US1718547A - Centrifugal separator - Google Patents

Description

June 25, 1929.

E. S. ECCLESTON GENTRIFUGAL SEPARA'IOR 2 Sheets-Sheet Filed June 1, 1926 In ventor .Z'arle Slccleston ver Attorney.

June 1929- E. s. ECCLESTON CENTRIFUGAL SEPARATOR Filed June 1, 1926 2 Sheets-Sheet m t a M; +06 M md r c m U nE v t 6 5 .1 2 Z m U" M 3 r 4 a .M 4 a W mm a 0 4 *K z J Patented June 25, 1929.

EARLE S. ECCLESTON, OF LOS ANGELES, CALIFORNIA.

CENTRIFUGAL SEPARATOR.

Application filed June 1,

In this specification, and the accompanying drawing, 1 shall describe and show a preferred form of my invention, and specltically mention certain of its more important objects. I do not limit myself to the forms disclosed, since rious changes and adaptations may be made therein without departing from the essence of my invention as hereinafter clain'ied: and objects and ad 'antages, other than those specifically mentioned, are included within its scope.

My invention relates to devices adapted for separating and concentrating composite materials of various kinds by the action of centrifugal force. Its principal objects are first, to provide improved means for accomplishing such separation by a continuous process; second, to furnish operating adjustments adapting devices of this kind for treat ng materials of different natures under various operating conditions; third, to inipi'ove'tlie operating efliciency of such machines y increasing the yield per unit of e zpended power and per unit of cubical capacity; and, fourth, to achieve these results by means of a relatively simple and inexpensive construction.

Ty objects are attained in the manner illustrated in the accompanying drawings, in which Figure 1 is an elevation of my improved separator, shown partly in section and with certain parts broken away to disclose its interior construction, the sections being taken on the line 1-1 of Fig. 2;

Figure 2 is a horizontal section of the above structure, taken on the line 22 of Fig. 1

Figure 3 is an enlarged fragmentary view of the nozzle construction and placement employed in my separator, the view being in vertical section and taken on the line 33 of Fig. 2;

Figure 4 is a front elevation of a portion of one of the above mentioned nozzl supports with a nozzle mounted thereon; and

Figure 5 is a fragmentary elevation of a portion of the rotatable bowl of the separa tor. showing diagrammat.ically the coopera tive action of the plural nozzles employed therewith.

Similar reference numerals refer t parts throughout the several views.

in an application for patent tiled by me in the United States Patent Ofiice on April 2nd,

(Serial No. 20,217) I showed and described a centrifugal separator of somewhat similar construction to that shown and de similar 1926. Serial No. 112,921.

scribed herein. The two constructions are patentably different however, and the claims of the present application do not conflict with those of the former one.

The embodiment of my present invention that I have selected for illustrative purposes comprises a housing 6 which preferably is made in the form of an upright truncated cone. At the top of this housing is a cover plate 7 carrying a central vertical journal bearing 8. The bottom plate 9 of the housing is provided with a similar bearing 10, and suspended from the bottom is a hanger 11 carrying a third journal bearing 12 and a ball thrust-bearing 13.

lVithin the housing is a. rotatable inverted bowl 14, closely conforming tothe shape and interior dimensions of the housing. This bowl has a cover plate 15 at the top provided with a short central quill-shaft 16 proje'cting upwardly and rotatable in bearing 8. Beneath cover 15, and spaced therefrom, is a suspended deflecting plate 17; The bowl is fixed upon a vertical shaft 18 at the bottom, the shaft being rotatable in bearings 10 and 12. Rotation of the bowl may be accomplished 'in any convenient and suitable manner, as by a pulley 19. The weight of the r0- tatable parts and the material therein is supported by thrust bearing 13.

The conical shell of bowl 14 is pierced by a multiplicity of narrow arcuate orifices 20, arranged in spaced circumferential rings. Just below the orifices, on the outside of the bowl, there are circular flanges 21. Thin retaining bands 22 are supported by these flanges and extend upwardly therefrom, the upper edges of the bands extending above the respective arcuate orifices and terminating considerably short of the circular flanges 21 above them.

