US958855A - Electric furnace. - Google Patents

Description

4-51 AVAILABLE COP.

H. A DANNB.

ELECTRIC FURNACE.

APPLICATION FILED JAN.15, 1910.

958,855. Patented May 24, 1910.

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H. A. DANNE.

ELECTRIC FURNACE. APPLICATION FILED JAN.15,1910.

Patented May 24, 1910.

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ELECTRIC FURNACE.

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Specification of Letters Patent.

Patented May '24, 1910.

Application filed January 15, 1910. Serial No. 538,234.

To all whom it may concern:

Be it known that I, HAROLD ALEXANDER DANNE, a subject of the King of Great Britain, residing at Clarksburg, in the county of Harrison and State of West Virginia, have invented certain new and useful Improve ments in Electric Furnaces, of which the following is a specification.

My invention relates to electric furnaces and particularly to a furnace of this type wherein the charge passes intermittently or continuously between the electrodes.

An important object of my invention is to provide an electric furnace of the type re ferred to wherein the electrodes are so disposed as to produce the maximum efficiency from the current employed.

Uther important advantages of my invention are the following: To provide ethcient means to electrically decompose mixtures of solids, liquids and gases passed between its electrodes. To so dispose the electrodcsof furnace of the character specified that the charge shall be decomposed as completely as possible during the completion of the electrical circuits made by passing through the charge from one electrode to another of opposite polarity. To so dispose the electrodes that when the charge is decomposed it will pass away and leave the electrodes free to treat a further portion of the charge, in contradistinction to the action of other furnaces wherein the charge more or less indefinitely passes in and out of the Zone of electrical action. To so dispose the electrodes that the heat of the are formed by them, and also the heat caused by the resistance of the charge to the passage of the current, shall be utilized to the fullest extent possible by reflection onto the treated charge, and also, by conduction and radiation into the untreated charge in the immediate vicinity of the electrodes. To provide an electric furnace wherein the gases liberated by the process of reduction, separating or refining of metals when passing between the electrodes and subsequently, may be utilized for initially heating or fluxing new material introduced into the furnace, and thereby cooled and treated to such a degree that valuable volatile products will be condensed and their loss avoided. To so dispose the electrodes and the passage way through them, that the fumes from the charge during both its immediate and subsequen treatc nt, will permit of their chem cal ction being greatest at the point of greatest need, namely, at or near the passage of the electrical current through the charge. To so dispose the electrodes and the passage way through them, that additional blast or currents of chemically active gases may be passed through them, either above or below the electrodes, with the same action as above set forth. To provide a furnace Which may be sealed so thatall gases issuing from it may be under control, and capable of being further treated when necessary and desirable for the recovery and utilization f th i contents.

Other objects and advantages will appear in the course of the following description.

In the accompanying drawings, forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same, Figure l is a central vertical section of a furnace embodying my invention. Fig. 2 is a central vertical section through the lower portion of the furnace, and showing in elevation a modified form of electrode arranged therein. Fig. 3 is a central vertical section .of the elect-rode shown in Fig. 2. Fig. 4: is a bottom plan view of the electrodes and associated members which are secured to the body of the furnace. Fig. 5 is a fragmentary detail view of a portion of the top of the crucible, showing electrodes secured therein.

In the drawing illustrating .a preferred embodiment of my invention, 1 designates a metal casing which forms the body or stack of the furnace and which is preferably cylindrical, as shown. At the lower end of the stack 1 and preferably formed integral therewith is an annular plate 2 forming the top or cover of the crucible to be hereinafter described. The cover 2, slopes downwardly and is provided at its outer peripheral edge with a vertically disposed circular flanged. The stack casing 1 is provided approximately centrally thereof with a circumferential flange 4 which is suitably spaced away from said casing 1 and rigidly connected thereto by any suitable means. The circumferential flange 4 is adapted to fit within grooves formed within the peripheral edges of bearing rollers 5, which are rotata'bly mounted in suitable brackets 6., fixedly secured upon a suitably supported platform 7. The stack is supported by the rollers 5, and capable of being rotated thereon. The flange 4 is provided with sprocket-teeth adapted for engagement with a sprocketchain 8, which is trained about a sprocket wheel 9, rigidly secured upon a rotary shaft 10. This shaft has its upper end journaled in a bracket 11, which is arranged upon the platform 7, and its lower end ournaled in a suitable bearing (not shown) within the platform 7. The shaft 10 is provided with a pulley 12, which is fixedly mounted upon the same, and is adapted to receive power by means of a belt (not shown) from any suitable source of power. The stack and cover 2 are lined with fire-brick 13, or like material in accordance with the usual practice.

