JPH0721561Y2 - Gas blow plug - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas blowing plug for stirring molten metal in the smelting field.

2. Description of the Related Art In recent years, in order to improve the quality of steel products, it has been increasing to remove non-metallic inclusions by blowing an inert gas such as argon or nitrogen into the molten metal in a molten metal container.

As shown in FIG. 2 of the related art, a gas blow-in plug 1 in which the outer side is surrounded by a dense refractory material 2 and the porous refractory material 3 is provided inside thereof is widely used. Although the gas can be blown into the molten metal and the stirring effect is good, the upper end surfaces of the dense refractory material 2 on the outside and the porous refractory material 3 on the inside have the same flat shape.

Therefore, in the early stage of using the conventional gas blowing plug, when the surface of the porous refractory is cleaned with oxygen in order to ensure air permeability, the molten steel, which becomes a fire source, blows gas into the porous structure. It was difficult to collect oxygen on the refractory and could not be easily cleaned with oxygen.

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, a dense refractory is arranged in a cylindrical shape,
A gas-blowing plug having a gas-blown columnar body of a porous refractory material inside thereof, wherein the entire upper surface of the gas-blown columnar body of the above-mentioned porous refractory material is arranged from the upper surface of the dense refractory body outside thereof. An object is to provide a gas injection plug characterized by being stepped in by a step as low as 5 to 20 mm.

Function When the gas blowing plug of the present invention is used by mounting it on a molten metal container, melting is accumulated over the entire upper end surface of the gas blowing columnar body of the stepped inner porous refractory in the initial stage, and oxygen cleaning is facilitated. You can do it. Further, since the gas blown columnar body of the porous refractory material inside is a simple columnar body, it is easy to manufacture.

Embodiment Hereinafter, the present invention will be described based on an embodiment.

FIG. 1 shows an embodiment of the present invention. The gas injection plug 1 for agitating the molten metal has a trapezoidal shape in which the cross section becomes smaller toward the upper part as shown in FIG. A dense refractory 2 is arranged in a cylindrical shape, and a gas-injected columnar body 5 of a porous refractory is provided inside thereof.

The upper end surface of the gas-injected columnar body 5 of the porous refractory material is
As shown in the figure, it is 5 ~ 20
It has a height of about 6 mm and is equipped with a step 6 so that oxygen cleaning can be performed easily at the beginning of use. 7 is a gas supply pipe.

Example of use In order to compare the above-mentioned gas blowing plug of the present invention with a conventional one, it was installed in a ladle of 50 ton molten steel, and gas was continuously blown 21 times and oxygen cleaning was performed.

As a result, with the present invention, oxygen cleaning and gas blowing could be performed without any problems. In the conventional case, the oxygen cleaning could not be successfully performed 5 times in total from the 1st time to the 5th time.

By lowering the upper end surface of the gas-injected columnar body of the porous refractory material by about 5 to 20 mm, the performance can be sufficiently exhibited from the beginning of use and the upper end surface of the dense refractory material can be slightly Since it is melted and damaged in advance, the gas can be smoothly and continuously blown.

In addition, it is preferable that the step of the gas-blowing columnar body is as small as about 5 to 10 mm because the life of the gas-blowing plug can be extended,
If it is deeper than 20 mm, the life of the gas injection plug is shortened, which is not preferable.

In the above embodiment, the trapezoidal single gas blowing plug is shown, but the present invention can also be applied to a gas blowing plug in which one or more are integrally attached to a block body having a rectangular parallelepiped shape or the like.

Effect of the Invention As described above, in the present invention, a so-called porous plug is used, and since the gas-injected columnar body is a porous refractory, it has a drawback that the melting rate is high, but the entire top surface of the porous refractory is The gas is blown into the molten metal from the inside, and the gas can be blown stably and uniformly, so that the stirring effect of the molten metal is great. Then, in the initial stage of its use, molten steel accumulates over the entire upper surface of the gas-injected columnar body of the inner porous refractory material on the cylindrical upper surface of the outer dense refractory material, facilitating oxygen cleaning and air permeability. It can be ensured, and the performance can be sufficiently exhibited from the initial stage of use, and the gas can be smoothly injected continuously until the life of the gas injection plug. Further, the upper end surface of the gas-blown columnar body of the porous refractory material is lower than the dense refractory material on the outside by about 5 to 20 mm, so that the life of the gas-blowing plug can be prevented from being shortened, and since it has a simple shape, It is easy to manufacture.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention, and FIG. 2 is a side sectional view of a conventional example. DESCRIPTION OF SYMBOLS 1 ... Gas injection plug, 2 ... Dense refractory material, 5 ... Porous refractory gas injection columnar body, 6 ... Step.

Claims (1)

[Scope of utility model registration request] 1. A gas-blowing plug having a dense refractory material arranged in a tubular shape, and a gas-blowing columnar body for the porous refractory material provided inside the gas-refractory material. A gas injection plug characterized in that the entire upper end of the blown columnar body is internally stepped by a height of 5 to 20 mm lower than the upper surface of the dense refractory material on the outside thereof.