US3076547A - Sonic apparatus for material separation - Google Patents

Description

Feb. 5,: 1963 A. G. Booms, JR 3,076,547

SONIC APPARATUS FOR MATERIEL SEPARATION Original F d Sept. 29. 1959 2 Sheets-Sheet l Fil-'-':'l-:::i;

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SONIC APPARATUS FOR MATERIAL SEPARATION Original Filed Sept. 29. 1959 2 Sheets-Sheet 2 IN VEN TOR. N

United States Patent 3,076,547 SONIC APPARATUS FOR MATERIAL SEPARATION Albert G. Bodinc, Jr., Sherman Oaks, Calif. (3300 Cahuenga Blvd., Los Angeles 28, Calif.)

Original application Sept. 29, 1959, Ser. No. 843,269.

Doitgged and this application Oct. 5, 1960, Ser. No.

2 Claims. (Cl. 20920) This invention relates generally to material moving and/ or separating apparatus operating by sonic principles, and has application in a number of fields, including, among others: classification and separation of granular materials of different densities, or particle size, for example, separation of metals from ore.

A general object of the invention is to perform such functions and operations through use of propulsive forces generated in simple acoustic apparatus in which powerful acoustic standing waves of high acceleration factor are maintained.

The invention in its various aspects depends upon materials motivating forces occurring between the nodes and anti-nodes of an acoustic standing wave. These forces operate differentially, in apparatus according to the invention, or particles of different densities and/ or particle size. Apparatus in accordance with the invention utilizes such forces to separate or classify heterogeneous mixtures of materials of different densities and/or particle size, for example, metals from ores.

In addition to the motivating force, and apparently of equal importance, is a particle agglomerating compulsion which arises by reason of wave action on the material. The oscillation of the particles of the material owing to this wave action occurs with an acceleration many times that of the acceleration of gravity, causing particles of like density to agglomerate. The agglomerated body of like-density, particulate material is then readily separated out of the carrier material. Such body travels longitudinally of the standing wave under the influence of the above-mentioned propulsive force between nodes and anti-nodes, and tends also to separate out of lighter carrier material by gravity. The over-all propulsive and separative force availed of by the invention is thus the resultant of both physical phenomena.

With this brief preliminary discussion in mind, the invention may best be further described in connection with the following detailed description of a number of typical forms and embodiments thereof, reference for this purpose being had to the accompanying drawings, in which:

FIG. 1 is a vertical medial section of a form of the invention;

FIG. 2 is a top plan view of the apparatus of FIG. 1; and

FIG. 3 is a section on broken line 33 of FIG. 1.

In FIGS. 1 to 3 is shown a species of sonic separator in accordance with the invention designed to carry out my sonic process of separating metallic constituents from ore which has been reduced to a granular state. The apparatus heredisclosed was specifically designed for and has demonstrated substantial effectiveness in the separation of uranium salts from ore. However, while I will refer to such materials hereinafter, no limitation thereto is to be implied.

A generally cylindric vessel 10 is provided, having an outer imperforate side wall 11, and an inner perforated wall 12 annularly spaced inside the wall 11. Wall 12 defines the side of an annular treatment chamber 13. The annular space between Walls 11 and 12 is packed with sound absorbent material, such as fibreglass packing 14. A ring-plate 15 is welded to the lower edges of plates 11 and 12, and immediately below plate 15 is a similar ring-plate 16. These ring-plates project outwardly beyond side wall 11, providing flanges which are bolted together, as indicated. The vessel is supported by legs 17 engaging under and welded to plate 16. A cylindric wall 18, of the same diameter as wall 11, extends downwardly from ring-plate 16 immediately inside legs 17, being welded at the top to member 16. A bottom ringplate 19 is welded to and extends inwardly from the lower edge of wall 18 and a perforated frusto-conical wall 20 is welded at the top to the inner edge of ring 16, and extends downwardly and inwardly therefrom to meet the inner edge of ring-plate 19, as shown best in FIG. 3. Fibreglass sound absorption packing 21 is placed in the annular space defined by the members 16, 18, 19 and 20, as indicated. Secured to the inner periphery of ring-plate 19 is a frusto-conical wall 22 forming a continuation of wall 20, to which is joined a materials outlet and air inlet tube 23. A frusto-conical wall 24 is mounted slightly inside perforated wall 20, and shields the latter from downwardly discharging material.

