US1034747A - Electric furnace. - Google Patents

Description

0. A. WEER ELECTRIC FURNACE.

APPLICATION FILED 0GT.23, 1909. 1 34,'74"" I Patenef'Aug. 6, 1912.

witwassen www Cl, Quia/Q mmh C. A. WEEKS.

ELECTRIC EURNAGE.

APPLICATION FILED 0GT.23,1909

mam?.

Patented Aug. 6, 1912.

3 SHEETS ASHEET 2 fluo/pmu:

C. A. WEEKS.

ELECTRIC FURNACE.

APPLICATION FILED 0GT.23,1909.

1,034,747. Patented Aug. 6, 1912,

3 SHEETSSHEET 3v WITH ESSES vCHARLES A. 'WEEKS`, 0F THILEADELPH'IA, ,PENNSYSVANIA.

ELECTRIC FURNACE,'

To all whom t may concern.'

3e it known that I, CHARLES A. W'EEKs,

a citizen of the United States,l and aresident of the city and county ofPhiladelphia,I State of Pennsylvania, have invented an: Improvement in Elect-ric Furnaces, of which thefollowing isa specication'.

My invention has reference to` electric fur'- naces and consists of certain improvements Which are fully setforth in the following specification andshown in the accompanying drawings Which form afpartthereof.

The object of my invention is to provide a suitable construction of furnace adapted to the employment of the high temperature of an electric arcfor thesmelting. of copper', 'iron .ando-ther ores both for .the purpose of reducing and refining.

' Riom-particularly theLobject ofmy inven-y tion. is to provide a -furnacein which the re.

ducingand refining, operations may becary ried onin a continuous mannerf andv at a minimum expense, and, moreover, under absolutecontrol as toftemperatureand charac. ter ofreducing gases. v

My object is also to'reduce the timenecessary in Which Ithe reduction of the ores and refningxof the ,metal may take. place, thereby ch'eapening the cost; and also to enable? .the refinement to be done under a hightemparat-ure which is capable of satisfactorily" treatingithe most refractory materials.k

The general character of my improved` 'furnace comprehends the employment cfa;

long, slightly inclined tubular rotary reL ducing flue, terminating at its highest end inthe chimney and ore'feedingfdevice, and.v communicating.. at.4 its .lower end with an=. electricfurnace. so. constructed as to have provisions for rocking orotherwise moving,

` itsfhearth While maintainingcommunicationl with the tubular iiue, and combining; With such structure meansfor-providing are ducing or other Aflame in'that portion oftheA tubular iue adjacent to its lower vend for completing ,the reduction ofthe ores before the metal is delivered to thehearth ofthe: electric furnace inWhich the retiningcis peri' formed. In the kpreferred construction of my improved furnace I support the. electric furnace proper by means of curved rockers guided upon suitable supporting` rollers and rocked `by means of mechanical power and in which the 'axis about Which vthe furnace rocks is concentric orsubstantially concenf..

Specication of Letters Patent. Appncatipn filed october 2a, 1909. Ser'i'arm. 524,240.

'secured andmoving with thesaid electricvfurnace proper.

the electric furnace.r A

Patented'A'ug. 6";1912.'

tric With-thelower end/of the .rotating tubnlar fine-and with? which communicatio'nismade by meansof a connect-ing. flue or neckl Myvlnventionmore fully-consists of conf l structlqnsvvhich are described'in the followE ing. specification. and more particularlyde fined Vinthe claims; andfthese improvements drawings, in-,Whichi Y Figure l`l is a.. sideelevation offmy` improved-furnace, complete; Fig. 2f'is afplanf view .of thesameonaflarger scale, vWitha large portion ofV the'- rotary flue broken.A away; Fig, 3 is a-sectional elevationsof'the,` same; and Fig. /'is across sectionithrough` will-bebetter understoodby referencetov thev Q/s a long,l sheetfmetalue built-of-secf 7 5 'tions and lined-:With fire vbrickor suit-ablefre fractory, material;A andV at intervals iin' its', length. it yis provided with circular bearings) 3 which.` runi'fupon. supporting rollers. 4t,4

