JP2009108371A - Plug for preventing flowing-out of slag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plug for preventing flowing-out of slag which can be manufactured at a low cost, can be preserved for a long term with the light weight, can be easily matched with the inner surface of a tapping-off hole and can correspond to in the case of enlarging the inner diameter of the tapping-off hole. <P>SOLUTION: This plug for preventing the flowing-out of the slag, includes a plug body 1 formed with a clay containing refractory into tapered shape toward the tip part, and a film 2 for preventing drying, covering the outer surface of the plug body 1, and is inserted into the tapping-off hole in a converter from the outside of the converter with a jig for inserting the plug. The clay containing the refractory to constitute the plug body 1, is further kneaded with water and oil and a tubular body pushing-formed with a tug mill, is shaved to form the tapered shape. The plug is preserved for the long term and can easily be inserted into the tapping-off hole with the jig for inserting the plug and can prevent the flowing-out of the slag at the initial stage of tilting the converter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a slag outflow prevention system that seals the outlet at the initial stage of discharge so that the slag floating on the surface of the molten steel does not flow out when discharging the molten steel from the outlet of the converter to the ladle in the steelmaking factory. It is about plugs.

  The converter is equipped with a tap on the upper side, and after finishing blowing, the converter is tilted and the molten steel inside flows out from the tap into the ladle. However, since slag floats on the surface of the molten steel inside the converter, when the converter is tilted, the slag first reaches the outlet and flows out. Since a large amount of P, S and other impurities are contained in the slag, when the slag is mixed in the steel, the P concentration and the like are increased and the quality of the product is deteriorated. Therefore, it is desired that the outlet of the converter is securely sealed with a plug at the beginning of discharge to minimize the outflow of slag from the converter to the ladle.

  For this purpose, cast plugs for preventing slag outflow have been used. This slag outflow prevention plug is inserted from the tapping outlet of the converter, but it is made of a casting and is heavy and not easy to handle, and because of the casting, the inner surface of the refractory tapping outlet The slag leaks and the plug is easy to come off, and the refractory hot water outlet gradually expands in inner diameter when the hot water is repeated.Therefore, it is necessary to prepare slag outflow prevention plugs of different sizes. There were many problems such as not being able to.

  In addition, attempts were made to use slag outflow prevention plugs such as those obtained by cutting logs into cylinders, or rounded and welded steel plates, but these hard plugs are still difficult to adhere to the inner surface of the tap. There is a problem that it is easy to come off, and that when the hot water is repeatedly discharged, since the inner diameter of the hot water outlet gradually increases, it is necessary to prepare plugs for preventing slag outflow of different sizes.

  Accordingly, a slag outflow prevention plug mainly composed of aluminum silicate and clay as shown in Patent Document 1 has been developed and put into practical use. The slag outflow prevention plug of Patent Document 1 is provided with a funnel-shaped end face plate at the front end and a base plate at the rear end of a plastic plug body mainly composed of aluminum silicate and clay.

  After inserting the plug for preventing slag outflow into the outlet, pull the claw through the center hole of the plug body to the inside of the funnel-shaped end plate, and pull the funnel-shaped end plate with the claw. Can be swelled in the radial direction to close the tap. This prevents the slag from flowing out at the beginning of discharge and prevents the slag from flowing out.However, when the molten steel reaches the outlet, the specific gravity of the molten steel is much higher than that of the slag, so the plug body is pulled out by the pressure, and the molten steel Does not prevent the outflow.

  Since the plug for preventing slag outflow of this Patent Document 1 is lighter than a cast iron plug, it has an advantage that it can be easily adapted to the inner surface of the tap, and can be accommodated even if the inner diameter of the tap is expanded. It is used for practical use. However, this plug for preventing slag outflow uses a special structure such as a refractory funnel-shaped end face plate or a tension claws, and therefore has a problem that the manufacturing cost is very high.

Further, the plug body of the slag outflow prevention plug of Patent Document 1 includes aluminum silicate and clay as well as cellulose as a temporary binder, silicate as a permanent binder, mineral oil as a lubricant, polyelectrolyte alcohol as a plasticizer, etc. In addition, the cost increases due to the fact that it contains many subcomponents, and the plug body hardens due to the evaporation of moisture when stored for a long period of time. In some cases, the gate could not be completely sealed.
Japanese Patent No. 3252909

  Therefore, the object of the present invention is to solve the problem of the slag outflow prevention plug of Patent Document 1, and can be manufactured at low cost without using a special structure or special raw material, and can be stored for a long time. Another object of the present invention is to provide a plug for preventing slag outflow, which is lightweight and easy to adapt to the inner surface of the tap, and can cope with an increase in the inner diameter of the tap.