Welded to the top of walls 11 and 12 is a ring-plate 26, engaged by a ring-plate 27 of the removable top 28 of the vessel, the projecting flange portions of plates 26 and 27 being bolted together, as indicated. The top of 28 comprises an exterior cylindric side wall 29 welded to and rising from ring-plate 27, a top wall 30 extending inwardly from the upper edge ofsidewall 29 and formed with a central opening 31, a depending cylindric wall 32 located somewhat outwardly from opening 31, and a perforate wall 33, joining the lower end of wall 32 with the inner edge of ring-plate 27. The annular space so formed is packed with fibreglass 34, also for sound absorption purposes.

A short vertical wall 40 rises from top wall 30, just outwardly of opening 31, and mounted on the top portion of the latter is a louvered chamber 41, equipped with a top 42, from which leads outlet pipe 43. The latter is coupled by flexible coupling 44, such as a rubber hose, to a pipe 45 leading to the inlet of a blower 46. Chamber 41 has sidewalls 47 formed with air louvers 48, anda lower conical portion 49 formed with louvers 50. Rising from the inner edge of the latter is a generally conical shield 51.

A plurality of vertical cylindrically shaped rubber posts 55 are mounted in cylinders 56 secured to lower ringplate 19, as by welding, these being located adjacent the inner periphery of the latter, as illustrated. The lowermost of a vertical series of horizontal, circular, steel vibratory plates 58 rests on and is secured to the rubber posts 55. For example, an insert 59 molded in the upper end of each post 55 has a projecting stud 60 passing through plate 58, a nut 61 screwed on the upper end of the stud securing the plate 58 in assembly with the rubber post. The plates 58 are spaced by means of slotted spacer sleeves 62. The slots 62a and 62b extending inwardly from opposite ends of the sleeves, and preferably staggered, as indicated, are simply to give the sleeves a desirable degree of flexibility.

A vibrator shaft 65 extends vertically through central apertures 66 in plates 58 and through the aforementioned spacer sleeves 62, having on its lower end a flange 67 to which is bolted vibration generator 68. A spacer sleeve 69, slotted downwardly part way, as at 70, is placed on shaft 65 between lowermost plate 58 and shaft flange 67; and a spacer sleeve 71, slotted part way up from the bottom, is placed on shaft 65 above uppermost plate 58. The upper extremity 73 of shaft 65 is reduced and screw-threaded, and a nut 74 threaded thereon is set up tightly and holds the parts in assembly, serving to clamp vibration generator 68 securely to the set of plates 58.

An eye '75 on the upper end of shaft 65 permits convenient lifting of said shaft together with the assembly of plates 58.

T he generator 68 may be of various types, provided sufficient power is provided. That her-e shown (FIGS. 1 and 3) provides the large output power required by the invention in a simple manner. The generator embodies a housing 80 bolted to the aforementioned shaft flange 67, carrying bearings for two parallel shafts 81 and 81. Tightly mounted on these two shafts are spur gears 82 and 83, respectively, meshing with each other, and carrying eccentric weights 84; and shaft 81 is coupled to a drive shaft 85 driven from any suitable prime mover, such as an electric motor, not shown. The shaft 85, as shown in FIG. 3, projects outside the apparatus through suitable openings. The weights 84 are phased so as to move vertically in unison. Hence, their unbalanced components of centrifugal force are additive vertically, exerting a vertically directed oscillating force through the shaft hearings to the generator housing and thence to the vertical shaft 65. It will be seen, however, that the unbalanced weights 84 develop horizontal components of forces which are always equal and opposed, and that these components of force are therefore cancelled. Generator 6% accordingly, acting through shaft 65 and the several spacer sleeves, exerts a vertically directed oscillating force on the inner peripheries of the plates 58. The latter are of a good grade of elastic steel, and are set into a mode of standing wave vibration when generator 68 is driven at proper frequency, in a manner to be more fully explained presently.

