JP3037566B2 - Cooling method of blast furnace body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cooling a blast furnace body.

[0002]

2. Description of the Related Art A stove provided in a blast furnace furnace is divided into several stages from a hearth wall portion to an upper portion of a shaft in order to provide a cooling capacity corresponding to a heat load level in a height direction of the blast furnace. An independent cooling water system is configured for each divided floor for cooling.

FIG. 4 shows a conventional cooling equipment row, in which staves H1 to H6 on the hearth wall, stave T1 on the tuyere,
The cooling system A for cooling the staves H1 to H6 of the hearth wall portion and the staves S2 to S5 of the shut portion mainly and the cooling system A for the hearth wall portion are formed by 15 stages in the height direction of the staves S1 to S8 of the shaft portion. Part stave H6, tuyere stave T1,
It is composed of two systems of a cooling system B for cooling the staves S1, S6 to S8 of the shaft portion.

The cooling water of the cooling system A is 40 ° C. in summer,
The temperature is about 20 ° C. in winter, and the flow is from the tank 11B to the downcomer 12B, the heat exchanger 13B, the circulation pump 14B,
Cooling of the hearth wall portion is performed by sequentially passing through the water supply header 7A, the staves H1 to H5 of the hearth wall portion, and the drainage header 8A. Then, the drainage passes through the water supply header 7D of the shaft portion, the staves S2 to S5 of the shaft portion, and the drainage header 8D in order, cools the shaft, and returns to the tank 11B.

The cooling water of the cooling system B is 4
The flow is about 0 ° C. to 20 ° C., and the flow is from the tank 11A to the downcomer 12A, the heat exchanger 13A, the circulation pump 14A,
After cooling from the hearth wall portion to the shaft portion through the water supply header 7B, the hearth wall stave H6, the tuyere portion stave T1, the shaft portion staves S1 to S6, and the drainage header 8B in this order, After cooling the upper part of the shaft through the water supply header 7C, the upper staves S7 to S8 of the shaft, and the drainage header 8C, the system returns to the tank 11A. Each of the cooling systems A and B is divided into four to six systems in the circumferential direction, and is cooled for each system.

However, in such a cooling method,
It was not possible to enhance the cooling of a part of the furnace body due to local erosion of the furnace body brick. For this reason, for example, in JP-A-56-96005,
In the cooling system, for example, the staves H1 and H2 on the hearth wall are separated, the circumferential direction of the separated staves H1 and H2 is divided into a plurality of groups, and an independent strong cooling device is provided for each stave group in each group. In addition, a method is disclosed in which a temperature measuring device is buried in a hearth wall portion and the temperature of the circulating cooling water of the strong cooling device is adjusted in accordance with the measurement value of the temperature measuring device.

[0007]

However, in this method, it is necessary to preliminarily divide each of the plurality of staves into a plurality of stave groups, and to provide a plurality of strong cooling devices (4 to 6) each having a cooler and a pump. In addition, the cooling capacity must be able to cool all the staves in each stave group, and there is a problem that the equipment becomes large, expensive and wide installation space is required, and the power cost is high. there were.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems by making a compact strong cooling device inexpensive, and by reducing the electric power cost with a small installation space.

[0009]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and a means for cooling a furnace wall by supplying cooling water to a stave provided on the furnace wall of a blast furnace. While cooling the furnace wall brick by supplying and discharging cooling water from the cooling water supply and discharge piping system of the normal cooling device to the stave, the stave is embedded in the furnace wall brick where the stave is disposed.
The furnace wall brick was locally eroded by the measured value of the thermometer
When this is detected , the stave at that location is switched from the cooling water supply / discharge piping system of the normal cooling device to the cooling water supply / discharge piping system of the strong cooling device to enhance cooling, and the cooling water supply / drainage of the strong cooling device is changed. the cooling water supply and discharge piping system of the normal cooling device is connected in a non-water supply and drainage conditions in the piping system, Tsu Na to a predetermined layer thickness adhering the deposits to the local erosion of the furnace wall brick by cooling strengthening of the staves Is checked by the measurement value of the thermometer.
If you knowledge, a method for performing normal cooling the stave is switched from the cooling water supply and discharge piping system of the strong cooling device to the cooling water supply and discharge pipes of the normal cooling device.

[0010]

According to the inventors' many years of experience and experiments, as shown in FIG. 5, the local brick erosion site of the furnace body mostly occurs on the hearth wall, and the occurrence occurs five years after the start-up. It starts around. In addition, the high heat load (the progress of brick erosion or the decrease in the thickness of the adhered substance) does not occur in a concentrated manner at a time, but there is a time lag in the generation timing. The number of local brick erosion sites is about 3 at most per year. The number of cooling staves to be cooled and strengthened at one local brick erosion site is four or less. If the erosion site is strongly cooled, the molten material inside the furnace cools and solidifies and adheres to the erosion site to become an adhered material. Did not require cooling.

