JPH0726311A - Structure for cooling furnace bottom part of blast furnace - Google Patents

Abstract

PURPOSE:To improve the cooling in the peripheral part of a furnace with cooling pipe lines of simple structure and to achieve the resistant of cooling at the center part of the furnace. CONSTITUTION:In the structure of the furnace bottom part of the blast furnace provided with plural cooling pipe lines 10 embedded parallel in refractory 3 having high heat conductivity under the bottom plate 3 at the furnace bottom so as to cross the whole width of the furnace bottom surface in the unidirection, besides the existing cooling pipe lines 10, plural pieces of additional cooling pipe lines 11 crossing the furnace center line forming the boundary line (a) in the same direction are added. IN the peripheral part of the furnace, the additional cooling pipe lines 11 are positioned at the lower level than the existing cooling pipe lines 10 and embedded into the refractory 2' having low heat conductivity, and in the center part of the furnace, this additional cooling pipe lines are positioned to the same level as the existing cooling pipe lines 10, and on the other hand, the existing cooling pipe lines 10 in the center part of the furnace are positioned by changing their positions downward, and cooing performance in the peripheral part of the furnace and in the center part of the furnace are independently controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a furnace bottom cooling structure for cooling a furnace bottom by embedding a cooling pipe in a refractory below the bottom bottom of a blast furnace.

[0002]

2. Description of the Related Art Cooling of the bottom of a blast furnace is important for protecting the bottom brick and suppressing the growth of a solidified layer in the furnace to activate the bottom of the furnace. Conventional bottom cooling is shown in Figure 7 (a),
As shown in (b), a plurality of cooling pipes 10 are embedded in parallel in a refractory 2 constructed below a bottom 3 of a furnace provided at the bottom of the furnace body 1 so as to traverse the bottom of the furnace in one direction. However, it is general that water or air is made to flow through this to cool it.

The bottom brick 4 of the blast furnace is continuously used for a long period of 10 years or more without being repaired. Due to such a long-time operation of the blast furnace, the erosion line of the bottom brick 4 often advances in the peripheral area of the furnace as compared to the central area of the furnace. As described above, the conventional cooling pipes 10 are arranged in parallel, the structure is extremely simple, and they do not have the function of adjusting the cooling capacity of the peripheral portion of the furnace and the central portion of the furnace. Therefore, it was not possible to perform cooling according to the erosion condition of the bottom brick 4 of the blast furnace.

On the other hand, as shown in FIG.
It is known that a is spirally arranged to cool. With such a cooling pipe 10a, it is possible to independently suppress the cooling of the peripheral portion of the furnace and the central portion of the furnace. For example, the cooling of the central portion of the furnace is suppressed,
By strengthening the cooling around the furnace, the condition of the hearth can be maintained in good condition. However, such a spiral arrangement of the cooling pipe 10a has a complicated structure and is difficult to be repaired during construction or after operation, resulting in a large cost.

Further, in JP-A-2-104603, as shown in FIG. 6, a cooling pipe 10b is provided with a bent portion, and
It is disclosed that b is divided into one for cooling the peripheral portion of the furnace and one for cooling the central portion of the furnace, and further, the pipe 10b for cooling the peripheral portion of the furnace is divided into a plurality of areas, each of which is independently controlled. Such a cooling pipe 10b is also the swirl cooling pipe.
Similar to 10a, the structure is complicated and has the same drawbacks.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a furnace bottom cooling structure for a blast furnace which has a simple structure and can independently control the peripheral area of the furnace and the central area of the furnace. It is intended to be provided.

[0007]

According to a first aspect of the present invention for attaining the above object, a plurality of pieces are embedded in parallel in a refractory under a bottom of a furnace bottom so as to traverse the bottom of the furnace in one direction. In the furnace bottom structure of the blast furnace equipped with the existing cooling pipes, in addition to the plurality of existing cooling pipes, a plurality of cooling pipes that cross the central part of the furnace in the same direction are added, and the added cooling pipes are added to the peripheral part of the furnace. Is located at the lower level of the existing cooling pipe, and at the center of the furnace at the level of the existing cooling pipe, while replacing the existing cooling pipe at the center with the lower part, the cooling capacity of the peripheral part of the furnace and the central part of the furnace are It is a furnace bottom structure of a blast furnace characterized by being configured to be controlled independently.

