JPH09323160A - Ladle for molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the reuseability and use frequency of a gas blowing plug by restraining the penetration of molten metal into the gas blowing plug at the time of shifting a ladle. SOLUTION: The ladle has a circuit constituted of a gas cylinder 3 for pressure accumulation, an air operated valve 8 for executing the pressure accumulation therein, two pieces of non-return valves 5a, 5b for preventing back flow of the gas and a shuttle valve 7 for changing over the flow passage of the gas by the gas pressure to prevent the penetration of the metal into the gas blowing plug 2 at the time of shifting the ladle. By this constitution, the gas accumulated in the gas cylinder 3 is supplied into the gas blowing plug 2 even at the time of shifting the ladle, and the penetration of the molten metal into the gas blowing plug 2 can be restrained. Therefore, the reuseability and the use frequency of the gas blowing plug can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas blowing plug which is buried in the bottom of a ladle for molten metal and used for blowing gas into the molten metal in the ladle, and does not blow gas when moving the ladle. At times, the present invention relates to a storage gas cylinder for preventing penetration of molten metal into a gas blowing plug and a ladle for molten metal formed by separately providing a special circuit for performing storage pressure.

[0002]

2. Description of the Related Art Conventionally, a gas blowing plug that is buried in the bottom of a ladle for molten metal and blows gas to the molten metal in the ladle,
When moving the ladle after the gas blowing process, the molten metal enters the inside of the gas blowing plug during movement because it moves after disconnecting the gas piping, and if you try to use it again, it will be blocked in the plug. Because of this, it was often impossible to use. Therefore, a technique has been devised in which, as shown in FIG. 1, the pressure is stored in the gas cylinder 3 when the gas is blown, and the molten metal is suppressed from entering the plug by the gas stored in the gas cylinder 3 when the gas is moved. (Actual application Sho 64-1565
6) However, even if this technique was used, the storage pressure in the gas cylinder was not exerted, it was not very effective, and the penetration of molten metal was not suppressed.

In a conventional ladle for molten metal having a gas cylinder, a high-pressure gas normally passes through the cylinder when the gas is blown, and the molten metal does not enter the gas-blowing plug, but a high-pressure gas when moving. When the connection of the gas is disconnected, the gas stored in the cylinder is stored only to the same level as the pressure at the bottom of the ladle due to the molten metal in the ladle. It is considered that the gas in the blown plug flows upward due to the difference in specific gravity, so that the effect of suppressing the permeation of the molten metal is weakened with time, and finally the molten metal permeates into the gas blown plug. For this reason, there is a need for a technique that allows the storage pressure in the gas cylinder to be higher than the pressure of the molten metal in the ladle.

[0004]

SUMMARY OF THE INVENTION In the method of FIG. 1 described above,
Since the storage pressure that exceeds the pressure generated by the specific gravity of the molten metal in the ladle cannot be performed in the gas cylinder, the permeation of the molten metal into the gas blowing plug cannot be sufficiently suppressed when moving the ladle, and the flow rate of the gas blowing plug decreases. At last, it became clogged, and it was difficult to reuse the gas blowing plug.

In order to prevent the molten metal from penetrating into the gas blowing plug when the ladle is moved, a storage pressure exceeding the pressure generated by the specific gravity of the molten metal in the ladle can be performed in the gas cylinder, and at the time of movement. Also in the case of (1), if the gas can be blown little by little, it is possible to suppress the permeation of the molten metal into the gas blowing plug when the ladle is moved.

The present invention has been made in order to meet the above-mentioned demands, and enables a storage pressure in the gas cylinder to exceed the pressure generated by the specific gravity of the molten metal in the ladle.
In addition, by allowing gas to be blown in small amounts even when moving, it is intended to suppress the permeation of molten metal into the gas blowing plug when moving the ladle, thereby reusing the gas blowing plug and improving the number of uses. .

