. No. 827,116. I PATEN'TED JULY 31, 1906.

PIOKARD. APPARATUS FOR ELECTROSTATIC SEPARATION.

APPLICATION FILED 831E127, 1905." v z'sanETs-snnm 1.

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N0'.'827,11V6.' PATENTED JULY31, 1906.

, I G. W. PIGKARD.

APPARATUS FOR ELECTROSTATIC SEPARATION.

APPLICATION mam) um. 27, 19

' mums-sum 2.

' I I I lit/verdan- T'o al l it concern: a Be it known-that I, GREENLEAF WHITTIER' PIOKABD, acitizen of the United States, and

(sally-arranged series of cylindrical metallic longitudinal heating-chain ers H, H", and i iiEENLE r wHIT'riER' PICKARD, or AMESBUR-Y. MASSACHUSETTS;

.ASSIGNOR, BY MESNEASSIGNMENTS, r 'HUFF ELECTROSTATIC smaymroa COMPANY, A CORPORATION- OF MAINE. y

' "APP RATUS FOR ELEcTRosT Tio'EP RArION.

a'resident of Amesbury, in the county of Essex and'State of Massachusetts,.have-invented new and useful Improvements in Ap aratus forzElectrostatic, eparation,'of whic the following is a spe'cification. I

. My invention relates to the art of electrostatic separation; and it" consists in improvementsina'pparatus whereby separation orconcentrationfvmay be more effectively accom lished than heretofore ,T e operation of the apparatus hereinbe 1 5 lowdescribed [which embodies my invention, involves the employment of an improved method'which is described and claimed inan' application filed concurrently herewith by flnthe drawings hereto annexed, which illustrate a structure which embodies my in- 'ventionand improvements, Figure. 1 is averme, (Serial No. 280,322, filed September 27,

.tical'cross-section of an apparatus by which my method is carried out; 2 is a vertif cal longitudinal section of a portion of the hopper for-feeding materiaLand Fig. 3 isa' detail'showing in longitudinal section one of .theielectrodes'of the apparatus. The separating devices consist of a vertielectrodes E,mounted upon bearings to rotate in the'direction indicated by the arrows. These electrodes are connected, as shown conventionally, with one terminus of an exciting-machine, these wires being shown as X X. The opposed electrodes E are arranged .in series, there being a plurality of such opposedf'electrodes-for each ofthe main cylin- 4o rical' electrodes E. These opposed electrodes E areof much smaller superficial extent than the electrode E and consist, prefer- Lably, of quite fine metal wires inclos'ed in rela- These tively thick glass tubes or envelops. wires are connected, as by Y Y, with the other terminal of the exciting-machine. Below theelectrodes E Ev there are located the dividers D. Thesev aresecured in any suitable manner to the inside of the casing C. Upon the top of the casing O is mounted'the hopper H, this hopper bein constructed with Specification of Letters Patent. Applica i film September 37, 1905- serill No. 280.323.

. this purpose.

pass on either side of'the he atingj-chamberH and next to the chamber H on one, side and -H- on the other. 1 Near the bottom of this hopper there is mounted the agitator A, which, as shown in Fig. 2, is operated by a crank andconnecting rod and serves to scrape and sift the comminuted material through the slot 0, so that it will fall in a regular stream upon the surface of the upper electrode E. Upon the end of the hopper H there isiformed the chamber H and upon the o posite enda similar. chamber H is provided? A pipe H serves to conduct heated gases, such as'steam or hot air, into the chem:

ers H H H so that the material falling through the hopper H will become thor- Patented m 31, 1906.

H, the latter extending from end to end. in-- side the hopper, so that the material mu'st' oughly andefiectively heated in its passage over the surfaces of .the heating-chambers. A vent'H 'at the chamber H at the opposite end serves to conduct the hot gases away to any desired oint. The electrodes E are mounted on chamber 0, and tubular trunnions e, secured to the electrodes E, serve to carry the elec 'trodes.and also as openings 'wherethrough toinduct heated gases to the interior of the electrodes E. Nozzles e" are rovided for trodes are shown at e. At the opposite end the hollow trunnions e serve to allow the gases to escape from inside the electrode.

