US1089300A - Electric furnace. - Google Patents

Description

C. C, WHITMORE.

ELEGTRIG FUBNAGE. APPLIOATION FILED @12.16, 1913.

Patented Mar. 3, 1914.

2 SHBBTS-SHEET L NVENTOR m, NN

Ek Lg ATTORNEYS C. G. WHITMORE.

Patented Mar. 3, 1914.

2 SHEETS-SHEET 2,

ATTORNEYS UNITED STATES PATENT OFFICE.

CLAUDE C. WHITMORE, OF BUTTE, MONTANA, ASSIGNOR OF-ONE-HALF TO WALKER B. CARROLL, OF BUTTE, MONTANA.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Mal'. 3, 1914.

T 0 all whom t may concern.'

Be it known that I, CLAUDE C. WHIT- MoRE, a citizen of the U itedStates, and a resident 'of Butte, in th county of Silverbow and State of Montana, have invented an Improvement in Electric Furnaces, of which the following is a specification.

My invention -relates to electric furnaces, and more particularly to electric furnaces of the kind used for smelting ores.

My invention comprehends a number of .distinct improvements relating to the construction and operation of electric furnaces of this type, and among the advantages sought to be accomplished by my invention are the following: I. The utilization of the current in two ways, to Wit, in heating the electrodes and in heating the ores and substances intermixed therewith by conductivity thereof.l II. To prevent overheating of the elecetrodes. III. T control the distribution of `the ores or other materials upon which the furnace operates,a greater amount of material being passed into the furnace at points where the heat thereof is comparatively great. IV. To enable agroup of electrodes to be readily moved relatively to another group thereof for purposes of distributing the current. V. To promote the general efficiency of furnaces of this kind.

Reference is made to the accompanying drawings-forming a part of this specification and in which like letters indicate like parts. v

Figure l is a vertical section through my improved furnace and is taken on the line l-l of Fig. 5, lookin in the direction 'of the arrow. Fig. 2 is a front elevation of the furnace complete. Fig. 3 is a detail showing in section one of the joints employed in connection with the electrodes. Fig. 4 is a fragmentary view, partly in elevation and partly broken away, showing the feeding mechanism. Fig. 5 is a vertical section on the line 5-5 of Fig. 1, looking in the direction of the arrow.

body is a smoke flue l2 for conveying away the smoke and gases produced during the operation of the furnace. Mounted upon the top of the furnace body are hoppers 13, 14, in this instance -two in number, these hoppers being supported by aid of standards 15. A revoluble shaft 16 extends across the hoppers and is mounted in bearings 17. Secured upon this shaft 16 are beveled Wheels 18, 19, which mesh with bevel wheels 20, 21, the latter being mounted rigidly upon vertical shafts 22, 23. These verticall shafts, at their lower ends, are provided with feed screws 24, 2'5,l as will be understood from Fig. 4. The feed screw 25 is of coarser pitch than the feed screw 24 and on this account` supplies material into the furnace with greater rapidity than does the'screw 24. 'This is because the screw 25 being located comparatively near the middle of the furnace, and at a point where the heat isvery great, tends to supply the orev at a rate commensurate with the rate at which it is likely to be used.

A number of electrodes are shown at 26.

lEach of these electrodes is of cylindrical form and is made of material offering comparatively-high resistance to the passage of the electric current. German silver is suitable for the purpose. The slag spout is shown at 26, the metal spout at 27, and the tap hole at 27. Conducting cables 28 are connected with the electrodes 26.

I find it advisable to insulate the ends of 4the electrodes, and for this purpose I employ an insulating joint which, as a whole, I designate as 29 and which is shown more particularly in Fig. 3. In this joint I provide a sleeve 29HL of insulating material, such as clay or earthenware, and bring this sleeve against the adjacent end of an eleotrode 26. Abutting the end of the sleeve 29a. opposite this electrode, is a which bends upwardly and thus orms a rounded elbow joint. Encircling each end of each electrode 26 is a sleeve 31 made of insulating material adapted to withstand a high degree of heat. Another sleeve 32, like the'sleeve 31, engages the opposite end of the sleeve 29 and encircles the pipe 30. The electrodes 26 and pipes 30 are provided with threaded portions 33, 34. Engaging these threaded portions are rings 35, 36, of insulating material serving to some extent as packings adapted to withstand heat.

