US3613989A

US3613989A - Gas centrifuges, their assembly and a process for enriching uranium 235

Info

Publication number: US3613989A
Application number: US768981A
Authority: US
Inventors: Yoshitoshi Oyama; Yoichi Takashima; Shigebumi Aoki
Original assignee: Doryokuro Kakunenryo Kaihatsu Jigyodan
Current assignee: Doryokuro Kakunenryo Kaihatsu Jigyodan
Priority date: 1967-10-26
Filing date: 1968-10-21
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19
Also published as: JPS4811278B1; DE1801307A1; GB1212449A; FR1589275A

Abstract

A gas centrifuge unit for assembly into a system for separation and enrichment of mixtures of gases according to minute differences between mass numbers of isotopes, each unit having an elongated rotor rotating at a high velocity within an outer cylinder, holes in each end of the rotor for the jetting of respectively enriched gas and depleted gas, calculated to establish a ratio of 1:1 of enriched uranium 235, containing gas mixture, to be jetted out of the upper holes to an upper chamber to depleted uranium 235 gas mixture jetted through the lower holes to the lower chamber, means to heat the upper rotor region and to cool the lower rotor region, an upper and a lower container and a circumferential chamber between them formed by the walls of the centrifuge housing and the rotor within it; orifices and means to supply a gas mixture into the rotor, and to withdraw gas mixture from the central region of the rotor, conduit means in the upper and the lower ends of the rotor to duct gas mixtures from the upper and lower regions of the rotor in the adjacent upper and lower containers, respectively, an orifice in the circumferential chamber to duct thereto gas withdrawn from the lower region of the rotor, orifices in the upper and lower chambers to withdraw therefrom, respectively, the gases collected there, and conduit means connecting each centrifuge unit with a successive centrifuge unit with means to controllably withdraw the enriched gases. A process for the separation and enrichment of uranium 235 comprising steps analogous to the above described means, whereby mixed uranium gas 235 is mixed with helium under high speed centrifugal force, simultaneously cooled at one end and heated at the other, thus aiding in its separation into different regions of gases of different mixtures and different mass numbers of isotopes and recycling some of the gases controllably into the system in a cascade of steps, by returning the depleted uranium 235 gas with the inner light gas back to the rotor and by feeding the enriched gas of uranium 235 with inert light gas to the rotor of the subsequent centrifuge.

Description

United States Patent [72] Inventors Yoshitoshi Oyama; ABSTRACT: A gas centrifuge unit for assembly into a system Yoichi Takashima; Shigebumi Aoki, all of, for separation and enrichment of mixtures of gases according Tokyo, Japan to minute differences between mass numbers of isotopes, each [21] Appl. No. 768,981 unit having an elongated rotor rotating at a high velocity [22] Filed Oct. 21, 1968 within an outer cylinder, holes in each end ofthe rotor for the [45] Patented Oct. 19, 1971 jetting of respectively enriched gas and depleted gas, calcu- [73] Assignee Doryokuro Kakunenryo Kaihatsu Jigyadan lated to establish a ratio of 1:1 of enriched uranium 235, con- Tokyo, Japan taining gas mixture, to be jetted out of the upper holes to an [32] Priority Oct. 26, 1967 upper chamber to depleted uranium 235 gas mixture jetted Japan through the lower holes to the lower chamber, means to heat [31] 42-68490 the upper rotor region and to cool the lower rotor region, an upper and a lower container and a circumferential chamber between them formed by the walls of the centrifuge housing and the rotor within it; orifices and mea: 3 to supply a gas mixture into the rotor, and to withdraw gas mixture from the central region of the rotor, conduit means in the upper and the lower ends of the rotor to duct gas mixtures from the upper and lower regions of the rotor in the adjacent upper and lower GAS CENTRIFUGES, THEIR ASSEMBLY AND A containers, respectively, an orifice in the circumferential PROCESS FOR ENRICHING URANIUM 235 chamber to duct thereto gas withdrawn from the lower region 27 Claims, 4 Drawing 8 of the rotor, orifices in the upper and lower chambers to [52] U.S.Cl 233/13, hdra herefrom, respectively, the gases collected there,

233/17 and conduit means connecting each centrifuge unit with a suc- 51 1m. 01 B04b 15/08 cessive centrifuge with means cmruably 50 Field of Search 233/17, 13, emiched gases- A Process the sepamim' and 18 19,21 H, 14 15 12, 1 richment of uranium 235 comprising steps analogous to the above described means, whereby mixed uranium gas 235 is [56] References Cited mixed with helium under high speed centrifugal force, simul- UNITED STATES PATENTS taneously cooled at one end and heated at tfhe othert, :IhFIfS aiding in its separation into different regions 0 gases 0 i erent i mixtures and different mass numbers of isotopes and recycling 3289925 12/1966 Zi e 233/13 some of the gases controllably into the system in a cascade of 3:332:6l4 7/1967 w siei 233/ steps, by returning the depleted uranium 23s gas with the Primary Examiner-Robert W. Jenkins Att0rney0tto John Munz inner light gas back to the rotor and by feeding the enriched gas of uranium 235 with inert light gas to the rotor of the subsequent centrifuge.

