US2428974A - Rotary drum stratifier for minerals - Google Patents

Description

Qct. 14,-1947. EKREH R 2,428,974

ROTARY DRUM S TRATIFIER FOR MINERALS Filed Nov. 6, 1942 4 Sheets-Sheet l v I [maaflireher 1 IL/(M l Oct. 14, 1947. E, KREHER 2,428,974

- 7 ROTARY DRUM STRATIFIER FOR MII I1:'JRALS Filed Nov. 6., 1942 4 Sheets-Sheet 2 ()Ct- 14, 1947. KREHER ROTARY DRUM STRATIFIER FOR MINERALS Filed Nov. 6, 1942' 4 Sheets-Sheet 3 Fig.5

gum/Wm EmeatKreher E. KREHER ROTARY DRUM STRATIFIER FOR'MINERALS Oct. 14, 1947,

Filed Nov. 6, 1942 4 Sheets-Sheet 4 fmaatKreher V Patented Oct. 14, 1947 ROTARY DRUM s'rRA'rIFIER FOR MINERALS Ernest Kreher, Tampa, Fla.

Application November 6, 1942, Serial No. 464,723

6 Claims.

The primary object of the present invention is to provide a novel and efiicient system and. apparatus for the separation and collection of gold, tin, and other valuable minerals occurring in their free state in alluvial or glacial deposits, in tailing deposits from mining operations, or in quartz after it has been reduced to a size suitable for handling by a centrifugal pump or by a water jet. The apparatus is particularly adapted for the treatment of relatively finely divided material which can be delivered to the sump of the suction pipe of a centrifugal pump by dredges, by hydraulicking, or by any other form of mining and conveying.

A further object of the invention is to utilize the varying effects of the pressure of flowing Water, of centrifugal force, and of gravitation upon materials of'different specific gravities as means to cause the removal of the lighter particles from the heavier ones; This object is accomplished by the provision of an inclined rotating shell or casing, enlarged beyond its inlet to reduce the speed of flow of a stream of water through the shell, and having means by which some of the materials are carried upward to fall through the stream. Riffles" surrounding the stream act as barriers against which the heavier particles engage andfall downward through the space between the webs of the rifiles where there is substantially no longitudinal movement of the water. The riffies have channels or passages between the outer edges of the webs and the inner surface of the shell to permit the heavier particles to gravitate down the inclined surface to a locked receptacle at the lowermost point of the shell.

The length and shape of the shell will be determined by the material to be treated and by such considerations as cost, weight, ease of transportation and of operation, and power requirements.

The speed of the stream of water will be regulated in accordance with the length of the chamber and its rate of rotation to secure the desired results with the material being treated.

Since the force exerted by flowing water is proportional to the area against which it engages, the same forcewill cause a greater travel ofa particle of small mass than of a particle of equal area but of greater'mass, and the efiect of gravitation or of centrifugal force will cause a particle of greater mass to overcome the resistance of the water in which it is suspended, more rapidly than a particle of equal area but of smaller mass will overcome the same resistance. Hence the lighter materials will be carried through the separator more rapidly and with heavier metallic particles;

In Patent No. 2,217,687, granted October 15,

- spaces between the rifiles fill with matrix in so short a time of operation that the time lost in cleaning and collecting the metal rendered the apparatus relatively inefficient. In the present device, the matrix will not clog the spaces between the rifiies and cleaning is needed only for repairs or replacements.

An important object of a modified form of the apparatus is the provision of means for the discharge of the lighter'materials at the upper end of the inclined shell and for the continuous escape of the heaviest particles at the lower end of the shell through an opening of a size chosen in accordance with the quantity or the heavy, valuable materials present in the matrix being treated.

Another object is theprovision of a receptacle for gold or other highly valuable metals, which can be locked to prevent theft.

Other objects of the invention will be evident during the consideration of a preferred embodiment selected for purposes of illustration. It will of course be understood that the invention is not limited to the details of construction shown in the accompanying drawings, but many changes in size, form, proportions and structure may be made without departure from the invention as claimed.