Wherebyetheue; 'as a v v'shole, may :be freely Y 80 rotated.; The bearings :are .supportedfupon pedestals 5 and .tlireseqare` gradually reduced. height softhatone .end ofthetubular flue. 2. issupported-- at a. higher elevation thanf the other. or 'lower end,` `said inclinati0n35 Abeing adapted tov cause the oreandlthrxesy to gradually work: downwardly through the flue' during/its rotation, and to cause the gaat Atopaaslsgupward through the sameor in a,- reverse direction; Thisyrotaryl flue 2=may`90 y ybe :rotated by means ofan electric motor 8,v y

a variable'speed-gear 7 'and an annular gear '6 surroundingthe .cylinder ofthe tubular flue 2.a Bymea-ns of the variable gearing?, the speedcf rotation of'theliue may be. made commensurate with the requirements, but -I 'do not limit myself 'to any particular; speed, The'tlue maybe rot-ated in any' suit; able mannerdesiredl 9 is the receivingchamber fonthe gases passingfrom the Hue Zand is provided with. aitubular opening '16 into which, the end 4.of the flueextends, as clearlyshown in Fig-3. Opening from this chamber 9'is the chimney. 10 which may be provided With a suitable damper 11 which controls the amountof draft. ,At the bottom of the*chamber'Q'fis a cleanout door 12 through'which the heavy deposit collected in the chamber may be removed. Afiue 40 may open from the chamber. 9 for conveying the .gas to the gas en` gine orv the furnace for heating the boilers when .the waste gases are free from substances which it -is desirable to collect; but

in the case where the ,gases 4are sulfurous, the

said flue 40 may be connected with textile bags 41 in whlch the sulfur is collected.4 'Any other desirable use ofthe escaping gas v flue 40 Imaybe employed, 'if so desired.

j 4 17v is the electric furnace and consists of-a.

from the large. body` part having. an -obliquely Aextending neck 21terIninating""inV-ahead 22 'provided with plates 23 having'ial tubular opening into which the lower. end of the tu bular` flue 2 extends, as shown Fig. 3. This head .22 opposite to the end of the flue '2 is provided with a Adoor'-2L1through which a 'nozzle 25 extends for .providing a Vblast efair, gas or fuel in subdivided form, the:A gas orfuel required being varied to, suit theparticular character ofA the ores to be reduced in their passage through the'rotary flue 2. The electric ,furnace is supported upon curved rockers 1 8, the curvature of at the middle approximately parallelwith' to compensate for their consump which is struckfrom the'axis .corresponding to the center of the opening in the 'plates 23 any'other mechanism, if so desired.

More particularly, the furnace'is 'con-. v structed of a sheetl iron shell supported on the bottom on al series oflongitudinall beams 35 which 'rests uponv the'rockers 18'L and the shell is'reinforced -over its upper,

part by a series of' curved beams 36. The sheet iron shell is lined with suitable re fractory material 28 and preferably provided with amagnesite hearth 27. Thefin-l terior part Vof the roof over the hearth is curved 1n transverse sections, as indicated in Fig. ifi and substantially straight in longi` tudinal section,- as indicated in Fig. 3. The

hearth 27 is preferablyVcurved downward the curvature of therockers 18 and has the ends curvedupward so that the general cross section of thevinterior of the furnace Each side of the vfurnace is provided with one or more, electrodes 29,

is elliptical.

which are carried by water cooled bushings and through which these electrodels are fed t'von. The water may be supplied to the bushing in any suitable manner. vThese electrodes on opposite sides are arranged lat an angle to each other, yas-in'dicated in Fig. 4.-, so as to causethe arc between' them to be vpresented 4 close to the'surface ofthe metal upon the hearth. The electrodes may be fed through cooled A'jackets 30 in any suitable manner, butas indicated, are adjustable b gearing 31 foreach electrode and connected by a transverse power shaft 32 which is rotated by worm and worm-wheel gearing 33 operated by a suitable electric or other motor 34. `-By rotatingthe shaft 32 inv one direct-ion "or the= o-ther,the electrodes; 29 may be ad# .vanced or retracted.A and in thismanner'the .length ofthe arc between the; opposite electrode maintained, asmay belrequired. The Y lelectrode'feeding mechanism is carried with the electricfurnace 17 and'these are rocked together, as a unit. The neck 21jaswell as 'theheartli 27 may be lined with magnesite 'and especially.,tliat portion o-f the neck over which the metal flows in passing'` from the flue 2 tothe hearth-27. l The refined metal may be drawn oif through a tappi-ng hole 37 and the slag may beVruned through the tapping hole 38 also infront of the furnace,

-gbut at. a higher elevation.

