JP2010189687A - Gas-blowing plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas-blowing plug which prevents an intrusion of a molten metal when the supply of a gas is stopped, and prevents the leakage of the molten metal through the gas-blowing plug. <P>SOLUTION: The gas-blowing plug 1 includes: a gas-permeable refractory layer 10; a casing 20 which covers the outer surface of the refractory layer except at least an end face 11; and a gas supply pipe 30 of which one end is connected to the inner part of the casing so as to be communicated with each other, and the other end is connected to a gas supply source. The casing is structured so that the long axis direction of the gas supply pipe approximately corresponds to the vertical direction, and the end face 11 directs to the inside of the container and is fitted in a hole which passes through the bottom part of the container; and includes a valve seat 41 which is projected from the inner peripheral surface of the gas supply pipe, and a valve body 51 which is accommodated above the valve seat in the gas supply pipe so as to move up and down freely and is seated on the valve seat to block the gas supply pipe. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas blowing plug used for blowing gas into molten metal.

  In the steelmaking process, a gas blowing plug using a gas-permeable refractory is attached to the bottom of a container such as a ladle to stir molten metal, adjust the temperature, and accelerate the removal reaction of nonmetallic components. A process of blowing a gas such as nitrogen into the molten metal is performed. This gas blowing plug is roughly divided into a porous plug using a porous refractory as a gas permeable refractory, and a slit plug in which a slit-like through hole is formed in a dense amorphous refractory layer. The continuous ventilation holes in the porous layer and the slit-shaped through holes in the dense layer serve as gas flow passages for allowing gas to flow through the refractory layer.

  In the above process, the supply of gas to the gas blowing plug may be stopped in a state where the molten metal is contained in a container such as a ladle. For example, in the secondary refining process, prior to the gas blowing process for secondary refining, the gas is also blown when the molten metal is introduced into the container, but the molten metal is introduced into the container. The molten metal is transported together with the container from the place where the refining is performed to the place where the secondary refining is performed, while the gas blowing plug is disconnected from the gas supply source.

  Therefore, when the gas is not circulating, the inside of the gas blowing plug has a low pressure, and the molten metal easily enters the gas flow passage in the refractory layer of the gas blowing plug. And there existed a possibility that the molten metal which penetrated might leak out of containers, such as a ladle, via the pipe which supplies gas to the refractory layer of a gas blowing plug. In addition, the metal that has entered the refractory layer is cooled and solidified, and the gas flow path is blocked, so that the next gas blowing process becomes difficult.

  Therefore, conventionally, a tank is attached to a container such as a ladle, gas is stored in this tank in a pressurized state, and gas is supplied from this tank to the gas blowing plug when disconnected from the gas supply source. Has been proposed (see, for example, Patent Documents 1 and 2). Here, the technique of Patent Document 1 is to fill a tank with gas prior to the start of supply of gas to the gas blowing plug, and the technique of Patent Document 2 is to supply gas to the gas blowing plug. The tank is filled with gas.

  According to the techniques of Patent Documents 1 and 2, gas can be continuously supplied to the gas blowing plug at a low pressure necessary and sufficient to prevent the intrusion of the molten metal, so that the intrusion of the molten metal into the refractory layer is effective. Can be deterred. However, it is necessary to install a tank for each container, and equipment for switching the gas flow is required for filling the gas into the tank and releasing the gas from the tank. At the same time, it takes time and effort to switch the gas flow.

  Accordingly, in view of the above circumstances, the present invention is a gas blowing plug that is attached to a container containing molten metal and blows gas into the molten metal, and the gas supply to the gas blowing plug is cut off with a simple configuration. It is an object of the present invention to provide a gas blowing plug that can suppress the intrusion of molten metal when sagging and can prevent leakage of the molten metal through the gas blowing plug.

