JP3688003B2 - Lance pipe for gas and powder injection - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a gas and a powder blowing lance pipe for injecting an inert gas or a mixture of an inert gas and a granular refining agent into hot metal or molten steel.
[0002]
[Prior art]
A conventional lance pipe structure of this type will be schematically described with reference to FIG.
Usually, a lance pipe is a pulsation at the time of gas ejection from the nozzle hole 5 when a gas or a mixture of gas and powder (hereinafter simply referred to as gas) is blown into a molten metal bath in a container such as a ladle, or melting that occurs after ejection. The lance pipe receives an extremely large external force due to the turbulent reflux of the metal.
Therefore, in order to withstand this external force, the gas introduction pipe 1 is made thicker and, if necessary, is reinforced such as by attaching a rib, and then a refractory lining reinforcing stud 6 is appropriately welded, and a refractory castable is attached to the outer periphery of the core metal. The cast molded body 2 is formed by construction.
Since the lance pipe is particularly eroded by the slag during use, the slag line part A has a larger outer diameter than that of the metal line part B, and the thickness of the refractory is increased. Moreover, the lance pipe of the cast molding 2 of the structure which changed the material of the cast molding 2 of the slag line part A into the fireproof material with high corrosion resistance with respect to slag, and was partially strengthened is common.
[0003]
[Problems to be solved by the invention]
However, the lance pipe for gas blowing having a conventional structure still has a large slag line portion A, and the lance pipe cannot be used due to the gas introduction pipe 1 being melted or gas leaking from the erosion portion. Although there was a remaining thickness of B refractory (cast-molded body), the life of the lance pipe was limited.
[0004]
[Means for Solving the Problems]
The present invention has been made to solve the conventional problems, and the slag line portion A of the conventional gas blowing lance pipe has high corrosion resistance against slag, alumina material, alumina-magnesia material, alumina- A fixed refractory material 4 such as a spinel material, an alumina-carbon material, an alumina-magnesia-carbon material, an alumina-spinel-carbon material, a magnesia-carbon material, or a silicon carbide material is provided. This is a lance pipe for gas injection. The fixed refractory 4 is characterized by being welded and fixed to the cored bar and gas introduction pipe 1 by a fixed refractory fixing hardware 3 .
[0005]
【Example】
Examples of the present invention will be described in detail. An embodiment of the present invention is shown in FIG. The fixed refractory 4 embedded in the slag line A is a cylindrical refractory formed in advance as HIP or precast with an upper end and a lower end inclined as shown in the enlarged view of FIG. The slag line part A has a shape with an outer diameter of 450 mm and a height of 500 mm, and the slag line part A of the metal core / gas introduction pipe 1 is formed into a slant structure on the upper and lower ends of the fixed refractory 4 with the fixed refractory fixing hardware 3. The fixed refractory 4 is prevented from dropping to the outer periphery by welding and fixing the upper and lower sides to the gas introduction pipe 1, and then the outer diameter 300 mm of the metal line part B and the splash prevention part is gas blown by the cast molding 2. A built-in lance pipe was made. The fixed refractory 4 is classified into a fixed refractory 4a (FIG. 3) and a fixed refractory 4b (FIG. 4) .
[0006]
【The invention's effect】
As a result of using the lance pipe for gas and powder injection according to the present invention in ladle refining, the slag line part A has a melting loss of about 70% compared to the conventional product, and the regular refractory has no cracks and is not damaged. Because the amount is small, the core metal / gas introduction tube is not melted or ruptured, and the average life is 1.8 times longer than that of the conventional product.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a conventional gas blowing lance pipe.
FIG. 2 is a longitudinal sectional view of a gas blowing lance pipe according to the present invention.
FIG. 3 is a perspective view of a regular refractory according to the present invention.
FIG. 4 is a perspective view of another shape of a regular refractory according to the present invention.
[Explanation of symbols]
1 Core metal / gas and powder introduction tube 2 Cast molded body 3 Fixed refractory fixture 4 Fixed refractory 4a Fixed refractory 4b Fixed refractory 5 Nozzle hole 6 Reinforcement stud A Slag line part B Metal line part

Claims (1)

In a gas and powder blowing lance pipe with a fixed refractory embedded in the slag line part (A) , the fixed refractory is welded and fixed to the metal core and gas introduction pipe with the fixed refractory fixing hardware. Characteristic gas and powder blowing lance pipe.

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