ipe 30` Encircling the sleeves 31, 32, are yplates 37 of insulating material, preferably massive asbestos, and extending through these plates are tie rods 38 provided with threaded portions 39, and upon these threaded portions are fitted nuts 40 for coupling the parts together as indicated in Fig. 3. By employing joints of this kind, each electrode 26 -is very effectively connected with a pipe section 30 and at the same time thoroughly insulated from the latter.. Each pipe section 3() is provided with a stuffing box 41 and extending through this stuiiing box is a pipe 42 for conveying a cooling medium through the pipe section 30 and into the electrode 26. The pipe 42 is provided with a valve 43 for controlling the -flow of the cooling medium, which may be air, water, or any kind of gas or liquid suitable for this purpose. I nd that if water be used, it should be under the pressure of at least forty pounds per square inch, and that it may, with advantage, be under a much higher pressure lthan this. Extending downwardly from each pipe section 30 is a pipe section 44 provided with a valve 45. The several pipe sections 44 are connected with a pipe section 46 extending across the entire width of the furnace, the pipe section last mentioned being connected with a pipe section 47 extending lengthwise of the furnace. Communicating with the pipe section 46 and extending upwardly from the same are a number of pipe sections 48 which extend into, and form telescopic connections with, a number of pipe sections 49. rlhese last-mentioned pipe sections are severally connected with pipe sections 50. A number of horizontally disposed pipe sections 51 are provided, as indicated in Fig. 2, these lastmentioned pipe sections each extending across from one of the pipe sections 50 to another, The several pipe sections 50 are, by aidof joints 29 of the kind above described and shown in Fig. 3, severally connected with a number of electrodes 52. These electrodes have the same structure as the electrodes 26 and extend loosely through slots 53, 54, located respectively in the end walls 11, 10, of the furnace body. The electrodes 52 are movable vertically within limits permitted by the slots 53, 54. provide sheave pulleys 55, 55, and engaging these pulleys and running between them is a cord 57, the cord and pulleys being supported from horizontally extending beams 56 secured to any appropriate part of the framework or building. The pipe sections -50 are provided at their upper ends with stuffing boxes 58 and extending through these stufling boxes and into the pipe sections 50 are pipes 59 for supplying a cooling medium for conveying the same from the pipe sections: 50, as hereinafter described. The pipes 59 are provided with valves 60 for controlling the flow of the. cooling medium. Connected with the electrodes 52 are cables 61 orother appropriate insulated conductors. At the ends of the electrodes 52 opposite the cables 61 are other cables 62. Near the cables 62 are cables 27a which are connected with the adjacent ends of the electrodes 26.

The ends of the electrodes 26 are, by aid of joints 29 above described and shown in Fig. 3, connected with pipe sections 63 which extend rearwardly and upwardly. Communicating with the pipe sections 63 and extending directly downward therefrom are'pipe sections 64 which are provided respectively with valves 65. The pipe sections 63 arc provided with stuiiing boxes 66 and extending into these stuffing boxes are pipes 67 used for conveying the cooling fluid into or out of the electrodes 26. The electrodes 52 are connected by joints 29, of the kind above described, with pipe sections 69. Communicating with these lastmentioned pipe sections and extending downwardly therefrom are pipe sections 70. The pipe sections 69 carry stuffing boxes 71, and extending into the latter are pipes 72 provided with valves 7 3 and used for controlling the iiow of the cooling medium. Pulleys 74, 76, connectedby a cord 75 and supported by a sustaining member 77, such as a beam, are connected with the pipe sections 69 and are used for raising and lowering these pipe sections, together with the adjacent ends of the electrodes 52. The pipe sections at the rear of the furnace have telescopic connections with the pipe 78 in much the same manner that the pipe sections 49 at the front of the furnace are telescopically connected with the pipe 46. By manipulating the cords 57, 75, the electrodes 52 may be raised and lowered as desired and may be made to assume slightly different angular positions relatively to the electrodes 26. Y

Current may be supplied in various ways through the cables 27, 28, 61, 62. For instance, ,current may be supplied to both ends of each of thevelectrodes 52 and caused to travel from these electrodes through the materials to be smelted to the electrodes 26 and thence out of the furnace to the source of supply and back to the electrodes 52. ,Agairn current may be supplied from a source of supply through cables 61 to electrodes 52, thence through the materials to bel smelted to the electrodes 26, thence out through cables 28 to the source of supply. As each individual electrode 52, 26, is 'provided with its own particular cables, one at each of its ends, the number'and variety of electrical connections which can be made is very great. The electrodes may, therefore, be connected l either in series with each other or arranged into groups and the groups connected in series with each other and various parallel connections may bemade at the will of the operator. Generally, however, I prefer to connect all of the electrodes 52 in parallel with each other and all of the electrodes 26 in parallel with each other, so that the group of electrodes 52 is in series with the group of electrodes 26, and so that the current passes from the electrodes 52 through the ore mass-to the electrodes 26.