The interior surface of housing 6 is provided with a plurality of equally spaced upright partition flanges 23, of which the machine illustrated has four. These partitions are connected by a multiplicity of inwardly and upwardly sloping circumferential webs 24. forming launders for the collection of material. thrown off by the revolving bowl. The webs are so placed that their upper edges will be intermediate the top and bottom edges of the respective bands 22, and they are helically positioned on the inner surface of the housin so as to have a slight downward slant in the direction of rotation of the bowl. The material caught by these interior launders escapes to the outside of the housing through long and relatively wide arcuate orifices through which a tool may be inserted in case of necessity, as when there is a tendency for the material to become clogged.

On the outer surface of the housing are a plurality of upright nozzle supports 26.

These are made integral with the shell of the housing, are box-like in section, anc. are placed on the shell adjacent to the angular position of the interior partitions 23. Exterior launders 27 extend helically downward from the respective nozzle supports in the direction of rotation of the bowl, and terminate short of the succeeding nozzle supports to provide space for inserting upright ducts 28 for carryin golf the concentrates that flow downwardly to them.

To provide a sufficiently close lit for ducts 28, the lower ends of the exterior launders may be milled parallel to the adjacent exterior walls of the succeeding nozzle supports, where indicated by 29 in Fig. 2. The ducts are provided with holes 30 opposite the respective launders, so that material in the latter may flow directly into them.

The nozzle supports are pierced radially by a plurality of holes 31 at levels just above each of the retaining bands 22 on the bowl. Composite nozzles of special construction, are inserted in these holes as shown at 32 in Figs. 1 and 2.

Typical nozzle construction is shown in Figs. 3 211(141. The form illustrated comprises positioning fittings 33 bolted to the nozzle supports. These fittings have interior chambers 3d communicating, by means of small pipes 35 and interposed valves 36, with headers 37 which contain water under pressure. Fittings 33 are provided with gland nuts 38 forming packed stuffing boxes 39. Closed end tubes 40, of smaller exterior diameter than the interior diameter of chambers 34, extend through packing 39 and the shell of housing 6. Their inner ends are slightly spaced from the rotatable bowl, and their outer ends project beyond gland nuts 38. These tubes have hexagonal extremities 41, whereby they may be rotated, and are longitudinally slidable as well as being rotatable. When correctly positioned, they may be held in place by th friction of packings 39. The tubes are intermediately pierced by orifices 42 and thus communication is established between their interiors and chambers 34, irrespective of the angular or longitudinal position of the tubes in fittings 33.

The respective ends of tubes are eccentrically and oppositely drilled for the insertion of considerably smaller nozzle tubes 43. The latter fit snugly in these end holes, are longitudin ally and an gularly movable therein, and may be maintained in their desired positions by their snug fits in the end holes. The outer extremities of the nozzle tubes have squared portions also that they may be conveniently turned. Their inner extremities, after insertion in tubes 40 are bent angularly downward, as at 45, to form discharge nozzles adapted for washing concentrates out of the spaces between the revolving bowland the retaining bands 22. Intermediate holes 46 establish communication between the bores of the nozzle tubes and the interior of tubes at), irrespective of their related angular positions.

The nozzle construction just described permits of discharging water under the desired pressure from headers 37 through the nozzle tips e5. It also permits of angularly and longitudinally positioning the nozzles, and of slightl 7 raising or lowering them by means of their eccentric mounting in the rotatable tubes 4C0. Nozzles terminate, as stated above, in the spaces between bowl 141; and bands 22 be low the upper edges of the bands, and they generally are directed slantingly downward against the direction of'rotation of the bowl.

in the operation of my invention for concentrating ores the material ordinarily is pulverized and mixed with water to form a tlowable pulp of the proper consistency. This pulp is fed into the top of the rotating bowl through quill-sh aft 16. It is prevented by deflecting plate 17 from dropping into the bowl and is thrown outwardly by centrifugal force, as shown by arrow d7, against the upper wall of the bowl. Centrifugal force will cause t e material to remain on the wall of the bowl, and it will gradually work downwardly under the influence of gravity and the down wardly increasing dian'ieter of the bowl. During this process the heavier particles of the mass will work outwardly through the lighter particles, and be thrown outwardly from orifices 20 into the spaces between the outer surface of the bowl and retaining bands 22. The rate of removal of the material in these spaces will determine the rate at which it passes through orifices 20 because, if not removed, the orifices will become choked and permit no more material to I pass through them.

