US3781449A

US3781449A - Monconsumable electrode for an electric arc furnace with integrated cooling and electrically conducting means

Info

Publication number: US3781449A
Application number: US00258731A
Authority: US
Inventors: C Wolf; R Akers
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1972-06-01
Filing date: 1972-06-01
Publication date: 1973-12-25
Anticipated expiration: 1990-12-25

Abstract

An electrode suitable for providing an electrical arc between the tip of the electrode and a melt in an electric furnace. The tip of the electrode upon which the arc plays also includes an electromagnetic coil which is used to move the arc over the entire circumferential area of the tip of the electrode by magnetic influence. Consequently, no single small section of the tip of the electrode becomes overheated. The heat generated both at the point of arc attachment to the tip and within the magnetic field coil creates a heat flux which must be removed to maintain the integrity of these parts. A channel is provided to conduct cooling fluid, such as water, simultaneously to both the tip and the electromagnetic coil to cool them. In addition, a portion of the electrode includes an electrical conductor which acts as a common conductor for the electrical power supply for the electromagnetic coil and for the arc producing tip of the electrode. This conductor also forms part of the cooling path.

Description

United States Patent [191 Wolf et al.

[451 Dec. 25, 1973 Primary Examiner-Roy N. Envall. Jr. Att0rney-A. T. Stratton et a].

[57] ABSTRACT An electrode suitable for providing an electrical are between the tip of the electrode and a melt in an electric furnace. The tip of the electrode upon which the arc plays also includes an electromagnetic coil which is used to move the are over the entire circumferential area of the tip of the electrode by magnetic influence. Consequently, no single small section of the tip of the electrode becomes overheated. The heat generated both at the point of arc attachment to the tip and within the magnetic field coil creates a heat flux which must be removed to maintain the integrity of these parts. A channel is provided to conduct cooling fluid, such as water, simultaneously to both the tip and the electromagnetic coil to cool them. In addition, a portion of the electrode includes an electrical conductor which acts as a common conductor for the electrical power supply for the electromagnetic coil and for the are producing tip of the electrode. This conductor also forms part of the cooling path.

38 Claims, 5 Drawing Figures we ac. MAG,

PATENTEDUEB25I973 3.781.449

SHEET 1 OF 4 IIA 62D FIG. IA 68 PATENTED 3,781,449

S'riEEI b UP 4 FIELD ARC POWER POWER UPP Y (SUPPLY ii I80 FIG. 2

BACKGROUND OF THE INVENTION This invention relates to electrodes for use in electric arc furnaces and it has particular relation to a noncon- LII sumable electrode employing a magnetic arc controlling and cooling means.

Nonconsumable electrically conducting electrodes are used in electric furnaces to provide an arc between a material such as titanium sponge which is to be reduced or melted and the tip of the electrode. The reduction or melting process is usually carried on by generating a large amount of heat in the are so that the sponge may be melted. Nonconsumable metallic electrodes which may be constructed from a copper based alloy for example are used in many cases to provide the arc for reduction. These electrodes have replaced the well'known graphite electrodes which are gradually consumed during a melting operation in an electric furnace. A nonconsumable electrode does not substantially deteriorate or become consumed in the are as time passes during a melting operation nor does it contaminate the meltpConsequently, there is no need to move it vertically to compensate for loss of material as in a graphite or carbon electrode which is gradually consumed nor is there a need to replace it as often as a carbon electrode, as anexample once every two or three hours of continuous melting.

In the consumable vacuum melting of many materials electrodes must be substantially hand fabricated for reactive metals and must be open air induction or arc melted for super-alloys. In both cases this represents an extra step in the process which adds expense and increases the probability of contaminating the material. The use of a nonconsumable electrode offers the advantage of being able to feed raw materials or scrap directly into a crucible and melting it directly into ingot or electrodes suitable for remelting thereby eliminating a step in the process and recovering virtually 100 percent of the scrap.

An important feature in a nonconsumable electrode is control of the are on the surface of the tip. Control may be caused in many ways, one of which is by the influence of an electromagnetic field. As an example of one method of control it is known that if current in a current conductor such as an arc in an arc furnace, passes with a perpendicular component through a magnetic field a force is generated which will cause the current conductor or are in this case to move perpendicularly to the plane of the magnetic field and current carrying path. An electromagnet to generate this field is usually placed adjacent to the tip of the electrode so that the magnetic flux will be of high strength and of the proper direction to interact with the arc current and cause the arc to precess around the tip of the electrode. In the past, separate cooling facilities or means were provided to the tip to remove the heat generated by the arc and to the electromagnet to remove the heat generated by the current flowing in the electromagnetic coil. This necessitated a minimum for four input and output portholes or connections, that is two input portholes or connections and two output portholes or connections, one input porthole being provided for providing cooling fluid to a separate channel for the electrode tip and an output porthole being provided for removing the same fluid. In addition, a separate porthole was provided for allowing fluid cooling means to be provided to the electromagnet and a separate output porthole was provided to remove the fluid. The electromagnet was energized by a separate power source than the power source from producing the are on the tip of the electrode. Consequently, an electrical current carrying path was provided to the electromagnet which was separate and insulated from the current carrying path for the tip. There are many applications such as specialty vacuum electric arc furnaces in which electrodes having diameters of perhaps; inc l 1 es or smaller are required. In an electrode of this size, space be comes a limiting factor. Consequently, it would be advantageous to provide an electrode with a small diameter having an improved cooling means for the tip and the electromagnet so that the number of channels and input and output portholes may be reduced thus conserving space. In addition, it would be advantageous to provide electrically conducting paths to the electrode tip and to the electro-magnet in the tip which are common in some portions thus saving space by eliminating certain electrical conductors. It would also be advantageous to provide an electromagnet having a reduced number of electrical conductors in which one of the electrical conductors acts not only as a single current carrying path for both the electrode tip and electromagnet but also forms part of a unitary channel for the conduction of a heat removing material which may flow adjacent to both the electromagnet and the tip consequently removing heat from both simultaneously, as distinguished from the teachings of U.S. Pat. No. 3,480,717. Also manufacturing efficiency of nonconsumable electrodes of all sizes is improved by virtue of the reduced number of parts required according to this invention.

