JPH11290606A - Multi-stage centrifugal extractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-stage centrifugal extractor designed for efficient transfer of substance between two liquids of different densities. SOLUTION: In centrifugal extracting means A, B, C, D, E, F, a radioactive substance contained in a dissolved salt entering an inlet channel, 28 to move through the individual centrifugal extracting means A, B, C, D, E, F and transfer passages 29 therebetween toward an outlet channel 30 travels to a molten metal entering an inlet channel 31 to move through the individual centrifugal extracting means F, E, D, C, B, A and transfer passages 32 therebetween toward an outlet channel 33, thus effecting efficient removal of the radioactive substance contained in the dissolved salt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multistage centrifugal extractor.

[0002]

2. Description of the Related Art For dry reprocessing of spent fuel taken out of a nuclear reactor, spent fuel is subjected to molten salt (LiCl
-KCl) is mixed with a molten metal such as cadmium (Cd) based on the molten waste radioactive salt generated by electrolytic purification using the radioactive substance (TR
U) is transferred to the molten metal side, and after separating the molten salt and the molten metal, there is a radioactive substance extraction step of repeatedly using the molten salt from which the radioactive substance has been removed for the electrolytic purification of the spent fuel again. .

FIG. 7 shows an example of a centrifugal extractor recently proposed as a means for separating molten salt and molten metal in the above-mentioned radioactive substance extraction step.

This centrifugal extractor has a substantially cylindrical rotating body having an inlet hole 1 penetrating vertically in the center of the bottom and a plurality of outlet holes 2 penetrating in the circumferential direction in a portion near the upper end. A supply chamber 4 surrounding the lower portion of the rotary drum 3 in the circumferential direction; and a liquid reservoir 18 of two upper and lower stages surrounding the upper portion of the rotary drum 3 in the circumferential direction and having an open portion near the rotary drum 3. And a drive device 10 for rotating the rotary drum 3 in one direction.

A molten salt supply port 6 through which a molten salt 5 containing a radioactive substance can flow into a supply chamber 4 and a molten metal 7 for removing the radioactive substance from the molten salt 5 are supplied to a portion near the lower end of the casing 9. Molten metal supply port 8 that can flow into chamber 4
Are pierced sideways.

[0006] A projection 16 is formed at an intermediate portion in the vertical direction in the casing 9 so as to surround the rotary drum 3 in the circumferential direction and to face the outer peripheral surface of the rotary drum 3 with a small gap therebetween.

The molten salt 5 supplied to the molten salt supply port 6 and the molten metal 7 supplied to the molten metal supply port 8 are supplied to the supply chamber 4.
Through the introduction hole 1 to flow into the inside of the rotary drum 3.

At this time, when the rotating drum 3 is continuously rotating in one direction, the rotating drum 3 is affected by the centrifugal force accompanying the rotation of the rotating drum 3 and the density difference between the molten salt 5 and the molten metal 7. Forming an annular liquid layer of molten metal 7 whose liquid level rises along the inner surface of 3 and an annular liquid layer of molten salt 5 whose liquid level rises along the inner surface of the liquid layer become.

At the upper end of the rotating drum 3, an annular outer weir 11 for guiding the molten metal 7 whose liquid level rises with the rotation of the rotating drum 3 to the outside of the rotating drum 3 is coaxial with the rotating drum 3. It is provided in.

In the vicinity of the upper end of the rotating drum 3, a molten salt 5, which is located below the outer weir 11 and whose liquid level rises with the rotation of the rotating drum 3, is discharged from the outlet hole 2 into the rotating drum 3. A hollow disk-shaped inner weir 12 that can be guided to the outside is provided coaxially with the rotating drum 3.

In the outer edge of the inner weir 12, there are provided a plurality of flow holes 13 which are located inside the rotary drum 3 and penetrate vertically.
However, the molten metal 7, which is drilled at intervals in the circumferential direction and whose liquid level rises with the rotation of the rotary drum 3, reaches the outer weir 11 through the above-described flow hole 13. I have.

An opening 14 is formed at the center of the bottom of the inner weir 12 to guide the molten salt 5 whose liquid level rises with the rotation of the rotary drum 3 to the outflow hole 2.

Further, a drive shaft 15 is connected to the inner weir 12 and extends downward from the drive unit 10 installed outside the upper part of the casing 9 through the upper part of the casing 9 and the inner weir 12. The rotational force of the device 10 is
And transmitted to the rotating drum 3 via the inner weir 12.