Pressured Source Hegting means Evacuattng Pump Depleted GaB Output;

[over Container ath mung- Evacuatln;

Pump

Enriched (Pas Output Eva c us 1. i ng l'ulnp PAIENTEDnmmsn 3,513,989

SHEET 10F 3 I Pressured Source 1st Orifice 1st t Means to rotate 1- Container 27 3| F Heating means Evacuating 4|- Pump f Depleted Gas Output: 20\

1 Q 11- 5th ORIFICE 5o PLlI'ifiC Centrifuge -28 2nd Orifice Lower Container l4 ach omngp jgE B 1 1; Jet Evucuating Pump Ev g. Enriched Gas Output Pump FIG. 5

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PATENTEDUET l 9 I97! v 3, 5 1 3 9 8 9 SHEET 2 OF 3 ENRICHED 3 URANI M GAS orn i Q 1 L- -fi L., ENRICHING T kfi FgtHe-l-bd} STEPS I RECOVERY STEPS DEPLETED URANIUM GAS INVENTOR YUSHI'IOSHI 5w MA YOICHI 'l'AlxASHIMA, snmmwxvn Aom BY WM ATTORNEY PATENTEDnm 19 I971 SHEET 3 BF 3 Enriched Uranium 8 8 output cont.

u to C from C 2 l 2 238 from C (2 Intermediate Enriching Centrifuges igs 1.

enriching Joint 2 18 T 3 13 Last 1st.

Enriching 19a Enriching 9 Centrifuge Centfl fuge Fig. l 1 Fig l. 1';

I 2 4a 2Llapurific purif 233 pply Joint 7 ---1 He. 3 supply 151;

Mix. Supply 9 Natural Ur. Chamb. Centrifuge gas supply Fig 1, 1 4

12 12 Additional intermediate He Recovery Centrifuges Figs 1. purif.

from C i t 23a :Q g miu I l l l3 3 L4.

1 1-, First Recovery Recovery 19a Centrifuge Centrifuge 1 Fig 1. ii Fig V C -1 [2% r (n 2 la HE e u purific urific INVENTOP vos m'rosm 6w. MA By YOICIH TAKASIIIMA,

sum. BUM! AOKI We A'ITOR "Y l GAS CENTRIFUGES, THEIR ASSEMBLY AND A PROCESS FOR ENRICHIN G URANIUM 235 BACKGROUND OF THE INVENTION 1. Field of the Invention A gas centrifuge cascading system and a process for separating uranium 235 to enrich it for purposes from isotopes of uranium hexafluoride.

2. Description of the Prior Art The prior art employs a process of centrifuging uranium hexafluoride having about 0.7 percent-uranium 235 comixed therewith in a rotor subjected to pressure diffusion and countercurrent separating and extracting thereby a gas of uranium 238 comprising a mass larger than the uranium hexafluoride and a gas of uranium 235 comprising a mass smaller than that. By repetitions of this process, an enriched uranium will result. This system necessitates taking out the two kinds of gases under precautions, to avoid their comixing. To accomplish this some additional method has to be employed, which increases the difiiculties and expenses of production and demands on power.

In U.S. Pat. No. 3,501,091, the same inventors Yoshitoshi Oyama and Yoichi Takashima disclosed an apparatus and a process for centrifuging and concentrating components of a gas mixture, including introduction of an inert light gas through pipes surrounding a fixed outer cylinder, into an annular space between the cylinder and a rotor, through neck portions provided near each of the upper and lower end plates of the rotor so that the inert light gas (for example, helium gas or hydrogen) is mixed respectively with uranium 238 rich gas and uranium 235 rich gas, jetted through holes of the upper and lower plates of the rotor, respectively. Thereby the mixed gases are taken out separately. In such a centrifuge, the outer surface of the rotor, rotating at a high velocity, will be surrounded almost entirely by the inert light gas having a small mass. This serves to reduce the power required for the centrifuge. In this prior centrifuge of the coinventors a separate cold trap must be provided to permit reevaportion of the remaining solidified uranium hexafluoride and transfer thereof to a next centrifuging step;

The centrifuging process depends, essentially, upon differences between minute masses of isotopes (that is, small separation effect) and therefore, as a result, numerous operating steps of centrifuging are required in order to obtain moderately enriched uranium 235 (for example, about percent). Especially, as tremendous numbers of centrifuges are demanded in each early step, it is not desirable that the cold trap should be applied in each early process of centrifuging in which the gas will be close to natural.