It has been recognized-from the'initiation of the art of electrostatic separation thattheprocesses are assisted materiallyby presenting the'substances to be treated in a perfectly dry state, and consequently it hasbeen the ractice for a long time to heat materials beore they are fed to the electrodes of an electrostatic separator, this heating servin to facilitate the separation of many materials. I have discovered, however, that if a heated atmosphere be maintained also near and aroun the electrodes themselves, especially if the electrodes themselves are heated, so that the atmosphere is hottest at the surface of the electrodes, the resulting separations are far more thorou h than under any other condition observed y me, and, moreover, many mixtures of material which, as far as I am aware, have heretofore resisted efiectual The bearings or the elec I oo 75 I earings e 111 the ends of the separation by the electrostatic method are by this improvement completely and easily separated.

thereafter, the successive small electrodes trode.

searching out the conductive particles from the mass and gleaning, as it were, after the separation effected at the first opposed elec- If the desired separation cannot be completed b a single set of electrodes E E,

the materia which has not been repelled from the upper electrode E is conducted by the sloping side of the divider D to a second "There electrode E, and so on, the electrical conditions at all the electrodes usually being preferably the same, the electrodes E being connected to one terminus of the exciting apparatus and the electrodes E to the other. At the close of this operation the heads are collect-ed in a proper receptacle, such as a box B, while the tails fall into another receptacle, as B. As has been observed in connection with the operation of such electrostatic separation apparatus as that described in the Dolbear atent, No. 685,508, dated October 29, 1901, equently some ofthe unrepelled particles cling to the rotating electrode E and are carried thereby and might be carried around throu h a complete rotation of the electrode. ore I provide rubbers or scrapers S S to clean the electrodes E at the bottom and top thereof, respectively. For simplicity of construction the rubbers S may be pivotally attached to the rubbers S, the latter being loosely guided, as by pins S set into the ends of the casing C, a sprin S attached to the rubber S, serving to ho d both into contact with their respective electrodes.

The exciting apparatus which I prefer to employ in connection with this separator is such a one as described in Letters Patent of the United States No. 796,001, dated August 1, 1905.

What I claim, and desire to secure-by Let-- ters Patent, is

1. In an electrostatic se arator, a source of electrical energy, electro es, means to supply material thereto, means to heat the material before it reaches the electrode, and means to heat the electrode to which-the material is delivered 2. In a electrostatic separator, a source of electrical energy, electrodes, means'to sup-.

ass 7,116

ply material thereto, means to heat the material before it reaches the electrode, and means to maintain a heated atmosphere about the electrode into contact with which the mate rial is delivered.

3. in an eli-actrostatic'separator, a source of electrical energy, electrodes, a ho per to feed material, heating-chambers in the hopper and means to heat the same, and a casing surrounding the electrodes, to provide a substantially confined atmosphere around the same.

4. In an electrostatic separator, a source of electrical energy, electrodes, a hopper to feed material, a heating-chamber on each side of the hopper, and an intermediate heating-chamber therein, and means to heat the several chambers:

5. In an electrostatic separator, a source of electrical energy, a plurality of electrode pairs, means to feed material to the first pair and thence to the others in succession, means to heat the material before it passes to an electrode, and means to heat an electrode of each pair.

6. In an electrostatic separator, a source of electrical energy, electrodes, a hopper to feed material, and means to heat that electrode to which the material is delivered.

7. In an electrostatic separator, a source of electrical energy, electrodes, whereof one is a hollow cylinder, means to supply material thereto and means to pass hot gases into the interior of said cylinder.

8. In an electrostatic separator, a source of electrical ener y, a hopper, heating-chambers adjacent said hopper, electrodes whereof one is a hollow cylinder, and means to pass hot gases into the interior of said cylinder.

9. In an electrostatic separator, a source of electrical energy, a hopper, heating-chambers adjacent thereto, electrodes, whereof one is a hollow cylinder, means to pass hot gases into the cylinder, and a caslng surrounding the electrodes. 10. In an electrostatic separator, a source of electrical ener y, means to deliver mate rial to an electro e, means to heat the-material before delivering, the electrode, opposed electrodes, each of the opposed electrodes being superficially much smaller than the first electrode, and the several opposed electrodes arranged to act successively on the material passing on the first electrode, and means to heat the first electrode.

Signed by me at Boston, Massachusetts, this 23d day of September, 1905.

GREENLEAF WHITTIER PICKARD.