JPH0685351U - Snorkel for ladle refining - Google Patents

Abstract

(57) [Summary] [Purpose] Quickly and completely remove the metal attached to the inner surface of the snorkel. [Structure] Bubbling lance deeply immersed in molten steel in a ladle is used to blow inert gas to stir molten steel, add exothermic agent to molten steel bath surface, and slag cut when oxygen blowing is performed with top blowing lance. In the snorkel 1 used for, the taper 2 is provided on the metal adhesion part on the inner surface of the snorkel 1, and the taper part is coated with the easy-peelable spraying material 3, and then the silica board 5, asbestos, rock wool, wire mesh 4, etc. The taper part is restored and repaired. [Effect] The removal and repair time of the adhered metal can be shortened to half that of the conventional method, and the metal adhered to the inner surface of the snorkel can be completely removed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a snorkel for ladle refining, which is used for cutting slag when a molten steel in a ladle is heated with oxygen by adding an exothermic agent to the molten steel to heat the molten steel.

[0002]

[Prior art]

 When ladle refining is performed, it is necessary to compensate the molten steel temperature. As a method of compensating for the molten steel temperature, a heat generating agent such as Al or Si is added to the molten steel contained in the ladle, and an inert gas is blown from the bottom of the ladle to blow oxygen with stirring the molten steel to obtain the molten steel temperature. (Japanese Patent Laid-Open No. 54-149313, Japanese Patent Laid-Open No. 59-89708, Japanese Patent Laid-Open No. 61-235506), an inert gas is introduced from the bottom while stirring the molten steel, and A method in which a linear metal or alloy that is stoichiometrically equivalent to or higher than the oxygen supply is fed from a blow immersion lance and melted by contact with molten steel at the lower end of the lance to raise the molten steel temperature (Japanese Patent Publication No. 54-29163). ) Is proposed. In the methods disclosed in JP-A-54-149313, JP-A-59-89708, JP-A-61-235506 and JP-B-54-29163, all of the molten steel is stirred at the bottom of the ladle. Since it is performed by blowing an inert gas from the porous plug installed in the, the repair plug's man-hours due to melting of the refractory material of the porous plug, clogging of the porous plug, etc. will increase, and the inert gas flow rate will increase. The stirring power cannot be increased. For this reason, it was not possible to raise the rate of acid transfer and raise the rate of heat rise by bottom blowing stirring with a porous plug.

As a method for solving the above-mentioned problems, as shown in FIG. 6, a bubbling lance 33 deeply immersed in the molten steel 32 in the ladle 31 is blown with an inert gas to stir the molten steel 32, and the snorkel 34 A method has been proposed in which the slag 35 is soaked by cutting the slag 35 and then the exothermic agent is added to the surface of the molten steel bath in the snorkel 34 to blow oxygen with the upper blowing lance 36. For example, in the method of raising the temperature of molten steel in a ladle by adding an exothermic agent to the molten steel contained in the ladle, blowing in an inert gas and blowing oxygen with stirring the molten steel, it was deeply immersed in the molten steel in the ladle. Bubbling lance blows an inert gas to stir the molten steel, dip a snorkel having a diameter smaller than the molten steel bath surface exposed by the plume generated at that time to cut the slag, and then to the molten steel bath surface inside the snorkel. A method in which an exothermic agent is added and oxygen is blown with a top blowing lance (Japanese Patent Laid-Open No. 64-56816) and a method in which a snorkel is immersed in molten steel in a ladle and gas stirring is performed with an immersion lance. A snorkel with a double cylinder structure consisting of a cylinder and an outer cylinder and an inner cylinder shorter than the outer cylinder is used.When the molten steel is heated, the inner and outer cylinders of the snorkel are immersed in the molten steel and the slag inside the inner cylinder is used. The surface of the molten steel is cut to expose it, and oxygen gas is blown onto this molten steel bare surface bath surface with an upper blowing lance.When desulfurizing, the snorkel is raised to separate the lower end of the inner cylinder from the bath surface to expose the molten steel bath surface. A method of covering with a slag and refining with the outer cylinder immersed in molten steel (JP-A-64-65226), in which molten metal is charged into a ladle, and a snorkel having an opening at the lower end is provided. The molten metal in the snorkel is immersed in the molten metal to further reduce the pressure in the snorkel, and gas is blown into the molten metal from near the lower end of the snorkel or at a position below the lower end. There is a method of stirring and refluxing the molten metal by floating the gas (Japanese Patent Laid-Open No. 3-6317).

