A catechism on the combustion of coal and the prevention of smoke; a practical treatise . ides of the fur-nace. Loss occasioned by difference of temperature betweenthe escaping gases and that of the atmosphere necessaryto produce natural draught. Loss by the waste of unburned fuel falling throughinto the ash pit. Loss by imperfect combustion—that is, by the forma-tion of carbonic oxide instead of carbonic-acid gas. 2l6 COMBUSTION OF COAL. Loss by excess of air passing through the furnace, doingno useful work. Q. How is the efficiency of a steam boiler measured? In steam boilersthe efficiency o
A catechism on the combustion of coal and the prevention of smoke; a practical treatise . ides of the fur-nace. Loss occasioned by difference of temperature betweenthe escaping gases and that of the atmosphere necessaryto produce natural draught. Loss by the waste of unburned fuel falling throughinto the ash pit. Loss by imperfect combustion—that is, by the forma-tion of carbonic oxide instead of carbonic-acid gas. 2l6 COMBUSTION OF COAL. Loss by excess of air passing through the furnace, doingno useful work. Q. How is the efficiency of a steam boiler measured? In steam boilersthe efficiency of thefurnace is measuredby the pounds ofwater evaporatedper pound of coalburned on the grate,under known con-ditions. The effi-ciency is expressedin a percentage in-dicating how nearlythe actual perform-ance attains to thetheoretical. If thelatter be expressedby ioo, the effici-ency will always bea less number. Suppose a coal isknown to contain13,100 heat unitsby calorimeter test,the equivalent evap-oration from andat 2120 F. wouldbe 13,100 -f- 966 = pounds ofwater per pound of. FURNACE DIMENSIONS. 217 coal. By actual test pounds of water are evaporated per pound of coal. We then have: T^rc • 9-25 X 100 ^0 Efficiency -—J — = per cent. loss of heat in this case amounts to per centof the total heat generated in the furnace. This loss, PLAN AT A B
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Keywords: ., bo, bookcentury1900, bookdecade1900, booksubjectcoal, bookyear1900
