JPS6229463Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention is an improvement of a gas blowing pipe that blows 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. Conventionally used gas blowing pipe 1
As shown in FIG. 1, a large number of studs 3 are welded and attached to the outer periphery of a metal tube 2, and a monolithic refractory layer 4 is formed by lining the studs with monolithic refractory material. In the gas blowing pipe 1 having such a structure, the work of welding a large number of studs 3 to the metal tube 2 is extremely complicated, and the thermal expansion coefficient of the metal tube 2 is higher than that of the monolithic refractory layer 4. is also large, especially
Since the elongation of the metal tube 2 in the longitudinal direction is extremely large,
Even if the expansion allowance 5 is provided to absorb the expansion of the metal tube 2 in the diametrical direction, it does not help the expansion of the metal tube 2 in the longitudinal direction. For this reason, while the gas injection pipe 1 is immersed in molten metal and used, tensile stress is generated in the monolithic refractory layer 4 due to the large number of welded studs 3 on the metal pipe 2, which has a remarkable elongation in the longitudinal direction. This causes a ring-shaped crack 6 to occur. Molten metal penetrates through the ring-shaped crack 6 and melts the metal pipe 2, rendering it unusable and shortening the life of the gas blowing pipe 1. It is an object of the present invention to provide a gas blowing pipe that eliminates the drawbacks of the conventional example and extends its service life. Hereinafter, the present invention will be explained in detail with reference to FIGS. 2, 3, and 4. As shown in FIG. 2, a required number of locking members 9 are welded to the longitudinal proximal end 15 and distal end 16 of the outer circumferential surface of the metal tube 8, and an expansion allowance 10 is provided.
The hooks 12 at both ends of the spring 11 are hooked onto the locking member 9 of 5 and the locking member 9 of the distal end 16, and a plurality of springs 11 are stretched between the locking members 9 and set at a constant interval. A plurality of springs 11 are tied to a metal tube 8 using a metal wire 13, and a monolithic refractory is lined around the outer periphery of the metal tube 8 to form a spring 1.
A monolithic refractory layer 14 in which 1 is buried is provided to form a gas blowing pipe 7. As shown in FIGS. 3 and 4, three to eight springs 11 are attached to the outer circumferential surface of the metal tube 8, either individually or entwined with each other. Further, the spring 11 may be attached by directly welding the hook 12 of the spring 11 to the metal tube 8. Even if the metal tube 8 thermally expands due to the high temperature of the molten metal while the gas blowing pipe 7 of the present invention configured as described above is used by being immersed in molten metal, the metal tube 8
Thermal expansion in the diametrical direction is absorbed by the expansion allowance 10, and elongation due to thermal expansion in the longitudinal direction does not affect the monolithic refractory layer 14 because the metal tube 8 and the monolithic refractory 14 are not directly fixed. Furthermore, in order to prevent thermal expansion of the monolithic refractory layer 14 itself, a spring 1 bound to the metal tube 8 with a metal wire 13 is used to prevent deflection.
1 follows and does not generate unreasonable stress, the generation of ring-shaped cracks is suppressed. Also, spring 1
1 to the metal tube 8 was easy and labor-saving. Examples of the present invention are shown below and compared with conventional gas blowing pipes. A comparison was made between the inventive product and a conventional product in a gas injection pipe in which a steel pipe with an outer diameter of 60.5 mmφ, a wall thickness of 5.5 mm, and a length of 4.7 m is lined with medium-alumina castable to an outer diameter of 250 mmφ.

【table】

[Table] In addition, the spring 11 has a wire diameter of 1.00 to 6.00 mmφ,
Spring diameter 30~100mmφ, pitch (P) 30~
It is preferable to use a 60mm one. The best distance between wire ties is 300 to 600 mm. When desulfurization work was carried out by blowing calcium carbide together with nitrogen gas into hot metal using the product of the present invention and the conventional product, the conventional product became unusable after 3 to 5 charges, but the product of the present invention had a limited service life. Improved to 6-8 charges. As described above, according to the present invention, the occurrence of ring-shaped cracks can be eliminated, the service life of the gas injection pipe can be greatly extended, and the production of the gas injection pipe can be made labor-saving.

[Brief explanation of drawings]

FIG. 1 is a partial vertical cross-sectional view of a conventional gas blowing pipe, FIG. 2 is a vertical cross-sectional view of an embodiment of the gas blowing pipe according to the present invention, and FIG. FIG. 4 is a cross-sectional view showing another embodiment of the gas blowing pipe according to the present invention. In the figure, 7... gas blowing pipe, 8... metal pipe, 9... locking member, 11... spring, 12
...Spring key, 13...Metal wire, 14...
...A monolithic refractory layer.

Claims (1)

[Scope of utility model registration request] A plurality of springs 11 are stretched in the length direction of the outer peripheral surface of the metal tube 8, the hooks 12 at both ends of the spring 11 are fixed, the springs 11 are tied to the metal tube 8 with a metal wire 13, and the outer circumference of the metal tube 8 is A gas blowing pipe comprising a monolithic refractory lining and a monolithic refractory layer 14 in which the spring 11 is embedded.