In the method using the snorkel disclosed in the above-mentioned JP-A-64-56816, JP-A-64-65226 and JP-A-3-6317, the problem of bottom blow stirring by the porous plug is solved. However, if the snorkel is immersed in molten steel and agitated, the molten steel scatters and the metal adheres to the inner surface of the snorkel, which interferes with the treatment and requires repair of the snorkel. have . The method of repairing the snorkel after ladle refining treatment is shown in Fig. 4 and Fig. 5. After removing the snorkel 34 from the ladle refining device, place the snorkel 34 on the repair work table 37, Using a pipe, a jet lance 38 and the like, oxygen is blown to the metal 39 attached to the inner surface of the snorkel 34 to dissolve and remove it.

[0005]

[Problems to be solved by the device]

 The method of blowing oxygen to the metal that adheres to the inner surface of the snorkel using the above-mentioned Carolina pipe, jet lance, etc. to dissolve and remove the metal not only requires 2 to 4 hours to dissolve and remove the metal, but There is a problem that it is difficult to completely remove the adhered metal.

An object of the present invention is to provide a snorkel for ladle refining which can quickly and completely remove the metal adhered to the inner surface of the snorkel after the ladle refining treatment.

[0007]

[Means for Solving the Problems]

 The present inventors have conducted various tests and examinations in order to achieve the above object. As a result, a taper was provided on the metal adhesion part on the inner surface of the ladle snorkel for refining, and after coating the taper part with a sprayable material, the taper part was restored with silica board, asbestos, rock wool, wire mesh, etc. By doing so, it was confirmed that the metal adhered to the inner surface of the snorkel could be easily separated and removed from the easily peelable spray material part of the restored taper part, and the inventors reached the present invention.

That is, the invention is that the bubbling lance deeply immersed in the molten steel in the ladle is used to blow an inert gas to agitate the molten steel, add a heating agent to the molten steel bath surface, and blow oxygen with the blowing lance. In the snorkel used for slag cutting at the time of performing, a taper is provided on the metal adhesion part on the inner surface of the snorkel, and an easily peelable spray material is coated on the taper part, and then silica board, asbestos, rock wool, wire mesh It is a snorkel for ladle refining, which is characterized by restoring the taper part with such as.

[0009]

[Action]

 In this invention, a taper is provided on the metal adhesion part on the inner surface of the snorkel, the taper part is coated with an easily peelable spraying material, and then the taper part is restored with silica board, asbestos, rock wool, wire mesh or the like. When the ladle is refined by immersing it in molten steel in the ladle, the scattered metal adheres to the restored tapered part of the inner surface of the snorkel. Therefore, the bare metal adhered to the restored tapered portion can be easily peeled from the easily peelable spray material portion, and the adhered metal can be completely removed in a short time. Also, the snorkel from which the adhered metal has been removed can be reused by coating the taper part again with an easily peelable spray material and then restoring the taper part with silica board, asbestos, rock wool, wire mesh, etc. Snorkel repair work can be greatly shortened.

The metal attached to the restored tapered portion of the inner surface of the snorkel is removed by removing the snorkel from the ladle refining device and using a separately provided inner surface metal removal tool to spray the metal on the taper portion with easy peeling property. After peeling from the part, the metal is removed by a crane on the repair work table. After removing the metal, the snorkel can be reused by coating the taper part with an easy-peelable spraying material on the repair work table and then restoring the taper part with silica board, asbestos, rock wool, wire mesh, etc. Can be offered. A silica-based spraying material is suitable as the easily peelable spraying material used in this invention. The wire mesh used to restore the taper on the coating of the easily peelable spray material is for reinforcement.

[0011]

【Example】

 Embodiment 1 The details of the present invention will be described below with reference to FIGS. 1 to 3 showing an embodiment. Fig. 1 is a side sectional view of a snorkel for ladle refining according to the present invention, Fig. 2 is an enlarged sectional view of a restored tapered portion of a snorkel for ladle refining according to the present invention, and Fig. 3 shows a removal state of deposited metal. Here, (a) is a side cross-sectional view when the adhered metal is peeled off by the metal removal tool, and (b) is a side sectional view when the adhered metal is removed on the repair work table. In FIGS. 1 and 2, 1 is a snorkel body for ladle refining, 2 is a taper provided on a metal adhesion portion of the snorkel body 1, and the taper portion is coated with a silica-based easy-peelable spraying material 3. After that, it is restored with a wire net 4 and heat-resistant castables 5, and when it is immersed in molten steel in the ladle for ladle refining treatment, the scattered metal is attached to the restoration part 6 on the inner surface of the snorkel body 1. There is.

