DEVELOPMENTS IN OIL BURNING. 



279 



PRINCIPAL SYSTEMS USED. 



This review of the subject of mechanical atomization of oil would not be 

 complete without some reference to the principal systems which have been 

 installed in our torpedo-boat destroyers and through the courtesy of the 

 editor of the Journal of the American Society of Naval Engineers, I am able 

 to reproduce illustrations of this apparatus which have been published in that 

 periodical. I also extend my thanks to Mr. John Piatt, Consulting Engineer ; 

 Mr. Chas. P. Wetherbee, Vice-President of the Bath Iron Works; Mr. H. 

 Brown, Assistant to the President of the Fore River Shipbuilding Company; 

 and the Schutte-Koerting Company for information relative to the apparatus 

 in which they are interested. 



Thorny croft (Fig. 32). — In this burner the oil receives a whirling motion 



Fig. 32. 

 by passing through a spiral groove into a central chamber communicating 

 with the outlet orifice of the tip. The tip fits on to a nozzle in which there 

 is a cylindrical hole about the same diameter as the central chamber, and 

 concentric with the axis of the burner. In the surface of this cylindrical hole 

 a thread of square section is cut, of very slight depth at the end coinciding 

 with the central chamber in the tip, but increasing rapidly in depth toward 

 the direction of the opposite end of the burner, at which the oil is admitted. 

 A spindle fits into the cylindrical hole of the nozzle and on this spindle there 

 is a corresponding thread, accurately fitting the thread of the nozzle and 

 tapering to practically nothing at the end. When the spindle is screwed 

 home the thread on the spindle bottoms on the tapered thread of the nozzle 

 and no oil can get to the tip. As the spindle begins to be unscrewed, however, 

 the marked taper of the two threads causes them to separate and form in 

 combination a spiral groove, the sectional area of which rapidly increases as 

 the spindle continues to be unscrewed. The central chamber is formed by 

 the combination of the end of the spindle and the burner tip. The output 

 of this burner is controlled by the revolution of the spindle which regulates 

 the area of the spiral oil passage. 