In the drawings, Figure 1 is a side elevation of a preferred form of the device including a cylindrical separator, a centrifugal pump, and an electric motor; Fig. 2 is a central longitudinal section On a scale four times as large as that of Fig. 1, showing the construction of the end members of the separator and their connection with the inlet and outlet tubes, the central part of the separator chamber being broken away; Fig. 3 is a plan view of the structures shown in Fig. 1, on the same scale; Fig. 4 is a View, partly in elevation and partly in section, on approximately the plane indicated by the line IVIV in Fig. 3; Fig. 5 is a transverse section through portions of the separator shell and of the intake end mem ber, looking towardthe right in Fig. 2 in the planes indicated by the line V-V; Fig. 6 is an end elevation of one of the riflles used in the separator shell; Fig. '7 is a diametral section of the same riflle looking toward the right in the plane indicated by the line VII-VII of Fig. 6; Fig. Bis a fragmentary view looking upward from the bottom of either Fig. 6 or Fig. 7; Fig. 9 is a fragmentary elevation with parts broken away, of the operating lever, the brake drum flange, the stop pawl, and the adjustable end member of the brake band; Fig; 10 is a side elevation of the" operating lever and the stop'pawl; Fig. 11 is a section through the spring-pressed collar which holds the discharge pipe in its seat; Fig. 12 is a side elevation with parts in section of the shifter yoke of the friction clutch; Fig. 13 is a fragmen tary longitudinal section of a modification of the structure shown in Fig. 2; Fig. 14 is a cross-section through the volute-shaped channel of Fig 13; and Fig. 15 is a plan View of the metal-collecting receptacle of Fig. 14.

The central portion of the shell or casing of the separator is shown as a cylinder I having secured upon its ends flanged members 2 and 3. To the member 2 is secured the flange 4 formed at one end of the intake member 5 which tapers down toward the inlet to a cylindrical bearing portion 6 within which is fitted the discharge end of the intake pipe 1, around which the portion 6 rotates within a bearing member 8. A suitable packing 9 around the pipe is compressed in a stuffing box by the gland I and the gland nut ll held in place by the lock nut 12. The intake pipe 1 may extend into the member to any desired distance since the end of the pipe will not interfere with the flow of material into the separator chamber. To the member 3 is secured the flange I3 of the outlet end member M which tapers to a cylindrical bearing portion [5 mounted within a bearing member I6.

At the discharge end of the separator, the interior of the outer end of the outlet member I4 is made flush with the interior of the inner end of the discharge pipe ll which has a rotating bearing in the socket l8 formed within the portion I5. A collar I9, best seen in Fig. 11, is secured to the pipe ll, preferably by one or more set screws 20. Within this collar are a plurality of sockets 2| for helical springs 22 which bear at their outer ends against a flange 23 of a mem ber 24 secured upon a support 25. A stud 26 secured in the collar l9 projects outward for slidable engagement within a slot 21 formed within the rear edge of the member 24. The stud prevents rotation of the collar l9 and thus of the pipe H, while permitting the pipe to be held within the rotating socket l8 by the thrust of the springs 22.

A liquid-tight joint between the pipe I! and the member I4 is provided by a packing 9 in a stufling box having a gland l0, nut H, and locking nut l2 such as are used with the pipe 1.

Within the shell I, throughout substantially its entire length, are a plurality of riflies 28 each consisting of a flat, annular web mounted radially of the axis of rotation of the shell. From each Web project a plurality of vanes 29 each having one wing 39 set more or less radially of the web and at right angles thereto and having a second wing 3| set substantially at right angles to the web and to the wing 39. The wings 31 extend across the outer edge of the annulus 28 to space it an eighth of an inch, more or less, from the interior surface of the cylindrical casing I as best seen in Figs. 5, 6, and 14. Six such vanes are shown in these figures, but obviously the number used is a matter of choice or convenience. On the outer end of one of the vanes on each riflle, a V-shaped point 32 will be formed to enter a corresponding recess 33 either in the next adjacent rifile plate toward the inlet or in one of the projections 34 formed on the inner periphery of the member 2 against which the outer ends of the endvanes of the series abut when the assembly of riflles is installed within the cylinder I. A plurality of screws 35 extending through the flange I3 are arranged to bear against the side of the outermost riffle to clamp the whole group of riffies together and force the lowermost riflie against the projections 35, thus preventing the group from turning within the cylindrical shell. Except for the projecting lugs 34, the interior of the member 2 is substantially flush with the inner surface of the cylindrical shell I, so that material sliding downward beneath the lowermost riffle web between the wings 3| may pass freely through the spaces between the lugs 34 into the tapered end member 5.

