1,778,144 also lead fr6iii the iiiali I I pi e 28 say to buri-ip ers, as will be, un(7tei-stood. Iiisteacl of- the coliduits, Li-i iir diiet built -@vitliii-i thc,, Tui-iiace wall nity serve to coi-iduit the air to tlio place desired. The e braiich@ cojiduits 29 and 30 are showii as provided AYith shtitters or dainpers 31 and 32 and siiiiilarly the outlets 24 leadiig to the bottoi-ii ro,,tstil@g chambei- -,re illustrated as controlled bv air cleflecti,,-lo@ and reglilating d,,tmpers 25, operable from the ex'uerior of the f tirnace. These daiiipers 31, 32 ai-id 25 control. the eiretilation of aii, through the b6t,toiii hearth aiid to t-l-ie ro,,isting chainbers iz, ,tnd buriiers aiid ivhell thev Lre Dreseiit, tl)o 0 Tliiidrical valve 20 ,iroul.-Icl the sl-ii'Lt bettol'il i--q,,iy be clispensed Nvith if desired. In 'Uhe illtistrated eiiibodii-iieii'u the.bolto.-,,i hearth coiiiprises t@vo spaced alid preferaloly 20 circular r.L-i6t,,tl 16 conveniently ef-@rried tipon the fpaiaio: of th6 furiia6e. The top plate sup orts the material ii-i the bott6in p roa-,tiii,o; chaiiiber a,-icl tli(@, bottoiii plat6 slipports the lt .17er IS of instilati o- iiiateiial iii @paced relatioii wi.th t'lle to 1)!aLe to 1) O@'i(le p the pas@ag@e 17. Ceiitr,,Llly, the lilate,@ I (o ,i r (' f6rii'led ivitli eirertliar aperti-ii-es "I-' re,""- ister with one :illother @@lileii receive th-, lindrica,l portion 36 enclosii-ig ill the u chainber i5. At its upl,)er edo-e c@linde.- 36 carries an iniN,,ar(113T exteiidiiag flang(, cc-iistruction 37, 38 i)rovided wi'uh a, stu@-'iiig bO@-at its inner pe,.,ipliery, @vhich iiiali:es t slil:, Ic,int with the sh,,tf'L, i2: so ts to I)reveiit the :35 es@al)e of aii- ancl tl-ie joilit is I)i,evei-ited froiti becoi-i,iinQ: clogg6d by iiiateri,,@l oii t'i'le bottoiii el-li,ing,iiia deflec'Uoi- 39 ,Ilso @hearth by an ov eftrried bv shaf-t-. 12. Ac its lowo@r ed.,e cylincler 36 carries an ii)v,,ai-cl,]-y e,- ,tendilig fial'lge I'vi 40 OF CC)livei-ging, 40 pi-ol-ided th. a st.ii ff iiip, box at its ;.iii-ior pet,ipliery Nihicli iiia@Kes ,i slip -joiiit ivith tlae shaft 'L2. By'u-h,- constrliction descri.becl, the theri-iittl losses 'Lroj-,l fill.l-iaces of this iiature ,Lre Fe45 (Itice@t siiiee tile eat ecl b the itir iii [I-ie i@abble, S'@TQt-IYI iS l@etur ecl t6 the I -,- n flirii.ace, as is al.so the b-lat libsorbed by the air iii c6o,,iiig tlie 1-iiatei-ial 6,i the bot'Loi,@i heartl-i. FLirtheriiiore, tlle-,Ii i I lie "Ite@@io" 50 o.r the bottoiii liedrth serves to redtice tiie Lem-)er ttire of '@@hc botlc!gm of the -1@'uriiace -,Pd a I ize racl,i, i oil logses. :The iiivc,,,itioli ;.s pirticiil,-,rly adaptable to lull.-i.,Laces fer pyrites, the calcii-ial.'Ioil 4-) zi of, soda ,tsli, Iiinesto,,ie oi@ o'u-hei@ ea,,-bo,iates, ,tr 0 ic]. f r tliei- Lui,jiac(, pi,oces,,@es pai-ticularly -kvlllore it is u-,-i-i@ei@essa-t-- .y t,o coiiserve siibsttiliqt. tillil 1)6rtiois of ti-le he-,qt in tli.