From the above findings, it is necessary to enhance cooling by local brick erosion two to three times a year,
With less than 10 cooling staves per time, the cooling period is 3 ~
Since it was four months, it turned out that one strong cooling device should be provided.

Then, when a local brick erosion site occurs, the blast furnace is shut down and the stave near the erosion site is temporarily reduced and the cooling water supply / discharge of the conventional normal cooling device is reduced. After disconnecting from the piping, switching to the cooling water supply / discharge piping of the strong cooling device and continuing, and after strengthening the cooling, blowing is started again and the operation is continued for about one to two months. Then, at the stage when the deposit has reached a predetermined thickness on the brick at the erosion site, switching to the cooling water supply / discharge pipe of the normal cooling device is again performed, and the supply of the cooling water from the strong cooling device is stopped. Restart the supply of cooling water from the cooling water supply / discharge pipe. Thus, it is sufficient to supply the cooling water from the strong cooling device only to the site where local brick erosion has occurred, and until the deposits adhere (about 1 to 2 months). This makes it possible to reduce the size of the apparatus, thereby significantly reducing initial costs such as equipment costs and running costs such as power costs.

Further, before switching to the normal cooling device as described above, the cooling water from the normal cooling device is connected in a non-supply / discharge state via a valve or the like between the connecting portion of the strong cooling device and the cooling stave. This makes it possible to switch between the normal cooling device and the strong cooling device only by switching the cooling water passage (water passage) by simply operating the valve or the like. This allows
When the switching from the strong cooling device to the normal cooling device or the switching from the normal cooling device to the strong cooling device is performed again, it is not necessary to shut down the air in the blast furnace.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a simplified flow diagram of the strong cooling device of the present embodiment, FIG. 2 is a simplified enlarged flow diagram for strongly cooling a stave near a brick where local erosion has occurred, and FIG. 3 (a) is a side cross section of a blast furnace BF. FIG. 3B is a plan view thereof. In the figure, H31 to H33 are circumferential staves in the row of stave H3, H41 to H44, H410 to H41.
3 is a circumferential stave in row H4 of staves, H5
10 to H513 are staves in the circumferential direction in the row of the stave H5, 1TH to 3TH are tapholes, P is a cooling water supply / discharge pipe that connects the cooling staves H1 to H6 in each stage in the circumferential direction of the blast furnace, and t is A thermometer (two-point type thermometer) provided in the circumferential direction of the blast furnace, 20k is a water supply pipe connecting the tank 21 to the water supply header pipe 24k via the circulation pump 22 and the reinforced cooler 23, and 20m is a drain header pipe. A drain pipe connecting the 24 m and the tank 21 in communication, 25 k is a cooling water supply branch pipe connecting the water supply header pipe 24 k and the cooling water supply / discharge pipe P of the stave H 32, and 25 m is a drain header pipe 24 m and the stave H
A cooling water return branch pipe which connects the 43 cooling water supply pipes P to each other,
26k (28k) is a water supply pipe connecting and connecting the cooling water supply branch pipe 25k (27k) and the water supply header 7A, and 26m (28k).
m) is a water supply pipe connecting the cooling water return branch pipe 25m (27m) and the drain header 8A, and 27k is a water supply header pipe 24m.
Water supply branch pipe for communicating and connecting the
7 m is a cooling water return branch pipe that connects the drain header pipe 24 m and the stave H512, and V1 to V8 are valves.

The case where the staves H32, H42 and H43 need to be strongly cooled will be described below. 1) First, when the thermometer t provided on the furnace wall detects that the furnace wall has been locally eroded as shown in FIG. 3A, the blast furnace is shut off. 2) Next, a cooling water supply / discharge pipe P connecting the staves H31 and H32 in communication, a cooling water supply / discharge pipe P connecting the staves H32 and H33 in communication, a cooling water supply / discharge pipe P connecting the staves H41 and H42 in communication, The cooling water supply / discharge pipe P connecting the staves H43 and H44 is disconnected. 3) The cooling water supply / discharge pipe P of the stave H31 and the cooling water supply / discharge pipe P of the stave H33 are connected to the bypass pipe b1.
To connect. 4) Further, the cooling water supply / discharge pipe P of the separated stave H41
And the cooling water supply / discharge pipe P of the stave H44 are communicatively connected by a bypass pipe b2. Thereby, staves H32 , H42,
In the staves H3 and H4 except H43, the cooling water starts to circulate again.

5) On the other hand, one side of the stave H32 to be strongly cooled and the other side of the stave H42 are connected to a water supply pipe Q.
And the other side of the stave H32 and the cooling water supply branch pipe 25k are connected to each other.
Is connected to the cooling water return branch pipe 25m. 6) Thus, after operating the circulation pump 22 and the enhanced cooler 23, the valves V1 and V2 are opened. (At this time, valves V3, V4 are kept in the closed state) thus being adjusted to a temperature of 3 to 5 ° C. at strengthening cold <br/>却機23 circulating cooling water sequentially stave H32, H42, H43 Return to the street tank 21 .

