KR900000085B1 - Method of operation of exhaust-gas treatment system of sealed-tape converter under abnormal conditions - Google Patents

Abstract

The emergency operation method includes stopping the refining operation when abnormality is detected, opening an emergency airtake valve while keeping the opening degree of the converter pressure damper in the continuous controlled open state, lifting the skirt to admit ambient air into the exhaust hood, and then completely opening the damper.

Description

Abnormal operation method of closed converter flue gas treatment device

1 is a schematic diagram showing the entirety of a converter flue gas treatment system.

2 and 3 are diagrams showing the conventional operation method, and FIG. 2 is a diagram showing the relationship between the furnace pressure control damper opening, the amount of attracted gas of the induction blower, the amount of converter gas and the skirt level.

FIG. 3 is a diagram showing a change in furnace pressure when operating in the relationship of FIG. 2, and FIG. 4 and FIG. 5 are diagrams showing one embodiment of an abnormal operation method of the present invention.

4 is a diagram showing the relationship between the furnace pressure control damper opening, the amount of attracted gas of the manned blower, the amount of generated converter gas, and the skirt level.

FIG. 5 is a diagram showing changes in furnace pressure when operated in the relationship of FIG. 4. FIG.

* Explanation of symbols for main parts of the drawings

1: converter 2: skirt

7: manned blower 12: furnace internal pressure control damper

TECHNICAL FIELD The present invention relates to a method of operating a closed type converter flue gas treatment device which operates in a closed or near closed state when an abnormal situation occurs in a converter operation and stops blowing.

First, the outline of the converter flue gas treatment system will be described using FIG.

In the drawing, the gap between the converter 1 and the hood 3 is sealed by the skirt 2 and the pure oxygen is blown from the oxygen blowing lance 11, and the carbon in the molten iron in the converter 1 Reaction is refine | purified (Hereinafter, this is called blowing).

At this time, a large amount of CO gas is generated. The CO gas is attracted into the hood 3 by the induction blower 7, cooled by the hood 3 and the cooler 4, and then dust is removed by the dust collectors 5 and 6 to obtain oil oil gas. It is stored in the gas holder 10.

This CO gas is not only very dangerous because it causes carbon monoxide poisoning if it leaks to the outside, but also burns rapidly in response to the outside air, and there is also a risk of a so-called explosion that burns instantaneously if it occurs in a low temperature region of the CO gas.

For this reason, in the normal converter operation, the internal pressure of the furnace is set to negative pressure by adjusting the opening degree of the furnace internal pressure control damper 12 in order to avoid leakage of CO gas to the outside.

For this reason, outside air is sucked from the gap between the furnace port and the skirt, at the expense of lowering the CO gas concentration.

However, in recent years, in order to increase the value of CO gas as a valuable gas, rare water of high purity CO gas is required.

In order to satisfy this demand, recent flue gas treatment systems have a structure in which the converter 1 and the skirt 2 are completely sealed or closer to the sealed state.

In this way, the operation when an abnormal condition occurred in the exhaust gas treatment apparatus before the sealed structure was performed as follows.

For example, when the manned blower stops due to a blackout, the oxygen blower is stopped and at the same time the opening degree of the furnace internal pressure control damper is expanded to use the manned blower that is rotated by the inertia force. The outside air is sucked from the gap between the and the combustion chamber, and the CO gas before cooling in the high temperature zone is combusted to form a CO ₂ gas layer, which is directly cooled by the CO ₂ gas and is in direct contact with the outside air being sucked into the CO gas in the apparatus. To prevent the explosion in advance.

However, in the exhaust gas treatment system in which the converter between the furnace furnace and the skirt is in a state of being closed or close to the seal, the exhaust gas treatment device cannot suck outside air from the gap between the furnace hole and the skirt, and even if it sucks, the amount is small. There is a problem that generation of a CO ₂ gas layer is insufficient.

Therefore, this closed type exhaust gas treatment device is provided with a special emergency air suction device 14 for sucking outside air.

In this hermetic flue gas treatment system, a conventional converter operation method in an emergency is performed as follows.

As shown in FIG. 2, the internal pressure control damper is developed at the same time as the occurrence of an emergency and at the same time as the interruption of blow (A point) (curve D). In addition, the damper 14a of the emergency air intake device 14 is opened by the signal for stopping blowing from the abnormality occurrence detection device 15.

However, there is a time delay of point AB, as shown in Fig. 2, until the damper of the emergency air intake device is developed after receiving the signal of the blow off, and the pressure in the furnace drops rapidly as shown in Fig. 3. do.

In this way, if the internal pressure decreases in a short time, the exhaust gas treatment device is not constructed to withstand a large negative pressure, so there is a risk of explosion due to air intrusion from an unexpected place.

In addition, if the pressure in the furnace drops sharply, a large amount of air enters from the emergency air intake device in an instant, and if the air reaches a low temperature zone without reacting with the internal CO gas, there is a risk of explosion.

Moreover, in FIG. 2, the line F raises the skirt 2 to the position of the imaginary line as indicated by the arrow R in FIG. 1 in order to attract outside air, thereby increasing the gap between the furnace port and the skirt. Indicates the level of the skirt. Line G represents the amount of gas generated from the converter. Curve E shows the amount of attracted gas in the manned blower.

