US1361342A - Flotation-machine - Google Patents

Description

H omwow MACHINE.

Mmmm@ BGG. 79

3 SHEETS*SHEET 2.

i. R. MRGETTS AND W. FAGERGREN.

APPLxcATloN FILED APR.9,1918.

UNITED il* TENT OFEFCE.

IRvnN It. ivIAnGnTTs AND WILLIAM FAGERGREN, er sALT LAKE CITY, UTAH, AssIGNoRs, BY DIRECT AND iunsnn Ass,rcnriunirrs, .or .oNETTHInnTo An- THUB. J. MILLER, cnn-THIRD To nn WITT Knorr, AND vcnn-.THIRD To WIL- LIAM ,FAGERGRELL ALL or SALT LAKE CITY, UTAH.

FLOTATION-MACHINE.

intensas.

Specification ci Letters Patent.

Patented Dec. 7, 1920.

Application led April 9, 1918. Serial No. 227,557.

To all whom t may concern:

Be it known that we, InvnN R. MAnenTTs and I/VILLIAM IFAGERGREN, both citizens of the United States, and residents of Salt Lake City, the county of Salt Lake, and the State of Utah, have jointly invented certain new and useful Improvements in Flotation- Machines, of which the following, together with the accompanying drawings, form a full, clear, and exact speciiication, which Awill enable others skilled in the art to which it appertains to make and use the same.

This invention relates to flotation machines and its principal objects are to provide a machine which shall:

l: Bc capable of producing a copious froth consisting of small bubbles.

2. Allow complete control of the amount of air used.

3. Cause the exposure of every part of the emulsified solution to the action of the air.

4. Require a minimum of attendance.

5. Effect a high percentage of mineral recovery.

6. Be simple in construction and operation, as well as durable, economical and efficient in operation.

7. Have few wearing' parts.

In attaining the objects mentioned, a housing is provided, whose bottom and sides are watertight, butwhich is open at the top. 'Rotatably mounted in this housing is a circular cylindrical impeller, preferably comprising a metallic spider at each end and `.having arms in the form of radial blades set after the manner of a fan and adapted to draw air from the outside of the impeller and to force the same to the interior thereof when the impeller is rotated. Around the periphery of the spiders may be spaced a plurality of staves paralleling the shaft on which the spiders are mounted, the staves being preferably made of wood and spaced about one-quarter of an inch apart. If desired, the impeller may be made of perforati cd sheet metal instead of wood. Extending l over the upper part of the impeller is a curved shield extending from end te end of the housing, contracted passages being left between the shield and the housing along the sides thereof. The shield is set just close enough to the impeller to prevent any interference with the latters rotation and is slightly eccentric therewith,.so as to allow the proper clearance and to prevent an undue suction between the impeller and the shield during rotation. The housing extends to a point above the top of the impeller equal to about the diameter of the impeller and the housing tapers from its greatest width near the top of the impeller to a more or less contracted width at the discharge surfaceof the housing. Immediately above the shield and in front of it, is a sharp angular pocket with bafiies adjacent, extending from end to end of the machine, through which the agitated pulp must necessarily pass before being discharged. The angular pocket is so arranged that the pulp is violently-thrown thereinto by the impeller and is compelled to pass through a narrow opening, the combined action thereof breaking up the pulp into small masses and allowing the air with which the pulp is impregnated to form large volumes of small bubbles. The` froth may overflow the sides of the machine and be discharged into the usual launders. Air for impregnating the agitated pulp may be supplied and controlled by pipes entering both ends of the machine, the pulp to be treated entering near the bottom'of the housing. The tailings are discharged just above the shield and iiow into a chamber whose outlet orifice may be controlled by movable` flash boards.

rI`he flotation process as applied to the eX- traction of minerals from their ores is now well known, therefore an explanation of the terms relating thereto and used herein, is not deemed necessary.

rlhe features of this invention on which protection is desired are collectively grouped in the appended claims.

In the accompanying drawings,

Figure l represents a vertical cross-section through the machine.

Fig. 2, a longitudinal vertical section therethrough, and

Iiig. 3, a vertical cross-section through a sc-called double machine.

Throughout the drawings, similar parts are designated by similar numerals.

Referring to the drawings, l() represents a watertight housing, which may be made of wood, metal or other suitable material. Inside the housing and extending longitudinally thereof, is a shaft 11, supported in the bearings 12, which are preferably located separate from, and outside of the housing. Where the shaft passes through the housing, stuffing boxes 13 may be provided and fitted with the glands 14. The space inside the housing and above the impeller forms a sorting column.

