JPS6328275B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that can clean the inside of a specific branch pipe inside a small-diameter tank, particularly in the field where remote control is required due to radioactive contamination or toxic gas atmosphere. The present invention relates to a cleaning device that does not damage the cleaning section and has a high cleaning effect.

No device has yet been developed that can remotely clean the inside of a branch pipe connected to the peripheral wall surface of a vertically installed small-diameter cylindrical tank (including piping). Conventionally, convenient methods for cleaning small-diameter tanks and piping include a method of firing sand or steel balls, a method of rotating a long coiled spring-like flexible tube to clean the inside, and a method of spraying a fluid jet. However, all of these methods have drawbacks such as damage to the object to be cleaned or the large size of the device, making it difficult to insert it into a small diameter tank. In particular, conventional methods have drawbacks such as difficulty in detecting the position of branch pipes, and the circumferential direction cannot be confirmed unless visually inspected, resulting in unreliable cleaning effects and extremely inefficient work. Ta.

The present invention was made in view of the actual state of the prior art, and its purpose is to enable remote control, to be able to reliably detect the position of branch pipes without visual inspection, and to be able to detect the position of branch pipes without damaging the objects to be cleaned. The purpose is to provide a device that can be operated safely and has a large cleaning effect.

Hereinafter, one embodiment of the present invention will be described based on the drawings. This embodiment is designed for cleaning a branch pipe of a dissolution tank, and in order to facilitate understanding of the present invention, the object to be cleaned will first be explained with reference to FIG. 1. The melting tank shown in FIG. 1 is a circulating batch melting tank for melting spent nuclear fuel. This involves equipping a barrel 1 with a basket 2, loading cut spent nuclear fuel into a basket 2 inside the barrel 1 through a distribution pipe 3, and transferring the loaded fuel to the barrel 1, which is connected to the barrel 1 through connecting pipes 4 and 4a. It is dissolved in the nitric acid filled in the slab 5. Melting is facilitated by reflux of the melt through barrel 1, slab 5 and connecting tubes 4 and 4a. This barrel 1 corresponds to a vertically installed small diameter cylindrical tank, and the connecting pipes 4 and 4a correspond to branch pipes. Finally, the fuel (U, Pu) and fission products dissolve,
The fuel cladding and undissolved residue remain in the basket 2. A swarf basket 6 is provided below the basket 2 in the barrel 1, and collects undissolved residues that have passed through the lattice of the basket 2 when the fuel is melted in the melting tank. When such a dissolution treatment is performed, undissolved residues and the like adhere to the tube wall of the lowermost connecting tube 4a, which may cause the conduit to become narrowed. Therefore, the apparatus of this embodiment is designed to clean and remove such deposits. As can be understood from the above explanation, the area to be cleaned is contaminated with high-level radioactive materials and is normally inaccessible to humans, and is located in a branch pipe in a vertical tank with a small diameter (approximately 22 cm) located approximately 5 m below the floor surface. Therefore, it has conventionally been very difficult to clean such areas, but according to the present invention, such areas can be easily and reliably cleaned by remote control.

An example of how this embodiment is used is shown in FIG. 2, and details thereof are shown in FIG. The cleaning device 10 of this embodiment has a main body frame that is movable within the barrel 1 and that incorporates various mechanisms as described below.
A cleaning mechanism including a connecting mechanism 12 that performs vertical movement by being connected to a general object machine 11, a cleaning nozzle 13 that sprays cleaning fluid onto the part to be cleaned, and positioning in the circumferential direction within the barrel. It has a positioning mechanism.

The main body frame mainly includes a weight 14 located in the upper part and a guide member 15 located in the lower part.
and a strut 16 that connects the two at intervals. Then, this weight 14 and the guide member 1
The cleaning mechanism and positioning mechanism are incorporated in the space created by 5 and can be easily inserted and moved into a small diameter barrel. Note that the weight 14 is
During cleaning, the body frame functions to be fixed to a predetermined cradle in the barrel (in this embodiment, the swarf basket 6) by its own weight, and accordingly, the guide member 15 has a shape that matches the predetermined cradle in the barrel. It is becoming.