  In order to solve the above problems, a gas blowing plug according to the present invention is a gas blowing plug that is attached to a container containing molten metal and supplies gas to the molten metal, and is a gas-permeable refractory layer, A casing that covers the outer surface of the refractory layer except at least one end face, and a gas that is connected to the casing so that one end communicates with the interior of the casing and the other end is connected to a gas supply source. The casing includes a supply pipe, and the long axis direction of the gas supply pipe substantially coincides with the vertical direction, and the end face of the refractory layer not covered by the casing faces the inside of the container. A valve seat protruding from an inner peripheral surface of the gas supply pipe, and a vertical movement self-moving above the valve seat in the gas supply pipe; Housed in comprises a valve body which closes the gas supply pipe is seated on the valve seat "is intended.

  As the "gas permeable refractory layer", a porous refractory layer, a refractory layer in which a large number of slit-like through-holes are formed in a dense refractory layer formed using an amorphous refractory material, or The refractory layer which compounded both can be illustrated. In addition, the dense refractory layer in which the slit-like through-hole is formed penetrates the flammable material of the filament that is burned down by combustion into a molded body formed into a predetermined shape using, for example, an amorphous refractory material. Thus, it can be manufactured by arranging a large number of them and then burning them.

  Here, the kind of the refractory material constituting the gas-permeable refractory layer is not particularly limited, and examples thereof include alumina-silica, high alumina, alumina-chromium, alumina-magnesia, magnesia-chromium, and the like. Refractory materials can be used. In addition, the outer shape of the refractory layer is not particularly limited, and may be, for example, a truncated cone shape, a truncated pyramid shape, a cylindrical shape, or a quadrangular prism shape.

  The “casing” can be formed of a metal such as iron, steel, alloy steel. In addition, since “the end face of the refractory layer not covered with the casing” is arranged “to face the inside of the container”, gas is blown into the molten metal from this end face. “Coating the outer surface of the refractory layer with a casing excluding at least one end face” means that, of the outer surface of the refractory layer, the end face where gas is blown into the molten metal is not covered with at least the casing. The outer surface other than the end surface may have a surface that is not covered by the casing. For example, when the refractory layer is formed in a frustoconical shape or a truncated pyramid shape, in addition to the end surface of the head (end surface on the reduced diameter side), the portion near the head on the side circumferential surface is not covered with the casing. It can be configured. In such a configuration, since the casing does not reach the end contacting the molten metal, it is possible to prevent the metal casing from being damaged by the molten metal. In the following description, for convenience, the end face in contact with the molten metal in the refractory layer will be referred to as a “gas blowing end face”.

  As a configuration in which the casing is “fitted into a hole that penetrates the bottom of the container”, a configuration in which the casing is inserted into the through hole formed in the bottom of the container such as a ladle via tuyere bricks is used. It can be illustrated.

  The shape of the “valve seat” is not particularly limited as long as it “projects from the inner peripheral surface of the gas supply pipe”, but the gas flow passage inside the gas supply pipe is narrowed by the valve seat. It is formed in a size and shape that will not be blocked. Further, the shape of the “valve element” is not particularly limited, but it is naturally formed in a size and shape that does not pass through the gas supply path narrowed by the valve seat. The valve body can be formed of metal, ceramics, or the like.

  According to the above configuration, since the major axis direction of the gas supply pipe is substantially vertical, gravity acts on the valve body so as to drop the gas supply pipe. Therefore, when no gas is supplied from the gas supply source, or when the pressure of the gas supplied from the gas supply source is low and the force by which the valve body is pushed up is smaller than the gravity acting on the valve body, The body sits on the valve seat and the gas flow passage is closed in the gas supply pipe. On the other hand, when gas is supplied from the gas supply source and the pushing force by the gas exceeds the gravity acting on the valve body, the valve body is lifted and a gap is formed between the valve seat and the valve body. As a result, gas flows in the gas supply pipe through this gap, gas is supplied to the gas-permeable refractory layer, and further, gas flows in the refractory layer and enters the molten metal from the gas blowing end face. Released.

  Thereafter, when the supply of gas from the gas supply source is stopped, the valve body descends due to gravity and sits on the valve seat, thereby closing the gas flow passage. In this state, the liquid in the refractory layer starts from the valve seat part where the gas supply pipe is closed, as if the liquid inside does not flow even if the straw is lifted after closing one end of the straw immersed in the liquid. Gas is held in the space reaching the blowing end face. Accordingly, even when the supply of gas from the gas supply source is stopped in a state where the molten metal is contained in the container, the molten metal is retained in the refractory layer in a state where the gas is filled. Can be prevented from entering the refractory layer.

