KR101267649B1 - Method for assuming liquid flow of blast furnace - Google Patents

Abstract

The present invention relates to a blast furnace melt flow estimation method, the step of deriving the furnace melt flow index (Hearth) by measuring the temperature data for each circumferential direction of the furnace bottom wall (D), and during the set period And determining core activation through the trend of the bottom melt flow index.
According to the present invention, since the core activation degree is determined through the change of the bottom melt flow index, it is possible to estimate whether the core fluidity is good or the cyclic flow is developed, thereby enabling the real-time bottom situation determination and appropriate operation response.

Description

Method for assuming liquid flow of blast furnace

The present invention relates to a blast furnace melt flow estimation method, and more particularly to a blast furnace melt flow estimation method for estimating the melt behavior of the bottom of the blast furnace furnace.

The blast furnace operation is a process in which the iron ore charged in the upper part of the blast furnace is melted by the hot air supplied through the tuyeres to produce melts (molten iron and slag), and the melts accumulated in the furnace are discharged continuously through the outlet .

An object of the present invention is to present a criterion for determining the fluidity of the core present in the bottom of the blast furnace, blast furnace melt flow estimation that can estimate the bottom melt flow behavior using the temperature data (TC temperature) of the bottom wall To provide a way.

According to a feature of the present invention for achieving the object as described above, the present invention comprises the steps of deriving the furnace melt flow index (Hearth) by measuring the temperature data for each circumferential direction of the furnace wall portion, and setting, And determining core activation through the trend of the bottom melt flow index derived during the period.

The deriving the furnace melt flow index may include calculating an average temperature of the two adjacent outlets using temperature data of two adjacent outlets among the temperature data of the circumferential direction of the furnace wall. Calculating the average temperature of the wall portion between the two adjacent outlets from the temperature data of the wall portion between the two adjacent outlets among the circumferential direction temperature data, wherein the lower melt flow index is the average temperature of the two adjacent outlets. It is the value divided by the average temperature of the wall portion between the two adjacent exits.

The outlet has four outlets of No. 1, No. 2, No. 3, and No. 4 outlets symmetrically in a 90 degree direction along the circumferential direction of the lower wall.

The lower melt flow index of the outlet 1 and the outlet 2, the outlet 2 and the outlet 3, the outlet 3 and the outlet 4, the 4 Measure the four sections of the first exit and the first exit section.

Temperature data for each circumferential direction of the lower wall part are averaged daily values.

Determining the core activation degree, if the trend of the lower melt flow index derived during the set period is increased, the core fluidity is good, it is estimated that the movement of the molten iron to the exit port is active, deduced during the set period If the trend of the lower melt flow index is lowered, the core fluidity is lowered, and it is estimated that an annular flow is induced in which the furnace wall flow of the molten iron is induced.

The setting period is 10 days to 30 days.

The present invention derives the furnace melt flow index by using a thermometer (T / C) of the furnace bottom wall, and determines the core activation degree through the trend of the furnace melt flow index derived during the set period.

In this case, it is possible to estimate whether the core fluidity is good or the cyclic flow is developed, and thus the real-time roadside situation judgment and appropriate operation response can be performed.

In addition, the present invention may be a guide for the operator to determine the starting stop in the starting work or to determine the starting work order and the core judgment.

1 is a schematic diagram of a furnace situation.
Figure 2 is a process diagram showing a preferred embodiment of the blast furnace melt flow estimation method according to the present invention.
Figure 3 is a view showing the height-specific thermometer (T / C) of the bottom wall.
Figure 4 is a view showing a thermometer (T / C) and the exit port for each direction of the lower wall part.
5 is a view showing an embodiment of the core fluidity good (a) and the cyclic flow development (b) according to the trend of the lower melt flow index at the time of starting the exit No. 2.
6 is a graph showing an experimental example of the blast furnace melt flow estimation through the trend of the bottom melt flow index.

Hereinafter, embodiments of the present invention will be described in detail.

In the blast furnace melt flow estimation method of the present invention, a step of deriving a furnace earth flow index (Hearth Flow Index) by measuring temperature data for each circumferential direction of the furnace bottom wall (D), and a furnace bottom melt flow derived during the set period. And determining the core activation degree through the trend of the index.

The blast furnace melt flow estimation is intended to provide a criterion for determining the fluidity of the core present in the blast furnace furnace (C). The fluidity of the core and the vitalization of the core can be seen in the same sense.

