JPS60137424A - Method and device for separating molecule and isotope - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molecular and isotope fractionation and an apparatus for carrying out the method.

Conventionally, several methods for separating molecules and isotopic mixtures are in the public domain, particularly for isotopes and more particularly uranium, which involve diffusion through tuyeres (Tevrel) in a gas phase in a suitable apparatus. This may be done by centrifugation or other means.

Gas diffusion methods are based on velocity differences in the flow path of gaseous fluids through porous walls. This method has the disadvantage of high energy consumption and the need for large equipment.

In gas phase centrifugation methods, fractionation is achieved through a centrifugal force field to concentrate the heaviest components in the system within the widest radial area. However, in addition to the high energy consumption, expensive and complex equipment is required in this case, and the rotor of the centrifuge must always be lowered into the magnetic field. The centrifuge has a cylindrical thin-walled rotor that rotates inside the shell at a speed close to 400 meters per second (mts/B6o). The gas feed is injected into the rotor near the center and its products and residues are continuously discharged through the upper and lower sections, respectively. The method of separation carried out by means of tuyeres (tewels'E or tuyeres) states that proper design, balancing and maintenance of the rotor in this type of equipment are severe and difficult to solve problems. is based on diffusing a gas flow extending through a curved wall.

In practice, this method is regulated by the large number of micrometer-level precision tuyeres required for a given device, resulting in complexity and expense. In addition to this, this type of device requires the use of large amounts of energy to recompress the gas, which is diffused at each separation stage to balance losses caused by viscous friction. Although the development of this method is known to achieve cost reduction, it cannot be used on a large scale.

French Patent No. 7,552,646 discloses a cylindrical container having a gas mixture source with pressure on the side thereof, a number of injection openings communicating with the inside of said container, and an initial gas mixture escaping through at least one extraction opening. A device is described which is characterized in that it has housing means for the parts.

The method for separating gases, which is the object of the present invention, is based on subjecting the gas mixture to be separated to a separation process using a hydrodynamic device without moving parts; or more non-radial tuyeres at high or different speeds, preferably at the speed of sound or at least close to the speed of sound, into chambers of variable or constant cross-section, preferably circular or cylindrical-conical axes, preferably cylindrical The process involves introducing the fluid into the shape development section and giving the fluid a helical path within the chamber.

In this way, the masses, forces and fields appearing in the fluid while in motion are continuous or partially continuous, with bending and/or spiral and/or straddling circular trajectories and/or combinations thereof. A curve is used to induce the separation phenomenon.

The invention also includes various apparatus for carrying out the above-described method.

The method according to the invention comprises: ta) passing the gas mixture through one or more tuyeres in a direction determined together with the radius of the chamber at 60° and 12C;
F' or more particularly at an angle of about 90°, injecting into a substantially cylindrical chamber at high speeds, preferably sonic speeds or different speeds; giving a path, the outer boundary part of which moves around the fine of the chamber along its cylindrical wall, said outer part being enriched and circulated by the heavier components by means of the centrifugal force generated as described above. The inner boundary of the gas stream is enriched with the lighter components of the mixture; (C) the inner boundary of the close circulation flow of the chamber is subjected to further acceleration caused by the combined action of aerodynamic elements; withdrawn through holes arranged on the adjacent inner surface of said element; the circulating flow near the axis, where the lightest component of the mixture is already enriched, is accelerated by the aerodynamic element, and the centrifugal force field increases. , and said flow is further enriched in the lightest component in a smaller radius section; this central flow section penetrates into the region located between said elements and is thus separated by a pressure difference across the holes; (d) Through a second nitrogen outlet arranged in the opposite circumferential part of the chamber, the outer boundary part enriched with the relatively heavier components of the gaseous stream is withdrawn; It is characterized by

More particularly, the method according to the invention features molecular and isotopic fractionation of a gas mixture in a fractionation chamber, the method comprising: (1) passing the gas mixture through one or more non-radial tuyeres; (11) giving said gas mixture a helical path in said chamber; 01υta+ causing a pulsating flow with non-static continuously varying pressure and velocity; (Dl to guide the lightest part of the gas mixture; prevent the free circulation of the mixture by means of aerodynamic elements; (■ withdraw said part separately from said chamber;
It consists of VI.

The method described above can be carried out in several types of suitable equipment.

The accompanying drawings depict in an illustrative manner only an apparatus that can be used to carry out the method according to the invention.

FIG. 1 shows a device comprising a generally cylindrical tube 1 having two axially extending aerodynamic profile tubes indicated at 3; Gas injection tuyere 2
and an outlet channel 5 through which the molded portion of the component is discharged.

Submerged internal piping 6 for withdrawing the fluid enriched with the lightest mixture component from the upper and/or lower lid of the cylindrical tube.
There is.

The profile tube 3 in the inner part of the cylindrical tube is provided with holes 4 for admitting light gas into the profile tube.

FIG. 2 shows a device in which an intermediate tube 8 is inserted between two profiled tubes 3, the intermediate tube 8 being provided with holes 9 for the outlet of light gases. In the embodiment of FIGS. 1 and 2, the fluid passes through the tuyere 2 in such a way that a high velocity is obtained at the throat of the tuyere 2, non-radially, for example tangentially with respect to the cylindrical tube. It is injected into a curved projectile trajectory with an identical profile along the entire length of the cylindrical tube.

