JP7702832B2 - Decontamination equipment, decontamination line - Google Patents

Description

The present invention relates to a technology for decontaminating a workpiece.

When metal pipes used in heat exchangers, etc. are discarded during the demolition of nuclear power plants, the pipes are processed into plates and then decontaminated by air blasting. Patent Document 1 is an example of a document that discloses technology related to the decontamination of metal materials.

Japanese Utility Model Application Publication No. 53-016992

Conventionally, a cover was installed to prevent scattering, and workers manually performed decontamination work using air blasting inside the cover. The conventional decontamination work had issues in that it was performed in a poor environment with a dusty atmosphere, and it was difficult to decontaminate the workpiece evenly because it was done manually.
An object of the present invention is to provide a decontamination apparatus that improves the environment for decontamination work and can decontaminate workpieces more evenly than manual work.

The decontamination device includes a blast box, a transport section that transports the workpiece from the entrance to the exit of the blast box, a blast head having a blast nozzle that ejects blast material, a connection section that is located at the top of the blast box and connects the blast head to the blast box, and a connection section that is attached to the bottom of the blast box and to which a suction hose that sucks in the blast material is connected. The connection section has a ventilation section that draws in outside air into the blast box as the blast head ejects blast material.

This configuration can prevent dust contaminated with blasting materials (abrasives) and radioactive materials from scattering into the surrounding area, allowing work to be done in a good working environment. The work surface can be decontaminated more evenly than with manual work. Continuous decontamination is possible, and work efficiency is higher than with manual work. The decontamination equipment occupies a small space, so it can be used even in small workplaces.

In one embodiment of the decontamination device, the ventilation section may be positioned so as to surround the entire circumference of the blast head.

As one embodiment of the decontamination device, the connecting part may include a stand fixed to the ceiling wall of the blast box and having a through hole penetrating vertically, a fixed plate having an annular holding member for holding the blast head, a columnar boss part receiving the underside of the fixed plate at a position a predetermined distance away from the stand, and an outer wall part provided along the outer periphery of the fixed plate and surrounding the sides of the blast head and the boss part between the fixed wall and the ceiling wall. The blast nozzle may pass through the through hole of the fixed plate so that the nozzle tip for ejecting the blast material faces the through hole of the stand. The outer wall part may be made of a brush and function as a ventilation part for taking in outside air into the through hole of the stand as the blast material is ejected by the blast head.

In one embodiment of the decontamination device, the stand may have an annular peripheral wall. In addition, the lower end of the brush outer wall may fit inside the peripheral wall of the stand.

In one embodiment of the decontamination device, the blast box may have a rubber protective layer on the inside.

The decontamination device disclosed in this specification can be used to decontaminate contaminated piping. In addition, the decontamination device can be used for decontaminating other workpieces, not just contaminated piping.

The present invention improves the environment for decontamination work and enables workpieces to be decontaminated more evenly than by manual work.

Process diagram of thin tube decontamination work Plan of the decontamination line Side view of the cutting device Plan view of the cutting device A perspective view of the main part of the cutting device Perspective view of piping and shaft rod A perspective view of the main part of the cutting device A perspective view of the main part of the cutting device Perspective view with part of the main body frame removed Side view of rolling equipment Plan view of the rolling mill A perspective view of a main part of a rolling mill FIG. 1 is a perspective view showing the internal structure of a rolling device; FIG. 1 is a perspective view showing the internal structure of a rolling device; Diagram showing the arrangement of rolling rollers FIG. 13 is a view of the rolling device from the direction A in FIG. Side view of the decontamination equipment Plan view of the decontamination equipment Perspective view of decontamination equipment Oblique view of the main parts of the decontamination equipment Perspective view of the conveying section Perspective view of the decontamination device body Vertical cross-sectional view of FIG. Conceptual diagram of air blast equipment Perspective view of the blast head and connecting part FIG. 3 is an exploded perspective view showing the structure of the outer wall portion. 26 is an exploded perspective view of FIG. Vertical cross-sectional view of FIG.