As shown in FIG. 1, the core refers to a furnace bottom coke filling layer in which coke charged to the blast furnace forms a kind of coke layer at the center of the furnace. The core serves to support the buffering or fusion zones that maintain the furnace furnace heat.

The core is divided into the upper core (a), the middle core (b), the lower core (c) in the height direction of the blast furnace (1). The upper core (a) is located on the road where the reaction gas rises from the tuyere (3), which affects the flow of the rising gas according to the core state, and the determination of the core state through the furnace wall or the top gas and the temperature measuring device. This is possible.

In the case of the central core (b), it is possible to determine the core coke state, the in-vehicle breathability, and the liquid permeability using coke sampling using a coke probe.

In the case of the lower core (c) in which the molten iron and the slag exist in the molten state, the core state may be determined by using the starting state, the molten iron temperature, and the slag exclusion time. However, since the lower core (c) accumulates the most heat in the blast furnace, there is a limitation in measuring data that can determine the situation in the furnace.

The real-time bottom part judgment is important because when the fluidity of the lower core c is deteriorated, the melt discharge of the bottom part C is poor and the molten iron temperature of each outlet (# 1, # 2, # 3, # 4) This is because the aging worsens, such as deviations.

That is, as the temperature of the core decreases and lasts for a considerable period of time, the temperature of the furnace lower portion C decreases and the temperature of the furnace lower wall portion D increases. The lowering of the temperature of the lower part C destabilizes the yellowing, such as poor melt discharge, lowering the speed of exiting the vessel, severe blockage of the exit opening, and an increase in the temperature of the lower wall D. The blast furnace life is shortened by promoting wear (wear due to drift) of the refractory material (flame) formed in the

Therefore, to provide a blast furnace melt flow estimation method in order to prepare a standardized index for real-time roadside situation judgment and appropriate operation response.

Blast furnace melt flow estimates are based on the Hearth Flow Index (H.F).

The bottom melt flow index is an index that estimates the melt behavior using the temperature ratio between the tapping outlet and the tapping outlet. Derivation of the bottom melt flow index is performed under the assumption that the refractory material inside the blast furnace is an operating index that can determine the core activation in real time.

This assumption is based on the experimental result that the temperature of the exit side wall facing the direction to go out rapidly rises when the melt forms a cyclic flow without passing through the core as a result of determining the melt behavior according to the shape of the bottom part and the liquid permeability.

As shown in FIG. 2, the furnace melt flow index is extracted with temperature data for each circumferential direction of the furnace bottom wall part (S1), and then adjacent to the temperature data of two adjacent outlets among temperature data for each circumferential direction of the furnace bottom wall part. Computing the average temperature (A) of the two outlets (S2) and the average temperature (B) of the wall portion between the two adjacent outlets with the temperature data on both sides of the wall between two adjacent outlets of the circumferential direction of the furnace wall portion After performing step (S3), the average temperature (A) of two adjacent outlets is divided by the average temperature (B) of the wall between two adjacent outlets.

Although it is not possible to accurately measure the temperature of the furnace bottom melt using the circumferential temperature data (T / C temperature) of the furnace bottom wall (D), in the case of the refractory material where the thermometer (T / C) is located, heat transfer from the melt Since the heat is well reflected, the flow of the melt can be estimated by using the temperature data of each circumferential direction of the lower wall part D.

The thermometer (T / C) is a thermal coupler (TC), a sensor used to measure temperature.

As shown in FIG. 3, a plurality of thermometers t are installed along the circumferential direction of the lower wall portion D, and in the present embodiment, are installed at both sides of the exit port and at both sides of the wall part between two adjacent exit ports. .

As shown in Figure 4, the exit port of the blast furnace 1 is the first exit port (# 1), the second exit port (# 2), symmetrically in a 90-degree direction along the circumferential direction of the lower wall portion (D), Four outlets # 3, # 4 and # 4 are formed. Due to the location of the exit port in the 90 ° direction of the lower wall, it is possible to determine the formation of annular flow and to make consistent analysis of the temperature ratio between the exit port and the exit port.

As shown in FIG. 5A, the core fluidity is good when the melt passes through the core. As shown in (b) of FIG. 5, the annular flow means that the melt does not pass through the core and flows to the exit wall side by rotating to the bottom wall side. When the annular flow is formed, the rotation moment is increased to increase the melt flow rate, thereby lowering the speed of tapping out and causing plugging of taping out. Therefore, it is possible to determine the cause for the decrease in the starting speed in forming the melt annular flow or the coke ejection to the tap opening.