According to the second aspect of the present invention, while the added cooling pipe is positioned at the level of the existing cooling pipe in the peripheral portion of the furnace, the existing cooling pipe in the peripheral portion of the furnace is replaced with the lower cooling pipe so as to be located in the center of the furnace. The furnace bottom part cooling structure for a blast furnace according to claim 1, wherein the part is located at a level below the existing cooling pipe. According to the third aspect of the present invention, the refractory under the bottom of the furnace bottom in which the existing cooling pipe is buried has high thermal conductivity, and the refractory in which the cooling pipe located below the existing cooling pipe is buried has low thermal conductivity. Claim 1 or 2 characterized by the above-mentioned.
It is the furnace bottom cooling structure of the described blast furnace.

Further, according to the present invention of claim 4, in addition to a plurality of existing cooling pipes embedded in parallel in the refractory under the bottom of the furnace bottom so as to cross the furnace bottom in one direction, the center of the furnace is Instead of adding a plurality of cooling pipes that traverse in the same direction, a level that does not interfere with the existing cooling pipes that traverse the central portion of the additional cooling pipes that intersect the furnace central portion at right angles to the existing cooling pipes. The blast furnace bottom cooling structure according to claim 1, 2, or 3, wherein the blast furnace bottom cooling structure is provided by replacing the blast furnace with the blast furnace.

[0010]

EXAMPLES The constitution and operation of the present invention will be described below based on examples. FIG. 1 shows an embodiment of the present invention.
1A is a plan view, and FIG. 1B is A- in FIG.
Sectional drawing which shows the A arrow view and CC sectional view. Moreover, FIG.1 (c) is sectional drawing which shows the BB arrow view of FIG.1 (a).

As shown in FIG. 1 (a), a plurality of furnaces (No. 1 to No. 1 in the drawing) are arranged in parallel so as to traverse the furnace bottom surface of the furnace body 1 in one direction.
7 cooling pipes up to No. 7) are provided. Conventionally, the cooling pipe 10 shown as No. 1 to No. 7 is shown in FIG.
As can be understood from the above, in the refractory 2 below the bottom plate 3 of the furnace bottom, both the peripheral part of the furnace and the central part of the furnace, which are bounded by the alternate long and short dash line (a), were buried at the same level. Such a cooling pipe 10 will be referred to as an existing cooling pipe 10 here.

On the other hand, according to the present invention, as shown in FIG.
As shown in (b) and (c), in addition to the existing cooling pipe 10, an additional cooling pipe 11 (No. 8, N) that crosses the central part of the furnace in the same direction.
o.9), and the additional cooling pipes 11 for No. 8 and No. 9 are shown in FIG. 1 (b) in the peripheral area of the furnace with the dashed line (a) in FIG. 1 (a) as a boundary. As shown in FIG. 3, it is buried in the refractory 2'located at the lower level of the existing cooling pipe 10.

In addition, in the central part of the furnace with the dashed-dotted line (a) as a boundary, as shown in FIG. 1 (c), the additional cooling pipes 11 of No. 8 and No. 9 are positioned at the level of the existing cooling pipe 10 and fireproof. Thing 2
While being buried inside, the existing cooling pipe (No.
No. 3, No. 4 and No. 5) are replaced with the lower position and buried in the refractory 2 '. It is preferable that the refractory material 2 located directly below the bottom plate 3 of the furnace bottom has a high thermal conductivity and the refractory material 2'constructed below the refractory material 2 has a low thermal conductivity.