Mounted on the shaft 11 and located inside the housing are the spiders 15, having the arms 16 in the forni of radial blades, set helically to the right in one spider and helically to the left in the other spider, so that in rotating, the air will be forced to the interior of the impeller from each end thereof. In this instance, the spiders 15 have attached to the outside thereof, the wooden staves 17, with small spaces 18 between them.v The staves 17 extend close to the sides of the housing at each end, leaving only room enough for clearance during rotation. Over the impeller formed by the staves 17 is the curved shield 19, which is slightly eccentric to the impeller and is set with the edge facing the direction of rotation, very close to the impeller, allowing only clearance for rotation. The shield 19 is supported by the angles 20, which may be bolted to the housing at each end thereof. Between the shield 19 and the housing 10 are the passages 21 and 22. J ust above the passage 21 is a baffle 23 and somewhat farther up is the baflie 24, the latter forming a sharp angular pocket against the side of the housing 10. The baflie 24 extends to within a short distance of the shield 19, forming the passage 25.

In order to lengthen the exposure of the pulp to the action of the air, baffles 48 may be provided, which are set very close to the outside circumference of the impeller allowing only clearance for rotation. rlhe batlies 48 fit tightly against' the bottom and one side of the housing and are inclined upwardly and in a direction away from the tailings discharge.

The passage 22 may be closed by the gate 26 slidingagainstthe guide 27 and adapted to be raised and lowered by a threaded rod 28 at each end of the machine. lRods 28 are actuated by hand wheels 29 rotatablyy mounted in brackets 30.

The housing 10 is contracted in width at its upper end so as to form a smaller area thanV at the bottom, thereby causing the banking up of the froth which accumulates on the top of the pulp.

Air may enter the machine at 31, being supplied through the pipe 32, either from the atmosphere, or under a reasonable pressure from a suitable source of supply and in either case, controlled by the valves 33.

The pulp to be treated is supplied near the bottom of the machine through the pipe 34, entering the machine at 35. At 36 are overflow lips, discharging into the coni-ew.

trates launders 37.

The tailings are discharged through nipple 38 (Fig. 2) into the box 39. which is provided with the flash boards 40 for vary ing the discharge level. The flash boards l0 may be built up to such a height as may be, desired. corresponding to the level of the material being treated inside of the housing. Foot walks 41 may be provided for convenience in attending to the machine. ln the, present embodiment. the machine is shown constructed of wood and supported on the sills 42 and the sub-sills 43. The shaft Il may be driven by the pulley 44 Fig. 2) rigidly mounted.

In Fig. 3 is illustrated a modified eonstruction of this invention, in which two impellers are used instead of one. as in the machine just described. .lsseutially, the op eration of both the single machine and the double machine are identical. though the details of construction are necessarily somewhat diiferently arranged in the two machines. ln the double machine, the impellers are inter-geared, a portion of each gear being shown in meshed position by dotted lines. The machine may be driven by a pulley 45, as indicated by dotted lines, mounted on one of the shafts 11. The gate 46 is adapted to regulate the opening between the two shields 19 and may be raised or lowered by means of rods 28 and hand wheels 29, as already described.

ln using this improved machine, the impeller or impellers, are given a. speed of approximately 200 revolutions per minute in the direction of the arrows 49 shown in the drawings. The pulp to be treated. enters by the pipe 35, and as its level rises in the housing, it is caught up by the impeller, and thrown, by centrifugal force, into the spaces between the baiiles 48, as indicated by the arrows in Fig. 2, and thereby switched upwardly and backwardly and violently splashed up through passage 21. (Figs. 'l and 3), into the pocket 47 where it encounters a part of the pulp already thrown thereinto, and which rebounding` downwardly,meets the rip-rushing current, causing the air which is taken into the machine, as described below. to be thoroughly whipped into the pulp.

A certain amount of the pulp (equal to the feed) is being continually forced down through the passage 50, and through the space 25, thus forming a sulnnerged current flowing into the lower part of the sorting column.

As the amount of pulp passing under the bafile 24 is considerably less than the amount pulled around by the impeller. it follows that a certain proportion of the pulp has been kept fiuctuating between the point where it is discharged by the impeller and the pocket 47, so that a largely augmented Whipping' action is given the pulp which causes a most thorough impregnation of the pulp with small isolated masses of air. When the impregnated pulp reaches the zone of lessened pressure in the sorting column, it is allowed to expand and causes the liberal formation of a fine bubbled froth rising to the overflow level of the sorting column.

When the action above described is taking place, air is being admitted at 3l Where it is caught up by the blades 16 and pushed into the interior of the impeller, from which it is discharged outwardly through the slots 18 and is projected into, and distributed uniformly, through the pulp encountered by the outside circumference of the impeller.

