KR200316238Y1 - Bubbling pipe used for impurity oxidation in hot metal pre-treatment process - Google Patents

Abstract

The present invention relates to a bubbling pipe, the bubbling pipe according to the present invention operates the molten iron preliminary treatment equipment for the operation of producing high-quality steel in the steelmaking industry, the molten iron preliminary treatment is a impurities contained in the molten iron ( High pressure reactive Cax (CaO based, CaCO ₃ based, MgO based, Na ₂ CO ₃ based, etc.) is forcedly applied using a lance to remove P), sulfur (S) and silicon (Si). Gaiters are subjected to hot and cold repetitive work to remove impurities that adversely affect the steel properties. LANCE used in this process is coated with refractory on long pipe (PIPE) and then used in molten iron, so it is structurally very unstable according to the physicochemical properties of pipe steel and refractory, and thermal shock by repeated hot and cold work. And the life of the lance is reduced due to the spalling phenomenon, dropping by the high-pressure gaiters, erosion by the reaction with Flux, crack generation due to expansion of the pipe (PIPE). The present invention draws attention to the economical effect of designing a bubbling pipe in the production method different from the above described lance pipe to suppress the damage of the refractory due to the expansion of the pipe to extend the life cycle by increasing the number of uses.

Description

Bubbling pipe used for impurity oxidation in hot metal pre-treatment process}

The present invention relates to a bubbling pipe for removing impurities during molten iron preliminary treatment. More specifically, the molten iron drawn from the blast furnace is charged into a torpedo ladle car, which is a molten iron container, and then, between the blast furnace and steelmaking It is used in the charter preliminary treatment process, which improves the quality of LANCE pipes such as DEPHOSPHORIZATION and DESULPHURIZATION to remove a large amount of impurities contained in molten iron. The present invention relates to a high quality bubbling pipe considering the coefficient of thermal expansion away from the method of coating the refractory on the surface of the pipe to extend.

Conventionally used lance pipe is composed of a pipe 10 and a steel mesh 11, as shown in Figure 1, in the case of the steel mesh 11 is composed by simply weaving a steel wire in the form of a net, steel mesh 11 After the coil 12 is mounted on the pipe 10, the refractory 13 is constructed.

Here, the steel net 11 is constructed by refractories 13 on the pipe 10 while spalling and cracking due to thermal expansion coefficient difference between the pipe 10 and the refractory 13 are generated and secured. In order to prevent the binding and spalling of the refractory (13) by installing between the pipe (10) and the refractory (13).

However, this conventional improvement method does not show a significant improvement effect. That is, when the fracture surface and surface condition of the lance pipe used two or three times were observed, when the surface of the pipe 10 swelled and the refractory was broken or cracks occurred in the transverse and longitudinal axes, the refractory fell off and repeated. It has been confirmed that there are big problems in using it (more than 6 times).

In addition, it is difficult for stable long-term use of the lance pipe because the environment in the TLC is very severe such as chemical erosion due to the reaction with slag or flux in the molten iron, generation of low melting point by chemical reaction, and melting loss due to this. There is this.

The present invention is to solve the above problems, the object of the present invention is to overcome the different coefficient of thermal expansion between the pipe and the refractory to prevent breakage of the external refractory by the expansion of the pipe to ensure durability and lifespan by repeated operation It is to provide a bubbling pipe for preliminary treatment of molten iron, which is a high-pressure jet passage of a highly reactive flux that can be extended.

Another object of the present invention in connection with the above object is to form a sleeve of a certain size by molding a highly refractory material into a press, as opposed to a castable method using a conventional refractory material in water to combine the refractory sleeve in the pipe The present invention is to provide a bubbling pipe for preliminary treatment of molten steel so that the molten steel does not penetrate, thereby enabling long-term use.

1 is a cross-sectional view showing a conventional lance pipe.

2 is a view illustrating a state of use of a general bubbling pipe.

3 is a cross-sectional view illustrating a bubbling pipe according to the present invention.

4 is a cross-sectional view illustrating a sleeve installed in a bubbling pipe according to the present invention.

5 is an enlarged exploded view of a mesh installed in a bubbling pipe according to the present invention.

