KR20110024829A - Method for preventing slopping during converter blowing - Google Patents

Abstract

PURPOSE: A method for suppressing slopping during blowing of a convertor is provided to prevent the decrease of yielding percentage of tapping and to prevent the burn of facilities due to slopping. CONSTITUTION: A hood pressure is measured by a hood pressure detector of a hood of a convertor facility(S10). The exhaust gas flow and carbon monoxide amount, generated during blowing, are measured by a gas analyzer(S20,S30). A slopping generation time point is detected by a controller based on the measured hood pressure, exhaust gas flow and carbon monoxide amount(S40). The exhaust gas controls a blower to be smoothly exhausted from the convertor(S50).

Description

How to suppress slope during converter blows {METHOD FOR PREVENTING SLOPPING DURING CONVERTER BLOWING}

The present invention relates to a method for suppressing slope during converter blow, and more particularly, to a method for suppressing slope during converter blow that can detect the timing of the occurrence of the slope and thereby quickly suppress the generated slope. will be.

The converter operation is repeated in the order of preparation stage → blowing → tapping → excavation (disposal of slag in the furnace after tapping). As shown in FIGS. 1 and 2, the double blow operation is performed by charging scrap and hot metal, which are main materials, into the converter 1 and supplying oxygen into the converter 1 using the lance 2. By this means the operation of removing impurities such as carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), titanium (Ti) and the like in the molten iron. In addition, during the drilling process, quicklime (the main component is calcium oxide CaO), light dolomite (the main components are calcium oxide and magnesium oxide CaO.MgO), sintered ore (main component is iron oxide), fluorite (main component is calcium fluoride CaF ₂ ) After the back is fed to the hopper 12 and then fed to the converter 1 through the feeder 13 to form a slag, impurities such as silicon (Si), phosphorus (P), manganese (Mn), titanium (Ti), etc. Can be removed.

On the other hand, the gas removed through the oxidation reaction as described above is carbon (C), carbon (C) is removed by carbon monoxide is collected through the following process for reuse.

1 and 2, the exhaust gas generated during the blowing operation is collected into the gas holder 10 by the rotation of the blower 6. On the other hand, in order to prevent the exhaust gas generated in the converter 1 from being regenerated, after a certain time has passed after the start of the blowdown, the skirt 14 is lowered to perform closed operation.

Meanwhile, carbon monoxide (CO) and carbon dioxide (CO ₂ ) occupy more than 80% of the components of the exhaust gas, and the remainder is a gas such as nitrogen (N), argon (Ar), hydrogen (H) and dust generated during blowing. Is done. In order to remove the dust, the exhaust gas is transferred to the primary dust collector 4 via the skirt 14, and the dust is primarily removed by the cooling water in the primary dust collector 4. The exhaust gas passing through the primary dust collector 4 is transferred to the electrostatic precipitator 5, and the fine dust that has not been collected by the primary dust collector 4 is removed from the electrostatic precipitator 5. The exhaust gas passing through the electrostatic precipitator 5 passes through the gas analyzer 7 and the gas analyzer 7 detects the flow rate of the exhaust gas and the concentration of carbon monoxide contained in the exhaust gas. Flue gas having a low carbon monoxide concentration in the flue gas passed through the gas analyzer 7 is burned and removed in the stack 8, and the flue gas having a high carbon monoxide concentration is collected in the gas holder 10 via the gas cooler 9.

On the other hand, when the exhaust gas is rapidly increased in the process of recovering the exhaust gas as described above, the exhaust gas is discharged to the outside of the skirt 14, in order to recover the exhaust gas discharged so that the exhaust dust collector (3) is installed and operated. The old dust collector 3 is installed above the dog house D formed to surround the converter 1.

Meanwhile, the hood pressure and the exhaust gas detected by the hood pressure detector 16 and the gas analyzer 7 respectively installed in the hood H in order to properly recover the exhaust gas while preventing the exhaust gas from leaking out of the skirt 14. The rotational speed of the blower 6 is controlled in accordance with the flow rate.

