KR20020088475A - METHOD FOR CHARGING LARGE ORE INTO BLAST FURNACE TO CONTROL CO GAS COEFFICIENT(ηCO) OF UTILIZATION - Google Patents

Abstract

PURPOSE: A method for charging large ore into a blast furnace to control CO gas coefficient (η CO) of utilization is provided which controls the CO gas coefficient (η CO) of utilization to optimum based on shock resistance index (I) of large ore charged into the blast furnace. CONSTITUTION: The method for charging large ore into a blast furnace to control CO gas coefficient (η CO) of utilization comprises the steps of connecting a monitor for confirming the CO gas coefficient (η CO) of utilization to a large ore shock resistance index calculating process computer, and connecting the large ore shock resistance index calculating process computer to an electric communication controller, an instrument communication controller connected to a furnace top gas analyzer, and a furnace top PLC (programmable logic controller); displaying the CO gas coefficient (η CO) of utilization calculated by the large ore shock resistance index calculating process computer on the monitor; calculating a large ore shock resistance index by a large ore shock resistance index expression, and displaying the calculated large ore shock resistance index on the monitor; increasing the number of revolution per notches of large ore on a charging matrix in a central direction of the blast furnace, inputting the reduced number of revolution by reducing the number of revolution to the furnace wall side, and setting charging so that the large ore shock resistance index reaches to the proper range when the calculated large ore shock resistance index is decreased less than a proper control index; and increasing the number of revolution per notches of large ore on a charging matrix in a furnace wall direction of the blast furnace, inputting the reduced number of revolution by reducing the number of revolution to the central direction of the blast furnace, and setting charging so that the large ore shock resistance index reaches to the proper range when the calculated large ore shock resistance index is increased higher than a proper control index.

Description

METHODS FOR CHARGING LARGE ORE INTO BLAST FURNACE TO CONTROL CO GAS COEFFICIENT (ηCO) OF UTILIZATION}

The present invention relates to a method of charging and receiving alleles in and out of alleles for controlling CO GAS utilization rate (ηCO). More specifically, the present invention relates to CO GAS utilization rate (ηCO) based on the seismic number (I) of the alleles charged in a blast furnace. ) To optimally manage the COGAS utilization rate (ηCO) to control the residence time of fuel and raw materials, auxiliary fuel (pulverized coal) and reducing gas generated during the combustion of hot air It is about charging method.

In general, the blast furnace operation, as shown in Figs. 1 to 2, charging iron ore and coke first charge (coke 12, opposing light 13) using a turning chute 9, which is a top charging device. , Small particle 14] advances by a certain angle (60 °) and charges the coke 12 so that the terrace is maintained at 1.0 to 1.2 m while being forward and reversed at every sixth charge. Then, the opposing light 13 is charged thereon so that the mixed layer is formed by the load of the charge, and the gas flow in the middle part and the central part of the blast furnace 1 is controlled by the radial direction of the blast furnace (1). The small particle 14 is charged for skin flow control so that the distribution of the charged matter in the circumferential direction is kept constant.

In addition, by inserting the central coke 15 into the center of the furnace, the flow of gas in the furnace is generally activated to prevent the wear of the blast furnace 1 in the furnace wall part by activating the central flow and suppressing the furnace wall. Central flow activation operation is carried out to suppress and dissipate heat.

To explain this in detail, as shown in the drop trajectory and the charging matrix diagram shown in Figs. 2A to 2B, the charging method of the blast furnace is loaded in the blast furnace 1 according to the angle 18 of each notch 17 of the swing chute 9. In the radial direction of the blast furnace (1), the central coke (15) having the highest air permeability among the charges in the center of the blast furnace, and the coke (12) and the opposing light (opposite sintered ore) Charged grained light + subsidiary material) 13 is charged to guide the mixed layer 16, and charged to the furnace wall side is a small-air light (small sintered ore) 14, the most breathable.