Formed-upon or secured to the central portion of the end member 5 is a brake drum 35 upon a side face of which is secured a bevel gear 31 in mesh with a smaller bevel gear 38 on a shaft 39. A pulley t5, driven by a belt 4! from an electric motor 42 and running freely on the shaft 39 may be connected to the shaft to cause rotation of the gears by the use of any suitable clutch, such as the expanding ring type of friction clutch shown at 43 in Fig. 3. The shifter yoke 44 for the clutch shown in Figs. 3 and 12 as carried by a sliding plate 55 operated by a push rod 46 is caused to move into and out of operative position by a lever ll to which the rod 45 is pivoted at the lowermost end of the lever. The lever 41 is pivoted on a support 58 closely adjacent to a flange '59 on the brake drum 36. The plate 45 may also carry a link '35 to operate a switch 42 controlling the motor 42.

The lever 47 is provided on the edge adjacent to the brake drum with a lug 59 engaged on opposite faces by the wings of a nut 5|. This nut is adjustable longitudinally of the threaded end of a rod 52 pivoted at 53 on one end of the brake band 54. After adjustment of the nut, it is secured upon the lug by a pivot 55.

The other end of the brake band is secured by links 56 to the member 48. A stop pawl 51 is pivoted beside the lever M on the member 48 with the pawl 1ying in the plane of the flange 49. A notch 58 is cut in the periphery of the flange and provided with a cushion, which may be formed of leather strips 59 glued together and. bolted upon the flange at the end of the notch for engagement with the end of the pawl 51. A bolt 69 has a terminal yoke 6| pivoted at 62 on the pawl, the shank of the bolt being surrounded by a helical spring 53. A lug 54 projects laterally from the rear edge of the lever 41 and has a perforation through which the bolt 69 passes. A nut 55 On the opposite face of the lug from the spring holds the bolt and the pawl in place with the ends of the spring engaging the yoke El and the lug 6 5.

As the lever 41 is pushed forward from the broken line inoperative position of Fig. 9 toward the brake drum, it acts to perform several operations in sequence: first, it pulls on the rod 46 to cause the plate 45 to slide to open the switch 62 of the motor and to move the shifter yoke M to disengage the clutch 43. The separator through its inertia will continue to revolve for awhile after the clutch is released and the operator at the proper time will move the lever farther forward to cause a downward pull on the nut 5! to tighten the brake band and thus to slow down the rotation of the shell. Forward movement of the lever will bring the pawl into contact with the rim of the flange 49 but it can be withdrawn if the speed is too great. As the notch 58 is seen approaching the pawl, the lever can be moved forward strongly to complete the action of the brake band just as the pawl engages the end of the notch, this being the positionin which the recep- T tacle 6T or? BB is apth'e lbwermo'st: point anther. separator-assembly; The. spring isicompressed: as the: lever moves to itsextreme forward posiition without corresponding movement of: the pawl;

This sequence of operations releases? the sepa:-= rator: from. the driving forceofithe'motor; applies. agradually increasingfrictiorr on theibrakeidrum; and finally stops the shell at a definite point,- which" i's th'e position shown. in: Figs; 1:. to.- 5,'. 13 and le.

The motor 4 2: is connected by belts 6a with the: drive shaft 110 of a centrifugal ump 11 having: an: intake pipe indicate at l2 and a: dischargenozzle at 13. The intake pipe 12 is of a len'gth'. to connect the pump with" a sump or tankptovidedto" receive'the matrix to bev treated and to: receive material discharged from: the shell; when; it has been stopped, as" for the removal. an'd'replacement of a receptacle,

As seen in Figs; 1- and 3,.the discharge; nozzle 13 is connected with the'pipe 1 by a flexible hosei 1-4 01 an suitable length. While it is shown in:

these figures short, it will" b'e' evidentthat the' hose serves merely the necessary connection: between the pump or water jet. at the sump and the separator which may be ate; considerable distance' away for greater convenience in use;

Thematerial to be treatedby' the present: separator will be of sizes no greater than can pass. readily through' the intake pipe 12-, larger piecesv being removed by screenson other apparatus; not shown, to' obviate" any danger of. clogging any of the assages in the a paratus.

The stream. (if water carrying: the mixture of minerals suspensionwill be driventhrough the pipe 7 into the upwardly inclined'rot'ating sepa-- rator whose shell has a diameter greater: than that of the pipe. The velocity of the stream. of water will be reducedbecause o'f'this larger diameter of the shell, while the riffles will. prevent a free flow of the water: along the outerportio'n of thechamber. The greatest velocity will be maintained substantially along" the axis of. rotation.