Carbon monoxide (CO) generated during the drilling process is not able to easily penetrate the slag layer generated in the furnace, but it is stagnant in the upper part of the molten iron and the slag layer, and may cause slag forming, a phenomenon in which the slag and the molten iron are rapidly pushed upwards. As a result, slag and molten iron are blown out of the converter 1 during the drilling operation. Sloping is affected by the amount and composition of the slag, the molten iron condition, the rate of carbon monoxide generation and the size of the bubbles. For example, when the content of silicon (Si) in the molten iron is more than 0.6%, a large amount of heat of reaction is generated initially, thereby increasing the quicklime dissolution rate. This means that a large amount of liquid slag may be formed from the initial stage of blowing, and the slope occurs when the blowing process reaches 30% of the time when the blowing process is vigorous.

When the above-mentioned slope phenomenon occurs, the slag is ejected out of the converter (1), the surrounding equipment is burned out, and a large amount of iron contained in the slag is lost, so that the falling error rate decreases, and according to the loss of slag As additional input is required, manufacturing cost of molten steel rises and flue gas generation suddenly increases, so the flue gas is ejected through the furnace and skirt and then exits the factory, causing serious air pollution.

The present invention has been proposed to solve the problems described above to detect the timing of the occurrence of the slope through the measurement of the hood pressure, the exhaust gas flow rate and the amount of carbon monoxide, it is possible to quickly suppress the slope generated by the control of the converter facility. It is an object of the present invention to provide a method for suppressing slopes during converter blow.

In order to achieve the above object, the method for suppressing the slope during converter blow according to the present invention includes a hood pressure measuring step of measuring the hood pressure through a hood pressure detector installed in a hood of the converter facility, and through a gas analyzer of the converter facility. Based on the exhaust gas flow rate measuring step for measuring the exhaust gas flow rate generated during the blow, the carbon monoxide measurement step for measuring the amount of carbon monoxide generated during the blowdown through the gas analyzer of the converter facility, based on the measured hood pressure, exhaust gas flow rate, and carbon monoxide Slope generation detection step for detecting the timing of the occurrence of the slope in the controller of the converter facility, and after the timing of the occurrence of the slope is detected through the controller to control the feeder, the lance motor, and the oxygen intake valve of the converter Reducing ping and controlling the blower to ensure that the flue gas increased due to slopes is discharged smoothly from the converter It characterized in that it comprises a step of suppressing the slope.

In the slope suppressing step, the skirt of the converter facility, the old dust collector, and the loop spray are further controlled through the controller, so that some of the slag and the exhaust gas which increase rapidly during the occurrence of the slope are discharged through the skirt. It is preferable to be discharged into the air after purification through this.

In the step of detecting the occurrence of slope, when the hood pressure is measured to be less than -150 Pa, the exhaust gas flow rate per hour is measured at 100,000 Nm3 / h or less, and the carbon monoxide is measured to be less than 40% of the exhaust gas, it is the time when the slope is generated. It is desirable to sense.

The step of suppressing the slipping is a step of injecting the sedative into the converter through the feeder, and by adjusting the height (L2) of the lance 2 through the lance motor 15 to the lance for the height (L1) of the hot water surface (S) (2) adjusting the height L2 to be 1.0 or less, adjusting the oxygen flow rate per minute blown into the converter 1 through the oxygen intake valve 18 to 2 Nm 3 / min or less, and a blower ( It is preferable to include a step of adjusting the number of revolutions per minute of the blower 6 so that the exhaust gas flow rate per hour treated through 6) is 180,000 Nm 3 / h or more.

The slope suppressing step S50 preferably includes a step of opening the skirt 14 by 50% or more, a step of maximally operating the old dust collector 3, and a step of operating the roof spray 11. .

