US3269546A

US3269546A - Apparatus for fractionating fluids

Info

Publication number: US3269546A
Application number: US283111A
Authority: US
Inventors: Kainz Anton
Original assignee: INTERNAT RES ESTABLISHMENT
Current assignee: INTERNAT RES ESTABLISHMENT; INTERNATIONAL RESEARCH ESTABLISHMENT
Priority date: 1963-05-24
Filing date: 1963-05-24
Publication date: 1966-08-30
Anticipated expiration: 1983-08-30

Description

Aug. 30. 1966 A. KAlNz APPARATUS FOR FRACTIONATING FLUIDS 5 Sheets-Sheet l Filed May 24. 1963 QQ D Umm Mm. imm Ema..

GQ Q E mm, Gm, @m,

um m INVENTOR.' Anfon Kainz Attorney Aug. 30, 1966 A. KAlNz APPARATUS FOR FRACTIONATING FLUIDS 5 Sheets-Shree?. 2

Filed May 24, 1963 Anfon Kainz 1N VENTOR.

Attorney Aug. 3o. 1966 A. KMNZ 3,269,546

APPARATUS FOR FRACTIONATING FLUIDS Filed May 24. 1963 3 SheecS--SlxeefI 3 Anfon Kainz INVENTOR.

t 3,269,546 ce Patented August 30, 1966 y 3,269,546 APPARATUS FOR FRACTIONATHNG FLUIDS Anton Kainz, Vienna, Austria, assignor to International Research Establishment, Vaduz, Liechtenstein Filed May 24, 1963, Ser. No. 283,111 9 Claims. (Cl. 210-377) The present invention relates to an apparatus for separating fractions of different specific weight from liquids r gases, e.g. aerosols, emulsions, aqueous solutions and other nonhomogeneous fluids.

When a fluid containing particles of different specific Weight is propelled at high velocity in a concentrated jet, the lighter particles will tend to stray off course more readily than the heavier ones so that, by a repeated interception and channeling of the particles constituting the central region or core of the jet, an increasing proportion of the heaviest particles will be recoverable from the fluid stream. With a sufficient number of intercepting and channeling nozzles disposed in cascade, a substantially pure stream of heavy particles along with a residual fluid mass virtually free from such particles can be simultaneously recovered in different collectors.

Earlier attempts at utilizing this principle for the separation of fluid fractions have not, however, been very successful on account of the limited efficiency of the propulsion systems lavailable for accelerating the fluid. Itis, therefore, the general object of the present invention to provide a new and improved apparatus for fractionating fluids by the aforementioned principle.

In accordance with the instant invention there is created a continuous flow of the fluid to be fractionated, this flow being set in rapid rotation about an axis located in the vicinity of the source of fluid supply. The resulting centrifugal force derives the fluid particles radially outwardly in and close to a transverse plane whose location is determined by the position of the point of supply, the heaviest particles tending to remain near that plane while the lighter ones will gravitate away from it to a greater or less extent. At progressively greater distances from the axis, within a zone of predetermined radius in which the fluid is subjected to the rotating force so that its radial velocity continues to increase, the particles in the viciniy of the aforementioned transverse plane (which defines the core of the fluid flow) are successively intercepted and channeledl further along that plane, the particles escaping interception being generally lighter than those which are forcibly brought back into line with the original path whereby the aforedescribed segregation of fractions of different specific weight will occur.

An advantageous device for carrying out the above method comprises, in accordance with another feature of the invention, a rotatable carrier on which a plurality of nozzles are supported for the purpose of intercepting and channeling the particles of a fluid streaming radially outwardly along the carrier surface. This carrier preferably includes a pair of closely spaced disks between which the nozzles extend in a generally peripheral direction; these nozzles may, for example, be in the form of concentric rings, successive turns of a spiral or segments of such rings or turns. For maximum efficiency it is desirable to provide each nozzle with an elongated slot having a flared inlet which converges in a radially outward direction, the width of the nozzle lat its narrowest point being advantageously of the order of microns. For relatively large fractions, e.g. in the separation of minerals from salt water, slot widths up to microns have been found suitable; for smaller particles, as for example in the separation of heavy water from ordinary water, widths of approximately 1 to 7 microns are preferred.