Suspended from plates 58, as by means of U-bent flat spring elements 90, are upwardly concave bafiie plates 91, formed with central apertures 92 of a diameter substantially larger than the outside diameter of the spacer sleeves 62. The outside diameter of the dish members 91 exceeds the outside diameter of the plates 58 sufliciently to catch material falling off the peripheries of the plates 58, and are only narrowly spaced from the vessel wall 12. The baffle plates 91 are also suspended sufficiently far below the plates 58 to accommodate any relative vibration between the members 58 and 91 so that these members will not strike one another during the operation of the apparatus.

The vessel is completed by a plurality of material inlets 100 extending through top wall 30, as shown, and discharging well inwardly on the uppermost plate 58.

It has been described how vibration generator 68, acting through post or shaft 65, exerts a vertically oscillating force on the inner periphery of the plates 58, i.e., in a direction normal to the plates. This action, when generator 68 is driven at proper frequency, sets the several plates 58 into a mode or pattern of standing wave vibration, characterized by an alternating upward and downward elastic bowing of the plates. In this pattern, there is an elastic vertical oscillation of the inner or central region of the plate, a similar elastic vertical oscillation, but of opposite phase, of the outer or rim portion of the plate, and an annular nodal region of minimized or zero oscillation between the two. In the apparatus as disclosed in the figures, the nodal region of minimized oscillation, designated N, is at or just slightly outside the point of mounting of the lower-most plate 58 to the rubber posts 55. Thus, at this region, the elastic deflection amplitude of the plates is minimized, and the vibratory deflection amplitude increases progressively in both directions, inward and outward, to maximums at its inner and outer edges. These edge regions are at velocity antinodes of the vibration pattern, designated by V and V respectively. In other words, the plate flexes elastically, deflecting upwardly at its central velocity antinode region while deflecting downwardly in its outer velocity antinode region, and then downwardly in the central region and upwardly in its outer region, while the intermediate nodal region remains substantially stationary. To accomplish this standing wave vibration, the generator 68 is driven at the fundamental resonant frequency of the plates for the desired vibration pattern. Higher harmonics may be used, if desired, by driving the generator at multiples of the fundamental frequency.

In operation, the material to be separated is introduced, preferably continuously, through the inlet 100. This entering material, which for example may be a uranium ore, is preliminarily pulverized to a relatively fine grain size. In my work with the apparatus shown in FIGS. 1 to 3, I have found that optimum results are obtained with the entering material pulverized to a maximum grain size of the order of inch. This is mentioned, however, by way of example, and without intention of limitation. The material so introduced to the vessel falls on the uppermost plate 58 somewhat inwardly of the nodal region.

The blower 46 is operated, and draws a strong current of air through the vessel, in through tube 23 at the bottom, out through louvers 48 and 50 at the top, and thence via pipes 4-3 and 45 to and through the blower. Broadly, the purpose is to create an air flow which will pick up the light particles of uranium salts which have been spacially differentiated from the pulverized ore owing to the standing wave vibration of plates 58 over which the ore passes downwardly in succession. Various upward air flow patterns may be used. The present apparatus, however, has been contrived such that a substantial proportion of the air travelling upwardly through the vessel around the plates '58 and batlles 9'1 is diverted radially inward so as to sweep over the plates 58, and then pass upwardly through the central apertures 92 in the baffles 91, and then travel radially outward between the upper sides of the battles and the plates 58 immediately above, in the pattern suggested by the arrows in FIG. 1.

