US2945590A

US2945590A - Adjustable permanent magnetic separator

Info

Publication number: US2945590A
Application number: US539162A
Authority: US
Inventors: Roswell H Stearns
Original assignee: Indiana General Corp
Current assignee: Indiana General Corp
Priority date: 1955-10-07
Filing date: 1955-10-07
Publication date: 1960-07-19
Anticipated expiration: 1977-07-19

Description

July 19, 1960 NS 2,945,590

ADJUSTABLE PERMANENT MAGNETIC SEPARATOR Filed Oct. 7, 1955 2 Sheets-Sheet 1 I /Z w //Z .2 a

IN V EN TOR.

Fa s we 1. H. TEHE A Tran/5Y6 July 19, 1960 ADJUSTABLE Filed Oct. 7, 1955 R. H. STEARNS PERMANENT MAGNETIC SEPARATOR 2 Sheets-Sheet 2 INVENTOR. Pow/54. H. Srsneu! Arra ENE v5 United States Patent ADJUSTABLE MAGNETIC SEPARATOR Roswell H. Stearns, Wauwatosa, Wis.,- assignor to Indiana General Corporation Filed Oct. 7, 1955, Ser. No. 539,162

14 Claims. (Cl. 209-423) This invention relates to an adjustable permanent magnetic separator.

It has been found that in the type of magnetic separator in which a flow of water carries the material past the magnets, and the magnets are. electrically activated, high humidity and water leakage tend to damage'the electro magnets and cause either ineflicient separation or complete failure. Accordingly permanentmagnets are used, but with a unique mode of drum adjustment which provides the fine control made necessary by the short range of action of permanent magnets compared with electromagnets, which is adaptable for either permanent or electromagnetic separators, and which provides greater flexibility and sensitivity than is usual.

Novel means on the drum of the separator form a part of the flow channel, in order to more efliciently channel the matter to be separated within the eflective range of the magnetic field, and further cooperates with novel flow plates underlying the drum. Means are provided to correlate adjustment in the magnetic field, adjustments in the flow plates underlying the drum, and adjustments in the concentrate discharge chute, in order tomaintain the proper operating relationship when applicants unique drum adjustment is used.

Also provided is an improved magnet support structure in which the soft iron pole pieces providesupport for the magnets, reducing the bulk and complexity of the support structure, particularly in the region of the magnetic field, to facilitate the placing of'the magnetic poles as close to the inside surface of the drum as possible and to reduce the weight of the structure for ready adjustability.

In the drawings:

Fig. 1 is a vertical axial cross-section of a magnetic separator embodying my invention.

Fig. 2 is a view on line 22 of Fig. 1.

Fig. 3 is a view of the drum bearing, partially broken away to show a modified adjusting means.

Fig. 4 is a view on line 4-4 of Fig. 1 with the drum hub removed, showing a further modification of the bearing adjusting means.

The drawings show a drum having a cylindrical wall portion 11, two annular flanges 12, and circular heads 13 having hub portions 14. On one of'the hub portions is mounted a sprocket 15 which is keyed to the hub at 16. Hubs 14 are rotatively mounted on sleeves 17 each of which has a cylindrical bearing surface '18 for its hub 14, an eccentric axial bore 19, and a flange 20 which serves to maintain the drum structure in its proper axial position and also serves as a worm wheel for ICC adjustment of the eccentric sleeves 17. Each bearing sleeve 17 is mounted rotatively on shaft 21. Shaft 21 is supported at its ends by frame members 22 in which it is rotatable, but it' is normally restrained from rotation by set screws 23.

Insideof the drum two magnet supporting hubs 25 are keyed at 26 to shaft 21. Extending from hubs 25 are spokes 27. An annular rim segment 28 joints the distal ends of the spokes of each hub. Secured to the annular rim segments are pole pieces 29 constructed of soft iron and extending axially between the rim segments. Permanent magnets 30 of axially elongated horseshoe form are supported on the iron pole pieces and may 'be secured thereto in any convenient manner. Proximate poles are of like polarity and rest side by side on the polar bars 29. The poles may be anchored. by screws, but gravity alone is suflicient.

The lower portion of the drum 11 lies Withintank 31 which is supplied with Water and ore from a curved entry passage 32' having a baffle 33 and a lip 34 of arcuate cross-section, which guides the entering mixture in a smooth stream over flow plate 37 into intimate contact with the rotating drum. Flow plate 37 is located just below lip 34, in a position to receive the flow therefrom. It is adjustable about a pivot 39 located at its flow receiving end. Adjustment is effected by cam 40 whichis mounted to rotate with adjustingshaft 41. Plate 37 has its marginal flanges 38 positioned between annular flange portions 42 of angular corner members 12 of the drum 10, and serves to direct the flow of separatable material into regulated proximity to the drum periphery and within the effective range of magnet 30.