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS.
When dismantling a nuclear power plant, it is necessary to remove and dismantle metal pipes (hereinafter, thin tubes) from a high-pressure feed water heater or a condenser. In this embodiment, the decontamination device 300 is used in a decontamination line L for a thin tube 1 removed from a high-pressure feed water heater or a condenser.

1. Procedure for decontamination of the thin tube 1 FIG. 1 is a process diagram of the decontamination work of the thin tube 1.
The decontamination work will be carried out through the following steps:
(a) A process for cutting out a straight portion of the capillary tube 1 from a heat exchanger or a condenser. (b) A process for cutting the cut-out capillary tube 1 to a fixed length. (c) A process for splitting the capillary tube 1 cut to a fixed length in half. (d) A process for rolling the halved capillary tube 1 into a flat plate. (e) A process for decontaminating the capillary tube 1 rolled into a flat plate.

By steps (a) to (e), the removed thin tube 1 can be decontaminated and can be disposed of as waste. Note that reference symbol 1A indicates the thin tube after halving, reference symbol 1B indicates the thin tube after rolling, and reference symbol 1C indicates the thin tube after decontamination.

In this embodiment, as shown in FIG. 2, the decontamination line L is composed of three devices: a cutting device 10, a rolling device 100, and a decontamination device 300, and steps (c) to (e) can be performed in an assembly line. The symbol U indicates the work space for workers.

The cutting device 10, rolling device 100, and decontamination device 300 will be described in order below. In addition, the direction in which the thin tube 1 is transported is defined as the X direction, the direction perpendicular to the X direction is defined as the Y direction, and the vertical direction is defined as the Z direction.

2. Description of the Cutting Apparatus 10 Fig. 3 is a side view of the cutting apparatus 10, Fig. 4 is a plan view of the cutting apparatus 10, and Fig. 5 is a perspective view of the main part of the cutting apparatus 10.

The cutting device 10 includes a stepped work table 11, a cutting device main body 15, a drive motor 70, a first roller conveyor 16, and a second roller conveyor 17.

As shown in Figures 4 and 5, the cutting device body 15 and the drive motor 70 are arranged separately on the first upper wall 11A and the second upper wall 11B of the workbench 11.

The first roller conveyor 16 is located on the right side (inlet surface) of the cutting device body 15, and the second roller conveyor 17 is located on the left side (outlet surface) of the cutting device body 15.

The cutting device body 15 is a device that uses an axial rod 3 to cut the thin tube 1 into two pieces at a cutting surface parallel to the axis V of the thin tube 1.

As shown in FIG. 6, the axial rod 3 is a rod longer than the pipe 1. The axial rod 3 has a circular cross section and is inserted into the inside of the pipe 1. The axial rod 3 is used to prevent the pipe 1 from deforming inward and escaping when it is cut by the rotary blades 50A and 50B.

As shown in Figures 7 and 8, the cutting device main body 15 includes a main body frame 20, a pair of rails 28A, 28B, a pair of conveying rollers 40A, 40B, a pair of roller holders 45A, 45B, a pair of rotary blades 50A, 50B, a pair of rotary blade 50 holders 55A, 55B, a pair of guide members 60, and a gear mechanism 75.

The main frame 20 is composed of a base 21, a pair of side panels 24, and a top plate 25. A pair of rails 28A, 28B are fixed to the inner surfaces of the pair of side panels 24. The pair of rails 28A, 28B extend parallel to the X direction, and both front and rear ends are fixed to the front and rear frames 29. The pair of rails 28A, 28B are located at approximately the mid-height of the main frame 20 in the Z direction (up and down direction). The space between the rails is the transport path for the pipe 1.

A pair of conveyor rollers 40A, 40B and a pair of rotary blades 50A, 50B are arranged between the two side panels 24.

The pair of conveying rollers 40A, 40B face each other in the Z direction (up-down direction). Each conveying roller 40A, 40B is supported by a roller holder 45A, 45B.

The roller holders 45A and 45B have a U-shaped cross section, and the two side walls located on either side of the conveying rollers 40A and 40B rotatably support the shafts 41 of the conveying rollers 40A and 40B.

