US2106469A - Conveyer mechanism for electric furnaces - Google Patents

Description

Jan. 25, 1938. sE 2,106,469

coNvEYER MECHANISM FOR ELECTRIC FURNACES Filed March 18, 1936 6 Sheets-Sheet 1 INVENTOR. GILBERT 5.55m,

ATTORNEY.

Jan. 25, 1938. s 2,106,469

CONVEYER MECHANISM FOR ELECTRIC FURNACES INVENTOR.

GILBERT E. SEIL,

mmauw ATTORNEY.

Jan. 25, 1938. G. E. SEIL 2,106,469

CONVEYER MECHANISM FOR ELECTRIC FURNACES Filed March 18, 1936 6 Sheets-Sheet 3 PIC-3.6.

INVENTOR.

GILBERT E. SEIL BYje ATTORNEY.

Jan. 25, 1938. G. E. SEIL 2,106,469

CONVEYER MECHANISM FOR ELECTRIC FURNACES Filed March 18, 1936 6 Sheets-Sheet 4 INVENTOR.

GILBERT E. SEIL,

BYO.

ATTORNEY.

Jan. 25, 1938. G. E. SEIL CONVEYER MECHANISM FOR ELECTRIC FURNACES Filed March 18, 1956 6 Sheets-Sheet 5 "INVENTORr- GILBERT E. SE'IL, BY

FIG.|I. 5 913 R ATTORNEY.

Jan. 25, 1938. s 2,106,469

CONVEYER MECHANISM FOR ELECTRIC FURNACES Filed March 18, 1956 6 Sheets-Sheet 6 1| Il 4015 I06 107 HHIIIIIH 9 Ho FIGJO.

BY GILBERT E. 55m,

ATTORNEY.

Patented Jan. 25, 1938 UNITED STATES PATENT OFFICE Gilbert E. Sell, Oynwyd, Pa., assignor, by mesne assignments, to Buflalo Electric Furnace Corporation, Buffalo, N. York Application March 18,

3 Claims.

This present invention relates to electric furnaces of the type equipped with one or more hollow electrodes through which an oxidizing reagent for the material. to be treated in the furnace is fed thereto by being impelled through the bore of the hollow electrode in the form of briquettes, or more often in the form of cylindrical cores, and relates more particularly to an improved conveying and propelling means for positively feeding the cylindrical cores through the bore of the hollow electrode.

In an electric furnace with which this present invention is adapted to cooperate, there is carried out the refining of ferro-alloys or other alloys and especially alloys containing chromium, and wherein the refining of the alloys is carried out by forming in a heated zone in the hollow electrode, under reducing conditions, a highly concentrated oxidizing reagent comprising essentially a reduced metal carrying therein a metal oxide. Such a reagent, when in liquefied condition and mixed with a molten bath of a metal mixture to be refined, exerts its oxidizing action on oxidizable impurities in the bath, such as carbon, thereby to reduce the content thereof in the bath. Since there is effected in the heated zone of the electrode a liquefying of the refining materials, fed thereto in core form, the speed of the cores to and through the bore of the electrode must be carefully controlled, as well as the positiveness of the force used to impel the cores fed thereto and therethrough.

It is an object of my present invention to provide for such furnaces simple, effective and dependable mechanisms for containing a supply of cores; for discharging cores from such source of supply in an orderly manner as they are required, and delivering the same to a positive feeding means; to a means for receiving the cores and positively feeding the same to and through the bore of the electrode in a continuous stream as required, and at a rate of speed which is carefully controllable in accordance with the speed of the reducing process being carried out within the furnace; and particularly to a feeding means for the cores which will permit relative movement of the feeding means with respect to the cores should the cores be stopped in their movement through the electrodes.

Other objects are that the assembly of the various instrumentalities for carrying out the above objects shall have proper cooperating relationship; shall have provision to allow for variations in the dimensions of the individual cores; and shall permit of ready access to all of the operat- Y., a corporation of New 1936, Serial No. 69,450

ing parts in case of need. And a still further object is that said instrumentalities shall carry out adequately the functions for which they were designed.

