254 



DEVELOPMENTS IN OIL BURNING. 



EFFECT ON CAPACITY OF HEATING Oily. 



Another means of varying the quantity of oil dehvered by all burners in 

 addition to alteration of oil-pressure is available in alteration of oil temper- 

 ature. Generally speaking, under working conditions any increase in tem- 

 perature of the oil results in decreased capacity of the burners, the pressure 

 remaining the same. The reverse is the case at low temperatures, the critical 

 point depending on the relationship between viscosity and specific volume of 

 the oil in question. This law is shown graphically in the diagram in Fig. 8 



27d 



260 

 250 

 240 



230 



220 



*^2I0 



J 200 



O 190 



HJ' >p~3 



4 i 



^ '^J^rfT "I" ' 



_! ^ _^ __; 



Curve ofBwrner- Capacity <jf d-ifferfniTemperalare 



,_ .,. , .-■ , Ps<bod.v Mechanical B 



_Roiin<3. FlSLTne. 

 2CO lbs P'r-e -j'tuTc 



TEXfli CRUDE Oil 



j-IZO - 



100 



90 



eo 



10' 





aijb-it^ 





ZtO Z60 ?80 300 320 340 550 380 4-00 4rO 44-0 460„_4BO 



250 Z70 290 310 330 150 370 590 410 4-50 450 4T0 



POUNDS OF OIL PER BURNER PER HOUR. 



Fig. 8. — Temperature-Capacity Chart. 



giving the results of a test on a sample of Texas oil of i8 "gravity " (degrees 

 Baume) and a flash-point of 240° F. The oil pressure was maintained con- 

 stant throughout the test at 200 pounds and the temperature was raised by 

 stages from 80° F. to the flash-point. The burner capacity increased rapidly 

 up to a temperature of 110° where it reached a maximum. With continued 

 heating it began to fall off and continued to do so throughout the range of 

 the experiment. 



