JPH09323158A - Ladle for molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the penetration of molten metal into a gas blowing plug at the time of shifting a ladle by arranging a circuit constituted with a gas cylinder for pressure accumulation for preventing the penetration of metal into the gas blowing nozzle at the time of shifting the ladle and three safety valves for executing the pressure accumulation into the pressure accumulation into the gas cylinder. SOLUTION: Gas is supplied from a gas supplying source connected with a piping connecting part 10 and the pressure is accumulated firstly into the gas cylinder 3 through the safety valve 7b. Successively, in the case the pressure in the gas cylinder 3 becomes the setting pressure of the safety valve 7a plus the back pressure of molten metal or higher, the safety valve 7a is opened and the gas blowing action is executed in the pressure accumulating condition into the gas cylinder 3. Then, after completing the gas blowing, the gas supplying source connected with the piping connecting part 10 is taken off, and at the time of stopping the gas supplying, the gas pressure- accumulated in the gas cylinder 3 is contracted into a regulating flow rate through the safety valve 7c and a switch valve 4 and supplied into the gas blowing plug 2, and the gas blowing is executed even at the time of shifting. Then, at the time of becoming the back pressure or higher, the safety valve 7c is closed.

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 end of the pressure, the safety valve is opened to blow normal gas. 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 from the gas supply source connected to the pipe connecting portion 10 in FIG. 2, and in the initial stage, the gas is stored in the gas cylinder 3 via the safety valve (gas cylinder inlet side) 7b. Next, when the pressure inside the gas cylinder 3 reaches the safety valve (gas cylinder outlet side gas blowing side) 7a valve switching pressure, gas is supplied to the pipe 6 and gas is blown in the gas cylinder 3 in a pressure-stored state. Take action. At this time, the safety valve (gas cylinder outlet side, gas blowing side from the gas cylinder) 7
c is closed by the back pressure from the pipe 6. 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 pressure in the gas cylinder 3 becomes lower than the pressure of the safety valve (gas cylinder outlet side gas blow side) 7a. Safety valve (gas cylinder outlet side, gas blow side)
7c is closed, and the circuit from the gas cylinder 3 to the safety valve (gas cylinder outlet side, gas blowing side from the gas cylinder) 7c is opened.
As a result, the gas stored in the gas cylinder 3 is throttled to a specified flow rate through the on-off valve (also serving as a throttle valve) 4 and supplied to the gas blowing plug 2.

[0008]

[Embodiment] 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 from a gas supply source (source pressure 7 ₂ ) connected to 0, and is first stored in the gas cylinder 3 via the safety valve (gas cylinder entry side) 7b. Then the pressure relief valve (gas cylinder outlet side gas blowing side) of the gas cylinder 3 7a when it becomes on the back pressure or by setting pressure + molten metal (usually 1-3 ₂ set), the safety valve (gas cylinder exit side gas blowing side )
7a is opened, and the gas blowing operation is performed in a state where the gas cylinder 3 is stored under pressure. After the gas is blown, the pipe connecting portion 10
When the gas supply source connected to is disconnected and the supply of gas is stopped, the gas stored in the gas cylinder 3 has a safety valve (gas cylinder outlet side, gas blow side from the gas cylinder) 7c (normally 0.
5 ₂ set), focused on defining the flow rate through the on-off valve (throttle valve combined) 4, is supplied to the gas blown plug 2, gas blowing is also performed at the time of movement. Then, when the back pressure due to the molten metal becomes +0.5 ₂ (set pressure of 7c), the safety valve (gas cylinder outlet side, gas blow side from gas cylinder) 7c is closed,
Holds pressure to prevent penetration of molten metal.

[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) 5 Check valve 6 Piping 7a Safety valve (gas cylinder outlet side gas blow side) 7b Safety valve (gas cylinder inlet side) 7c Safety valve (gas cylinder outlet side gas cylinder Gas blowing side from) 8 Gas blowing pipe 9 Gas blowing pipe from gas cylinder 10 Pipe connection

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 ladle for molten metal, characterized by having a circuit composed of three safety valves for performing storage pressure to the ladle.