' It will be understood that the electric fu'rnace used. in refining, may be of any {lel'lgthA desired and provided with one, twoormorepairs of electrodes, dependentupon the lcapacity of the-furnace, and I therefore do not limit myself tothe use of a plurality .ofpairs ofelectrodes. 4 ,-The'ores t-o be treated in my improved furnacd are first pulverized and fed into a hopper 13 and from this hopper the pulverized ore passes into an oblique chute 14 an d, by means of a feeding screw 15, is delli'vered` info the-upper end of the tubular 'rotary flue 2, as shown in Fig. 3. If desired, -1

the extreme upper end oft-he lining of the "flue 2 -Inay be thickened, so as to reduce the tubular outlet tol a Adiameter considerably -lessthan the diameterfat the remaining por- /tionvof 'the flue, as clearlyndicated. The

means for supplyingV fuel, either in gas or pulverized form'. tov the lower end ofthe due 2, may beof any character desiredand that shown at 25 is only given by way of illus l tration. The particular characterof burn- `ers for this purpose would be especially de- -slgned for .the character` of work to be donel in the furnace and may vary in the same lfurnace when applied to the smelt-ing of different ores.

26 is a valve to control the' fuelsupplied the burner25. The fuel supplied by the nozzle or burner 25 is usually of a reducingv character, so. that in passing through the lflue 2,*inthe' reversedirection to the travel of the .crushed 'ores,l the latter will be re,- duced gradually from the time of its (nl trance into the rotary line and throughout its travel toward the lower end thereof or into zone of dissociation and preliminary to i the ow of the metal formed down the neck A21 into the electric furnace. On the other hand, the electric furnace is adapted to'treat the crude metal that is produced in the ro-.

t-ary flue to the intense heat of the electric arc and reverberatory action of tlie'heat energy, Without special requirements either as to reducing or oxidation. In tbisfurnace 17, the metal is refined by a high temperature and the lighter slags are caused to separate and rise to the surface of the molthe oscillation of the electric furnace 17, the

head 22 thereof'at all times maintains its connection with the lower end of the rotary flue 2, because 'of the fact that the curvature' of the rockers 18 are struck from a center in axial alinement through the axis of the rotary flue where it enters the head 22 of the neck of the electric furnace.

In using my improved vfurnace in the' smelting of iron ores for the vmanufacture of viron and steel, substantially the same reactions take place in the apparatus as take place in a blast furnace but with more satisfactory results and' with morevpositivev action as to final outcome and product. Assuming that proper pulverized'mixture of sesquioxidof iron and lime stone were fed into the upper end of the fiue2 from the hopper 13, we would have essentially the following reactions if it be understood that the gases which are fed in from the nozzle 25 were produced from carbon. If we assumed that pulverized carbon be injected with the proper airand supplemented by the high temperature rising from the electric furnace through the neck 21 thereof, we will have a very hightemperature in the lower part of the fiue 2 and a gradually lessening temperature as'we approach the st-ack end. The ores, mixed with carbon and limestone, delivered in the upper Vend of the rotary flue, are reduced at a dull red heat by the learbon-monoxid gases and as the materials pass therefrom down'the flue the lime-stoneis decomposed, giving oif carbonic acid, which, by combination with carbon, forms carbon-monoxid and assists in the reduction of the iron oxid. At a full red relative amount of carbon present in the gas or mixture. The crude metal which is Athe desired grade .of the refined steel.

thus produced is then subjected to a higheri vtemperature equivalent to a very bright red heat and vat this fusion takes place with gradual separation of slag. The mixture of metal and slag are then subjected to an increased `temperature, equivalent to white l heat and approximately from 27 OO to 3000O Fh., where they enter the furnace .17 by the neck 21. Within this electric furnace the temperature may be raised to considerably over 3000o Fh. and thereby produce a clear separation of the slag and other impurities from the steel and which is treated to agi tation when being subjected to higher te1nperature as an open hearth proposition. Thelslag may then be run ott and finally the refined steel tapped from the hearth.