  The slag outflow prevention plug of the present invention made to solve the above problems is a slag outflow prevention plug inserted from the outside of the furnace into the outlet of the converter by a plug insertion jig, containing a refractory It is characterized by comprising a plug main body formed by shaping the clay into a tapered shape and an anti-drying film covering the outer surface of the plug main body, and a jig insertion hole is formed at the center of the plug main body.

  As described in claim 2, the taper-shaped plug body has a tip diameter equal to or smaller than the outlet of the converter and a base diameter larger than the outlet of the converter. Is preferred.

  Further, as described in claim 3, it is preferable that the plug body is configured by further kneading moisture and oil into clay containing refractory, and in this case, the plug body is formed as described in claim 4. The clay containing the refractory constituting the main body preferably contains 70% by mass or more of clay and less than 30% by mass of a chamotte refractory.

  Further, as described in claim 5, it is preferable that the plug body is formed by cutting a cylindrical body extruded by a kneader into a tapered shape.

  In addition, as described in claim 6, it is preferable that the drying prevention film is a polyethylene resin film or a polypropylene resin film.

  Furthermore, as described in claim 7, the jig for plug insertion includes a disk for pressing the bottom surface of the base of the plug body at the tip of the rod, and the jig for inserting the plug body is further inserted at the tip of the disk. It is preferable to have a rod-like portion inserted into the hole.

  The plug for preventing slag outflow of the present invention comprises a plug body formed of a refractory-containing clay in a tapered shape, and a drying prevention film covering the outer surface of the plug body. Is inserted from the outside of the furnace to seal the outlet of the converter. For this reason, the entire structure is simple and can be manufactured at a very low cost without using special structures or special raw materials. In addition, since the outer surface is covered with an anti-drying film, it is difficult to dry for a long period of time, and it is lightweight and easy to adapt to the inner surface of the tap. There is no need to make many sizes.

  If the tapered taper plug body has a tip diameter equal to or smaller than the outlet of the converter and a base diameter larger than the outlet of the converter as in the invention of claim 2. In addition, the insertion work into the tap is easy, and sealing is possible even when the refractory tap is worn out and the inner diameter is enlarged.

  If the plug body is constituted by further kneading moisture and oil into clay containing refractory as described in claim 3, the plasticity by clay and the fire resistance by refractory ensure Sealing is possible. Also, moisture and oil are effective for viscosity adjustment. Thereby, the plasticity required for sealing the outlet of the converter can be provided without using many subcomponents.

  In particular, as described in claim 4, if the clay containing the refractory constituting the plug body includes 70% by mass or more of clay and less than 30% by mass of chamotte refractory, an inexpensive raw material Thus, the characteristics required for sealing can be obtained, and there is an advantage that the cost can be significantly reduced as compared with the conventional product.

  As described in claim 5, if the plug body is formed by cutting a cylindrical body extruded by a kneader into a tapered shape, it can be manufactured at low cost, and any It can be processed into a tapered shape.

  If the film for preventing drying is a polyethylene resin film or a polypropylene resin film as described in claim 6, it is inexpensive and can prevent drying over a long period of time because of its low moisture permeability.

  According to a seventh aspect of the present invention, the plug insertion jig includes a disk that presses the bottom surface of the base of the plug body at the tip of the rod, and the jig insertion hole of the plug body at the distal end of the disk. If it is provided with a rod-like portion inserted into the plug, the structure of the plug insertion jig can be simplified, and handling is easy.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a central sectional view showing a slag outflow prevention plug according to an embodiment of the present invention. Reference numeral 1 denotes a plug body, and 2 denotes a drying prevention film covering the outer surface of the plug body 1. The plug body 1 is formed into a tapered shape as shown in the figure, and the tip diameter d is the same as or slightly smaller than the inner diameter of the tap 4 of the converter 3 shown in FIG. The diameter D is preferably slightly larger than the inner diameter of the tap 4. A small-sized jig insertion hole 5 is formed at the center of the plug body 1. The jig insertion hole 5 may be penetrated to the tip as shown in FIG. 1, or the tip may be sealed to a depth halfway.

  The plug body 1 is made of clay containing a refractory, and it is best to use the clay as it is from the viewpoint of cost reduction. However, if the refractory composed of ceramic particles is contained, the fire resistance is improved. It is preferable. Here, the clay is a raw material for ceramics.

  Furthermore, it is also preferable to uniformly add 5 to 30% by mass of moisture to the clay containing refractory and knead to give an appropriate viscosity and plasticity. Depending on the properties of the raw soil, in order to further adjust the viscosity and plasticity You may add 10 mass% or less oils, such as mineral oil or vegetable oil.