T he shield 19 prevents the pulp from fall ing back on top of the impeller and compels it to re-enter the agitation chamber in which the impeller moves. rlhe re'e'ntrance of the pulp into the agitation chamber can be regulated in the single machine by the gate 26 (Fig. l) or in the double machine by the gate 46 (Fig. It will be observed that when the machine is in motion, there is a continual circulation of the pulp around the lower portion of the impeller and through the upper portion of the machine, while the interior of the impeller is kept clear of the pulp by the act-ion of centrifugal force, thereby leaving all the slots 18 free to discharge air into the surrounding pulp at all points. The circulation of the pulp thus obtained, and the many points at Which air is discharged, brings every point of the circulating pulp into intimate contact With the intaken air, thus thoroughly1 impregnating the pulp and causing a liberal frething of the pulp.

Une of the features of this machine which is desired to strongly emphasize, is the construction which compels all the air which is used, to pass in bubbles up through the pulp as there is no point of escape for the air, excepting through the sorting column and out at the top of the housing.

While one embodiment of this machine has been described, all the details thereof are not necessarily in the preferred form as shown and specified, and therefore, many changes might be made in both the arrangement and design of the details of the machine and in the kinds of materials used, withoutdeparting from the spirit of this invention in any particular.

Having fully described our invention, what ive claim as neu7 is:

l. In a flotation machine, the combination With a suitable framework, of a Water tight housing, an impeller adapted to rotate within the said housing, a shield over the said impeller, suitable baffles above the said shield, means for supplying air to the interior of the said impeller, 'means for supplying pulp to the interior of the said housing, a source of supply for pulp and means for rotating the said impeller as specified.

2. In a flotation machine, the combination with a suitable housing, of an impeller rotatably mounted therein, a curved shield above the said impeller, suitable baffles above the said shield, and means for rotating the said impeller as specified.

3. In a flotation machine, the combination With a suitable housing, of a rotatable shaft extending through the said housing, means for making a Water-tight joint between the said shaft and the said housing, means for supporting the said shaft outside the housing, a circular cylindrical impeller rigidly mounted on the shaft inside the housing, blades for projecting air from the ends of the impeller to the interior thereof, ashield over the said impeller slightly eccentric therewith, a longitudinal baffle above the said shield, a second longitudinal baffle slightly spaced apart from the first baille, and means for rotating the -said shaft.

d. In a flotation machine, the combination with a housing having a cross-section eX- tended at the bottom and contracted at the top, of a rotatable impeller suitably mounted, a shield above the said impeller, the said shield being` laterally spaced apart from both sides of the housing; a longitudinal baffle above the said shield and spaced apart from one side Wall of the said housing, a second baffle spaced apart from the first baffle, the second baffle forming an acuteangled pocket with the said side of the housing, and means for rotating the said impeller.

5. ln a flotation machine, the combination with a housing having a cross-section extended at the bottom and contracted at the top, of a rotatable impeller suitably mounted; a shield above the said impeller, the said shield being laterally spaced apart from both sides of the housing; a longitudinal baille above the said shield. and spaced apart from one side Wall of the said housing; a second baffle spaced apart from the `first bafii'e, the second baffle forming an acute-angled pocket with the said side of the housing: means for rotating` the said impeller: means for adjustably regulating that space between the said shield and the said housing, lying opposite the side on which the said baflies are located. and means for projecting air through the interior of the said impeller.

6. ln a flotation machine, the combination with a suitable housing, of a rotatable impeller mounted therein, the said impeller being adapted to discharge air at its circumference; a circular shield over the impeller, the said shield being slightly eccentric to the said impeller; a longitudinal baille forming an acute angled pocket with a wall oi' the said housing, above the shield, the lower edge of said baille bein spaced apart from the shield; a second baille spaced apart from the first baille projecting upwardly into the said acute angled pocket; and means for rotating the said impeller.

7. in a flotation machine, the combination with a housing having a cross-section extended at the bottom and contracted at the top, of a rotatable impeller mounted in the extended portion of the said housing, a curved shield located slightly above the said impeller and spaced apart from the walls of the housing along both edges of the said shield, a longitudinal baiile forming an acute-angled pocket with a wall of the said housing above the shield, the lower edge said baille being spaced apart from the shield; a second baiile spaced apart from the lirst bailie and contacting the said shield, the second baiile projecting upwardly into the said acute-angled pocket; means for rotating the said impeller; means for varying the space between the said shield and the said housing along that edge of the shield opposite the said battles; and means Jfor projecting air through the interior of the said impeller.

8. ln a flotation machine, having a sorting column, the combination with a suitable framework, of a water-tight housing, an impeller adapted to rotate within the said housing, inclined baiiies between the said impeller and the said housing on the discharge side of the said impeller, the said inclined baiiles being adapted to deflect any pulp which may be passing through the machine and cause the same to assume a circuitous path to the said sorting column.

