JP2022165030A - gas blowing pipe - Google Patents

Abstract

To provide a gas blowing pipe preventing bumping and backflow of molten metal into the gas pipe.SOLUTION: Gas 22 is blown into molten metal in a molten metal container through a gas blowing pipe 1 immersed thereinto. The gas blowing pipe 1 has a connection member 2 having a first end 7 and a second end 8, a porous member 3 formed in the connection member 2, and a gas pipe 4 connected to the second end 8 of the connection member 2. A through-hole part 9 is formed inside the connection part 2. The porous member 3 is formed to cover a first end periphery 7a jointed to the first end 7, to close the through-hole part 9 facing the first end 7, and further, to close at least a part of the inside in the through-hole part 9. The gas blowing pipe 1 is immersed in the molten metal in the molten metal container, and when gas 22 is introduced through the gas pipe 4, the gas 22 is blown into the molten metal container through the porous member 3.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a gas blowing pipe that is immersed in molten metal in a molten metal container and blows gas into it.

Conventionally, in order to eliminate gases such as oxygen and hydrogen mixed in the molten metal, gas injection is performed by blowing an inert gas into the molten metal. For example, as a conventional example, a gas injection device for a holding furnace described in Patent Document 1 has a gas injection pipe installed in the molten metal holding furnace, and the tip of the gas injection pipe is extended to the vicinity of the bottom surface of the molten metal holding furnace. is. A porous blower is connected to the tip of the gas blowing pipe. The inert gas flows into the holding furnace through the blowing pipe and diffuses into the molten metal through the pores of this blowing tool. According to this configuration, the inert gas physically adsorbs oxygen in the molten metal and renders the oxygen inactive.

Japanese Patent Laid-Open No. 4-200858

However, in the conventional example, the blowout tool is connected only to the tip of the gas blowing pipe, so there is a risk that the blowout tool will fall off and be damaged due to the pressure of the gas when the gas is blown. In that case, there is a risk of sudden boiling, in which the gas is vigorously blown out from the tip. In addition, when the holding furnace is pressurized, the molten metal may flow back into the gas injection pipe.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas blowing pipe which prevents bumping and reverse flow of molten metal into the gas pipe.

A gas blowing pipe according to an aspect of the present invention is a gas blowing pipe that is immersed in a molten metal in a molten metal container and blows gas, and comprises a connection member having a first end and a second end, and and a gas pipe connected to the second end of the connection member, wherein the connection member has a through hole formed therein, and the porous member is connected to the first end. covering the outer peripheral part of the first end connected to the part, closing the through hole facing the first end, and further, in the through hole, formed so as to block at least a part of the inside, in the molten metal container When the gas is introduced from the gas pipe, the gas is blown into the molten metal container through the porous member.

According to this, the porous member covers the outer peripheral portion of the first end portion connected to the first end portion, closes the through hole portion facing the first end portion, and further at least partially fills the interior of the through hole portion. Formed to block. Since the gas blown into the molten metal passes through the porous member, the pressure is reduced and the occurrence of bumping can be prevented. Moreover, since the porous member is provided in at least a part of the inside of the through-hole portion, even if the porous member at the first end falls off, the molten metal can be prevented from flowing back into the gas pipe.

Further, in the gas injection pipe, the porous member includes a first porous member and a second porous member, and the first porous member is the first porous member connected to the first end. The second porous member may cover the outer peripheral portion of the end portion and block the through hole portion facing the first end portion, and block at least part of the interior of the through hole portion.

In this case, since the porous member is divided into two members, each member can be easily formed as a connecting member independently. In addition, since the first porous member and the second porous member can be formed in independent shapes, the degree of freedom in manufacturing increases.

Further, in the gas injection pipe, the through-hole portion is located on the end face of the second porous member on the first end side and the end face of the first porous member on the second end side. and the gas injected through the gas pipe passes through the space after passing through the second porous member, and further through the first porous member It may be blown into the molten metal.

In this case, a space is formed in the gas blowing pipe. Since the space is not filled with the porous member, compared with the case where the space is filled with the porous member, the volume of material corresponding to the space is reduced, and the material cost can be reduced.