The presence of two closely spaced rotating disks creates CII a definite Zone within which rotation is positively imparted to a stream of fluid issuing in the region of the disk axis with the result that an accelerating force acts upon the fluid particles throughout the entire fractionating process. The system is, therefore, capable of operating very efficiently and of being extended to any desired number of cascaded nozzles, depending upon the degree of purity desired in the final product. Suitable operating speeds range upwardly of about 10,000 r.p.m. and may go as high as several hundred thousand rpm., a speed of 100,- 000 to 200,000 r.p.m. being preferred in most cases. To facilitate the operation at such high rotary speeds, air bearings of a type known per se may be used to support the rotating system.

The invention will be described hereafter in greater detail with reference to the accompanying drawing in which:

FIG. l is a partly diagrammatic view of an apparatus according to the invention, shown in axial section;

FIG. 2 is a perspective detail View illustrating part of a nozzle of the apparatus shown in FIG. 1;

FIG. 3 is a face view, partly in section on the line III- III of FIG. l, of the rotatable nozzle carrier constituting part of the apparatus; and

FIGS. 4 and 5 are fragmentary views similar to FIG. 3, illustrating certain modifications.

The apparatus shown in FIGS. l-3 comprises a shaft 10 rotatably journaled in air vbearings 11, 12. A thrust bearing 13, also of the air-cushion type, resists axial displacement of the shaft 10 as the latter is vbeing rotated by a suitable driving mechanism such as a gas turbine here schematically represented by a set of vanes 14. The air bearings 11-13 receive compressed air via respective supply tubes lla, 12a, 13a in order to maintain the rotating shaft out of contact with any solid surface, e.g. in the manner described in U.S. Patent No. 2,660,484; the bearing 11 and 12 could, however, also operate without a supply of compressed air in accordance with the principle disclosed in U.S. Patent No. 2,879,111. The turbine 14 may develop a speed of, say, 10,000 to 400,000 r.p.m.

Fixedly secured to shaft 10, for rotation therewith, is a carrier 15 comprising two closely spaced inner disks 16', 16" flanked by two outer plates 17', 17" which are approximately coextensive therewith. The members 16', 16", 17', 17 are supported on the shaft 10 with the aid of a solid hub 20 against which the plate 17' rests, this plate being separated by an annular spacer 21 from the adjoining disk 16' which in turn is clamped .between this spacer and a second, similar spacer 22 in contact with a washer 23. The

entire assembly

20, 17', 21, 16', 22, 23 is held in place by two

sleeves

24, 25 which are press fitted, welded or otherwise secured to the shaft 10. The other disk 16" rests -against a flange 26a of a tubuIar hub 26, 4of frusto-conical configuration, whose inner surface converges toward an open mouth 2Gb at the end opposite flange 26a; hub 26 is mounted on the ring member 22 by circumferentially spaced brackets 27 which maintain a small annular clearance between this ring member and the flange 26a, that clearance constituting an outlet gap for the discharge of a fluid into the space encompassed by the disks 16', 16". The fluid to be fractionated is aspirated into the interior of hub 26 from a convenient source, not shown, by way of a supply pipe 28 opening freely into that hub.

The annular gap defined by the spacer 22 and the flange 26a constitutes the first of a series of concentric and copla-nar slots through which the aspirated fluid, or at least the heaviest fraction thereof, must pass on its way toward the periphery of the carrier 15 along which it is propelled by centrifugal force. The other slots are formed by an array of concentric annular nozzles 29a,

3 29b, 29C, 29d, 29e, 29j disposed between the disks 16' and 16". Each of these nozzles, as illustrated for the one generally designated 29 and shown in part in FIG. 2, consists of two coextensive rings 29', 29 spaced apart by a small distance d to form an annular slot 30. The rings 29', 29" are provided with triangularly profiled inner edges 31', 31" defining a ared inlet 31 for the slot 30, this inlet converging in radially outward direction so that all particles arriving at the nozzle 29 are either intercepted and channeled into the slot 30 or deviated outwardly via inclined exit ports 32', 32" in disks 16', 16" (FIGS. 1 and 3) into one of two lateral compartments 33', 33" formed between the disks `and the adjoin ing plates 17', 17". With the particular arrangement illustrated in FIGS. l and 2, each nozzle will intercept those particles which in their random lateral motion will have strayed from the common plane P of the slots by not more than half the distance of that plane from either disk surface. The last nozzle 29,7c differs from the preceding ones in that its slot widens outwardly into a peripheral clearance 34 through which the intercepted particles may pass out of the fractionating zone between the disks 16', 16" and into a stationary annular trough 35 serving as a collector for the heaviest fraction which can thus be recovered through a pipe 35a; a similar stationary collector 36, with discharge pipe 36a, surrounds the plates 17', 17" for the recovery of the remaining, lighter fraction or fractions from the compartments 33', 33" which these latter fractions leave through annular clearances formed between outwardly flared marginal zones 17a', 17al of plates 17', 17" and similarly inclined peripheral extensions 16a', 16a" of disks 16', 16". Angularly spaced shims 37 in the clearance 33 help maintain the desired distance d between the rings 29',

