JPS6335334B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a double tube nozzle that allows two types of gas to flow through.

Conventionally, a nozzle 1 for blowing high-pressure gas into a furnace in metal refining is formed into a double tube as shown in FIG. Inert gas is pressurized into the circulation space 4 between the nozzle and the nozzle to cool the nozzle.

The nozzle 1 supports the inner circumferential surface of the outer tube 3 with a large number of protrusions 21 formed by applying spots on the outer circumferential surface of the inner tube 2, thereby keeping the inner and outer tubes 2 and 3 concentric.

However, applying the spots on the outer circumferential surface of the inner tube 2 requires skill and effort, and it is also necessary to polish the spots to make the heights of the protrusions 21 uniform, which reduces production efficiency. There was also the problem that the inert gas collided with the protrusions, resulting in poor gas flow.

Furthermore, on the tip side of the nozzle, the protrusion portion of the inner tube is more severely affected by heat than other portions due to heat conduction from the outer tube, causing early damage to that portion and shortening the life of the nozzle.

The present invention provides a method for manufacturing a double tube nozzle that solves the above problems at once by forming a protrusion on the outer circumference of the inner tube that comes into close contact with the rear inner surface of the outer tube.

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 shows a situation in which a double tube nozzle 1 according to the present invention is installed by penetrating a side wall 91 of a furnace 9.

In the nozzle 1, the inner tube 2, which is slightly longer than the outer tube, is fitted concentrically into an outer tube 3 having a length corresponding to the thickness of the side wall 91, with the tips aligned, and the inner circumferential surface of the outer tube 3 and the outer circumference of the inner tube 2 are fitted concentrically. A circulation space 4 is formed between the surfaces.

According to the present invention, the double tube nozzle 1 is manufactured by the following method.

A plurality of grooves 22 are formed at equally spaced positions on the circumference over the entire length of the inner tube 2 in the axial direction, and the thickness increases from the center to the rear in the length direction of the grooves 22. A metal wire 5 larger than the depth is fitted.

In this embodiment, the inner tube 2 is formed by pultrusion molding or extrusion molding, and the groove 22 is formed at the same time as the molding.
The groove 22 is not limited to this, and the groove 22 may be formed by cutting.

The metal wire 5 is a round wire, and the concave groove 22 is a round bottom groove,
It is also possible to use a combination of square grooves and square wires.

The metal wire 5 fitted into the groove 22 is fixed to the inner tube 2 by spot welding or adhesive at both ends.

Next, cover the inner tube 2 with an outer tube 3 whose inner diameter is a little more than the metal wire 5.
In this state, the outer tube 3 is inserted into the drawing die (not shown).
By performing a drawing process through the wire, the inner surface of the outer tube 3 is brought into pressure contact with the metal wire 5 and integrated, thereby firmly fixing the inner and outer tubes 2 and 3. As a result, a double-tube nozzle is completed in which a flow space 4 is formed between the inner and outer tubes, the rear part being divided straightly by the metal wire, and the front part surrounding the inner tube and forming an annular shape. do.

The nozzle 1 is connected to a side wall 9 of a furnace 9 as shown in FIG.
1, and connect the oxygen pressurized nozzle 11 to the inner tube 2 and the inert gas pressurized nozzle 12 to the outer tube 3, respectively.

The base end of the inner tube 2 is fitted into the mounting plate of the oxygen pressure feeding mouthpiece 11 and welded 13, and furthermore, the inner tube 2 is fitted into a disc 15 with a flow hole 14 fixed in the inert gas pressure feeding mouthpiece 12 and welded 16. . The inner tube 2 is connected to the oxygen pressurized nozzle 11
By further welding and fixing to the base 12 on the outside of the mounting plate, the inner tube 2 is prevented from slipping out from the outer tube 3 due to oxygen pressure.

Oxygen is blown into the furnace through the inner pipe 2 from the oxygen pressure feeding nozzle 11 to burn impurities in the hot water and obtain highly pure molten metal.

The cooling inert gas blown out from the inert gas pressure feed mouthpiece 12 is sent into the furnace through the circulation space 4 between the inner tube 2 and the outer tube 3, and during this time, the
This cools the outer tubes 2 and 3.

On the tip side of the nozzle 1, an annular space is left between the inner tube 2 and the outer tube 3, and there are no protrusions that would obstruct the passage of the inert gas flow, so the inner tube 2 has a circular space around the entire circumference. Cools uniformly and uniformly.

As described above, the present invention provides the concave groove 22 on the outer periphery of the inner tube 2.
The metal wire 5 is fitted into the outer tube 3, and then the outer tube 3 is covered with a drawing process. can be firmly fixed.

Moreover, since the metal wire 5 is fitted into the groove 22 and fixed to the inner tube, it will not bend when the outer tube 3 is fitted and drawn, and therefore the inner and outer tubes 2 and 3 and the metal wire 5 will not bend. A straight circulation space 4 can be formed between them, and the flow force of the gas passing through the circulation space 4 will not be degraded.

Furthermore, when the inner tube 2 is extruded or pultruded, the amount of the metal wires 5 protruding from the surface of the inner tube 2 can be adjusted by simply fitting the metal wires 5 into the grooves 22 that can be formed at the same time as the inner tube 2. Therefore, since the thickness of the annular space 4 can be made constant, the purpose of the invention is achieved, such as eliminating the trouble of adjusting the height as in conventional spot mounding, and improving production efficiency.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing how the nozzle is used;
The figure is a sectional view taken along the line shown in Fig. 1, Fig. 3 is a perspective view of the metal wire fitted into the groove of the inner tube, Fig. 4 is a sectional view of the inner tube covered with the outer tube, and Fig. FIG. 5 is a sectional view of a conventional example. 2... Inner pipe, 3... Outer pipe, 4... Distribution space, 2
2... Concave groove.

Claims (1)

[Claims] 1. A step of opening a plurality of straight grooves 22 extending in the axial direction on the outer circumference of the inner tube 2 and at approximately equal intervals in the circumferential direction; Metal wire 5 with a required length that is thicker than the depth and shorter than the total length of the inner tube
The process of fixing the metal wire 5 to the inner tube 2 by welding, gluing, etc., covering the inner tube 2 with the outer tube 3 and drawing the outer tube 3 to bring the inner surface of the outer tube 3 into close contact with the protrusion. By this,
A step of fixing the inner tube 2 and the outer tube 3 and forming a flow gap 4 between the two tubes, the rear portion of which is partitioned by a metal wire 5, and the front portion of which is annular and surrounds the inner tube. A method for manufacturing a double tube nozzle, characterized by carrying out a series of steps.