JPH02267206A - Method for preventing gas leakage at iron tapping in blast furnace - Google Patents

Abstract

PURPOSE:To secure gas seal at the boundary joined between monolithic refractory layer and brickwork perfectly and to prevent leakage of gas in the neighborhood thereof by embedding a refractory-made cylindrical sleeve at the boundary. CONSTITUTION:A large diameter hole 11 is bored to the prescribed depth penetrating the monolithic refractory layer 13 at iron tapping hole with a boring bit 12 having the diameter larger than the hole diameter of the iron tapping hole 1. Successively, the refractory-made cylindrical shape sleeve 14 having pressing-in hole 15, the inner diameter of which is larger than that of the iron tapping hole, the outer diameter smaller than that of the large diameter hole 11 and the depth shorter than that of the large diameter hole 11, is inserted into the large diameter hole 11. Further, a pipe for pressing-in is connected with the pressing-in hole 15 under condition of sticking the sleeve 14 to bottom part of the large diameter hole 11, and the mortar 16 is pressed and packed into gap between the sleeve 14 and the large diameter hole 11, and also pressed and packed in the sleeve 14 and the large diameter hole 11 to embed the whole of large diameter hole 11 with the mortar 16.

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a method for preventing gas leakage from brick joints and joints with steel skin during blast furnace tapping, and particularly to the outside of the furnace wall brickwork. The present invention relates to a method for preventing gas leakage occurring near the boundary between the monolithic refractory layer and furnace wall brickwork when the outer opening of a tap hole is closed by providing a monolithic refractory layer.

Conventional technology As is well known, the taphole of a blast furnace has a diameter of 6 mm called the taphole on the furnace wall.
This is done by drilling holes of about 0 mm, but the pressure inside the furnace is 4.
Since the pressure is as high as KydG, the gas in the furnace may leak from the brick joints around the taphole or the joints with the steel skin and blow out together with the hot metal.

When the gas inside the furnace blows out along with the hot metal, the gas burns the moment it flows out of the furnace, disrupting the flow of hot metal, causing sparks to fly out of the hot metal, commonly referred to as blow-off, and hindering work at the front of the furnace. It may cause damage.

In addition, when tapping with a gas-liquid mixed phase of hot metal and gas, the outflow speed of the hot metal increases, and when the amount of gas increases, the outflow speed slows down due to the breathing phenomenon. It also affects not only the blast furnace condition but also the blast furnace condition.

Conventionally, as a countermeasure against this problem, as shown in Figure 3, holes were opened in the steel skin (2) around the taphole (1) and monolithic refractories (3) were press-fitted into this area. Ta. (4) is the furnace wall brickwork.

However, with the method described above, which is taken as a measure to prevent gas leakage during blast furnace tapping, the filling of the monolithic refractory may be insufficient depending on the opening position for press-fitting the monolithic refractory. Gas leakage was likely to occur from the boundary with the wall brickwork, and preventive measures during blast furnace tapping were not sufficient.

Problems to be Solved by the Invention In view of the above-mentioned actual situation, this invention solves the above-mentioned problems in a method of filling the vicinity of a tap hole with monolithic refractories to prevent gas leakage. The purpose of this paper is to propose an effective sealing means to prevent gas leakage from the boundary between the monolithic refractory layer and the brickwork, where gas leakage is likely to occur.

Means for Solving the Problems This invention prevents gas leakage by embedding a cylindrical refractory sleeve at the boundary between the monolithic refractory layer and the brickwork, which is considered to have the greatest impact on gas leakage. The purpose of this measure is to drill a hole in the blast furnace taphole with a diameter larger than the taphole to a depth that penetrates the monolithic refractory layer that forms the taphole and reaches a part of the furnace wall. A refractory cylindrical sleeve with a press-fit hole having an inner diameter larger than the tap hole, an outer diameter smaller than the diameter of the hole, and a length shorter than the depth of the hole is installed in the large diameter hole. By press-fitting and filling mortar into the large-diameter hole and the cylindrical sleeve with the tip of the cylindrical sleeve in close contact with the bottom of the large-diameter hole, the monolithic refractory layer and the brickwork are connected. This method completely prevents gas leakage from the joints between the steel shell and brickwork at the boundary and around the taphole during tapping.

Operation: A cylindrical sleeve is inserted into the large diameter hole provided in the blast furnace taphole, and by filling the large diameter hole with mortar and burying the sleeve, the area is reopened and the furnace wall is penetrated. When the tap operation begins, the boundary between the monolithic refractory layer and the brickwork around the tap hole is completely closed by the cylindrical sleeve and mortar, so that the gas in the furnace flows through the tap hole. There is no leakage that disrupts the hot metal flow, a stable hot metal flow is obtained, and therefore there is no hot metal blowing phenomenon.

The reason why the size of the cylindrical sleeve to be buried in the tap hole is limited is as follows.