Operation In operation, the centrifugal effect of rotation of the shaft 10 and its carrier 15 at the high speeds indicated results in a displacement of air in the region of the gap between the plates 17' and 17" so that the fluid to be subjected to fractionation is drawn into the hub 26. The hub 26, as has previously been noted, is provided with a clearance between the ring member 22 and the flange 26a from which this fluid emerges into the compartment inwardly of the nozzle 29a. The heavier particles of this fluid, because of their greater inertia and momentum, pass between the ared lips of the nozzle 29a and thence through the slots thereof into the next compartment forwardly of the nozzle ring 29h. The lighter particles, however, which are defiected from the plane of the slots because of their lesser inertia and the greater tendency of such particles -to migrate, are diverted outwardly by these same lips and pass through the ports 32' and 32" in the disks 16' and 16" and are accumulated in the compartments between these disks and the plates 17' and 17". This process continues through the number of fractionation stages equal to the number of nozzles and associated ports 32', 32". The heavy fraction is then drawn off at 35a after passing successively through the nozzles whereas the light fraction is recovered ait-36a and is accumulated from these ports.

FIG. 4 illustrates a modified system according to the invention in which the disk 116', rotating on shaft 101 in the direction of arrow A, carries a spirally shaped ffuid-intercepting strip 129 whose construction and prole are substantially identical with those of the double ring 29 (FIG. 2) whereby it forms a narrow passage slot in the median plane between the disk 116' and its companion disk (not shown), the strip 129 extending from the fluid-dispensing hub 126 to the periphery of the disks so that its individual turns constitute a series of nozzles successively encountered by the radially outwardly propelled fluid (arrows F). In FIG. 5 a somewhat similar arrangement is shown except that the disk 216', rotating on shaft 201 in the direction of arrow B, carries a solid rib 240 of spiral configuration whose convolutions define a spiral fluid channel obstructed, at progressively increasing distances from the disk axis, by a plurality of cascaded arcuate nozzles 229e, 22911, 229C, etc. of the 4general structure previously described; the fiuid issuing from hub 226, though again moving radially in space, has a motion relative to the guide rib 240 substantially as indicated by the arrows G so as to be successively intercepted by the nozzles 229a etc. in the manner and for the purpose set forth above. It will be noted that the arcuate nozzles shown in FIGS. 4 and 5, while not precisely centered on the axis of rotation, still extend in a generally peripheral direction, in substantially the same manner as in the embodiment of FIGS. 1-3. Naturally, the remainder of the carrier structure in the systems of FIGS. 4 and 5 may be identical with .that of the first embodiment.

The nozzle-forming rings, ring segments, spirals etc. (such as the elements 29.', 29" in FIG. 2) may be secured to their respective disks by any convenient means or may be integrally cast or molded therewith. Further modifications of the arrangements specifically described and illustrated are, of course, possible without departing from the spirit and scope of the disclosed invention as defined in the appended claims.

What is claimed is:

1. An apparatus for separating fractions of different specific weight in a fluid, comprising a carrier rotatable about an axis; discharge means on said carrier `in the region of said axis, said discharge means being connectable to a source of fluid to be fractionated and being provided with at least one outlet directed radially away from said axis; a plurality of nozzles on said carrier positioned at increasing distances from said axis for successively receiving particles of uid from said outlet, each of said nozzles being provided with an `arcuate elongated slot extending in generally peripheral direction over a substantial arc length across the path of fiuid issuing from said outlet, the slots of all said nozzles lying in a common plane transverse to said axis and having flared inlets converging in a radially outward direction; and drive means for rotating said carrier about said axis at a speed giving rise to a centrifugal force sufficient to drive fiuid particles of a predetermined minimum specic weight from said outlet through all said nozzles in cascade.

