KR102147042B1 - Convergence Cutting Device and Metod for Metal Cutting - Google Patents

Abstract

The present invention relates to a fusion cutting apparatus for cutting metal and a method thereof. An object of the present invention is to provide a convergence cutting head which combines only advantages of oxygen cutting and laser cutting in order to disassemble a metal structure in an aging nuclear power plant regardless of material. Therefore, cutting which combines the advantages of the oxygen cutting and the laser cutting has an advantage of increasing a cutting speed and reducing secondary flying products. The metal fusion cutting method comprises the following steps of: forming a drag line; and completely cutting a thick metal structure.

Description

Fusion cutting device and method for metal cutting {Convergence Cutting Device and Metod for Metal Cutting}

The present invention is a fusion cutting technology and apparatus for cutting a major metal structure in a nuclear power plant, and more specifically, a major metal device in a nuclear power plant is a carbon steel material, and a thermal cutting technology such as oxygen cutting and a pulse or CW ) It relates to a fusion cutting apparatus and method for cutting metal by combining laser cutting using a laser.

Metal structures, which are the main facilities of a nuclear power plant that has been shut down, are difficult to cut and dismantle by accessing radioactive wastes such as steam generators and radioactive wastes such as the reactor body and high-radiation reactor internal structures.

In addition, when cutting and dismantling the metal structure of a nuclear power plant from a few mm to several hundred mm or more, the conventional oxygen cutting method is used in proportion to the cutting width and thickness, such as sludge, fume and aerosol. ) Type of radioactive secondary waste causes safety problems such as exposure of workers, and in the case of thick plates, the cutting speed is slow and the working time required for cutting is long, resulting in a high cost.

In addition, most metal structures of nuclear power plants are made of carbon steel and can be cut by the oxygen cutting method, but some structures are not made of carbon steel but of stainless steel or an alloy such as Inconel, so cutting by oxygen cutting is difficult.

In a metal structure such as a nuclear reactor, a thick metal structure surrounding a bundle of nuclear fuel exists in order to prevent radiation leakage and maintain robustness, so a method and an apparatus for efficiently cutting the thick structure are required.

In addition, in the case of a metal structure made of an alloy other than a carbon steel material, a cutting method and apparatus capable of cutting it are required.

In addition, in order to reduce the radiation exposure of workers, there is a need for a cutting method and apparatus that generates less secondary waste such as aerosol.

Republic of Korea Patent Publication: 10-2015-0006959 Republic of Korea Patent Publication: 10-2016-0035708

The problem to be solved by the present invention is a pulse or CW laser cutting method when cutting a metal structure in a nuclear power plant, that is, when cutting a thick structure such as a thick plate, and oxygen cutting using a gas or high pressure oxygen that is harmless to the human body. The method is to blow molten material continuously or periodically so that it can be cut faster than the conventional oxygen cutting method by fusing the method.

Another problem to be solved by the present invention is to provide an apparatus capable of cutting using high pressure oxygen and laser cutting technology as a fusion cutting technology in order to cut and dismantle a metal structure made of an alloy other than a carbon steel material.

Another problem to be solved by the present invention is to provide a fusion cutting device capable of reducing the amount of radioactive secondary waste generated when cutting a metal structure in a nuclear power plant, and improving work speed to reduce the exposure of workers.

The solution to the problem of the present invention is to cut a thick metal structure such as a thick plate in a nuclear power plant by continuously or periodically applying a gas or high pressure oxygen that is harmless to the human body to blow out the molten material, and the high-power pulse or seed oil ( CW) It is to implement a fusion cutting apparatus and method capable of cutting while melting by applying the heat of a laser to the metal structure that follows.

Another problem of the present invention is that the amount of secondary pollution caused by small metals scattered by the melt generated by high-pressure air and oxygen during cutting is reduced according to the contribution of laser cutting performed following oxygen cutting, thereby reducing the amount of secondary waste. In addition, it is possible to minimize the operator's influence of the secondary waste by further comprising a suction device for collecting and collecting secondary contaminants generated during cutting by suction.

In order to minimize the cutting time and secondary pollution of the cutting object, the focus of the laser beam is formed on the subsequent cutting object, but the high-pressure oxygen flame axis and the irradiation axis of the laser beam can be adjusted differently. It is to provide a fusion cutting device that can maximize the effect or solve a spatial problem.

The solution to another problem of the present invention is to manufacture a fusion cutting device to cut metal structures other than carbon steel, but provide an independent and fused cutting device so that oxygen cutting and laser cutting can be applied independently. There is.

The present invention can be applied irrespective of the thickness when dismantling a metal structure in a nuclear power plant, and since it cuts at least 20% faster than the conventional oxygen cutting method, there is an effect of reducing labor costs and working time to reduce cutting costs, etc. .

Another effect of the present invention is to install a suction device to inhale the scattered secondary waste generated during cutting in order to reduce and minimize the amount of secondary waste such as aerosol scattered when cutting metal structures compared to the existing oxygen cutting method. Thus, there is an increased effect that can prevent or reduce secondary pollution.

Another effect of the present invention is that it is designed and manufactured so that oxygen cutting and laser cutting can be applied independently or by fusion, so that the cutting of alloy materials that are difficult to be cut by oxygen cutting can be efficiently performed. There is an elevated effect that makes it possible.

1 shows the principle of the fusion cutting apparatus and method according to the present invention.
Figure 2 shows a head portion of the fusion cutting device according to the present invention.
3 shows a laser beam focusing optical system of the fusion cutting device according to the present invention.
Figure 4 shows the overall configuration of the fusion cutting device according to the present invention.
5 shows a reactor and a steam generator among metal structures in a nuclear power plant to be cut by the fusion cutting device according to the present invention.

Look at the specific content for carrying out the present invention.

The present invention relates to a method and apparatus capable of cutting and dismantling metal structures in nuclear power plants.

Low-level or ultra-low-level radioactive structures are cut and dismantled using the oxygen cutting method, and the reason for applying the thermal method such as oxygen cutting to these metal structures is economical, has a fast cutting speed, and is applicable to thick thick plates. Because it is possible.

However, when a thermal cutting method such as oxygen cutting is applied to a radioactive structure, a lot of secondary wastes such as aerosol are generated, and there is a problem that there is a risk of internal exposure of workers.

In order to overcome this, if oxygen cutting and laser cutting method using pulse or CW laser are combined, the cutting speed is increased to generate economic benefits, and secondary waste such as aerosol, which is the disadvantage of oxygen cutting, is reduced. It is a technology that can contribute to the reduction of radioactive waste and safety of workers, and provides a fusion cutting device and method that simultaneously irradiates a laser beam while cutting a metal structure (carbon steel) with a high-pressure oxygen flame.

The application of the present invention will be described using a steam generator as an example.

The steam generator is made up of a thick carbon steel material, and the lower part has a hemispherical shape. Inside, a U-shaped Inconel tube is installed. The body is made of carbon steel only, but the lower hemispherical structure is a structure that is welded with stainless steel inside.

It is important to quickly cut metal structures in nuclear power plants to ensure economic efficiency and minimize secondary waste for worker safety.

In order to cut the body of the steam generator and the lower head of the hemispherical shape, the molten metal structure is blown out by continuously or periodically applying a gas or high pressure oxygen that is harmless to the human body and melting the remaining metal with a subsequent high-power pulse or CW laser beam And cutting while cutting.

In order to quickly cut a YouTube tube such as Inconel, which is difficult to cut by hyperbaric oxygen cutting, it includes the step and means of cutting while melting by independently irradiating a laser beam.

The present invention is a fusion cutting apparatus and method capable of economically and rapidly cutting metal structures in a nuclear power plant.

The present invention prevents secondary pollution by installing a suction device to inhale the scattered secondary waste generated during cutting in order to reduce the amount of secondary waste such as aerosol scattering during cutting compared to the conventional oxygen cutting method, and to minimize it. have.

The present invention manufactures a fusion cutting device that combines oxygen cutting and laser cutting for a thick plate, but cuts a metal structure by fusion of oxygen and laser cutting designed and manufactured so that oxygen cutting and laser cutting can be applied independently and fused.

The present invention is a cutting device for safe and economical dismantling of radioactive metal structures such as steam generators and radioactive metal structures such as nuclear reactors, minimizing secondary waste generated during cutting, and performing work at a high cutting speed, It is a method and apparatus for cutting metal structures by independently or fusing oxygen and laser cutting suitable for the field situation.

1 shows the principle of the fusion cutting apparatus and method according to the present invention.

During oxygen cutting, the dragline (1) is made, and the lower side is not straight in the thickness direction, but a slope is made in the cutting direction to create a shape that follows.

When such dragline 1 is properly formed, cutting is performed.

However, when the cutting speed is increased, the inclination of the lower dragline 1 changes rapidly, and cutting is not performed (FIG. 1A).

In other words, the maximum speed of oxygen cutting is formed depending on the inclination of the dragline 1.

If the cutting speed is applied faster than the maximum oxygen cutting speed according to the thickness in order to improve the cutting speed than the conventional oxygen cutting, the sharply inclined dragline 1 is formed in the lower part, and thus cutting is not performed (FIG. 1B).

However, cutting is possible by fusing other cutting methods and cutting the inclined dragline 1 from behind the oxygen cutting torch or head. There may be various cutting techniques to be fused, such as laser cutting techniques (FIG. 1C).

The reason why the laser cutting method is fused is because the secondary scattering product generated during laser cutting is small. This has a direct impact on the generation of secondary waste when dismantling a nuclear power plant. Since waste must be minimized during disassembly, it is desirable to combine laser cutting methods to obtain them.

Figure 2 shows a head portion of the fusion cutting device according to the present invention.

It is a convergence cutting head that combines the oxygen cutting torch (2) and the laser cutting head (3).
Referring to FIG. 2, the head bracket 4 combines the oxygen cutting torch 2 and the laser cutting head 3 to be combined.

The laser cutting head 3 changes the position of the laser cutting head 3 by using the transfer part in the head bracket 4 manually or automatically so that it can focus and cut the inclined dragline 1 according to the thickness. It has a function and means to change the focal position or to allow the optical system in the head to adjust the focal position according to the thickness.

It is preferable to install the oxygen cutting torch 2 and the laser cutting head 3 independently.

A drag line is formed by the oxygen cutting torch 2, and the angle of the laser cutting head is set based on the horizontal (based on the drawing) as in FIGS. 2 and 4 so that the formed drag line can be focused. It is designed and manufactured to be able to adjust about ±15 degrees.

In addition, when cutting metal with an oxygen cutting torch, the angle of the oxygen cutting torch can be adjusted by ±15 degrees based on the horizontal so that the drag line can be minimized.

As shown in Fig. 4, the gas or oxygen cutting torch 2 performs the cutting operation beforehand, and then the cutting operation is performed using the laser cutting head 3 and the focusing optical system 6 to perform cutting.
The oxygen cutting torch 2 and the laser cutting head 3 manufactured as in FIG. 4 are coupled to the head bracket 4, and the gas or oxygen cutting torch 2 performs the cutting operation as shown in FIG. 1C. Then, the laser cutting head 3 and the focusing optical system 6 are used to perform a cutting operation to completely cut.

3 shows a laser beam 5 focusing optical system 6 of the fusion cutting apparatus according to the present invention.

The focusing optical system that focuses the laser beam 5 (6) passes the laser beam 5 through an optical system composed of a lens so that a focus is created at a desired position.

The lens a (7) makes the laser beam (5) into a parallel beam, and the lens b (8) serves to focus the laser beam (5).

The lens b (8) is connected to the motor (9) and can automatically adjust the focus position of the laser beam by controlling the focusing position by adjusting the motor left and right.

