JPS6229468Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention is a lance pipe for molten metal processing that injects inert gas or various processing agents into molten metal together with inert gas, which is used for processing molten metal such as desulfurization, desiliconization, dephosphorization, and temperature adjustment of hot metal or molten steel. Regarding improvements. Conventionally, the lance pipe 1 used is
As shown in Figure A, there are studs 3 on the outer periphery of the metal tube 2.
A large number of refractories are welded and attached, and a monolithic refractory is lined to form the monolithic refractory layer 4. In the gas blowing pipe 1 having such a structure, the coefficient of thermal expansion of the metal tube 2 is larger than that of the monolithic refractory layer 4, and the elongation of the metal tube 2 in the longitudinal direction is particularly large, so that the expansion allowance 5 is Install metal pipe 2
Although the expansion in the diametrical direction of the metal tube 2 can be absorbed, it does not help the elongation of the metal tube 2 in the longitudinal direction. Therefore, when the gas blowing pipe 1 is immersed in molten metal and used, as shown in FIG. Due to the tensile stress caused by the studs 3 welded to the stud 2, a ring-shaped crack 6
occurs. Molten metal penetrates through the ring-shaped crack 6 and melts the metal pipe 2, rendering it unusable and shortening the life of the lance pipe 1. It is an object of the present invention to provide a lance pipe for processing molten metal which eliminates the drawbacks of the above-mentioned conventional examples and extends its service life. Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. As shown in FIG. 2, the outer periphery of the metal tube 8 is covered with a metal flexible tube 9, which has a plurality of studs 10 fixed to the outer periphery by welding and has an inner diameter slightly larger than the outer diameter of the metal tube 8. The flammable material is received by a receiving metal fitting 11 fixed to the upper part of the blow-off pipe 15 by welding, and is wrapped around the gap between the metal tube 8 and the metal flexible tube 9 and the outer circumference of the metal flexible tube 9 and the metal flexible tube 9. Refractory particles 13 in the gap between 12 and 12
Fill it. At this time, the stud 10 is a combustible material 1
Make it stick out more than 2. Next, a castable refractory material is lined around the periphery of the combustible material 12 and the protruding studs 10 are buried to form an amorphous refractory layer 14, thereby forming the lance pipe 7 for processing molten metal. In addition, metal flexible tube 9
To fill the gap between the refractory particles 13 and the combustible material 12, the refractory particles 1 are wrapped around the combustible material 12
3, and at the stud 10, seal the gap between the rolled combustible material 12 with tape, and add refractory particles 1
Make sure that 3 is not leaked. Lance pipe 7 of the present invention configured in this way
When the metal tube 8, the metal flexible tube 9, and the monolithic refractory layer 14 are immersed in high-temperature molten metal, the metal tube 8, the metal flexible tube 9, and the monolithic refractory layer 14 expand according to their respective thermal expansion coefficients. There is no problem with the expansion of the refractory granules 1 between the metal tube 8 and the metal flexible tube 9 due to thermal expansion as the metal flexible tube 9 expands in the diametrical direction.
If pressure is generated in 3, refractory grain 13
is absorbed and resolved by being tightly packed. The expansion of the metal flexible tube 9 in the diametrical direction is absorbed by the expansion margin created by the disappearance of the combustible substance 12. Since the metal tube 8 and the metal flexible tube 9 are not directly fixed, the expansion in the length direction of the metal tube 8 only appears as a gap between the monolithic refractory layer 14 and the flange 16, and the expansion in the monolithic refractory layer 1
4 will not be adversely affected. The metal flexible tube 9 is directly fixed to the monolithic refractory layer 14 via the studs 10, and the inner and outer peripheries are filled with refractory particles 13 so that it can expand and contract freely. It follows the movement caused by thermal expansion well, locks the monolithic refractory layer 14 with the studs 10, and does not generate tensile stress.
The occurrence of ring-shaped cracks is suppressed. Examples of the present invention are shown below and compared with conventional lance pipes. A stainless steel flexible tube with an outer diameter of 60.5 mmφ, a wall thickness of 5.5 mm, and a length of 4.7 m is covered with a stainless steel flexible tube with an inner diameter of 100 mmφ and a wall thickness of 1 mm, with many studs attached to the outer circumference by welding, and the gap between the steel tube and the stainless steel flexible tube is And silica grains (SiO ₂ 98%) were placed in the gap between the stainless steel flexible tube and the expansion cardboard rolled to an outer diameter of 130 mmφ.
Filled with grains of mm to 0.3 mm, high alumina castable refractory (75% Al ₂ O ₃ , 22% SiO ₂ ) with an outer diameter of 250
The lance pipe of the present invention lined to a thickness of mmφ and the conventional lance pipe are compared in Table 1.

[Table] The tensile strength of the monolithic refractory layer 14 is 30
The monolithic refractory layer ¹⁴ has a cross-sectional area of 270 cm ² and a cross-sectional total tensile strength of 8100 Kg, and the stainless steel flexible tube 9 with studs has a tensile deformation load and a compressive deformation load of 200 Kg. It follows the movement of No. 14 due to thermal expansion well. The packing density of 1 mm to 0.3 mm silica grains (SiO ₂ 98%) is about 1.5 g/cm ³ , which is 50% for a compressive force of about 10 Kg/cm ²
It has more compressibility. Vinyl, paper, felt, etc. can be used as the combustible material 12. When desulfurization work was carried out using the inventive product and the conventional product by blowing calcium carbide together with nitrogen gas into hot metal, the conventional product became unusable at 2 to 4 channels per tube, but the inventive product was durable. Number of times is 8~
Improved to 10ch/book. After use, when observing ring-shaped cracks, they occur at a pitch of 100 to 300 mm in the conventional product, but they occur in a pitch of 500 to 1000 mm in the invented product, which increases the service life of the invented product. This confirmed the effect of As described above, according to the present invention, the occurrence of cracks is reduced, and the useful life of the lance pipe can be greatly extended.

[Brief explanation of the drawing]

Figure 1A is a partial vertical sectional view of a conventional gas blowing pipe, Figure 1B is a partial vertical sectional view after using the 5 charges in Figure 1A, and Figure 2 is an implementation of the lance pipe according to the present invention. A partial vertical cross-sectional view of an example. In the figure, 7...Lance pipe, 8...Metal pipe, 9
... Metal flexible tube, 10 ... Stud, 11 ... Receptacle, 12 ... Flammable material,
13... Refractory grains, 14... Amorphous refractory layer, 1
5...Blowout pipe.

Claims (1)

[Scope of utility model registration request] A metal flexible tube 9 having a plurality of studs 10 fixed to the outer periphery is placed on the outer periphery of the metal tube 8, and is received by a receiving metal fitting 11 fixed to the upper part of the outlet pipe 15 of the metal tube 8. The combustible material 12 is placed at appropriate intervals and surrounded by the studs 10 protruding, and refractory particles 13 are placed in the gaps between the metal tube 8 and the metal flexible tube 9 and between the metal flexible tube 9 and the combustible material 12. and the combustible material 1
A lance pipe for processing molten metal, which is provided with an amorphous refractory layer 14 of a desired thickness on the outer periphery of the lance pipe.