For the realization of these objects, the invention revolves about the various components of core reservoir, discharging, conveying and feeding means for an electric'furnace of the hollow electrode type wherein the hollow electrode thereof is both rotatable and reciprocable. The manner of carrying out the invention generally is to mount the hollow electrode on an automatically reciprocable carriage provided also with means for rotating the electrode. A container or reservoir for a supply of the cores is provided and equipped with a discharging mechanism arranged to prevent jamming of the cores in the reservoir, or as they are discharged therefrom into a conveying mechanism.

The conveying mechanism coacts with a core feeding mechanism and delivers thereto a plurality of cores in succession, and arranged in axial alignment, and said core feeding mechanism subjects each core as received to a gripping or pinching action which prevents relative movement of the cores with respect to the feeding mechanism or to each other, and positively propels such cores in succession into thebore of the electrode with the operative force necessary to positively propel the same through the bore. These various mechanisms derive their motivating power from the motor or motors used for reciprocating the electrode supporting carriage and for rotating the electrode.

Accordingly, with these and other objects, as well as features of advantage, one embodiment of my invention will be hereinafter described for illustrative purposes, because obviously the invention is capable of a number of embodiments. The form of the invention chosen to be described is illustrated in the accompanying drawings in which:

Fig. 1 is a side elevation, partly in section, of a furnace chamber equipped with diametrically opposed hollow electrodes, and with my present invention shown interposed between the core magazine or reservoir and the hollow electrodes;

Fig. 2 is a partial view of Fig. 1;

Fig. 3 is a side elevation, in skeleton form, of the driving mechanism for the material charging devices, and the rotating means for the hollow electrodes;

Fig. 4 is a plan view of the instrumentalities shown in Fig. 3;

Fig. 5 is a section, taken on the line 33 of Fig. 4;

' Fig. 6 is an elevation, on an enlarged scale, of the right hand end of Fig. 1, showing the core magazine in side elevation, and the core receiving conveyer at the discharge end thereof;

Fig. '7 is an end view of Fig. 6;

Fig. 8 is a side elevation, on an enlarged scale, of the positive feeding means for the cores, and located between the discharge end of the core conveyer and the entrance end of the hollow electrode;

Fig. 9 is an end elevation of Fig. 8;

Fig. 10 is a plan view of Fig. 9, and

Fig. 11 is a detail illustrating the construction of the conveyer belt employed in structure shown in Figs. 8 and 9.

Referring to the drawings, and particularly to Fig. 1, there is shown a type of electric furnace to which the present invention has been applied. Such furnace comprises essentialy a chamber I0, into which, and from the opposite sides thereof, extend tubular or hollow open ended electrodes II and I2. The chamber i0 is usually a metal casing or shell lined with a suitable refractory material I3, and supported on suitable base members, such as the base member i6. Within the chamber I0 is a hearth |1 arranged to receive a bath of metal I8 normally covered with a layer of slag l9. Oxidizing reagent material 20, in liquid form, drops onto the layer of slag I! from hollow electrodes through the arc 2| formed in the gap 22 between the spaced ends of the electrodes II and I2. The reagent material 20 is obtained from cores fed through the hollow electrodes H and I2 and reduced to liquid form in the arc 2|.

The reagent forming material 20, in the form of cores or briquettes, as will be apparent from an inspection of Fig. 7, is fed into the entrance end of the hollow electrodes H and i2, or the end remote from the gap 22, and is liquefied within the electrode. Due to the great heat generated by the arc 2|, and the consequent liquefaction of the reagent material in the electrode, there is a tendency toward derangement of the normal and continuous movement of the cores or briquettes 20 through the bore of the electrodes II and I2 and the flow of liquefied reagent therefrom. This invention therefore provides for the positive and uninterrupted movement of cores or briquettes through the bore of the electrodes regardless of any disturbing conditions that may exist therein.

Each electrode H and I2 has its own independent operating means for rotating the same, moving the same axially to compensate for the inevitable erosion due to the maintenance of the are 2 I, and means for receiving cores or briquettes from a magazine or reservoir and positively feeding the same through the bore of the electrode. These operating means are identical in character and construction and therefore a description of but one is necessary. Such independent operating may be so controlled as to operate in synchronism with each other, or may be interconnected, either by mechanical or electrical means, so as to operate as a unit. Also, each electrode is preferably slightly inclined downwardly toward the furnace, as clearly shown in Fig. 1, the degree of inclination from the horizontal being approximately three degrees, in the preferred form of construction.

