JPS60174997A - Electrolytic grinding decontaminating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electrolytic polishing decontamination apparatus for decontaminating radioactively contaminated metallic objects using an electrolytic polishing decontamination method.

[Technical background of the invention and its problems]

In general, an electrolytic polishing decontamination method is known as a method for decontaminating metal contaminants that have survived in a nuclear power plant or the like. This electrolytic polishing decontamination normal line The object to be decontaminated is used as an anode, a cathode made of a conductive material is arranged at a position facing the object to be decontaminated, and an electrolyte is passed between the cathode and the object to be decontaminated. This is a method of dissolving the surface layer of the object to be decontaminated and removing contaminants attached to the surface by applying a DC voltage while flowing the decontamination object, and it has the feature of obtaining extremely high decontamination effects.

By the way, when performing decontamination work using this electropolishing method, in order to decontaminate more effectively, it is necessary to make the current density as uniform as possible between the surface to be decontaminated and the cathode of the object to be decontaminated. ,
It is important to make the cathode face the surface to be decontaminated at regular intervals to uniformly dissolve the surface to be decontaminated. However, if the object to be decontaminated has a complicated shape, such as a bulb, it is necessary to face a cathode that is similar in shape to the surface to be decontaminated, but it is not possible to use a cathode with such a complicated shape. There were problems in that it took a lot of time to manufacture the cathode, and the cost was relatively high because the cathode had no wave compatibility when used.

[Purpose of the invention]

The present invention has been made to solve the above problems, and its purpose is to provide an electrolytic polishing decontamination device that can economically and efficiently decontaminate complex-shaped objects to be decontaminated. This is what we are trying to provide.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized by having the following configuration.

That is, the electrolytic polishing decontamination apparatus according to the present invention includes a flexible cathode that faces the decontamination target surface of the decontamination target at a constant interval, and an electrolytic solution between the cathode and the decontamination target surface. It is equipped with means for passing current through, and means for applying a DC voltage to the cathode and the object to be decontaminated.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings.

The drawing shows an embodiment of the present invention, and shows an example in which a stretchable net-like conductor is attached to the outer surface of a stretchable rubber balloon-like object as a cathode. In the figure, 1 is an object to be decontaminated made of metal, and a rubber balloon-like object (hereinafter referred to as a rubber balloon) 2 that can be expanded and contracted is inserted into the object 1 to be decontaminated through an opening 1a. . A stretchable mesh-like conductor (hereinafter referred to as wire mesh) 3 is attached to the outer surface of the rubber balloon 2, forming the cathode of this embodiment. Further, this rubber balloon 2 has an opening 2a formed therein, and this opening 2a is connected to one end of a rubber tube 4 provided inside the rubber balloon 2. The air injection port 2b of the rubber balloon 2 is attached to the open end of an air injection tube 5, and the air injection tube 5 forms a triple tube together with an electrolyte injection tube 6 and an electrolyte suction tube 7, which will be described later. There is.

An air injection valve 8 and an air discharge valve 9 are provided on the air injection side of the air injection pipe 5, and the inlet side of the air injection valve 8 is connected to a blower 10.

The electrolyte injection pipe 6 is connected to an electrolyte storage tank 12 via a circulation pump 11, and the electrolyte in the tank 12 is pumped through the circulation pump 11 to the inner surface of the object 1 to be decontaminated and to the rubber. It is press-fitted between the outer surface of the balloon 2 and the outer surface of the balloon 2.

The electrolyte storage tank 12 is connected to one end of the electrolyte suction pipe 7 via a filter 13, and the other end of the electrolyte suction pipe 7 is connected to one end of the rubber tube 4. Therefore, the electrolytic solution pressurized between the inner surface of the decontamination object 1 and the outer surface of the rubber balloon 2 by the circulation pump IIVC passes through the rubber tube 4 through the opening 2 and the opening 2 formed at the tip of the rubber balloon 2. , from the electrolyte suction pipe 7 to the filter 1
3 and then returns to the electrolyte storage tank 12.