SUMMARY OF THE INVENTION In accordance with the invention a nonconsumable electrode having a relatively small diameter and adapted for use in a vacuum electric arc furnace is considered which provides for the simultaneous cooling of the electrode tip and the electromagnet by a unitary fluid conducting heat removing means. This means is generally formed by providing three concentric generally cylindrical tubes of different diameters. This provides a tubular structure having a spaced path between the outermost tube and the first concentric inner tube. In addition, another spaced path or return path is provided between the first inner tube and a second smaller diameter, concentrically spaced inner tube. A cooling fluid may be introduced into the space between the cylindrical tube having the largest diameter and the cylindrical tube having the next smaller diameter, which fluid may be provided to the inner portion of an electrode tip. Disposed concentrically within the electrode tip may be an electromagnetic coil or solenoid adpatable for the production of magnetic flux within the region of the electrode tip. The second mentioned space between the first inner cylindrical tube and the second electrical inner tube may also be provided to the region of the tip at the inner portion or the smaller diameter of the previously mentioned solenoid or electromagnetic coil for removing the previously introduced cooling fluid. Certain portions of the electromagnetic coil previously mentioned may be maintained in spaced re- 3 lationship with respect to the previously mentioned tip, consequently forming a channel between the inner portion of the tip and the electromagnet which is mounted concentrically within the are producing tip such that a unitary spaced portion between the electromagnet and the tipmay be connected to the first mentioned fluid conducting path and the second mentioned spaced path so that the fluid may be introduced into the first spaced path and may flow downwardly around the inside surface of the electrode tip and concurrently around the outside surface of the electromagnet to the innermost path for conducting fluid out of the electrode-The third mentioned tubular shell or cylindrical structure which, as was previously mentioned forms part of one of the fluid conducting paths along its outer diameter, may be completely open along its inner diameter so that a hollow opening exists through the central portion of the electrode which may be adpated to conduct gases or other matter from a point or location exte'rnal to the electric arc furnace to the melt in the electric arc furnace directly. To further take advantage of the three concentric shells or tubes in the column portion of the electrode, the outermost tube is used as the common electrical conductor for the magnetic structure and for the electrode tip. As such a terminal from the power supply for the arc producing tip and a terminal from the power supply for the electromagnet are both provided or connected to this outermost cylindrical structure. Electricalcurrent is carried along the cylindrical conductor to the bottom thereof near the region of the tip assembly whereupon the intermediate tube or the one between the innermost tube and the outermost tube becomes the common electrical conductor to the point of the tip attachment whereupon that portion of current which is provided to the tip for producing an arc flows only through the tip across the space between the tip and'the meltin the form of an electrical are then through the melt and back through a conductor to the other side or terminal of the power supply which is used to produce the are. Simultaneously, that portion of the current which is provided to the electromagnet for the production of magnetic flux flows into the electromagnet or solenoid through the electromagnetic coils to the other side electrically of the electromagnet whereupon it is conducted to the innermost cylindrical tube which returns it to the other terminal or noncommon terminal of the power supply which is used to produce the magnetic field or flux. The means whereby the electrical current for the magnet is provided from the previously mentioned terminal or other side of the magnet to the innermost electrically conducting tube is a fingered means mounted concentrically upon the innermost electrically conducting tube. The previously mentioned electrical current flows from one end of the electromagnet across the bridging fingers to the innermost conductor and then to the power supply for the electromagnet. The spaces between the fingers of the previously mentioned bridging structure or member is provided to allow cooling fluid to flow into the previously mentioned region between the first concentrically disposed inner tube and the innermost or second concentrically disposed inner tube. The electrode column may be provided with additional plumbing or cooling hardware fixtures as well as electrically conducting terminals to facilitate the energizing of the previously mentioned magnet and arc-producing r tip and to also facilitate the conducting of cooling fluids such as water through the electrode passageways to cool both, the tip and the electromagnet simultaneously. The tip is cooled'from its inside and the electromagnet is cooled from its outside region or portion. The electromagnet is especially constructed so that the inner portion of each winding is exposed to the flowing water which inner portions conduct heat from the bulk or mass of the electromagnet to the water for subsequent removal. Any shorting of the adjacent windings is avoided because the conducting properties of the water are much less favorable to conducting electrical current than the conducting properties of the material comprising the turns of the electromagnetic solenoid.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention reference may-be had to the preferred embodiment exemplary of the invention shown in the accompanying drawings in which FIGS. 1A, 1B and 1C show a nonconsumable electrode for use in an electric furnace;

FIG. 2 shows an enlarged portion of the nonconsum able electrode shown in FIG. 1 which represents the region of the electrode in the vicinity of the electrode tip; and

FIG. 3 shows a special bridging member which is used to simultaneously conduct electricity from one portion of the electrode column to another portion and to allow fluid flow between the spaced fingers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and FIG. 1 in particular, a portion of an electrode 10 suitable for use in an electric arc furnace is shown. Electrode 10 comprises a structurally ridged header section 11 which forms the support structure for certain ports, structures, bolts, and threaded sections which are important structural components of the electrode 10. A first important structural member is a stud 12 having an eyelet or open hole 12A and a threaded section or end 13. Eyelet 12A is adaptable to be connected in some convenient fashion to a hoisting means or external electrode positioning means so that the entire electrode structure 10 may be vertically moved when necessary, such as to replace or repair electrode 10. When the electrode is installed in a furnace and in operation stud 12 is normally replaced with an attachment device which connects to the electrode drive and positioning apparatus such that the furnace operator can drive the electrode up and down and suitably position it as he desires. The threaded portion 13 is screwed or twisted into a metallic, rigidly strong, disc-like member 14 which has a central opening having a corresponding threaded section 13A so that the threads of portion 13 may be joined and twisted, turned or screwed into threads 13A thus rigidly attaching or securing stud 12 to the disc-like metallic supporting member 14. On either vertical side as viewed of the disc-like structural member 14 are electrically insulating members or drive

connector insulators

16 and 18. Insulator I6 is positioned above structural member 14 and insulator 18 is positioned below structural member 14.

Insulators

16 and 18 have central holes or

openings

16A and 18A respectively which allow stud or bolt 12 with its threaded portion 13 to be easily screwed into member 14. Placed immediately below insulator 18 is the topmost portion of an inner structural member 24. Inner structural member 24 has a field connector insulating member 26 placed immediately below a portion of it in the vertical arrangement of the upper portion of the electrode 10. Placed immediately beneath the field connector insulator 26 is the previously mentioned header section 11 which acts as a main supporting structure for the entire portion of the electrode column 10. The field connector insulator 26 is provided with a central opening 26A in which a portion of the innermost supporting and electrically conducting tube member 24 may be disposed. In addition, once assembled, structural members 16, l4, 18, 24, 26 and 11 which correspond respectively to the first drive connector insulator, the disc-like supporting structure, the second drive connector insulator, the inner cylindrical shell assembly the field connector insulator and the header 1 l are aligned vertically in such fashion that an electrically insulating tube 22 maybe disposed in aligned holes common to each of the previously described members with the exception of the header 11. The tube 22 may be formed from an electrically insulating material of the polytetrafluoroethylene type such as that sold under the trademark TEFLON. The tube 22 may provide a passage for a bolt 20 which may be fed through the previously mentioned members such that its threaded end 20A may be screwed into a corresponding complementary thread 11A in header section 11. This upper assembly is also uniquely designed such that the order of pieces can be changed to 14, 16, 18, 24, 26 and 11 which puts member 14 into direct and electrically conducting contact with member 11 through member 20 and the threaded end 20A. This unique arrangement allows for the conduction of the current both for the arc and the electromagnetic field coil to be made in conjunction with the electrode drive connection which offers a much simpler arrangement in many installations. ln addition, field connector insulator 26 is so placed with respect to the inner tube section 24 and header 11 that resilient O-rings or dielectric or electrically insulating

circular members

30 and 32 may be placed in

grooves

30A and 32A respectively in the central tube assembly 24 and the header 11 respectively so that a seal between

members

24 and 26 and 26 and 11 respectively may be provided and be effective to prevent fluid leakage. The central tubular section assembly 24 may have a horizontal hole 34 disposed in it which intersects a central vertical hole 48. Horizontal hole or drilled section 34 may have internally disposed threads 36 which may be adapted to be connected to an external source of gas or pulverized material which may be introduced either by force or gravity through the horizontal hole 34 into the vertical hole 48 from where it may be subsequently deposited or introduced into the internal sections of the associated furnace. Another portion of header 1] may comprise a horizontally oriented opening 60 having an internally placed or disposed threaded section 603 which is adapted to receive a threaded adaptor 62 having a threaded section 60A adapted to be screwed or turned into threaded section 60B. Adaptor 62 may also have a threaded section 62D adapted to be connected to an external threaded member through which fluid or other cooling substances pass. Threaded member 62 has an intermediate flange section 58C which abuts firmly against the outside surface of header 111 thus positioning a sealing-ring 58A which is disposedin groove or O-ring retainer 583. Member 62 includes an internal bore or hole 62E which provides an opening to the internal portion of header 11 for transmittal of certain fluids which may be flowing in portions of the electrode 10 in the region of header 11. In similar fashion, another adaptor or member 68 is fastened or secured to header 11 by means of threads 66A engaging corresponding threads 66B machined or cast into an opening or hole 66 in header ll. Adaptor or threaded member 68 may have another threaded portion 68D suitable for connecting in a watertight or fluidtight fashion if necessary to an external means, hose adaptor or plumbing fixture (not shown) which may be used to provide or supply fluid for cooling purposes to electrode 10. A resilient O-ring 64A may be disposed into a grooved section 648 such that when the flange 64C of member 68 is tightened against the O-ring or gasket 64A it substantially expands to form a generally tight seal. Connecting members or threaded

members

68 and 62 are used to furnish and remove water or other cooling fluids for the purpose of cooling the electrode 10 or the parts thereof. Header 11 is adapted to be connected at the bottom to the main electrode column 37. Main electrode column 37 may comprise three concentrically disposed electrically conducting,

