JP2011206884A - Chip contamination prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent chips inevitably generated during cutting a tube from contaminating an inside of the tube.SOLUTION: In a chip contamination prevention device that is used when a conduit such as a boiler tube 11 is cut at a cutting position, to prevent chips generated during cutting the conduit from contaminating the inside of the conduit, there are provided with an electromagnet 31 arranged on an outer circumference of the conduit at a part farther than the cutting position, and a chip collecting fixture 41 inserted from a conduit cutting face side and having a collecting part in a shape of an umbrella 41a for collecting the chips. After the conduit is cut and the chip collecting fixture is inserted from the cutting face, the magnet is removed from the outer circumference of the conduit, and the chip collecting fixture is pulled off the conduit.

Description

  The present invention relates to a chip mixing prevention device for preventing chips from being mixed into a pipe or the like when cutting a pipe or the like, and in particular, a thin tube (for example, a steam pipe) provided in a boiler used in a power plant. The present invention relates to a chip mixing preventive device used when cutting.

  In general, a boiler used in a power plant such as a thermal power plant is provided with a large number of thin tubes (hereinafter referred to as a boiler tube). ing. The thickness of the boiler tube may be reduced due to external corrosion or the like, and it is necessary to periodically inspect the boiler tube and replace the corroded portion.

  Referring to FIG. 11, when partially replacing the boiler tube 11, the boiler tube 11 is cut at the cutting position 13 by using a cutting tool 12 such as a grinder to remove the corroded portion, and a new boiler tube ( (Not shown). In this case, that is, when the boiler tube 11 is cut, the swarf 14 is inevitably generated, and the swarf 14 is often mixed in the boiler tube 11. Often scattered.

  When the chips 14 are mixed into the boiler tube 11, the chips 14 hinder the circulation of water or steam in the boiler tube 11, not only reducing the efficiency of the boiler, but also in the boiler tube itself. Can also have adverse effects. For this reason, it is necessary to remove the chips 14 mixed in the boiler tube 11 or prevent the chips 14 from mixing into the boiler tube 11 when the boiler tube is cut.

  Conventionally, when cutting a metallic pipe line, a metal chip removing device for removing chips mixed in the pipe line is known, this metallic chip removing device is a rod-shaped main body, It has a magnet for adsorbing chips, a coiled spring that freely connects the magnets at the end of the rod-shaped main body, and a removable vinyl that covers the magnet so that the chips are not adsorbed directly.

  When removing the chips mixed in the pipe, a metallic chip removing device is inserted into the pipe from the branch port, and the magnet is moved in the pipe to adsorb the chips. Thereafter, the metallic chip removing device is pulled back, the vinyl is removed, and the chips adsorbed by the metal chip removing device are collected (for example, see Patent Document 1).

JP-A-8-38932

  By the way, in the metallic chip removal device described in Patent Document 1, in order to insert the rod-shaped main body portion into the pipe from the branch port, in order to remove the chips mixed in the pipe deep from the branch port, The length of the rod-shaped body must be increased.

  Furthermore, when the pipe line extends in the vertical direction such as the vertical direction, the chips inevitably fall in the pipe line, so that the chips are mixed deep inside the pipe line. Therefore, the chips cannot be easily removed. That is, in the above-described metallic chip removing device, it is difficult to satisfactorily remove the chips mixed in the pipe.

  Moreover, in the above-mentioned metallic chip removal device, it is not possible to prevent the chips from being scattered to the outside at the time of pipe cutting to such an extent that the chips mixed in the pipe can be removed.

  In any case, the above-mentioned metallic chip removal device only removes the chips once mixed in the pipe line, so it is difficult to completely remove the chips, and the boiler tube It is also difficult to apply to such tubules.

  An object of the present invention is to provide a chip mixing preventing device that can easily prevent chips, which are inevitably generated when cutting a pipe, from being mixed into the pipe.