The pair of conveying rollers 40A, 40B rotate with the power of the drive motor 70, and can send the pipe 1 with the shaft rod 3 inserted therein along the conveying path located between the two rails 28 to the downstream cutting position.

The pair of rotary blades 50A, 50B are disposed downstream of the pair of conveying rollers 40A, 40B. Specifically, they are disposed at a cutting position on the conveying path. The pair of rotary blades 50A, 50B face each other in the vertical direction (Z direction). Each rotary blade 50A, 50B is supported by a rotary blade holder 55A, 55B. The rotary blade holders 55A, 55B have a U-shaped cross section, and two side walls 57 located on both sides of the rotary blade 50 rotatably support the shaft portion 51 of the rotary blade 50A, 50B.

As shown in Figures 7 and 8, the gear mechanism 75 includes a first gear G1, a second gear G2, a third gear G3, a fourth gear G4, a fifth gear G5, a sixth gear G6, a seventh gear G7, and an eighth gear G8. The first gear G1 and the second gear G2 are disposed on the front side of the main body frame 20.

The first gear G1 is fixed to the end of the shaft 41 of the lower conveyor roller 40B, and the second gear G2 is fixed to the end of the shaft 41 of the upper conveyor roller 40A. The first gear G1 and the second gear G2 are meshed with each other, and the first gear G1 is also meshed with the motor gear 73.

As a result, the power of the drive motor 70 can be transmitted to the two conveying rollers 40A and 40B via the gears 73, G1, and G2, causing the two conveying rollers 40A and 40B to rotate.

The third gear G3 to the eighth gear G8 are arranged on the back side of the main body frame 20. The third gear G3 is fixed to the end of the shaft portion 41 of the lower conveying roller 40B, and the fifth gear is fixed to the end of the shaft portion 51 of the lower rotary blade 50B. The fourth gear G4 is located between the third gear G3 and the fifth gear G5 and meshes with both gears. The fourth gear G4 is an idle gear for transmitting power between the gears.

The sixth gear G6 is fixed to the end of the shaft 41 of the upper conveyor roller 40A, and the eighth gear G8 is fixed to the end of the shaft 51 of the upper rotary blade 50A. The seventh gear G7 is located between the sixth gear G6 and the eighth gear G8 and meshes with both gears. The seventh gear G7 is an idle gear for transmitting power between the gears.

As a result, by transmitting the power of the drive motor 70 to the two rotary blades 50A and 50B via the gears G3 to G8, it is possible to rotate not only the two conveyor rollers 40A and 40B but also the two rotary blades 50A and 50B.

When cutting the thin tube 1, first, the start switch installed on the workbench 11 is operated to drive the drive motor 70. The drive motor 70 rotates the two conveyor rollers 40A, 40B and the two rotary blades 50A, 50B.

Next, the shaft rod 3 is inserted into the thin tube 1 on the first roller conveyor 16, and then the pipe 1 with the shaft rod 3 inserted is inserted between the two conveyor rollers 40A and 40B that rotate from the front of the cutting device main body 15.

When the pipe 1 with the shaft rod 3 inserted is inserted up to the conveying rollers 40A and 40B, it is sent in the X direction along the conveying path by the two conveying rollers 40A and 40B.

The thin tube 1 moving along the conveying path is divided into two parts, left and right, by cutting the upper and lower ends of the outer circumference by two rotating blades 50A and 50B. Then, the two thin tubes 1A, divided into left and right parts, together with the shaft rod 3, are discharged from the main frame 20 onto the second roller conveyor 17.

3. Description of the Rolling Apparatus 100 Fig. 10 is a side view of the rolling apparatus 100, Fig. 11 is a plan view of the rolling apparatus 100, and Fig. 12 is a perspective view of the main part of the rolling apparatus 100.

The rolling device 100 includes a work table 110, a rolling device main body 120, a drive motor 170, a work guide 113, and a roller conveyor 115.

As shown in Figures 11 and 12, the rolling device body 120 and the drive motor 170 are arranged on the upper wall 110A of the workbench 110.