Tank 31 his two'sump portions 310 for tailings and 311 for middlings divided by a transverse portion 312. Nonmagnetic'solids falling off the end of flow plate 37 descend into the tailings sump 3'10 and are drawn off from time to time through valves 43. Matter adhering to'the drum other than by magnetic force is-wiped off by rubber wiper .44 mounted on partition 312 and sufliciently flexible to bear lightly against drum surface 11.

Material which is susceptible of magnetic attraction adheres to the surface of drum 11 by reason of the mag.- netic force concentrated in pole pieces 29, and passes scraper 44 without being dislodged. The scraper will dislodge nonmagnetic material which is merely mechanically adherent. It will also Wash the magnetic material by holding back liquids'in which such material is immersed, thus occasioning relative movement between the magnetic material and the liquid bath.

Flow table 46 having stiffening marginal flanges 47 is pivoted on shaft-49 and rests at its free end on adjusting cam'48. The plate 46 is' adjustable in the same manner as flow table 37 between the flange portions 42 of the drum. Nozzles 50 mounted on pipe 51 are arranged :to direct jets of water against the concentrate on the drum and to cause allow of a sheet of Water in the channel defined by flow plate 46, fianges'42, and drum surface 1 1, which flow is counter to the rotation of theadiiurn. The effect of the jets from nozzles 50 may be variedeither by varying the water pressure or :by .c'hangingthe angular position of the nozzles by rotating pipe :51. .Nozzles 52 and-pipe 53 :are similarly adjustable and provide :a third washing .of the magnetic concentrate. Jet. 52'-is-located close to the end of the angular extent of the magnetic field and tends to wash the concentrate ofi of the drum.

Dislodged weakly magnetic middlings flow back down plate 46 into sump 311 for discharge subject to control valve 55. More strongly magnetic concentrates drop from the drum and flow onto chute 54 for delivery into a conventional concentrate bin which is not shown.

Chute S4 is adjustable by means of rack 55 and pinion 56 to vary its distance from the drum for a purpose which will be indicated later. Further sprays may be provided at other points on the periphery of the drum to wash off any concentrates which fail to fall of their own weight when removed from the magnetic field, in a man: ner well known in the art.

Each flange 20 of each bearing sleeve 17 comprises a worm gear having teeth 57. A worm 58 meshes with each worm gear and is axially aligned between supports 59. A shaft 60 extends from the worm and passes through frame member 61, terminating in a hand wheel 62 for the purpose of rotating the bearing sleeve to adjust the position of the drum 10. As the bearing sleeves are rotated through equal angles the eccentric axis of the drum is likewise rotated.

Fig. 3 shows a modified form of adjusting means in which shaft 21 is channeled at 70 to receive screw 71 which is engaged in threads in lug 72, which lug projects axially from flange of bearing sleeve 17. Axially of flange 20 a set screw 73 penetrates into channel 74, which is an annular channel in the end of hub 14. In normal use of the machine, set screw 71 is tightened in channel '70, locking bearing sleeve 17 to shaft 21. Set screw 73 is not in contact with channel 74 and does not impede free rotation of hub 14 on bearing sleeve 70. When it is desired to adjust sleeve 17, set screw 71 is loosened and set screw 73 is tightened, so that hearing sleeve 17 is locked to hub 14 but is free to rotate on shaft 21. The

from the magnets becomes particularly significant after the material passes scraper 44. Beyond the scraper the material moves counterflow respecting water from jets 50 which is traversing table 46. In conjunction with the counterflow of water from jets 50 the weakened field allows the washing of weakly magnetic middlings from the drum. These pass downwardly in middlings sump 311 to valve controlled outlet spout 55, through which a flow of water proportioned to the influx of water is maintained.

Jets 52 dislodge strongly magnetic particles from the surface 11 of the drum as they pass out of the magnetic field. Concentrate chute 54 is adjusted by means of rack 55 and pinion 56 in such a manner as to catch these particles as they fall free of the drum surface.