Further, in the gas injection pipe, the first porous member and the second porous member may be made of the same material. In this case, by forming the first porous member and the second porous member from the same material, the material cost can be reduced, and the same construction method can be used.

Further, in the gas injection pipe, the first porous member and the second porous member may be made of different materials. In this case, in the gas flow path, by forming the first porous member and the second porous member that are arranged in series with different materials, , the properties of different porous materials can be exploited.

FIG. 2 is a diagram showing a state in which the gas blowing pipe 1 of the present invention is immersed in a molten metal container 20; 1A and 1B are diagrams showing a gas injection pipe 1a (11a, 12a) which is a first embodiment of the present invention, and includes a space portion 6 inside a through hole portion 9, and (a) and (b) are through hole portions The second end side of is filled with the second porous member, and in (c), a recess 16 without the second porous member is formed in a part of the through hole on the second end side indicates when FIG. 11A is a diagram showing a gas injection pipe 1b (11b) according to a second embodiment of the present invention, in which the through-hole portion 9 does not have a space portion 6; (b) shows a case where the first porous member 13 is formed up to the inside of the through-hole portion 9, and the through-hole portion 9 is formed between the second porous member 23 and the first porous member 23; It shows the case of being filled with the porous member 13 . Fig. 10 is a diagram showing a gas injection pipe 1c (11c) according to a third embodiment of the present invention, in which the porous member 3 is formed by one, and (a) shows a case where the porous member 3 is made of a shaped refractory; and (b) shows the case where the porous member 3 is made of a monolithic refractory. A diagram showing a gas injection pipe 1d (11d) that is a fourth embodiment of the present invention, showing a case where the first porous member 13 and the second porous member 23 are made of different materials, (a) shows the case where the second porous member is made of a shaped refractory and the first porous member is made of a monolithic refractory, and (b) shows the case where the second porous member is made of a monolithic refractory or It is made of ceramic fibers and the first porous member is made of a regular refractory. 2(a) and 2(c) in the gas blowing pipe of the present invention; FIG. FIG. 4 is a diagram showing a method of manufacturing the gas blowing pipe of the present invention in the cases shown in FIGS. 2(b), 3, 4(a), and 4(b). It is a figure which shows the conventional gas injection pipe|tube, and shows the case where only the member corresponded to the 1st porous member 13 is formed.

Hereinafter, a gas blowing pipe 1 embodying the present invention will be described with reference to the drawings. The referenced drawings are used to explain technical features that the present invention can employ. The configuration of the device described in the drawings is not meant to be limiting, but merely illustrative.

<Configuration Common to Each Embodiment>
A configuration common to each embodiment of the gas blowing pipe 1 according to the present invention will be described with reference to FIGS. 1 and 2 as an example. As shown in FIG. 1, the gas blowing pipe 1 of the present invention is immersed in a molten metal 21 in a molten metal container 20 to blow gas 22 into it.

As shown in FIG. It comprises a gas pipe 4 connected to two ends 8 . The connection member 2 has a through hole portion 9 formed therein. The porous member 3 covers the first end outer peripheral portion 7a connected to the first end portion 7, closes the through hole portion 9 facing the first end portion 7, and furthermore, at least part of the inside of the through hole portion 9 formed to block the

The gas blowing pipe 1 is immersed in the molten metal 21 in the molten metal container 20 , and when the gas 22 is introduced from the gas pipe 4 , the gas 22 is blown into the molten metal container 20 through the porous member 3 . Gas 22 is, for example, argon gas or nitrogen gas. Further, the molten metal 21 is made of, for example, non-ferrous metals such as aluminum and copper. As will be described later, the porous member 3 may be formed by one connected member, or may be formed by being separated into a plurality of members. The porous member 3 includes either shaped refractories such as ceramic fibers or shaped bricks, or monolithic refractories such as castables.

Next, the case where the porous member 3 is composed of the first porous member 13 and the second porous member 23 will be described with reference to FIG. 2 and the like. The first porous member 13 and the second porous member 23 are members independent of each other. The first porous member 13 is formed so as to cover the first end outer peripheral portion 7a connected to the first end portion 7 and block the through hole portion 9 facing the first end portion 7 . The second porous member 23 is formed so as to block at least part of the interior of the through-hole portion 9 .

