FR2538719A1 - Ultracentrifuge and method for making its rotor - Google Patents

Abstract

ULTRACENTRIFUGE ROTORS FOR SEPARATION OF HETEROGENOUS MIXTURES ARE MADE OF COMPOSITE MATERIALS REINFORCED WITH FIBERS ACCORDING TO THE INVENTION TO INCREASE THEIR STRENGTH. THE ENCLOSURE OF ROTOR 1 IS MANUFACTURED BY A WIRE WINDING PROCESS, A ROTOR CENTRAL BODY 10 POSSIBLY IN SEVERAL PARTS AND MADE IN REFRACTORY MATERIAL (CERAMIC) SERVING AS A CHUCK WHICH, WHILE WINDING A REINFORCING WIRE COATED, IS SUBJECTED TO A GALVANIZATION PROCESS SO THAT THE REINFORCING WIRES ARE EMBEDDED IN A METAL MATRIX.

Description

The present invention relates to an ultracentrifuge

  machine and a process for the manufacture of its rotor.

  the centrifuges are, among others, used for separating

  heterogeneous mixtures by using extremely large mass forces. Rotor casings of known ultracentrifuges are usually cold-rolled thin-walled steel or alloy tubes with

  very high specific resistance characteristics.

  In order to increase the entraining forces and consequently

  As for the separation power of the ultracentrifuges, it has been proposed to make the rotor no longer in the form of a cylinder, but in the form of a trough or trough in the marginal zone from which the centrifugal forces are considerably larger because of the more large diameter It has also been proposed to install in crs marginal areas containers

  or receptacles for the product to be separated.

  The rotors used up to now are no longer able to withstand the centrifugal forces generated by rotational speeds of the order of 75,000 rpm. The structure of their

  material breaks up and they tend to crush

  This flaring can cause bursting of the rotor which takes the form of an explosion. The dislocation of the material structure is further favored when, as a result of a considerable frictional resistance of the air being in the air. intermediate space between the rotor and the casing 9 the rotor is heated by itself or when it is known in conventional centrifuges,

  the rotor is intentionally heated to increase the power

  separation sauce (German Patent Application No. 18 1835). The rotor material of these ultracentrifuges must therefore satisfy extremely severe conditions.

  of high specific resistance to ambient temperature.

  (breaking length approx. 60 1-m), he must also

  a high specific resistance at about 1500 (breaking length about 50 km) If, as already proposed, the product to be separated is to be heated inductively, the rotor shell or other parts of the centrifuge

  in addition, a good conduictibility.

  The object of the invention is, therefore, to

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  make an ultracentrifuge capable of carrying out solid and other reactions under extreme mechanical and possibly heat conditions. It is also a question of improving the known ultracentrifuges so as to avoid the high temperatures required for their operation. -

  and jeopardize the resistance of

  necessarily. This result is achieved according to the invention in that the rotor is made using a composite material

fiber reinforced.

  In the design of ultracentrifuges, such a material has an appreciable quality in the sense that in case of overloads or hidden defects, this material, when it is subjected to the action of forcing extreme centrifugals, does not break up. explosively, but in frayed elements

consistent coherence.

  According to another particularity of the invention, the marginal zone of the rotor, which is of a larger diameter than the latter, can protrude outwardly and be made of a material reinforced with fibers present in excess quantity dental This higher proportion of fibers in the marginal area causes an increase in rotor rotor resistance

  against the centrifugal forces which exercise there.

  According to another improvement provided by the invention, the fibers reinforcing the envelope of the rotator are embedded in a metal matrix shaped by electroplastyq the envelope of the rotor can then be made in the form of a body

made by enroulemrent.

  The advantages of the invention reside, first and foremost, in the astonishing resistance characteristics of a composite material with a metal matrix.

  heat is sufficient and almost comparable to that of

  For example, the known reliability of ultracentrifuges depends on the characteristics of the material used. in

the occurrence, 1 preponderant.