The lower liquid reservoir 17 is formed on the inclined surface 1 having a downward gradient from the upper edge of the outflow hole 2 to the outside in the radial direction.
9, and the upper liquid reservoir 18 has an inclined surface 20 that slopes downward from the upper part of the outer weir 11 radially outward.

The molten salt 5 scattered to the outside of the rotating drum 3 via the inner weir 12 and the molten metal 7 scattered to the outside of the rotating drum 3 via the outer weir 11 collide with the above-mentioned inclined surfaces 19 and 20,
The liquid will be trapped in the liquid reservoirs 17 and 18.

The molten salt 5 trapped in the liquid reservoir 17 flows out of the molten salt discharge port 21 formed in the portion near the upper end of the casing 9 to the outside. Numeral 7 flows to the outside from a molten metal discharge port 22 formed in the casing 9 near the upper end in a lateral direction.

Further, the supply chamber 4 is provided at the inner bottom of the supply chamber 4.
A plurality of introduction promoting wings 23 are radially provided so that the inflow of the molten salt 5 and the molten metal 7 from inside to the inside of the rotary drum 3 is promoted with the rotation of the rotary drum 3, and the lower end of the drive shaft 15 is provided. The disk-shaped deflecting plate 2 for allowing the molten salt 5 and the molten metal 7 to flow from the supply chamber 4 toward the inner surface of the rotary drum 3
4 is attached so as to face the introduction hole 1 and to be located near the inner bottom of the rotating drum 3.

When the radioactive material is removed from the molten salt 5 using the centrifugal extractor shown in FIG. 7, the rotary unit 3 is continuously rotated in one direction by the driving device 10 and the molten salt containing the radioactive material is removed. 5 flows into the supply chamber 4 from the molten salt supply port 6 and a molten metal 7 capable of taking in radioactive substances.
From the molten metal supply port 8 into the supply chamber 4.

The molten salt 5 and the molten metal 7 flowing into the supply chamber 4 are mixed with the rotation of the rotary drum 3 while
From the bottom through the introduction hole 1 into the rotary drum 3.

At this time, the radioactive substance contained in the molten salt 5 moves to the molten metal 7, and the radioactive substance is removed from the molten salt 5.

The molten metal 7 containing the radioactive material flows through the inside of the rotary drum 3, the outer weir 11, and the liquid reservoir 18, flows out of the molten metal outlet 22 to the outside of the casing 9, and the molten metal from which the radioactive material has been removed is removed. The salt 5 flows out of the casing 9 from the molten salt discharge port 21 through the inside of the rotary drum 3, the inner weir 12, and the liquid reservoir 17.

[0022]

However, in order to improve the efficiency of the work of separating the molten salt 5 and the molten metal 7,
When the rotating drum 3 is driven at a high rotation speed, the liquid mixture of the molten salt 5 and the molten metal 7 interposed between the outer peripheral surface of the rotating drum 3 and the inner peripheral surface of the supply chamber 4 is rotated. The liquid level rises due to the centrifugal force caused by the pressure.

As a result, the liquid mixture of the unseparated molten salt 5 and the molten metal 7 leaks upward from the gap between the outer peripheral surface of the rotary drum 3 and the inner peripheral surface of the projection 16 of the casing 9 to be liquid. It will flow into the reservoir 17.

That is, in the centrifugal extractor shown in FIG. 7, it is not possible to improve the efficiency of the transfer of the radioactive substance from the molten salt 5 to the molten metal 7 simply by increasing the rotation speed of the rotating drum 3.

The present invention has been made in view of the above circumstances, and has as its object to provide a multistage centrifugal extractor capable of efficiently transferring a substance between two types of liquids having different densities.

[0026]

In order to achieve the above object, in the multistage centrifugal extractor according to the present invention, an introduction hole penetrating vertically is formed at the center of the bottom and an outlet hole penetrating circumferentially at a portion near the upper end. , A supply chamber surrounding the lower portion of the rotating drum in the circumferential direction, and a low density surrounding the upper portion of the rotating drum in the circumferential direction and the rotating portion closer to the opening. The liquid reservoir and the high-density liquid reservoir, and the high-density liquid provided at the upper end of the rotary drum and flowing into the rotary drum through the supply hole from the supply chamber into the rotary drum can be guided to the high-density liquid reservoir by centrifugal force accompanying rotation of the rotary drum. An outer weir and a low-density liquid that is provided near the upper end of the rotating drum so as to be located below the outer weir and that flows into the rotating drum from the supply chamber through the introduction hole by centrifugal force accompanying rotation of the rotating drum. Guide to low-density fluid reservoir through outlet hole A plurality of centrifugal extraction means each having an inner weir and a low-density liquid inlet flow path that is externally connected to the supply chamber of the centrifugal extraction means located at the forefront end, and between each centrifugal extraction means. And a low-density liquid transfer passage communicating from the low-density liquid reservoir of the centrifugal extraction means located on the front side to the supply chamber of the centrifugal extraction means located on the rear side; A low-density liquid outlet flow path communicating from the high-density liquid reservoir to the outside, a high-density liquid inlet flow path communicating from the outside to the supply chamber of the centrifugal extraction means located at the rearmost end, and located between and behind each centrifugal extraction means A high-density liquid transfer flow path communicating from the high-density liquid reservoir of the centrifugal extraction means located on the side to the supply chamber of the centrifugal extraction means located on the front side, and from the high-density liquid reservoir of the centrifugal extraction means located at the foremost end to the outside. High-density liquid communicating with And an outlet flow passage.