6 is an enlarged cross-sectional view of the bubbling pipe according to the present invention.

7 is a cross-sectional view showing another embodiment of a bubbling pipe according to the present invention.

FIG. 8 is a perspective view illustrating a bent sleeve installed in the bubbling pipe of FIG. 7.

** Description of the symbols for the main parts of the drawings **

100 ... bubbling pipe

200 ... pipe

300 ... sleeve

400 ... thermal expansion space

500 ... Metal Mesh

Bubbling pipe for molten iron preliminary treatment according to the present invention for achieving the above object is used in the T.L.C equipment during molten iron preliminary treatment pipe having a straight portion and a curved portion to remove impurities; A plurality of sleeves mounted on an outer side of the pipe to protect the pipe and made of a heat resistant material; A stepped portion formed at an end portion of the sleeves positioned in the straight portion of the sleeve and overlapping the coupling portions of the sleeves coupled to each other; And a thermal expansion space formed between the inner diameter of the sleeve and the outer diameter of the pipe.

Preferably, the sleeve positioned at the curved portion is integrally formed, and a metal mesh is inserted between the curved portion and the sleeve of the pipe, and a refractory is coated on the outside of the metal mesh.

Also preferably, the sleeve positioned at the curved portion is formed of a plurality of stages.

Hereinafter, preferred embodiments of the bubbling pipe for molten iron preliminary treatment according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, the bubbling pipe 100 for hot water preliminary treatment according to the present invention is used in a TLC facility and has a pipe 200 having a straight portion 210 and a curved portion 220 to remove impurities. In order to protect the pipe 200, it is mounted on the outside of the pipe 200 and has a plurality of sleeves 300 of heat resistant material.

As shown in FIG. 3, the end portions of the straight sleeves 300 positioned in the straight portion 210 of the pipe 200 among the sleeves may have a stepped portion for overlapping portions of the sleeves 310 coupled to each other. 301 is formed. In addition, a thermal expansion space 400 is formed between the inner diameter of the sleeve 300 and the outer diameter of the pipe 200 as shown in FIG. 6.

Also, the curved sleeve 310 may be integrally formed as shown in FIG. 3, or alternatively, the curved sleeve 320 may be formed by dividing the curved sleeve 320 into a plurality of stages as illustrated in FIGS. 7 and 8. . In this case, in the curved sleeve 310 of FIG. 3, a metal mesh 500 as illustrated in FIG. 5 is inserted and installed between the curved portion 220 and the sleeve 310 of the pipe 200. And to the outside of the metal mesh 500 is provided with a refractory coating.

Hereinafter, the use and working conditions of the bubbling pipe for molten iron according to the present invention will be described.

The use of the bubbling pipe for the molten iron preliminary treatment according to the present invention is used to remove impurities contained in the molten iron 22 inserted into the TLC 20 carrying the molten iron as shown in FIG. Therefore, the outside of the pipe 100 should be protected with refractory to suppress melting and sedimentation by the molten iron 22.

The molten iron 22 of the TLC 20 is pulled out of the blast furnace and contains a large amount of impurities and slag 21. The upper portion of the molten iron 22 solidifies with time so that the bubbling pipe 100 can be introduced. In order to suppress this, the insulation 22 is added to impart fluidity to the upper surface. The upper part of the bubbling pipe 100 introduced into the molten iron 22 is exposed to the outside, so there is no problem in using it for a long time, but the middle part is bubbling pipe 100 due to the reaction between the slag 21 and the flux floating in the molten iron 22. Will cause great damage to the refractory.

In addition, the lower part of the pipe 100 is an outlet through which high reactivity flux is discharged, and the outside of the pipe 100 maintains a high temperature by the molten iron 22. However, the inside of the pipe 100 ejects the flux at a high pressure. You will receive a lot.

As a result, the refractory outside the pipe 100 is the above-described configuration in order to suppress the occurrence of cracks due to thermal expansion after the reaction with the slag and flux and the pipe 100 is moved out of the molten iron 22 of the TLC 20. As in the description of the refractory sleeve 300 is used.