<Problem to be solved and effect common to each embodiment>
The gas blowing pipe 1 described above solves the following problems and produces the effect. In the conventional gas blowing pipe, as shown in FIG. 8, the blowing tool is connected only to the tip of the gas blowing pipe. . In that case, there is a risk of sudden boiling, in which the gas is vigorously blown out from the tip. Also, if the molten metal container is pressurized, the molten metal may flow back into the gas injection pipe.

In general, by blowing an inert gas such as argon gas or nitrogen gas into molten aluminum or copper, the concentration of hydrogen mixed in the molten metal can be lowered. In addition, impurities such as oxides in the molten metal are aggregated by the gas bubbles and can be separated from the molten metal as slag, so that the performance of the metal can be improved. As a device for this degassing process, a stirring type that blows gas bubbles into small pieces from the tip of a rotating blade that rotates at high speed was often used, but trouble with the device occurred due to high speed rotation. In addition, when the amount of gas is large, it is difficult to subdivide the bubbles.

The gas blowing pipe 1 of the present invention solves these problems. Since the gas 22 blown into the molten metal 21 in the molten metal container 20 from the gas blowing pipe 1 passes through the porous member 3, the bubbles can be finely divided and the degassing performance is improved. Further, the gas 22 can separate impurities such as oxides from the molten metal 21 into slag by aggregating them with the bubbles of the gas 22 . Furthermore, since the pressure of the gas 22 is reduced, the occurrence of bumping can be prevented.

Further, as shown in the example of FIG. 2 and the like, at least part of the through-hole portion 9 is provided with the porous member 3 (in the example shown in FIG. 2, a second porous member 23 to be described later). Even if the porous member 3 around the portion 7 (in the example shown in FIG. 2, the first porous member 13 to be described later) falls off, the porous member 3 formed inside the through-hole portion 9 ( In the example shown, the second porous member 23) serves as a breakwater. Therefore, it is possible to prevent the molten metal 21 from flowing back into the gas pipe 4 .

Moreover, when the porous member 3 is composed of the first porous member 13 and the second porous member 23, the following effects are obtained. That is, since the gas blowing pipe 1 is formed by serially forming the first porous member 13 and the second porous member 23, even if one of the members is detached, the other can compensate for its function. be able to. The functions are a function of breaking up the bubbles of the gas 22 and blowing them into the molten metal 21 and a function of preventing the molten metal 21 from flowing back into the gas pipe 4 .

Furthermore, in the gas blowing pipe 1, the gas 22 blown from the gas pipe 4 passes through the second porous member 23, which is the porous member 3, and the first porous member 13, and blows into the molten metal 21. can be subdivided. The gas 22 can improve degassing performance. In addition, the effect of aggregating impurities such as oxides in the molten metal 21 by the bubbles and separating them as slag can be further enhanced.

<Configuration of First Embodiment>
Next, with reference to FIG. 2, the configuration of the gas blowing pipe 1a of the first embodiment according to the aspect of the present invention will be described. Descriptions of common parts that have already been described are omitted. The gas injection pipe 1a has a through-hole portion 9 formed between an end surface 23a of the second porous member 23 on the first end portion 7 side and an end surface 13a of the first porous member 13 on the second end portion 8 side. A space 6 is formed between The gas 22 injected through the gas pipe 4 passes through the space 6 after passing through the second porous member 23 , and further passes through the first porous member 13 to blow into the molten metal 21 .

In the examples shown in FIGS. 2(a) and 2(b) (gas injection pipe 1a and gas injection pipe 11a, respectively), the second porous member 23 extends through the through-hole portion 9 to the second end portion 8 of the connecting member 2. is filled to On the other hand, in the example (gas blowing pipe 12a) shown in FIG. A recess 16 is formed between the In the connection member 2 shown in FIG. 2 and the like, a stepped portion 9a is formed in the through hole portion 9, and the space portion 6 is formed between the stepped portion 9a and the first end portion 7. As shown in FIG.

