JPH08189777A - Melting furnace - Google Patents

Abstract

PURPOSE: To ladle molten metal at an appropriate temperature immediately after charging a solid material into the molten metal in a melting furnace. CONSTITUTION: A melting furnace 1 is provided with a crucible 2, a cover 3 for covering the crucible 2, and a cylindrical member 5 having a branching tube 4. The branching tube 4 branches slantingly downward from the upper part of the cylindrical member 5 and is so formed that a lower opening 14 of the branching tube 4 can be seen through an upper opening 9 of the cylindrical member 5. The cover 3 is provided with a non-combustible gas feed pipe 16a having an opening which opens to a space 15 of the melting furnace 1, while a large-diameter part 11 of the cylindrical member 5 is provided with a non-combustible gas feed pipe 16b having an opening which opens to a space 17 of the cylindrical member 5, and non-combustible gas is fed into the spaces 15, 17 from a bomb 19 through the non-combustible gas feed pipes 16a, 16b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melting furnace in which the surface of a molten metal is covered with a non-combustible gas and the molten metal having a proper temperature can be pumped out immediately after a solid material is put into the molten metal.

[0002]

2. Description of the Related Art As a melting furnace in which the surface of a molten metal is covered with a non-combustible gas, a lid for covering the upper opening of the crucible of the furnace is provided, and the lid has a size large enough to pump out the molten metal at its upper end. Japanese Unexamined Patent Application Publication No. Hei 6 (1999) -6200, which is provided with a cylindrical member having an opening for the bottom and an opening at the lower end for reaching the inside of the molten metal.
-93352 publication.

[0003]

The above-mentioned conventional melting furnace is
In order to suppress the consumption of nonflammable gas when pumping out the molten metal, the molten metal is pumped out from the upper opening of the cylindrical member whose lower end is immersed in the molten metal. However, in this melting furnace, when a solid material, which is a raw material for the molten metal, is charged through the upper opening of the tubular member to replenish the molten metal, the solid material is melted in the molten metal in the tubular member and Since the temperature of the molten metal decreases, there is a problem in that the molten metal at an appropriate temperature cannot be pumped out of the tubular member immediately after the solid material is charged.

Therefore, the present invention solves the above-mentioned problems, and when the solid material is charged from the upper opening of the tubular member, the temperature of the molten metal in the tubular member is hardly lowered, and the molten metal at an appropriate temperature is pumped. The object is to provide a melting furnace that can be put out.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a melting furnace having a lid having a tubular member through which a nonflammable gas can flow inserted therein, and the inside of which is pressurizable. It is characterized in that a branch pipe branched from the upper portion of the tubular member to the diagonally downward direction is provided.

[0006]

When the solid material as the raw material for the molten metal is replenished to the molten metal in the melting furnace, the solid material is introduced into the molten metal through the branch pipe, and the solid material is in the molten metal in the branch pipe or at the tip of the branch pipe. Melts in the vicinity of the pipe, and the temperature of the melt in the branch pipe or the temperature of the melt near the tip of the branch pipe locally drops. However, since the molten metal in the branch pipe or the molten metal in the vicinity of the tip of the branch pipe is separated from the molten metal in the tubular member, the local decrease in the molten metal temperature due to the melting of the solid material is It has almost no effect on the temperature of the molten metal in the member,
The temperature of the molten metal in the tubular member is kept substantially constant.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the melting furnace 1 includes a crucible 2 and a lid 3.
And a tubular member 5 having a branch pipe 4. The crucible 2 is connected to an external heat source (not shown), and a molten metal (for example, a molten metal containing magnesium as a main component) M is stored in the crucible 2. As shown in FIG. 2, the lid 3 that covers the crucible 2 is composed of a divided body 3 a having a semicircular concave portion 6 and a divided body 3 b having a semicircular concave portion 7. When the divided body 3a and the divided body 3b are integrally joined together, a circular opening 8 is formed, and the tubular member 5 having the branch pipe 4 is inserted into the opening 8.

An upper opening 9 is formed at the upper end of the tubular member 5, a lower opening 10 is formed at the lower end thereof, and an upper diameter of the tubular member 5 is larger than that of the opening 8 of the lid 3. ,And,
A large diameter portion 11 that engages with the lid 3 is formed. Further, on the upper surface of the large-sized portion 11, an opening / closing lid 1 for opening / closing the upper opening 9 is formed.
2 is attached via a hinge member 13.