9. ln a flotation machine,the combination, with a suitable housing, of an impeller rotaj tably mounted therein, a curved shield above the said impeller, inclined deflecting bailies, set transversely with the longitudinal center line of the said impeller and on the discharge side thereof, the said baliles extending from the bottom of the housing to the said shield, and means for rotating the said impeller as specified.

l0. In a flotation machine, ha ving; ing column, the combination with a suitable framework, of a water-tight housing open at the top, an. impeller adapted to rotate within the said housing and a plurality of deiecting baffles, inclined with reference to the bottom ot the said housing and set transversely thereof, the said battles forming circuitous channels extending toward the top of the said housing.

ll. In a flotation machine, the combination with a suitable housing, of an impeller rotatably mounted therein, inclined baiiles adjacent the said impeller, a curved shield above the said impeller, suitable battles above the said shield, means tor conducting air to the said impeller and means ior rotating the said impeller as specified,

l2. In a flotation machine, the combination with a suitable housing ot an impeller rotatably mounted therein, inclined ballles adjacent the said impeller, a curved shield above the said impeller, suitable baliles above the said shield, means :tor controllably conducting air to the said impeller, and means for rotating the said impeller.

13. In a liotation machine, the combination with a suitable housing, oi an impeller rotatably mounted therein, a curved shield above the impeller, a sorting column above the said shield meansl for supplying air to the ends of the said impeller, means tor drawing the said air to the inside of the said impeller, means for controlling the amount of air thus supplied to the said impeller, means for discharging the air from the impeller, means for conducting the said discharged air to the said sorting column, and means for rotating the said impeller as specified.

let. In a liotation machine, the combination with a housing having a cross-section extended at the bottom and contracted at the top, rotatable impellers suitably mounted in the said housing, a plurality of inclined bai'iles adjacent the said impellers mainly on the discharge side thereof, the said batlies being located in the lower part of the said housing and adapted to form deilecting channels for causing material discharged by the said impellers, to flow in circuitous paths.

l5. in a flotation machine, the combination with a housing open at the top and tightly closed around the sides and bottom thereof, of a suitably supported impeller inside the said housing, a sorting column located above the said impeller, a shield lior separating that portion of the housing containing the impeller from the said sorting column, means for supplying air to the ends of the said propeller, means for drawing the said air to the inside oi" the said impeller, means for centrifugally expelling the said air from the said impeller, means tor conveying the said expelled air to the said sorting column, and means for definitely controlling the amount ot air supplied to the said impeller.

1G. n a flotation machine, the combina,- tion with a suitable housing, of a rotatable impeller mounted therein, the said impeller being adapted to discharge air at its circumference, means for controllably supplying air to the said impeller, a circular shield over the impeller, inclined, transverse baiiles spaced apart from the shield; a second baille spaced apart from the irst batiie; and means 'tor rotating the said impeller.

17. The combination with a housing adapted to contain a liquid mass, oi' a hollow impeller rotatably mounted therein, a sorting column located above the impeller, a shield for separating the portion of the housing containing the impeller from the sorting column, means for supplying air to the ends of the impeller, means for drawing the said air into the impeller, means for discharging the said air from the impeller, means for conducting the discharged air to the said sorting column, and means for thoroughly diffusing the said discharged air through the said liquid mass, while en route to the said sorting column.

18. The combination with a housing adapted to contain a liquid mass, ci" a hollow impeller rotatably mounted therein, the said inipeller comprising fan-like ends adapted to create a suction toward the inside of the impeller when in motion, the impeller, further, comprising a cylindrical shell supported by the fan-like ends, the said shell being adapted, when in motion, to discharge air circumferentially into the said liquid mass; a sorting column located above the said impeller, means tor supplying air to the said tan-like ends, means for rotating the said impeller, and means for conductl ing the air discharged by the said shell, to

the said sorting column.

19. The combination with a housing hav ing a lower portion and an upper portion, of aerating means located in the said lower' portion, the said upper portion being adapted to have a sorting column formed therein, a shield for suitably separating the said upper portion from the said lower portion, and Hash boards for varying the levels of the said sorting column.

20. The combination with a housing having a lower portion and an upper portion, of an impeller rotatably mounted in the said lower portion, a sorting column formed in the said upper portion, a shield for suitably separating the said upper portion from the said lower portion, means for oontrollably supplying air to the said impeller, means for conducting air from the impeller to the sorting column and means for varying the height o't the said sorting column.

ln testimony that we claim this invention as our own, we allix our signatures in the presence of two subscrihino witnesses.

invita n. i/ianenr'rs. WILLIAM FAGERGREN. Witnesses:

G. MoKiMMiNs, ARTHUR J. MILLER.

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