JPH0377403B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water supply control method for a converter boiler that improves the safety of converter operation and the safety of the converter boiler.

First, an overview of converter operation will be explained. The hot metal produced in the blast furnace is charged into the converter (hereinafter referred to as charging).
be done. Next, pure oxygen is blown into the converter charged with hot metal (hereinafter referred to as blowing), and carbon contained in the hot metal is removed (hereinafter referred to as refining) to produce steel. During this blowing, high temperature and large amounts of CO gas are generated.
After refining, the molten steel in the converter is removed (hereinafter referred to as tapping) and the process moves on to the next step.

Figure 1 shows an outline of the converter factory.
A large amount of high-temperature CO gas generated from the converter 1 during blowing is drawn into the hood 3 by the induced blower 8, cooled by the boiler 5, removed by dust removers 6 and 7, and collected in the gas holder 10. be done.

In addition, exhaust gas with a low CO concentration at the beginning and early stages of blowing is combusted at the top of the tower through the chimney 9 by the switching damper 11, and then released into the atmosphere. In addition, 4
is an oxygen lance for blowing pure oxygen. In this way, in the converter operation, one steelmaking process is completed by each process of charging, blowing, and tapping, and this process is repeated.

Therefore, CO gas is generated from the converter intermittently during each blowing process, and accordingly, the converter boiler is also operated intermittently.

Also, this CO gas is extremely dangerous if it leaks outside, and conversely, there is a risk of explosion if outside air enters the equipment, so keep the converter boiler, dust remover, and other equipment tightly sealed. There is a need.

The outline of the above converter boiler will be explained below. In FIG. 2, the hood 3 and the boiler 5 are formed by a water-cooled wall, into which cooling water is supplied by a boiler circulation pump 13.

The high temperature CO gas generated in converter 1 is transferred to hood 3.
The cooling water absorbs the heat of the CO gas and evaporates.
It is stored in the boiler drum 12. 19 is a steam pipe.

In this way, the heat of the CO gas is absorbed and evaporated, and the steam is consumed by the steam pipe 19, so that the water level in the boiler drum 12 is lowered. In order to compensate for this, water is supplied to the deaerator 16 from the deaerator feed water pump 17, heated and deaerated by the steam supplied from the piping 20, and this water is fed to the boiler by the boiler feed water pump 14. The water is introduced into the drum 12, the water level in the boiler drum 12 is maintained, and the boiler is operated.

Furthermore, since the converter boiler is operated intermittently, the water supply by the boiler feed water pump 14 is also intermittently,
In this control, the rotation speed of the motor 15 is controlled by the rotation speed control device 18, thereby changing the rotation speed of the water supply pump 14, thereby performing water supply control for intermittent operation.

Conventionally, this boiler water supply control has been performed according to a control pattern shown in FIG. Second
To explain with reference to the diagram, as soon as blowing begins,
A large amount of high-temperature CO gas is generated from the converter 1, the cooling water circulating in the hood 3 and the boiler 5 evaporates, and the water level in the boiler drum 12 decreases.

In FIG. 3, this state appears after a certain period of time after the start of blowing, and at this time, the rotation speed control device 1
8 operates at 100%, and accordingly, the motor load power becomes 100%, and the water supply pump 14 becomes rated operation, and the water supply amount to the boiler is also adjusted to the amount corresponding to the amount (rated flow rate). Water was supplied and the water level in the boiler drum 12 was maintained.

In this way, conventionally, when blowing is started and the water level in the boiler drum 12 falls, the rotational speed control device 18 is activated to supply water.

However, for some reason, the rotation speed control device 1
If 8 fails and does not operate, blowing has already started, so the water level in the boiler drum 12 will drop, and if the operation continues in this state, the cooling water will eventually run out and the hood 3 and boiler Not only will the CO gas burn out, but the dust removers 6 and 7 and the induced blower 8 located downstream will also burn out as the CO gas is not cooled and flows at a high temperature, resulting in an extremely dangerous situation. It turns out.

In order to avoid such a situation, there is no other way than to stop the blowing, which will have a negative effect on the refining.

