KR101176018B1 - Method for regulating temperature of furance in blast furnace process - Google Patents

Abstract

The present invention relates to a furnace control method in a blast furnace process, comprising the steps of: (a) preparing a furnace impact calculation sheet indicating a furnace effect and a reductant correction value according to fluctuations in coke temperature and moisture content, and (b) in the blast furnace Measuring the temperature and moisture content of the coke to be introduced, (c) obtaining a reducing agent ratio correction value from the reducing agent ratio correction value calculation sheet using the measured temperature and moisture content of the coke, and (d) obtaining Calculating a correction reducing agent ratio by summing the reduced reducing agent ratio correction value and the current reducing agent ratio, and (e) introducing an amount of reducing agent corresponding to the correction reducing agent ratio into the blast furnace.
According to the present invention, it is possible to determine the effect of the blast furnace according to the change of temperature and moisture content of the coke, and to automatically adjust the amount of the reducing agent injected into the blast furnace according to the blast furnace effect to adjust the amount of the reducing agent injected into the blast furnace quickly and accurately according to the change of the furnace. Can be. Therefore, the yellowing relief is prevented and the heat is stabilized, thereby improving productivity. In addition, the amount of work required for the management of the furnace can be reduced to reduce manpower consumption and solve the difficulty of managing the furnace, which had to be relied on by a high-skilled person.

Description

Furnace control method in blast furnace process {METHOD FOR REGULATING TEMPERATURE OF FURANCE IN BLAST FURNACE PROCESS}

The present invention relates to a furnace control method in a blast furnace process for compensating the heat effect of the coke (coke) temperature and moisture content change, more specifically to the blast furnace to compensate for the heat effect of the coke temperature and moisture content change. The present invention relates to a furnace control method in a blast furnace process for preventing the yellowing relief and improving productivity by controlling the amount of reducing agent (coke, pulverized coal) introduced.

In general, when the blast furnace is charged with iron ore and coke from the top of the blast furnace, and the hot air from the bottom of the blast furnace is blown through the tuyere, the iron ore is reduced and It is a process of melting and forming molten iron and slag.

Coke is the main fuel in blast furnace operation, and the heat generated from combustion and CO gas not only play the role of the main heat source and reducing agent in the blast furnace operation, but also exist in the solid state throughout the blast furnace. It also has the function of liquidity in the lower part of the blast furnace. In recent years, the use of pulverized coal, which is relatively inexpensive, is used instead of expensive coke as a reducing agent for iron ore, thereby reducing the cost of using coke. However, the use of pulverized coal also has a problem that the operation state of the blast furnace is unstable because it adversely affects breathability and liquidity than when using only coke.

1 is a schematic configuration diagram of a charging facility for a general blast furnace charge.

Referring to FIG. 1, in general, in the blast furnace process, the method of charging lead and raw materials is carried out from the coke storage tanks 81 to 88 to coke to the particle size sorter 180 at the bottom, and the particle size sorter 180 has a particle size of 35 to 55 mm. Separation of the coke is distributed through a conveyor belt 190, a certain amount is distributed and stored in two sets of coke basis weight hopper (100, 110). In addition, the iron ore from the iron ore storage tank (1-8) is discharged to the particle size sorter (30) at the lower end, and the particle size sorter (30) selects alleles having a particle size of 12 to 30 mm. After a certain amount of the basic raw material hopper (21 ~ 28) and the secondary raw material from the alleles and sub-fuel storage tank (11 ~ 18) selected by the particle size sorter (30), the basis weight is distributed and stored, and the opposing light basis hopper (120,130) ) Stored in two sets. Meanwhile, after the small particles having a particle size of 5 to 12 mm selected through the particle size selector 30 are stored in the small particle storage tank 60, the small particle weight hopper 140 is stored. In general, the coke basis hopper (100, 110), the opposing light basis weight hopper (120, 130) and the small-size light basis hopper 140 collectively referred to as intermediate weight basis hopper.

For reference, in the concept of blast furnace charge, coke, which is a raw material stored in two coke basis hoppers 100 and 110, is referred to as 'batch', and 'batch + 1 batch' of fuel to be injected into the blast furnace 300. It is called a 'charge'. In addition, the batch and charge concepts of allergic luminous coke, which is a raw material stored in the allergic light basis hoppers 120 and 130, are the same. Further, the ore stored in one small particle size hopper 140 for charging by size is called 'primary', and the three kinds are referred to as 'primary materials of charging'.