2. An apparatus as defined in claim 1 wherein said nozzles are in the shape of concentric rings.

3. An apparatus as defined in claim 1 wherein said nozzles are successive turns of a continuous spiral.

4. An apparatus as defined in claim 1 wherein said carrier includes guide means forming a channel leading away from said outlet, said nozzles extending across said channel.

5. An apparatus as defined in claim 1 wherein said slots at their narrowest poi-nt have a Width of substantially l to 20 microns.

6. An apparatus for separating fractions of different specific weight in a fluid, comprising a pair of parallel disks rotatable about an axis; discharge means between said disks in the region of said axis, said discharge means being connectable to a source of fluid to be fractionated and being provided with at least one outlet directed radially away from said axis; a plurality of nozzles between said disks positioned at increasing distances from said axis for successively receiving heavier particles of fluid from said outlet, said nozzles each being provided with an elongated arcuate slot extending in generally peripheral direction across the path of fluid from said outlet, the slots lying in a common plane for channeling said particles along a predetermined path, said disks being provided with exit ports just ahead of said nozzles for axially deviating lighter particles; and drive means for rotating said disks about said axis at a speed giving rise to a centrifugal force suicient to drive lluid particles of a predetermined minimum specific weight from said outlet through all said nozzles in cascade, said disks forming part of a carrier further including a pair of plates on opposite sides of said disks and substantially coextensive therewith, said plates being axially spaced from the `adjoining disks and forming therewith compartments for lighter particles deviated outwardly through said ports.

7. An apparatus .as defined in claim 6 wherein said compartments are peripherally open, further comprising first collector means surrounding said carrier for receiving said lighter particles therefrom, and second collector means for said heavier particles adjoining the peripheries of said disks.

8. An apparatus as dened in claim 6 wherein said disks are provided with a common shaft, further comprising airbearing means supporting said shaft for rotation by said drive means, said drive means including tur- 6 bine means on said shaft adapted to impart thereto rotary speeds upwards of substantially 10,000 rpm.

9. An apparatus as defined in claim 6 wherein said discharge means comprises Ia tubular'hub on one of said disks, said hub terminating -in an annular gap between said disks constituting said outlet, said hub having an end remote from said gap open into the atmosphere and an inner wall surface converging from said gap toward said open end.

References Cited by the Examiner UNITED STATES PATENTS 2,422,464 6/ 1947 Bartholomew 210--78 X 2,660,484 1l/1953 Gerard et al 308-9 2,893,629 7/1959 Darnell 233-27 FOREIGN PATENTS 606,777 10/ 1960 Canada.

7,346 1894 Great Britain. 839,622 6/1960 Great Britain.

REUBEN FRIEDMAN, Primary Examiner.

J. L. DE CESARE, Assistant Examiner.

Claims

1. AN APPARATUS FOR SEPARATING FRACTIONS OF DIFFERENT SPECIFIC WEIGHT IN A FLUID, COMPRISING A CARRIER ROTATABLE ABOUT A AXIS; DISCHARGE MEANS ON SAID CARRIER IN THE REGION OF SAID AXIS, SAID DISCHARGE MEANS BEING CONNECTABLE TO A SOURCE OF FLUID TO BE FRACTIONATED AND BEING PROVIDED WITH AT LEAST ONE OUTLET DIRECTED RADIALLY AWAY FROM SAID AXIS; A PLURALITY OF NOZZLES ON SAID CARRIER POSITIONED AT INCREASING DISTANCES FROM SAID AXIS FOR SUCCESSIVELY RECEIVING PARTICLES OF FLUID FROM SAID OUTLET, EACH OF SAID NOZZLES BEING PROVIDED WITH AN ARCUATE ELONGATED SLOT EXTENDING IN GENERALLY PERIPHERAL DIRECTION OVER A SUBSTANTIAL ARC LENGTH ACROSS THE PATH OF FLUID ISSUING FROM SAID OUTLET, THE SLOTS OF ALL SAID NOZZLES LYING IN A COMMON PLANE TRANSVERSE TO SAID AXIS AND HAVING FLARED INLETS CONVERGING IN A RADIALLY OUTWARD DIRECTION; AND DRIVE MEANS FOR ROTATING SAID CARRIER ABOUT SAID AXIS AT A SPEED GIVING RISE TO A CENTRIFUGAL FORCE SUFFICIENT TO DRIVE FLUID PARTICLES OF A PREDETERMINED MINIMUM SPECIFIC WEIGHT FROM SAID OUTLET THROUGH ALL SAID NOZZLES IN CASCADE.