cylindrical members

52, 42 and 44 which may be referred to as the outer cylindrical, electrically conducting or power supply common shell 52, the first inner or intermediate tubular cylindrical, shell 42 and the second cylindrical, electrically conducting inner or innermost tubular shell 44. The second tubular shell 44 may be a member which protrudes downwardly from the previously mentioned tubular assembly 24. Tubular member 44 may have on its outer perimeter an electrically insulating sheathing 46 which is made from a polytetrafluoroethylene type, such as that sold under the trademark TEFLON and which cooperates with a field connector insulator 26 previously discussed to completely insulate the field power tube assembly 24 from certain other portions of the electrode 10 in the vicinity of the header 1 1. It will be remembered that tube 44 protrudes through the center of the field power tube assembly 24 and has as its outer wall the inner diameter of the previously mentioned innermost tubular cylindrical member or electrically insulating sheathing 46. A passageway 50 exists between sheathing 46 and the next outermost tubular member 42. This passageway 50 may be used to confine and conduct heated water from other lower portions of the electrode which may have been heated during certain arc furnace processes, to remove heat from certain portions of the electrode column 37 or certain portions of the electrode 10. The direction of fluid 74 flowing through chamber or spaced region 50 is shown out through hole 62E of the connector 62. The space 40 between the first inner cylindrical tubular member 42 and the outermost electrically conducting tubular cylindrical member 52 may be used or is provided as a chamber to conduct relatively cool fluid, such as water, to other portions of the electrode column 10 to absorb heat or conduct heat away from certain operative means in the electrode column 37 which tend to produce heat under normal operating circumstances or conditions. The direction of flow 72 is shown into the hole 68E of connecting member 68 and down through chamber 40 between the concentric cylindrical memy 7 posed tubes 42 may have a threaded portion 56 adapted to bescrewed into or twisted into a correspon- I screwing in of the threaded

sections

56 and 54 into the corresponding threaded

portions

56A and 54A respectively secures the main portion of electrode column 37 to the upper electrodemeans or header 11. To complete the assembly of outermost electrically conducting member 52 to header section 11 a compressible O-ring 33 is disposed in'a grooved section 33A in headerll such that when column member 52 is screwed into header ll,'O-ring 33 is compressed into the grooved section 33A thus forming a watertight or fluidtight seal or joint.- A spanner or'knurled ring shaped member 70 having inner threads 70A is adapted to-be screwed on corresponding threads 54 of column memb'er52 to be tightened to abut against header section 11 from the bottom so that column member 52 is more rigidly attached to header section 11 by the tightening of the spanner or adjustable threaded section 70.

. Referring now to FIG. 1B, another portion of the electrode 10 comprising electrode column 37 is shown which may be-visualized as an integral part. of and adjacent to that portion of the electrode 10 shown in FIG. 1A. The three concentric hollow cylinders, namely outermost tube 52, firstinner tube 42, and innermost tube 44 are shown. In addition, the direction of incoming cooling fluid 72 and outgoing heated fluid 74 are once again indicated. These members and directional paths including the

chambers

40 and 50 which correspond'to like members in FIG. 1A may be considered as continuations thereof A first set of spacer pins 7 6 one of which is shown with its head disposed in chamber 40 so that the spaced 'disp'osition or spacing between the first inner concentric tubular member 42 and the outer tubular, electrically conducting member 52 may be maintained. Spacer pins 76 are disposed in a radial manner and spaced from one another around the circumference of theelectrode 10 to provide adequate spacing and yet allow free passage of a cooling fluid such as indicated by arrow 72. Innermost tubular member 44 is Y shown having a threaded section 82 formed or machined at its outer perimeter. Threaded section 82 is adapted to be connected to the power tube finger hub 80 with a corresponding inner threaded section 82A on the previously mentioned hub 80. Each previously mentioned spacer 76 extends through an opening 78 in inner tubular conductor 42 and is disposed to abut flush against the power tube finger hub 80 in a region near the threaded portion 82A but on the outer side of the hub 80. The power tube finger hub 80 is screwed onto or fastened to the field power tube 44 so that fingers 88 which maybe referred to as power tube fingers which are spaced in a symmetrical pattern about power tube hub 80, may be oriented in a vertical disposition adjacent to the end portion 44C of field power tube 44. The power tube fingers 88 are resilient so that the end portion 86 of a second portion 84 of the field power tube assembly may be interposed between the radially disposed fingers 88 and the end portion 44C of the first portion of the field power tube 44. A sandwich like rigid grasping contact may be made between the fingers 88 and power tube end 86. This assures good electrical contact and provides an intimate mechanical joint. A groove or similar section 90B is cut into the end section 44C of field power tube assembly 44 so that a compressible resilient O-ringv member 90 may be compressed between the end 86 of the continuing or second power tube portion 84 and the end 44C of the first portion 44 of the field power tube assembly.

It will be noted that where the first portion 44 of the power tube assembly ends and the second portion 84 begins, the continuity of the innermost hole or chamber 48 through the center of the electrode continues. In a similar fashion first inner concentric cylindrical member 42 is continous with a corresponding first inner member 92. Likewise in a groove 94A in member 92 a compressible rubber of similar O-ring or sealer 94 is placed which may be compressed upon the axial, joining of member 42 to member 92. Member 92 has disposed thereon a threaded section 100 which is adapted to fit inside and engage a corresponding threaded section 100A which may face inwardly'or be mounted or disposed on the inner surface of a cylindrical tubular concentric member 93. Immediately below j the threaded portion 100A of member 93 is a plurality of holes 98 which may be adapted to conduct-heating or cooling fluid, suchas water, the flow of which may be indicated by arrow 72 from chamber 40 into an additional chamber 104 fonned between member 93 and the second portion of first inner member 92. In addition, a groove or similar section 104A is cut into member 93 in which is placed a resilient rubber like member or seal 104B which may be compressed upon insertion of member 93 to cause a waterproof or fluid tight joint to be formed between member 93 and outer tubular conductor 52. In a second portion of the outermost shell which corresponds to the outermost shell portion 52, previously described, is provided a groove or retaining ring receptacle 108A in which is placed or disposed a retaining or sealing ring or electrically insulating compressible member 108 which may be compressed between the member 93 and the previously mentioned lower outermost concentric cylindrical shell 106. In an inwardly facing slot or section 110A which is formed between a portion of member 93 and the end of the previously described outermost shell 106 is spaced a retaining, spacing loaded Belleville spring 110 which loads outermost cylindrical shell portion 106 aganist the electrode tip shown in FIG. 1C. Any differential expansion between

members

106 and 92 due primarily to the heating of the outermost surface of member 106 due to radiation from the molten pool is accepted by the Belleville springs 110. Surface 93A on member 93 is held in intimate and electrically conducting contact with surface 52A through the use of a spanner nut 95 which surface 95A firmly contacts surface 93B. The current for the arc and the current for the electromagnetic field coil are conducted from column 52 to tube 92 by the

path

52A, 93A, 93, A, 100.

Referring now to FIG. 1C, the tip assembly or last portion of the vertical electrode 10 is shown. The top portion of FIG. 1C shows the continuity between FIG. 1C and FIG. 1B in that the electrically conducting cylindrical

tubular shells

106, 92 and 84 are shown from the outside to the inside respectively of tip assembly 38. In addition the chambers formed therein, namely, chamber between

shells

106 and 92 and chamber between

shells

92 and 84 and finally the innermost chamber 48 for the introduction of gas or pulverized or fluid substances into the melt are shown. The direction of moving fluid 72 in chamber 40 is once again indicated as well as the direction of fluid flow 74 in chamber 50. Direction of flow 72 may indicate the movement of a cooling fluid, such as water, before it has been substantially heated and direction of flow arrow 74 indicates the same fluid after it has passed through those regions of the electrode 10 which are to be cooled. A spacer or spacing rivet or member 112 is disposed in electrically conducting cylinder 92 such that the head of rivet 112 projects into the region 40 between shells 9 2 and 106 to maintain or

space shells

106 and 92 so that the fluid chamber 40 is preserved.

