JPH0435523B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a lance for stirring molten steel or injection ejection, for example. (Prior Art) A conventional manufacturing method for this type of lance will be explained below with reference to FIG. First, a cylindrical construction frame 1 is placed and fixed on a construction table 2. Then, the lance tube 3 is suspended and inserted into the construction frame 1, and the gas or powder discharge hole 4 of the lance tube 3 is aligned with the hole 5 previously opened in the construction frame 1. Hold. Next, the lance pipe body 3 is passed through the hole 5 of the construction frame 1.
A stopper 6 is placed in the discharge hole 4 of the valve. Thereafter, the monolithic refractory 7 mixed with water is poured into the construction frame 1 from above, while the construction table 2 is vibrated to form a lance. After a certain period of curing, the plug 6 is removed and the construction frame 1 is removed, and after curing again, a certain period of drying is performed to manufacture the lance. Note that 8 in the figure is a stud welded to the outer circumferential portion of the lance tube body 3 in advance. (Problems to be Solved by the Invention) However, when the lance is manufactured using the conventional method described above, it is difficult to remove air bubbles and moisture generated during molding, that is, when pouring the monolithic refractory 7, and As a result, the filling of the monolithic refractory 7 becomes uneven, and as many microbubbles can be seen on the surface of the refractory after de-framing, it is thought that there are a considerable number of microbubbles inside the refractory. Sexuality becomes worse. In addition, if the studs 8 are simply welded to the lance tube body 3 in a staggered manner, the adhesion of the monolithic refractory 7 will be weak, and as the number of times it is used increases, local spalling will occur, and eventually, this will become the starting point for horizontal spalling. Cracks and vertical cracks will occur and the lance tube body 3 will be destroyed. Due to these problems, it could not withstand continuous use. (Means for solving the problems) The present invention aims to provide a method for manufacturing a lance that can solve the above problems, and its gist is as follows:
After placing and fixing a construction frame on a construction table, in which a large number of small holes with a diameter of 1 to 8 mm were opened at predetermined intervals, and a hole was provided on the tip side facing the discharge hole of the lance tube body, which will be described later, Inside the construction frame, after welding a large number of studs to the outer peripheral surface, wire rods are spirally wound around these studs, and a lance tube body is inserted and installed, which is made by welding a wire through the inside of the spiral wire rod,
Thereafter, a monolithic refractory is poured between the construction frame and the lance tube body, and vibration molding is performed. In the present invention, the reason why the diameter of the large number of small holes formed in the construction frame is set to 1 to 8 mm is that if the diameter is less than 1 mm, air bubbles and moisture will not come out during vibration molding, which is the same problem as when using a conventional construction frame. This is because if the diameter exceeds 8 mm, the monolithic refractory will overflow from the small hole during vibration forming. (Example) The method of the present invention will be explained in detail below based on FIG. Note that the same numbers as in FIG. 2 indicate the same or corresponding parts. The lance tube body 3 used in the method of the present invention has Y-shaped studs 8 welded on its outer periphery in a staggered manner as in the past.
A wire rod 9 of ~8 mm is helically wound around the head of the Y-shaped stud 8 while being sequentially welded by spot welding or the like, and a similar wire rod 9 with an outer diameter of φ1~8 mm is placed at, for example, four locations inside the spiral wire rod 9. The wire rod 10 is passed through and spot welded. Similarly, the construction frame 1 using the method of the present invention is provided with a hole 5 at its tip end facing the discharge hole 4 of the lance tube body 3, as in the conventional case.
1 diameter in a staggered manner at 4 locations on the outer circumference at intervals of 150 to 300 mm
A large number of small holes 11 of ~8 mm are provided. Vibration molding is then carried out using the construction frame 1 and lance tube body 3 in the same manner as in the past. (Experimental Results) A component adjustment lance and an injection lance were manufactured using the method of the present invention and the conventional method. The wire rods 9 and 10 welded to the lance tube body 3 used in the method of the present invention each have a diameter of φ3 mm, and the small hole 11 provided in the construction frame 1 has a diameter of φ5 mm.
When manufacturing lances for component adjustment, 4 points are installed in a staggered manner with a pitch of 300 mm in the circumferential direction, and when manufacturing injection extension lances, 4 points are installed in the circumferential direction.
I used a staggered pattern with a 200mm pitch. Further, the curing and drying of the monolithic refractory 7 were performed under the following conditions. Curing in the form: 24 to 48 hours Curing after removing the frame: 24 to 48 hours Heat drying: 24 to 48 hours at 100 to 650°C The results are shown in the table below.

[Table] As is clear from the table above, the lance manufactured by the method of the present invention has good air bubble and moisture removal during vibration molding, has good local spalling resistance and cracking resistance, and can withstand repeated use. I was able to confirm that I could get it. (Effects of the Invention) As described above, according to the method of the present invention, the filling of monolithic refractories becomes uniform, and the welding strength to studs and wires is improved. Cracks and vertical cracks are drastically reduced, allowing repeated use.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the method of the present invention, A is a longitudinal sectional front view, B is a perspective view of the construction frame, C is a cross-sectional view of A, and Fig. 2 is an explanatory diagram of the conventional method. B and C are drawings similar to FIG. 1 is the construction frame, 2 is the construction table, 3 is the lance pipe body, 4
1 is a discharge hole, 5 is a hole, 7 is a monolithic refractory, 8 is a stud, 9 and 10 are wire rods, and 11 is a small hole.

Claims (1)

[Claims] 1 After placing and fixing a construction frame on a construction table, in which a large number of small holes with a diameter of 1 to 8 mm are opened at predetermined intervals, and a hole is provided on the tip side opposite to the discharge hole of the lance pipe body, which will be described later. After welding a large number of studs to the outer circumferential surface of the construction frame, wire rods are spirally wound around these studs, and a lance pipe body is inserted and installed, which is made by penetrating and welding wire rods to the inside of the spiral wire rods. . After that, a monolithic refractory is poured between the construction frame and the lance tube body, and vibration molding is performed.