The design and operation of gas‐heated furnaces

Abstract

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 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 bcing brought about Ly limiting tlic imolllit of prilnnry air ~iipplicd to the produccr. Gnscs froin t~ produccr mny coiisist citlicr of carbon nionosidc :ilonc or a niisturc of tlic inonosidc with tho dioxide, mct.linue, hyclrogcn and wntcr, togctlicr with tlic nit.rogcn wliich is tnkcn in with thc osygcn froin tlic ntmosplicrc nnd acts mcrcly :is n, dilncnt.N'licrc tlic furnncc is ilirccf-fircd, tlic wnstc gnscs proiluccd by tllc combustion of thc gas in, or surrounding, tlic working chonibcr pass to tlic wnstc-gcis fluc a t tlic tcmpcrnturc of tlic coinbustion chnmbcr. Tlic cshnusting of tlic wastc giises is usunl...