According to the above-described method of suppressing slope during converter blow, the occurrence of the slope is sensed by measuring the hood pressure, the exhaust gas flow rate and the carbon monoxide amount, and the slope generated by the control of the converter facility can be suppressed quickly. By doing so, it is possible to solve the problem of the burnout of the surrounding equipment, the fall of the tapping error rate, the increase of the manufacturing cost of the molten steel, and the air pollution problem, which were a problem when the slope occurs.

Hereinafter, referring to FIGS. 3 and 4, a method of suppressing slopes during converter blow according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2 described above.

Slope suppression method during the blowdown of the converter according to an embodiment of the present invention is a hood pressure measuring step (S10), exhaust gas flow rate measuring step (S20), carbon monoxide amount measuring step (S30), and a slope generation detection step (S40) And a slope suppressing step (S50).

The hood pressure measuring step S10 is a step of measuring the hood pressure through a hood pressure detector 16 installed in the hood H of the converter facility, and the exhaust gas flow rate measuring step S20 is a gas analyzer of the converter facility. It is a step of measuring the exhaust gas flow rate generated during the blow through 7), the carbon monoxide amount measuring step (S30) is a step of measuring the amount of carbon monoxide generated during the blow through the gas analyzer (7) of the converter facility. Here, the hood pressure measuring step (S10), the exhaust gas flow rate measuring step (S20), and the carbon monoxide amount measuring step (S30) may be made sequentially or simultaneously.

The slope generation detection step (S40) is a slope of the controller 17 of the converter facility based on the hood pressure measured by the hood pressure detector 16, the exhaust gas flow rate and the carbon monoxide amount measured by the gas analyzer 7. In the case of detecting the occurrence time of the, the controller 17, the hood pressure is measured to be less than -150Pa, the exhaust gas flow rate per hour is measured to 100,000Nm3 / h or less, the carbon monoxide is measured to be less than 40% of the exhaust gas It is sensed that it is the time when the slope occurred.

Here, the hood pressure of -150Pa means that the difference between the internal pressure of the hood (H) and the atmospheric pressure is 150Pa, the internal pressure of the hood (H) is lower than the atmospheric pressure. In addition, when the internal pressure of the hood H and the atmospheric pressure match, it means that the converter facility is operated with the hood pressure at 0 Pa. If the internal pressure of the hood H is higher than the atmospheric pressure, the hood pressure is + ( Plus) means that the converter is operating under pressure. Furthermore, when the hood pressure is operated at + (plus) pressure, the exhaust gas generated from the converter 1 may leak to the outside, causing environmental pollution, and when the hood pressure is operated at-(minus) pressure, air in the atmosphere Is introduced into the hood (H) to include air in the exhaust gas, the carbon monoxide in the exhaust gas can be secondary combustion.

On the other hand, as one of the detection conditions at the time of the occurrence of the slope, it is assumed that the hood pressure is -150Pa or less, the carbon monoxide generated by the oxygen supplied to the converter (1) when the hood pressure is -150Pa or less is in the converter (1) This is because the stagnation in the slag layer eventually causes the sling to occur, whereas when the hood pressure is higher than -150 Pa, the carbon monoxide stagnated in the converter 1 can be discharged directly from the converter 1 so that no slope occurs. .

In addition, as one of the detection conditions at the time of the occurrence of the slope, assume that the exhaust gas flow rate per hour is 100,000 Nm3 / h or less, carbon monoxide in the slag layer in the converter (1) when the hourly exhaust gas flow rate is 100,000 Nm3 / h or less This is because when stagnant and eventually the slope is generated, on the other hand, when the exhaust gas flow rate per hour is 100,000Nm 3 / h or more, the flue gas is smoothly discharged so that the slope does not occur.

In addition, as one of the detection conditions at the time of the occurrence of the slope, it is assumed that the amount of carbon monoxide is less than 40% in the flue gas, the carbon monoxide stagnates in the slag layer when the carbon monoxide amount is less than 40% in the flue gas, the temperature in the converter (1) increases This is because when the volume of carbon monoxide increases explosively and eventually slopes, when the amount of carbon monoxide is more than 40% of the exhaust gas, carbon monoxide is smoothly discharged from the converter 1 so that no slope occurs.