Each operating unit is mounted on a framework or carriage 23 provided with wheels 23a which track on spaced channel irons 23 and 25, and which constrain the carriage 23 to move toward and from the furnace II in a fixed path whereby the length of the arc may be varied as desired. Such channel irons 23 and 25 are supported, relative to the furnace II, on a framework 26 of structural shapes.

Mounted on a frame ill, suspended from the carriage 23, is a motor H3. This motor has a drive shaft I23 which extends outwardly from each end of the motor, and on each end is accured a pinion |2|. Secured to the channels 23 and 25, and extending for a distance commensurate with the desired length of travel of the carriage 23, are racks I22, with which the pinions |2| mesh. The motor H9, being fixed to the carriage 23, the rotation of the shaft I23, of the motor will cause a movement of the carriage 23, along the channels 23 and 25, toward and from the furnace l0, it being assumed that the motor H9, is of the reversible type, and that control means is provided, not only for accomplishing this result, but also for controlling the speed of travel of the carriage 23, in accordance with the rate of erosion of the electrode II or due to the maintenance of the desired extent of arc 2|.

The framework or carriage 23 is provided at the end adjacent the furnace III, with spaced bearings 21, in which is rotatably mounted a sleeve 28. This sleeve is provided at one end with a flange 29, for removable attachment to the entrance end of the hollow electrode II, and at the other end with a gear 33. Attached to the sleeve 28, is a slip ring 3|, with which engages a brush 32, that is connected to a suitable source of power for supplying power or current to the electrode The bearings 21, and the slip ring 3|, are so constructed as to permit the flange 29 to be removed whenever it is necessary to remove or replace the electrode At the end of the framework or carriage 23, remote from the bearings 21, is a support or platform 33, on which is mounted an electric motor or other suitable prime mover 33. The electric motor 33, is directly connected to a speed reduction device 35, the output shaft 35, of which is connected to the drive shaft 31, of a transmission or speed changing device 33. This speed changing or transmission device is mounted on supports 39, secured to the framework or carriage 23.

Connected to the train of gearing of the speed changing or transmission device 33, is a shaft 33, rotatably mounted in bearings secured to the carriage 23. This shaft 33, extends toward the electrode II, and has=mounted on its end a pinion 3|, which meshes with and drives the gear 33, secured to the sleeve 23. To prevent leakage of power from the brushes 32, the shaft 33, is made in sections connected by means of insulating couplings, such as the coupling 32.

The cores or briquettes 20, of reagent forming material are stored in a magazine or reservoir 33, shown in Figs. 6 and 7, and mounted on the carriage 23, adjacent to the motor 33. The magazine 33, includes an upper inclined platform 33, and a lowerly disposed oppositely inclined platform or support 35. The cores or briquettes 23, travel down the inclined platform 33, by gravity and are deposited on the inclined support 35, from whence they are delivered to a discharging device.

Such discharging device is located adjacent to the discharge end of the inclined support 35, and is mounted on a shaft 33, rotatably mounted in spaced aligned bearings 31, secured to the framework of the magazine 33. Secured to the shaft 46, adjacent to the bearings 41, are circular discs 49. Equally spaced around the shaft 46, between the discs 49, and extending radially outward from such shaft 46, are plates 50, forming angular pockets or receptacles 5|, into which the cores or briquettes 20, successively drop from the inclined support 45, as the shaft 46, is rotated.

Each plate has hingedly mounted at its outer edge an angularly shaped member 52, which acts as a gate to retain the cores or briquettes 26 in the receptacles 5|, when in one position, and allows such cores or briquettes 28, to drop out of the receptacles 5|, when in another position.

The various positions of the members 52, are obtained by means of the following instrumentalities: at each end of each hingedly mounted member 52, is rotatably mounted a cam roller 53, which engages in a cam race 54 formed in a cam plate 55, fixed to the bearing members 41. The cam race 54, is so designed as to oscillate the angular gate members 52, in their mounting from the position shown in the upper right hand por tion of Fig. '1, where they act as means for retaining the core or briquette 28, in the receptacle 5|, into which the core has dropped by gravity from the inclined support 45; to the position diametrically opposite, where it will be seen that the angular gate member 52, is positioned to permit the free passage of the core 28, through the exit passage of the magazine 43, by gravity onto the conveying mechanism. The shaft 46, is rotated in timed relation to the other parts of the mechanism in a manner to be hereinafter described.

