DEVELOPMENTS IN OIL BURNING. 259 



boiler, discharging the waste gases into the uptake at temperatures but little 

 above that of the steam generated. These conditions combined to relieve 

 us of any worry about furnace design, or, to put it another way, we had been 

 through all that before with steam atomizers. 



Our experiments therefore developed principally into a search for the 

 best method for admitting the air for combustion. 



IDAI.IA EXPERIMENTS. 



Having completed preliminary experiments with the atomizers in con- 

 nection with a fire-brick oven built for the purpose and entirely separate from 

 a boiler, the apparatus was removed to The Babcock & Wilcox Company's 

 dock at Bayonne, N. J., where the steam yacht Idalia was moored prepara- 

 tory to being laid up for the season. This vessel is fitted with a Babcock & 

 Wilcox marine boiler containing 2,560 square feet of heating surface and 340 

 square feet of superheating surface. A simple and effective system of induced 

 draft fans is installed capable of giving a suction in the uptake of i to if 

 inches of water, and in addition to this a forced draft fan was set up on 

 the dock and connected by means of a flexible duct to a sheet steel casing 

 enclosing the oil burners on the front of the boiler. The tanks and scales 

 ■ for weighing the oil and water, and the oil pump and heater were set up on 

 the dock and connected with the vessel by means of flexible pipes, the regular 

 feed pump of the plant being used taking weighed water from the filter box. 

 The engine and other auxiliaries were not in use, the steam being discharged 

 to the atmosphere through a muffler so arranged, however, as to maintain 

 regular working pressures on the boiler. All precautions were taken to 

 prevent leaks and secure accurate data. 



The object of these tests was to burn oil with mechanical atomizers, 

 to bum as much oil as possible without smoke, and to secure the best possible 

 evaporation per pound of oil. 



Fifteen evaporative tests were made under a variety of conditions, the 

 results given in Table I being selected as representative of the progress made. 

 In between these tests considerable experimenting was done with various 

 air-distributing arrangements, flat-flame burners, etc. The best perform- 

 ance was an evaporation of 7.47 pounds of water per square foot of heating 

 surface per hour from and at 212° at an efficiency of 82.8 per cent at a rate of 

 combustion of 6.17 pounds of oil per cubic foot of furnace volume per hour, 

 with a draft in the uptake of .84 inch of water. The air in this test was 

 admitted to the furnace through what we call an impeller plate (Fig. 11, 

 Plate 97). Beginning with the cast iron cone with air slots on the side as. 



