JPH0726136B2 - Blast furnace hot stove structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot blast stove structure for a blast furnace.

[0002]

2. Description of the Related Art A hot blast stove is one of the incidental facilities of a blast furnace. The hot blast stove is a heat exchanger for giving heat to the blast furnace to heat the blast air to a high temperature. As shown in FIG. 4, in the external combustion hot blast stove 1, a heat storage chamber 2 for giving heat to the blast, It is composed of a combustion chamber 4 for heating the heat storage chamber 2.
Gitter bricks are piled up in the heat storage chamber 2 in the upper and lower areas indicated by the arrow a. Among the piles of gitta brick, silica-based gittar brick 17A is used for its high temperature characteristics, especially for the upper part that is exposed to high temperatures, and it is used at a low price, and the lower part is made of high alumina or clay. Gitter brick
17B is used.

The Gitter brick 17 is shown in FIGS. 3 (a) and 3 (b).
As shown in FIG. 2, for example, the planar shape is hexagonal, a large number of canal holes 16 are provided in the vertical direction, and a half-divided hole is formed on the outer periphery of the canal hole 16. Along with 17 canal holes for the upper and lower Gitter bricks
16 match. Conventionally, the diameter of the canal hole provided in the Gitta brick 17 that alternately switches the cold air and hot air introduced into the heat storage chamber 2 and passes through for a certain period of time is generally 45.7 mmφ, and the upper Gitta brick 17A and the lower Gitta brick are The 17B canal holes are constructed with the same diameter.

Thereafter, during the heat storage period of the hot stove 1, the fuel gas and the combustion air are taken into the combustion chamber 4 and burned. The gas burned in the combustion chamber 4 is guided to the upper part of the heat storage chamber 2 through the combustion chamber dome 3, the dome connecting pipe 5 and the heat storage chamber dome 6, passes through the canal hole 16, and the heat amount of the combustion gas in the Gitter brick 17 is increased. As a result, the temperature is raised for about 2 hours to store heat. An expansion joint 7 is attached in the middle of the dome connecting pipe 5. 8 is a dome connection truss.

Next, during the air blowing period, cold air is introduced from the lower part of the heat storage chamber 2 and is heated to about 1100 to 1200 ° C. by passing through the canal hole 16 of the Gitter brick 17, and as shown by the arrow, is the combustion period. Due to the reverse flow, hot air is supplied to the blast furnace from the combustion chamber 3 in the blowing period of about 2 hours. As the operation method, a stacker parallel system is generally used in which the blowing and combustion timings of the two hot blast stoves are shifted by about half a period for parallel blowing, but a single system may also be adopted.

If hot-blast stove operation is continued for many years, the deterioration of the Gitta bricks will progress and it will be necessary to renew the bricks. In particular, silica brick 17A on the upper part is used because it has excellent high-temperature characteristics and is inexpensive, but it is difficult to maintain the temperature during operation due to systematic disintegration below 350 ° C, and it is prone to deterioration and disintegration and can be quickly renewed. Will be needed. As means for destroying and removing the brick of the repaired part when renewing the hot blast stove, for example, Japanese Patent Laid-Open No. 57-120605 discloses a first step of providing a brick discharge chute along the outer wall of the heat storage chamber, and a dome portion. It is disclosed that a second step of destroying a brick and discharging it by using a carry-out chute, a third step of removing the iron skin of the dome portion by using a crane, and the like are disclosed.

As a means for stacking and repairing a gitter brick in a heat storage chamber of a hot-air stove, for example, in Japanese Patent Laid-Open No. 51-67203, a hoisting rod is fixed to a hoist plate when stacking the gitter brick in the repair part. After that, the lifting plate is lifted together with the block for loading the bricks, and the lifting plate is conveyed to a predetermined position of the hot air stove to load the bricks. As described above, the canal holes of the Gitta bricks stacked in the heat storage chamber are generally stacked concentrically in the height direction with the same diameter, but as an example in which the hole diameter is changed, the actual opening Sho 53-102905 is disclosed. Discloses that two or several kinds of getter bricks having canal holes having different hole diameters are concentrically and alternately stacked.

