88 



Indiana University Studies 





Pounds of Steam 



Steam 



Type of Engine 



PER HORSE-POW- 



Pressure, 





ER PER Hour 



Pounds 



xiign-speed. simpie 



oz 



QA_i nn 



oU— lUU 



Uigli-spced. compound. non-condBiisiiig 



OA 9ft 



ZD 



1 ^n_i 1 n 



lOU— 1 lU 



High-speed compound condensing .... 



19-21 



150-110 



Corliss simple non-condensing 



26 



80-100 



Corliss simple condensing 



21 



80-100 



Corliss compound non-condensing .... 



20-22 



150-110 



Corliss compound condensing 



14-15 



150-125 



It would be safe to say that the coal in use in the district 

 would, with favorable boiler equipment, evaporate 6 pounds of 

 water per pound of coal; so that the annual fuel cost of an engine 

 could be calculated by the following formula: 



Annual fuel cost equals P X H. P. X h X c divided by (6 X 2,240) 

 In this formula, P equals the pounds of steam used by the 

 engine per horse-power per hour. H.P. equals the average 

 horse-power developed, h equals the number of hours during the 

 year that the power is used, c equals the cost of coal in dollars 

 per long ton of 2,240 pounds. 



• The amount of detail included in full specifications for a steam 

 engine might seem unnecessary to some persons, but this detail 

 is made necessary by the large number of manufacturers in the 

 field and the numerous types of engines produced. To do a 

 given amount of work, an engine should be selected with about 

 double the power required to drive the machinery, because this 

 margin is necessary in order to allow for the loss of power in the 

 form of friction and other losses in belts, shafting, etc., and losses 

 due to wear in service or to neglect. 



Transmission. When properlj^ cared for, the leather belt 

 is one of the most generally satisfactorj^ means of power trans- 

 mission in the long run; but in a few instances rope drive is in use 

 in the stone belt and is giving very good satisfaction. Narrow, 

 double belts are preferable to wide, single belts. A belt speed not 

 to exceed 3,000 feet per minute gives good results, but where 

 higher speeds are desired rope transmission should be used since 

 ropes can be driven at least one-half faster than belts. 



The following is a satisfactory method of determining the 

 horse-power of leather belting: Multipty the diameter of the 