As shown in FIG. 1, the charge loaded with the layered layer is molten iron and slag (melt) from iron ore while undergoing preheating, reduction, and dropping by a chemical reaction of hot air gas and iron ore supplied from the tuyere 2. (3) is generated and the softening fusion table (6) is lowered to the lower part through the slits, and when a certain amount is gathered, it is discharged to the outside of the blast furnace (1) through the exit port (4). Alternately and continuously.

In addition, the blast furnace by-product gas (hereinafter referred to as BFG) generated in the direct or indirect reduction process is a main component of BFG, which is regenerated as combustion gas of a hot blast furnace for supplying hot air of blast furnace, such as nitrogen (N 2), carbon monoxide (CO), and carbon dioxide ( CO2) and hydrogen (H2) are divided into two, and CO and CO2 are the main factors that determine the CO GAS utilization rate (ηCO).

The formula for calculating the CO GAS utilization rate (ηCO) is as follows.

The optimum management range of the above-mentioned CO GAS utilization rate (ηCO) is 50 to 52%. However, the CO GAS, which is unreduced gas due to the rapid discharge of reducing gas by activation of the central flow due to the ingress of the opposing dust (direction toward the furnace side), This results in an increase in the CO GAS utilization (ηCO) that is significantly reduced.

In addition, the operation of blast furnaces is a relatively low cost alternative to coke, a costly fuel for economical operation in many furnaces in the world. The pulverized coal produced by crushing is directly injected into the blast furnace blast furnace, and it is trying to inject a large amount of pulverized coal competitively in order to reduce the cost of charter manufacturing.

The increase in the pulverized coal injection cost means an increase in the amount of ore charged in the furnace, and the center of the center of the blast furnace to secure the flow path of the GAS due to the thinning of the coke layer due to the decrease of the coke charge in the blast furnace. I charge coke.

However, the charging of the core coke as described above increases the GAS discharge rate to the center, and as the rise of the center of the softening zone gradually shortens the length of the charged material, which shortens the reaction time between the reducing gas and the charged material. As a result, the reduction with the charge and the preheating time are shortened.

Therefore, it leads to an increase in CO GAS among the components of blast furnace gas (BFG) discharged from the furnace, resulting in a decrease in E-CO (CO GAS utilization) and converting E-CO (CO GAS utilization) into fuel costs. When the utilization rate (ηCO) decreases by 1%, the fuel rises by 5 kg per ton of molten iron, and the blast furnace pressure increases due to the shortening of the discharge time due to the decrease in temperature of the melt due to the decrease in temperature of the furnace part due to the lowering of the furnace. It will lead to a decrease in production due to long-term yellowing relief due to a slowed production rate.

In addition, when the CO GAS utilization rate (ηCO) is increased (greater than 52%), the thermal efficiency of BFG, which is used as a heat source of the hot blast furnace, decreases due to the increase of the CO2 ratio in the blast furnace gas (BFG). In addition to causing a decrease in the blowing temperature, the absence of a quantitative operation index for adjusting the CO GAS utilization rate (ηCO) of the BFG to the appropriate management range as described above, causing a time loss for adjustment to the management range.

Accordingly, the present invention has been made to solve the above problems, fuel and raw materials charged in the furnace by optimally managing the CO GAS utilization (ηCO) based on the seismic digit (I) of the alleles charged in the furnace. And control the residence time of the reducing gas generated during the combustion of auxiliary fuel (pulverized coal) and hot air to minimize the heat released with the reducing gas so that the operator can optimally manage the heating of the furnace. The purpose of this study is to provide a method for charging and receiving alleles for CO GAS utilization (ηCO) control in the Belles blast furnace.

