JPH08334589A - Powder removing device for pressure guide tube for measurement - Google Patents

Abstract

PURPOSE: To remove powder without giving vibration and shock to pipe by repeating reciprocal move of projecting shaft in a pressure guide pipe for measurement and crushing powder depositing in the pipe. CONSTITUTION: Two air cylinder mechanisms 22 are located in the up and down direction and pistons 20 slide in the axial direction of the mechanism. A moving body 24 fixed at the top end of the piston 20 moves up and down in the axial direction by the guide of a linear guide bush 44 of a linear guide mechanism 26. Also, a twisting rotation mechanism 30 consisting of a shaft with spiral groove 28 and fixed boss 50 converts the up and down movement of the moving body 24 to twisting reciprocal movement of the shaft 28. A projection shaft 10 fixed to the lower end of the shaft 28 repeats go-in and come-out freely rotating around the center axis in the pressure guide tube 12 owing to the twisting reciprocal movement of the shaft 28. Thus, it crushes and removes the powder depositing on the inner surface of the tube 12 with the tip part having a shape like a drill tip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder removing device for measuring pressure guiding pipes connected to towers and the like, the inside of which is under negative pressure control. The present invention relates to a device for removing powder accumulated in the measurement pressure guiding pipe by twisting and rotating the pipe to advance and retreat.

[0002]

2. Description of the Related Art In towers and tanks of various nuclear power facilities, the inside of the tanks is always maintained at a negative pressure in order to prevent leakage of radioactive materials. The same applies to tower tanks that handle powdered nuclear fuel substances.The measurement pressure piping is connected outward from the wall surface of the tower tank, and a negative pressure gauge is attached to the measurement pressure piping to install the internal pressure of the tower tanks. Is measured and maintained at an appropriate negative pressure.

Inside the tower tanks, the powdery radioactive material rises and scatters when it is transported or due to the flow of internal gas, so that not only adheres to the inner walls of the tower tanks but also the measurement pressure guiding pipe. It also enters inside and accumulates.
If the accumulated amount of the powder reaches an excessive amount, the piping may be blocked, and the pressure may not be measured.

Therefore, a device for removing the powder adhering to the measurement pressure guiding pipe is required, but this type of device has not been developed yet. However, generally, as a technique for removing powder accumulated in a pipe or the like, there is a method in which vibration or shock is applied from the outside of the pipe to remove the adhered powder from the pipe wall.

[0005]

However, in the method of directly vibrating or impacting the pipe, in the case of the measurement pressure guiding pipe, the measuring instrument such as a negative pressure gauge connected to the pipe is also vibrated or impacted. Therefore, problems such as failure and quick deterioration occur. Therefore, this method is difficult to apply to the measurement pressure piping of towers and tanks of nuclear facilities, which are difficult to be replaced frequently because they handle radioactive materials. Furthermore,
When the measurement pressure guiding pipe is installed in the lateral direction, it is possible that the clogging powder cannot be removed by simply giving vibration or impact to the pipe.

An object of the present invention is to provide a device capable of removing powder accumulated in a measurement pressure guiding pipe without giving vibration or impact to the pipe. Another object of the present invention is to provide a powder removing device for a measurement pressure guiding pipe that can reliably remove accumulated powder by remote control regardless of the mounting direction of the measurement pressure guiding pipe.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to an air cylinder mechanism in which a piston slides in an axial direction, a movable body attached to the piston, and a plurality of linear guide bushes for guiding the movable body in the axial direction. Linear guide mechanism consisting of a linear guide shaft and end plates for holding each linear guide shaft at both ends, and a spiral groove rotatably attached to the movable body so as to have a central axis parallel to the piston axis. A torsion rotation mechanism configured to convert a reciprocating motion of the piston into a torsion reciprocating motion of the shaft having the spiral groove, which is composed of a shaft and a fixed boss that meshes with the shaft having the spiral groove, and is fixed to a tip of the shaft having the spiral groove. And an airtight mechanism inside and outside the measurement pressure guiding pipe, which includes an O-ring arranged so as to surround the protruding shaft. A powder removal device are measured electrical pressure pipes.

More specifically, in the above, a mounting flange provided at one end of the measurement pressure guiding pipe, a mounting plate having a circular opening in the center installed on the mounting flange, and a cylinder projecting from the circular opening. Body, the air cylinder mechanism is placed on the mounting plate, a fixing boss is provided at the other end of the cylindrical body, and one end plate of the linear guide mechanism is fixed to the outer periphery of the intermediate portion of the cylindrical body. It is preferable that a pair of bellows holders are used to attach the bellows between the plate and the movable body to hermetically seal the bellows.