The material will consist of'parti'cles" differing: in specific gravity. With equal-pressure of the flowing water, the lighter portions willbe' carried faster and farther thanthe heavier ones, but the speed offlow will be so regulated thatthe heavier materials to be retained will drop down at the reduced speed'of'flow within the intake member 5 or between the webs 28 of the riffles where there is substantially. no forward; movement of the water.

The centrifugal force caused by the rotation o the shell will exert a greater outward pressure of the heavier particles than of the lighter ones, toward thewall of the casing. The lighter particles suspended in the central rapid current will be very little affected by the centrifugal force.

In locations where clay or the like causes the matrix to adhere in lumps, one or more breaker bars I6- may be secured to the wings 30 of the riffies as indicated in Fig. 6, to extend across the middle of the stream to be engaged by the lumps to cause them to disintegrate. Material between the webs of the riifles encountering the Wings 38 will be carried upward and dropped again into the top of the flowing stream. The repeated-tumbling over of the matrix assists in washing and scouring from the metallic particles films or incrustations of lighter materialsby the attrition of the individual bits orp'iecesagainst each other and against the apparatus.

The "lighter'portionswill .travelzupwardandloutewardiat aaratersubstantially'in proportion to thei'r weight after deducting. th weight of the water; they displace: The heaviest particles falling and. being: thrown by centrifugal force against the in. terionsurface of the shell: will. slide. downward: along the inclined surface, passing through the: spaces: between; theiwingss'tl' and: between. the: outeredgesot the rifilewebs-: and the inner surface" of the? shell;

A' steady andfree flow of 'the' materials may be assisted by the: ercussive impacts of .elekztro-mag neti'c vibratorsindicated at 1 5- in Figs; 1 and; 13.. The angle of inclination can be reduced if the nretalliccasing is vibrated. to eliminate friction betweenthematerial' and: the surface along whichit musttravel'. With: such vibrators in use, the possibility of clogging of the spaces between thewebs of the rifil'es is materially reduced.

The heaviest particles, sliding downward along the inclined inner surface of the shell, will finally reach the lowermo'st end and will enter the widest portion of. the member'5. In Figs. 2 and 13, the interior of the member 5 is shown as' expanding or widening toward the left from the flange 4' to a channel 66 which: maybe formed as a volute in section. as best seen in Fig. 14, with the receptacle' 61 at the greatestdi'stance of the curve from the axis of rotation, or the channel may be sub-- stantially concentric with the axis as shown in Figs.= 2 and 5, with the receptacle 68 at the end of a lateral pocket.

In Fig. 2, the member 5 is shown as. provided on its interior with a protector ring 1.5 whichv may consist of one or more pieces secured to the; member 5 by screws TI. This ring extendsiforward. beyond the channel to direct the stream of water into the eylindricalshell I. to prevent the. stream. from? directly entering the channel. to: wash out'materi'al that has gravitated into it, while if. anysuchmaterial should be carried upward. and fall from the receptacle, it would engage the outer surface of t e .r and s be prevented from falling into the stream.

The structure shown in Fig. 13 omits the protector ring, since, with the volute' channel, the centrifugal force of' rotation at a proper speed will be sufficient to hold the heavy metal in the receptacle.

Inboth Fig. 2 and Fig. 13, a padlock 18 is shown in a stud 19 secured. in the member 5' to prevent sidewise' outward movement ofthe receptacle 6'! or '68: each of which has an ear'80 to receive the stud asv the receptacle is slid into position between the lugs 8| and 82. The front edge of the rim of the receptacle is beveled at 83 to engage within a correspondingly undercut notch in the member 5. The lug M has a beveled upper. surface tobe engaged by the tapering smaller end of the receptacle while the lug 82 has a set screw .84 to thrust the receptacle longitudinally and upward to bring the smoothly ground upper surface into liquid-tight contact with the smooth lower surface surrounding the outlet of the chanopening 86 at the outermost point radially from the axis of rotation for the continuous escape of water and for the escape of any minerals that may gravitate to this outlet. A metallic hood 8'! surrounds the shell I at its lower end and the end member near the channel 66 to receive the concentrate discharged from the opening 86. Re ceptacles will be provided having openings of different sizes from which to select the proper outlet to agree with the rate of concentration, which will be dependent upon the relative quality of metal in the matrix, on the proportion of solids to water in the flowing stream, on the speed of the stream, and on other factors.