As already explained, when the porous member 3 consists of the first porous member 13 and the second porous member 23, the stepped portion 9a is formed. The stepped portion 9 a serves to hold the second porous member 23 . That is, when the gas 22 is sent from the gas pipe 4 and reaches the second porous member 23 , the gas 22 exerts a force to push the second porous member 23 toward the first end portion 7 side. At that time, if there is no step portion 9a and the through hole portion 9 is straight, the second porous member 23 has no portion that receives the pressure of the gas 22, and there is a possibility that the second porous member 23 will be pushed out toward the first end portion 7 side. be. The difference between FIG. 2(a) and FIG. 2(b) will be described later.

<Effects of First Embodiment>
The gas blowing pipe 1a of the first embodiment described above has the following effects. The gas blowing pipe 1a can blow the gas 22 into the molten metal 21 at a stable pressure.

In addition to the effect common to each embodiment, the gas blowing pipe 1a has the effect of reducing the material cost by forming the space portion 6 . That is, since the space portion 6 is not filled with the porous member 3, compared with the case where the space portion 6 is filled with the porous member 3, the volume of the material corresponding to the space portion 6 is reduced, and the material cost is reduced. can be reduced.

In addition, when the second porous member 23 is a standard refractory, forming the space 6 has the effect of facilitating manufacturing. In the case of a standard refractory, the second porous member 23 is formed in advance according to the internal shape of the through-hole portion 9, but unevenness may occur on the end surface 23a on the first end portion 7 side. By forming the space 6, the end surface 23a and the end surface 13a of the first porous member 13 on the side of the second end portion 8 do not come into contact with each other. Because you can.

Furthermore, the following effects may be expected. The gas 22 passing through the gas pipe 4 enters the space 6 after passing through the second porous member 23 and is blown into the molten metal 21 through the first porous member 13 . The space 6 pools the gas 22 injected through the second porous member 23 and is maintained at a constant pressure. Then, even if the pressure of the gas 22 on the upstream side fluctuates, the space part 6 produces a damper effect that can send the gas 22 to the first porous member 13 on the downstream side at a certain range of pressure. . Therefore, the gas blowing pipe 1a can blow the gas 22 into the molten metal 21 at a stable pressure even if the pressure of the supply device for supplying the gas 22 fluctuates. Therefore, it is possible to prevent bumping that occurs when the pressure fluctuates and the gas 22 is blown in at high pressure. The above can be expected to be particularly effective when the gas 22 is blown in at a large volume.

<Structure of Gas Injection Pipe 1b of Second Embodiment>

Next, with reference to FIG. 3, the configuration of the gas injection pipe 1b (11b) of the second embodiment according to the aspect of the present invention will be described. In FIG. 3, components common to the gas blowing pipe 1a in FIG. 2 are given the same reference numerals or omitted. Also, the description of the common configuration is omitted.

The second porous member 23 and the first porous member 13 are in contact with each other in the first end portion 7 or the inside of the through-hole portion 9 of the gas blowing pipe 1b. The gas 22 injected through the gas pipe 4 is blown into the molten metal container 20 through the first porous member 13 after passing through the second porous member 23 . The surfaces of the second porous member 23 and the first porous member 13 in contact with each other may be in close contact with each other without a gap, or may be in partial contact with a partial gap.

In the gas blowing pipe 1 b shown in FIG. 3( a ), the through hole portion 9 of the connecting member 2 is filled with the second porous member 23 . The through-hole portion 9 is filled with the second porous member 23 from the first end portion 7 to the second end portion 8 of the connecting member 2 and contacts the first porous member 13 at the first end portion 7 . In the gas injection pipe 11b shown in FIG. 3(b), the through-hole portion 9 of the connection member 2 is filled with the second porous member 23 from the second end portion 8 to the step portion 9a of the connection member 2, and the first The porous member 13 is filled from the step portion 9 a to the first end portion 7 .

<Effects of Second Embodiment>
The gas blowing pipe 1b of the second embodiment described above solves the following problems and produces effects. Like the gas blowing pipe 1a, the gas blowing pipe 1b can blow the gas 22 into the molten metal 21 at a stable pressure.