As shown in FIG. 11, the work guide 113 is located on the left side (entrance surface) of the rolling device body 120, and the roller conveyor 115 is located on the right side (discharge surface) of the rolling device body 120.

The rolling device main body 120 is a device that rolls the thin tube 1A, which has been divided into two by the cutting device 10, into a flat plate.

As shown in FIG. 12, the rolling device main body 120 has an introduction section 121 and a main body frame 130.

The main frame 130 is composed of a lower frame 131 and an upper frame 135, and inside it, rolling rollers 150A to 150D are arranged in four stages in the X direction (see Figure 13).

As shown in Figures 14 and 15, the rolling roller 150 is composed of a lower roller 151 and an upper roller 155. The lower roller 151 and the upper roller 155 are made of metal. The first to fourth lower rollers 151A to 151D are supported at both ends by two roller guides 132 and 133 fixed to the lower frame 131.

The roller width of the lower rollers 151A to 151D increases from the first to the second to the third row, with the third and fourth rows being the same width.

On the other hand, the first to fourth upper rollers 155A to 155D are supported at both ends by roller guides 137, which have a U-shaped cross section and are fixed to the upper frame 135. Four roller guides 137 are provided, one for each of the four upper rollers 155A to 155D. In Figure 14, the roller guide 137 is L-shaped, but part of the wall has been omitted to show the rollers.

The roller width of the upper rollers 155A to 155D is the same from the first to fourth rows, and is wide (the same width as the lower rollers 151C and 151D on the third and fourth rows).

The rolling device body 120 has a gear mechanism 160. The gear mechanism 160 includes a first gear G1 to an eighth gear G8. The first gear G1 is disposed on the back side of the lower frame 131 (see FIG. 16). The first gear G1 meshes with the motor shaft of the drive motor 170.

The second gear G2 to the eighth gear G8 are arranged on the front side of the roller guide 132, as shown in FIG. 13. The second gear G2 is fixed to the shaft end of the roller shaft of the first-stage lower roller 151A, and the fourth gear G4 is fixed to the shaft end of the roller shaft of the second-stage lower roller 151B. The fourth gear G4 is a main gear coaxial with the first gear G1, that is, the first gear G1 is fixed to one side of the roller shaft of the second-stage lower roller 151B, and the fourth gear G4 is fixed to the other side.

The sixth gear G4 is fixed to the end of the roller shaft of the third-stage lower roller 151C, and the eighth gear G8 is fixed to the end of the roller shaft of the fourth-stage lower roller 151D.

The third gear G3 is located between the second gear G2 and the fourth gear G4 and meshes with both gears. The third gear G3 is an idle gear for transmitting power between the gears. The fifth gear G5 and the seventh gear G7 are also idle gears for transmitting power between the gears.

As a result of the above, the power of the drive motor 170 can be transmitted to each of the lower rollers 151A to 151D via each of the gears G1 to G8.

When rolling the thin tube 1A cut into two pieces, first, the start switch of the workbench 110 is operated to drive the drive motor 170. The drive motor 170 rotates the lower rollers 151A to 151D.

Next, the thin tube 1A on the work guide 113 is inserted into the introduction section 121 with the cut surface facing upward. When the tip of the thin tube 1A reaches the first rolling roller 150A, the thin tube 1A is sandwiched from above and below between the two rollers 151, 155 and sent in order to the subsequent rolling rollers 150B to 150D.

The thin tube 1A is rolled into a flat plate by the rolling rollers 150A-150D at each stage, which corrects the curvature in the cross-sectional direction. The thin tube 1B that has been rolled into a flat plate is then discharged from the rolling device main body 120 onto the roller conveyor 115.

4. Description of the Decontamination Apparatus 300 Fig. 17 is a side view of the decontamination apparatus 300, Fig. 18 is a plan view of the decontamination apparatus 300, and Figs. 19 and 20 are perspective views of the main parts of the decontamination apparatus 300.

The decontamination apparatus 300 includes a work table 310, a decontamination apparatus main body 320, a work guide 313, and a roller conveyor 315.