-I disebai-gecl ,iiid inelin@ iiieludiii(--, passages t h ; o t l g l - l t h e s h , @ f t - @ v a l l a t a p o i n @ - w h e r e t h e s h a f t p a s s e s ;6 Variorts iiiociii'lettiois will occu@ to t,iose tli@ougli fh s@ia bottom -125 e heaith, to concILiet -ifigtircutioi-i aiicl ,iir f - wer - t s ici sl@illed in: the art, in the coi rom the j@ part of said sbaft 0 a (I.ispositioii Of 'ulie coinpoiieiit eleiiieiit s g.oing passaue to naake U") the i,-ivention is a -wliol.e, a@ ivell 1 8. lii a ro@,kstino- furnace, iri combinttio-n, a as in the oniissio-@i of one or rqo,,e f e,,itLire-.S, @plur-@.i.if,'y of st-i,per,@osed hea,rtlas I d,- fiii@ng ,@5 @llet iio liniita@iol'i is i@atended b-v the Dhrase- roastin b ear b g cham ers, the bott6in h th eing ology of ',-he foregoing descriptioll or illustrations in the accoiiipaiiyiiig draiviiigs except L) s indicated in the tppeiided clliiiis. WI-iat I clain-i as liew aiid depire to secure @by Lettei@s Patent is: 1. Ii-i a roisting furn.ace,- in coi-iibii)-,ttio,,-i, a plur,,il-ity of superposed lie,,trths. oi-ie of @tlie 16werniost heartlis havinat cavity foii-eceivino- coolilig fluid, said cavity being sea'ied a(lytinst coiiiinunication with the spaces be- 75 t@ieeii- lie,.ti@ths, a i@otary Lir-cool_d rabble systeiii iiioluci-I.ng a shaft ancl iiieans to intr6dtice the air from the lower T)art of said shtf'u- to t!4e, iiitei-ior of slid;liearth hav'ng a eavily. 2. 1-@i a roastiiig ftiril.,@ce. iii comb]-n,,Itioil., 80 t Plu ality oj' siipe-@pos-d lieA.-tlls, i-otirv r a air-cool@ed i-abble systeiii inel-uding ,I ttn@i a ceiidliit coiiinitinicatiiig (lirec- i%-ith '@-he bottoiii, of said shaft Lncl Nvith the iliterio, of a lower heartl-i '85 3. in "I roasting -fv@rnace ill coift'oiiiat,'o-@i plilrality,of.@su i@posed liearti a r,lc;t@, PC is@ TS -I.illeliidiii ir-Qooled i-abble sl _tell 0 iree -imujiicatii-i6- d'- tly, @,vith tli Co u e jidiiil @c ii t, bottoiyl of said shaLt',q@id Avith@a chaii-iber bl@- 90 i!citli the lowe@n-iost heai-th 'Aiid . ii-ie,,,i)s t6 codti ol the flovt of air in sa,id c ndii':' IL. 4. 1 i a roi,sting fui,ntoe, in coiiibiii'ltioll, , 'I c t pli ralitv of stii)ei-posed i-oasiiiig h,@ti,.ibei,s, rotary tir-co ed r,,tbbl6 s@ ol stem in@liidii.iy 95 a i shaft, a Colicluit commi -iiifc,,tting with the bottoni o f saia shaft @nd ivith a ch,,tiiibey, oncl a circular Vtlve ca-rried with @"%Id sliaft q, nd controllili2- tb-e fl,61,,v of air in said co-Ticllit,. 5. Iii a rovsti g fti t(e, @i c, 'b-iiiatio I @i, n r@-I ii 0111 11 011'cer Avall, a plii"lit' of @tiperi,)ose-@i a y r6,istinp; cbaitibers a rotar,y air-c,ool.-bd @,I'ijble tein incltidiiio- ai-i ic)r6 coo@liii-- ii-i6riis tt the bottom (,f tile furiia I ce coiit@iiiiiiii,6 e-@,tei@161@ 105 coiiduit con-imlinicat' ii4g di,,-ec@iv i-vitii till, bot"to,-,, of the shaft. 