JPH05302995A - Solid-liquid separator - Google Patents

Abstract

PURPOSE:To obtain a solid liquid separator which has high reliability and easy disassembling and assembling maintenance capability. CONSTITUTION:A solid liquid separator eliminates solid particles of fission products out of the solution of spent nuclear fuel by centrifugal separation. It is constituted of a centrifugally separating rotation vessel 22 arranged in high radiation level region and a rotation shaft 21 penetrating a radiation shield and rotating the rotation vessel 22 which are assembled in one. These rotation parts are supported by bearings 25 putting in between a sleeve coupled with the rotation shaft 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separator for removing solid particles of insoluble fission products from a solution in which spent nuclear fuel is dissolved by centrifugation.

[0002]

2. Description of the Related Art In reprocessing nuclear fuel, a centrifugal solid-liquid separator is used which removes solid fine particles of insoluble fission products from a nitric acid solution containing spent nuclear fuel by centrifugation.

FIG. 2 shows a conventional example of a centrifugal solid-liquid separator. As shown in FIG. 2, the concrete wall 1 of the spent fuel reprocessing plant has a solid-liquid separator 2 installed at the upper opening.
Upper casing 3 and solid-liquid separator 2 provided at the lower opening
Is connected to the lower casing 4 via a processing liquid receiving tray 5.

A rotary container 7 for centrifugation suspended from a rotary shaft 6 is housed in the lower casing 4, and a clad outlet 9 formed in a bottom plate 8 of the rotary container 7 is housed in the rotary container 7.
The waste liquid introduction nozzle 10 and the cleaning nozzle 11 are drawn in through. A clad discharge pipe 12 is connected to the lower end of the lower casing 4.

Furthermore, the top plate 13 of the rotary container 7 is provided with treatment liquid guide holes 14 in a radial pattern.
The treatment liquid guide vane 15 is provided on the upper portion of the treatment liquid receiving tray 5 of FIG.
On the other hand, the processing liquid discharge pipe 16 is connected to the bottom of the processing liquid receiving tray 5. The rotating shaft 6 is supported by a bearing 17, passes through the concrete wall 1, and is housed in the upper casing 3. The upper end of the rotary shaft 6 is connected to the shaft of the motor 19 via the coupling 18.

In the centrifuge-type solid-liquid separator thus constructed, waste liquid (solid liquid) containing solid content (clad)
Is guided into the rotary container 7 through the waste liquid introduction nozzle 10, and is centrifugally separated into the clad and the treatment liquid by the centrifugal action accompanying the rotation of the rotary container 7. After that, the clad is discharged from the clad outlet 9 into the lower casing 4, and further discharged from the solid-liquid separator 2 through the clad discharge pipe 12.

On the other hand, the treatment liquid reaches the inside of the treatment liquid receiving tray 5 through the treatment liquid guide hole 14, and at this time, the treatment liquid is guided below the treatment liquid receiving tray 5 by the treatment liquid guide vanes 15 and the treatment liquid discharge pipe. It is discharged from 16 to the outside of the solid-liquid separator 2. The level of radioactivity is a high level on the lower side of the concrete wall 1 and the maintenance is extremely difficult. Further, the upper side of the concrete wall 1 is an area where maintenance by a manipulator is possible.

[0008]

However, in the conventional solid-liquid separator 2 as described above, the rotary container 7 and the rotary shaft 6 are bolt-flange-joined to each other at the end face of the top plate 13. In addition, crevice corrosion occurs due to the processing liquid. When this crevice corrosion occurs, the rotary container 7 and the rotary shaft 6
There is a possibility that the coupling strength with and may be reduced, and the rotary container 7 may come off.

Further, it is difficult for the conventional solid-liquid separator 2 to perform maintenance, especially to replace the bearing 17. This bearing 1
All replacements of 7 will be done at the equipment installation site. In other words, due to the restriction that the manipulator must carry out the detailed work of disassembling the old parts and assembling the new parts, there is a problem that the replacement work of the bearing 17 is almost impossible. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solid-liquid separator that has high reliability and facilitates maintenance such as disassembly and assembly.

[0010]

In order to solve the above-mentioned problems, a solid-liquid separator according to the present invention is a solid-liquid separator for removing solid fine particles of fission products from a solution in which spent nuclear fuel is dissolved by centrifugation. In the liquid separator, a rotary container placed in a high radioactivity level region for centrifugal separation and a rotary shaft that penetrates through a radioactivity shield and rotates the rotary container are integrated into one unit, and these rotary parts are provided on the rotary shaft. It is supported by a bearing through a fitted sleeve.

