JPS59186657A - Centrifuge - Google Patents

Abstract

PURPOSE:To enlarge the diameter of a rotary body by hanging a cylindrical baffle plate around an external surface of the bottom of the rotary body and providing also a receiver provided with a baffle plate along the internal periphery of the above described baffle plate. CONSTITUTION:A baffle plate 10 is hung down on the extension of a peripheral wall of a rotary body 1 at its bottom end, and a cylindrical baffle plate 8a is provided with a specified clearance between the inside periphery of the baffle plate 10 and a receiver 8 having an annular conical covering plate 8b of the bottom receiver inclining from the bottom end of the baffle plate 8a toward the inside periphery of a casing 2. By this constitution, clear liquid flowing out of an extraction holes 3 collides with the casing 2 and then flows down by the gravity along the inside peripheral surface of the casing 2 and is discharged via the receiver 8 and a liquid discharge pipe 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to centrifuges, particularly centrifuges used in nuclear fuel reprocessing processes.

[Technical background of the invention and its problems]

During nuclear fuel reprocessing, spent fuel from a nuclear reactor is broken up, dissolved in nitric acid, etc., and useful substances such as geltonium and uranium are extracted from the solution, or insoluble fission products are extracted from the solution. must be removed prior to sending the solution to the extraction process. The removal of insoluble fission products is carried out using a type of centrifugal separator called a centrifugal clarifier.

Since the above centrifugal separator contains a liquid containing a large amount of plutonium during operation, it must be designed so that the liquid does not reach criticality.

Means for maintaining a subcritical state include controlling the concentration of the solution and using neutron poison, but it is most reliable to design the shape and dimensions so that even in the worst case, it will not reach criticality. That is, it is desirable that the diameter of the centrifugal separator is small.

However, it is desirable to increase the diameter of the rotating body in order to increase the solids collection capacity and to obtain a high solids removal ability at low rotational speeds.

FIG. 1 and FIG. 2 show the main parts of two typical examples of conventional centrifugal separators. What is shown in FIG. 1 is a casing 2 that concentrically surrounds a rotating body 1. A receiver 4 is placed on the upper part of a casing 2 that concentrically surrounds a rotary body 1, and a receiver 4 is placed around the outer circumference of the goo song 2 to receive the solution flowing out and splashed from the extraction hole 3 of the upper end plate of the rotating body 1. It is provided so as to bulge out from the surface. In addition,
In this figure, 5 indicates a liquid supply pipe, 6 indicates a liquid drain pipe, and 7 indicates a drive shaft.

In a centrifugal separator with this configuration, the diameter of the receiver 4 must be made considerably larger than that of the rotating body 1 in order to prevent the solution from scattering. Therefore, in order to maintain subcriticality even if this part is filled with solution due to blockage of the drain pipe 6, etc., the diameter of the rotating body 1 must be made extremely small.
It is unfavorable in terms of solids collection capacity and collection ability.

What is shown in FIG. 2 is a receiver that has a cylindrical baffle plate 8a close to the upper end of the rotating body 1 in the casing 2, and a conical annular bottom plate 8b that connects the lower end and the inner circumference of the casing. 8 is provided at the upper end of the rotating body 1, a cylindrical baffle plate 9a that hangs down along the outer periphery of the flange 1 plate 8a, and an annular upper surface plate 9b that connects the upper end of the cylindrical baffle plate 9a and the vicinity of the outer periphery upper end of the rotating body. A seal 9 having a diameter is provided. In this type of centrifugal clarifier, the distance at which the clarified liquid coming out of the extraction hole 3 of the rotating body 1 collides with the inner circumferential surface of the casing 2 is short, and the clarified liquid is turned into mist by the collision. However, the baffle board 8a,
Since the structure is such that the mist is prevented from flowing out to the outside by 9a, the clarified liquid is eventually discharged from the discharge pipe 6.

Therefore, the difference between the diameter of the receiver and the diameter of the rotating body 1 may be smaller than that of the type shown in FIG. 1, and the diameter of the rotating body 1 can be increased when the inside of the receptor is subcritical.

By the way, the clearance between the 1st floor plates 8a and 9a, between the baffle plate 8a, and the outer circumferential surface of the rotating body 1 must be as large as possible, considering the ease of assembly of the centrifugal clarifyer, vibrations during earthquakes, etc. be. Therefore, although the diameter of the rotating body 1 can be made smaller than that shown in FIG. 1, it must be made smaller by the gap formation amount.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and provides a centrifugal separator that can maintain subcriticality even when the receiver is filled with clear liquid, and that can also increase the diameter of the rotating body. The purpose is to obtain.

