JPS6029919B2 - Cleaning equipment for equipment with sodium adhesion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides fuel assemblies used, for example, in fast breeder reactors;
The present invention relates to a cleaning device for sodium-adhered equipment that can quickly remove sodium adhering to equipment such as parts and instruments.

Conventionally, equipment contaminated with sodium has been cleaned using steam, alcohol, water, or the like.

However, with this method, it is difficult to remove sodium adhering to the small recesses of the equipment, the cleaning efficiency is poor, and waste liquid treatment is required, making the equipment large and complicated.

In addition, a device has been developed in which the equipment to be cleaned is housed in a cleaning tank and high-temperature inert gas is circulated within the tank to evaporate sodium adhering to the equipment, but conventional devices of this type This method requires an inert gas heater, an inert gas circulation pump, an inert gas exhaust system, and a sodium vapor exhaust system in addition to a cleaning tank, which also has the disadvantage of making the equipment large and complicated. The present invention was made in order to eliminate such disadvantages of the conventional system, and its purpose is to effectively and quickly remove sodium adhering to equipment to be cleaned by evaporating it, and to cool the sodium vapor. It is an object of the present invention to provide a cleaning device for equipment adhering to sodium, which can be liquefied and flowed out of the cleaning tank, thereby omitting attachments, and which can be simplified in shape and configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a longitudinal cross-sectional view showing a cleaning device for sodium-adhered equipment.A cleaning tank 1 has a cooling cylinder 3 airtightly connected to the upper end of an equipment housing cylinder 2, and a small-diameter pipe connected to the upper end of the cooling cylinder 3. It is configured by airtightly connecting exhaust pipes 4.

A flowing sodium receiver 5 is installed inside the equipment-to-be-cleaned housing cylinder 2 .

This flowing sodium receiver 5 has a flange portion 7 protruding outward from the lower end of the heating cylinder 6.
As shown in FIG. 2, a large number of magnetic tubes 8 are provided at equal intervals in the circumferential direction and through the flange portion 7, so that the entire outer periphery of the flange portion 7 extends along the inner periphery of the housing cylinder 2. It is attached to the surface and is removable. Then, the heating cylinder 6
A cap body 9 in the shape of a conical cylinder is removably attached to the upper end of the cap. This shade body 9 has a vent hole 9A at the top and is disposed within the cooling cylinder 3. Further, the upper end of the exhaust pipe 4 is airtightly closed off from the cover plate 1.
A sodium vapor condenser 11 is attached to the bottom of the 0.

This sodium vapor condenser 11 has a mandrel 12 disposed between the center of the lower surface of the cover plate 10 and the approximately central position within the cooling cylinder 3, that is, a position near the vent 9A of the shade body 9.
A large number of circular wire meshes 13 are mounted at equal intervals from the approximate center of the exhaust pipe 4 to the vicinity of the vent 9A. In addition, this sodium vapor condenser 1
1 can be removed from the cleaning tank 1 together with the lid plate 10 by removing the lid plate 10. The cooling cylinder 3
As shown in FIG.
They are installed at equal intervals in all directions, avoiding the upper position of the ventilation pipes 8, and being located between the ventilation pipes 8.

Furthermore, a large number of vertically long cooling fins 15 are mounted on the outer circumferential surface of the cooling tube 3 at equal intervals in the circumferential direction. Furthermore, a large number of vertically long cooling fins 16 are mounted on the outer peripheral surface of the exhaust pipe 4 at equal intervals in the circumferential direction. Coil-shaped heaters 17 and 18 are attached to the inner peripheral surfaces of the heating cylinder 6 of the flowing sodium receiver 5 and the shade body 9, respectively. Further, coil-shaped heaters 19A and 1 are provided on the outer peripheral surface of the housing cylinder 2 and the lower surface of the bottom plate, respectively.
9B, coil-shaped heaters 20A, 20B are attached to the outer circumferential surface and upper surface of the cooling tube 3, respectively, and coil-shaped heaters 21A, 21B are attached to the outer circumferential surface of the exhaust tube 4 and the upper surface of the cover plate 10, respectively. is installed. An inert gas cylinder (not shown) is connected to the lower part of the peripheral wall of the housing cylinder 2 via an inert gas supply pipe 22, and an on-off valve 22A is connected to the middle of the supply pipe 22.

Further, an inert gas exhaust pipe 23 is provided at the upper part of the peripheral wall of the exhaust pipe 4.
A vacuum pump (not shown) is connected through the exhaust pipe 23, and an on-off valve 23A is connected in the middle of the exhaust pipe 23. Furthermore, a drain pipe 24 is connected to the upper part of the peripheral wall of the storage cylinder 2 so that the lower inner surface of the pipe and the upper surface of the flange portion 7 of the flowing sodium receiver 5 are on the same level. The liquefied sodium that has fallen onto the receiver 5 is allowed to flow into the drain tank 25.
An on-off valve 22A is connected to the middle of the drain pipe 24. Note that a sodium vapor remover 26 is connected to the upper part of the drain tanker 25. Coil-shaped heaters 26, 27, and 28 are attached to the outer peripheral surfaces of the inert gas supply pipe 22, drain pipe 24, and drain tank 25, respectively. Inside the storage cylinder 2, a support rod 29 is installed horizontally below the flowing sodium receiver 5, and this support rod 29 is attached via a hanging fitting 30.
A device 32 to be cleaned to which sodium 31 has adhered is suspended.

Next, the operation of the cleaning device configured as described above will be explained.