Summary of the Invention An object of the present invention is to provide a gas centrifuging process and an apparatus for use directly in the process wherein uranium 235 is enriched and separated, without using a cold trap, from mixed gas of inert light gas with uranium hexafluoride which are fed as a starting material.

According to the present invention, mixed gas of nearly an equal amount of uranium hexafluoride with inert light gas is fed into a rotor, rotating at a high velocity, so that the mixed gas may be separated into an enriched gas of uranium 235, depleted gas of uranium 235 and an inert light gas. The separated inert light gas of a high purity is taken out through a hollow center shaft of the rotor and is circulated again around the outer surface of the rotor. The pure inert light gas fed around the rotor is divided into an upper and a lower flow so that they are mixed respectively with the depleted uranium 235. Enriched uranium 235is jetted out through holes of the end plates of the rotor. The mixed gas of enriched gas of uranium 235 with the inert light gas is fed to a rotor of the next step while the mixed gas of depleted gas of uranium 235 with the inert light gas is fed to a rotor of the former step as constructed to be cascade formation.

Contrary to the parent case, with the present invention, the ratio of the inert light gas, for example, helium gas, to the uranium hexafluoride to be fed into the rotor as mixed gas is changeable. Preferably, the ratio of the helium gas to the uranium hexafluoride is in the range of from 1 to l to 3 to I. If the amount of the helium gas is beyond this range, the cost for operating power cannot be disregarded. As the inert light gas in the rotor is to be collected in the center part of the rotor, it is taken out through another rotating hollow shaft from the rotor to the outside thereof so that it may be introduced into the space between the sidewall of the rotor and the fixed outer cylinder. On the other hand, the size and position of small holes in the end plates of the rotor are arranged so accurately that the ratio of amount of uranium hexafluoride from the upper plate to that from the lower plate, to be jetted out through holes, respectively, is almost perfectly I to 1. Each gas, is then, mixed with the inert light gas introduced into the space between the sidewalls of the rotor and the cylinder so as to provide equal amounts by means of valve operation of suction pipes above and below the rotor. The mixed gas of enriched uranium 235 with the inert light gas is fed to a rotor of the next step while the mixed gas of depleted gas of uranium 235 with the inert light gas is fed back to another rotor of the former step.

The gas material balance is such that the amount of the gas fed to a certain rotor is equal to the sum of the amount of the mixed gas of the enriched uranium 235 with the inert light gas from a rotor of the former step and that of the mixed gas of the depleted gas of uranium 235 with the inert light gas from a rotor of the next step.

The present invention provides for a cascade formation comprising a supply step as a center thereof with a plurality of enriching steps for enrichment of uranium 235 and a plurality of recovery steps for depleting uranium 235. Thereby uranium hexafluoride gas of moderately enriched degree of uranium 235 is obtained from the enriching step without using a cold trap.

The uranium gas enriched to a higher degree gained from the successive enriching step is separated and may be enriched by using a cold trap because the amount of uranium gas handled becomes much smaller in the successive steps.

Other objects of the invention will become apparent to those skilled in the art as the disclosure is made in the following detailed description of the preferred embodiment of the invention as illustrated in the accompanying drawings.

Brief Description of the Drawings FIG. I is a cross-sectional view of a gas centrifuge unit of the invention with portion between the broken lines omitted, which unit is self sustaining but also may serve as the first, the last, or an intermediate unit of a cascade system of such units;

FIG. 2 is a view in cross section along lines II-II of FIG. I;

FIG. 3 is a flow sheet explaining the method of the invention; and

FIG. 4 is a diagrammatical representation of the cascade system of and method and apparatus of the present invention.

Description of the Preferred Embodiment In the drawings like reference numerals designate like or equivalent parts throughout the figures thereof, of which FIGS. 1 and 2 are drawn to scale.