In the step of detecting the occurrence of the dropping operation S40, the controller 17 detects that the slope has occurred when all of the detection conditions at the time of the occurrence of the dropping are satisfied, and then, the slope suppressing step S50 is started.

The slope suppressing step (S50) is generated by controlling the feeder 13, the lance motor 15, and the oxygen intake valve 18 of the converter facility through the controller 17 after the timing of the occurrence of the slope is detected. It is to reduce the slope and to control the blower 6 so that the flue gas increased due to the slope smoothly discharged from the converter 1, and also through the controller 17 and the skirt 14 of the converter installation , The dust collector 3 and the roof spray 11 are further controlled so that some of the slag and flue gas which are rapidly increased when the slope is generated are discharged through the skirt 14 so that the dust collector 3 and the roof spray 11 It is to be discharged into the air after being purified through.

The slope suppressing step (S50) is a step of injecting the sedative into the converter (1) through the feeder 13, and adjusts the height (L2) of the lance (2) through the lance motor (15) The ratio of the height (L2) of the lance 2 to the height (L1) of 1.0) and the flow rate of oxygen per minute blown into the converter (1) via the oxygen intake valve 18 is 2Nm3 / min And adjusting the number of revolutions per minute of the blower 6 so that the hourly exhaust gas flow rate processed through the blower 6 is 180,000 Nm 3 / h or more, and the skirt 14 is further reduced. The method may further include a step of opening more than%, a step of operating the epoch dust collector 3 to the maximum, and a step of operating the roof spray 11.

The reason for introducing the sedative into the converter (1) through the feeder (13) is that the sedative is dropped from the top of the converter (1) and penetrates the slag layer, since the stagnant carbon monoxide in the slag layer is easily discharged. to be.

The reason for adjusting the height L2 of the lance 2 so that the ratio of the height L2 of the lance 2 to the height L1 of the bath surface is 1.0 or less is because the height of the lance 2 is increased and the water surface S is increased. When the ratio of the height L2 of the lance 2 to the height L1 of 1.0 is equal to or greater than 1.0, the stirring effect in the converter 1 due to the oxygen ejected from the lance 2 decreases, thereby increasing the thickness of the slag layer. This is because the slope can be further enlarged, while the slope can be reduced when the ratio of the height L2 of the lance 2 to the height L1 of the hot water surface is 1.0 or less.

The reason for adjusting the oxygen flow rate per minute blown into the converter 1 to 2Nm3 / min or less is that when the oxygen flow rate per minute blown into the converter 1 is 2Nm3 / min or more, the amount of carbon dioxide generated increases rapidly and the slope is further expanded. On the other hand, when the oxygen flow rate per minute blown into the converter (1) is less than 2Nm 3 / min because the generation of carbon monoxide is suppressed and the slope can be reduced.

The reason for controlling the number of revolutions per minute of the blower 6 so that the hourly exhaust gas flow rate processed through the blower 6 is 180,000 Nm 3 / h or more is generated when the slag layer is ejected at the same time when the sling occurs, and the exhaust gas is generated at this time. This is because the exhaust gas flow rate was measured to be at least 180,000 Nm 3 / h or more. On the other hand, when using the blower 6 having an hourly flow rate of 180,000 Nm 3 / h can be processed, the number of revolutions of the blower 6 should be maintained at 1800rpm or more.

On the other hand, the reason why the skirt 14 is opened more than 50% is to discharge a portion of the slag and the exhaust gas ejected by the slope phenomenon toward the furnace port of the converter 1 so that the slag and the exhaust gas which increases rapidly during the occurrence of the slope is dispersed. It is for.

The reason why the exhaust dust collector 3 is operated to the maximum is to prevent the exhaust gas and the slag that has escaped toward the furnace port of the converter 1 by the opening of the skirt 14 so as not to flow out of the dog house D.

