. Railway mechanical engineer . er. The rate of firingreached 189 lb. an hour per square foot of grate, and at thisrate the evaporation per square foot of heating surface was 6II I- J I- s V ■^^ 1-^ A/J . ! k r »-»-2 1 i- O S o o_^ . r /IS ISOO 2000 ZSOO 3000 Fig. 5. Indicated Horse Power and Steam (Average for all Cut-offs) The maximum rate of firing, in pounds per liour,was 13,226. Evaparation.—The evaporation of this boiler appears tobe less tlian was obtained from the smaller Lis boiler, butwhen the higher pressure and superheat of the lis are con-sidered, tlie maximum equivalent eva
. Railway mechanical engineer . er. The rate of firingreached 189 lb. an hour per square foot of grate, and at thisrate the evaporation per square foot of heating surface was 6II I- J I- s V ■^^ 1-^ A/J . ! k r »-»-2 1 i- O S o o_^ . r /IS ISOO 2000 ZSOO 3000 Fig. 5. Indicated Horse Power and Steam (Average for all Cut-offs) The maximum rate of firing, in pounds per liour,was 13,226. Evaparation.—The evaporation of this boiler appears tobe less tlian was obtained from the smaller Lis boiler, butwhen the higher pressure and superheat of the lis are con-sidered, tlie maximum equivalent evaporation of the lis isconsiderably above that of the Lis. The equivalent evap-oration per pound of coal is illustrated by Fig. 15. Theevaporation per pound of coal and the boiler efficiencyresults are about the same as were obtained in 1917 (seeFig. 1.). The equivalent evaporation per square foot of heat-ing surface for the lis reached a maximum of lb. perhour. Superheat.—The lis shows a maximum superlieat of about. SOO 1000 ISOO ZOOO ZSOO 3000 3S00 Indicaied Horsepoiver Fig. 6. Water Rates at All Cut-offs, Class Ms 280 deg. and at a rate of firing of 11,000 lb. per hour thesuperheat is about 15 per cent higher than for the Liswhen equipped with a superheater of the same lengthas in the lis, or 18 ft. When these two superheater surfacesare compared, that of the lis is larger by about 20 per cent,on account of the larger number of elements. The normal saturated steam temperature for the lis is4(1(1 det;. and for the Lis, with a boiler pressure of 205 lb., itis . deg. It would appear to be more difficult then tosuperheat the steam from tlie lis boiler on account of its higher initial temperature, but notwithstanding this, a liighermaximum superheat was obtained, although it is somewhatlower over part of the range. The water heating surface of the lis boiler is percent, the total heating surface per cent, and the fire areathrough the tubes 7 per cent gre
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