1 is a schematic diagram showing a general blast furnace shape and the charge input path;

Figure 2a is a state diagram showing the drop trajectory and charging state according to the angle according to the notch of the blast furnace charge;

Figure 2b is a notch charging matrix diagram of the blast furnace charge according to the conventional charging method;

Figure 3 is a block diagram for a method for charging the opposite light in and out for the CO GAS utilization (ηCO) control according to the present invention;

4 is a flowchart of a method for charging an allergic light in and out of alleles for controlling CO GAS utilization (ηCO) according to the present invention;

FIG. 5 is a notch charging matrix diagram of the blast furnace charges charged according to the method of charging and receiving the opposing light source for controlling CO GAS utilization rate ηCO according to the present invention; FIG.

6 is a graph showing the upper temperature of the blast furnace charge charged according to the conventional charging method;

7 is a graph showing the upper temperature of the blast furnace charge charged in accordance with the method for charging and receiving the opposing light for the CO GAS utilization (ηCO) according to the present invention.

♣ Explanation of symbols for main part of drawing ♣

1: Blast furnace 2: Balloon 9: Turning suit 12: Coke 13: Opposition light 14: Small particle light

15: center coke 21: computer for calculating the seismic index of the opposing light 26: electric signal controller

29: Trip PLC 29: Trip gas analyzer 34: Alternative seismic index 35: Charging matrix

In order to achieve the above object, the method for charging the opposing light in or out of dust for controlling CO gas utilization rate (ηCO) according to the present invention includes a monitor installed so that an operator can check the CO gas utilization rate (ηCO), An electric signal controller for controlling an electric signal, and an instrumentation signal controller connected to a gas analyzer 34 to control an instrumentation signal, and a PLC to a station PLC. Making a step;

The ratio of CO2 to CO is calculated using the CO GAS utilization rate (ηCO) equation. The CO GAS utilization rate (ηCO) calculated by the process computer for calculating the allele seismic index is calculated using the CO GAS utilization rate (ηCO) equation. Displaying on the monitor;

Calculating, by the process computer for calculating the allergic seismic index, an allelic seismic index (I) based on an allelic seismic calculation formula on the rotational speed of the allergic notch on the charging matrix and displaying it on the monitor;

If the decrease in the appropriate management index based on the calculated allergic seismic seismic index (I) is increased by the electric signal of the telecommunication controller, the number of revolutions of the notch on the charging matrix by the notch in the charging matrix increases the rotational speed toward the center of the furnace, Reducing the number of rotations to the side, and setting the charging so that the anti-optical seismic index I reaches a proper range;

If it is increased from the appropriate management index on the basis of the calculated allied seismic seismic index (I) by the electric signal of the telecommunications controller, the number of revolutions by the notch on the charging matrix is increased in the direction of the furnace wall, and the center is increased. Entering by reducing the number of revolutions in the direction, and setting the charging so that the allergic seismic index (I) reaches the appropriate range through By controlling the flow of reducing gas in the furnace, it is possible to smoothly distribute the gas flow in the furnace by maintaining the upper temperature of the furnace contents.

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

Figure 3 is a block diagram for the method for charging the opposing light in and out for the CO GAS utilization rate (ηCO) according to the present invention, Figure 4 is a method for charging the opposing light for the CO GAS utilization rate (ηCO) according to the present invention. Is a flowchart of.

In the alternative method for charging and receiving the opposing light for controlling the CO GAS utilization rate ηCO according to the present invention configured as shown in FIGS. 3 to 4, a monitor 20 is installed so that an operator can check the CO GAS utilization rate ηCO. It is connected to a process computer 21 for calculating the allergic seismic index, and the process computer 21 for calculating the allergic seismic index is a CO GAS utilization calculation means 30 and an allergic seismic index calculation means 31. It is connected to the setting input unit 23, the seismic index setting input unit 24, the seismic index calculation input unit 25 of the charging matrix, and an electric signal controller (Electric Communication Controller) 26 and the blast furnace for electric signal control Instrument instrumentation controllers (Instrument Communication Controller) 28 for controlling the instrumentation signal of the gas gas analyzer (27) for detecting the gas component in (1) is installed and connected to the stationary PLC (Programmable Logic Controller) (29).

