JPS6071021A - Exhaust gas treating apparatus of metallurgical furnace - Google Patents

Abstract

PURPOSE:To perform the recovery or exhausion of exhaust gas easily and safely, by cooling the exhaust gas of a molten iron pretreating process, and introducing the same to the inlet side of the second dust collector of a metallurgical furnace exhaust gas treating apparatus through a dust collector with backflow preventing function. CONSTITUTION:The exhaust gas from a molten iron pretreating laddle or furnace 9 is cooled by a cooler 10 and guided to the secondary dust collector 4C of a metallurgical furnace exhaust gas treating apparatus C through an opened change-over valve 15 while dust therein is removed by a molten iron pretreating dust collector 14. Because the operation of this metallurgical furnace exhaust gas treating apparatus C is stopped because of the re-lining of brick and a primary dust collector 3C is sealed by water, the invasion of air from the metallurgical furnace exhaust gas treating apparatus C is blocked and, after the dust in the exhaust gas is removed by a secondary dust collector 4 in such a state that the danger of explosion is removed, the dust removed gas is recovered or discharged. When the molten iron pretreating apparatus is stopped, the dust collector 4 is sealed by water and the molten iron pretreating laddle 9 is isolated while the dust collector 3C is sealed by water to prevent the invasion of the open air into metallurgical furnace exhaust gas apparatuses A, B during operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metallurgical furnace exhaust gas treatment device that makes it possible to treat exhaust gas generated during hot metal pretreatment.

(1) In recent years, in order to produce steel with a high quality, the steel industry pre-treats the hot metal produced in blast furnaces to remove impurities such as phosphorus, silicon, and sulfur contained in the hot metal. It's starting to look like this.

In the hot metal pretreatment process, a large amount of flammable gas is generated at a high temperature (approximately 1500°C) and from the pot or furnace used in this process.

Before explaining the treatment of combustible gas, an overview of the metallurgical furnace exhaust gas treatment system will be explained. In FIG. After the dust is removed by the first dust collector 3 and the second dust collector 4, the changeover valve 8 switches the gas with a high CO concentration to a valuable gas and transfers it to the metallurgical furnace 1.
If the CO gas generated from the exhaust gas treatment equipment leaks outside, there is a risk of carbon monoxide poisoning, and if outside air enters the exhaust gas treatment equipment, there is a risk of explosion, so extreme caution is required. .

(2) Furthermore, since the metallurgical furnace 1 has severe burnout of the lining brick, the wrench must be periodically replaced, and therefore two or more systems of metallurgical furnace exhaust gas treatment equipment are installed.

Now, as mentioned above, leakage of CO gas and intrusion of outside air into the apparatus are not allowed in the metallurgical furnace exhaust gas treatment apparatus, so it is necessary to handle the apparatus itself with care.

For this reason, the gas generated during the conventional pretreatment of hot metal has been treated by a treatment device provided separately from the metallurgical furnace exhaust gas treatment device, as shown in FIG.

In the figure, high-temperature exhaust gas generated from a ladle or furnace 9 for hot metal pretreatment is induced by an induced blower 12, and a cooler 1
After cooling at 0, the dust was removed by a dust collector 11 and emitted from the chimney 13.

As a result, a large and bulky treatment device ranging from the same size as a metallurgical furnace exhaust gas treatment device to about 60 inches is required, and even if good quality steel is obtained, the equipment costs will eventually increase, resulting in high production costs. There was a drawback.

The present invention enables the metallurgical furnace exhaust gas treatment device to treat the exhaust gas generated in the hot metal pretreatment process while satisfying the safety of the metallurgical furnace exhaust gas treatment device, thereby reducing the equipment cost required for the hot metal pretreatment. At the same time, it is an object of the present invention to provide a metallurgical furnace exhaust gas treatment device that also makes it possible to recover combustible gas.

The metallurgical furnace exhaust gas treatment device of the present invention cools the exhaust gas generated in the hot metal pretreatment process with a cooler, and passes the cooled exhaust gas through a hot metal pretreatment dust collector equipped with a backflow prevention function.
It is characterized in that it is connected to the inlet side of the second dust collector of the metallurgical furnace exhaust gas treatment equipment.

An embodiment of the present invention will be described in detail below. In Fig. 3, 1 is a metallurgical furnace, 2 is a cooler, 3 is a primary precipitator,
4 is a secondary dust collector, and 5 is an induced blower. On the other hand, 9 is a hot metal pretreatment pot or furnace. 10 is a cooler for cooling exhaust gas discharged from the hot metal pretreatment ladle or furnace 9.

Reference numeral 14 is a dust collector for hot metal pretreatment which is equipped with a backflow prevention function, and in this embodiment, a water seal check valve is used.

In FIGS. 4 and 5, the primary dust collector 3 of the metallurgical furnace exhaust gas treatment equipment can be water-sealed, and in the case of FIG.
The throat is closed to store water, and the fifth
In the case shown in the figure, the gas inlet is placed in water, creating a reversible gas seal.

In FIG. 6, a hot metal pretreatment device is connected to a plurality of metallurgical furnace exhaust gas treatment devices A, B, and C (normally, steelmaking is equipped with a plurality of exhaust gas treatment devices). In the case of this embodiment, the devices are connected through one dust collector 14 for hot metal pretreatment. In the figure, 14 is a switching valve provided in the duct 16. In FIG. 7, one hot metal pretreatment dust collector 14 is provided for each of the metallurgical furnace exhaust gas treatment devices A, B, and C, and the hot metal pretreatment devices are connected to the metallurgical furnace exhaust gas treatment devices 1-9.

The operation of this embodiment configured as above will be explained.