[0007]

According to the present invention, in the initial stage of gas blowing according to the method of FIG. 2, forcibly pressure is applied to the inside of the gas cylinder, and after the pressure is finished, the valve is switched and the normal gas is blown. To do. When the ladle is moved after the gas is blown, the gas stored in the tank has a function of being supplied to the gas blowing plug and suppressing the permeation of the molten metal into the gas blowing plug. (Operation) Gas is supplied by the gas supply source connected to the pipe connecting portion 10 of FIG. 2, and in the initial stage, the air operated 3 port valve 8 and the check valve (on the side of the gas cylinder)
After being exposed to 5b, the gas cylinder 3 stores the pressure. At this time, since the supply pressure from the gas cylinder 3 of the shuttle valve 7 is higher than the pressure of the gas blowing pipe 11,
The circuit is such that the gas from is supplied to the gas blowing plug 2. Next, when the pressure in the gas cylinder 3 is supplied to the pilot portion of the air operated 3 port valve 8 through the pilot pipe 9, and reaches the valve switching pressure,
The air operated 3 port valve 8 is switched to supply the gas to the gas blowing pipe 11, and the shuttle valve 7 has a higher pressure in the gas blowing pipe 11 than in the gas cylinder 3 side. After switching, the circuit on the side of the gas cylinder 3 is closed, the circuit of the gas blowing pipe 11 and the pipe 6 is opened, and the gas blowing operation is performed in a state in which the gas cylinder 3 is under pressure. After the gas is blown, the pipe connection part 1
When the gas supply source connected to 0 is disconnected and the gas supply is stopped, the shuttle valve 7 is switched because the pressure in the gas cylinder 3 becomes higher than the pressure in the gas blowing pipe 11.
The circuit from the gas cylinder 3 to the pipe 6 is opened, and the circuit from the gas blowing pipe 11 to the pipe 6 is closed. As a result, the gas stored in the gas cylinder 3 has a check valve (gas cylinder outlet side).
It is supplied to the gas blowing plug 2 through 5a.

[0008]

EXAMPLE The operation of the circuit described in the above section (action) in actual use will be described. Pipe connection part 1 in FIG.
Gas is supplied by a gas supply source (source pressure 7 ₂ ) connected to 0, and the gas is first stored in the gas cylinder 3. Next, when the pressure of about 1/2 of the supply pressure is stored in the gas cylinder 3,
It is supplied to the pilot part of the air operated 3 port valve 8 through the pilot pipe 9, the valve is switched, the circuit of the gas blowing pipe 11 and the pipe 6 is opened,
The gas blowing operation is performed in a state where the pressure is stored in the gas cylinder 3. After the gas is blown, the gas supply source connected to the pipe connecting portion 10 is disconnected, and when the gas supply is stopped, the gas stored in the gas cylinder 3 releases the check valve (gas cylinder outlet side) 5
The gas is supplied to the gas blowing plug 2 through a, and gas is blown even during movement. (Adjust the flow rate by changing the thickness of the gas cylinder outlet side pipe)

[0009]

As described above, according to the present invention, in the ladle for molten metal, by using the gas cylinder and the special circuit for accumulating the gas, the gas compressed by the gas cylinder is blown even when the gas is moving. It has become possible to suppress the penetration of molten metal into the gas-blowing plug by supplying it to the plug. Therefore, the gas blowing plug can be reused and the number of times of use can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a conventional ladle for molten metal.

FIG. 2 is a vertical sectional side view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Ladle for molten metal 2 Gas blow plug 3 Gas cylinder 4 Open / close valve (also used as throttle valve) 5a Check valve (gas cylinder outlet side) 5b Check valve (gas cylinder inlet side) 6 Piping 7 Shuttle valve 8 Air operated 3 port valve 9 Pilot piping 10 Piping connection 11 Gas blowing piping

Claims (1)

[Claims] 1. A ladle for molten metal having a gas blowing plug for blowing a stirring gas at the bottom, in order to prevent penetration of metal into the gas blowing plug when the ladle is moved, a gas cylinder for livestock pressure. And a molten metal characterized by having a circuit composed of an air-operated valve for performing storage pressure therein, two check valves for preventing backflow of gas, and a shuttle valve for switching gas flow paths by gas pressure Ladle.