  (1) The present invention is a chip mixing prevention device that is used when cutting a pipeline at a cutting position and prevents mixing of chips generated when the pipeline is cut into the pipeline. A chip having a magnet disposed on the outer peripheral surface of the pipe line at a position away from the cutting position, and a collecting part that is inserted from the cut surface side of the pipe line and collects the chip. And after the pipe is cut, after inserting the chip collecting jig from the cut surface, the magnet is removed from the outer peripheral surface of the pipe, and the chip collecting jig is It is characterized by being pulled out from the pipeline.

  In the chip mixing preventing apparatus described in (1), a magnet is disposed on the outer peripheral surface of the pipe at a position slightly away from the cutting position of the pipe, and the chips are captured from the cut surface of the pipe. Since the chip collecting jig having the collecting part to be collected is inserted, the chips generated at the time of cutting the pipe are once trapped on the inner peripheral surface of the pipe at the position where the magnet is arranged. It will be. After that, if the magnet is removed from the outer peripheral surface of the pipe and the chip collecting jig is pulled out of the pipe, the chips captured on the inner peripheral surface of the pipe are collected in the collecting section and collected. The jig is pulled out from the pipe line, and chips generated inevitably when the pipe line is cut can be easily collected to prevent chips from entering the pipe line.

  (2) The present invention is the chip mixing prevention device according to (1), wherein the magnet is an electromagnet, a direct current is supplied to the electromagnet, and the chip collecting jig is inserted into the pipe line. Then, a reverse direct current is supplied to the electromagnet.

  In the chip mixing preventing apparatus described in (2), an electromagnet is used as a magnet, a direct current is supplied to the electromagnet, and a reverse current is applied to the electromagnet after the chip collecting jig is inserted into the conduit. Since it was supplied, it is possible to demagnetize the chips once captured on the inner peripheral surface of the pipe and the pipe itself, and as a result, the chips can be easily collected in the collecting section. it can.

  (3) The present invention has the chip mixing prevention device according to (2), including a power source that supplies the DC current to the electromagnet, and a switch unit that changes the direction of the DC current supplied to the electromagnet. It is characterized by.

  In the chip mixing prevention apparatus according to (3), since the power supply for supplying a direct current to the electromagnet and the switch means for changing the direction of the direct current supplied to the electromagnet are provided, the chip and the pipe line can be easily It can demagnetize itself.

  (4) The present invention provides the chip mixing prevention device according to any one of (1) to (3), wherein the chip collection jig includes an umbrella unit that functions as the collection unit, and the umbrella unit. It has a support bar part to support and an operation part to open and close the umbrella part, and the umbrella part is in a closed state when the chip collecting jig is inserted into the pipe line from the cut surface side. It is characterized by this.

  In the chip mixing prevention device according to (4), the chip collecting jig includes an umbrella part that functions as a collecting part, a support bar part that supports the umbrella part, and an operation part that opens and closes the umbrella part. When the chip collecting jig is inserted into the pipe line from the cut surface side, the umbrella part is in a closed state, so that the chips once captured on the inner peripheral surface of the pipe line touch the umbrella part. It will not fall out and get mixed in the pipeline.

  (5) The present invention provides the chip mixing prevention device according to (4), wherein an elastic body is disposed along an outer edge of the umbrella portion with the umbrella portion open, The umbrella portion is in contact with the inner peripheral surface of the pipe line in the opened state.

  In the chip mixing preventing device described in (5), an elastic body is disposed along the outer edge of the umbrella portion with the umbrella portion opened, and the elastic body is further connected to the pipe line with the umbrella portion open. Since it is in contact with the inner peripheral surface, it is possible to collect all the chips once captured on the inner peripheral surface of the pipe line into the umbrella part, and when removing the chip collecting jig, the chips from the umbrella part can be collected. There is no fear of leaking.

  As described above, according to the present invention, the magnet is disposed on the outer peripheral surface of the pipeline at a position slightly away from the cutting position of the pipeline, and chips are collected from the cut surface side of the pipeline. Inserting a chip collecting jig with a collection part, removing the magnet from the outer peripheral surface of the pipe and pulling out the chip collecting jig from the pipe, so that the chips generated when cutting the pipe Once the magnet is disposed on the inner peripheral surface of the pipe, the chip is collected in the collecting section and the chip collecting jig is pulled out from the pipe. There is an effect that chips that are inevitably generated when the road is cut can be easily collected to prevent the chips from entering the pipe.

