle blocking side. It is a tapping brick that is a feature.

[0006] In order to suppress the outflow of slag at the end of tapping,
Close the tap hole. When the ingot grows on the exit side of the tap hole,
The stopper collides with the metal, impacts the sleeve brick, and a crack is generated on the exit side. This crack propagates inside the furnace, causing erosion and chipping. Therefore, a short refractory is separately attached to the tip of the sleeve brick to suppress the propagation of the crack generated by the impact to the inside of the furnace. Short bricks are 20-300 mm long, preferably 50-100 mm
And

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the past, a split sleeve divided into a plurality of openings in the tapping direction was used instead of an integrally formed sleeve. The split sleeve was found to differ in its damaged state at the boundary of the sleeve. As shown in FIG. 3, by separately attaching a short (for example, 50 mm long) perforated brick 10 to the exit side of the tapping brick (sleeve brick 1), a crack 11 generated by the impact of the (stopper) appears. Suppresses the propagation growth inside the steel mouth brick.

[0008] The replacement of the tapping brick is determined by shortening the hole time accompanying the hole diameter enlargement due to damage to the brick. As shown in FIG.
Enlarge the hole to a large hole of about 0 to 200 mm, insert the sleeve brick 1 set in the iron pipe 2 in advance, and fix the flange 3 to the furnace from outside the iron plate with the fixing pin 7 so that the sleeve brick 1 does not fall. An irregular-shaped refractory 5 is poured into a gap between the sleeve brick 1 and the furnace body brick 6, and is baked by heat held by the furnace body. The steel pipe 3 inside is melted by tapping after the replacement, and the inside diameter of the sleeve brick 1 becomes the inside diameter.

In order to suppress the outflow of slag at the end of tapping,
The tapping port is closed using a pneumatic slag stopper. As shown in FIG. 5, since the base metal 8 may grow on the exit side of the tapping brick (sleeve brick 1) during tapping, if a stopper is used in this state, sufficient clearance cannot be maintained. The slag stopper collides with the ingot, and an impact is applied to the sleeve brick 1 indirectly. When this happens repeatedly,
A crack 4 is generated on the outlet side of the sleeve brick 1, and furthermore, the brick on the outlet side is broken as shown in FIG. 6, and the crack 4 propagates inside the furnace, causing erosion and breakage. Becomes like a damaged sleeve 9, which accelerates deterioration of the shape of the tap hole and expansion of the hole diameter, and shortens the service life of the tap hole brick. Therefore, as shown in FIG. 3, a steel tapping brick in which a short refractory is separately attached to a tip of a sleeve brick, for example, 900 to 1600 mm in length is applied. This suppresses the propagation of cracks generated by the impact to the inside of the furnace, and delays the expansion of the hole diameter.

[0010]

EXAMPLE A 50 mm plastic brick having the properties shown in Table 2 was attached to the tip of an integrally molded sleeve brick made of the material shown in Table 1, and a tapping brick in which irregular shaped refractories having the properties shown in Table 3 were backed. In the converter using (sleeve brick 1), the tapping port closing device was used at a usage rate of 0 to 80%.

In the conventional example in which the plastic brick is not inserted, when the slag stopper is used, the slag stopper adheres to the tapping hole and the impact is applied to the sleeve brick, cracks are generated and the life of the hole is reduced. Therefore, in the example, by inserting a plastic brick having a thickness of 50 mm at the tip of the sleeve brick (on the flange of the tapping hole), crack propagation to the sleeve brick was suppressed, and a decrease in hole life was suppressed (see FIG. 3). FIG. 4 shows the relationship between the slag stopper usage rate and the hole life. Curve 21 (prior art), curve 22 (Example) in FIG.
, The approximation formula is as follows.

Prior art y = 234.40-1.1876x (r = 0.37) Example y = 239.01-0.35854x (r = 0.49) The slag stopper is used by inserting the plastic brick of the example. The hole life at a rate of 100% was improved from 116 ch / book (conventional product) to 203 ch / book (with plastic brick).

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

[0016]

According to the present invention, the life of the tapping brick is significantly improved as compared with the conventional one-piece sleeve brick because the tapping brick of the refining furnace is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment.

FIG. 2A is a perspective view and FIG. 2B is a longitudinal sectional view of a conventional example.

3A is a perspective view and FIG. 3B is a longitudinal sectional view of the embodiment.

FIG. 4 is a longitudinal sectional view showing a process of attaching a sleeve.

FIG. 5 is a vertical cross-sectional view showing a use progress of the sleeve.

FIG. 6 is a vertical cross-sectional view showing the use progress of the sleeve.

FIG. 7 is a graph showing a relationship between a slag stopper usage rate and a hole life.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sleeve brick 2 Iron pipe 3 Flange 4 Crack 5 Irregular refractory 6 Furnace brick 7 Fixing pin 8 Ingot 9 Damaged sleeve 10 Perforated brick 11 Crack 21 Curve 22 Curve

Claims (1)

[Claims] In a smelting furnace in which a tap hole is closed by a slag stopper, an integral molded sleeve brick is used for the tap hole, and another short refractory is attached to a tip end of the sleeve brick on a nozzle closing side. Steel tap bricks that are characteristic.