The stack is provided near its upper end with a feed opening 1 1, which registers with the lower end of a feed-chute 16, rigidly connected to the stack. This feed chute may be closed by a removable plate 17, when material is not being fed into the furnace. The upper portion of the stack is provided, opposite the opening 14: with an outlet 15 for uncondensed gases. The upper end of the stack is closed by means of a circular cap or cover 18, provided with a circular flange 19, which receives the upper end of the stack. The cap 18 is preferably formed of metal and may be insulated from the easing as shown at 20. The cap 18 is provided centrally thereof with a depending boss 21, having an opening for the reception of the upper end of a rotatable shaft 22. The lower end of the rotatable shaft 22 is journaled within bearings formed centrally within a spider 23, secured within the lower end of the stack. The shaft 22 is provided near its upper end with a screw-threaded portion 23, for the reception thereon of an internally screw-threaded ring 2%, which may be locked to the shaft by means of a clamping bolt 25. The ring 24 serves to provide means for positively supporting the shaft during its rotation, and means whereby the shaft 22 may be vertically adjusted. Rotation is imparted to the shaft 22 by means of a sprocket chain 26, which is trained about asprocket wheel 27, which may be insulated therefrom as at 28 and rigidly mounted upon the shaft 22. Rigidly secured upon the shaft 22 near its upper end, is a collector ring 29, which is engaged by suitable brushes 30. These brushes are support-ed by but insulated from a suitable support 31. The positive terminal of a source of electric-current is connected with the brushes 30 as at 32, whereby current is conveyed to the rotatable shaft 22.

Rigidly mounted upon the lower end of the rotatable shaft 22, is an electrode 32 which is suitably spaced away from the inner lining of the section 2, and adapted to a tte istwe.

partially close the lower end of the casing l. The electrode 82 is preferably formed of powdered carbon suitably cemented together and reinforced as will be hereinafter more particularly described in connection with the form of electrode shown in Figs. 2 and 8. The electrode 32' is circular and increases in diameter downwardly in the step by step arrangement shown at- 33.

Arranged upon the outer surface of the crucible cover 2, is an annular collector-ring 34L insulated from the cover as at 35, and secured thereto by means of suitable pins 36, the outer ends of which are flush with the ring 34. A fixed support 37 is arranged near the ring 34, and carries a suitable brush 38, which is insulated from the support 37 as at 39, and has its free end disposed to contact with the collector ring 3 1. The brush 38 is connected with the negative terminal of the source of current above referred to.

Embedded within the fire-bricks 13 adj acent the lower end of the casing 1, are a plurality of spaced concentric rings 40, each of which is formed of substantially semicircular sections 41 which are bolted or otherwise secured together as at 41-2. The innermost of the rings 40 has the form of a plain strip or band and the outermost of the rings 40 is substantially L-shaped in cross section. The remaining rings 4C0 are substantially U-shaped in cross-section, as clearly shown in Fig. 5. Between the rings 40 are disposed at spaced intervals, electrodes 1-1 which are insulated from each other as at 12 and from the rings are as at 43. The electrodes 4-1 are arranged in radial alinement as shown in Fig. t. The circular sets of electrodes 41 are preferably connected in multiple, as shown at 14 and the electrodes of each circular set are preferably connected in multiple as shown at 4C5. The outermost circular set of electrodes 41 are connected as at 16 to the pins 36. It will be noted that the pins pass through the outermost ring 40 and hold the same in a proper position. Each circular set of elec trodes 41 is-so disposed that their free ends are adjacent the upper peripheral edge of a corresponding step 33 of the electrode 82. The electrodes ll are preferably arranged in different vertical planes, as illustrated in Fig. 1.