In FIGS. 1 and 2, three helium gas feeding pipes 11 are shown radially connected at angular intervals of degrees to orifices in the central part of a long, fixed outer housing 10 on the outside thereof. As shown in FIG. 2, each pipe 11 has a small nozzle 12 within the respective orifice for control of helium flow rate of an angle suitable for aiming the flow in the same direction as the rotation of a rotor 20 and tangentially to the outer surface thereof.

Suction pipes

13 and 14, for separated gas having

valve devices

15 and 16, respectively, are fixed respectively near both end regions of the fixed outer cylinder 10.

An elongated rotor 20 is fitted within said fixed outer housing and is supported with bearings 17 and 18, respectively, so as to be rotated in counterclockwise direction, indicated by the arrow, at such high velocity that its peripheral velocity reaches, for example, 350 meters/second. An upper shaft 23 and a lower shaft 24 having a gas introducing port 23a and a gas pulling-out port 240 therein are integral with an upper end plate 21 and a lower end plate 22, respectively, so as to connect the inside of the rotor with the outside of the housing. Conventional commutators are provided to connect airtight the rotating shafts with stationary feeding conduits. The upper and lower end plates 21 and 22 have gas jetting

small holes

25 and 26 therein, respectively. The inside wall surface of the outer housing 10 opposite to the respective end plates 21 and 22 has circumferential flange-shaped projecting

parts

27 and 28 so as to form with the end plates annular

narrow clearance

31 and 32, respectively. A heating device 41 and a cooling device 42, respectively, are provided at the upper and lower ends of the rotor.

During operation, a gas mixed in the ratio of 1:1 of uranium hexafluoride to helium gas is fed into the rotor through the gas introducing port 230 by a pump. The mixed gas in the rotor is subjected to pressure diffusion by means of rotation of the rotor at a high velocity and is subjected to countercurrent flow by means of a heating device 41 and cooling device 42. Therefore, the arrangement in FIG. 1 forms a flow pattern as shown by arrows. A gas containing only a comparatively depleted uranium 235 mixed as it collects in the upper part of the rotor, a gas containing a comparatively enriched uranium 235 mixed as it collects in the lower part thereof and a helium gas collects in the center part thereof. The position of the gas jetting

small holes

25 and 26 is drawn to scale. Their size is calculated so that the ratio of amount of the gas, containing depleted uranium 235 as mixed, to be jetted through the holes 25 to a chamber A in FIG. 1, to the gas, containing enriched uranium 235 as mixed, to be jetted through the holes 26 to a chamber B is l to 1, By way of example, three or six holes of 0.2 millimeters in diameter are positioned at intervals of nine-tenths radius from the center of the end plates, respectively. The radial spacing of the holes on the upper end plates corresponds with that at the lower end plates accurately as shown in FIG. 2. The helium gas collected in the axially central part of the rotor is pulled out through the gas pulling-out port 24a at a high purity and is then jetted through a valve device 19, tangentially to the outer surface of the rotor, into the circumferential chamber 50 through small orifices 12 at the tip of each feeding pipe so that the stability of the rotor, rotating at a high velocity is not disturbed and may be that the rotor is surrounded on the greater part of its outer surface with the helium gas. Optionally, the helium gas pulled out from the rotor to the outside thereof may be further purified before it is fed to the outside of the rotor, for example, by using a purification centrifuge. The valve device 19 is, preferably, an automatic regulating valve with an inlet pressure arranged at a fixed pressure so that the amount of the helium gas to be jetted through the valve device corresponds at a predetermined ratio with that of the helium gas fed into the rotor for the first time. Optionally, metering means of the helium passing through the valve and of the newly introduced gas and means to control the supply by the output of the metering means may be interposed. As the helium gas sweeps out through

annular clearance

31 and 32 into the chambers A and B, respectively, it is mixed respectively with the gases jetted out through the

holes

25 and 26 and is then evacuated by vacuum pumps through

pipes

13 and 14. Means are provided to control the flow of the helium gas, divided into the upper and lower flow into amounts equal to each other by providing flow control arranging valve devices a and 160, respectively.

FIG. 3 shows a flow sheet of the process of the invention in a cascade formation through a plurality of centrifuging apparatus. Each supply step Cf, enriching step C0,, CCg and Ccm, and recovery step Cr,, Cr, and Crn are combined with one another, so that each step may be arranged in parallel having a great number of centrifuges, especially, greater number thereof in the vicinity of the supply step and a decreasing number in the direction toward the last step. These relations will be understood by those skilled from material balance. From the last step of the enriching steps, a gas containing uranium 235 of desired enrichment will be obtained.

