US832822A - Magnetic ore-separator. - Google Patents

Description

No. 832,822. PATENTED ooT. 9, 1906.

H. H. WAIT z P. YDER.

MAGNETIG oRB s ATOR.

APPLIOATION AR.9, 1905.

rator; and its object is to 'improve the detailedE construction of the separator in such a ma nner as to provide for a greatly-increas'ed .UNITED sTATEs PATENT OFFICE.

HENRY' H. WAIT, CHICAGO, AND FREDERICK T. SNYDER, OF OAK PARK, ILLINOIS.

MAGNETIG ORE-SEPARATQR.

Speciflcation of Letters Patent.V

Patented Oct. 9, 1906.

Application filed Hatch 9,1905.` Serial No. 249.275.

'siding at Chicago, and FREDERIO l; T. SNY DER,

residmg at Oak Park, in the county of Cook, State of Illinois, citizens of the United States, have. invented a certain new and useful Improvement in Magnetic Ore-Separators, of Which the following is a full, clear, concise, and exact description.

Our invention relates to a magnetic sepapower of separationin a machine of given Weight and size. e

Our invention concerns more particularly the general type of machine in which the material to be separated is fed upon a horizontal rotating cylinder or separating-carrier which in its rotation carries said material through thevertical air-gap between said carrier and a magnet'pole-piece facing the side thereof. IOur invention is concerned especially with the shape of the pole-piece, which in combination With the armature forms 'the Working gap, the object being to form this pole-piece so as to secure the best and most economical 1 plan view thereof. i

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same parts in both figures.

The ore-separator illustrated in the drawings is of the general type in which a cylinder or separating-carrier is arranged to rotate adjacent to the ole of a owerful magnet placed at the side t ereof, the material toI be se arated being fed onto the to of the cylin er, so as to be carried around in ,the rotation thereof through the Working air-gap formed between said cylinder and said magnet-pole. In the machine illustrated the cylinder or armature ais of laminated construction, formed of circular disks assembled u on a shaft b, and said armature is arrangedp to rotate-be- The same 'letters of reference indicate the i tween' two opposed magnet-poles N S of opposite polarity placed on diametrically opposite sides thereof. Said Ole-pieces are shown as projecting inwardly om the sides of the magnet-frame' r, of holloW box form, o en top and bottom, and the armature-sha t is journaled in bearings in the neutral sides of said frame, The pole-pieces are rovided Withsuitable magnetizing-Windin s d. The space between the magnet-pole and the armature a is utilizedf as la-working air-gap, the

balancing, so 'far as practicable, the magnetic ull upon the armature; The armature is aminated, Vasl above described, in order to suppress eddy-,currents to 'permit the rotation of said armatureV in the intense magnetic field With the least expenditure of energy. The armature should be provided with means for producing dispersions of the magnetic .flux at its periphery in order that the magand t e magnetole may be attracted to the armature instea of to the magnet. Aconvenient construction is to' rovide teeth or serrations upon the circum erential edges of i tureflis built up. The magnetic lines of force leaving the pole-piece N will converge upon the points of the teeth and will also tend to converge upon the edges of the individual laminations or disks.

A divider-plate e is provided on the under side of the armature in close proximity thereto. The edge of this divider-plate may be located just inside a vertical plane tangent to the armature, so that non-magnetic material fallin straight down Will pass on one side of said ivider-plate, While the ma netic material adhering to the surface of t e armature will be. carried past the edge of the divider and fall upon the other side thereof. I A neutral point is formed upon the surface of the armature a by the coperating action of the two magnet-poles N and S of opposite polarity. The magnetic material attracted to the armature Will therefore fall off as it is carried beyond the region of the intense field and toward said neutral point.

Heretofore in machines of this type it has been customary to make the face of the magnet-pole vertical, so that it most closely approaches the armature a at the horizontal plane through the axis of said armature.

