KR100418996B1 - The method of prevention errosion with brick at blast furnace - Google Patents

Abstract

The present invention is to extend the life of the blast furnace by preventing the rise of the furnace bottom temperature and erosion of the blast furnace, and to maintain a stable aging and to perform a normal operation, at the time of starting the blast furnace operation, the site where the temperature of the lower part of the outlet opening rises According to the method of the present invention relates to a method of preventing blast furnace erosion and erosion by adjusting the level of the residual water below the portion and filling the mud material to sufficiently secure the length of the exit port.

Description

Roger smoke and erosion prevention method of blast furnace {THE METHOD OF PREVENTION ERROSION WITH BRICK AT BLAST FURNACE}

The present invention relates to a method of preventing the erosion of the bottom of the outlet of the blast furnace, in particular, when the discharge of the melt in the blast furnace is completed, to prevent the erosion of the bottom smoke through the formation of a protective wall of the bottom of the outlet by the mud material filling and extending the length of the outlet. It is about how to.

In general, the blast furnace operation transfers the ore and the sintered ore cut out from the raw material bin to the top of the blast furnace through a charging belt conveyor, as shown in Figure 1 and then the flap gate 24 and the hopper upper sealing valve (UPPER SEAL VALVE: 23) After storage in the hopper (HOPPER: 20), through the light quantity control valve 21 is charged by the particle size through the rotary chute (ROTATION CHUTE: 22). Charged gas is stable in the upper part of the blast furnace in the order of coke (particle size: 35 ~ 55mm), allelic sintered light (particle size: 12 ~ 50mm), and small sintered light (particle size: 5 ~ 12mm) in order to be charged and distributed evenly inside the blast furnace. The flow ensures maximum breathability and gas utilization. When the raw material and the fuel is charged in the upper part and the hot air blows in the lower blower tube 12, the raw material and the fuel are melted while sinking to the lower part to form molten iron.

In the blast furnace, several units are formed according to the state, and in the lower part of the center, a soft fusion zone 11 is formed in which the central temperature is high and the gas flow of the middle part and the furnace wall is kept uniform. In the lower part of the blast furnace, the charged coke forms a core coke 14 formed by periodic replacement. Hot air from 34 air vents enters the hearth of the blast furnace through the coke layer between the core coke 14 through the combustion zone to form a stable central flow and proper periphery and gas flow of the furnace wall. ) To form a molten iron (13) by reducing and melting the ore through heat exchange with the charge as the hot gas rises over the blast furnace.

Figure 2 is a diagram showing the division for each zone according to the above furnace reaction and the thermometer attached to the bottom of the blast furnace. Raw materials and fuel charged from the upper part of the blast furnace are divided into a block 15, a fusion band 11, and a dropping bag 18 according to the state. Thermometers 30 and 40 are attached to the lower part of the exit port and the lower part of the blast furnace, respectively. have.

Such blast furnace operation can be economically operated only if the temperature of the lower part of the blast furnace, that is, the lower part of the outlet, remains stable and the temperature does not rise, and at the same time, it can increase the yield and prolong the blast furnace life in the long term. There is a number.

Recently, blast furnaces are increasing the use of relatively cheap pulverized coal instead of expensive coke for economical operation. This increase in production greatly contributes to the economic operation of the post-process, so that the production is performed as much as possible. However, this increase in operation has a problem of causing the wear of the blast furnace side wall portion and the rise of the temperature (30a ~ 30g) of the bottom side wall thereby.

Such temperature rises (30a to 30g) and erosion of the sidewall edges of the blast furnace outlet will cause instability in the blast furnace furnace operation (hereinafter referred to as "yellowing"). This results in uneconomical operations, such as reducing production and reducing production of pulverized coal, in order to reduce the temperature and prevent lead and erosion wear from the outlet.

In particular, from the point two years after the start of the blast furnace fire as the progress of the blast furnace operation, the blast furnace side wall portion begins to erode and wear, the melt 13 by the opening of the exit port 16 repeated 10 times a day Due to movement and impact, the wear and erosion of the lead continuously occurs.