First, the equipment 32 to be cleaned to which sodium 31 has adhered is first cleaned.
As shown in the figure, heaters 19A, 19B, 17, 18 are suspended from the support rod 29 inside the cleaning tank and attached to the storage tube 2, the flowing sodium receiver 5, the shade body 9, and the inert gas supply pipe 22.
and 26 to heat the inside of the housing cylinder 2, and
Inert gas is supplied into the housing cylinder 2 through the supply V supply pipe 22.

Therefore, the sodium 31 adhering to the equipment 32 to be cleaned evaporates continuously, mixes with the high-temperature inert gas, rises, passes through the vent hole 9A of the shade body 9, and flows into the cooling cylinder 3. And most of the sodium vapor is in the sodium vapor condenser 11.
It comes into contact with the wire mesh 13, condenses, and is captured. Further, the remaining sodium vapor also comes into contact with the inner surface of the cooling cylinder 3 and the surface of the sodium vapor condensing fins 14, condenses, and is captured. On the other hand, since the inside of the cooling cylinder 3, especially the vicinity of the peripheral wall of the cooling cylinder 3, is kept at a relatively low temperature by the action of the cooling fins 15, the cooling fins 15 together with sodium vapor are kept at a relatively low temperature.
The inert gas flowing into the inside descends along the inner circumferential surface of the cooling cylinder 3, returns downward from the flowing sodium receiver 5 through the ventilation pipe 8, and is heated again to remove the sodium 31 that has adhered to the equipment 32 to be cleaned. This will contribute to the promotion of evaporation.

After removing the sodium 31 from the equipment 32 to be cleaned in this way, the condenser 11, the inner surface of the cooling cylinder 3, and the fins 14 are cleaned.
Sodium adhering to etc. is removed as follows.

That is, along with the heaters 17 and 18 attached to the flowing sodium receiver 5 and the shade body 9, the heaters 20A, 20B, 21A attached to the cooling tube 3, the exhaust tube 4, the cover plate 10, the drain pipe 24 and the drain tank 25, 21B, 27 and 2
When the inside of the cooling tube 3, exhaust tube 4, drain pipe 24, and drain tank 25 is heated by applying electricity to the condenser 11,
The sodium adhering to the inner surface of the cooling cylinder 3 and the fins 14, etc. is dissolved, the sodium adhering to the condenser 11 is transmitted along the upper surface of the cap body 9, and the sodium adhering to the inner surface of the cooling cylinder 3, the fins 14, etc. is directly dissolved. , respectively, flow down onto the flange portion 7 of the flowing sodium receiver 5. and drain pipe 24
It flows out into the drain tank 25 through the drain tank 25. Note that the present invention is not limited to the above embodiments, and various types of sodium vapor condensers can be used, for example. As described above based on the embodiments, the cleaning apparatus of the present invention connects a cooling cylinder equipped with a sodium condenser to a cleaning cylinder containing a heating source for evaporating sodium to form a cleaning tank. further comprising means for introducing an inert gas into the cleaning tank,
Furthermore, there is a vent between the cooling cylinder and the storage cylinder that allows a mixed flow of high-temperature inert gas and sodium vapor generated by evaporation to rise into the cooling cylinder by natural convection, and A shade-shaped flowing sodium receiver with a vent pipe that returns active gas to the storage cylinder by natural convection is installed, so the natural convection of inert gas can effectively and quickly remove sodium adhering to the equipment. Can be removed.

In this case, the sodium is kept confined in a narrow space called the cleaning tank, and the sodium is removed using the natural convection phenomenon of inert gas, which not only ensures sufficient safety but also Since power for circulating the inert gas can be eliminated, economic efficiency can also be improved. Furthermore, after cleaning the equipment, the inside of the cooling cylinder is heated to melt the condensed sodium and flow down onto the flowing sodium receiver, which is then flowed out of the cleaning tank through the drain pipe. Since a sodium vapor exhaust device and a waste liquid treatment device are not required, the configuration is simplified and the entire device can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view of Rollo in FIG. 1...Cleaning tank, 2...Equipment housing cylinder to be cleaned, 3...Cooling cylinder, 4...Exhaust pipe, 5
...Liquid sodium receiver, 9...Kasa body, 11...Sodium vapor condenser, 17, 18, 1
9A, 19B, 20A, 20B, 21A, 21B, 27
, 28... Heater, 22... Inert gas supply pipe, 23... Inert gas exhaust pipe, 24... Drain pipe, 25... Drain tank. Oh figure 2 figure

Claims (1)

[Claims] 1. A cleaning tank consisting of a housing cylinder with an open top that accommodates the equipment to be cleaned and a cooling cylinder connected to the housing cylinder so as to close the upper end opening of the housing cylinder, and introducing an inert gas into this cleaning tank. a first heater installed in the housing cylinder and heating the inside of the housing cylinder to evaporate sodium adhering to the equipment to be cleaned housed in the housing cylinder; and the cooling cylinder. a sodium condenser that is provided within the cooling cylinder to condense and supplement the sodium vapor that has flowed into the cooling cylinder; It has a vent that allows a mixed flow of inert gas and sodium vapor to rise into the cooling cylinder by natural convection, and the inert gas cooled in the cooling cylinder is flowed into the accommodation chamber by natural convection at the periphery. A flowing sodium receiver is attached to the cooling cylinder and is energized after cleaning is completed to dissolve the sodium that has been collected on the inner surface of the sodium condenser and the cooling cylinder and onto the flowing sodium receiver. A cleaning device for equipment adhering to sodium, comprising: a second heater that causes the sodium to flow down; and a drain pipe that causes the sodium that has fallen onto the flowing sodium receiver to flow out of the cleaning tank.