JPH0735528B2 - Lance pipe refractory coating method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating a refractory material on a lance pipe for bubbling gas or flux into a molten metal or injecting it.

BACKGROUND ART Lance pipes for bubbling gas or flux into molten metal or for injecting lance pipes are known to have a thick refractory coating of 30 to 200 mm and a thin coating of 5 to 30 mm. There is.

Conventionally, the following two main methods have been known as methods for coating the latter lance pipe with a thin refractory material.

One of them is to insert a core metal pipe into the center of the frame like an extruder, pressurize and push out a plastic refractory material around the core metal pipe, and press the core metal pipe at a constant speed. It is a method of pulling out.

In this method, the refractory material was limited to the refractory material having sufficient plasticity and good adhesiveness, and the refractory material to which the metal fiber was added or the low moisture castable refractory material could not be coated.

Another method is a method in which a core metal pipe is installed in a casting frame body, a plastic refractory material is poured into the frame body, and the refractory material is coated around the core metal pipe.

Compared with the former method, this method has an advantage that the range of refractory materials that can be coated is expanded and that other good characteristics can be utilized even if the characteristics of plasticity and adhesiveness are not sufficiently good.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the latter method described above, as shown in FIGS. 3 and 4, the core metal pipe 2 is installed in the frame body 1 whose cross section is recessed in an arc shape or a rectangular shape, Pouring refractory 4 from the opening 3 of
As shown in FIG. 5, the core metal pipe 2 was installed in the frame body 1 having a split structure along the axis, and the refractory material 4 was poured from the opening 3 in the upper part.

However, in the cases of FIGS. 3 and 4, the thickness of the refractory material remarkably differs depending on the site, and under the usage conditions of high temperature rapid quenching and rapid cooling of the lance pipe, it is weak against heat spalling and the refractory material is efficient. It is difficult to remove from the mold because the resistance of the vertical surface is large when the mold is removed from the mold after it is not used.

Also, in the case of FIG. 5, although the above problems are solved, if the opening on the upper surface of the frame is large, the thickness of the refractory material at that part becomes thin, and the same as other parts. If so, there is a problem that the opening becomes very narrow, which makes it difficult to pour the refractory.

Means for Solving the Problems The present invention has been made in view of the above points, and in order to solve the above problems, bubbling gas or flux in the molten metal, or a lance pipe for injection. The core metal pipe is installed in the central portion of the frame body having a polygonal hollow section having a pentagonal or more cross section in a split configuration along the axial direction with one side open, and one of the frame bodies having the above polygonal cross section is installed. (EN) A method for coating a refractory material for a lance pipe, characterized in that a predetermined refractory material is poured into a cavity from an opening on a side surface to coat the refractory material around a cored bar pipe, and the mold is removed and molded. .

Effects According to the present invention, the addition of metal fibers, which has made significant progress in other fields of refractories, is achieved by the opening of one side of the polygon of the frame having the polygonal cavity having a pentagonal cross section or more. Refractory and low moisture castable refractory can be poured with good workability. Also, by making the cross section of the frame body a pentagonal or more polygonal shape, the refractory can be coated as thinly as possible around the core metal of the lance pipe, and the frame body can be gently curved in the axial direction. Even with the split structure, the resistance surface of the vertical portion is reduced, and the lance pipe can be easily removed from the mold.

Examples Hereinafter, the present invention will be described based on Examples.

1 and 2 show an embodiment of the present invention in which the lance pipe has a hexagonal shape. A frame body 6 for molding the lance pipe 5 has a split type structure of a lower frame 7 and an upper frame 8 as shown in FIG. 1, and has a hollow portion 9 having a hexagonal cross section in the central portion thereof. 8 is divided left and right into an upper left frame 10 and an upper right frame 11, and one side of the hexagonal upper surface is an opening for pouring refractory 12
13 The core metal pipe 14 of the lance pipe 5 is installed at the center of the hollow portion 9 having a hexagonal cross section as shown in the figure, and the plastic castable refractory material 12 is poured from the opening 13 on the upper surface, as shown in FIG. Refractory around the core pipe 14
12 is covered, and a suitable vibration treatment is performed to sufficiently fill it, and at the same time, the upper opening surface is finished and molded. After curing the refractory 12 in this way, the upper left frame 10,
Core bar pipe 14 with refractory 12 removed by removing upper right frame 11
Is removed from the lower frame 7, and the lance pipe 5 is molded as shown in FIG.

In this way, since the refractory can be poured from the opening on one side of the hexagonal cross section, the plastic refractory can be installed with good workability, and since there is no vertical surface on the side of the lance pipe, demolding can be performed. There is little resistance to time, and it is possible to smoothly demold.

Example of use Based on the above example, the core metal pipe of the lance pipe has a diameter of 40 mm and a length of 4 m, the refractory coating is 3.
A metal hexagonal circumscribed hexagon with a diameter of 5 mm and a diameter of 70 mm was cast into the core metal pipe by casting a metal fiber-containing refractory material or a low-moisture castable refractory material.

As a result, refractory materials with metal fibers and refractory materials with low moisture castable, which could not be used with conventional molding methods, can be poured efficiently and can be installed, and the life of molded lance pipes is more than four times longer than before. did it.

In the above, a lance pipe having a hexagonal cross-section has been described, but it is also applicable to a polygonal cross-section having a pentagonal shape or more that can be formed so that the wall thickness does not vary depending on the part. Although the wall thickness can be made uniform, it is preferably a pentagonal to octagonal polygonal shape in consideration of the manufacturing surface of the frame body.

As described above, in the present invention, a refractory having metal fibers added and a castable refractory having a low water content, which are known in other fields where the technical progress of refractory is remarkable, are used as a frame work with good workability. It can be poured into the cavity, and the wall thickness of the refractory layer at the lance pipe can be made as uniform as possible,
The durability of the lance pipe can be remarkably improved.
Further, the demolding after molding can be performed extremely smoothly because the vertical surface portion is small and the resistance can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining a lance pipe molding according to an embodiment of the present invention, FIG. 2 is a perspective view of a lance pipe molded by the same as above, and FIGS. 3, 4, and 5 are conventional molding methods. It is a sectional view for explaining. 5 ... Lance pipe, 6 ... Frame, 9 ... Cavity, 12 ... Refractory, 13 ... Opening.

Claims (1)

[Claims] 1. A lance pipe for bubbling or injecting gas or flux into a molten metal, one side of which is opened, and one side of which is open, and a split type structure having a pentagonal or more cross section is formed along the axial direction. It is installed in the center of the frame with a rectangular cavity, and the specified refractory is poured into the cavity from the opening on one side of the frame with a polygonal cross section to cover the core metal pipe with the refractory. A method for coating a refractory material on a lance pipe, which comprises: