JP2956010B2 - How to remove equipment piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing equipment piping for handling harmful substances such as radioactive substances, and more particularly to an equipment for cutting and removing metal piping in which piping is contaminated with harmful substances. It relates to a method for removing piping.

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional general method for removing equipment piping is a metal piping provided between a device 1 for handling harmful substances such as radioactive substances and a mother pipe 2. When cutting 3 and detaching it from the device 1 and the mother tube 2, it was cut and removed by an electric saw 4 using a cutting force.

However, in the case of the above-described method of removing the equipment piping, since the cutout of the piping 3 is opened, harmful substances in the piping 3 leak from the piping 3 to the outside. Also,
Since the cutting is performed by the cutting force of the electric saw 4 or the like, swarf to which harmful substances adhere is generated. As a result, there is a risk that a worker or the outer surface of the device 1 around the cutting may be contaminated with harmful substances, and a safe removal operation cannot be performed. In addition, there is a disadvantage that it takes time to remove a large number of pipes 3 and the working efficiency is poor.

[0004] Therefore, as a method of removing the equipment piping to solve the above-mentioned drawbacks, there has been proposed a method of flattening the cutting position of the mother pipe by pressure bonding and then cutting the flattened portion by a plasma cutting torch (particularly). Kaikai 61-25349
7).

[0005]

However, in the crimping operation in the method of removing the equipment pipe disclosed in Japanese Patent Application Laid-Open No. 61-253497, a part of the mother pipe is simply crimped from above and below and flattened, and the crimping tool is removed. In addition, a springback phenomenon in which the crimped portion of the mother tube is restored due to the elastic force inherent in the metal tube easily occurs. For this reason, since the cut end face of the cut mother pipe is easily opened, there is a drawback that general cutting such as saw cutting using a cutting force or cutting with a cutting blade using a shearing force cannot be performed. .

[0006] For this reason, it is necessary to perform melting cutting with a plasma cutting torch capable of closing the cut end face at the same time as cutting, and such a cutting requiring a special cutting device and a special technique is not practical. There's a problem. The present invention has been made in view of such circumstances, and when removing pipes disposed between equipment and contaminated with harmful substances from the equipment, the harmful substances inside the pipes can be safely and without leaking to the outside. An object of the present invention is to provide a method for removing equipment piping, which can easily perform a removal operation and can further improve the operation efficiency.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a facility pipe which is disposed between facilities and is separated from the facility by removing metal pipes which are internally contaminated with harmful substances. In the method of removing, the disconnection position of both ends of the pipe to be separated from between the equipment, crushed in the axial direction of the pipe so that the number of peaks having a vertex angle of a predetermined angle is at least three waveforms, A substantially central portion of each of the disconnection positions of the pipe crushed into a waveform is cut by a shearing force to remove the pipe from between the facilities.

According to the present invention, in the case where metallic pipes disposed between equipment and contaminated with harmful substances are separated from the equipment and removed, disconnection of both ends of the pipe separated from the equipment is performed. Since the position is crushed in the axial direction of the pipe so as to have a waveform having a vertical angle of a predetermined angle, the inside of the pipe to be removed from the facility can be sealed.

[0009] Next, since a substantially central portion of the disconnection position of the pipe crushed into a waveform is cut by a shearing force, the inside of the pipe is maintained in a sealed state even after disconnecting the pipe from the equipment. And cutting by shearing force does not generate chips to which harmful substances adhere. In the crushing and cutting operations, if the crushing is performed so that the predetermined angle of the apex angle of the waveform is preferably 120 ° ± 5 °, the sealing performance of the pipe can be reliably obtained. In other words, the best sealing property at the apex of the corrugation is obtained at the collapsed separation position. For this reason, it is necessary to make the angle of the apex angle as sharp as possible.However, if the angle is too sharp, there is a risk of cracks entering the apex portion when the pipe is crushed, and furthermore, there is a danger that the apex portion will be broken torn. Inability to obtain sealing. On the other hand, if the angle of the apex angle is too obtuse, a gap is formed at the apex angle, and good sealing performance cannot be obtained. In addition, since the number of peaks forming the waveform is crushed so as to be at least three, and cut at substantially the center of the crushed separation position, the inside of the pipe removed from between the facilities is completely It is possible to maintain proper sealing. That is, since the three peaks of the waveform have five apex angles, if the apex angle portion of the middle crest is cut, the cut pipe has two apex angles. In other words, a double blocking effect can be obtained with these two apex angles, so that complete sealing can be maintained.

