US1013359A - Electric furnace. - Google Patents

Description

M. APPEL.

ELECTRIC PURNACB. APPLIUATION FILED SEPT. 9, 1911.

1,01 3,359. Patented .121112, 1912.

2 SHEETS-SHEET 2.

alzi/(70566 e6.-

"uesrsim Bulimie-4 ons, ma l ELECTRIC* rtriamrcna. f

B e it known ,that I, Moses a citizen Vof the United States, residing-at- Balti-v more, lin th'e State of Maryland, have invented -certainnew end useful Improvements in Elect'ric. ,Furna ces., of which the 'following is a specification. 4 Y

'the object-fof the invention beingthefpro- This invention relates ,to electric furnaces,

visi Qf'an eilicient furnace of :theresistancA pe adapted `'primarily for the refining of7 iron, steel, ferro-alloys and;` other metals, although capable of use for the pro-pl duction from their ores o f iron, ferro-alloys,- Zinc and other metals@ The furnace .may also be used in themanufactureof glass.

Thev invention lwill be 'described by.4 reference to the accompanyingj drawings illustrating oneembodiment thereof, wherein Figure 1 is an end elevation of the furnace; Fig. 2 is ahor'izontal section on line 2-2 of Fig. 1; Fig. B isa transversevertical section on line V3 3 of 'F ig.'2';.jand Fig. 4 is a vertical longitudinal section on line 4-4 of Fi 3. c

'Izhe furnace shown comprises a refractory furnace body 1, supported by a metal Vshell Band suitably mounted upon curved rails or beams 3 carried by*` a stationary sup- 'port 4. These features of construction may conform to the approved practice ,in tilting open-hearth furnaces, Athe indications of the drawing being 4more or Aless;diagrammatic in character.

The terminals-or electrodes 5, G enter the ends of thefurnaceand, for the manufacture of crucible or other high-grade steel,

are preferably of metal of like character, being composed vin this case of `wrought iron or steel. posed one or more main bodies or baths 7 of the metal to be refined. `Three suchybaths are indicated, although alarger or smaller number may be' provided.l Each of .these bodies is connected by a' tap hole 8 with the spout 9, in such manner that the molten metal may'be pouredfromthese baths by tilting the furnace at a sufficient angle.

f 8 is a refracto plug.

The several mam baths 7 are partly 'sep-f arated from each other by partial partitions 10 of vhighly vrefractory material, having provided therein open channels 11, which extend below the normal level 12 of. the molten metal, in such manner as to provide interconnecting metal bodies of reduced cross- -connectiom Similar electrodes 5, 6.- f

Between the, electrodes are dis-` L spammen@ 'of Margraten-.1 Patented Jn, 2,1912, fljagpncaaonniee september a, 1911. y 1

- serial No. 648,426.

the molten bath, whereby the surface portions only of the main baths are in metallic .arate the end baths of the series from the 13, 13 represent cooling pipes for cirof the electrodes 5, 6. 'These-electrodes are sutliciently cooled to guard against melting thelr outer ends, while the inner portions of partialpartitions Sep section as compared with `that ofthemain .baths 7. As illustrated, the contracted the-electrodes may be fluid in the normaloperation of the furnace. In eneral, the portion' ofv the electrode which Aextends 'through the furnace wall. should bel of as small cross-section as is'consistent with the current to be carried, and should be operatedat such temperature as will afford the best heat-economy, as i'swell .understood in the The protruding ends of the electrodes may be connected in an electrical circuit of any appropriate character and in any desired way. Thus a direct or alternating current of appropriate volume may be passed through the molten metal, or the construction may be adapted for use with a. twoor three-phase current, orv induced currents may be used.- Thus as illustrated in Figs. 1 and 2, the terminals 5, 6 may be connected by a short, heavy copper lead 14, of s'uilicient cross-section to carry the lcurrent without undue heating, this lead traversing a primary coil 15, whereby the molten contents of the furnace' and the lead 14, together with the electrodes, constitute a closed heating secondary circuit. As shown, the coil 15, is so carried upon the furnace body b v brackets 16. with appropriate insulation 17 as to avoid interference with the tilting or pouring operation.