  Conventionally, not only when the supply of gas is stopped in a state where the molten metal is contained in the container, but even after the molten metal is discharged from the container, the molten metal remaining in the container is in the refractory layer. There was a problem of getting in. According to the present invention, even in this case, as described above, the gas supply pipe is closed with the valve body before the molten metal is discharged from the container, and the inside of the refractory layer is kept filled with gas. Therefore, it is possible to prevent the molten metal remaining in the container from entering the refractory layer.

  Furthermore, when the molten metal is accommodated in the container, the refractory layer is heated by the high-temperature molten metal, and even after the molten metal is discharged, the refractory layer is heated by the residual heat. . For this reason, the volume of the gas held in the refractory layer expands, and the gas corresponding to the expansion leaks little by little from the gas blowing end face. Such a phenomenon can more reliably prevent the molten metal from entering the refractory layer.

  In addition, even if the molten metal that has entered the refractory layer flows into the gas supply pipe, the molten metal flows down on the valve body provided in the gas supply pipe. As a result, due to the gravity acting on the metal having a large specific gravity, the valve body is pushed down against the force of the gas pushing up the valve body, and the gas flow passage is closed in the gas supply pipe. Thereby, the leakage of the molten metal through the gas blowing plug can be effectively prevented.

  Here, when focusing only on the action of closing the gas flow passage when the gas supply is stopped, a configuration in which a valve body is provided on the casing side from the connection portion between the gas supply pipe and the casing can be conceived. For example, when the gas pool part for expanding the gas flow path is provided in the casing, the end of the gas supply pipe is closed by the valve body falling from the gas pool part side when the gas supply is stopped. I can think of it. However, in such a configuration, if the molten metal flows in for some reason such as cracking or cracking of the refractory layer in a state where the gas is supplied, that is, the valve body is lifted, the gas supply It is not possible to stop the molten metal from flowing into the tube. On the other hand, in the present invention, since the valve body is provided in the gas supply pipe, even if the valve body is lifted by the gas supply, the molten metal that has flowed down flows onto the valve body, Since the body is pushed down and the gas flow passage is closed, leakage of the molten metal through the gas blowing plug can be effectively prevented.

  As described above, according to the present invention, the gas supply pipe is naturally closed when the gas supply is stopped and when the molten metal flows in, so that the refractory does not require any manual operation or monitoring. Intrusion of molten metal into the layer and leakage to the outside can be prevented. And since it is the very simple structure which provides a valve body and a valve seat in a gas supply pipe | tube, the gas blowing plug which shows said outstanding effect at low cost can be manufactured.

  The gas blowing plug according to the present invention includes, in addition to the above-described configuration, “an annular protrusion that is annularly provided above the valve body and along the inner peripheral surface of the gas supply pipe”. be able to.

  According to the present invention having the above configuration, no matter how the molten metal infiltrated into the refractory layer flows, it is guided by the annular protrusion protruding in an annular shape along the inner peripheral surface of the gas supply pipe, It is easy to fall near the center of the gas supply pipe. As a result, the molten metal is highly likely to drop onto the valve body, and the leakage of the molten metal can be more reliably prevented by blocking the gas flow passage by pushing down the valve body.

  In addition to the above-described configuration, the gas blowing plug according to the present invention may include “a spring member that is biased in a direction in which the valve body is pushed down or pushed up”.

  In the above configuration, when the valve body is urged in the direction in which it is pushed down, only gravity acts on the valve body in order to push up the valve body against this force and open the gas flow passage. Compared to the case, it is necessary to supply the gas at a large pressure. On the other hand, when the valve body is urged in the direction in which it is pushed up, it is possible to open the gas flow path by pushing up the valve body with a gas having a lower pressure than when only gravity acts on the valve body. it can. Therefore, according to the present invention, conditions for opening or closing the gas flow passage can be easily adjusted as compared with the case where the size, shape, mass, etc. of the valve body are adjusted only by setting the valve body. . Further, by using springs with different tensions, the above conditions can be easily finely adjusted.

