I4O CALORIFIC POWER OF FUELS. 



volume of air introduced. A coal containing 5 per cent of 

 hydrogen would use 279 litres. 



The volume of oxygen needed for various percentages of 

 hydrogen is as follows : 



Per kilo of coal. Per Ib. of coal. 

 i% hydrogen uses of oxygen 55.9 litres, 0.9 cubic feet. 



2 " " " 112 " 1.8 " 



3 " " 168 " 2.7 " " ' 



u n 223 " 3.6 ' ' " 



5 " " 279 " 4.5 " il 



Calling H the per cent of hydrogen, the formula given 

 above becomes 



C-c 



V/ = 



or 



C c' 

 V/ = 0.03 3 5 (/+/) + 0.06693^' + * 9 H * 



To make this applicable to normal air saturated with 

 moisture at o C. and 760 mm. (32 F. and 29.922 inches) 

 containing 0.4 per cent of CO,, we must divide by 99.12, 

 the composition of air being: 



Nitrogen ................................ 78.35 



Oxygen .................................. 20. 77 



Water ............... .............. 0.84} 



/- i i c O.oo 



Carbonic acid ........ , ................ 0.04 ) 



IOO.OO 



And 100 0.88 = 99.12. The formula then becomes 



1.0806?" 

 or 



55-9 



C c r 

 V ' = 0.0337(2; + O + 0.06752^ + ' 9 H< 