The branch pipe 4 branches obliquely downward from the upper part of the tubular member 5, and the lower opening 14 of the branch pipe 4 is provided above the lower opening 10 of the tubular member 5, and the tubular member 5 is provided. The lower opening 14 of the branch pipe 4 can be seen through the upper opening 9 of the above, and a solid material (not shown) can be provided in the branch pipe 4 through the upper opening 9.
Are formed so that they can be input.

The lid 3 penetrates through the lid 3, and the lid 3 inside the crucible 2
A nonflammable gas supply pipe 16a having an opening is provided in the space 15 covered with. Further, the large-diameter portion 11 is provided with a non-combustible gas supply pipe 16b which penetrates the large-diameter portion 11 in the radial direction and has an opening in a space 17 inside the tubular member 5. The non-combustible gas supply pipes 16a and 16b are connected to the non-combustible gas (for example, SF ₆ /
It is connected to a cylinder 19 filled with CO ₂ . The non-combustible gas supply pipes 16a and 16b do not necessarily have to be fixed to the lid 3 or the large-diameter portion 11,
It suffices if the non-combustible gas can be supplied into the spaces 15 and 17 as needed. For example, each time the supply of the noncombustible gas is required, the pipe connected to the cylinder 19 is arranged in the spaces 15 and 17 to supply the noncombustible gas, and the supply of the noncombustible gas is not required. , Space 1
You may make it take out from inside 5,17.

Next, the operation will be described. The molten metal M in the tubular member 5 is pumped out from the upper opening 9 while supplying the noncombustible gas into the spaces 15 and 17 through the noncombustible gas supply pipes 16a and 16b. When the liquid level of the molten metal M in the crucible 2 is lowered to a predetermined position by pumping out the molten metal M, the pumping of the molten metal M is interrupted and a solid material (not shown) for replenishing the molten metal M is branched from the upper opening 9. It is poured into the molten metal M through the pipe 4. At this time, the supply of the non-combustible gas into the space 15 is stopped, and only the supply of the non-combustible gas into the space 17 is continued.

When the charged solid material (not shown) is melted in the molten metal M near the lower opening 14 of the branch pipe 4, the temperature of the molten metal M near the lower opening 14 is locally lowered, but the temperature is lowered. Heat is supplied from the surrounding molten metal M to the lowered molten metal portion, and the heat necessary for raising the temperature of the lowered molten metal to a predetermined temperature is supplied from an external heat source (not shown) to the crucible 2
The molten metal M is heated to a predetermined temperature while gradually equalizing the temperature of the molten metal that has become non-uniform due to the introduction of the solid material (not shown). At this time, since the lower opening 10 of the tubular member 5 and the lower opening 14 of the branch pipe 4 are separated from each other,
The local decrease in the temperature of the molten metal in the vicinity of the lower opening 14 due to the melting of the solid material (not shown) has almost no effect on the temperature of the molten metal in the tubular member 5, and further, the molten metal M lowered as described above Since the heat required to raise the temperature to a predetermined temperature is supplied to the crucible 2 from the outside, the temperature of the molten metal in the tubular member 5 hardly changes when the solid material (not shown) is charged.

Further, when a solid material (not shown) is charged into the molten metal M through the branch pipe 4, if an oxide of the molten metal M floats on the surface of the molten metal M, the oxide is a solid material (see FIG. (Not shown) is dispersed in the molten metal M by being charged and floats or sinks in the molten metal M in the vicinity of the lower opening 14 of the branch pipe 4, and at this time also, the lower opening 10 of the tubular member 5 and the branch pipe Four
The oxide dispersed in the molten metal M does not reach the molten metal M in the tubular member 5 because it is separated from the lower opening 14.

[0014]

EFFECTS OF THE INVENTION According to the present invention, there is almost no effect on the temperature of the molten metal in the tubular member due to the introduction of the solid material.
Immediately after the solid material is charged, the molten metal at an appropriate temperature can be pumped out of the tubular member, and the productivity is improved.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of the lid of the crucible of the above embodiment.

[Explanation of symbols]

 1 Melting furnace 3 Lid 4 Branch pipe 5 Cylindrical member

Claims (1)

[Claims] 1. A melting furnace having a lid through which a cylindrical member into which an incombustible gas can flow is inserted, and the inside of which is pressurizable, wherein the cylindrical member is obliquely downward from the upper part of the cylindrical member. A smelting furnace characterized by having a branch pipe branched toward the.