250 DEVELOPMENTS IN OIL BURNING. 



With all ordinary oils it may be considered that heating within 50° F. of 

 the flash-point will be sufficient to render the oil suitable for use with the 

 mechanical burner, and in the case of many of the lighter oils even this 

 heating is unnecessary, the oil being sufficiently limpid at ordinary atmos- 

 pheric temperatures. 



MECHANICAL SPRAYING. 



Several methods of spraying oil by mechanical means have been sug- 

 gested, such as forcing the liquid through a very fine aperture, forcing a jet 

 of oil at high velocity against some object or against another oil jet, throwing 

 the oil off from a rapidly revolving table or disc, or giving the liquid itself a 

 whirling motion and reducing it to spray by centrifugal force. 



In 1902 the writer tried the first idea and succeeded in making a very 

 poor flat-flame mechanical atomizer by forcing the oil between two flat surfaces 

 pressed closely together, and in 1907, when in answer to the Navy's call we 

 took up the matter of mechanical atomizing seriously, we tried some of the 

 other schemes. The experiment of making two round jets of oil strike each 

 other, on the principle of the acetylene burner, resulted very interestingly in 

 a flat spray — not fine enough, however, with heavy oils to be practicable. 

 A mechanical atomizer, or, as it was called, a "self -atomizer," consisting of 

 eight small jets meeting at a central point, was patented in England in 1904 

 by Mr. Charles Ferdinand de Kierskowski Steuart. It is a good example 

 of spraying by forcing jets of oil to strike each other, but otherwise has 

 attained no importance in the art. 



The only method of atomizing fuel oil mechanically which has attained 

 any practical success is that wherein the oil is given a whirling motion inside 

 the burner tip. There are two distinct means for doing this, first, by forcing 

 the oil through a passage of helical form, like a screw thread, and second, by 

 delivering the oil tangentially to a circular chamber from which there is a 

 central outlet. 



Fig. 3. — ScHUTTE Sprayer. 



As an illustration of the first form I have selected the "spraying nozzle' ' 

 patented in the United States in 1895 by Mr. L. Schiitte. This is shown in 

 Fig. 3. Judging by the patent, the inventor had principally in mind, with 

 regard to this particular apparatus, the spraying of water, but the device is 