  In known manufacturing processes of materials

  composites with the last metal matrix is applied

  Such impregnation processes have, however,

  time, in this case, I have the disadvantage that the liquid matrix

  acts relatively long time on the wires of the material of renbrcr-

  as a result of the impregnation temperatures

  high, this may be damaged.

  Electrolytic deposition of materials from aqueous or organic solutions only requires that

  temperatures below 100 ° C.

  Strength of reinforcement due to high temperature is therefore excluded.

  Another advantage of using composite materials

  with metal matrix deposited electrolytically

  in the combination of electrolytic molds with simultaneous coating or drowning of the wires In the composite material made in this way, the reinforcing material can in fact be

coated at the desired location.

  The invention is further characterized by the fact that the volume proportion of reinforcement yarns on the composite material of the rotor increases outwardly as the winding progresses and that in the marginal areas of the envelope of the rotor

  rotor, it is larger than at the beginning of the winding.

  The winding installation for the manufacture of

  fiber-reinforced composite materials electrolytically

  that can be achieved from already known elements and 9 be

  each time adapted to the case that presents itself Such an installation -

  lation allows, without difficulty, special services

  and by using appropriate control means, for example

  With electronic wire guiding devices, the distances separating the deposited wires can be varied so that, as the winding progresses, the interspaces between the deposited wires decrease constantly, that is to say that the proportion of the wire in the composite material increases constantly. The winding process for the manufacture of a fiber-reinforced composite mabtoriau rotor casing is advantageously carried out batchwise, since in the opposite case, that is to say in case of winding and simultaneous electroplating as the length of the winding increases, a cone-shaped structure is produced more and more

  of the matrix between the layers of wires, which

  a decrease in the volume proportion of the material

  reinforcement in the composite material.

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  According to another particularity of the invention, the method is characterized by the fact that the wire is wound

  reinforcement, preferably a resilient reinforcing

  temperature, on a multi-part mandrel, which is then subjected to electrolysis

  tick enveloping the reinforcing threads and forming the matrix

  after which unnecessary elements of the mandrel are removed, which can preferably be effected by chemical dissolution or

  by extraction of mandrels which will then be reusable.

  The inner parts of the rotor, that is to say the optionally divided and dissolvable mandrels are, according to another feature of the invention, replaced by a central body which may preferably be made of a material of which the

  coefficient of expansion is equal to or close to that of the

composite material used.

  After dissolving a mandrel or parts of it

  it is possible, according to another particularity of the process, to introduce

  a central rotor body in the coiled portion of the casing

pe of the latter.

  The construction of the rotor and its central body may be different; 3 ways According to the invention, the

  symmetrically arranged parts of the mandrel

  in the coiled portion of the rotor casing while other parts are eliminated and replaced by the body

central introduced later.

  The invention also provides for treating the reinforcing wire before winding, for example to provide it with a

  protector or guard deposited by silicon carbide diffusion

  Such a reinforcement of the reinforcing wire, preferably

  a boron wire, protects the latter against adverse reactions.

  likely to occur at operating temperatures

of the rotor.

  An ultracentxifuge carried out in this way makes it possible to solve the problems of alloying and doping, in particular if additional heating of the marginal zone of the rotor is carried out by separating the disturbing impurities and

  in addition to compacting, it is possible to realize

  Very pure materials and elements from many mixtures in the liquid state In this respect, the semiconductor industry and the production of

2538719

  industrial diamonds In addition, for example, the manufacture of hard materials such as silicate, boron ritrate, diamond, etc., can be simplified. It is also possible to prepare old metals (relycling) and obtain a clean separation of the slag and the melt. The present invention also makes it possible to better solve and update the field of diffusion kinetics. The present invention also makes it possible to carry out high-pressure synthesis experiments without having to resort to hydraulic or other conventional presses.