[0010] This makes it possible to remove the pipe without harmful substances in the pipe leaking outside.
Removal work can be performed safely. In addition, since the pipe is cut with a shearing force in a crushed state, the cutting time can be shortened as compared with the conventional cutting using an electric saw or the like using a cutting force, thereby improving the efficiency of removing work. Can be.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for removing equipment piping according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an example of equipment connected by an aluminum pipe 14 disposed between a radioactive substance handling device 10 and a mother pipe 12. Then, in the case where the pipe 14 is cut at the disconnection positions 16A and 16B indicated by arrows in the figure, and the pipe 14 is removed from the device 10 and the mother pipe 12, an example in which the method for removing facility piping of the present invention is applied. This will be described below.

First, as shown in FIG. 2, a pair of dies 20A and 20B having corrugated die surfaces 18A and 18B and having the dice surfaces 18A and 18B fitted to each other are prepared by a press machine 22 in preparation for the removal operation. Install and fix. Further, all the apex angles θ of the waveforms of the die surfaces 18A and 18B are formed at 120 ° ± 5 °. Also,
The press 22 is operated by a hydraulic mechanism (not shown).

Next, the method for removing the equipment pipe according to the present invention will be described. The disconnection position 16A of the pipe 14 to be removed shown in FIG. 1 on the side of the mother pipe 12, as shown in FIG. 22 dies 20A and 20B,
A pair of dies 2 corresponding to the hydraulic mechanism of the press machine 22
0A and 20B are operated in the direction of the arrow in the figure. Then, the pipe 14 is crushed in the axial direction of the pipe 14 so that the separation position 16A of the pipe 14 has a waveform as shown in FIG. As a result, the disconnection position 16A of the pipe 14 on the mother pipe 12 side is closed.

Next, as shown in FIG. 3 (B), the apex portion of the central peak of the three peaks of the waveform formed at the separation position 16A is cut by a cutter 26 utilizing a shearing force. As shown in FIG. Similarly, the separation position 16B on the device 10 side shown in FIG.
2 and crushed by a cutter 26. As a result, both ends of the pipe 14 shown in FIG. 1 are separated from the mother pipe 12 and the device 10 while being crushed into a waveform as shown in FIG. 4, and the inside of the pipe 14 is sealed. 1
4 without leaking the radioactive material inside
Can be removed.

Further, since the cutting of the pipe 14 is performed by the cutter 26 using a shearing force that does not generate chips, it is possible to prevent contamination due to scattering of chips to which radioactive substances adhere. Also, by making the apex angle of the waveform forming the die surfaces 18A and 18B of the press machine 22 to be 120 ° ± 5 °, it is possible to obtain the sealing property of the crushed pipe 14 in a good and reliable manner. Can be. That is, the sealing performance of the crushed cutting positions 16A and 16B is the best sealing performance at the apex of the waveform,
It is necessary to make the apex angle as acute as possible. But,
If the angle is too sharp, there is a danger that the crooked pipe 14 will crack at the apex or break torn off. On the other hand, if the angle of the apex angle is too obtuse, a gap is formed at the apex angle, and good sealing performance cannot be obtained. Also, by crushing the pipe 14 into a waveform, it is possible to prevent a springback peculiar to the metal pipe that occurs after the pipe 14 is crushed.
It is difficult to form an opening at the cutting positions 16A and 16B.

Further, the number of peaks forming the waveform on the surface of the die 18A is at least three, and the cutting is performed at the center of the crushed cutting positions 16A and 16B. 14 can completely maintain the hermeticity. That is, since the three peaks of the waveform have five apex angles, if the apex portion of the middle crest is cut off, the cut pipe 14 has two apex angles. Thus, a double blocking effect can be obtained with these two apex angles, so that complete sealing can be maintained.

As described above, according to the method for removing equipment pipes of the present invention, the cutout of the pipe 14 cut as in the conventional method for removing equipment pipes is not opened, and chips are cut at the time of cutting. Does not occur, the radioactive substance in the pipe 14 does not leak to the outside or scatter. Further, since the equipment piping can be easily removed without requiring a special cutting device or a cutting technique as in the conventional method for removing equipment piping, it is extremely practical.

Further, since the pipe 14 is crushed and then cut by the cutter 26 utilizing the shearing force, the cutting time can be shortened as compared with the conventional cutting using an electric saw utilizing the cutting force. Work efficiency can be improved. Therefore, by using the method for removing equipment piping of the present invention, the removal operation can be performed more safely and easily than the conventional method for removing equipment piping, and the efficiency of the removal operation can be improved.