This injection is finally combined with withdrawal in the outlet channel, ensuring restoration of the helical hydrodynamic configuration concentric with the axis of the cylindrical tube.

The centrifugal force generated tends to concentrate the lightest components of the gas mixture near the axis of the chamber and the umbrella components near the walls of the chamber. In the helical morphology produced, the principle of conservation of angular momentum demonstrates an increase in tangential velocity with decreasing radius, and the increase in tangential velocity is due to the radial gradient of the tangential force and It creates a corresponding radial force gradient that pulls the fluid toward the center of the cylindrical tube. The fluid carrying out a layered helical movement in the proposed device is drawn in the central part of the chamber by means of the profiled tubes 30 and by the suction transmitted through the holes in the intermediate region between the two profiled tubes. It will be further accelerated.

The fluid from said central part is separated by the Coanda effect occurring along the profiled tube, while the pressure gradient induced by suction advantageously controls the corresponding boundary layer phenomenon. Under these conditions, the lightest part is hole 4 (
(in the device shown in FIG. 1) and through hole 9 (in the device shown in FIG. 2). The severe portion advances to match its helical projectile trajectory, and successive encounters with the deformed tube repeat the above-described separation. The central pipe in FIG. 2 is provided with an outlet pipe 10 for the light section.

In FIG. 5, four profiled tubes are indicated at 11-14, respectively, through which fluid is injected into seven chambers 16 through the injection tuyeres and withdrawn through holes 24.

Of course, FIG. 5 shows an embodiment with more than two profiled tubes; for example, three profiled tubes could also be provided.

FIG. 6 shows a device provided with one or more tuyeres a and an optional lining C. This lining serves the sole purpose of matching the inlet pressures in each panel.

The following describes an experiment conducted using a tube having a core with an aerodynamically deformed tube as shown in FIG. The hydrogen/methane mixture is fed into a flow path through the device and the gas at both outlets is gas chromatograph Parian (V
arian) 1800.

Changes in the peak areas corresponding to hydrogen and methane serve as an indicator of composition changes. The result is as below
Met. R represents the relationship, and the subphase numbers 1 and e refer to the inlet and outlet, respectively (at the outlet, high molecular weight components are expected to be concentrated): (2.5 and 2 atm (-tm), respectively) ) Experiment 1 Ri = 4.7 Re = 6.9 Difference = 22% Experiment 2 Ri = 4.6 Re = 4.1 Difference = 12% As shown in Figures 1 and 2 In the device, piping 6
It should be noted that and 10 are in no way essential and can be omitted and in their place an opening can be provided in the corresponding face or base of the cylindrical tube 1 concentrically with the profiled tube or intermediate tube 8. It is.

[Brief explanation of the drawing]

FIG. 1 shows an apparatus in which the most constituent part of the mixture to be separated is sucked through two aerodynamically profiled tubes, the corresponding holes of which are located in the internal central part of each profile tube. FIG. 2 shows a device similar to that of FIG. 1 in which suction takes place through a central tube provided with holes, which tube is inserted between two profiled tubes; FIG. 61
Figure 4 shows the movement of fluid in the apparatus shown in Figure 2; Figure 5 shows the movement of fluid in the apparatus shown in Figure 1; 6 is a cross-sectional view of fluid movement; FIG. 6 shows a device provided with one or more tuyeres and an optional lining; FIG. DESCRIPTION OF SYMBOLS 1... Cylindrical tube, 2... Gas injection tuyere, 3... Aerodynamic profile tube, 5... Outlet channel, 8... Intermediate tube. Agent Akira Asamura

Claims (1)

[Claims] (1) A method for molecular and isotopic fractionation of a gas mixture in a separation chamber, comprising: passing the gas mixture through one or more non-radial tuyeres; (11) give said gas mixture a helical path in said chamber; (11υ(a) create a pulsating flow with a non-static continuously varying pressure and velocity; (b) ) guiding the lightest part of the gas mixture; (C) separating said lightest part; (dJ controlling the inner boundary layer of said part to avoid turbulence; above (a) to (d)' preventing the free circulation of said mixture by means of aerodynamic elements in order to
+ Separately pull out the part from the chamber;
A method for molecular and isotopic fractionation of a gas mixture, characterized in that it consists of zelkova. (2) a compartment equipped with one or more tuyeres for introducing the gas mixture and aerodynamic elements to create a pulsating flow and guide the lightest part of said gas mixture; Molecules and isotopes, characterized in that they have means for imparting a helical path to said gas mixture by means to separate said portions and control an inner boundary layer, and means for separately withdrawing said portions from said chamber. Body sorting device. (3) % Permissible A separation device according to claim 2, characterized in that the separation device includes tuyeres for introducing the gas mixture. (4) A separation device according to claim 2, characterized in that the separation device includes two or more tuyeres for introducing the gas mixture. (5) According to any one of claims 2 or 3, the aerodynamic element is a hollow air space provided with an opening for withdrawing the most part of the gas mixture. A sorting device characterized by a mechanically deformed tube. (6) % Allowance The sorting device according to any one of claims 2, 6, or 5, wherein the aerodynamic element is two or more irregularly shaped tubes. . (7) In the recitation of any one of claims 2 or 6, the aerodynamic element comprises two tubes having a central tube inserted between a plurality of deformed tubes and provided with an opening. A sorting device characterized in that it is one or more irregularly shaped tubes.