As shown in Figures 18 and 19, the decontamination device main body 320 is disposed on the upper wall 310A of the workbench 310.

As shown in FIG. 18, the work guide 313 is located on the left side (inlet surface) of the decontamination apparatus main body 320, and the roller conveyor 315 is located on the right side (exhaust surface) of the decontamination apparatus main body 320.

The decontamination device main body 320 is a device that decontaminates the surface of the thin tube 1B that has been rolled into a flat plate by the rolling device 100.

As shown in FIG. 20, the decontamination device main body 320 includes a base plate 330, a blast box 350, a transport section 400, a blast head 500, a connecting section 600, and a connection section 700.

The base plate 330 is for fixing to the workbench 310. A through hole is formed in the center of the base plate 330 for passing the blasting material B through.

The blast box 350 is a box-shaped box with an open bottom, and is made up of four side walls 360A-360D and a ceiling wall 370. A through hole 371 is provided in the center of the ceiling wall 370 (see Figure 27). The first side wall 360A faces the second side wall 360C, and the third side wall 360B faces the fourth side wall 360D. In Figures 20 and 21, the reference numerals for the second side wall 360C and the fourth side wall 360D have been omitted.

A flange 355 is provided at the bottom of the blast box 350. The blast box 350 is fixed to the base plate 330 via the flange 355.

The first side wall 360A of the blast box 350 is the workpiece introduction surface, and the second side wall 360C is the workpiece discharge surface. The first side wall 360A has an opening (entrance) for introducing the workpiece, and the second side wall 360C has an opening (exit) for discharging the workpiece.

The conveying section 400 is composed of a first conveying section 400A and a second conveying section 400C. The first conveying section 400A is located in front of the first side wall 360A, and as shown in Figures 20 and 21, includes a roller panel 405, a movable plate 408, a first roller 410, a second roller 420, and a drive motor 450.

As shown in FIG. 21, the roller panel 405 is L-shaped and is fixed to the front of the first side wall 360A. The movable plate 408 is supported on the top wall 407 of the roller panel 405 via shaft pins 407A and 407B so that it can move up and down. A coil spring 409 is provided between the top wall 407 and the movable plate 408. The coil spring 409 biases the movable plate 408 downward.

The first roller 410 is fixed to the front wall of the roller panel 405 via a first roller holder 415. The second roller 420 is fixed to the movable plate 408 via a second roller holder 425. The second roller 420 is a movable roller that can move in the vertical direction. The two rollers 410, 420 face each other vertically. The second roller 420 is biased by a coil spring 409 so that it comes into contact with the first roller 410.

As shown in FIG. 22, the drive motor 450 is attached below the first roller 410. A first gear G1 is attached to the motor shaft of the drive motor 450. The first gear G1 meshes with a second gear G2 fixed to the shaft end of the first roller, and the second gear G2 meshes with a third gear G3 fixed to the shaft end of the second roller.

As a result, the power of the drive motor 450 can be transmitted to the first roller 410 and the second roller 420 via the gears G1 to G3. The structure of the second conveying section 400C is the same as that of the first conveying section 400A. In addition, the first conveying section 400A and the second conveying section 400C are each provided with sensors S1 and S2 that detect the thin tube 1B (see FIG. 23).

As shown in FIG. 23, a work introduction section 380A is provided between the first transport section 400A and the first side wall 360A, and a work discharge section 380B is provided between the second transport section 400C and the second side wall 360C.

The workpiece introduction section 380A has an introduction port for the capillary tube 1B. A brush 383 and a guide roller 385 are provided at the introduction port. The brush 383 prevents contaminants decontaminated from the capillary tube 1B from leaking out of the introduction port. The guide roller 385 is used to guide the capillary tube 1B.

The work discharge section 380C has a structure similar to that of the work introduction section 380A. The work discharge section 380C has a discharge outlet for the thin tube 1B. A brush 383 and a guide roller 385 are provided at the discharge outlet. The brush 383 prevents contaminants decontaminated from the thin tube 1B from leaking out of the discharge outlet. The guide roller 385 is used to guide the thin tube 1B.