  The invention will be better understood with the aid of

  description of embodiments taken as e xamples, but not limiting, and illustrated by the appended drawing, in which

  FIG. 1 represents in section the rotor of a hundred

fugeuse-

  FIG. 2 is a plan view of the rotor according to FIG. 1 but without a cover; FIG. 3 also shows in plan another embodiment of the rotor test vessels.

  FIG. 4 represents in section the rotor of an ultrasonic

  centrifuge performed by the method d 2 winding-W Figure 5 is a section along V-V of Fig O 4 "

  Fig 6 schematically shows an installation

  The rotor I comprising a cover 2 is mounted rotatably about the axis 3 o It is driven by the shaft 4 connected to the driving mote-ur, not shown, and by the fingers

  5 and 6 which engage in corresponding recesses.

  correspondents 7, 8 of a metal fitting 9 embedded in the lower part of the rotor 1 Instead of the driving rules 6 and recesses 7, 89 the rotational energy can also be transmitted by means of a magnetic coupling or The rotor 1 is constituted by a central body 10 having a slightly domed bottom surface and by a

  marginal or lateral part 1 i disposed approximately parallel

  to the axis 3 of the rotor, protruding-outward and made of carbon reinforced with high-strength carbon fibers (carbon-carbon) or graphite reinforced with carbon fibers, this part being able to withstand

  both mechanical and thermal.

  The central body 10 contains test containers 12 regularly distributed over the periphery of the rotor 1. These containers are extended in the marginal or lateral part 11 and are embedded in silicon nitride or in graphite.

  In the example shown, these test containers 12 con-

  hold cylindrical containers 14 platinum sheet or other high-melting and non-reactive material, receptacles where the materials to be centrifuged to extract them after the completed operation O The connection between the central body 10 and the marginal or lateral portion 11 can be performed simultaneously during graphitization, that is to say during the manufacture of the composite material for the marginal or lateral portion 110 For the manufacture of the central body 10 and the test vessels 12 with the receptacles 149 it is advantageous

  to use materials that have about the same co 9 ffi-

  Expansion cients that the fiber-reinforced composite material used for the marginal or lateral portion 110 The test vessels can be made under

  various forms Figure 3, for example, represents, in

  in the central body 10 of the rotor 1, four test vessels 15 of greater capacity and having a surface

wider background.

  Fig 4 shows the rotor 1 made by the winding method This rotor is driven by the shaft 4 connected to the drive motor, not shown? and by-fingers

  5 p 6 training which engage in corresponding recesses.

  79 8 of a metal insert 9 embedded in the

  lower part of the rotor 1 Instead of these fingers of drive-

  59 6 rotational energy can also be transmitted

  by means of a magnetic coupling or the like.

  The rotor 1 according to FIG. 4 consists of a body

  central part 20 in several parts made of a ceramic material

  that or similar and by a marginal or lateral part 11

  protruding outwards and made of a composite material

  fiber reinforced with metal matrix.

  FIG. 5 is a plan view representing the rotor 1 in section along VV of FIG. 4. The central body 20 is here produced in the form of a mandrel comprising a plurality of parts 21, 22, 23, etc. constituted by materials which , after

  winding construction: of the marginal or lateral part

  Fiber-reinforced web 11 may be wholly or partly removed or chemically dissolved and replaced by a central body remaining in the rotor and optionally in several parts. As can be seen from FIGS. 4 and 5, on the periphery of the rotor 1 there are arranged regularly distributed test containers 12. These test containers 12 extend in the marginal or lateral part 11 and are, in the embodiment illustrated represented with cylindrical receptacles 14 platinum sheet or other material with high melting point and non-reactive It is in these receptacles that place

  the materials to be centrifuged to extract them after the

  tion. For the construction of the central body 20 or the test vessels 12 with the receptacles 142 it is advantageous to use materials having about the same coefficients of expansion as the fiber-reinforced composite material used for the construction of the marginal or lateral part. 11 o