6. In a roastiiio; fi,,@riiace, in coll]Lbiiia.,.@1-011, an outer ival.1, a plurality of superposbd r6-astii-ig cli :i)-ibers, a rotary-'ai cooled ri@bble,,@.3-s- 110 tei,.-l ineltidina a sl-ia,ft a c6-ndiiit exteriorlv o tii c, oliter wall ,ind eoiiiiilllllicttil-lu clirectl' @-1, y with the bott6m 'of said sliaf t to ileceive air there-f'roin, bra-ncli conduits leadi-,ig froiii said ce;t, id condtiits -coiBmt1ni- 1:15 cc" "in O' S" h ro,@st,in@- chaii4bei-s, -wit 9 ( i",e ic g i tively @Inc I nl eLl, _s 0 control the flow Of aii ip. said oll@tuit c S. I a roasting furna(,6, in c@nib:ination , @i i)l,,ii--ality.of sul)e.-p I o@6d I b.oaitbs the bottom 120 lie'artli b'eing rmed Nvith a passage, a rotat-@y fo ir r @t -cooled' abble systeni incliidinp-, a S

1,778,144 formed witli a passage, a. rotary air-cooled rabble systeiii ilicludilig a sh,,tft, meaiis to coli duct air from said shaft to said passage, aiid ineans to conduct air from said passage to t roasting chamber. 9. In a roasting f urnace, in combinati6ii, a l@lurality of superposed heartlis, the bottoiii hearth being formed with a passage, a rotal@y air-cooled rabble system including IL 10 shaft, nieans to conduct air from said shaft to said passage, and means to c6ndiLiet air from said Dassage to, the space above the bottom heart@. 10. In a roastidg ful-nace, iii combinatioli, a, plurality of sLip6rposed hearths definin roastin@2: chambers, flie bottoiii hearth being f6rmed witli a passao-e, a i@otary aircooled rabble system ineludinff a sh,,tft h,,tving cooling aiipassing therethrough., n-ieans to con20 trol the fl6w of air from said shaft to said passage and means to conduct air fron-1 said passage to a chamber. 11. In a roastino- fui-nace in combiiiatioii aii @ut@r -wall, @illrality of superposed 25 hearths definiiig roasting el-iainbers, ttie bottoil-i liearth being holloav, the outer ivall bein,), @n formed with a periphei-al passage proximate the bottom roasting cliainber and communicatiii@@ -@vith the interior of the bottom hearth 30 a l'otary air-cooled@ rabble systeiii incliidiii(, a sl,iaft, means to conduct air frorn the lo@,er part of the shaft to the iiiterior of the botton-i heprth, and meaiis to control the flow of siieli air. 35 12. In@a roasting furiiace iii coiiibination, an outer wall, a, plurllity of slipei,posed heartl-is defining i-oastiiig ch,,tmbers, the bottom lieartli being hollow tnd the outer wall beino- forined with a peripheral passage iii 10 coinmuiiication with the iiiterior of the bottom heai@th, means to conduct air froiyi said shaft, to the interi6r of the botton-i hearth, I-acans to coiidluct aii, froni said peripheral passage to a roastiiig chamber, and iii6ai-is to 45 control tile flow of s-Lich air. 13. Iii ti roastiiig furiiaee, in coinbiiiatioii, aii I outei, wall a plurality