US1556377A - Electric furnace - Google Patents

Description

S. L. TINGLEY ELECTRIC FURNACE Filed Dec. 13, 1920 I ea "\\\\ \I Inventor SIEDhCfl L.Tingley YMMkW AHys Patented Oct. 6, 1925.

, UNITED STATES PATENT OFFICE.

STEPHEN L. TINGLEY, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO SMELTIIRIS, RE-

FINEBS & CHEMICALS CORPORATION, OF NITRO, WEST VIRGINIA, A CORPORATION OF VIRGINIA.

Application filed December 13, 1920.

T all whom it wwy concern:

Be it known that I, STEPHEN L. TINGLEY, a citizen of the United States, residing at Boston, county of Suffolk, State of Massachusetts, have invented anlmprovement in Electric Furnaces, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to electric furnaces and particularly to furnaces of that type that are constructed to produce a circular or hollow arc and in which the material to be 16 treated isdelivered into the center of the are.

One of the objects of the invention is to provide an electric furnace of the above type which is constructed so that the material to 20 be smelted or otherwise treated is delivered into the middle of an annular are, or in other words, is delivered into a space which is entirely surrounded by an arc.

Another object of the invention is to provide an improved electric furnace of this type in which the hollow electrode not only provides a channel through which the material to be treated is delivered to the hollow annular are but also acts as a means for preheating the material as it is being delivered to the arc.

Still another object of the invention is to provide an electric furnace of this type in which one of the electrodes is provided with assages through which gases that are ormed at the arcing point may escape.

Still another object of the invention is to provide an im roved electric furnace of the above type which has a. series of circular or hollow arcs by means of which the material can be more economically treated.

Another object of the invention is to rovide an improved electric furnace by w ich the smelting o eration may be greatly facilitated, thus ena ling the furnace to treat material faster than can be done in furnaces as heretofore constructed.

Other objects of the invention are to pro,- vide an im roved means of sup rting and 59 adjusting the electrodes and ot rwise imroving electric furnaces, all as will be more My hereinafter set forth.

In order togive an understanding of my ELECTRIC FURNACE.

Serial No. 430,114.

invention, I have illustrated in the drawin a selected embodiment thereof which mil to now be described after which the novel features will be pointed out in the appended claims.

In the drawings, the figure is a vertical section of a furnace embodying my invention.

The two terminals between which the arc is formed are indicated at 1 and 2, respectively. These terminals may be made of carbon or any other suitable material. The 66 electrode 1 is provided at its end with a circular crater 3 and with a central peak for the protuberance 4. The electrode 2 is provided with a central passageway or conduit 5 through which the material to be smelted is 10 fed to the arcing point, and it is formed on its lower end with a circular grove 7 that forms an anuular ridge 6 surrounding the protuberance 4, and also an annular portion 8 adjacent the peripheral ortion 9 of the electrode 1 that is situate outside of the crater 3. The electrode 1 is connected to a source of electricity by a suitable cable 10, and the electrode 2 is also connected to said source of electricity by a cable 11. With this construction there will be an anuular are formed between the peak 4 and the annular ridge 6, and a circular'arc formed between the circular portions 8 and 9 of the electrodes.

The material which is delivered through the conduit 5 passes first through the arc existing between the ridge 6 and the peak 4, and as it becomes melted it accumulates in the crater 3. The electrode 1 is provided with one or more tap holes 12 leading from the crater 3, these tap holes communicating with spouts 13 through which the molten material may be delivered to any suitable rece tacle.

e are formed between the portions 8 and 9 of the electrodes is situated exterior to the crater, and this are not only assists in melting the material in the crater which may not have been melted by the inner are, but it also prevents any material from escaping from the crater through the space between the electrodes.

I have illustrated herein electrodes constructed to provide two concentric arcs, but the number of concentric arcs is immaterial and the electrodes might be arranged to produce more than two arcs without departing from the invention.

These electrodes may be supported in any suitable way. The electrode 1 is shown as having its lower end enclosed in a housing 14 of insulating material and as being supported on the upper end of an adjusting screw 15 which has screw-threaded engagement with a nut 16 that is supported on a rest or plate 17. The nut 16 is in the form of a bevel gear which meshes with a bevel gear 18 carried by a shaft 19, the latter havmg a crank 20 by which it may be turned. This shaft 19 is journaled in a bearing 21 that is carried by the plate 17. With this construction the turning of the shaft 19 will operate to rotate the nut 16 in one direction or the other thereby raising or lowering the electrode 1, thus providing for its proper adjustment as well as furnishing it a suitable support. The supporting plate 17 is shown as sustained on buffer springs 22, the purpose of which is to give a resilient support to the electrode 1, thereby to prevent any in'ury due to a kicking action of the electro (-3 when the electricity is turned on.

The lower end of the electrode 1 is shown as being suitably guided in a stationary curb or wall 23. The electric cable 10 is shown as connected to'a copper plate 24 which is secured to the end of the electrode 1 thereby making a good electrical contact.

