JPH05237608A - Method for washing nozzle in continuous casting equipment - Google Patents

Abstract

PURPOSE:To remove stuck material in the inner part of a nozzle used to a ladle or a tundish in continuous casting equipment with scuffing by using a washing nozzle injecting mixed gas of oxygen gas and combustible gas with a robot or remote operation. CONSTITUTION:The nozzle 2 is withdrawn from the using position by a holding device 8 and shifted onto a splash preventing pot 9. The washing nozzle 13 is fitted to the lower side of a pipe 15 supported so as to be freely rotated to a cylinder 14 held by a manipulator 12 and driven with a motor 16 and rotated with the remote operation of the robot. The washing nozzle 13 is abutted on the upper end of the nozzle 2 by the manipulator 12, and the mixed gas of the oxygen gas and the combustible has is injected into the inner part of the nozzle 2. As plural injecting holes of the washing nozzle 13, are formed in diagonally downward at the constant interval and further, the washing nozzle 13 is rotated, the mixed gas is injected to the inner wall of the nozzle 2 at an acute angle in every corner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding nozzle provided in a ladle or a tundish of a continuous casting facility, a long nozzle provided between a ladle and a tundish, a dipping nozzle provided between a tundish and a mold, and the like. It relates to a cleaning method used for cleaning similar nozzles.

[0002]

2. Description of the Related Art In a continuous casting facility, molten steel in a ladle is poured into a tundish 3 through a sliding nozzle 1 and a long nozzle 2 as shown in FIG. It is supposed to be injected inside. The various types of nozzles 1, 2, 4 and 5 used in the continuous casting facility have metal bars,
Slag, slag, etc. (hereinafter simply referred to as metal) adheres, or molten steel causes precipitation of alumina in steel types with a high aluminum content, such as aluminum killed steel, and as a result, the nozzle gradually narrows and the injection amount increases. May decrease, and in extreme cases, the nozzle may be blocked and injection may not be possible. As is often seen in long nozzles and immersion nozzles, deposits such as metal ingots and alumina precipitates are unevenly distributed and the molten steel flow in the nozzles is unevenly distributed, which causes local melting loss of the nozzles, resulting in nozzle life. There was a problem such as shortening.

In order to remove such metal deposits and alumina deposits that adhere to the inside of such nozzles, a long nozzle is conventionally used as an example. Hold the iron pipe in your hand and touch the tip of the iron pipe to the adhered part of the metal or alumina deposit that is detected while observing the inside of the long nozzle with the naked eye, and blow oxygen gas from this to melt the iron pipe end. At the same time, deposits such as metal and deposits such as alumina were removed by melting.

[0004]

The above-mentioned work is a dangerous work to be performed in a harsh working environment where an operator approaches a high temperature nozzle to handle oxygen gas, and a splash accident when burned due to splashes when melted. is happening. Moreover, in the case of a long nozzle, the cleaning work is carried out during the swing tower turning during the replacement of the ladle, which is dangerous, and the cleaning work must be completed within an extremely short time of about one minute. There are also time constraints. For this reason, it has long been desired to automate or remotely operate the nozzle cleaning work, but since the work environment is poor and the work content requires skill, automation or remote operation has not been realized.

In order to automate the above-mentioned work, there is a method in which an industrial robot is used instead of the worker, and the nozzle is cleaned by the same procedure as the worker grips the iron pipe by the robot. It is possible, but this had the following problems. (1) In order to detect the place where metal is adhered and the place where alumina is deposited, it is conceivable to take a picture of the inside of the nozzle with a camera and detect it by image processing. Because it is difficult to detect, even if it can be detected by complicated image processing, the operator can identify the place in an instant, but it takes too much time.

(2) Since the method of melting and removing the adhered portion of the metal or the like and the deposited portion of the alumina or the like by burning the iron pipe, the tip of the pipe is melted and its length is gradually shortened. In order to hit the pipe tip to the deposition site, it is necessary to recognize the tip position of the pipe and position the pipe tip to the deposition site. Difficult to do. Therefore, while cleaning the entire inner circumference of the nozzle while advancing the tip of the pipe, the work time becomes longer because it also cleans unnecessary parts without deposits such as metal and deposits such as alumina. thing.

It is an object of the present invention to provide a method capable of automatically cleaning a nozzle without causing the above problems.

[0008]

According to the cleaning method of the present invention, therefore, a cleaning nozzle carried by a robot or by remote control is applied to the nozzle of the continuous casting equipment after one or several charges, and oxygen gas is supplied from the cleaning nozzle. And a combustible gas are ejected from the opening of the nozzle to remove deposits such as alumina and deposits such as metal in the nozzle by scuffing.

According to the present invention, a mixed gas of oxygen gas and a combustible gas is injected into the nozzle, and sprayed and burned all over the inside of the nozzle to cause deposits such as alumina inside the nozzle and deposits such as metal. Are melted and removed. In the case of a long nozzle such as a long nozzle or a dipping nozzle, scuffing is performed by increasing the pressure and flow rate of the mixed gas. In the present invention, the place where alumina or the like is deposited or the place where the metal or the like is attached is not detected, and the entire area inside the nozzle is washed at once by simply injecting the mixed gas from the nozzle opening, thus reducing the time required for washing. Or sufficient cleaning will be performed.

