US2331769A - Magnetic separator - Google Patents

Description

oct. 12, 1943. s. G. FRANTZ 2,331,769

SEPAR R Zi/gl 20 17 19 16 zz Pzo Yceptibility from cost and lowoperating cost.

Patented oct. 12,1943

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yuNrlrn" Y MAGNETIC snranarort samuel c. Frantz,

. P'rinceton, N. d. Q

Application August 4, 1941,` serial-Nc. 405,331

/ 6 plains; (ci. '20e- 224) IThis invention relates tio-magneticsp'al'airrs, and although notL restricted to such' use is par; ticulaly effective in' 'removing .iron and' iron.- bearing particlesof -fairly high magne ic sus-(1 aireehilowingV stream of ydry ma-Y 5 terials.H

An instance of such use is the placing] sand used `in the saggers in which glass and pottery ware-is red. Where such sand is exposed to Y iron contamination, vsurfacespots of iron and im' iron-bearing particlesgform on the red ware and have to be subsequently removed by mechanical means., `1 j Thesejspot-forming particles o ccur in lthe sand as an impurity and represent only a. very small l5.

percentage of the total sand, lbut itis essential that' any separator for removing themmagneti-` cally from the sand or other grain stream shall be of high capacity and highelciency,

' 'My- 'separatcr .has these charact ristlcs to an 1210.

. i9 integral with said ring and all inclined in the.

unusual degree, and isv moreover of low initial In constructing my separator, 1 utilize the general principle oi? Athe screen'type'wet separator disclosed in my prior Patent No. 2,074,085, granted Z? March 16, 1937, but in place of the stack of Imag-V j' -netized attractor screens shown insaidf patent, l'y employ a stack oi magnetized vanes in the-form of grids. The vanes of one grid are inclined in opposite direction to those ofthe grids next above and below in the stack. rlihs causes the sand or other free-flowing material to repeatedly change direction as it falls from top to bottom offthe Stack, thus hmmag thercmcitycf the .s1-.realliA and aiording themagnetized edges of the vanes ample opportunity to attract and hold any mag'.- netically susceptible particles in the stream.

The greatest concentration of magneticat- Vtraction is at the sharpened lupper and lower edges ofV the varies, and inasmuch as these edges 40 are very closely placed to the zones where the sand stream is changing` direction and yhence movingmost slowly, thereis little or no ldanger that the magnetic particles will be carried past said highly magnetized edges without being- '45 caught and held thereby.

ln the accompanying drawing: 4 Fig.,1 is a vertical central section throughtl magnetic separator in Aaccordance with my present invention. f Fig.` 2 is atop plan view o fone of the'attractor grids removed from the stack, and

Fig. 3 vis a diagram illustr ting my separator. f My improved magnetic separator .comprises a ,electric current.

the action of coil c ase includingalhouslng'orshell I0 and,top and. bottom platesl Hand 12. Eastened tojthe top plate His a 'feed byvlor .hop'perxI3:I Thel bottompiate 1 2 is fastened /to'a Isuitable, sup# porting base I4. The shell lyplates I I and .|2,- hoppergfandbase M are made ofairon; steel. or other-.suitable magnetizable material'to prof `virale a magnetic circuit. Mounted'within the shell'ill and spaced therefrom is a cylinder' l5 of brass or other' nommagnetizable material...."In thespace between the shell I0 and `cylinder=|5"`is a 'coil IB adapted to be 'connected to any suitable source -of direct Removably mounted the cylinder 'l5 so as to be magnetized bythe coil 16,- a vertical jstack o f attractor units I1 of magnetizable`ma-- teri'al'. Thesefare yconstructed as grids each come prising an annular/ ring I8 and-a plurality of uniformly spaced and suitably reinforced' yanes.:

, same direction. The Avanes are sharpatt their upper andlower Aedges to provide the "concentration of magneticrfluin andare thickened between .said edges both for IStrength and to reduce the magnetic reluctance. The several grids are suitably spaced from one. another inthe stack'of spacers 20 of Ynon-mag-y netic material.- i At each end o f the/ stack is a spider-2l and 22 or'its equivalent-,made of magnetizable material. The purposes of these spiders is to carry themagnetic u-x from the ends of the; shell i0 and distribute vit eiciently over the Ieridrnost grids of the stack, l-thereby reducing the reluctance of the magnetic circuit andincreasing the mag-v netization of the grids', l The grids are so po sitioned'withinv the cylinder l5 that the vanes of one grid extend in opposite, direction to the vanes ofthe grids-immediately above and below. Any number o f grids maybe' employed, depending upon the size of the sep- 'aratonl and preferably, the`,vanes of each grid 'are inclined vat an angle 'of 45 so that the stream will change itsv direction o fmotion by approximately in passing through each two adiacent grids, although this angle may obviously be varied as desired.

