JPS624447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metallurgical lance used for blowing a gas or a mixture of gas and solids below the surface of molten metal in a blast furnace or ladle.

Metallurgical lances are typically formed from heavy metal tubes housed in refractory sleeves and are large in length.

When the lance is introduced into the molten metal bath through the slag layer, the lance is subjected to impact and the refractory sleeve of the lance often cracks, reducing the life of the lance. This problem is exacerbated by the flexing during use caused by the large length of the lance and by the differential expansion between the refractory sleeve and the metal tube.

It is an object of the present invention to provide a metallurgical lance that is less likely to crack than conventional lances and has higher hardness.

According to the invention, a tubular member for passing a gas or a mixture of gas and solids;
A metallurgical lance is provided having a sleeve of refractory material; and a number of reinforcing members housed within the sleeve and spaced longitudinally around the tubular member. Preferably, the reinforcing member is secured to the tubular member by a spacer member.

By forming an enclosure of reinforcing elements in the refractory material sleeve, the strength of the lance is increased over conventional lances, so that bending during use is greatly reduced, a major cause of premature failure of lances. is removed. The increased strength of the lance reduces the size of the tubular member and reduces the amount of iron in the sleeve, allowing for lower lance manufacturing costs without reducing lance performance. Preferably, the reinforcing members are joined in pairs at their lower ends, and each pair of reinforcing members are spaced apart from each other about the circumference of the tubular member.
The reinforcing members may be formed from relatively hard metal bars or rod-like members that are bent into a U-shape to form a pair of connected reinforcing members. Another solid or tubular U-shaped connecting member may be employed and this connecting member may be joined to the bar or rod-like member, for example by welding. Preferably, the bar or rod-like member has a circular cross-section, thereby avoiding the formation of sharp corners that constitute stress points.
Alternatively, the reinforcement member may be tubular and adjacent tubular members may be connected to the U-shaped tubular member, for example by welding, or to the U-shaped bar member, for example by welding. If the reinforcing member is itself tubular and in particular this tubular reinforcing member is connected in pairs to a U-shaped tubular connecting member,
This constitutes a passage for the coolant flowing within the lance,
As a result, impact effects on the refractory sleeve through immersion of the lance in the molten metal furnace are reduced and differential expansion is reduced. A refractory material of the sleeve is formed between the reinforcing member and the tubular member;
This refractory material is held in place during use.
In order to further enhance the retention effect of the refractory material, it is desirable to embed a perforated body, for example a wire mesh sleeve, in the refractory material surrounding the reinforcing member. A spacer is used to hold the porous body before embedding the porous body.

In order to reduce the destructive effects due to differences in thermal expansion between the refractory sleeve, the reinforcing member and the tubular member,
The reinforcing member and the tubular member may be coated with a coating of a low melting point compound or thermally destructible material. This film is applied at temperatures of, for example, 300℃ to 500℃ during the firing of the refractory sleeve.
℃ is removed to leave a very small spacing between the reinforcing member, tubular member, and refractory sleeve, which allows for differential thermal expansion without reducing the ability of the reinforcing material to retain the refractory material. To permit expansion, it is desirable to expose each end of the tubular member and reinforcing member at the inlet end of the lance.

The outermost end of the tubular or rod-shaped reinforcing member along the tubular member connects to a main adapter housed within the refractory sleeve, which adapter connects the lance to a support mechanism for feeding the lance into the melting furnace. It works like this. If secondary cooling of the lance is required, a tubular reinforcing member extends to the end of the lance for connection to a suitable cooling source. In this case, a collecting pipe attached to the end of the lance is used for the connection for introducing and removing the coolant.

Embodiments of the present invention will be described below based on the drawings.