As shown in FIG. 4, a process computer for calculating a CO GAS utilization rate ηCO using a CO GAS utilization rate equation ηCO as a ratio of CO2 and CO through a gas analysis result of the gas gas analyzer 27. (21) is calculated and displayed on the monitor (31).

5 is a charging matrix diagram of a blast furnace charge charged according to an allergic or external dust charging method for controlling CO GAS utilization rate ηCO according to the present invention.

As shown in FIG. 5, an allergic seismic index 34 calculated according to the rotational angle 19 ′ of the allergic notch 17 on the charging matrix is displayed on the charging matrix, and the allergic seismic index is displayed. On the basis of this, the internal and external earthquake calculation part 32 which calculates the rotation speed for each notch and the charging setting part 33 to charge are comprised.

According to the method as described above, when the decrease in the appropriate management index based on the calculated allergic seismic seismic index (I) by the electric signal of the electric signal controller 26 by the notched by the notch ( 17) inputting the rotation speed 19 'by increasing the rotation speed toward the center of the blast furnace, decreasing the rotation speed toward the furnace wall, and setting the charging so that the opposing light seismic index I reaches an appropriate range;

On the basis of the calculated allied seismic index (I), if the increase is greater than the appropriate management index, the number of revolutions (19) by the notch (17) on the charging matrix 35 by the electric signal of the electric signal controller 26 ) Is inputted by increasing the number of revolutions in the furnace wall direction, decreasing the number of revolutions in the center direction, and setting the charging so that the anti-optic seismic index (I) reaches an appropriate range. The ellipsis charge charging method for controlling ηCO) is performed.

Hereinafter, a preferred embodiment of the present invention will be described in detail.

EXAMPLE

In general, in a large blast furnace having an internal content of 3800 Nm 3 or more, as illustrated in FIG. 1, an air blowing amount of 6000 N m 3 / min is blown through the air vent 2 at a temperature of about 1150 to 1200 ° C. at a flow rate of about 220 m / sec.

The hot air blown into the blast furnace (1) is heated to 2200 ~ 2300 ℃ to react with oxygen, pulverized coal, coke blown with the hot air at the tip of the tuyere (2), and reacts with the fuel raw material charged in the blast furnace (1) Reduction gasification causes melting reaction with the raw materials in the softening fusion zone (6), while passing through the charge layer at a flow rate of 2 to 3 m / sec while being reduced and reacted and discharged to the gas pipe through the upper part of the charge, part of the blast furnace gas reservoir ( BFG Holder (not shown) and some are used as combustion gases in hot stoves.

At this time, the gas analyzer 27 installed in the gas pipe 36 is to sample the discharged BFG to continuously analyze the components to calculate the CO GAS utilization (ηCO) using CO and CO2 GAS in the blast furnace gas [Equation 1] The CO GAS utilization rate ηCO is displayed on the monitor 20 via the process computer 21.

On the other hand, the allergic seismic index (I) to the charging matrix 35 through [Equation 2] to obtain the allergic seismic index on the charging matrix input through the charging matrix setting input unit 23 of the electric signal controller 26. Is displayed.

Equation 2 for obtaining the allele seismic index is explained in more detail, and the number of revolutions 19 'for each notch set in the charging matrix 35 is multiplied by the number of revolutions, and the sum of the notches is added. The value divided by the total number of revolutions is the seismic index, and the meaning of this value is a figure indicating how far the opposing ore is located on the furnace wall side or the center side.