The above process is referred to as the basis weight process of the fuel and iron ore set value required by the blast furnace 300, the lead and raw material weighted in this way is imported into the charging hopper of the furnace through the large charging conveyor belt (70) When a predetermined time (6-7 hours) has elapsed in the standby state after the import, the contents of the blast furnace 300 fall through the reduction reaction of iron ore to reach the charging baseline, thereby signaling the charging start. As a result, charging is carried out in the order of the coke 1 charge, the opposing light 1 charge, the central coke 1 charge (C3), and the small particle 1 light in order. Charging is performed sequentially in the order of the first charge.

The coke is manufactured at the coke manufacturing plant and supplied to the blast furnace charging facility, and the coke production is lowered due to an abnormality in the coke dry quenching (CQQ) facility or other coke manufacturing facility of the coke manufacturing plant, resulting in a large amount of coke production. When the stock is insufficient, the coke stored in the yard (wet) or wet coke without the CDQ equipment is irregularly incorporated in the coke storage hopper (81 ~ 88), so that the coke with a large deviation of properties in the blast furnace 300 It is charged. Usually, coke has a temperature deviation of at least 100 ° C and a moisture content deviation of at least 8 to 10% depending on the type.

Although the main fuel has a significant influence on reducing agent ratio (RR), which affects the blast furnace 300, depending on the change of temperature and water content of coke, the driver constantly monitors the coke state and reflects it in operation. Since it is not possible to cause severe yellowing relief caused by frequent changes in heat, there was a problem that the productivity is lowered.

The present invention has been made to solve the above problems, by controlling the amount of reducing agent (coke, pulverized coal) is added to the blast furnace to compensate for the effect of the furnace due to changes in the temperature and moisture content of the coke, to prevent the occurrence of yellowing relief and productivity To provide a furnace control method for improving the furnace, its purpose is to.

The furnace control method in the blast furnace process according to one aspect of the present invention, (a) preparing a furnace effect calculation sheet showing the furnace effect and reducing agent correction value according to the temperature and moisture content of the coke and (b) the Measuring the temperature and moisture content of the coke to be introduced into the blast furnace, (c) obtaining a reducing agent ratio correction value from the reducing agent ratio correction value calculation sheet using the measured temperature and moisture ratio of the coke, and (d) Comprising a step of calculating the correction reducing agent ratio by summing the obtained reducing agent ratio correction value and the current reducing agent ratio and (e) injecting the amount of reducing agent corresponding to the correction reducing agent ratio to the blast furnace. .

Characterized in that it is displayed on the monitor so that the operator can confirm the aging effect, reducing agent ratio correction value and correction reduction agent ratio obtained in the step (c) and (d).

After the step (d) and before performing the step (e), the air flow rate of the blast furnace is more than 3000 ㎥ / min, wind pressure standard deviation is less than 50, and the current coke charging speed at the average charging speed of the last 10 coke charging Determining whether the charging speed deviation obtained by subtracting satisfies a condition of 5 or less; if the condition is satisfied, proceeds to step (e). And providing a user interface to compensate.

After the step (d) and before the step (e), further comprising the step of selecting the type of reducing agent to be used for compensation of the furnace, wherein the step of selecting the type of reducing agent is the wind pressure standard deviation in the blast furnace It is characterized in that it is performed to use pulverized coal when it is 25 or less and the injection amount of the pulverized coal injection facility satisfies a condition of 80% or less, and when the condition is not satisfied, coke is used.

After the step (e), the step of measuring the furnace heat, obtaining a further reducing agent ratio correction value from Table 1 according to the measured furnace heat, the obtained reducing agent ratio further correction value and the current reducing agent ratio Comprising the step of calculating the re-correction reduction ratio and characterized in that it further comprises the step of introducing the amount of reducing agent corresponding to the calculated re-correction reduction ratio to the blast furnace.