In practice, the iuxing and the proportion of carbon supplied, either from the nozzle 25 alone or by mixtures with the crushed ore, may be varied to suit the character of the iron to be treated, as theseconditionsl would vary according as to whether` the iron was red-hematite above mentioned as sesquioxid of iron, or iron ores such as brownhematite and spathic iron ores. When the percentage of carbon reaches 1.4, thel metal begins to assume the characteristics of cast iron and approximately from to 1.5 may be taken as steel, as ordinary form of steel approximately contains about 1.2 of carbon. It is-further seen that some care in the action of thefurnace will be necessary to cause proper carbon absorption to'insure In a furnace of this character, it is also possible to conveniently free the iron from sulfur and phosphorus'whereby the ,finished steel l will be free from these detrimental elements.

' In using the'furnace for smelting ofcopexample. The ores would be pulverized and fed into the rota-ry flue'2 from the hopper 13 and in the upper portion of the flue 2 they would be subjected to a reducing action. The sulfur, when present, passes 0H through the chamber 9 and by flue ll0 and collects in the textile bags 41. The metal regulus formed by the actionof the gas in the rotary flue 2 during the passage of the copper `ores through the same, will be essentially a mixture of copper, sulfuret of copper, and iron or other metals and is treated in the higher temperature zone to fusion and by the rotary action of the flue 2, is fed down into the electric furnace 17. Duringthe reducing operation of the smelting within the flue *the rotary flue and the metal separatedv freely from the slag by the time they reach the electric furnace, and in which the separation of the vslag' and copperis completed, the refining of the copper taking place in the electric furnace because of its high temperature and capacity for agitation. Dur ing the reducing operation, which is essen- .tially :an oxidizing onemthe regulus becomes black due tothe oxidizing of iron and oxid present, 'whereas the gas, with other sub stances are conveyed o and the sulfur collected,` as hereinbefore stated. The reduction lof the ores is practically completed before the copper and slag enter the lelectric furnace, so that nothing is required in such part, excepting high temperature with or f withoutvfagitation Aas desired. When the operation is' completed the slag is run o and then the refined copper thereof discharged in the molten form. u y

The foregoing explanation as to theoperation of my improved furnace is given by way of illustration only, to indicate its applicability to smelting action generally and not by way .of limitation with respect to its use. It will also be understood that the general details of construction mayl be'genf erallyv variedV without departing from .the

^ spirit of the invention, and I therefore `do not restrict myself to the details shown, althoughI prefer them in the actual construction and use of my invention.- A

Having now described my invention, what I claim as new and desire to secure by Let-- ters Patent, is

'1. The'combination of 'cylindrical fluesmelting furnace of great length arranged on an incline and having distinct zones of temperature for roasting `and reducing the ores and for melting the metals thereof, means to 'rotate the said smelting furnace, means for supplying ores to the upper end of thesaid furnace, and anl electric refining furnace ihaving a hearth of refractory material adjacent to and opening into the lower end of f the flue ofthe smelting'furnaceI by a passage for guiding'the molten metal into the hearth and also having electrodes of' opposite polarity arranged above the hearth.

2. The combination of a cylindrical flue smelting furnace of great length arranged jon an incline and having distinct zones of temperature for roastinguand reducing thev ores and for melting the metals thereof,

