JPH0334838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for cutting a concrete heat shield wall used in dismantling a nuclear reactor, and a cutting machine used to carry out this cutting method.

(Technical background) Conventional methods for thermally cutting structures such as concrete include the fire jet method, plasma jet method, powder jet method, and burning bar method.

There is no problem when cutting and dismantling ordinary concrete buildings using these methods, but when cutting concrete heat shield walls contaminated with radioactivity, such as in nuclear reactors, workers may be exposed to radiation, etc. will pose a great danger. Therefore, once the cutting operation is started, these concrete heat shield walls must be cut mechanically and continuously using remote control without manually replacing the burning bar or supplying fuel.

(Object of the invention) The present invention has been devised in view of the above points, and
An object of the present invention is to provide a cutting method and a cutting machine for use in the cutting method that can mechanically continuously cut a concrete heat shield wall efficiently, with high precision, and safely.

(Summary of the Invention and Examples) Hereinafter, the cutting method and cutting machine of the present invention will be explained in detail based on the drawings.

FIG. 1 is a schematic front view of a cutting machine 1 implemented in the cutting method of the present invention, and FIG. 2 is a schematic plan view of the same.

The cutting machine 1 has a leading burning bar 20 disposed on the upper surface of a base 10, and injects fuel from the burning bar 20 to cut a concrete heat shielding wall.

That is, in front of the base 10, there is a pedestal 21 for holding the burning bar 20, and an ignition device 2 that ignites the tip of the burning bar 20 by piezoelectric ignition or the like.
2 is provided, and grips 23, 23 for holding the burning bar 20 are provided behind the ignition device 22. Grips 23, 23 are cylinders 24, 24
The burning bar 20 is held in a pinched state by driving. A holder 31 for receiving the trailing burning bar 30 supplied from the supply device S is provided approximately at the center of the base 10.

On the other hand, further behind the base 10, a feeding table 41 is provided for advancing the burning bar 30 received by the holder 31.

Moreover, the cutting machine 1 can be moved forward and backward, up and down, etc. via the operating arm attached to the lower surface of the base 10, and the angle and horizontal position can be adjusted using the elevation cylinder 51 and shift cylinder 52. It is something.

FIG. 3 shows a pedestal 2 provided in front of the base 10.
1 and the ignition device 22;
The figure is an explanatory view of the same side. That is, the pedestal 21 of the burning bar 20 is used to fit the burning bar 20 and serve as a guide when the burning bar 20 moves forward, and also causes the tip of the burning bar 20 to protrude from the front side during combustion. .

In order to ignite the tip of the burning bar 20, the ignition device 22 is moved to the slide cylinder 22a.
A burner 22b that protrudes from the igniter 22c and is ignited by an igniter 22c is placed at the tip of the burning bar 20, and the valve of the fuel supply pipe is opened to inject and burn the fuel.

As shown in FIG. 2, the grip 23 consists of a pair of fan-shaped grippers 23a, 23b and cylinders 24, 24 that drive them, respectively.
As shown in FIG. 5, which is a view taken along the line A--A, the leading burning bar 20 is held between both grippers 23a and 23b. The holder 31 that receives the trailing burning bar 30 supplied from the supply device S has a pair of receiving pieces 31a, 31, as shown in FIG. 2 and FIG.
b is driven by the cylinder 32, and the receiving piece 31
and 31b are placed on semi-concave curved surfaces 33a and 33b formed at the outer periphery tips. Further, a feed table 41 provided at the rear of the base 10 has a long screw (not shown) rotated by a feed motor 42.
The burning bar runs through the guide cell in the same direction as the axis of the burning bar. As a result of this running, as shown in FIG. 7, which is a view taken along line C-C in FIG.
The catcher 43 approaches from the rear end side of the trailing burning bar 30 and has a circular hole 43 that is provided in the catcher 43 and communicates with a fuel supply hole (not shown).
Insert the rear end into a.

As a result, the trailing burning bar 30 is caught by the catcher 43. If the catcher 43 is run as described above in such a state, the trailing burning bar 30 can be connected to the preceding burning bar 20, and the burning bar 20 can be pressed against the cutting surface. .

A method of cutting a concrete heat shielding wall using the cutting machine 1 having the above configuration is shown in FIGS. 8a to 8k.
This will be explained in order.

First, the remaining (preceding) burning bar 20 used for another cutting surface is held by the grip 22, and the feed table 41 is returned to its normal position, which is the initial setting state (FIG. 8a).