In the multistage centrifugal extractor according to the second aspect of the present invention, in addition to the configuration of the multistage centrifugal extractor according to the first aspect of the present invention, each rotating body is rotated in the same direction at the same rotational speed. A tuning rotation mechanism is provided.

In the multistage centrifugal extractor according to the third aspect of the present invention, in addition to the configuration of the multistage centrifugal extractor according to the first or second aspect of the present invention, the multistage centrifugal extractor is connected to the supply chamber and has a rotary drum. And a stagnation chamber which surrounds in the direction and is open at a portion close to the rotating body.

In any one of the multistage centrifugal extractors according to the first to third aspects of the present invention, the supply chamber of each centrifugal extraction unit is connected to the low-density liquid inlet channel through each centrifugal extraction unit and between them. The substance contained in the liquid flowing to the low-density liquid outlet flow path through the low-density liquid transfer flow path passes through the centrifugal extraction means from the high-density liquid inlet flow path and the high-density liquid transfer path through the high-density liquid transfer flow path therebetween. Transfer to liquid going to outlet channel.

[0030] In the multistage centrifugal extraction means according to the second aspect of the present invention, the rotating drum of each centrifugal extraction means is rotated in the same direction at the same rotation speed by the synchronous rotation mechanism.

[0031] In the multistage centrifugal extraction means according to the third aspect of the present invention, the centrifugal force acting on the liquid in the supply chamber with the rotation of the rotary drum is reduced by the retention chamber, and the liquid level rise in the supply chamber is reduced. To prevent.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 6 show an embodiment of a multistage centrifugal extractor according to the present invention. In the drawing, the same reference numerals as those in FIG. 7 denote the same parts.

In this multi-stage centrifugal extractor, similarly to the centrifugal extractor shown in FIG. 7, the rotary drum 3, the supply chamber 4, the liquid reservoir 17,
18, a plurality of centrifugal extraction means A, B, C, D, E, and F each having an outer weir 11 and an inner weir 12 are constituted by a casing body 25 and a lid 26 so as to be arranged in a row in the horizontal direction. Is incorporated in the casing 27 to be manufactured.

The casing body 25 has an inlet passage 28, a transfer passage 29, and an outlet passage 30 through which the molten salt 5 flows.
An inlet channel 31, a transfer channel 32, and an outlet channel 33 through which the molten metal 7 flows are formed.

The inlet passage 28 communicates the outside of the casing body 25 with the supply chamber 4 of the centrifugal extraction means A located at the forefront end.

The transfer channel 29 includes centrifugal extraction means A, B,
C, D, E liquid reservoirs 18 and these centrifugal extraction means A,
Other centrifugal extraction means B, C, adjacent to B, C, D, E
The supply chambers 4 for D, E, and F are communicated.

The outlet channel 30 communicates the liquid reservoir 18 of the centrifugal extraction means F located at the rearmost end with the outside of the casing body 25.

The inlet channel 31 communicates the outside of the casing body 25 with the supply chamber 4 of the centrifugal extraction means F located at the rearmost end.

The transfer channel 32 is provided with centrifugal extraction means F, E,
D, C, B liquid reservoirs 17 and these centrifugal extraction means F,
Other centrifugal extraction means E, D, adjacent to E, D, C, B
The C, B, and A supply chambers 4 are in communication.

The outlet channel 33 communicates the liquid reservoir 17 of the centrifugal extraction means A located at the foremost end with the outside of the casing body 25.

Inside the casing main body 25, there is formed a staying chamber 34 which is continuous with the supply chamber 4 and surrounds the rotary drum 3 in the circumferential direction.
A plug 35 corresponding to each supply chamber 4 is attached.

The lid 26 has plugs 36 corresponding to the inlet channel 28, the transfer channel 29 and the outlet channel 30, respectively, and the inlet channel 31, the transfer channel 32 and the outlet channel 33.
Are attached.