Further, in the above embodiment, the crushing and cutting of the pipe 14 are described in separate steps, but FIGS. 5A and 5B
As shown in (1), crushing and cutting may be performed in one step. That is, the dies 20A and 20B are formed in a state where they are further divided into two parts 21A, 21B, 21C and 21D at the center, respectively, and the two divided surfaces are cutting blades 28A and 28B. Thereby, as shown in FIG. 5A, first, the pipe 14 is sandwiched between the pair of dies 20A, 20B to crush the pipe 14, and then the dies 21B, 21D on one side are formed.
Is displaced, giving a shearing force to the pipe 14 and causing the pipe 1
Cut 4 In this case, the same effect as in the above embodiment can be obtained, and the crushing / cutting step can be performed in one step, so that the working efficiency can be further improved.

In this embodiment, an example has been described in which a pipe provided between equipment for handling radioactive substances is removed. However, the present invention is not limited to this. For example, a pipe for a chemical plant or the like handling harmful substances is removed. The case can also be applied. Further, although the present embodiment has been described with reference to the aluminum pipe, the present invention is not limited to this. In particular, it is most suitable for a metal pipe having a high ductility such as copper or lead, and a metal pipe such as a stainless pipe having a small ductility. In the case of a pipe, it is preferable to perform a ductile treatment such as heating the metal pipe before crushing.

[0021]

As described above, according to the method for removing equipment pipes according to the present invention, both ends of a metal pipe which is disposed between equipments and whose inside is contaminated with harmful substances are removed from between the equipments. The separation position to be cut was crushed in the axial direction of the pipe so as to have a waveform having a vertical angle of a predetermined angle, and then the approximate center of the cut position of the pipe crushed into the waveform was cut by shearing force. . Accordingly, the pipe can be cut off from the facility in a sealed state, so that the pipe can be safely removed without harmful substances in the pipe leaking to the outside, and the cutting of the pipe can be performed by a shearing force that does not generate chips. Since the cutting is performed by the cutting method, the swarf to which the harmful substance adheres does not scatter.

Further, since the equipment piping can be easily removed without requiring a special cutting device or a cutting technique as in the conventional method for removing equipment piping, it is extremely practical. In addition, since the pipe is cut with a shearing force in a crushed state, the cutting time can be shortened as compared with the conventional cutting using an electric saw or the like using a cutting force, so that the removal work efficiency can be improved. it can.

Therefore, by using the method for removing facility piping according to the present invention, it is safer and easier than conventional methods for removing facility piping, and the removal work efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a position where a pipe is separated by a method for removing a facility pipe according to the present invention.

FIG. 2 is an explanatory view showing a press machine used in the method for removing facility piping according to the present invention.

FIG. 3 is an explanatory view showing work steps of a method for removing facility piping according to the present invention.

FIG. 4 is a piping state diagram after the method for removing facility piping of the present invention is performed.

FIG. 5 is an explanatory view showing another embodiment of the method for removing equipment piping according to the present invention.

FIG. 6 is an explanatory view illustrating a conventional method of removing equipment piping.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Equipment 12 ... Main pipe 14 ... Piping 16A, 16B ... Disconnection position 18A, 18B ... Die surface 20A, 20B ... Die 22 ... Press machine 26 ... Cutter

──────────────────────────────────────────────────続 き Continuing from the front page (72) Tatsuo Nishizawa, Inventor Hitachi Plant Construction Co., Ltd. 1-11-1 Uchikanda, Chiyoda-ku, Tokyo (72) Yoshiki Shibano 3-1-1, Sachicho, Hitachi City, Ibaraki Prefecture No. Hitachi, Ltd. Hitachi Plant (72) Inventor Shigeru Yonekawa 1550, Kamisaihara-mura, Tomata-gun, Okayama Prefecture Power Reactor and Nuclear Fuel Development Corporation Ningyotoge Works (56) References JP-A-58-181514 (JP, A) JP-A-61-253497 (JP, A) JP-A-62-80599 (JP, A) JP-A-62-189000 (JP, A) JP-A-63-7213 (JP, A) (58) (Int.Cl. ⁶ , DB name) G21F 9/30

Claims (3)

(57) [Claims] 1. A method for removing a metal pipe which is disposed between equipment and which has metal inside contaminated with a harmful substance and which is separated from the equipment, wherein both ends of the pipe are separated from the equipment. Is crushed in the axial direction of the pipe so that the number of peaks having a vertex angle of a predetermined angle becomes at least three waveforms, and a substantially central portion of each of the separated positions of the pipe crushed into a waveform is crushed. A method of removing equipment piping, wherein the piping is removed from between the equipment by cutting with a shearing force. 2. The method according to claim 1, wherein the predetermined angle of the apex angle is crushed so as to be 120 ° ± 5 °. 3. The method according to claim 1, wherein the steps of crushing and cutting the pipe are performed in one step.