The eccentricity of the bore in bearing sleeve 17 is calculated, with respectto the distance from the bottom of the pole piece to shaft 21, so that when the drum axis is at its highest point with respect to shaft 21, the pole pieces 29 are a few thousandths of an inch from the inner surface of portion 11 of drum 10. This insures that the magnetic flux may be made very great at the drum surface radially outward from the thinnest portion of sleeve hearing 17, whereas radially outward from the thickest portion of sleeve bearing 17 (if that portion is adjusted so that the magnets lie radially from that portion), the distance from the pole pieces to the drum surface is relatively great, and the magnetic flux will be materially reduced. Thus it is possible to have not only a field of the desired intensity but zones of flux of differing intensity according to the adjustment of sleeve 17. For instance if the thinnest portion of bearing sleeve 17 is below the 4 axis of shaft 21 the strongest zone of flux will be in the drum 10 is then turned until the corrected position of ment means for hearing sleeves 17. Attached to flange 20 of bearing sleeve 17 is a stud shaft or pin 80 upon which a collar 81 is pivoted. Rod 83 connected to the collar extends through hub 84 of a hand wheel 85. Hub 84 is rotatable in frame member 88 and is in threaded connection with rod 83. Upon rotation of hand wheel 85 the shaft 83 is pushed or pulled according to the direction of rotation, thereby adjusting the angular position and the direction of eccentricity of the bore 17.

In operation, drum 10 being rotated conventionally by sprocket 15, the material to be separated enters inlet passage 32, is skimmed by baffle 33 and passes over lip 34. Flow table 37 is adjusted into sufficiently close relation with the surface 11 of drum 10 so that magnetic material in the mixture is attracted by the magnetized stationary pole pieces 29 within the drum and clings to the non magnetic surface 11 of the drum. The changing field at the surface of the rotating drum as the magnetic material is rotated past the alternate north and south poles of the magnets produces movement among the magnetic particles. This facilitates the separation and dropping off of tailings and middlings. As the nonmagnetic tailings reach the turned down edge 64 of the flow table 37 they drop downwardly in the bin 31. A flow of water proportioned to the flow of nonmagnetic tailings is withdrawn from region of scraper 44. The intensity will be at a maximum throughout the entire angular extent of the magnets because the are formed by the pole pieces is concentric to the arc of the inside of the drum.

However, if the thinnest portion of bearing sleeve 17 is between the center of shaft 21 and the pivot 39 of flow table 37 (as shown in Fig. 2), the flux will be at a maximum near the flow distributing lip 34 and will be greatly weakened at a point near

jets

50 and 52. The converse l situation can of course be effected as easily. The foregoing assumes that the pole pieces are disposed on a segment of a cylinder as in the preferred embodiment shown.

It will be noted that as bearing sleeve 17 is adjusted, the drum 10 as a whole, rather than the magnets, is

- raised or lowered. Since the magnets are very heavy,

this effects a substantial saving in the effort required. However, it becomes necessary to adjust flow tables 37 and 46 to correspond to the new position of the drum, in order to maintain the proper relationships between the flow tables and the drum for eflicient separating. Likespout 43 in a well-known manner to avoid piling up of V wise it may become necessary to adjust

jets

50 and 52, and it may also be necessary to adjust chute 54.

The water within the tank is maintained at the proper level by overflow pipe 35 from which water is discharged at 36.

If necessary the entire group of magnets may be rotated about its axis by loosening set screws 23 in pedestals 22 and rotating shaft 21 by means of a hand wheel or by any other appropriate means.

Since the field strength adjustment is made solely by rotating the eccentric bearings for the drum, the rotation of the magnet assembly adjusts the flux cutoff point without appreciable change in distribution of field strength.

Thus the operator can change the operating characteristics of my magnetic separator within a wide range, to

frame comprising end segments spaced axially of the drum and polar bars spaced circumferentially of; the inner periphery of the drum and in close proximity thereto and connected with respective end segments, and permanent magnets of channeled form in cross-section elongated axially of the drum and having polar ends mounted upon and supported by the polar bars of the frame, proximate ends of the magnets being of like polarity and being mounted on the same polar bar, said frame ends having mounting means projecting at opposite ends of the drum and provided with supports to which the mounting means is adjustably fixed, the drum having eccentric bearings rotatably adjustable respecting the mounting means and the drum being supported on the eccentric bearings in a position of eccentricity with regard to said polar bars, the extent and direction of eccentricity being adjustable by the rotation of said bearing means.

2. In a magnetic separator, the combination with a rotatable drum and means for feeding to the periphery thereof material having a separable magnetic content, of a set of magnets within the drum having outwardly directed poles spaced circumferentially of the drum in arcuate series, the inner periphery of the drum progressively deviating in the direction of drum rotation from the arc of said series of poles, supporting means for the series of magnets within the drum, and bearings for the drum mounted for rotatable adjustment respecting the supporting means and having bearing surfaces eccentric with respect to said supporting means and upon which the drum rotates, the adjustment of said bearings being adapted to vary the spacing and direction of eccentricity of the drum respecting said arcuate series of poles.

3. The device of claim 2 in which the magnets are permanent magnets of horseshoe form in cross-section and elongated axially of the drum, the magnet supporting means comprising segmental end members, and the poles comprising bars connecting said members and upon which the ends of the permanent magnets rest to constitute said bars as the arcuate series of poles aforesaid.

