. Electric railway review . y inefficient installation. The head onthe injection pipe is entirely wasted,being resisted by closing the injec-tion valve at the condenser. The distance from thepump to the outlet at the top of the cooling toweris Frequently as much as 60 feet. Assuming 18 poundssteam per horsepower-hour of the main engine and 40pounds of circulating water per pound of steam a pump requiring 120 pounds of steam per horsepowerhour and having an efficiency of 60 per cent, we findthat the circulating pump requires pounds of steam foreach 100 pounds of steam deliver
. Electric railway review . y inefficient installation. The head onthe injection pipe is entirely wasted,being resisted by closing the injec-tion valve at the condenser. The distance from thepump to the outlet at the top of the cooling toweris Frequently as much as 60 feet. Assuming 18 poundssteam per horsepower-hour of the main engine and 40pounds of circulating water per pound of steam a pump requiring 120 pounds of steam per horsepowerhour and having an efficiency of 60 per cent, we findthat the circulating pump requires pounds of steam foreach 100 pounds of steam delivered to the main engine. Inother words, the condenser pump requires as much steam tooperate it as is saved by operating the engine may be that a slight economy is secured in such aninstance, due to the auxiliary exhaust steam being deliveredto the feed water heater, but the question is, why is notapparatus which is suited to each particular installation em-ployed? By using a surface condenser and the distance ■2 -//^/sr Figure 267-H9-3). 10 feet, the steam consumption of the condenser pump wouldbe but 1-6 as great as in the preceding case, or about 4pounds of steam for each 100 horsepower delivered to theengine. This steam, however, would be condensed in theheater and the heat returned to the boiler, thus a very goodreturn on the investment in the cooling tower, condenser,• tc, would be secured. The heat required to operate the pump would be aboutfour times 46 British thermal units and the engine 100 pounds at 913 British thermal units, or. =.2 British thermal 913 units for the condenser for each 100 British thermal units required by the main engine. The most conspicuous loss in the operation of condens ing machinery in conjunction with cooling towers is that
Size: 896px × 2788px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectstreetr, bookyear1906
