KR20060028531A - A nozzle for making iron or making steel - Google Patents

Abstract

The present invention relates to a nozzle that can improve the end structure of the nozzle to improve the life. To this end, the nozzle of the present invention is a nozzle used for manufacturing molten iron or molten steel, and includes a main body in contact with the molten iron or the molten steel, a tip member attached to an end of the main body, and the tip member in a circumferential direction. And a cover member attached thereto.

Nozzle, Steelmaking, Steelmaking, Amorphous Refractory, Heat Resistant Steel

Description

Steel Nozzle for Steelmaking {A NOZZLE FOR MAKING IRON OR MAKING STEEL}

1 is a cross-sectional view of a steelmaking nozzle according to an embodiment of the present invention.

2 is a cross-sectional view of the tuyere according to the prior art.

The present invention relates to a steelmaking nozzle, and more particularly, to a nozzle that can improve the end structure of the nozzle to improve the life.

The steel industry is a key industry that supplies basic materials to the entire industry, including automotive, condition, home appliances, and construction. Various steel making processes and steel making processes are researched and developed to manufacture steel.

The iron making process generally manufactures pig iron by charging a material containing iron ore into a blast furnace and injecting hot air through a tuyere. Representative methods of the steelmaking process are the blast furnace method, but research and commercialization of the COREX method and the FINEX method are actively progressing to solve the problems of supply and demand and environmental pollution of the furnace method.

The steelmaking process removes steel by removing carbon and other impurities contained in iron, which is composed of molten iron preliminary treatment, converter steelmaking, and secondary refining. The converter steelmaking process is a process of removing carbon by charging raw materials, such as molten iron, and blowing oxygen gas into a steelmaking furnace.

As such, in the steelmaking process and the steelmaking process, a certain gas must be supplied for steelmaking and steelmaking. For this purpose, a gas supply part containing oxygen must be present in a furnace or a steelmaking furnace. As an example of such a gas supply unit, FIG. 2 is a cross-sectional view showing a conventional air vent.

As shown in Figure 2, the tuyere is formed with a through hole 130 for supplying gas to the furnace or steelmaking furnace. Cooling holes 113 and 115 are formed in the tuyere to cool the tuyere, and cooling water flows. Conventional tuyere is generally formed of copper.

However, since the tuyere is made of copper, the end of the tuyere located inside the melting furnace or the steelmaking furnace may be damaged in contact with the hot molten iron or molten steel. That is, gas may unstablely flow into the furnace or the steelmaking furnace, and cooling water flowing through the tuyere may flow out of the furnace or the steelmaking furnace. This has a problem of lowering the stability of the steelmaking or steelmaking process, reducing the life of the tuyere, thereby lowering the productivity and efficiency of the steelmaking or steelmaking process.

In order to solve this problem, Japanese Patent Application Laid-Open No. 1994-172834 and Japanese Patent Laid-Open No. 1989-240608 disclose a tuyere with a modified structure of an end portion located in a blast furnace or a steelmaking furnace.                         

Japanese Laid-Open Patent Publication No. 1994-172834 discloses a tuyere in which a ceramic chip is installed at an end of a tuyere and a casting is poured thereon to form a ceramic-metal composite material at the end. However, such a tuyere may cause a crack phenomenon in the manufacturing step, there is a problem in effectiveness.

 Japanese Laid-Open Patent Publication No. 1989-240608 discloses a tuyere in which a ceramic made of chromium oxide is mounted at the end of the tuyere in the form of a ring of a predetermined size. However, such a tuyere has a problem of low economic efficiency because the work process is complicated and expensive ceramics are required.

The present invention is to solve the above-mentioned problems, an object of the present invention is to provide a nozzle for manufacturing steelmaking steel that can be manufactured at a low cost and the life is improved.

The nozzle of the present invention for achieving the above object is a nozzle (nozzle) used for manufacturing molten iron or molten steel, a main body in contact with the molten iron or the molten steel, a tip member attached to the end of the main body, and the tip member It includes a cover member attached while surrounding in the circumferential direction.

The tip member may be made of alumina amorphous refractory. In this case, the tip member may include Al ₂ O ₃ as a main component, and may include at least one or more components selected from the group consisting of SiO ₂ , Fe ₂ O ₃ , CaO, and MgO.

The tip member may be made of magnesia amorphous amorphous refractory. In this case, the tip member may include MgO as a main component, and may include at least one or more components selected from the group consisting of SiO ₂ , Fe ₂ O ₃ , CaO, MnO, and Al ₂ O ₃ .

The cover member may be made of heat resistant steel.

A threaded protrusion may be formed at an end of the main body so that the tip member may be attached to the threaded protrusion.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. These examples are merely to illustrate the invention, but the invention is not limited thereto.

1 is a cross-sectional view of a steelmaking nozzle according to an embodiment of the present invention. As shown in FIG. 1, the steelmaking nozzle according to an embodiment of the present invention includes a main body 10 and a protective part 20 formed at an end of the main body. The steelmaking nozzle is formed with a through hole 30 through which a gas such as oxygen can be supplied to the melting furnace or the steelmaking furnace.

The main body 10 is provided with cooling parts 13 and 15. Cooling water is purified through the cooling units 13 and 15 to cool the nozzles used at a high temperature such as in a furnace. At this time, since the cooling units 13 and 15 are separated from each other to include a cooling unit 13 for cooling the main body in the longitudinal direction and a cooling unit 15 for cooling one end of the main body, even when the nozzle end is damaged, There is no risk of leakage of coolant.