As shown in Figures 23 and 28, a blast head 500 is attached to the ceiling wall 370 of the blast box 350 via a connecting part 600. The blast head 500 is cylindrical with an axial hole 500A that penetrates vertically, and a blast nozzle 510 is attached to the tip. The blast nozzle 510 has a thin tubular tip and has a nozzle hole 511 along the axis. The nozzle hole 511 is connected to the axial hole 500A of the blast head 500, and the blast material B passes through the axial hole 500A and the nozzle hole 511 and is ejected from the nozzle tip.

The blast head 500 is connected to an air blast device 550 via a blast hose 530. The air blast device 550 is a device that sprays blast material B (abrasive material) (see FIG. 24). The air blast device 550 may be of a direct pressure type or a vacuum type.

The direct pressure type sends compressed air into a blast tank 560 containing blast material B, mixes the blast material B with the compressed air at the bottom of the tank, and sprays the blast material B together with the compressed air at high pressure.

The vacuum type blows compressed air from a nozzle like a spray bottle, sucking up blasting material B with an ejector effect and mixing the blasting material B with the blown compressed air.

In this embodiment, a direct pressure type with excellent abrasive cleaning power is used. Note that alumina is used as blasting material B, but alternatively, iron-based (steel shot, steel grid, reduced iron powder, etc.), plastic-based (polyplus, polyextra, nylon, etc.), and plant-based (walnut, peach, corn, etc.) materials can also be used.

In addition, in this embodiment, as shown in FIG. 23, a rubber protective layer 365 is provided on the inner surface of the blast box 350. The protective layer 365 is provided on the four inner surfaces of the blast box 350. By providing the protective layer 365, the blast box 350 can be protected from the blast material B and wear of the inner surface can be suppressed.

As shown in Figures 25 to 27, the connecting portion 600 is made up of a base 610, a fixing plate 620, a boss portion 630, and four outer wall portions 650A to 650D.

The stand 610 is made of metal and is fixed to the ceiling wall 370 of the blast box 350. The stand 610 is rectangular in shape when viewed from above, and has a through hole 611 in the center. The stand 610 is also provided with four peripheral walls 615A to 615D, which surround the entire perimeter.

The fixed plate 620 is a rectangular metal plate. A circular retaining member 625 is provided in the center of the fixed plate 620. A bolt hole 627 is formed in the retaining member 625. The bolt hole 627 is provided so as to penetrate from the outer peripheral surface to the inner peripheral surface of the retaining member 625.

The boss portion 630 is cylindrical and is provided in four locations corresponding to the four corners of the fixed plate 620. The boss portion 630 is located between the base 610 and the fixed plate 620, and supports the fixed plate 620 at a position spaced apart from the base 610 by the height of the boss portion 630.

As shown in FIG. 26, the four outer wall portions 650A-650D are composed of a metal base portion 660 and a brush portion 670. The brush portion 670 is made of synthetic fiber, metal fiber, or natural fiber bristles and is fixed to the base portion 660. The four outer wall portions 650A-650D are each fixed to the four sides of the fixed plate 620 with bolts via fasteners 680.

As shown in FIG. 27, the fixing plate 620, the boss portion 630, and the stand 610 are fixed to the ceiling wall 370 by a bolt B that passes through them vertically.

In addition, in this embodiment, a rubber spacer 375 is placed between the stand 610 and the ceiling wall 370 to eliminate any gaps between the two and improve adhesion.

As shown in FIG. 28, the blast head 500 has a stepped portion 501 at the tip. By fitting the stepped portion 501 into the holding member 625, the blast head 500 can be positioned in the axial direction (up and down direction). Then, by inserting a bolt BS into the bolt hole 627 and tightening it, the blast head 500 can be prevented from coming loose from the holding member 625.

The blast nozzle 510 penetrates the fixed plate 620, with the nozzle tip 510A, which emits the blast material B, facing the through hole 611 of the stand 610.

