KR20020051386A - Device and method to remove dusts generated from ladle of iron-making plant - Google Patents

Abstract

PURPOSE: An apparatus and a method for suppressing dust are provided to suppress dust which is generated from the upper part of a continuously moving ladle in a steelmaking plant and pollutes the plant. CONSTITUTION: In a dust suppressing apparatus for reducing a dust amount generated from a ladle(L) in a steelmaking plant, the apparatus for suppressing dust generated from the ladle comprises a crane(2) which is installed at the ceiling of the plant to transfer the ladle after hooking hooks(14) into lugs of the ladle; a nitrogen storage tank(4) which is installed at the crane so that it is moved along with the crane; a pipe(6) connected to the nitrogen storage tank; and a nozzle(8) connected to the end part of the pipe. In a dust suppressing method using the dust suppressing apparatus for reducing a dust amount generated from a ladle in a steelmaking plant, the method comprises the process of ejecting nitrogen to the inner side of the ladle by controlling a nitrogen amount proportionally to a size of the ladle, wherein an appropriate nitrogen ejection amount is maintained to 150 Nm¬3/min or more in case of a ladle having an inner diameter of 4.64 m and an inner height of 4.75 m.

Description

Device and method to remove dusts generated from ladle of iron-making plant}

The present invention relates to a steel making facility, and more particularly, to a dust suppression apparatus and method generated in the ladle that can effectively suppress the dust generated in the ladle after the pig iron contained in the converter.

In the steel making plant, molten pig iron is placed in a ladle to remove excess carbon contained in the molten pig iron, poured into the converter, and oxygen is injected into the converter to reduce the carbon content of pig iron.

In this process, dust is generated in various places, but most of the dust generated in the fixed facilities is sucked with air from the dust suction hood installed at the top of the fixed equipment, and the dust inside the sucked mixed air is separated from the dust collector, Allow clean air to escape.

The dust suppression method in such a fixed installation has been commercialized by a very common technology has been applied in various ways.

However, dust is also generated in ladles that continue to move to carry pig iron, especially in empty ladles after pouring pig iron into the converter than when it contains pig iron.

This is because the air contact surface of the empty ladle is wider and the temperature of the contact surface exposed to air immediately after discharging the molten iron is high.

Another reason for the large amount of dust generated is that it is not possible to install a hood on top of the continuously moving ladle, so dust generated in the ladle is not collected and is discharged into the factory to contaminate the factory.

It is pointed out as a chronic problem because there is no measure to solve these problems.

Meanwhile, according to the dustsuppression during casting of Integrated Pollution, Prevention and Control, page 189 of the well-known technology "IPPC Draft Reference Documet on BAT in Iron and Steel industry 1998", when the pig iron produced in the blast furnace is poured into topedoca, It is a technology that can reduce the amount of dust generated by injecting gas to create an inert atmosphere.

However, this known technique has been used as a means for reducing the amount of intake air in the dust collection hood installed in a fixed installation.

It is an object of the present invention to provide a dust suppression apparatus and method for suppressing dust generated at the top of a continuously moving steel mill ladle to contaminate a plant.

1 is a schematic view showing a dust suppression device generated in the ladle according to the present invention.

<< Explanation of symbols for main part of drawing >>

2 ... crane 4 ... nitrogen storage tank

6 ... Piping 8 ... Nozzle

10 ... frame 12 ... cab

14 ... hook

L ... ladle

In order to achieve the object described above, the dust suppression apparatus of the present invention, the crane is installed in the factory ceiling to hook the hook to the lugs of the ladle and then transport; A nitrogen storage tank installed in the crane and movable with the crane; Piping connected to the nitrogen storage tank; And a nozzle connected to the end of the pipe.

And dust suppression method of the present invention is characterized in that the injection of nitrogen to the inside of the ladle, by adjusting the amount of nitrogen in proportion to the size of the ladle.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a schematic view showing a dust suppression device generated in the ladle according to the present invention.