[0009]

When the piston slides in the axial direction by the air cylinder mechanism, the movable body attached to the piston also moves linearly. The spiral grooved shaft that is rotatably attached to the movable body also moves in the axial direction, but at that time, because it meshes with the fixed boss, it moves while twisting and rotating. Therefore, the protruding shaft fixed to the tip of the shaft with the spiral groove also enters the measurement pressure guiding pipe while rotating, and breaks down the powder accumulated in the measurement pressure guiding pipe. Further, when the piston slides in the opposite direction, the protruding shaft retracts while rotating in the reverse direction with respect to the inside of the measurement pressure guiding pipe. By repeating this, the adhering accumulated powder is removed. By incorporating a solenoid valve into the compressed air system for driving and performing the operation remotely, and controlling it with a timer or the like, the powder removal operation can be automatically performed at a fixed cycle.

[0010]

FIG. 1 is an explanatory view showing an embodiment of the powder removing apparatus according to the present invention, and FIG. 2 is a detailed view of its mechanical portion. Basically, the projecting shaft 10 is capable of advancing and retracting while rotating around the central axis inside the measurement pressure guiding pipe 12, whereby powder accumulated on the inner wall of the measurement pressure guiding pipe 12 is accumulated. Configured to remove.

The apparatus shown in the embodiment is attached to a measurement pressure guiding pipe 12 connected upward from the upper wall of the tower tanks. A plurality (here, two) of air cylinder mechanisms 22 are positioned in the vertical direction, and the piston 20 is
2 slide in the axial direction. This air cylinder mechanism 22,
A movable body 24 fixed to the upper end of the piston 20 and a linear guide mechanism 26 for guiding the vertical movement of the movable body 24.
And the reciprocating motion of the movable body 24 by the spiral grooved shaft 28
And a twist rotation mechanism 30 for converting into a twist reciprocating motion. The protruding shaft 10 has a shape similar to the tip of a drill, and is fixed to the lower end of the shaft 28 with a spiral groove so that the protruding shaft 10 can advance and retract with respect to the inside of the measurement pressure guiding pipe 12. An O-ring 32 is provided so as to surround the protruding shaft 10, and an airtight mechanism pressed by an O-ring retainer 34 is provided.

Here, a mounting flange 36 is provided immediately above the measurement pressure guiding pipe 12, and a mounting plate 38 having a circular opening in the center is installed on the mounting flange 36. The O-ring 32 and the O-ring retainer 34 are provided on the mounting flange 36 at the circular opening portion of the mounting plate 38,
The protruding shaft 10 penetrates the center hole of the mounting flange 36 and enters the measurement pressure guiding pipe 10.

The air cylinder mechanism 22 is mounted on the mounting plate 38. The linear guide mechanism 26 of the movable body 24 includes four linear guide shafts 40 arranged at the corners of a quadrangle, end plates 42a and 42b for holding the linear guide shafts 40 at the upper and lower ends, and the linear guide shafts. And a linear guide bush 44 that moves up and down along 40 to guide the vertical movement of the movable body 24. The torsion rotation mechanism 30 meshes with the spiral grooved shaft 28, which is rotatably supported on the lower surface of the movable body 24 by a bearing 46 about a vertical center axis, and the spiral grooved shaft 28. This is a mechanism that is composed of a fixed boss 50 having a ball screw structure and converts the reciprocating motion of the piston 20 into the twist reciprocating motion of the shaft 28 with a spiral groove. The fixing boss 50 is attached to the upper end of a cylindrical body 52 that stands from the circular opening of the attachment plate 38. In FIG. 1, the cylindrical body 52 is supported by the bracket 54, but this has a rectangular flange structure and is used when it is necessary to support the apparatus more firmly.

In this embodiment, the lower end plate 42b of the linear guide mechanism 26 is fixed to the outer periphery of the intermediate portion of the cylindrical body 52,
A bellows 58 is attached between the movable body 24 and the lower end plate 42b by upper and lower bellows holders 56a and 56b, which is also a part of the airtight mechanism. In addition, an O-ring is appropriately incorporated in the joining portion of each member so that airtightness is maintained.

The piston 2 is driven by the air cylinder mechanism 22.
When 0 moves up and down, the movable body 24 fixed to it
Is guided by the linear guide mechanism 26 and moves up and down. Along with this, the bellows 58 connected to the movable body 24 expands and contracts, and the shaft with spiral groove 28 moves up and down while being twisted and rotated by meshing with the fixed boss 50. Projecting shaft 1 fixed to shaft 28 with spiral groove
0 also moves up and down while twisting and rotating in the measurement pressure guiding pipe 12. Since the powder may be solidified (compacted state) by simply moving the ejecting shaft 10 up and down, in the present invention, the powder is accumulated while being vertically rotated while being twisted and rotated. Remove the powder that is present. Further, in order to enhance the powder removing effect, the tip of the protruding shaft 10 is shaped like a blade edge of a drill.

Since this apparatus is used for decompressing tower tanks, it is important to maintain airtightness. Therefore, the O-ring 32 at the intersection of the mounting flange 36 and the protruding shaft 10
Keeps it airtight. Further, in this embodiment, even if the O-ring 32 is damaged, the bellows 58 can keep airtightness.

