FUEL OIL FOR NAVAL AND MARITIME PURPOSES.
The supply of a fuel is one of the most important problems with which the navies and steamship com panies of the world have had to deal. That fuel oil has practically solved this problem is clearly indi cated by the number of vessels at present in use in which oil is the principal or only fuel.
A method of using oil at sea was successfully worked out over 40 years ago by the marine engineers on the Caspian Sea. The process used was most care fully kept secret as the shipowners considered it a most valuable asset. Thus when large quantities of oil were discovered in Texas and California, it re mained for the engineers in those localities to work out the problem for themselves. The success they achieved is indicated by the economies effected, the high evaporative results obtained and the reports, showing an engine horsepower produced on one pound of oil or leSs. Exhaustive tests were conducted some years ago by the naval engineers, in order to determine the most practical method of using fuel oil, and of storing oil in vessels. As a result of these tests, which were carried out by the U. S. Naval "Liquid Fuel" Board, under the direction of Rear Admiral George W. Melville, some of the newest battleships have been equipped to use fuel oil exclusively, while others are so arranged that both coal and oil may be burned at the same time, or either fuel can be burnt separately.
These gave very satisfactory results, but were costly to install and operate. Probably, the most satisfac tory method that has been invented is the mechanical system of atomizing. This was first brought to the writer's attention in 1907, when an installation known as the "Meyers Liquid Fuel Burner," was invented on the S. S. Romany, an oil tanker of 1600 i.h.p. The results of the first test show that an i.h.p. was de veloped by 1.21 lb. of oil. Prof. E. H. Peabody stated, in a paper read before the Society of Naval Architects and Marine Engineers in New York, Nov. 22, 1912, that "the mechanical atomizer," so called, is under stood to mean a device which sprays or atomizes oil or other liquids by pressure alone, without the use of compressed air, steam or other exterior atomizing agents. He also calls attention to the fact that no mechanical atomizer produces a revolving spray, but states that the particles of oil fly off in straight lines under the influence of centtrifugal force, thus forming a hollow conical spray.
A number of burners operating on this system are illustrated herewith. Fig. 83 shows a front and sec tional elevation of the Spray Engineering Company's oil burner installation as applied to the average boiler. Fig. 84 shows the Coen Mechanical system, in which air is pre-heated by passing under the bottom of the furnace. In the design of the furnace, Mr. Coen paid particular attention to the following important fea tures : first, the uniform distribution of heat in the fire-box ; second, uniform admission of air for combus tion; third, control of the direction and volume of this air ; and fourth, the avoidance of heat losses due to radiation from the furnace to the fire-room. By re ferring to the figure, one can readily see how well these points have been covered. The distribution of the heat is absolutely uniform and the diameter and length of the flame from the burner is under perfect control. Two different and distinct supplies of air are provided for, each individually controlled; primary air is admitted at A, and auxiliary air at B. The flexi bility of this arrangement permits a combination of different air currents in varying proportions, which take care of any draught conditions experienced by a steamer at sea. The radiation baffle C prevents the heat of the furnace from entering the fire room.
In the White patent fuel oil system, the use of fire bricks has been eliminated. The air supply is delivered by means of a patented air heating front, fitted with radial vanes which conduct the heat from the furnace to the incoming air, and convey the air to the center and around the burner. There is a further arrange ment of air-regulating cones which control the supply when running, and entirely close the air admission when not burning oil. A sliding cone regulates the length and spread of the flame. This system of reg ulating cones permits complete control of the air admitted to the furnace, thus insuring perfect mix tures of air and oil. No air can pass through the furnace without coming into contact with the flame, and complete combustion is obtained when the cones are correctly set.