  As described above, the effect of the present invention is a gas blowing plug that is attached to a container containing molten metal and blows gas into the molten metal, and the gas supply to the gas blowing plug is cut off with a simple configuration. In addition, it is possible to provide a gas blowing plug that can suppress the intrusion of molten metal and prevent leakage of the molten metal through the gas blowing plug.

It is an end elevation which shows the structure of the gas blowing plug of 1st embodiment. It is explanatory drawing of the use condition of the gas blowing plug of FIG. It is explanatory drawing which shows the motion of the valve body in the gas blowing plug of FIG. It is an end view which shows the structure of the gas blowing plug of 2nd embodiment. It is explanatory drawing which shows the motion of the valve body in the gas blowing plug of FIG. It is an end view which shows the structure of the gas blowing plug of 3rd embodiment. It is explanatory drawing which shows the motion of the valve body in the gas blowing plug of FIG. It is an end view which shows the structure of the gas blowing plug of other embodiment.

  Hereinafter, the gas blowing plug 1 which is 1st embodiment of this invention is demonstrated based on FIG. 1 thru | or FIG. FIG. 1 is an end view when the gas blowing plug 1 is divided at the center in the vertical direction.

  The gas blowing plug 1 according to the first embodiment is a gas blowing plug 1 that is attached to a container 90 that contains a molten metal M and supplies gas to the molten metal M. The gas blowing plug 1 includes a gas-permeable refractory layer 10 and a refractory. The casing 20 that covers the outer surface of the layer 10 except at least the end face 11, and one end 31 is connected to the casing 20 so as to communicate with the inside of the casing 20, and the other end 32 is a gas supply source The casing 20 has a gas supply pipe 30 connected to the casing 20, the major axis direction of the gas supply pipe 30 substantially coincides with the vertical direction, and the end surface 11 of the refractory layer 10 not covered with the casing 20 is the container 90. The valve seat 41 is fitted into a hole 95 penetrating the bottom of the container 90 so as to face the inside of the container 90, and protrudes from the inner peripheral surface of the gas supply pipe 30, and the gas supply pipe 30. To be vertically movably housed above the valve seat 41, and a valve element 51 for closing the gas supply pipe 30 is seated on the valve seat 41.

  More specifically, the gas-permeable refractory layer 10 is formed in a frustoconical shape, and excluding the end surface 11 on the diameter-reduced side, the side peripheral surface and the end surface 12 on the expanded side. Is covered by a metal casing 20. Here, the side peripheral surface of the refractory layer 10 is not covered with the casing 20 on the end surface 11 side, and the casing 20 does not reach the end surface 11. Further, a space as a gas pool portion 25 is formed in the casing 20 between the end surface 12 and the refractory layer 10. The casing 20 is welded to the surface covering the end face 12 so that one end 31 of a metal-made cylindrical gas supply pipe 30 is opened, and the inside of the gas supply pipe 30 and the casing are welded. 20 communicates with the inside. The gas supply pipe 30 is connected to the casing 20 so as to be perpendicular to the end face 12.

  As described above, the casing 20 that covers the refractory layer 10 and is connected to the gas supply pipe 30 has a hole penetrating through the bottom of the container 90 containing the molten metal M, as schematically shown in FIG. The portion 95 is fitted with the end surface 11 facing upward (inside the container 90). Thereby, the major axis direction of the gas supply pipe 30 substantially coincides with the vertical direction. The end 32 of the gas supply pipe 30 (the end opposite to the end 31) is connected to a gas supply source (not shown). With the above configuration, the gas supplied from the gas supply source flows from the bottom to the top in the vertical gas supply pipe 30 (in the direction of the arrow in the drawing), and flows into the casing 20 through the end portion 31. Then, after the gas is expanded in the gas pool section 25, the gas flows into the refractory layer 10, flows through the refractory layer 10, is released from the end face 11, and is supplied into the molten metal M. The end face 11 corresponds to the above-mentioned “gas blowing end face”.

