DEVELOPMENTS IN OIL BURNING. 255 



REQUIREMENTS OF MECHANICAL BURNER. 



It will be obvious, if oil is to be atomized by centrifugal force, that the 

 best spray will be obtained by giving the oil the maximum whirling motion 

 and reducing to a minimum the friction in the burner so that the whirling 

 motion once obtained shall not be diminished before the oil is liberated. 

 These are axiomatic principles, recognized by all, and no doubt each inventor 

 believes he has best met the requirements. 



It seems to me that the tests are these — that these are the controlling 

 factors in the "survival of the fittest:" — 



1. How heavy an oil will a burner thoroughly atomize? 



2. What pressure and temperature are necessary? 



3. What degree of simplicity has been attained in the design? 



USE OP HEAVY OIL. 



I might say here that any apparatus which will not handle heavy oil 

 will have a very limited usefulness. Already the market is beginning to be 

 supplied with very heavy oils from Mexico, there is considerable crude oil in 

 California below 15° gravity, and the tendency will be more and more to use 

 the heavier residiums. I believe that in a few years we will be using oils of 

 12° to 15° Baume as commonly as we are consuming oil of 27 and 30 degrees 

 gravity to-day. 



The Babcock & Wilcox Company recently received from the Texas 

 Company, for experimental purposes, some Mexican crude oil having the 

 following characteristics : — 



Specific gravity at 60° F . 981 



Degrees Baume at 60° F 12.6 



Moisture and silt, per cent 3.5 



Flash-point, degrees F 310 



Burning point, degrees F 347 



B. T. U. per pound (oil as received) 1 7.551 



In appearance this oil was black and at temperatures of about 80° 

 very sticky and viscous. On heating to 212° it turned to foam owing to the 

 presence of so much water, and this failed to separate out, a sample of the 

 oil being thinned down with ether to determine the percentage. Ordinary 

 settUng tanks would have been practically useless as the oil was so near the 

 specific gravity of water. This oil was, however, successfully sprayed and 