The diagram of FIG. 4 represents schematically the system of the invention in the combination of a plurality of centrifuges, showing the interconnections from the first supply centrifuge to the first recovery centrifuge, to the last recovery centrifuge with broken line indicating a chain of additional interposed recovery centrifuges and from the first supply centrifuge to the first enriching centrifuge and to the last enriching centrifuge with a broken line indicating a chain of additional interposed enriching centrifuges, each centrifuge having an additional helium purification centrifuge interposed between the output of its parent centrifuge and its feedback to it. Every of these centrifuges is provided with its own three evacuating pumps, an enriched U-235 evacuating pump, a depleted U-235 evacuating pump and a helium pump, as shown in greater detail schematically in FIG. 1 only.

The mixing chamber shown in FIG. 4 is provided only for the first centrifuge. Only the last recovery centrifuge and the last enriching centrifuge each have an enriched Uranium output means and depleted uranium output means, respectively.

While there have been described herein what are at present considered preferred embodiments of the invention, it will be obvious to those skilled in the art that many modifications and changes may be made therein without departing from the spirit of the invention. It is therefore to be understood that the exemplary embodiments are illustrative and not restrictive of the invention, the scope of which is defined in the appended claims, and that all modifications that come within the meaning and range of equivalency of the claims are included therein.

What is claimed is:

1. A gas centrifuge for separating and enriching mixtures of gases in accordance with minute differences between mass numbers ofisotopes, comprising:

a. an outer housing,

b. a rotary chamber coaxially situated within said outer housing, mounted rotatably thereto having an upper and a lower end-plate; the radius of said housing being larger than the radius of said rotary, the said housing and said rotary chamber thus providing a circumferential chamber in between their walls; said housing provided internally at the levels of said upper and lower end plates with flanges, forming with said plates an upper and lower jetting containers with jet inlets;

c. a first duct means including a first orifice in said housing to feed a mixture of gases into said rotary chamber through the upper end-plate thereof;

d. a first jet means to jet enriched gas of a smaller mass number of said mixture of gases from the internal axially peripheral region of said rotary chamber into said lower jetting container;

e. a second orifice in the lower container of said housing and a second duct means including a pressure valve connected to said second orifice to duct the enriched gas from said lower jetting container to the outside of said housing;

f. a second jet means to jet depleted gas of a smaller mass number of said mixture of gases from the internal axially peripheral region of said rotary chamber into said upper container;

g. a third orifice in the upper container of said housing and a third duct means including a pressure valve connected to said third ducting orifice to drain gas from said upper container to the outside of said housing;

h. a fourth orifice and a fourth duct means to pull out light gas collected in the axially central part of said rotary chamber through said lower end plate and said lower container out of said housing;

plate being hollow and connected with said first duct means.

i. a fifth duct feeding means to feed said light gas into said circumferential chamber and from there from the upper and lower regions thereof into said upper and lower containers, respectively;

j. a fifth orifice in said outer housing in the middle portion of 5 said circumferential chamber and a fifth duct means connecting said fifth orifice with said fourth orifice.

2. A centrifuge as claimed in claim 1, further comprising a heating device adjacent the upper region of said rotary chamber and a cooling device adjacent the lower region of said rotary chamber.

3. A centrifuge as claimed in claim i, each said end plate provided with an integral shaft axially protruding to the outside of said rotary chamber through a first and fourth orifice, respectively, for rotation through the said housing, and means connected to at least one of said shafts to rotate said rotary chamber.

4. A centrifuge as claimed in claim l, the shaft of said upper 5. A centrifuge as claimed in claim 8, wherein said light gas is inert.

6. A centrifuge as claimed in claim 1, said first duct means comprising a pressure control valve and a pump means.

7. A centrifuge as claimed in claim 1, said first duct means including a pressurized source of a mixture of first gases to be separated and enriched; a pressurized source of a second gas to be admixed to said first gases, a pressurized comixing chamber and a conduit leading from said comixing chamber to said first feeding means.

8. A centrifuge as claimed in claim 1, said first jet means comprising orifices spaced in said lower endplate.

9. A centrifuge as claimed in claim 1, said second jet means comprising orifices spaced in said upper end-plate.

10. A centrifuge as claimed in claim 1, said second duct means comprising a pressurized valve and a pump means.

11. A centrifuge as claimed in claim ll, said third duct means comprising an evacuating pump and pressurized valve means.

12. A centrifuge as claimed in claim 1, said fourth duct means comprising a pump and conduits between said shaft of said lower end-plate and said pump.