Inoperation, sandor -other free-flowing material'containingironor other magnetically susceptible impurities is fed-into the hopperl and falls by gravity through the stack of grids I1..

Due to the reversely inclined arrangement'of the Vanes in the several grids composing they stack the velocity of the streams is reduced t0 "by Letters Patent is:

changedirection at each successive grid. In the the point where the particles arerslowly sliding i androlling rather than freely falling as they.

. of non-magnetizable material, asupport for said shells and a feed hopper supported by said shells,

region of these direction changes, that is to say,

at the upper and lower edges of the vanes in any grid.- the magnetic field Vstrength and convergence is strongest and consequently the particles of iron or other. magnetically susceptible contamination in the stream are attracted to and held by said edges. y l, I l

At suitable intervals the current is turned off, thereby demagnetizing the attractors, so fthatv l the accumulatedcontaminations may dropl by gravity from their edges. Whenl more thorough cleaning is desirable, the stack of attractors may be removed from the machine and mechanically l cleaned.

will likewise be understood that various modiii-` -cations in the construction and arrangement of the grids may be made, depending upor the type of material being separated, and the degree of separation wanted.

`What I therefore claim 1. A magnetic separator for removing magnetically susceptible particles from a stream,

and desirev to 'secure n a winding in the space between said shells, and a stack of superposed spaced magnetlzed attractors within said inner shell, each attractor comprising a. rim and spaced inclined vanes, and thev attractors belnghoriz'ontally positioned in the stack with the vanes of one attractor inclined ppositely to those of the attractors above and below it so as to reduce the velocity of the stream by causing it to change direction at each attractor, the upper and lower edges of the vanes oi?A each attractor being located at the regions where the stream is changing direction and hence movl5 ing most slowly, and being formed to producel concentrations of the magnetic iiuxjso that mag- Y netically susceptible yparticles in theI stream, are

. attractedto and held by said edges.

.5. 'Anattractor to be placed horizontally across f the path of a streampassing through a magnetic separator, said attractor being formed of mag- Vnetizable materialand comprising a relatively narrow rim and a plurality of spaced vanes excomprising a stack of superposed spaced` magnetized attractors each attractor comprising a j i vanes extending longitudinally-within the inner periphery ofy said rim and secured at their ends to said rim, said vanes being inclined transversely tors above and below it so as to reduce the veloc' ityv of the stream by causing it to change direction at each attractor and 4the upper and lower edges of the vanes of each attractor being located at the regions'where therstream is changing direction and hence moving most slowly, and means for producing concentrations of. magnetic ux upon'the upper and lower-edges of said vanes whereby magnetically susceptible particles in the stream are` attracted to and held by said edges.

2. 'I'he separator of .claim 1, the upper and lower edges of the vanes being sharpened to increase the concentration of magnetic flux thereon. and the bodies of the vanes being thickened to decrease their magnetic reluctance.

3. The separator of claim 1, the rim of each attractor being of less depth than the overall depth of said attractor through the vanes, and spacing 'rings ofthe same shape as said rim, each ring being of non-magnetic material and being of a depth to spacethe upper and lower edges of the vanes of adjacent attractors out, of contact with each other.

4. A magnetic separator for removing magnetically susceptible particles from a stream,

` relativelynarrow rim and a' plurality of spaced tending longitudinallywithin the inner periphery of said rim and secured at their ends to said rim, said vanes being inclined transversely of ltheir length the upper and lower edges of said vanes being formed-to produce concentrations of the' magnetic flux whereby magneticallysusceptible" particles in the stream are attracted to and held by said edges. j V6. A magn'etlcseparator for removing magnetically susceptiblq particles from a stream,

' comprising a supporting base and an outer cylindrical shell surmounting said base, both said base and shell being of magnetizable materia] to provide 'a magnetic circuit, a hopper surmounting said shell for directing a iiow stream therethrough, an inner cylindrical' shell of non-mag:- netizable material and of less diameter than said outer shell mounted within said outer shell-and defining therewith an annular space to receive a coil,'a coil in said space to be connected with a. source of electric current, and a stack of spaced superposed attractor units of magnetizable material removably mounted within said inner shell, said units being in the form of horizontally disposed grids and each grid comprising an annular ring, and a. plurality of spaced vanes integral with said ring, all vanes of each ring being inclined in the same direction and the grids being so arranged in the stack that the vanes of one grid are reversed to the vanes of the grids next above and below so as to reduce the velocity of the flow stream by causing it repeatedly to change direction as it passes through said stack, the upper and lower edges of the vanes of each grid being sharpened to create the maximum concentration of ilux at said edges and said edges being located at the regions where the stream is changing direction and hence moving more slowly, and spiders of magnetizable material at the ends of the stack for carrying the magnetic ilux from the ends of the outer shell to the endmost grids of the stack.

SAMUEL G. FRANTZ.

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