JPH0426448Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nozzle for blowing gas or powder into molten metal.

[Prior art] Gas or gas is introduced into molten metal through a nozzle.
When powder is injected, depending on the type of gas or powder being injected, the temperature near the discharge port becomes extremely high or low. Furthermore, chemical reactions may occur, and the tip of the nozzle may be significantly damaged due to melting or deterioration due to the chemical reaction. Also, due to supercooling,
The molten metal solidifies at the discharge port and obstructs the injection of gas or powder. In order to avoid these problems, depending on the type of molten metal to be blown and the type of gas or powder to be blown, a single tube, double tube, or triple tube can be used, and the material of the entire nozzle can be selected as appropriate, such as metal or ceramic. It is known to use a spiral nozzle.

For example, Japanese Patent Publication No. 57-24397 discloses a triple tube nozzle structure and an example in which spiral blades are provided on the outer surface of the inner tube. Furthermore, the applicant of the present application filed Utility Application No. 62-107005 for a device in which a spiral guide vane is provided in the gap between the inner tube and the middle tube at the tip of the triple tube.

FIG. 4 shows a typical triple-pipe nozzle structure for blowing oxygen and coal powder into molten iron. Coal powder is blown in together with carrier gas from the inner pipe 1 located at the center, and oxygen is blown from the middle pipe 2 located in the middle. Furthermore, LPG is flowed as a cooling gas from the groove of the outer tube 3 on the outside to prevent nozzle erosion. Also, inner tube 1
Four plate-shaped ribs 4 are fixed to the inner tube 1 and the middle tube 2.
A structure that secures a gap, that is, an oxygen flow path, is common.

Further, in the middle pipe 2 into which oxygen is blown, droplets of molten iron enter the pipe due to fluctuations in gas pressure near the discharge port, and the heat of reaction with oxygen gas tends to burn out the middle pipe. Therefore, as shown in FIG. 5, a spiral blade 5 is often used instead of the rib 4 at the tip of the nozzle.

[Problems to be solved by the invention] However, even if a variety of nozzles with different structures and materials are selected as described above, in actual operation, the tip of the nozzle may melt earlier than the protective refractory on the outer periphery, or Solidified molten metal may adhere and block the discharge port. In particular, when gas or powder is injected into molten iron, the temperature becomes higher, so it is impossible to completely avoid these problems with current technology. Therefore, when the above situation occurs, the actual situation is to replace the entire set including the nozzle body or protective refractory.

[Means and effects for solving the problem] The present invention was made in view of the above points, and it is possible to divide the nozzle into multiple parts in the length direction, and the tip of the nozzle is made wear-resistant (erosion-resistant). By using a rich metal or ceramic tube, corrosion damage can be prevented. In addition, when replacing a nozzle due to melting damage, by replacing only the tip, the other parts can be used again, and if the nozzle tip is to be adjusted to the level of damage to the hearth bottom refractory or protective refractory of the nozzle, it can be divided. By removing the middle tube, the nozzle length can be easily adjusted.

[Example] The present invention will be explained in detail below based on the figures.

FIG. 1a shows an example of the present invention in which the inner tube of a double or triple tube is divided into two in the length direction. 1st
FIG. b is a diagram of the same case where the image is divided into three parts.

The tip 6 is made of a material (for example, metal, ceramic, etc.) that has higher wear resistance than other parts, and its length is about 30% of the total length of the nozzle. Further, the intermediate portion 7 shown in FIG. 1b is made of the same material as the lower end portion 8 described later, and its length is 10 to 30% of the total length of the nozzle, and it may be divided into a plurality of parts. The lower end portion 8 is
It is made of the same material as the intermediate part 7, and its length is the total length of the nozzle.
It is best to set it at around 40-60%. The upper end portion 6, intermediate portion 7, and lower end portion 8 are joined using various known methods. In other words, it is best to use the screw-in method in most cases, but in other cases, it is better to use patch welding at several points in the circumferential direction of the joint, or to hold the joint by the surrounding nozzle protection refractory without using any joining method. Also good.

Also, although the figure shows only the inner tube for convenience, the middle tube and outer tube are also divided into the same length as the inner tube, and the upper end 6, middle section 7, and lower end 8 are each The inner tube, middle tube, and outer tube are combined and used as one body.

FIGS. 2a and 2b show another example of the present invention, in which spiral blades 5 are provided on the outer periphery of the inner tube 1 at the upper end 6. FIG. In this case as well, 2
The same purpose as in FIG. 1 is achieved by dividing the image into three parts as shown in FIG. 2b.

[Function] Since the present invention is configured as described above, it brings about the following effects.

By using a material with high wear resistance for the tip part 6, which is subject to severe wear, it is possible to extend the life of the nozzle by making it almost equal to the life of other parts. If a complete set is replaced when a part of the product reaches the end of its lifespan, it is possible to avoid the situation of discarding the remaining part of the product's lifespan. Further, even if the material is changed, even if the upper end portion 6 is severely worn and its life reaches its end before the other parts, the split structure makes it easy to replace only the upper end portion.

As shown in Fig. 3a, the action of the intermediate part 7 is that when the hearth bottom refractory 9 and the nozzle protection refractory 10 are damaged over time up to the part indicated by the broken line C, as shown in Fig. 3a. The nozzle length is shortened by the length l as shown in b. At this time, the total length of the nozzle can be easily adjusted by removing the intermediate tube 7 shown in FIGS. 1b and 2b.

[Effects of the invention] As described above, the present invention extends the life of the nozzle, makes it easy to replace a part of the nozzle, and makes it easy to adjust the nozzle length, making it extremely practical.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the present invention, Fig. 2 is a diagram showing another example of the present invention, Fig. 3 is a diagram showing nozzle length adjustment when the furnace bottom and nozzle protection refractory are damaged, Fig. 4,
FIG. 5 is a conventional explanatory diagram. 1... Inner tube, 2... Middle tube, 3... Outer tube, 4...
Rib, 5...Spiral blade, 6...Top end,
7... Middle part, 8... Lower end part, 9... Hearth bottom refractory, 10... Nozzle protection refractory.

Claims (1)

[Scope of utility model registration request] A gas or powder blowing nozzle characterized in that a converter bottom blowing nozzle is divided into a plurality of parts in the length direction, and the upper end is made of a material with high wear resistance that is different from the other parts.