The apparatus will thus provide a continuously operating separator from which the lighter materials will be discharged at the upper end and the heavier materials at the lower end. While some of the lighter minerals may accompany the heavier minerals to the receptacle, there is no force acting on the heavier minerals that can discharge them at the upper end once they have dropped from the flowing stream, unless they are embedded in or attached to lighter bodies of which they form a minor portion.

Lugs 88 shown in Fig. 14 serve as a pedestal to support the receptacle when it is removed and set down on a fiat surface and also provide a place to be struck with a hammer to dislodge the receptacle when taking it ofi the shell.

It will be understood that the details of construction shown and described are purely illustrative and the invention is to be construed broadly within the full scope and meaning of the claims.

I claim:

1. A separator for minerals difiering in specific gravities comprising a separator chamber having an inlet member, a central portion of greater diameter than that of the inlet member, and an outlet member, the inlet and outlet members being mounted for rotation in bearings of which the bearing for the outletmember is the higher, a plurality of annular riilles having their outer edges separated from the inner surface of the central portion and theirinner edges surrounding the central opening substantially concentric with the axis of rotation of the chamber, means for forcing a stream of Water having finely divided minerals in suspension therein through the inlet member into the separator chamber, means for rotating the separator chamber, and means carried by a rotating member to engage material between the rifiles and to carry it upward to the upper portion of the flowing stream;

2. A separator for a mixture of finely divided minerals differing in specific gravities which comprises means providing an inlet passageway for a stream of Water carrying the mixture in 1 suspension, an upwardly inclined shell of larger internal diameter than that of the inlet, whereby to cause the speed of flow of the stream to be lessened, a plurality of annular riflles having webs extending transversely of the shell and having portions of their outer edges spaced from the interior of the shell, the webs having wings extending into the spaces between the Webs, and means for rotating the rifiles around the stream, whereby material engaged by the wings will be moved sidewise from below the stream, upward at one side of the stream, and discharged into the stream,,and whereby heavier particles may slide downward within the inclined shell.

3. A mineral separator comprising a rotating shell havingan end member at its lower end,

8 means within the shell permitting gravitation of heavy minerals down the inner surface of the shell, the end member being provided with a channel to receive material from the shell, the bottom of the channel gradually increasing in radial distance from the axis of rotation of the shell, and a receptacle at the point of greatest distance of the bottom of the channel from the axis,

4. A structure as in claim 3 in which the receptacle is provided with an opening for the escape of material entering the receptacle, and in which there is a hood surrounding the locus of travel of the receptacle to receive material leaving the opening,

5. A separator fOr minerals comprising a tubular conveyor for flowing water, including an intake portion and an inclined rotary separator chamber, a plurality of annular riflies mounted within the chamber transversely of its axis of rotation and having portions of their exterior peripheries separated from the inner wall of the chamber, each riflle having a central aperture substantially concentric with the axis of rotation of the chamber and of greater area than that of the intake portion whereby to reduce the rate of flow of water through the chamber, means for rotating the chamber, and means for forcing water carrying minerals of difierent specific gravities in suspension upward through the tubular conveyor, the arrangement being such that heavier particles of the suspended materials at the slower rate of flow within the chamber will engage the baffies to arrest forward movement.

6. A mineral separator comprising a substantially cylindrical shell having an annular end member secured upon the lower end thereof, a plurality of riflles having projecting portions engaging the inner surface of the shell to space the outer edges of the rifiles from the shell to provide passageways between the riifles and the shell, the rifiles being slidable longitudinally of the shell for assembly in spaced relation with their webs radial to the shell, the said end member having lugs projecting inward for engagement with the lowermost rifiie of the assembly and having the inner edge of the annular member substantially flush with the inner surface of the shell in spaces between the lugs, and means for clamping the riffies removably within the shell for rotation therewith,

ERNEST KREHER.

REFERENCES CITED The following references are'of record in the file of this patent:

UNITED STATES PATENTS- Number Name Date 888,767 Trottier May 26, 1908 969,591 Abeel Sept. 6, 1918 987,677 Hogan Mar. 21, 1911 1,027,952 Wick May 28, 1912 1,034,252 Lewis July 30, 1912 1,034,259 Lewis July 30, 1912 1,064.459 Du Pont June 10, 1913 1,362,448 Sudlow Dec. 14, 1920 1,660,551 Garson Feb. 28, 1928 1,673,675 Hanciau June 12, 1928 1,930,075 Bentley Oct. 10, 1933 1,983,968 Clark Dec. 11, 1934 FOREIGN PATENTS Number Country Date 131,969 Germany June 28, 1902

Images