  For the manufacture of the lateral part 11, it is

  the installation of winding and immersirn shown schematically

  tically in FIG. 6 and made of known elements, installs

  in which the multi-part mandrel 20 to be wound is attached to the end of an oscillating arm 24 o The oscillating arm 24 carries, in addition, the drive unit, not shown, for the winding mandrel and can by means of a worm gear 25 driven by a motor 32, to be immersed in a tank 26 containing the electrolyte O In mechanical connection with the oscillating arm 24 is a conventional layered winding apparatus comprising a coil 28 , a slide 29 and a device

  tensioner 30, apparatus serving as a supplier for the reinforcement thread

  31 and allowing the adjustment of the respective distances

  between the different turns of the wire to be deposited on the mandrel 20.

  The apparatus 27 for windings in layers is arranged on a base 33 which is adjustable in height. The wire brake belonging to the winding apparatus may, for example, be of the F 9 M 2 type of the firm ETS Parvex, Dijonq, France, using licences

  U.S. Patent Nos. 3,090,880 and 3,144,574.

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  -To satisfy the imposing requirement, in the external areas of the envel, ppt, a growing proportion of the wire '

  reinforcement 31 on the composite material it is necessary that the

  Above 2 years Electrolytic debiting of the electrodes is carried out alternately. Simultaneous winding and deposition of the core is also possible but only

  have extremely low current densities (0.1 A / dmr 2).

R'ENVDICAT IONS

  1 Ultra-centrifuge characterized by the fact that the rotor is made using a reinforced zomtosite material

of fi Dres.

  2 Ultracentrifuge according to claim 1, characterized in that the marginal zone of the rotor is greater than the diameter of the latter protrudes outwardly and is constituted by a fiber-reinforced composite material present in excess of 3 Ultracentrifuge according to claims 1 and 2 caraoterized by the fact that, as my-terilau ocmposite,

  uses carburetted carbon fiber (carbon-carbon).

  4 Ultracentrifuge according to any one of

  Claims 1 to 3, characterized in that the fibers

  reinforcing the rotor envelope are embedded in a metal matrix applied by electroplasty Ultracentrifuge according to any one of

  Claims 1 to 49, characterized by the fact that the envelope

  the rotor is in the form of a winding body.

  6 Ultracentrifuge according to any one of the

  1 to 5, characterized by the fact that the volume proportion of the reinforcing fibers on the rotor composite material increases outwardly as the winding progresses and in the marginal areas of the envelope. of

  rotor is larger than at the beginning of the winding.

  7 Ultracentrifuge according to any of the

  claims 1 to 69 because of the fact that

  internal rotor constituting a central body preferably consisting of a material whose dilatatiorn coefficient is equal to or approximately equal to that of the composite material

refilled fiber used.

  R Process for the manufacture of the rotor of a

  Itracentrifuge according to any one of the claims

  1 to 7, characterized by the fact that the wire reinfo: _e-

  Preferably, a heat-resistant reinforcing material, on a multi-part mandrel, is then subjected to the winding, a galvanization wrapping the reinforcing threads and constituting the matrix, after which it is lifted.

  the elements of the mandrel become useless.

  9. Process according to claim 89, characterized by the fact that the elements of the mandrel are extracted by chemical dissolution.

  Process according to any one of the claims

  1 to 99 characterized by the fact that a central body is introduced

  rotor in the coiled side of the rotor.

  Process according to any one of the claims

  1 to 10, characterized by the fact that, as test vessels, symmetrically arranged elements of the mandrel are used

constituting the central body.

  Process according to any one of the claims

  1 to 11, characterized by the fact that, as mandrel, a profiled element consisting of a heat-resistant material is used and which remains permanently in the wound part of the envelope

  13 o Process according to any one of the claims

  1 to 12, characterized by the fact that before winding, the reinforcing thread is treated, for example it is provided with a layer

  protector deposited by diffu 4 ion silicon carbide.