The metallurgical furnace 1 (see FIG. 1) has an inner surface lined with bricks, and the bricks are burnt out when they come into contact with hot hot metal. For this purpose, the metallurgical furnace exhaust gas treatment equipment will be stopped and brickwork will be carried out i4, while operation will continue using other metallurgical furnace exhaust gas treatment equipment.

To explain using FIG. 6 as an example, metallurgical furnace exhaust gas treatment equipment A, B
It is assumed that the metallurgical furnace 1 is being laid with bricks iζ: by operating C and stopping C.

In this steel plant, metallurgical furnace exhaust gas treatment equipment A,
The primary dust collectors 3A and 3B of H are in an open state and normally pass through the exhaust gas generated from the metallurgical furnace 1 (see FIG. 1).

On the other hand, the primary dust collector 3C of the metallurgical furnace exhaust gas treatment device C is water-sealed, and the exhaust gas from the hot metal pretreatment pot or the furnace 9 is cooled by the cooler 10, and dust is removed by the hot metal pretreatment dust collector 14. After that, it is guided to the secondary precipitator 4C of the metallurgical furnace exhaust gas treatment device C via the opened switching valve 15.

Since the primary dust collector 3c is water-sealed as described above, the exhaust gas led to the secondary dust collector 4C is blocked from entering from the lower opening of the cooler 2 of the metallurgical furnace exhaust gas treatment equipment C. Therefore, there is no risk of explosion, and the dust is cooled and removed, and it can be recovered or dissipated by switching the switching valve 8 (see Fig. 1).

When the hot metal pretreatment device is to be stopped, water is injected into the hot metal pretreatment dust collector 14 to seal it with water, and the hot metal pretreatment pot or furnace 9 is isolated. By isolating the hot metal pretreatment pot or furnace 9 in this way, and by sealing the secondary dust collector 3C with water and sealing the switching valve 15 with water or N2, the metallurgical furnace exhaust gas during operation can be treated. There is no intrusion of outside air into Preparations A and B. The metallurgical furnace exhaust gas treatment equipment uses CO gas instead of CO gas. In the case of a combustion type exhaust gas treatment device that processes gas, the switching valve 15 does not need to be tightly sealed with water or N2.

When restarting the operation of the hot metal pretreatment equipment, the primary dust collector 3C of the metallurgical furnace exhaust gas treatment equipment C is water-sealed, the induced blower 5 (see Fig. 3) is driven, and then the dust collector for hot metal pretreatment is restarted. Drain the water from the vessel 14 and start up.

In the case of the embodiment shown in FIG. 7, the hot metal pretreatment dust collector 14 connected to the metallurgical furnace exhaust gas treatment devices A and H in operation is water-sealed to prevent outside air from entering. The other points are the same as those described in connection with FIG.

As detailed above, the present invention connects the hot metal pretreatment cooling system to the inlet side of the secondary precipitator of the metallurgical furnace exhaust gas treatment equipment via the hot metal pretreatment dust collector having a backflow prevention function. Although the primary dust collector of the metallurgical furnace exhaust gas treatment equipment was sealed to prevent outside air from entering, it was possible to collect or release the exhaust gas emitted from the hot metal pretreatment ladle or furnace.

In addition, we used a dust collector for hot metal pretreatment with a backflow prevention function, which prevents outside air from entering even when hot metal pretreatment is not being performed.
The metallurgical furnace exhaust gas treatment equipment in operation was able to operate safely.

Furthermore, as mentioned above, since the exhaust gas generated from the ladle or furnace for hot metal pretreatment is treated using the metallurgical furnace exhaust gas treatment equipment, there is no need for large-scale treatment equipment, and moreover, the exhaust gas generated from the metallurgical furnace exhaust gas that is not in use can be treated using the metallurgical furnace exhaust gas treatment equipment. Since the processing equipment is used, the operating efficiency of the steel plant can be improved, and high quality steel can be obtained at low production cost, which has excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a metallurgical furnace exhaust gas treatment equipment, Fig. 2 is a system diagram showing a conventional hot metal pretreatment equipment, Figs. Figures 4 and 5 are diagrams showing the water-sealed state of the primary dust collector, Figure 6 is a diagram showing the water-sealed state of the primary dust collector, Figure 6 is a diagram showing the water-sealed state of the primary dust collector, Figure 7 is a system diagram showing the water-sealed condition of the primary dust collector, Figure 7 is a system diagram showing the water-sealed state of the primary dust collector, FIG. 2 is a system diagram showing a hot metal pretreatment device connected to a plurality of metallurgical furnace exhaust gas treatment devices using a processing dust collector. 1... Metallurgical furnace 2... Cooler 3... Secondary dust collector 4... Secondary dust collector 9... Hot metal pre-treatment pot or furnace 10... Cooler 14...・Hot metal pre-treatment dust collector 01 with backflow prevention function Fig. 4 Fig. 5

Claims (1)

[Claims] After cooling the exhaust gas generated from the metallurgical furnace with a cooler,
In a metallurgical furnace exhaust gas treatment system that removes dust using a dust collector and a second dust collector, and collects the exhaust gas via a switching damper or dissipates it from the chimney, the metallurgical furnace exhaust gas generated from the hot metal pretreatment pot or furnace A hot metal pretreatment cooling system that cools exhaust gas with a cooler, and a hot metal pretreatment dust collector that has a function of removing dust from the exhaust gas of the hot metal pretreatment cooling system and preventing backflow, A metallurgical furnace exhaust gas treatment device, characterized in that the exhaust gas outlet side of the pretreatment dust collector is connected to the secondary dust collector inlet side of the metallurgical furnace exhaust gas treatment device.