If the angle of the exit port and the exit port formed along the circumferential direction of the lower wall part D does not form 90 degrees, it is difficult to determine whether there is an annular flow formation because the difference between the adjacent exit ports is not the same and the temperature deviation is different. The cause becomes difficult to identify.

In addition, since one of the four outlets is basically at rest, it is difficult to clearly interpret temperature deviations and trends resulting from the melt behavior caused by one outlet stop, which makes it less reliable to analyze the temperature correlations of each outlet. .

The melt flow index for the lower part of the furnace is divided into the 1st exit (# 1) and the 2nd exit (# 2), the 2nd exit (# 2) and the 3rd exit (# 3), and the 3rd exit. Measure the 4 sections of (# 3) and the 4th exit (# 4) section, the 4th exit (# 4) and the 1st exit (# 1).

For example, as shown in Figure 4, the bottom melt flow index of the first exit (# 1) and the second exit (# 2) section is

Temperature data on both sides of No. 1 outlet (# 1) is 17, 18

Temperature data on both sides of exit 2 (# 2) is 2, 3

Assuming that the wall temperature data between exit 1 (# 1) and exit 2 (# 2) is 1 and 20,

Temperature averages (A) of temperature data 17, 18, 2, and 3 at exit 1 (# 1) and exit 2 (# 2) are displayed at exit 1 (# 1) and exit 2 (# 2). ) Derived by dividing by the temperature average (B) of the wall temperature data 1 and 20 of the wall. That is, the bottom melt flow index for estimating the melt behavior based on the temperature ratio between the exit port and the exit port is derived.

In deriving the furnace melt flow index, the circumferential direction of temperature data of the furnace wall D uses daily average values.

In addition, the blast furnace melt flow estimation using the derived bottom melt flow index is determined using the 10 to 30 day period of the bottom melt flow index. That is, the core activation degree is determined based on the trend of the lower melt flow index derived during the set period (S5).

Trends in the bottom melt flow index over a set period (10-30 days) are more important than the bottom melt flow index itself, which means that coke is charged and coke forms the bottom coke filling layer to affect core activation. This is to take into account the period of time that may be affected.

Less than 10 days in the set period does not affect the core activation due to the formation of the filling layer, and more than 30 days in the set period also affects the core activation because the coke forming the filling layer is burned and new coke is charged. Does not reach.

The setting period is most preferably 15 days, since the average period over which coke is charged and the filling layer can affect core activation is on average 15 days.

If the lower melt flow index is increased during the set period, the core liquidity is good, and it is estimated that the flow of molten iron to the exit port is active.If the lower melt flow index is lowered during the set period, the core melt flow index is lowered. It is presumed that an annular flow developed in which the liquidity is lowered and the flow of the furnace wall of the molten iron is developed.

If the flow rate of the lower melt flow index derived during the set period is increased, the average temperature of the wall part between the exit ports is lower than the exit port temperature. Therefore, it can be determined that the melt has actively moved to the exit port through the core.

On the other hand, if the flow rate of the lower melt flow index derived during the set period falls, the average temperature of the wall of the tapping section is higher than the temperature of the tapping outlet side, and thus it may be determined that an annular flow inducing the wall flow of the melt is developed.

Proper blast furnace operation can be achieved by improving the quality of coke that is charged to prevent the instability of cyclic flows, increasing the heat, or by charging a blank coke (if only coke is charged alone) for compensation of heat. Do.

In addition, trends in the bottom melt flow index can be guides for operators to determine the starting stops for the starting work, or to determine the starting work order and the core judgment.

Hereinafter, the blast furnace melt flow estimation method of the present invention will be described through examples.

<Example 1>

1. Derived furnace melt flow index

First, temperature data for each circumferential direction of the lower wall part is extracted.

The temperature data extraction is extracted from a thermometer T / C provided for each circumferential direction of the lower wall part.

The extracted temperature data is used to calculate the average temperature (A) of two adjacent outlets and the average temperature (B) of two adjacent outlets.

Next, the bottom melt flow index is derived by dividing the average temperature A of two adjacent outlets by the average temperature B of the wall portion between two adjacent outlets.