In general, the notch of the charging light (Notch) is used to select the number of revolutions per notch while using up to 3 to 10 notches, taking into consideration the gas flow changes in the furnace, increase or decrease in CO GAS utilization rate, and the available charge rotational speed is expressed in equation (2). As a result of substitution, the seismic index is in the range of 4.5 to 6.5,

The CO GAS utilization rate (increased as the amount of gas generated in the furnace and increased gas residence time is increased) increases as the seismic index increases and the amount of charged opposing light toward the furnace center increases. As a result, the air resistance was increased by blocking the core part. On the contrary, when the seismic index was 4.5 or less, the opposing light was excessively charged to the wall, resulting in an adverse effect of raising the furnace center temperature and increasing the fuel cost. There was a positive correlation with gas utilization.

That is, as shown in the charging matrix 35 shown in FIG. 5, the charging notches of the opposing light are 4, 5, 6, 7, 8, and 9 notches, respectively, and the charging rotation speeds for each notch are 2, 2, In 2, 1, 1, 1 revolutions, the seismic index of the opposing light becomes 5.78 by Equation 2, wherein the CO GAS utilization rate is determined to be at an appropriate level in the 50% range.

Therefore, when the operator decides the charge rotational speed of each notch, the charge rotational speed 19 'by each notch 17 of the alternative light 13 to be used is determined based on the calculated value of the CO GAS utilization rate (ηCO). The seismic calculation 32 is executed on the charging matrix, and when the CO GAS utilization rate (ηCO) exceeds 52% based on Table 1, the number of rotations of the opposing light on the charging matrix is increased to the furnace wall side, and the confrontation of the furnace center is performed. When the light rotation speed is reduced and the allergic seismic index is calculated in the range of 5.8 to 6.2, the charging setting 54 is executed to determine the mounting rotation speed.

In addition, when the CO GAS utilization rate (ηCO) decreases to less than 50%, the number of rotations of the opposing light on the charging matrix 35 is reduced to the furnace wall side, and the number of rotations of the opposing light 13 at the center of the furnace is increased to perform the seismic calculation (32). When the allergic seismic index is calculated to be in the range of 5.8 to 6.2, the charging setting 33 can be executed to determine the mounting rotation speed 19 ', so that the CO GAS utilization rate 'To be in range.

In other words, the CO GAS utilization rate (ηCO) exceeded 52% during operation, and as a result of checking the notch and the rotation speed of the allele to change the notch of the allele in use, the results showed that 4, 5, 6, It was 7, 8, 9, 10 notches, and the charging rotation speed was 2, 2, 2, 1, 1, 1, 1 rotation. As a result of performing the seismic calculation 32 on the charging matrix 35 of FIG. 5, the seismic index of the opposing light was 6.40.

Input the charging speed so that the seismic index of the opposing light may be in the range of about 6, and when the seismic calculation (32) is performed, the charging notch satisfying the result value between the appropriate range of the seismic index of the opposing light (5.8-6.2) (17 ) And the number of revolutions 19 'are 2, 2, 2, 1, 1, 1 revolutions at 4, 5, 6, 7, 8, and 9 notches, respectively. Notch and rotation speed are changed and input. Until the result value is found, the seismic calculation 32 is performed two or three times.

By doing so, the charge amount of 10 notches on the furnace center side is eliminated, so that the amount of charge of the opposing light on the furnace center side decreases, and the amount of charge on the furnace wall increases relatively.

Conversely, if the CO GAS utilization rate (ηCO) is reduced to 50% or less, the seismic calculation (32) and the charge setting (33) are executed in the reverse order of the above procedure to satisfy the appropriate CO GAS utilization rate (ηCO) and seismicity index conditions. The charging notch 17 and the rotation speed 19 'of the opposing light can be obtained.

Figure 6 is a graph showing the upper temperature of the blast furnace charge charged according to the conventional charging method, Figure 7 is a blast furnace charge charged according to the opposing ore dust charging method for controlling CO GAS utilization (ηCO) according to the present invention. It is a graph showing the upper temperature.