With the increase in the size of the blast furnace, the hot blast stove is also required to have a larger size and higher thermal efficiency. If the entire hot blast stove is renewed and the height and diameter are increased, higher thermal efficiency can be achieved, but the cost and construction period are too large. Hot blast furnace repair is 4 during blast furnace operation.
It is a good idea to suspend one of the units and make the minimum necessary modifications.

[0009]

That is, as disclosed in the above publication, in order to carry out repair (remodeling) work on a hot stove economically and in a short time, it is necessary to avoid a full repair and to minimize the deterioration part. It is necessary to carry out partial repair limited to. In other words, as mentioned above, it is possible to modify and renew only the dome iron skins such as the silica gitta brick 7A on the upper part of the heat storage chamber, which easily deteriorates, and the combustion chamber dome 3 and the heat storage chamber dome 5, which easily crack. It is a good idea. Moreover, it is important to limit the above modification range to increase the capacity by improving the thermal efficiency of the hot stove.

As can be seen from the above-mentioned publication, it is known that the hot-air stove is renewed by partial repair, but the canal holes of the Gitta brick have the same diameter. In Japanese Utility Model Application Laid-Open No. 53-102905, it is proposed to change the diameter of the canal hole, but it is said that the structure in which the Gitta bricks with different canal holes are alternately stacked causes an increase in pressure loss of the passing gas. Therefore, it is not normally used.

The present invention was devised in view of the above circumstances, and an object thereof is to provide a hot blast stove structure of a blast furnace suitable for partial repair of a heat storage chamber of the hot stove.

[0012]

Means for Solving the Problems The present invention for achieving the above-mentioned object is to provide a Gitta brick having a small canal diameter in the renewal range of the upper brick among the Gitta bricks stacked in the heat storage chamber of the hot-blast stove using the Gitta brick. It is a hot-blast stove structure of a blast furnace in which an existing Gitta brick with a large canal diameter is placed at the bottom.

Further, according to the present invention, at the boundary between the Gitta brick having a small canal hole diameter arranged at the upper portion and the existing Gitta brick having a large canal hole diameter arranged at the lower portion, the small canal brick having the small canal hole diameter and the large canal brick having the large lower canter hole diameter are provided. It is preferable to place a getter brick with tapered canal holes that each match the diameter and.

[0014]

[Operation] In the present invention, the canal hole diameters of the Gitta bricks, which were conventionally the same diameter in the upper and lower portions of the heat storage chamber, are made different, and the diameter of the canal hole of the upper Gitta bricks is made smaller than that of the lower Gitta bricks. The diameter is smaller than the diameter. Specifically, by changing the canal hole diameter of the Gitta brick from the current 45.7 mmφ to, for example, 40 mmφ, the flow velocity in the canal hole increases even if the same amount of air is sent, thereby increasing heat transfer and increasing heat efficiency. It is possible to let

According to the present invention, the upper brick of the Gitter brick stack has a small canal diameter (eg, 40 mm) in the renewal range.
φ) Gitta brick is used, and a heat storage chamber is constructed by using a Gitta brick with a tapered canal diameter (eg, 40 to 45.7 mmφ) at the joint with the existing brick. By doing so, it is possible to improve the thermal efficiency of the hot stove by remodeling the minimum required number of deteriorated brick brick renewal parts.

[0016]

Embodiments of the present invention will be described below with reference to FIGS. In the figure, the same parts as those in FIG. 4 are designated by the same reference numerals to simplify the description. First of all,
In, 10 indicates the upper part of the renewal part of the bricks,
11 indicates the existing lower Gitta brick pile that is not renewed (the canal hole diameter in this part is small), 12 indicates the boundary between the upper Gitter brick stack 10 and the lower Gitter brick stack 11 (the canal hole diameter in this part is large). The canal hole to be arranged shows a taper type Gitter brick.