The gas blowing pipe 1b (11b) extends through the entire length of the through-hole portion 9 in the connecting member 2 and the portion beyond the first end portion 7 where the gas 22 is blown. It is a structure in which the material member 13 is continuous. Therefore, the flow path of the gas 22 through the second porous member 23, which is the porous member 3, and the first porous member 13 becomes longer, and the pressure during blowing becomes more stable.

Further, the through hole portion 9 of the gas blowing pipe 1 b ( 11 b ) may be filled with the second porous member 23 or the second porous member 23 and the first porous member 13 . In this case, since the gas 22 passing through the through-hole portion 9 always passes through either the first porous member 13 or the second porous member 23, the pressure when blowing into the molten metal 21 in the molten metal container 20 is more stable.

<Configuration of the third embodiment>
Next, with reference to FIG. 4, the configuration of the gas injection pipe 1c (11c) of the third embodiment according to the aspect of the present invention will be described. The gas blowing pipe 1c (11c) differs from the gas blowing pipes 1a and 1b in that the porous member 3 is made of a member connected to one.

In the example shown in FIG. 4(a), the porous member 3 is made of a shaped refractory, and the mortar 14 is injected between the connecting member 2 and the porous member 3 to fix them without gaps. The example shown in FIG. 4(b) shows the case where the porous member 3 is made of a monolithic refractory, and the connecting member 2 is set in a mold and the material is poured into the mold.

Both the gas blowing pipe 1c shown in FIG. 4(a) and the gas blowing pipe 11c shown in FIG. It closes the through hole portion 9 facing the first end portion 7 and is formed so as to close the entire inside of the through hole portion 9 .

Since the gas 22 blown into the molten metal 21 in the molten metal container 20 from the gas injection pipes 1c and 11c passes through the porous member 3, the bubbles can be subdivided and the degassing performance is improved. Also, impurities such as oxides in the molten metal 21 can be aggregated by the bubbles of the gas 22 and separated as slag. Furthermore, since the pressure of the gas 22 is reduced, the occurrence of bumping can be prevented. In addition, since the through-hole portion 9 is provided with the porous member 3, even if the porous member 3 around the first end portion 7 falls off due to a crack, the porous member 3 formed inside the through-hole portion 9 will still serve as a breakwater. becomes. Therefore, it is possible to prevent the molten metal 21 from flowing back.

<When the first porous member and the second porous member are made of the same material and its effect>
Next, the configuration and manufacturing method when the first porous member 13 and the second porous member 23 are made of the same material will be described. The examples shown in FIGS. 2(a) and 2(c) show the case where both the first porous member 13 and the second porous member 23 are made of standard refractories. In this case, the first porous member 13 and the second porous member 23 are made of the same material. In addition, the same kind of material here means that both the first porous member 13 and the second porous member 23 are formed of a shaped refractory whose shape is fixed in advance, or both Indicates either of the cases where the refractory material is used. In addition, the case where it forms with the same raw material is also included.

The examples shown in FIGS. 2B and 3 show the case where the second porous member 23 is made of ceramic fiber or monolithic refractory. When the first porous member 13 is formed of a monolithic refractory and the second porous member 23 is formed of a monolithic refractory, the first porous member 13 and the second porous member 23 are made of the same kind of material.

Next, with reference to FIGS. 6 and 7, a method of manufacturing the gas blowing pipe 1 when the first porous member 13 and the second porous member 23 are made of the same material will be described. As shown in FIG. 6, when the first porous member 13 is a standard refractory material and the second porous member 23 is a standard refractory material, the first porous member 13 and the second porous member 23 are preformed according to the shapes of the portions to be formed in the connecting member 2 respectively. Alternatively, it is processed and attached to the connection member 2 . At that time, the connecting portions between the connecting member 2 and the second porous member 23 and the first porous member 13 are filled with the mortar 14 so that they are bonded without gaps.

In the example shown in FIG. 2 and the like, the connection member 2 uses a nipple or the like having male screw portions 7b and 8b formed on the first end portion 7 and the second end portion 8 sides, respectively. The gas pipe 4 is formed with a female screw in advance, and is screwed to the male screw portion 8b formed on the second end portion 8 of the connecting member 2 . The shape of the connection member 2 is not limited to the nipple shape, and any shape can be used as long as the member has the through hole portion 9 . For example, it may be a simple cylindrical member, in which case bonding, welding, or other methods can be applied to the connection with the gas pipe 4 . However, as already explained, when the porous member 3 consists of the first porous member 13 and the second porous member 23, the through-hole portion 9 is formed with a stepped portion 9a.