The above process is repeated at each circun'iferential row of orificesworking down wardly and, when the bottom row of, orifices has been reached, if the device has been properly operated, the separation process has been completed and only tailings remain. The latter pass freely outward through the bottom orifices 48, as shown by arrow 49. flow downwardly over the sloping surface of bottom plate 9, and are discharged through the tailing-s chute 50.

The jets from nozzles 45 operate to con inuously remove theconcentrates from the spaces between the bowl and the retaining ban ds 22. The rate at which this removal takes place is adjusted by means of valves 36 whereby the force and volume of the jets is controlled. The jets, when properly positioned in the way described act in the manner illustrated in Fig. 5. The accumulated concentrates 51 are washed upwardly by the streams from the nozzles as shown at 52. Part of this material is centrifugally thrown off from the upper edges of the retaining bands, as at 53; part is washed up ardly against the under surfaces of flanges 21 and is thrown off from the bottom edges of their retaining bands, as at 5A; and a third part clings to the surface of the bowl and tends to work downwardly again, as at 55. However, the cooperative action of the succeeding nozzle prevents the return of this material, in the manner indicated at 56.

The use of cooperating plural nozzles in the manner described may be made to increase the efficiency of operation of each nozzle, and to thus increase the total yield of the machine in a manner entirely out of proportion to the mere plurality of nozzles. The actual number of nozzles that it is best to employ in a given case must be determined with relation to the diameter of the bowl, its rotative speed, and such other factors as jet velocity, specific gravity of the concentrates, fiuid characteristics of the concentrates, direction of the jets, etc.

The concentrates thrown ofi from the re volving bowl are caught by the inner launders of the housing and flow outwardly therefrom, through orifices 25, into the outer launders. At this point the concentrates become visible and may be sampled for analysis. They flow downwardly in the outer launders and through holes 30 into such of the upright d ducts 28 as is desired.

The use of plural ducts at 28 permits of making operating adjustments of each nozzle independently, to secure the maximum yield therefrom. This may be done without interference with the regular operation of the machine. Thus, for example, corks may be inserted in all but one of the holes 30 in one of the ducts to prevent inflow, and thus determine the yield per unit of time from the nozzle causing the flow into the open hole of this duct.

Another, and more important, use of plural ducts is to permit of grading and separating the concentrates that come from different portions of the machine. The heavier particles in the ore mass are thrown off first, and appear in the upper banks of launders. The concentrates gradually become lighter and the character of their content is altered as the ore mass passes downward in the bowl. By means of plural ducts and the use of corks in their intake holes, the yield of the machine may be graded in various ways as desired. For instance the yield from several of the upper banks of launders may be made to pass wholly into one of the ducts, and the yield from the other banks below may be wholly diverted into another duct. The machine'then will yield two grades of concentrates. Obviously it is perfectly feasible to employ three or more ducts at 28 to classify the concentrates into as many grades as there are ducts.

The use of an inverted bowl in a centrifugal separator, as herein described, results in a number of great practical advantages over separators that employ upright bowls. The more important of these will now be explained.

In the previous upright bowl types of separators the ore mass is introduced at the bottom and works upwardly against gravity by reason of the progressively increasing centrifugal force due to the flare of the bowl. The diameter at the top of the bowl necessarily must be much greater than it is at the bottom, and the difference between the centrifugal forces at these points is great for this reason. This great variation in centrifugal force is objectionable. It results in making the ore mass at the top of the bowl so dense and compact that it is hard to secure proper stratification of the material; and it becomes very diflicult to remove the concentrates by means of the jets.