As shown in FIG. 2, a steel shell 13 in the heat storage chamber 2
An amorphous refractory material 14, a wall brick 15 and a brick side wall are formed inside the, and the heat storage chamber 2 is loaded with the Gitter brick 9
Is being built. The diameter of the canal hole 10a of the upper gitter brick 10 to be renewed by repair is, for example, 40 mm, and the diameter of the canal hole 11a of the lower gitter brick 11 which is not repaired is 45.7 mm.
The diameter is smaller than φ.

A boundary brick 12 having a tapered canal hole 12a is arranged at the boundary between the upper and lower gitter bricks 10 and 11, and the upper end diameter of the tapered canal hole 12a is equal to that of the upper gitter brick 10. The diameter is 40 mmφ according to the diameter of the canal hole 10a, and the lower end diameter is 45.7 mmφ according to the diameter of the canal hole 11a of the lower Gitter brick 11. That is, the boundary tapered canal hole 12a has a gently tapered shape with an upper end diameter of 40 mmφ and a lower end diameter of 45.7 mmφ.

It should be noted that the boundary part Gitter brick 12 is omitted,
Small diameter upper gitter bricks 10 and large diameter lower gitter bricks 11
And may be brought into direct contact with each other. Regarding the hot stove using the Gitta brick of the present invention in which the diameter of the canal hole is changed between the upper part and the lower part, and the conventional stove using the same kitter brick in which the diameter of the canal hole is the same at the upper part and the lower part, heat transfer calculation is performed under the following conditions. When the thermal efficiency was obtained by performing the test, the results shown in Table 1 were obtained, and it can be seen that the present invention improves the thermal efficiency as compared with the prior art.

Thermal efficiency = (hot sensible heat of hot air-sensible heat of cold air) / (heat input meter) heating area 89900m ² / base airflow 6800Nm ³ / min cold air temperature 250 ° C airflow temperature 1300 ° C M gas calorie 1300kcal / Nm ³ switching 2H combustion, 2H ventilation, dome temperature 1400 ℃

[0021]

[Table 1]

[0022]

As described above, the present invention has the following effects. The thermal efficiency of the hot stove can be improved. Minimize the renewal range of Gitta bricks and reduce the cost of remodeling. The rebuilding period can be shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of the present invention.

FIG. 2 is a partial cross-sectional view showing details of the present invention.

FIG. 3 is a plan view (a) and a side view (b) showing a conventional getter brick structure.

FIG. 4 is a cross-sectional view showing a conventional overall configuration.

[Explanation of symbols]

 1 Hot-blast stove 2 Heat storage chamber 3 Combustion chamber dome 4 Combustion chamber 5 Dome connecting pipe 6 Heat storage chamber dome 7 Expansion joint 8 Dome connecting truss 9 Gitter bricks 10 Upper gitter bricks 11 Lower gitter bricks 12 Border gitter bricks 13 Iron skin 14 No Standard refractories 15 Wall bricks 16 Canal holes (conventional) 17 Gitter bricks (conventional)

Claims (2)

[Claims] 1. A blast furnace hot blast stove in which a Gitta brick with a small canal diameter is arranged in the renewal range of the upper brick among the Gitta bricks stacked in the heat storage chamber of the hot stove, and an existing Gitta brick with a large canal diameter is arranged in the lower portion. Construction. 2. A small canal diameter of the upper Gitta brick and a large canal diameter of the lower Gitta brick are formed at the boundary between a Gitta brick having a small canal hole diameter arranged at an upper portion and an existing Gitta brick having a large canal hole diameter arranged at a lower portion. 2. The hot stove structure of the blast furnace according to claim 1, wherein the getter bricks each having a tapered canal hole are arranged.