It is a block diagram which shows roughly an example of the thermal power plant in which the chip mixing prevention apparatus by embodiment of this invention is used. It is a flowchart for demonstrating operation | movement of the chip mixing prevention apparatus by embodiment of this invention. It is a figure which shows the state which mounted | wore the outer peripheral surface of the boiler tube with the electromagnet of the chip mixing prevention apparatus by embodiment of this invention. It is a figure which shows the state which inserts the chip collection jig | tool of the chip mixing prevention apparatus by embodiment of this invention into a boiler tube. It is a figure which shows the state which opened the umbrella part of the chip collection jig. It is a figure which shows the state which switched the direction of the electric current supplied to an electromagnet with the switch apparatus. It is a figure which shows the state which stops the electric current supply to an electromagnet and raises a chip collection jig. It is a figure which shows the state which took out the chip collection jig out of the boiler tube. It is a figure which shows the structure of a chip collection jig. It is a figure for demonstrating the connection of a new boiler tube after cutting a boiler tube, (a) is sectional drawing for demonstrating insertion of the paper for welding back seals, (b) is a new boiler tube match | combining Sectional drawing which shows the state welded, (c) is a figure which shows the state which joined the new boiler tube by welding. It is a figure for demonstrating the cutting | disconnection of the conventional boiler tube.

  Hereinafter, an example of a chip mixing prevention device according to an embodiment of the present invention will be described with reference to the drawings. Here, a case where a thin tube (metal tube: magnetic body) that is provided in a boiler used in a thermal power plant and in which steam flows, such as a boiler tube, is described will be described. It can be applied in the same way when cutting.

  FIG. 1 is a block diagram schematically showing a thermal power plant. In FIG. 1, fuel such as heavy oil is supplied to a boiler 21 where combustion is performed. Condensate (water) from the condenser 22 is supplied to the boiler 21 by a pump 23.

  Although not shown, the boiler 21 is provided with (arranged) a thin tube (boiler tube), and the water supplied from the condenser 22 passes through the boiler tube. Then, the water is heated while passing through the boiler tube of the boiler 21, becomes steam, and is supplied to the steam turbine 24, thereby driving the steam turbine 24.

  The generator (G) 25 is driven by driving the steam turbine 24 to generate power. The steam that has passed through the steam turbine 24 reaches the condenser 22 where it is condensed by the cooling water to become water, and is sent again to the boiler 21 by the pump 23 (note that the condenser 22 supplies water as necessary) Is done).

  By the way, the above-described boiler tube needs to be partially replaced due to a reduction in wall thickness due to external corrosion or the like, and at this time, the boiler tube needs to be cut. When cutting the boiler tube, chips are inevitably generated. Here, however, the chips are prevented from being mixed into the boiler tube as follows.

  FIG. 2 is a flowchart for explaining the operation of an example of the chip mixing preventing apparatus according to the embodiment of the present invention. With reference to FIG.2 and FIG.3-9, the chip mixing prevention apparatus has the magnet (electromagnet) and chip collection jig which are mentioned later. First, the boiler tube (metal tube, for example, 28 mm in diameter) 11 is slightly separated from the cutting position 13 (lower side in the example shown in FIG. 2, for example, about 10 cm below the cutting position 13). An electromagnet (magnet) 31 is mounted on the outer peripheral surface of the tube 11 (step S1).

  The electromagnet 31 is connected to a power supply device (DC power supply device) 33 via a switch device 32. The switch device 32 has first to fourth contact terminals 32a to 32d, and the first and second contact terminals 32a and 32b are provided with first and second switches 32e and 32f, respectively. . The first and second contact terminals 32 a and 32 b are connected to the electromagnet 31, and the third and fourth contact terminals 32 c and 32 d are connected to the power supply device 33.