The upper electrode 2 is adjustabliy supported so that it may be readily a 'usted vertically, and is also so supported t at it may be readily removed in order to be relaced by another electrode. This electrode has secured to its u per end a copper plate 25 to which the ca le 11 is attached, thus making the proper electrical connection. The electrode is also secured in a sup orting ring 26 which encircles the upper en thereof and which is adjustably suspended from brackets 27 that project from the walls of a housing 28 that forms the wall of the furnace. Forthis urpose the supportin collar 26 is provided with two arms 29 t rough which are screw-threaded adjustable suporting screws 30 that in turn are swiveled 1n the brackets 27, said screws havin heads 31 by which they may be turned an which also serve by their enga ement with the brackets 27 to support t e screws. The turning of the screws in either direction will raise or lower the electrode 2 and by this means the electrode can be maintained in its proper adjusted position. The adjusting screws 30 provide means for makin a limited adjustment of the electrode 2 1n a vertical direction.

I have also provided other means by which the electrode may be removed from the furnace and a new electrode inserted in position. This other means is in the form of one or more blocks and tackle 32, one block 33 of each block and tackle being connected to the plate 25, and the other block 34 of each block and tackle bein connected to the top 35 of the housing 28. y this means theelectrode 2 may be raised entirely away from the electrode 1, thus facilitating the installation of a new electrode or the removal of an old one.

The casing 28 of the furnace is formed with a bridge wall 37 which is situated above the arcing oint and which supports a suitable guide or the electrode 2. This guide is herein shown as com risin an inner cylindrical member 38 o cruci le clay through which the electrode 2 passes, and an outer shell 39 of some suitable material, such, for instance, as ordinary tile pipe, the space between the outer shell 39 and the inner member 38 being filled with asbestos wall, as shown at 40.

The space 41 beneath the brid e wall will be of sufficient size to accommo ate the operator or operators who have charge of the furnace, and in order to protect such workmen from= the arc, I propose to employ a circular shield 36 of some non-fusible materiaIwhich encloses the arcing point. This shield 36 is in the form of a cylinder of the proper size and it is shown as ad'ustabl supported so that it can be raised or lowere \Vhen in o erative position the upper end thereof will come either against the bridge wall or the supporting guide for the upper electrode. This shield 36 is shown as carried by a collar 42 which has arms 43 extending I therefrom, each arm having swiveled therein an adjusting screw 44 that has screw-threaded engagement with a suporting arm or bracket 45 carried by the easmg 28. This shield 36 is provided with suitable openings 46 to receive the sockets 13. My improved furnace is provided with means for taking care of any gases that may be generated during the operation of the furnace and thereby preventing such gases from accumulating in the space 41 occupied by the operator. For this urpose I provide a pipe or conduit 47 whic leads to a suitable blower or suction apparatus (not shown) and which communicates with the interior of the casing 28. Any gases, therefore, which accumulate in the casing 28 are drawn off through the pipe 48, 47. The operation of melting the material at the arcing point results in the production of certain gases, and to provide for the disposal of such gases, I ropose to make the electrode 2 with a plurality of ducts 48 which lead into the groove 7 and which extend longitudinally through the electrode and communicate at their upper end with pipes 49 that lead into the pi e 47. The suction produced in the pipe 4 will operate, to draw an gases up through the ducts 48 and pipes 9. I have also provided a pipe 50 which extends through the bridge wall 37 and into the pipe 47, so that the suction in the pipe 4'? will result in withdrawing from the space ll any gases that may accumulate therein. With this construction, therefore, the space occupied by the operator will be at all times free from obnoxious or disagreeable gases.

The material to be treated is delivered to the conduit 5 through a delivery pipe 51 which extends up through the. top of the casing 28 and communicates with a suitable hopper 52. This type of furnace is usually used in treating granular material and in operating the furnace it is simply necessary to keep the hopper 5:2 tilled with the granular material, the latter gravitating through the pipe 51 and conduit 5 to the arcing point as the material is melted and drawn oil through the tap holes 12. The electrode 2 becomes quite hot during operation and thus it acts as a means for pie-heating the material while in the conduit This preheating of the material will oftentimes result in the formation of gases, and to provide for eliminating these gases, I employ a pipe 53 which extends longitudinally of the pipe 51 and is open at its lower end, and the upper end of which leads through the pipe 51 into the pipe 47. The suction in the pipe 47 will, therefore, draw out of the conduit 5 any gases'that may be formed therein by the pre-heating operation. The pipe 51 is also formed with vent openings 54 that lead directly into the pipe 47, and these vent openings, together with the pipe 53 serve to prevent the accumulation of any gas in the delivery pipe 51.

I claim:

1. A pair of electrodes for an electric furnace, one of said electrodes having a shape relative to the other such as to produce a plurality of concentric annular arcs.

2 A pair of electrodes for an electric furnace, one of said electrodes having at its arcing end a plurality oi. annular ridges and the other electrode having its arcing end shaped to co-operate with said ridges to produce a plurality of concentric annular arcs.