The outer walls 650A-650D surround the entire periphery of the blast nozzle 510. Because the outer walls 650A-650D are made of brushes, when the blast nozzle 510 sprays the blast material B at high pressure, outside air is drawn into the inside of the stand 610 through the outer walls 650A-650D, creating a downward airflow inside the blast box (Figure 28).

The lower end 651 of the outer wall 650 fits inside the peripheral wall 615 of the stand 610, and the outer wall 650 overlaps the stand 610 by the height of the peripheral wall 615.

This makes it possible to reduce the gap between the outer wall 650 and the stand 610, making it less likely for contaminants to leak to the outside.

The connection part 700 is a tubular joint that is flange-connected to the underside of the base plate 330. The connection part 700 communicates with the inside of the blast box 350 via the through hole 331 of the base plate 330.

The inner diameter of the connection part 700 becomes smaller from the top to the bottom. A suction hose 750 for sucking up blasting material B is flanged to the tip of the connection part 700. A vacuum device (not shown) is connected to the hose 750, and the blasting material B inside the blasting box 350 can be collected.

When decontaminating the flat-rolled plate (thin tube) 1B, first, the start switch of the workbench 310 is operated to drive the drive motor 450. The drive motor 450 rotates the rollers 410 and 420 of the first conveying section 400A and the second conveying section 400B.

Next, the rolled plate (thin tube) 1B on the work guide 313 is inserted between the rollers 410, 420 of the first conveying section 400A with the surface to be decontaminated (the inner surface of the tube) facing upward. When the tip of the rolled plate (thin tube) 1B reaches between the rollers, the rolled plate (thin tube) 1B moves inside the blast box 350 while being sandwiched from above and below by the two rollers 410, 420.

While moving through the blast box 350, blast material B is sprayed from the blast head 500 at high pressure onto the surface of the rolled plate (thin tube) 1B, removing contaminants from the surface. The decontaminated rolled plate (thin tube) 1C is discharged from the second transport section 400B onto the roller conveyor 315.

As described above, by using the decontamination line L, the following three operations can be carried out in an assembly line, which improves workability.
(1) Cutting the thin tube 1 into two pieces on a plane horizontal to the tube axis V. (2) Rolling the thin tube 1A cut into two pieces into a flat shape. (3) Decontaminating the rolled plate 1B (thin tube).

5. Description of Effects This configuration can prevent dust contaminated with blasting material B (abrasive cleaning material) and radioactive materials from scattering around, allowing work to be done in a good working environment. In addition, continuous decontamination is possible, and work efficiency is higher than manual work. The decontamination device 300 occupies a small space, so it can be used even in a small work area.

In addition, the decontamination device 300 is configured to take in outside air into the blast box 350 (external wall portion made of brush) as the blast nozzle 510 ejects the blast material B, so turbulence is unlikely to occur inside the blast box 350. Therefore, as shown in FIG. 23, the blast material B can be ejected evenly onto the surface of the rolled plate (thin tube 1), and the surface of the rolled plate (thin tube 1) can be decontaminated evenly.

As shown in FIG. 23, the decontamination apparatus 300 has a rubber protective layer 365 on the inner surface of the blast box 350. By providing the protective layer 365, the blast box 350 can be protected from the blast material B and wear of the inner surface can be suppressed.

The conveying section 400 is equipped with a first roller 410 and a second roller 420. The first roller 410 is fixed and the second roller 420 is movable (can move up and down), so even if there is variation in the thickness of the rolled material (thin tube 1B), the difference in thickness can be absorbed. Therefore, poor conveying of the rolled material is unlikely to occur, and decontamination work can be carried out efficiently.

<Other embodiments>
The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention.

(1) In the above embodiment, the decontamination device 300 is used as part of the decontamination line L, but it can also be used alone.

(2) In the above embodiment, the decontamination device 300 was used to decontaminate the thin tube 1, but it may also be used to decontaminate workpieces other than the thin tube 1.

(3) In the above embodiment, the outer wall portion 650 is made of brush to provide breathability, but breathability may be provided by other methods. For example, ventilation holes may be provided in the outer wall portion 650. Furthermore, ventilation holes may be provided in all of the outer wall portions 650A to 650D, or only in some of the outer wall portions 650A and 650C.