of sliperposed he,,ti-tlis clefiiiing i@oastiiig cliaiiibei@s, the bottoiii hearth beiiig liollow and the I o-Liter -wall 50 beiiig formed @,i7itll ',t pel-i@lleral I)assage in COI'Ilniunic@,iti6n Nvith the illterior of the bottoin liearth, said@passage liavino: outlets into the bottom roasting cliaii.ibei-, a i-otai-y aircoolocl i@abble systeill ilieltidiiigl,,t sliaft, II-ieaiis r) i to condliet air froiyi the lower part of said shaft into s:iid passao-e a cond-Liit exteriorly o'l the otiter wall aiid leadino- froni said passao,e to a roastiiig cliambei,,ti-id ineiiiis to coiltrol the flo", of air tlirou@-li said coiiduit. 6o Iii testimony wliereof I litive signed iiiy iiaiiie to this specificatioll. GEO. El. CONNOI,LY. 65

Patented Oct. 14, 1930 1 9 7 7 8 9 1 4 @ 4 UNITED STATES PATENT OFFICE GEORGE E.@ CONNOLT-Y. 0 @7@ OAKLAND, CALIFORNIA.. ASSIGNOR TO NICHOLS COPPER COXPANY, OF NEW YORR, N. Y., A CORPOPATION OF NEW YOR-K FURNACP- CONSTRUCTION This invention relates to f urnaces and iiiore p@@rticul,,trly to f Lirnaces desiomecl for the heating or roasting of oreg, coiieentrates and the like and in which the iii,,tl@-ei-ial is coiiveyed downwardly in a eirciiitous path over a series of hearths, by @ means of rabble or stirrin(,y -arms.- The obipets Of tl-lp,- inveiition ilieltide the provision in a: ]practical f urnftce stiuctui-e of io sii-nple and offici6nt means ior utilizino tii' r to a bsorb heat at thp, bott6in lie,,trtli of t-iie fui-nace. Cert,,tin phases of the inventiall ,ti-SO coiitrib-Lite to the efficiency of the f utiiace by tiae 15 redtiction of heat losses tlierein. To this end, the air which has passed throlio.h tl-ie bottoin ,hearth . and absorb,cdl , I-,eat 1, t-herefroiii and whic7h is preferably air 'Which h,,ts been 7@Nlarmed previo,,tsly by a heftt interelia,,ize 20 Nvith the stirrin@2: or rabble ,triDs, ina b-, iiiY troduced into one or more 6f the ro,,tlsting .chambers to raise,:or regulate the teml)erattires therein. These and other objects of the invention iiient Avill be 25 and the means fot their .Lttaiii I'fiore a@p@rent from the follolving det-,tiled descript,ion, taken in c6niiection Nvith tl-ie aecompanylng drawiiigs illustratinf,,, one eiiibodiiiient by which the inveiition iiiay be real3o ized, and in whiel-i Fig. i is a transierse sectioiial iieiv takei-i in the planes indicated bIT the biol@eii liiies 2-2 in Fig. 2 and lool@ii@o@ iii tllo directi6ii of ti-ie arrows. Fig- 2 is t'-vie-w -,,howing, in side elevatioli, the lower part of a ftirnace in accorclaiiee, AA7ith this inventi6n, I)arts beino@ @ll the ir.