13. A centrifuge as claimed in claim 1, said circumferential chamber comprising an orifice to the outside, said second duct means comprising a pump and conduits between said orifice and said pump and between said pump and said second duct means.

M. A centrifuge as claimed in claim 1, said circumferential chamber comprising a third and fourth jet means connecting it with said upper container and with said lower container, respectively.

115. A centrifuge as claimed in claim 14, said third jet means comprising means to control the amounts of gases to be drained respectively to the outside of said upper and lower containers to be equal to each other.

16. A centrifuge as claimed in claim 1, said fourth duct means comprising a helium purification means.

117. A centrifuge as claimed in claim 1 said fifth duct including means of flowing the ducted light gas in vector directions parallel to the velocity vectors of said cylindrical surface of said rotary chamber.

18. A centrifuge as claimed in claim 1 further comprising means of providing a thermal gradient within said cylindrical chamber.

19. A centrifuge as claimed in claim 1, said mixture of gases including uranium 235 mixed with uranium hexafluoride.

20. A centrifuge as claimed in claim 1 as a first centrifuge in an assembly with several additional intermediate centrifuges and a last centrifuge, each said centrifuge as defined in claim 1, said first centrifuge functioning as a first supply centrifuge further comprising: a first source of a mixture of natural uranium hexafluoride comixed with uranium 235; a source of helium; a pressurized mixing chamber of said first mixture of gases with said helium; first conduit means to connect said mixing chamber with said first duct means; a first, a second of a plurality of successive and a last enriching centrifuge, each as defined in claim 1; said supply centrifuge having a supply joint connecting its first duct means, the duct means from said mixing chamber and the third duct means of said first enriching centrifuge, said first enriching centrifuge further comprising an enriching joint connecting said first duct means of said first enriching centrifuge with the second duct means of said first supply centrifuge and with the third duct means of the next ad jacent successive enriching centrifuge, said successive enriching centrifuges interconnected in an analogous manner, the second duct means of said last enriching centrifuge further comprising a collecting container of enriched uranium 235 gas output; a first, a second, a plurality of successive and a last recovery centrifuges, each as defined in claim 1, said second duct means of said first recovery centrifuge connecting with said supply joint, said first recovery centrifuge further comprising a recovery joint connecting said first duct means of said first recovery centrifuge with the second duct means of the successive recovery centrifuge and with the third duct means of the first supply centrifuge, said successive centrifuges interconnected in analogous manner, the third duct means of said last recovery centrifuge further comprising a collecting container of depleted uranium 235 gas output.

21. A centrifuge as claimed in claim 20 wherein said light gas pulled out from the rotor to the outside thereof may be further subjected to purification before it is fed to the outside of the rotor by using another type of centrifuge.

22. A centrifuge as claimed in claim 20, wherein said cascade formation has a greater number of centrifuges in the vicinity of first a supply and a decreasing number toward the last centrifuge.

23. A process for separating and enriching uranium 235 in accordance with minute difference between mass numbers of isotopes using a greater number of centrifuges arranged in a cascade formation and each of which includes an outer chamber and a rotary chamber situated within said outer chamber and mounted rotatably thereto, comprising the steps of centrifuging a gas including uranium 235 and a light gas thereby separating an enriched gas of uranium 235, a light gas and a depleted gas of uranium 235 from each other into separate spatial regions lower, axially central and an upper, respectively, evacuating said light gas collected in the central region, ducting said light gas into a separate circumferential region therefrom sweeping it into an enriched gas and a depleted gas region, mixing said light gas with said enriched gas of uranium 235 and with said depleted gas of uranium 235 respectively, draining respectively said mixed gases from said different regions and thence subjecting said mixture of enriched gas of uranium 235 with said light gas to analogous sub sequent centrifuging step simultaneously repeating the steps of ducting said mixture of depleted gas or uranium 235 with said light gas to a centrifuging former step, said centrifuging steps arranged in a cascade formation.

24. A process for separating and enriching mixture of gases in accordance with minute difference between mass numbers of isotopes, using a centrifuge,

said centrifuge including an outer chamber and a rotary chamber situated within said outer chamber and mounted rotatably thereto;

said process comprising the steps of feeding the mixture of gases with a light gas into said rotary chamber through one end plate thereof;

jetting enriched gas of a smaller mass number of said mixture of gases from the internal axially peripheral region of said rotary chamber into one between said outer chamber and said rotary chamber;

jetting depleted gas of a larger mass number of said mixture of gases from said internal axially peripheral region of said rotary chamber into another region between said outer chamber and said rotary chamber;

pulling out the light gas collected in the center axial part of said rotary chamber through another end-plate thereof; feeding the light gas into a circumferential space between said rotary chamber and said outer chamber;

sweeping said light gas into the one region and the other reglon;

mixing said light gas with said enriched gas within said one region;

mixing said light gas with said depleted gas within said other region;

draining the mixed gas within one region to the outside of said outer chamber,

and draining the mixed gas within said other region to the outside of said outer chamber.

