US2360129A - Multiple separation apparatus - Google Patents

Description

Oct. 10, 1944. c, B. HEBBARD I MULTIPLE SEPARATION APPARATUS Filed Feb. 14, 1942 5 Sheets-Sheet 1 Inventor UHARL E s B. HEBBAIPD.

By and Oct. 10, 1944. c. B. HEBBARD MULTIPLE SEPARATION APPARATUS r w 2 my M m b fl w E v w E w B 3 w W n M W a c M w 4 m. 1 b w m M 1944- c. B. HEBBARD MULTIPLE SEPARATION APPARATUS Filed Feb; 14, 1942 3 Sheets-Sheet 5 Inventor Gan/P455 ,B f/EBBARD Patented Oct. 10, 1944 I PATENT OFF-ICE MULTIPLE ssrsas'rron mums Charles B. Hebbard, Joplin, Mo., assignor of onehalt to Kelsey Norman, Henry Wax-ten, and

Helen E. Bedding, all of Joplin, Mo.

. Application February 14, 1942, Serial No. 430,976 1 3 Claims.

I The invention relates. generally to improved means of producing multiple separation of components of fragmentary material, the said com- 1 ponents-having different specific gravities, and

more particularly to process and apparatus pro- 5 ducing such separation by means of the combined agencies of flotation and rising fluid currents of a heavy density medium, whereby fluid circuits are established which automatically operate to congregate and draw oil particles of predetermined specific gravity at corresponding predetermined levels in the medium, whereby an indefinite number of components of progressively different speciflc gravities may beemciently separated from v the other components of the fragmentary material originally charged into the medium simply by providing and proportioning the necessary number of stages. v

Important objects and advantages of the invention will be apparent from a reading of the following description and the appended drawings wherein preferred embodiments of the invention are set forth for illustrative purposes.

In the drawings:

Figure 1 is a general side elevatlonal view of 5 the apparatus in accordance with the present invention.

, Figure 2 is a top plan view of Figure 1.

Figure 3 is a schematic sectional and elevational view of the apparatus with portions of the casing broken away to disclose the interior structure. Figure 4 is an enlarged fragmentary vertical I a sectional view taken through Figure 2 along the line' 4- -4. I

Figure 5 is an enlarged horizontal sectional view taken through Figure 1 along the line 5 -5.

Referring in detail to the drawings, the numeral 5 generally designates an upright substantially cylindrical casinghaving suitable support means rises the tube I! which has a downtumed goosenecl: is on its upper end discharging onto a particular section of the multiple screen 20. An

air jet is is arranged through the bottom oi. the

short horizontal tube section 16 and projects axially upwardly into the lower part of the tube 'l'l, with a valved air supply pipe 22 connected to the air jet.

. The upper end of the tube l5 has'eccentrically mountedthereon' the cylindrical hopper 22' which; has laterally displaced tapering bottom portions 23 and 24, the upper end of the pipe i5 being connected to the bottom portion 23. An adjustable partition 25, horizontally hinged at 25 between the two tapering bottom sections. is operable by a hand crank equipped screw 21. for a purpose to be explained herein. The bottom portion 24 is connected by a short declining tube 28 to the short vertical tube 29 at a point between its upper and lower ends. The lower endof the tube 29 depends into the upper end of the casing 5, while the upper end of the tube 29 which projects above the casing 5 is provided with a hopper 30 to properly receive the material, such as ore, from the conveyor conduit 3] which discharges theremtio; s

, At each separation stage orzone or region in the casing 5 defined by the indentations and-by the tapered bottom l2, there is provided a drawofl. These draw-offs are similar in form and arrangement in the casing but are graduated in size and in diameter from the upper part of the casing to the lower part thereof, the correspond- 1 ing draw-oils being generally designated by the numerals 32, 33 and 34.

