JPS58210112A - Gas blow nozzle - Google Patents

Abstract

PURPOSE:To provide a gas blow nozzle with which the adjustment in the flow rate of gases to be blown is free by bringing the corrugated surface side of a metallic plate having the corrugated surface on one surface into tight contact with the flat surface side of a metallic plate having the flat surface on one surface and adhering refractory materials to the respective other surface sides. CONSTITUTION:The corrugated surface side of a metallic plate 15 at least one surface of which is a corrugated surface is brought into contact with the flat surface side of a metallic plate or ceramics 14 at least one surface of which is a flat surface, and a gas flow passage 18 is formed in the clearances thereof in a nozzle to be used for blowing gases into the molten metal in a vessel from the outside of the vessel. Refractory materials 13 are adhered to the respective rear sides of the plates 14, 15, and the shape of the nozzle is assured by a metallic frame 10. The frame 10 is connected to a supporting fitting 12 and the gases are supplied into the passages 18 from a pipe 11 through the clearance 16 between the fitting 12 and the metallic plate 19 in the bottom part. The nozzle which is simple in construction, is easy to manufacture and has high durability is thus obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nozzle used for blowing gas into molten metal in a container from outside the container, and particularly to a nozzle structure suitable for freely controlling the flow rate of the blown gas.

Gas blowing nozzles into molten metal have conventionally been used with various structures, such as those shown in Figures 1, 2, 3,
FIGS. 4 and 5 show typical nozzle structures.

In both figures, (al shows a top view, and (b) shows an AA sectional view of (al).

The one in Figure 1 is usually called a porous plug, and is a refractory molded body with a loose structure containing many voids.
, which is preserved with refractory T. The refractory molded body 1 that serves as the gas flow path has a weak structure and therefore has extremely low durability.

The one in Figure 2 has a circular pipe 2 made of metal or ceramic embedded in the refractory T, and the one in Figure 3 uses a double pipe 3. In this case, a circular hole 4 is drilled through the refractory T. Second
In the examples shown in FIGS. 3, 3, and 4, the gas flow path is a circular hole in each case. In a circular hole, the circumference of the hole is the minimum relative to the cross-sectional area of the gas flow path, and the interfacial tension that acts between the hole wall and the molten metal is small, so if the gas flow rate is reduced, the gas will not flow smoothly or at all. It has the disadvantage that when it is stopped, molten metal easily enters the hole and blocks the gas flow path.

The one shown in FIG. 5 has a structure in which a spacer 5 made of metal or ceramic is installed in the gap between the opposing refractory pieces T' to ensure a gas flow path. The disadvantage of this structure is that it is difficult to ensure the distance between the spacers is consistent with the design value when manufacturing the nozzle, and during use, the refractory piece
The point is that spall wear is likely to occur at the edge portions.

The present invention is a gas blowing nozzle that solves the drawbacks of the conventional nozzle structure described above.The gist is that a nozzle for blowing gas into molten metal in a container from outside the container has at least one corrugated surface. The corrugated surface side of a certain metal plate is brought into close contact with the flat side of a metal plate or ceramic plate whose at least one surface is flat, and a refractory is adhered to the back of each other surface, so that the corrugated surface The point is that the gap with the plane is used as a gas flow path.

Hereinafter, the present invention will be explained in detail based on examples.

FIG. 6 and FIG. 7 are diagrams showing embodiments of the present invention.
(al is a top view, fcl is a partially enlarged view of the part marked with ○ in (al), (bl is fa). In the figure, 1
0 is a metal frame that secures the nozzle shape, and is connected to a pipe 11 that introduces gas into the nozzle. It is not necessary and can be any shape such as a polygon or circle. Reference numeral 14 is a metal plate or ceramic plate having at least one flat surface (a metal plate having flat surfaces on both sides in the illustrated embodiment), and 15 and 17 are metal plates having at least one corrugated surface (in the illustrated embodiment). So 15 is single wave type,
17 is wavy on both sides).

The flat side of the metal plate 14 and the corrugated surface of the metal plate 15 or 170 are in close contact with each other, and a gas flow path 18 is formed with a gap therebetween. Further, a refractory material 13 is bonded to the back side of each metal plate. The refractory 13, metal plate 14, 15 or 17 is supported by a support metal fitting 12 connected to the metal frame 0. An appropriate gap 6 is formed between the supporting hardware 12 and the bottom metal plate 19, and the structure is such that the gas introduced from the pipe 11 is distributed to the respective gas passages 18.

The present invention is characterized in that a gas flow path is formed using a metal plate having at least one surface having a corrugated surface and a metal plate or ceramic plate having at least one flat surface. By doing so, the following effects can be obtained. The first is to make the cross section of the gas flow channel slender and long, thereby increasing the ratio (L/A) of the circumference of the hole (L) to the cross-sectional area of the flow channel (A). It is possible to increase the interfacial tension with the wall surface of the channel and prevent the molten metal from entering into the gas flow channel. Second, the thermal stress generated within the nozzle during use can be absorbed by the deformation of the corrugated metal plate, thereby preventing damage to the nozzle. Third, by inserting a metal plate with high thermal conductivity, the refractory can be cooled and the life of the nozzle can be extended.

Since the gas blowing nozzle of the present invention has the above-described structure, it has a simple structure, is easy to manufacture, has high durability, and is easy to control the elutriation of the blowing gas (including temporary suspension).
It is extremely practical as it can also be used.

[Brief explanation of the drawing]

Figure 1(a), (bl) to Figure 5(al), (bl is a top view and cross-sectional view showing a typical example of a conventional nozzle structure, Figures 6(a), (bl, (C) and 7). Figure (al,
(b), (C1 is a top view, a partially enlarged view, and a sectional view of a nozzle structure in an example of the present invention. 13... Refractory 14... Metal plate (or ceramic &) 15... Metal Plate 17...Metal plate 18...Gas flow path

Claims (1)

[Claims] In a nozzle for blowing gas into molten metal in a container from outside the container, the corrugated side of a metal plate with at least one corrugated surface and the flat side of a metal plate or ceramic plate with at least one flat surface. A gas blowing nozzle characterized in that a refractory is adhered to the back of each other surface side, and a gap between the corrugated surface and the flat surface is used as a gas flow path.