US1082459A - Electric furnace. - Google Patents

Description

J. BURKE.

ELECTRIC FURNACE.

APPLICATION FILED mo. 10, 1910.

1,082,459. Patented Dec. 23, 1913.

To all whom it may concern t TED STATES PATENT orr on.

JAMES BURKE, OF PENNSYLVANIA, ASSIGNOB 1'0 BURKE ELECTRIC COMPANY, A CORPORATION OF PENNSYLVANIA.

I ELECTRIC FURNACE.

Be it known that I, JAMES BURKE, critizen of the United States, residing at Erie, m the county of Erie and State of Pennsylvania, have invented certain new and useful Improvements in Electric Furnaces, of which the following is a full, clear, and exact specification.

This invention relates to a construction and arrangement embodying an electric furnace and energy-supplying means, and to the method of operating the same.

More specifically, this invention relates to an arrangement and construction embodying a source of polyphase currents, such as a transformer, or the like, and an electric furnace in which the several phases constituting the polyphase currents are separately utilized to effect heating or electrolysis.

My invention contemplates further the method of leading the several currents gen erated by a polyphase transformer, or the like, to distinct electrodes of an electric furnace where the full energy of each phase is available in the interior of the furnace.

It has been heretofore proposed to employ polyphase currents for supplying energy to the electrodes of an electric furnace; however, such prior organizations of a source of polyphase currents and an electric furnace have entailed arran ements in which the full energy of the polyp ase currents is not ut-ili ized to the best advantage in the furnace, In such prior constructions the several phases of the polyphase currents are combined before reaching the interior of the furnace so that an electrode is supplied with a current which is the resultant of two or more phases, which resultant has a watt value which is less than the arithmetical sum of the watt values of the component currents. According to my invention, the separate phases of polyphase currents generated by the transformer, or the like, are led by distinct paths to the interior of the furnace in such manner that the full energy of each phase is available to effect reactions in heat and electrolysis.

My invention may be described in one form as applied to an electric furnace of the arc type, the electrodes of which are individually connected to the mains supplying the polyphase currents, that is, to the conductors leading from the secondary coils of the transformer or the like. In the pre- Specmcaflon of Letters Intent.

Application filed December 10, 1810. Serial Ila. 696,732.

Patented Dec. 23, 1913.

ferred forms of my invention, the number of electrodes is chosen as twice the number of separate phases of polyphase currents, each electrode being disposed so that an arc will be formed between the same and the charge to be treated in the furnace. In such preferred forms, each end of the secondary coil or coils is supplied with a separate terminal, so that the several phases generated in the windings of the respective secondaries are individually) led to the electrodes of the furthree-phase currents from a transformer in accordance with my invention.

The transformer 1 .having primary coils 2, 3, 4, is shown connected to the mains 5, 6, 7 in star connection; however, the delta connection or any other form of connection may be employed, as will be readily understood. The secondary coils 8, 9, 10 are disposed in proper relation to the primary coils 2, 3, 4, respectively, to convert the several phases of currents to the desired voltage, as will be understood. Said seconda coils are provided with distinct terminals, designated in pairs as 11 and 12, 13 and 14, and 15 and 16, said terminals being connected to the pairs of leads 17 and .18, 19 and 20, and 21 and 22, respectively.

The furnace 23 is provided with six electrodes 24, 25, 26, 27, 28 and 29, electrically connected with the respective leads 17, 18, 19, 20, 21 and 22. Said electrodes 24 to 29 are supported in any approved manner, as at their upper ends and projecting into the body of the electric furnace. The specific details as to feeding the electrodes into the interior of the furnace will be determined by certain conditions, as will be understood. The electrodes and any other parts or portions of the furnace may be rovided with coolin means of any ap rove construction. The character of the e arge and the purposes for which the charge is treated, will determine the construction and arrangement of the parts of the furnace, as well as the nature of the lining of the furnace parts.

It will be noted that I have grouped the electrodes in the specific form shown in the figure, so that the electrode 24: connected to lead 17 is closely disposed to electrode 29 connected to lead 22; similarly, the remaining electrodes are so related that those electrodes connected to the adjacent terminals of the secondary coils are positioned in close proximity to each other. The arrangement shown in the figure is highly advantageous, but it will be seen that the electrodes may be grouped in the interior of the furnace in any desired order or series, since there is at all instants a difference of potential between any electrode and the charge or portion of the charge.

I wish it to be understood that my method may be carried out by means of three singlephase transformers connected to the respective three-phase conductors, as well as by a unitary three-phase transformer. It will also be understood that the number of phases of the secondary circuit need not necessarily be the same as that of the phases of the primary circuit, since my invention may. be carried out in any alternating current-supplying system, in which two or more phases are obtained in the transformer or groups of transformers.

Specific reference has been made to threephase currents, but such reference has been made for the purpose of describing my invention as to certain specific forms thereof which are particularly advantageous at the present time owing to the prevailing use of three-phase currents for long distance transmission. I have found that by reason of my arrangement and my method of operating there results an increase of seventeen or more per cent. in energy available in the interior of the furnace when employing threephase currents, thus effecting a material increase. In like manner, two, four, six, and other polyphase currents may be utilized to effect my invention.

Having thus described my invention, I declare that what I claim as new and desire to secure by Letters Patent, is-

1. The combination of a polyphase transforming device having secondary coils unconnected with one another, conductors running from the terminals of said secondary coils and an electric furnace having electrodes connected to said conductors.

2. The combination of a three-phase -transf0rming device, the secondary colls of which are unconnected with one another, conductors connected to the terminals of said secondary (3011s, and an electric furnace phases,

having electrodes connected to said conductors.

3. The method of energizing a furnace with polyphase electric currents, comprising transforming alternatin current to produce a plurality of secon ary alternating currents of different phases, and leading said phases of alternatin current independently to pairs of electro es of said furnace.

4. The method 'of supplying a furnace with polyphase electrical energy, comprising producin a plurality of alternatin currents of itferent phase relation, an leading said alternating currents independently to pairs of electrodes of said furnace. 75

5. In combination with an electric are i furnace, a polyphase transforming device having secondary coils unconnected with one another, and electrodes disposed in said furnace in arcing relation with the charge and connected to the terminals of said unconnected secondary coils.

6. In combination with an electric furnace, a source of polyphase alternating currents, means for transforming said currents into distinct alternating currents of different and means for leading said phases independently to pairs of electrodes'of said furnace.

7. The combination of a source of polyphase currents, a polyphase transformer having its secondary coils unconnected with one another, conductors running from the terminals of said secondary coils, and electrodes in arcing relation with the charge in the furnace and connected individually to said conductors.

8. The combination of an electric furnace, a sourceof three-phase currents, a threephase transforming device, the secondary coils of which are unconnected with one another, conductors running from the terminals of said secondary coils, and electrodes disposed in said furnace and divided into sets, said sets being connected to said conductors.

9. The combination of a source of polyphase currents, av transforming device having at least two secondary windings electrically unconnected with one another, conductors connected to the terminals of said secondary windings, and at least two sets of electrodes disposed in said furnace and connected to said conductors.

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

JAMES BURKE.

Witnesses HENRY J. LUoKE, Gno. N. KERR.

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