The melt flow index for the lower part of the furnace is divided into exit 1 and exit 2 (1-2), exit 2 and exit 3 (2-3), exit 3 and 4, respectively. Derived four sections: pioneer section (section 3-4), exit 4 and exit 1 (section 4-1).

2. Blast Furnace Melt Flow Estimation by Trends in the Bottom Melt Flow Index

The blast furnace melt flow is estimated by the trend of the bottom melt flow index derived during the set period.

Table 1 below shows the trend of the bottom melt flow index.

division Exit Primary (12/1-12/15) 2nd (12/30 ~ 1/13) 3rd (1/26 ~ 2/9)
HF Index
1-2 segments ▼ ▼ △ 2-3 sections ▼ △ △ 3-4 section ▼ △ △ 4-1 section ▼ △ △ Melt Flow Estimation Circulation around all cores Melt Flow Through Core Good core fluidity in all sections

[H.F Index: Lower melt flow index]

According to Table 1, the lower melt flow index trend is lower in the first period, and the lower melt flow index trend is higher in the second period except for 1-2 sections. The bottom melt flow index trend has turned upward.

The fall of the bottom melt flow index trend is due to the increase in the mean temperature of the wall between the exit ports due to the induction of cyclic flow, which is the wall flow of the molten iron, due to the lower core fluidity. This is due to the fact that the molten iron flows to the exit port according to good condition and the average temperature in the exit port rises.

The core activation degree can be determined based on the trend of the lower melt flow index.

The data in Table 1 is confirmed in more detail in the graph of FIG. 6, which shows that the lower melt flow index trends are confirmed, which are converted into a fall in the first period, a partial rise in the second period, and a rise in the third period. Can be.

The scope of the present invention is not limited to the embodiments described above, but may be defined by the scope of the claims, and those skilled in the art may make various modifications and alterations within the scope of the claims It is self-evident.

1: blast furnace 3: air balloon
A: Upper part B: Old part
C: Lower part D: Lower part wall part
a: Upper core b: Central core
c: lower core t: thermometer
# 1: 1 exit # 2: 2 exit
# 3: exit 3 # 4: exit 4

Claims (7)

delete Determining a bottom melt flow index (HF) by measuring temperature data for each circumferential direction of the bottom wall of the furnace bottom wall;
Determining the core activation degree through the trend of the bottom melt flow index derived during the set period;
Deriving the furnace bottom melt flow index,
Calculating an average temperature of the two adjacent outlets from the temperature data of the circumferential direction of the lower wall of the furnace by the temperature data of the two adjacent outlets;
Computing the average temperature of the wall portion between the two adjacent outlets from the temperature data for each circumferential direction of the lower wall portion of the wall portion between the two adjacent outlets,
The bottom melt flow index is
Blast furnace melt flow estimation method, characterized in that the average temperature of the two adjacent outlets divided by the average temperature of the wall portion between the two adjacent outlets. The method according to claim 2,
The exit port is a blast furnace melt flow, characterized in that four outlets of the first outlet, the second outlet, the third outlet, the fourth outlet are formed symmetrically in the 90-degree direction along the circumferential direction of the lower wall portion Estimation method. The method according to claim 3,
The bottom melt flow index is
The first exit and the second exit, the first exit and the third exit, the first exit and the fourth exit, the fourth exit, the fourth exit and the first exit Blast furnace melt flow estimation method characterized by measuring the four sections of the outlet section. Determining a bottom melt flow index (HF) by measuring temperature data for each circumferential direction of the bottom wall of the furnace bottom wall;
Determining the core activation degree through the trend of the bottom melt flow index derived during the set period;
The blast furnace melt flow estimation method, characterized in that the temperature data for each circumferential direction of the lower wall portion is a daily average value. Determining a bottom melt flow index (HF) by measuring temperature data for each circumferential direction of the bottom wall of the furnace bottom wall;
Determining the core activation degree through the trend of the bottom melt flow index derived during the set period;
Determining the core activation degree,
If the trend of the lower melt flow index derived during the set period is increased, the core liquidity is good, and it is assumed that the molten iron is actively moved to the exit port.
The blast furnace melt flow estimation method, characterized in that if the trend of the bottom melt flow index derived during the set period is falling, the core fluidity is lowered to develop a cyclic flow leading to the flow of the furnace wall portion of the molten iron. The method according to any one of claims 2, 5 and 6,
The set period is blast furnace melt flow estimation method, characterized in that 10 to 30 days.

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