JPH10287913A - Lance pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lance pipe which can simply and effectively prevent the development of crack. SOLUTION: In the lance pipe 1 linearly fixing many studs 3 in the longitudinal direction on the outer periphery of a steel-made gas introducing core pipe 2 for treating molten metal and formed by laminating prepared unshaped refractories 4 surrounding the core pipe 2 containing studs 3, the studs 3 are arranged in one spiral line so as to becomes single on the horizontal cross section at the stud existing position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lance pipe for blowing gas used in the treatment of molten metal such as deoxidation, desiliconization, dephosphorization and temperature control of molten iron or steel for iron making.

[0002]

BACKGROUND OF THE INVENTION Various gas blowing lance for steel which has been used conventionally, B ₁ in FIG. 4 in FIG. 4 elevational, Figure 5 .about.B
_As shown in the cross-sectional view of each part of FIG.
A large number of refractory supporting V studs b are welded in a radial direction and a longitudinal direction of an outer periphery of the core tube (hereinafter, simply referred to as a core tube),
A mold is assembled around the core tube a at appropriate intervals, and the castable refractory material c is poured and cured between the mold and the core tube a to form a molded article having the shape shown in FIG. is there.

[0003] In the lance pipe for gas injection molded in this way, the elongation of the core tube a in the longitudinal direction becomes extremely large during use due to the influence of the high heat of the molten metal and the erosion of the slag line portion. In addition, the slag line portion is deformed in a curved manner, and cracks are generated in the lining refractories.

In particular, as shown in FIG. 5, a large number of V-studs b are arranged evenly around the outer circumference of the core tube a on one horizontal plane. c had a major drawback of cracking.

[0005]

In order to solve such a problem, for example, Japanese Utility Model Laid-Open No. 58-38771, Japanese Utility Model Laid-Open No. 58-38772, and Japanese Utility Model Laid-Open No. 58-72154.
Gazette, Japanese Utility Model Publication No. 60-28680, Japanese Utility Model Publication No. 62-
Various improved techniques such as Japanese Patent No. 29466 and Japanese Utility Model Publication No. 62-29473 are disclosed.

[0006] That is, Japanese Unexamined Utility Model Publication No. 58-38771 discloses a product in which a large number of core tubes are bundled and fixed, and a refractory material is lined at a portion in contact with a molten metal via a stud. Japanese Patent Publication No. 38772 discloses
A steel pipe for the cooling channel is arranged outside the core pipe, and water or carbon dioxide gas is circulated in the pipe to cool it, and the part in contact with the molten metal is lined with a refractory material. It is an improvement.

In Japanese Utility Model Application Laid-Open No. 58-72154, a plurality of steel core tube reinforcing ribs are provided outside a core tube, and a plurality of wires are buried outside the core tube to provide a fireproof around the core tube. It is a material lined.

In Japanese Utility Model Publication No. Sho 60-28680, an integral large-sized refractory brick preformed at a high pressure by embedding a steel core tube is attached to a slag line portion or a highly damaged portion, and a castable refractory material is provided at a lower portion. It is lining.

In Japanese Utility Model Publication No. Sho 62-29466, an expansion allowance is provided on the outside of the core pipe, and a perm lining is provided around which a refractory sleeve brick or irregular-shaped refractory material is provided, and a stud is provided on the outside. The one fastened with a band is buried in the work lining, and the one disclosed in Japanese Utility Model Publication No. Sho 62-29473 installs a plurality of rails in the length direction of the outer peripheral surface of the core pipe, A large number of sliders with studs are slidably arranged, and the rail tracks are filled or sealed with tape with a solid material that melts or disappears when the temperature rises. The studs are buried in the amorphous refractory layer, all of which are designed for durability of the amorphous refractory layer. Measures such as the conventional example shown in FIG. 5 have been made.

Therefore, although these improved techniques have a certain effect, all of the measures are complicated and large-scale, resulting in a significant cost increase.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lance pipe which can easily and effectively prevent the occurrence of cracks without adding anything to conventional parts. As a solution, the present invention provides a steel gas introduction core pipe for molten metal processing, in which a number of studs are arranged and fixed in the longitudinal direction on the outer circumference of the core pipe, and an irregular refractory is laminated around the core pipe including the studs. In the lance pipe formed as described above, the stud is formed as a single spiral arrangement so as to be single in a horizontal cross section at the stud existing position.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows an elevational view of the outer appearance of a core tube 2 of a lance pipe 1 according to the present invention. Specifically, for example, the outer diameter is 60 mmφ, the length is 4 m (the wall thickness is 5.5 m).
A V-stud 3 is fixed to the outer periphery of the core tube 2 of m) by welding or the like to form a single spiral arrangement in the longitudinal direction.

In this case, the pitch p between the adjacent V studs 3 is about 50 to 80 mm, and the angle formed by the spiral arrangement with the horizontal plane is 30 to 60 °.

If this angle is less than 30 °, the number of windings increases, the number of V studs 3 increases, and the filling property of the irregular refractory 4 deteriorates. Conversely, when the angle is 60
When the angle exceeds 0 °, the number of V studs 3 to be wound decreases, and peeling from the irregular refractory 4 easily occurs. Therefore, most preferred is between 40 and 50 °.

A layer of an amorphous refractory 4 including a V-stud 3 is formed around the core tube 2 to form the lance pipe 1 shown in FIG.

In the embodiment shown in FIG. 2, the refractory 4 has a perm lining 4a having a thickness of 50 mm, an outer work lining 4b having a thickness of 50 mm, and a work lining 4c having an outer diameter of 300 mmφ. It may be a structure.

FIG. 3 shows a state in which FIG. 1 is cut horizontally at an arbitrary position A-A of the V stud 3. According to this cross section, the V stud 3 is formed in the layer of the amorphous refractory 4. Only one exists in the horizontal plane, and therefore, when compared with the conventional product (see FIG. 5) in which many exist, the layer of the amorphous refractory 4 is formed by the V-stud due to the longitudinal extension of the core tube 2 during use. The probability that a crack will be formed from a certain point of 3 is reduced.

According to the experimental results of the component manufactured according to the present invention, the number of charges was about twice as large as that of the conventional product shown in FIGS. 4 and 5.

Although the stud is a V stud in the description of the drawing, it goes without saying that the same effect can be obtained by using a Y stud or the like.

[0020]

As described above, the present invention is constructed as described above. Therefore, the occurrence of the conventional cracks in the circumferential direction is greatly reduced by the present invention, whereby the service life of the gas injection lance pipe can be significantly extended. At the same time, the cost can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is an elevation view showing a part of a core pipe of a lance pipe according to the present invention.

FIG. 2 is an elevational view, partially in section, showing the structure of the lance pipe of the present invention.

FIG. 3 is a sectional view corresponding to AA in FIG. 2;

FIG. 4 is an elevation view of a conventional lance pipe.

FIG. 5 is a sectional view taken along B _{1 to} B ₃ of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lance pipe 2 Core pipe 3 V stud 4 Irregular refractory 4a Perm lining 4b, 4c Work lining

Claims (1)

[Claims] 1. A plurality of studs are fixedly arranged in the longitudinal direction on the outer periphery of a steel gas introducing core tube for molten metal treatment, and an irregular refractory is laminated around the core tube including the studs. A lance pipe, wherein the stud is formed as a single spiral arrangement so as to be single in a horizontal cross section at a position where the stud is present.