As stated above, the incoming granular material falls from inlet onto uppermost plate 58 at a point which may be somewhat inward from node N. The plate 58, vibrating in the standing wave pattern previously described, has a component of vibration normal to its upper surface which is in contact with the granular material supported thereon. This component of vibration of the plate takes place with high acoustic power, and with an acceleration many times that of gravity. Under the influence thereof, the different granular materials, e.g., carrier ore and uranium salts, are differentially motivated and agglomerate. The materials, under the severe sonic agitation, may be observed to become dynamically suspended or sustained in a free flowing condition like a liquid. The materials move toward the nodal region N, where vibration amplitude is minimized, and the lighter or more finely divided constituent, which is the uranium salt desired to be recovered, simultaneously rises to the top. The precise mechanism by which this performance occurs is still somewhat obscure, and acoustics experts who have observed the phenomena differ somewhat as its precise nature. In the foregoing, I have given the best explanation known to me. However, the phenomena described are readily observed, and occur when the plate 58 is vibrated with suficient acoustic power to produce a high acceleration factor, whence the materials can be seen to be in a highly agitated, dynamically sustained and free flowing state, moving to all intents and purposes substantially as freely as a liquid.

The material on the plate 58 can be observed to form an annular mound, such as indicated X, highest over the nodal region. As this mound builds up, athin edge of the material spills radially outward, and falls over the peripheral edge of the vibrating plate, to be caught by the bafiie plate 91 immediately below. The lighter or more finely divided constituent, i.e., the uranium salt, moves to the top of the mound, and forms a dust cloud thereover. This differential material, partly rising in a cloud and partly residing at the surface of the mound in a dynamically sustained state, is caught up by the air current flowing radially inward over the plate 58, and is discharged with the air via the blower.

The material spilling over the edge of the plate 58 onto the bafile plate 91 still contains a substantial amount of the salt to be recovered. This material slides down the bafiie member, aided by vibration of the latter owing to its spring suspension from the vibrating plate, and falls through aperture 92 onto the plate 58 immediately below. There the performance is repeated, the material migrating, under the standing wave of the plate, to the nodal region, where it forms a mound, and spilling oif the edge of the plate when the mound becomes high enough that its natural slope, under the sonic agitation, causes the material to reach the edge. Again the lighter or finer particles move to the top, and are picked up by the air current over the plate, to be separated out.

Thus recovery is progressive, the ore giving up a proportion of its metallic constituent at each plate 58. The remaining ore going oil the lowermost plate 58 is caught within the conical bottom portion of the apparatus, and discharged at 23.

The material so discharged may still contain a valuable proportion of recoverable mineral, and may be run through a second similar separator. Also, the separated material going off through the blower may still contain a substantial proportion of the carrier ore, and may be subjected to further separative treatment.

Granular uranium ore may contain particles of carrier ore, and particles of uranium salt. The particles of carrier ore may also have adhering thereto substantial amounts of uranium salt. In the course of the sonic agitation of the material within the apparatus, the uranium salt adhering to the particles of carrier ore is largely abraded away, and becomes a fine dust. Grains of uranium salt initially present are also reduced to a fine size in the process, and the salt is recovered in a finely divided form.

The previously mentioned air flow paths through the vessel are in no way critical. It is merely necessary to provide unidirectional air movement through all parts of the main chamber of the machine, so that the dust cloud of uranium salts which have been sonically separated from the parent ore by the above described mechanism, and which have become thrown up from the plates and reside in a dynamically sustained state at the top of the ore bodies on the plates will be transported to a collection point. Many standard forms of dust collectors can be employed at the collection point, to remove the uranium material from the air stream.

This application is a division of my prior application entitled Sonic Materials Separation Process and Apparatus, Serial No. 843,269, filed September 29, 1959, now abandoned.

The invention has now been shown in an illustrative form. It will of course be understood that this is for illustrative purposes only, and that many variations in design, structure and arrangement are possible within the scope of the appended claims.