The roof spray 11 is installed in the roof R of the steelmaking plant in which the converter facility is installed, and despite the maximum operation of the exhaust dust collector 3, the exhaust gas flows out of the dog house D to be arrowed (A). The roof spray 11 is operated so that dust contained in the flue gas is collected before the flue gas is discharged into the atmosphere because the gas is discharged to the atmosphere.

According to the above-described method of suppressing slope during converter blow, the occurrence of the slope is sensed by measuring the hood pressure, the exhaust gas flow rate and the carbon monoxide amount, and the slope generated by the control of the converter facility can be suppressed quickly. By doing so, it is possible to solve the problem of the burnout of the surrounding equipment, the fall of the tapping error rate, the increase of the manufacturing cost of the molten steel, and the air pollution problem, which were a problem when the slope occurs.

While specific embodiments of the present invention have been illustrated and described, those of ordinary skill in the art may vary the present invention without departing from the spirit of the invention as set forth in the following claims. It is to be understood that modifications and variations are possible.

1 shows a converter installation.

2 is a diagram illustrating a connection relationship between a converter facility and a controller.

Figure 3 is a view showing the flow of the slope suppression method during the converter blow in accordance with an embodiment of the present invention.

4 shows the height of the hot water surface and the height of the lance;

<Description of the symbols for the main parts of the drawings>

S10: hood pressure measuring step S20: flue gas flow measuring step

S30: carbon monoxide measurement step S40: slope occurrence detection step

H: Hood 13: Feeder

14: Skirt 15: Lance Motor

16 hood pressure detector 17 controller

18 oxygen injection valve 16 hood pressure detector

17: controller 3: the old dust collector

6: blower 11: loop spray

Claims (5)

Hood pressure measuring step (S10) for measuring the hood pressure through the hood pressure detector 16 installed in the hood (H) of the converter facility; An exhaust gas flow rate measuring step (S20) of measuring an exhaust gas flow rate generated during the blowdown through the gas analyzer 7 of the converter facility; Carbon monoxide amount measuring step of measuring the amount of carbon monoxide generated during the blowing through the gas analyzer (7) of the converter facility (S30); A slope generation detection step (S40) of detecting a timing of occurrence of the slope at the controller 17 of the converter facility based on the measured hood pressure, exhaust gas flow rate, and carbon monoxide amount; And After the occurrence of the slope is detected, the controller 17 controls the feeder 13 of the converter facility, the lance motor 15, and the oxygen intake valve 18 to reduce the generated slope, and the blower 6 And a slope suppression step (S50) for smoothly exhausting the flue gas increased due to the slope from the converter (1). The method according to claim 1, In the slope suppressing step S50, the skirt 14 of the converter facility, the old dust collector 3, and the roof spray 11 are further controlled through the controller 17, so that the slag rapidly increases when the slope occurs. And a part of the exhaust gas is discharged through the skirt (14), purified through the furnace dust collector (3) and the roof spray (11), and then discharged into the air. The method according to claim 1 or 2, In the slope generation detection step (S40), when the hood pressure is measured at -150Pa or less, the exhaust gas flow rate per hour is measured at 100,000Nm3 / h or less, and when the carbon monoxide is measured to be less than 40% of the exhaust gas, the slope is generated. Slope suppression method during the converter blow, characterized in that the detection as a point in time. The method according to claim 1, The slope suppressing step (S50) is a step of injecting the sedative into the converter (1) through the feeder 13, and adjusts the height (L2) of the lance (2) through the lance motor (15) The ratio of the height (L2) of the lance 2 to the height (L1) of 1.0) and the flow rate of oxygen per minute blown into the converter (1) via the oxygen intake valve 18 is 2Nm3 / min And adjusting the number of revolutions per minute of the blower 6 so that the hourly exhaust gas flow rate processed through the blower 6 is 180,000 Nm 3 / h or more. Inhibition method. The method according to claim 2, The slope suppressing step (S50) includes a step of opening the skirt 14 or more by 50%, a step of operating the epoch dust collector 3 to the maximum, and a step of operating the loop spray 11 Slope suppression method during converter blow.

Images