means 'to rotate the said 'smelting furnace,

means for su l in ores to the a1 r end of the said flii-Iriaicen electric refirlfilfg furnace having a hearth ofrrefractory material adjacent toand l.opening into the lower end of the flue of th'e smelting furnace by la passage forguiding the molten metal into the hearth and also having electrodes of opposite polarity Varranged above the hearth, and blast means for supplying fuel in nely subdivided state into the lower end of the. flue of Lthe smelt-ing furnace wholly in addition to the hot gases coming from the electric furnace." 31 Y 43. In an electric furnace, the combination of-a long inclined rotary flue in which .ores are .smelted having distinct zones of temperature for roasting and reducing the ores, and then melting the metals thereof,` ycombined with a'chimney at theupper end of the Hue, means to positivelyv feed -thevores and fluxes into the upper end of the rotary flue and directly across the chimney passage, an electric furnace arranged at a lower-level than the lower end of the rotary flue and having a hearth of refractory material, anl inclined .connecting-flue for vconnecting the hearth of the electric furnace with the lower end o f therotary flue for guiding the Vfluid metal as smelted in the rotary flue iin-to the -hearth of the electric furnace withoutV perv mitting it to drop unsupported, .and means independent of the electric furnace for lsup- :plyinga fuel into the lower end o f the rotary 'flue for producing a smelting temperature therein;-

4. In a furnace," the combination of a long inclinedwrotary flue, means .to supply ores .to the uI pier .endof the rotary flue, means' to rota e .theflue., an electric furnace. havingnahearth at a lower level than the end of therotary flue and connected with it,

means *to support and rock the electric furrnace while maintaining connection with the rotary lflue, and means ,tosupply fuel intov Y the lower end of-` the rotary flue.

5. In la furnace, lthe combination of a long inclined rotary fiue, means to supply ores to the upper end -of the rotary flue, means to rotate the flue, anA electric. furnace 'at ai lower level -than the fend ofthe rotary iue and having a neck portion extending upward to and formingwan adjustable conneet-ion with ,the flue, and means for giving lio las

to the electric furnacea reciprocating motion.

while maintaining its connection with the flue. f l' 6.V In a furnace, the combination of a; `rot-ary iiue arranged on an incline, a chim-l ney in connection with the upper end'of the rotary flue andprovided with a damper, means to feed ores into the end of the rotary flue adjacent tothe chimney, means to r0- tate the rotary flue, an electricfurnace having its hearth in communication with the v lower :end of the rot-ary flue, and means for 30 ing of'rockers under the electric furnace Supporting and rocking the electric furnace `about the end of the rotary Hue.

7 In a furnace, the combination of a rotary flue arranged on an incline, a chimney in connection with the upper'end of the rotary Hue and provided with a damper, means to feed ores into the endof'the rotary Hue adjacent to the chimney, means to rotate the rotaiy flue, an electric furnace having its hearth in communication with the lower end of the rotary Hue, and a tubular neck connecting the hearth of the electric furnace with the lower end vof the rotary Hue, and

means for sinaportingand rocking theelectric' furnace about the end of the rotary Hue consisting of rockers under the electric furnace and rocking upon support-ing rollers.v

8.*In a furnace,`the combination of arotary Hue arranged On an incline, a chimney in connection with the-upper endof the r0- tary Hueand provided .with a damper,means to feed ores into the end of the rotary Hue adjacent to the chimney, means to rotate the rotary Hue, an electricfurnace having its hearth in communication with the lower end of the rotary Hue and a tubular neck connecting the hearth of the electric furnace with the lower'end ofthe rotary Hue, means for supporting and rocking the electricI furnace about the end of the'rotaryflue consistand rocking upon supporting roller-s, and means for delivering a fuel'into the lower end of the rotary Hue.

9. The combination of an inclined rotary tubular smelting furnace of great length in which the ores are smelted to provide Huid metal, a chimney in communication with the higher end of the tubular smelting furnace,

power devices for rot-ating the said smelting furnace, an electric refining furnace .adjacent to'and in direct communication with the lower end of the rotary tubular smeltiug furnace and having a hearth adapted to receive the molteninetal from the smeltiiig fuinace, andv means independent of the electric furnace or products for delivering fuel from an outside source into the lower end of the rotary tubular snielting furnace in addition to the heat directly delivered thereto from the electric furnace. y