Shell 92 is uniquely adapted to function or act as a common electrical bus or conductor for two power supplies which may be used to energize various means in the remaining part of the tip assembly 38. Outermost external tube 106 terminates at end 118B. A portion of this shell 106 then abuts in a vertical manner against the top portion of an electrode tip 120. A groove 118C is cut in the bottom of column 106 and a corresponding groove 118A cut in the top of tip 120 such that a compressible, fluidtight O-ring 118 may be compressed between tip 120 and column 106. The next intermediate concentric tube 92 or the common bus connector and mechanical supporting column 92 also terminates at tip 120 but in a different manner. Column 92 has a threaded portion 114 along the bottommost part of its outer perimeter. Threaded portion 1 14 is adapted to fit into a corresponding set of threads or threaded section 114A machined or cast into the inner surface at the top of tip 120 so that tip 120 may be screwed onto column 92, firmly and removably securing electrode 92 to tip 120 and also providing the means whereby the previously mentioned O-ring 118 is compressed against the bottom surface or groove 118C of outer shell 106. The threads 1 14A are continuous around the inner perimeter of tip 120, however the threads 114 on the bottom portion of the first inner electrode 92 are not continuous but are interrupted periodically by substantially vertical grooves 116 cut into the bottom portion of the cylindrical column 92. These grooves are equally spaced around the entire length of the bottom perimeter of electrode 92. The grooves or openings 116 are provided to form passageways or channels between the previously mentioned channel 40 and a corresponding channel 170 in the tip 120. The innermost column or the return column 84, which may also be referred as the innermost cylindrical shell is terminated vertically of the lower ends of the previously described

electrodes

106 and 92 by a predetermined distance. The bottom portion of cylindrical shell 84 has a threaded section 124 cast or machined thereon. In addition, a groove or receptacle is placed above the threaded portion 124 to accommodate a resilient, rublber-like O-ring 125A which may be used to form a watertight or fluidtight seal. Complementary threads 124A which are provided on an electrically conducting bridge 122 are spaced to correspond to threads 124 so that the generally cylindrical shell 84 supports a bridge 122 having a hub section 124B. Hub section 1248 is screwed onto or twisted onto the bottom portion of shell 84 at threads 124 such that O-ring 125A is compressed between overlapping portions of the bottom part of shell 84 and the hub 1243 of bridging member 122. Abutted vertically against the bottom portion of shell 84 and an overlapping portion or edge of the hub 124B of bridging section or member 122 is a field coil insulator 128. Field coil insulator 128 is also abutted horizontally against another portion of hub 122 so that an O-ring 130 resting in groove 130A cut into field coil insulator 128 may form a fluid tight joint or seal between field coil insulator 128 and a vertical portion of member 122. Projecting into a recess 126A in field coil insulator 128 is a rivet-like spacer 126 which protrudes through the adjacent portion of bridging member 122 from second innermost electrode 92 thus maintaining and preserving the channel 50 in the region of bridging memher or section 122. The bottom portion of field coil insulator 128 has machined threads 136 therein which are adapted to be screwed into threads 136A disposed on the upper, outer surface or periphery of a central hub 134 which may be an electrically conducting central hub. Field coil insulator 128 may comprise an electrically insulating material such as those sold under the trademarks TEF LON or MICARTA or the like. Immediately below the engaged

threads

136A and 136 of central hub 134 and field coil insulator 128 respectively is placed an O-ring 138 which is retained in groove 138A in central hub 134 so that the joining of central hub 134 to the field coil insulator 128 compresses the rubber O-ring 138 to form a watertight or fluidtight joint or seal between the two previously mentioned components. The central hub 134 has threads 140A cut into the inner perimeter of the bottom portion such that these threads may be screwed into or adjusted on the threaded portion 140 of the tip 120. A groove 142B is machined or in some manner provided in a portion 142A of tip 120 so that an O-ring 142 typical of the same types previously mentioned may be disposed and compressed between the inner portion 142A of tip 120 and the bottom portion of central hub 134.

The tip 120 has a unique generally circular or cylindrical shape which may be visualized as including outer and inner vertically oriented cylindrical sections having a space interposed between the outer and inner vertical sections. The outer section or vertical portion may be referred to as 120A and the inner section or vertical section may be referred to as 142A. A horizontally oriented or disposed section or portion 120B may bridge the space between outer vertical section 120A and inner vertical section 142A at the bottom of tip 120. The inside surface of portion 142A or the surface closest to the center of the electrode column 10 of the electrode tip 120 forms a portion of the previously described channel 48. Consequently, electrode tip 120 includes a U-shaped cross section comprising a vertical section 120A, a second vertical section 142A and a bottom section 120B forming a toroidal tip 120 having an opening at the top and a closed bottom which is spaced about a central hole or opening such as 48.

The previously mentioned tip 120 has three identifiable inner surfaces, at first vertical surface A which is the inner surface of the outer vertical portion 120, a

' second horizontal surface 1703 which is the inner porate magnetic flux. This coil is indicated as solenoid or magnetic coil 144. A portion of the structural part of coil 144 has a plurality of spaced toothed protrusions 156 around the outer portion of its perimeter. Interspaced between the tooth portions 156 are vertical grooves 160. The tooth portions are adapted to fit snugly against a portion of the inner wall 170A of tip 120 and to rest on ledge or shoulder 158 which has been machined into or provided in the innerportion 170A of tip 120, This arrangement supplies support for the electromagnetic coil 144 and provides spacing for coil 144 from portions of the

inner surface

170A and 170B oftip 120. In addition, it provides electrical continuity'between the electromagnetic coil 144 and tip 120 suchthat electrical current which maybe flowing for example in the second innermost cylindrical shell 92 may flow in one sense through the electrically conducting toothed portion 156 into the electromagnetic coil 144. The previously mentioned grooves or openings 160 serve the purpose of providing inlets from the previously mentioned channel 40 into a new channel 170 which completely surrounds a significant portion of the electromagnetic coil 144 so that channel 170 may be used to conduct the flowing cooling fluid 72 to both the inner portion or surface 170A of the tip 120 and the outerportion of the electromagnetic coil 144. As the fluid travels around the bottom portionof magnetic coil 144 and begins to move vertically up the passageway 17 between the coil 144 and the second vertical inner. portion 142A of tip 120, heat which is gradually being transferred to the fluid during the operation of the overall electrode is conducted away by the movement of the fluid.

It should be'noted that tip 120 is arcuate or curved or rounded at the-bottom as indicated at 168 to provide better are moving properties.

Electromagnetic coil 144 may comprise an external cylindrical shell of an electrically conducting material such as copper, silver, aluminum, or any similar copper, silver, or aluminum based alloy which may also be thermally conducting or suitable for conducting heat away from the coil 144 and for supporting coil 144 as well as conducting electrical current. The coil 144 also includes or comprises a plurality of closely pitched, helically wound coil sections or turns of a relatively rectangular cross-sectioned electrical conductor as indicated at 150 which are separated by relatively thin layers of electrically insulating material, such as mica, laminated insulating material such as that sold under the trademark MICARTA or any similar insulating material as indicated at 148. The end portion 164 or the portion of the electromagnetic coil 144 which is electrically opposite from the terminal 158 is an elongated generally cylindrical circular shell insulated electrically by insulating material 162 from the second innermost electrical .conductor 92 and the extension of terminal 158. Insulator 162 also continues downward and assures insulation of turns l50from conducting shell 146. Electrical conductor or second terminal 164 is connected electrically to a main coil section such as 150 in intimate physical low resistance electrical contact through an electrically conducting epoxy resin or glue 154. The first electrical terminal as indicated at 158 is connected to the main body 146 of the electrically conducting coil and in turn to the bottom portion of a coil such as at 150 with a similar electrically conducting epoxy resin or glue 152. The electrically conducting cylindrical second terminal or end terminal 164 is placed with the previously mentioned electrically conducting hub 122 through a series of longitudinally, vertically, extending fingers 131 which project or extend downwardly from main hub section 124B. Fingers 13] make intimate electrical contact with electrically conducting portion 164 at one or more points 166. It ,will be noted that the fingered spring sections 131 are resilient and are forced inwardly upon assembly to create the inti mate contact pressure necessary to conduct electrical current from electrically conducting portion 164 on coil 144 to electrically conducting fingers 131 on electrically conducting hub 122. It will be notedthat the heated output fluid or water indicated by arrows 74 flows into channel 50 through the slots or openings 132 interposed between the previously mentioned fingers second, to form a channel for hot fluid which may be flowing from heated portions of the electrode 10 to be eventually removed to-a location external to thenonconsumable electrode 10. Thefluid may flow in the direction of arrows 74 once it reaches channel 50.