In this state, a new (following) burning bar 30 is supplied from the supply device S, and the holder 3 is
1 (Figure 8b). Next, the rear end of this burning bar 30 is grasped and held by the catcher 43 of the feeding table 41, and the burning bar 2 is moved forward.
0 (Fig. 8c). Burning bar 20
is held in a pinched state by grippers 23a and 23b of the grip 23. In this state, the socket 60 is fitted to the tip of the burning bar 30 that has been advanced by the feeding table 41.
is inserted into the rear end of the burning bar 20 to connect both the burning bars 20 and 30.

When both the burning bars 20 and 30 are connected by the socket 60, the cylinder 24 of the grip 23
is driven to release the burning bar 20 from the clamped state, and the cylinder 32 of the holder 31 is driven to retract the receiving pieces 31a and 31b (FIG. 8e).

Thereafter, the ignition device 22 is pushed forward by the slide cylinder 22a, and the tip of the burning bar 20 is brought into the ignited state (FIG. 8f).

When the tip of the burning bar 20 is ignited, the valve of the fuel supply pipe is opened to inject and burn fuel. Next, the ignition device 22 is moved backward by the slide cylinder 22a, and the feed motor 42 is rotated to advance the feed table 41, thereby bringing the tip of the burning bar 20 into contact with the cutting site (FIG. 8g).

As both the burning bars are moved forward by the feeding table 41 as the injection combustion occurs, the holes are drilled one after another (Fig. 8h). After forming a perforation of a predetermined length by this injection combustion, the feed motor 42 is reversed and the feed table 4
By retracting the burning bar 1, the remaining burning bar 30 is also retracted (FIG. 8i).

Next, hold this burning bar 30 in the grip 23.
(Fig. 8j), release the catcher 43 from the burning bar 30, and move the feed table 4.
1 to the set position (Fig. 8k). Then, when the cutting machine 1 is moved to a new cutting surface, it becomes the initial setting state shown in FIG. 8a.

By sequentially repeating the above steps, the burning bar is mechanically and continuously supplied.

(Effects of the Invention) As explained above, the method and cutting machine for cutting concrete heat shielding walls of the present invention are not long enough to protect workers from radiation exposure, etc. If carried out in a controlled manner, large facilities such as nuclear reactors can be safely and efficiently continuously cut and dismantled.

[Brief explanation of the drawing]

Fig. 1 is a front schematic diagram illustrating the cutting machine of the present invention, Fig. 2 is a schematic plan view thereof, Fig. 3 is a front explanatory diagram of the ignition device, and Fig. 4 is a side view of the ignition device. Explanatory drawings, FIG. 5 is a view taken along the line A-A in FIG. 2, FIG. 6 is a view taken along the line B-B in FIG. 2, and FIG. 7 is a view taken along the line C-C in FIG. The arrow views and FIGS. 8a to 8k are partially omitted views illustrating the cutting method of the present invention. DESCRIPTION OF SYMBOLS 1... Cutting machine, 10... Base, 20... Leading burning bar, 21... cradle, 22... Ignition device, 23... Grip, 30... Trailing burning bar, 31... Holder , 41... feed table, 50... operating arm, 51... elevation cylinder, 52... shift cylinder.

Claims (1)

[Claims] 1. Hold the leading burning bar with a grip, receive the supplied trailing burning bar with a holder, advance the trailing burning bar with a feeding table, and connect it to the leading burning bar. After that, the holder is opened, and then the tip of the preceding burning bar is ignited, fuel is supplied, and the burning bar is injected and combusted, and the preceding burning bar is pressed against the cutting surface while advancing the following burning bar on the feeding table. After drilling and forming a hole of a predetermined length, the trailing burning bar is moved back and held by the grip, and the feeding table is returned to its normal position and a new trailing burning bar is inserted. How to cut concrete heat shielding walls to supply. 2 A holder for the burning bar, an ignition device for igniting the burning bar, and a grip for holding the burning bar are provided in front of the base, a holder for receiving the burning bar from the supply device is provided approximately in the center, and a holder for receiving the burning bar from the supply device is provided at the rear. A cutting machine for concrete heat shielding walls, comprising a feeding table for advancing a burning bar on the holder. 3. The concrete heat shield wall cutting machine according to claim 2, wherein the base is attached to an operating arm via an elevation cylinder and a shift cylinder.