Further, the outer surface of the wire mesh 3 attached to the outer surface of the rubber balloon 2 is entirely covered with a bag-shaped insulator 14 having flexibility and fluid circulation, such as sponge, etc. is designed so that it does not come into electrical contact with the inner surface of the object to be decontaminated.

The end of the wire mesh 3 is connected to the end of an electrolyte injection tube 6, and the electrolyte injection tube 6 is connected to a direct current. to prevent the electrolyte from flowing out.

Next, a case will be described in which the inner surface of the object to be decontaminated 1 is decontaminated in the above configuration. First, the rubber balloon 2 expands due to air so as to come into close contact with the inner surface of the object 1 to be decontaminated, and as a result, the thickness of the insulator 14 is reduced by the wire mesh 3 against the inner surface of the object 1 to be decontaminated. They will face each other at a certain distance. Next, the circulation pump 11 supplies the electrolyte from the electrolyte injection pipe 6 between the inner surface of the object to be decontaminated 1 and the outer surface of the rubber balloon 2 . The electrolytic solution supplied between the inner surface of the object to be decontaminated and the outer surface of the rubber balloon passes through the insulator 14, and as described above (
From the opening 2a at the tip of the rubber balloon, the rubber passes through the tube 4 and the electrolyte suction pipe 7, returns to the tank 12 via the filter 13, and is again used by the circulation pump 11 to connect the inner surface of the object to be decontaminated with the outer surface of the rubber balloon. supplied in between. In this way, while circulating the electrolyte between the decontamination target 1 and the rubber balloon 2, a DC voltage is applied between the wire mesh 3 and the decontamination target 1, thereby decontaminating the inner surface of the decontamination target 1. is uniformly dissolved.

Contaminants and the like adhering to the inner surface of the object to be decontaminated 1 are mixed into the electrolytic solution, and these are collected by the filter 13.

In this way, in this embodiment, by using a flexible mesh-like conductor attached to the outer surface of an extensible rubber balloon as the cathode, the cathode can be attached to the inner surface of the object 1 to be decontaminated. They can be faced at regular intervals along the line. Therefore, according to this embodiment, there is no need to use a cathode with a complicated shape similar to the surface to be decontaminated, and the simple structure of attaching the wire mesh 3 to the outer surface of the rubber balloon 2 saves time and effort in producing the cathode. Moreover, it is versatile for decontaminating objects of all shapes.

In the above embodiment, the cathode was formed of two materials, the rubber balloon 2 and the wire mesh 3, but the present invention is not limited to the above embodiment, and for example, a material having two properties of conductivity and flexibility may be used. It is also possible to form the cathode with one material and apply a voltage of 5Vc.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, there is provided a flexible cathode that faces the surface to be decontaminated of the object to be decontaminated at a constant interval, and a gap between the cathode and the surface to be decontaminated. The structure includes means for passing an electrolyte through the electrodes, and means for applying a DC voltage to the cathode and the object to be decontaminated, so that the object to be decontaminated with a complex shape can be deelectrified economically and efficiently. It is possible to provide an electrolytic polishing decontamination device that can be used for decontamination.

[Brief explanation of drawings]

The drawing is a sectional view showing an embodiment of the present invention. 1...Decontamination target object, 2...Rubber balloon, 3...Wire mesh, 4...Rubber tube, 5...Air injection pipe, 6...
- Electrolyte injection pipe, 7... Electrolyte suction pipe, 10... Blower, 11... Circulation pump, 14... Insulator, 15
...DC power supply.

Claims (1)

[Scope of Claims] A flexible cathode facing the surface to be decontaminated of the object to be decontaminated at a constant interval, and means for flowing an electrolyte between the cathode and the surface to be decontaminated. and means for applying a DC voltage to the cathode and the object to be decontaminated.