  Inside the gas supply pipe 30, an annular protrusion 61 that protrudes annularly along the inner peripheral surface in the vicinity of the end portion 31 is provided. Further, the valve seat 41 is provided in a ring-like manner along the inner peripheral surface of the gas supply pipe 30 below a predetermined distance from the annular protrusion 61. A valve body 51 is accommodated in the space between the valve seat 41 and the annular protrusion 61. Further, the valve body 51 of the first embodiment is spherical, and the diameter thereof is larger than the inner circumference of the valve seat 41 and the inner circumference of the annular protrusion 61 and is movable in the gas supply pipe 30. The diameter is set. That is, the valve body 51 is movable up and down between the valve seat 41 and the annular protrusion 61. In the first embodiment, the upper surface of the valve seat 41 and the lower surface of the annular protrusion 61 are formed in a cross-sectional arc shape along the spherical surface of the valve body 51.

  Next, the movement of the valve body 51 in the gas blowing plug 1 of the first embodiment will be described with reference to FIG. Here, FIG. 3 is an enlarged view of the range A in FIG. First, in a state where no gas is supplied from the gas supply source, the valve body 51 is seated on the valve seat 41 by gravity as shown in FIG. When gas is supplied from the gas supply source, a force that pushes up the valve body 51 by the gas flowing from the bottom to the top in the gas supply pipe 30 acts. When the pushing force becomes larger than the gravity acting on the valve body 51, the valve body 51 is lifted as shown in FIG. 3B, and a gap is formed between the valve seat 41 and the valve body 51. As a result, as shown by the arrows in the figure, the gas flows and flows into the gas pool portion 25, and the gas is blown into the molten metal as described above.

  When the supply of gas from the gas supply source is stopped, the force to push up the valve body 51 against gravity is lost, so that the valve body 51 naturally falls and again returns to the valve seat 41 as shown in FIG. Sit down. As a result, the gas flow passage 35 is closed in the gas supply pipe 30 and the refractory layer 10 is held in a state filled with gas, so that molten metal can be prevented from entering the refractory layer 10. . In addition, since the upper surface of the valve seat 41 is formed in a shape that follows the outer shape of the spherical valve body 51, the valve seat 41 and the valve body 51 are in surface contact with each other, and the gas flow passage 35 is reliably closed. Is done.

  On the other hand, as shown in FIG. 3 (b), the molten metal is introduced into the gas blowing plug 1 due to the occurrence of cracks or cracks in the refractory layer 10 in the state where the valve body 51 is lifted and the gas is circulating. When flowing in, the molten metal flows down onto the valve body 51 in the gas supply pipe 30 as indicated by an arrow in FIG. At this time, since the annular protrusion 61 is formed above the valve body 51, the molten metal is guided by the annular protrusion 61 and easily flows down near the center of the gas supply pipe 30. Fall. Accordingly, the gravity acting on the molten metal having a large specific gravity depresses the valve body 51 against the force by which the gas pushes up the valve body 51, and as shown in FIG. Is blocked. As a result, the molten metal does not flow downward from the valve seat 41, and the molten metal is prevented from leaking outside through the gas blowing plug 1. Moreover, as mentioned above, when the valve seat 41 and the valve body 51 are in surface contact, the molten metal is reliably prevented from flowing down.

  The annular protrusion 61 acts as a stopper for the valve body 51 that is lifted by the pushing-up force of the gas, in addition to the effect of guiding the molten metal as described above. Accordingly, even when gas is supplied from the gas supply source at a pressure equal to or higher than a predetermined value due to some abnormality, the valve body 51 jumps out of the gas supply pipe 30 and collides with the refractory layer 10, and the refractory layer 10 is damaged. In addition to preventing the gas from being received, the gas can be prevented from being supplied to the refractory layer 10 at an abnormally high pressure.

  Next, the gas blowing plug 2 of 2nd embodiment is demonstrated using FIG.4 and FIG.5. The difference in configuration from the first embodiment is the shapes of the valve body 52, the valve seat 42, and the annular protrusion 62. Below, the same code | symbol is attached | subjected about the structure similar to 1st embodiment, and detailed description is abbreviate | omitted.