Referring now to FIG. 3, another view of the hub 122 is shown in which the threads 124A are shown disposed on the inner portion of the hub 122. In addition, a machined groove or flange 125C (also shown in FIG. 1C) is shown which is adapted to assist in compressing the previously mentioned O-ring or circular rubber sealing means 125A. The main hub section 1248 is shown and a plurality of circumferentially spaced holes 127 (also shown in FIG. 1C) are shown through which the previously mentioned spacing insulator 126 is assembled or fitted. In addition, the finger portions 131 are shown orientedin a downward vertical fashion about the cirflow. In addition, the primary contact regions 166 on fingers 131 are shown.

REMOVAL OF HEAT FROM THE ELECTRODE As was previously mentioned, a fluid such as water, or any other type of suitable fluid may be introduced into certain passageways within the electrode 10 which may generally be considered as a nonconsumable electrode. It is understood that there are very critical relationships governing the types of fluids and the manner in which they remove heat from the electrode. These critical relationships must be understood and applied for satisfactory cooling of the electrode. More specifically, however, the fluid may be provided to flow around certain portions of the electrode to remove heat which may be generated from electrical current flow in some portions and are attachment in others.

Referring again to FIG. 1A, the introduction of fluid into the electrode 10 through connector or adaptor 68 may be in a direction as indicated by the arrow 72.

Fluid is introduced horizontally and then flows downwardly along a vertical path through the channel 40 formed between the outermost cylindrical tubular shell 52 and the first inner tubular shell 42.

Referring once again to FIG. 1B again, it can be seen that the fluid continues to flow in channel 40 through the main portion of electrode past and around the spacer pins 76 and around a portion of assembly 93 through the holes 98 which may be spaced at intervals around the perimeter of a portion of the assembly 92 and into a continuation of channel 40 which is provided between the outermost tubular shell 106 and the first inner tubular shell 92.

Referring once again to FIG. 1C the fluid as indicated by arrow 72 continues to flow downwardly past spacer 112 through the regions of the tip assembly 38 until it reaches the threaded portion 114A of the second shell 92 whereupon it flows through the previously mentioned vertical grooves or openings 1 16 to a second set of grooves or openings 160 spaced between the previously mentioned toothed portions 156 of the electromagnet assembly 144. At this point, the fluid flows into channel 170 where it removes heat simultaneously from the inner walls such as 170C, 170B and 170A of the tip 120 and from the electromagnet 144. The fluid changes direction at region 170B to move upwardly between a portion of the tip 120 and the electromagnet 144. The heat may be removed conveniently from the electromagnet 144 through the innermost portions of the electromagnet 144 because the innermost portions of electrical conducting material which form the coil sections 150 are exposed to the fluid such as water, so that the heat may be easily conducted from the coil section 150, for example, into the moving water such as indicated by 74. It will be noted that the effect of any conducting paths or circuits between adjacent turns of electromagnet 144 is relatively slight or minimal since the electrically conducting material such as 150 normally has a relatively much higher electrical conductivity than the moving water. This construction of the field coil with the copper exposed to the heat removing fluid or water is the preferred embodiment, however it is also possible and in some cases desirable to completely isolate the copper conducting turns from the fluid or water path to place the field coil in a more favorable position. It has been determined that cooling of the coils through such a structure is also attractive. The now heated moving water 74 becomes output water or water to be eventually removed as indicated by arrow 74 which is shown flowing through the toothed portion of the previously mentioned hub 122 into a second inner chamber. 50 which is formed between the first inner shell 92 and the second inner shell 84. Water, as indicated by arrow 74, flows upwardly along the inner side of inner shell 92 and water'as indicated by arrow 72 flows downwardly on the outer side of wall 92.

Referring again to FIG. 1B, the water is shown continuing to flow upwardly in direction 74 between

shells

92 and 84 of the tip assembly 38. The upwardly flowing water passes a rivet-like spacer 1008 which aids in spacing the innermost shell 84 from the second inner shell 92.

Referring again to FIG. 1A, the direction of fluid flow 74 is shown to be upward until the fluid reaches the previously described output connector 62 whereupon it changes to a horizontal direction, flowing to the left where it is removed for cooling and possible recirculation.

THE ELECTRICAL PROPERTIES OF THE ELECTRODE Referring now to FIG. 2, an enlarged view of a portion of the tip and tip assembly 38 of electrode 10 is shown. Particular emphasis is placed on the electrical properties ofthese particular regions. As was described previously, the second or middle shell of the three concentric shells such as may be represented by 92 serves several purposes. One purpose is to act, as was previously described, as part of two separate channels, namely 50 and 40 for example, for the channeling of cooling fluid. Another purpose is to act as a mechanical structural component for supporting the tip. And still another purpose is to act as an electrical conductor for the simultaneous supplying of electrical current to the arc tip 120 to form an arc 184A and to the electromagnet 144 to produce magnetic flux which may cause the arc 184A to move or precess over the base of the tip 120. Two direct current power supplies or sources of electrical power are shown, namely the magnetic field power supply 176 and the are power supply 178. It will be noted that the positive tenninals of the supply 176 and the supply 178 are joined and shown to be connected to cylindrical shell or electrical conductor 92 whereupon a current which may be provided to establish arc 184A and to provide electrical energy to coil 144 may flow simultaneously in conductor 92. That portion 184 of the electrical current flowing in the shell or electrical conductor 92 which is useful to establish the arc 184A flows through the toothed section 114 into tip 120 to establish arc 184A between tip 120 and melt 182 whereupon electrical current flow 184 continues as through a return wire 180 to the supply 178. That portion 186 of the electrical current which is to provide electrical energy to the electromagnet 144 may flow to the portion of the electromagnet 144 which abuts vertically, upwardly against the conductor 92 or may flow into a portion of tip 120 and back into the electrically conducting electromagnetic coil conductor 146 through teeth or toothed section 156. At this point the unidirectional electrical current 186 may flow through the previously mentioned-electrically conducting portion 146 of the substantially cylindrical magnet or solenoid assembly 144 through a first electrically conducting epoxy resin cement 152 to a first coil section or winding portion C of the solenoid or coil 144. The electrical current 186 may then flow in a helical path through other sections of the electrical coil 144 such as through sections 150A and 1503. Finally, the electrical current 186 may flow into the uppermost coil section 150 from whence it may flow through a second portion or layer of electrically conducting epoxy cement 154 to the second terminal or cylindrical electrically conducting section 164. The current may then flow into the fingered sections 131 of the electrically conducting bridging member 122. The current 186 which may be considered as the magnetizing current continues to flow through portions of the remainder of the bridging section 122 through its hub portion 124B and through the threads 124A to the innermost tubular cylindrical shell 84 whereupon the current 186 is shown to flow to the other side or the negative terminal of the magnetic field current supply 176.

In summary, it can be seen that the electrical conductor or first inner shell 92 comprises a common electrical conductor for current flowing to generate an arc 1 l84A,and tov create magnetizing currentsuch as 186 in an electromagnet 144. This provides a more compact or space saving construction'by using a common conductorfto perform two functions which would normally beperformed by two conductors. By examining the electromagnet 144 it can be seen that the current flowing through the helically wound adjacent insulated electrically conducting sections, as. indicated by turns 150C, 150A,'15 0B, and 150 for example produce or generate magnetic flux as indicated by flux lines 188 which may flow upwardly into the opening 48 of the electrode and outwardly through the shell. At the bottom portion of the electrode tip the flux lines 188 may intersect arc 184A at point 190. The intersection of the magnetic flux lines 188 and the electrical current flowing through arc 184A may be shown by well known electromagnetic principles to cause the arc to move perpendicularly with respect to the plane containing both the electromagnetic flux path 188 and the electrical current path 184A such that the arc may precess in a counterclockwise direction asviewed from below around the buttom surface 1203 of tip 120. Consequently, the arc does not remain on any one portion of surface 120B for any significant length of time so that burning or damaging of the tip material 120 does not occur. The electromagnet 144 may also be considered as a magnetic arc controlling means. Also note that the direction of current flow may be reversed.