In this embodiment, the one end of the main body 10 is formed with a screw-shaped protrusion 17 protruding along the longitudinal direction of the main body. Threaded protrusion 17 serves to increase the coupling force of the main body 10 and the protection unit 20. The threaded protrusion 17 is cooled by the cooling unit 15 cooling one end of the main body, thereby preventing a shape change that may occur due to the high temperature of the blast furnace or the steelmaking furnace.

At one end of the main body 10, the protection unit 20 is mounted while surrounding the threaded protrusion 17. The protection part 20 includes a tip member 21 formed surrounding the threaded protrusion 17 of the main body, and a cover member 22 attached while enclosing the tip member 22 in the circumferential direction. At this time, the first portion 21 is made of amorphous refractory and the second portion 22 is made of heat resistant steel.

Since the tip member 21 is made of refractory, it serves to protect the tip of the nozzle. Since the refractory material is hard to soften or melt even at high temperatures, the end of the steelmaking nozzle can suppress the nozzle from being damaged even in a high temperature environment. One end of the nozzle is installed in the furnace or the steelmaking furnace to prevent the nozzle from being damaged by exposure to the molten iron or the molten steel. Therefore, it is possible to prevent the cooling water inside the nozzle from leaking into the furnace or the steelmaking furnace due to the nozzle breakage, and to improve the productivity of the steelmaking or steelmaking process by extending the life of the nozzle.

The refractory may be classified into a fixed refractory having a certain shape according to the physical form, and an irregular refractory that can be deformed by kneading or kneading. Facilitates the formation of

That is, the second portion 22 is formed at the outer end of the nozzle, and the amorphous refractory having fluidity is poured into the second portion 22 by mixing with water, followed by curing and drying. Form part 21.

Here, the amorphous refractory uses alumina amorphous refractory or magnesia amorphous refractory. Here, the alumina refractory refers to a refractory mainly composed of Al ₂ O ₃ and may include SiO ₂ , Fe ₂ O ₃ , CaO, MgO, or the like. In addition, the magnesia refractory refers to a refractory mainly composed of MgO, and may include SiO ₂ , Fe ₂ O ₃ , CaO, MnO, Al ₂ O _3, or the like. Alumina refractory and magnesia refractory can have a high melting point to effectively prevent damage to the nozzle due to the molten iron, and the price is low, thereby increasing the productivity.

Hereinafter, the present invention will be described in more detail through experimental examples. These experimental examples are only for illustrating the present invention, and the present invention is not limited thereto.

The nozzle manufactured according to the present invention and the nozzle manufactured by the method according to the prior art were tested in the following manner.

Experimental Example 1

The nozzle of the structure shown in FIG. 1 was produced. Wherein the tip member was formed of alumina amorphous refractory and the cover member was formed of heat resistant stainless steel. The nozzle thus produced was immersed 10 times in molten iron at about 1650 ° C.

Experimental Example 2

The nozzle of the structure shown in FIG. 1 was produced. Wherein the tip member is formed of magnesia amorphous refractory and the cover member is formed of heat resistant stainless steel. The nozzle thus produced was immersed 10 times in molten iron at about 1650 ° C.

Comparative example

The copper nozzle which does not form an amorphous refractory body at the edge part of the tuyere was produced. The nozzle thus produced was immersed 10 times in molten iron at about 1650 ° C.

As a result, in Experimental Example 1 and Experimental Example 2, there was no damage to the end of the nozzle, whereas in the comparative example, the tip of the nozzle was damaged and the coolant flowed out into the furnace or the steelmaking furnace.

That is, in Experimental Example 1 and Experimental Example 2, damage to the nozzle end caused by hot molten iron or molten steel is suppressed. As a result, the cooling water can be prevented from flowing into the furnace or the steelmaking furnace, and the life of the nozzle can be extended.

As described above, according to the steelmaking nozzle according to an embodiment of the present invention, a protective part made of heat-resistant steel and a refractory is formed at the end of the nozzle so as to withstand high temperature molten iron or molten steel. That is, damage at the end of the nozzle is suppressed to prevent the outflow of cooling water. Therefore, the life of the nozzle can be extended and productivity and efficiency can be improved in the steelmaking and steelmaking processes.

In addition, by forming the refractory portion in the threaded projection at the end of the nozzle, the bonding force of the main body and the protection portion can be increased, and the protection portion can be easily formed.

In addition, the protective part alumina amorphous refractory and magnesia amorphous refractory high melting point can effectively prevent damage to the nozzle by the molten iron, and the price is low, it is possible to increase the productivity.

In addition, the cooling unit formed inside the nozzle prevents the expansion of the threaded protrusion that may occur at a high temperature, thereby suppressing the dropping of the protection unit.

Although the present invention has been described above, it will be readily understood by those skilled in the art that various modifications and variations are possible without departing from the spirit and scope of the claims set out below.

Claims (7)

A nozzle used for manufacturing molten iron or molten steel, A main body in contact with the molten iron or the molten steel, A tip member attached to an end of the body, and Cover member attached while surrounding the tip member in the circumferential direction Nozzle comprising a. The method of claim 1, And the tip member is made of alumina amorphous refractory. The method of claim 2, The tip member has Al ₂ O ₃ as a main component and comprises at least one component selected from the group consisting of SiO ₂ , Fe ₂ O ₃ , CaO and MgO. The method of claim 1, And the tip member is made of magnesia amorphous refractory material. The method of claim 4, wherein The tip member is a nozzle composed of MgO as a main component and at least one component selected from the group consisting of SiO ₂ , Fe ₂ O ₃ , CaO, MnO and Al ₂ O ₃ . The method of claim 1, The cover member is a nozzle made of heat-resistant steel. The method of claim 1, And a threaded protrusion formed at an end of the main body such that the tip member is coupled to the threaded protrusion.

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