Therefore, conventional water supply control for converter boilers has had major problems in terms of the safety of converter operation and the safety of converter boilers.

The present invention aims to solve the above conventional problems and provide a water supply control method for a converter boiler that improves the safety of converter operation and the safety of the converter boiler.

That is, in the present invention, before the start of blowing, the rotation speed control device is activated, the motor load power is increased, the water supply pump is rotated to the rated rotation speed, and the operation state of the water supply system is confirmed, and then blowing is started. It was made so that
Immediately before the start of blowing, the load power of the water pump drive motor is increased to a certain value, the water pump is rotated at the rated speed, and then blowing is started.
Water is supplied in accordance with the water level in the boiler drum, and at the end of blowing, the rotation speed of the water pump and the load power of the water pump driving motor are reduced in accordance with the water level in the boiler drum.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. In Fig. 4, hot metal produced in a blast furnace is charged into the converter 1, and after T ₁ second and before the start of blowing, the rotation speed control device 18 is activated, and at the same time, the motor load power is increased and the feed water pump is rated. After rotating to the maximum rotation speed and checking the operating status of the water supply system, blowing begins. During the initial few seconds of blowing, the amount of CO gas is small, and therefore the water level in the boiler drum 12 does not fluctuate. Next, entering the peak of blowing, a large amount of
CO gas is generated, the cooling water in the hood 3 and boiler 5 evaporates, and the water level in the drum 12 begins to drop. At this time, a predetermined amount of water is supplied to the boiler drum 12.
Water is supplied within the tank and the water level is maintained. Therefore, at the peak of blowing, the boiler circulation pump 13 circulates cooling water, and the water feed pump 14 pumps the boiler drum 1 by the amount of steam that is removed from the steam pipe 19.
2 and keep the water level in the boiler drum 12 constant to safely operate the converter boiler.

Next, after the blowing is finished, the amount of CO gas generated from the converter 1 decreases, but it is necessary to supply water to the boiler drum 12 by the amount of steam that has already evaporated in the hood 3 and boiler 5. The water supply pump 14 operates for T ₂ seconds after the completion of blowing, and the boiler drum 12
water is supplied inside. When the water level in the boiler drum becomes normal, the rotation speed control device 18 controls the motor 1.
5 and the motor load power also decreases. This completes one steelmaking process.

During non-blowing, the motor 15 is rotated at a low speed by the rotation speed control device 18, thereby reducing power consumption.

As detailed above, according to the water supply control method for a converter boiler according to the present invention, the rotation speed control device is operated to 100% before the start of blowing, the motor load power is increased,
Since blowing is started after confirming that the boiler water supply system operates reliably, if the rotation speed control device malfunctions for some reason and does not operate, blowing will not start. There is no need to stop the refining process midway through, and there is no risk of burnout of the converter boiler or other equipment. In this way, the safety of the converter operation and the safety of the converter boiler are greatly improved, which is an excellent effect.

[Brief explanation of drawings]

Figure 1 shows an overview of a converter factory, Figure 2 is a system diagram of a converter boiler, and Figure 3 shows the relationship between the rotation speed control pattern, motor load power, and boiler water supply amount in the conventional water supply method. FIG. 4 is a diagram showing the relationship over time, which is an embodiment of the present invention, and is a diagram showing the relationship between the rotational speed control pattern, motor load power, and boiler water supply amount over time. 1... converter, 2... skirt, 3... hood,
5... Boiler, 12... Boiler drum, 13...
Boiler circulation pump, 14...Boiler water supply pump,
15...Motor (boiler feed water pump drive electric motor),
16... Deaerator, 18... Rotation speed control device.

Claims (1)

[Claims] 1 Immediately before the start of blowing, increase the load power of the feed water pump drive motor to a certain value and rotate the feed water pump at the rated speed, then start blowing, and during blowing, feed water according to the water level of the boiler drum. A water supply control method for a converter boiler, characterized in that, at the end of blowing, the rotation speed of the water supply pump and the load power of the water supply pump drive motor are reduced in accordance with the water level of the boiler drum.