The conveying mechanism above referred to is shown in Figs. 6 and '7, and is mounted on spaced uprights 56 and 51 secured to the carriage 23. In the uprights 56 are spaced bearings 58, in which is rotatably mounted an idler shaft 59, while in the uprights 51, are spaced bearings 60, in which is rotatably mounted a drive shaft 6|.

On the shaft 59, are secured parallelly arranged spaced sprockets 62 and 63, which are in alignment respectively with spaced sprockets 64 and 65, secured to the shaft 6|. Over the sprockets 62 and 63, runs a chain 66, while over the sprockets 63 and 65, runs a chain 61. Secured to these chains in straddling or bridging position is a conveyer belt 68 of any suitable material, but preferably of a fabric and rubber composition. The conveyer belt 68, is slit at intervals S inwardly from each edge toward the center at equally spaced points along its edges, and the belt material is secured to the chains 66 and 61, by rivets R between adjacent slits to each alternate link in said chains. The upper reach of the conveyer 68, lies adjacent to and slightly below the exit end of the magazine 43, and moves transversely to the movement of the cores 20, as they drop from the receptacles 5|. Mounted on the bracket 69, on the upright 56, is a stop 18, against which the cores engage as they drop from the receptacles 5|, and which positions such cores on the conveyer belt 68.

Secured to one of the pair of uprights 51, is a casing 1|, through which one end of the shaft 6| extends, and in which the said end of the shaft 6|, is rotatably mounted. Within the easing 1|, and secured to the shaft 6|, is a worm wheel 12. Formed in the casing 1|, are aligned bearings 13, in which is rotatably mounted a shaft 14. Secured to the shaft 14, is a worm 15, which meshes with and drives the worm wheel 12, and therefore the shaft 6| One end of the shaft 14, extends toward the transmission 38, and is connected to a drive shaft 16, of such transmission by an insulating coupling 11.

The end of the shaft 6|, remote from the casing 1|, extends outwardly beypnd the upright 51, and has secured thereto a gear 18, which meshes with and drives a gear 19, secured to a shaft 80. The shaft has secured thereto a worm 8|, which meshes with and drives a worm wheel 82, which in turn is secured to the shaft 46, on which is mounted the core discharging mechanism shown in Figs. 6 and '7, and above described. discharge mechanism and the conveyer just described operate in synchronism with each other, and at speeds predetermined in accordance with desired or necessary speed of travel of the cores 28, into and through the bore of the tubular electrodes The cores 26, when on the conveyer 68, are free and unrestrained, and in order that such cores may be positively fed into and through the bore of the tubular electrode II, it is necessary to transfer them to a device adapted for this purpose. Such device forms the specific object of my present invention, and is shown in detail in Figs. 8, 9 and 10. Referring to said figures the device is shown as comprising spaced uprights 83 and 84, secured to the carriage 23, .21

between the conveyer 68, and the entrance end of the bore of the tubular electrode At the upper end of the uprights 83, are formed aligned bearings 85, in which is rotatably mounted a shaft 86. wardly beyond the bearings 85, arid secured to such ends are collars 81, spaced from the bearings 85, for a purpose to be hereinafter described.

On the upright 84, and lying in the same horizontal plane as the bearings 85, are aligned bearings in which is rotatably mounted, parallel to the shaft 86, a shaft 88. On the shaft 86, are secured sprockets 89 and 96 spaced apart from each other. Secured to the shaft 88, are similar sprockets, in alignment with the sprockets 89 and 90 respectively. Over such sprockets run chains 9| aind 92 respectively. Carried by these chains 9| and 92 and bridging them is a conveyer belt 93, which is secured along the edges thereof at every alternate link thereof by means of rivets R. or other fasteners. This conveyer belt is slitted at intervals inwardly along each edge thereof such as at S thereby permitting a ready flexing or concaving of such conveyer belt as shown in Figs. 7 and 9 to permit the conveyer to take around or grip the cores coacting to cause movement thereof. This arrangement of conveyer belt has a certain resilience which is useful in avoiding breaking of the cores 28, in exerting a pinching or gripping action on such cores when a core is held between the two superposed conveyers 99 and 93, between which cores 29, are gripped (Fig. 9), and in permitting a slipping movement of the conveyers 99 and 93 should the motion of the cores be arrested for any reason.