Since the electrodes 52, 26, vare made of heat-resisting metal (preferably German silver as above` stated), the electrodes'are themselves heated by the passage of the current through the ore and the ore itself by virtue of its ohmic resistance is heated somewhatindependently of .the thermal effect of the electrodesvu'pon them; that is toy say, the ore is heated in two ways, to wit, by proximity to the heated electrodes and by the passage through the material of a current adapted to heat them in transit. As ores usually'contain more o r less moisture, anderen dry ores frequently contain water of crystallization which is driven off during the action of the furnace, the moisture thus produced increases the facility with which the materials are heated by the passage of the electric current.

A cooling medium is supplied through the various pipes 42, 59, 67, 72, and may be distributed in various ways. For instance, it may be desirable to cause the cooling liquid tomove to the right through the electrodes 26 according to Fig. 1. To do this, the pipe sections 64 are closed by aid of the valves 65; the pipes 67 are opened-by the valves 68; the pipe sections 44 are opened by turning the valves 45. 'The coolllng liquid now enters through the pipes 67 and passes throughout the entire length of the electrodes 26, being collected together and makinr its escape through the pipe section 47. gain, by closing the valves 45 and opening the valves 43 and 65, the cooling liquid may be caused to moye from right to left, according to Fig. 1, through the electrodes 26. Similarly, the cooling liquid may be forced in either of two directions through the electrodes 52.

As above indicated. I may use 'any variety of cooling fluids. Compressed air is suitable for cooling-and so is water. Generally speaking, I prefer to use the cooling fluid under comparatively high pressure and in case of using air or gas, Iallow. the pressure of the cooling fluid to relax within the electrodes in order to cause expansion and thus withdraw heat. Of course, some de.- gree of care is necessary to enable the operator to ascertain just how hot the electrodes may become-before the cooling fluid is turned on. If it be turned on too early, it wastes the heat of the furnace and if it be turned on too late, the electrodes may be endangered.

The operation of my device is as follows.'

The parts being assembled and arranged asv Y the middle or center of the furnace receives more ore than the upper end of the furnace. In this manner, the various portions of the furnace receive quantities of ore roughly i proportioned to the relative capacities of different portions of the furnace to dispose of the ore. In other Words, the largest quantities o-f ore are fed to the hottest portions of the furnace. The cooling uid being now turned on and caused to circulate as above described and the electriccurrent being also turned on, the ore is heated in the manner above described, partly by the elevated temperature of the electrodes and partly by thedirect heating effect of the current in passing through the ores.

Among the ores especially adapted for reduction 1n my improved furnace may be mentioned all iron ores, the sulfid ores of copper, silver ores of all lrinds, gold ores, lead ores, zinc, mercury and antimony ores. Other ores, however, in Which the electrical conductivity is inferior to that of the ores just mentioned may be operated upon. In starting the furnace, and especially in start-- ing with ores of inferior conductivity, any of the conventional primings may be employed for the purpose of rendering the ore sufficiently conductive to carry enough current to begin work. The furnace being once inaction, almost any material thrown into it will, by fusing, become sufficiently conductive to continue the operation, so long as the` electric current is supplied.

I do not limit myself to the particular construction shown, as various changes may bc made therein without departing from the spirit of my invention.

Having thus described my invention, what I claim asnew and desire to secure by Letters Patent is as follows 1. An elect-ric furnace, comprising a furnace body provided at its ends with slots, an electrode of longitudinal form extending through said furnace body, a second electrode extending through said furnace body and disposed approximately parallel to said first mentioned electrode, said second electrode being of tubular form, means for cooling said second electrode, and mechanism controllable at the will of the operator for adjusting said second mentioned electrode to different angles relatively to said first mentioned electrode.

2. An electric furnace, comprising a furnace body, an electrode mounted therein, a

second electrode located Within said furnace body and movable relatively to said irst' mentioned electrode, said second-mentioned electrode having substantially the form of a long cylinder, means controllable at the Will of the operator for tiltingI said second-mentioned electrode to different angles relatively to'said first mentioned electrode, and means for supplying current to both of said electrodes.

3. An electric furnace. comprising a furnace body provided atits ends with slots an electrode extending through said furnace body and through said slots, means controllable at the Will of the operator for raising and lowering said electrode,another electrode located Within said furnace body, and electrical connections to said electrodes.

4. An electric furnace comprising a furnace body, electrodes of tubular form eX- tending into said furnace body and disposed approximately parallel with each other, means for supplying a cooling fluid into each of said electrodes and mechanism controllable at the Will of the operator-for shiftz.

ing the general position of one of said electrodes relatively to the other.

EMMA V. OBRIEN, ANNIE M. VVHI'TMORE.

Images