4. In a magnetic separator of the type described, the combination with supports and a shaft extending therebetween, of bearing members mounted on the shaft for rotation with respect thereto and having bearing surfaces eccentric respecting the shaft, a magnetic supporting frame mounted on the shaft and comprising pole members spaced circumferentially in arcuate series and magnets for energizing the pole members, and a drum mounted on the eccentric bearing surfaces of said bearing members and provided with means for its rotation, the inner periphery of the drum being in immediate proximity to the arcuate series of polar members and progressively deviating therefrom in the direction of drum rotation, the extent and direction of eccentricity being controllable by the rotation of the bearing members.

5. The device of claim 4 in combination with means for feeding to the periphery of the drum material having a separable magnetic component and means advanced from the last mentioned means in the direction of drum rotation for catching tailings and magnetic concentrates.

6. The device of claim 5 in further combination with means for securing the shaft in angular adjustment, the shaft and the magnets being bodily adjustable respecting the supporting means for varying the point of discharge of concentrates.

7. In a magnetic separator, the combination with a drum provided with bearing means upon which it is rotatable, the bearing means having mounting means in which the bearing means is rotatably adjustable, the axis of the mounting means being eccentric with respect to the axis of drum rotation on said bearing means, of magnetic pole members in arcuate series Within the drum,

said members being spaced circumferentially of the drum and disposed along an arcuate path progressively deviating from the inner periphery of the drum to an extent and direction determined by the position of said bearing means, magnets forener gizing the pole members, a tank in which the periphery of the drum rotates, said being partitioned axially of the drum. to provide. separate collecting sumps for a less magnetic and more magnetic material, means for introducing into the tank material having a separable magnetic component, and means for confining the introduced material respecting the drum periphery and comprising an arcuate plate having mountings upon which portions of the plate are adjustable to and from the drum.

8. The device of claim 7 in which said arcuate plate terminates adjacent the partition, the partition having a flexible wiper extending toward the drum periphery and positioned to engage material magnetically held to such periphery as the drum rotates.

9. The device of claim 7 in further combination with a second plate spaced axially of the drum in the direction of drum rotation from the plate first mentioned and likewise having mounting means upon which portions of the second plate are adjustable to and from the drum, and discharge means for concentrates extending from the periphery of the drum outwardly of said tank at the end of the arcuate series of magnetic members.

10. The device of claim 9 in which the respective plates have supports at their mutually remote ends upon which the plates are pivoted, the plates having rotatable means for adjustably supporting their proximate ends.

11. The device of claim 9 in which a flexible wiper extends from the tank partition toward the periphery of the drum in a position to act on material carried with the periphery in the course of drum rotation.

12. In a magnetic separator, the combination with a drum mounted for rotation and means for feeding to the periphery of the drum material having a separable magnetic content, of a frame disposed within the drum and with respect to which the drum is normally rotatable, magnetic pole means disposed Within said drum and carried by said frame and having poles of successively opposite polarity disposed in arcuate fashion in close proximity to and along the inner periphery of the drum, mounting means supporting said frame within said drum and projecting at opposite ends of the drum, supports to which the mounting means is adjustably fixed, the drum having eccentric bearings rotatably adjustable with respect to said mounting means, and the drum being supported on said eccentric bearings in a position of eccentricity with respect to said poles, the extent and direction of eccentricity being adjustable by the rotation of said bearing means relative to said mounting means.

13. In a magnetic separator, the combination with a drum provided with bearing means upon which it is rotatable, the bearing means having mounting means on which the bearing means is rotatably adjustable with the axis of the mounting means being eccentric with respect to the axis of drum rotation on said bearing means, of magnetic pole members in arcuate series within the drum, said members being spaced circumferentially of the drum and disposed along an arcuate path progressively deviating from the inner periphery of the drum to an extent and direction determined by the position of said bearing means. I

14. In a magnetic separator, the combination with a drum mounted for rotation on a longitudinal axis, of a permanent magnet assembly comprising magnetic pole members spaced circumferentially of the drum and disposed along an arcuate path along the inner periphery of the drum, permanent magnet means extending between successive pole members for establishing magnetic fields therebetween at the outer surface of said drum, and means for adjusting the strength of the magnetic fields at the outer surface of said drum comprising incrementally operating adjustment means continuously adjustable over a range of positions while the permanent magnet assembly remains stationary and without relative rotation between the magnet assembly and the drum to correspondingly vary the strength of the magnetic fields-from the permanent magnet assembly.

Refereucc Cited in the file of this patent UNITED STATES PATENTS 306,778 Ripley Oct. 21, 1884 500,604 Payne July 4, 1893 1,414,170 Bethke Apr. 25, 1922 1 l l l 4 l