Melting temperature (degree: ℃) Additional reducing agent ratio correction value (kg / THM) 1480-1490 +5.0 1470-1480 +7.5 1470 or less +10.0

According to the present invention, it is possible to determine the effect of the blast furnace according to the change of temperature and moisture content of the coke, and to automatically adjust the amount of the reducing agent injected into the blast furnace according to the blast furnace effect to adjust the amount of the reducing agent injected into the blast furnace quickly and accurately according to the change of the furnace. Can be. Therefore, the yellowing relief is prevented and the heat is stabilized, thereby improving the productivity. In addition, the amount of work required for the management of the furnace can be reduced to reduce manpower consumption and solve the difficulty of managing the furnace, which had to be relied on by a high-skilled person.

1 is a configuration diagram for a general blast furnace charging facility.
2 is a flowchart illustrating a furnace control method in a blast furnace process according to the present invention.
3 is a view schematically showing equipment associated with the furnace control method of the present invention.

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

The furnace control method according to the present invention calculates the influence of the furnace according to the change in the temperature and moisture content of the coke, and adjusts the reducing agent ratio according to the furnace effect to control the amount of the reducing agent (pulverized coal, coke) injected into the blast furnace to keep the furnace constant. To be maintained.

In other words, the coke's temperature and moisture content have a significant influence on the blast furnace change, and the amount of reducing agent (pulverized coal, coke) correction dose required to calculate the heat effect according to the coke's temperature and moisture rate and to compensate the calculated furnace effect. To calculate the amount of reducing agent introduced into the blast furnace. However, at the operation site, the amount of reducing agent (coke, pulverized coal) input to the blast furnace is expressed in kg by the amount of reducing agent (coke, pulverized coal) used to produce 1 ton of molten iron in the blast furnace. It is more convenient to use in terms of conversion. In the following, the amount of reducing agent input is used in terms of reducing agent ratio.

FIG. 2 is a flowchart illustrating a furnace control method in a blast furnace process according to the present invention, and FIG. 3 is a view schematically illustrating equipment related to the furnace control method of the present invention.

In the present invention, as described above, since the reducing agent ratio is adjusted to compensate for the heating effect due to the fluctuation of the coke temperature and moisture content, first, the setting of the heating influence value according to the temperature and moisture content of the coke is required (S101).

To this end, the temperature and moisture content of the coke is measured using a thermometer 150 and a moisture meter 160 installed on the conveyor belt 190, which transfers the coke to the coke basis hoppers 100 and 110 shown in FIGS. After measuring the temperature (heating) of the molten iron produced after the coke is put into the blast furnace, the value of the furnace when the coke having a specific temperature and moisture content, for example, a temperature of 100 ℃ and a moisture content of 0% is used As the reference value, the heat effect is calculated by subtracting the reference value from the heat value at each coke temperature and moisture content. For the accuracy of the data, it is desirable to accumulate the data obtained through the long-term operation process of 6 months or more, and calculate the thermal effect by calculating the average value of the accumulated data. However, in the blast furnace operation, if necessary, the blast blast, which is a task to reduce the hot air blown into the blast furnace installed in the lower part of the blast furnace, or decreases or increases the charging speed of the charges (coke, allele, small particle). In the present invention, a change in furnace heat occurs even when the charging speed is changed. In the present invention, when the furnace speed is stabilized because the charge speed change is not large and the change in charging speed is not large, that is, the air volume is 3000 m 3 / min or more and the wind pressure standard deviation is 50. Sampling is carried out only when the coke charging speed deviation is 5 or less, so that more accurate data can be calculated. Here, the charging speed deviation is calculated through the following equation (1).

[Equation 1]

Charging speed deviation = [average charging speed at last 10 charging]-[current charging speed]

When measuring the temperature and moisture content of the coke, it is necessary to measure the temperature and water content of the coke is moved to the conveyor belt 190, so that the thermometer 150 and the moisture meter 160 is a non-contact thermometer capable of measuring the temperature and moisture content in a non-contact manner And the use of a moisture meter. For example, an infrared ray (IR) thermometer is used as the thermometer 150, and an infrared moisture meter is used as the moisture meter 160. Alternatively, a non-contact thermometer and moisture meter using a laser may be used.

On the other hand, the reducing agent ratio correction value is calculated by multiplying the heating effect value by 0.25, which is the coefficient of change of the reducing agent ratio to the change of the heating effect. Here, 0.25, which is the coefficient of change of the reducing agent ratio with respect to the change in the thermal effect, can be determined through measurement at the shop floor. This method is convenient because it is difficult to determine by uniform conditions and principles because the heat is determined by various factors.