(4) In the above embodiment, the lower end 651 of the outer wall portion 650 is fitted inside the peripheral wall 615, but it may be located outside the peripheral wall 615 as long as it overlaps with the peripheral wall 615.

(5) In the above embodiment, the decontamination device main body 320 is attached to the work table 310 via the base plate 330, but the base plate 330 may be omitted.

(6) In the above embodiment, the decontamination line L is composed of the cutting device 10, the rolling device 100, and the decontamination device 300. The "cutting device" may be a device other than the cutting device 10 as long as it is a device that cuts the contaminated pipe in a plane along the pipe axis. The "rolling device" may be a device other than the rolling device 100 as long as it is a device that rolls the contaminated pipe divided into two by the cutting device into a horizontal plate material. The "decontamination device" may be a device other than the decontamination device 300 as long as it is a device that decontaminates the surface of the plate material rolled by the rolling device with blast material B.

(7) In the above embodiment, the decontamination line L is composed of the cutting device 10, the rolling device 100, and the decontamination device 300. A cutter that cuts the thin tubes cut from the heat exchanger to a fixed length may be added upstream of the cutting device 10.

REFERENCE SIGNS LIST 1 Thin tube 10 Cutting device 100 Rolling device 300 Decontamination device 350 Blast box 500 Blast head 510 Blast nozzle 600 Connection part 610 Stand 615 Peripheral wall stand 620 Fixing plate 630 Boss part 650 Outer wall part (brush)
700 Connection part

Claims (5)

A decontamination apparatus comprising:
Blast box and
A conveying unit that conveys the workpiece from the entrance of the blast box to the exit of the blast box;
A blast head having a blast nozzle for ejecting blast material;
a connecting portion located on an upper portion of the blast box for connecting the blast head to the blast box;
A connection portion attached to a bottom of the blast box and to which a suction hose for sucking the blast material is connected,
The connecting portion has a ventilation portion that takes in outside air into the blast box as the blast material is ejected by the blast head,
The decontamination apparatus , wherein the ventilation section is positioned so as to surround the entire circumference of the blast head . A decontamination apparatus comprising:
Blast box and
A conveying unit that conveys the workpiece from the entrance of the blast box to the exit of the blast box;
A blast head having a blast nozzle for ejecting blast material;
a connecting portion located on an upper portion of the blast box for connecting the blast head to the blast box;
A connection portion attached to a bottom of the blast box and to which a suction hose for sucking the blast material is connected,
The connecting portion has a ventilation portion that takes in outside air into the blast box as the blast material is ejected by the blast head,
The connecting portion is
A stand fixed to a ceiling wall of the blast box and having a through hole extending vertically therethrough;
a fixed plate having an annular holding member for holding the blast head;
a columnar boss portion that receives a lower surface of the fixing plate at a position spaced a predetermined distance from the base;
An outer wall portion is provided along the outer periphery of the fixed plate and surrounds the side of the blast nozzle between the fixed plate and the ceiling wall,
the blast nozzle passes through the through hole of the fixed plate, and a nozzle tip for ejecting the blast material faces the through hole of the base,
The outer wall portion is made of a brush and functions as a ventilation portion that draws outside air into the through hole of the frame as blast material is ejected by the blast head . The decontamination apparatus according to claim 2 ,
The frame has an annular peripheral wall,
A decontamination apparatus, wherein a lower end of the brush outer wall portion fits into the inside of the peripheral wall of the stand. The decontamination apparatus according to any one of claims 1 to 3 ,
The decontamination apparatus, wherein the blast box has a rubber protective layer on the inner surface. A decontamination line for contaminated piping,
A cutting device that cuts the contaminated pipe in a plane along the pipe axis;
a rolling device that rolls the contaminated pipe divided into two by the cutting device into a horizontal plate material;
A decontamination device that decontaminates the surface of the plate material rolled by the rolling device with a blast material,
The decontamination apparatus comprises:
A decontamination line , which is the decontamination apparatus according to any one of claims 1 to 4 .

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