  The valve body 52 of the second embodiment has a shape in which a cylinder is extended below a frustoconical shape with the reduced diameter side facing downward. And the upper surface of the valve seat 42 is formed in the taper shape which has the same inclination as the inclination of the taper part of the valve body 52. On the other hand, the lower surface of the annular protrusion 62 is formed on a horizontal surface corresponding to the upper surface of the valve body 52.

  The movement of the valve body 52 in the gas blowing plug 2 of the second embodiment is shown in FIG. 5 is an enlarged view of the range B in FIG. 4. FIG. 5A shows the case where there is no supply of gas, or the pushing force by the gas is smaller than the gravity acting on the valve body 52. FIG. 5B shows a case where the pushing force by the gas is larger than the gravity acting on the valve body 52, and FIG. 5C shows a case where the molten metal flows through the refractory layer 10. Since the movement of the valve body 52 in each state is the same as that of the first embodiment described with reference to FIG. 3, detailed description thereof is omitted.

  Next, the gas blowing plug 3 of 3rd embodiment is demonstrated using FIG.6 and FIG.7. The difference in configuration between the first embodiment and the second embodiment is that a spring member 71 that biases the valve body 53 is provided in addition to the shapes of the valve body 53 and the valve seat 43. Further, an annular protrusion 63 having the same configuration as the annular protrusion 62 is provided.

  The valve body 53 of the third embodiment has a disk shape, and the upper surface of the valve seat 43 and the lower surface of the annular protrusion 63 are both formed on a horizontal surface. The spring member 71 is a coil spring. One end of the spring member 71 is attached to the lower surface of the valve body 53, and the other end is attached to a spring support member 33 projecting from the inner peripheral surface of the gas supply pipe 30. .

  The movement of the valve body 53 in the gas blowing plug 3 of the third embodiment is shown in FIG. FIG. 7 is an enlarged view of the range C in FIG. Below, the same code | symbol is attached | subjected about the structure similar to 1st embodiment and 2nd embodiment, and detailed description is abbreviate | omitted.

  First, when gas is not supplied from the gas supply source, or when the force by which the valve body 53 is pushed up by the gas is smaller than the force that acts to push down the valve body 53, as shown in FIG. The valve body 53 is seated on the valve seat 43, and the gas flow pipe 30 is closed. Here, when the spring member 71 is a tension spring (when the spring member 71 is stretched and the valve body 53 is in contact with the valve seat 43), the valve body 53 has a force larger than the gravity acting on the valve body 53 itself. Pressed down. On the other hand, when the spring member 71 is a compression spring (when the spring member 71 is compressed between the spring support member 33 and the valve body 53 and the valve body 53 is in contact with the valve seat 43), the valve body 53 is It is pushed down with a force smaller than the gravity acting on the valve body 53 itself.

  Therefore, when the gas is supplied from the gas supply source, when the spring member 71 is a tension spring, the valve element 53 is lifted as shown in FIG. 7B with a larger gas pressure than when the spring member 71 is not provided. Therefore, even if gas is supplied, if the condition is set so that the gas flow passage 35 is closed when the pressure is smaller than a predetermined value, the adjustment is easy. On the other hand, when the spring member 71 is a compression spring, the gas flow passage 35 is released when the gas is supplied at a lower pressure than when the spring member 71 is not provided. Thereby, when the valve body 53 is formed of a material having a large specific gravity such as metal, the gas flow passage 35 can be opened even if the gas pressure is not so high.

  As shown in FIG. 7C, when molten metal flows in through the refractory layer 10 in a state where the gas is supplied from the gas supply source and the valve body 53 is lifted, the valve body is caused by the molten metal flowing down. The lowering operation of 53 is more sensitive when the spring member 71 is a tension spring than when there is no spring member 71, and when the spring member 71 is a compression spring, the response is slower than when there is no spring member 71. Responsiveness can be adjusted by the tension of the member.