In the inverted bowl of the present invention the ore mass is introduced at the top and gravity aids it to Work downwardly over the interior revolving surface. Consequently the bowl may have much less taper than upright bowls and may even be almost cylindrical in form. Great variation in the centrifugal forces is avoided in this way; the body of the ore mass becomes more uniform in thickness and density; the rate of yield of concentrates at different portions of the machine is more nearly the same; and the output efficiency of the machine is increased for these reasons.

It follows from what has just been said that the inverted bowl type of separator may be operated at lower rotative speeds than the upright bowl types. This reduction of speed coupled with the fact that it is not necessary to raise the material therein against gravity, calls for less expenditure of power and, in combination with the lower center of gravity of the inverted bowl, results in much less vibration and more satisfactory mechanical operation.

Another advantage of the inverted bowl, and its more nearly cylindrical shape, is the very slight difference in diameter between the top and bottom of retaining bands 22. In the upright bowl the equivalent skirt ring construction necessarily has to have a much greater difference in the corresponding (liameters, since the concentrates are retained therein by centrifugal force opposing gravity. It follows that the spouting velocity of the jets required to remove the concentrates on the inverted bowl of the present invention need be only a fraction of what is required in the case of the former upright bowl types with their skirt rings. Ordinarily only mill or city water pressure is required for the inverted bowl. A further saving in power is made in this way since the retarding effect of the jets on the bowl is much less.

I desire to call attention to the fact that, although the drawings illustrate a complete operative structure embodying the principles of my invention, 1 have simplified the construction as much as possible to avoid unnecessary confusion. There are a number of structural features, as for instance the nozzle assembly and details, that perhaps could be elaborated to practical advantage; and the proportions and'relation of parts can be varied, in many respects, as desired. For instance it may be desirable to make use of con'ipressed air jets instead of water jets, or to do away with jets altogether and make use of scrapers or other purely mechanical devices in their place. The number of ducts at 28 may be changed, the number of the segregating launder banks may be raised or lowcred, and different means may be employed for distributing the pulp upon the upper peripheral wall of the revolving bowl. Such changes are contemplated by me in the construction of commercial machines.

Having thus fully described my invention in a manner that will make its construction and operation clear to those familiar with the art involved, it claim 1. A centrifugal separator comprising; an inverted rotatable bowl having circumferentially arranged orifices in its peripheral wall; means for feeding material into the revolving bowl against its peripheral surface above said orifices; means for rotating the bowl at a speed adapted to cause the material to cling to said surface while working downwardly;

means on. the outside of the bowl for retain-v ing material discharged from the orifices to variably obstruct the flow therethrough and means for continuously removing said discharged material.

2. A centrifugal separator com 'irising; an

inv rted rotatable bowl having plural circumferential rings of arcuate orifices in its peripheral wall; means for feeding material into the revolving bowl against its peripheral surface above said orifices means for rotating the bowl at a speed adapted to cause the mate rial to cling to said surface while working downwardly; annular channels on the outside of the bowl having outer walls opposite the orifices and adapted to catch and retain material discharged therefrom to variably obstruct the flow thercthrough; and'means for continuously ren'ieving said discharged material.

3. A centrifugal separator comprising; an inverted rotatable bowl having plural circumferential rings of arcuate orifices in its peripheral wall and circular flanges'on its outer surface; means for feeding material into the revolving bowl against its peripheral surface above the orifices; means for rotating the bowl at a speed adapted to cause the material to cling to said surface while working downwardly; circular bands extending upwardly from said flanges above the orifices to form channels adapted for catching and retaining material discharged therefrom to variably obstruct the flow therethrough; and means for continuously removing said discharged material at controllable rates.

4t. A centrifugal separator comprising; an inverted rotatable bowl having plural circumferential rings of arcuate orifices in its pe ripheral wall and anaXial quill-shaft; means whereby material maybe fed into the revolving bowl through said shaft and against the peripheral surface of the bowl above the orifices; means for rotating the bowl at a speed adapted to cause the material to cling to'said surface while working downward ly under the influence of gravity; annular channels on the outside of the bowl having outer walls opposite and extending above the orifices whereby material discharged therefrom may be caught and retained to variably obstruct the flow thercthrough; and means for directing a plurality of angularl v spaced jets downwardly into each of said channels whereby said dis charged material may be washed upwardly to be centrifugally thrown from the bowl.