The conveyer belts 93 and 99, being of resilient material, and so connected to their respective chains as to permit a ready flexing or concaving of their cooperating reaches to thereby exert a pinching or gripping action on the cores, P

have also the important function of permitting the cooperating reaches to slip relative to the cores when, for any reason, the force required to feed the cores forward is greater than the pinching or gripping action of the conveyer belts.

It will be seen therefore that the The ends of the shaft 86 extend out- It may sometime happen that a refractory piece of metal becomes lodged in the space between the opposed electrodes II and I2 in such a manner as to temporarily prevent further feeding movement of the cores through the electrodes. Due to the resilient character of the conveyers 99 and 99, the cooperating reaches thereof will slip or slide relatively to the cores being fed, and such slipping or sliding movement will continue until such time as the piece of refractory metal has been reduced, usually until such metal has been brought into proper position with respect to the arc 2| by rotation of the electrodes.

On the upright 99, above the bearings in which rotate the shaft 99, are arranged aligned bearings 99. In these bearings 99, is rotatably mounted a shaft 95 parallel to the shafts 99 and 99.

Mounted on the shaft 95 is a framework 99, such framework being rotatable on the shaft "from the full line position shown in Fig. 8 to the dot and dash position in such figure.

Rotatably mounted on the framework 99, at

the end remote from the shaft 99, and directly above the shaft 96 in the bearings 99, is a shaft 91. Secured to the shafts 95 and 91, are spaced and aligned sprockets, similar to the sprockets on the shafts 89 and 89, and over these sprockets run sprocket chains 98, to which is secured a conveyer belt 99. This conveyer belt 99, is similar in all respects to the conveyer belt 99.

The upper reach of the conveyer belt 99, lies in substantially the same horizontal plane as the upper reach of the conveyer 99, leading from the magazine 93, and above described. The upper reach of the conveyer belt 99, lies substantially parallel to but spaced apart from the lower reach of the upper conveyer belt 99, and together the two reaches define a. passage in which rests the cores 29, as they are fed from the conveyer 68, to the entrance end of the electrode II.

In the superposed flexible conveyer belts 99 and 99, the coacting reaches thereof have a tendency to move away from each other as the cores 29, are positioned therebetween, therefore there is provided means for limiting .such movement. Such means comprises a plate I95, located adjacent to the inner surface of the upper reach of the conveyer belt 93, this plate being secured to an extension I99 of the uprights 93, while the means associated with the conveyer belt comprises a plate 96, located adjacent the upper surface of the lower reach of such conveyer belt 99, the plate being secured to the framework 96.

The space between the coacting reaches of the conveyer belts 93 and 99, is slightly less than the average diameter of the cores 29, with the result that such conveyer belts exerta pinching or gripping action on the cores, which'are therefore positively fed toward and into the entrance end of the tubular electrode II.

In order to maintain the conveyer 99, in operative relation to the conveyer 93, as well as to permit access to the entrance end of the hollow tubular electrode I I, or for any other purpose, I have provided the following instrumentalities: the shaft 91, extends outwardly beyond the limits of the bearings therefor in the frame 96, and on such extended ends are placed the combined lever and spacing arms I9I. Such combined lever and spacing arms are rotatably mounted on the shaft 91, intermediate their ends, and collars I92, secured to the shaft 91, retain them in position.

The arms I9 I, extend normally downward from the shaft 91, as viewed in Figs. 8 and 9, and at their lower end have formed the hook members I99, which partially encircle the shaft 99, between the bearings 99, and the collars 91. With the lower ends of the arms "I, in this position, the conveyer 99 has its lower reach maintained substantially parallel to the upper reach of the conveyer 99.