case thereforepasses from the pole-piece to the disks or laminations of which the arma-- other magnet-pole Szbeing for the purpose of' f netic articles passing between the armature I IOO The greater part of the magnetic flux in such the separati on of the magnetic material from the rest may be properly effected. As the armature carries an attracted particle around there is from the moment it leaves the vertical plane tangent to the armature an increasing component, due to gravity, which must be overcome by the attractive power of the armature in order to hold the magnetic particle to its surface. We therefore construct the pole-piece N with reference to the armature a, so that the magnetic flux instead of being concentrated at the horizontal plane through the axis of the armature shall be concentrated just above the edge of the dividerplate. To secure the greatest concentration of the flux at this point, it is desirable that the pole-piece N should here approach the armature a. more closely than elsewhere; but it is desirable for the purposes of rapid working that the permeable particles in the mixture being treated should be magnetized while they are still supported upon the armature that is to say, before they approach a position at which they would otherwise slide off. It is therefore desirable that a certain amount of ymagnetic flux should occur between the armature and the pole-piece N from the entire face of the pole-piece. For these reasons we prefer to construct the polepiece N, asshown, with its face curved ap- -proximately concentric With the surface of the armature, se that the magnetic flux will be at least as strong at a point just above the edge of the divider-plate as it is anywhere else. The strongest flux being required at this point, Which we term the point of separation, it is evident that any more intense flux at another point, as in machines heretofore constructed, is wasetful. The lace of separation must be at a point conslderably lower than a horizontal plane through the axis of the armature, because the non-magnetic material will fall straight down, and the edge of the divider-plate must therefore be we l inside of a vertical plane tangent to the armature, which necessarily means that the magnetic particles can be held onto the surface of the armature for a considerable arc in the rotation thereof in order to get them past the edge of the divider-plate,`and this must be against an increasing component of gravity. By providing a flux of maximum density just above the edge'of thedivider-platethat is, at a point considerably below the horizontal plane through the axis of the armature-the most efficient and economical. separation is obtained. If the magnet-pole were constructed, as heretofore, with a vertical pole-face approaching the armaturesurface most closely at a horizontal plane through the axis of the armature, it will be evident that in order to obtain a flux of requisite strength at the place of separation just above the divider-plate the total flux would have to be much greater than would be required in our construction, in which the principal part of the pole-face is cut back. VVe prefer to provide a non-magnetic shield over the face of the pole-piece N which will not nec'essarily follow the contour of the magnetpole face, but will be curved around the armature-surface, so as to hold the material close to the armature through the arc above the horizontal plane through the armatureaxis. The shield f should be at least vertical downwardlyfrom said horizontal plane in order to permit the free fall of the non-attracted material. In other Words, neither the magnet-pole N nor the non-magnetic shield f therefor should approach the armature below the horizontal axis thereof more closely than a vertical plane tangent to the surface of theV armature -or slightly outside of it.

There may be an open space back of the shieldf between the shield and the pole-piece N, or this space may be filled with non-magnetic material. The distance between the armature and theinner curved surface of the pole-piece is determined by the sum of the spaces/on each side of the divider-plate 'e Which will be required by the streams of magnetic and non-magnetic material, these spaces being determined by the size of the particles which are to pass through.

'By forming the magnet-pole as above described, so as to provide a flux of maximum density at the place of se aration just above the edge of the divider-p ate and in this way reducing the total flux required to produce the necessary density at this point, it Will be seen that not only is there economy yof the energy required for producing the flux, but the ma net-frame may be made much -smaller t an would otherwise be required.

Having thus described our invention, we claimf 1. In a magnetic separator, the combination with a magnetizable cylinder, of a vider located under said cylinder with its ed e closely adj acent thereto behind a verticaI plane tan ent to said cylinder, a ma netpole facing t e side of said cylinder av ove said divider, said pole being whol'ly outside a vertical tangent to said armature, but formed to provide a magnetic flux ofmaximu'm density near the edge of said divider and below a plane passin horizontally through the axis of said cylin er, andme'ans lOO IOS

IIO

for passing material to be separated through i the working gap between said pole and said armature.

2. In a magnetic separator, the combination with a cylindrical armature, of a magnet-pole facing the side of said armature, the face of said pole being formed substantially 'concentric with the armature, but having the portion thereof which is below the plane pass- V ing horizontally through the aXis of the armature, said pole approaching closest to said armature below a plane passing horizontally through the aXis of said armature lying outside a vertical tangent to said armature,

means for feeding material to be separatedonto the top surface of the cylinder, and

means for rotating the cylinder to carry saidl lface being formed to recede upwardly from such point, a non-magnetic shield over the face of said magnet-pole passing upward from said point of closest approach of said pole-face, and being curved toward said armature and around the upper surface thereof leaving a space between said shield and said pole-face, means for assin material to be separated between sai shiel and said armature, and means for .'rotating said armature to carry said material past said pole.

4. In a magnetic separator, the combination with a cylindrical armature built up of transverse laminae, of a magnet-pole facing the side .of said armature, said pole having a concave face of substantially the same curvature as that of the armature, the portion of said pole below the plane passing horizontally through the axis of the armature approaching closer to said armature than the portion above said plane, said pole lying Wholly outside a vertical tangent to said armature, means for causing dispersions of the magnetic fluX at the periphery of said armature, means for feeding material to be sepau rated to said armature, and means for rotating said armature. i

n Witness Whereof we hereunto subscribe our names this 10thday of October, A. D.

HENRY H. WAIT. FREDERIOK T. SNYDER. Witnesses:

ALFRED H. MooRE, DE WrrT C. TANNER.

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