5. A centrifugalseparator comprising; an inverted rotatable bowl having plural circun ferential rings of arcuate orifices in, its pcripheral wall; means whereby material may be fed into the revolving bowl against its peripheral surface above the orifices; means for rotating the bowl at a speed adapted to cause the material to cling to said surface while working downwardly; means for retaining circumferential banks of material on the outside of the bowl opposite the orifices to variably obstruct the flow therethrough; and means for directing a plurality of angularly spaced jet-s against each of said banks whereby material may be removed therefrom at controllable rates; said-jets being so positioned that each is adapted to cooperate with the preceding etof its series to prevent material dislodged thcreby from being returned to its bank.

6. A centrifugal separator comprising; an inverted rotatable bowl having cii cumfcrentially arranged arcuate orifices in its peripheral wall and a tubular eurnal at the top through which material maybe introduced; a plate :fiXed within the bowl below said journal and above the orifices whereby said material maybe centrifugally thrown against the inner surface of said wall; means for rotating the bowl at a speed adapted to cause the material to cling to said surface while working downwardly; means for retaining circiui'iferential banks of material, on the outside of the bowl opposite the orifices to variably obstruct the flow therethrough; means for directing a plurality of angularly spaced jets against each of said banks whereby material may be removed therefrom at controllable rates to be centrifugally thrown from the bowl; and means for separately collecting the material thus removed from the respective banks; said jets being so positioned that each is adapted to cooperate with the preceding jet of its series to prevent material dislodged thereby from being returned to its bank.

7. A centrifugal separator comprising; a rotatable bowl having means for segregating exterior circumferential banks of material upon its peripheral wall; means for removing material from said bank separately; and a housing surrounding the bowl having interior circumferential pockets respectively adapted for receiving material removed from the banks; and exterior circumferential launders respectively communicating with the interior pockets.

8. A centrifugal separator comprising; a rotatable bowl having means for segregating exterior circumferential banks of material upon its peripheral wall; means for removing material from said banks separately to be centrifugally thrown from the bowl; a housing surrounding the bowl having interior circumferential pockets respectively adapted for catching material thrown oh? from the banks, and exterior circumferential launders respectit ely communicating with the interior pockets; and selective means for discharging the launders separately or in desired combinations.

9. A centrifugal separator comprising; a rotatable bowl having means for segregating exterior circumferential banks of material upon its peripheral wall; angularly spaced means for removing material from each of said banks; and a housing surrounding the bowl having interior circumferential pockets respectively adapted for receiving material removed from the banks, and exterior circumferential launders respectively communicating with the interior pockets; each of said pockets and launders being sub-divided by partitions whereby the products of the said removing means may be separated.

10. A centrifugal separator comprising; a rotatable bowl having means for segregating exterior circumferential banks of material upon its peripheral wall; angularly spaced means for removing material from each of said banks separately to be centrifugally thrown from the bowl; a housing surrounding the bowl having interior circumferential pockets respectively adapted for catching material thrown off from the banks and exterior circumferential launders respectively communicating with the interior pockets; partitions subdividing each of said pockets and launders whereby the products of the said removing means may be separated; and selective means for discharging the subdivisions of the launders separately or in desired combinations.

11. A construction as set forth in claim 7 wherein the launders and interior pockets are oppositely disposed on the shell of the housing and are in communication through relatively long circumferential orifices in the shell.

12. A construction as set forth in claim 7 wherein the launders and interior pockets are oppositely and helically disposed on the shell of the housing and are in communication through relatively long circumferential orices in the shell at the bottoms of the launders and pockets.

13. A construction as set forth in claim 8 wherein the selective discharging means consist of upright duets with plugable orifices therein respectively communicating with the launders.

14. A construction as set forth in claim 10 wherein the selective discharging means con sist of upright ducts with plugable orifices therein respectively communicating with the subdivisions of the launders.

EARLE S. ECOLESTON.

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