Tu F ig. 2 I have illustrated a slightly modified form of electrode which is substantially frusto-conieal in shape and is formed of powdered carbon suitably cemented together and molded. It is desirable to reinforce the body of the electrode by means of metal st ips as, which may be of iron and preferably in direct electrical communication with a source of current supply. The body of the electrode a? may also be reinforced by means of sections of metal fabric as shown at 49 and connected to the metal strips 48. Embedded within the electrode and centrally thereof, is an internally screw-threaded tube 50, adapted for the reception of a screw-threaded pin 51 which in turn is fixedly mounted upon an enlarged frusto-conical end 52, formed upon the rotatable shaft 22. The rotatable shaft 22 may be covered for the greater portion of its length with a tube or jacket of fire-proof material, as shown at 58. The fire-proof covering of the enlarged end 52 may be extended laterally in opposite directions to form guide arms 54, adapted to fit snugly within the lower end of the stack to keep the shaft 22 properly centered therein. As

shown in Fig. 2 the electrodes 41 are inclined, instead of being vertically disposed as illustrated in Fig 1.

The crucible 55 of which the section 2 forms a cover is preferably cylindrical and is lined internally with fire-bricks 56 along its sides and bottom. The bottom of the crucible is inclined so as to discharge the contents through a suitable tap hole 57. Upon the upper edge of the side lining 56 of the crucible 55 is arranged a metallic grooved ring or trough 58, within which projects the flange 3 which depends from the crucible cover 2. The trough 58 is to be filled with a suitable liquid, such as molten lead to form a liquid seal whereby the vapors liberated within the crucible 55 will be prevented from escaping therethrough.

In order that material may not become clogged within the lower end of the stack, I rigidly mount two or more propelling or agitator blades 59 upon the rotatable shaft 22, which blades will stir the material within the stack and insure its continuous downward movement during the operation of the furnace.

In the operation of my improved furnace the stack 1 together with the crucible cover 2 is rotated very slowly say about three revolutions to the minute. The shaft 2 may also be rotated at a faster rate and in an opposite direction to the rotation of the casing 1. Either the stack or the shaft 22 may be rotated independently of the other. The charge is then introduced into the stack 1 through the chute 16. The electric current having been turned on, arcs are formed between the electrodes ll and the electrode 32, and the material passing adja cent the arcs is subjected to their action at very close range. The molten metal together with the slag will be discharged into the crucible 55.

It is to be noted that the heat developed at the electrodes will be reflected by the crucible cover downwardly upon the contents of the crucible whereby they are maintained in a freely fluid condition until withdrawn. It will be obvious that my furnace AVAiLABLE GOP is not only admirably adapted to prevent the escape of injurious gases, but to con dense and retain them within said furnace, after utilizing them to initially heat and flux the charge of newly fed material.

While I have shown and described the preferred embodiment of my invention it is to be understood that many changes in arrangement and details of construction may be made without departing from the spirit of my invention or the scope of the subjoined claims.

Having fully described my invention, I claim 1- 1. sin electric furnace comprising a circular electrode increasing in diameter clownwardly, and a plurality of annularly disposed groups of electrodes surrounding said first named electrode, each group being disposed in a difierent horizontal plane.

2. An electric furnace comprising an electrode formed of a plurality of vertically disposed cylindrical sections increasing in diameter downwardly, and a plurality of electrodes disposed adjacent the outer upper edge of each section, substantially as described.

3. An electric furnace comprising an electrode circular in cross-section, the outer wall thereof having the form of a plurality of annular steps, and a series of groups of annularly disposed electrodes arranged in different horizontal planes in proximity to said first named electrode.