I claim:

1. In an apparatus for separating unlike granular particles, the combination of: a stack of vertically spaced, generally horizontally disposed elastic disks, said disks being elastically vibratory in a fiexural mode at one common resonant frequency, means structurally and substantially rigidly uniting the central portions of the disks of said stack to one another, a vibrator connected to said uniting means for vibrating said means vertically at said resonant frequency, so as to induce high amplitude resonant fiexural vibration of said disks, means for feeding said materials to the uppermost of said disks, sloping, flow directing bafiles located between said disks and extending from outside the peripheral edge line of the disks to a region inwardly thereof and above the disk below, whereby overflow off the peripheries of the disks is delivered to the disks below by gravity flow, a housing around said disks for confining dust created by the vibration of the plates, said housing having an opening in the lower portion thereof for discharging the overflow from the lowermost of the disks, and an air and dust conduit connected to the upper portion of said housing for discharging said dust.

2. in an apparatus for separating unlike granular materials the combination of: a stack of vertically spaced, generally horizontally disposed elastic disks, each having a central hole therein, said disks being elastically vibrat-ory in a flexural mode at one common resonant frequency, a vertical post extending through said holes in said disks and rigidly fastened to said disks adjacent said holes, a vibrator connected to said vertical post for vibrating said post vertically at said resonant frequency, so as to induct high amplitude resonant flexural vibration of said disks, means for feeding said materials to the uppermost of said disks, sloping, flow directing batfies located between said disks and extending from outside the peripheral edge line of the disks to a region inwardly thereof and above the disk below, whereby overflow off the peripheries of the disks is delivered to the disks below by gravity flow, a housing around said disks for confining dust created by the vibration of the plates, said housing having an opening in the lower portion thereof for discharging the overflow from the lowermost of the disks, and an air and dust conduit connected to the upper portion of said housing for discharging said dust.

References Cited in the file of this patent UNITED STATES PATENTS 1,983,968 Clark Dec. H, 1934 2,071,260 Holden Feb. 16, 1937 2,591,083 Maier Apr. 1, 1952 2,755,927 Brooks July 24, 1956 2,766,881 Westervelt Oct. 16, 1956 FOREIGN PATENTS 508,675 Great Britain June 26, 1939 718,588 Great Britain Nov. 17, 1954

Claims (1)

1. IN AN APPARATUS FOR SEPARATING UNLIKE GRANULAR PARTICLES, THE COMBINATION OF: A STACK OF VERTICALLY SPACED, GENERALLY HORIZONTALLY DISPOSED ELASTIC DISKS, SAID DISKS BEING ELASTICALLY VIBRATORY IN A FLEXURAL MODE AT ONE COMMON RESONANT FREQUENCY, MEANS STRUCTURALLY AND SUBSTANTIALLY RIGIDLY UNITING THE CENTRAL PORTIONS OF THE DISKS OF SAID STACK TO ONE ANOTHER, A VIBRATOR CONNECTED TO SAID UNITING MEANS FOR VIBRATING SAID MEANS VERTICALLY AT SAID RESONANT FREQUENCY, SO AS TO INDUCE HIGH AMPLITUDE RESONANT FLEXURAL VIBRATION OF SAID DISKS, MEANS FOR FEEDING SAID MATERIALS TO THE UPPERMOST OF SAID DISKS, SLOPING, FLOW DIRECTING BAFFLES LOCATED BETWEEN SAID DISKS AND EXTENDING FROM OUTSIDE THE PERIPHERAL EDGE LINE OF THE DISKS TO A REGION INWARDLY THEREOF AND ABOVE THE DISK BELOW, WHEREBY OVERFLOW OFF THE PERIPHERIES OF THE DISKS IS DELIVERED TO THE DISKS BELOW BY GRAVITY FLOW, A HOUSING AROUND SAID DISKS FOR CONFINING DUST CREATED BY THE VIBRATION OF THE PLATES, SAID HOUSING HAVING AN OPENING IN THE LOWER PORTION THEREOF FOR DISCHARGING THE OVERFLOW FROM THE LOWERMOST OF THE DISKS, AND AN AIR AND DUST

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