  In a preferred embodiment, the clay containing the refractory constituting the plug body 1 is composed of 70 mass% or more clay and less than 30 mass% chamotte refractory. Clay is a basic component for obtaining viscosity and plasticity, and has a certain level of fire resistance by itself, but the fire resistance can be further improved by mixing less than 30% by mass of a chamotte refractory. However, if the ratio exceeds 30% by mass, not only the viscosity and plasticity required for the plug for preventing slag outflow are lowered, but also the cost is not preferred. The particle diameter of the chamotte refractory preferably has an equivalent circle diameter of 2 mm or less in order to maintain a balance between viscosity, plasticity and fire resistance.

  Clay containing such a refractory is extruded into a cylindrical shape from a clay kneader, cut to an appropriate size, and formed into a tapered shape on a rotating table such as a potter's wheel. These series of operations are those generally performed in the technical field of ceramics, and can be formed into an arbitrary size and an arbitrary taper shape without requiring a mold. At this time, the jig insertion hole 5 can be formed. In addition, since it is also possible to extrude from a kneader into a cylindrical shape having a center hole, the center hole can be used as the jig insertion hole 5.

  In addition, as shown in Patent Document 1, it is known that the slag outflow prevention plug has a cylindrical shape, but in that case, the plug is inserted into the outlet 4 of the converter 3 and then radially inserted. It is indispensable to expand the operation. For this purpose, a jig having a special structure for pulling the front end face for preventing slag outflow backward is required. On the other hand, if the plug is formed into a tapered shape as in the present invention, the tap 4 can be reliably sealed only by a simple pushing operation by the plug insertion jig.

  In order to prevent the molded plug body 1 from drying, the outer surface thereof is coated with a film 2 for preventing drying. As the film 2 for preventing drying, a polyethylene resin film or a polypropylene resin film that is inexpensive and has low moisture permeability can be used. However, it goes without saying that other resin films may be used. It has been confirmed that the plug body 1 of the present invention covered with such a film 2 maintains viscosity and plasticity even after being molded and stored in a room temperature room for more than half a year, and there is no problem in use. .

  The plug for preventing slag outflow of the present invention is inserted into the outlet 4 of the converter 3 by manually lifting the plug as shown in FIG. 3 using the plug insertion jig 6 whose tip is shown in FIG. The The plug insertion jig 6 includes a disc 7 that presses the bottom surface of the base of the plug body 1 at the tip of a long rod, and is inserted into the jig insertion hole 5 of the plug body 1 at the tip of the disc 7 further. The rod-shaped part 8 is provided. The overall length is about 2 to 5 m. If it is too short, the worker must approach the converter. If it is too long, the tip is heavy and difficult to operate. Good. The diameter of the disk 7 is preferably substantially the same as the base diameter of the plug body 1, but it may be slightly larger or smaller.

FIG. 4 and below show how to use the slag outflow prevention plug of the present invention.
FIG. 4 shows a state in which a plug for preventing slag outflow is inserted into the outlet 4 in a state where the converter 3 is upright. Although there are molten steel 10 and slag 11 inside the converter 3, the surface of the slag 11 is located lower than the outlet 4 in the state of FIG. 4. In addition, the film 2 for drying prevention is melted and burnt down by being inserted into the hot tap 4, and only the plug body 1 is pushed into the tap 4. Since the plug body 1 has appropriate viscosity and plasticity, it is in close contact with the inner surface of the tap 4.

  When the converter 3 is tilted from this state as shown in FIG. 5, the position of the tap 4 is lowered, so that the slag 11 floating on the surface of the molten steel 10 reaches the tap 4. However, since the plug body 1 seals the outlet 4, the outflow of the slag 11 is prevented. At this time, a part of the slag 11 flows into the jig insertion hole 5 of the plug body 1, but immediately solidifies and seals the jig insertion hole 5, so that the slag 11 does not flow out of the jig insertion hole 5. . Moreover, although the contact part with the slag 11 of the plug main body 1 is exposed to high temperature, since the plug main body 1 has fire resistance and hardens | cures at high temperature, the outflow of the slag 11 is prevented reliably.

  When the converter 3 is further tilted, the molten steel 10 reaches the tap 4 as shown in FIG. Since the molten steel 10 has a much higher specific gravity than the slag 11, the plug body 1 falls off due to the pressure of the molten steel 10. And only the molten steel 10 in which the slag 11 is not mixed is discharged | emitted from the tap 4 to the ladle like FIG. Since the plug body 1 is made of clay and has the same components as the slag 11, even if it falls into the molten steel, it immediately floats. And since the mass is very small compared with the mass of the whole molten steel, it does not contaminate molten steel.