Alternatively, the focusing optical system 6 composed of the optical fiber 12, the lens a (7) and the lens b (8) can be connected to the motor 9 to automatically control the focusing position of the laser beam 5.

Figure 4 shows the overall configuration of the fusion cutting device according to the present invention.

The fusion cutting device is composed of an oxygen cutting torch (2), a laser cutting head (3), a head bracket (4), a laser oscillator (10), and a gas utility (11).

The laser beam 5 is generated by the laser oscillator 10 and transmitted using the optical fiber 12, and transmitted to the object to be cut through the laser cutting head 3.

Oxygen cutting basically consists of three lines, and consists of a line that transmits high-pressure oxygen, preheating gas, and propane or acetylene gas. The object to be cut is cut with oxygen using this gas.

5 shows a reactor 13 and a steam generator 14 among metal structures in a nuclear power plant to be cut by the fusion cutting device according to the present invention.

The reactor is the thickest metal structure in a nuclear power plant and is made of carbon steel. The maximum thickness of 500mm should be cut.

In addition, since it is radioactive, it is difficult for an operator to approach the high radiation area and perform the cutting operation.

In order to cut the reactor 13, a thick plate cutting technology is required, and since the operation must be performed in a short time while minimizing secondary scattering generated during cutting, a fusion cutting technology that satisfies this is required.

In this case, the fusion cutting device must be combined with an automatic manipulator. The steam generator 14 is made of carbon steel in the reactor body, but the YouTube 15 is made of Inconel. It is difficult to cut with only the oxygen cutting method, but it is possible to cut with one device by using the device proposed in the present invention.

In addition, the fusion cutting device according to the present invention is economical and can achieve the purpose of disassembly to minimize secondary waste.

A summary of the protection scope of the metal fusion cutting method and the metal fusion cutting device according to the present invention described above will be described.

In one embodiment according to the present invention, in the metal fusion cutting method, cutting with an oxygen cutting torch faster than a maximum oxygen cutting speed according to the thickness, and sharply inclined dragline in a high-power pulse or CW laser. It includes the step of focusing and cutting the generated laser beam.

In the metal fusion cutting device,

Another embodiment according to the present invention is to rapidly cut metal structures and minimize secondary fugitives by forming a high-pressure oxygen flame in an oxygen cutting torch using oxygen supplied through a high-pressure oxygen supply pipe, thereby breaking maximum oxygen. It includes a metal fusion cutting device for cutting faster while oxidizing carbon steel, focusing and irradiating a laser beam emitted through the laser cutting head on the dragline generated underneath, melting and cutting it.

In another embodiment according to the present invention, the head of the fusion cutting device is a laser cutting head that transmits a laser beam, and at least one of a high pressure oxygen supply pipe, a low pressure oxygen supply pipe, a propane gas supply pipe, and a high pressure air supply pipe is independently combined. Consists of.

As another embodiment of the present invention, the laser cutting head includes a laser beam focusing optical system, and has a structure capable of changing a laser beam focusing position according to a thickness by controlling the laser beam focusing optical system.

In addition, the metal fusion cutting device is composed of an oxygen cutting torch and a laser cutting head so that an appropriate cutting torch can be fused or used independently depending on the material.

The metal fusion cutting device is manufactured by integrating an optical fiber for long distance transmission of a laser beam and a gas supply hose for long distance oxygen cutting so that workers can easily work in a narrow space without being exposed to high radiation.

The metal fusion cutting device is equipped with a monitoring device for checking and controlling the cutting state of the target metal, and the monitoring device is composed of a camera and a sensor to check the cutting state of the target metal and based on the monitoring signal, the fusion cutting head It is configured to control the cutting operation by sending a control signal to it.

The metal fusion cutting device includes a suction device for inhaling secondary waste generated in order to reduce the generation of secondary waste generated and scattered during cutting.

It can be configured to adjust the angle of the laser cutting head by ±15 degrees based on the horizontal so as to focus on the drag line formed by the oxygen cutting torch.

