JPH0860213A - Slow cooling stave cooler - Google Patents

Abstract

PURPOSE: To provide a slow cooling stave cooler whose service life containing the repairing of a heat insulating refractory arranged at the side surface in a furnace is prolonged while preventing the supercooling. CONSTITUTION: This stave cooler protects the furnace body shell 4 from the in-furnace heat load. Plural through-holes 11b are opened from the side surface side in the furnace to the side surface side at the out of the furnace of the stave cooler body 11. In these through-holes 11b, structural bodies 12 constituted with a cylindrical body 12a fitted in each through-hole 11b and a cooling pipe 12c projected in each cylindrical body 12a penetrating a cover body 12b plugging the side surface side at the out of the furnace of the cylindrical body 12a and cooling the heat insulating refractory 12d filled up in the cylindrical body, are fitted. By this constitution, the supercooling through the stave cooler can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slow cooling stave cooler mounted on the upper part of a shaft of a blast furnace, which is particularly called a furnace mouth.

[0002]

2. Description of the Related Art An example of a sectional view of a blast furnace is shown in FIG. Brickwork structure is adopted. However, in such a brick-laying structure, the laminated bricks 2 begin to fall off about 2 to 3 years after burning, and a step is formed at this drop-off portion, causing irregularities in the furnace circumferential direction. The generation of the unevenness deteriorates the surface profile of the charging material at the furnace mouth portion, destabilizes the gas flow in the furnace, and contributes to the deterioration of the furnace condition.

Therefore, as shown in FIG. 4, the refractory 3 is sprayed on the falling portion so as to eliminate the unevenness of the inner wall of the furnace. However, since the refractory 3 has a short life, it is regularly used. Spraying is required, which increases the work and cost burden. Reference numeral 4 in FIG. 4 indicates a furnace shell, and 5 indicates a nozzle for spraying the refractory material 3.

Therefore, in recent years, a stave cooler 7 (see FIG. 5 (a)) in which a brick 6 is held on the inner side surface of a furnace, as described in JP-A-61-37904, or
There is proposed a stave cooler 9 [see FIG. 5 (b)] in which a heat-castable castable 8 is sprayed or hand-painted on the inner surface of the furnace, as described in JP-A-3-211121.

[0005]

However, even with the stave cooler proposed in Japanese Patent Laid-Open No. 61-37904, the hugging bricks fall off in a short period of time, which is the same as in the conventional brick-laying structure. The problem occurs. In addition, the stave cooler itself is made of cast metal, and the cooling structure is provided with a wrapping brick on the inner surface of the furnace (total heat transfer coefficient is 36-40 kcal / m ² h
Therefore, if the embraced bricks fall off, the inner surface of the furnace will be supercooled and some of the heat used for the reduction reaction will be taken from the furnace, and the pulverization phenomenon of the iron ore raw material will occur. Then, due to this effect, the gas flow becomes non-uniform (single flow), which leads to deterioration of the furnace condition.

Further, the stave cooler proposed in Japanese Patent Laid-Open No. 3-211121 is effective in the initial state, but when the wear of the castable progresses, the stave cooler is repaired in the case of the conventional brickwork structure. Similarly, spray repair from inside the furnace is required. When this is repeated, the wear of the fixed studs 10 protruding from the stave cooler body progresses and the life of the castable itself is shortened. In addition, the strength of the surface of the residual castable with a thermal history is significantly reduced, so even if the castable is sprayed on the surface, there is a high possibility of peeling from the boundary surface, similar to the case of the conventional brickwork structure. The problem occurs.

The present invention has been made in view of the problems with the conventional stave cooler as described above, and in particular, supercooling is provided when the stave cooler is installed at the furnace mouth which is a part of the upper part of the shaft in the blast furnace. An object of the present invention is to provide a slow cooling stave cooler that can extend the life of the heat insulating refractory disposed on the inner surface of the furnace while repairing it.

[0008]

In order to achieve the above-mentioned object, a slow cooling stave cooler of the present invention is a stave cooler for protecting a furnace shell from a heat load in the furnace. A plurality of through holes are opened from the inner side surface to the furnace outer surface side, and through these through holes, a cylinder body fitted into these through holes and a lid body closing the furnace outer surface side of the cylinder body are penetrated. Then, a structure constituted by a cooling pipe that projects into the cylinder and cools the heat insulating refractory filled in the cylinder is fitted.

[0009]

Since the slow cooling stave cooler of the present invention has a structure in which a heat insulating refractory is provided on the inside surface side of the stave cooler body inside the furnace, the cooling capacity of the stave cooler is higher than that of the conventional stave cooler. Supercooling can be prevented without being transmitted to. If the heat-resistant refractory located on the inner side of the stave cooler body inside the furnace wears out or falls to the allowable limit and needs to be repaired, pull out the structure to the outside of the furnace and then penetrate the new structure. Repair can be completed simply by inserting it in the hole.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a slow cooling stave cooler of the present invention.
A description will be given based on an example shown in FIG. 1A and 1B are drawings showing an embodiment of a slow cooling stave cooler of the present invention. FIG. 1A is a perspective view, FIG. 1B is a front view seen from the outside of the furnace, and FIG. 1C is a sectional view.

In FIG. 1, reference numeral 11 denotes a stave cooler main body, which is a water cooling pipe 11 like a conventional stave cooler.
Although the structure is cooled by the cooling water supplied to the inside via a, in the present invention, since a plurality of through holes 11b are opened from the furnace inner side surface of the stave cooler body 11 to the furnace outer surface side, As shown in FIG. 1B, these through holes 1
The water cooling pipe 11a is buried to avoid 1b.