  Subsequently, as shown in FIG. 3, the first and second switches 32e and 32f are closed to connect the first contact terminal 32a and the third contact terminal 32c, and the second contact terminal 32b and the second contact terminal 32b. 4 contact terminals 32d are connected (step S2). As a result, current is supplied to the electromagnet 31 and the electromagnet 31 is magnetized.

  Thereafter, the boiler tube 11 is started to be cut at the cutting position 13 by using a cutting tool 12 such as a grinder (step S3). At this time, chips 14 are inevitably generated. A part of the chips 14 enters the boiler tube 11, and the rest is scattered outside.

  However, as described above, the electromagnet 31 is mounted on the outer peripheral surface of the boiler tube 11 and magnetized, so that the chips 14 that have entered the boiler tube 11 are in the portion where the electromagnet 31 is mounted. Is captured by the inner peripheral surface (see FIG. 3). Similarly, most of the chips scattered outside are captured by the electromagnet 31.

  After the cutting of the boiler tube 11 is completed, the cut surface is polished into a predetermined shape using a groove processing machine (not shown). Subsequently, the chip collecting jig 41 is inserted into the boiler tube 11 from the cut surface side (step S4). As shown in FIG. 9, the chip collecting jig 41 is an umbrella-shaped jig, and has an umbrella part 41a and a holding bar part 41b that holds the umbrella part 41a. The holding bar part 41b includes An operation unit 41c for opening and closing the umbrella unit 41a is provided.

  And when the umbrella part 41a is opened, the elastic body (for example, rubber | gum) 41d is provided along the outer edge of the umbrella part 41a. In addition, the umbrella part 41a is produced with a thick resin film etc., for example.

  The chip collecting jig 41 is inserted into the boiler tube 11 from its tip end from the cut surface side with the umbrella portion 41a closed. At this time, the chip collecting jig 41 is inserted below the mounting position of the electromagnet 31 (see FIG. 4). Then, the operation part 41c is operated and the umbrella part 41a is opened (step S5). Thereby, the umbrella part 41a becomes a collection part (refer FIG. 5).

  When the umbrella part 41 a is opened, the outer edge of the umbrella part 41 a is in close contact with the inner peripheral surface of the boiler tube 11. That is, since the elastic body 41d is provided on the outer edge of the umbrella portion 41a, the elastic body 41d is pressed against the inner peripheral surface of the boiler tube 11 by the force of opening the umbrella portion 41a.

  Next, the first and second switches 32e and 32f are operated, the first contact terminal 32a and the fourth contact terminal 32d are connected by the first switch 32e, and the second switch 32f is used for the second operation. The contact terminal 32b and the third contact terminal 32c are connected (switch switching: step S6 (see FIG. 6)).

  As a result, a reverse current flows through the electromagnet 31. For example, the N pole and the S pole are reversed (reverse magnetic force lines are generated), and the boiler tube 11 is demagnetized. .

  Thereafter, the first switches 32e and 32f are opened, and the supply of current to the electromagnet 31 is stopped (step S7). As a result, the chips 14 captured on the inner peripheral surface of the boiler tube 11 fall, but these chips 14 are collected in the umbrella portion 41a located below the mounting position of the electromagnet 31. As a result, it does not enter the boiler tube 11 (see FIG. 7).

  Then, the chip collecting jig 41 is pulled up by the holding bar 41b and is taken out from the boiler tube 11 (operation for removing the chip collecting jig: step S8). The chips 14 collected by the umbrella part 41a are discharged from the boiler tube 11 (see FIG. 8).

  In this way, the chips 14 are once captured on the inner peripheral surface of the boiler tube 11 using the electromagnet 31, and then the chips 14 captured on the inner peripheral surface of the boiler tube 11 by the chip collecting jig 41. Therefore, when the boiler tube 11 is cut, the chips 14 are not mixed deeply into the boiler tube 11, and the chips 14 can be easily collected. That is, it is possible to easily prevent chips from being inevitably generated when the boiler tube 11 is cut.

