JPH0137806Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention prevents oxidation of the molten metal by air and seals out harmful gases and fumes when injecting the molten metal into the injection pipe in the bottom pouring agglomeration method. and a sealing device for injection flow used when collecting dust.

[Conventional technology]

When casting molten metal, the injection stream is protected by a sealing gas in order to prevent the injection stream from atmospheric oxidation. In the bottom pouring ingot method, for example, 42109-42109,
No. 143333, and when adding alloys, those disclosed in Japanese Patent Application Laid-open No. 133523/1983 are used. Since these devices do not have a closed structure, a large amount of sealing gas is required for sealing. In order to eliminate this drawback, closed-type sealing devices have recently been used.
The sealing device shown in c has been used. In the figure, the molten metal is injected from the ladle nozzle 2 of the ladle 1 into the injection pipe 3, but in order to prevent the molten metal from being oxidized by the atmosphere, the injected molten metal is sealed with a sealing device 12, and from the addition tube 7 into the sealing device 12. Seal gas is injected inside.

However, in recent years, from the perspective of pollution problems, etc.
The sealing device 12 illustrated in the figure has the following problems. In FIG. 4a, the inside of the sealing device 12 becomes under positive pressure due to the supply of sealing gas and the expansion of the sealing gas due to the temperature of the molten metal. However, ladle 1 and sealing device 1
2, it is difficult to achieve complete adhesion, and it is impossible to completely eliminate leakage of harmful gases.

Therefore, since it is necessary to collect dust from the leaked gas, a shift is being made to a sealing device 12 shown in FIGS. 4b and 4c which has an exhaust function.

In FIG. 4b, since the dust collecting pipe 8 is connected, leakage of harmful gases can be prevented, but the inside of the sealing device 12 is under negative pressure, and the atmosphere may get mixed into the sealing device 12. Therefore, the molten metal may be oxidized, and the molten metal may be contaminated by the oxides. Moreover, it is very difficult to control the pressure to balance the supply gas and the exhaust flow rate from the dust collector, to prevent the mixture of atmospheric air, and to collect harmful gases and fumes, and the equipment becomes large-scale.

FIG. 4c shows the sealing device 12 in the device of FIG. 4a.
It is equipped with an opening device to collect harmful gases and fumes leaked from the pipe. However, once the harmful gases and fumes are released to the outside from the sealing device 12, they are affected by atmospheric flow and are not completely collected.

[Problem that the invention attempts to solve]

Since the injection flow in the lower pouring ingot is sealed by joining the seal plate of the ladle and the injection flow sealing device, it is impossible to create a completely sealed structure.

Therefore, it is necessary to create a positive pressure inside the sealing device by supplying sealing gas to prevent atmospheric air from being sucked into the sealing device. However, when pouring molten metal,
To prevent the leakage of harmful gases and fumes generated by additives such as Pb, Ca, and REM, they must be exhausted using a dust collector, and for this reason it is necessary to create a negative pressure inside the sealing device. Creating a negative pressure inside the sealing device may cause air to enter the molten metal, causing the molten metal to be oxidized and contaminated with oxides.

The object of the present invention is to provide a device that separates these conflicting pressures within the seal device, prevents air from entering the device, and reliably collects harmful gases and fumes.

[Means for solving problems]

The present invention is intended to solve the above-mentioned problems, and employs the following technical means.

1. An inner cylinder hood that is arranged around the top of the molten metal injection pipe and is vertically extendable to maintain a positive pressure inside by injecting inert gas from the inert gas addition pipe.2. installed, leaking gas,
It consists of a vertically extendable external hood 3 that covers dust and connects a gas suction pipe to maintain a negative pressure inside, and a dust collector that collects dust from the gas suction pipe.

[Effect]

As can be seen from the cross-sectional view of the injection flow sealing device directly above the injection pipe 3 shown in Fig. 1, the injection pipe 3 is double sealed with a seal of double pipe structure, and inside the internal seal, The inside of the type inner cylinder hood 5 (hereinafter referred to as the inner cylinder hood 5) is always at a positive pressure due to the seal gas being supplied from the addition pipe 7, and the inside of the external seal, that is, the telescoping outer cylinder hood 6 (hereinafter referred to as the outer cylinder hood) A negative pressure is maintained between the hood 6) and the inner cylinder hood 5 by suction from the dust collector.