[0011]

In the present invention having the above-mentioned structure, since the rotary container and the rotary shaft are integrally structured, there is no connecting portion, crevice corrosion does not occur, and the bolt does not loosen. Further, since the rotating portion is supported by the bearing through the sleeve fitted to the rotating shaft, the non-rotating portion can be disassembled and assembled integrally, and maintenance becomes extremely easy.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the solid-liquid separator according to the present invention. It should be noted that parts that are the same as or correspond to those of the conventional configuration will be described using the same symbols as in FIG.

As shown in FIG. 1, an upper casing 3 and a lower casing 4 of a solid-liquid separator 2 are connected to a concrete wall 1 as a shield in a spent fuel reprocessing plant via a processing liquid receiving tray 5. The lower casing 4 accommodates a rotary container 22 for centrifugal separation, which is integrated with the rotary shaft 21, and the waste liquid is introduced into the rotary container 22 through a clad outlet 9 formed in the bottom plate 8. The nozzle 10 and the cleaning nozzle 11 are pulled in. A clad discharge pipe 12 is connected to the lower end of the lower casing 4.

Further, the processing liquid guide hole 1 is provided in the rotary container 22.
4 are provided in a radial manner, and a treatment liquid guide vane 15 is arranged above the treatment liquid guide hole 14 on the treatment liquid receiving tray 5 side, while a treatment liquid discharge pipe 16 is provided at the bottom of the treatment liquid receiving tray 5. It is connected. The sleeve 23 is attached to the rotary shaft 21.
Is fitted and the sleeve 23 is fixed by a fixing nut 24. The upper and lower ends of the sleeve 23 are supported by a rolling bearing 25 fixed to the upper casing 3. The upper end of the rotary shaft 21 is connected to the shaft of the motor 19 via the coupling 18. A stopper 26 is provided in the lower casing 4 so as to project therefrom. Next, the operation of this embodiment will be described.

The rotary shaft 21 and the rotary container 2 which constitute the rotary unit.
Since the two are integrated, the rotary shaft 21 and the rotary container 22
There is no joint with and no crevice corrosion occurs,
Looseness of bolts disappears. As a result, it is possible to prevent the strength of the rotating part from being reduced or the rotating container 22 from falling off, and the reliability as a solid-liquid separator for special purposes is significantly improved.

Further, since the rotating portion is supported by the rolling bearing 25 via the sleeve 23 fitted to the rotating shaft 21, by disassembling and assembling the motor 19, the coupling 18 and the fixed nut 24, the sleeve is formed. 23, the rolling bearing 25, and the upper casing 3 can be integrally disassembled and assembled.

Further, by preparing the sleeve 23, the rolling bearing 25 and the upper casing 3 as an integral structure and preparing a spare, even if the rolling bearing 25 is defective, it can be replaced in a short time. If the defective rolling bearing 25 is moved together with the sleeve 23 and the upper casing 3 to another room, it can be disassembled and assembled by human hands, and the assembling accuracy is greatly improved. As a result, the manipulator work is simple and only simple work can be performed.

[0018]

As described above, according to the solid-liquid separator of the present invention, since the rotary container and the rotary shaft are integrally structured, there is no connecting portion and crevice corrosion is prevented. , Looseness of bolt is eliminated and reliability is improved. Further, since the rotating portion is supported by the bearing through the sleeve fitted to the rotating shaft, maintenance such as disassembly and assembly becomes extremely easy.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a solid-liquid separator according to the present invention.

FIG. 2 is a vertical sectional view showing a conventional solid-liquid separator.

[Explanation of symbols]

 1 Concrete wall (shield) 2 Solid-liquid separator 3 Upper casing 4 Lower casing 21 Rotating shaft 22 Rotating container 23 Sleeve 24 Fixed nut 25 Rolling bearing

Claims (1)

[Claims] 1. A solid-liquid separator which removes solid fine particles of fission products from a solution in which spent nuclear fuel is dissolved by centrifugation, and a rotary container which is placed in a high activity level region for centrifugation and a radioactive container A solid-liquid separator characterized in that a rotary shaft that penetrates through the shield and rotates the rotary container is integrally structured, and these rotary parts are supported by bearings via a sleeve fitted to the rotary shaft.