As described above, in the conventional operation method in which the pressure control damper is developed at the same time as the blowdown stop and the damper of the emergency air suction device is opened by receiving the signal of blowdown stop, the pressure in the furnace drops rapidly and there is a risk of explosion. There was a flaw.

An object of the present invention is to provide a method for operating a closed converter flue gas treatment device of high safety and to prevent the furnace pressure from being drastically reduced by solving the above drawbacks.

According to the present invention, the control damper is not developed at the same time as the interruption of the blow, but the blow is stopped and the damper of the emergency air suction device is opened, and the opening degree of the furnace internal pressure control damper is maintained at the opening degree at the time of blow interruption. The skirt is raised in the state, and the opening degree of the furnace internal pressure control damper is opened to a predetermined opening degree.

An embodiment of the present invention will be described in detail. The emergency air suction is installed in the hood as close to the furnace as possible. It demonstrates in FIG. 1 and FIG.

In the case of an emergency, the blowing is stopped (point A). At this time, the furnace internal pressure control damper 12 is maintained at the damper opening degree when the blowdown is stopped. At this time, the attracted gas amount of the attracting blower 7 becomes the amount of gas at the time of blow interruption as indicated by the curve (E). In response to the signal of blow interruption, the emergency air suction device 14 is operated to delay the blow interruption (point A) for a predetermined time (point B) so that the damper 14a operates and expands.

At this time, the furnace internal pressure control damper 12 is maintained at the opening degree at that time, so the sum of the amount of outside air sucked from the emergency air suction device 14 and the amount of CO gas (line G) generated from conduction due to the interruption of blow operation are controlled by the furnace internal pressure. The amount corresponding to the opening degree of the damper 12 is balanced so that the reduction of the CO gas generated from the converter and the increase of the outside air sucked from the emergency air suction device 14 are balanced so that the outside air enters the furnace and the furnace pressure does not suddenly change. maintain.

After a certain time (D 'point after a few seconds), opening of the furnace pressure control damper 12 is started (line D), and the skirt 2 is slightly delayed than opening of the damper 12. Air is released (line F), and the air that fits the opening degree of the furnace pressure control damper 12 is formed by the sum of the outside air sucked from the gap between the furnace port and the skirt 2 and the outside air from the emergency air suction device 14. Aspirated into the furnace.

The outside air sucked into the furnace in this way reacts with CO gas (line G) generated from the converter 1 at the time of blowdown to become CO ₂ gas, and the CO gas previously cooled and stored in the exhaust gas treatment device is the CO ₂ gas layer. It is blocked by outside air which is later sucked by.

Fig. 5 shows changes in the furnace pressure when this operation method is implemented.

Blowing is stopped at the point A in the drawing, and the furnace pressure control damper 12 is maintained at the opening degree at that time. In addition, the emergency air suction device 14 is operated by receiving the signal of interruption of blowing, and the outside air is sucked in (B). In this case, a time delay from the point of blow interruption (A) to the point at which the emergency air suction device 14 is operated to attract the outside air (B) occurs and is sucked by the induction blower 7 during this time delay, The furnace pressure decreases in an instant. It is sensitive because it is sealed.

However, since the opening degree of the furnace internal pressure control damper 12 is maintained at the opening degree at that time, the attraction amount of the attracting blower 7 is limited, and the difference between the amount of CO gas reduced by the blowdown and the attraction amount acts as the attraction force of the converter furnace section. This lowers the furnace pressure. Therefore, the fall in the furnace pressure at this time is very slight.

Next, after a certain time (a few seconds later), the furnace internal pressure control damper 12 reaches the deployment position and draws outside air from the gap between the furnace port and the skirt as the rise of the skirt 2 is continued.

In this case, the operation of the elevator of the skirt 2 and the opening speed of the furnace internal pressure control damper 12 do not necessarily coincide, and there is a pressure fluctuation as indicated by point C in accordance with the change of the time.

The pressure fluctuations in this case are also very small.

As described in detail above, according to the operating method of the closed converter flue gas treatment device of the present invention, the blowing is stopped in an emergency to maintain the opening degree of the furnace pressure control damper at the opening degree when the blowing is stopped, so that the outside air is sucked from the emergency air suction device. The attraction of the manned blower is suppressed, the blowdown is stopped and the CO gas is reduced, but the pressure in the furnace does not drop rapidly.

After a certain time, the furnace pressure control damper was developed to raise the skirt to draw a large amount of outside air from the furnace port and the skirt, so that a sufficient CO ₂ gas layer could be generated.

In this way, it is possible to eliminate the sudden change in the pressure in the furnace and to generate a sufficient CO ₂ gas layer, so that a large amount of air does not enter the emergency air suction device at the time of blowdown, and all the invaded air is CO gas. And no unexpected intrusion of outside air from other parts of the flue gas treatment system, and a large amount of CO ₂ gas layer is generated, so there is no risk of explosion of the closed converter flue gas treatment device, and it can be a safe or reliable flue gas treatment device. It has such an outstanding effect.

Claims (1)

In the closed converter flue gas treatment system, when the converter operation abnormality occurs, the blowdown is stopped, the emergency air intake device is opened, and the opening degree of the furnace pressure control damper is maintained at the opening degree when the blowdown is stopped.In this state, the skirt is raised and the furnace pressure control is performed. An abnormal operation method of a closed converter flue gas treatment device, characterized in that the opening of the damper to a predetermined opening.

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