  Also in the third embodiment, since the annular protrusion 63 is provided above the valve body 53, the molten metal that has flowed in is guided by the annular protrusion 63 and easily flows down near the center of the gas supply pipe 30. Further, leakage of molten metal can be reliably prevented.

  As described above, according to the gas blowing plugs of the first embodiment to the third embodiment, when the gas supply is stopped and when the molten metal flows in through the refractory layer 10, the gas supply pipe 30 naturally. Since the gas flow path 35 is closed in the inside, it is possible to prevent the molten metal from entering the refractory layer 10 or leaking to the outside without any manual operation or monitoring. And since it is the very simple structure of providing a valve body and a valve seat in the gas supply pipe 30, the gas blowing plugs 1, 2, and 3 which show said outstanding effect at low cost can be manufactured.

  Further, since each of the gas blowing plugs 1, 2, 3 has an annular protrusion formed along the inner peripheral surface of the gas supply pipe 30 above the valve body, the molten metal passes through the refractory layer 10. Even when it flows in, the molten metal is highly likely to drop onto the valve body, and the leakage of the molten metal can be surely prevented by the blockage of the gas flow passage 35 due to the depression of the valve body.

  Furthermore, since the gas blowing plug 3 of the third embodiment includes the spring member 71, the condition for opening or closing the gas flow passage 35 can be easily adjusted by setting the valve body 53 and the spring member 71. ing.

  The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements can be made without departing from the scope of the present invention as described below. And design changes are possible.

  For example, although the case where the shape of the gas-permeable refractory layer is a frustoconical shape is illustrated, the present invention is not limited to this, and a cylindrical shape or a truncated pyramid shape can be used. Further, the shapes of the valve body and the valve seat are not limited to the shapes exemplified above as long as the gas flow path can be closed by the contact of both.

  Further, in the above, the case where the annular protrusion also serves as a stopper that prevents the valve body from popping out is illustrated. However, as illustrated in FIG. 8, a plurality of protrusions separated from the inner peripheral surface of the gas supply pipe 30 are projected. A stopper 64 constituted by the above member can be provided below the annular protrusion 65. Here, FIG. 8A shows a portion corresponding to the range A in FIG. 1, and FIG. 8B is an end view taken along line XX in the gas supply pipe 30 of FIG. 8A. FIG. 8C is an end view taken along line YY in the gas supply pipe 30 of FIG. With such a configuration, the gas flow passage 35 is formed by the valve body 51 while the valve body 51 pushed up by the pressure of the gas supplied from the gas supply source to the gas supply pipe 30 is in contact with the stopper 64. Gas is blown into the molten metal through the refractory layer 10 without being blocked.

1, 2, 3 Gas blowing plug 10 Refractory layer 11 End face 20 of refractory layer not covered with casing Casing 30 Gas supply pipes 41, 42, 43 Valve seats 51, 52, 53 Valve bodies 61, 62, 63 Annular Projection 71 Spring member 90 Container 95 Hole through the bottom of the container

Japanese Patent No. 2844322 Japanese Patent No. 4107409

Claims (3)

A gas blowing plug that is attached to a container containing molten metal and supplies gas to the molten metal,
A gas-permeable refractory layer, a casing covering the outer surface of the refractory layer excluding at least one end surface, and one end connected to the casing so as to communicate with the inside of the casing and the other end being a gas A gas supply pipe connected to the supply source;
The casing penetrates the bottom of the container so that the major axis direction of the gas supply pipe substantially coincides with the vertical direction, and the end surface of the refractory layer not covered by the casing faces the inside of the container. Fitted into the hole to be
A valve seat protruding from the inner peripheral surface of the gas supply pipe;
A gas blowing plug comprising: a valve body which is accommodated in the gas supply pipe so as to be movable up and down above the valve seat, and which is seated on the valve seat and closes the gas supply pipe.   2. The gas blowing plug according to claim 1, further comprising an annular protrusion protruding annularly along an inner peripheral surface of the gas supply pipe above the valve body.   The gas blowing plug according to claim 1, further comprising a spring member that is biased in a direction in which the valve body is pushed down or pushed up.

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