Thc design of gns-Iicntcd furnnccs is intcrcsting in vicm of thc cvcr-increasing dcninnd for plnnt cnpnblc of rcgulation within w r y finc tcmpcrnturc Iiniits, to dcnl with ninny heat-trcatnicnt opcrations carried 011 in tlic cnginccring tmdcs. Iuiprovcnicii ts during rccciit y c y s haw rcsultcd in grcntly incrcased cfiicicucics, c~inbll~ig work to bc ciirried out nutonintknlly. Tlic modcrn trcnd, cspcciaIly in plant for t.lic lic:it-trc~tnic~it of coniponcnts of tIic nutoniobik ii1id othcr trades, xrliich arc now produccd iri Inrge qurintitics, is to iiicrcnsc still furtlicr their autoniiLticity, witli tlic rcsult tlirit n 1iiod~r11 hat-trcntnicnt furnace for iiinss-~~roductio~i work iilny oftcn be considcrcd to bc nothing less t.hnu n I~iirtlcning iuncliiiic, \vIiich will :iutoiii:tticnlly carry goods t.lirough t,hc Iicnting and cooling cl~nuibcrs nnil dischrpc tlicni into suitnbly nrrnngctl I~oslics, ivlierc qucncliing takes placc ; iiftcr this, if iicccssnry, an nutoinntic tcnipcring trcat,iiicnt cnu IN givcii, wlicii the part iculiir component will tlicii be finislicd nud ready for use.
Oiily wlicii coniponcnts nrc produccd in w r y lurpc qwintitics ciw R furiiacc bc opcratctl iii this uiniiiicr, Init \vIicrc nutonint,ic Iinn(1ling can 1Jc nrr:tiigccl t4ic general results will Le h r supcrior t o thosc protlnccd by Iiniid-co~itrollcd furnnccs. I n niitoiii:itic furiiiiccs tcnipcrnturc lias t o be coutrollcd wit.liin very fiuc liniits, nnd this opcrntion also lins lxcn iiiadc iiutoniiitic.
\'hen oiic considers tlic ciioruioiiti st,ridcs Illiitlc in furnncc design, tlic furnace nirikcrs nrc t o IJC cougrnt.ulnttcd oil t h good work cnrricd out; aid tlic liirgc :nnoiiiit of rcscctrcli work \i-hicli liris Iwcn ncccssary to bring about t.lic impro~cnicuts niailc during the Inst, fcw As I iiitcnil to dcnl with furnnccs ol~cratiiip oil gns itsit fuel, I will refer gcncrally to t l ~c viirious compoiiclits which, in coinbinatiou, constitute n coiiipletc furnncc, C~LCII of wliicli plnys n dcfinitc p r t in tlic \.orli of tlic coniplctc furnitcc, niid tlicrcforc lins to IJC dcsigiictl with tluc coiisitlcrntion of t,lic otlicr conipo~~cnts.
llic main orgnns of gns-licntcd fiminccs :ire ns f O l l O \ ~S :-Y'he worliiy c l r ~t b e r or I~citrth, i n which t,Iic miitcrin.1 to bc hcatcd is pliiceil, iiiny consist of n niafllc, OVCII, or slab of rcfrnctoi*y mntcrinl licirtcii by tlic conibust ion of tlic fucl to thc dcsircd teiiipcrnttirc, this licclt bcing trausfcrrcd to tlic lond by conduction, rndiiition, or convcction, according to tlic pnrticuli~r hccrt.ing opriitioii.
In gas-fired fiiri~nccs tlic conibustioii 01 tho fuci is usunlly coniplctcd in thc working clinmbcr, or in tljc mulllo typo in n cornbefition cliiinil~cr siirroiinding it, 197 the nrlditioii of sccondnry nir.
The ~1r0~7rtcer.-\'l~cii working on pruiliiccr giis, tlic produccr is that part of tho furnacc in ~& l i tlic colilbustiblc gnscs itrc produccd I J ~ tlic incomplctc CoIiibIIstion of tlic fucl, thc inco~nplctcncss of this coliilustion