Further, above the casing 27, each drive shaft 1 of each of the centrifugal extraction means A, B, C, D, E and F is provided.
A gear type tuning rotation mechanism 39 having a plurality of rotation force transmission shafts 38 extending coaxially toward 5 is arranged.

An output shaft 41 of a driving device (not shown) is connected to an input shaft 40 of the tuning rotation mechanism 39. When the output shaft 41 rotates, each torque transmitting shaft 38 rotates at the same rotational speed. It is configured to rotate in the same direction.

The tuning rotation mechanism 39 is supported by the casing main body 25 via a support post 42,
Are connected to the drive shafts 15 of the respective centrifugal extraction means A, B, C, D, E and F.

When removing radioactive substances from the molten salt 5 using the multi-stage centrifugal extractor shown in FIGS. 1 to 6, the driving device is operated and the rotational force of the driving device is adjusted by the tuning rotation mechanism 39.
To the drive shaft 15 of each of the centrifugal extraction means A, B, C, D, E, and F to rotate the respective rotating drums 3 in the same direction at the same rotation speed.

Next, when the molten salt 5 is supplied to the inlet channel 28, the molten salt 5 is directed to the outlet channel 30 via each of the centrifugal extraction means A, B, C, D, E, F and the transport channel 29 therebetween. At the same time, the molten metal 7 flows into the inlet channel 31.
, The centrifugal extraction means F, E, D, C, B, A
The flow of the molten metal 7 toward the outlet flow path 33 via the transfer flow path 32 therebetween is generated.

Thus, each of the centrifugal extraction means A, B, C,
The molten salt 5 and the molten metal 7 that have flowed into the supply chambers 4 of D, E, and F are mixed with the rotation of the rotary drum 3 from the bottom of the supply chamber 4 through the introduction hole 1 while being mixed with the rotation of the rotary drum 3. It flows inside.

At this time, the radioactive substance contained in the molten salt 5 moves to the molten metal 7 and the radioactive substance is removed from the molten salt 5.

That is, the centrifugal extraction means A, B, C, D,
From the molten salt 5 flowing in the order of E and F, radioactive substances are sequentially removed by the molten metal 7 flowing in the order of the centrifugal extraction means F, E, D, C, B and A in the opposite direction to the molten salt 5. Will be.

Each of the centrifugal extraction means A, B, C, D,
In E and F, the centrifugal force acting on the liquid mixture of the molten salt 5 and the molten metal 7 in the supply chamber 4 due to the rotation of the rotary drum 3 is reduced by the retention chamber 34 surrounding the rotary drum 3 in the circumferential direction. Is done.

This prevents the unseparated liquid mixture of the molten salt 5 and the molten metal 7 from leaking from the supply chamber 4 to the liquid reservoir 17, and prevents the mixed fluid from flowing from the supply chamber 4 to the rotary drum 3. As a result, turbulence occurs in the mixed liquid in the retention chamber 34, and the transfer of the radioactive substance from the molten salt 5 to the molten metal 7 is promoted.

As described above, in the multistage centrifugal extractors shown in FIGS. 1 to 6, in each of the centrifugal extraction means A, B, C, D, E, and F, the centrifugal extraction means A, B, C, D, E, F, and radioactive substances contained in the molten salt 5 flowing to the outlet flow path 30 via the transfer flow path 29 therebetween are supplied from the inlet flow path 31 to the respective centrifugal extraction means F, E, D. ,
C, B, A and the outlet channel 3 via the transfer channel 32 between them
Since the transition to the molten metal 7 toward 3 occurs, the removal of radioactive substances from the molten salt 5 can be performed efficiently.

The retention chamber 34 reduces the centrifugal force acting on the liquid mixture of the molten salt and the molten metal 7 in the supply chamber 4 of each of the centrifugal extraction means A, B, C, D, E and F. Therefore, it is possible to drive the rotating drum 3 at a high rotation speed to improve the efficiency of the separation work of the molten salt 5 and the molten metal 7.

Further, since each rotary drum 3 is rotated in the same direction at the same rotation speed by the tuning drive mechanism 39, the molten salt 5 in each of the centrifugal extraction means A, B, C, D, E, and F is rotated.
And the molten metal 7 have the same separation efficiency, and no leakage occurs due to the difference in the liquid delivery amount.

The multi-stage centrifugal extractor of the present invention is not limited to the above-described embodiment, but may be modified without departing from the scope of the present invention.

[0058]

As described above, the multistage centrifugal extractor of the present invention can provide various excellent effects as described below.