There is provided a means for locking the arms III, in the position above noted. This means comprises an eccentric shaft I99, rotatably mounted in the upper ends of the arms "I. Becured to the eccentric shaft I99 and extending radially outward therefrom is a handle I 99, by means of which the eccentric shaft I99, is rotated from the locking position shown in full lines in Fig. 8 to the open position shown therein in dot and dash lines.

Pivotally mounted on the frame 99, adjacent to the shaft 99 is a hollow frame I99. Such frame I99, extends toward the eccentric shaft I99, and has its closed end perforated to allow free sliding movement therethrough of the threaded bar or rod I91, the outwardly extending end of such bar or rod being rotatably mounted on the eccentric shaft I99. Within the hollow frame I99, and surrounding the rod I91, is a coil spring I99 held compressed between one end of the hollow frame and a nut I99 on the threaded rod I91, II9 indicates a stop. Downward movement of the handle I99 rotates the eccentric shaft I99 so as to move the threaded rod I91, to compress further the spring I99, there will be a tendency to rotate the arms I9I, so as to move the hook members I99, more firmly into engagement with the shaft 99. Continued rotary movement of the eccentric shaft I99, brings the handle I99 to the full line position shown in Fig. 8, where it will be noted that the center of the eccentric portion of the shaft I99, is above the center of rotation of such shaft. The arms I9I are therefore, locked in engaging position with shaft 99.

Attached to one end of the upright 99 is a casing H9 in which is a bearing -I I9, in which turns the shaft 99. Secured to the shaft 99, within the casing H9, is a worm wheel I29. Formed in the casing II9 are bearings I2I in which is rotatably mounted one end of a shaft I22, this shaft being connected by the insulating coupling I29, to the shaft 19, driven from the transmission 99. On the shaft I22, between the bearings I2 I, is secured a worm I29 which meshes with and drives the worm wheel I29, and therefore the shaft 99.

Secured to the other end of the shaft 99 is a gear I25, which meshes with and drives a similar gear I29, secured to the shaft 95. The gears I25 and I29 are housed in a casing I21, secured to the upright 99.

By means of the gears I25 and I29 and the worm and worm wheel I29 and I29 respectively, opposing reaches of the conveyer belts 9I and 99 are driven in the same direction at the same speed, and in timed relation to the speed of the conveyer belt 99, by the power transmitted through the transmission 99.

Should it be desired to obtain access to the conveyer 99, or to the entrance end of the electrode II, or to any structure interposed between the superposed conveyers 99 and 99 and the entrance end of the electrode II, the shaft I99 is moved in a counter-clockwise or upward direction, as viewed in Fig. 8, to relieve the tension on the spring I99. This permits the arms IIII to be released from the shaft 99, whereupon ti-) frame 96 may be rotated about the shaft 95 as a center into the dash position shown in Fig. 8, thus allowing access to the cenveyer 93, or to adjacent parts of the mechanism.

Preferably the entrance end of the bore of the electrode H is spaced apart from the discharge end of the superposed conveyers 93 and 99. To bridge the gap thus formed there is preferably provided a guide and support for. the cores 20 in their passage from the convcyers 93 and 99 to the bore of the electrodes Such guide and support is composed of some heat re sistance material like Alberene and is made in two parts, a lower part III and an upper part H2. Rods H3, pivotally mounted on opposite sides of the lower part I H rest in vertical grooves in the sides of the upper part H2, and are threaded to receive wing nuts H4 for maintaining the parts in operative relation with each other. Acting as a unit, the parts ill and H2 are provided with a bore H5 in alignment with the bore of the electrode II. This bore 5 is chamfered at the end adjacent the conveyers 93 and 99, as indicated by the reference numeral H6. The upper part is provided with a handle 1.

With the apparatus constructed and arranged as above described, and assuming the bath l8, of molten metal, to be refined, to be located within the furnace ID and covered with a layer of slag i9, the operation will be as follows: the hollow electrodes II and i2, have one end thereof inserted into the furnace i9, and are attached, at their other end, to the sleeve 28, by means of the flange 29. Power is applied from a suitable source to the electrodes through the slip ring 3|, and brush 32, to the electrodes II and I2, to form the arc 2|, in the gap 22, between adjacent ends of such electrodes.

