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BEl.L SYSIEM TECIISICAI. JOURNAL 



suffict's for each installation. In orticr to conserNO the heat, these 

 tanks are co\ereci by a li-^inch coat of magnesia block heat insulating 

 material, the outside of which is covered by }i inch of asliestos ci-inc-nt 

 and 'i inch of half and half asliestos and Portland cement. 



Boii.KKs, Kauiatoks, PkicsstkI'; Ri,(.i i.atoks and Othkk Sti;a\i 

 l*j.)iii'Mi':Nr 



I'or these iiisiallaiiniis, a self-contained t\'pe of steam boiler was 

 used because of its c(ini|)arati\el\- high etificiencN' in the sizes icquired 

 and alMi i)ccausc of iIk- case of installation. 'I'iic boilers userl \arv 



liw. 



1 loi i/oi,i.,l ( -,,1,1 ( )il r.Liilis ,111,1 \ 111 ir.il lid Oil r.ink 



from 3U to 80 horsepower cap.iiiix dcpcmlinL; iipni ilic >i/cs ol the 

 plants. These b:)ilers are of the iciurii iiihuLif i\pr with tlir tire 

 bo.xes and sm:)ke b.).\es lined with kc\cil-iii lire brick. 



The boilers are opi-rated at ,t pressuic ol .ihoiit 100 llis. which is a 

 suitable pressure for tlic steam turbine ,mil for liie steam hoisting 

 engines in the plam> \\ iierc these are used. Tliis bniler steam pressure 

 is too high for the cast iron radiators which are usi'd lo heal oil in the 

 hot and cold tanks and, for the smaller plants, in the treating tanks. 

 Steam for these radiators should l)e sujiplied at a pressure of about 

 40 pounds. Ill order to meet this* recjuiremenl a pressure reducer is 

 iiMtl to convert the steam from the boiler pressure, whate\er it may 

 be, to a pressure of alxnit 40 pounds, before it enters the radiators. 



The water condensed from the \arioiis radiators is ret iiiiud to the 

 boiler in order lo conser\'e its hi'. it. Small .iiitoiii.itii sUmiu traps 