' FINGERED' BRIDGING MEANS I Referring once again to FIG. 3, the fingered bridging means 122 is shown. This fingered bridging means has a unique function in that the fingers or tines 131 and the interposed or interspaced open areas 132 perform two unique functions, that is, the tines 131 provide electrical conducting paths for electrical current such as 186 which may be used to generate a magnetic field as indicated by flux lines 188 in FIG. 2 in the magnetic are moving means 144, and the spacers 132 regions or absence of conducting material between the fingers 131 form channels whereby fluid may flow or move into other portions of the electrode for removal to an external heat exchanger. By referring to FIG. 2 it'will be noted that it is essential that electrical continuity be established between the hub section 1248 and one electrode such as 84 and concurrently heat generated by the electrical current be removed from the arc moving means to the heat conducting path 50, in order that the purposes for using a single or unitary cooling means or channel and a single electrically conducting means be accomplished. Consequently, the tines or fingers 131 provide a dual function of providing a channel for fluid flow between them and providing electrical conduction through them.

It is to be understood that the disclosed invention may be applied to any type of electrode whether it be used in an electric arc furnace or vacuum furnace or in any other kind of furnace or whether it be employed in any kind of heating or processing apparatus. It is also to be understood that the electrically conducting shells, such as 106, 92 and 84 for example, may be comprised of any of suitable electrically conducting material such as copper, aluminum, silver or any alloy of the same or any other electrically conducting material which provides the proper electrical conductivity and mechanical supporting features desired. It is also to be understood that the direct current power supply such as 176 and 16 178 which otherwise be known as energizing means may be oriented or connected so that the negative terminals are joined at the common electrode 92 and that the positive terminals are notjoined or that the positive 5 terminal of either could be connected to the negative terminal of the other as desired. It is also to be understood that the power supplies 176 and 178 may be alternating current power supplies depending upon the exact application desired; It is'also to be understood that even a single electrical power supply may be used to provide both functions simultaneously or that only one power supply may be used if only one of the desired function is desired, for example, if only the electric arc 184A is to be generated or if only the magnetic flux such as 188 is to be generated. it is also to be understood that the O-rings or seals may comprise a resilient rubber, electrically insulating sealing type material or may comprise generally rigid insulating material. It is also to be understood that the insulating portions may comprise various combinations of laminated thermosetting resins, such as epoxy resins, mica, insluating material or any other suitable insulating material which may have the insulating properties and mechanical support properties required such as those sold under the trademarks MICARTA, TEFLON or BAKELITE. It is also to be understood that the central hole 48 which heretofore has been mentioned as a possible means for introducing material into the melt may be completely omitted or may be altered appreciably for any desired or particular purpose. It is also to be understood that the shells such as 106, 92 and 84 need not be circular in cross section but may be of any convenient tubular cross section including rectangular. It is also to be understood that the are 184A may be of the defused type.

The apparatus embodying the teachings of this invention has many advantages. One advantage lies in the fact that an electrode having a small diameter may be used in aparticular electric arc furnace because the number of cooling paths and electrically conducting paths may be reduced by using a heat removing or fluid cooling path having dual cooling functions and electrically conducting paths which may conduct current to two different means simultaneously in a single path. In addition, another advantage lies in the fact that more current may be provided to establish an arc in any given power range because the arc may be caused to rotate so as not to burn or destroy any portion of the tip of the electrode. Another advantage lies in the fact that by connecting the magnetizing current power sup ply in a positive to negative fashion as shown in FIG. 2, the periodic effect of the galvanic voltage drop from coil or winding section to coil or winding section of the are generating means 144 which may cause corrosive ionization activity, such as at the exposed coil portions 150A and 1508 may be taken care of by the simple removal and replacement of the electrode tip 120 rather than the more extensive are generating means 144 as the galvanic action will tend to corrode the tip 120 rather than the field generating means. Another advantage lies in the fact that since there is only a unitary heat removing path, less cooling hardware is necessary in the electrode so that a reduction or saving may be realized in material and the lesser likelihood of a mechanical failure. As an example, only two connectors or plumbing fittings need be provided on the upper portion of the electrode rather than four. Another advantage lies in the fact that since the electrode can be made smaller for a given amount of heat to be generated, less material is required to produce the electrode and it may be more easily moved in and out of the arc furnace or closer or farther away from the melt because of its lighter mass. Consequently, the control of the arc and its length may be much more easily controlled than if a wider or larger electrode is used.

We claim as our invention:

1. An electrode for use in an electric arc furnance comprising a magnetic field generating means, an elongated outer tubular shell, a first inner tubular shell, a second inner tubular shell and an electrode tip upon which an electric arc may play, one end of said outer tubular shell being disposed adjacent to said tip, said first inner tubular shell being disposed within and spaced from said outer tubular shell forming a first channel therebetween, said second inner tubular shell being disposedwithin and spaced from said first inner tubular shell forming a second channel therebetween, said magnetic field generating means being disposed near to and spaced from said tip forming a third channel therebetween, said first, second and third channels communicating serially to form an exclusive unitary heat removing channel for said field generating means and said tip generally simultaneously, a heat conducting medium disposed in said unitary channel for providing a heat conducting means adjacent said tip and said field generating means for accomplishing said heat removal.

2. An electrode for use in an electric arc furnace comprising a magnetic field generating means, an elongated outer tubular shell, a first inner tubular shell, a second inner tubular shell and an electrode tip upon which an electric arc may play, one end of said outer tubular shell being disposed adjacent said tip, said first inner tubular shell being disposed within and spaced from said outer tubular shell thus providing a first channel therebetween said second inner tubular shell being disposed within and spaced from said first inner tubular shell forming a second channel therebetween, said magnetic field generating means being disposed near to and spaced from said tip thusproviding a third channel therebetween, said first, said second and said third channels bein'g disposed structurally in series to form a single overall heat conducting channel, a conducting medium being disposed in said single channel for providing a heat conducting means adjacent said tip and said field generating means substantially simultaneously.

3. The combination as claimed in claim 2 wherein said medium comprises a fluid.

4. The combination as claimed in claim 3 wherein said single heat conducting channel is provided to substantially remove heat simultaneously from said tip and said magnetic field generating means.

5. The combination as claimed in claim 4 wherein said fluid substantially comprises moving water.

6. The combination as claimed in claim 5 wherein said electrode comprises an input water port and an output water port, said input water port and said output water port being provided respectively to generally introduce and remove said moving water from said single heat conducting channel so that heat generated in said tip and said magnetic are moving means may be conductedaway by said moving water.

7. The combination as claimed in claim 6 wherein said input water port is disposed adjacent to said portion of the said single heat conducting channel comprising said first channel, said first channel is disposed adjacent to said portion of said single heat conducting channel comprising said third channel, said third channel is disposed adjacent to the said portion of said single heat conducting channel comprising said second channel, and said second channel is disposed adjacent to the said output water port, so that water may be introduced into said electrode at said input water port and then flow, in order through said first channel portion, said third channel portion, and said second channel portion to said output water port from where said water may be removed from said electrode.

8. The combination as claimed in claim 6 wherein said input water port is disposed adjacent to said portion of the said single heat conducting channel comprising said second channel, said second channel is disposed adjacent to the said portion of said single heat conducting channel comprising said third channel, said third channel is disposed adjacent to the said portion of said single heat conducting channel comprising said first channel, and said first channel is disposed adjacent to the said output water port, so that water may be introduced into said electrode at said input water port and then flow, in order through said second channel portion, said third channel portion, and said first chan nel portion to said output water port from where said water may be removed from said electrode.

.9. The combination as claimed in claim 7 wherein said outer tubular shell is generally cylindrical, said first inner tubular shell is generally cylindrical and disposed generally concentrically within said outer generally cylindrical, tubular shell and said second inner tubular shell is generally cylindrical and disposed generally concentrically within said first inner generally cylindrical, tubular shell.