Generally, in the operation of the blast furnace, it is desirable to cool the bottom of the furnace to improve the cooling capacity of the peripheral part of the furnace and suppress the cooling of the central part of the furnace. In order to realize this, as mentioned above, No. 3, No. 4, which crosses the central part of the furnace with the dashed-dotted line (a) as the boundary,
When the three existing cooling pipes No. 5 are located in the periphery of the furnace with the dashed-dotted line (a) as a boundary, they are positioned at the level of the existing cooling pipes 10 as shown in FIG. It is buried in 2. Also these No.3, No.4, N
When the o.5 is located in the center of the furnace, it is buried in the lower-level low-conductivity refractory 2'as shown in FIG. 1 (c).

And No. 8 and No. crossing the central part of the furnace
When the two additional cooling pipes 9 of 9 are located in the peripheral part of the furnace bounded by the alternate long and short dash line (a), they are placed below the existing cooling pipe 10 as shown in FIG. 2 '
Buried inside. When the No. 8 and No. 9 additional cooling pipes 11 are located in the center of the furnace, they are positioned at the level of the existing cooling pipe 10 as shown in FIG.
The existing cooling pipes of No. 4 and No. 5 are replaced below and buried in the refractory 2'of low thermal conductivity.

In addition to the above-mentioned structure, the amount of cooling water flowing through the existing cooling pipe 10 and the additional cooling pipe 11 is set to the bottom brick 4
Independent control according to the erosion condition (see FIG. 7) can improve the cooling capacity of the peripheral portion of the furnace and easily achieve cooling suppressing the cooling of the central portion of the furnace. FIGS. 2 (a) and 2 (b) show changes in the temperature of the bottom of the furnace and in the center of the furnace and changes in the amount of cooling water in the bottom when the bottom of the blast furnace is cooled by the configuration of the present invention as described above. Here is an example: As shown in FIG. 2, according to the present invention, by controlling the cooling water amount of the existing cooling pipe 10 and the additional cooling pipe 11 independently, the temperature of the peripheral portion of the furnace and the central portion of the furnace are controlled according to the erosion condition of the bottom brick. It becomes possible to adjust.

Although omitted from illustration in some cases, contrary to the above, the added cooling pipe 11 is positioned at the level of the existing cooling pipe 10 in the peripheral part of the furnace, while the cooling pipe 11 in the peripheral part is located. It is also possible to replace 10 in the lower position and position it at the lower level of the existing cooling pipe 10 in the central part of the furnace so that the cooling of the central part of the furnace is promoted by the peripheral part of the furnace.

FIG. 3 shows another embodiment of the present invention, FIG. 3 (a) is a plan view, and FIG. 1 (b) is FIG.
Sectional drawing which shows the BB arrow of (a), FIG.1 (c) is FIG.
FIG. 1A is a cross-sectional view taken along the line AA and CC of FIG. 1A, FIG. 1D is a cross-sectional view taken along the line E-E of FIG. 1A, and FIG. It is sectional drawing which shows the DD arrow and FF arrow arrow of 1 (a).

In FIG. 3, the additional cooling pipes 12 (five in the figure) are crossed at right angles to the existing cooling pipes 10 instead of being in the same direction as the existing cooling pipes 10 like the additional cooling pipes 11 shown in FIG. Further, a plurality of additional cooling pipes 12 that cross the central portion of the furnace are provided. As shown in FIGS. 3 (a), 3 (b), 3 (c), 3 (d), and 3 (e), when the existing cooling pipe 10 that crosses the center of the furnace with the dashed-dotted line (a) as a boundary is located in the periphery of the furnace, As in the conventional case, it is at the level position of the existing cooling pipe 10 (see FIG. 1C), and when it is in the center of the furnace, it is at the lower level of the existing cooling pipe 10 (see FIG. 1B). On the other hand, an additional cooling pipe that intersects the existing cooling pipe 10 at right angles and crosses the center of the furnace.
Twelve (five) are located below the existing cooling pipe 10 when they are located in the periphery of the furnace with the dashed line (a) as a boundary [Fig.
(See (e)]. When the additional cooling pipe 12 is located in the center of the furnace, it is located at the level of the existing cooling pipe 10 [Fig.
(See (d)], the cooling water is independently guided to the existing cooling pipe 10 and the additional cooling pipe 12 for cooling, as in the case described above.