Next, as shown in FIG. 7, the case where the first porous member 13 is made of monolithic refractory and the second porous member 23 is made of monolithic refractory or ceramic fiber will be described. . The second porous member 23 is formed by injecting a monolithic refractory or ceramic fiber into the through-hole portion 9 of the connecting member 2 . On the other hand, for the first porous member 13, a mold corresponding to the first end portion 7 of the connection member 2 is manufactured, and the monolithic refractory is molded while the first end portion 7 side of the connection member 2 is attached to the mold. is injected and molded. The connection between the connecting member 2 and the gas pipe 4 is the same. In addition, even when the porous member 3 has the form shown in FIG. 4A, it is formed in the same manner as the case shown in FIG.

As described above, if the first porous member 13 and the second porous member 23 are made of the same kind of material, it is possible to reduce costs such as material management and arrangement. Moreover, when it can be formed into a fixed shape in advance by molding, such as a regular refractory, it can be formed by forming or processing it into a required shape in advance and bonding it to the connection member 2 . When ceramic fiber is used as a shaped material, it is handled in the same way as a shaped refractory.

<When the first porous member and the second porous member are made of different materials and their effects>
Next, the configuration and manufacturing method when the first porous member 13 and the second porous member 23 are made of different materials will be described. As shown in FIG. 5, the gas injection pipe 1d (11d) of the fourth embodiment shows the case where the first porous member 13 and the second porous member 23 are made of different materials. Here, the dissimilar materials refer to a so-called shaped refractory whose shape can be preliminarily fixed and a monolithic refractory or ceramic fiber on the other side, but also include the case where they are formed from different raw materials.

The gas injection pipe 1d shown in FIG. 5(a) shows the case where the second porous member 23 is made of a shaped refractory and the first porous member 13 is made of a monolithic refractory. The gas injection pipe 11d shown in FIG. 5(b) shows the case where the second porous member 23 is made of monolithic refractory or ceramic fiber, and the first porous member 13 is made of shaped refractory. Each manufacturing method is as already explained.

When the first porous member 13 and the second porous member 23 are made of different materials, they can have different properties. For example, the strength, weight, density, and porosity of each member can be easily varied.

1, 1a, 1b, 1c, 1d, 11a, 11b, 11c, 11d, 12a Gas injection pipe 2 Connection member 3 Porous member 4 Gas pipe 6 Space 7 First end 7a First end outer peripheral portion 8 Second End 9 Through hole 13 First porous member 13a End face 20 Molten metal container 21 Molten metal 22 Gas 23 Second porous member 23a End face

Claims (5)

A gas blowing pipe for blowing gas by immersing it in the molten metal in the molten metal container,
a connecting member having a first end and a second end;
a porous member formed on the connection member;
a gas pipe connected to the second end of the connecting member;
The connection member has a through hole formed therein,
The porous member is
It covers the outer periphery of the first end connected to the first end, closes the through hole facing the first end, and further closes at least a part of the interior of the through hole,
a gas blowing pipe which is immersed in the molten metal in the molten metal container and blows the gas into the molten metal container through the porous member when the gas is introduced from the gas pipe; The porous member comprises a first porous member and a second porous member,
The first porous member covers the outer periphery of the first end connected to the first end and closes the through hole facing the first end,
2. The gas blowing pipe according to claim 1, wherein said second porous member closes at least part of the interior of said through-hole portion. In the through-hole portion, a space is formed between an end face of the second porous member on the first end side and an end face of the first porous member on the second end side. is,
3. The gas injected through the gas pipe according to claim 2, after passing through the second porous member, passes through the space and further passes through the first porous member to blow into the molten metal. gas injection pipe. 4. The gas blowing pipe according to claim 2, wherein said first porous member and said second porous member are made of the same material. 4. The gas blowing pipe according to claim 2, wherein said first porous member and said second porous member are made of different materials.

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