As shown in Fig. 6 to 7, when the charge is charged to the blast furnace by the conventional charging method, the seismic index is out of the range of 5.8 to 6.2, the temperature of the center of the blast furnace is 600 ℃ or more, the CO GAS utilization rate (ηCO) is The thermal efficiency of the blast furnace gas (BFG), which is used as a heat source of the hot blast furnace, decreases to 47.2% to 48.9%, and the CO gas ratio decreases.

49.9 to 51.2% of the CO GAS utilization rate (ηCO) in the range of 5.8 to 6.2 seismic index controlled according to the method for charging the CO GAS utilization rate (ηCO) according to the present invention is about 500 ℃ Therefore, the conditions for reducing the thermal efficiency of the blast furnace gas (BFG), which is used as a heat source of the hot blast furnace, are satisfied due to sufficient reduction reaction conditions and a lower ratio of CO gas in the blast furnace.

As mentioned above, when the external seismic index rises to the furnace wall by increasing the seismic index, the flow of reducing gas passing through the blast furnace is accelerated, and the seismic index is lowered to the management range. When the seismic index of alleles decreases, the penetration of the sedimentary ore into the center of the blast furnace slightly reduces the air permeability to the center of the blast furnace, thereby reducing the flow of reducing gas passing through the blast furnace. To induce

The method for charging the allele into and out of the allele for controlling the CO GAS utilization rate (ηCO) according to the present invention is based on the seismic digit (I) of the allele charged in the furnace to optimally manage the CO GAS utilization rate (ηCO). By controlling the residence time of the fuel, raw materials, auxiliary fuel (pulverized coal), and reducing gas generated during the combustion of hot air, the heat discharged with the reducing gas is minimized, and the thermal efficiency of the hot blast furnace is effectively blown into the blast furnace. By maintaining a constant hot air temperature, the operator can manage the furnace optimally, and thus there is an effect that the lowest fuel cost operation can be performed in the high shipping cost operation.

Claims (2)

A monitor 20 installed so that an operator can check the CO GAS utilization rate ηCO, and the monitor 20 are connected to an allergic seismic index calculation computer 21, and the allergic seismic index calculation computer 21 Connecting an electric signal controller 26 for controlling an electric signal, an instrumentation signal controller 28 connected to the gas gas analyzer 27, and a PLC PLC 29 for controlling the instrumentation signal; Through the gas analysis result of the gas analyzer 27 connected to the instrumentation signal controller 28, the process computer 21 for calculating the allele seismic index using the CO GAS utilization rate (ηCO) equation Displaying the calculated CO GAS utilization rate ηCO on the monitor 20; The process computer 21 for calculating the allergic light seismic index calculates the number of revolutions 19 'of the allered light 13 and the notches 17 on the charging matrix 35 by using the allergic seismic calculation formula (I). Computing) and displaying it on the monitor (20); The number of revolutions of each of the notched light 13 on the charging matrix 35 by the electric signal of the electric signal controller 26 when the decrease in the appropriate management index based on the calculated allied seismic seismic index I is achieved. Inputting (19 ') the rotational speed toward the blast furnace center direction, reducing the rotational speed toward the furnace wall side, and setting the charging so that the opposing light seismic index (I) reaches an appropriate range; The number of revolutions of each of the notched light 13 on the charging matrix 35 by the electric signal of the electric signal controller 26 is increased according to the notched management index based on the calculated allied seismic seismic index I. And (19 ') to increase the rotational speed in the furnace wall direction, decrease the rotational speed in the center direction, and set the charging so that the opposing light seismic index (I) reaches an appropriate range. A method of charging and receiving the opposing light source for controlling the CO GAS utilization rate (ηCO). The method of claim 1, The step of setting the charging so that the allele seismic index (I) reaches an appropriate range may be performed so that the calculated allergic seismic index (I) achieves a CO GAS utilization rate (ηCO) in an appropriate range of 50 to 52%. And setting the charging to reach an appropriate management index range of the seismic index (I), 5.8 to 6.2. 2.