The uppermost draw-0d 32 which is largest in size and diameter connects with the air lift tube 32' which has a goose neck in its upper end discharging onto the section 32a of the multiple (not shown), and indented 'circumferentially at screen 20. The next smaller intermediate drawsuccessively reduced distances from the top 6, as indicated by the numerals 1 and 8, respectively. The indentations are characterized by oppositely tapering walls 9 and I0 joined to produce interior annular restrictions II. The casing 5 is divided 5 into three chambers or zones 5a, 5b and 5c diminishing in volume, all of the same diameter. The

lower end i2 of the lowermost casing section defined'by the-presence of the indentations is downwardly tapered to a relatively small diam- 501 screen section 36a.

eter neck l3 which connects with the top wall of a declining tube section i4 passing beneath the casing 5 Theupper end of the tube section it connects with the lower end of the tube l 5 which rises alongside of the casing to'a point sufliciently 5 horizontal section i6 from the outer end of which formed with'a small hole 50' to prevent an air of! 83 connects with the air lift tube 33' which has a gooseneck on its upper end discharging onto the section 33a of the screen, which the smallest draw-oil 34 connects with the air lift tube 34' having its gooseneck discharging onto the sec tion 34a of the screen 20.

The overflow mouth 35 at the side of the top 6 of the casing 5 discharges onto the section 35a of the said screen, while the gooseneck IS on the upper end of the tube l1 discharges onto the Each draw-off comprises a vertically disposed cylindrical conduit 31 arranged concentrically in the casing 5 withits open lower end 38 positioned close to the level of the upper boundary 39 of the related constriction. The upper part of the conduit 31' is conical as indicated at 40 and rises to a point at or beyond the middle height of the related casing section. The apex of the cone is trap in the cone. A lateral tube 4|, somewhat smaller in diameter than the conduit, 31, declines at the same angle as and communicates with the conical top 4! of the conduit. The depressed laterally outward end of the tube 4| passes horizontally through the side of the casing 5 as indicated at 42 at substantially the same level as the open lower end of the conduit 31. An air jet 43 rises through the bottom of the horizontal portion 42 and rises axially well into the corresponding one of the described air lift pipes, the jet being fed by a related valved air pipe 44. A vertical baflle 45 depends below the top of the horizontal portion 42 and somewhat below the upper end of the air jet 43 to confine the action'of the air jet to its lift P p lects in the tube l4 and is raised through the tube l1. Beyond the hopper 46 the screen 29 has a hopper 55, not involved in the operation of the described system, but provided'to catch the washings from separated particles moving along the screen sections from the region of the hopper, and carrying the diluted medium to the thickener; (not shown). As shown in Figure 3 the screen sections may be declined away from the casing 5 or otherwise suitably arranged to effect the desired transit of the particles retained on the screens.

The multiple screen 29 has a tapered hopper 46 receiving the strained medium from all of the screen sections 34a, 33a, 35a, 36a, and 32a, this hopper emptying into the declining tube 41 which connects with the lower part of the lift tube 48 at a point above its lower closed end 49. An air jet 5!! fed by an air supply pipe 5| projects through the said closed end 49 and axially upwardly into the tube 48. The upper end of the tube 48 is formed with a downturrzed gooseneck 52 which, as shown in Figure 4 of the drawings, discharges into the hopper 22 midway between its distinct bottom sections 23 and 24, so that the partition 25 can be adjusted by tilting to direct more or less of the recirculated medium flowing from the tube 48, either into the pipe l5 or into the'pipe 29, thereby determining whether more or less of the recirculated medium is returned to the bottom or to the top of the casing 5. In actual practice the liquid medium level in the casing 5 is at the point indicated by the numeral 53, while the liquid level in the section 23 of the hopper and in the tube 48 is at the point 54. The difference in elevation of the two liquid levels creates a hydrostatic head in the tube 48 which acts to circulate the medium downwardly therein, to produce rise of the medium in the casing 5 and in the draw-offs.

A suitable flotation medium of selected specific gravity being present in the casing to the proper level and some of the material to be handled having been charged onto the top of the medium by the conveyor conduit 3|, the floatable material such as tailings overflows with the medium through the overflow 35 onto the screen 20. Th particles of next higher specific gravity sink through the medium to the region of the first indentation where they are arrested and confined by the fact of their having reached a point in the medium whereat the velocity of the uprising current of medium ofisets the specific gravity of the particles and prevents their sinking any further in the medium. The congregation of the arrested particulars adjacent to the open lower end of the uppermost draw-off 32 enables the arrested particles to be drawn oil by the controlled rising current of medium through the draw-off, to the region of the air jet 43 whereby they join the resultant rising column of fluid and are discharged onto the screen 29 and retained, while the medium returns into the system via the pipe 41.

