Apparatus for burning liquid fuel

Application filed March 9, 1922. Serial No. 542,263.

To dll whom it may concern:

Be it known that I, Ebnest H. Peabody, a citizen of the United States, and resident of Pellham Manor, in the county of West0 Chester and State of New York, have invented certain new and useful Improvements in an Apparatus for Burning Liquid Fuel, of which the following is a fullj clear, and exact description.

This invention relates to an improved method of burning liquid fuel particularly in furnaces whereby the currents of air and gases produced by combustion are controlled, complete combustion is promoted, and higher 16 capacity and economy are assured. The invention applies particularly to the combustion of liquid fuel when atomized- and sprayed into a furnace by means of mechanical atomizers, and the air for combus20 tion is admitted with and around the oil spray through a properly designed air‘register. ,

It has long been understood that in certain types of furnaces great advantages are 20 derived through giving to the air for combustion a rotary or whirling motion around the oil spray. The latter is usually conical in form and does not itself rotate although the spray be produced by centrifugal force 30 set up by rotating the liquid within the burner tip. The particles of liquid which leave the orifice under the influence of centrifugal force fly off in straight lines diverging from the orifice and forming a thin 35 hollow cone of various degrees of angle.

However, in the event that the air entering for combustion around the spray is given a rotary motion, the particles of the liquid are picked up and whirled along by 40 the air in the spiral path taken thereby with the result that there is not only an intimate mixture of liquid and air, but the products of combustion, as they, in gaseous form, rapidly take the place of the oxygen 45 of the air and mix with the nitrogen, continue on through the furnace with the same rotary or whirlwind effect.

Tests have shown that in a furnace into which a number of burners are simultane50 ously injecting liquid fuel, particularly in those cases where the combustion rate is high, the combustion is more perfect when a rotary motion of the gases is set up around the axis and extended axis of each indi⁵⁵ yidual burner. It has heretofore, when using this plan, been the invariable custom to rotate the air in the _ same , direction around each burner, either, clock-wise or counter-clock-wise,, the burner'sSeiiig. set adjacent to each other, equally spaced and in 60 symmetrical arrangement through She boiler front or front furnace wall. So'· long as the gases travel completely away from the front toward the rear of the furnace, the effects, as stated, have be'en found to be 65 satisfactory. Furthermore, in those forms _e of furnaces where the gases do not all flow back from the front but immediately pass sideways into the bank of tubes of the boiler, the rotation of the gases around each 70 burner axis in the same direction is still beneficial and preferable to the non-rotary method of combustion so long as the rotation of the air and gas does not take place at ‘too high a rate of speed. 75

However, experimental tests have shown that a high speed rotary motion causes an unequal or one-sided flow of gas when the rotation about all of the burners is in the same direction, this being particularly no- 80 ticeable in the side flow type of furnace above mentioned. This unequal distribution of gases and air may cause smoke, poor combustion, decrease of efficiency and pulsation. 85

An object of my invention is to correct these defects, retain the recognized advantages. of high rotary speed of the gases around the burner axis and secure superior results as regards economy of fuel and the 90 capacity of the burners.

I accomplish this result by a combination of clock-wise and counter-clock-wise rotation of the entering air. Experimental investigations show a decided superiority over the 95 previous methods of combustion, both under the special furnace conditions named above and also in those cases where the single direction of rotation has heretofore appeared satisfactory. ioo

In the drawings:

Figure 1 is the front elevation of a well known type of furnace with a common arrangement of five burners.

Figure 2 is a horizontal section of the ¹⁰⁵same.

_ The furnace front A is provided with five oil burners 1 of any usual or desired type of spray burner, and surrounding each burner is an air director also of a well known type ¹¹⁰in which blades may be set at different angles to admit a greater or less amount of £

1,608,718 air but to always give the same a rotaiy motion. The burners 1 and associated air directors 2, 3, 4, 5 and 6 are arranged as shown in two rows, three in the lower row 5 and two. in the upper in a symmetrical group.

The air directors 2, 3 and 4, being in this instance the two at the left side and the lower middle one are set to give the air passing through a left hand or counter10 clock-wise rotation, while the directors 5 and 6, or the two at the right hand side are designed to give the air passing therethrough a clock-wise or right hand rotation. While this is the preferred arrangement in 15 the furnace shown, various other combinations of clockwise and counter-clockwise rotation may be used with beneficial result.

As indicated in Figure 2, the air passing through the director 2 forms a gradually 20 increasing spiral B with a left hand, twist, while the air passing through the director 6 .moves in the path indicated by a similar spiral C with a right hand twist.

Obviously my invention is not limited to 25 the precise arrangement of burners illustrated as it can be applied to any group of burners. Neither is it necessary that the selection of burners for right and left hand rotation be precisely the same as herein 30 illustrated. In any symmetrical arrangement it will probably be found that as nearly as possible there should be an equal number of air whirls of each type and that these should be symmetrically arranged. 35 Tests may be necessary in some cases to determine just what arrangement will give the most advantageous results.

While the mechanical atomizer is the preferred type, the liquid may be sprayed by any suitable means, for example steam or 40 compressed air, so long as the air for combustion is admitted around the spray in a manner which will give the gases a rotary motion.