Table 2 below is a thermal effect calculation sheet showing the thermal effect (heat fluctuation) and reducing agent ratio correction value according to the temperature and moisture content of the coke. This aging effect calculation sheet is obtained empirically in the working environment of the present inventors, there may be some variation in the specific correction amount according to the operating equipment and conditions, it is not necessarily limited to the numerical values shown in the following table.

Coke star Aging effect
(℃) Reducing agent correction value
(Kg / THM) Temperature (℃) Moisture content (%) 100 0.0 - - 90 0.2 3.2 0.8 80 0.4 6.4 1.6 70 0.6 9.6 2.4 60 0.8 12.8 3.2 50 1.0 16.0 4.0 40 1.2 19.2 4.8 30 1.4 22.4 5.6 20 1.6 25.6 6.4 10 1.8 28.8 7.2 0 2.0 32.0 8.0

After the heating effect calculation sheet is prepared, the temperature and moisture content of the coke are measured using a thermometer 150 and a moisture meter 160 installed on the conveyor belt 190 to transfer the coke to the coke basis hoppers 100 and 110 ( S102).

When the temperature and moisture content of the coke is measured, the table 1 (heat impact calculation sheet) is searched to obtain a correction value of the heat effect and reducing agent ratio according to the measured temperature and moisture content (S103).

After the aging effect and the reducing agent ratio correction value are obtained, the correction reducing agent ratio is calculated by adding the obtained reducing agent correction value and the current reducing agent ratio (S104).

In addition, various types of operation-related data such as a heat effect, a reducing agent ratio correction value, and a correction reduction agent ratio are displayed on the monitor 170 so that an operator can check the operation state.

Then, it is determined whether to perform the automatic heating control process (S105).

As described above, the change in furnace heat occurs even by the change in the wind speed and the charging speed. In the present invention, when the furnace speed is stable because the change in the charge speed is not large and the furnace speed is constant, that is, the amount of air is more than 3000㎥ / min. The sampling was conducted only when the wind pressure standard deviation was less than 50 and the charging speed deviation was 5 or less. In addition, since the heating effect is calculated based on the sampling data obtained under the above conditions, the automatic heating process of the present invention is limited to the case where the control object is satisfied. In other words, only when the air volume is 3000 m 3 / min or more, the wind pressure standard deviation is 50 or less, and the charging speed deviation is 5 or less, the shift to the braking control process is performed. On the other hand, if the above conditions are not satisfied, a user interface (user interface) is provided so that an operator can manually compensate for aging.

In the case of shifting to the automatic heating control process, the type of reducing agent to be used for the heating compensation is selected (S106).

Coke and pulverized coal may be used as the reducing agent. As is well known, coke is charged in bulk and plays an important role in maintaining breathability in the blast furnace, but has the disadvantages of being expensive and complicated in the manufacturing process. On the other hand, pulverized coal is blown into the blast furnace in the form of powder (powder), and as the blowing amount increases, the coke decreases relatively, resulting in deterioration of air permeability and an increase in wind pressure and unstable yellowing.

In view of this point, the present inventors selected pulverized coal when the wind pressure standard deviation of the blast furnace was 25 or less and the blowing amount was 80% or less relative to the capacity of the pulverized coal injection facility, and otherwise selected coke.

After selecting the type of reducing agent, a reducing agent corresponding to the correction reducing agent ratio is added to the blast furnace (S108).

The reducing agent input is calculated using the following equation.

&Quot; (2) "

Reductant Input [ton]

= {Reduction ratio correction value + current reducing agent ratio} [kg] × molten iron production per blast furnace × 10 ^-3

= Correction reduction fee [kg] × Charter production per blast furnace load × 10 ^-3

The amount of reducing agent corresponding to the correction reduction ratio is added to the blast furnace, and thus the effect of the aging due to the change of the coke temperature and moisture content is compensated.

On the other hand, in the case of manually compensating for the aging, the aging compensation is performed according to the operating conditions input by the operator through the user interface (S106A).

After the furnace compensation is automatically or manually performed, the temperature (heat) of the molten iron produced in the blast furnace is measured again (S107).