10. An electrode for use in an electric arc furnace comprising, a first source of power for the generation of an electric arc, a second source of power to provide magnetizing electrical current, a magnetic field generating means having electrical terminals, an electrode tip upon which an electric arc may be produced, a first electrical conductor and a second electrical conductor, said first electrical conductor being connected at a first end to said tip and being connected at its other end to one terminal of said first source of power, another terminal of said first source of power being electrically interconnected in circuit relationship with the melt of said furnace, said first source of power energizing said tip for the production of an electric arc in a space between said tip and said melt in said furnace, said first electrical conductor also being connected at its said other end to one terminal of said second source of power to provide magnetizing electrical current for said magnetic field generating means, said first end of said first conductor also being connected to one of said electrical terminals of the said field generating means to provide the last-mentioned electrical current thereto, the other of said terminals of said field generating means being connected to one end of said second electrical conductor, the other end of said second elec trical conductor being connected to another terminal of said second source of power for magnetizing current, whereby said first electrical conductor comprises a common conductor for said are producing first source of power and said magnetizing current second source of power.

11. The combination as claimed in claim wherein said are producing source of power comprises a direct current power source and said magnetizing current source of power comprises a direct current power source.

12. The combination as claimed in claim 11 wherein second electrical conductor is adapted to be maintained at a more negative value of direct current voltage than that at said first electrical conductor.

13. The combination as claimed in claim 12 wherein said first electrical conductor comprises a tubular shell.

14. The combination as claimed in claim 12 wherein said second electrical conductor comprises a tubular shell.

15. The combination as claimed in claim 14 wherein said first electrical conductor comprises a tubular shell.

16. The combination as claimed in claim 15 wherein said first electrical conductor comprises a generally cylindrical tubular shell and said second electrical conductor comprises a generally cylindrical tubular shell of a generally smaller diameter than the said diameter of said first cylindrical tubular shell at corresponding points along their respective lengths so as to provide an effective electrically insulating space between them along the lengths thereof.

17. The combination as claimed in claim 16 including a fluid cooling means wherein said second generally cylindrical tubular. shell is concentrically spaced within said first generally cylindrically shell to form a channel for the passage of said fluid cooling means.

'18. The combination as claimed in claim 10 wherein said are producing source of power comprises an alternating current power source and said magnetizing current source of power comprises a direct current power source.

19. An electrode for use in an electric arc furnace comprising a first electrically conductive tubular shell, said shell having an arcing surface adjacent thereto, and a second electrical conductor disposed within said first tubular shell, portions of said first tubular shell and said second *electrical conductor being disposed in spaced relationship to form portions of a channel therebetween, an electrically conducting fingered bridge, said fingered bridge being disposed adjacent to the inside surface of said first tubular shell and outside surface of said second electrical conductor in said channel so as to make concurrent electrical contact with both said first tubular shell and said second electrically conductor, said fingered bridge comprising tines, said tines being disposed in spaced relationship with respect to each other forming at least one portion therearound for providing an opening to maintain channel continuity on opposite sides of said bridge.

20. An electrode for use in an electric arc furnace comprising a first and a second electrically conducting means, portions of said first and said second electrically conducting means being disposed in spaced relationship to form portions of a channel therebetween an electrically conducting fingered bridging means, said fingered bridging means being disposed adjacent to both said first and said second electrically conducting means so as to make concurrent electrical contact with both said first and said second electrically conducting means, said fingered bridging means comprising tines, said tines being disposed in spaced relationship with respect to each other forming at least one pather therearound for providing channel continuity on opposite sides of said bridge, said first electrically conducting means comprising in combination a first electrical conductor and a magnetic field generating means connected in series electrical circuit relationship with each other, said magnetic field generating means being provided with a portion thereof to be assembled in intimate electrical contact with portions of said tines of said bridging means so that electrical current may flow through a series electrical circuit comprising in order said first conductor, said magnetic field generating means, said bridging means and said second electrical conducting means, said electrical current being provided from a source of electrical power connected electrically between said first conductor and said second electrically conducting means.

21. The combination as claimed in claim 20 wherein said second electrically conducting means comprises a second tubular cylindrical shell, said first electrical conductor comprises a first tubular cylindrical shell, said second tubular cylindrical shell being disposed within and spaced from said first tubular cylindrical shell, said channel being formed in the space between said first and said second tubular cylindrical shells, said fingered bridging means comprising a hub-like portion disposed on said second electrical conductor, said tines extending from said hub-like portion.

22. The combination as claimed in claim 21 wherein said second tubular cylindrical conductor is generally concentrically spaced from and disposed within said first tubular cylindrical conductor, said tines being generally equispaced about said hub, said tines being resilient and having contact portions placed in electrical contact with the said special portion on said are moving means, said tines being resilient and stressed inwardly toward the center of said hub in a spring-like manner to provide a mechanically charged connection between said hub and said portion on said arc moving means to provide low resistance electrical contact between each said contact portion of said tine and said special portion, said regions between said tines providing paths for conducting flowing water which also flows in said last mentioned channel.

23. The combination as claimed in claim 22 wherein said water flows through said last mentioned paths into said last mentioned channel.

24. The combination as claimed in claim 23 wherein said bridging means comprises a copper-based alloy.

25. An electrode for use in an electric arc furnace comprising a magnetic field generating means for moving said arc, an electrode tip upon which an electric arc may be produced, means for providing electrical magnetizing power to said field generating means including a source of electrical power, means for providing electrical power to said tip to produce said arc including a source of power for that purpose, an electrode column, said tip being disposed on said electrode column, said tip having a recess, said field generating arc moving means being disposed within a portion of said recess and spaced from portions of said tip, the last mentioned spaced relationship forming a generally exclusive serially continuous unitary channel in said electrode for the purpose of heat removal from said tip and said field generating means.

26. The combination as claimed in claim 25 wherein said channel isprovided with a medium for conducting heat.

27. The combination as claimed in claim 26 wherein said medium is provided to remove heat generally simultaneously from both said field generating means and said tip.

28. The combination as claimed in claim 27 wherein said medium flows.

29. The combination as claimed in claim 28 wherein said flowing medium generally comprises water.

30. An electrode for use in an electric arc furnace comprising a magnetic field generating means for moving said arc, an electrode tip upon which an electric arc may be produced, means for providing electrical magnetizing power to said field generating means including a source of electric power, means for providing electric power to said tip to produce said arc including a source of power for that purpose, an electrode column, said tip being disposed on said electrode column, said tip having a recess, said field generating means being disposed within a portion of said recess and spaced from portions of said tip, the last mentioned spaced relationship forming a channel between portions of said tip and said field generating are moving means, said channel being provided with flowing water for removing heat generally simultaneously from both said field generating means and said tip, said field generating means comprising a section of electrically conducting material helically wound into the general shape of a solenoid having adjacent windings which are insulated from each other between complementary points on said solenoid, said solenoid when energized converting electrical energy from said electrical magnetizing power source into electromagnetic flux which causes said electric arc to be suitably controlled on said tip, a portion of at least one of said windings being disposed adjacent to said channel at said last named portion of said winding, heat being conducted from said solenoid to said water when said winding is energized, the conductivity of said flowing water being relatively much less than that between any two of said adjacent winding portions of said solenoid which are adjacent to said water for thereby preventing significant short circuiting of windings.

31. The combination as claimed in claim 30 wherein said portion of the said solenoid which is adjacent to the said channel comprises the inner portion of said solenoid.

32. A tip for use in an electrode comprising electrically conducting material upon which an electric arc may play, a magnetic arc moving means for rotating said are on said tip, said tip and said are moving means being electrically interconnected at one portion of said arc moving means, said tip and said are moving means being adapted to be energized from separate sources of power said portion of said arc moving means where said tip and said are moving means are interconnected comprising a common electrically conducting path for the energy for said are moving means and the arc on said tip.

33. The combination as claimed in claim 32 wherein said tip has an inner portion which cooperates with said field generating means to form a channel, said channel being generally filled with a heat conducting material.

34. The combination as claimed in claim 33 wherein said field generating means is disposed generally concentrically within said recess in said tip, said medium generally comprising flowing water for the simultaneous removal of heat from said tip and said field generating means.