The connecting mechanism 12 is for connecting to the lifting device 18 of the general lifting machine 11 using the general lifting machine 11 in order to move the device in the vertical direction economically and easily. It consists of a connecting rod 20 that is connected to a hanging device 18 by means of a lever, and the entire device can be moved in the vertical direction by driving the lift machine 11.

Next, the cleaning mechanism will be explained. In the present invention, a cleaning method using fluid jetting is adopted. This ensures that the cleaning agent can be reliably and easily recovered after use without damaging the object to be cleaned, and that gas or acid
This is because a large cleaning effect can be obtained by appropriately selecting a neutral or alkaline liquid. In this embodiment, in order to further improve the cleaning effect, the cleaning nozzle 13 is attached to the injection nozzle pedestal 25 at a slightly deviated angle from the vertical position, and the injection nozzle pedestal 25 is further connected to the conduit 28 with couplers 26 and 27 to inject. This structure allows the nozzle pedestal 25 to be rotated and removed. Note that a coupler 29 is attached to the other end of the conduit 28, and is connected to a pipe that supplies cleaning fluid. In other words, in this embodiment, the direction of fluid jetting can be changed by rotating the jet nozzle pedestal 25, and cleaning nozzles with different diameters and shapes can also be mounted on the jet nozzle pedestal 25.
It can be used by attaching and detaching 5. The injection nozzle base 25 and the conduit 28 can be easily attached and detached by moving the operating rod 34. That is, by pulling the operating rod 34, the coupler (socket type)
27 moves, and the other coupler (plug type) 2
6 can be inserted, and after insertion, operation rod 3 can be inserted.
4, both couplers 26 and 27 are connected and can be rotated. In this way, by using the fluid injection nozzle, the entire device can be downsized, and the device can be assembled and operated by a manipulator.

The positioning mechanism is constructed as shown in FIG. A rotary drive nozzle 30 having an L-shaped distal end is attached at its base end so as to be swingable in a horizontal plane, and is housed in the main body frame by a spring 31 when not in operation. When fluid is ejected from the rotation drive nozzle 30, the reaction force is generated by the spring 3.
The nozzle 30 overcomes the tensile force of 1 and swings out of the main body frame, contacts the tank wall, and rotates the main body frame. After that, the rotation drive nozzle 3
When the contact part 0 enters the branch pipe, the nozzle 30 comes out further outside and is fixed to the main body frame by a stopper mechanism as shown in FIG.
comes into contact with the wall of the branch pipe and the position is detected by the micro switch 33, and at the same time the rotation of the main body frame is blocked. In this embodiment, the stopper mechanism consists of an engagement hole 35 drilled at a predetermined position in the main body frame, a pin 36 provided on the rotational drive nozzle 30, and a spring 37, and the stopper mechanism is configured to supply driving fluid to the rotational drive nozzle 30. When the pressure is supplied, an upward force is applied to the pin 36 against the force of the spring 37, and when the pin 36 is exactly aligned with the position of the engagement hole 35, the pin 3
6 is inserted and fixed. Therefore, when the supply of the driving fluid is stopped, the pin 36 is pushed down by the force of the spring 37 and the fixation is released.

Vertical positioning is possible in the same way as circumferential positioning as described above, but in this embodiment, in order to simplify the structure and operation, the material machine 1
1, the machine is moved in the vertical direction, and positioning is performed by detecting that the wire 40 of the lift machine becomes slack when the main body of the machine is placed on a predetermined cradle in the barrel.

Finally, the usage and operation of this embodiment will be summarized. First, the basket 2 is taken out, and as shown in FIG. 2, the washing apparatus is lifted up by the lifting machine 11 and lowered into the barrel 1.
By detecting that the wire 40 of the lifting machine 11 is slack, it is possible to detect when the main body frame has reached the cradle provided in the barrel 1 (which also serves as the swarf basket 6 as described above). You can know from. In this state, the apparatus is designed so that the cleaning nozzle 13 is at the same height as the branch pipe (connecting pipe 4a) to be cleaned. When the body frame reaches the cradle, the lift machine 11 lifts the body frame slightly (slightly floating above the cradle) so that it can rotate freely. Then, a driving fluid (for example, high-pressure water) is supplied from the high-pressure pump 41 to the rotational drive nozzle 30 via a hose, a coupler, or the like. Then, the reaction force overcomes the tensile force of the spring 31, causing the rotary drive nozzle 30 to swing outward from the main body frame, and the tip of the presser plate 45 comes into contact with the barrel wall. Thereafter, the entire suspended cleaning device is rotated slowly by this jet reaction force while twisting the wire 40 of the lifting machine 11 and with the tip of the presser plate 45 rubbing against the barrel wall (Fig. 6A
reference).