In addition, a reducing agent ratio additional correction value is obtained from the following Table 2 using the measured furnace value, and the obtained reducing agent ratio additional correction value and the current reducing agent ratio are added to calculate a recalibration reduction agent ratio (S109).

Table 3 below shows a further correction value of reducing agent ratio according to aging. The data in Table 3 is obtained empirically at the working site of the present inventors, there may be some variations depending on the operating equipment and conditions and are not necessarily limited to the numerical values shown in the following table.

Furnace (℃) Additional reducing agent ratio correction value (kg / THM) 1480-1490 +5.0 1470-1480 +7.5 1470 or less +10.0

Thereafter, the amount of reducing agent corresponding to the recalibrated reducing agent ratio is added to the blast furnace (S110).

According to the present invention, it is possible to determine the effect of the blast furnace according to the change of temperature and moisture content of the coke, and to automatically adjust the amount of the reducing agent injected into the blast furnace according to the blast furnace effect to adjust the amount of the reducing agent injected into the blast furnace quickly and accurately according to the change of the furnace. Can be. Therefore, the yellowing relief is prevented and the heat is stabilized, thereby improving the productivity. In addition, the amount of work required for the management of the furnace can be reduced to reduce manpower consumption and solve the difficulty of managing the furnace, which had to be relied on by a high-skilled person.

In the detailed description of the present invention described above with reference to the embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the present invention described in the claims and It will be appreciated that various modifications and variations can be made in the present invention without departing from the scope of the art.

Claims (7)

(a) preparing a thermal impact calculation sheet indicating a thermal effect and a reducing agent correction value according to fluctuation of temperature and moisture content of the coke;
(b) measuring the temperature and moisture content of the coke to be introduced into the blast furnace;
(c) obtaining a reducing agent ratio correction value from the reducing agent ratio correction value calculating sheet using the measured temperature and moisture content of the coke;
(d) calculating a correction reducing agent ratio by summing up the obtained reducing agent ratio correction value and a current reducing agent ratio;
(e) a method for controlling the furnace in a blast furnace process, comprising the step of adding a reducing agent corresponding to the correction reduction agent ratio to the blast furnace. The method of claim 1,
The method for controlling the furnace in a blast furnace process, characterized in that the display of the furnace effect, reducing agent ratio correction value and correction reduction agent ratio obtained in the step (c) and (d) on the monitor for the operator to confirm. The method of claim 1,
After performing step (d) and before performing step (e),
Whether the air flow rate of the blast furnace is more than 3000㎥ / min, wind pressure standard deviation is 50 or less, and the charging speed deviation obtained by subtracting the current coke charging speed from the average charging speed during the last 10 coke charging is satisfied the condition of 5 or less Determining; and
In the blast furnace process characterized in that the step (e) if the condition is satisfied, and if the condition is not satisfied, providing a user interface so that the operator can manually compensate for the aging. Furnace control method. The method of claim 1,
After the step (d) and before the step (e), further comprising the step of selecting the type of reducing agent to be used for the compensation of the furnace, the furnace control method in the blast furnace process. The method of claim 4, wherein
The step of selecting the type of reducing agent is used when the pulverized coal is used when the standard deviation of the wind pressure in the blast furnace is 25 or less and the blowing amount of the pulverized coal blowing facility satisfies the condition of 80% or less and does not satisfy the above conditions. The method of controlling the furnace in a blast furnace process, characterized in that performed to use coke. The method of claim 1,
After step (e), measuring the furnace;
Acquiring a reducing agent ratio additional correction value from Table 1 according to the measured furnace heat;
Calculating a recalibration reduction ratio by summing the obtained reducing agent ratio additional correction value and the current reducing agent ratio;
The method of controlling the furnace in a blast furnace process, characterized in that it further comprises the step of adding the amount of reducing agent corresponding to the calculated recalibration reduction ratio to the blast furnace.
[Table 1]
Melting temperature (heating: ℃) Additional reducing agent ratio adjustment value (㎏ / THM)
1480 ～ 1490 +5.0
1470 ～ 1480 +7.5
1470 and below +10.0 The method of controlling a furnace in a blast furnace process according to claim 1, wherein the temperature measurement of step (b) is carried out in a non-contact manner.

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