The bubbling pipe 100 according to the present invention is a sleeve 300 using a high fire-resistant material is fastened to the stepped portion 301 of the concave-convex shape, but the above-described method of manufacturing an outlet that is the end of the pipe 100 Two other embodiments are provided as described in the configuration.

In FIG. 3, the curved sleeve 310 is integrally formed. In addition, in FIGS. 7 and 8, the refractory sleeve 320 is not caught by a rounded portion of the pipe 100 when the refractory sleeve 320 is assembled in a manner of fastening the sleeve 320 in multiple stages. ) Is designed to be separated into maximum and bonded with high temperature ceramic bond.

Alternatively, as shown in FIG. 5, the metal mesh 500 used to insert the two rows of steel metal meshes 500 into the pipe 200 to improve the coupling force between the pipes 200 and the sleeves 310 and 320 is provided. Was bent to the wire itself rather than the general wire to be installed on the pipe 200 surface to maximize the contact surface of the sleeve (310, 320). In addition, the bending of the wire wavelength type was intended to suppress the increase in the binding strength of the refractory and the spalling (shock) phenomenon by the wave wire absorbs the external shock and acts as an anchor at the same time.

On the other hand, the straight portion sleeve 300, although the step portion 301 is coupled by a high-temperature ceramic bond. A multi-stepped stepped portion 301 is formed as a safety device to prevent the pipe 100 from being damaged by defects or microcracks that may occur in the sleeve joint due to thermal expansion and contraction inside the TLC 20. .

The stepped portion 301 is designed for the purpose of extending the life of the bubbling pipe 100 by protecting the pipe even if molten steel penetrates.

6 is a view showing the process of assembling the refractory sleeve 300 and the internal state of the pipe 200, the most noteworthy point here is that of the sleeve 300 is coupled to the pipe 200 rather than the outer diameter of the pipe 200 The inner diameter is made slightly larger to secure the thermal expansion space (400).

The movement of the sleeves 300 coupled by the thermal expansion space 400 is fixed by using a ceramic bond and gives only a space to the left and right. This thermal expansion space 400 is a thermal expansion space of the inner pipe 200. . Existing design is because there is no space between the pipe and the refractory because the construction of the refractory on the pipe does not endure the thermal expansion of the pipe when it is injected into the molten steel and cracks occur on the surface of the refractory, but in the present design the thermal expansion space (400) that the pipe is thermally expanded In addition, external refractories can suppress the occurrence of microcracks and other defects due to pipe thermal expansion.

The bubbling pipe according to the present invention is a pipe and refractory with different thermal expansion coefficients due to repeated hot and cold working environment, the internal stress is generated due to expansion and contraction, so that the microcracks grow during long repetitive work. Initially, it grows vertically and laterally laterally. The bubbling pipe according to the present invention secures the expansion space of the pipe with a large coefficient of thermal expansion between the inner pipe and the outer refractory sleeve, thereby causing microcracks in the refractory. Not to. In the repetitive work, the microcracks grow and eventually cause a breakdown of the refractory, and the breakage of the refractory means a loss of the pipe, so that no further impurities can be removed. As the life of the pipe is shortened as above, the cycle and replacement time of the pipe is increased, which wastes a lot of work time, and the number of pipes required increases compared to a certain amount of work, resulting in economic loss due to the cost increase during operation. Is reduced, but in the case of bubbling pipes according to the present invention, it is possible to secure the economics due to a lot of cost savings by increasing the average number of times of use.

Claims (3)

A pipe having a straight portion and a curved portion to be used in a T.L.C facility to remove impurities during the molten iron preliminary treatment; A plurality of sleeves mounted on an outer side of the pipe to protect the pipe and made of a heat resistant material; A stepped portion formed at an end portion of the sleeves positioned in the straight portion of the sleeve and overlapping the coupling portions of the sleeves coupled to each other; And a thermal expansion space formed between the inner diameter of the sleeve and the outer diameter of the pipe. The method of claim 1, wherein the sleeve positioned in the curved portion is integrally formed, a metal mesh is inserted between the curved portion and the sleeve of the pipe, and the refractory is coated on the outside of the metal mesh. Bubbling pipe for molten iron preliminary treatment. The bubbling pipe according to claim 1, wherein the sleeve positioned at the curved portion is formed of a plurality of stages.