25. A process as claimed in claim 24 wherein said mixture of gases includes uranium 235 and uranium 238, and the ratio of amount of said mixture of gases and said light gas to be fed into the rotary chamber is substantially in the range of from I to l to 3.

26. A process as claimed in claim 24, wherein an amount of gases to be jetted respectively to the said different regions is equal to each other.

27. A process for separating and enriching uranium 235 in accordance with minute difference between mass numbers of isotopes using a great number of centrifuges arranged in a cascade formation and each of which comprising a cycle of steps of:

pressurizing said gas mixture; centrifuging said gas mixture into a first (upper) and second (lower) region; heating said gas in said first region; cooling the gas in said second region; jetting said gas from said first region into a depleted gas zone and said gas from said second region into an enriched gas zone; providing an intermediate gas zone; simultaneously centrifuging the gas from said second zone to said intermediate zone, and withdrawing gas from said lower region to said intermediate zone; withdrawing gas from said first zone; and repeating said cycle using the last mentioned step of said withdrawing said gas as the initial step of pressurizing said gas mixture in said subsequent cycle.

Claims

1. A gas centrifuge for separating and enriching mixtures of gases in accordance with minute differences between mass numbers of isotopes, comprising: a. an outer housing, b. a rotary chamber coaxially situated within said outer housing, mounted rotatably thereto having an upper and a lower end-plate; the radius of said housing being larger than the radius of said rotary, the said housing and said rotary chamber thus providing a circumferential chamber in between their walls; said housing provided internally at the levels of said upper and lower end plates with flanges, forming with said plates an upper and lower jetting containers with jet inlets; c. a first duct means including a first orifice in said housing to feed a mixture of gases into said rotary chamber through the upper end-plate thereof; d. a first jet means to jet enriched gas of a smaller mass number of said mixture of gases from the internal axially peripheral region of said rotary chamber into said lower jetting container; e. a second orifice in the lower container of said housing and a second duct means including a pressure valve connected to said second orifice to duct the enriched gas from said lower jetting container to the outside of said housing; f. a second jet means to jet depleted gas of a smaller mass number of said mixture of gases from the internal axially peripheral region of said rotary chamber into said upper container; g. a third orifice in the upper container of said housing and a third duct means including a pressure valve connected to said third ducting orifice to drain gas from said upper container to the outside of said housing; h. a fourth orifice and a fourth duct means to pull out light gas collected in the axially central part of said rotary chamber through said lower end plate and said lower container out of said housing; i. a fifth duct feeding means to feed said light gas into said circumferential chamber and from there from the upper and lower regions thereof into said upper and lower containers, respectively; j. a fifth orifice in said outer housing in the middle portion of said circumferential chamber and a fifth duct means connecting said fifth orifice with said fourth orifice.

3. A centrifuge as claimed in claim 1, each said end plate provided with an integral shaft axially protruding to the outside of said rotary chamber through a first and fourth orifice, respectively, for rotation through the said housing, and means connected to at least one of said shafts to rotate said rotary chamber.

4. A centrifuge as claimed in claim 1, the shaft of said upper plate being hollow and connected with said first duct means.

5. A centrifuge as claimed in claim 4, wherein said light gas is inert.

8. A centrifuge as claimed in claim 1, said first jet means comprising orifices spaced in said lower end-plate.

11. A centrifuge as claimed in claim 1, said third duct means comprising an evacuating pump and pressurized valve means.

14. A centrifuge as claimed in claim 1, said circumferential chamber comprising a third and fourth jet means connecting it with said upper container and with said lower container, respectively.

15. A centrifuge as claimed in claim 14, said third jet means comprising means to control the amounts of gases to be drained respectively to the outside of said upper and lower containers to be equal to each other.

17. A centrifuge as claimed in claim 1 said fifth duct including means of flowing the ducted light gas in vector directions parallel to the velocity vectors of said cylindrical surface of said rotary chamber.