- tere8t of clearness. In the dra@vings, th(, furil,,tce is illust,,-ate(I 40 as having ,t wall 5, 6,colisistiiig of the o,,iter illetallic shell 5 suitably Iiiiod witti hc,,,it iesistaiit@n-iate,rial 6. @lt is provided witli i ilurality, of s-Lip6rposed hetil-ths 7 @defiiiiiig the F roasting chainbers of the filirnace. The mate45 ialtobeti,eatedisintroclueedat,thetoi-)6fthe fili,nace, tncl is elctusecl to trhvel clowiiwardly through the wo@rl,-in,@,' chanibers in a 6ircuitoiis path, as is well uiiclerstood in the ar @by ry ai - o r liieans of a rot,,t r co ledstirrin4o ra 50 systein. This sv,-,terfl coinprises generally a .4pplicatioii filed December 19,1928. Seriel No. 326,942. plui.@al'14uy of stirring or rtl)ble,,trms 10 carried by ,i centr@tl double Avalled sh,,Lft 11) 12 which is rotatecl in any convenient P-iannei-. Air ento,-,s the iniier co-ii-,Iviit 11 of this shaft through any I convenieiit'air inlets, stich as are shoiin U5 ,it 13 and as es the p s refroin into and tlii-oiigh tl-ie rabble arilis 10 to cool th e saiue. The ,III, noav rtised in t(,.iiiperatilre by tbsorption o he,,tt f i-om tli(,, stirrino.,tri-fis re-ttiril.,@ to tl-ie ail,,r spac ilul e I'@) of ti@e-shaft. As illiistrit(@(1, the IoNvc@i- I)ot-tioii of the otiter sl)aee 19- is ,)i-ovi.ded ivith one or iiiore outlets 14-- froi-yi A@,liielt the -@v,,iriiie,,@L ,tir iiiiy be diseliai:,o@ed iiito t cliliniber 15 stirroundiiig the shilt ai-id conveiiiently carriecl witli the 65 bottoiii he,,trth 16. This ellaillb(-,r 15 colyiin-Linicates with a 1)assage 17 in the boutom hearth. Preferabiy the bottoi-ii h(@,irth is of metal ii-id is hol..'LoNv, the I)assige 17 thus coinprising the, iiiterior of tle lie,,ii,th 16. to To redilee heat losses, tile bott6iii is ii-islilated,, as at 18. The flow of air, f i-oiyi the oliter sl-iaft sl)ace l@) iilto tlic, cliaiiil)ei- 1,-) iiitty be coiltrolled by ai-i 111(@Ijii@--,4Lib!G@ cyliii(,Ii@icil villte ,Ijusted by -i 5 19. T@Iiis valve intiy bG 11 line aiis of a iiack 20 oii ilitiei @ I)--ri h.(@i-y p NA @Iiieh is ad,-iP'U-ecl to Ai'L li a rfiaii-u@,@illy ope r,,tbl(,, piiaion 21 cirri d w'tli tlae, si-iaft li@ 12. The tir I)assijici luilroti,-h the I'@ so ibsorbs 1-ie,,it f-i-oiii tho, iiiatei@i@il in t@@riE@ 1- owel,- iiiost roasti,iiopp ittir e of desi red, a reductioii i@i telfl -r. the b6ttoiil of tile the n-iateri,-LI tl)ere;lii to ],)e at a s -a lo%Aer temper,,tture. Froi-ii the ii-iterior of tl,.,.o bottoi@ll 'iyo,)rtli tile li.eated a;r rii, @iy, if be directed ii-ito OnC Or DIO,"O l.'Oas'L'I'Dg chambers. To this eiid, the wall r)., C, i@@ Nvit ltl a 40 %II il@ OI)O II i ill t - I)as sage 2'-) lit, 2' coiiiiiil-. ing iiith th(,, i t(@@,-ioi@ IT ()f 'L-,hc, '@)o@L"tor.,.i and froii:i spaeg, 2), the heited ,II,' be iiitrodliced iiito the I)ottoiii chaiiie r gh c)ii'ulet,,, 24. Also eoiiil(lcted ivitli 1)5 b r th ou :the sp,,ice 1)2 i@, .IioAiTii ), cotililit 28 ',I,(!(,tpted to condlict W,,ii-ii-iod Iiii- froiii the p,,,scia(ye 29to oiie or inore of the til,,,pe, roist@i-]_g bers o Y f tile @-flirnace as b br@-,iieli 1)ii)e@, 29 lea(iiii(,y thei-efi-()j)i. piijc@@ll 30 iii@ly 100