10. In a furnace, the combination of a rotary Hue of great lengthV in which the ores are sinelted, a chimney in communication vwith one end of the Hue, power devices for rotating the flue,- an electric furnace in com- `munication with the end of the rotary Hue most distant from the chimney and constructed and supported to have a movement of the hearth thereof independent of the movement of the rotary Hue, 'and means separate `from the furnace for delivering fuel from lan outside source to the rotary flue in addition to the heat directly delivered thereto from the electric furnace and said delivery of heat and-fuel being at a point adjacent to the' connection of the electric furnace with the rotary Hue. 1 f 1l. In an electric furnace, the combination of an inclosedhearth having an upwardly extending tubular neck opening from one end Yand provided lwith rockers, a Hue independent from the hearth -and having adjustable.communication With the neck thereof supports for the rockers of the i' inclosed hearth, means for` rocking the in` l vclosed hearth on the supports while maintaining communication with the Hue, and

electrodes extending into the hearth for maintaining one ore more electric arcs therein. y

12. In an electric furnace, the combination of an inclosed hearth having an upwardly v extending tubular neck opening from one end and provided with rockers, a Hue independent from the hearth and having adjustable communication with the neck thereof, supports for the rockers of the inclosed hearth, means for rocking the inclosed hearth on the supports' while main-r taining communication with the Hue, electr'odes extending into the hearth for maintaining one or more electric arcs therein,

and means carried with the rocking inclosed 4 hearth for adjust-ing the electrodes.

13. An electric furnace comprising an in-v clos'ed hearth having an upwardly extending tubular neck at one end having a lateral outlet at the upper end for escape of gases, and .rockers under the hearth having their curvature struck from an axial line through t-he lateral'loutlet from' the neck,

supports for the rockers, means for rocking the hearth and rockers upon, the supports and electrodes extending through the inclosed hearth for providing one or more electric arcs in the hearth'. v

lll. An electric furnace comprising an inclosed hearth having an upwardly extending tubular neck at one end and having a lateral outlet at the, upper endfor the escape of gases, and rockers underthe hearth having their curvature struck from an axial nace having a hearth of refractory material arranged at a lower level than the compartment andalso communicating directly with the smelting furnace whereby the molten metal may flow into the'hearth of the electric refining furnace, and means vfor producing and maintaining one Vor more electric arcs in the electric furnace above the hearththereof. c

16. Inl a furnace, the combination of a reducing compartment through lwhich'. the ores and iuxes are fed, means for supplying carbonaceous'f fuel to the lower end of said compartment an electric furnace'an ranged at a' lower level than the compartment. and having a tubular-neclf communicat-ing with the compartment through which the molten metal may flow into the hearth of the elect-ric furnace,means for producing and maintaining one or more electric arcs in the electric furnace, means for rocking t-he electric furnace relatively to the reducing compartment. V 17. The hereiny described method of .smelting ores which consist in subjecting the ores to be treated associated with 'the fluxes to the simultaneous action of hot reducing gases of gradually increasing temperature while the said oresand iiuXes are kept in a vstate of agitation by being continually rolled over-.and over upon themselves while beingfed in contact'with the smelting gases and while traveling in contact. with said f gases from their coolest conditiontoward their hottest condition and thereb separating themetal from the gangue an `fluxes, by causing it to melt, transferring the moltenmetal under action of gravity to a hearth of refractory materiaL'subjecting the molten metal to the high temperature of an electric arc and at the same time keeping it in a state'of agitation, and'finally separating the refined metal from the slag.

"18; The method of smelting and refining ores, which consistsv in firstf subjectingthe ores and iuxes to agitation and a gradually increasing temperature to positively smelt the ores and free the metal' thereof in a fluid state, then causing said fluid metal thus formed toat once flow into an inclosed chamber, subjecting the metal agitation within the inclosed chamber,.and while sov agitated subjecting it to the rening action of an electric arc.

19.A A combined smelting and refining apparat-us which consists of a rotating smelt-4 ing furnace ofgreat length and having a' ofthe sinelting furnace, anda flue throughwhich theuid metal may flow from the smelting furnace into the electric refining furnace and the gases from the electric rening furnace pass in' a reverse direction into the-snielting. furnace.

In testimony ofxwliich invention, I hereunto set my hand. 4

CHAR-LES A. l WYEEKS. Witnesses:

E. G. FARLEY, R. M. KELLY.

Images