The entire system including this device is shown in FIG. The powder removing device may be the same as that shown in FIG. 1, and is therefore drawn in a simplified manner. The measurement pressure guiding pipe 12 is connected to the upper wall surface of the tower tanks 60, and the negative pressure gauge 64 is connected to the pipe 62 drawn out from the upper side thereof. Air cylinder mechanism 2
The three-way solenoid valves 66a, 66
An air pipe having b is connected, and a compressed air source is connected to the air supply system. Also, the exhaust system has a speed controller 68.
Connect. The ascending / descending switch 70 controls the three-way solenoid valves 66a and 66b.

When the ascending / descending changeover switch 70 is set to the ascending mode, the compressed air passes through the three-way solenoid valve 66b into the lower cylinder chamber, and the air in the upper cylinder chamber is pushed to the speed controller from the three-way solenoid valve 66a. It is discharged to the exhaust system through 68 and the piston 20 is pushed up. When the ascending / descending changeover switch 70 is set to the descending mode, the compressed air passes through the three-way solenoid valve 66a to enter the upper cylinder chamber, and the air in the lower cylinder chamber is pushed to pass from the three-way solenoid valve 66b through the speed controller 68. It is discharged to the exhaust system and the piston 20 is pushed down. Rise
If a timer control device is incorporated in the descending changeover switch, it can be automatically operated in a fixed cycle.

In each figure, the reason why the measurement pressure guiding pipe is thicker in the vicinity of the tower tanks is that the corrosion allowance of the measurement pressure guiding pipe near the tower tanks is the same as the corrosion allowance of the tower tanks. is there. The powder removing device is installed inside a shielded chamber called a cell, and the negative pressure gauge is installed outside the cell. Therefore, the outside of the cell has a thin tube structure to facilitate the construction. In some cases, the measurement pressure guiding pipes are connected not in the upper part of the tower tank but in the lateral direction or the oblique direction. In such a case, the device is also installed in the lateral direction or the oblique direction. Since it is easy to use compressed air as a drive source as a utility, an air cylinder mechanism is used in the present invention. Although it is possible to adopt a hydraulic type as another drive source, a hydraulic source (hydraulic unit) is required and the apparatus becomes large in size.

[0020]

As described above, according to the present invention, the compressed air for driving is used to convert the axial movement of the piston into the reciprocating movement accompanied by the torsional rotation of the shaft so as to move back and forth in the measurement pressure guiding pipe. With this configuration, the powder accumulated in the measurement pressure guiding pipe can be reliably removed without giving vibration or impact to the pipe and regardless of the mounting direction of the measurement pressure guiding pipe. Further, by using a solenoid valve in the drive air compression system and incorporating a timer or the like, it becomes possible to perform powder removal automatically by remote control at a fixed cycle.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a powder removing apparatus according to the present invention.

FIG. 2 is a detailed view of the mechanism section.

FIG. 3 is an overall view of a system including a powder removing device.

[Explanation of symbols]

 10 Protruding Shaft 12 Measuring Pressure Piping 20 Piston 22 Air Cylinder Mechanism 24 Movable Body 26 Linear Guide Mechanism 28 Shaft with Spiral Groove 30 Torsion Rotating Mechanism 32 O-ring 40 Linear Guide Shaft 42a Upper End Plate 42b Lower End Plate 44 Linear Guide Bushing 50 Fixed boss 58 Bellows

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Fukuari 4-4 Muramatsu, Tokai-mura, Naka-gun, Ibaraki Prefecture Reactor and Nuclear Fuel Development Corp. Tokai Works (72) Inventor Junji Ueda 5 Shiba, Minato-ku, Tokyo Chome 33-7 Criharant Co., Ltd. Tokyo Head Office

Claims (2)

[Claims] 1. An air cylinder mechanism in which a piston slides in an axial direction, a movable body attached to the piston, a plurality of linear guide shafts for guiding the movable body in the axial direction by a linear guide bush, and each linear guide. A linear guide mechanism composed of end plates for holding the shaft at both ends, a spiral grooved shaft rotatably attached to the movable body so as to have a central axis parallel to the piston axis, and the spiral grooved shaft. A torsion rotation mechanism that is configured to mesh with a fixed boss and that converts the reciprocating motion of the piston into a torsion reciprocating motion of a shaft with a spiral groove, and a torsion boss that is fixed to the tip of the shaft with a spiral groove and moves back and forth in the measurement pressure guiding pipe. A free protruding shaft,
A powder removing device for a measuring pressure guiding pipe, comprising: an airtight mechanism inside and outside the measuring pressure guiding pipe, which comprises an O-ring arranged so as to surround the protruding shaft. 2. A mounting flange provided at one end of the measurement pressure guiding pipe, a mounting plate having a circular opening in the center installed on the mounting flange, and a cylindrical body projecting from the circular opening, The air cylinder mechanism is placed on the mounting plate, a fixing boss is provided at the other end of the cylindrical body, and one end plate of the linear guide mechanism is fixed to the outer periphery of the intermediate portion of the cylindrical body. The powder removing device for a measurement pressure guiding pipe according to claim 1, further comprising an airtight mechanism in which a bellows is attached by a pair of bellows holders.