Thus, if the plug for slag outflow prevention of this invention is used, only the molten steel 10 in which the slag 11 does not mix can be taken out. In addition, the slag outflow prevention plug of the present invention can be manufactured at low cost, and is lightweight and easily adaptable to the inner surface of the tap, and can easily cope with an increase in the inner diameter of the tap. Moreover, since the outer peripheral surface of the plug body 1 is covered with the film 5 for preventing drying, it can be stored indoors for a long time.
Next, examples of the present invention will be described.

  A clay containing refractory is made by mixing 25 parts by mass of a chamotte refractory made of ceramic particles with 75 parts by mass of clay made from porcelain excavated from the Seto district of Aichi Prefecture. A mixture containing 25 mass% of the above mixture is used in Example 1, 95 mass parts of the clay is mixed with 5 mass parts of a chamotte-based refractory material made of chamotte ceramic particles to form a clay containing a refractory, and further to this. Example 2 was prepared by mixing 20% by mass of water and 5% by mass of vegetable oil to adjust viscosity and plasticity. The above-mentioned chamotte ceramic particles had an equivalent circle diameter of 1.8 mm or less. Examples 1 and 2 were put into a kneader and extruded into a cylindrical shape having an outer diameter of 130 mm. This was cut into a length of 200 mm and cut into a tapered shape with a tip diameter of 120 mm and a base diameter of 130 mm. Immediately after molding, the outer surface was completely covered with a polyethylene resin film for preventing drying.

  The slag outflow prevention plugs according to Examples 1 and 2 were inserted into the hot water outlet of the converter using a jig and sealed. The initial inner diameter of the hot water outlet of the converter is 130 mm. This sealing work was performed 20 minutes before the start of blowing by the converter, and the hot water was discharged. In both cases of Examples 1 and 2, the slag was completely blocked to the extent that it was suspected that the tap was clogged, and after that, when the molten metal reached the tap, it fell off at once. Therefore, it was confirmed that the purpose of preventing slag outflow was completely achieved.

  In addition, it was confirmed that the slag outflow prevention plug of the present invention has a cost of 1/2 or less as compared with the conventional product described in Patent Document 1 and can be stored for a long period of 6 months or more.

  Since the outlet of the converter gradually wears and becomes gradually larger in diameter, a plug for preventing slag outflow having a tip diameter of 130 mm and a base diameter of 140 mm was separately manufactured and used separately according to the increase in diameter.

It is sectional drawing which shows the plug for slag outflow prevention. It is explanatory drawing of the front-end | tip part of the jig for plug insertion. It is a perspective view which shows a use condition. It is sectional drawing which shows the state inserted in the hot water outlet of a converter. It is sectional drawing which shows the state which prevents the outflow of slag. It is sectional drawing of the state from which the plug for slag outflow prevention fell off with the pressure of molten steel. It is sectional drawing which shows the outflow state of molten steel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plug body 2 Drying prevention film 3 Converter 4 Hot water outlet 5 Jig insertion hole 6 Plug insertion jig 7 Disc 8 Rod-shaped part 10 Molten steel 11 Slag

Claims (7)

  A plug for preventing slag outflow, which is inserted from the outside of the furnace into the outlet of the converter using a plug insertion tool, and a plug body formed of clay containing a refractory in a tapered shape, and the outer surface of the plug body being dried. A plug for preventing slag outflow, comprising a prevention film and having a jig insertion hole formed in the center of the plug body.   2. The taper-shaped plug body has a tip diameter equal to or less than the same as the outlet of the converter and a base diameter larger than the outlet of the converter. Slag prevention plug.   The plug for preventing slag outflow according to claim 1, wherein the plug body is constituted by further kneading water and oil into clay containing refractory.   The slag outflow prevention plug according to claim 3, wherein the clay containing the refractory constituting the plug body contains 70 mass% or more of clay and less than 30 mass% of the chamotte refractory.   2. A plug for preventing slag outflow according to claim 1, wherein the plug body is formed by cutting a cylindrical body extruded by a kneader into a tapered shape.   The slag outflow prevention plug according to claim 1, wherein the drying prevention film is a polyethylene resin film or a polypropylene resin film.   The plug insertion jig includes a disc that presses the bottom surface of the base of the plug body at the tip of the rod, and further includes a rod-like portion that is inserted into the jig insertion hole of the plug body at the tip of the disc. The slag outflow prevention plug according to claim 1, wherein the slag outflow prevention plug is provided.

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