Conventional techniques for improving this include installing another outlet at a height of 1 to 2 m above a typical outlet in Japan, thereby increasing the bottom side edge and the temperature (30a to 30g) and the temperature of the bottom of the furnace (40a to 40d). The method of managing the low dose 13 by opening the exit openings provided at the upper and lower sides through the lowering tendency is proposed.

However, in order to install outlets from the blast furnace to the upper and lower parts, the design conditions of the blast furnace must be changed, and additional equipment supplementation and enormous manufacturing costs are required. There is also no blast furnace installed. And when the low dose (13) is managed high, rather than the buoyancy and specific gravity of the molten iron has a problem that the mud material filled with the tap opening floats over the melt to form a protective wall below the tap opening.

In addition, various methods have been proposed in the actual industry, but most of the measures have been proposed in the case of blast furnace rest, and it is difficult to be an effective countermeasure when the bottom wall temperature (30a to 30g) during normal operation rises. Furnace has a problem that it is difficult to be a fundamental countermeasure against the bottom side wall temperature and the edging and erosion of the lower part of the outlet.

Accordingly, the present inventors solve the problems listed above and at the same time prevent the erosion and abrasion of the bottom of the blast furnace, and in order to perform economic blast furnace operations, such as high cost-of-ship operation, high pulverized coal operation, the same amount of mud The inventors have invented a method for adjusting the content level of the furnace so that the length of the tap opening can be extended while the ash is pushed into the tap opening 16.

The present invention has been made to solve the above problems, and the object of the present invention is to extend the blast furnace life by preventing the blast furnace lower lead and temperature rise and lead and erosion, and to perform a normal operation by maintaining a stable aging.

1 is an explanatory view showing a schematic cross section of a typical blast furnace

Figure 2 is a cross-sectional view showing the installation position of the bottom side wall thermometer for each stage in the bottom of the blast furnace

3 shows the melt level according to the nozzle sidewall edge and wear location

4A shows the relationship between the melt level and the length of the exit port.

4B is a diagram showing the relationship between the length of the exit port and the furnace wall temperature.

※ Explanation of code for main part of drawing ※

10: blast furnace 11: softening zone

12: blower 13: melt

14: Core Coke 15: Bullies

16: Exit 17: Mud Ash

18: Armed Forces 20: Top Hopper

21: light control valve 22: charging chute

23: sealing valve 24: flap gate

30: lower outlet thermometer 40: lower-noise thermometer

In order to achieve the above object, the present invention at the time of starting the blast furnace operation, the level of the hot water is adjusted below the portion according to the portion where the temperature of the lower portion of the outlet rises, and the mud material is filled to sufficiently length the outlet. Provides secured furnace smoke and erosion prevention methods.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention.

2 is a view showing a state in which a thermometer is installed in the lower part of the lower part in order to adjust the level of the melt in accordance with the present invention. In a preferred embodiment of the present invention, the thermometer is installed so that the installation depth is 100 mm or less.

In order to prevent the erosion of the lower edge of the outlet, the depth of the outlet (16) should be maintained for a certain length. If the tap length 16 is short, the flow of an annular flow through which the melt 13 accumulated in the furnace flows to the bottom wall portion is encouraged to promote erosion of the bottom wall edge, and the tap length 16 is made. If the length is long, the melt 13 accumulated in the furnace flows between and below the central core core coke layer to minimize the flow of the melt to the furnace bottom edge and the side wall portion, and that the length of the exit port is deep as the exit port 16. Since the filled mud material forms a protective wall above and below the exit port, when the melt is discharged to the exit port, the side wall temperature is maintained stably and the erosion of the furnace edge is also canceled by offsetting the force directly on the edge of the furnace wall. To the maximum extent possible.

As a means to secure the depth of the exit, the operation is usually employed to maximize the filling amount at the closing point after completion of the departure for each exit. In general, when the starting line is completed in the blast furnace operation, the mud material 17 is filled into the exit port so that the mud material contacts the core coke to form a matrix, and the matrix thus formed serves as a protective wall portion of the Roger side wall portion. .

However, the present invention provides a method capable of securing a sufficient depth of the exit port while filling the same amount of mud material.