(1) In any one of the multistage centrifugal extractors according to the first to third aspects of the present invention, each supply chamber of each centrifugal extraction unit is connected to each centrifugal extraction unit from the low-density liquid inlet channel. And the substance contained in the liquid flowing to the low-density liquid outlet flow path via the low-density liquid transfer flow path therebetween, from the high-density liquid inlet flow path through each centrifugal extraction means and the high-density liquid transfer flow path therebetween Since the liquid is transferred to the high-density liquid outlet flow path, the transfer of the substance from one liquid to the other liquid can be performed efficiently.

(2) In the multistage centrifugal extractor according to the second aspect of the present invention, since each rotating body is rotated in the same direction at the same rotation speed by the synchronous rotation mechanism, two types of centrifugal extraction means are used. Liquid separation efficiency becomes equal,
No leakage due to the difference in liquid delivery rate occurs.

(3) In the multistage centrifugal extractor according to claim 3 of the present invention, the centrifugal force acting on the liquid in the supply chamber with the rotation of the rotary drum is alleviated by the retention chamber, and the liquid in the supply chamber is reduced. Since the rise in the position is prevented, the rotating drum can be rotated at a high speed, and the separation efficiency of the two types of liquids can be improved.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view showing an example of an embodiment of a multistage centrifugal extractor of the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 1;

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 1;

FIG. 5 is a view taken in the direction of arrows VV in FIG. 1;

FIG. 6 is a view taken in the direction of arrows VI-VI in FIG. 1;

FIG. 7 is a longitudinal sectional view showing an example of a centrifugal extractor proposed in recent years.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Introducing hole 2 Outflow hole 3 Rotating drum 4 Supply chamber 11 Outer weir 12 Inner weir 17 Liquid reservoir (low-density liquid reservoir) 18 Liquid reservoir (high-density liquid reservoir) 28 Inlet flow path (low-density liquid inlet flow path) 29 Transfer Flow path (low-density liquid transfer flow path) 30 Outlet flow path (low-density liquid outlet flow path) 31 Inlet flow path (high-density liquid inlet flow path) 32 Transfer flow path (high-density liquid transfer flow path) 33 Outlet flow path (High-density liquid outlet channel) 34 Retention chamber 39 Synchronous rotation mechanism A, B, C, D, E, F Centrifugal extraction means

Claims (3)

[Claims] 1. A substantially cylindrical rotating drum having a bottom hole formed with an introduction hole penetrating in the vertical direction and an outlet hole penetrating in the circumferential direction at a portion near the upper end, and a lower portion near the rotating drum. A supply chamber surrounding the portion in the circumferential direction, a low-density liquid reservoir and a high-density liquid reservoir surrounding the upper portion of the rotary drum in the circumferential direction and opening the portion closer to the rotary drum, and a supply chamber provided at the upper end of the rotary drum. An outer weir that can guide the high-density liquid flowing into the rotary drum through the introduction hole to the high-density liquid reservoir by centrifugal force accompanying rotation of the rotary drum, and near the upper end of the rotary drum to be located below the outer weir And a plurality of inner weirs provided in the portion and capable of guiding the low-density liquid flowing into the rotary drum from the supply chamber through the inlet hole to the low-density fluid reservoir through the outlet hole by centrifugal force accompanying rotation of the rotary drum. Centrifugal extraction means are arranged in a row in the horizontal direction And a low-density liquid inlet flow path that is externally connected to the supply chamber of the centrifugal extraction means located at the forefront end,
A low-density liquid transfer passage communicating between the low-density liquid reservoir of the centrifugal extraction means located on the front side and located between the centrifugal extraction means and the supply chamber of the centrifugal extraction means located on the rear side; A low-density liquid outlet flow path communicating from the low-density liquid reservoir of the centrifugal extraction means to the outside; a high-density liquid inlet flow path communicating from the outside to the supply chamber of the centrifugal extraction means located at the rearmost end; And a high-density liquid transfer passage communicating from the high-density liquid reservoir of the centrifugal extraction means located on the rear side to the supply chamber of the centrifugal extraction means located on the front side; A multi-stage centrifugal extractor comprising: a high-density liquid outlet flow path communicating from the high-density liquid reservoir to the outside. 2. The multi-stage centrifugal extractor according to claim 1, further comprising a tuning rotation mechanism for rotating each rotating drum in the same direction at the same rotation speed. 3. The multi-stage centrifugal extractor according to claim 1, further comprising a staying chamber connected to the supply chamber, surrounding the rotating drum in the circumferential direction, and having an opening at a portion close to the rotating drum.