3. A pair of electrodes for an electric furnace, one of said electrodes having a central passage and a plurality of ridges at its arcing end and the other electrode having a shape to co-operate with said first-named electrode to produce a plurality of annular arcs.

4. In an electric furnace, the combination with two electrodes, one of which is tubularand the other of which has a. protuberance projecting slightly into the bore of the tubular electrode, of means to deliver the mate rial to be treated to the are through the tubular electrode, and the relation of the electrodes at the arcing point being such as to retard the passage of the material through the tubular electrode whereby the material will remain in the latter for a length of time and thereby become preheated.

5. A pair of electrodes for an electric turnace, one of said electrodes having a passage therethrough for the delivery of material to the arc and also having other passages therethrough for the escape of gases formed at the arcing point.

6. A pair of electrodes for an electric turnace, one of which has a passage therethrough for the delivery, to the arc, of the material to be treated and also other passages theret-hrough for the escape of gases produced at the are.

7. A pair of electrodes for an electric furnace, one of said electrodes having a protuberance on its end and the other having a central bore or openingof large diameter than the protuberance.

8. A pair of electrodes for an electric fun nace, one of which is tubular and the other of which has a protuberance on its end surrounded by annular groove.

9. A pair of electrodes for an electric turnace, the upper electrode being tubular and the lower electrode having a central protubcrance and an annular depression in its upper face surrounding the protuberance and constituting a puddling bed.

10. A pair of electrodes for an electric furnace, the upper electrode having a central passage therethrough for the delivery of material to the arcing point and the lower electrode having a protuberance and an annular depression surrounding the protuberance and forming a puddling bed, said electrodes being constructed to produce a circular arc surrounding the puddling bed.

11. In an electric furnace, the combination with two electrodes, of means to support the same, the lower electrode having an annular depression forming a puddling bed, said upper electrode having a central channel through which material to be treated is delevered to the arc, and said electrodes being so constructed as to produce an annular arc surrounding the puddling bed and another annular are inside the puddling bed and through which the material passes as it is delivered to the bed.

12. A pair of electrodes for an electric furnace, the lower electrode having an an nular depression forming a puddling bed, and a cone-shaped protuberance situated centrally ct said puddling bed, and said electrodes being constructed to produce an annular arc surrounding the puddling bed and another annular are centrally of said bed.

13. A pair of electrodes for an electric furnace, the lower electrode having in its upper face a central protuberance and an ldtl annular depression constituting a puddling bed surrounding the protuberance, said electrodes being constructed to produce an annular arc surrounding the puddling bed, said lower electrode having tap holes situated to discharge through said annular arc.

14. A pair of electrodes for an electric furnace, the upper electrode having in its lower end an annular groove and being rovided with one or more gas vents leading from said groove.

15. In an electric furnace, the combination with a pair of electrodes, of resilient means for yieldingly supporting the lower electrode.

16. In an electric furnace, the combination with a pair of electrodes, of means for raising and lowering the lower electrode and resilient means providing at all times a resilient support for said electrode.

17. In an electric furnace, the combination with a pair of electrodes,of a cylindrical jacket of fire-clay or other heat resisting material closely surrounding the central ortion of the upper electrode and insulating the latter against heat radiation.

18. In an electric furnace, the combination with a pair of electrodes, of a cylindrical jacket of heat resisting material surrounding the central portion of the upper electrode, and a packing of asbestos exterior to and surrounding said jacket. I 19. In an electric furnace, the combination with a furnace structure or casing, of a bridge wall within the same, a pair of electrodes, the upper one of which is provided with a feed conduit and extends through said bridge wall and a heat-insulatedjacket sustained by said bridge wall and surrounding the upper electrode.

20. In an electric furnace, the combination with a furnace housing, of a bridge wall within said housing forming beneath it an operating chamber, a pair of electrodes within the housing and arranged so that the arcing point is within said operating cham' ber, the up er electrode having a feed conduit theretl irough.

21. In an electric furnace, the combination with a furnace housing, of a bridge wall within said housing forming beneath it an operating chamber, a pair of electrodes within the housing and arranged so that the arcing point is within said operating chamber, and a gas vent extending through said bridge wall permitting the escape of gas from said chamber, one of said electrodes having a feed conduit through which material is fed to the arcing point.

22. A pair of electrodes for an electric furnace, one of said electrodes having means for preheating the material delivered to the arcing point and also having gas vents leading from the arcing point.

23. A pair of electrodes for an electric furnace, said electrodes being constructed to produce a hollow arc and one of the electrodes having a passage to deliver material to the arcing point and gas vents leading from the arcing space.

24. In an electric furnace. the combination with two electrodes, one of which has a channel therethrough for the delivery of material to the arcing space, and a gas vent leading from the upper end of said channel for the purpose of taking off gas which generates in said channel.

25. In an electric furnace, the combination with a pair of electrodes, one of which is provided with a channel for the delivery of materialto the arcing space, one or more gas vents leading from the arcing space, a gas vent leading from the upper end of said channel, and a conduit leading to a stack and with which all gas vents communicate. I

In testimony whereof, I have signed my name to this specification.

STEPHEN L. TINGLEY.

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