35. A field generating means for disposition adjacent an electrode tip of an electric arc furnace, said tip having a channel for the flow of cooling water comprising a section of electrically conducting material adapted to be helically wound into the general shape of a solenoid having adjacent partially insulated windings, which solenoid when energized converts electrical energy from an electrical magnetizing power source connected thereto into electromagnetic flux which will cause an electric arc to be suitably controlled on said tip, adjacent complementary portions of said windings of said solenoid being spaced and generally electrically insulated from each other except at certain portions adjacent to said channel containing said flowing water at which said portions said heat is conducted from said solenoid to said water, the conductivity of said flowing water being relatively much less than that of the said adjacent winding portions of said solenoid.

36. The combination as claimed in claim 35 wherein an end portion of said solenoid is electrically connected to said magnetizing source of power with electrically conducting epoxy resin.

37. The combination as claimed in claim 1 wherein said elongated outer tubular shell comprises a lower tubular shell portion and an upper tubular shell portion one of which is connected to an electrode tip, said lower tubular shell portion being spaced and located from said upper tubular shell portion by a spring means, means for preventing leakage from said unitary channel at said spaced region.

38. The combination as claimed in claim 37 wherein said spring means comprises a Belleville type spring.

Claims

1. An electrode for use in an electric arc furnance comprising a magnetic field generating means, an elongated outer tubular shell, a first inner tubular shell, a second inner tubular shell and an electrode tip upon which an electric arc may play, one end of said outer tubular shell being disposed adjacent to said tip, said first inner tubular shell being disposed within and spaced from said outer tubular shell forming a first channel therebetween, said second inner tubular shell being disposed within and spaced from said first inner tubular shell forming a second channel therebetween, said magnetic field generating means being disposed near to and spaced from said tip forming a third channel therebetween, said first, second and third channels communicating serially to form an exclusive unitary heat removing channel for said field generating means and said tip generally simultaneously, a heat conducting medium disposed in said unitary channel for providing a heat conducting means adjacent said tip and said field generating means for accomplishing said heat removal.

2. An electrode for use in an electric arc furnace comprising a magnetic field generating means, an elongated outer tubular shell, a first inner tubular shell, a second inner tubular shell and an electrode tip upon which an electric arc may play, one end of said outer tubular shell being disposed adjacent said tip, said first inner tubular shell being disposed within and spaced from said outer tubular shell thus providing a first channel therebetween said second inner tubular shell being disposed within and spaced from said first inner tubular shell forming a second channel therebetween, said magnetic field generating means being disposed near to and spaced fRom said tip thus providing a third channel therebetween, said first, said second and said third channels being disposed structurally in series to form a single overall heat conducting channel, a conducting medium being disposed in said single channel for providing a heat conducting means adjacent said tip and said field generating means substantially simultaneously.

3. The combination as claimed in claim 2 wherein said medium comprises a fluid.

6. The combination as claimed in claim 5 wherein said electrode comprises an input water port and an output water port, said input water port and said output water port being provided respectively to generally introduce and remove said moving water from said single heat conducting channel so that heat generated in said tip and said magnetic arc moving means may be conducted away by said moving water.

8. The combination as claimed in claim 6 wherein said input water port is disposed adjacent to said portion of the said single heat conducting channel comprising said second channel, said second channel is disposed adjacent to the said portion of said single heat conducting channel comprising said third channel, said third channel is disposed adjacent to the said portion of said single heat conducting channel comprising said first channel, and said first channel is disposed adjacent to the said output water port, so that water may be introduced into said electrode at said input water port and then flow, in order through said second channel portion, said third channel portion, and said first channel portion to said output water port from where said water may be removed from said electrode.

9. The combination as claimed in claim 7 wherein said outer tubular shell is generally cylindrical, said first inner tubular shell is generally cylindrical and disposed generally concentrically within said outer generally cylindrical, tubular shell and said second inner tubular shell is generally cylindrical and disposed generally concentrically within said first inner generally cylindrical, tubular shell.

10. An electrode for use in an electric arc furnace comprising, a first source of power for the generation of an electric arc, a second source of power to provide magnetizing electrical current, a magnetic field generating means having electrical terminals, an electrode tip upon which an electric arc may be produced, a first electrical conductor and a second electrical conductor, said first electrical conductor being connected at a first end to said tip and being connected at its other end to one terminal of said first source of power, another terminal of said first source of power being electrically interconnected in circuit relationship with the melt of said furnace, said first source of power energizing said tip for the production of an electric arc in a space between said tip and said melt in said furnace, said first electrical conductor also being conneCted at its said other end to one terminal of said second source of power to provide magnetizing electrical current for said magnetic field generating means, said first end of said first conductor also being connected to one of said electrical terminals of the said field generating means to provide the last-mentioned electrical current thereto, the other of said terminals of said field generating means being connected to one end of said second electrical conductor, the other end of said second electrical conductor being connected to another terminal of said second source of power for magnetizing current, whereby said first electrical conductor comprises a common conductor for said arc producing first source of power and said magnetizing current second source of power.

11. The combination as claimed in claim 10 wherein said arc producing source of power comprises a direct current power source and said magnetizing current source of power comprises a direct current power source.

17. The combination as claimed in claim 16 including a fluid cooling means wherein said second generally cylindrical tubular shell is concentrically spaced within said first generally cylindrically shell to form a channel for the passage of said fluid cooling means.

18. The combination as claimed in claim 10 wherein said are producing source of power comprises an alternating current power source and said magnetizing current source of power comprises a direct current power source.

19. An electrode for use in an electric arc furnace comprising a first electrically conductive tubular shell, said shell having an arcing surface adjacent thereto, and a second electrical conductor disposed within said first tubular shell, portions of said first tubular shell and said second electrical conductor being disposed in spaced relationship to form portions of a channel therebetween, an electrically conducting fingered bridge, said fingered bridge being disposed adjacent to the inside surface of said first tubular shell and outside surface of said second electrical conductor in said channel so as to make concurrent electrical contact with both said first tubular shell and said second electrically conductor, said fingered bridge comprising tines, said tines being disposed in spaced relationship with respect to each other forming at least one portion therearound for providing an opening to maintain channel continuity on opposite sides of said bridge.

22. The combination as claimed in claim 21 wherein said second tubular cylindrical conductor is generally concentrically spaced from and disposed within said first tubular cylindrical conductor, said tines being generally equispaced about said hub, said tines being resilient and having contact portions placed in electrical contact with the said special portion on said arc moving means, said tines being resilient and stressed inwardly toward the center of said hub in a spring-like manner to provide a mechanically charged connection between said hub and said portion on said arc moving means to provide low resistance electrical contact between each said contact portion of said tine and said special portion, said regions between said tines providing paths for conducting flowing water which also flows in said last mentioned channel.

26. The combination as claimed in claim 25 wherein said channel is provided with a medium for conducting heat.

28. The combination as claimed in claim 27 wherein said medium flows.

30. An electrode for use in an electric arc furnace comprising a magnetic field generating means for movinG said arc, an electrode tip upon which an electric arc may be produced, means for providing electrical magnetizing power to said field generating means including a source of electric power, means for providing electric power to said tip to produce said arc including a source of power for that purpose, an electrode column, said tip being disposed on said electrode column, said tip having a recess, said field generating means being disposed within a portion of said recess and spaced from portions of said tip, the last mentioned spaced relationship forming a channel between portions of said tip and said field generating arc moving means, said channel being provided with flowing water for removing heat generally simultaneously from both said field generating means and said tip, said field generating means comprising a section of electrically conducting material helically wound into the general shape of a solenoid having adjacent windings which are insulated from each other between complementary points on said solenoid, said solenoid when energized converting electrical energy from said electrical magnetizing power source into electromagnetic flux which causes said electric arc to be suitably controlled on said tip, a portion of at least one of said windings being disposed adjacent to said channel at said last named portion of said winding, heat being conducted from said solenoid to said water when said winding is energized, the conductivity of said flowing water being relatively much less than that between any two of said adjacent winding portions of said solenoid which are adjacent to said water for thereby preventing significant short circuiting of windings.

32. A tip for use in an electrode comprising electrically conducting material upon which an electric arc may play, a magnetic arc moving means for rotating said arc on said tip, said tip and said arc moving means being electrically interconnected at one portion of said arc moving means, said tip and said arc moving means being adapted to be energized from separate sources of power said portion of said arc moving means where said tip and said arc moving means are interconnected comprising a common electrically conducting path for the energy for said arc moving means and the arc on said tip.