While the first separation above described is taking place, the still denser particles sink through the arrested particles and are in turn arrested at levels within the casing 5 corresponding to their specific gravity and where they are in turn drawn oil? by the related draw-off. This operation proceeds until the final separation, such as free metal in an ore separation operation col- In actual operation of the apparatus, the drawofl air jets are adjusted to produce draw-ofl' of the desired particles from the related separation regions in the casing 5. If the draw-ofi air jets are jetting too much air they are valved down so that the draw-oil action will not be excessive and tend to draw-oft particles other than those congregating in the particular region which otherwise would properly sink to a lower region in the medium.

The jet 50 in the conduit 41, 48 is adjusted to keep the medium in the screen hopper 46 at a constant predetermined level.

The jet l9 in the conduit l4, I1 is adjusted so as to produce positive rise in the tube l1 of the heaviest material reaching the horizontal portion 16.

The partition 25 is adjustable by the crank 21 to properly apportion the flow of medium from the tube 48. For instance, if the upflow in the casing 5, caused by too much medium coming down the tube is keeping separated particles from sinking through the neck 13 into the tube l4, the partition 25 is adjusted to cause less of the medium from the tube 48 to fiow down in the tube I5 and cause more of the medium from the tube 48 to by-pass and flow into the top of the casing 5 through the tube 29.

The fragmentary material to be processed in accordance with the present invention does not require to be ground to uniform or small mesh sizes, so that the trouble and expense of preliminary grinding is reduced over other separation processes. However, in order to avoid spoiling the medium the crushed or ground material is washed to remove slime and fine sand, before charging it into the casing 5. Much larger material can be separated and recovered with the present process than can be successfully handled by other available processes. Material of 10- mesh size and larger can be successfully handled by the present invention.v

Although there are shown and described here spaced, circumferential constrictions defining cylindrical zones of one diameter and graded length containing a body of high density fluid medium having a specific gravity greater than that of the lightest particles and less than that of the heaviest particles, charging means for charging the fragmentary material into the top zone of the tank, overflow means at the top zone 0f the tank for overflowing the lightest particles floating on the top of the body of medium and draw-01f means in middle and lowermost zones of the medium, the heaviest particles sink relatively rapidly through the medium in the middle zone and reach the bottom zone of said tank while the particles of intermediate weights sink into the middle zone through said medium at slower rates according to their respective specific gravities, circulating means for producing a rising current in said medium andmeans for positively drawing off the heaviest particles accumulating in the bottom zone, said draw-off means located in the respective zones at different levels in said tank acting vertically and at levels corresponding to the points in the medium at which the velocity of uprise of the medium oilsets the sinking rate of the difi'erent intermediate weight particles, said draw-offs operating to draw-off the particles arrested in the mediumof their corresponding zones in the medium and conveying drawn oil! particles to points outside said tank; each of said draw-of! means comprises a radial conduit extending through the side of the tank and a vertical air-lift connected with the outward end of the conduit, said conduit comprising a radially inwardly inclined portion terminating in a vertical portion depending substantially axially in said tank, said vertical portion being open at its bottom to receive the combination of intermediate particles and medi at the level corresponding thereto.

2. Apparatus for multiple separation of particles of different specific gravity, comprising a vertical tank composed of a series of tubular zones in alinement one above the other of one diameter but of different length joined together by annular restrictions, means for circulating media upwardly through the tank, the upper one of said zones being adapted for containing a rising current of density media of lower velocity than the zone next below after such media having been charged into the bottom zone; a vertical draw-off colunm for each of said zones, each draw-01f column of a smaller diameter than in the zone next above, an exterior connecting conduit for said draw-off columns and means adjacent the top of said tank for screening and removing the media and particles and returning them to the bottom of said vertical tank.

3. Apparatus for multiple separation of particles of different specific gravity, comprising a vertical tank composed of a series of tubular zones in alinement one above the other of one diameter but of difierent length joined together by annular restrictions, means for circulating media upwardly'through the tank, the upper one of said zones being adapted for containing a rising current of density media of lower velocity than the zone next below after such media having been charged into the top zone; a vertical draw-off column for each of said zones, each draw-01f column of a smaller diameter than in the zone next above, an exterior connecting conduit for said draw-off columns and means adjacent the top of said tank for screening and removing the media and particles and returning them to the bottom of -said vertical tank, and

air lifts provided at the bottom of each of said exterior columns for removing media. CHARLES B. HEBBARD.

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