It is also preferable that those located at the level of the existing pipe 10 are buried in a refractory having a high thermal conductivity and those buried below the existing pipe 10 are buried in a refractory having a low thermal conductivity. Is. 4 (a) and 4 (b) show changes in the flow rate of the bottom cooling water and the bottom temperature in the peripheral portion and the central portion of the furnace according to the embodiment of the present invention shown in FIG. As shown in FIG. 4, at the time point “a”, the flow rate of the cooling water for the bottom of the furnace was decreased only in the central part of the furnace, and thereby the temperature of the central part of the furnace was raised. After that, since the temperature around the furnace increased, at the time point b, the flow rate of the cooling water for the bottom of the furnace was increased, so that the temperature increase of the bottom of the furnace could be suppressed easily. .

[0021]

As described above, in the present invention, in addition to the existing cooling pipes buried in the refractory under the bottom of the furnace bottom in parallel so as to traverse the bottom of the furnace in one direction, the center of the furnace is in the same direction or at a right angle. We made a simple structural improvement by providing an additional cooling pipe that intersects with and crosses the existing cooling pipe and the additional cooling pipe as an independent control system, and adjusted the cooling water flow rate according to the temperature condition of the furnace bottom. With this, it is possible to perform cooling according to the furnace bottom temperature without causing overcooling of the furnace bottom.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing changes in the bottom temperature and the bottom cooling water flow rate according to the present invention.

FIG. 3 is an explanatory diagram showing another embodiment of the present invention.

FIG. 4 is a diagram showing a transition of a furnace bottom cooling water flow rate and a furnace bottom temperature according to the present invention.

FIG. 5 is a plan view showing a conventional example.

FIG. 6 is a plan view showing a conventional example.

FIG. 7 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 1 Furnace body 2 Refractory material 3 Furnace bottom base 4 Furnace bottom brick 10 Existing cooling pipe 11 Additional cooling pipe (same direction) 12 Additional cooling pipe (right angle direction)

Claims (4)

[Claims] 1. A furnace bottom cooling structure for a blast furnace, comprising a plurality of existing cooling pipes embedded in parallel in a refractory below the bottom of a furnace bottom so as to traverse the bottom of the furnace in one direction. In addition to the piping, multiple cooling pipes that traverse the central part of the furnace in the same direction are added, and the added cooling pipes are located below the existing cooling pipes in the peripheral part of the furnace, and at the existing cooling pipe level in the central part of the furnace. On the other hand, the existing cooling pipe of the central part is replaced with the lower part and is positioned so as to independently control the cooling ability of the peripheral part of the furnace and the central part of the furnace. Bottom structure. 2. The additional cooling pipe is positioned at the level of the existing cooling pipe in the peripheral part of the furnace, while the existing cooling pipe of the peripheral part is replaced by the lower part, and is positioned at the level below the existing cooling pipe in the central part of the furnace. The blast furnace bottom cooling structure according to claim 1, wherein the blast furnace bottom cooling structure is located. 3. The refractory below the bottom of the furnace bottom in which the existing cooling pipe is buried has a high thermal conductivity, and the refractory buried in the cooling pipe below the existing cooling pipe has a low thermal conductivity. The furnace bottom cooling structure for a blast furnace according to claim 1 or 2. 4. In addition to a plurality of existing cooling pipes embedded in parallel in the refractory below the bottom of the furnace bottom so as to traverse the bottom of the furnace in one direction, a plurality of cooling pipes that traverse the center of the furnace in the same direction. Instead of adding pipes, a plurality of additional cooling pipes intersecting the existing cooling pipes at right angles and crossing the central part of the furnace were replaced with a level not interfering with the existing cooling pipes crossing the central part and positioned. The furnace bottom cooling structure for a blast furnace according to claim 1, 2, or 3.