In other words, in the case of blocking the exit port with mud material, the level of the melt 13 accumulated below the exit port is adjusted according to the worn out portion of the bottom side wall edge of the exit port, thereby filling the same amount of mud material. The depth of the exit can be secured enough.

This will be described in more detail as follows.

The molten iron and slag forming the melt at the bottom of the exit port have a density of 6,600 kg / m 3 and 2,600 kg / m 3, respectively. In addition, the mud material is generally filled with a tap opening has a density of about 2,200kg / ㎥.

In other words, the density of the melt at the bottom of the outlet is higher than that of the mud material filled into the outlet, so that the mud material 17 entered into the furnace is floated up by the melt, meeting the core coke 14 as originally intended. It becomes difficult to combine to form a protective wall.

Therefore, the molten material filled in the lower part of the exit port as much as possible to form a protective wall in front of the exit port so that the length of the exit port can be extended.

In other words, when the molten melt is high, no matter how many mud materials are filled in the outlet, the mud material having a lower density than the melt floats in the melt 13, and thus, the core cos 14 cannot be contacted. It will not be able to form depth and protection walls at all.

In this preferred embodiment of the present invention by the principle as described above, as shown in Fig. 2, the bottom side of the outlet is divided into a total of seven stages, and each stage is installed to have a depth of 100 mm or less. If the temperature rises by more than 300 ℃ in the thermometer installed in each stage, it is to adjust the height of the furnace melt accordingly. In other words, when the temperature of the furnace side wall rises by a certain value, it means that the wear of the edge of the site has progressed by a certain value, so that the protection wall due to the mud material needs to be sufficiently secured.

Figure 3 shows the relationship of adjusting the height of the melt in accordance with the site where the temperature of the furnace side wall rises in this way. As can be seen in the figure, when the furnace side wall temperature rises above a certain level at the 7th stage (30g), the melt is kept below 50% of the height of the hot air pipe, and the temperature rises at the 6th stage (30f). Maintain% or less, when temperature rises at 5th stage (30e), 30% or less, Temperature rise at 4th stage (30d), 20% or less, Temperature rises at 1,2,3rd stage (30a ~ c) Maintain the melt level below 10% and then fill the mud material. As such, the reason for limiting the melt level according to the position of each stage thermometer in the embodiment of the present invention is that when the temperature rise detected by the thermometer installed at each stage rises above the reference value, wear of the edge of the region where the thermometer is installed is severe. This means that it is necessary to increase the amount of protective walls formed at the stage. In order to form a protective wall up to the thermometer position, it is necessary to lower the level of the melt at least below the thermometer position in order to fully achieve the object of the present invention.

The reason why the melt level is commonly limited to 10% or less when the temperature rises at the 1,2,3 stages (30a to c) is 1,2,3 stages (30a to c) far from the exit. Not only is the temperature hard to rise, but it is practically difficult to manage the melt below 5% in normal operation. This was confirmed through 62 real industry test results.

Figure 4a is a view of the length of the exit port secured as a result of managing the melt level of the present invention as described above, Figure 4b shows the change in temperature of the furnace side wall portion according to the length of the exit port. According to the present invention, when the mud material is filled by lowering the melt level, it can be seen that the length of the exit port is secured, and the furnace wall temperature is reduced as the length of the exit port becomes longer.

According to the present invention as described above it is possible to ensure a long length of the exit port, thereby filling the same amount of mud material to prevent wear with the bottom wall edges to obtain the effect of extending the blast furnace life.

In addition, according to the present invention, even after performing economic blast furnace operation, such as high-shipping cost operation, high pulverized coal operation, it is possible to improve the productivity of the post-process without giving a great burden to the blast furnace.

Claims (2)

After the blast furnace is completed, at the time of discharging the melt in the furnace, Adjusting the level of the melt (13) left after being left below the portion where the temperature rises according to the portion where the temperature at the bottom of the outlet opening (16) rises; Roger smoke and erosion prevention method of the blast furnace, characterized in that consisting of the step of filling the mud material (17) with the outlet (16). The method of claim 1, The rise of the temperature is the lower edge of the thermometer (30) installed on the lower outer wall of the exit port 16, the temperature rise value of the furnace edge and erosion prevention method of the blast furnace, characterized in that more than 300 ℃.