At the time of cleaning according to the present invention, splashing of the mixed gas causes the splashing of the mixed gas, and the amount thereof increases as the pressure and flow rate of the mixed gas increase. Is performed manually or by remote control, and there is no worker around the nozzle, so there is no safety problem. Since the cleaning of the nozzle according to the present invention can significantly reduce the working time and there is no problem of safety, it has been conventionally impossible to clean the nozzle from the tundish in terms of time constraint and safety. It becomes possible to perform a work procedure in which a long nozzle or a dipping nozzle that could not be moved from the mold is moved to another place, washed, and then returned to the original state after washing. As a result, the nozzle can be moved to a position where it is completely retracted from the molten steel in the tundish or the mold for cleaning, and it is possible to prevent deterioration of the quality of the molten steel due to gas.

The cleaning nozzle may be provided with a single outlet to diffuse the sprayed gas so that the sprayed gas can be sprayed evenly inside the nozzle, but it is also possible to ensure that it is sprayed on the inlet side of the nozzle. In order to do so, it is desirable to provide a plurality of air outlets at regular intervals in the circumferential direction, more preferably the air outlets are formed into an annular slit or rotated so that they can be uniformly blown in the circumferential direction, and more preferably The angle of spraying on the inner wall of the nozzle is made acute. This makes it possible to prevent local wear of the inner circumference of the nozzle due to the blowing gas.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a method for cleaning a long nozzle, in which a long nozzle 2 supported by a holding device 8 is changed from a tundish 3 to a splash prevention pot 9 during replacement of a ladle 7 after charging. It is moved up and retracted from above the molten steel 11 of the tundish. Next, the cleaning nozzle 13 carried on the manipulator 12 is carried onto the long nozzle and applied to the upper end of the long nozzle. And
As a result, a mixed gas of oxygen gas and combustible gas is injected into the long nozzle.

The cleaning nozzle 13 is fixed to the lower end of a pipe 15 which is inserted into a cylindrical body 14 carried by a manipulator 12 and is rotatably supported, and is rotationally driven by a motor 16. As shown in FIGS. 2 and 3, a large number of outlets 17 directed obliquely downward are formed at regular intervals in the circumferential direction, and the mixed gas of oxygen gas and combustible gas supplied to the pipe 15 forms an acute angle on the inner wall of the long nozzle. It can be sprayed with.

The manipulator 12 is covered with a jacket 18 consisting of a sandwich structure of flame resistant fibers and a heat insulating material, which hardly causes splash of splashes scattered by scouring, and also inside the manipulator and the manipulator 12 and the jacket. The space between 18 is cooled by an air spray so that it can move without trouble even under severe conditions such as high temperature, dust, and splash.

[0015]

The present invention is constructed as described above and has the following effects. As described above, the cleaning method according to claim 1 realizes automation of the nozzle cleaning work by the combination of the robot or remote control technology and the scuffing cleaning, and the worker is not good at high temperature like the nozzle cleaning work. It is possible to release from dangerous work under various working environments, and because it is not necessary to detect precipitates such as alumina and ingots, the cleaning work can be significantly shortened or sufficient. It is possible to eliminate variations in the cleaning state due to the skill level of the operator.

By using the cleaning nozzle according to the second aspect, it is possible to uniformly clean the inner circumference of the nozzle in the circumferential direction. According to the method of the third aspect, it is possible to prevent local wear of the inner circumference of the nozzle.

If the cleaning is performed at a position retracted from the molten steel as in the method according to the fourth aspect, deterioration of the quality of the molten steel due to the cleaning gas can be prevented.

[Brief description of drawings]

1 shows a schematic sectional view during a cleaning operation according to the invention.

FIG. 2 shows a cross-sectional view of a cleaning nozzle used in the present invention.

FIG. 3 shows a bottom view of the cleaning nozzle.

FIG. 4 shows a schematic sectional view of a continuous casting facility.

[Explanation of sign]

1,4 Sliding nozzle 2 Long nozzle 3 Tundish 5 Immersion nozzle 6 Mold 7 Ladle 8 Holding device 9 Splash prevention pot 11 Molten steel 12 Manipulator 13 Cleaning nozzle 16 Motor 17 Air outlet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazu Sawamura ▲ Hiro ▼ 11-11 Showa-machi, Kure City, Hiroshima Prefecture Nisshin Steel Co., Ltd. Kure Works (72) Inventor Masato Aoki, Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture 5-3 28 Hitachi Shipbuilding Co., Ltd. (72) Inventor Nobuyuki Kameda 5-3-28 Nishikujo, Nishikojo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd.

Claims (4)

[Claims] 1. A cleaning nozzle, which is carried by a robot or by remote control, is applied to the nozzle of a continuous casting facility after one or several charges, and a mixed gas of oxygen gas and combustible gas is introduced from the nozzle opening. A method for cleaning a nozzle in a continuous casting facility, characterized in that a deposit such as alumina or the like and a deposit such as a metal in the nozzle are jetted out to remove by a scuffing. 2. The method for cleaning a nozzle in a continuous casting facility according to claim 1, wherein the outlet of the cleaning nozzle is formed as an annular slit or is rotated. 3. The method for cleaning a nozzle in a continuous casting facility according to claim 2, wherein the spray angle of the mixed gas onto the inner wall of the nozzle is set to an acute angle. 4. The method for cleaning a nozzle in a continuous casting facility according to claim 1, wherein the long nozzle or the dipping nozzle is moved from the tundish or the mold, and cleaning is performed at a position retracted from the molten steel.