With the above configuration, when the snorkel of the present invention is immersed in molten steel in a ladle (not shown) for ladle refining treatment, the scattered metal adheres to the restoration part 6 on the inner surface of the snorkel body 1. Therefore, the adherent metal 7 can be easily separated from the 3 parts of the easily peelable spray material of the restoration part 6, and the adhered metal 7 can be completely removed in a short time. As shown in FIG. 3, the adhered metal 7 is removed by lifting the snorkel body 1 with a crane 11 or the like from a ladle refining device (not shown), and inserting the snorkel body 1 into the protrusion 13 of the metal removal tool 12. By doing so, the protrusion 13 comes into contact with the lower end of the adherent metal 7 and the adherent metal 7 is separated from the easily peelable spraying material 3 portion of the restoration part 6. Then, the snorkel body 1 is placed on the repair work table 14, and the adhered metal 7 peeled off from the easily peelable spray material 3 portion of the restoration portion 6 is lifted and removed by a crane 15 or the like. The snorkel body 1 from which the adhered metal 7 has been removed can be reused by coating the taper portion with the easily peelable spraying material 3 again, and then restoring and repairing the taper portion with the wire net 4 and the heat resistant castable 5. The repair work of the snorkel body 1 can be greatly shortened.

Example 2 C: 0.02-1.00% molten steel produced in a 160 Ton converter was treated by a ladle refining apparatus using the snorkel of the present invention of Example 1, and then ladle refining apparatus The snorkel body was removed from the snorkel, and the bare metal was peeled off from the easily peelable spray material part of the restoration part using a metal removal tool, and the bare metal peeled off from the easily peelable spray material part on the repair work table. After removing it and coating the taper part with a sprayable material that is easy to peel off, the taper part was restored and repaired with a wire net and heat resistant castable. The conventional snorkel was used and the metal was removed by the method shown in Fig. 5. Compared with the case of removing and repairing the metal, the time required for removing and repairing the adhered metal was reduced to half, and the adhered metal was completely removed.

[0014]

[Effect of device]

 As described above, the snorkel for ladle refining of the present invention can shorten the time for removing and repairing adherent metal to half that of the conventional method, and can completely remove the adherent metal adhered to the inner surface of the snorkel. .

[Brief description of drawings]

FIG. 1 is a side sectional view of a snorkel for ladle refining of the present invention.

FIG. 2 is an enlarged sectional view of a restored tapered portion of the snorkel for ladle refining of the present invention.

FIG. 3 is a view showing a state of removing the deposited metal of the present invention,
FIG. 5A is a side sectional view when the adhered metal is peeled off by a metal removal tool, and FIG. 7B is a side sectional view when the adhered metal is removed on a repair work table.

FIG. 4 is a side sectional view of a conventional snorkel for ladle refining.

FIG. 5 is a side sectional view showing a state of removing a conventional adherent metal.

FIG. 6 is a side sectional view of a ladle refining apparatus using a snorkel.

[Explanation of symbols]

 1 Snorkel body 2 Taper 3 Easily peelable spraying material 4 Wire mesh 5 Heat resistant castable 6 Restoration part 7 Adhesive metal 11, 15 Crane 12 Metal removal tool 13 Projection part 14, 37 Repair work table 31 Ladle 32 Molten steel 33 Bubbling lance 34 Snorkel 35 Slag 36 Kamifuki Lance 38 Jet Lance 39 Bullion

Claims (1)

[Scope of utility model registration request] 1. A method for blowing oxygen with a bubbling lance deeply immersed in molten steel in a ladle to stir the molten steel, add an exothermic agent to the molten steel bath surface, and perform oxygen blowing with an upper blowing lance. In the snorkel used for slag cutting, a taper is provided on the metal adhesion part on the inner surface of the snorkel, and the taper part is coated with an easily peelable spraying material, and then the taper part is made with silica board, asbestos, rock wool, wire mesh, etc. A snorkel for ladle refining characterized by being restored and repaired.