JPS6379913A - Bottom blowing plug - Google Patents

Abstract

PURPOSE:To reduce the effect of injecting gas at the time of repairing a bottom blowing plug, to remarkably improve the adhesive quantity of repairing material and to lengthen the service life of the plug by positioning concentratedly multi small pipes for the bottom blowing plug at small intervals. CONSTITUTION:In the bottom blowing plug 2 for converter, etc., the small pipes 4 having smaller intervals than the conventional small pipes are opened on the tuyere face at the inner side of furnace by 100-130 pieces. That is, as the number of pieces of pipes 4 for the above plug is not reduced as compared with the conventional plug, the bottom blowing gas flowing rate is secured and the stirring action of molten steel is executed in similar manner as the conventional plug. And, in case of damaging bricks 7 of the furnace wall 1 by bubbling, etc., repairing is executed by covering the damage part by the repairing material in an ordinary method. In this case, as the small pipes 4 have close intervals mutually and are positioned concentratedly in a straight line or ring-like, the area of gas injection becomes small. Therefore, the non- opening area in pipes 4 is widened and the effect by bottom blowing gas at the time of repairing is reduced, and the adhesion of repairing material is remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a bottom-blowing plug for blowing bottom-blowing gas into a furnace such as a converter.

[Prior Art] As shown in FIG. 4, a converter equipped with a bottom blowing plug generally has a structure in which a gas blowing plug 2 is provided in a work brick of a furnace wall 1.

A collective type of gas blowing plug 2 is known in which a large number of small pipes 4 are arranged penetrating inside the plug body 3, and this collective type plug is shown in FIGS. 5 and 6. There are single pipe plugs and double pipe plugs shown in FIGS. 7 and 8.

The single pipe plug 2 shown in FIGS. 5 and 6 includes a truncated cone-shaped plug body 3 made of a carbon-free refractory or a carbon-containing refractory. A small pipe 4 is arranged to penetrate therethrough. Further, a pressure equalizing chamber 5 is provided at the bottom of the plug body 3 to evenly distribute the gas supplied from the gas introduction pipe 6 to each small pipe 4.

Further, the heavy pipe plug shown in FIGS. 7 and 8 includes a double-structured gas supply pipe 6 for supplying gas to the plug body 3 similar to the single pipe plug. Pressure equalization chamber 5a.

Approximately 100 small pipes 4a inside the plug body 3 supply CO2, A+, or N2 gas for stirring molten steel through the plug body 3, and approximately 32 small pipes 4a on the outside supply N2 or N2 gas for cooling the plug. Supply Ar gas.

As shown in FIGS. 6 and 8, generally in these small pipe collection type plugs, a large number of small pipes 4 are evenly distributed and installed in order to reduce thermal stress.

In this converter, the bricks are easily damaged by bubbling, as shown by dotted lines 7 in FIG.

As a method for repairing a damaged plug, methods have been developed in which a repair material such as a spraying material, a baking material, or a slag coating is applied to the damaged portion of the plug.

[Problems to be Solved by the Invention] However, in any repair method, in order to prevent the plug from clogging the small pipes, the repair is performed while blowing out gas from these small pipes. The adhesion of the repair material is extremely low.

For this reason, the conventional plug structure has a problem in that the life of the plug is shortened due to preliminary erosion of the plug portion.

The present invention has been made to solve the above problems,
It is an object of the present invention to provide a plug in which the influence of ejected gas during plug repair is reduced, the adhesion of a repair material is significantly improved, and the life of the plug can be extended.

[Means for Solving the Problems] In order to achieve the above object, the bottom blowing plug of the present invention is provided with a large number of small pipes that eject bottom blowing gas into the furnace, and the small pipes are connected to each other. The bottom blow plug is characterized in that the bottom blow plug has a reduced surface area by closely arranging the plugs in a predetermined shape with close spacing between adjacent plugs.

[Operation] According to the present invention, the same number of small pipes as in the past, which are closely arranged with narrower intervals between them, are intensively arranged in a fixed shape. Therefore, the molten steel stirring action can be performed in the same way as a conventional plug, and the area on the upper surface of the plug where the small pipe is not opened is expanded.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIGS. 1 to 3 are diagrams schematically showing the implementation state of the present invention, and each shows the arrangement of small pipes as seen from the surface of a bottom blowing plug used in a converter or the like, that is, from the upper side.

The plug 2 has a small pipe 4 on the top surface, that is, on the tuyere surface inside the converter.
In this embodiment, approximately 100 to 130 small pipes 4 of a predetermined size are opened. The minimum value of this small pipe 4 is preferably 6n+m or more for welding work.

These small pipes 4 are shaped like a single character as shown in FIG. 1, a ring shape as shown in FIG. 2, or a third shape when viewed from the surface.
The tuyeres are centrally arranged in an arbitrary shape such as the cross shape shown in the figure, and the tuyere area is reduced.

The number of small pipes 4 shown in FIGS. 1 to 3 is the same as in the conventional case, and therefore the intervals between the small pipes are smaller than in the conventional case. "Although Figures 1 to 3 above show the case of a single-pipe plug, a double-pipe plug can also be formed in the same way, and it can also be formed into a circular shape or a slit shape. They can also be arranged in a concentrated manner in any shape.

Since the number of small pipes in the plug with this tuyere structure has not been reduced, it ensures the same bottom-blown gas flow rate as the conventional plug, and has the same molten steel stirring effect as the conventional plug. .

If damage occurs due to bubbling or the like, repair is performed by covering the damaged part with a repair material using a normal method.

In this case, the small pipes are closely spaced from each other and are centrally arranged in a line shape or a ring shape, so the area from which gas is ejected is small, and the opening of the small pipe 4 is located on the top surface of the plug 2. A wide area is formed that is not covered. For this reason, the influence of bottom-blown gas ejected to prevent small pipes from clogging during repair is reduced, and the adhesion of the repair material is significantly improved. In particular, when performing slag coating, the molten repair material is partially solidified to ensure that it adheres to the damaged plug surface, and then the molten repair material is further applied, a so-called bridging process, to improve adhesion. Extremely effective when repairing.

[Effects of the Invention] As is clear from the above, according to the present invention, a large number of small pipes of a bottom blowing plug are arranged centrally at small intervals, so that the adhesion of the repair material to the damaged part inside the furnace of this plug is improved. It can improve and extend the life of the bottom blow plug.

Furthermore, since the adhesion of the repair material is improved, the amount of repair material can be reduced, and repair costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a bottom blowing plug according to an embodiment of the present invention, a plan view of a bottom blowing plug according to a second embodiment of the present invention, and a top view of a bottom blowing plug according to a second embodiment of the present invention.
FIG. 4 is a plan view of a bottom blowing plug according to another embodiment.
The figure is an explanatory diagram of the furnace bottom, Figure 5 is a simplified cross-sectional view of the single pipe plug, Figure 6 is a plan view of the plug in Figure 5, Figure 7 is a simplified cross-sectional view of the double-pipe plug, and Figure 8 is a simplified cross-sectional view of the plug in Figure 5. The figure is a plan view of the plug of FIG. 7. 1... Furnace wall, 2... Plug, 4... Small pipe, 5
... Pressure equalization chamber, 6... Gas introduction pipe. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] In a bottom-blowing plug equipped with a large number of small pipes that eject bottom-blowing gas into the furnace, the small pipes are arranged closely in a predetermined shape with close spacing between the small pipes, and the tuyere area of the bottom-blowing plug is A bottom blowing plug characterized by reduced.