A supply of cores 20, is placed in the magazine 43 and power is then turned into the motor 34, and also into the motor 9. The speed of the motor H9, is controlled to provide for the proper reciprocating longitudinal movement of the electrodes H and i2, to maintain the proper width of gap 22, therebetween. The speed of the motor 34, is controlled so as to maintain the proper slow speed of rotation of the electrodes and also the proper rate of delivery of the cores 20, from the magazine 43, into and through the bore of the electrodes to bring the same into the influence of the heat generated by the arc 2|, wherein they are reduced to liquid form, and drop onto the slag bed I9, to refine the metal bath l8. 'I'he interconnection of the various instrumentalities on the carriage 23, and operated by the motor 34, is such that all such instrumentalities operate in synchronism with each other and at the proper speeds, such speeds being predetermined in accordance with the speed of liquefaction of the cores in the arc 2|.

The cores 2|, are delivered in groups from the magazine 43, at timed intervals by the mechanism operated from the shaft 46, onto the conveyer 68, and from thence delivered in succession to the positive conveying and feeding device shown in Figs. 8 and 9. This conveying and feeding device exerts a pinching and gripping action on each core 20, individually and therefore such cores are fed positively into and through the bore of the electrodes.

The action of the apparatus is continuous and may continue without interruption until the carriage 23, reaches the limit of its travel on the channels 24 and 25, or until some mechanical fault or breakdown necessitates the replacement of some part or parts of the apparatus, or the removal of the electrodes. Should such breakdown occur to the positive conveying and feeding means forming the subject matter of my present invention, access to such conveying and feeding means is easily and readily obtained by rotating the frame 95, and parts carried thereby, about the shaft 95, as an axis, and into the dot and dash position, as clearly shown in Fig. 8.

The process which the electric furnace of this invention can be used to carry out is described in my co-pending patent applications, Serial Numbers 724,024; 59,690; 59,691; and 59,692, and comprises essentially feeding to the hollow electrodes charges of reagent forming materials in briquetted comminuted form. The arc between the two electrodes causes a zone of the electrode to become heated to a sufficiently high temperature whereby a reducing reaction takes place between difierent reactant materials in the charge or burden in the electrode as well as a liquefying action so that there issues from the arc end of the electrodes a liquid oxidizing reagent comprising a liquid reduced metal having a metal-oxide carried thereby and therein. This reagent formed in the electrode drops onto the molten metal bath on the furnace hearth and through the slag thereon, by virtue of which the impurities or undesirable oxidizable constituents of the bath of metal on the hearth which is to be refined, are oxidized and removed therefrom.

For preventing localization of erosion at the arc ends of the electrodes, they are caused to be rotated during operation of the furnace, and in order to control the desired length of the arc (and thereby the heat generated by the arc) the electrodes are reciprocated toward and away from each other. For this double purpose, each electrode is mounted on a reciprocable carriage which is also equipped with driven mechanism for rotating the electrode. Also mounted on the propelled carriage and reciprocating therewith as a unit, are the various components of this invention, including the hollow electrode, means for rotating it, the core magaine, the core conveyer, the core discharger, and the core feeding means, all heretofore described both as to structure and operation.

I claim:

1. A core feeding means for electric'furnaces comprising, a frame, a second frame, pivotally mounted at one end on said first frame, endless flexible conveyer belts mounted in said frames and having coacting faces thereof arranged parallel to and spaced apart from each other, means for driving said flexible conveyer belts simultaneously and at the same speed, and with the coacting faces movable in the same direction, and means for locking said second frame relative to the said first frame, whereby to maintain the coacting faces of the endless conveyer belts parallel to each other.

2. A core feeding means for electric furnaces comprising, a frame, a second frame, pivotally mounted at one end on said first frame, endless flexible conveyer belts mounted in said frames and having coacting faces thereof arranged parallel to and spaced apart from each other, means for driving said flexible conveyer belts simultaneously and at the same speed, and with the coacting faces movable in the same direction, means for locking said second frame relative to the said first frame, whereby to maintain the coacting faces of the endless conveyer belts parallel to ponent thereof, a pair of endlms propellable flexible elements arnnged parallel to and spaced apart from each other, and an endless flexible belt carried thereby having slits extending thereinto fromrthe edges thereof and terminating at 5 1 point to the medial portion of the belt.

GILBERT E. SEIL.

Images