  By the way, in the boiler 21, for example, 16 boiler tubes 11 are arranged at intervals of 9.5 mm at the entrance of the fourth superheater. On the other hand, since the diameter of the cutting tool 12 such as a grinder is approximately 180 mm, when the boiler tube 11 is to be cut, a plurality of boiler tubes 11 including the adjacent boiler tubes are cut. Therefore, chips may be mixed from the adjacent boiler tube 11 or the like.

  In such a case, it is desirable to supply the electric current to the electromagnet by mounting the above-described chip mixture preventing device on the boiler tube 11 to be cut at once. If it does in this way, even if it scatters from the adjacent boiler tubes 11 etc., it will be captured by the electromagnet as described above, and mixing of the chips into all the boiler tubes 11 to be cut at once will be prevented. can do.

  As described above, after the boiler tube 11 is cut, a new boiler tube 11a is connected by welding. Referring to FIG. 10, a welding back seal paper 52 is inserted into the boiler tube 11 from the cut surface side using a rod-shaped insertion jig 51. The weld back seal paper 52 is positioned at a depth of 250 mm to 350 mm from the cut surface, for example (see FIG. 10A).

  Subsequently, the new boiler tube 11a into which the welding back seal paper 52 is inserted is positioned on the cut surface of the boiler tube 11 and temporarily welded by the mating weld 53 (see FIG. 10B). Then, after temporarily welding by the mating welding 53, the boiler tube 11 and the boiler tube 11a are completely joined by the welding 54 (see FIG. 10C).

  In the above-described embodiment, the example in which the electromagnet 31 is mounted on the outer peripheral surface of the boiler tube 11 and the chips 14 are once captured on the inner peripheral surface of the boiler tube 11 has been described. May be used.

  At this time, after the chip collecting jig 41 is inserted into the boiler tube 11, the umbrella 41 a is opened, the permanent magnet is subsequently removed, and the chip collecting jig 41 is pulled out of the boiler tube 11. .

  Furthermore, you may make it perform operation of the above-mentioned switch apparatus 32, and insertion / extraction of the chip collection jig 41 automatically. For example, the above steps may be sequentially performed by sequence control (sequence control unit (not shown)). At this time, the chip collecting jig 41 is attached to the drive device (lifting device), and the cutting is performed. What is necessary is just to raise / lower the powder collection jig | tool 41 and to operate the operation part 41c remotely.

DESCRIPTION OF SYMBOLS 11, 11a Boiler tube 12 Cutting tool 14 Chip 21 Boiler 22 Condenser 23 Pump 24 Steam turbine 25 Generator 31 Electromagnet 32 Switch device 33 Power supply device 41 Chip collecting jig

Claims (5)

It is used when cutting a pipe line at a cutting position, and is a chip mixing preventing device for preventing mixing of chips generated when cutting the pipe line into the pipe line,
A magnet disposed on the outer peripheral surface of the pipe line at a position away from the cutting position;
A chip collecting jig inserted from the cut surface side of the pipe, and having a collecting section for collecting the chips,
After cutting the pipe, after inserting the chip collecting jig from the cut surface, the magnet is removed from the outer peripheral surface of the pipe so that the chip collecting jig is pulled out from the pipe. A device for preventing chips from mixing. The magnet is an electromagnet, a direct current is supplied to the electromagnet,
2. The chip mixing preventing apparatus according to claim 1, wherein a reverse direct current is supplied to the electromagnet after the chip collecting jig is inserted into the conduit. A power source for supplying the direct current to the electromagnet;
3. The chip mixing preventing apparatus according to claim 2, further comprising a switch unit that changes a direction of the direct current supplied to the electromagnet. The chip collecting jig includes an umbrella part that functions as the collecting part, a support bar part that supports the umbrella part, and an operation part that opens and closes the umbrella part.
The chip mixing prevention device according to any one of claims 1 to 3, wherein the umbrella portion is in a closed state when the chip collecting jig is inserted into the pipe line from the cut surface side. . With the umbrella part open, an elastic body is disposed along the outer edge of the umbrella part,
The chip mixture preventing device according to claim 4, wherein the elastic body is in contact with an inner peripheral surface of the pipe line with the umbrella portion opened.

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