7) In this state, air is blown from the tuyere and the blast furnace is started to start operation. 8) Thus, the staves H32 , H42, H43
By increasing the cooling of the furnace, the deposits grow on the eroded portion of the hearth wall. This is measured by the thermometer t. 9) stave H32, H42, H43 of the strong cooling in accordance with the rest wind blast to be carried out after the start, the water supply pipe 26k and water supply header 7A of the normal cooling device shown in FIG. 4, the drainage pipe 2
6m and the drainage header 8A are connected to each other. 10) When the thermometer t detects that the deposit attached to the locally eroded portion has a predetermined layer thickness, the valves V1 and V2 are closed, the valves V3 and V4 are opened, and the water supply is performed. Normal cooling water from the header 7A is supplied to the staves H32, H42, H43 and returned to the drain header 8A. 11) Thereby, the switching of the staves H32, H42, and H43 to the normal cooling device is completed.

12) If the operation of the blast furnace is continued in this state, the adhered substances are eroded, and the staves H32, H4
2. When the cooling of H43 becomes necessary, the valves V1 and V2 are opened and the valves V3 and V4 are closed.

Further, other parts of the furnace body (Stave H41)
1, H412, H511, and H512) are locally eroded, and the staves H412, H512 communicate with the cooling water supply branch pipe 27k and the cooling water return branch pipe 25m in the same manner as the staves H32, H42, and H43. Connecting. Then, the staves H411, H412, H511, and H are operated by opening and closing the valves V5 to V8 in the same manner as described above.
512 cooling enhancement. In this way, a strong cooling device,
FIG. 5 shows the result of cooling the hearth wall while switching the normal cooling device.

In the present embodiment, the cooling medium in the strong cooling device is cooling water. However, if CFCs or other low-temperature cooling medium is used, the cooling medium at 0 ° C. or less (± 0 to −50 ° C.). Cooling is also possible, which is preferable.

[0021]

According to the present invention, cooling is performed by selecting only the staves that need to be strengthened and connecting a strong cooling device.
When it is no longer necessary to enhance the cooling, the ordinary cooling system is easily switched, so that a large number of strong cooling devices are not required, so that the equipment is reduced to 1/3 to 1 /
5, and the installation space is reduced. Furthermore,
Running costs such as power costs are 1/5 to 1/1
This has effects such as being able to be reduced to about 0.

[Brief description of the drawings]

FIG. 1 is a simplified flow diagram of a strong cooling device of the present embodiment.

FIG. 2 is a simplified enlarged flowchart for strongly cooling a stave near a brick where local erosion has occurred.

3 (a) is a side sectional view of a blast furnace BF, and FIG. 3 (b) is a plan view thereof.

FIG. 4 is a simplified flowchart of a conventional ordinary cooling device.

FIG. 5 is a diagram showing the state of attachment of deposits at a locally eroded site in the present embodiment.

[Explanation of symbols]

 7 water supply header 8 drainage header 11 tank 12 downcomer 13 heat exchanger 14 circulation pump 20k water supply pipe 20m drainage pipe 21 tank 22 circulation pump 23 reinforcement cooler 24k water supply header pipe 24m drainage header pipe 25k cooling water supply branch pipe 25m cooling water return Branch pipe 26k Water supply pipe 27k Cooling water supply branch pipe 27m Cooling water return branch pipe A, B Cooling system H Furnace floor wall stave T Tuyere stave S Shaft stave P Cooling water supply and discharge pipe t Thermometer TH Taphole V valve b1, b2 Bypass pipe Q Water supply pipe

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shinji Miyaoka 1 Nishinosu, Oita, Oita City, Oita Prefecture Nippon Steel Corporation Oita Works (58) Field surveyed (Int. Cl. ⁷ , DB name) C21B 7 / 10 F27D 1/12

Claims (1)

(57) [Claims] 1. A method of cooling a furnace wall by supplying cooling water to a stave disposed on a furnace wall of a blast furnace, wherein the stave is supplied with cooling water from a cooling water supply / discharge piping system of a normal cooling device to supply and discharge the cooling water to the stave. When the wall brick is being cooled, the temperature of the furnace is determined based on a measurement value of a thermometer embedded in the furnace wall brick where the stave is provided.
When it is detected that the wall brick has locally eroded, the stave at that location is switched from the cooling water supply / discharge piping system of the normal cooling device to the cooling water supply / discharge piping system of the strong cooling device to enhance cooling, and The cooling water supply / discharge piping system of the normal cooling device is connected to the cooling water supply / discharge piping system of the strong cooling device in a non-supply / drain state, and the adherence adheres to the locally eroded portion of the furnace wall brick by strengthening the cooling of the stave. before that it was Tsu name to a predetermined thickness and
If it detected by measurement of serial thermometer, blast furnace, characterized in that for normal cooling by switching the staves to the normal cooling water supply and discharge pipes of the cooling device from the cooling water supply and discharge piping system of the strong cooling device Furnace cooling method. How to operate the furnace.