JPH042995Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the structure of a porous plug for injecting inert gas, mainly angone, into molten metal. The purpose of this invention is to ensure gas sealing by the iron plate case and to facilitate the work of removing the porous plug after use.

In recent years, the levitation of non-metallic inclusions in molten metal,
Techniques for blowing inert gas (hereinafter abbreviated as gas) such as angone or nitrogen have become commonplace for the purpose of temperature adjustment and uniformity or reaction acceleration. Particularly in special refining, the top-blowing method using a lance pipe and the bottom-blowing method using a porous plug are commonly used as techniques that are indispensable at present. Of these, various structures have been adopted or proposed as porous plugs for blowing gas used in the down-blowing method, but as shown in Figs. A structure in which the outer periphery and bottom are surrounded by an iron plate case 3 with a gas supply pipe 2 (Fig. 1), the outer periphery of a porous refractory 1 is surrounded by a dense refractory 4
A structure (second
), and a structure in which the outer periphery and bottom of the porous refractory 1 are surrounded by an iron plate case 3 with a gas supply pipe 2, and the outer periphery of the porous refractory 1 and the iron plate case 3 is surrounded by a dense refractory 4 (a third The ones shown in Figure) are commonly used. However, although all of these structures basically satisfy the function of blowing gas into molten metal,
There are the following problems.

The outer periphery and bottom of the porous refractory 1 shown in FIG.
In the case of a structure surrounded by an iron plate case 3 with a gas supply pipe 2, since it does not have a dense refractory material 4 on the outer periphery, if the porous refractory material 1 is damaged, thermal shock during use or damage to the molten metal may occur. The porous refractory 1 was directly affected by the slag erosion, and the porous refractory 1 was seriously damaged. In addition, during use, the iron plate case 3 used for the purpose of gas sealing on the side (outer periphery) of the porous refractory 1 and the porous refractory 1 have different thermal expansion coefficients, so after repeated use, the porous A gap is created between the side surface (outer periphery) of the porous refractory 1 and the iron plate case 3, gas sealing properties are lost, and gas bubbling from the gas discharge surface of the porous refractory 1 is not possible.
It will not be able to perform its original function. Furthermore, if a gap occurs between the side surface (outer periphery) of the porous refractory 1 and the steel plate case 3, the leaked gas will leak into the porous refractory 1.
The metal passes through the mortar between the porous mass bricks, scatters the mortar, or cracks occur in the mortar, and when gas is not injected, the metal gets stuck in the mortar spattered part and the cracked part, and in the worst case. In some cases, this may lead to steel leakage.

In the case of a structure in which the outer periphery of the porous refractory 1 shown in FIG. 2 is surrounded by a dense refractory 4, and the entire outer periphery and bottom of the dense refractory 4 is surrounded by an iron plate case 3 with a gas supply pipe 2, the above-mentioned The problem of large damage to the porous refractory 1 and loss of gas sealing properties can be solved by surrounding the outer periphery of the porous refractory 1 with a dense refractory 4, but the above-mentioned gas leakage from the side (outer periphery) The issue of bullion insertion has not been resolved.

In the case of the structure shown in FIG. 3, the outer periphery and bottom of the porous refractory 1 are surrounded by an iron plate case 3 with a gas supply pipe 2, and the outer peripheries of the porous refractory 1 and the iron plate case 3 are surrounded by a dense refractory 4. The above-mentioned porous refractory 1
However, when replacing the porous plug, the method of pulling out the gas supply pipe 2 only removes the porous refractory 1. It is pulled out, leaving the dense refractory 4 in the molten metal container. Therefore, in order to remove the dense refractory material 4, either break and remove the dense refractory material 4 from the bottom side of the molten metal container with a hammer or vibrator, or remove it from the bottom of the molten metal container with a prick rod. method has been adopted. However, since both methods involve hot work, they require considerable labor and take a long time, so each user must consider a structure or method that can easily remove the porous plug. It's getting old.