The mechanism of dust generation in the ladle is that the remaining amount of pig iron and slag in hot molten state is attached to the inner surface of the ladle immediately after the pig iron is poured into the converter, and oxides are rapidly generated by reacting with the melt and oxygen in the air. Let's do it.

Dust suppression apparatus according to the invention is a crane (2) installed on the ceiling of the steel mill, the nitrogen storage tank (4) installed on the crane (2) and move together, the pipe (6) connected to the nitrogen storage tank (4) And a nozzle 8 provided at the end of the pipe 6.

The crane 2 is composed of a hook 14 installed in the lower end of the frame 10 so that the cab 12 is installed in the frame 10, the ladle (L) can be lifted.

By supplying nitrogen to the inner space of the ladle (L) by using the dust suppressor having such a configuration to suppress the generation of dust due to oxidation on the inner surface of the ladle (L), or the dust collecting hood on the upper It is possible to keep the plant clean by minimizing dust generation in the ladle (L) without installing.

Example 1

The analysis results of the dust generated in the steel mill are shown in Table 1 below.

ingredient SiO ₂ Na ₂ O K ₂ O CaO MgO PbO Cr ₂ O ₃ Al ₂ O ₃ MnO ZnO T-Fe content(%) 3.45 0.98 3.86 9.74 4.41 0.33 0.04 0.39 2.31 6.16 40.91

As shown in the table, it can be seen that the main components are oxides of pig iron and slag.

Example 2

1kg of iron was added to the heat-resistant crucible and melted for 1 hour in a melting furnace at 1600 ° C. Then, it was taken out and moved in a circumferential direction to increase the contact area between molten iron and air and to maintain the contact area in the molten state. A small amount of dust was generated at the contact surface between iron and air.

Example 3

1kg of steel slag was put into a heat-resistant crucible and melted for 1 hour in a melting furnace at 1600 ° C. A large amount of dust was generated at the contact surface of slag and air. Therefore, it was confirmed that more dust is generated in the molten slag than in the molten iron.

Example 4

Experiments similar to those of Examples 3 and 4 above were carried out by spraying nitrogen on top of the heat-resistant crucible. The amount of injected nitrogen should be sprayed to the extent that the molten surface can minimize contact with oxygen. At this time, the higher the amount of nitrogen injected, the less dust was generated.

However, it is not desirable that the ladle is cooled too much because the amount of nitrogen injection is too high. Therefore, it is necessary to determine the appropriate nitrogen amount. In one embodiment, the appropriate nitrogen injection rate is 150 Nm ³ / min in a ladle with an inner diameter of 4.64 m and an inner height of 4.75 m.

In addition, the smaller the ladle size, the smaller the amount of nitrogen to be injected, the larger the larger the amount of nitrogen must be injected. The injection of nitrogen is preferably carried out only during the period of discharging the molten iron into the converter and then moving to the molten iron treatment plant.

As described above, the present invention continuously removes dust by injecting nitrogen stored in a nitrogen storage tank through a pipe and a nozzle to the upper part of the ladle where the dust suction hood cannot be installed. It is possible to suppress the occurrence, thereby maintaining a clean environment by reducing the dust concentration in the factory.

Claims (3)

In the dust suppression apparatus for reducing the amount of dust generated in the ladle of the steel mill, A crane installed at the ceiling of the factory and transferring the hook to the lugs of the ladle; A nitrogen storage tank installed in the crane and movable with the crane; A pipe connected to the nitrogen storage tank; And Dust suppressor generated in the ladle comprising a nozzle connected to the end of the pipe. In the dust suppression method using a dust suppression device used to reduce the amount of dust generated in the ladle steel mill, Injecting nitrogen to the inside of the ladle, dust suppression method generated in the ladle, characterized in that for controlling the amount of nitrogen in proportion to the ladle spraying. The dust generated in the ladle according to claim 2, wherein the ladle having an inner diameter of 4.64 m and an inner height of 4.75 m is sprayed while maintaining an appropriate nitrogen injection amount of 150 Nm ³ / min or more. Inhibition method.