JPS6028653Y2 - Blast furnace bottom refractory structure - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a blast furnace hearth structure, and more specifically, to a blast furnace hearth structure that can prevent the blast furnace hearth from becoming too cold.

Recently, carbonaceous bricks (carbon bricks) with excellent resistance to hot metal and slag have been used for the bottom of blast furnaces in order to extend their lifespan, but as blast furnaces become larger, the center of the bottom in particular becomes too cold. There is a tendency.

Therefore, a problem arises in that solidified deposits are formed on the upper surface of the furnace bottom, the flow of hot metal at the furnace bottom becomes a peripheral flow, and the area around the furnace bottom is locally eroded.

Up until now, as a countermeasure to this problem, the furnace bottom cooling has been controlled by adjusting the amount of water in the cooling pipe buried under the furnace bottom plate, but the thermal conductivity of carphone bricks is extremely high ( Thermal conductivity = 10~12KCa1/m, h
0°C), heat dissipation at the bottom of the furnace occurs not only in the direction of the bottom plate but also from the side walls via the bottom. There are limits.

The present invention solves the above-mentioned problem of cooling the blast furnace hearth, namely, a bottom thermally conductive refractory such as chamotte bricks is arranged in a ring shape at the distance from the furnace core to the blast furnace hearth. By doing so, heat dissipation toward the bottom side wall of the furnace is suppressed,
It is an object of the present invention to provide a blast furnace hearth structure that can prevent the central part of the hearth bottom from becoming too cold and can effectively control cooling from the blast furnace bottom plate.

The feature of the blast furnace hearth structure according to the present invention is that low thermal conductivity refractories are arranged in a ring shape at the blast furnace hearth bottom, and the rest is high thermal conductivity refractories.

BEST MODE FOR CARRYING OUT THE INVENTION The blast furnace hearth structure according to the present invention will be specifically explained below with reference to embodiments shown in the drawings.

However, it goes without saying that the invention is not limited to what is shown in this drawing.

FIGS. 1a and 1b are a schematic longitudinal sectional view and a cross sectional view showing the bottom structure of a blast furnace according to the present invention.

That is, in FIGS. 1a and 1b, a ring of low thermal conductivity refractories 2 is placed on the bottom plate 3 of the blast furnace bottom at an appropriate distance from the core of the blast furnace bottom toward the furnace periphery. The structure of the bottom of the blast furnace is shown, in which the refractories 1 and 2 are arranged continuously in the form of a refractory material 1 with high thermal conductivity.

5 is a cooling pipe, and 4 is the upper surface of the furnace bottom.

In the blast furnace bottom structure according to the present invention shown in FIGS. 1 and 2, during operation of the blast furnace, the cooling pipe 5
Since the ring-shaped low thermal conductivity refractory 2 prevents the furnace from becoming too cold, solidification deposits are not formed on the upper surface 4 of the furnace bottom, and the flow of hot metal at the furnace bottom does not become a peripheral flow, so that the area around the furnace bottom is not cooled too much. is not eroded.

In this way, by disposing the low thermal conductivity refractory at the blast furnace hearth bottom, the blast furnace hearth bottom can be extremely effectively cooled without impairing the advantages of the high thermal conductivity refractory.

Therefore, as a refractory with low thermal conductivity, it is generally preferable to use chamotsite or high alumina bricks, etc., which have a thermal conductivity of about 4Kcal 7m or less than h℃, but the important thing is that they have excellent corrosion resistance and have a higher thermal conductivity than carbonaceous bricks. Any refractory material with a low refractory value can be used.

In addition, in the above-mentioned embodiment, the refractory with low thermal conductivity was arranged continuously in a ring shape as shown in Fig. 1, but depending on the case, it may be a discontinuous type as shown in Fig. 3. It may be composed of

The blast furnace hearth structure according to the present invention will be explained in more detail.

In FIGS. 1a and 1b, a ring-shaped low thermal conductivity refractory with a height h1 and a width l is constructed at a position r from the furnace core at the bottom of the blast furnace.

The values of r, h, and l are preferably within the ranges shown below in order to achieve the desired purpose.

r, al/4D: D is the hearth diameter h≧1/3H: H is the thickness of the hearth carbonaceous refractory l>
150mm: Chamotte brick (varies depending on the thermal conductivity of the refractory brick used.

) d=2r: Inner diameter of IJ song-shaped low thermal conductivity refractory Within these ranges of r, h, and l, the structure of the low thermal conductive refractory is, for example, as shown in FIG. 2a.

Structures b and c are also possible.

Note that the structure of the low thermal conductivity refractory does not need to be a perfectly circular ring with a uniform thickness, and the distance r1 thickness l and height h may be within the above range depending on the position in the circumferential direction. At the very least, it is okay to decide on something as long as it is a distant relative of the intended purpose.

Since the blast furnace bottom structure according to the present invention has such a configuration, it is possible to prevent the central part of the blast furnace bottom from becoming too cold without impeding the cooling effect of the surrounding area of the blast furnace bottom. The cooling control from below the bottom plate of the hearth becomes effective, thus extending the life of the hearth and suppressing the rise of the hearth bottom due to excessive cooling, which leads to stable furnace conditions.

Furthermore, it is economically advantageous because a portion of the expensive carbonaceous bricks can be replaced with inexpensive bricks.

[Brief explanation of drawings]

FIGS. 1a and 1b are schematic vertical and cross-sectional views of a blast furnace bottom structure according to the present invention, and FIGS. 2a and 2b are partially cutaway views showing another example of the blast furnace bottom structure according to the present invention. The vertical cross-sectional view and FIG. 3 are schematic cross-sectional views showing another example. 1... High thermal conductivity refractory, 2... Low thermal conductivity refractory, 3... Bottom plate, 4... Furnace bottom top surface, 5... ...cooling pipe.

Claims (1)

[Scope of utility model registration request] At the bottom of a blast furnace made of carbonaceous bricks, a refractory having a lower thermal conductivity than the carbonaceous bricks is placed around the core,
A blast furnace bottom heavy-duty structure characterized by a ring-shaped arrangement.