20. A centrifuge as claimed in claim 1 as a first centrifuge in an assembly with several additional intermediate centrifuges and a last centrifuge, each said centrifuge as defined in claim 1, said first centrifuge functioning as a first supply centrifuge further comprising: a first source of a mixture of natural uranium hexafluoride comixed with uranium 235; a source of helium; a pressurized mixing chamber of said first mixture of gases with said helium; first conduit means to connect said mixing chamber with said first duct means; a first, a second of a plurality of successive and a last enriching centrifuge, each as defined in claim 1; said supply centrifuge having a supply joint connecting its first duct means, the duct means from said mixing chamber and the third duct means of said first enriching centrifuge, said first enriching centrifuge further comprising an enriching joint connecting said first duct means of said first enriching centrifuge with the second duct means of said first supply centrifuge and with the third duct means of the next adjacent successive enriching centrifuge, said successive enriching centrifuges interconnected in an analOgous manner, the second duct means of said last enriching centrifuge further comprising a collecting container of enriched uranium 235 gas output; a first, a second, a plurality of successive and a last recovery centrifuges, each as defined in claim 1, said second duct means of said first recovery centrifuge connecting with said supply joint, said first recovery centrifuge further comprising a recovery joint connecting said first duct means of said first recovery centrifuge with the second duct means of the successive recovery centrifuge and with the third duct means of the first supply centrifuge, said successive centrifuges interconnected in analogous manner, the third duct means of said last recovery centrifuge further comprising a collecting container of depleted uranium 235 gas output.

23. A process for separating and enriching uranium 235 in accordance with minute difference between mass numbers of isotopes using a greater number of centrifuges arranged in a cascade formation and each of which includes an outer chamber and a rotary chamber situated within said outer chamber and mounted rotatably thereto, comprising the steps of centrifuging a gas including uranium 235 and a light gas thereby separating an enriched gas of uranium 235, a light gas and a depleted gas of uranium 235 from each other into separate spatial regions lower, axially central and an upper, respectively, evacuating said light gas collected in the central region, ducting said light gas into a separate circumferential region therefrom sweeping it into an enriched gas and a depleted gas region, mixing said light gas with said enriched gas of uranium 235 and with said depleted gas of uranium 235 respectively, draining respectively said mixed gases from said different regions and thence subjecting said mixture of enriched gas of uranium 235 with said light gas to analogous subsequent centrifuging step simultaneously repeating the steps of ducting said mixture of depleted gas or uranium 235 with said light gas to a centrifuging former step, said centrifuging steps arranged in a cascade formation.

24. A process for separating and enriching mixture of gases in accordance with minute difference between mass numbers of isotopes, using a centrifuge, said centrifuge including an outer chamber and a rotary chamber situated within said outer chamber and mounted rotatably thereto; said process comprising the steps of feeding the mixture of gases with a light gas into said rotary chamber through one end plate thereof; jetting enriched gas of a smaller mass number of said mixture of gases from the internal axially peripheral region of said rotary chamber into one between said outer chamber and said rotary chamber; jetting depleted gas of a larger mass number of said mixture of gases from said internal axially peripheral region of said rotary chamber into another region between said outer chamber and said rotary chamber; pulling out the light gas collected in the center axial part of said rotary chamber through another end-plate thereof; feeding the light gas into a circumferential space between said rotary chamber and said outer chamber; sweeping said light gas into the one region and the other region; mixing said light gas with said enriched gas within said one region; mixing said light gas with said depleted gas within said other region; draining the mixed gas within one region to the outside of said outer chamber, and draining the mixed gas within said other region tO the outside of said outer chamber.

25. A process as claimed in claim 24 wherein said mixture of gases includes uranium 235 and uranium 238, and the ratio of amount of said mixture of gases and said light gas to be fed into the rotary chamber is substantially in the range of from 1 to 1 to 3.

27. A process for separating and enriching uranium 235 in accordance with minute difference between mass numbers of isotopes using a great number of centrifuges arranged in a cascade formation and each of which comprising a cycle of steps of: pressurizing said gas mixture; centrifuging said gas mixture into a first (upper) and second (lower) region; heating said gas in said first region; cooling the gas in said second region; jetting said gas from said first region into a depleted gas zone and said gas from said second region into an enriched gas zone; providing an intermediate gas zone; simultaneously centrifuging the gas from said second zone to said intermediate zone, and withdrawing gas from said lower region to said intermediate zone; withdrawing gas from said first zone; and repeating said cycle using the last mentioned step of said withdrawing said gas as the initial step of pressurizing said gas mixture in said subsequent cycle.