When cutting metal with the oxygen cutting torch, the angle of the oxygen cutting torch can be adjusted to ±15 degrees based on the horizontal so that the drag line can be minimized.

The present invention is a fusion cutting method and apparatus that combines gas cutting and laser cutting such as oxygen cutting, etc., and can provide a faster working time than conventional gas cutting from several mm to several hundreds mm regardless of material, and generated secondary scattering Since water is also small, it is highly likely to be used in general industries as it has an increased effect in terms of the environment.

One; Dragline 2; Oxygen cutting torch
3; Laser cutting head 4; Head bracket
5; Laser beam 6; Focusing optical system
7; Lens a 8; Lens b
9; Motor 10; Laser oscillator
11; Gas utility 12; Optical fiber
13; Reactor 14; Steam generator
15; Youtube

Claims (12)

In the metal fusion cutting method for cutting a thick metal structure constituting a reactor body,
In order to cut thick metal structures, an oxygen cutting torch for forming a drag line and a laser cutting head for completely cutting the formed drag line are combined with a head bracket.
Forming a drag line to perform rapid moving cutting of thick metal structures while minimizing radioactive secondary waste using an oxygen cutting torch, and
By performing the cutting with the oxygen cutting torch, the uncut drug line absorbing heat energy is focused on the drug line using a laser cutting head coupled by the head bracket to form a thicker body of the reactor. Comprising the step of completely cutting the metal structure,
To reduce the cutting time of thick metal structures and minimize secondary contamination, the angle of the laser cutting head coupled to the head bracket is adjusted so that the focus of the laser beam is formed on the drag line formed by the oxygen cutting torch to completely cut the thick metal structure. Metal fusion cutting method, characterized in that. delete delete In the metal fusion cutting device for cutting thick metal structures constituting the reactor body,
In order to cut the thick metal structures that make up the reactor body, a fusion cutting head is constructed by combining an oxygen cutting torch and a laser cutting head with a head bracket.
Using an oxygen cutting torch, it minimizes radioactive secondary waste and moves quickly while cutting thick metal structures to form drag lines.
By performing cutting with the oxygen cutting torch, the uncut drug line absorbing heat energy is irradiated with a laser beam to the drug line using a laser cutting head coupled by the head bracket to constitute the reactor body. Configured to completely cut through thick metal structures,
To reduce the cutting time of thick metal structures and minimize secondary contamination, the angle of the laser cutting head coupled to the head bracket is adjusted so that the focus of the laser beam is formed on the drag line formed by the oxygen cutting torch to completely cut the thick metal structure. Metal fusion cutting device, characterized in that configured to be. delete delete The method of claim 4,
A fusion cutting head is composed of an oxygen cutting torch and a laser cutting head combined with a head bracket,
A laser cutting head that transmits a laser beam,
A metal fusion cutting device comprising an oxygen cutting torch in which at least one of a high-pressure oxygen supply pipe, a low-pressure oxygen supply pipe, a propane gas supply pipe, and a high-pressure air supply pipe is combined. The method according to claim 4 or 7,
The laser cutting head includes a laser beam focusing optical system, and further comprising a laser cutting head capable of changing a laser beam focusing position according to a thickness by controlling the laser beam focusing optical system. delete The method according to claim 4 or 7,
A metal fusion cutting device manufactured by integrating optical fiber for long distance transmission of laser beam and gas supply hose for long distance oxygen cutting so that workers can easily work in a narrow space without being exposed to high radiation. The method according to claim 4 or 7,
A monitoring device is attached and installed to check and control the cutting status of the thick metal structures that make up the reactor body.
The monitoring device consists of a camera and a sensor to check the cutting state of the thick metal structure constituting the reactor body and transmit a control signal to the fusion cutting head based on the monitoring signal to control the cutting operation. The method according to claim 4 or 7,
Metal fusion cutting device further comprising a suction device for inhaling secondary waste generated to reduce the generation of radioactive secondary waste generated and scattered when cutting with a metal fusion cutting device.

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