1. An electric furnace comprising a stack, a crucible in communication therewith, a central electrode supported from the upper portion of said stack and a plurality of electrodes of opposite polarity supported from the upper portion of said crucible in proximity to said first named electrode.

5. An electric furnace comprising a stack, a crucible in communication therewith, a shaft extending from the upper portion of the stack into said crucible, an electrode carried by said shaft and a plurality of electrodes of opposite polarity disposed in proximity to said first named electrode.

6. An electric furnace comprising a stack, a shaft extending longitudinally thereof and supported from the upper portions of said stack, means for adjusting the said shaft, an electrode carried at the lower portion of said shaft and a plurality of electrodes of opposite polarity disposed in proximity to said first named electrode.

7. An electric furnace comprising a central electrode, electrodes of opposite polarity disposed about and in proximity thereto and means for independently rotating the central electrode and the surrounding electrodes.

8. An electric furnace comprising a stack, a rotatably mounted shaft, extending longitudinally thereof, an electrode carried at the lower end of said stack, and a plurality of BEST'AVAiLABLE COP,

electrodes disposed about and in proximity to said first named electrode.

9. An electric furnace comprising a stack, a rotatably mounted shaft extending longitudinally thereof, means for propelling the charge carried by said shaft, means for rotating said shaft, an electrode carried at the lower end of said shaft, and a plurality of electrodes of opposite polarity disposed about and in proximity to said first named electrode.

10. An electric furnace comprising a stack, a crucible disposed below and in communication with said stack, an electrode approximately but not wholly closing the lower end of said stack, said electrode increasing in width downwardly, and a plurality of groups of electrodes of opposite polarity disposed adjacent said first named electrode in different horizontal planes thereof.

11. In an electric furnace, a central electrode, electrodes of opposite polarity disposed in proximity to and above said electrode, and means for rotating said central electrode.

12. In an electric furnace, a central electrode, increasing in width downwardly, a plurality of electrodes of opposite polarity arranged in proximity to and above said central electrode, and means for rotating said plurality of electrodes.

13. In an electric furnace, a crucible, a rotatable stack having communication with said crucible, an annular section connected to the stack for forming a cover for said crucible, an electrode arranged within said crucible, and a plurality of electrodes of opposite polarity arranged approximately to said electrode and connected to said stack.

14. In an electric furnace, a crucible, a rotatable stack having communication with said crucible, means carried by said stack for forming a cover for said crucible, a central electrode arranged near the lower end of said stack for approximately closing the same, and a plurality of electrodes connected to said stack for cooperation with said central electrode.

15. In an electric furnace, a crucible, a stack having communication with said crucible, means carried by said stack for forming a cover for said crucible, a central electrode arranged near the lower end of said stack for approximately closing the same, means for rotating said central electrode, and a plurality of electrodes of opposite polarity connected to said stack and disposed to cooperate with the central electrode.

16. In an electric furnace, a crucible, a rotatable stack arranged concentrically with relation to said crucible, an electrode arranged within said crucible,and a plurality of electrodes of opposite polarity connected to said stack for cooperation with said electrode.

17. In an electric furnace, a crucible, a rotatable stack arranged concentrically with relation to said crucible, a cover for said crucible connected to said stack, a central electrode having its periphery formed in a series of steps, and annular groups of electrodes of opposite polarity connected to said cover to cooperate with the central electrode.

18. In an electric furnace, a central electrode, a plurality of electrodes of opposite polarity disposed in proximity to and above said central electrode, and means for independently rotating said central electrode and plurality of electrodes.

19. In an electric furnace, a working chamber, a stack having communication with said working chamber, means connected to said stack to form a cover for said working chamber, electrodes of opposite polarity arranged to cooperate with said working chamber, and neans to rotate said stack.

In testimony whereof I atlix my signature in presence of two witnesses.

HAROLD ALEXANDER DANNE.

WVitnesses TRUMAN J. LYNCH, W. FRANK STOUT.

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