Thereafter, when the tip of the presser plate 45 enters the connecting pipe 4a, the rotary drive nozzle 30 swings further outward with respect to the main body frame, and the stopper mechanism is activated (see FIGS. 6B and 5). That is, the upper end of the pin 36 fits into the engagement hole 35. After the stopper mechanism is activated, the main body frame and the rotary drive nozzle 30 rotate together again, and when the actuating plate 32 comes into contact with the wall of the connecting pipe 4a, the movable part of the micro switch 33 installed is activated. is pressed to activate the micro switch 33 (see FIG. 6C). The output of the micro switch 33 is led to the outside, so the rotational drive nozzle 30 is connected to the connecting pipe 4a.
It is possible to detect externally that the device is set at a predetermined position within the device.

Once the position of the connecting pipe 4a is confirmed by the micro switch 33 in this way, the lifting machine 11
is activated to lower the cleaning device, place it on a cradle, secure its position by its own weight, stop supplying the driving fluid to the rotational drive nozzle 30, and store the rotational drive nozzle in the frame. . Thereafter, the cleaning fluid is supplied from the high pressure pump 41 to the cleaning nozzle 13.
When the cleaning fluid is supplied to the cleaning nozzle 13, the cleaning fluid is injected toward the connecting pipe 4a, which is the part to be cleaned, and can be cleaned. The deposits (removed materials) during cleaning can be collected by receiving them in a swarf basket 6 installed in advance.
Generally, liquid is used as cleaning fluid, so
The cleaned fluid can be recovered using a liquid delivery equipment attached to the object to be cleaned (for example, a jet pump or the like). After cleaning, the entire cleaning device may be pulled up from inside the barrel 1 by operating the lifting machine 11.

The usage and operation of the apparatus of this embodiment have been described above, but it goes without saying that the present invention can be modified in various ways within the scope of the claims.

Since the present invention is configured as described above, it is possible to miniaturize the device and remotely assemble it, and it is possible to reliably detect the position of the branch pipe in a small diameter tank by remote control. The interior can be cleaned reliably and efficiently. In addition, since the present invention uses fluid for cleaning, it does not damage the object to be cleaned, and the cleaning agent can be easily recovered.
Work efficiency, safety, maintainability, and reliability are all significantly improved compared to conventional technology.
The industrial effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an object to be cleaned, FIG. 2 is an explanatory diagram showing a usage state of an embodiment of the apparatus according to the present invention, and FIG. 3 is an explanatory diagram showing an example of the apparatus according to the present invention. FIG. 4 is a front view, FIG. 4 is a sectional view thereof, FIG. 5 is an explanatory diagram of the stopper mechanism, and FIG. 6 is an explanatory diagram of the operation of the positioning mechanism. 10...Cleaning device, 12...Connection mechanism, 13...
... Cleaning nozzle, 14 ... Weight, 15 ... Guide member, 16 ... Support column, 30 ... Rotation drive nozzle, 31 ... Spring, 33 ... Micro switch, 35 ... Engagement hole, 36 ... pin.

Claims (1)

[Scope of Claims] 1. A remotely controllable cleaning device for cleaning the inside of piping connected to a peripheral wall surface of a substantially vertically provided cylindrical tank, the cleaning device movable within the tank. A main body frame of any size for incorporating the following various mechanisms; A connecting mechanism that connects the main body frame to a hanging tool connected to a wire for suspending the main body frame into or lifting it from the inside of the tank; a cleaning nozzle that spouts cleaning fluid outward in a substantially radial direction of the tank; piping that supplies cleaning fluid to the cleaning nozzle; A rotary drive nozzle that spouts driving fluid when the main body frame rotates and the cleaning nozzle faces the opening of the piping to be cleaned. A remotely controllable cleaning device characterized by having: a positioning mechanism that detects and outputs the output to the outside and stops rotation.