Therefore, the injection flow of molten metal is protected from oxidation by the atmosphere by the sealing gas, and even if toxic gas or fume leaks from the inner cylinder hood 5, it will not leak outside because it will be removed by suction by the dust collector.

〔Example〕

An embodiment of the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1 shows a sectional view of the sealing device for the injection flow directly above the injection pipe, and FIG. 2 shows a view taken along the line A--A in FIG.

As shown in Fig. 1, the sealing device of the present invention includes an upper hood 4 attached to a ladle 1, an outer hood 6 having a double-pipe structure located on the outside, and an inner hood 6 located inside the outer hood 6 for injection flow. It is composed of an inner cylinder hood 5 with a double-tube structure for sealing, an injection tube 3, and the like.

The upper hood 4 is attached to the lower surface of the ladle nozzle 2. This upper hood 4 constitutes two concentric spaces surrounded by the inner cylinder hood 5 and the outer cylinder hood 6, and each space is kept airtight by inserting sealing material 11 at key points as necessary. is maintained.

The outer cylinder hood 6 has a double pipe structure with a spring 9 interposed therebetween so that the outer cylinder hood 6 and the upper hood 4 are sufficiently sealed.

As can be seen from FIGS. 1 and 2, an annular pipe 13 with four suction ports is shown on the outer periphery of the outer hood 6 via a dust collection pipe 8 (gas suction pipe) on the fixed equipment side. is not connected to a dust collector.

The inner cylinder hood 5 is provided for the purpose of preventing oxidation of the molten metal, and like the outer cylinder hood 6, a spring 9 is installed to ensure sufficient sealing between the upper hood 4 on the ladle 1 side and the inner cylinder hood 5. It has a double tube structure. Additives such as ferroalloy are charged into the inner cylinder hood 5 through an addition pipe 7 and added to the molten metal.

The present invention is characterized in that the area directly above the injection pipe 3 is completely surrounded by a hood, and the suction duct is connected not to the ladle 1 side but to the fixed equipment side. In other words, the molten metal needs to be injected without oxidation, and the inner cylinder hood 5
Ar gas is sealed inside from the addition tube 7, and the inside of the inner cylinder hood 5 is always maintained at a positive pressure. Therefore, the injection flow of molten metal is protected from oxidation by the atmosphere by the Ar gas, and even if a gas such as toxic gas leaks for some reason, the flow directly above the injection pipe 3 is protected by the outer cylinder hood 6 and the upper hood 4. Because it is completely enclosed and removed by suction with dust collectors and equipment,
There will be no leakage to the outside. Furthermore, in a conventional sealing device, after the injection is completed and the ladle is moved, the surface of the injection flow of molten metal is exposed to the atmosphere, but in the sealing device of the present invention, a lid is placed directly above the outer cylinder hood 6. By placing it in place, it is sealed and the molten steel can be protected for the necessary period of time.

In the structure of the present invention, the suction duct is connected to the fixed equipment even after the ladle has been moved, making it possible to collect dust at all times and significantly improving dust collection efficiency.

Fig. 3 shows an overall diagram of ingot casting with dust collection piping, but when adding Pb, Ca, and REM materials, in addition to dust collection using a sealing device as shown in Fig. 3, By placing the mold hood 10 above the mold to collect dust, complete removal of fumes can be achieved.

[Effect of idea]

The device of the present invention protects the injected stream from oxidation, etc., and significantly improves the dust collection efficiency, thereby improving product quality and preventing pollution.

[Brief explanation of drawings]

1 is a cross-sectional view of the injection flow sealing device directly above the injection pipe according to the embodiment of the present invention, FIG. 2 is a view taken along the arrow A-A in FIG. 4a, b, and c are cross-sectional views of a conventional injection flow sealing device directly above an injection pipe. 1... Ladle, 2... Ladle nozzle, 3... Injection pipe, 4...
Upper hood, 5...inner cylinder hood, 6...outer cylinder hood,
7... Addition pipe, 8... Dust collection pipe, 9... Spring, 10... Mold hood, 11... Seal material, 12... Seal device,
13...Annular tube.

Claims (1)

[Scope of utility model registration request] A vertically extendable inner cylinder hood that is equipped with an inert gas addition pipe and surrounds the top of the molten metal injection pipe to maintain positive pressure inside, and a vertically extendable outer cylinder that surrounds the inner cylinder hood and is connected to a gas suction pipe. 1. A sealing device for injection flow in ingot pouring casting, comprising a hood and a dust collector for collecting dust from the gas suction pipe.