■ If it penetrates into the furnace, the press-fitting material will leak into the furnace when the mortar is press-fitted, making the press-fit uneven, and a sufficient sealing effect cannot be obtained.

■ The reason why the tap diameter was made larger than the normal tap hole diameter was to prevent the cylindrical sleeve from being damaged by the hole drilling machine used during the hole drilling process in preparation for tapping.

Embodiment FIG. 1 is an explanatory diagram showing the gas leakage prevention method of the present invention.
(Fig. 1) shows a state in which a hole is drilled through a monolithic refractory layer to a predetermined depth, and (n) shows a cylindrical refractory sleeve inserted into a large diameter hole drilled to a predetermined depth. (III) is a diagram showing the state in which mortar is press-fitted and filled into the large diameter hole, and FIG. 2 is a perspective view showing the cylindrical sleeve.

That is, in the method of the present invention, first, holes are drilled with hole pits 1 to (12) having a diameter larger than that of the tap hole (1), and the large diameter holes (12) are drilled through the monolithic refractory layer (13) to a predetermined depth. 11) Drill holes (art and crafts).

This large-diameter hole (11) is drilled to a position that does not penetrate the furnace wall brickwork (4), but the depth of the hole will vary depending on the size of the blast furnace and the thickness of the furnace wall, but it is usually from the taphole entrance. 100
A depth of about 0 to 2500+ nm is desirable.

Once this large diameter hole (11) is drilled to a predetermined depth, a refractory cylindrical sleeve (14) is inserted into the large diameter hole (Fig. ■).

As shown in Fig. 2, this cylindrical sleeve has a mortar press-fit hole (15), the size of which is as described above, the inner diameter is larger than the tap hole, and the outer diameter is larger than the large diameter hole (11). It has a small diameter and a length shorter than the depth of the large diameter hole (11).

Next, with the cylindrical sleeve (14) in close contact with the bottom of the large-diameter hole (11), a press-fitting pipe (not shown) is connected to the press-fitting hole (15) of the sleeve, and the mortar (16) is In addition to press-fitting and filling the gap between the sleeve and the large-diameter hole, the mortar (16) is also press-fitted and filled into the sleeve and the large-diameter hole (11) to fill the entire large-diameter hole with mortar (16) (Figure ■).
.

When tapping the blast furnace, the large-diameter hole filled with mortar is reopened to penetrate the furnace wall, and the taping operation begins.

At this time, since the boundary between the monolithic refractory layer (13) and the furnace wall brickwork (1) around the taphole is completely closed by the mortar (16), the gas in the furnace is There is no leakage that disrupts the hot metal flow, and the hot metal flow is stable.
Therefore, the phenomenon of hot metal blowing away is completely eliminated.
It does not interfere with work in front of the furnace.

Furnace volume 2700m3, blowing pressure 3. OK! The method of the present invention was applied to the tap ports of 14 blast furnaces to tap the iron.

Table 1 shows the length of the tap hole, the inner diameter and depth of the large diameter hole, the outer diameter and inner diameter of the cylindrical sleeve, the length, and the filling pressure and amount of mortar in this example.

As a result, the blow-off phenomenon that occurred about once a day before the construction of the present invention disappeared completely after the construction.

As described in detail in Table 1, according to the method of the invention, the gas seal is perfect, especially at the joint between the monolithic refractory layer and the brickwork, and there is no possibility of blowing during tapping due to gas leakage from this area. Since the scattering phenomenon can be prevented, a stable flow of hot metal can be obtained, which not only does not interfere with the work at the front of the furnace, but also has a great effect on stabilizing the furnace conditions.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the method for preventing gas leakage of this invention.
1) is a diagram showing a state in which a large diameter hole is drilled to a predetermined depth through the unshaped refractory layer in the taphole part, and (II) is a diagram showing mortar being drilled into the large diameter hole drilled to a predetermined depth. (I [I) is a diagram showing a state in which mortar is press-fitted and filled into a large diameter hole, Figure 2 is a perspective view showing the same cylindrical sleeve, and Figure 3 1 is a longitudinal sectional side view showing an example of a conventional gas leakage prevention method. 1... Tapping port 11... Large diameter hole 13...
Monolithic refractory layer 14...Cylindrical sleeve 16...
mortar

Claims (1)

[Claims] A hole with a diameter larger than the taphole is drilled in the blast furnace taphole through the monolithic refractory layer that forms the taphole to a depth that does not penetrate the furnace wall brickwork, and the inner diameter is larger than the taphole. Then, a refractory cylindrical sleeve with a press-fit hole having an outer diameter smaller than the hole diameter and a length shorter than the hole depth is inserted into the large diameter hole, and the tip surface of the cylindrical sleeve is enlarged. Press the mortar into the large diameter hole and sleeve while keeping it in close contact with the bottom of the diameter hole.
A method for preventing gas leakage during tapping of a blast furnace, characterized by filling the blast furnace with iron.