In operation,I lthe furnace is charged with metal, usually in a, melted state, and by passage ofthe current the metal is broughtl to the required temperature and so maintained for the required time, vwith the addition if desired of the usual reagents employed for the production of refined or alloy-steels. The heat is chiefly developed in the contracted passages between themain baths of metal and 'between these baths and the electrodes or terminal bodies of metal, and is transferred largely by` conduction; assisted by any natural circulation of metal. In this manner it is practicable maybe varied and controlled by merely tilti furn'acefor the production of various carbon l direction of the broken arrow will have the to bring the entire mass'ofmetal to any del sired temperature below the melting point of the lining of the contracted' channels. p AIt will be noted that in the construction illustrated 'the' contracted channelsor passages 11 are located at one side of the centerv plane of the furnace. Owing to this construction, the cross-section of metal 1n these passages or channels varies w1th every position of the-furnace; and` conversely,I 'the cross-section lof metal in these channels, andl hence its temperature under constant current conditions, and with it the-temperature of the Ventire metal contents of the furnace,

ing the furnace. Thus if the furnacebe tilted in the direction of the solid arrow, Fig. 3, the effect will be to diminish the cross-sectional area of metal in ea'ch 'channel' 11 and to increase correspondingly the heat` ing effect of the current; while tilting in the contrary effect. In other words, the temperature of the furnace rma be accuratell controlled, regulated or. varied, at 'the'w' of the operator, bytilting it'forward or backward asconditionsmay require. -Any arrangement or disposition of the channels to secure this result may be used.

The 'process as above described presentsv several important-advantages:

(1) Although depending forthe development of heat. u on the resistance of the molten metal, it 1s very compact for a given capacity, whereby the radiation losses are minimized.

(2) The expense of carbon electrodes as well as the laborcost of repairing and renewing such electrodes is avoided. At the same time all contamination of the 'bath by carbon is prevented, permitting the furnace to be employed for the manufacture of highgrade or cruciblesteels.

(3) The temperature of the furnace may l be regulated with greater nicety and through a wider range than is the case with ordinary arc or resistance furnaces, ;by merely tilting the furnace, with or -without the simultaneous control of the heating circuit. In case constant temperatures are required, a thermostatic control of the furnace temperature isv easily rovided, it being merely, necessary that t e position of the furnace should be automatically adjusted in accordance with the temperature indications.

(4.) The furnace presents certain special advantages relating to the manufacture of steel. For instance, assuming the-metal to have been poured into the furnace and refined -to the required degree, the furnace may be slightly tilted in the proper direc-- tion for pouring, whereby the temperature is further increased, and the metal brought l baths.

to fluid.: condition. Athe same time,.. if,1des ired, the flow of cooling water vmaybe"iiicreasd, in order to solidi all, or

-theprincipal portion, of the' termina masses 5, 6. Under these conditions the furnace mayr be `discharged without lossof the materlal of tle electrodes. By removing the plug 8 a""branch circuit is estabhshed throughtaps, 8, to maintain the proper fluidity of metal'therein.

For the retiningof'non-ferrous metals the internal structure may remain as above de' scribed,` the electrodes beingv constructed of suchimaterials, as for example iron, carbon or copper, as may present a'dyantages under particular conditions. e

This furnace can also be used as a heating and'other compounds. The construction of the furnacewould betheA same as for the 'manufacture-of steel, b ut the spaces occu- Avpied by Steel would be occupied by iron, silica or other material which would act as a resister and.l also as a conductor of heat.

jIt.would,beh'eated to high temperature as *described-'under the refining of steel. The carbon -or'` otherv `material would then be addedlat the top of the molten resister and heated by.conduction from it to any desired temperature.'` VAny gases'or other' materials desired could be passed through the furnace and the variouscompounds made.

It is to be understood that the invention is not limited to the details of construction herein described by way ofillustration, and that` the form',.size` and proportion of the `parts `may be varied according to the character of material treated and the scale of operations.

I claim 1. VAnelectric resistance furnace'mounted' for oscillation and comprising a plurality of metal baths electrically interconnected at Atheirsurfaces, in combination with metallic electrodes lin conductive relation with said 2. An electric resistance furnace mounted for oscillationgsaidfurnace comprising a plurality of metal baths electricall interconnected by relatively contracted c annels, said channels so 'arranged that the crosssectional area of conductor therein maybe i varied by tilting/thc` furnace.

3. An electric resistance furnace mounted for "oscillation and "comprising oppositely -disposed electrodes and a plurality of intermediate metal baths, vsaid baths electrically interconnected at their surfaces by channels of relatively small cross-'sectional area.

'4. An electric resistance furnace mounted for A oscillation and comprising oppositely disposed electrodes and a plurality of intermediate metal baths, said baths -electri- 'cally interconnected by channels of relatively small cross-sectional area and so disposed that the cross-sectional area of the interconnected metal baths,

varied by tilting furnace mounted comprising electrically and electrodes in conductive contact therewith, a conductor connecting said electrodes secondary circuit, and a to form a closed primary Winding 10 supported by the furnace in inductiye relation to saidsecondary circ 6. An electric reslstance uit.

furnace mounted for oscillation and comprising a plurality of main baths oi metal electrically interconnected at their surfaces, electrodes in conduc-` 15 tive relation to the end baths, and a metaltap for each of said main baths:

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

MOSES APPEL. Witnesses:

W. H. PAmo, HARRY B. KINGER.

Images