[Summary of the invention]

In the present invention, a baffle plate having an annular cross section whose lower end does not protrude from the outer peripheral surface of the rotor is suspended from the outer bottom surface of the rotor, and a predetermined gap is formed at the lower part of the casing at the inner periphery of the baffle plate. A receiver having one plate is provided to achieve the above object.

Embodiment of the Invention] FIG. 3 shows an embodiment of the present invention, in which the same parts as in FIGS. 1 and 2 are given the same reference numerals. In this figure, a bellows plate 10 is suspended from the lower end of the rotating body at an extension of its circumferential wall, and inside the casing 2F is a cylinder that forms a predetermined gap between it and the inner circumference of the bushing plate 10. Receiver 8 which has a round plate 8a and a conical annular bottom plate 8b that slopes from its lower end toward the inner circumference of the goo song 2.
is provided.

In this embodiment, the clarified liquid flowing out from the extraction hole 3 collides with the casing 2 and then flows down along the inner peripheral surface of the cane puffer 2 due to gravity, and is discharged through the receiver 8 and the drain pipe 6.

In this embodiment, the baffle plate 8a is the baffle plate 10.
Since it is located on the inner circumference of the rotating body 1, even if the gap is set to a specified value,
There is no restriction on the diameter of the rotating body 1, and the diameter of the rotating body 1 can be maximized.

FIG. 4 shows another embodiment. In this embodiment, the rotating body 1
A cylindrical shield plate 11 is suspended from the periphery of the bottom opening. The lower end of this baffle plate 11 is the baffle plate 8a-
It is located below the H end. In this embodiment, even if the supplied stock solution leaks from the bottom opening, it will be scattered by the centrifugal force from the lower end of the first plate 11, so the scattered liquid will be blocked by the first plate 8a and clarified. It will not mix with the liquid.

FIG. 5 shows another embodiment of the invention. In this embodiment, the baffle plate 10' provided on the bottom surface of the rotating body 1 includes:
The baffle plate 8'a of the receptor 8' is tapered so that the diameter of its lower end is less than the diameter of the rotating body.
It is provided on the inner periphery of 0' and parallel to the ridge plate 8'a. Further, at the upper end of the baffle plate 8'a, there is provided an upper surface plate 8'c of the buried plate 1--which has an opening 1-] concentric with the bottom opening of the rotating body 1 and having a larger diameter than the opening.

Also in this embodiment, wire plates 10', 8'a
Even if the gap between them is set to a predetermined value, there is no restriction on the diameter of the rotating body 1, as in the embodiment shown in FIG. The air containing the soil and mist-formed clarified liquid enters between the baffle plates 10' and 8'a, passes through them, and moves the gap between the bottom surface of the rotor 1 and the top plate 8'c to the center of the rotor 1. When the mist travels toward , it becomes a swirling flow due to the rotation of the rotor 1, and is moved radially outward by the centrifugal force due to the high specific gravity of the mist in the air. The liquid collides with the mist bar and cutting plate 10' and is captured there, flows down along the plate 10' and is finally discharged from the drain pipe 6. Therefore, there is no possibility that the clear liquid will flow into the coo song 2.

[Effects of the invention] As is clear from the description, even if the diameter of the receptor is made small, the diameter of the rotating body can be made sufficiently large, so the solid particle collection capacity can be increased, and even at low rotational speeds. However, the ability to separate solid particles can be increased. In addition, since the diameter of the rotating body can be increased, it is possible to easily disassemble and reassemble structures within the rotating body, such as cleaning nozzles, in the centrifugal separator. becomes.

Furthermore, if the centrifugal separator of the present invention is used in the clarification process of fuel reprocessing, the difference between the diameter of the receiver and the diameter of the rotating body is small, so the centrifugal separator of the present invention is more efficient than a conventional centrifugal clarifier equipped with a rotating body of the same diameter. too,
It becomes easier to maintain criticality safety.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional views of main parts of two examples of conventional centrifugal separators, and FIGS. 3 to 5 are longitudinal sectional views of first to third embodiments of the present invention. 1 Rotating body, 2 Casing, 3 Extraction hole, 4.8.8' Receiver, 6 Drain pipe,
9° seal, 8a,, 8a', 9a, 10.10', 1
1. Jiya Sunban Application Agent Patent Attorney Kikuchi Part 5/Figures, 2 Figures 3 Figure 4 Figure 5

Claims (1)

[Claims] A cylindrical baffle plate is suspended from the outer bottom surface of the rotor so that its maximum diameter does not protrude from the outer peripheral surface of the rotor, and a predetermined gear knob is formed at the lower part of the case song surrounding the rotor along the inner circumference of the baffle plate. A centrifugal separator characterized in that it is provided with a receptor having a baffle plate.