Reference numeral 12 denotes a structure which is fitted and arranged in the through hole 11b, and has a cylindrical body 12a having an outer diameter substantially the same as the inner diameter of the through hole 11b and a furnace outer surface side of the cylindrical body 12a. The lid 1 having a through hole 12ba formed in the center thereof
2b and the cooling pipe 1 which is arranged in a protruding manner from the outside of the furnace into the cylindrical body 12a through the through hole 12ba of the lid 12b.
2c and a heat insulating refractory material 12d filled in an annular space formed by the cylindrical body 12a, the lid body 12b and the cooling pipe 12c.

By the way, as the heat insulating refractory material 12d constituting the structure 12, it is desirable to adopt, for example, a chamotte refractory material having a thermal conductivity λ of about 1.0 to 1.5 kcal / mh ° C. . This is because it is possible to obtain an arbitrary cooling capacity by appropriately selecting the size and number of the through holes 11b.

As an example, the size and number of the through holes 11b are determined so that the total area of the through holes 11b is 50% of the furnace inner surface area, and the thermal conductivity λ is set as the heat insulating refractory 12d constituting the structure 12. If a chamotte refractory of 1.5 kcal / mh ° C is used, the overall heat transfer coefficient (cooling capacity) of the water-cooled stave cooler is 20 kcal / m ² h ° C, which is about half that of conventional stave coolers. It becomes the numerical value of. Further, instead of water as the refrigerant of the stave cooler body 11, N
_{If 2} is used (weight flow rate 100 kg / H), the cooling capacity of the stave cooler main body 11 is halved, so that the overall stave cooler has an overall heat transfer coefficient (cooling capacity) of about 5 to 10 kcal / m ² h ° C.

Since the gently cooling stave cooler of the present invention is installed at the upper portion of the shaft where the heat load in the furnace is relatively low, N ₂ gas can be used as the refrigerant instead of water. Further, for the same reason, if N ₂ gas is used as the refrigerant of the heat-insulating refractory material 12d forming the structure 12, life extension by cooling and slow cooling can be achieved at the same time.

In this embodiment, in order to firmly hold the heat insulating refractory material 12d, a plurality of studs 12ca are provided on the outer periphery of the cooling pipe 12c, but these studs 12ca are not essential. Absent. Also, the through hole 1
In the present embodiment, the shape of 1b is a square shape whose corners are arcs, but an appropriate shape such as a circle may be adopted.
Further, in the present embodiment, the refractory 1 is provided in addition to the opening position of the through hole 11b on the inner surface side of the furnace of the stave cooler body 11.
Although the thing which installed 1c was disclosed, this refractory material 11c is not essential.

Next, the slow cooling stave cooler of the present invention is installed at the furnace opening 1a of the blast furnace 1, and the heat insulating refractory 1 is operated.
A repair procedure when the inner part of the furnace 2d is worn will be described with reference to FIG.

First, when the inner part of the heat insulating refractory material 12d is worn [Fig. (A)], the furnace body iron shell 4 is covered with the lid 12
Loosen the bolts and nuts (not shown) to which the structure 12 is attached via b, and pull out the structure 12 having the adiabatic refractory 12d worn from the slow cooling stave cooler of the present invention to the outside of the furnace [(b ) Figure].

Next, the new structure 12 is fitted into the pulled-out through hole 11b, the bolts and nuts are tightened, and the structure 12 is attached to the furnace shell 4 through the lid 12b. After that, repair is completed by injecting mortar between the cylindrical body 12a and the furnace shell 4 [Fig. (C)].

[0020]

As described above, the slow cooling stave cooler of the present invention can prevent overcooling and
The life of the heat insulating refractory can be extended. Further, even when the heat insulating refractory is worn or dropped to an allowable limit and repaired, the repair can be easily performed and a new structure is inserted, so that the life of the heat insulating refractory becomes long.

In this embodiment, the slow cooling stave cooler of the present invention is installed at the furnace opening of the blast furnace, but the installation location is not limited to this, and it can be used as a water-cooled metal object for a reaction furnace. .

[Brief description of drawings]

FIG. 1 is a drawing showing an embodiment of a slow cooling stave cooler of the present invention, (a) is a perspective view, (b) is a front view as seen from the outside of the furnace, and (c) is a sectional view.

FIG. 2 is a diagram sequentially illustrating a repair procedure when the heat insulating refractory of the slow cooling stave cooler of the present invention is worn.

FIG. 3 is a sectional view illustrating a furnace body structure of a blast furnace.

FIG. 4 is an explanatory diagram of a repair situation of a conventional furnace opening brick.

5A is an explanatory view of a stave cooler described in JP-A-61-37904, and FIG. 5B is a JP-A-3-2.
It is explanatory drawing of the stave cooler described in 11211 gazette.

[Explanation of symbols]

 4 Iron body shell 11 Stave cooler body 11b Through hole 12 Structure 12a Cylindrical body 12b Lid body 12c Cooling pipe 12d Insulating refractory material

Claims (1)

[Claims] 1. A stave cooler for protecting a furnace body iron shell from a heat load in the furnace, wherein a plurality of through holes are formed from the inner side surface of the stave cooler body to the outer side surface of the furnace, and the through holes are formed in the through holes. , A cooling pipe for cooling the heat-resistant refractory filled in the cylinder by penetrating a cylinder fitted into these through holes and a cover closing the outer side of the furnace of the cylinder to project into the cylinder. A slow cooling stave cooler characterized by being fitted with a structure constituted by.