1 to 3, a metallurgical lance 1 has a metal tube 2 for passing a gas or a mixture of gas and solids, which tube 2 is housed in a refractory sleeve 3. Six reinforcing members with rod-shaped or bar-shaped cross-sections are embedded in the refractory sleeve surrounding the metal tube 2, and these rods or bars are arranged in pairs as shown in FIGS. It is separated from tube 2. The reinforcing rod 4 is attached to the metal tube 2 via a spacer member 5 which joins the rod and the tube, for example by welding. A wire mesh sleeve 6 is embedded in the refractory sleeve outside the reinforcing rod and is held apart from the reinforcing rod by crimping it at one or two points on the rod. There is. Preferably, each pair of reinforcing rods is connected. Therefore, as shown in FIG.
may be bent into a U-shape. Alternatively, the lower ends of each rod may be joined through a U-shaped connecting member 7, as shown in FIG. 6, or through a solid U-shaped connecting member 8, as shown in FIG. Good too. Preferably, as shown in FIG.
The rod 4 and the metal tube 2 are exposed at the inlet end of the lance, and the end of the metal tube 2 is fixed to the connecting block 9, so that the lance can be easily connected to a transfer mechanism and a gas or gas/solids source. be done. The reinforcing element is also fixed to the connecting block, for example by welding.

In FIG. 7, the reinforcing member is formed from a tube 10, which is arranged in pairs spaced apart around a metal tube 11 and connected to a spacer member 12, as shown in FIGS. 8 and 9. It is held by twisting. The tubes 10 may be individual tubes, but are preferably connected in pairs. Therefore, as shown in FIG.
11, 1.
As shown in Figure 2 and Figure 13, each tube 1
0 may be connected by a tubular U-shaped connecting member 13 or a solid U-shaped connecting member 14 or 15, respectively. A wire mesh sleeve 16 is embedded in the refractory and the reinforcing tube 10 and metal tube 11 are exposed at the entrance end of the lance. As mentioned above, because the lance of the present invention is surrounded by a refractory sleeve and has a reinforcing member embedded therein, the strength of the lance is greatly increased over conventional lances, and the lance is more durable during use. The bending of the lance is greatly reduced, thereby eliminating the main cause of premature failure of the lance. And the above-mentioned strength improvement reduces the size of the metal tubes 2 and 11 compared to the conventional one, thereby reducing the amount of metal in the refractory sleeve, achieving weight reduction, and reducing the performance and life of the lance. Manufacturing costs can be lowered without any problems.

Reinforcement member 4 or 10 and tube 2 or 11
By exposing the ends of the lance at the inlet end of the lance, destructive effects due to differential thermal expansion between the refractory material of the sleeve and the reinforcing member and the metal of the tube can be reduced. This reduction effect can be achieved by coating the tube 2 or 11 and the reinforcing member 4 or 10 with a low melting point compound or heat destructible substance before forming the refractory sleeve, followed by firing, e.g.
This is further enhanced by heating to 500 DEG C. to remove the coating, thereby leaving a very small gap between the reinforcing member, the tube, and the refractory.

During use of the lance of the invention, the cooling effect of the lance can be increased by passing a gas or a gas/solid mixture through the tubes 2 or 11. This cooling effect is further improved by secondary cooling of the lance. For example, the reinforcing member 10
When the tubes 10 are connected as in FIGS. 10 and 11, the exposed end of the tube 10 at the inlet end of the lance is in communication with a cooling fluid, such as air, via a collecting pipe.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the metallurgical lance of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line in Fig. 1, and Fig. 4 is a sectional view taken along the - line in Fig. 1. 6 to 6 are sectional views showing a method of connecting a pair of reinforcing members, FIG. 7 is a sectional view of another embodiment, FIG. 8 is a sectional view taken along line - in FIG. 7, and FIG. A cross-sectional view taken along the line -- in FIG. 7, and FIGS. 10 to 13 are cross-sectional views showing a method of connecting the reinforcing members shown in FIG. 7. 2, 11... Tubular member, 3... Refractory sleeve,
4, 10... Reinforcement member.

Claims (1)

[Scope of Claims] 1. A tubular member through which a gas or a mixture of gas and solids passes; a sleeve that houses the tubular member and is made of a refractory material; and a sleeve that is housed within the sleeve and surrounds the tubular member. A metallurgical lance comprising a number of longitudinally spaced reinforcing members. 2. The reinforcing members are joined in pairs at their lower ends, and each pair of reinforcing members are spaced apart from each other around the tubular member. Metallurgical lance. 3. The metallurgical lance according to claim 1, wherein the reinforcing member is tubular.