The present invention solves this problem by surrounding the outer periphery and bottom of the porous refractory 1 with an iron plate case 3, surrounding the outer periphery with a dense shaped refractory 4, and further surrounding the outer periphery and bottom with an iron plate case 3'. Moreover, by arranging the gas supply pipe 2 at the bottom, a porous plug for blowing gas is provided which ensures gas sealing performance even when used many times and facilitates removal work after use.

Hereinafter, an embodiment of the present invention will be explained in detail based on FIG. 4. The outer periphery and bottom (gas injection side) of a porous refractory 1 manufactured in a predetermined shape are surrounded by an iron plate case 3. The height of the iron plate case 3 surrounding the outer periphery is preferably 2/5 or more of the height of the porous refractory 1. Next, a dense shaped refractory 4 manufactured to be able to fit into the porous refractory 1 is combined. The dense shaped refractory 4 is made by combining shaped refractories such as alumina with mortar at the joints, and then using an iron plate case 3' so that the outer periphery and bottom of the dense shaped refractory are doubled. surround. The height of the steel plate case 3' that surrounds the outer periphery of the dense shaped refractory 4 must be large enough to ensure that the dense shaped refractory 4 can be pulled out at the time of extraction. The height of the iron plate case 3 surrounding the outer periphery of the refractory 1 is approximately equal to or slightly higher than that of the dense shaped refractory 4.
It is desirable to set the height to about 1/2 of the height of the

Generally, the height of the steel plate cases 3, 3' surrounding this outer periphery is shorter than the height of the porous refractory 1 and the dense shaped refractory 4. This is to prevent steel leakage due to melting of the steel plate cases 3 and 3' in Figs. 4 and 5 by covering them with mortar.
Sometimes it extends to the top. In addition, as a method for surrounding the steel plate cases 3 and 3', there is a method using shrink fitting, and the height of the steel plate case surrounding the outer periphery,
There are no regulations regarding the enclosing method.

In addition, as shown in FIG. 5 showing another example of the present invention, a recess is provided at the bottom of the porous refractory 1 in order to uniformly inject gas, and the iron plate cases 3 and 3' are prevented from being eroded. Therefore, there is a method of making the inner and outer peripheries of the dense shaped refractory 4 concave by the thickness of the steel plate cases 3, 3'. There are no restrictions on the shape or material of the material. After surrounding the dense shaped refractory 4 with an iron plate case 3' so that the outer periphery and bottom are doubled, a pipe for the gas supply pipe 2 is attached to the center of the bottom iron plate cases 3, 3' by a method such as welding, Connects by screwing in when in use.

By using the porous plug for gas blowing of the present invention with such a structure, the removal work when replacing the porous plug after use is completed by holding the pipe for gas supply pipe 2 from the bottom side of the molten metal container. Porous refractories 1 and dense shaped refractories 4 can be reliably extracted from the molten metal container by simply pulling them out.In actual work, by using a hydraulic extraction device, it takes about 5 minutes. It is possible to extract almost 100%. Furthermore, even when used many times, gas leakage does not occur between the porous refractory 1 and the iron plate case 3 provided around the outer periphery of the porous refractory, and the gas injection function can be reliably performed. .

[Brief explanation of drawings]

Figures 1 to 3 are vertical cross-sectional views of the conventional structure;
The figure is a longitudinal cross-sectional view of an embodiment of the present invention, and FIG. 5 is a longitudinal cross-sectional view of another example of the embodiment of the present invention. In the figure, 1...porous refractory, 2...gas supply pipe, 3, 3'...iron plate case, 4...dense shaped refractory.

Claims (1)

[Scope of utility model registration request] The outer periphery and bottom of the porous refractory 1 are surrounded by an iron plate case 3, the outer periphery is surrounded by a dense shaped refractory 4, and the outer periphery and bottom of the dense shaped refractory 4 is further surrounded by an iron plate case 3'. An easily attachable and detachable external gas-blown porous plug characterized in that the bottom of the quality refractory 1 has a double iron plate structure and a gas supply pipe 2 is arranged at the bottom.